3,6-dichloro-1,2,4,5-Tetrazine Assayed at High Doses in the Metastatic Breast Cancer Cell Line MDA-MB-231 Reduces Cell Numbers and Induces Apoptosis

Background: The lack of treatment options for patients with chemotherapy-resistant cancers is pushing the field toward the development of new therapies. 1,2,4,5-tetrazine derivatives are a class of heterocyclic compounds that exhibit a broad spectrum of antitumor activities. Objective: The purpose of this study was to assess the biological activity of four s-tetrazine derivatives by substitution of two chloride atom of 3,6-dichloro-1,2,4,5-tetrazine with long hydrophobic side chains. Methods: We analyzed the anti-proliferative effects of four s-tetrazine derivatives with MTT assay and their pro-apoptotic effect with AV/ IP flow cytometry analysis and Hoechst 33342 staining. Results: We demonstrated that 3,6-dichloro-1,2,4,5-tetrazine (compound (1)) has a cytotoxic effect and induces apoptosis. Conclusion: 3,6-dichloro-1,2,4,5-tetrazine presents a new cytotoxic drug against metastatic breast cancer cell line MDA-MB-231 in vitro.