Bioinformatics And Clinical Significance Of GARS In Bladder Cancer

Objectives: glycyl-trna synthetase(GARS)is an important enzyme for intracellular biosynthesis.At present,GARS is rarely studied in tumors.Based on the clinical data and TCGA database,we investigated the bioinformatics and clinical value of GARS in bladder cancer.Methods: Based on Sangerbox 3.0,the TCGA database was selected to download the GARS mRNA data of bladder cancer and the corresponding clinical patient data,and the differential expression level of GARS mRNA in bladder cancer and adjacent normal bladder tissues was analyzed and compared.TIMER and GEPIA databases were used for verification.Chi-square test was used to analyze the relationship between GARS and clinicopathological features,and UALCAN database was used for validation.Kaplan-meier analysis was used to evaluate the correlation between GARS and patient survival,and GEPIA database was used for validation.TIMER database was used to study the relationship between mutation,immune cell infiltration and tumor malignant markers.The TISIDB database was used to study the relationship between GARS and the corresponding biomarkers of immune cells.The WGBS and ChIP-seq data of bladder cancer cells were visualized using the Encod database.GO and KEGG were used to evaluate the biological functions of GARS,and STRING database was used to construct the GARS-interacting protein network.Formalin fixed paraffinembedded tissue(FFPE)was collected from 40 cases of bladder cancer,10 cases of paracancerous tissue and 6 cases of normal bladder tissue in our hospital for immunohistochemistry.The expression of GARS protein was detected by immunohistochemistry.The correlation between GARS protein expression and clinical features and prognosis was analyzed.HPA database was used to further validate GARS protein expression levels.Results: FFPE immunohistochemical analysis showed that the expression of GARS protein was significantly higher than that in normal tissues.Clinical characteristics analysis showed that GARS protein was related to the pathological grade of bladder cancer,and the expression of GARS protein was higher in high-grade bladder cancer than low-grade bladder cancer.The receiver operating characteristic(ROC)curve analysis showed that GARS protein and GARS mRNA had certain diagnostic value.TCGA data and analysis of various databases showed that GARS mRNA expression was significantly higher compared with normal tissues.Analysis of clinical characteristics showed that GARS mRNA expression was higher in older,higher grade and higher grade bladder cancer than in younger,lower grade and lower grade bladder cancer.Prognostic analysis showed that patients with high expression of GARS mRNA had shorter overall survival time and worse prognosis.Tumor microenvironment analysis showed that GARS high expression was associated with more immune cell infiltration such as dendritic cells,CD8+T cells and macrophages,and negatively correlated with tumor-inhibiting CD4+T cells.Patients with GARS high expression and low CD4+T cell infiltration had a poor prognosis.Immunoassays showed that GARS positively correlated with immune checkpoints that inhibit tumor immunity.GARS was significantly and positively correlated with malignant markers of bladder cancer.In addition,GARS may not be the cause of elevated levels in bladder cancer.Pathway and functional network analysis revealed that GARS and their co-expressed genes regulated cell cycle,lysosome and spliceosome pathways.Conclusions:(1)GARS was highly expressed in bladder cancer tissues,and its high expression was associated with higher grade,stage and shorter overall survival time of bladder cancer.(2)GARS was associated with a more suppressive immune microenvironment characterized by decreased expression of CD4+ T cells and increased expression of inhibitory immune checkpoint molecules.(3)GARS may not be caused by promoter methylation.GARS may affect the development,metastasis and invasion of bladder cancer through cell cycle,cell division,cell proliferation and other pathways,and then affect the survival and prognosis of patients.GARS has great potential as a diagnostic and prognostic marker for bladder cancer.