1. A mitochondrial unfolded protein response inhibitor suppresses prostate cancer growth in mice via HSP60
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Kumar, Rahul, Chaudhary, Ajay K., Woytash, Jordan, Inigo, Joseph R., Gokhale, Abhiram A., Bshara, Wiam, Attwood, Kristopher, Wang, Jianmin, Spernyak, Joseph A., Rath, Eva, Yadav, Neelu, Haller, Dirk, Goodrich, David W., Tang, Dean G., and Chandra, Dhyan
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Prostate cancer -- Development and progression ,Proteases -- Physiological aspects -- Health aspects ,Heat shock proteins -- Physiological aspects -- Health aspects ,Mitochondria -- Physiological aspects -- Health aspects ,Health care industry - Abstract
Mitochondrial proteostasis, regulated by the mitochondrial unfolded protein response ([UPR.sup.mt]), is crucial for maintenance of cellular functions and survival. Elevated oxidative and proteotoxic stress in mitochondria must be attenuated by the activation of a ubiquitous [UPR.sup.mt] to promote prostate cancer (PCa) growth. Here we show that the 2 key components of the [UPR.sup.mt], heat shock protein 60 (HSP60, a mitochondrial chaperonin) and caseinolytic protease P (ClpP, a mitochondrial protease), were required for the development of advanced PCa. HSP60 regulated ClpP expression via c-Myc and physically interacted with ClpP to restore mitochondrial functions that promote cancer cell survival. HSP60 maintained the ATPproducing functions of mitochondria, which activated the [beta]-catenin pathway and led to the upregulation of c-Myc. We identified a [UPR.sup.mt] inhibitor that blocked HSP60's interaction with ClpP and abrogated survival signaling without altering HSP60's chaperonin function. Disruption of HSP60-ClpP interaction with the [UPR.sup.mt] inhibitor triggered metabolic stress and impeded PCa-promoting signaling. Treatment with the [UPR.sup.mt] inhibitor or genetic ablation of Hsp60 inhibited PCa growth and progression. Together, our findings demonstrate that the HSP60-ClpP-mediated [UPR.sup.mt] is essential for prostate tumorigenesis and the HSP60-ClpP interaction represents a therapeutic vulnerability in PCa., Introduction Maintaining protein homeostasis (proteostasis) is essential for normal cellular functions and dysregulated proteostasis has been implicated in many types of cancer (1-3). Proteostasis is regulated by the unfolded protein [...]
- Published
- 2022
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