MicroRNAs: Crucial Regulators of Stress

BACKGROUND: Signaling pathways including gene silencing, cellular differentiation, homeostasis, development and apoptosis are regulated and controlled by a wide range of miRNAs. OBJECTIVE: Due to their potential binding sites in human-protein coding genes, many studies have also linked their altered expressions in various cancer types making them tumor suppressors agents. METHODS: Moreover, each miRNA is predicted to have many mRNA targets indicating their extensive regulatory role in cell survival and developmental processes. Nowadays, diagnosis of early cancer stage development is now dependent on variable miRNA expression levels as potential oncogenic biomarkers in validating and targeting microRNAs for cancer therapy. RESULTS: As the majority of miRNA, transcripts are derived from RNA polymerase II-directed transcription, stress response could result on a general reduction in the abundance of these transcripts. Over expression of various microRNAs have lead to B cell malignancy, potentiated KrasG12D-induced lung tumorigenesis, chronic lymphocytic leukemia, lymphoproliferative disease and autoimmunity. CONCLUSION: Altered miRNA expressions could have a significant impact on the abundance of proteins, making them attractive candidates as biomarkers for cancer detection and important regulators of apoptosis.