Upregulation of Cytotoxic T-Lymphocyte-Associated Protein 4 and Forkhead Box P3 Transcripts in Peripheral Blood of Patients with Bladder Cancer

BACKGROUND: Regulatory T cells (Tregs) play a key role in the progression of tumors. These cells express forkhead box P3 (FOXP3) and cytotoxic T-lymphocyte-associated protein 4 (CTLA4), which are the potential targets for cancer immunotherapy. The present study aimed to evaluate FOXP3 and CTLA4 transcripts in patients with bladder cancer (BC) compared with healthy individuals. METHODS: Transcripts of CTLA4 and FOXP3 genes in the peripheral blood mononuclear cells (PBMCs) of 50 patients with histologically confirmed BC and 50 healthy individuals were assessed at the Institute for Cancer Research, Shiraz University of Medical Sciences (Shiraz, Iran) during 2014-2016. RNA was extracted from PBMCs, then cDNA was synthesized and subjected to quantitative real-time PCR (qRT-PCR) using appropriate primers. Statistical analysis was performed using SPSS software (version 21.0). RESULTS: Significantly higher amounts of CTLA4 and FOXP3 gene transcripts were found in the peripheral blood of BC patients compared with healthy individuals. The expression of both genes was significantly higher in patients with non-invasive and grade I/II BC. The median of CTLA4 and FOXP3 transcript expressions was 3.74 and 5.39, respectively, in non-invasive BC patients, which was significant compared with the control group (P=0.0016 and P=0.009, respectively). The median of target gene mRNA expression in grade I/II BC patients was 2.9 for CTLA4 and 6.61 for FOXP3, which was significant compared with the controls (P=0.013 and P=0.0037, respectively). CONCLUSION: This study highlights the functional activity of Tregs in early stages of bladder cancer and showed the importance of CTLA4 and FOXP3, when it comes to screening BC.