[Significance of membrane type-1 matrix metalloproteinase expression in breast cancer]

Recent researches manifested that MT1- MMP (Membrane type-1 matrix metalloproteinase) is essential for breast cancer invasion and metastasis, but there are few reports about the clinical value of MT1- MMP. This study was designed to investigate the clinical significance of MT1-MMP protein and mRNA expression in human breast cancers.

Forty-six human breast cancer tissues were collected. MT1-MMP protein and mRNA expression were detected by semi-quantitative reverse transcriptase chain reaction (RT-PCR) and immunohistochemistry assay and their correlations with clinicopathological factors were analyzed.

The expression of MT1-MMP protein was positive in 52.2% of forty-six breast cancer tissues. The positive rates were 12.5%, 54.8% and 85.7% in stageI, stage II and stage III human breast cancers, respectively (P < 0.05), and 11.1%, 59.4% and 80.0% in the group of T(1), T(2) and T(3) (P < 0.05), and 27.3%, 66.7% and 100.0% in the group of N(0), N(1) and N(2) (P < 0.05). MT1-MMP mRNA expression were detected in all of the carcinomas. The means of MT1-MMP mRNA expression relative quantities were 0.4730, 0.6950 and 0.9100 in stageI, stage II and stage III human breast cancers, respectively (P < 0.05), and 0.5240, 0.7150 and 0.8220 in the group of T(1),T(2) and T(3) (P < 0.05), and 0.6305, 0.7022 and 0.8700 in the group of N(0), N(1) and N(2)(P < 0.05). There were no relations between the MT1-MMP protein or mRNA expression and ER, PR or C-erbB-2(P >0.05).

MT1-MMP protein and mRNA expression in human breast cancers had positive correlation with the stage,the tumor size and lymph node metastasis. MT1-MMP can be a predictor for the ability of breast cancer invasion and metastasis.