Vascular Endothelial Growth Factor Expression Correlates with p53 Mutation and Angiogenesis in Squamous Cell Carcinoma of the Head and Neck

Abstract

Vascular endothelial growth factor (VEGF) has potent angiogenic activity and has been identified in a wide variety of malignancies, including head and neck squamous cell carcinoma (HNSCC). The tumour-suppressor gene p53 has been thought to regulate VEGF. Cryostat sections of 33 head and neck squamous cell carcinomas (HNSCC) were immunostained for VEGF using a standard streptavidin-biotin complex procedure. To evaluate angiogenesis, microvascular density was counted by staining endothelial cells immunohistochemically using anti-vWF monoclonal antibody. The p53 gene status was analysed using a PCR-SSCP analysis and direct sequencing. VEGF positive staining was detected in 18 (55%) out of 33 tumours. VEGF immunoreactivity did not correlate with the main clinicopathological characteristics of the patients (localization, T-stage, N-status, histological grading). Statistical analysis gave a clear correlation between the tumour vascularity and the VEGF protein expression (p = 0.0036). VEGF negative tumours showed a lower mean number of microvessels per microscopic field (60.3 +/- 15.5) than VEGF positive tumours (79.6 +/- 22.9). P53 mutations were identified in 12 (36.4%) of 33 tumours. The association of p53 mutations and VEGF expression level was significant (0.027). The higher microvessel density in VEGF positive tumours supports the importance of VEGF for tumour angiogenesis in HNSCC. Our results support the hypothesis of a p53 regulation on the angiogenic process through a VEGF up-regulation.