Head and neck squamous cell carcinomas (HNSCC) exhibiting resistance to the EGFR targeting drug cetuximab poses a challenge to their effective clinical management. Here we report a specific mechanism of resistance in this setting based upon the presence of a single nucleotide polymorphism encoding EGFR-K521 (K-allele), which is expressed in >40% of HNSCC cases. Patients expressing the K-allele showed significantly shorter progression-free survival upon palliative treatment with cetuximab plus chemotherapy or radiation. In several EGFR-mediated cancer models, cetuximab failed to inhibit downstream signaling or to kill cells harboring a high K-allele frequency. Cetuximab affinity for EGFR-K521 was reduced slightly but ligand-mediated EGFR activation was intact. We found a lack of glycan sialyation on EGFR-K521 that associated with reduced protein stability, suggesting a structural basis for reduced cetuximab efficacy. CetuGEX™, an antibody with optimized Fc glycosylation targeting the same epitope as cetuximab, restored HNSCC sensitivity in a manner associated with antibody-dependent cellular cytotoxicity (ADCC) rather than EGFR pathway inhibition. Overall, our results highlight EGFR-K521 expression as a key mechanism of cetuximab resistance to evaluate prospectively as a predictive biomarker in HNSCC patients. Further, they offer a preclinical rationale for the use of ADCC-optimized antibodies to treat tumors harboring this EGFR isoform.
from #AlexandrosSfakianakis via Alexandros G.Sfakianakis on Inoreader http://ift.tt/2hxOcGR
via IFTTT
Εγγραφή σε:
Σχόλια ανάρτησης (Atom)
Δημοφιλείς αναρτήσεις
-
Publication date: Available online 4 January 2018 Source: European Journal of Radiology Author(s): Peiyao Zhang, Jing Wang, Qin Xu, Zhen...
-
Background Hyperthyroidism is associated with increased thrombotic risk. As contact system activation through formation of neutrophil extrac...
-
Dtsch med Wochenschr DOI: 10.1055/s-0043-100054 Hintergrund und Fragestellung Ein etablierter Weg, die optimale Behandlung von Tumorpatien...
-
Publication date: March 2017 Source: Free Radical Biology and Medicine, Volume 104 from #AlexandrosSfakianakis via Alexandros G.Sfak...
-
Related Articles Anatomic parameters of the sacral lamina for osteosynthesis in transverse sacral fractures. Surg Radiol Anat....
-
Medicine by Alexandros G. Sfakianakis,Anapafseos 5... Medicine by Alexandros G. Sfakianakis,Anapafseos 5... Heralding change: The evolution ...
-
BACKGROUND AND PURPOSE: Dengue is a common arboviral disease, which uncommonly involves the brain. There has been a recent surge in dengu...
-
Purpose. We present a case of a patient with Soemmering ring after cataract surgery and a potential complication that can arise as a result ...
-
Abstract Purpose Investigate in patients with metastatic and/or irresectable colorectal cancer treated with systemic treatment with cape...
Δεν υπάρχουν σχόλια:
Δημοσίευση σχολίου