MicroRNAs (
miRNAs) are small non-coding RNAs that function as endogenous silencers of numerous target genes. Hundreds of
miRNAs have been identified in the human genome.
miRNAs are expressed in a tissue-specific manner and play important roles in cell proliferation, apoptosis, and differentiation. Aberrant expression of
miRNAs may also contribute to the development and progression of human hepatobiliary and
pancreatic cancers. Recent studies have shown that some
miRNAs play roles as
tumor suppressors or oncogenes in hepatobiliary and
pancreatic cancers. miR-122, let-7 family, and miR-101 are down-regulated in
hepatocellular carcinoma (HCC), suggesting that it is a potential
tumor suppressor of HCC. miR-221 and miR-222 are up-regulated in HCC and may act as oncogenic
miRNAs in hepatocarcinogenesis.
miRNA expression profiling may be a powerful clinical tool for diagnosis and regulation of
miRNA expression could be a novel therapeutic strategy for hepatobiliary and
pancreatic cancers. In this review, we summarize current knowledge about the roles of important
tumor suppressor
microRNAs and oncogenic
microRNAs in hepatobiliary and
pancreatic cancers.