Year: 2016
Type: article
Abstract: // Swapna Asuthkar 1 , Lusine Demirkhanyan 1 , Samuel Robert Mueting 1 , Alejandro Cohen 2 , Eleonora Zakharian 1 1 University of Illinois College of Medicine, Department of Cancer Biology and Pharmacology, Peoria, IL 61605, USA 2 Proteomics and Mass Spectrometry Core Facility, Life Sciences Research Institute, Dalhousie University, Halifax, NS B3H 4R2, Canada Correspondence to: Eleonora Zakharian, email: [email protected] Keywords: transient receptor potential melastatin 8 channel (TRPM8), androgens, testosterone, prostate cancer, protein degradation Received: August 31, 2016 Accepted: November 22, 2016 Published: December 26, 2016 ABSTRACT The Ca 2+ -permeable ion channel TRPM8 is a hallmark of the prostate epithelium. We recently discovered that TRPM8 is an ionotropic testosterone receptor. This finding suggested that testosterone-induced TRPM8 activity regulates Ca 2+ homeostasis in the prostate epithelium. Since androgens are significantly implicated in prostate cancer development, the role of the novel testosterone receptor TRPM8 in cancer was assessed in our study. Although TRPM8 mRNA levels increase at the early prostate cancer stages, we found that it is not proportionally translated into TRPM8 protein levels. High-throughput proteome analysis revealed that TRPM8 degradation is enhanced in human prostate cancer cells. This degradation is executed via a dual degradation mechanism with the involvement of both lysosomal and proteasomal proteolytic pathways. The evaluation of the TRPM8 expression pattern in prostate cancer patients further confirmed the incidence of TRPM8 removal from the plasma membrane and its internalization pattern coincided with the severity of the tumor. Together, our results indicate that enhanced TRPM8 hydrolysis in prostate cancer could present an adaptation mechanism, sustained via bypassing testosterone-induced rapid Ca 2+ uptake through TRPM8, thus, diminishing the rates of apoptosis. In this light, recovery of TRPM8 may pose a novel therapeutic strategy for an anti-tumor defense mechanism.
Source: Oncotarget
Institution: Dalhousie University
Language: English
Subfield: Pulmonary and Respiratory Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: diamond
OpenAlex ID: W2564299789