Abstract
OBJECTIVES: The chemotherapy drug resistance is a major challenge for non-small-cell lung cancer (NSCLC) treatment. Combination of immunotherapy and chemotherapy has shown promise for cancer. The goal of this study was to evaluate the anti-tumour efficacy of interleukin-7 (IL-7) combining cisplatin against NSCLC. MATERIALS AND METHODS: Cell proliferation was analysed using CCK-8 assay, EdU proliferation assay and colony-forming assay. Cell apoptosis was evaluated using HOECHST 33342 assay and flow cytometry. The protein expression levels were analysed by Western blot. The blocking antibody against the IL-7 receptor and the inhibitors of STAT5 and JAK3 were used to investigate the pathway involved. A xenograft model was established to assess the anti-tumour efficacy of IL-7 combining cisplatin in vivo. RESULTS: Here we found IL-7R was increased in A549/DDP cells compared with A549 cells. The block of IL-7R reversed the inhibitory effects of IL-7 combined with cisplatin and decreased the numbers of apoptosis cells induced by treatment of IL-7 combined with cisplatin. The JAK3 inhibitor and STAT5 inhibitor were used to identify the pathway involved. The results showed that JAK3/STAT5 pathway was involved in enhancing role of cisplatin sensitivity of NSCLC cells by IL-7. In vivo, cisplatin significantly inhibited tumour growth and IL-7 combined with cisplatin achieved the best therapeutic effect. CONCLUSION: Together, IL-7 promoted the sensitivity of NSCLC cells to cisplatin via IL-7R-JAK3/STAT5 signalling pathway.