The Mechanism Of SOX17 In The Carcinogenesis Of Bladder Cancer

?Background?Worldwide,the incidence of bladder cancer is increasing year by year,ranking 11 th among malignant tumors.Bladder cancer has a poor prognosis,high mortality and high cost of treatment.About 60% of NMIBC will relapse after transurethral resection,and 20-30% will progress to MIBC.The 5-year survival rate of MIBC patients after radical bladder cancer resection was 60% ~ 70%.Therefore,it is very important to explore the key pathogenic genes and biological pathogenesis of bladder cancer.The Cancer Genome Atlas(TCGA)study of The genetic characteristics of tumors provides information not only on The gene drivers that may be therapeutic targets,but also on The subtypes or clusters of invasive diseases.These clusters may be associated with prognostic factors and unique treatments that improve our ability to diagnose,treat,and prevent cancer.We can further study and analyze the pathogenesis,therapeutic targets,and subtypes or clusters of invasive diseases of bladder cancer.These may be related to prognostic factors and treatment and may ultimately lead to a step towards individualized patient management.To this end,we analyzed the differentially expressed genes of bladder cancer according to the TCGA database and carried out verification and biological function research.?Objective?Bioinformatics analysis of transcriptome data from TCGA database was used to screen differentially expressed genes between bladder cancer and normal urinary tract epithelium,and verify them to study their biological functions.?materials and methods?1.Using the TCGA database to download the RNASeqV2(n=433)correction data file,screened the differentially expressed genes of bladder cancer,carried out gene set variation analysis(GSVA)and differential gene enrichment analysis,and screened the candidate genes.2.RNA was extracted from paired bladder cancer tissues and normal urothelial tissues(n=40)and qrt-pcr was performed to verify the mRNA differential expression of SOX17 in bladder tumor tissues and normal urothelial tissues3.To explore the relationship between SOX17 gene expression and pathological staging and prognosis of bladder cancer through public database.4.Immunohistochemical staining of paraffin sections of tumor tissues(n=150)and normal urothelial tissues(n=50)of bladder cancer patients were used to explore the differential expression of SOX17 in bladder tumor tissues and normal urothelial tissues,as well as the relationship between SOX17 expression and pathological grading and staging of bladder cancer and its prognosis.5.Expressions of SOX17 gene mRNA and coding protein in normal urothelial cell line and bladder cancer cell line were detected by qrt-pcr and Western Blot.The high SOX17 gene expression line biu-87 was interfered by transient interfering RNA(siRNA),and the low SOX17 gene expression line umuc-3 was overexpressed by plasmid transfection.Cck-8 assay was used to detect the effect of SOX17 gene knockdown on the proliferation capacity of cell line biu-87,and the effect of SOX17 gene overexpression on the proliferation capacity of umuc-3 cells.6.The effects of SOX17 gene interference and overexpression on the migration ability of bladder cancer cells were investigated through cell scratch and Transwell migration experiments.7.Transwell cell invasion assay was conducted to investigate the effects of SOX17 gene interference and overexpression on the invasion ability of bladder cancer cells,respectively.?results?1.RNASeqV2(n=433)correction data file analysis revealed a large number of differentially expressed bladder cancer molecules.In this study,further screening of differentially expressed genes was performed under the following conditions:(1)differentially expressed multiple log2foldchange(log2FC)2;(2)false discovery rate(FDR)<0.01;There is no literature report at present.According to the above conditions,we found that the candidate SOX17 gene meets all the above conditions.The expression level of SOX17 gene was significantly higher in normal urothelial than in bladder cancer,and its log2FC=-2.879 and FDR=1.52E-37.Through literature search and analysis,no studies have reported the relevant role of SOX17 gene in bladder cancer.2.Paired bladder cancer tissues and normal urothelial tissues(n=40)RNA were extracted for qrt-pcr to verify the differential expression of SOX17 gene,and the expression level of SOX17 in bladder cancer tissues of 33 patients was lower than that of the paired normal urothelial tissues.3.Data analysis of TCAG database showed that the expression level of SOX17 in normal tissues was significantly higher than that in bladder cancer tissues,and the expression level of SOX17 in Stage I & II was higher than that in Stage III & IV.Oncomine database analysis showed that the expression of SOX17 in normal urothelial tissue was higher than that in bladder cancer tissue,and the expression in NMIBC was higher than that in MIBC.4.Immunohistochemical staining analysis of SOX17 gene in paraffin sections of bladder cancer(n=100)and normal urothelial paraffin sections(n=50)confirmed that the expression level of SOX17 in normal urothelial cells was higher than that in NMIBC,and the expression level of SOX17 gene in NMIBC was higher than that in MIBC.The overall survival rate of bladder cancer patients with high SOX17 expression was significantly higher than that with low SOX17 expression.5.The proliferation experiment of cck-8 cells showed that siRNA interfered with the expression of SOX17 gene,and there was no significant change in the proliferation ability of bladder cancer cell BIU-87.The proliferation of UMUC-3 in bladder cancer cells transfected with SOX17 gene was significantly lower than that of the negative control group.6.Scratch test confirmed that siRNA interfered with the migration ability of SOX17 gene expression bladder cancer cell BIU-87,and the migration ability of plasmid overexpression of SOX17 gene UMUC-3 was significantly weaker than that of the negative control group.Transwell assay confirmed that the migration ability of BIU-87 of bladder cancer cells expressing SOX17 gene by siRNA interference was no significant change,and the migration ability of UMUC-3 of bladder cancer cells expressing SOX17 gene by plasmid overexpression was significantly weaker than that of the negative control group.7.Transwell cell invasion assay confirmed that there was no significant change in the invasion ability of bladder cancer cells expressing SOX17 gene by siRNA interference with BIU-87,and that the invasion ability of bladder cancer cells UMUC-3 over expressing SOX17 gene by plasmid was significantly weaker than that of the negative control group.?Conclusion?SOX17 was down-regulated in bladder cancer,and its expression in muscle-infiltrating bladder cancer tissue was lower than that in non-muscle-infiltrating bladder cancer tissue.The expression level of SOX17 gene is an independent prognostic factor,and the low expression level of SOX17 gene obviously has a poor prognosis.Over expression of SOX17 gene significantly inhibited the proliferation,migration and invasion of bladder cancer cells.Interfering with SOX17 gene significantly promoted the proliferation,migration and invasion of bladder cancer cells.SOX17 gene is closely related to the occurrence and progression of bladder cancer.