Effect of miR-1269a expression on the radiotherapy sensitivity of H460 stem cell like cells / 解放军医学杂志

ABSTRACT

Objective To investigate the effect of miR-1269a expression on the radiotherapy sensitivity of H460 stem cell-like cells of non-small cell lung cancer. Methods Non-small cell lung cancer H460 cell line was selected for serum-free suspension culture, and CD133 and CD44 positive H460 stem cells were screened by flow cytometry. qRT-PCR was performed to detect the expression levels of miR-30a, miR-148a, miR-148b, miR-152, miR-411, miR-497, miR-598, miR-424, miR-761, miR-1269a, miR-1280 and CD44, CD133 mRNA in H460 stem cell-like cells. The effects of miR-1269a expression on the radiotherapy sensitivity of H460 stem cell-like cells were analyzed using CCK-8 experiments, stem cell pelleting experiments, flow cytometry, and comet experiments. Results The expressions of CD133 and CD44 mRNA increased 1.30±0.03 times and 1.19±0.02 times, respectively, in H460 stem cell-like cells than in H460 cells (P<0.05). The expression level of miR-1269a was the highest in H460 stem cell-like cells, and was higher than that in H460 cells (P<0.05). After transfection of miR-1269a inhibitor and X-ray treatment, the growth inhibition rate of H460 stem cell-like cells increased significantly (72.11%±2.45%), the apoptosis rate reached to 17.70%±0.54%, and the fragmentation of DNA double-strand breaks in cells also increased significantly. After 2 Gy of X-ray radiation, the tail moment was 1.19±0.02 times of that before transfection, implying that transfection of miR-1269a inhibitor significantly increased the sensitivity of H460 stem cell-like cells to radiotherapy (P<0.05). After transfection of pcDNA3.1-SOX7, the effect of X-ray treatment on H460 stem cell-like cells was similar to that of miR-1269a inhibitor transfection. Simultaneous transfection of pcDNA3.1-SOX7 and miR-1269a mimics reversed the inhibitory effect of transfection of pcDNA3.1-SOX7 on the malignant biological behavior of H460 stem cell-like cells. Conclusion Inhibition of miR-1269a may enhance the radiotherapy sensitivity of non-small cell lung cancer, and the mechanism may be caused by up-regulation of SOX7 expression.