Investigation of zebularine effect on caspase-3, caspase-8 and caspase-9 involved in apoptotic pathway in SKBR3 breast cancer cell line

DNA methyl transferase inhibitor (DNMTi) nucleotide analogues can reorganize the expression of the genes related to apoptosis and tumour suppressor genes which are silenced by methylation. Thus, it can trigger apoptosis formation in tumour cell. Zebularine which is DNA methyl transferase inhibitor (cytidine analogue) is one of these agents. This study aimed to analyse the effects of zebularine in SKBR3 breast cancer cell line on cytotoxic and apoptotic mechanism and it is important in the sense that it is the first study on the issue in the literature. SKBR3 cell line used in the study is grown at DMEM medium. In order to evaluate the effects of Zebularine on cell viability, cell growth, cell transformation and cell migration, MTT assay, cell survival assay, soft agar colony formation assay, wound healing assay were done respectively. At the same time, in order to understand the effects on apoptotic mechanism, Methylation Sensitive High Resulation Melting (MS-HRM) was done for the methylation analysis of caspase-3, caspase-8 and caspase-9 genes after bisulphite modification. As a result of the findings, it is observed that Zebularine considerably decimates the cell viability, growth (p<0,0001), cell migration (p<0,001) and cell transformation (p<0,001). However, Zebularine shows cell viability at 47% after treatment at 48 hours. At the same time, Zebularine don't cause significant change on methylation in caspase-3, caspase-8 and caspase-9 genes administered dose and time in SKBR3 cells. These results support that Zebularine can be a new anticancer agent in chemotherapy in breast cancer cells and this is the first work on this subject. However, for the understanding of the mechanisms of action, it is necessary to carry out studies aiming at understanding the caspase-related apoptosis mechanism in the future.