Clinical significance of MT1-MMP mRNA expression in breast cancer

Membrane-type 1 matrix metalloproteinase (MT1-MMP) is known as an activator of MMP-2. We reported that the expression of MT1-MMP is a powerful indicator of lymph node metastasis in gastric cancers. We now examined the possibility that MT1-MMP expression also is an indicator of lymph node metastasis in breast cancer. We examined the clinicopathologic significance of the expression of MT1-MMP mRNA in 53 breast cancer specimens by the semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR) assay. The highest expression of MT1-MMP was found in those specimens showing lymph node metastasis and/or lymph vessel invasion. Therefore, an analysis of MT1-MMP can predict the presence of lymph node metastasis in breast cancer patients by RT-PCR assay in minute amounts of tissue. We believe this is an objective assay for determining the role of MT1-MMP for metastasis in patients with breast cancer.