Analysis of APC and IGFBP7 promoter gene methylation in Swedish and Vietnamese colorectal cancer patients

Gene promoter methylation in colorectal cancer and healthy adjacent mucosa specimens

“…19 Present results are in agreement with recent reports in Swedish and Vietnamese CRC patients, where methylation of the APC gene was detected with similar frequencies between the cancerous and normal tissues. 19 We also observed that APC methylation in normal colonic mucosa increased significantly with age. This is in agreement with some previous reports of an age-related methylation of tumor suppressor genes in normal colorectal mucosa, that might represent physiological changes and/or constitute pre-neoplastic lesions.…”

“…16 APC hypermethylation is also frequent in sporadic CRC and may cause transcriptional silencing occurring early during colon neoplasia progression, but the reported methylation status of the APC promoter varies greatly among studies performed in different populations. [16][17][18][19] Moreover, hypermethylation of the APC promoter has been shown to be relatively common in the normal colonic mucosa. 19 Present results are in agreement with recent reports in Swedish and Vietnamese CRC patients, where methylation of the APC gene was detected with similar frequencies between the cancerous and normal tissues.…”

“…[16][17][18][19] Moreover, hypermethylation of the APC promoter has been shown to be relatively common in the normal colonic mucosa. 19 Present results are in agreement with recent reports in Swedish and Vietnamese CRC patients, where methylation of the APC gene was detected with similar frequencies between the cancerous and normal tissues. 19 We also observed that APC methylation in normal colonic mucosa increased significantly with age.…”

Application of Artificial Neural Networks to Link Genetic and Environmental Factors to DNA Methylation in Colorectal Cancer

“…Previous literature reports showed that APC mutations and promoter hypermethylation tend to be more frequent in distal colon cancers, and less frequent in those CRCs showing MSI [35]. Indeed, with the exception of CIMP high CRCs, most of the sporadic CRCs show low or absence of CIMP, and are believed to progress following the adenoma-carcinoma pathway, with APC mutation or epigenetic silencing being one of the earliest events [7,8]. Consistently, APC hypomethylation is clustered in the central pathway characterized by hypomethylation of the other four genes and the MTR 2756AA genotype (Figure 3), and hypermethylation was linked to a cluster of variables characterized by advanced age (>70 years), certain polymorphisms of genes of the folate pathway, including the MTRR 66GG genotype and DNMT3B heterozygous genotypes, but also by MGMT hypermethylation, adenoma stage and other polymorphisms (Figure 2).…”

“…Among epigenetic mechanisms, DNA methylation has gained particular interest in cancer studies because it was linked to the silencing of tumor suppressor genes and DNA repair genes [3]. Several genes are frequently hypermethylated in sporadic CRC, including MLH1, APC, CDKN2A, MGMT and RASSF1A [4][5][6][7][8][9][10][11][12][13][14].…”