| Background:Bladder cancer(BC)is a malignant tumor originating from urinary tract epithelium in bladder tissue,which is caused by uncontrolled abnormal growth of bladder inner wall cells,and is one of the most common malignant tumors of urinary system.In 2016,the number of new cases of bladder cancer in China was 77000,and it will increase to 86000 by 2020,with a compound annual growth rate of 2.68%.It is estimated that the number of new cases of bladder cancer in China will continue to grow,exceeding 100000 in 2025.Therefore,it is very important for BC prevention and clinical practice to understand the molecular regulation and biological dysfunction in the progress of BC.In order to understand its carcinogenesis process,TCGA database was used to search for genes that promote the overall survival rate(OS)in BC.The study found that the group with high expression of T-cell immunoglobulin and mucin domain 1(TIM-1)showed better OS(P=0.001)and disease-specific survival(DSS)(P=0.001).TIM-1 is an important costimulatory molecule,which can be used as a surface marker for the activation of T cells,especially Th2 cells,and plays an important role in regulating tumor-related immune responses,and is expected to become a new target for cancer treatment.Many studies have shown that TIM-1 plays different biological functions in different types of cancer: TIM-1 is a tumor promoting factor in gastric cancer and liver cancer,but it can also promote the apoptosis of colorectal cancer cells.Some literatures show that the high expression of TIM-1 is associated with better disease-free survival(DFS)in bladder cancer patients(BLCA).Therefore,this study attempts to find out how TIM-1 regulates anti-tumor response in BC and clarify its regulatory mechanism.Methods:The relationship between TIM-1 and the prognosis of bladder cancer patients was observed by TCGA database and immunohistochemistry;Through TNM-PLOT database to explore the expression of TIM-1 in cancer tissue.Then,analysis the expression of TIM-1 in patient tissue and bladder cancer cells.The role of TIM-1 in bladder cancer cells was studied through in vitro(cell count experiment,CCK8 experiment,scratch experiment,migration experiment,and cycle experiment);The role of TIM-1 in bladder cancer cells was also studied in vivo(nude mouse tumorigenesis experiment).Then,in order to verify its mechanism,we performed RNA-seq analysis to determine the signal pathway of TIM-1’s biological role in BC.Finally,we will analyze the enriched possible signal pathway.We have verified the key molecules on this pathway at the m RNA and protein levels,and selected the possible target genes from them,and then carried out the reply verification.Result:1: TIM-1 expression is markedly reduced in bladder cancer cells and tissues;2: High TIM-1 expression is associated with better prognosis;3: TIM-1 inhibits bladder cancer cell proliferation and migration in vitro;4: TIM-1 knockdown in J82 cells enhanced the migration and growth of BC cells in vitro;5: TIM-1 overexpression inhibits bladder cancer cell proliferation in vivo;6: TIM-1 upregulates the expression of IFIT2 via p-STAT1;7: TIM-1 upregulates IFN-α in bladder cancer cells.Conclusion:In our study,we report that TIM-1 is lower expressed in BC cells and tissues,that high TIM-1 expression is associated with better BC prognosis.in vivo and in vitro experimental results confirmed that TIM-1 served as a tumor suppressor and reduced the growth potential of BC cells.In addition,the expression of IFIT2 was significantly increased after TIM-1 overexpression.Moreover,our results revealed that TIM-1 increased IFIT2 expression by promoting the phosphorylation of STAT1.Significantly,TIM-1 overexpression promotes the release of IFN-α from BC cells,which may be potential evidence that TIM-1 inhibits the growth of BC cells and promotes the expression of IFIT2.Overall,our findings support the notion that TIM-1could serve as a tumor suppressor for BC by activating the p-STAT1/IFIT2 pathway and provide a potential therapeutic target for BC. |
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