| Nitric oxide (NO) is a kind of simple but important signal molecule functioning as a kind of second messenger and taking part in many physiological and pathological processes including tumor. Endogenous NO production depends on conversion of the amino acid L-arginine to L-citrulline by a family of enzymes named NO synthase (NOS). NOS has three isoforms: endothelial type NOS (eNOS), neuronal type NOS (nNOS) and inducible type NOS (iNOS). Research so far has proved that NOS exists in many kinds of tumor cells including cell of liver cancer, of breast cancer and of squamous cell carcinoma in head and neck. It is also reported that expression of NOS and its production NO have correlation to prognosis in certain malignant tumors. Angiogenesis existing in many tumor tissues and regarded as an inevitable phase in tumor progress is correlative to tumor growth, local invasion and metastasis. Vascular endothelial growth factor (VEGF) is thought to be the most important promoting factor of angiogenesis.Objectives of this research include: 1. investigating expressions of three isoforms of NOS in oral squamous cell carcinomas (OSCC); 2. investigating expressions of VEGF in OSCC; 3. examining microvessel density (MVD) of tumor tissues and investigating angiogenesis in OSCC; 4. investigating NOS expression's relationship with metastasis in OSCC; and 5. investigating NOS expression's relationships with VEGF expression and MVD in OSCC. Materials and Methods:1. 41 cases of OSCC (SCC of tongue, of mandibular gingivae and of buccal mucosa) were selected. Information of these cases was collected including age, gender, location, pathological type, metastases and TNM stage. 9 cases of normal oral mucosa were used as controls to detect NOS expression.2. Using immunohistochemical SP staining, we examined MVD (labeled by CD34) and investigated expressions of three isoforms of NOS and VEGF in paraffin slices of 41 OSCC cases. As controls, expressions of three isoforms of NOS in 9 cases of normal oral mucosa were also detected.3. Relationships of NOS expression with metastasis, pathological type and TNM stages were analyzed in OSCC, and so were relationship of NOS expression with VEGF expression and MVD. Results:1. The positive eNOS expression rate of 41 cases of OSCC was 48.80%. There were a significant statistical difference of positive eNOS expression rate between LN- group (19.05% ) and LN+ group (80.00%) (x 2=15.23, P=0.000), no statistical difference between Gl group (52.00%) and G2+G3 group (43.75%), and a statistical difference between TNM stage (I+ II) group (25.00%) and TNM stage (III+IV) group (64.00%) ( x 2=5.939,2. The positive nNOS expression rate of 41 cases of OSCC was 51.20%. There were no statistical difference of positive nNOS expression rate between LN- group (38.09%) and LN+ group (65.00%), no statistical difference between Gl group (52.00%) and G2+G3 group (50.00%), and no statistical difference between TNM stage ( I + II ) group (37.50%) and TNM stage (III+IV) group (60.00%).3. The positive iNOS expression rate of 41 cases of OSCC was 63.41%. There were a significant statistical difference of positive iNOS expression rate between LN- group (42.90%) and LN+ group (85.00%) ( x 2=7.84, P=0.005), no statistical difference between Gl group (72.00%) and G2+G3 group (56.25%), and a statistical difference between TNM stage ( I +11) group (43.75%) and TNM stage (III+IV) group (76.00%) ( x 2=4.374, P=0.036).4. There was no positive expression of eNOS, nNOS and iNOS in 9 cases of normal oral mucosa.5. The mean value of 41 cases of OSCC was 39.707?1.230. The mean value of MVD of LN- group was 33.048?.657 as that of LN+ group 46.700?.280, and there was a significant statistical difference between them (/=4.874, P=0.000). The mean value of MVD of TNM stage ( I + II ) group was 34.43 8? 1.530 as that of TNM stage (III+IV) group 33.048?.657, and there was a statistical difference between them (/=2.566, /MX014).6. The positive VEGF expression rate of 41 cases of OSCC was 61.00%. There... |
