Among CpG loci with the largest difference in methylation between right- and left-colon adenomas, probes associated with PRAC (prostate cancer susceptibility candidate) gene showed hypermethylation in right-colon adenomas whereas those associated with CDX2 (caudal type homeobox transcription factor 2) showed hypermethylation in left-colon adenomas.
Loss of epithelial markers, (CK20, CDX2 and E-cadherin) and intense vimentin expression was observed in RCTs but neither in the normal mucosa or adenomas.
CDX2 has been considered to play a role as a tumor suppressor gene in colorectal cancer because its expression is lacking in colorectal carcinomas, but preserved in adenomas.
The expression levels of CDX2 mRNA was significantly lower in the CRC group in comparison to HP/adenoma and control groups, P<0.05, and showed a further decrease with a higher degree of TNM staging.