Transcription profiling by array of 5-Aza-2’-deoxycytidine treated gastric cancer cell lines

DNA methylation is a key contributor to normal mammalian development, although, abnormal CpG islands methylation has been described to have a role in carcinogenesis. In gastric cancer, it is observed a global hypomethylation within the bulk genome and local hypermethylation at specific tumor suppressor genes. Conversely, the absence of DNA methylation may be an important step in stable transcriptional activation of oncogenes, contributing to tumor development. The screening of genes modulated by DNA methylation in gastric cancer may contribute to the identification of tumor suppressor genes and/or oncogenes modulated by DNA methylation never described in this neoplasia. In this experiment we aimed to identify differentially expressed genes by comparing 5-Aza-2’-deoxycytidine (5-AZAdC)-treated and non-treated gastric cancer cell lines. 5-AZAdC is a demethylation agent and has received FDA approval for the treatment of myelodysplastic syndromes. This drug has also showed capacity to treat solid tumors with low dose. The ACP02 and ACP03 gastric cancer cell lines used in this experiment were previously established by our research group from primary gastric adenocarcinomas classified as diffuse and intestinal types, respectively. Both cell lines present chromosome 8 trisomy, MYC amplification, and TP53 loss of copy. Moreover, ACP03 is able to start a tumorigenesis process in Cebus apellas.