Hacer Kaya Cakır - Department of Molecular Biology and Genetics, Faculty of Science and Letters, Bilecik Seyh Edebali University, Bilecik, Turkey
Onur Eroglu - Department of Molecular Biology and Genetics, Faculty of Science and Letters, Bilecik Seyh Edebali University, Bilecik, Turkey

Objective(s): Mouse breast cancer cell line ۴T۱ can accurately mimic the response to immune receptors and targeting therapeutic agents. Combined therapy has emerged as an important strategy with reduced side effects and maximum therapeutic effect. Mocetinostat (MGCD۰۱۰۳) is one of the members of Class I Histone Deacetylase Inhibitors (HDACi) and its mechanism of action has not been defined, yet. Capecitabine (Xeloda) is an antimetabolite and currently is widely utilized to treat a wide range of solid tumors. The aim of this study was to investigate the effects of the capecitabine, mocetinostat and their combined application on the ۴T۱ cell line.  Materials and Methods: The effects of combined administration of mocetinostat and capecitabine on ۴T۱ cells were investigated by cell viability and migration assays, apoptosis analysis, and Western blotting technique.Results: The concentrations of drugs that give a half-maximal response (IC۵۰) were detected for capecitabine (۱۷۰۰ µM), mocetinostat (۳,۱۲۵ µM), and ۵۰ µM Capecitabine+۱,۵ µM Mocetinostat for ۴۸ hr. In capecitabine+mocetinostat combine group, we observed that cell migration decreased, DNA fragmentation increased compared to the control group. capecitabine + mocetinostat group induced apoptosis by decreasing Bcl-۲, PI۳K, Akt, c-myc protein levels, while increasing Bax, Caspase-۳, PTEN, cleaved-PARP, Caspase-۷, Caspase-۹, p۵۳, cleaved-Cas-۹ protein levels in ۴T۱ cells. Conclusion: Capecitabine and mocetinostat played a toxic role through inducing apoptosis on ۴T۱ cancer cells in a time- and concentration-dependent manner. These results showed that combined therapy with low concentrations were detected to be more effective than that with high-concentration alone drug treatment. 

Apoptosis, Breast neoplasms, Drug synergism, Capecitabine, Histone deacetylase inhibitors