Τρίτη, 14 Φεβρουαρίου 2017

Correction: CpG Blocks Immunosuppression by Myeloid-Derived Suppressor Cells in Tumor-Bearing Mice



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Neddylation E2 UBE2F Promotes the Survival of Lung Cancer Cells by Activating CRL5 to Degrade NOXA via the K11 Linkage

Purpose: Recent studies have shown that the process of protein neddylation was abnormally activated in several human cancers. However, it is unknown whether and how UBE2F, a less characterized neddylation E2, regulates lung cancer cell survival, and whether and how NOXA, a proapoptotic protein, is ubiquitylated and degraded by which E3 and via which ubiquitin linkage.

Experimental Design: Methods of immunohistochemistry and immunoblotting were utilized to examine UBE2F protein expression. The biological functions of UBE2F were evaluated by in vitro cell culture and in vivo xenograft models. The in vivo complex formation among UBE2F-SAG-CUL5-NOXA was measured by a pulldown assay. Polyubiquitylation of NOXA was evaluated by in vivo and in vitro ubiquitylation assays.

Results: UBE2F is overexpressed in non–small cell lung cancer (NSCLC) and predicts poor patient survival. While UBE2F overexpression promotes lung cancer growth both in vitro and in vivo, UBE2F knockdown selectively inhibits tumor growth. By promoting CUL5 neddylation, UBE2F/SAG/CUL5 tri-complex activates CRL5 (Cullin-RING-ligase-5) to ubiquitylate NOXA via a novel K11, but not K48, linkage for targeted proteasomal degradation. CRL5 inactivation or forced expression of K11R ubiquitin mutant caused NOXA accumulation to induce apoptosis, which is rescued by NOXA knockdown. Notably, NOXA knockdown rescues the UBE2F silencing effect, indicating a causal role of NOXA in this process. In lung cancer tissues, high levels of UBE2F and CUL5 correlate with a low level of NOXA and poor patient survival.

Conclusions: By ubiquitylating and degrading NOXA through activating CRL5, UBE2F selectively promotes lung cancer cell survival and could, therefore, serve as a novel cancer target. Clin Cancer Res; 23(4); 1104–16. ©2016 AACR.



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Correction: Synergistic Activity of PARP Inhibition by Talazoparib (BMN 673) with Temozolomide in Pediatric Cancer Models in the Pediatric Preclinical Testing Program



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miR-206 Inhibits Stemness and Metastasis of Breast Cancer by Targeting MKL1/IL11 Pathway

Purpose: Effective targeting of cancer stem cells is necessary and important for eradicating cancer and reducing metastasis-related mortality. Understanding of cancer stemness-related signaling pathways at the molecular level will help control cancer and stop metastasis in the clinic.

Experimental Design: By analyzing miRNA profiles and functions in cancer development, we aimed to identify regulators of breast tumor stemness and metastasis in human xenograft models in vivo and examined their effects on self-renewal and invasion of breast cancer cells in vitro. To discover the direct targets and essential signaling pathways responsible for miRNA functions in breast cancer progression, we performed microarray analysis and target gene prediction in combination with functional studies on candidate genes (overexpression rescues and pheno-copying knockdowns).

Results: In this study, we report that hsa-miR-206 suppresses breast tumor stemness and metastasis by inhibiting both self-renewal and invasion. We identified that among the candidate targets, twinfilin (TWF1) rescues the miR-206 phenotype in invasion by enhancing the actin cytoskeleton dynamics and the activity of the mesenchymal lineage transcription factors, megakaryoblastic leukemia (translocation) 1 (MKL1), and serum response factor (SRF). MKL1 and SRF were further demonstrated to promote the expression of IL11, which is essential for miR-206's function in inhibiting both invasion and stemness of breast cancer.

Conclusions: The identification of the miR-206/TWF1/MKL1-SRF/IL11 signaling pathway sheds lights on the understanding of breast cancer initiation and progression, unveils new therapeutic targets, and facilitates innovative drug development to control cancer and block metastasis. Clin Cancer Res; 23(4); 1091–103. ©2016 AACR.



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Found in Translation: Maximizing the Clinical Relevance of Nonclinical Oncology Studies

Purpose: The translation of nonclinical oncology studies is a subject of continuous debate. We propose that translational oncology studies need to optimize both pharmacokinetic (drug exposure) and pharmacodynamic (xenograft model) aspects. While improvements in pharmacodynamic translatability can be obtained by choosing cell lines or patient-derived xenograft models closer to the clinical indication, significant ambiguity and variability exists when optimizing the pharmacokinetic translation of small molecule and biotherapeutic agents.

Experimental Design and Results: In this work, we propose a pharmacokinetic-based strategy to select nonclinical doses for approved drug molecules. We define a clinically relevant dose (CRD) as the dosing regimen in mice that most closely approximates the relevant pharmacokinetic metric in humans. Such metrics include area under the time–concentration curve and maximal or minimal concentrations within the dosing interval. The methodology is applied to six drugs, including targeted agents and chemotherapeutics, small and large molecules (erlotinib, dasatinib, vismodegib, trastuzumab, irinotecan, and capecitabine). The resulting efficacy response at the CRD is compared with clinical responses.

Conclusions: We conclude that nonclinical studies designed with the appropriate CRDs of approved drug molecules will maximize the translatability of efficacy results, which is critical when testing approved and investigational agents in combination. Clin Cancer Res; 23(4); 1080–90. ©2016 AACR.



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A Phase I Study of Topotecan, Carboplatin and the PARP Inhibitor Veliparib in Acute Leukemias, Aggressive Myeloproliferative Neoplasms, and Chronic Myelomonocytic Leukemia

Purpose: The PARP inhibitor veliparib delays DNA repair and potentiates cytotoxicity of multiple classes of chemotherapy drugs, including topoisomerase I inhibitors and platinating agents. This study evaluated veliparib incorporation into leukemia induction therapy using a previously described topotecan/carboplatin backbone.

Experimental Design: Employing a 3+3 trial design, we administered escalating doses of veliparib combined with topotecan + carboplatin in relapsed or refractory acute leukemias, aggressive myeloproliferative neoplasms (MPN), and chronic myelomonocytic leukemia (CMML).

Results: A total of 99 patients received veliparib 10–100 mg orally twice daily on days 1–8, 1–14, or 1–21 along with continuous infusion topotecan 1.0–1.2 mg/m2/d + carboplatin 120–150 mg/m2/d on days 3–7. The MTD was veliparib 80 mg twice daily for up to 21 days with topotecan 1.2 mg/m2/d + carboplatin 150 mg/m2/d. Mucositis was dose limiting and correlated with high veliparib concentrations. The response rate was 33% overall (33/99: 14 CR, 11 CRi, 8 PR) but was 64% (14/22) for patients with antecedent or associated aggressive MPNs or CMML. Leukemias with baseline DNA repair defects, as evidenced by impaired DNA damage–induced FANCD2 monoubiquitination, had improved survival [HR = 0.56 (95% confidence interval, 0.27–0.92)]. A single 80-mg dose of veliparib, as well as veliparib in combination with topotecan + carboplatin, induced DNA damage as manifested by histone H2AX phosphorylation in CD34+ leukemia cells, with greater phosphorylation in cells from responders.

Conclusions: The veliparib/topotecan/carboplatin combination warrants further investigation, particularly in patients with aggressive MPNs, CMML, and MPN- or CMML-related acute leukemias. Clin Cancer Res; 23(4); 899–907. ©2016 AACR.



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First-in-Human Study Testing a New Radioenhancer Using Nanoparticles (NBTXR3) Activated by Radiation Therapy in Patients with Locally Advanced Soft Tissue Sarcomas

Purpose: This phase I study aimed to determine the recommended dose (RD), safety profile, and feasibility of a procedure combining intratumoral injection of hafnium oxide nanoparticles (NBTXR3; a radioenhancer) and external beam radiotherapy (EBRT) for preoperative treatment of adults with locally advanced soft tissue sarcoma (STS).

Experimental Design: Patients had a preoperative indication of EBRT for STS of the extremity or trunk. Baseline tumor volume (TV) was calculated by MRI. NBTXR3 was injected percutaneously into tumors at 53.3 g/L. Dose escalation was based on four levels equivalent to 2.5%, 5%, 10%, and 20% of baseline TV. NBTXR3 was visualized in the tumor 24 hours postinjection, and EBRT was initiated (50 Gy over 5 weeks). Surgery was performed 6 to 8 weeks after EBRT completion.

Results: Twenty-two patients completed NBTXR3 injection, EBRT, and surgery and were followed for a median 22 months (range, 6–40). At NBTXR3 20% of TV, two dose-limiting toxicities occurred: injection-site pain and postoperative scar necrosis. The RD was defined as 10%. No leakage of NBTXR3 into surrounding tissues occurred; intratumor NBTXR3 levels were maintained during radiotherapy. At the RD, median tumor shrinkage was 40% (range 71% shrinkage, 22% increase); median percentage of residual viable tumor cells was 26% (range, 10%–90%). Patients receiving 20% of TV demonstrated pathologic complete responses. Seven grade 3 adverse events occurred, which were reversible.

Conclusions: A single intratumoral injection of NBTXR3 at 10% of TV with preoperative EBRT was technically feasible with manageable toxicity; clinical activity was observed. Clin Cancer Res; 23(4); 908–17. ©2016 AACR.



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Therapeutic Inhibition of the MDM2-p53 Interaction Prevents Recurrence of Adenoid Cystic Carcinomas

Purpose: Conventional chemotherapy has modest efficacy in advanced adenoid cystic carcinomas (ACC). Tumor recurrence is a major challenge in the management of ACC patients. Here, we evaluated the antitumor effect of a novel small-molecule inhibitor of the MDM2–p53 interaction (MI-773) combined with cisplatin in patient-derived xenograft (PDX) ACC tumors.

Experimental Design: Therapeutic strategies with MI-773 and/or cisplatin were evaluated in SCID mice harboring PDX ACC tumors (UM-PDX-HACC-5) and in low passage primary human ACC cells (UM-HACC-2A, -2B, -5, -6) in vitro. The effect of therapy on the fraction of cancer stem cells (CSC) was determined by flow cytometry for ALDH activity and CD44 expression.

Results: Combined therapy with MI-773 with cisplatin caused p53 activation, induction of apoptosis, and regression of ACC PDX tumors. Western blots revealed induction of MDM2, p53 and downstream p21 expression, and regulation of apoptosis-related proteins PUMA, BAX, Bcl-2, Bcl-xL, and active caspase-9 upon MI-773 treatment. Both single-agent MI-773 and MI-773 combined with cisplatin decreased the fraction of CSCs in PDX ACC tumors. Notably, neoadjuvant MI-773 and surgery eliminated tumor recurrences during a postsurgical follow-up of more than 300 days. In contrast, 62.5% of mice that received vehicle control presented with palpable tumor recurrences within this time period (P = 0.0097).

