ABSTRACT
Objective: Radiotherapy has been widely used to treat lung cancer. However, non-small
lung cancer cells are insensitive to radiation, diminishing their radiotherapy effects.
Although the radiosensitivity of the non-small lung cancer cells was reported to
be enhanced through regulating miR-34a, the regulation effects of miR-34a expression
on radiosensitivity of lung adenocarcinoma cells through target genes CDK4, CDK6,
CyclinD1, and Bcl-2/Bax have not been systematically investigated. Methods: In this study, we investigated the effect of miR-34a expression on the Bcl-2, CDK4,
and CDK6 pathways in lung adenocarcinoma cells, to provide new insights into the sensitization treatment of lung cancer. We first studied the effect
of miR-34a expression on H1299 and A549 cell activity. Then to investigate the
mechanisms of radiosensitivity, we focused on apoptosis, cell cycle, and target
genes. Results: We find that overexpression of miR-34a in lung adenocarcinoma
cells inhibits cell activity, and improves radiosensitivity. Specifically, overexpression
of miR-34a suppresses the expression of target genes CDK4, CDK6, CyclinD1, and Bcl-2/Bax,
which leads to cell cycle arrest and promotes apoptosis of lung adenocarcinoma cells. Conclusions: Overall, our results demonstrate that the overexpression of
miR-34a enhances the radiosensitivity of lung adenocarcinoma cells, indicating that
miR-34a is a sensitizer for lung adenocarcinoma radiotherapy.