Potential therapeutic GSK-3β inhibitor 9-ING-41 is active in combination with venetoclax in double-hit lymphoma (DHL).

[BACKGROUND] Double-hit lymphoma (DHL) exhibits aggressive behavior due to dysregulated proliferation and resistance to apoptosis. Current therapies, including R-CHOP, show limited efficacy, necessitating novel strategies. 9-ING-41, a novel ATP-competitive small-molecule inhibitor that targets glycogen synthase kinase-3β (GSK-3β), has emerged as a promising therapeutic agent because of its ability to disrupt oncogenic signaling pathways associated with tumor progression and treatment resistance. However, the antitumor effects of 9-ING-41 in DHL remain unclear.

[MATERIALS AND METHODS] DHL cell lines (Karpas-422 and SuDHL2) were treated with venetoclax and 9-ING-41, either alone or in combination. Cell viability in cytotoxicity assays was assessed using the CCK-8 assay, while apoptosis and cell cycle changes were analyzed via flow cytometry. Western blotting was employed to evaluate alterations in the levels of GSK-3β and WNT/β-catenin pathway proteins following treatment.

[RESULTS] In preclinical studies utilizing DHL cell models, the single agent 9-ING-41 demonstrated robust biological activity through inducing significant G1/S phase cell cycle arrest and triggering apoptosis. When coadministered with venetoclax, a clinically approved BCL-2 inhibitor, the combination exhibited marked synergistic cytotoxicity in DHL cells, achieving superior inhibitory effects compared to either agent alone. The combined treatment enhanced cell cycle arrest, significantly reducing the number of S-phase cells and reinforcing G0/G1 arrest. Further mechanistic studies revealed that the combination modulated key proteins in the GSK-3 pathway and downstream WNT/β-catenin pathway, revealing a potential synergistic mechanism.

[CONCLUSION] The demonstrated single-agent efficacy and combination synergy with venetoclax support the potential of 9-ING-41 as a novel therapeutic strategy for DHL. These findings provide a proof-of-concept that may serve as a basis for future preclinical investigations in DHL.