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Objective: To investigate the expression and significance of transforming growth factor-β(1) (TGF-β(1)) and Ki-67 nuclear antigen in salivary gland mucoepidermoid carcinoma., Methods: The expression of TGF-β(1) and Ki-67 nuclear antigen in 20 cases of salivary gland pleomorphic adenoma and 45 cases of mucoepidermoid carcinoma were detected by the streptavidin-peroxidase immunohistochemical method., Results: Expression of TGF-β(1) (39/45) and Ki-67 nuclear antigen (43/45) in mucoepidermoid carcinoma was significantly higher than in pleomorphic adenoma (P < 0.05). TGF-β(1) expression was significantly higher in moderately/poorly differentiated mucoepidermoid carcinoma (16/16) than that in well differentiated mucoepidermoid carcinoma (23/29) and pleomorphic adenoma (12/20) (P < 0.05), but not different between well differentiated mucoepidermoid carcinoma (6/23) and pleomorphic adenoma (8/12) (P > 0.05). The expression of Ki-67 was increased with the increment of TGF-β(1) expression in mucoepidermoid carcinoma (P < 0.05)., Conclusions: The high expression of TGF-β(1) may play an important role in cell differentiation and malignant proliferation of mucoepidermoid carcinoma.

Objective: to determine the effects of survivin antisense oligonucleotide (ASODN) on the expression levels of survivin mRNA and human mucoepidermoid carcinoma cell line (highly metastatic Mc3) apoptosis and to explore the feasibility of survivin gene as the mucoepidermoid carcinoma therapeutic targets., Methods: the survivin ASODN was designed and synthesized and then respectively transfected into Mc3 cells. The morphological changes of the Mc3 cells were observed 24, 48 and 72 h after transfection by inverted microscope and the apoptosis rate detected by flow cytometry. Methyl thiazolyl tetrazolium (MTT) assay was used to detect the effect of the transfection on cell poliferation, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) method for analysis of apoptotic index, and semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) to detect the expression of survivin., Results: in survivin ASODN transfection group, there was less Mc3 cells than in other groups. The suspended cells dropping from the wall increased and showed typical apoptotic changes and time-dependent. Mc3 cell apoptosis rate in survivin ASODN transfection group transfected for 24, 48, 72 h was 12.96%, 14.43%, 22.69%, respectively, which were significantly higher than in other groups (P < 0.01) and time-dependent (P < 0.05). The inhibitory rate of Mc3 cells in survivin ASODN transfection group was 22.35%, 39.04%, 43.46%, which were significantly higher than other groups (P < 0.01) and time-dependent (P < 0.05). The apoptosis index (AI) of Mc3 cells in survivin ASODN transfection group was 11.038%, 12.172%, 18.900%, significantly higher than other groups (P < 0.01) and time-dependent (P < 0.05). The survivin mRNA levels in Mc3 cells were 0.739 ± 0.008, 0.668 ± 0.007, 0.500 ± 0.006, and the relative inhibition rate in these cells was 18.21%, 26.06%, 44.82%, significantly lower than other groups (P < 0.01) and time-dependent manner (P < 0.01)., Conclusions: survivin ASODN could inhibit the proliferation of Mc3 cells and induce the apoptosis of Mc3 cells. It also can inhibit the expression of survivin mRNA. Survivin can be used as a gene therapy targets for mucoepidermoid carcinoma.

