Conclusion
SFI can be a valuable therapeutic option to address gefitinib resistance in NSCLC by suppressing the IL-22/STAT3/AKT pathway.
Methods
We established gefitinib-resistant PC9-GR cells by exposing gefitinib escalation from 10 nM with the indicated concentrations of SFI in PC9 cells (1, 4, and 8 mg/mL). Quantitative real-time polymerase chain reaction was performed to assess gene expression. PC9/GR and H1975 cells were treated with 50 ng/mL of interleukin (IL)-22 alone or in combination with 10 mg/mL of SFI. STAT3, p-STAT3, AKT, and p-AKT expression were evaluated using Western blot. The effects on cell proliferation, clonogenicity, and apoptosis in NSCLC cells were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), colony formation and flow cytometry assays.
Objective
This study investigates the molecular mechanism of SFI when combined with gefitinib in regulating cell progression among EGFR-TKI-resistant NSCLC. Materials and
Results
SFI treatment alleviated the development of gefitinib resistance in NSCLC. PC9/GR and H1975 cells treated with SFI significantly exhibited a reduction in IL-22 protein and mRNA overexpression levels. SFI effectively counteracted the activation of the STAT3/AKT signaling pathway induced by adding exogenous IL-22 to PC9/GR and H1975 cells. Moreover, IL-22 combined with gefitinib markedly increased cell viability while reducing apoptosis. In contrast, combining SFI with gefitinib and the concurrent treatment of SFI with gefitinib and IL-22 demonstrated the opposite effect.