Infection phase‐dependent dynamics of the viral and host N6‐methyladenosine epitranscriptome in the lifecycle of an oncogenic virus in vivo

alexandrossfakianakis shared this article with you from Inoreader Infection phase‐dependent dynamics of the viral and host N6‐methyladenosine epitranscriptome in the lifecycle of an oncogenic virus in vivo via Journal of Medical Virology ABSTRACT Dynamic alteration of the epitranscriptome exerts regulatory effects on the lifecycle of oncogenic viruses in vitro. However, little is known about these effects in vivo because of the general lack of suitable animal infection models of these viruses. Using a model of rapid-onset Marek's disease lymphoma in chickens, we investigated changes in viral and host mRNA N6-methyladenosine (m6A) modification during Marek's disease virus (MDV) infection in vivo. We found that the expression of major epitranscriptomic proteins varies among viral infection phases, reprogramming both the viral and the host epitranscriptomes. Specifically, the METTL3/14 complex was suppressed during the lytic and reactivation phases of the MDV lifecycle, whereas its expression was increased during the latent phase and in MDV-induced tumors. METTL3/14 overexpression inhibits, whereas METTL3/14 knockdown enhances, MDV gene expression and replication. These f indings reveal the dynamic features of the mRNA m6A modification program during viral replication in vivo, especially in relation to key pathways involved in tumorigenesis. This article is protected by copyright. All rights reserved. View on Web

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Inverted repeats in the monkeypox virus genome are hot spots for mutation

alexandrossfakianakis shared this article with you from Inoreader Inverted repeats in the monkeypox virus genome are hot spots for mutation via Journal of Medical Virology Abstract The current monkeypox virus (MPXV) strain differs from the strain arising in 2018 by 50+ single nucleotide polymorphisms (SNPs) and is mutating much faster than expected. The cytidine deaminase apolipoprotein B mRNA editing enzyme, catalytic subunit B (APOBEC3) was hypothesised to be driving this increased mutation. APOBEC has recently been identified to preferentially mutate cruciform DNA secondary structures formed by inverted repeats (IRs). IRs were recently identified as hot spots for mutation in SARS-CoV-2, and we aimed to identify whether IRs were also hot spots for mutation within MPXV genomes. We found that MPXV genomes were replete with IR sequences. Of the 50+ SNPs identified in the 2022 outbreak strain, 63.9% of these were found to have arisen within IR regions in the 2018 reference strain (MT903344.1). Notably, IR sequences found in the 2018 reference strain were significantly lost over time, with an average of 32.5% of these sequences being cons erved in the 2022 MPXV genomes. This evidence was highly indicative that mutations were arising within IRs. This data provides further support to the hypothesis that APOBEC may be driving MPXV mutation and highlights the necessity for greater surveillance of IRs of MPXV genomes to detect new mutations. This article is protected by copyright. All rights reserved. View on Web

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STEM-28. THE ROLE OF LONP1 IN DRIVING ENHANCED PMT IN THE 'LEADING EDGE' NICHE IN GLIOBLASTOMA

alexandrossfakianakis shared this article with you from Inoreader STEM-28. THE ROLE OF LONP1 IN DRIVING ENHANCED PMT IN THE 'LEADING EDGE' NICHE IN GLIOBLASTOMA via # Neuro-Oncology Current Issue Abstract Glioblastoma (GBM), a high grade brain tumor, possesses poor overall survival with less than 5% surviving past five years. Previously, the TCGA classifications for GBM have included the mesenchymal, proneural, classical and neural subtypes with their own respective expression profiles and survival. Recent omics analysis has revealed other key aspects of GBM pathology, including intratumoral heterogeneity spanning all subtypes and enhanced stemness and treatment resistance and other hallmarks of proneural mesenchymal transition (PMT) following treatment with first-line standard of care treatment with radiation therapy and temozolomide (TMZ). Invading glioma stem cells (GSC) with high Nestin and hypoxia-inducible factor 1 alpha (HIF-1α) expression have been theorized to contribute to recurrence. HIF-1α acts as a master regulator driving increased stemness, invasiveness and angiogenesis. Interestingly, HIF-1α and nuclear respiratory factor-2 both upregulate Lon peptidase 1 (LonP1) in response to increased hypoxia or reactive oxygen species (ROS) production. LonP1 has been shown to drive increased metastasis, tumor growth and epithelial-mesenchymal transition (EMT), an analog of PMT, in colon cancer, melanoma and other cancer types. In a recently elucidated GBM organoid model, we present new findings demonstrating the importance of LonP1 in driving enhanced, transient PMT near the 'invading edge'. This includes the enhanced expression of several key drivers of PMT and phenotypic hallmarks, such as increased invasiveness, proliferation and poorer survival. View on Web

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18F‐fludeoxyglucose positron emission computed tomography (18F‐FDG‐PET/CT) versus 68Ga‐DOTATATE‐PET/CT in patients with head and neck cancer: Comparisons and implications for treatment

alexandrossfakianakis shared this article with you from Inoreader 18F‐fludeoxyglucose positron emission computed tomography (18F‐FDG‐PET/CT) versus 68Ga‐DOTATATE‐PET/CT in patients with head and neck cancer: Comparisons and implications for treatment via Head & Neck Abstract Background Tumor-specific molecular imaging in head and neck squamous cell carcinoma (HNSCC) is not well established. Somatostatin receptors (SSTRs) are found in solid tumors, including HNSCC. 68Ga-DOTATATE, a commercially available radionuclide that binds SSTRs, may have utility in imaging HNSCC. Methods Patients with HNSCC received pretreatment imaging with 18F-FDG-PET/CT and 68Ga-DOTATATE. Imaging was compared for concordance. When available, surgical resection specimens were compared to pretreatment imaging findings. Historic HNSCC tumor specimens were assessed for both SSTR and p16/human papilloma virus (HPV) expression. Results Twenty patients were imaged. Fifteen had oropharyngeal cancer. Primary tumor site was concordant between imaging modalities for all patients. One of 45 lymph nodes was discordant. Retrospective specimen review showed a significant correlation with SSTR expression and HPV/p16 expression. No adverse events occurred. Conclusions 68Ga-DOTATATE imaging is safe and effective in HNSCC. SSTR expression may be increased in HPV-mediated tumors. Targeted therapies to SSTR should be explored. View on Web

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