Objective: To study the effects of 17 beta-estradiol on the adhesion, invasion and motility potential of salivary mucoepidermoid carcinoma Mc3 cells., Methods: The effects of 17 beta-estradiol on adhesion, invasion and motility potential of salivary mucoepidermoid carcinoma Mc3 cells were investigated with cell attachment assay on fibronectin (FN), wound assay, chemotaxis assay, and gelatin-incorporated SDS-PAGE electrophoresis. The expression of estrogen receptor in Mc3 cells was determined by immunohistochemistry assay., Results: Attachment rates of Mc3 cells treated with E2 at 10(-9), 10(-8), 10(-7), 10(-6) mol/L were 38.3%, 50.4%, 69.2% and 91.1% respectively, and the rate in control was 25.0%. When exposed to 17 beta-estradiol at 10(-9), 10(-8), 10(-7) and 10(-6) mol/L for 48 h, motility of Mc3 cells on FN increased by 16.9%, 40.9%, 36.4% and 38.8% respectively. When at 10(-6) mol/l, 17 beta-estradiol increased chemotaxis potential of Mc3 cells to FN by 60.3%. The activity of 68 000 matrix metalloproteinase (MMP-2) of Mc3 cells was enhanced at different levels by 10(-9), 10(-8), 10(-7), 10(-6) mol/L of 17 beta-estradiol, and estrogen receptor was also detected in nucleus of Mc3 cells by immunohistochemistry assay., Conclusions: 17 beta-estradiol at physiological concentration may enhance the adhesion, invasion and motility potential of salivary mucoepidermoid carcinoma Mc3 cells.

Objective: To investigate the effects of hexamethylene bisacetamide (HMBA) on related genes expression of apoptosis and cell proliferating in human mucoepidermoid carcinoma cell line MEC-1., Methods: MEC-1 was induced 72 hours by 0.002 mol/L HMBA in vitro. The morphologic observation and the expression of PCNA, bcl-2, bax protein and bcl-2 mRNA were determined by microscope, immunohistochemistry, in situ hybridization and image analysis., Results: The expression of bax, bcl-2 protein and bcl-2 mRNA were higher than control group (P < 0.01). The related genes of cell proliferating PCNA were decreased in control group., Conclusions: HMBA could inhibit the MEC-1 cell proliferation by down-regulation of PCNA expression, it could also induce apoptosis effectively that might be through the way of up-regulation of bax and bcl-2 gene expression.

In recent years, a tumor suppressor gene nm23 has been found to be associated with decreased tumor metastatic potential. Allelic deletion, mutation and low expression of this gene has been correlated with tumor metastatic potential in a number of tumors. We examined the expression of nm23 in 40 cases of salivary gland malignant carcinomas by immunohistochemical method. The results showed that nm23 lower expression tumors were associated with a higher rate of metastasis (81.8%) than nm23 higher expression (3.4%, P < 0.005). There is no correlation between nm23 lower expression and tumor size, location and pathologic type (P > 0.05). This result indicates that nm23 gene plays an important role in the metastasis of salivary gland malignant carcinoma.

The expressions and distributions of PCNA and p53 protein were studied with anti-PCNA and anti-p53 protein MoAbs, using immunohistochemical staining method in salivary gland tumour. The relationship between PCNA and p53 protein was also studied. Results indicated: Malignant mixed tumour (MmT) had a higher proliferating index (PI) of PCNA. The PI could be used as one of adjuvant diagnostic criteria; and as an important parameter for grading mucoepidermoid carcinoma (MEC); The positive expression of p53 might be a good tumour marker for MmT; Tumour tissues with positive expression of p53 had been shown higher PI of PCNA, however there was no significance difference in our group; It remained to be studied later.

To explore the expression of proliferating cellnuclear antigen (PCNA) and tumor suppressor gene P53 product in mucoepidermoid carcinoma of the salivary glands, we studied 41 cases by immunohistochemical method. All of the cases were PCNA positive. The positive index, distribution pattern and cellular staining intensity for PCNA expression were correlated with carcinoma grade. P53 protein expression was found in 17 (41.5%) of the 41 cases; among them the expressions were weak in 9 cases. These results indicate that positive index, distribution pattern and cellular staining intensity of PCNA expression may be served as an indicator for evaluating the differentiating degree of the tumor.

Mucoepidermoid carcinoma is the most common malignant tumor of salivary glands. In this report, we used hexamethylene bisacetamide (HMBA) as a inducer to induce human mucoepidermoid carcinoma cell line MEC-1 cells to differentiate. The growth kinetics, morphological changes and DNA contents of the cells were investigated. The results showed that HMBA-treated MEC-1 cells tend to become mature cells, implying that HMBA can induce differentiation of MEC-1 cells in vitro.