Variability, Expression, and Methylation of IL-6 and IL-8 Genes in Bladder Cancer Pathophysiology

Abstract

Bladder cancer (BC) is the 10th most common form of cancer globally, but its complete aetiology is still unknown. Nevertheless, there is evidence that chronic inflammation plays a role in the development and progression of BC. Therefore, the presented study aimed to detect a potential association between selected single nucleotide polymorphisms (SNPs)—rs1800797 and rs2069845 in IL-6 and rs2227307 in IL-8—and BC development, as well as to identify the impact of BC on the level of expression and methylation of IL-6 and IL-8 promoters in PBMCs with the use of the TaqMan SNP genotyping assay, TaqMan gene expression assay, and methylation-sensitive high-resolution melting techniques. We did not find any association between the genotypes and combined genotypes of all studied polymorphisms and the occurrence of BC. However, we found that BC patients were characterised by decreased IL-6 and IL-8 mRNA expression levels compared to the controls. Additionally, the methylation status of the IL-6 promoter was higher in controls than in BC patients. Our findings suggest that inflammation may be involved in the development and progression of BC.