CAJ | 학술논문

Objective This study investigated the role of the STAT3/survivin signaling pathway in the EML4-ALK–positive lung adenocarcinoma cel line H2228 before and after crizotinib-induced resistance. The mecha-nism of resistance was studied. Methods Cel viability was determined using the MTT assay. Crizotinib-induced apoptosis in H2228 and H2228 crizotinib-resistant cel s treated with the indicated doses of crizotinib was measured at dif erent times (24 h, 48 h, 72 h) using flow cytometry. The levels of p-ALK, ALK, p-STAT3, STAT3, and survivin after treatment of cel s with 0, 0.3, and 1μM crizotinib for 72 h were determined using Western blot analysis. DNA sequencing was used to identify mutations in H2228 crizotinib-resistant cel s. Results The crizotinib IC50 values in H2228 and H2228 crizotinib-resistant cel s at 72 h were 334.5 nM and 3418 nM, respectively. The resistance index of H2228 crizotinib-resistant cel s was 10.20. Crizotinib induced apoptosis in H2228 cel s and reduced the levels of p-ALK, p-STAT3, and survivin. In contrast, no changes in the levels of p-ALK, p-STAT3, and survivin were observed in H2228 crizotinib-resistant cel s. The mutations 2067G→A and 2182G→C in EML4-ALK were present in the H2228 crizotinib-resistant cel s. Conclusion Crizotinib decreased the viability of H2228 cel s in a dose- and time-dependent manner. In the STAT3/survivin pathway, downregulation of p-ALK, p-STAT3, and survivin might contribute to crizo-tinib-induced apoptosis in H2228 cel s. However, the STAT3/survivin pathway in H2228 crizotinib-resistant cel s was unaf ected by crizotinib treatment. Acquired resistance in H2228 cel s might be related to ALK mutations.