Cytotoxic and cytostatic activity of five new imidazotetrazine derivatives on breast cancer cell cultures MDAMB231, BT474, and MCF-7

Introduction: The work presents the results of the study of new imidazotetrazine derivatives to establish the possibility of using them as anticancer agents, including for chemotherapy of metastatic breast cancer. The relevance of the work is due to the wide spread of oncological diseases and high cancer mortality, which dictates the need to constantly obtain cell lines and improve cultivation protocols for testing new antitumor drugs. The goal of this study is to check the potential of five new imidazotetrazine derivatives to become new antitumor drugs, in the scope of studying their cytotoxic and cytostatic activities on breast cancer cell cultures. Materials and Methods: The culturing MCF-7, MDAMB231, BT474, and MCF-10a cells with determining cytotoxic and cytostatic activities of five new azolotetrazine derivatives are base methods used in this study. Results: For the MCF-7 culture, MCS of comparison drug temozolomide was equal to 2.44 and IC50 was 6.81 mM/L; for other cultures CTA indicators were worse. Imidazotetrazine 2 and imidazotetrazine 3 demonstrated CTA indicators lower than those of temozolomide. IC50 was not achieved, and the MCS value varied between 1.34 and 1.74. These two derivatives were classified as the compounds with an extremely low CTA. Imidazotetrazine 1 and iminothiotriazine 5 showed cytotoxic activity higher than that of the comparison drug and we classified these compounds as the ones with a moderate CTA. Finally, we found imidazotetrazine 4 with IC50 of 0.85 mM/L and CTA of 7.34 as a compound with a potentially strong anticancer effect for further investigation. The cytostatic activity of four of the five azoloazine derivatives studied was in a narrow range corresponding to the survival rate from 0.21 to 0.32, depending on the compound and cell culture. Against this background, imidazotetrazine 4 demonstrated a higher CSA, determined by the survival rate from 0.17 to 0.20. Conclusion: As a result of an in vitro study, we found that five new azolotriazine derivatives can be evaluated in the ascending order of these properties, as a combination of CTA+CSA in order imidazotetrazine 2, imidazotetrazine 3 < temozolomide < imidazotetrazine 1, iminothiotriazine 5 < imidazotetrazine 4, although the CSA of all the studied compounds turned out to be high. Thus, 3-Cyclohexyl-4-oxoimidazo[5,1-d]-[1,2,3,5]tetrazine-8-N-piperidinyl-carboxamide (imidazotetrazine 4) is an unconditional leader in the tested series of new azoloazine derivatives and we recommend it for further preclinical trials.