Dataset Information

PBX1 attributes as a determinant of connexin 32 downregulation in Helicobacter pylori-related gastric carcinogenesis.

ABSTRACT: To clarify the mechanisms of connexin 32 (Cx32) downregulation by potential transcriptional factors (TFs) in Helicobacter pylori (H. pylori)-associated gastric carcinogenesis.Approximately 25 specimens at each developmental stage of gastric carcinogenesis [non-atrophic gastritis, chronic atrophic gastritis, intestinal metaplasia, dysplasia and gastric carcinoma (GC)] with H. pylori infection [H. pylori (+)] and 25 normal gastric mucosa (NGM) without H. pylori infection [H. pylori (-)] were collected. After transcriptional factor array analysis, the Cx32 and PBX1 expression levels of H. pylori-infected tissues from the developmental stages of GC and NGM with no H. pylori infection were measured by real-time polymerase chain reaction (RT-PCR) and Western blot analysis. Regarding H. pylori-infected animal models, the Cx32 and PBX1 mRNA expression levels and correlation between the gastric mucosa from 10 Mongolian gerbils with long-term H. pylori colonization and 10 controls were analyzed. PBX1 and Cx32 mRNA and protein levels were further studied under the H. pylori-infected condition as well as PBX1 overexpression and knockdown conditions in vitro.Incremental PBX1 was first detected by TF microarray in H. pylori-related gastric carcinogenesis. The identical trend of PBX1 and Cx32 expression was confirmed in the developmental stages of H. pylori-related clinical specimens. The negative correlation of PBX1 and Cx32 was confirmed in H. pylori-infected Mongolian gerbils. Furthermore, decreased PBX1 expression was detected in the normal gastric epithelial cell line GES-1 with H. pylori infection. Enforced overexpression or RNAi-mediated knockdown of PBX1 contributed to the diminished or restored Cx32 expression in GES-1 and the gastric carcinoma cell line BGC823, respectively. Finally, dual-luciferase reporter assay in HEK293T cells showed that Cx32 promoter activity decreased by 30% after PBX1 vector co-transfection, indicating PBX1 as a transcriptional downregulator of Cx32 by directly binding to its promoters.PBX1 is one of the determinants in the Cx32 promoter targeting site, preventing further damage of gap junction protein in H. pylori-associated gastric carcinogenesis.

SUBMITTER: Liu XM

PROVIDER: S-EPMC5550783 | biostudies-other | 2017 Aug

REPOSITORIES: biostudies-other

ACCESS DATA

Similar Datasets

Project description:BACKGROUND & AIMS: Gastric cancer results from a combination of Helicobacter pylori (H pylori) infection, exposure to dietary carcinogens, and predisposing genetic make-up. Because the role of these factors in gastric carcinogenesis cannot be determined readily in human beings, the present study examined the role of an oral carcinogen and H pylori infection in rhesus monkeys. METHODS: Gastroscopies were performed in 23 monkeys assigned to 4 groups: controls; nitrosating carcinogen ethyl-nitro-nitrosoguanidine administration alone; and inoculation of a virulent H pylori strain alone (H), or in combination with ethyl-nitro-nitrosoguanidine (EH). Follow-up gastroscopies and biopsies were performed at 3-month intervals for 5 years for pathologic and molecular studies. RESULTS: Postinoculation, H and EH groups showed persistent infection and antral gastritis. Starting at 2 and 5 years, respectively, gastric intestinal metaplasia and intraepithelial neoplasia developed in 3 EH monkeys but in no other groups. Transcriptional analysis of biopsies at 5 years revealed group-specific expression profiles, with striking changes in EH monkeys, plus a neoplasia-specific expression profile characterized by changes in multiple cancer-associated genes. Importantly, this neoplastic profile was evident in nonneoplastic mucosa, suggesting that the identified genes may represent markers preceding cancer. CONCLUSIONS: Gastric intraglandular neoplasia is induced in primates when H pylori infection is associated with consumption of a carcinogen similar to the nitrosaminesfound in pickled vegetables, suggesting that H pylori and the carcinogen synergistically induce gastric neoplasia in primates. Monkey arrays used for analysis of the affect of Helicobacter pylori and diet on development of gastric cancer. Each RNA was hybridized against a common reference. Biopsy numbers represent the following in terms of descriptions used in publication of the paper... Each set of numbers/descriptions is organized in the following order: Biopsy#; Monkey#; Group Code on Fig 5 Biopsy #4674; AB24; E; E1 Biopsy #4684; 16G; E; E2 Biopsy #4716; 89G; H; H1 Biopsy #4724; 54H; H; H2 Biopsy #4720; 20G; H; H3 Biopsy #4710; 92F; C; C1 Biopsy #4714; 26G; C; C2 Biopsy #4712; 92G; C; C3 Biopsy #4726; 08G; H; H4 Biopsy #4722; 57G; H; H5 Biopsy #4718; 85G; H; H6 Biopsy #4694; 48H; HE NON; HE1 Biopsy #4686; 59H; HE NON; HE2 Biopsy #4690; 81G; HE NEO; HE3 Biopsy #4696; 36G; HE NEO; HE4 Biopsy #4692; 63G; HE NEO; HE5 Biopsy #4680; 76G; E; E3 Biopsy #4682; 52G; E; E4 Biopsy #4678; 15G; E; E5 Biopsy #4676; 93G; E; E6 Biopsy #4688; 47H; HE NON; HE6 A pathogenicity experiment design type is where an infective agent such as a bacterium, virus, protozoan, fungus etc. infects a host organism(s) and the infective agent is assayed. Infection: Rhesus monkeys were infected with H. pylori (+/-) Compound Based Treatment: Rhesus monkeys were treated with ENNG (N-ethyl-N-nitrosoguanidine) (+/-)

Dataset Information

PBX1 attributes as a determinant of connexin 32 downregulation in Helicobacter pylori-related gastric carcinogenesis.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure