Comparison of caffeic and chlorogenic acids effects on methylation, cytotoxicity, genotoxicity and gene expression on human cells Jurkat, HL-60 and JMA exposed to 5-azacytidine demethylating agent

Abstract

The influence of dietary bioactive compounds in genome has been evidenced in recent years, focusing on the important role of these compounds on epigenetic modulation. The combination between dietary compounds and drugs used in cancer therapy represents a promising alternative in order to increase treatment effectiveness and to minimize side effects. DNA demethylating agents have been used in leukemia treatment, and they act modifying the DNA methylation pattern. This mechanism promotes the expression of silenced genes, as tumor suppressor genes, and this approach is already demonstrated in several studies with leukemic cell lines. The hypothesis of this project is that drugs that epigenetically modulate DNA, such as 5-azacytidine, could provide a greater effectiveness and reduction of side effects in combination with dietary bioactive compounds. Then, chlorogenic and caffeic acids may represent a promising possibility, since these phenolic compounds are present in many foods of the human diet. Moreover, the inhibition of cell growth in tumor cell lines and the protective effects in normal cell lines may improve the effectiveness of DNA demethylating agents used in cancer treatment. Therefore, this study aims to assess the influence of caffeic and chlorogenic acids exposed or not to the demethylating agent 5-azacytidine on methylation in the promoter regions of tumor suppressor genes CDKN2 and CDH13 in leukemic cell lines HL-60 and Jurkat and in cell line JMA, derived from human bone marrow fibroblasts. Additionally, it will be performed cytotoxicity assays, genotoxicity assessment by the comet assay and by analysis of Cytome and apoptosis detection by flow cytometry. Besides, in order to evaluate the influence of these nutrients in the transcription of tumor suppressor genes, messenger RNA expression of CDKN2 and CDH13 genes will be analyzed by real-time PCR.