MiR-15a expression analysis in non-small cell lung cancer A549 cells under local hypoxia microenvironment

OBJECTIVE: Lung cancer is a common tumor in the clinic. Hypoxia is an important biological characteristic in the solid malignant tumor. MiRNA participates in cell proliferation, differentiation, and apoptosis. This study tested hypoxia-inducible factor 1-alpha (HIF-1 alpha) in lung cancer patients and analyzed the microRNA-15a (miR-15a) expression in A549 cells under different local hypoxia microenvironments. PATIENTS AND METHODS: A total of 40 non-small cell lung cancer (NSCLC) patients in First Affiliated Hospital of Zhengzhou University between Jan 2015 and Jan 2016 were involved in this study. The serum and tissue samples of lung cancer were collected. Serum HIF-1 alpha level was tested by enzyme-linked immunosorbent assay (ELISA) assay. HIF-1 alpha expression in tissue was evaluated by using the immunohistochemistry. A549 cells were cultured under normoxic, hypoxic, and anaerobic environment, respectively. HIF-1 alpha mRNA and miR15a levels were determined by RT-PCR. RESULTS: HIF-1 alpha levels were up-regulated in serum and tissue (p<0.05). HIF-1 alpha mRNA increased, while miR-15a down-regulated in A549 from hypoxia and anaerobic groups compared with control (p<0.05). HIF-1 alpha shRNA transfection significantly reduced HIF-1 alpha and elevated miR15a level (p<0.05). MiR-15a shRNA transfection exhibited no statistical impact on HIF-1 alpha expression (p>0.05). CONCLUSIONS: HIF-1 alpha highly expressed in lung cancer patients. MiR-15a levels were down-regulated in A549 cells under hypoxia and anaerobic conditions.