To explore the effect of microRNA-26b (miR-26b) in non-small cell lung cancer (NSCLC) cells, we investigated the mRNA levels of miR-26b in 4 NSCLC cell lines and 10 clinical samples from human patients with NSCLC by quantitative reverse transcriptase polymerase chain reaction. It was found that miR-26b was significantly down-regulated in both NSCLC cells and human carcinoma tissues. Synthetic oligonucleotides were used to up-regulate or down-regulate miR-26b in NSCLC cell lines H1299 and A549 cells. Results showed that both down-regulating and up-regulating miR-26b had no effect on cancer cell proliferation in H1299 or A549 cells, whereas miR-26b over-expression increased cancer cell migration and reduced cisplatin chemosensitivity. Phosphatase and tensin homolog (PTEN) was confirmed to be directly bound by miR-26b by dual-luciferase reporter assay, and was down-regulated in miR-26b over-expressing NSCLC cells. Finally, when PTEN was up-regulated in NSCLC cells, it reversed the effects of miR-2b over-expression on NSCLC migration and cisplatin chemosensitivity. In conclusion, our data showed a functional mechanism of miR-26b in regulating NSCLC. It indicates that miR-26b may regulate NSCLC migration and chemosensitivity through the regulation of PTEN.
Keywords: NSCLC; PTEN; cisplatin; miR-26b; migration.
© The Author 2015. Published by ABBS Editorial Office in association with Oxford University Press on behalf of the Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences.