A Comprehensive Review on miR-200c, A Promising Cancer Biomarker with Therapeutic Potential

MicroRNAs (miRNAs) are small single stranded non coding RNA molecules (similar to 22 nucleotides) which impede protein production by directly interacting with 3'untranslated regions of the target mRNAs. Interestingly, miR-200c is often dysregulated in various cancers that normally exhibits tumor suppressive behavior by blocking epithelial to mesenchymal transition (EMT) of cancer cells. However, elevation of miR-200c in various cancer tissues contradicts the tumor suppressive role of this microRNA. This review addresses the molecular mechanisms involved in the regulation of the endogenous level of miR-200c in various cancers such as breast, ovarian, prostate, endometrial, lungs, colon, pancreatic, etc. and its differential role in regulation of proliferation and EMT phenotype of cancer cells. Further, this review discusses whether abnormal level of miR-200c in cancer tissues or in blood circulation can be used as a biomarker. Importantly, how the level of miR-200c can be used to predict the effectiveness of the cancer therapy is also discussed. Accumulating evidences suggest that use of miR-200c alone may not be sufficient for treatment of cancer patients, but the combination of miR-200c with an anti-proliferating drug could be a better choice to prevent invasiveness of cancers as well as tumor growth both in primary and in metastatic sites. This article also proposes that the tumor microenvironment may have a role in influencing epigenetic silencing of miR-200c expression.