title: Investigating the role of introns in the regulation of regenerating gene 1 expression.
abstract: Gastrin is a hormone that physiologically regulates gastric acid secretion and contributes to the maintenance of gastric epithelial architecture by regulating the expression of genes such as regenerating gene 1 (Reg1). Reg1 is involved in gastric carcinogenesis as an antiapoptotic factor. The current study explores the molecular mechanism of gastrin-regulatedReg1expression in human gastric cancer cells. In total, five intron fragments of theReg1gene were cloned by polymerase chain reaction and inserted into luciferase reporter vector pGL3 to construct intron-luciferase reporter vectors. After confirmation by Xho I/Hind III digestion and DNA sequencing, the five constructs were transfected into the SGC7901 gastric cancer cell line. The luciferase activity of the cells transfected with each of the five constructs was detected following incubation without or with gastrin. The five intron fragments ofReg1were also randomly labeled with digoxin as a probe, and nuclear proteins of gastric cancer cells were extracted following treatment with or without gastrin. Southwestern blotting was subsequently performed to detect transcription factors that bind to the introns. The results indicated that the luciferase activity was significantly higher in cells transfected with recombinant vectors containing introns 2, 3, 4 or 5 than that in the cells transfected with an empty vector (P<0.05). However, no statistically significant difference in luciferase activity was identified between cells transfected with pGL3-intron 1 and those transfected with pGL3-Basic (P>0.05). Following incubation with gastrin, no significant difference was identified (P>0.05). The five introns ofReg1can bind a number of transcription factors and gastrin may affect this interaction. Introns 2-5 ofReg1potentially have transcriptional control over gene expression in gastric cancer cells. In conclusion, gastrin may regulate the expression of theReg1gene via the interaction of the introns by binding to the transcription factors.
authors.affiliation: Department of Histology and Embryology, College of Basic Medicine, Zhengzhou University, Zhengzhou, Henan 450001, P.R. China.
authors.forename: Yurong
authors.initials: Y
authors.lastname: Chai
authors.affiliation: Department of Histology and Embryology, College of Basic Medicine, Zhengzhou University, Zhengzhou, Henan 450001, P.R. China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Department of Histology and Embryology, College of Basic Medicine, Zhengzhou University, Zhengzhou, Henan 450001, P.R. China.
authors.forename: Linxia
authors.initials: L
authors.lastname: Guo
authors.affiliation: Department of Histology and Embryology, College of Basic Medicine, Zhengzhou University, Zhengzhou, Henan 450001, P.R. China.
authors.forename: Dan
authors.initials: D
authors.lastname: Li
authors.affiliation: Department of Histology and Embryology, College of Basic Medicine, Zhengzhou University, Zhengzhou, Henan 450001, P.R. China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Ding
keywords: gastrin; human gastric cancer; intron; regenerating gene 1; transcription factors