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The mTOR pathway in hepatic malignancies
Author(s) -
Bhat Mamatha,
Sonenberg Nahum,
Gores Gregory J.
Publication year - 2013
Publication title -
hepatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.488
H-Index - 361
eISSN - 1527-3350
pISSN - 0270-9139
DOI - 10.1002/hep.26323
Subject(s) - pi3k/akt/mtor pathway , everolimus , cancer research , rptor , carcinogenesis , biology , protein kinase b , mechanistic target of rapamycin , signal transduction , medicine , cancer , microbiology and biotechnology
The mechanistic/mammalian target of rapamycin (mTOR) pathway plays a critical role in cellular metabolism, growth, and proliferation and has been evaluated as a target for therapy in various malignancies. The mTOR pathway is a major tumor‐initiating pathway in hepatocellular carcinoma, with up‐regulation seen in up to 50% of tumors. Metformin, which represses mTOR signaling by activating adenosine monophosphate–activated protein kinase, has been shown to decrease liver carcinogenesis in population studies. mTOR inhibitors such as everolimus have been evaluated as adjunctive chemotherapy with some success, although efficacy has been limited by the lack of complete mTOR pathway inhibition. The active site mTOR inhibitors hold greater promise, given that they offer complete mTOR suppression. There is also evidence of mTOR pathway activation in cholangiocarcinoma, although its biological significance in initiating and promoting tumor progression remains ambiguous. This review provides an overview of the complex biochemistry behind the mTOR pathway and its role in carcinogenesis, especially as it pertains to hepatic malignancies. (H EPATOLOGY 2013;58:810–818)