Conclusions: Collectively, these data demonstrate that therapeutic inhibition of MDM2–p53 interaction by MI-773 decreased the CSC fraction, sensitized ACC xenograft tumors to cisplatin, and eliminated tumor recurrence. These results suggest that patients with ACC might benefit from the therapeutic inhibition of the MDM2–p53 interaction. Clin Cancer Res; 23(4); 1036–48. ©2016 AACR.



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Biospecimen Complexity--the Next Challenge for Cancer Research Biobanks?

Purpose: Biospecimens (e.g., tissues, bloods, fluids) are critical for translational cancer research to generate the necessary knowledge to guide implementation of precision medicine. Rising demand and the need for higher quality biospecimens are already evident.

Experimental Design: The recent increase in requirement for biospecimen complexity in terms of linked biospecimen types, multiple preservation formats, and longitudinal data was explored by assessing trends in cancer research publications from 2000 to 2014.

Results: A PubMed search shows that there has been an increase in both raw numbers and the relative proportion (adjusted for total numbers of articles in each period) of the subgroups of articles typically associated with the use of biospecimens and both dense treatment and/or outcomes data and multiple biospecimen formats.

Conclusions: Increasing biospecimen complexity is a largely unrecognized and new pressure on cancer research biobanks. New approaches to cancer biospecimen resources are needed such as the implementation of more efficient and dynamic consent mechanisms, stronger participant involvement in biobank governance, development of requirements for registration of collections, and models to establish stock targets for biobanks. In particular, the latter two approaches would enable funders to establish a better balance between biospecimen supply and research demand, reduce expenditure on duplicate collections, and encourage increased efficiency of biobanks to respond to the research need for more complex cases. This in turn would also enable biobanks to focus more on quality and standardization that are surely factors in the even more important arena of research reproducibility. Clin Cancer Res; 23(4); 894–8. ©2016 AACR.



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Synergistic Drug Combinations with a CDK4/6 Inhibitor in T-cell Acute Lymphoblastic Leukemia

Purpose: Although significant progress has been made in the treatment of T-cell acute lymphoblastic leukemia (T-ALL), many patients will require additional therapy for relapsed/refractory disease. Cyclin D3 (CCND3) and CDK6 are highly expressed in T-ALL and have been effectively targeted in mutant NOTCH1-driven mouse models of this disease with a CDK4/6 small-molecule inhibitor. Combination therapy, however, will be needed for the successful treatment of human disease.

Experimental Design: We performed preclinical drug testing using a panel of T-ALL cell lines first with LEE011, a CDK4/6 inhibitor, and next with the combination of LEE011 with a panel of drugs relevant to T-ALL treatment. We then tested the combination of LEE011 with dexamethasone or everolimus in three orthotopic mouse models and measured on-target drug activity.

Results: We first determined that both NOTCH1-mutant and wild-type T-ALL are highly sensitive to pharmacologic inhibition of CDK4/6 when wild-type RB is expressed. Next, we determined that CDK4/6 inhibitors are antagonistic when used either concurrently or in sequence with many of the drugs used to treat relapsed T-ALL (methotrexate, mercaptopurine, asparaginase, and doxorubicin) but are synergistic with glucocorticoids, an mTOR inhibitor, and gamma secretase inhibitor. The combinations of LEE011 with the glucocorticoid dexamethasone or the mTOR inhibitor everolimus were tested in vivo and prolonged survival in three orthotopic mouse models of T-ALL. On-target activity was measured in peripheral blood and tissue of treated mice.

Conclusions: We conclude that LEE011 is active in T-ALL and that combination therapy with corticosteroids and/or mTOR inhibitors warrants further investigation. Clin Cancer Res; 23(4); 1012–24. ©2016 AACR.

See related commentary by Carroll et al., p. 873



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ABBV-399, a c-Met Antibody-Drug Conjugate that Targets Both MET-Amplified and c-Met-Overexpressing Tumors, Irrespective of MET Pathway Dependence

Purpose: Despite the importance of the MET oncogene in many malignancies, clinical strategies targeting c-Met have benefitted only small subsets of patients with tumors driven by signaling through the c-Met pathway, thereby necessitating selection of patients with MET amplification and/or c-Met activation most likely to respond. An ADC targeting c-Met could overcome these limitations with potential as a broad-acting therapeutic.

Experimental Design: ADC ABBV-399 was generated with the c-Met–targeting antibody, ABT-700. Antitumor activity was evaluated in cancer cells with overexpressed c-Met or amplified MET and in xenografts including patient-derived xenograft (PDX) models and those refractory to other c-Met inhibitors. The correlation between c-Met expression and sensitivity to ABBV-399 in tumor and normal cell lines was assessed to evaluate the risk of on-target toxicity.

Results: A threshold level of c-Met expressed by sensitive tumor but not normal cells is required for significant ABBV-399–mediated killing of tumor cells. Activity extends to c-Met or amplified MET cell line and PDX models where significant tumor growth inhibition and regressions are observed. ABBV-399 inhibits growth of xenograft tumors refractory to other c-Met inhibitors and provides significant therapeutic benefit in combination with standard-of-care chemotherapy.

Conclusions: ABBV-399 represents a novel therapeutic strategy to deliver a potent cytotoxin to c-Met–overexpressing tumor cells enabling cell killing regardless of reliance on MET signaling. ABBV-399 has progressed to a phase I study where it has been well tolerated and has produced objective responses in c-Met–expressing non–small cell lung cancer (NSCLC) patients. Clin Cancer Res; 23(4); 992–1000. ©2016 AACR.



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Patient-Derived Xenograft Establishment from Human Malignant Pleural Mesothelioma

Purpose: Malignant pleural mesothelioma (MPM) is a rare but aggressive disease with few therapeutic options. The tumor–stromal interface is important in MPM, but this is lost in cell lines, the main model used for preclinical studies. We sought to characterize MPM patient-derived xenografts (PDX) to determine their suitability as preclinical models and whether tumors that engraft reflect a more aggressive biological phenotype.

Experimental Design: Fresh tumors were harvested from extrapleural pneumonectomy, decortication, or biopsy samples of 50 MPM patients and implanted subcutaneously into immunodeficient mice and serially passaged for up to five generations. We correlated selected mesothelioma biomarkers between PDX and patient tumors, and PDX establishment with the clinical pathologic features of the patients, including their survival. DNA of nine PDXs was profiled using the OncoScan FFPE Express platform. Ten PDXs were treated with cisplatin and pemetrexed.

Results: A PDX was formed in 20 of 50 (40%) tumors implanted. Histologically, PDX models closely resembled the parent tumor. PDX models formed despite preoperative chemotherapy and radiotherapy. In multivariable analysis, patients whose tumors formed a PDX had significantly poorer survival when the model was adjusted for preoperative treatment (HR, 2.46; 95% confidence interval, 1.1–5.52; P = 0.028). Among 10 models treated with cisplatin, seven demonstrated growth inhibition. Genomic abnormalities seen in nine PDX models were similar to that previously reported.

Conclusions: Patients whose tumors form PDX models have poorer clinical outcomes. MPM PDX tumors closely resemble the genotype and phenotype of parent tumors, making them valuable models for preclinical studies. Clin Cancer Res; 23(4); 1060–7. ©2016 AACR.



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Genotype-Guided Dosing Study of FOLFIRI plus Bevacizumab in Patients with Metastatic Colorectal Cancer

Purpose: UGT1A1*28 confers a higher risk of toxicity in patients treated with irinotecan. Patients with *1/*1 and *1/*28 genotypes might tolerate higher than standard doses of irinotecan. We aimed to identify the MTD of irinotecan in patients with metastatic colorectal cancer (mCRC) with *1/*1 and *1/*28 genotypes treated with FOLFIRI plus bevacizumab, and to determine whether bevacizumab alters irinotecan pharmacokinetics.

Experimental Design: Previously untreated patients with mCRC (25 *1/*1; 23 *1/*28) were given FOLFIRI plus bevacizumab every 2 weeks. The irinotecan dose was escalated using a 3 + 3 design in each genotype group as follows: 260, 310, and 370 mg/m2. The MTD was the highest dose at which <4/10 patients had a dose-limiting toxicity (DLT). Pharmacokinetics of irinotecan and SN-38 were measured on days 1 to 3 (without bevacizumab) and 15 to 17 (with bevacizumab).

Results: For *1/*1 patients, 2 DLTs were observed among 10 patients at 310 mg/m2, while 370 mg/m2 was not tolerated (2 DLTs in 4 patients). For *1/*28 patients, 2 DLTs were observed among 10 patients at 260 mg/m2, while 310 mg/m2 was not tolerated (4 DLTs in 10 patients). Neutropenia and diarrhea were the most common DLTs. Changes in the AUCs of irinotecan and SN-38 associated with bevacizumab treatment were marginal.

Conclusions: The MTD of irinotecan in FOLFIRI plus bevacizumab is 310 mg/m2 for UGT1A1 *1/*1 patients and 260 mg/m2 for *1/*28 patients. Bevacizumab does not alter the pharmacokinetics of irinotecan. The antitumor efficacy of these genotype-guided doses should be tested in future studies of patients with mCRC treated with FOLFIRI plus bevacizumab. Clin Cancer Res; 23(4); 918–24. ©2016 AACR.



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Neoadjuvant Chemotherapy of Ovarian Cancer Results in Three Patterns of Tumor-Infiltrating Lymphocyte Response with Distinct Implications for Immunotherapy

Purpose: Some forms of chemotherapy can enhance antitumor immunity through immunogenic cell death, resulting in increased T-cell activation and tumor infiltration. Such effects could potentially sensitize tumors to immunotherapies, including checkpoint blockade. We investigated whether platinum- and taxane-based chemotherapy for ovarian cancer induces immunologic changes consistent with this possibility.

Experimental Design: Matched pre- and post-neoadjuvant chemotherapy tumor samples from 26 high-grade serous carcinoma (HGSC) patients were analyzed by immunohistochemistry (IHC) for a large panel of immune cells and associated factors. The prognostic significance of post-chemotherapy TIL patterns was assessed in an expanded cohort (n = 90).

Results: Neoadjuvant chemotherapy was associated with increased densities of CD3+, CD8+, CD8+ TIA-1+, PD-1+ and CD20+ TIL. Other immune subsets and factors were unchanged, including CD79a+ CD138+ plasma cells, CD68+ macrophages, and MHC class I on tumor cells. Immunosuppressive cell types were also unchanged, including FoxP3+ PD-1+ cells (putative regulatory T cells), IDO-1+ cells, and PD-L1+ cells (both macrophages and tumor cells). Hierarchical clustering revealed three response patterns: (i) TILhigh tumors showed increases in multiple immune markers after chemotherapy; (ii) TILlow tumors underwent similar increases, achieving patterns indistinguishable from the first group; and (iii) TILnegative cases generally remained negative. Despite the dramatic increases seen in the first two patterns, post-chemotherapy TIL showed limited prognostic significance.

Conclusions: Chemotherapy augments pre-existing TIL responses but fails to relieve major immune-suppressive mechanisms or confer significant prognostic benefit. Our findings provide rationale for multipronged approaches to immunotherapy tailored to the baseline features of the tumor microenvironment. Clin Cancer Res; 23(4); 925–34. ©2016 AACR.



