Figure 1.

Methylation and expression profiles of CDO1 in pancreatic ductal adenocarcinoma (PDAC) cell lines. A, CDO1 mRNA expression was assessed by RT‐PCR. The positive control for RT‐PCR was the HepG2 cell line, and the negative control was the DLD1 cell line. CDO1 mRNA expression was not detected in any of the PDAC cell lines. B, Promoter DNA methylation of CDO1 was quantified by quantitative methylation‐specific PCR (Q‐MSP) (mean ± SD). The positive control for Q‐MSP was the DLD1 cell line, and the negative control was the HepG2 cell line. In all PDAC cell lines, CDO1 promoter DNA was hypermethylated. C, CDO1 mRNA expression after treatment with the demethylating agents, 5‐aza‐2′‐deoxycytidine (5‐Aza‐dC, 1 or 5 μmol/L) in the presence or absence of trichostatin A (TSA), a histone deacetylase inhibitor, by RT‐PCR. It was confirmed that CDO1 expression was regulated by epigenetics. AUC, area under the receiver operating characteristic curve