title: Hypermethylation of multiple tumor-related genes associated with DNMT3b up-regulation served as a biomarker for early diagnosis of esophageal squamous cell carcinoma.
abstract: This study was designed to determine the significance of DNA methyltransferases (DNMTs) in DNA hypermethylation in esophageal squamous cell carcinoma (ESCC) and to identify DNA methylation markers in serum for the early diagnosis of ESCC. A promoter methylation profile of 12 tumor-related genes was assessed using methylation-specific PCR in ESCC and paired non-tumor tissue samples from 47 patients. Expression levels of DNMTs were examined by real-time reverse transcription-PCR and immunohistochemistry. Using MethyLight, the methylation status of 5 genes was analyzed in serum samples from 45 patients and 15 healthy individuals. A total of 46 (97.9%) of 47 ESCC samples showed methylation in at least one of the examined genes, and methylation was most frequent for RAR-β (46.8%), DAPK (46.8%), p16 (44.7%), and CDH1 (42.6%). Methylation of RASSF1A was significantly correlated with the poorly differentiated tumors and the early pathologic tumor classification (P=0.035 and P=0.046, respectively). Tumoral DNMT3b mRNA up-regulation was significantly correlated with hypermethylation of multiple tumor-related genes (P=0.021). In addition, hypermethylation of cell-free serum DNA was common in ESCC patients, and diagnostic accuracy was increased when methylation of multiple genes (RAR-β, DAPK, CDH1, p16 and RASSF1A) were analyzed in combination (ROC AUC 0.911, 82.2% sensitivity and 100% specificity). The present study suggests that hypermethylation of multiple tumor-related genes may be involved in the pathogenesis of ESCC and mediated by the increase of DNMT3b expression. A cluster of multiple methylated genes in serum DNA has the potential as a novel biomarker for ESCC diagnosis.
authors.affiliation: National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Li
authors.forename: Bing
authors.initials: B
authors.lastname: Wang
authors.forename: Li-Juan
authors.initials: LJ
authors.lastname: Niu
authors.forename: Lei
authors.initials: L
authors.lastname: Jiang
authors.forename: Chang-Chun
authors.initials: CC
authors.lastname: Qiu
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000235:genetics* / Q000378:metabolism; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000235:genetics; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000235:genetics / Q000378:metabolism*; D019175:DNA Methylation; D004938:Esophageal Neoplasms / Q000175:diagnosis* / Q000235:genetics; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015854:Up-Regulation; D000097584:DNA Methyltransferase 3B
chemical_list: D014408:Biomarkers, Tumor; D004248:DNA (Cytosine-5-)-Methyltransferases; D000097584:DNA Methyltransferase 3B