Expression of Reversion-Inducing Cysteine-Rich Protein with Kazal Motifs and Matrix Metalloproteinase 9 in Middle Ear Squamous Cell Carcinoma

Objective: Reversion-inducing cysteine-rich protein with kazal motifs (RECK) may negatively regulate matrix metalloproteinase 9 (MMP9) activity and suppress tumor invasion and metastasis. The aim of this study was to investigate whether RECK and MMP were involved in regulating middle ear carcinoma invasion and metastasis. Methods: RECK and MMP9 were measured in 30 middle ear squamous cell carcinoma tissues and 20 adjacent normal external ear canal skin tissues using immunohistochemical analysis. Results: The positive rate of RECK expression in the middle ear squamous cell carcinoma was much lower than that in the normal external ear canal skin. In contrast, the positive rate of MMP9 expression was higher in middle ear squamous cell carcinoma tissue than that in normal external ear canal skin tissue. The expressions of RECK and MMP9 were correlated with the histological grade and tumor stage, but not with patient age or gender. Conclusions: RECK and MMP9 are involved in middle ear squamous cell carcinoma and may serve as markers to evaluate progression and metastasis.