MMP7 and MMP8 genetic polymorphisms in bladder cancer patients

Breakdown of the extracellular matrix by matrix metalloproteinases (MMPs), as we know, is one of mechanisms involved and required in tumor invasion. MMP7 is a negative prognostic factor of various malignances, while MMP8 exhibits an inhibitory effect on tumorigenesis and metastasis. We evaluated the potential association of functional polymorphisms in the promoter of the MMP7 (rs11568818) and MMP8 (rs11225395) genes and bladder cancer (BCa) risk.

The study included 241 BCa cases and 199 healthy population controls that were collected at the First Department of Urology, Medical University (Łódź, Poland) and at the Nofer Institute of Occupational Medicine (Łódź, Poland). Genomic DNA samples were isolated from venous blood and genetic polymorphisms were analyzed by real-time polymerase chain reaction using TaqMan fluorescent probes. Associations between genotype and allele status were estimated by logistic regression models adjusted for classic risk factors (e.g. age, gender and cigarette smoking).

MMP7 and MMP8 genotypes were distributed similarly in BCa patients and in controls and at least one variant allele was not associated with BCa cancer risk (OR, 0.91; 95% CI, 0.60-1.39; p = 0.662 for MMP7 and OR, 0.96; 95% CI, 0.63-1.46; p = 0.836 for MMP8). We observed higher prevalence of MMP7 GG genotypes among BCa patients than in controls (OR, 1.54; 95% CI, 0.93-2.55; p = 0.093). Additionally, genetic polymorphisms in the MMP7 and MMP8 were not associated with the tumor grade or stage.

Our results suggest that genetic variations in two genes encoding members of the MMP7 and MMP8 are not associated with a risk of BCa in the Caucasian population.