Down-regulation of EphA7 by aberrant methylation in colorectal cancer / 医学研究生学报

ABSTRACT

Objective:Ephs have been found to be over-expressed in numerous human tumors,and relate to the development and prognosis of cancers.The expression of EphA7 in colon cancer cell lines and primary colorectal cancers was detected.The role of EphA7 in the development of colorectal cancer was investigated. Methods:Quantitative reverse transcription-polymerase chain reaction was used to detect the expression of EphA7.Methylation specific PCR and bisulfite sequencing were used to examine the methylation status of EphA7.pEGFP-EphA7 plasmid was constructed and was transfected into HCT116 which lost the expression of EphA7.Gene chip was analyzed for the expression of genes between transfectant and mock cell. Results:Down-regulation of EphA7 was observed in cell lines of primary colorectal cancers,and the evidence of aberrant methylation was found in CpG island of EphA7 promoter.The methylation status of EphA7 gene was related to sex,differentiation and location of colorectal cancers.Some genes were up or down regulated in pEGFP-EphA7 transfectant. Conclusion: EphA7 gene may be involved in the carcinogenesis of colorectal cancer.The hypermethylation of CpG island is an important mechanism leading to the down regulation of EphA7 in colorectal cancer.