Chaperone-mediated autophagy promotes PCa survival during ARPI through selective proteome remodeling

ABSTRACT: Defining acute stress response mechanisms that mediate prostate cancer (PCa) treatment resistance will help improve therapeutic outcomes of patients treated with androgen receptor pathway inhibition (ARPI). ARPI causes abrupt environmental changes, subjecting PCa cells to acute metabolic stress. We identified the up-regulation of chaperone-mediated autophagy (CMA) in response to acute ARPI stress, which persisted in castration-resistant PCa (CRPC). CMA is a selective protein degradation pathway and a key stress response mechanism up-regulated under several stress stimuli, including metabolic stress. As mediator of selective protein degradation, CMA orchestrates cellular pathway changes mediating the cellular stress response. Broad-spectrum proteomic analysis identified CMA induced proteome remodeling acutely after ARPI stress. CMA sustained PCa growth and survival during ARPI, promoting metabolic reprogramming through the upregulation mTORC1 signaling and pathways associated with PCa biosynthesis and energetics. The upregulation of CMA promotes PCa cell proliferation after ARPI, and emergence of CRPC in-vivo. CMA inhibition compromised PCa metabolism, leading to ATP depletion and profound anti-proliferative effects on PCa cells, enhanced when combined with ARPI. CMA inhibition prevented in-vivo tumour formation, while also re-sensitizing enzalutamide-resistant cell lines in-vitro. The profound anti-proliferative effect of CMA inhibition was attributed to cell cycle arrest mediated through p53 transcriptional repression of E2F target genes. This study established CMA as an acute ARPI stress response mechanism, essential in alleviating ARPI induced metabolic stress to promote PCa growth and survival. CMA plays a critical role in the development of ARPI resistance in PCa.

INSTRUMENT(S): Orbitrap Fusion Lumos

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Epithelial Cell, Cell Culture

DISEASE(S): Prostate Adenocarcinoma

SUBMITTER: Nicholas Nikesitch  

LAB HEAD: Martin Gleave

PROVIDER: PXD036227 | Pride | 2023-01-26

REPOSITORIES: Pride