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Molecular Profiling to Determine Clonality of Serial Magnetic Resonance Imaging/Ultrasound Fusion Biopsies from Men on Active Surveillance for Low-Risk Prostate Cancer

Purpose: To determine whether MRI/ultrasound (MRI/US) fusion biopsy facilitates longitudinal resampling of the same clonal focus of prostate cancer and to determine whether high-grade cancers can evolve from low-grade clones.

Experimental Design: All men on active surveillance who underwent tracking MRI/US fusion biopsy of Gleason 6 prostate cancer, on at least two distinct occasions, between 2012 and 2014 were enrolled. MRI/US fusion was used to track and resample specific cancer foci. IHC for ERG and targeted RNA/DNA next-generation sequencing (NGS) were performed on formalin-fixed paraffin-embedded prostate biopsy specimens to assess clonality.

Results: Thirty-one men with median age and PSA of 65 years and 4.6 ng/mL, respectively, were analyzed. The median sampling interval was 12 months (range, 5–35). Of the 26 evaluable men, ERG IHC concordance was found between initial and repeat biopsies in 25 (96%), indicating resampling of the same clonal focus over time. Targeted NGS supported ERG IHC results and identified unique and shared driving mutations, such as IDH1 and SPOP, in paired specimens. Of the nine men (34.6%) who were found to have Gleason ≥7 on repeat biopsy, all displayed temporal ERG concordance. Prioritized genetic alterations were detected in 50% (13/26) of paired samples. Oncogenic mutations were detected in 22% (2/9) of Gleason 6 cancers prior to progression and 44% (4/9) of Gleason ≥7 cancers when progression occurred.

Conclusions: Precise tracking of prostate cancer foci via MRI/US fusion biopsy allowed subsequent resampling of the same clonal focus of cancer over time. Further research is needed to clarify the grade progression potential of Gleason 6 prostate cancer. Clin Cancer Res; 23(4); 985–91. ©2016 AACR.



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A Phase II Trial of Abiraterone Combined with Dutasteride for Men with Metastatic Castration-Resistant Prostate Cancer

Purpose: Despite the efficacy of abiraterone, a CYP17A1 inhibitor, in metastatic castration-resistant prostate cancer (CRPC), nearly all patients develop resistance. The purpose of this phase II study was to evaluate mechanisms of resistance to more complete androgen synthesis inhibition with abiraterone and dutasteride.

Experimental Design: Eligible patients with metastatic CRPC underwent a baseline metastasis biopsy. Patients received abiraterone and prednisone for two 4-week cycles. After this time, high-dose dutasteride (3.5 mg daily) was added. Patients continued therapy until study withdrawal or radiographic progression. Repeat metastasis biopsy was obtained at progression. The primary endpoint was to assess mechanisms of resistance. Serum hormone and abiraterone levels were assessed. Tissue was assessed for androgen receptor (AR) and AR splice variant-7 (ARV7) expression.

Results: Forty patients were enrolled. Sixty percent (n = 24) achieved a ≥50% reduction in prostate-specific antigen (PSA). The median time to radiographic progression was 11 months. Nearly all baseline (n = 29 of 31) and posttreatment (n = 16 of 16) tumors tested for AR nuclear expression were positive. Of those tested, ARV7 expression was present in 48% (n = 10 of 21) of baseline and 42% (n = 5 of 12) of treatment discontinuation specimens. Compared with patients with higher serum abiraterone levels at treatment discontinuation, patients with lower levels had higher circulating androgens.

Conclusions: Despite increased androgen synthesis inhibition, we demonstrate that tumor AR axis remains important in disease progression. We highlight that abiraterone metabolism and pharmacokinetics may play a role in resistance. The noncomparative design limits conclusions on the efficacy of dual therapy with abiraterone and dutasteride, but the results support development of further multifaceted approaches toward AR inhibition. Clin Cancer Res; 23(4); 935–45. ©2016 AACR.



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Drug-Driven Synthetic Lethality: Bypassing Tumor Cell Genetics with a Combination of AsiDNA and PARP Inhibitors

Purpose: Cancer treatments using tumor defects in DNA repair pathways have shown promising results but are restricted to small subpopulations of patients. The most advanced drugs in this field are PARP inhibitors (PARPi), which trigger synthetic lethality in tumors with homologous recombination (HR) deficiency. Using AsiDNA, an inhibitor of HR and nonhomologous end joining, together with PARPi should allow bypassing the genetic restriction for PARPi efficacy.

Experimental Design: We characterized the DNA repair inhibition activity of PARPi (olaparib) and AsiDNA by monitoring repair foci formation and DNA damage. We analyzed the cell survival to standalone and combined treatments of 21 tumor cells and three nontumor cells. In 12 breast cancer (BC) cell lines, correlation with sensitivity to each drug and transcriptome were statistically analyzed to identify resistance pathways.

Results: Molecular analyses demonstrate that olaparib and AsiDNA respectively prevent recruitment of XRCC1 and RAD51/53BP1 repair enzymes to damage sites. Combination of both drugs increases the accumulation of unrepaired damage resulting in an increase of cell death in all tumor cells. In contrast, nontumor cells do not show an increase of DNA damage nor lethality. Analysis of multilevel omics data from BC cells highlighted different DNA repair and cell-cycle molecular profiles associated with resistance to AsiDNA or olaparib, rationalizing combined treatment. Treatment synergy was also confirmed with six other PARPi in development.

Conclusions: Our results highlight the therapeutic interest of combining AsiDNA and PARPi to recapitulate synthetic lethality in all tumors independently of their HR status. Clin Cancer Res; 23(4); 1001–11. ©2016 AACR.



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High-Risk Premenopausal Luminal A Breast Cancer Patients Derive no Benefit from Adjuvant Cyclophosphamide-based Chemotherapy: Results from the DBCG77B Clinical Trial

Purpose: Luminal A breast cancers have better prognosis than other molecular subtypes. Luminal A cancers may also be insensitive to adjuvant chemotherapy, although there is little high-level evidence to confirm this concept. The primary hypothesis in this formal prospective–retrospective analysis was to assess interaction between subtype (Luminal A vs. other) and treatment (chemotherapy vs. not) for the primary endpoint (10-year invasive disease-free survival) of a breast cancer trial randomizing women to adjuvant chemotherapy, analyzed in multivariate Cox proportional hazards models using the Wald interaction test.

Experimental Design: The Danish Breast Cancer Cooperative Group 77B clinical trial randomized 1,072 premenopausal women to no systematic treatment (control), levamisole, cyclophosphamide, or cyclophosphamide–methotrexate–fluorouracil arms. All arms included radiotherapy but no endocrine therapy. Researchers with no access to clinical data performed intrinsic subtype analysis on tissue microarrays using published immunohistochemical methods based on estrogen receptor, progesterone receptor, HER2, Ki67, and basal markers.

Results: Patients (n = 709) had tissue available; chemotherapy benefit in these patients was similar to the original trial (HR, 0.56). Immunohistochemistry classified 165 as Luminal A, 319 Luminal B, 58 HER2-enriched, and 82 core basal (among 91 triple-negative). Patients with Luminal A breast tumors did not benefit from chemotherapy [HR, 1.06; 95% confidence interval (CI), 0.53–2.14; P = 0.86], whereas patients with non–luminal A subtypes did (HR, 0.50; 95% CI, 0.38-0.66; P < 0.001; Pinteraction = 0.048).

Conclusions: In a prospective–retrospective analysis of a randomized trial, patients with Luminal A breast cancers did not benefit from adjuvant cyclophosphamide-based chemotherapy. Clin Cancer Res; 23(4); 946–53. ©2016 AACR.



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Identification of CCR2 and CD180 as Robust Pharmacodynamic Tumor and Blood Biomarkers for Clinical Use with BRD4/BET Inhibitors

Purpose: AZD5153 is a novel BRD4/BET inhibitor with a distinctive bivalent bromodomain binding mode. To support its clinical development, we identified pharmacodynamic (PD) biomarkers for use in clinical trials to establish target engagement.

Experimental Design: CCR2 and CD180 mRNAs, initially identified from whole transcriptome profiling, were further evaluated by quantitative PCR in hematologic cell lines, xenografts, and whole blood from rat, healthy volunteers, and patients with cancer. MYC and HEXIM1 mRNAs were also evaluated.

Results: RNA-sequencing data showed consistent decreases in CCR2/CD180 expression across multiple hematologic cell lines upon AZD5153 treatment. Evaluation of dose dependence in MV4,11 cells confirmed activity at clinically relevant concentrations. In vivo downregulation of CCR2/CD180 mRNAs (>80%) was demonstrated in MV4,11 and KMS-11 xenograft tumors at efficacious AZD5153 doses. Consistent with in vitro rat blood data, an in vivo rat study confirmed greater inhibition of CCR2/CD180 mRNA in whole blood versus MYC at an efficacious dose. Finally, in vitro treatment of whole blood from healthy volunteers and patients with cancer demonstrated, in contrast to MYC, almost complete downregulation of CCR2/CD180 at predicted clinically achievable concentrations.

Conclusions: Our data strongly support the use of CCR2 and CD180 mRNAs as whole blood PD biomarkers for BRD4 inhibitors, especially in situations where paired tumor biopsies are unavailable. In addition, they can be used as tumor-based PD biomarkers for hematologic tumors. MYC mRNA is useful as a hematologic tumor-based biomarker but suboptimal as a whole blood biomarker. Utility of HEXIM1 mRNA may be limited to higher concentrations. Clin Cancer Res; 23(4); 1025–35. ©2017 AACR.



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Complement-Regulatory Proteins CFHR1 and CFHR3 and Patient Response to Anti-CD20 Monoclonal Antibody Therapy

Purpose: Anti-CD20 mAb therapies, including rituximab and obinutuzumab (GA101), are common treatments for follicular lymphoma. In an effort to better understand the role of complement in mAb action, we recently performed germline SNP profiling on 142 follicular lymphoma patients and found rs3766404 genotype correlated with patient response to rituximab. To assess the role of three SNP-associated complement-regulatory proteins (CFH, CFHR1, and CFHR3) in clinical response to anti-CD20 mAb, we studied two cohorts of patients treated with anti-CD20 mAb.

Experimental Design: Cohorts included the Iowa/Mayo Lymphoma SPORE observational cohort of subjects with a new diagnosis of follicular lymphoma treated with rituximab and the GAUSS prospective randomized trial cohort of follicular lymphoma subjects randomized to receive single-agent rituximab or obinutuzumab. Circulating protein expression was measured for CFH, CFHR1, and CFHR3 and correlated to clinical outcome.

Results: rs3766404 genotype correlated with expression of the related downstream genes CFHR1 and CFHR3. Loss of CFHR1 expression correlated with inferior patient outcome in the observational cohort, but not in the GAUSS cohort. Loss of CFHR3 correlated with superior event-free survival in GAUSS subjects treated with obinutuzumab, but not rituximab.

