The clinical implications of MMP-11 and CK-20 expression in human breast cancer

Background: Tumor invasiveness and metastasis in cancer progression is manifested by epigenetic abnormality. However, it remains unknown whether transcription regulation of matrix metalloproteinase-11(MMP-11) and cytoskeleton-20 (CK-20) genes for the homoeostasis of epithelial/connective interface that can enhance cell dissemination and invasion may act as alternative mutators to tumor clinicopathology. Methods: Paired cancerous and tumor-adjacent normal tissues from 72 breast cancer patients were assayed for the expression of MMP-11 and CK-20 by using real-time RT-PCR. The expression profiles were evaluated for the association with clinicopathological factors. Results: Breast tumor tissues displayed higher expression levels of MMP-11 and CK-20 than those of the adjacent non-cancerous tissues. Overexpression of either MMP-11 or CK-20 correlated with patients having poorly differentiated tumors (PMMP-11 = 0.01 and PCK-20 = 0.05) and lymph node metastasis (LNM) (PMMP-11 = 0.004 and PCK-20 = 0.001). A synergistic effect between MMP-11 and CK-20 on risk elevation was significant in patients with advanced tumor stage (OR = 2.03, 95%CI = 1.10-3.77) and LNM (OR = 2.83, 95%CI = 1.20-4.71). Additionally, patients lacking progesterone receptor exhibited high expression of MMP-11 and CK-20. Conclusion: We demonstrate that MMP-11 and CK-20 are probable prognostic markers whose expression reflects the stages of tumor differentiation and LNM of breast cancer.