No difference in the gene methylation status of
tumor-suppression genes between
pancreatic cancer tissues and adjacent non-
cancer tissues is observed. The present study investigated whether the promoter CpG islands of the
cysteine dioxygenase 1 (CDO1),
tachykinin precursor 1 (TAC1) and checkpoint with forkhead and ring finger domains (CHFR) genes were methylated in
pancreatic cancer and adjacent non-cancerous pancreatic tissue in order to determine if they could be considered as markers for the detection of
pancreatic cancer. A total of 38
Formalin-fixed and
paraffin-embedded pancreatic
adenocarcinoma tissues and their adjacent non-cancerous specimens from patients with
pancreatic cancer, as well as 9 non-cancerous pancreatic samples from patients without pancreatic
adenocarcinoma were obtained following surgical resection. The hypermethylation of CpG islands was detected using a methylation-specific quantitative PCR. The methylation values were calculated using the ∆Cq method and were expressed as 2-ΔCq. The 2-ΔCq value of the CDO1 promoter from pancreatic
adenocarcinoma specimens was significantly higher compared with that of adjacent non-cancerous and
tumor-free pancreatic tissues (P<0.0001 and P=0.0008, respectively). The 2-ΔCq value of the TAC1 promoter of pancreatic
adenocarcinoma was also significantly higher compared with that of adjacent non-cancerous tissues and
tumor-free pancreatic samples (both P<0.0001). However, there was no significant difference in the 2-ΔCq value of the CHFR promoter among the
pancreatic cancer, adjacent non-
cancer tissue and
tumor-free pancreatic samples. Furthermore, 12 out of the 38 pancreatic
adenocarcinoma cases (31.6%) presented some methylation in the CHFR promoter. The results from Kaplan-Meier analysis between CHFR promoter methylation values and the clinicopathological characteristics of patients with pancreatic
adenocarcinoma demonstrated that CHFR promoter methylation was significantly associated with
lymph node metastasis. The methylation values of CDO1 and TAC1 promoters in
cancer tissues were higher compared with adjacent tissues. However, whether hypermethylation of CDO1 and TAC1 promoters may serve as a
biomarker in the diagnosis of pancreatic
adenocarcinoma remains unclear.