Flavokavain C Suppresses Breast Cancer Cell Viability and Induces Cell Apoptosis by Triggering DNA Damage.

Abstract

Breast cancer, presented by multiple breast cancer subtypes that coexist within a diagnosed tumor in clinical, has ranked as the most common malignancy in women in recent years. Evidence suggested that limited effective drugs caused the unsatisfactory therapeutic efficacy of breast cancer. Flavokavain C exhibited anticancer activity on colon cancer cells HCT116. It is yet unknown if it can be used to treat breast cancer. This study aims to believe the mechanisms by which Flavokavain C suppresses cell proliferation and the pathways that impact on this effect in breast cancer. 3-(4,5-Dimethythiazol)-2,5-diphenyltetrazolium bromide assay was chosen to evaluate cell cytotoxicity. Colony formation and cell proliferation assays using 5-ethynyl-2'-deoxyuridine staining were performed. Cell cycle progression and apoptosis were examined via flow cytometry and Western blotting, respectively. Five methods (comet assay, immunofluorescence, Western blotting, agarose gel electrophoresis and molecular docking) were used to quantify DNA damage and its cellular response. Compared to cisplatin, Flavokavain C possessed a comparable or more substantial inhibitory effect on breast cancer cell viability while having lower cytotoxicity on human mammary cells. Breast cancer cells treated with Flavokavain C had their colony formation suppressed, DNA replication blocked, the G2/M phase cell cycle arrested, and apoptosis. Furthermore, the results indicated that Flavokavain C would directly interact with DNA and induce DNA cleavage, demonstrating that DNA is an attractive substrate for Flavokavain C. These results suggested that Flavokavain C had strong anticancer activity against multiple subtypes of breast cancer cells.