Expression pattern of integrin adhesion molecules in endometriosis and human endometrium

Integrins are cell adhesion molecules that undergo cell-specific dynamic ch anges during the normal menstrual cycle in the human endometrium. Here, usi ng immunohistochemistry, we have investigated the expression pattern of the integrins alpha(v), alpha(2)beta(1), alpha(3)beta(1), alpha(3), alpha(6), beta(1), beta(2) and beta(3) in the human ectopic endometrium of 30 patient s and in nine cases in the corresponding eutopic endometrium. The biopsies were obtained during the early or late follicular phase (25 cases), during the corpus luteum phase (four cases) and in one case after 6 months' treatm ent with a gonadotrophin releasing hormone (GnRH) agonist, The integrin exp ression was independent of the ovarian steroid situation at the time of bio psy. The integrin alpha(6) was expressed in all endometriotic and endometri um samples. The integrin alpha(3) was absent in all endometrium tissues of patients with endometriosis, However, the corresponding endometriotic lesio ns re-expressed this adhesion molecule in 15 cases,No change in integrin be ta(3) expression pattern could be demonstrated in either endometriotic lesi ons or endometrium samples, regardless of the menstrual cycle phase. A corr elation between serum oestradiol and progesterone concentrations and the ex pression of the investigated integrins was not observed, thus indicating th at these two hormones play a minor role in the regulation of the cell adhes ion molecules examined. Our investigation suggests that endometriosis is a dedifferentiated disease as it expressed different integrins in comparison with the eutopic endometrium, and independently of the hormonal situation. The ability of endometriotic tissues to express integrins may explain the h igh recurrence rates in patients with endometriosis, as these samples retai n their adhesion potency after retrograde menstruation and are thus able to establish cell-cell and cell-matrix intel actions with the surrounding per itoneum.