Objective: To evaluate the expression of vascular endothelial growth factor (VEGF), angiopoietin 1 and 2 (ANGPT1/ANGPT2), and matrix metalloproteinases 1, 2, and 9 (MMP-1, MMP-2, MMP-9) in eutopic and ectopic endometrium.
Design: Experimental retrospective study.
Setting: University hospital.
Patient(s): Eutopic and ectopic endometrium samples from 30 women with endometriosis and endometrium biopsy samples from 30 healthy women.
Intervention(s): Biopsies of ovarian endometriomas and eutopic endometrium.
Main outcome measure(s): Immunohistochemical staining to evaluate the expression of VEGF, ANGPT1, ANGPT2, MMP-1, MMP-2, and MMP-9, and real-time polymerase chain reaction analysis to quantify mRNA expression.
Result(s): Patients with endometriosis had higher levels of angiogenic factors and metalloproteinases in endometriotic cysts than in eutopic endometrium. These substances were also overexpressed in eutopic endometrium of patients with endometriosis when compared with normal controls.
Conclusion(s): Overexpression of angiogenic factors and metalloproteinases may be the characteristic feature of endometrium with greater potential to transform into endometriotic lesions in the peritoneal cavity. Structural and/or functional differences of eutopic endometrium could have a role in the pathogenesis of endometriosis secondary to the backward passage of endometrial cells into the peritoneal cavity. Whether these local factors may induce, promote, and/or regulate this transformation remains to be determined.