Increased expression of nestin and VEGF in endometrial polyps: an immunhistochemical study

Background: Pathogenesis of endometrial polyps have not been fully understood however the increased proliferation of blood vessells and fibrosis may play an important role in the pathogenesis of endometrial polyps. Vascular endothelial growth factor (VEGF) is a a key regulator of angiogenesis and vascular function. Nestin is another molecule which has been reported to be associated with the process of angiogenesis. The aim of this study was to evaluate the expression of Nestin protein and VEGF in pathogenesis of endometrial polyps. Methods: A total of 20 women who had hysteroscopic and histologic confirmation of benign endometrial polyps and their normal endometrial tissue were recruited into the study. Immunohistochemical analysis for VEGF, Nestin and CD34 were performed on formalin fixed, paraffin-embedded tissue using the streptavidin-biotin-peroxidase technique. Angiogenesis was assessed by immunohistochemistry using monoclonal antibody against CD34. Results: Immunostaining of VEGF in glandular epithelial cells and stromal fibroblasts, and immunostaining of Nestin in newly formed vessels were determined. Immunopositivity staining of VEGF in endometrial polyps were significantly stronger than normal endometrium (P<0.05). Nestin expression was observed in vessels which were smaller than that of CD34-positive preexisting large blood vessels. Endometrial polyps demonstrated significantly greater expression of Nestin in proliferating endothelial cells, compared with control endometrium (P<0.05). Conclusion: This study suggests that the increased expression of VEGF and Nestin protein which are may have a role in the pathogenesis of endometrial polyps.