title: Rabeprazole exhibits antiproliferative effects on human gastric cancer cell lines.
abstract: Intracellular proton extrusion in gastric cancer cells has been reported to promote cancer cell survival under acidic conditions via hydrogen/potassium adenosine triphosphatase (H+/K+-ATPase). Rabeprazole is a frequently used second-generation proton pump inhibitor (PPI) that irreversibly inactivates gastric H+/K+-ATPase. Therefore, we hypothesized that rabeprazole could reduce the viability of gastric cancer cells. In the present study, four human gastric cancer cell lines and one non-cancer gastric cell line were cultured. Cell viability, the α- and β-subunits of H+/K+-ATPase and cellular apoptosis were analyzed by dye exclusion assay, reverse transcription-polymerase chain reaction and annexin V-fluorescein isothiocyanate/propidium iodide staining, respectively. The expression level of total extracellular signal-regulated protein kinase 1/2 (ERK 1/2) and phosphorylated-ERK protein was detected by western blot analysis. Gastric cancer cell lines were more tolerant of the acidic culture media than non-cancer cells. Administration of rabeprazole led to a marked decrease in the viability of MKN-28 cells. Exposure to rabeprazole induced significant apoptosis in AGS cells. Rabeprazole completely inhibited the phosphorylation of ERK 1/2 in the MKN-28 cells, whereas the same effect was not observed in either the KATO III or MKN-45 cells. The ERK 1/2 inhibitor, PD98059, attenuated the viability of the AGS cells. A similar antiproliferative effect was observed in the rabeprazole treatment group. In addition, PD98059 and rabeprazole were able to efficaciously inhibit the phosphorylation of ERK 1/2 in the gastric cancer cells. Therefore, it was concluded that rabeprazole can attenuate the cell viability of human gastric cancer cells through inactivation of the ERK1/2 signaling pathway. The results of the present study demonstrate that rabeprazole inhibits the viability of gastric cancer cellsin vitroand may serve as a novel antineoplastic agent.
authors.affiliation: Department of Gastroenterology, The First Affiliated Hospital of Medical College of Zhejiang University, Hangzhou, Zhejiang, P.R. China.
authors.forename: Mengli
authors.initials: M
authors.lastname: Gu
authors.affiliation: Department of Gastroenterology, The First Affiliated Hospital of Medical College of Zhejiang University, Hangzhou, Zhejiang, P.R. China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Gastroenterology, The First Affiliated Hospital of Medical College of Zhejiang University, Hangzhou, Zhejiang, P.R. China.
authors.forename: Xinxin
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Department of Gastroenterology, The First Affiliated Hospital of Medical College of Zhejiang University, Hangzhou, Zhejiang, P.R. China.
authors.forename: Han
authors.initials: H
authors.lastname: Ma
authors.affiliation: State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital of Medical College of Zhejiang University, Hangzhou, Zhejiang, P.R. China.
authors.forename: Hangping
authors.initials: H
authors.lastname: Yao
authors.affiliation: Department of Gastroenterology, The First Affiliated Hospital of Medical College of Zhejiang University, Hangzhou, Zhejiang, P.R. China.
authors.forename: Feng
authors.initials: F
authors.lastname: Ji
keywords: antineoplastic therapy; extracellular signal-regulated protein kinase 1/2; gastric cancer; proton pump inhibitors; rabeprazole