A Novel Bcl-2 Inhibitor, BM-1197, Induces Apoptosis in Malignant Lymphoma Cells Through the Endogenous Apoptotic Pathway

Abstract

Background: Bcl-2 family members play an important role in the development of malignant lymphoma and can induce drug resistance in anticancer treatment. The development of small molecules targeting Bcl-2 family protein can be new strategy for malignant lymphoma treatment. In this study, we investigate the antitumor effect and the cellular mechanism of a novel Bcl-2/Bcl-xL dual inhibitor BM-1197 in DCBCL and Burkitt lymphoma cells. Methods: CCK-8 assay was used to detect cell viability. Apoptosis was determined by Hoechst 33258 staining and flow cytometry. The activity of caspase-3/caspase-9 was determined using the caspase-3/ caspase-9 activity kit. Western blotting analysis was performed to evaluate the change of protein expression. The functional analysis was evalueated via immunoprecipitation and siRNA interference. Human malignant lymphoma xenograft models in nude mice were established for in vivo efficacy detection. Results: We find that BM-1197 exerts potent growth-inhibitory activity against lymphoma cells which harbor Bcl-2 and Bcl-xL high expression in vitro and has synergistic effect with chemotherapeutic drugs. Mechanistically, we see that the intrinsic apoptosis pathway is activated upon BM-1197 treatment. BM-1197 affects the protein interaction of Bak/Bcl-xl, Bim/Bcl-2, Bim/Bcl-xl, PUMA/Bcl-2 and induced conformational change in the Bax protein.which results in activation of Bax and release cytochrome c, and activated caspase -9, -3, -7 and finally induce cell apoptosis. Furthermore, our data demonstrates that BM-1197 exhibits strong anti-tumor effects against established human malignant lymphoma xenograft models. Conclusions: Our study demonstrated BM-1197 exerts potent antitumor effects both in vitro and in vivo, and provides promising preclinical data for further development of BM-1197 in malignant lymphoma. Funding Statement: This work is supported by National Natural Scientific Research Fund of China (Project Number: 81301904), Medical Scientific Technology and Research Fund of Guangdong (Project Number: A2016023), Special Project by Guangdong Science and Technology Department (2018YJ021), and National Natural Scientific Research Fund of China (Project Number: 81101671) Declaration of Interests: The authors declare that they have no competing interests. Ethics Approval Statement: All animal experiments were performed under the guidance of Sun Yat-Sen University Committee for Use and Care of Laboratory Animals and approved by the animal experimentation ethics committee.