Association of matrix metalloproteinases 3 and 9 single nucleotide polymorphisms with breast cancer risk: A case-control study.

Two single nucleotide polymorphisms (SNPs) of matrix metalloproteinase (MMPs) 3 and 9 are functionally implicated in the progression of various types of cancer, including breast cancer (BC). However, the roles of these SNPs remain controversial. In addition, they also vary between one population and another. Therefore, the present study aimed to investigate the possible association between MMP3-1171 5A/6A and MMP9-1562 CT SNPs and the risk of BC among Egyptians, and to elucidate the alteration of MMP3 and MMP9 gene expression in patients with BC. The present case-control study enrolled 162 patients with BC and 146 control subjects. Restriction fragment length polymorphism-PCR was performed for analysis of the selected SNPs, gene expression of MMP3 and MMP9 was also assessed in 50 patients and 50 control subjects by reverse transcription-quantitative PCR. The frequencies of 5A/6A genotype and 5A allele of MMP3 were significantly higher in patients with BC compared with in healthy subjects. On the other hand, the distributions of MMP9 genotypes and alleles were not significantly different among patients and healthy subjects. Compared with healthy subjects, the expression levels of the two genes were found to be upregulated in patients with BC. Therefore, the present study indicated that MMP3-1171 5A/6A SNP, not MMP9-1562 C>T SNP may be a risk factor for developing BC among Egyptian females.