Downregulation of basic fibroblast growth factor increases cisplatin sensitivity in A549 non-small cell lung cancer cells.

The objective of the study is to investigate the role of basic fibroblast growth factor (bFGF) in sensitivity to cisplatin in non-small cell lung cancer (NSCLC) A549 cells and its effect on the stemness characteristics of NSCLC cells, revealing possible mechanisms of cisplatin resistance. After A549 cells were treated with cisplatin, bFGF protein expression was analyzed by Western blot. A549 cells were transfected with bFGF small interfering RNAs (siRNAs), and the knockdown efficiency was confirmed by quantitative reverse transcription polymerase chain reaction and Western blot. After bFGF downregulation, A549 cell proliferation was assessed by Cell Counting Kit-8 assay. The effect of bFGF siRNA on the sensitivity to cisplatin was evaluated by cell viability assays and flow cytometry for cell apoptosis. Colony formation assay was performed to explore whether bFGF affected the stemness characteristics of A549 cells, and OCT-4 protein expression was analyzed by Western blot after bFGF siRNA treatment. Cisplatin treatment enhanced bFGF expression in A549 cells. After A549 cells were transfected with bFGF siRNAs, bFGF expression was significantly decreased compared to that in the negative control siRNA group. In addition, bFGF knockdown inhibited A549 cell proliferation. bFGF siRNA treatment enhanced the inhibitory effect of different concentrations of cisplatin on cell viability and promoted cisplatin-induced apoptosis in A549 cells. Further analyses showed that bFGF siRNA treatment not only significantly decreased colony formation in A549 cells but also downregulated OCT-4 protein expression. bFGF decreased NSCLC sensitivity to cisplatin in vitro, while it enhanced colony formation ability and increased OCT-4 expression of A549 cells, which might account for its involved mechanisms of cisplatin resistance.