Ectopic Expression of miRNA-21 and miRNA-205 in Non-Small Cell Lung Cancer

Lung cancer is the leading cause of death, related to cancer in both men and women. MicroRNAs (miRNAs) play key roles in regulating the genes that are responsible for apoptosis, and regulation of gene expression. MicroRNA expression is deregulated in cancer. Many efforts have been made to detect cancer biomarkers. Extracellular miRNAs, which are directly released from tumors, can be detected in circulating blood. The aim of this study was to examine the expression of miRNA-205 and -21 in lung cancer patients relative to healthy controls. This cross sectional study was performed in 50 healthy blood sample controls and 50 non-small cell lung cancer (NSCLC) blood samples. The expression of two miRNAs (miR-21 and miR-205) in peripheral blood mononuclear cells (PBMCs) was evaluated, using real-time polymerase chain reaction (real-time PCR) techniques. Statistical tests were carried out via the Mann-Whitney test. The miR-205 levels of expression in the patients with lung cancer significantly increased in comparison to healthy controls (6.8 ± 0.42 and 1.2 ± 0.19, respectively), (P = 0.014). The expression of miR-21 in lung cancer (5.2 ± 0.52) significantly increased compared to the control group (1.6 ± 0.14) (P < 0.001). Based on our findings, lung cancer can enhance the ectopic expression of several miRNAs, which, in turn, play key roles in impaired apoptosis and further cancerous progression.