2. Academic Validation
  3. Chaperone-mediated autophagy promotes PCa survival during ARPI through selective proteome remodeling

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

  • Oncogene. 2023 Jan 7. doi: 10.1038/s41388-022-02573-7.
Nicholas Nikesitch 1 2,  Eliana Beraldi 1 2,  Fan Zhang 1 2,  Hans Adomat 1,  Robert Bell 1 2,  Kotaro Suzuki 1 2,  Ladan Fazli 1 2,  Sonia Hy Kung 1,  Christopher Wells 1,  Nicholas Pinette 1 2,  Neetu Saxena 1 2,  Yuzhuo Wang 1 2,  Martin Gleave 3 4
Affiliations

Affiliations

  • 1 Vancouver Prostate Centre, University of British Columbia, Vancouver, BC, Canada.
  • 2 Department of Urologic Sciences, University of British Columbia, Vancouver, BC, Canada.
  • 3 Vancouver Prostate Centre, University of British Columbia, Vancouver, BC, Canada. [email protected].
  • 4 Department of Urologic Sciences, University of British Columbia, Vancouver, BC, Canada. [email protected].
PMID: 36611121 DOI: 10.1038/s41388-022-02573-7
Abstract

The Androgen Receptor (AR) plays an important role in PCa metabolism, with Androgen Receptor pathway inhibition (ARPI) subjecting PCa cells to acute metabolic stress caused by reduced biosynthesis and energy production. Defining acute stress response mechanisms that alleviate ARPI stress and therefore mediate prostate Cancer (PCa) treatment resistance will help improve therapeutic outcomes of patients treated with ARPI. We identified the up-regulation of chaperone-mediated Autophagy (CMA) in response to acute ARPI stress, which persisted in castration-resistant PCa (CRPC); previously undefined in PCa. CMA is a selective protein degradation pathway and a key stress response mechanism up-regulated under several stress stimuli, including metabolic stress. Through selective protein degradation, CMA orchestrates the cellular stress response by regulating cellular pathways through selective proteome remodeling. Through broad-spectrum proteomic analysis, CMA coordinates metabolic reprogramming of PCa cells to sustain PCa growth and survival during ARPI; through the upregulation of mTORC1 signaling and pathways associated with PCa biosynthesis and energetics. This not only promoted PCa growth during ARPI, but also promoted the emergence of CRPC in-vivo. During CMA inhibition, PCa metabolism is compromised, leading to ATP depletion, resulting in a profound anti-proliferative effect on PCa cells, and is enhanced when combined with ARPI. Furthermore, CMA inhibition prevented in-vivo tumour formation, and also re-sensitized 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. In summary, CMA is an acute ARPI stress response mechanism, essential in alleviating ARPI induced metabolic stress, essential for ensuring PCa growth and survival. CMA plays a critical role in the development of ARPI resistance in PCa.

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