MicroRNAs, signaling pathways and diseases

Intracellular signalling pathways controlled by environmental stimuli and gene expression play key roles in cellular functions. Tightly regulated signalling pathway activities are necessary for normal development and maintenance of cells. Dysregulation of signaling results in diseases including cancer and heart disease. For example, increased PI3K/Akt pathway activity causes increased cell proliferation, survival and immune escape abilities, leading to carcinogenesis (1,2). MicroRNAs (miRNAs) can regulate gene expression and thus affect activity status of signalling pathways. Not surprising, aberrantly expressed miRNAs are associated with many diseases.