Transcription factor NRF2 and the expression of the Hippo pathway effector TAZ in bladder tumorigenesis are significantly correlated

Bladder cancer ranks as the 11th most frequent form of cancer and is the most common malignancy of urinary tract cells. A major contributor to bladder cancer development is oxidative stress. The nuclear factor erythroid 2-related factor 2 (NRF2) is a transcription factor that regulates the expression of the transcriptional coactivator with PDZ-binding motif (TAZ) and is found to regulate oxidative stress in cancer cells. This study aimed to investigate the relationship between oxidative stress and the NRF2/TAZ pathway in bladder cancer. In this study, a total of 35 bladder cancer patients and 35 healthy subjects were recruited. The expression of NRF2 and TAZ genes was evaluated using real-time PCR. Total Oxidant Status (TOS) and total antioxidant capacity (TAC) of the samples were measured. Our findings revealed a higher expression of NRF2 (p < 0.001) and TAZ (p < 0.001) mRNA in cancerous tissue as compared to healthy subjects. We also found that there is a positive correlation between tumor grading and NRF2 (r = 0.522, p = 0.001) as well as TAZ (r = 0.462, p = 0.02) genes mRNA expression. Also, our results revealed that there is a significant correlation between TAZ and NRF2 genes mRNA expression in bladder cancer patients. Furthermore TAC level was considerably lower in bladder cancer patients (p < 0.01), while the TOS level was significantly higher compared to the control group(p < 0.05). Finally, our findings suggested that NRF2 and TAZ, as transcriptional factors, are associated with higher grades of bladder cancer as well as oxidative stress in patients with bladder cancer.