MicroRNAs in cell cycle progression and proliferation: molecular mechanisms and pathways

The microRNAs (miRNAs) are a family of 23 nucleotide non-coding RNAs can regulates protein expression through miRNAs destabilization or translational silencing; circulating miRNAs are potential biomarkers for various diseases, including cancer. In addition, miRNAs also are important therapeutic targets by inhibiting or activating signaling pathways in imbalance and modulate important cellular events such as proliferation, cell cycle and apoptosis. These non-coding RNAs can regulate the expression of cell cycle components such as cyclins, cyclin-dependent kinases (CDKs), CDK inhibitors (CKI) and growth factors. In this review, we provide a comprehensive understanding of the roles of miRNAs in proliferation and cell cycle, considering their key role in physiological and pathological process. In particular, the miRNAs: miR-199b-5p, miR-193a-5p, miR-125b-5p, miR-30a-5p and human miR-27b-3p, which are frequently observed in the regulation of proliferative and cell cycle pathways. In this regard, different molecular mechanisms and cellular targets involved in both their ability to limit and amplify proliferation and cell cycle progression have been reported. A single miRNA could target different genes encoding proteins involved in proliferation, cell cycle and apoptosis. Coordinated regulation of a miRNAs may influence a variety of biological cascades. Finally, the critical problems regarding the selectivity of genes and target proteins of these miRNAs from a clinical perspective are discussed. Despite the growing study in this area, further research assesses its role as a biomarker and possible therapy.