1‐(4‐((5‐chloro‐4‐((2‐(isopropylsulfonyl)phenyl)amino)pyrimidin‐2‐yl)amino)‐3‐methoxyphenyl)‐3‐(2‐(dimethylamino)ethyl)imidazolidin‐2‐one (ZX‐42), a novel ALK inhibitor, induces apoptosis and protective autophagy in H2228 cells

Objectives: To examine the antiproliferative effects of 1‐(4‐((5‐chloro‐4‐((2‐(isopropylsulfonyl)phenyl)amino)pyrimidin‐2‐yl)amino)‐3‐methoxyphenyl)‐3‐(2‐(dimethylamino)ethyl)imidazolidin‐2‐one (ZX‐42) on the echinoderm microtubule‐associated protein‐4/anaplastic lymphoma kinase fusion gene (EML4‐ALK) positive lung cancer cell line H2228 and its underlying mechanism. Methods: The MTT assay was used to study the effect of ZX‐42 on H2228 cell growth. Propidium iodide (PI) staining and Western blotting were used to investigate the cell cycle changes. ZX‐42‐induced cell apoptosis was determined using the Annexin V‐FITC/PI (AV/PI) apoptotic assay kit, acridine orange/ethidium bromide (AO/EB) and Hoechst 33258 staining, Rhodamine 123 (Rh 123) fluorescence assay and Western blotting. ZX‐42‐induced reactive oxygen species (ROS) production was examined by ROS assay kit. Transmission electron microscope, monodansylcadaverine (MDC) staining and the AV/PI apoptotic assay kit were used to demonstrate the relationship between autophagy and apoptosis. Key findings: ZX‐42 had good cell viability inhibitory effect on H2228 cells. ZX‐42 dramatically inhibited ALK and its downstream pathways. ZX‐42 also blocked H2228 cell cycle at G1 phase and then induced apoptosis by activating the mitochondrial pathway. Next, ZX‐42 induced the production of ROS, and antioxidant N‐acetylcysteine (NAC) reduced ROS production and also decreased apoptotic rates. We also found that ZX‐42 induced protective autophagy in H2228 cells. Conclusions: In summary, ZX‐42 is a novel ALK inhibitor that significantly inhibits the cell viability of H2228 cells and ultimately induces apoptosis through the mitochondrial pathway, in which autophagy plays a protective role. Therefore, inhibition of autophagy might enhance the anti‐cancer effect of ZX‐42. [ABSTRACT FROM AUTHOR]