Bladder Cancer Patients with Elevated SPRR1B Expression Experiencing a Poor Prognosis.

Background: SPRR1B, a member of the small proline-rich protein family, is implicated in various epithelial cancers as a potential oncogene linked to tumour growth and poor survival outcomes. However, its role in urothelial bladder carcinoma (UBC) remains to be fully elucidated.

Methods: Transcriptional profiling data from The Cancer Genome Atlas grouped UBC samples in accordance with SPRR1B expression. Bioinformatic analysis was conducted to evaluate whether SPRR1B is a prognostic factor and a survival factor in UBC. Gene set enrichment analysis (GSEA) was performed to study immune cells and pathways. Reverse transcription quantitative real-time polymerase chain reaction detected gene expression. Immunohistochemistry assessed protein expression. Spearman correlation test analysed the correlation between SPRR1B and the protein p53.

Results: The bioinformatics results indicated that the expression level of SPRR1B in UBC tissues was significantly increased compared with that in normal bladder tissues, correlating with clinical characteristics. A high expression predicted poor prognosis and survival. Univariate Cox statistics showed that a high expression level of SPRR1B was correlated with UBC patients having poor overall survival (OS) (p < 0.05). In addition, on the basis of the multivariate Cox analysis, SPRR1B expression was independently correlated with OS (p = 0.005). GSEA analysis revealed enrichment in the p53, apoptosis, and cell cycle signalling pathways, and an association with B cells, lymphocytes, and natural killer cells. In addition, SPRR1B was found to be associated with immune infiltration based on the analysis of immune cell infiltration. Performing corresponding verification on a small number of tissues collected from bladder cancer patients revealed that the expression of this protein was negatively correlated with the expression of p53.

Conclusions: SPRR1B overexpression predicts poor UBC outcomes, suggesting its role as a prognostic marker and therapeutic target. Further research is necessary to elucidate its role in UBC progression.