MicroRNAs (miRNAs) are endogenous small non-coding RNAs with the capacity to regulate gene expression post-transcriptionally. The miRNA-29 family consists of miR-29a, miR-29b, and miR-29c, among which miR-29b is the most highly expressed and is found at two genomic loci. Recently, numerous studies have demonstrated that aberrant expression of miR-29b is common in the majority of human cancers. miR-29b is known to critically affect cancer progression by functioning as a tumor suppressor. However, it may also act as an oncogene under certain conditions. In this review, we illustrate the role of miR-29b in cancer regulation, function, and signaling. This is the first review highlighting the role of miR-29b in cancer. Our review aims to summarize the effects of miR-29b on cancer activity and its interactions with target genes and signaling pathways, as well as to provide therapeutic implications for overcoming cancer chemoresistance.
Keywords: biological function; cancer; chemoresistance; miR-29b; oncogene; tumor promoter.