Daoyot DaorueangPeti ThuwajitSittiruk RoitrakulThewarach LahaSasithorn KaewkesYaeta EndoChanitra ThuwajitKhon Kaen UniversityThailand National Center for Genetic Engineering and BiotechnologyEhime UniversityMahidol University2018-06-112018-06-112012-03-01Parasitology International. Vol.61, No.1 (2012), 155-16118730329138357692-s2.0-82655181919https://repository.li.mahidol.ac.th/handle/20.500.14594/14354Opisthorchis viverrini can develop mitogenic substances into the excretory/secretory product (ESP) that may play an important role in promoting the genesis of cholangiocarcinoma (CCA). In the present study, glutathione S-transferase (GST) is identified as being secreted into Ov-ESP and acting as one of the parasitic mitogens. Its proliferative effect and possible mechanism were explored and its association with the tumor development is proposed. Ov-ESP was concentrated and purified by gel filtration chromatography. SDS-PAGE, 2-DE, and LC-MS/MS identified GST predominantly expressed in the proliferative ESP fraction. The recombinant OvGST (r. OvGST) was produced by wheat germ cell-free expression and confirmed by an MTS assay to have a proliferative function on NIH-3T3 murine fibroblasts and MMNK1 non-tumorigenic human bile duct epithelial cells in a dose dependent manner with different optimal doses. The cell surface binding of r. OvGST was confirmed in vitro and the activation of both pAKT and pERK was revealed as the mechanism of OvGST-mediated cell proliferation. With support from the observation of secreted OvGST on the biliary cells surrounding the parasites, it is suggested that OvGST can promote cell proliferation that consequently may accelerate the genesis of CCA. © 2011 Elsevier Ireland Ltd.Mahidol UniversityImmunology and MicrobiologyMedicineArticleSCOPUS10.1016/j.parint.2011.07.011