Effect of a Single Nucleotide Polymorphism (NP) on Breast Cancer Invasion

Abstract

SUPPLEMENTARY NOTES 12a. DISTRIBUTION / AVAILABILITY STATEMENTApproved for Public Release; Distribution Unlimited 12b. DISTRIBUTION CODE Abstract (Maximum 200 Words) (abstract should contain no proprietary or confidential information)The lethality of breast cancer is derived from its ability to metastasize, and matrix metalloproteinases (MMPs) facilitate cellular invasion by degrading the extracellular matrix. One component of MMP regulation is transcription. We have identified a single nucleotide polymorphism (SNP) that enhances the transcriptional activity of MMP-1 promoters in transient transfections.The SNP consists of an extra guanine nucleotide that creates an ETS family transcription factor binding site (2G). We utilized cotransfection experiments, and determined that MMP-1 promoters containing the 2G polymorphism can interfere with transcriptional activity of promoters with the IG polymorphism, but only at high concentrations of DNA. Analysis of five breast cancer cell lines with transient transfections reveals that the transcriptional effect of the 2G SNP is only observed in one cell line, and this cell line was the only one examined that expressed endogenous MMP-1. To better address the role of the polymorphism in endogenous gene expression, more samples are needed, and a source of those samples is human foreskin fibroblasts (HFFs References 9 Appendices 10 Introduction:The lethality of breast cancer is derived from its ability to metastasize, and a critical component of the metastatic mechanism is the degradation of extracellular matrix (ECM). Degradation of ECM is largely mediated by a family of proteins known as matrix metalloproteinases (MMPs). One subfamily of MMPs, the collagenases, are able to degrade stromal collagens type I, II, and III, and the most widely expressed collagenase is collagenase 1 (MMP-1). We have identified a single nucleotide polymorphism (SNP) that enhances the transcriptional activity of the MMP-1 promoter in tumor cell lines and normal stromal cells. The SNP consists of an additional guanine nucleotide creating an Ets transcription factor-binding site (5'-AGGA-3') at position -1607 in the MMP-1 promoter. When this 2G polymorphism is present, transcriptional activity from the MMP-1 promoter, as measured by transient transfections, is increased an average of 6 fold over the IG polymorphism. A possible role for the SNP in cancer was suggested by observations of increased frequency of the 2G polymorphism in breast cancer cell lines and Japanese cancer patients as compared to normal DNA samples and non-patients(l, 2, 3). The MMP-1 gene is located on chromosome 11 (1 lq22.2-22.3) in a region associated with loss of heterozygosity in breast cancer patients. The studies outlined in this proposal are designed to characterize the mechanism of enhanced transcription from promoters with the 2G polymorphism, and to determine the effect of the polymorphism on transcription of the endogenous MMP-1 gene. We also hope to elucidate the role of the polymorphism and increased MMP-1 production...

Polymorphisms of Matrix Metalloproteinases (MMP) in COPD

“…The insertion of a second G nucleotide at position -1607 of MMP1 (-1607insG, rs1799750) generates a new 5'-GGA'3' sequence that corresponds to a recognition sequence for members of Ets family of transcriptional factors (22,56). The functional analyses have proven that the 2G (insG) allele and homozygosity results in increased transcriptional activity in different cell types compared to 1G (G) allele and homozygotes (21,56,72,80 …”