title: Galectin 3 acts as an enhancer of survival responses in H. pylori-infected gastric cancer cells.
abstract: Galectin 3 (Gal-3) is upregulated in gastric epithelial cells as a host response to Helicobacter pylori infection. However, the significance of Gal-3 expression in H. pylori-infected cells is not well established. We analyzed Gal-3 intracellular expression, localization, and its effects in H. pylori-infected gastric epithelial cells. The predominantly nuclear confined Gal-3 was shown to be upregulated and exported out to the cytoplasm in H. pylori-infected AGS cells. The nuclear export was channeled through CRM-1 (exportin-1) protein. Interestingly, knock down of Gal-3 expression led to reduced NF-κB promoter activity and interleukin-8 (IL-8) secretion, suggesting its pro-inflammatory roles. Furthermore, Gal-3 was found to be pro-proliferative and anti-apoptotic in nature, as its knock down caused a reduction in cell proliferation and an increase in apoptosis, respectively. Taken together, our data suggest the expression and upregulation of Gal-3 as a critical endogenous event in H. pylori infection that interferes with various intracellular events, causing prolonged cell survival, which is characteristic in carcinogenesis.
authors.affiliation: Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.|Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore.
authors.forename: Vinod Vijay
authors.initials: VV
authors.lastname: Subhash
authors.affiliation: Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore. bow_ho@nuhs.edu.sg.
authors.forename: Bow
authors.initials: B
authors.lastname: Ho
mesh_terms: D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000502:physiology; D004847:Epithelial Cells / Q000378:metabolism / Q000382:microbiology; D037502:Galectin 3 / Q000096:biosynthesis*; D005753:Gastric Mucosa / Q000378:metabolism / Q000382:microbiology / Q000473:pathology; D016481:Helicobacter Infections / Q000378:metabolism* / Q000473:pathology; D016480:Helicobacter pylori / Q000378:metabolism*; D006801:Humans; D016209:Interleukin-8 / Q000378:metabolism; D028884:Karyopherins / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D021381:Protein Transport; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D015398:Signal Transduction; D013274:Stomach Neoplasms / Q000378:metabolism* / Q000382:microbiology* / Q000473:pathology; D015854:Up-Regulation; D000097606:Exportin 1 Protein
chemical_list: D051017:Apoptosis Regulatory Proteins; D037502:Galectin 3; D016209:Interleukin-8; D028884:Karyopherins; D016328:NF-kappa B; D018160:Receptors, Cytoplasmic and Nuclear; D000097606:Exportin 1 Protein
keywords: Galectin 3; H. pylori; Host response; Inflammation; Proliferation