Conclusions: We conclude that the relationship between complement-regulatory proteins CFHR1 and CFHR3 and response to anti-CD20 mAb therapy varies based on the specific anti-CD20 mAb used. We propose that CFHR3 is a candidate biomarker for obinutuzumab response. Further studies are needed to validate these findings and to better understand how complement pathways and complement-regulatory proteins impact on the efficacy of anti-CD20 mAb therapy. Clin Cancer Res; 23(4); 954–61. ©2016 AACR.



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Allergic asthmatic subjects have elevated levels of IgE+B-cells in the airways



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Clinical use of magnetic resonance imaging across the prostate brachytherapy workflow

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Publication date: Available online 30 January 2017
Source:Brachytherapy
Author(s): P. Blanchard, C. Ménard, S.J. Frank
MRI produces better soft tissue contrast than does ultrasonography or computed tomography for visualizing male pelvic anatomy and prostate cancer. Better visualization of the tumor and organs at risk could allow better conformation of the dose to the target volumes while at the same time minimizing the dose to critical structures and the associated toxicity. Although the use of MRI for prostate brachytherapy would theoretically result in an improved therapeutic ratio, its implementation been slow, mostly because of technical challenges. In this review, we describe the potential role of MRI at different steps in the treatment workflow for prostate brachytherapy: for patient selection, treatment planning, in the operating room, or for postimplant assessment. We further present the current clinical experience with MRI-guided prostate brachytherapy, both for permanent seed implantation and high–dose-rate brachytherapy.



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A novel missense mutation in the SLC26A4 gene causes nonsyndromic hearing loss and enlarged vestibular aqueduct

We aimed to investigate the genetic causes of hearing loss in a Chinese proband with nonsyndromic hearing loss and enlarged vestibular aqueduct syndrome.

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Refractory sleep-disordered breathing due to unilateral lingual tonsillar hypertrophy in a child with Proteus Syndrome

Proteus Syndrome (PS) is a rare congenital overgrowth disease affecting bones, skin, adipose and the central nervous system. The result is asymmetric, disfiguring hypertrophy which can manifest as craniofacial dysmorphia and aerodigestive tract abnormalities. We report the case of obstructive lingual tonsillar hypertrophy resulting in residual sleep disordered breathing after adenotonsillectomy in a child with PS, a previously unrecognized manifestation of the disease. Endoscopic treatment with coblation effectively and safely treated the obstructive symptoms.

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Pediatric post-tonsillectomy hemorrhage in the setting of post-transplantation immunosuppression

Long-term immunosuppressants form an integral part of therapy for post-transplantation patients. Immunosuppressants may also have an anticoagulant effect, and little is known about their effects on bleeding risk after adenotonsillectomy. Our objective was to investigate whether there is an increased observed rate of post-tonsillectomy hemorrhage in a population of pediatric patients on long-term immunosuppressants after solid organ transplantation, compared to healthy controls.

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Teratoma of the Neonatal Head and Neck: A 41-Year Experience

To review our institution’s experience with the presentation, evaluation, and management of teratoma of the head and neck in the neonatal population.

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Cystic cervical teratoma: A diagnostic and management challenge

Cervical teratomas are relatively rare congenital tumors pathologically defined by their three germ cell layer composition. Classically they manifest as solid or mixed solid-cystic lesions. Purely cystic teratomas pose a diagnostic challenge due to their clinical and radiologic similarity to lymphatic vascular malformations. Sclerotherapy, rather than operative excision, may be offered as therapy. We present an unusual cystic neck mass to highlight this dilemma.

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Retrieval of tracheobronchial foreign bodies by short flexible endoscopy in children

Flexible endoscopy (FE) is frequently used to diagnose tracheobronchial foreign bodies (TBFB). However, it is still controversial for retrieval of TBFB in pediatric field. This study aims at reporting and evaluating our experiences of using short-length FE with a non-invasive ventilation (NIV) technique and intensive care unit (ICU) support in retrieving pediatric TBFB.

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Machine Learning Principles Can Improve Hip Fracture Prediction

Abstract

Apply machine learning principles to predict hip fractures and estimate predictor importance in Dual-energy X-ray absorptiometry (DXA)-scanned men and women. Dual-energy X-ray absorptiometry data from two Danish regions between 1996 and 2006 were combined with national Danish patient data to comprise 4722 women and 717 men with 5 years of follow-up time (original cohort n = 6606 men and women). Twenty-four statistical models were built on 75% of data points through k-5, 5-repeat cross-validation, and then validated on the remaining 25% of data points to calculate area under the curve (AUC) and calibrate probability estimates. The best models were retrained with restricted predictor subsets to estimate the best subsets. For women, bootstrap aggregated flexible discriminant analysis (“bagFDA”) performed best with a test AUC of 0.92 [0.89; 0.94] and well-calibrated probabilities following Naïve Bayes adjustments. A “bagFDA” model limited to 11 predictors (among them bone mineral densities (BMD), biochemical glucose measurements, general practitioner and dentist use) achieved a test AUC of 0.91 [0.88; 0.93]. For men, eXtreme Gradient Boosting (“xgbTree”) performed best with a test AUC of 0.89 [0.82; 0.95], but with poor calibration in higher probabilities. A ten predictor subset (BMD, biochemical cholesterol and liver function tests, penicillin use and osteoarthritis diagnoses) achieved a test AUC of 0.86 [0.78; 0.94] using an “xgbTree” model. Machine learning can improve hip fracture prediction beyond logistic regression using ensemble models. Compiling data from international cohorts of longer follow-up and performing similar machine learning procedures has the potential to further improve discrimination and calibration.



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Role of HSP60 (HSPD1) in diabetes-induced renal tubular dysfunction: regulation of intracellular protein aggregation, ATP production, and oxidative stress [Research]

Because underlying mechanisms of diabetic nephropathy/tubulopathy remained poorly understood, we aimed to define a key protein involving in hyperglycemia-induced renal tubular dysfunction. All altered renal proteins identified from previous large-scale proteome studies were subjected to global protein network analysis, which revealed heat shock protein 60 (HSP60, also known as HSPD1) as the central node of protein–protein interactions. Functional validation was performed using small interfering RNA (siRNA) to knock down HSP60 (siHSP60). At 48 h after exposure to high-glucose (HG) (25 mM), Madin-Darby canine kidney (MDCK) renal tubular cells transfected with controlled siRNA (siControl) had significantly increased level of HSP60 compared to normal-glucose (NG) (5.5 mM), whereas siHSP60-transfected cells showed a dramatically decreased HSP60 level. siHSP60 modestly increased intracellular protein aggregates in both NG and HG conditions. Luciferin–luciferase assay showed that HG modestly increased intracellular ATP, and siHSP60 further enhanced such an increase. OxyBlot assay showed significantly increased level of oxidized proteins in HG-treated siControl-transfected cells, whereas siHSP60 caused marked increase of oxidized proteins under the NG condition. However, the siHSP60-induced accumulation of oxidized proteins was abolished by HG. In summary, our data demonstrated that HSP60 plays roles in regulation of intracellular protein aggregation, ATP production, and oxidative stress in renal tubular cells. Its involvement in HG-induced tubular cell dysfunction was most likely via regulation of intracellular ATP production.—Aluksanasuwan, S., Sueksakit, K., Fong-ngern, K., Thongboonkerd, V. Role of HSP60 (HSPD1) in diabetes-induced renal tubular dysfunction: regulation of intracellular protein aggregation, ATP production, and oxidative stress.



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Extracellular matrix receptor expression in subtypes of lung adenocarcinoma potentiates outgrowth of micrometastases

Mechanisms underlying the propensity of latent lung adenocarcinoma (LUAD) to relapse are poorly understood. In this study, we show how differential expression of a network of extracellular matrix (ECM) molecules and their interacting proteins contributes to risk of relapse in distinct LUAD subtypes. Overexpression of the hyaluronan receptor HMMR in primary LUAD was associated with an inflammatory molecular signature and poor prognosis. Attenuating HMMR in LUAD cells diminished their ability to initiate lung tumors and distant metastases. HMMR upregulation was not required for dissemination in vivo, but enhanced ECM mediated signaling, LUAD cell survival and micrometastasis expansion in hyaluronan-rich microenvironments in the lung and brain metastatic niches. Our findings reveal an important mechanism by which disseminated cancer cells can co-opt the inflammatory ECM to persist, leading to brain metastatic outgrowths.

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Elevated basal antibody-dependent cell-mediated cytotoxicity (ADCC) and high epidermal growth factor receptor (EGFR) expression predict favourable outcome in patients with locally advanced head and neck cancer treated with cetuximab and radiotherapy

Abstract

Background

Antibody-dependent cell-mediated cytotoxicity (ADCC) may contribute to the antitumor activity of cetuximab. However, the extent of this contribution is unclear. In this study, we investigated the impact of baseline ADCC on the outcome of patients with locally advanced squamous cell carcinoma treated with cetuximab and radiotherapy.

Methods

We determined baseline ADCC in 28 patients treated with cetuximab and radiotherapy and in 15 patients treated with chemoradiation. We linked the values observed with complete response and with overall survival. We also considered the role of epidermal growth factor receptor (EGFR) expression and studied the combined effect of EGFR and ADCC.

Results

We observed a wide range of baseline values of ADCC. Complete response did not correlate with either ADCC or EGFR expression. However, when ADCC and EGFR were considered together using a mixed score, they significantly correlated with achieving a complete response (p = 0.04). High baseline ADCC significantly correlated with outcome compared to low (p = 0.03), but not in patients treated without cetuximab. Patients showing high baseline levels of both ADCC and EGFR3+ achieved the best outcome compared to the others (p = 0.02).

Conclusions

In this study, patients treated with cetuximab and radiotherapy, showing high baseline of both ADCC and EGFR3+, have significant higher probability of achieving a complete response and a long overall survival compared to the others.



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Lifetime weight gain linked to oesophageal and stomach cancers

People who are overweight in their twenties and become obese later in life may be three times more likely to develop cancer of either the oesophagus (food pipe) or upper stomach, according to a study published in the British Journal of Cancer. Those who...

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Synaptic activity drives a genomic program that promotes a neuronal Warburg effect [Gene Regulation]

Synaptic activity drives changes in gene expression to promote long-lasting adaptations of neuronal structure and function. One example of such an adaptive response is the buildup of acquired neuroprotection, a synaptic activity- and gene transcription-mediated increase in the resistance of neurons against harmful conditions. A hallmark of acquired neuroprotection is the stabilization of mitochondrial structure and function. We therefore re-examined previously identified sets of synaptic activity-regulated genes to identify genes that are directly linked to mitochondrial function. In mouse and rat primary hippocampal cultures synaptic activity caused an upregulation of glycolytic genes and a concomitant downregulation of genes required for oxidative phosphorylation, mitochondrial biogenesis and maintenance. Changes in metabolic gene expression were induced by action potential bursting, but not by glutamate bath application activating extrasynaptic NMDA receptors. The specific and coordinate pattern of gene expression changes suggested that synaptic activity promotes a shift of neuronal energy metabolism from oxidative phosphorylation toward aerobic glycolysis, also known as Warburg effect. The ability of neurons to upregulate glycolysis has, however, been debated. We therefore used FACS sorting to show that, in mixed neuron glia co-cultures, activity-dependent regulation of metabolic gene expression occurred in neurons. Changes in gene expression were accompanied by changes in the phosphorylation-dependent regulation of the key metabolic enzyme, pyruvate dehydrogenase. Finally, increased synaptic activity caused an increase in the ratio of L-lactate production to oxygen consumption in primary hippocampal cultures. Based on these data we suggest the existence of a synaptic activity-mediated neuronal Warburg effect that may promote mitochondrial homeostasis and neuroprotection.

