Methylation Status Of The Cx32 Gene Promoter And Its Impact On Protein Expression In Colon Carcinoma Cell Line HT-29

Purpose: This study examined whether the promoter of Cx32 gene in HT-29 cell line-a colon carcinoma cell line-was methylated and the relationship between the demethylation of Cx32 gene and the Cx32 expression, and also investigated the possible role of Cx32 in the development of colon cancer.Methods: Methylation-Specific Polymerase Chain Reaction (MSP) was used to test whether the promoter of Cx32 gene in HT-29 cell line was methylated. Then the expression of Cx32 both before and after demethylation was examined by immunohistochemistry.Results: 1. The promoter of Cx32 gene in HT-29 cell line was hyper-methylated. Thus no Cx32 was expressed. 2. After exposed to 5-Aza-CdR, the Cx32 gene in the HT-29 cell line was demethylated, therefore, Cx32 was re-expressed and the growth of HT-29 cells was restrained.Conclusions: 1. Hyper-methylation of Cx32 gene promoter may be relavant to the unexpression of Cx32, and re-expression of Cx32 gene may have the effect of tumor suppression. 2. 5-Aza-CdR can effectively de-methylate the hypermethylated Cx32 gene promoter, therefore, activate the gene expression, and suppress the growth of tumor cells, which provides us a new way to treat colon cancer.