Investigation of the Correlation Between Selected miRNAs, Proinflammatory Cytokines, and Serum Trace Elements in Bladder Cancer Development and Progression

In our study, we aimed to investigate the relationship between miRNA-21, miRNA-155, miRNA-34a, IL-6, TGF-β, and TNF-α expression levels and serum trace element levels in the development and progression of bladder cancer. RT-PCR was used to establish miRNA-21, miRNA-155, and miRNA-34a expression levels while serum IL-6, TGF-β, and TNF-α levels were determined using the ELISA and measured with an atomic absorption spectrophotometer. In the patient group, miRNA-21 and miRNA-155 expression levels were significantly higher compared with the healthy control group (<i>p</i> < 0.001). Furthermore, in the patient group, miRNA-34a expression was significantly lower compared with the control group (<i>p</i> < 0.001). IL-6, TNF-α, TGF-β, copper levels, and the copper to zinc ratio were significantly higher in the patient group (<i>p</i> < 0.001). Serum iron and zinc levels in the patient group were significantly lower compared with the control group (<i>p</i> < 0.001). There was a significant positive correlation between miRNA-155 and IL-6 and TNF-α (r = 0.279, <i>p</i> = 0.015*; r = 0.325**, <i>p</i> = 0.004). A significant positive correlation was detected between miRNA-34a and IL-6 and TGF-β (r = 0.294*, <i>p</i> = 0.010; r = 0.447**, <i>p</i> < 0.001). By evaluating these important biomarkers together, it might be possible to implement clinical applications for bladder cancer treatment and develop individual therapeutic strategies.