Molecular mechanisms underlying the role of microRNAs (miRNAs) in anticancer drug resistance and implications for clinical practice.

Drug resistance remains a major problem in the treatment of cancer patients for both conventional chemotherapeutic and novel biological agents. Intrinsic or acquired resistance can be caused by a range of mechanisms, including increased drug elimination, decreased drug uptake, drug inactivation and alterations of drug targets. Recent data showed that other than by genetic (mutation, amplification) and epigenetic (DNA hypermethylation, histone post-translational modification) changes, drug resistance mechanisms might also be regulated by microRNAs (miRNAs).