Micro RNAs in Cancer

Abstract

Initially considered an epiphenomenon, micro ribonucleic acids (also called miRNAs) and other small noncoding RNA molecules are now considered major players in cell biology. MiRNAs regulate gene expression through effects on translation, transcription and chromatin modification. Multiple miRNAs are dysregulated in human cancer and affect the proliferation and apoptosis, metastatic behaviour, invasiveness and phenotype of cancer cells. Virtually every cell type and cancer have a particular expression pattern of miRNA expression. This miRNA profile permits to classify cancer and often gives prognostic information. Profiling based on miRNAs may be more specific and robust than profiling based on mRNAs. MiRNAs can be studied in virtually all tissues including plasma. More work is necessary, but miRNAs have already improved our understanding of the pathogenesis of cancer and appear promising for diagnostic purposes as biomarkers and for the development of new genetic treatments. Key Concepts: MicroRNAs regulate gene expression. MicroRNAs are important in the pathogenesis and progression of human cancer. MicroRNAs can function as tumour suppressors and as tumour promoters (oncomirs). MicroRNAs can serve as biomarkers for cancer and may become useful for the treatment of cancer.