VEGF AND HIF-1α EXPRESSION IN NEPHROBLASTOMA CORRELATES WITH ANAPLASIA

HIF-1 alpha (hypoxia inducible factor la) is a transcription factor that has a role in maintaining oxygen homeostasis. Increased expression of HIF-1 alpha leads to a rise in amount of VEGF (vascular endothelial growth factor), thus inducing neovascularization. The aim of this study was to determine the expression of VEGF and HIF-1 alpha in nephroblastoma and to compare it with the clinical and pathohistological characteristics of this tumour (dominant histological component, presence of anaplasia and necrosis, size of the turnout; age and sex of the patient). Expression of VEGF and HIF-1 alpha was determined by immunohistochemistry of the tumour tissue. Monoclonal mouse anti-VEGF and polyclonal rabbit anti-HIF-1 alpha antibodies were used. For immunoscoring of both markers the degree of positive staining was evaluated semiquantitatively. The chi(2)-test, which includes Spearman 's rank correlation and the ANOVA test were used for statistical analysis of data. Most of the tumours were positive for VEGF (38/40) and HIF-1 alpha (37/40). Significant statistical correlation was found between HIF-1 alpha and the presence of anaplasia (p-0.02986). A clear correlation between VEGF and tumour size was established (Spearman's rank correlation: p=0.0027), showing strong positivity in larger tumours. Based on this study we can conclude that VEGF and HIF-1 alpha are present in Wilms 'tumours, playing an important role in angiogenesis and tumour progression.