Format

Send to

Choose Destination
Oncotarget. 2018 Jan 6;9(11):9925-9939. doi: 10.18632/oncotarget.24066. eCollection 2018 Feb 9.

Bile acid metabolism regulated by the gut microbiota promotes non-alcoholic steatohepatitis-associated hepatocellular carcinoma in mice.

Author information

1
Division of Pharmacotherapeutics, Faculty of Pharmacy, Keio University, Minato-ku, Tokyo 105-8512, Japan.
2
Graduate School of Media and Governance, Keio University, Fujisawa, Kanagawa 252-0882, Japan.
3
Division of Gastroenterology and Hepatology, Department of Internal Medicine, Keio University, Shinjuku-ku, Tokyo 160-8582, Japan.
4
Division of Gastroenterology, Department of Internal Medicine, The University of Michigan Medical School, Ann Arbor, MI, 48109, USA.

Abstract

Gut microbiota plays a significant role in the development of hepatocellular carcinoma (HCC) in non-alcoholic steatohepatitis (NASH). However, understanding of the precise mechanism of this process remains incomplete. A new class steatohepatitis-inducing high-fat diet (HFD), namely STHD-01, can promote the development of HCC without the administration of chemical carcinogens. Using this diet, we comprehensively analyzed changes in the gut microbiota and its metabolic functions during the development of HCC in NASH. Mice fed the STHD-01 developed NASH within 9 weeks. NASH further progressed into HCC by 41 weeks. Treatment with antibiotics significantly attenuated liver pathology and suppressed tumor development, indicating the critical role of the gut microbiota in tumor development in this model. Accumulation of cholesterol and bile acids in the liver and feces increased after feeding the mice with STHD-01. Treatment with antibiotics did not reverse these phenotypes. In contrast, accumulation of secondary bile acids was dramatically reduced after the treatment with antibiotics, suggesting the critical role of the gut microbiota in the conversion of primary bile acids to secondary bile acids. Secondary bile acids such as deoxycholic acid activated the mTOR, pathway in hepatocytes. Activation of mTOR was observed in the liver of mice fed STHD-01, and the activation was reduced when mice were treated with antibiotics. Collectively, bile acid metabolism by the gut microbiota promotes HCC development in STHD-01-induced NASH.

KEYWORDS:

bile acid metabolites; deoxycholic acid; hepatocellular carcinoma; mTOR

Conflict of interest statement

CONFLICTS OF INTEREST The authors declare that no conflict of interest existed in this study.

Supplemental Content

Full text links

Icon for Impact Journals, LLC Icon for PubMed Central
Loading ...
Support Center