Data Entry: Please note that the research database will be replaced by UNIverse by the end of October 2023. Please enter your data into the system https://universe-intern.unibas.ch. Thanks
Liver damage, inflammation, and enhanced tumorigenesis after persistent mTORC1 inhibition
Journal
Cell Metabolism
Volume
20
Number
1
Pages / Article-Number
133-144
Abstract
Obesity can result in insulin resistance, hepatosteatosis, and nonalcoholic steatohepatitis (NASH) and increases liver cancer risk. Obesity-induced insulin resistance depends, in part, on chronic activation of mammalian target of rapamycin complex 1 (mTORC1), which also occurs in human and mouse hepatocellular carcinoma (HCC), a frequently fatal liver cancer. Correspondingly, mTORC1 inhibitors have been considered as potential NASH and HCC treatments. Using a mouse model in which high-fat diet enhances HCC induction by the hepatic carcinogen DEN, we examined whether mTORC1 inhibition attenuates liver inflammation and tumorigenesis. Notably, rapamycin treatment or hepatocyte-specific ablation of the specific mTORC1 subunit Raptor resulted in elevated interleukin-6 (IL-6) production, activation of signal transducer and activator of transcription 3 (STAT3), and enhanced HCC development, despite a transient reduction in hepatosteatosis. These results suggest that long-term rapamycin treatment, which also increases IL-6 production in humans, is unsuitable for prevention or treatment of obesity-promoted liver cancer.