Expression of endothelial nitric oxide synthase and vascular endothelial growth factor in oral squamous cell carcinoma: its correlation with angiogenesis and disease progression.

Angiogenesis is a crucial step in the successful growth, invasion, and metastasis of a tumor. It has been popularly accepted that vascular endothelial growth factor (VEGF) is the most potent angiogenic factor in tumor angiogenesis. As another possible star molecule responsible for tumor angiogenesis, the role of nitric oxide (NO) in tumor biology has gained much attention in recent years. The aim of this study was to investigate whether the expression of endothelial nitric oxide synthase (eNOS) and VEGF in oral squamous cell carcinoma (OSCC) is associated with angiogenesis. The present study also made a preliminary exploration of the possible cross-talking existing between eNOS and VEGF during tumor angiogenesis. In this study, expression of eNOS and VEGF were studied immunohistochemically in tissue sections from 40 patients with OSCC and 20 normal controls. To exclude eNOS antibody cross-reactivity with inducible or neuronal nitric oxide (iNOS or nNOS), eNOS expression was confirmed by using an eNOS mRNA in situ hybridization kit. The intratumoral microvessels were highlighted by immunostaining with anti-factor VIII-related antigen monoclonal antibody and counted as well-established methods. Then, chi-square test or Student's t-test was performed to study the correlations between the expression of eNOS and VEGF, microvessel density (MVD), and various clinicopathologic factors. Both eNOS and VEGF expression significantly increased in OSCC tissues, with a positive rate of 47.5% and 50%, respectively. The average MVD in OSCC tissues was 23.45 per high-power field (HPF), showing an obvious association with lymph node metastasis and clinical stages of patients with OSCC. Either eNOS or VEGF positivity was correlated with vessel involvement and OSCC progression. The mean MVD was significantly higher in eNOS- or VEGF-positive tumors than in eNOS- or VEGF-negative tumors. An obvious, correlation was also seen between eNOS and VEGF expression in OSCC tissues in this study. Overexpression of eNOS and VEGF might make an important contribution to the tumor angiogenesis in OSCC. NO generation by eNOS might be implicated in the VEGF-associated angiogenic process. Further investigation of the possible cross-talking between eNOS and VEGF with respect to tumor angiogenesis is necessary.

Shang ZJ ，Li JR 《JOURNAL OF ORAL PATHOLOGY & MEDICINE》

Expression of endothelial nitric oxide synthase and vascular endothelial growth factor in human malignant melanoma and their relation to angiogenesis.

Angiogenesis is the major and key factor for growth and invasion of tumours, including malignant melanoma (MM), but the factors that contribute to tumour angiogenesis are still unclear. To study expression of endothelial nitric oxide synthase (eNOS) and vascular endothelial growth factor (VEGF) in human MM and their relation to angiogenesis. To investigate the correlation between eNOS and VEGF and the role of nitric oxide (NO) generated by eNOS in the process of mediating angiogenesis by VEGF. Tissue sections from 31 patients with MM were examined using immunohistochemistry and morphological quantitative analysis for protein expression of eNOS and VEGF. Microvessel density (MVD) was counted in endothelial cells in immunostained by anti-FVIII:RAg antibody. Positive eNOS and VEGF immunostaining were observed in 77.4% and 83.9% of MM lesions, respectively, whereas pigmented naevi never expressed eNOS and VEGF. A positive correlation between eNOS and VEGF in MM was observed. Expression of eNOS and VEGF was positively correlated with MVD expression in MM, and MVD expression in MM was stronger than in pigmented naevi. Expression of eNOS and VEGF was not correlated with lymph node metastasis. CONCLUSIONS. On the basis of the current data showing that malignant melanocytic tumours displayed strong VEGF and eNOS expression, whereas benign melanocytic proliferations showed no immunoreactivity for VEGF and eNOS, such expression may be used as a discriminating factor to distinguish malignant melanoma from pigmented naevi. Expression of eNOS and VEGF may contribute to angiogenesis of MM, eNOS probably plays an important role in mediating VEGF-induced angiogenesis.

Tu YT ，Tao J ，Liu YQ ，Li Y ，Huang CZ ，Zhang XB ，Lin Y ... -  《CLINICAL AND EXPERIMENTAL DERMATOLOGY》

Upregulation of serum and tissue vascular endothelial growth factor correlates with angiogenesis and prognosis of oral squamous cell carcinoma.

