MIR-26-5P INHIBITS THE PROLIFERATION AND INVASION OF LUNG CANCER CELLS BY TARGETING PTPN3

Tieying Tian^#, Xiyuan Xu^#, Baoying Bu, Pengfei Xuan, Xiaonan Li, Jingping Yang, Hongjun Tian^*

Department of Respiratory and Critical Medicine, The Third Affiliated Hospital, Inner Mongolia Medical University, 20th Shaoxian Road, KunDuLun District, Baotou, Inner Mongolia, P.R.China

Objective: To explore the relationship between miR-26-5p and PTPN3 and its role in the tumour immunity of lung cancer. 

Methods: First, the clinical lung cancer patients samples were used for data analysis, and the expression of miR-26-5p was verified by RT-qPCR assay in a non-small cell lung cancer (NSCLC) lung cancer cell line. MiR-26-5p was over-expressed in lung cancer cell line H460, and the expression of PTPN3 protein was detected by western blotting. Simultaneously, CCK-8 and cell scratch tests were carried out to detect the proliferation ability of H460 cells. The invasive ability of miR-26-5p over-expressed H460 cells was detected by Transwell assay. The binding sequence of miR-26-5p and PTPN3 was predicted by Targetscan database, and the function of miR-26-5p through directly targeting PTPN3 was proved by dual luciferase reporter assay. The PTPN3 over-expression cell line was constructed, and the proliferation and invasion ability of H460 cells was tested by CCK-8 assay and Transwell experiments, respectively.

Results: GEO analysis of NSCLC clinical samples showed a significant decrease of miR-26-5p expression in NSCLC cells, while RT-qPCR assay also showed a reduction of miR-26-5p expression in NSCLC cells. After the over-expression of miR-26-5p in lung cancer cell line H460, the results of Western blotting demonstrated that miR-26-5p over-expression inhibited the expression of PTPN3. Meanwhile, the results of the CCK-8 and cell scratch tests showed that the expression of miR-26-5p inhibited the proliferation of lung cancer cells. Moreover, transwell results revealed that the expression of miR-26-5p suppressed the invasion ability of lung cancer cells. Finally, a PTPN3 over-expression cell line was constructed and the results indicated that the over-expression of PTPN3 completely reversed the proliferation and invasion inhibition of lung cancer cells induced by miR-26-5p.

Conclusion: This findings of this study demonstrate that miR-26-5p can inhibit the proliferation and invasion of lung cancer cells by directly targeting the expression of PTPN3.