[Expression of vascular endothelial growth factor receptors in the ectopic and eutopic endometrium of women with endometriosis].

OBJECTIVE: To study the localization and expression of the vascular endothelial growth factor receptors (VEGFR) Fms-like tyrosine kinase (Flt-1) and kinase insert domain-containing receptor (KDR) in human ectopic and eutopic endometrium of patients with endometriosis.
METHODS: Specimens of endometriosis patients, aged (38 +/- 8) years, including 37 specimens of entopic endometrium, 34 specimens of ovarian chocolate cyst, 34 specimens of ovarian chocolate cyst, 15 specimens of red peritoneal endometriosis lesions, and 4 abdominal wall endometriosis lesions were collected. Specimens of endometrium of 33 patients with other gynecological diseases, aged (36 +/- 8) years, were collected during operation and used as controls. Immunohistochemistry was used to detect the location and expression of Flt-1 and KDR protein in different tissues. Western blotting was used to detect the protein expression of Flt-1 and KDR protein in different tissues. The mRNA expressions of Flt-1 and KDR were detected by RT-PCR.
RESULTS: Flt-1 and KDR were expressed in the endometrial glandular epithelium and stromal cells besides the endometrial blood vessels. The positive expression rate of Flt-1 and KDR in the ectopic endometrium of endometriosis patients were 94.3% and 91.4% respectively, both significantly higher than those in the ovarian endometrial cyst (74.3% and 77.1% respectively, both P < 0.05), and similar to those in the eutopic endometrium of the endometriosis patients (93.8% and 90.6% respectively, both P > 0.05). In the eutopic endometrium of the endometriosis patients, the Flt-1 mRNA expression level was 2.4 +/- 1.2 and the Flt-1 protein expression level was 31 +/- 17, and the KDR mRNA expression level was 3.0 +/- 1.4 and the KDR protein expression level was 36 +/- 24, all significantly higher than those in the ovarian endometrial cyst (1.5 +/- 0.9 and 1.8 +/- 1.0 for the Flt-1 and KDR mRNA expressions, and 17 +/- 6 and 20 +/- 11 for the Flt-1 and KDR protein expressions, all P < 0.05), and similar to those in the eutopic endometrium of the non-endometriosis patients (1.9 +/- 0.8 and 2.3 +/- 1.3 for the Flt-1 and KDR mRNA expressions, and 24 +/- 18 and 25 +/- 16 for the Flt-1 and KDR protein expressions, all P > 0.05)
CONCLUSION: VEGF may play certain biological role in the development of endometriosis through VEGFR (Flt-1 and KDR). The expression of Flt-1 and KDR in the endometriotic lesion appears to be associated with neovascualization.