Gastrin, acting via the cholecystokinin-2 receptor (CCK2R), activates its own promoter in a positive-feed-forward loop that may result in hypergastrinemia. Activity of the gastrin promoter is also stimulated by exogenous Zn ions. Here, the role of intracellular zinc and calcium signaling in the gastrin positive-feed-forward loop was investigated. Gastrin promoter activity was measured in the human gastric carcinoma cell line AGS-CCK2R and in Jurkat cells transfected with various gastrin promoter-luciferase constructs after treatment with gastrin in the presence and absence of zinc- and calcium-chelating agents. The free intracellular zinc ion concentrations were measured in the same cells with the fluorescent indicator FluoZin-3. Cell proliferation and migration/invasion were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide cell proliferation assay and in Boyden chamber assays, respectively. The zinc chelator N,N,N,N-tetrakis-(2-pyridylmethyl)-ethylenediamine (TPEN) abolished gastrin-stimulated gastrin promoter activity, and the inhibition was completely reversed by exogenous Zn ions. In contrast, the calcium chelator 1,2-Bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetrakis(acetoxymethyl ester) (BAPTA-AM) potentiated gastrin-stimulated gastrin promoter activity. Treatment with gastrin increased the intracellular concentration of free Zn ions, and the increase was blocked by TPEN, but not by BAPTA-AM. TPEN also inhibited the stimulation of cell proliferation and migration/invasion by gastrin, but BAPTA-AM had no effect. These results, which are the first report of the existence of Zn signaling downstream of CCK2R activation, suggest that zinc chelation therapies may be effective in counteracting gastrin-dependent tumor growth.
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http://dx.doi.org/10.1210/en.2016-1270 | DOI Listing |
Mol Ther
September 2023
Inflammation and Immune Mediated Diseases Laboratory of Anhui Province, The Key Laboratory of Anti-inflammatory of Immune Medicines, Ministry of Education, Anhui Institute of Innovative Drugs, School of Pharmacy, Anhui Medical University, Hefei 230032, China. Electronic address:
Gut Microbes
September 2022
Department of Gastroenterology, the First Affiliated Hospital of Nanjing Medical University, Nanjing China.
Intestinal metaplasia (IM) is the inevitable precancerous stage to develop intestinal-type gastric cancer (GC). Deoxycholic acid (DCA) is the main bile acid (BA) component of duodenogastric reflux and has shown an increased concentration during the transition from chronic gastritis to IM associated with continued STAT3 activation. However, the mechanisms underlying how DCA facilitates IM in the gastric epithelium need exploration.
View Article and Find Full Text PDFMol Metab
December 2021
Laboratory of Biochemistry, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, 060-0818, Japan. Electronic address:
Objective: The regulation of food intake is a major research area in the study of obesity, which plays a key role in the development of metabolic syndrome. Gene targeting studies have clarified the roles of hypothalamic neurons in feeding behavior, but the deletion of a gene has a long-term effect on neurophysiology. Our understanding of short-term changes such as appetite under physiological conditions is therefore still limited.
View Article and Find Full Text PDFAnal Chem
November 2021
State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, P. R. China.
This work designed a signal amplification strategy for construction of a highly sensitive electrochemiluminescence (ECL) biosensor by doping Cu in a terbium luminescent metal organic framework (Cu:Tb-MOF) to act as a co-reaction promoter, which enhanced the generation of SO radical during the cathodic process in the presence of KSO as a co-reactant. The porous and hollow morphology and the size of Cu:Tb-MOF could be efficiently tuned via changing the molar ratio of Cu and Tb and the reaction time, which were related to the specific surface area, pore diameter, and the ECL intensity of the MOF structure. To further improve the sensitivity of the ECL biosensor, HO was introduced into the ECL system to act as another co-reaction promoter, leading to a new ECL mechanism involving dual co-reaction promoters.
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