Shenqi Fuzheng injection restores the sensitivity to gefitinib in non-small cell lung cancer by inhibiting the IL-22/STAT3/AKT pathway

Abstract

Context Non-small cell lung cancer (NSCLC) is the most common type of lung cancer. Gefitinib is a first-line treatment for NSCLC. However, its effectiveness is hindered by the development of drug resistance. At present, Shenqi Fuzheng injection (SFI) is widely accepted as an adjuvant therapy in NSCLC. Objective This study investigates the molecular mechanism of SFI when combined with gefitinib in regulating cell progression among EGFR-TKI-resistant NSCLC. Materials and 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. 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. Discussion and Conclusion SFI can be a valuable therapeutic option to address gefitinib resistance in NSCLC by suppressing the IL-22/STAT3/AKT pathway.