Hypoxia correlates with angiogenesis in cervical cancers

Abstract

Tissue hypoxia stimulates the induction of the angiogenic substances vascular endothelial growth factor and erythropoietin in the locus of the tissue. We have previously demonstrated that erythropoietin promotes angiogenesis by binding to its receptor in the endothelial cells of uterine and ovarian malignancies. In the present study, we examined whether malignant uterine cervix tissue showed hypoxia and whether hypoxia correlated with high vascular density through vascular endothelial growth factor. To detect tissue hypoxia, we estimated the content of ATP in squamous cell carcinoma of the uterine cervix and in the normal cervix, using liquid chromatography columns. Surgically resected samples were fixed in Zamboni solution and processed for immunohistochemical microscopy to identify the endothelial cells and the location of vascular endothelial growth factor, with the use of anti-factor VIII and anti-vascular endothelial growth factor165 antibody, respectively. The microvessels in a definite area were counted in sections of each specimen. Significantly lower ATP levels and significantly higher vascular density were seen in squamous cell carcinoma than in the controls (P<0.05). The microvessel number in relation to ATP content was significantly higher in squamous cell carcinoma than in the controls (P<0.001). Moreover vascular endothelial growth factor, the hyperplastic epithelium of the squamous cell carcinoma contained the immunoreactivity, with characteristic histopathological features suggesting retention of tissue fluid. Squamous cell carcinoma of the uterine cervix showed hypoxia which correlated with abundant vascularity. Vascular endothelial growth factor expressed in the hyperplastic epithelium appears to promote angiogenesis in squamous cell carcinoma of the uterine cervix.