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SGLT2 Expression is increased in Human Diabetic Nephropathy: SGLT2 Inhibition Decreases Renal Lipid Accumulation, Inflammation and the Development of Nephropathy in Diabetic Mice [Metabolism]

There is very limited human renal sodium gradient dependent glucose transporter protein SGLT2 mRNA and protein expression data reported in the literature. Aim 1 of this study was to determine SGLT2 mRNA and protein levels in human and animal models of diabetic nephropathy. We have found that the expression of SGLT2 mRNA and protein is increased in renal biopsies from human subjects with diabetic nephropathy. This is in contrast to db-db mice which had no changes in renal SGLT-2 protein expression. Furthermore, the effect of SGLT2 inhibition on renal lipid content and inflammation is not known. Aim 2 of this study was to determine the potential mechanisms of beneficial effects of SGLT2 inhibition in progression of diabetic renal disease. We treated db/db mice with a selective SGLT2 inhibitor JNJ 39933673. We found that SGLT2 inhibition caused marked decreases in systolic blood pressure, kidney weight/body weight ratio, urinary albumin and urinary thiobarbituric acid-reacting substances (TBARS). SGLT2 inhibition prevented renal lipid accumulation via inhibition of ChREBP-β, LPK, SCD-1 and DGAT1, key transcriptional factors and enzymes that mediate fatty acid and triglyceride synthesis. SGLT2 inhibition also prevented inflammation via inhibition of CD68 macrophage accumulation, and expression of p65, TLR4, MCP-1 and OPN. These effects were associated with reduced mesangial expansion, accumulation of extracellular matrix proteins fibronectin and type IV collagen, and loss of podocyte markers WT1 and synaptopodin, as determined by immunofluorescence microscopy. In summary, our study showed that SGLT2 inhibition modulates renal lipid metabolism and inflammation and prevents the development of nephropathy in db/db mice.

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S-Palmitoylation of Junctional Adhesion Molecule C Regulates Its Tight Junction Localization and Cell Migration [Enzymology]

Junctional Adhesion Molecule C (JAM-C) is an immunoglobulin superfamily protein expressed in epithelial cells, endothelial cells, and leukocytes. JAM-C has been implicated in leukocyte transendothelial migration, angiogenesis, cell-adhesion, cell polarity, spermatogenesis and metastasis. Here, we show that JAM-C undergoes S-palmitoylation on two juxtamembrane cysteine residues, Cys264 and Cys265. We have identified DHHC7 as a JAM-C palmitoylating enzyme by screening all known palmitoyltransferases (PATs or DHHCs). Ectopic expression of DHHC7, but not a DHHC7 catalytic mutant, enhances JAM-C S-palmitoylation. Moreover, DHHC7 knockdown decreases the S-palmitoylation level of JAM-C. Palmitoylation of JAM-C promotes its localization to tight junctions and inhibits transwell migration of A549 lung cancer cells. These results suggest that S-palmitoylation of JAM-C can be potentially targeted to control cancer metastasis.

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Structural insights unravel the zymogenic mechanism of the virulence factor gingipain K from Porphyromonas gingivalis, a causative agent of gum disease from the human oral microbiome. [Microbiology]

Skewing of the human oral microbiome causes dysbiosis and preponderance of bacteria such as Porphyromonas gingivalis, the main etiological agent of periodontitis. P. gingivalis secretes proteolytic gingipains (Kgp and RgpA/B) as zymogens inhibited by a pro-domain that is removed during extracellular activation. Unraveling the molecular mechanism of Kgp zymogenicity is essential to design inhibitors blocking its activity. Here, we found that the isolated 209-residue Kgp pro-domain is a boomerang-shaped all-β protein similar to the RgpB pro-domain. Using composite structural information of Kgp and RgpB, we derived a plausible homology model and mechanism of Kgp-regulating zymogenicity. Accordingly, the pro-domain would laterally attach to the catalytic moiety in Kgp and block the active site through an exposed inhibitory loop. This loop features a lysine (K129) likely occupying the S1-specificity pocket and exerting latency. K129 mutation to glutamate or arginine led to misfolded protein that was degraded in vivo. Mutation to alanine gave milder effects but still strongly diminished proteolytic activity, without affecting the enzyme's subcellular location. Accordingly, the interactions of K129 within the S1 pocket are also essential for correct folding. Uniquely for gingipains, the isolated Kgp pro-domain dimerized through an interface, which partially overlapped with that between the catalytic moiety and the pro-domain within the zymogen, i.e. both complexes are mutually exclusive. Thus, pro-domain dimerization, together with partial rearrangement of the active site upon activation, explain the lack of inhibition of the pro-domain in trans. Our results reveal that the specific latency mechanism of Kgp differs from those of Rgps.

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Identification of a Transcriptional Activation Domain in Yeast Repressor Activator Protein 1 (Rap1) Using an Altered DNA-Binding Specificity Variant [Gene Regulation]

Repressor Activator Protein 1 (Rap1) performs multiple vital cellular functions in the budding yeast Saccharomyces cerevisiae. These include regulation of telomere length, transcriptional repression of both telomere-proximal genes and the silent mating type loci, and transcriptional activation of hundreds of mRNA-encoding genes, including the highly transcribed ribosomal protein- and glycolytic enzyme-encoding genes. Studies of the contributions of Rap1 to telomere length regulation and transcriptional repression have yielded significant mechanistic insights. However, the mechanism of Rap1 transcriptional activation remains poorly understood because Rap1 is encoded by a single-copy essential gene and is involved in many disparate, essential cellular functions, preventing easy interpretation of attempts to directly dissect Rap1 structure-function relationships. Moreover, conflicting reports on the ability of Rap1-heterologous DNA-binding domain fusion proteins to serve as chimeric transcriptional activators challenge use of this approach to study Rap1. Described here is the development of an altered DNA-binding-specificity variant of Rap1 (Rap1AS). We used Rap1AS to map and characterize a 41-amino acid activation domain (AD) within the Rap1 C-terminus. We found that this AD is required for transcription of both chimeric reporter genes and authentic chromosomal Rap1 enhancer-containing target genes. Finally, as predicted for a bona fide AD, mutation of this newly identified AD reduced the efficiency of Rap1 binding to a known transcriptional coactivator TFIID-binding target, Taf5. In summary, we show here that Rap1 contains an AD required for Rap1-dependent gene transcription. The Rap1AS variant will likely also be useful for studies of the functions of Rap1 in other biological pathways.

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mTORC1 Activity is Required to Maintain Canonical Endocytic Recycling Pathway against Lysosomal Delivery [Metabolism]

The plasma membrane of mammalian cells undergoes constitutive endocytosis, endocytic sorting and recycling, which delivers nutrients to the lysosomes. The receptors, along with membrane lipids, are normally returned to the plasma membrane to sustain this action. It is not known, however, whether this process is influenced by metabolic conditions. Here we report that endocytic recycling requires active mTORC1, a master metabolic sensor. Upon mTORC1 inactivation, either by starvation or by inhibitors, plasma membrane lipids and recycling receptors, such as sphingomyelin and transferrin receptors, are delivered to the lysosomes. This lysosomal targeting is independent of canonical autophagy: both wt and in Atg5-/- MEFs responded similary. Furthermore, we identify Hrs, an ESCORT-0 component, as a downstream target of mTORC1. Hrs requires mTORC1 activity to maintain its protein expression level. Silencing Hrs without decreasing mTORC1 activity is sufficient to target transferrin to the lysosomes. It is thus evident that the canonical recycling pathway is under the regulation of mTORC1 and likely most predominant in proliferating cells where mTORC1 is highly active.

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Mechanistic Understanding of N-Glycosylation in Ebola Virus Glycoprotein Maturation and Function [Glycobiology and Extracellular Matrices]

The Ebola virus (EBOV) trimeric envelope glycoprotein (GP) precursors are cleaved into the receptor-binding GP1 and the fusion-mediating GP2 subunits and incorporated into virions to initiate infection. GP1 and GP2 form heterodimers, which have 15 or 2 N-glycosylation sites (NGSs), respectively. Here, we investigated the mechanism of how N-glycosylation contributes to GP expression, maturation, and function. As reported before, we found that although GP1 NGSs are not critical, the two GP2 NGSs, N563 and N618, are essential to the GP function. Further analysis uncovered that N563 and N618 regulate GP processing, demannosylation, oligomerization, and conformation. Consequently, these two NGSs are required for GP incorporation into EBOV-like particles (E-VLP) and HIV-1 pseudovirions, and determine viral transduction efficiency. Using CRISPR/Cas9 technology, we knocked out the two classical endoplasmic reticulum (ER) chaperones calnexin (CNX) and/or calreticulin (CRT) and found that both CNX and CRT increase the GP expression. Nevertheless, NGSs are not required for the GP interaction with CNX or CRT. Together, we conclude that although N563 and N618 are not required for EBOV GP expression, they synergistically regulate its maturation, which determines its functionality.

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Molecular Determinants of the N-Terminal Acetyltransferase Naa60 Anchoring to the Golgi Membrane [Protein Structure and Folding]

Nα-acetyltransferase 60 (Naa60 or NatF) was recently identified as an unconventional N-terminal acetyltransferase (NAT) since it localizes to organelles, in particular the Golgi apparatus, and has a preference for acetylating N-termini of transmembrane proteins. This knowledge challenged the prevailing view of N-terminal acetylation as a co-translational ribosome-associated process and suggested a new mechanistic functioning for the enzymes responsible for this increasingly recognized protein modification. Crystallography studies on Naa60 were unable to resolve the C-terminal tail of Naa60, which is responsible for the organellar localization. Here, we combined modeling, in vitro assays, and cellular localization studies to study secondary structure and membrane interacting capacity of Naa60. The results show that Naa60 is a peripheral membrane protein. Two amphipathic helices within the Naa60 C-terminus bind the membrane directly in a parallel position relative to the lipid bilayer via hydrophobic and electrostatic interactions. A peptide corresponding to the C-terminus is unstructured in solution and only folds into an α-helical conformation in the presence of liposomes. Computational modeling and cellular mutational analysis revealed the hydrophobic face of two α-helices to be critical for membranous localization. Furthermore, we found a strong and specific binding preference of Naa60 towards membranes containing the phosphatidylinositol PI4P, thus possibly explaining the primary residency of Naa60 at the PI4P-rich Golgi. In conclusion, we have defined the mode of cytosolic Naa60 anchoring to the Golgi apparatus, most likely occurring post-translationally and specifically facilitating post-translational N-terminal acetylation of many transmembrane proteins.

