A Prognostic Biomarker for Bladder Cancer Correlated with Immune Infiltration Is PAEP

Abstract

Background: A major cause of cancer death worldwide is bladder cancer, which is the most common malignant tumor of the urinary tract. PAEP is a member of the kernel lipocalin superfamily whose members share relatively low sequence similarity but have highly conserved exon/intron structure and three-dimensional protein folding. Most lipocalins are clustered on the long arm of chromosome 9. The purpose of this study was to clarify the correlation between PAEP expression level and bladder cancer. Methods: In the TCGA database, we obtained clinical and RNA sequencing data of 431 BLCA patients, including 412 BLCA tissues and 19 normal bladder tissues in the study. Analyses of bioinformatics were conducted in this study to determine the role of PAEP in bladder cancer. A quantitative real-time PCR method was used to quantitate the gene expression profile. Additionally, the effect of PAEP on tumor immune infiltration and prognosis was analyzed. Results: PAEP was a poor prognostic biomarker of bladder cancer because it was significantly upregulated. bladder cancer patients with higher PAEP expression had poor outcomes. An AUC of 0.780 was calculated from the area under the ROC curve. PAEP was associated with T stage, pathologic stage, Histologic grade and Subtype of bladder cancer patients, and served as an independent predictor of overall survival in bladder cancer patients. Functional enrichment analysis revealed PAEP was obviously enriched in pathways connected with carcinogenesis and immunosuppression. The expression of PAEP was significantly associated with tumor immune cells and immune checkpoints according to ssGSEA and Spearman correlation analysis. Conclusions: In this study, we screened and detected a mRNA, PAEP is a prognostic and immune-related biomarker in BLCA, which may contribute to the early diagnosis and treatment of BLCA.