Tu1289 - Induction of Cellular Plasticity Through the Regulation of Casein Kinase 2 in Gastric Cancer Cells

the low-gastric-cancer-risk (LGCR) region of Tumaco, Colombia, and the high-gastric-cancerrisk (HGCR) region of Pasto, Colombia.Multiple OTUs were detected exclusively in either LGCR or HGCR regions.In this study, a population of 37 patients (19 from HGCR, 18 from LGCR) consisting of 17 male (average age 50) and 20 females (average age 49) were recruited for gastric endoscopy.Antral biopsies were processed for microbiome analysis and bacterial isolation.Sixty-six distinct species of 26 genera were isolated by culture and confirmed by 16S rRNA analysis.Staphylococci species were isolated from 15 biopsies and Streptococci species were cultured from 21 biopsies.Staphylococcus epidermidis were found significantly more often in the low risk region of Tumaco.We asked whether coinfection of urease positive Streptococcus salivarius and S. epidermidis, when coinfected with H. pylori, had a demonstrable effect on H. pylori-induced gastritis in the INS-GAS mouse model.The strains consisted of H. pylori SS1, S. salivarius (14-1770-C1; HGCR region), and S. epidermidis (14-1777-C6; LGCR region).The study design used germfree (GF) 7-8 week-old, INS-GAS mice in the following groups: control (10M, 6F), H. pylori /S.salivarius (11M, 9F), H. pylori/ S. epidermidis (9M, 12F), and H. pylori (10M, 10F).S. salivarius and S. epidermidis were dosed one week after H. pylori dosing.Coinfections of S. salivarius and S. epidermidis did not affect gastric H. pylori colonization.The GF INS-GAS mice co-infected with H. pylori and S. salivarius had statistically higher inflammation, hyperplasia, and dysplasia scores in the stomachs when compared with H. pylori only and H. pylori/S.epidermidis groups at 5 months post infection (p<0.05).S. epidermidis co-infection with H. pylori did not change stomach pathology significantly, but pro-inflammatory cytokines IL1 b and IL22 levels were significantly lower than these cytokines in H. pylori only group.Sera IgG2a antibody (proinflammatory isotype) to H. pylori was significantly lower in H. pylori/S.epidermidis mice when compared to H. pylori only mice (p<0.02).IgG1 antibody (anti-inflammatory isotype) was suppressed in H. pylori /S.salivarius mice (p<0.0001) to greater extent than in H. pylori/ S. epidermidis mice (p<0.008).This study reinforces the argument that non-H.pylori bacteria play a role in the severity of H. pylori induced gastric cancer. Tu1289