DNA polymerase β expression in bladder cancer: a preliminary analysis

Bladder cancer is the eighth most prevalent cancer in Sri Lanka and is characterized by high recurrence and mortality rates. Diagnosis is primarily performed using cystoscopy, an invasive and uncomfortable procedure, followed by histopathological confirmation. During follow-up, patients undergo routine cystoscopy-based examinations to monitor recurrence and disease progression. The primary objective of this preliminary study was to analyse the expression of DNA polymerase β (POLB) in bladder cancer, with the aim of evaluating its potential as a biomarker. Midstream urine samples were collected from healthy volunteers and patients prior to bladder tumour resection, following informed consent. Samples were immediately processed to extract RNA from exfoliated urothelial cells. Differences in POLB gene expression between healthy individuals and patients with bladder cancer were analysed using quantitative polymerase chain reaction (qPCR), and fold changes were calculated relative to a reference gene. POLB expression was significantly upregulated in patients with bladder cancer. The mean fold change in patient samples was 6.67, compared to 1.19 in healthy controls (p < 0.05). These findings describe the expression pattern of POLB in exfoliated urothelial cells and provide a foundation for future investigations into its potential as a non-invasive diagnostic and prognostic biomarker for bladder cancer.