Abstract:
Research question: How closely related are adenomyotic and endometrial glands?
Design: In this study, the mRNA and protein database www.proteinatlas.org was searched for proteins expressed
predominantly in the endometrial glands. Specificity was tested with tissue microarrays. Biopsy specimens of
endometrial, adenomyotic tissue, or both, were collected after surgery from 21 women without endometriosis,
20 women with endometriosis, 18 women with adenomyosis together with endometriosis and 12 women with
adenomyosis alone. Tissue expression was analysed by immunohistochemistry.
Results: Two proteins were identified: calcyphosine (CAPS), and msh homeobox 1 (MSX1). A high abundance and
good specificity in endometrial glands were found. Both proteins, CAPS and MSX1, showed a high specificity for
endometrium and are both localized in the luminal cells and epithelial cells of the glandular and adenomyotic glands.
No significant differences were found between CAPS- and MSX1-positive endometrial glands between cases with
and without endometriosis. Also, no cycle-specific different expression was found. Furthermore, a close relationship
between the adenomyotic glands and the endometrial glands for CAPS (range 63.0–98.3%) and for MSX1 (range
87.1–99.3%) could be demonstrated. Only 11.2% and 6.8% negative glands for CAPS and MSX1 were identified in all
tissues from all patients, respectively; none were negative for both proteins.
Conclusions: Taken together, our results show that the protein expression pattern of adenomyosis is nearly identical
to those of the endometrium with and without endometriosis, thus suggesting endometrial glands as the main source
for adenomyotic glands.
