Expression And Significance Of Notch Gene Family In Salivary Gland Tumors

Objective:On the basis of analyzing the bioinformatics of the expression profiles constructed by the different metastasis cell lines of salivary adenoid cystic carcinoma(ACC-M, ACC-2), to study the expressions of notch gene family in the cell lines. To investigate the expressions of the products of notch-1 gene in salivary adenoid cystic carcinoma, pleomorphic adenoma and the adjacent normal salivary gland tissue, then to explore the effects of notch gene family in the tumorigenesis and progression of salivary gland tumors.Methods: The migration distance of the expression profile fragments on the gel was measured by image analysis software. SAS statistical software was used to fit the curves. Calculate the base pairs of the fragments which had the best fitting curves. The Notch gene family was screened through bioinformatics analysis. Semi-quantitative RT-PCR was used to examine the mRNA level of notch gene family in the ACC-M and ACC-2. Immunohistochemical assay was applied to determine the expression of the notch-1 protein in 25 salivary adenoid cystic carcinoma, 22 pleomorphic adenoma and 10 normal salivary gland tissue. All datas were analyzed by SPSS l1.5 software package.Results: Notch gene family was detected in the two cell lines by analyzing the bioinformatics of the gene expression profile constructed by ACC-M and ACC-2. The expression levels of these four homologues were different. The results of the Semi-quantitative RT-PCR demonstrated that Notch-1, Notch-2, Notch-3 and Notch-4 were expressed in the ACC-M and ACC-2, the expression of Notch-1, Notch-2 and Notch-4 in ACC-M were significantly higher as compared with ACC-2(P<0.05). The expression of Notch-3 was no statistical significantly difference between the two cell lines. The results of the immunohistochemistry showed that the Notch-1 protein was localized in the cytoplasm of malignant cells in salivary adenoid cystic carcinoma. Notch-1 protein was detected in the epithelial components in pleomorphic adenoma and was undetected in the cartilaginous components and mucous components. Notch-1 was undetected or expressed lowly in gland alveolus cells in normal tissue. It was expressed in the ductal epithelial cells. The expression of Notch-1 protein in salivary adenoid cystic carcinoma was considerably higher than those in the pleomorphic adenoma (P<0.05). The expression of Notch-1 protein in pleomorphic adenoma was considerably higher than those in the normal tissue (P<0.05). Furthermore, It was statistical significantly difference between the metastatic salivary adenoid cystic carcinoma and the non-metastatic samples (P<0.05).Conclusions: Notch-1 may play a certain role in the tumorigenesis and progression of salivary adenoid cystic carcinoma. The upregulated expression may be related to the tumor,s malignancy and metastasis. More investigations are needed to demonstrate the role of Notch gene and Notch signaling pathway in the tumorigenesis, progression, invasion and metastasis of salivary adenoid cystic carcinoma.