5-chloro-N4-(2-(isopropylsulfonyl)phenyl)-N2-(2-methoxy-4-(4-((4-methylpiperazin-1-yl)methyl)-1H-1,2,3-triazol-1-yl)phenyl)pyrimidine-2,4-diamine (WY-135), a novel ALK inhibitor, induces cell cycle arrest and apoptosis through inhibiting ALK and its downstream pathways in Karpas299 and H2228 cells.

Anaplastic lymphoma kinase (ALK)-positive cancers have rising morbidity and mortality in recent years, and novel chemotherapeutic drugs with no drug resistance and high activity for treating ALK-positive cancers are needed urgently. In this study, we investigated the anti-cancer effect of 5-chloro-N4-(2-(isopropylsulfonyl)phenyl)-N2-(2-methoxy-4-(4-((4-methylpiperazin-1-yl)methyl)-1H-1,2,3-triazol-1-yl)phenyl)pyrimidine-2,4-diamine (WY-135), a novel ALK inhibitor, on nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) positive cancer cell line Karpas299 and echinoderm microtubule associated protein like 4-anaplastic lymphoma kinase (EML4-ALK) positive cancer cell line H2228. In vitro enzyme assay showed that WY-135 had better enzyme inhibitory activity than ceritinib. MTT assay showed that WY-135 had similar inhibitory activity with ceritinib in Karpas299 and H2228 cells. The cell cycle analysis proved that WY-135 induced cell cycle arrest at G1 phase in a dose-dependent manner and subsequently progressed into apoptosis. Real-time PCR analysis revealed that the mRNA level of ALK was significantly reduced in Karpas299 and H2228 cells treatment with WY-135. Furthermore, western blot analysis showed that WY-135 significantly suppressed ALK and its downstream protein expression. Taken together, WY-135 exhibits significant anti-cancer activity through inhibiting ALK and its downstream protein expression, arresting cell cycle and eventually inducing cell apoptosis in Karpas299 and H2228 cells. WY-135 is a promising ALK inhibitor with novel structure that has tremendous potentials for therapeutic treatment of NPM-ALK or EML4-ALK positive cancers.