1. Aberrant cholesterol metabolic signaling impairs antitumor immunosurveillance through natural killer T cell dysfunction in obese liver
- Author
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Wenshu Tang, Jingying Zhou, Weiqin Yang, Yu Feng, Haoran Wu, Myth T. S. Mok, Lingyun Zhang, Zhixian Liang, Xiaoyu Liu, Zhewen Xiong, Xuezhen Zeng, Jing Wang, Jiahuan Lu, Jingqing Li, Hanyong Sun, Xiaoyu Tian, Philip Chun Yeung, Yong Hou, Heung Man Lee, Candice C. H. Lam, Howard H. W. Leung, Anthony W. H. Chan, Ka Fai To, John Wong, Paul B. S. Lai, Kelvin K. C. Ng, Simon K. H. Wong, Vincent W. S. Wong, Alice P. S. Kong, Joseph J. Y. Sung, and Alfred S. L. Cheng
- Subjects
Mammals ,Carcinoma, Hepatocellular ,Liver Neoplasms ,Immunology ,Article ,Mice ,Cholesterol ,Infectious Diseases ,Liver ,Monitoring, Immunologic ,Non-alcoholic Fatty Liver Disease ,Tumor Microenvironment ,Animals ,Humans ,Natural Killer T-Cells ,Immunology and Allergy ,Obesity - Abstract
Obesity is a major risk factor for cancers including hepatocellular carcinoma (HCC) that develops from a background of non-alcoholic fatty liver disease (NAFLD). Hypercholesterolemia is a common comorbidity of obesity. Although cholesterol biosynthesis mainly occurs in the liver, its role in HCC development of obese people remains obscure. Using high-fat high-carbohydrate diet-associated orthotopic and spontaneous NAFLD-HCC mouse models, we found that hepatic cholesterol accumulation in obesity selectively suppressed natural killer T (NKT) cell-mediated antitumor immunosurveillance. Transcriptome analysis of human liver revealed aberrant cholesterol metabolism and NKT cell dysfunction in NAFLD patients. Notably, cholesterol-lowering rosuvastatin restored NKT expansion and cytotoxicity to prevent obesogenic diet-promoted HCC development. Moreover, suppression of hepatic cholesterol biosynthesis by a mammalian target of rapamycin (mTOR) inhibitor vistusertib preceded tumor regression, which was abolished by NKT inactivation but not CD8(+) T cell depletion. Mechanistically, sterol regulatory element-binding protein 2 (SREBP2)-driven excessive cholesterol production from hepatocytes induced lipid peroxide accumulation and deficient cytotoxicity in NKT cells, which were supported by findings in people with obesity, NAFLD and NAFLD-HCC. This study highlights mTORC1/SREBP2/cholesterol-mediated NKT dysfunction in the tumor-promoting NAFLD liver microenvironment, providing intervention strategies that invigorating NKT cells to control HCC in the obesity epidemic.
- Published
- 2022