Predictive Role Of RPN1 In The Recurren Of Non-muscle Invasive Bladder Cancer After Surgery

Objective: Glycomics and glycoproteomics are considered to be promising areas for diagnostic and prognostic markers,and OST subunits as the main part of N-glycolytic transfer,have been found to play an important role in the development and progression of various cancers and are potential diagnostic and prognostic markers.However,the expression pattern,clinical value and function of OST subunits in bladder cancer have yet to be systematically and comprehensively analyzed.Therefore,this study explored the relationship between OST subunit expression levels and bladder cancer prognosis through public databases to select potential diagnostic and prognostic biomarkers that could be used as bladder cancer.Then,we focused on the function of RPN1 in bladder cancer and explored its feasibility as a new tumour marker to determine the recurrence of bladder cancer after surgery,providing a theoretical basis for clinical application.Methods: Based on the GEPIA2,UALCAN,c Bio Portal,DAVID and TIMER databases,transcript levels,prognostic survival,genetic alterations,biological functions and immune cell infiltration of OST subunits in bladder cancer were investigated.Protein-protein interaction networks were built by Gene MANIA and GO and KEGG analyses were visualised using version R(3.6.3)software.In addition,We collected 76 paraffin specimens from patients who underwent transurethral resection of tumors in Xuzhou Hospital affiliated to Jiangsu University from May2018 to May 2021,and 30 normal bladder tissues.Immunohistochemical techniques were used to detect the expression of RPN1 protein in non muscle invasive bladder cancer tissues and normal bladder tissues,and to study the relationship between its expression and the clinicopathological parameters and prognosis of non muscle invasive bladder cancer.Results: Database analysis revealed a significantly increased expression pattern of OST subunits in bladder cancer,except for STT3 B and MAGT1,and expression levels of STT3 A,RPN1,RPN2,DAD1 and OSTC genes were significantly correlated with tumour stage.Furthermore,high expression levels of RPN1,RPN2 and DAD1 were associated with poorer overall and recurrence-free survival in bladder cancer patients,whereas STT3 A was associated with poorer recurrence-free survival,and STT3 A,RPN1,RPN2 and DAD1 were found to be associated with N-glycan biosynthesis,protein processing in the endoplasmic reticulum and various N-glycan biosynthesis functions.In addition,OST subunit expression levels correlated with immune cell infiltration,suggesting that OST subunits may reflect the immune status of bladder cancer.Immunohistochemical assays showed that RPN1 was highly expressed in nonmuscle-infiltrating bladder cancer and that RPN1 expression correlated with tumour size,pathological stage,histological grade,recurrence and prognosis.In addition,large tumour diameter,more advanced pathological staging and histological grading,and high RPN1 expression were risk factors for recurrence after surgery in non-muscle invasive bladder cancer,and high RPN1 expression was an independent risk factor for recurrence after surgery in nonmuscle invasive bladder cancer.Conclusion: High expression of STT3 A,RPN1,RPN2 and DAD1 correlated with late clinical stage and prognosis of bladder cancer and may be potential molecular markers for diagnosis and prognosis of bladder cancer.RPN1 was highly expressed in non-muscle invasive bladder cancer and its expression level correlated with recurrence and prognosis,which is expected to be a predictor of recurrence of non-muscle invasive bladder cancer after surgery.