Expression of matrix metalloproteinase-7 in cycling human endometrium and endometrial cancer

Objective:To study the expression of MMP-7 protein and mRNA in cycling human endometrium and endometrial cancer,and correlations with tumor clinical characters.Methods:A total of 41 cases of endometrial carcinoma samples and 76 of normal endometrial tissue were tested for expression of MMP-7 by immunohistochemistry and RT-PCR.Normal endometrial specimens were classified according to 28-day reproductive cycle as early(n=10),mid(n=11)and late(n=13)proliferative phase,early(n=11),mid(n=12)and late(n=10)secretory phase,and menstrual phase(n=9).Rank test was used to evaluate the significance of differences between the groups.Results:MMP-7 localized in epithelial glandular and luminal cells.Semi-quantifications with RT-PCR and immunohistochemistry revealed maximal levels of MMP-7 in late secretory and menstrual phase whereas early and mid secretory phases had no MMP-7 expression(u=2.13 P=0.032;u=4.178 P=0.0001).The levels of MMP-7 altered with loss of tumor histological differentiation,myometrial invasion and lymphatic metastases in malignant tissue.Conclusion:High expression of MMP-7 in menstrual and proliferative phases suggests that MMP-7 be involved in the broken down and growing of endometrium;Elevated expression of MMP-7 in advanced tumors and its correlation with myometrial invation suggest its role in endometrial tumor progression.