To investigate both serum vascular endothelial growth factor (VEGF) concentrations and VEGF expression in patients with oral squamous cell carcinoma (OSCC), and to clarify whether upregulation of VEGF in OSCC patients is associated with increased microvessel density and various clinicopathologic features of patients with OSCC. The study population included 31 patients with OSCC and 10 normal individuals. Concentration of serum VEGF was determined by using an ELISA kit. Immunohistochemistry was used to evaluate VEGF expression and microvessel density in OSCC. Our results showed that both serum VEGF levels and VEGF positivity were closely associated with both regional lymph node status and clinical stage of patients with OSCC. Increased microvessel density in oral cancer tissues was significantly higher in VEGF-positive tumors than VEGF-negative tumors. Our present study indicated that upregulation of VEGF in oral cancer was correlated with both tumor angiogenesis and disease severity.

Shang ZJ ，Li JR ，Li ZB 《JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY》

Expression of pro-inflammatory protein, iNOS, VEGF and COX-2 in oral squamous cell carcinoma (OSCC), relationship with angiogenesis and their clinico-pathological correlation.

One main etiology for oral squamous cell carcinoma (OSCC) is inflammation. Inducible nitric oxide synthase (iNOS), vascular endothelial growth factor (VEGF) and cyclooxygenase-2 (COX-2) are the important molecules showing close relation to not only inflammation but also carcinogenesis and angiogenesis. Angiogenesis is defined as the formation of new blood vessels from existing vasculature. It is necessary for tumor growth and progression and also involved in metastasis. The objective of this research was to study the expression and relationship among iNOS, VEGF, COX-2, angiogenesis and their clinico-pathological correlation in OSCC. In this study, standard indirect immunohistochemical technique using polyclonal antibodies specific to human iNOS, VEGF, COX-2 and CD31 was performed in formalin-fixed paraffin-embedded tissue sections of 66 OSCC samples. The staining patterns and intensity are measured and analyzed statistically. The results showed that epithelial components of squamous cell carcinomas demonstrated moderate to intense staining for iNOS, VEGF and COX-2. iNOS shows correlation with cervical lymph node metastasis and tumor staging (TNM) of the patients and angiogenesis. VEGF shows correlation with tumor grading, tumor staging and angiogenesis. COX-2 shows correlation with cervical lymph node metastasis. In conclusion, the expression of iNOS, VEGF and COX-2 exists in OSCC. The data provided show the expression of these chemical mediators associated with carcinogenesis and angiogenesis in OSCC. It can be the primary database before using angiogenesis drug against these mediators for OSCC treatment.

Sappayatosok K ，Maneerat Y ，Swasdison S ，Viriyavejakul P ，Dhanuthai K ，Zwang J ，Chaisri U ... -  《Medicina Oral Patologia Oral y Cirugia Bucal》

Hypoxia inducible factor-alpha expression correlates with vascular endothelial growth factor-C expression and lymphangiogenesis/angiogenesis in oral squamous cell carcinoma.

The number of blood vessels correlates with metastasis in solid tumors, including oral squamous cell carcinoma (OSCC). Hypoxia inducible factor-1alpha (HIF-1alpha) could play a role in tumor lymphangiogenesis by regulating the lymphatic expression of vascular endothelial growth factor-C (VEGF-C). HIF-1alpha protein expression, VEGF-C protein expression, lymphatic vessel density (LVD) and blood vessel density (BVD) in OSCC were investigated. HIF-1alpha and VEGF-C protein expression were investigated by means of immunohistochemistry in samples from 65 cases of OSCC. The density of the lymphatic microvessels and blood microvessels immunohistochemically stained by LYVE-1 and CD34 antibody, respectively, was calculated. The association between the HIF-1alpha expression and the clinicopathological parameters was evaluated. HIF-1alpha overexpression occurred in 43 out of the 65 tumor samples (66.2%), while VEGF-C overexpression was observed in 34 out of the 65 tumor samples (52.3%). Higher LVD was found in both high HIF-1alpha and high VEGF-C expression cases. HIF-1alpha overexpression was significantly correlated with VEGF-C overexpression (p = .018, Chi-square test), higher LVD (p < 0.001, Mann-Whitney U-test), and regional lymph nodal involvement (p = 0.004, Chi-square test) as well as UICC TMN classification (p = 0.043, Chi-square test), respectively. In addition, higher BVD existed in the high HIF-1alpha and VEGF-C expression groups (p < 0.001, Mann-Whitney U-test). HIF-1alpha might play a crucial role in regional lymph node metastasis as a regulator of lymphangiogenesis and angiogenesis in OSCC with a possible novel pathway involving VEGF-C. Therefore, HIF-1alpha might be a particularly promising target for controlling regional lymph node metastases by a combination of antiangiogenic and anti-lymphangiogenic effects in OSCC.

Liang X ，Yang D ，Hu J ，Hao X ，Gao J ，Mao Z ... -  《ANTICANCER RESEARCH》