title: DNA polymerase β promoter mutations and transcriptional activity in esophageal squamous cell carcinoma.
abstract: The present study analyzed the correlation of DNA polymerase β (DNA polβ) promoter mutations and activity in esophageal squamous cell carcinoma (ESCC). The DNA polβ promoter was amplified from 108 ESCC samples and adjacent paracancerous samples by PCR and cloned into the pGL3-enhancer luciferase vector. The recombined vectors were transfected into esophageal carcinoma cells (EC9706, Eca109, and KYSE30), and luciferase activity was detected using dual luciferase reporter gene technology. Eleven polβ promoter mutations were identified and submitted to GenBank. The mutation rate of the DNA polβ promoter was higher in ESCC tissues (36/108, 33.3 %) than in the paired paracancerous tissues (21/108, 19.4 %) (P = 0.021). The C → A mutation at locus -37 was the hotspot mutation in cancerous tissues, and its frequency was higher in ESCC tissues (26/108) than in paracancerous tissues (7/108) (P = 0.00). The highest relative luciferase activity (RLA) was observed in the DNA polβ promoter, with a C → A mutation at -37. Significant differences in RLA were observed between mutant DNA polβ promoters (except for C detected at -19, T → C at -194, C → A at -37, and T → C at 30) and the wild-type DNA polβ promoter (P = 0.000), and RLA was significantly higher in ESCC tissues than in paracancerous tissues (P = 0.003). Our findings suggest that the upregulation of transcriptional activity induced by mutations in the DNA polβ promoter in ESCC tissues may be one of the molecular mechanisms mediating abnormal overexpression of DNA polβ in ESCC.
authors.affiliation: College of Basic Medical Sciences, Zhengzhou University, No. 100, Kexue Road, Zhengzhou, 450001, China.
authors.forename: Min
authors.initials: M
authors.lastname: Li
authors.forename: Wenqiao
authors.initials: W
authors.lastname: Zang
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Wang
authors.forename: Yuebai
authors.initials: Y
authors.lastname: Li
authors.forename: Yunyun
authors.initials: Y
authors.lastname: Ma
authors.forename: Na
authors.initials: N
authors.lastname: Wang
authors.forename: Yue
authors.initials: Y
authors.lastname: Tang
authors.forename: Lulu
authors.initials: L
authors.lastname: Liu
authors.forename: Ziming
authors.initials: Z
authors.lastname: Dong
authors.forename: Guoqiang
authors.initials: G
authors.lastname: Zhao
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000201:enzymology / Q000235:genetics*; D045744:Cell Line, Tumor; D019951:DNA Polymerase beta / Q000235:genetics* / Q000378:metabolism; D004938:Esophageal Neoplasms / Q000201:enzymology / Q000235:genetics*; D000077277:Esophageal Squamous Cell Carcinoma; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D017930:Genes, Reporter; D006801:Humans; D049410:Luciferases, Renilla / Q000096:biosynthesis / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation; D011401:Promoter Regions, Genetic; D017422:Sequence Analysis, DNA; D014158:Transcription, Genetic
chemical_list: D049410:Luciferases, Renilla; D019951:DNA Polymerase beta