Chapter 2 - Clinical and Therapeutic Applications of MicroRNA in Cancer

Abstract

MicroRNAs (miRNAs) are small noncoding RNAs (ncRNAs) of ∼22 nucleotides in length which posttranscriptionally regulate gene expression. Aberrant expression of miRNA has been implicated to play a central role in the development and progression of many disease states, including cancer. These ncRNAs work to target messenger RNA to bring about changes and instability that ultimately result in the inhibition of translation. Recently, isolation of miRNA from a diverse array of body fluids, has redefined their role to include functioning as biomarkers and indicators of disease evolution of many malignant conditions. However, one of the major challenges of miRNA-based cancer therapy is to achieve specific, efficient, and safe systemic delivery of miRNAs in vivo. As novel therapeutic strategies, several miRNA modulators have been entered into clinical trials. Locked nucleic acid-antimir-122 is the first drug to successfully enter phase II trials for the treatment of hepatitis C virus infection, providing hope for future identification and development of other miRNAs that could be utilized as identifiers and effectors of other disease manifestations, including cancer. While the field of epigenetic research continues to grow exponentially, miRNAs have ultimately been proven to share close relationships with a multitude of solid organ and hematological malignancies. The manner in which their true potential can be harbored by identification, amplification, and effectors of cellular-specific targeting strategies is still of great debate. There is hope, nonetheless, that the noninvasive nature of miRNA identification in human serum and body fluids will one day bring about a shift in the current paradigm of preventative and diagnostic therapeutics, thereby impacting the management and treatment of cancer.