Caspase-3–Induced Activation of SREBP2 Drives Drug Resistance via Promotion of Cholesterol Biosynthesis in Hepatocellular Carcinoma

作者：Etienne Ho Kit Mok, Carmen Oi Ning Leung, Lei Zhou, Martina Mang Leng Lei, Hoi-Wing Leung, Man Tong, Tin Lok Wong, Eunice Yuen-Ting Lau, Irene Oi‐Lin Ng, Jin Ding, Jing‐Ping Yun, Jun Yu, Hui Lian Zhu, Chi Ho Lin, Dan Lindholm, Kin Sum Leung, Jonathan D. Cybulski, D. M. H. Baker, Stephanie Ma, Terence K. Lee · 发表于：Cancer Research · 年份：2022 · DOI：10.1158/0008-5472.can-21-2934 · 被引用次数：112 · 研究领域：Cancer, Lipids, and Metabolism、Cancer, Stress, Anesthesia, and Immune Response、Cholesterol and Lipid Metabolism

Accumulating evidence has demonstrated that drug resistance can be acquired in cancer through the repopulation of tumors by cancer stem cell (CSC) expansion. Here, we investigated mechanisms driving resistance and CSC repopulation in hepatocellular carcinoma (HCC) as a cancer model using two drug-resistant, patient-derived tumor xenografts that mimicked the development of acquired resistance to sorafenib or lenvatinib treatment observed in patients with HCC. RNA sequencing analysis revealed that cholesterol biosynthesis was most commonly enriched in the drug-resistant xenografts. Comparison of the genetic profiles of CD133+ stem cells and CD133- bulk cells from liver regeneration and HCC mouse models showed that the cholesterol pathway was preferentially upregulated in liver CSCs compared with normal liver stem cells. Consistently, SREBP2-mediated cholesterol biosynthesis was crucial for the augmentation of liver CSCs, and loss of SREBP2 conferred sensitivity to tyrosine kinase inhibitors, suggesting a role in regulation of acquired drug resistance in HCC. Similarly, exogenous cholesterol-treated HCC cells showed enhanced cancer stemness abilities and drug resistance. Mechanistically, caspase-3 (CASP3) mediated cleavage of SREBP2 from the endoplasmic reticulum to promote cholesterol biosynthesis, which consequently caused resistance to sorafenib/lenvatinib treatment by driving activation of the sonic hedgehog signaling pathway. Simvastatin, an FDA-approved cholesterol-lowerin...