Clinicopathologic and Prognostic Significance of MMP-7 (Matrilysin) Expression in Human Rectal Cancer

Objective: There is increasing evidence to indicate that MMP-7 plays a more important role in tumor progression than other MMPs. The aim of this study was to detect MMP-7 expression in human rectal cancer and normal rectal tissue and to determine whether it is correlated with invasion and metastasis of human rectal cancer. Methods: Eighty-six paired samples of rectal cancer and distant normal rectal tissue obtained from 100 inpatients were allocated into two groups (cancer group and control group). MMP-7 mRNAwasdetectedbyrelativequantitativereal-timeRT–PCRandMMP-7proteinwasexamined by immunohistochemical staining and computerized image analysis. Results: MMP-7 mRNA expression in cancer group was higher than that in control group (P = 0.006), the expression ratios of 31 samples (37.35%) were 1. The mRNA expression level was correlated with Dukes Staging, histological differentiation grade and CEA level. The MMP-7 protein expression was in accordance with mRNA expression level. The positive degreeofimmunohistochemical staining in cancergroup(1.82 – 0.03) wasdifferent fromthatincontrolgroup(1.17 – 0.13,P = 0.002).Moreover,incancergroupthepositivestaining degreeinhigh-levelmRNAcancers(2.04 – 0.18,n = 52)washigherthanthatinlow-levelmRNA ones (1.58 – 0.23, n = 31, P = 0.008). Conclusions: Our results suggest that MMP-7 plays an important role in the progression of human rectal cancer. MMP-7 may be selected as a clinical diagnosis and prognosis index in rectal cancer.