CpG island methylation as an early event during adenoma progression in carcinogenesis of sporadic colorectal cancer.

摘要: Background and Aims:  CpG island methylation is present in various tumors, including colorectal carcinomas, thought to be an important mechanism carcinogenesis. We evaluated the status of primary tumors determine its role adenoma carcinoma sequence. Methods:  The APC, THBS1, MGMT, hMLH1 GSTP1, as determined by specific PCR (MSP), microsatellite instability (MSI) using three mononucleotide markers were assessed 40 adenomas 36 adenocarcinomas. correlations MSI with clinicopathologic parameters determined. Results:  Of adenomas, 24 (60%) methylated at one or more loci, 12 (30%) two loci (CpG phenotype-high, CIMP-H). 27 (75%) 11 (30.5%) (CIMP-H). THBSI was most frequently locus both (n = 19, 47.5%) carcinomas (n = 16, 44.4%). Overall, did not differ significantly (P = 0.53), nor individual genes. For size (P = 0.049) histologic classification villous components (P = 0.018) each associated status. however, no variable related detected (7.5%) five (13.9%), closely correlated (P < 0.001). Conclusions:  In tumor suppressor genes appears common may involved progression adenomas. © 2005 Blackwell Publishing Asia Pty Ltd