The role of microRNA-21 in predicting brain metastases from non-small cell lung cancer

OBJECTIVE This study aimed at exploring the role of microRNA-21 (miR-21) in predicting brain metastases (BM) from non-small cell lung cancer (NSCLC). METHODS A total of 132 NSCLC patients, including 68 patients with BM and 64 patients without BM, were included in the study. NSCLC cells were collected and assigned to the inhibitor (IN) group, the mock group, and the negative control (NC) group. The quantitative real-time polymerase chain reaction assay was used to detect the miR-21 expression. Cell proliferation, migration, invasion, and apoptosis were detected by colony-forming assay, MTT assay, transwell assay, and flow cytometry, respectively. Angiogenesis was measured by endothelial cell tube formation assay. RESULTS The miR-21 expression was higher in NSCLC patients with BM than in those without BM. The miR-21 expression in the IN group was lower than that in the NC and mock groups. Compared with the NC and mock groups, the values of optical density (OD) and the colony-forming number decreased in the IN group. Compared with the NC and mock groups, cell invasion and migration abilities significantly reduced in the IN group. The IN group had higher apoptosis rate than the NC and mock groups. The tube length was shorter and the number of junction points was less in the IN group in comparison to the NC and mock groups. CONCLUSION miR-21 might be a potential biomarker for the development of BM in NSCLC patients and could promote the proliferation, migration, invasion, and angiogenesis of NSCLC cells.