Significance of a reversal expression of the angiopoietin-1 and 2 in oral squamous cell carcinoma

Abstract

To investigate the significance of Angiopoietin-1 (Ang-1), Angiopoietin-2 (Ang-2) expression in angiogenesis, vessel maturation, progress and prognosis of oral squamous cell carcinoma (OSCC). The expression of Ang-1, Ang-2, vascular endothelial growth factor (VEGF), CD34 and alpha-smooth muscle actin (alpha-SMA) were studied in 62 human OSCCs, 30 adjacent noncancerous oral tissues and 10 normal oral mucosa by conventional immunohistochemistry. Microvessel density (MVD) and vessel maturation index (VMI) were also assessed with double-labeling immunohistochemistry staining against CD34, a marker of pan-endothelial cells, and that against alpha-SMA, a marker of mural cells (pericytes/smooth muscle cells). The images were analyzed with BioMias system. Ang-1/Ang-2 protein expression ratio were significantly lower in OSCC than that in adjacent noncancerous oral tissues and normal oral mucosa (t were -5.42 and -6.234, all P<0.01). There were significantly different Ang-1/Ang-2 protein expression ratio in different tumor' lymph node metastasis status and MVD groups and VMI groups, respectively (t were 3.421, -3.221, 3.824, all P<0.01). The patients with low Ang-1/Ang-2 protein expression ratio and high VEGF protein expression were found to have a significantly higher MVD when compared to others (t were 2.055, 2.345, 2.985, all P<0.05). Ang-1/Ang-2 protein expression ratio had a tendency to be a prognostic factor (chi2=3.383, P=0.066). The reversion of Ang-1 and Ang-2 expression may plays an important role in the development and progression of OSCC. It is closely associated with the angiogenesis, vessel maturation and prognosis of OSCC.