A novel carbazole derivative, MHY407, sensitizes cancer cells to doxorubicin-, etoposide-, and radiation treatment via DNA damage

In this study, we synthesized a novel carbazole derivative, MHY407, as a sensitizer of cancer cells to increase DNA damage. We then evaluated the anticancer effects of MHY407 and identified the molecular mechanism for the sensitization of breast cancer cell lines. MHY407 significantly increased DNA damage as determined by DNA breakage, levels of damage-responsive proteins, and DNA foci. In addition, MHY407 increased p21 and decreased cyclin D1 protein levels. MHY407 also involved increased cell cycle arrest at the S phase. Furthermore, in doxorubicin and etoposide-treated breast cancer cells, co-treatment with MHY407 reduced cell viability and increased apoptosis. Co-treatment of MHY407 with doxorubicin or etoposide increased DNA damage-related proteins and foci formation, suggesting that increased DNA damage by MHY407 plays an important role in the sensitization. In addition, MHY407 also sensitized the cancer cells to DNA damaging radiation treatment. These results may contribute to the development of MHY407-based treatments for cancer patients receiving DNA-damage therapy.