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Conformational Changes in the Activation Loop of Mitochondrial Glutaminase C: A Direct Fluorescence Read-Out that Distinguishes the Binding of Allosteric Inhibitors from Activators [Signal Transduction]

The first step in glutamine catabolism is catalyzed by the mitochondrial enzyme glutaminase, with a specific isoform, glutaminase C (GAC), being highly expressed in cancer cells. GAC activation requires the formation of homo-tetramers, promoted by anionic allosteric activators such as inorganic phosphate. This leads to the proper orientation of a flexible loop proximal to the dimer-dimer interface that is essential for catalysis (i.e. the activation loop). A major class of allosteric inhibitors of GAC, with the prototype being BPTES (bis-2-(5-phenylacetamido-1,2,4-thiadiazol-2-yl)ethyl sulfide), and the related molecule CB-839, binds to the activation loop and induces the formation of an inactive tetramer (2 inhibitors bound per active tetramer). Here, we describe a direct readout for monitoring the dynamics of the activation loop of GAC in response to these allosteric inhibitors, as well as allosteric activators, through the substitution of phenylalanine at position 327 with tryptophan (F327W). The tryptophan fluorescence of the GAC(F327W) mutant undergoes a marked quenching upon the binding of BPTES or CB-839, yielding titration profiles that make it possible to measure the binding affinities of these inhibitors for the enzyme. Allosteric activators like phosphate induce the opposite effect (i.e. a fluorescence enhancement). These results describe direct read-outs for the binding of the BPTES-class of allosteric inhibitors, as well as for inorganic phosphate and related activators of GAC, which should facilitate screening for additional modulators of this important metabolic enzyme.

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Biallelic Insertion of a Transcriptional Terminator via CRISPR/Cas9 Efficiently Silences Expression of Protein-coding and Non-coding RNA Genes [Methods and Resources]

The type II bacterial CRISPR/Cas9 system is a simple, convenient and powerful tool for gene editing that allows for gene targeting. Here, we describe a CRISPR/Cas9-based approach for silencing both protein-coding and non-protein-coding genes by biallelic integration of a PolyA signal. Because of the integration of a BGH PolyA signal into the target genes, gene expression was drastically terminated. Two anti-antibiotic genes were used as markers in the selection of clonal cell lines with biallelic integration of a PolyA signal. Genotyping analysis indicated that 65-93% of the cell lines displayed the desired biallelic silencing after a short time selection. In conclusion, we, for the first time, established an efficient CRISPR/Cas9-based approach to gene silencing using biallelic integration of a PolyA signal with the advantages of double marker selection. It is an easy, convenient and efficient novel technique for gene silencing in cell line. This approach may be especially suitable for cell lines, in which gene integration is difficult due to low efficiency of homology-directed repair.

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An Interaction between the Inner Rod Protein YscI and the Needle Protein YscF Is Required to Assemble the Needle Structure of the Yersinia Type Three Secretion System [Microbiology]

The type III secretion system is a highly conserved virulence mechanism that is widely distributed in Gram-negative bacteria. It has a syringe-like structure composed of a multi-ring basal body that spans the bacterial envelope, and a projecting needle that delivers virulence effectors into host cells. Here, we showed that the Yersinia inner rod protein YscI directly interacts with the needle protein YscF inside the bacterial cells, and that this interaction depends on amino acid residues 83-102 in the carboxyl-terminus of YscI. Alanine substitution of W85 or S86 abrogated the binding of YscI to YscF, as well as needle assembly and the secretion of effectors (Yops) and the needle tip protein LcrV. However, yscI null mutants that were trans- complemented with YscI mutants that bind YscF still assembled the needle and secreted Yops, demonstrating that a direct interaction between YscF and YscI is critical for these processes. Consistently, YscI mutants that did not bind YscF resulted in greatly decreased HeLa cell cytotoxicity. Together, these results show that YscI participates in needle assembly by directly interacting with YscF.

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The NCLX-type Na+/Ca2+ exchanger NCX-9 is required for patterning of neural circuits in Caenorhabditis elegans [Signal Transduction]

NCLX is a Na+/Ca2+ exchanger that uses energy stored in the transmembrane sodium gradient to facilitate the exchange of sodium ions for ionic calcium. Mammals have a single NCLX, which has been shown to function primarily at the mitochondrion and is an important regulator of neuronal physiology by contributing to neurotransmission and synaptic plasticity. The role of NCLX in developmental cell patterning, for example, in neural circuits, is largely unknown. Here we describe a novel role for the Caenorhabditis elegans NCLX-type protein, NCX-9, in neural circuit formation. NCX-9 functions in hypodermal seam cells that secrete the axon guidance cue UNC- 129/BMP, and our data revealed that ncx-9-/- mutant animals exhibit development defects in stereotyped left/right axon guidance choices within the GABAergic motor neuron circuit. Our data also implicate NCX-9 in a LON-2/heparan sulfate and UNC-6/Netrin-mediated, RAC-dependent signaling pathway to guide left/right patterning within this circuit. Finally, we also provide in vitro physiology data supporting the role for NCX-9 in handling calcium exchange at the mitochondrion. Taken together, our work reveals the specificity by which NCLX handling of calcium exchange can map to neural-circuit patterning and axon-guidance decisions during development.

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Inonotus obliquus polysaccharide regulates gut microbiota of chronic pancreatitis in mice

Polysaccharide is efficient in attenuation of metabolic ailments and modulation of gut microbiota as prebiotics. The therapeutic effect of Inonotus obliquus polysaccharide (IOP) on chronic pancreatitis (CP) in mi...

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Quantifying bacterial attachment and detachment using leaching solutions of various ionic strengths after bacterial pulse

In this study, we quantified the attachment and detachment of bacteria during transport in order to elucidate the contributions of reversible attachment on bacterial breakthrough curves. The first set of break...

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Vasodilator-Stimulated Phosphoprotein (VASP) depletion from breast cancer MDA-MB-231 cells inhibits tumor spheroid invasion through downregulation of Migfilin, β-catenin and urokinase-plasminogen activator (uPA)

Publication date: Available online 14 February 2017
Source:Experimental Cell Research
Author(s): Vasiliki Gkretsi, Andreas Stylianou, Triantafyllos Stylianopoulos
A hallmark of cancer cells is their ability to invade surrounding tissues and form metastases. Cell-extracellular matrix (ECM)-adhesion proteins are crucial in metastasis, connecting tumor ECM with actin cytoskeleton thus enabling cells to respond to mechanical cues. Vasodilator-stimulated phosphoprotein (VASP) is an actin-polymerization regulator which interacts with cell-ECM adhesion protein Migfilin, and regulates cell migration.We compared VASP expression in MCF-7 and MDA-MB-231 breast cancer (BC) cells and found that more invasive MDA-MB-231 cells overexpress VASP. We then utilized a 3-dimensional (3D) approach to study metastasis in MDA-MB-231 cells using a system that considers mechanical forces exerted by the ECM. We prepared 3D collagen I gels of increasing concentration, imaged them by atomic force microscopy, and used them to either embed cells or tumor spheroids, in the presence or absence of VASP. We show, for the first time, that VASP silencing downregulated Migfilin, β-catenin and urokinase plasminogen activator both in 2D and 3D, suggesting a matrix-independent mechanism. Tumor spheroids lacking VASP demonstrated impaired invasion, indicating VASP’s involvement in metastasis, which was corroborated by Kaplan-Meier plotter showing high VASP expression to be associated with poor remission-free survival in lymph node-positive BC patients. Hence, VASP may be a novel BC metastasis biomarker.



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Lipoxin A4 suppresses osteoclastogenesis in RAW264.7 cells and prevents ovariectomy-induced bone loss

Publication date: Available online 14 February 2017
Source:Experimental Cell Research
Author(s): Changyu Liu, Hanfeng Guan, Cong Cai, Feng Li, Jun Xiao
Lipoxin A4 (LXA4; 5S, 6R, 15Strihydroxy- 7,9,13-trans-11-eicosatetraenoic acid) is a metabolic product of arachidonic acid under the action of lipoxidase. This lipid molecule plays important roles in several biological functions, especially inflammatory processes. In vivo, LXA4 regulates the inflammatory response through several signaling pathways. Its mechanism suggests that it might have an effect on osteoclastogenesis and bone loss. Using both in vitro and in vivo studies, it was here observed that LXA4 could significantly inhibit the formation and function of osteoclasts and these effects could be blocked by Boc-2, the specific inhibitor of FPR2/ALX (the receptor of LXA4). Meanwhile, LXA4 reduce the amount of ovariectomy-induced bone loss. These protective effects was found to be associated with inhibition of nuclear factor-κB (NF-κB), activator protein-1 (AP-1), PI3K-AKT, and p-38, ERK, and JNK in MAPKs. The expression of the receptor activator of the NF-κB ligand RANKL:osteoprotegerin ratio and serum levels of TNF-α, IL-1β, and IL-6 were decreased by LXA4. Moreover, LXA4 prevented the production of reactive oxygen species (ROS), the expression of osteoclast-specific genes, including tartrate-resistant acid phosphatase (TRAP), cathepsin K (CK), matrix metalloproteinase (MMP)−9, RANK, and osteoclastic related transcription factors of c-Fos, NFATc1 could also be significantly inhibited by LXA4 in a dose-dependent manner. Studies have demonstrated that LXA4 can inhibit the formation and function of osteoclasts through modulation of several pathways both upstream and downstream of RANKL signaling and FPR2/ALX wasinvolved in the procedures. This shows that LXA4 may be used as a new strategy for the treatment of osteoclast-related diseases.



