Background: MicroRNAs are non-coding RNAs which regulate gene expression
by binding to 3’ UTR site on mRNA. These small RNAs repress gene expression by
interfering with the process of translation or by degrading the target mRNA. Abnormal
expression of miRNAs has been implicated in a wide spectrum of human diseases like
atherosclerosis, cancers and diabetes. Traditionally, pharmacogenomics focuses on single
nucleotide polymorphisms and copy number variants of genes implicated in pharmacokinetics
and pharmacodynamics. Recently, drug response has been proposed to be regulated
by microRNAs. Mutations involving miRNAs can contribute to disease pathogenesis and
modulation of drug response.
Objective: The main objective of this review is to highlight the role of miRNAs in biological
processes leading to disease states as well as in the field of drug action and pharmacogenomics.
Method: A literature review was performed incorporating the latest insights in the field of
miRNA therapeutics, diagnostics and pharmacogenomics.
Results: Altered expression of miRNAs is seen in diabetes, vascular inflammation, atherosclerosis,
infection and cancers. In the field of miRNA- pharmacogenomics, maximum
work has been done studying the resistance to anticancer drugs. Some examples of microRNAs
regulating drug response are miR-24 influencing the response to methotrexate,
miR-125b affecting the action of calcitriol and miR-27b regulating the expression of
CYP3A4. Among miRNAs currently being targeted in therapeutics are miR-122, miR- 33,
miR-21, let-7 and miR-34.
Conclusion: A significant fraction of all mRNAs transcribed in a cell are regulated by
miRNAs. miRNAs implicated in a given disease may interfere with drug action and metabolism.
Further research is needed to understand the association between miRNA,
mRNAs, diseases and pharmacokinetics and dynamics.