Objective To detect the expression levels of miR-7-5p and POLE4 in non-small cell lung cancer cells and their effect on cells proliferation, migration and invasion.

Methods qRT-PCR was used to detect the relative expression levels of miR-7-5p and POLE4 mRNA in NSCLC tissues, adjacent tissues, tumor cells and human normal bronchial epithelial cells. Luciferase reporter gene was used for analyzing of the targeting relation between POLE4 and miR-7-5p in NSCLC cells. si-NC and si-POLE4 were transfected into SPC-A-1 cells as the si-NC group and si-POLE4 group, and the control group was set at the same time. MTT method, scratch test and Transwell test were used to detect cell proliferation, migration and invasion.

Results The expression levels of miR-7-5p in NSCLC tissues and cells were reduced, and the expression levels of POLE4 were increased. miR-7-5p could target to combine with POLE4. After 72 hours of culture, the OD value in si-POLE4 group was significantly lower than those in the control group and si-NC group (P < 0.05). The migration rate and the number of transmembrane cells in the si-POLE4 group cultured for 48 hours were lower than those in the control group and the si-NC group (P < 0.05).

Conclusion miR-7-5p may inhibit the proliferation, migration and invasion of non-small cell lung cancer cells by targeting POLE4.