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Platelet rich plasma (PRP) induces chondroprotection via increasing autophagy, anti-inflammatory markers, and decreasing apoptosis in human osteoarthritic cartilage

Publication date: Available online 13 February 2017
Source:Experimental Cell Research
Author(s): Mayssam Moussa, Daniel Lajeunesse, George Hilal, Oula El Atat, Gaby Haykal, Rim Serhal, Antonio Chalhoub, Charbel Khalil, Nada Alaaeddine
ObjectivesAutophagy constitutes a defense mechanism to overcome aging and apoptosis in osteoarthritic cartilage. Several cytokines and transcription factors are linked to autophagy and play an important role in the degradative cascade in osteoarthritis (OA). Cell therapy such as platelet rich plasma (PRP) has recently emerged as a promising therapeutic tool for many diseases including OA. However, its mechanism of action on improving cartilage repair remains to be determined. The purpose of this study is to investigate the effect of PRP on osteoarthritic chondrocytes and to elucidate the mechanism by which PRP contributes to cartilage regeneration.MethodsOsteoarthritic chondrocytes were co-cultured with an increasing concentration of PRP obtained from healthy donors. The effect of PRP on the proliferation of chondrocytes was performed using cell counting and WST8 proliferation assays. Autophagy, apoptosis and intracellular level of IL-4, IL-10, and IL-13 were determined using flow cytometry analyses. Autophagy markers BECLIN and LC3II were also determined using quantitative polymerase chain reaction (qPCR). qPCR and ELISA were used to measure the expression of ADAMDTS-5, MMP3, MMP13, TIMP-1–2–3, aggregan, Collagen type 2, TGF-β, Cox-2, Il-6, FOXO1, FOXO3, and HIF-1 in tissues and co-cultured media.ResultsPRP increased significantly the proliferation of chondrocytes, decreased apoptosis and increased autophagy and its markers along with its regulators FOXO1, FOXO3 and HIF-1 in osteoarthritic chondrocytes. Furthermore, PRP caused a dose-dependent significant decrease in MMP3, MMP13, and ADAMTS-5, IL-6 and COX-2 while increasing TGF-β, aggregan, and collagen type 2, TIMPs and intracellular IL-4, IL-10, IL-13.ConclusionThese results suggest that PRP could be a potential therapeutic tool for the treatment of OA.



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Dissolution Kinetics of Oxidative Etching of Cubic and Icosahedral Platinum Nanoparticles Revealed by in Situ Liquid Transmission Electron Microscopy

TOC Graphic

ACS Nano
DOI: 10.1021/acsnano.6b07541
ancac3?d=yIl2AUoC8zA


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Piezoelectric Micro- and Nanostructured Fibers Fabricated from Thermoplastic Nanocomposites Using a Fiber Drawing Technique: Comparative Study and Potential Applications

TOC Graphic

ACS Nano
DOI: 10.1021/acsnano.6b08290
ancac3?d=yIl2AUoC8zA


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Editorial Board

Publication date: April 2017
Source:Cellular Signalling, Volume 32





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Nuclear lamins and progerin are dispensable for antioxidant Nrf2 response to arsenic and cadmium

Publication date: Available online 14 February 2017
Source:Cellular Signalling
Author(s): Kazunori Hashimoto, Rima Majumdar, Yoshiaki Tsuji
Lamins are important constituents of the nuclear inner membrane and provide a platform for transcription factors and chromatin. Progerin, a C-terminal truncated lamin A mutant, causes premature aging termed Hutchinson-Gilford Progeria Syndrome (HGPS). Oxidative stress appears to be involved in the pathogenesis of HGPS, although the mechanistic role of progerin remains elusive. Here we examined whether nuclear lamins are important for a cellular antioxidant mechanism, and whether progerin compromises it. We investigated the activation of nuclear factor-E2-related factor 2 (Nrf2) which regulates various antioxidant genes including heme oxygenase-1 (HMOX1), following exposure to sodium arsenite or cadmium chloride in lamin knockdown human cell lines and primary HGPS human fibroblasts. Knocking down lamin A/C, or B, or all nuclear lamins simultaneously in three human cell lines (HaCaT, SW480, and K562) did not impair arsenite- or cadmium-induced activation of Nrf2. Progerin-expressing human primary HGPS fibroblasts showed lower basal levels of HMOX1 and NQO1 expression; however, in response to arsenic stress both normal and HGPS primary fibroblasts showed Nrf2 nuclear accumulation along with upregulation and phosphorylation of p62/SQSTM1 at Ser351, downregulation of Keap1, and comparable expression of an array of downstream Nrf2-regulated antioxidant genes. We also observed new forms of cleaved lamin A, B1 and B2 induced by cadmium stress although their roles in the Nrf2 antioxidant system need further investigation. These results suggest that the nuclear lamins and progerin have marginal roles in the activation of the antioxidant Nrf2 response to arsenic and cadmium.



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CSN5/JAB1 suppresses the WNT inhibitor DKK1 in colorectal cancer cells

Publication date: Available online 14 February 2017
Source:Cellular Signalling
Author(s): Sandra Jumpertz, Thomas Hennes, Yaw Asare, Anke K. Schütz, Jürgen Bernhagen
The COP9 signalosome (CSN) is a multi-protein complex that is highly conserved in eukaryotes. Due to its regulatory impact on processes such as cell cycle, DNA damage response and apoptosis, the CSN is essential for mammalian cells. One of the best-studied functions of the CSN is the deNEDDylation of cullin-RING ligases (CRLs) via its catalytically active subunit CSN5/JAB1, thereby triggering the degradation of various target proteins. CSN5 was found to be overexpressed in many human cancer entities, including colon adenocarcinoma. Overactivation of WNT signaling is known as a key step in colon cancer development. Recently, we found that depletion of CSN5 in colorectal cancer (CRC) cells affects WNT signaling by downregulation of β-catenin. To investigate changes in gene expression associated with the CSN5 knockdown, we performed a microarray using cDNA from the CRC cell line SW480. We found the WNT ligand WNT6 and the WNT inhibitors DKK1 and DKK4 differentially regulated in CSN5 knockdown cells. DKK1 expression and DKK1 protein levels depended on CSN5 in different CRC cell lines. In addition, DKK1 secretion was increased following CSN5 knockdown, affecting WNT signaling in SW480 cells. Consequently, blocking of secreted DKK1 in cell-conditioned media abolished β-catenin downregulation in SW480 cells, while treatment with recombinant DKK1 mimicked the CSN5 knockdown effect. Furthermore, knockdown of DKK1 was able to rescue the proliferative deficiency of CSN5 knockdown cells. We conclude that downregulation of WNT signaling in colorectal cancer cells resulting from CSN5 knockdown is mediated, at least in part, by elevated DKK1 secretion. Moreover, experiments with the NEDDylation inhibitor MLN-4924 indicated that DKK1 expression is regulated by a so far unidentified repressor, the stability of which could be controlled by a CSN-regulated CRL.



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GPR43 activation enhances psoriasis-like inflammation through epidermal upregulation of IL-6 and dual oxidase 2 signaling in a murine model

Publication date: Available online 14 February 2017
Source:Cellular Signalling
Author(s): Ahmed Nadeem, Sheikh F. Ahmad, Naif O. Al-Harbi, Ahmed M. El-Sherbeeny, Mohammed M. Al-Harbi, Talal S. Almukhlafi
The gut is densely inhabited by commensal bacteria, which metabolize dietary fibers/undigested carbohydrates and produce short-chain fatty acids such as acetate. GPR43 is one of the receptors to sense short-chain fatty acids, and expressed in various immune and non-immune cells. Acetate/GPR43 signaling has been shown to affect various inflammatory diseases through Th17 responses and NADPH oxidase (NOX)-derived reactive oxygen species (ROS) generation. However, no study has previously explored the effects of GPR43 activation during psoriasis-like inflammation. Therefore, this study investigated the effect of acetate/phenylacetamide (GPR43 agonists) on imiquimod induced skin inflammation in mice. Mice were administered phenylacetamide/acetate followed by assessment of skin inflammation, NOXs (NOX-2, NOX-4, dual oxidases), and Th17 related signaling. Our study showed induction of epidermal GPR43 after imiquimod treatment, i.e. psoriasis-like inflammation. Acetate administration in psoriatic mice led to further increase in skin inflammation (ear thickness/myeloperoxidase activity) with concurrent increase in Th17 immune responses and epidermal dual oxidase-2 signaling. Further, topical application of GPR43 agonist, phenylacetamide led to enhanced ear thickness with concomitant epidermal IL-6 signaling as well as dual oxidase-2 upregulation which may be responsible for increased psoriasis-like inflammation. Taken together, dual oxidase-2 and IL-6 play important roles in GPR43-mediated skin inflammation. The current study suggests that GPR43 activation in psoriatic patients may lead to aggravation of psoriatic inflammation.



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Casein Kinase 2 Interacting Protein-1 regulates M1 and M2 inflammatory macrophage polarization

Publication date: Available online 14 February 2017
Source:Cellular Signalling
Author(s): Yuhan Chen, Wen Liu, Yiwu Wang, Luo Zhang, Jun Wei, Xueli Zhang, Fuchu He, Lingqiang Zhang
The importance of macrophage plasticity, albeit being discovered recently, has been highlighted in a broad spectrum of biological processes operative in physiological and pathological environments. Macrophage polarized activation and inactivation has profound effects on immune and inflammatory responses with several major pathways being elucidated in the past few years. However, transcriptional regulation mechanisms governing macrophage polarization is still preliminary. In this study, we identify the Casein Kinase 2 Interacting Protein 1 (CKIP-1) as a molecular toggle manipulating macrophage speciation. CKIP-1 expression was strongly induced by pro-inflammatory M1 stimuli (LPS and IFN-γ) and robustly suppressed by M2 stimuli (IL-4 and IL-13) in human and murine macrophage. Gain and loss of function studies suggest that CKIP-1 is a prerequisite for optimal LPS-induced pro-inflammatory gene activation, which exhibits its roles in a NF-κB dependent manner. Furthermore, CKIP-1 inhibits anti-inflammatory gene expression by negatively regulating JAK1-STAT6 activation in macrophages. Taken together, these data integrated CKIP-1 expression and function as a novel transcriptional regulator of macrophage polarization and identified a double feedback loop consisting of CKIP-1 and the key regulators of the M1 and M2 macrophage effectors in polarization pathway. Moreover, the inhibitory roles of CKIP-1 in LPS-mediated sepsis and TPA-mediated cutaneous provide a new target for treatments of acute inflammation.



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Healthcare experiences of patients with age-related macular degeneration: have things improved? Cross-sectional survey responses of Macular Society members in 2013 compared with 1999

Objective

To investigate healthcare experiences of patients with age-related macular degeneration (AMD) and determine whether a previous survey and Royal College of Ophthalmologists (RCOphth) management guidelines brought improvements.

Design

Cross-sectional survey of Macular Society members in 2013 compared with previous 1999 survey.

Setting

UK Postal Questionnaires.

Participants

1169 respondents in 2013 (1187 in 1999).

Intervention

Publication of 1999 survey results (2002), and RCOphth AMD guidelines (2009).

Main outcome measures

Respondents answered questions about experiences at diagnosis. Five questions were replicated from the 1999 survey for direct comparison in the 2013 survey which included additional questions based on 2009 RCOphth recommendations for information and support provision for patients with AMD.

Results

Most 2013 survey respondents were given the name of their macular condition (91%), felt the healthcare professional was interested in them (71%) and were satisfied overall with the diagnostic consultation (76%). These outcomes show significant improvement since 1999. Within the 2013 sample, multivariable analyses showed gradual trends of improvement over time in: provision of written information, Macular Society information and receiving appropriate help, support and advice at diagnosis. Only overall satisfaction with the diagnostic consultation (but not the other nine areas of information and support provision studied) significantly improved in the time after publication of the RCOphth 2009 guidelines. There were no significant improvements associated with the publication of the 1999 survey results. Low information and support provision remained, for example, 44% of respondents diagnosed after the RCOphth 2009 guidelines reported not receiving information on what to do if vision deteriorated. Lack of such information at diagnosis was significantly associated with registration as sight impaired (p<0.01). Reports of general practitioner (GP) knowledge of AMD remained low: 39% reported their GP was ‘not at all well informed’. The 2013 respondents reported lower levels of help and support from GPs than 1999 respondents (p<0.001).

