Methylation status of Runx3 gene promoter in colorectal cancer and tubular adenoma

Purpose To investigate the expression and methylation status of the Runx3 gene in the colorectal carcinoma and tubular adenoma,to verify the function and clinical significance of the Runx3 gene in the pathway of adenoma to adenocarcinoma,and to analyze the levels of methylation of Runx3 in different age groups. Methods TaqMan probe qPCR( MethyLight) was used to detect the methylation status of CpG island of Runx3 gene,and sequencing strategy to validate sequencing of amplified,and immunohistochemical staining to test the protein expression of Runx3 gene in 40 cases of tubular adenoma,50 cases of colorectal cancer,and 20 cases of normal colorectal mucosa tissues. Results The methylation rates of Runx3 gene promoter were 84%,45%,and 10%( P 0. 05),and the protein expression rates of Runx3 gene were 18%,45%,and 80%( P 0. 05) in the groups of colorectal carcinoma,tubular adenoma and normal tissues,respectively. A significant inverse correlation was found between the methylation rate of Runx3 gene and the protein expression rate of Runx3 gene in the three groups( Pearson's correlation coefficients: r =- 0. 667,r =- 0. 616,r =- 0. 790,respectively,all P 0. 05). A significantly positive correlation was found between the methylation rate of Runx3 gene and age in the groups of tubular adenoma and colorectal carcinoma( Pearson's correlation coefficients: r = 0. 376,r = 0. 304,respectively,both P 0. 05). Conclusion The methylation of Runx3 gene may result in decreased protein expression,which plays an important role in the pathway of adenoma to adenocarcinoma. And the methylation of Runx3 gene may correlate with ages: along with aging,the methylation level increases.