RESUMO
OBJECTIVES: The basic fibroblast growth factor (bFGF)/fibroblast growth factor receptor (FGFR) signal transductional pathway plays an important role not only in tumour, but also in tumour stem cells. Thus, this study was designed to investigate the effects of bFGF signalling on cancer stem cells of lung cancer. METHODS: We blocked bFGF/FGFR signalling in cisplatin (DDP) selected A549 by knocking down bFGF via RNA interference, and subsequently, the stem cell marker of OCT-4 was determined, and cell proliferation, clone formation, invasiveness, apoptosis and drug resistance abilities of DDP selected A549 cells were investigated. KEY FINDINGS: The expressions of bFGF and OCT-4 in DDP selected A549 were higher than that of A549 cells. The findings suggested blocking of bFGF/FGFR signalling resulted in downregulation of bFGF, reduction in cell proliferation, clone formation, invasion and drug resistance abilities, and increase in cell apoptosis. Furthermore, our results also revealed OCT-4 was reduced after bFGF signalling blocking. CONCLUSIONS: In conclusion, our study suggested that bFGF/FGFR signalling plays an important role in maintaining lung cancer stem cell characteristics and regulating expression of cancer stem cell marker of OCT-4.
Assuntos
Fator 2 de Crescimento de Fibroblastos/antagonistas & inibidores , Fator 2 de Crescimento de Fibroblastos/metabolismo , Células-Tronco Neoplásicas/metabolismo , Fator 3 de Transcrição de Octâmero/metabolismo , Receptores de Fatores de Crescimento de Fibroblastos/fisiologia , Células A549 , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cisplatino/farmacologia , Regulação para Baixo/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Fator 2 de Crescimento de Fibroblastos/genética , Técnicas de Silenciamento de Genes , Humanos , Neoplasias Pulmonares/patologia , Paclitaxel/farmacologia , RNA Interferente Pequeno , Transdução de Sinais/efeitos dos fármacosRESUMO
OBJECTIVES: 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. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSION: 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.