Conclusions

Patients diagnosed with AMD after 1999 (vs before 1999) reported better experiences at diagnostic consultation. However, information and support provision at diagnosis, and satisfaction with GPs remained low.



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Association between community management of pneumonia and diarrhoea in high-burden countries and the decline in under-five mortality rates: an ecological analysis

Objective

The objective of the paper is to explore if the adoption of national policies to use community-based health providers for the management of pneumonia and diarrhoea is associated with the decline in under-five mortality, including achievement of the Millennium Development Goal (MDG)4 target, in high-burden countries.

Setting

This country level analysis covers 75 high-burden low-income and middle-income countries which accounted for 98% of the 5.9 million global under-five deaths in 2015. One-fourth of these deaths were due to pneumonia and diarrhoea.

Methods

2 tests and multiple regression analysis were used to examine the association between reduction in under-five mortality rates and community case management of pneumonia and diarrhoea by adjusting for the influence of other possible determinants.

Participants

No patient or population interviewed/examined for this analysis. Countries were the unit of analysis.

Interventions

Community case management (CCM) of pneumonia and diarrhoea policies.

Outcome measures

Changes in under-five mortality rates over time.

Results

Countries that had adopted both CCM policies were three times more likely to achieve the MDG4 target than countries that did not have both policies in place. This association was further confirmed by the multivariate analysis (β-coefficient=10.4; 95% CI 2.4 to 18.5; p value=0.012).

Discussion

There is a statistically significant association between adoption of CCM policies for treatment of pneumonia and diarrhoea and the rate of decline in child mortality levels. It is important to promote CCM in countries lagging behind to achieve the new target of 25 or fewer deaths per 1000 live births by 2030.



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Medical students' opportunities to participate and learn from activities at an internal medicine ward: an ethnographic study

Objectives

To optimise medical students’ early clerkship is a complex task since it is conducted in a context primarily organised to take care of patients. Previous studies have explored medical students’ perceptions of facilitation and hindrance of learning. However, the opportunities for medical student to learn within the culture of acute medicine care have not been fully investigated. This study aimed to explore how medical students approach, interact and socialise in an acute internal medicine ward context, and how spaces for learning are created and used in such a culture.

Design and setting

Ethnographic observations were performed of medical students' interactions and learning during early clerkship at an acute internal medicine care ward. Field notes were taken, transcribed and analysed qualitatively. Data analysis was guided by Wenger's theory of communities of practice.

Participants

21 medical students and 30 supervisors participated.

Results

Two themes were identified: Nervousness and curiosity—students acted nervously and stressed, especially when they could not answer questions. Over time curiosity could evolve. Unexplored opportunities to support students in developing competence to judge and approach more complex patient-related problems were identified. Invited and involved—students were exposed to a huge variation of opportunities to learn, and to interact and to be involved. Short placements seemed to disrupt the learning process. If and how students became involved also depended on supervisors' activities and students' initiatives.

Conclusions

This study shed light on how an acute internal medicine ward culture can facilitate medical students' possibilities to participate and learn. Medical students' learning situations were characterised by questions and answers rather than challenging dialogues related to the complexity of presented patient cases. Further, students experienced continuous transfers between learning situations where the potential to be involved differed in a wide variety of ways.



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Association of passive and active smoking with self-rated health and life satisfaction in Iranian children and adolescents: the CASPIAN IV study

Objective

To assess the joint association of passive and active smoking with self-rated health and life satisfaction among Iranian children and adolescents.

Methods

Using a multistage random cluster sampling method, a representative sample of 14 880 school students were selected from urban and rural areas of 30 provinces of Iran. Data were gathered using a questionnaire, a weight scale and metre. Participants were classified into four groups based on their smoking patterns: ‘non-smoker’, ‘only active smoker’, ‘only passive smoker’ and ‘active and passive smoker’. Life satisfaction (LS) and self-rated health (SRH) were assessed by self-administered validated questionnaires based on the WHO-Global School-based student Health Survey (WHO-GSHS). Data were analysed using a t-test, 2 test and multiple logistic regression.

Results

A total of 13 486 individuals (6640 girls and 6846 boys) out of 14 880 invited participated in the study (response rate 90.6%). LS and good SRH showed linearly negative associations with smoking status in both sexes. The proportions of LS and SRH categories were significantly different among all subsets of smoking status. Those classified as ‘non-smokers’ had the highest proportions of LS and good SRH, followed by ‘only passive smokers’ and ‘only active smokers’, while those with ‘active and passive smoking’ had the lowest proportions of LS and good SRH. In a multivariate model, students in the ‘active and passive smoking’ group had lower odds of LS (OR 0.43; 95% CI 0.32 to 0.57) and good SRH (OR 0.51; 95% CI 0.38 to 0.68) than those in the ‘non-smoker’ group. Students in the ‘only passive smoker’ group also had lower odds of LS (OR 0.75; 95% CI 0.67 to 0.83) and good SRH (OR 0.72; 95% CI 0.66 to 0.80) compared with the ‘non-smoker’ group.

Conclusions

Adolescents with different smoking habits and exposure patterns have poorer SRH and LS than non-smokers. Both active and passive smoking status could affect LS and SRH in adolescents. Therefore, smoking prevention strategies should be considered as a health priority in school health services for promoting psychological well-being in children and adolescents.



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Revalidation and quality assurance: the application of the MUSIQ framework in independent verification visits to healthcare organisations

Objectives

We present a national evaluation of the impact of independent verification visits (IVVs) performed by National Health Service (NHS) England as part of quality assuring medical revalidation. Organisational visits are central to NHS quality assurance. They are costly, yet little empirical research evidence exists concerning their impact, and what does exist is conflicting.

Setting

The focus was on healthcare providers in the NHS (in secondary care) and private sector across England, who were designated bodies (DBs). DBs are healthcare organisations that have a statutory responsibility, via the lead clinician, the responsible officer (RO), to implement medical revalidation.

Participants

All ROs who had undergone an IVV in England in 2014 and 2015 were invited to participate. 46 ROs were interviewed. Ethnographic data were gathered at 18 observations of the IVVs and 20 IVV post visit reports underwent documentary analysis.

Primary and secondary outcome measures

Primary outcomes were the findings pertaining to the effectiveness of the IVV system in supporting the revalidation processes at the DBs. Secondary outcomes were methodological, relating to the Model for Understanding Success in Quality (MUSIQ) and how its application to the IVV reveals the relevance of contextual factors described in the model.

Results

The impact of the IVVs varied by DB according to three major themes: the personal context of the RO; the organisational context of the DB; and the visit and its impact. ROs were largely satisfied with visits which raised the status of appraisal within their organisations. Inadequate or untimely feedback was associated with dissatisfaction.

Conclusions

Influencing teams whose prime responsibility is establishing processes and evaluating progress was crucial for internal quality improvement. Visits acted as a nudge, generating internal quality review, which was reinforced by visit teams with relevant expertise. Diverse team membership, knowledge transfer and timely feedback made visits more impactful.



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Individualised risk assessment for local recurrence and distant metastases in a retrospective transatlantic cohort of 687 patients with high-grade soft tissue sarcomas of the extremities: a multistate model

Objectives

This study investigates the effect of surgical margins and radiotherapy, in the presence of individual baseline characteristics, on survival in a large population of high-grade soft tissue sarcoma of the extremities using a multistate model.

Design

A retrospective multicentre cohort study.

Setting

4 tertiary referral centres for orthopaedic oncology.

Participants

687 patients with primary, non-disseminated, high-grade sarcoma only, receiving surgical treatment with curative intent between 2000 and 2010 were included.

Main outcome measures

The risk to progress from ‘alive without disease’ (ANED) after surgery to ‘local recurrence’ (LR) or ‘distant metastasis (DM)/death’. The effect of surgical margins and (neo)adjuvant radiotherapy on LR and overall survival was evaluated taking patients' and tumour characteristics into account.

Results

The multistate model underlined that wide surgical margins and the use of neoadjuvant radiotherapy decreased the risk of LR but have little effect on survival. The main prognostic risk factors for transition ANED to LR are tumour size (HR 1.06; 95% CI 1.01 to 1.11 (size in cm)) and (neo)adjuvant radiotherapy. The HRs for patients treated with adjuvant or no radiotherapy compared with neoadjuvant radiotherapy are equal to 4.36 (95% CI 1.34 to 14.24) and 14.20 (95% CI 4.14 to 48.75), respectively. Surgical resection margins had a protective effect for the occurrence of LR with HRs equal to 0.61 (95% CI 0.33 to 1.12), and 0.16 (95% CI 0.07 to 0.41) for margins between 0 and 2 mm and wider than 2 mm, respectively. For transition ANED to distant metastases/Death, age (HR 1.64 (95% CI 0.95 to 2.85) and 1.90 (95% CI 1.09 to 3.29) for 25–50 years and >50 years, respectively) and tumour size (1.06 (95% CI 1.04 to 1.08)) were prognostic factors.

Conclusions

This paper underlined the alternating effect of surgical margins and the use of neoadjuvant radiotherapy on oncological outcomes between patients with different baseline characteristics. The multistate model incorporates this essential information of a specific patient's history, tumour characteristics and adjuvant treatment modalities and allows a more comprehensive prediction of future events.



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Referral pathways for patients with TIA avoiding hospital admission: a scoping review

Objective

To identify the features and effects of a pathway for emergency assessment and referral of patients with suspected transient ischaemic attack (TIA) in order to avoid admission to hospital.

Design

Scoping review.

Data sources

PubMed, CINAHL Web of Science, Scopus.

Study selection

Reports of primary research on referral of patients with suspected TIA directly to specialist outpatient services.

Data extraction

We screened studies for eligibility and extracted data from relevant studies. Data were analysed to describe setting, assessment and referral processes, treatment, implementation and outcomes.

Results

8 international studies were identified, mostly cohort designs. 4 pathways were used by family doctors and 3 pathways by emergency department physicians. No pathways used by paramedics were found. Referrals were made to specialist clinic either directly or via a 24-hour helpline. Practitioners identified TIA symptoms and risk of further events using a checklist including the ABCD2 tool or clinical assessment. Antiplatelet medication was often given, usually aspirin unless contraindicated. Some patients underwent tests before referral and discharge. 5 studies reported reduced incident of stroke at 90 days, from 6–10% predicted rate to 1.3–2.1% actual rate. Between 44% and 83% of suspected TIA cases in these studies were referred through the pathways.

Conclusions

Research literature has focused on assessment and referral by family doctors and ED physicians to reduce hospitalisation of patients with TIA. No pathways for paramedical use were reported. We will use results of this scoping review to inform development of a paramedical referral pathway to be tested in a feasibility trial.

Trial registration number

ISRCTN85516498. Stage: pre-results.



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