A study on the overexpression of microRNAs and lung cancer

MicroRNAs (miRNAs), which contains approximately 22 nt, belong to a small endogenous, non-coding regulatory single-stranded RNA molecules. They are posttranscriptional regulators of gene expression and highly conserved in evolution. Many researches show that miRNAs involved in many processes, including tumor formation, cell proliferation and apoptosis and proliferation and metastasis of cancer cells. Among that, the relationship between miRNAs and lung cancer is one of the most focal areas for the researchers, because the abnormal expressions of miRNAs were significantly associated with the occurrence and development of lung cancer. The expression level of different miRNAs in lung cancer cells exist differences, compared with normal lung tissue cells, there are two classes of expression: over-expression level and low expression level. In this review, we focused on studying the mechanism of overexpression miRNAs in lung cancer.