MMP8 and MMP9 gene polymorphisms were associated with breast cancer risk in a Chinese Han population

Matrix metalloproteinases (MMPs) are a group of zinc-dependent endopeptidases that can breakdown almost all extracellular matrix components. MMP8 and MMP9 have been shown to be associated with breast cancer (BC) risk in European and American populations. However, few studies have focused on the polymorphisms of MMP8 and MMP9 in Chinese Han BC patients. We investigated nine single nucleotide polymorphisms (SNPs) in 571 BC cases and 578 controls to evaluating their association with risk of BC. The frequency of the "A" allele of rs3787268 was significantly lower in BC cases than in controls (P = 0.025). In the genetic model analysis, the minor allele "T" of rs11225394 in MMP8 was associated with increased risk of BC under the recessive model (P = 0.019), and the minor allele "A" of rs3787268 was associated with decreased risk of BC under the dominant model (P = 0.014). Additionally, the haplotype "AGTCA" constructed by rs3740938, rs2012390, rs1940475, rs11225394, and rs11225395 and the haplotype "CCG" constructed by rs3918249, rs3918254 and rs3787268 were associated with increased risk of BC (P < 0.05). Our data showed that polymorphisms of MMP8 and MMP9 may be associated with BC risk in the Chinese Han population.