Objective : To explore the causal relationship between 46 phenotypes ( including 15 seropositive case- control phenotypes and 31 quantitative antibody-measurement phenotypes) and ulcerative colitis( UC) using two- sample bidirectional Mendelian randomization( TSMR) . Methods: Single nucleotide polymorphisms ( SNPs) sig- nificantly associated with the relative abundance of the 46 antibody sera were extracted as instrumental variables ac- cording to preset thresholds . Summary statistics for UC were obtained from the OPEN GWAS database ( n = 47 745) . MR-Egger regression , weighted median method ( WME) , inverse variance weighting ( IVW) , the simple mode method (SM) , and weighted multitude method (WM) were used to estimate the causal relationship between antibody levels and UC , primarily using the IVW method . The results were assessed according to the effect indica- tor dominance ratios (OR) and 95% confidence intervals (CI) . Sensitivity analysis , heterogeneity test , gene plei- otropy test , and outlier test (MR-PRESSO) were combined to verify the stability and reliability of the results , and the causal association study was performed again using reverse Mendelian randomization(MR) . Results : IVW re- sults showed that Epstein-Barr( EB) virus EA-D antibody levels ( OR = 0. 806 , 95% CI = 0. 693 - 0. 939 , P < 0. 01) , Epstein-Barr virus EBNA-1 antibody levels ( OR = 1 . 870% , 95% CI = 1 . 480 - 2. 360 , P < 0. 000 1) , Anti-polyomavirus 2 IgG seropositivity (OR = 0. 570 , 95% CI = 0. 435 - 0. 746 , P < 0. 000 1) were associated with UC . The inverse MR analysis revealed a causal effect on anti-polyomavirus 2 IgG seropositivity , and none of the a- bove revealed genetic pleiotropy or significant heterogeneity of IVs . Conclusion EB virus EBNA-1 antibody levels are positively associated with the risk of UC , while EB virus EA-D antibody levels and anti-polyomavirus 2 IgG se- ropositivity are negatively associated with the risk of UC , indicating that they are protective factors for UC .

Background/Aims: The increased mortality of gastric cancer (GC) is mainly attributed to the development of chemoresistance. Circular RNAs, as the novel type of biomarkers in GC, have attracted wide attention. The purpose of this study was to investigate the functional role of circ_0081143 in GC with doxorubicin (DR) resistance and its potential action mechanism. Methods: The expression of circ_0081143, miR-129-2-3p and YES proto-oncogene 1 (YES1) in GC tissues and cells was measured by quantitative real-time polymerase chain reaction. The half maximal inhibitory concentration value was calculated based on the MTT cell viability assay. Cell proliferation and apoptosis were monitored by MTT and flow cytometry assays. Transwell assays were employed to check cell migration and invasion. The protein levels of YES1 and apoptosis-related proteins were detected by western blotting. The interaction between miR-129-2-3p and circ_0081143 or YES1 was verified by dual-luciferase reporter and pull-down assays. A tumorigenicity assay was conducted to verify the role of circ_0081143 in vivo. Results: Circ_0081143 was highly expressed in DR-resistant GC tumor tissues and cells. Depletion of circ_0081143 reduced DR resistance and inhibited DR-resistant GC cell proliferation, migration and invasion. Circ_0081143 targeted miR-129-2-3p and inhibited the role of miR-129-2-3p. In addition, YES1 was a target of miR-129-2-3p, and its function was suppressed by miR-129-2-3p. Importantly, circ_0081143 positively modulated the expression of YES1 through mediating miR-129-2-3p. Circ_0081143 knockdown weakened the DR-resistant GC tumor growth in vivo. Conclusions Circ_0081143 knockdown weakened DR resistance and blocked the development of DR-resistant GC by regulating the miR-129-2-3p/YES1 axis. Our data suggest that circ_0081143 is a promising target for the treatment of GC with DR resistance.