Discrimination Effectiveness of CK18 on Cell Death Modes in Colon Cancer Cells

Objectives: Cytokeratin-18 is an intermediate filament that could be a candidate cell death marker in monitoring chemotherapy efficiency. The aim of this study was to evaluate cell death determination effectiveness of CK18 ELISA assay in HCT-116 colon cancer cells treated with clinical compatible dosages of FOLFIRI chemotherapy combination. Methods: Cytotoxicity of different FOLFIRI combinations was evaluated with MTT assay in HCT-116 cells. Apoptotic and non apoptotic cell deaths were evaluated with M30 and M65 CK18 ELISA assays. Flow cytometric Annexin V assay was used to verify apoptotic /non-apoptotic cell death ratios found with CK18 ELISA assays. Results: FOLFIRI (15/1) treatments significantly increased apoptotic M30 levels at 24 and 48 hr (p 0.05) but did not cause any change at 72 hr (p > 0.05). While low levels of M65 were found at 24 and 48 hr (p > 0.05), high levels of M65 were detected at 72 hr (p > 0.05). CK-18 and Annexin V results were correlated with each other. Conclusion: It was demonstrated for the first time that CK 18 ELISA assay has the capacity to determine apoptotic and non apoptotic cell death in colon cancer cells caused by FOLFIRI treatment in a time dependent manner. We concluded that CK18 measurement may be useful for assessment of chemotherapy efficiency in an earlier time as a therapy monitoring marker in colon cancer cells.