Expression of thymidine phosphorylase and vascular endothelial cell growth factor in human head and neck squamous cell carcinoma and their different characteristics.

Abstract

Thymidine phosphorylase (dThdPase) is identical to platelet-derived endothelial cell growth factor (PD-ECGF). dThdPase is known to promote the development of new blood vessels, which are fundamental to tumor growth and metastasis. Vascular endothelial growth factor (VEGF) is a 34-42 kilodalton (kD) protein that induces both angiogenesis and vascular permeability. Proliferating cell nuclear antigen (PCNA) is a 36 kD nuclear protein, and its expression is associated with DNA synthesis and cell proliferation. The authors investigated the correlations of dThdPase and VEGF with the growth of head and neck squamous cell carcinoma (HNSCC) in 95 patients by examining PCNA expression as a marker of tumor proliferation. They also retrospectively examined the expression of dThdPase in primary HNSCC and its association with angiogenesis and clinicopathologic findings. Microvessel count was significantly correlated with the expression of VEGF (P = 0.046) but not with dThdPase expression. The expression of PCNA was significantly correlated with dThdPase (P < 0.001) but not VEGF expression. A significant correlation was found between VEGF and dThdPase expression (P = 0.003). Neither dThdPase nor VEGF correlated with clinicopathologic findings, except for the correlation between tumor location and VEGF expression (P 0.020). These findings suggest that VEGF is involved in angiogenesis in HNSCC. dThdPase may have effects on tumor growth other than angiogenic activity in HNSCC.