Expression of EMMPRIN in adenoid cystic carcinoma of salivary glands: correlation with tumor progression and patients' prognosis

Abstract

Extracellular matrix metalloproteinase inducer (EMMPRIN) plays a critical role in the progression of malignancies by stimulating expression of metalloproteinases (MMPs) and vascular endothelial growth factor (VEGF) in stromal cells. However, the expression of EMMPRIN in adenoid cystic carcinoma (ACC) of salivary glands, and its correlation with patients' prognosis have never been investigated thus far. In the present study, the expression of EMMPRIN was examined in 72 ACCs and 20 normal salivary gland tissues by immunohistochemistry. The expression of MMP-2, MMP-9, VEGF, Ki-67 index, and microvessel density (MVD) labeled by CD31 were also assessed by immunohistochemistry in ACCs. The positivity of EMMPRIN in ACCs was 62.5%, which was significantly higher than that in normal salivary gland tissues (P<0.01). EMMPRIN expression was positively correlated with tumor size, histotypes, clinical stage, perineural invasion, vascular invasion, metastasis, expression of MMP-2, MMP-9, VEGF, Ki-67 index, and MVD (P<0.05), but not with gender, age, tumor site or recurrence (P>0.05). Multivariate analysis showed that EMMPRIN expression, Ki-67 index, and solid histotype had an independent prognostic effect on overall survival (P<0.05). According to our findings, EMMPRIN might actively be involved in the growth, angiogenesis, invasion and metastasis of ACCs. Measurement of EMMPRIN may be helpful in predicting patients' prognosis and understanding the malignant behaviors of ACCs.