Guanine residues of precursor microRNA’s terminal loop as a potential target for cancer therapy and prevention

MicroRNAs (miRNAs) are small endogenous RNA molecules with diverse biological functions that have been implicated in various human diseases, including cancer. Global downregulation of miRNA expression in different human cancer types, after exposure to cigarette-smoke, or to the hormone estrogen, have been shown to be associated with guanine (G) enrichment in the terminal loops (TLs) of their precursors. Here, we describe the role of G content of TLs in the regulation of miRNA expression, and highlight its potential as a target in cancer prevention and treatment.