An actionable sterol-regulated feedback loop modulates statin sensitivity in prostate cancer

Area of Science:

• Oncology
• Pharmacology
• Molecular Biology

Background:

• Statins inhibit HMG-CoA reductase (HMGCR), the rate-limiting enzyme in the mevalonate pathway, inducing tumor-specific apoptosis.
• Statin use may delay prostate cancer (PCa) progression, but sensitivity determinants are unclear.

Purpose of the Study:

• Identify molecular features of statin-sensitive PCa.
• Explore strategies to potentiate statin-induced PCa cell death.

Main Methods:

• Evaluated HMGCR expression in PCa via immunohistochemistry.
• Assessed PCa cell line response to fluvastatin using viability and apoptosis assays.
• Investigated the sterol-regulated feedback loop involving SREBP2 and its modulation of statin sensitivity.

Main Results:

• High HMGCR expression correlated with poor PCa prognosis.
• PCa cell lines developed resistance to fluvastatin via SREBP2-mediated feedback, upregulating HMGCR and lipid metabolism genes.
• Inhibiting SREBP2 or using dipyridamole potentiated fluvastatin-induced apoptosis in resistant PCa cells.

Conclusions:

• Statin-induced SREBP2 activation represents a PCa vulnerability.
• This vulnerability can be therapeutically exploited using clinically approved agents to enhance statin efficacy.