B-cell specific Moloney murine leukemia virus insertion site 1 contributes to invasion, metastasis, and poor prognosis in salivary adenoid cystic carcinoma.

Background/purpose: Upregulation of B-cell specific Moloney murine leukemia virus insertion site 1 (BMI-1) has been involved in the invasion, metastasis, and poor prognosis of many cancers. The aim of this study was to evaluate the levels and clinical significance of BMI-1 in saliva of patients with salivary adenoid cystic carcinoma (SACC), and to analyze biological function and mechanism of BMI-1 in the invasion and metastasis of SACC. Materials and methods: The levels of BMI-1 in saliva and tumor tissues of SACC patients were determined. The correlation of salivary BMI-1 levels with clinicopathological parameters and clinical outcomes in patients with SACC was analyzed. Additionally, the effects of BMI-1 on wound-healing, transwell invasion, and epithelial-mesenchymal transition (EMT)-related protein expression in vitro as well as on tumorigenicity and experimental lung metastasis in vivo were investigated through exogenous overexpression and silencing of BMI-1 in SACC cells. Results: BMI-1 levels increased in saliva and tumor tissues in SACC patients with invasion or metastasis. High salivary BMI-1 levels were correlated with poor TNM stage, poor overall survival, and disease-free survival. Exogenous expression of BMI-1 in SACC-83 promoted its migration and invasion, while silencing BMI-1 in SACC-LM inhibited its migration and invasion in vitro and suppressed tumorigenesis and lung metastasis in vivo. Furthermore, BMI-1 regulated the expression of EMT-related proteins in SACC. Conclusion: Our study shows that BMI-1 can serve as a valuable biomarker to identify tumor invasion and metastasis in SACC, predict its prognosis, and act as a promising therapeutic target for SACC.

Salivary Heparanase Level Is a Potential Biomarker to Diagnose and Prognose the Malignant Salivary Gland Tumor.

BACKGROUND: Upregulation of heparanase has been reported in an increasing number of human cancer tissues. However, the level of salivary heparanase and its clinical significance in patients with salivary gland tumors remain unclear. METHODS: Salivary heparanase levels in patients with salivary gland tumors were detected using enzyme-linked immunosorbent assays (ELISAs) and the clinical significance was evaluated by analyzing the correlations among salivary heparanase levels, clinicopathological parameters, and clinical outcomes. RESULTS: The levels of salivary heparanase were significantly higher in patients with malignant salivary gland tumors than in benign tumors and normal controls (P<0.0001). High salivary heparanase levels were positively correlated with increased lymph node metastasis (P = 0.0235) and poorer tumor node metastasis stage (TNM) (P = 0.0183). Survival analyses revealed that high salivary heparanase levels were associated with worse overall survival (P = 0.0023) and disease-free survival (DFS) (P = 0.0025). CONCLUSIONS: The study shows that salivary heparanase levels, as detected by the ELISAs, can be used to diagnose and provide an accurate prognosis for malignant salivary gland tumors. Salivary heparanase level was an independent predictor in patients with malignant salivary gland tumors.