Genisteinin Dna Hasarı Üzerindeki Etkilerinin Kolon Kanseri Hücrelerinde Tek Hücre Jel Elektroforez (Comet) Yöntemiyle Değerlendirilmesi

Abstract

Çal Doğan, T., Evaluation of The Effects of Genistein on DNA Damage by Single Cell Gel Electrophoresis (Comet) in Colon Cancer Cells, Hacettepe University Institute of Health Sciences Doctor of Philosophy Thesis on Pharmaceutical Toxicology , Ankara, 2021. Today, cancer causes more deaths than heart diseases and colorectal cancer is one of the most common cancers. However, surgical intervention and chemotherapy provide limited benefit in the recovery and survival of patients. The most important factors in not observing the expected treatment efficacy are the drug resistance that develops in patients and the need for targeted treatment that can reduce side effects and allow patient compliance. In order to contribute to the studies conducted to increase the efficacy of colorectal cancer treatment, in this thesis we investigated the exposure cytotoxic effects of SW480 and SW620 (colon adenocarcinoma cells) to genistein, anticancer drug 5-fluorouracil and TRAIL (Tumor Necrosis Factor-related apoptosis inducing ligand). Cytotoxicity was investigated by MTT method, genotoxic effects were investigated by Comet method. Also, reactive oxygen species (ROS), mitochondrial membrane potential and caspase 3-8-9 activities were investigated. The apoptotic effects were determined real time polymerase chain reaction (RT – PCR) method. It has been found that genistein, 5-fluorouracil and TRAIL had cytotoxic effects and caused increases in DNA damage in both cell lines. These substances showed synergistic apoptotic effects in combination and the increases in ROS and caspase 3-8-9 levels and decreases in mitochondrial membrane potential might be effective in apoptosis induction. In addition, TRAIL was found to induce Death receptor 5 (DR5) - mediated apoptosis in cell lines. In the double and triple combinations of the applied substances, there were decreases in Decoy receptor 1 (DcR1) and X-linked inhibitor of apoptosis protein (XIAP) antiapoptic gene expressions in both cell lines compared to the group in which TRAIL ligand was applied alone. Such effects may contribute to the studies that investigate TRAIL resistance problem.