Effects of disulfiram on proliferation, apoptosis and gefitinib resistance of lung cancer cell line H1975

Abstract

Objective To investigate the effects of disulfiram (DSF) on the proliferation, apoptosis and gefitinib sensitivity of non-small cell lung cancer H1975 cells. Methods H1975 cells were cultured in vitro and treated with different concentrations of disulfiram for 24, 48, and 72 hours. The CCK-8 assay was used to assess the impact of disulfiram on cell proliferation, and appropriate concentrations were selected for subsequent experiments. Cells were treated with varying concentrations of gefitinib alone or in combination with disulfiram for 48 hours, and the half-maximal inhibitory concentration (IC50) was calculated to determine the reversal fold. Cells were treated with gefitinib, disulfiram and N-acetylcysteine alone or in combination for 48 hours. Apoptosis was detected by flow cytometry, intracellular reactive oxygen species levels were measured using the DCFH-DA method, and Western blotting was performed to assess the expression of stemness-related markers (ALDH1A1, SOX2), pathway-related markers (p-STAT3, STAT3), and apoptosis-related markers (Bax, Bcl-2). Results Disulfiram significantly inhibited H1975 cell proliferation in a concentration-dependent (0-10 μmol/L) and time-dependent (24-72 hours) manner (P＜0.05). The IC50 of gefitinib alone was 11.13 μmol/L, which decreased to 4.148 μmol/L when combined with 1 μmol/L disulfiram, indicating that disulfiram effectively reversed gefitinib resistance by 2.68 times. Disulfiram significantly suppressed the upregulation of stem cell-related proteins SOX2 and ALDH1A1 induced by gefitinib (P＜0.05), and this effect was partially counteracted by the reactive oxygen species inhibitor N-acetylcysteine. Compared to gefitinib and disulfiram monotherapy groups, the combination therapy group exhibited significantly increased apoptosis rates, elevated reactive oxygen species levels and pro-apoptotic Bax expression, and reduced p-STAT3 and anti-apoptotic Bcl-2 expression (P＜0.05). Further clearance of reactive oxygen species with N-acetylcysteine reversed disulfiram′s inhibitory effect on the STAT3 pathway(P＜0.05). Conclusions Disulfiram may enhance gefitinib sensitivity by upregulating reactive oxygen species levels and inhibiting the STAT3 signaling pathway.