Hepatocellular carcinoma (HCC) is a highly malignant tumor that often follows an aggressive clinical
course. Consequently, the 5-year survival of most patients remains low. Despite the growing knowledge of HCC
tumor biology, the transcriptional regulation of many causative tumor suppressors or oncogenes remains unclear.
MicroRNAs (miRNAs) have emerged as key posttranscriptional regulators of genes expression. Although the
miRNA family represents only a minor fraction of the genome, they hold vital importance in diverse
physiological and pathological processes, including cell survival, differentiation, responses to external stress and
morphogenesis. It is also apparent that specific miRNAs can contribute to cellular transformation and
tumorigenesis through their influence on the protein translation of multiple cancer-related genes. Recent studies
further ascribe causative links between miRNA dysregulations and HCC oncogenesis. An understanding on the
molecular mechanisms by which miRNAs regulate HCC development may provide new avenues of research that
could aid in the early diagnosis and treatment of this highly aggressive tumor. In this review, we briefly discuss
how miRNAs can act as oncogenes and tumor suppressors in HCC, and discuss the miRNAs that potentially
govern important cancer-related pathways.
Keywords: MicroRNA, hepatocellular carcinoma, oncogenes, tumor suppressor genes.
