Gene Expression of Matrix Metalloproteinases and their Inhibitors (TIMPs) in Meningiomas of Dogs

BACKGROUND

Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) are considered to be key mediators of tumor invasion and metastasis. MMP-2 and MMP-9 are expressed in meningiomas of dogs, but TIMP expression, and variations of specific MMP/TIMP ratios still are unknown in this tumor.

HYPOTHESIS/OBJECTIVES

Expression of MMP/TIMP might increase progressively from grade I to grade III meningioma. Therefore, genetic expression of MMP-2 and MMP-9, and specific TIMP-2 and TIMP-1, respectively, has been investigated in meningiomas of different grades.

ANIMALS

Selected formalin-fixed paraffin-embedded tissue from 43 meningiomas of dogs was evaluated.

METHODS

Genetic material was obtained from pathologic samples and used for quantitative reverse transcriptase real-time polymerase chain reaction (RT-qPCR).

RESULTS

MMP-9 was not expressed in all of the tumors, but MMP-2 was significantly more expressed in papillary meningioma. Likewise, the MMP-2/TIMP-2 ratio was numerically higher in papillary meningiomas compared to all grades (>3.5 times) showing a strong bias in favor of metalloproteinase. In the papillary meningioma, TIMP-1 gene expression was significantly higher than in grades I and III.

CONCLUSIONS AND CLINICAL IMPORTANCE

MMP-2/TIMP-2 imbalance might contribute to the aggressive biologic behavior of papillary meningiomas in dogs. TIMP-1 expression may play a role independent of MMP-9 expression in neoplastic progression. These results further support that therapeutic and prognostic evaluations of dogs with meningioma need to be addressed according to different histologic patterns as is performed in humans.

Impact of MMP-3 and TIMP-3 gene polymorphisms on prostate cancer susceptibility in North Indian cohort

PURPOSE

Matrix metalloproteinases (MMPs) have been implicated in progression and metastases of different tumors. The balance between the MMPs and their natural inhibitors (tissue inhibitors of matrix metalloproteinases; TIMP) seem to be an important factor related to its role. The purpose of this study was to evaluate polymorphisms in the MMP-3 and TIMP-3 genes for their associations with prostate cancer (PCa) risk in North Indians.

MATERIALS AND METHODS

Genotypes were determined by PCR-RFLP (Polymerase Chain Reaction Restriction Fragment Length Polymorphism) method in 150 PCa patients and 200 age matched controls of similar ethnicity.

RESULTS

We found significant association in the MMP-3(1171)5A/6A and TIMP-3 (1298) C/T polymorphism with PCa risk. Variant genotype (5A/5A) of MMP-3(1171)5A/6A polymorphism had a high PCa risk (p=0.037, OR=3.52, 95%CI=1.08-11.5). Individuals with TIMP-3 (1298) CT genotype as well as T allele showed reduced risk of PCa (p<0.001; OR=0.31; 95%CI=0.18-0.52, and p=0.001; OR=0.49; 95%CI=0.32-0.75). This effect was even more evident in case of T allele carrier (CT+TT) (p<0.001; OR=0.36; 95%CI=0.22-0.59). Overall no significant association was observed statistically in MMP-3 and TIMP-3 with any of the grading stages and smoking habits in PCa. Haplotype analysis of MMP-3 showed that A-5A-A was associated with three folds (OR=3.06; 95%CI=1.71-5.47; p<0.001) increased risk in PCa patients.

CONCLUSION

This is the first reported association between polymorphisms in the MMP-3 and TIMP-3 gene and PCa risk and supports the hypothesis that the protease/antiprotease balance has an important role. Due to the small sample size further investigations need to be done to prove a statistical significant correlation between the MMP/TIMP expression and clinicopathological parameters.