The Mechanism Of RIPK2 In The Occurrence And Development Of Gastric Cancer And Its Pan-cancer Analysis In Human Tumors

Objective: To investigate the expression features of RIPK2 in gastric cancer(GC)and its association with clinicopathological parameters.Methods: We explored the differential RIPK2 m RNA and protein expression analysis in GC tissues and normal gastric tissues based on GEO,TCGA,Oncomine,TNMplot,and HPA databases.Next,we analyzed the correlation between RIPK2 expression and clinicopathological characteristics(survival,gender,race,primary tumor,lymph node metastasis,degree of tumor differentiation,stage and radiotherapy)in GC using the TCGA database and bioinformatic analysis.Finally,the functional enrichment analysis of RIPK2 and its related proteins were explored using DAVID and GSEA databases.Results: Compared with normal gastric tissues,both m RNA and protein expression levels of RIPK2 were upregulated in GC tissues,and we found that RIPK2 protein was located in the cytoplasm and membrane.Furthermore,RIPK2 was upregulated in helicobacter pylori-positive gastric tissues.High RIPK2 expression predicts poor disease-specific prognosis of patients with GC.However,no significant relationship between RIPK2 expression and gender,race,primary tumor,lymph node invasion,histological grade,stage,and radiotherapy were observed in GC.Finally,molecular function and pathway enrichment analysis showed that RIPK2 was associated with apoptosis,cell cycle,cytokine production,immune signal transduction,regulation of protein kinase cascade,Toll-like receptor signaling,NOD-like receptor signaling,and the regulation of IκBα/NF-κB signaling pathway.Conclusion: RIPK2 were significantly overexpressed in GC tissues and helicobacter pylori-positive gastric tissues.Patients with high RIPK2 expression may have poor disease-specific survival.Nevertheless,RIPK2 expression has no significant correlation with the clinicopathological characteristics.RIPK2 may be involved in tumor conformation and progression by regulating cell cycle,apoptosis,and NOD/IκBα/NFκB signals.Objective: RIPK2 is a member of the receptor interacting protein kinases(RIPK)family.It was previously demonstrated that RIPK2 might play a role in promoting malignant tumor progression;however,the precise function of RIPK2 in the onset and progression of GC remains unclear.In the current study,we investigated the role of RIPK2 in GC.Methods: First,we compared the expression levels of RIPK2 between GC tissues and cells using reverse transcription quantitative PCR and Western-blot analysis.We downregulated the expression of RIPK2 in GC cells,subsequently,CCK8 and clone formation assays were used to determine the effects of RIPK2 on cell growth;woundhealing and transwell migration assays were used to assay the cell migration;flow cytometry assay was used to investigate the effects of RIPK2 on apoptosis.Then,we investigated the effects of RIPK2 on the growth of implanted human GC in nude mice.Finally,we used Western-blot to test the protein expression level of Bcl-2,Bax,cleavedcaspase 3,cyclin D1,cyclin E1,PCNA and IκBα/NF-κB signaling pathway associated protein involved in the regulation of GC progression.Results: Compared with normal gastric tissues,RIPK2 was upregulated in our GC samples.And we showed that RIPK2 was significantly overexpressed in all four GC cells(MGC-803,SGC-7901,HGC-27 and AGS)comparing the GES-1 cell.Silencing of RIPK2 could reduce the capability of GC cells growth and clone formation by downregulating PCNA protein expression.Silencing of RIPK2 could inhibit GC cells migration.In addition,knockdown of RIPK2 could impair cell cycle progression at G0/G1 phase by downregulating cyclin D1 and cyclin E1 protein expression.And,knockdown of RIPK2 induced apoptosis by upregulating the protein expression of Bax and cleaved-caspase 3 and downregulating the protein expression of Bcl-2.Besides,knockdown of RIPK2 could inhibit GC growth in vivo.Finally,knockdown of RIPK2 decreased the phosphorylation protein level of IκBα and NF-κB.Conclusion: We demonstrated that RIPK2 was upregulated both in GC tissues and cells.RIPK2 plays an important role in modulating GC cells proliferation,migration,and apoptosis through the IκBα/NF-κB signaling pathway.Therefore,RIPK2 functions as a potential oncogene.We believe that RIPK2 can be used as a candidate therapeutic target for GC.Objective: Although previous studies have shown that RIPK2 plays an oncogenic role in the process of tumor formation,no pan-cancer analysis is available.Considering the complexity of tumor genesis and development,we analyzed the clinical prognosis and potential molecular mechanism of RIPK2 from the perspective of pan-cancer.Methods: We first explored the expression of RIPK2 across thirty-three tumors based on the TCGA and Oncomine databases.Next,we analyzed the phosphorylation protein level of RIPK2 in tumors using UALCAN database.Then,the prognostic value of RIPK2 in tumors was analyzed using GEPIA2 and Progno Scan database.The gene variation of RIPK2 in tumors was analyzed online by c Bioportal.Furthermore,the correlation between RIPK2 expression and immune cells and tumor-associated fibroblast infiltration levels in pan-cancer were explored using Timer2 database.Finally,the molecular function and pathway enrichment analysis of the proteins interacting with RIPK2 were conducted using DAVID and Metascape database.Results: RIPK2 is highly expressed in most cancers,and distinct associations exist between RIPK2 expression and prognosis of tumor patients.And,gene amplification is the main type of RIPK2 gene variation in tumors.Besides,RIPK2 protein phosphorylation sites vary in different tumors,and we observed an enhanced phosphorylation level of S363 in several tumors.RIPK2 expression was associated with the CD4+T-cell,CD8+T-cell,B cells,neutrophils,macrophages,and tumor-associated fibroblasts infiltration in many tumors.Moreover,IκBα/NF-κB signaling,regulation of programmed cell death,metabolism of RNA,and protein polyubiquitination-associated functions were involved in the functional mechanisms of RIPK2.Conclusion: RIPK2 is highly expressed in most cancers,and high RIPK2 expression predicts poor prognosis of tumor patients.RIPK2 gene variation and protein phosphorylation sites vary in different tumors.RIPK2 expression was associated with immune cells and tumor-associated fibroblasts infiltration in many tumors.RIPK2 might be involved in tumorigenesis and progression via regulating the IκB/NF-κB signaling pathway,ubiquitination,and programmed cell death.