Impact of miRNA-200c on Methotrexate Resistance of Non-small Cell Lung Cancer Cells A549

Objective  To explore the effect of microRNA-200c (miR-200c) on methotrexate (MTX) resistance of non-small cell lung cancer cells A549 (A549/MTX) and elucidate its related mechanism.

Methods  Quantitative real-time PCR (qRT-PCR) was used to detect the miR-200c expression in A549 cells, A549/MTX cells transfected with miR-200c mimic (A549/MTX-M) and A549/MTX cells transfected with miR-negative control (A549/MTX-N). MTT assay, Trypan blue staining and flow cytometry analysis were sequentially performed to detect the sensitivity of A549, A549/MTX-M and A549/MTX-N cells to MTX, cell proliferation and apoptosis. qRT-PCR was used to detect the gene expressions of P53 and P21 in these cells.

Results The miR-200c expression in A549 cells was significantly higher than that in A549/MTX-N cells. The miR-200c expression in A549/MTX-M cells was significantly higher than that in A549/MTX-N cells. Compared with A549/MTX-N cells, the proliferation inhibition and apoptosis of A549/MTX-M cells were increased after treated with MTX in a concentration-dependent manner, with significant difference. Furthermore, the up-regulated P53 and P21 expression were observed in A549/MTX-M cells, with significant difference compared with A549/MTX-N cells(P=0.023, P=0.015).

Conclusion  miR-200c could reduce the resistance of A549/MTX cells to MTX with the possible mechanism of inducing the apoptosis through the P53/P21 pathway.