Association between elevated PRIM1 expression and poor prognosis in human urothelial carcinoma

Urothelial cancer, the most frequently diagnosed cancer of the urinary tract, is the tenth most common cancer globally. DNA primase subunit 1 (PRIM1) is necessary for cancer onset and progression. PRIM1 also serves as a prognostic indicator in invasive breast carcinoma, gastric cell carcinoma, and liver hepatocellular carcinoma. Despite its importance, little is currently known regarding PRIM1's clinical function in urothelial cancer.

In this study, we investigated PRIM1 expression in urothelial carcinoma, assessed its molecular interactions with other regulatory genes (Retinoblastoma 1 RB1, Ankyrin Repeat Domain 30A (ANKRD30A), Filamin A (FLNA), and Tectonin Beta-Propeller Repeat Containing 2 (TECPR2), and determined its influence on tumor behavior and patient prognosis, including overall survival.

This retrospective observational study was based on publicly available datasets consisting of 21 normal bladder tissue samples and 169 urothelial carcinoma samples collected and prepared from the archives of the Pathology Clinic of Uppsala University Hospital (Uppsala, Sweden). Overall survival was monitored from the start of therapy until either the last follow-up or death due to cancer recurrence or metastasis.

Urothelial carcinoma tissues overexpressed PRIM1 at both the mRNA and protein levels, and this elevated PRIM1 expression was significantly associated with advanced urothelial carcinoma and diminished patient survival rates (p < 0.05), as demonstrated by integrated analysis of TCGA/GEO dataset statistics (The Cancer Genome Atlas) and validation. Clear PRIM1 upregulation was observed in cancerous bladder samples compared with non-cancerous tissues, indicating elevated transcriptional activity in malignant cells. The parallel increases in both mRNA transcripts and protein products suggested coordinated transcriptional-translational regulation. Furthermore, significant upregulation of PRIM1 expression was found to be associated with mutations in Retinoblastoma 1 (RB1), Ankyrin Repeat Domain 30A (ANKRD30A), Filamin A (FLNA), and Tectonin Beta-Propeller Repeat Containing 2 (TECPR2) in bladder cancer. These genetic modifications might potentially lead to PRIM1 up-regulation and promote more efficient DNA replication and tumor development.

Our findings advance knowledge regarding the molecular causes of bladder cancer and might facilitate the development of personalized therapies. PRIM1 might serve as a potential therapeutic target for urothelial carcinoma. Therefore, further investigation of how PRIM1 is regulated in this cancer type is essential. This association between PRIM1 and advanced urothelial carcinoma highlights the crosstalk between DNA replication machinery and genetic mutations in bladder cancer, which may open new possibilities for targeted therapies and biomarker discovery.