Altered Expression Of Matrix Metal;loproteinase9, E-cadherin And CD44 Splice Variant 6 In Oral Squamous Cell Carcinoma And Their Significance

Objective: To study the expression of Matrix metalloprateinase-9 (MMP9), E-cadherin (E-cad) and CD44 splice variant 6 (CD44v6) in oral squamous cell carcinoma (OSCC) and their relationships with clinical pathological characteristics and to investigate their roles in carcinogenesis, development, invasion and metastasis of OSCC.Methods: The expression of MMP9, E-cad and CD44v6 was examined by immunohistochermistry S-P method in 30 cases of normal oral mucosa, 40 cases of atypical hyperplasia of oral epithelia and 82 cases of OSCC.Results:(1) The positive rate of MMP9 was 84.1% in OSCC, which was significantly higher than that in atypical hyperplasia (17.5%) and that in oral mucosa (6.6%). Significant correlations were found between MMP9 expression in OSCC and tumor size, differentiation, clinical stage and lymph-node metastasis.(2) All 30 cases of normal mucosa expressed E-cad. The positive rate of E-cad was 76.9% in OSCC, which was significantly lower than that in normal mucosa. The strong positive staining for E-cad in OSCC was closely related with tumor size, its differentiation and lymph-node metastasis, but it had no relation with the clinical stage.(3) The positive rate of CD44v6 was 78.4% in OSCC, which was significantly higher than that in atypical hyperplasia (30.0%) and in oral mucosa (13.3%). The expression of CD44v6 in OSCC was closely related with the turner differentiation andlymph-node metastasis, but had no relation with tumor size and clinical stage.(4) In OSCC, MMP9 expression was negatively related to that of E-cad, while positively to CD44v6, no relation of E-cad to CD44v6 was evident.(5)In OSCC with high expression of MMP9, there were high rates of lymph-node metastasis (70.4% and 71%,respectively) in case of the lower expression of E-cad and high expression of CD44v6. While in OSCC with high expression of E-cad, the rate of lymph-node metastasis was very low, which was only 4.3%, in case of the low expression of CD44v6.Conclusion: The altered expression of MMP9, E-cad and CD44v6 may take important roles in the carcinogenesis and development of OSCC. Low expression of E-cad, high expression of MMP9 and CD44v6 might have advantages for the metastasis of OSCC. They take roles independently or by cooperation in tumor invasion and metastasis through different pathways. The expression of MMP9, E-cad and CD44v6 may be important markers reflecting the biological behaviors of invasion and metastasis in OSCC. The combined of the three markers is helpful for judging the potential of invasion and metastasis of OSCC.