The Research On The Relationship Between Infiltrative B Cells And The Progression Of Gastric Cancer And The Related Mechanisms

BackgroundGastric cancer(GC)is one of the most common malignancies of the digestive tract.In recent years,the importance of immune-infiltrating B cells in GC has been gradually recognized,but its impact on the survival prognosis of GC patients and their mediated immune processes are still very limited,so it is urgent to conduct indepth investigations of immune-infiltrating B cells in gastric cancer tissues.Objectives1.Analysis of the immune mcroenvironment of gastric cancer tumors.2.Analyze the density of immune infiltrating B cells in gastric cancer tissues and paracancerous tissues,and explore the correlation between B cells and T cells,as well as other immune cells.3.To explore the correlation between immune infiltrating B cells and their subtypes and survival in GC patients.4.Collect clinical information and follow-up data to evaluate the correlation between immune-infiltrating B cells and GC prognosis.5.To explore the effect of immune B cell infiltration on GC cells and investigate its potential mechanism of action.Methods1.Single-cell sequencing data was mined to analyze the heterogeneity and enrichment of cells in GC patient samples.2.Immunohistochemistry was used to detect the infiltration of B cells,T cells and other immune cells in 584 gastric cancer tissues and 69 cases in adjacent tissues and analyzed the correlation,and the TCGA database was used to analyze the correlation between B cell and T cell isotypes.3.Clinical data of GC patients were obtained through the TCGA database,and Kaplan-Meier survival analysis and Cox regression model were used to analyze the correlation between B cells and subtypes and prognosis.4.General clinical data of patients undergoing radical gastrectomy were collected,follow-up was performed to record overall survival and disease-free survival time,Kaplan-Meier survival analysis and COX regression analysis were performed to construct a risk prediction model.5.The co-culture of HGC-27 cells with CD20+B cells inhibited the expression of IL-6,IL-10,TNF-α and INF-γ,as well as CXCL13,CXCR5,CCL21,and CCR7.This reduced the survival rate and migration ability of cancer cells and promoted their apoptosis;The levels of EMT marker proteins were regulated,and the expression of JAK2,STAT3,p-STAT3,and Bcl-6 proteins was inhibited.Results1.Cell clustering and typing annotations were annotated and 12 cell populations were identified by marker gene expression analysis.CD8+CD4+T cells and plasma cells accounted for a large proportion of GC tissues.2.The level of invasion of CD20+B cells was higher than that of paracancerous tissues(P<0.01).CD20+ B cells and CD3+ T cells were weak correlated,and there was no association with neutrophils,macrophages,and NK cells.Analysis of TCGA data revealed that B cells were positively correlated with CD4+CD8+T cells,and negatively correlated with TH1,TH2,and Treg cells.3.Prognostic analysis results showed that high levels of CD20+ B cell infiltration,class-switching memory B cells and plasma cell infiltration had positive effects on the survival prognosis of GC patients.4.COX regression analysis showed that immunoinformatic B cells in GC patients were significantly correlated with the depth of invasion,lymph node involvement and TNM stage of tumor tissues,and the clinicopathological conditions of patients with a high level of B-cell infiltration were significantly alleviated.In the Kaplan-Meier survival analysis,high levels of B-cell infiltration prolonged overall survival and disease-free survival in GC patients.5.The co-culture of HGC-27 cells and CD20+ B cells inhibited the expression of IL-6,IL-10,TNF-α and INF-y,CXCL13 and receptors CXCR5,CCL21 and receptor CCR7.Reduces the survival rate and migration ability of gastric cancer cells and promotes their apoptosis.N-cadherin,Vimentin and SNAIL were reduced,JAK2,STAT3,p-STAT3,and Bcl-6 protein expression were reduced.Additionally,E-cadherin expression was increased.Conclusion:B-cell infiltration in gastric cancer is associated with CD4+ CD8+T cells.B-cell infiltration,specifically class-converting memory B-cell and plasma cell infiltration may be independent protective factors in GC patients.B cells may improve gastric cancer by inhibiting inflammatory responses,levels of chemokines,EMT capacity,and promoting the apoptosis of cancer cells.