Vascular Endothelial Growth Factor in the Pathogenesis of Endometriosis

Oh, S T; Lee, M C; Park, C S

Abstract

There were many reports about the development of endometriosis and progression of endometriotic lesions, but not exactly established. Recently angiogenic factors as well as various growth factors and cytokines were reported to be involved in the progression of endometriotic lesions. Several researches about the role of vascular endothelial growth factor (VEGF), one of an angiogenic factor, in endometriosis were reported, but the role of VEGF was not certain yet. In order to investigate the role of VEGF in endometriosis we studied VEGF expression in normal endometrium (n=10) and endometriotic lesions (n=10) by immunohistochemistry, and the effect of VEGF on proliferation of endometrial stromal cell after adding VEGF into culture system by autoradiography. The tissues from 10 patients with endometriosis were all early proliferative phase due to preoperative treatment with gonadotropin releasing hormone (GnRH) agonist and those of control women were 5 proliferative and 5 secretory phases. Followings were the results. 1. In control women, the expression of VEGF in endometrial stromal cells was weak in proliferative phase but progressively strong in edematous area of secretory phase. The expression of VEGF in stromal cells of endometriotic lesions was strong in spite of early proliferative phase due to preoperative GnRH agonist therapy. 2. The addition of VEGF into endometrial stromal cells stimulated the proliferation of stromal cells in both normal endometrium and endometriotic lesions. However there was no statistical differences among stimulation effect of growth after adding VEGF. Above results indicated that VEGF was thought to have the effect of stimulation of the proliferation of stromal cells in normal endometrium and endometriotic lesions. Expression of VEGF in normal endometrium suggest autocrine mechanism of increased expression in secretory phase and decreased expression in proliferative phase. However in endometriosis, it is suggested that this autocrine mechanism was failed and increased production of VEGF during proliferative phase. Therefore this failure of autocrine action resulted in progression of endometriosis by continuous proliferation of endometrial tissue. In conclusion, VEGF plays important role in the pathogenesis of endometriosis.