New vessel formation in peritumoral area of squamous cell carcinoma of the head and neck.

Abstract

This study was conducted to investigate the dynamic process of new vessel formation, fundamental for tumor growth and metastasis, in head and neck squamous cell carcinoma (HNSCC). We used immunohistochemistry, confocal laser-scanning microscopy, and reverse transcriptase-polymerase chain reaction to study endothelial cell and concomitant pericyte development with markers CD133, CD34, VEGFR-2, CD31, vWF, and STRO-1 in tumor and peritumoral tissues of 18 patients with HNSCC. Highly compressed and structurally abnormal vessels with barely any activity of new vessel formation were found in tumor tissue, whereas the adjacent peritumoral tissue vessels showed a normal architecture with tight endothelial cell-pericyte interaction and a high activity of angiogenesis. Endothelial precursor cells expressing CD133/VEGFR-2 could be incorporated into these newly formed vessels, forming cell clusters from which a thin endothelial lining could emanate. These data show a high activity of new vessel formation in the peritumoral stroma of HNSCC, with endothelial precursor cells being incorporated into these structures.