Expression of focal adhesion kinase in the eutopic endometrium of women with adenomyosis varies with dysmenorrhea and pelvic pain

Adenomyotic glands are highly related to endometrial glands

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.

FAK regulates epithelial‑mesenchymal transition in adenomyosis

Epithelial‑mesenchymal transition (EMT) has been associated with the pathogenesis of adenomyosis; focal adhesion kinase (FAK) serves an important role in the EMT process. The aim of the present study was to determine whether FAK regulates EMT in adenomyosis and to investigate the potential pathway in this process. The expression of FAK and EMT‑associated molecules in adenomyosis and control cells were determined by immunohistochemical staining and immunofluorescence at the protein level, and at the mRNA level by reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR). Small interfering RNAs were designed to knock down FAK expression. Subsequently, molecular expression was detected by immunofluorescence, RT‑qPCR and western blotting; cell migration was investigated via Transwell assays. In addition, the expression levels of members of the phosphoinositide 3‑kinase (PI3K)/protein kinase B (AKT) signaling pathway was also analyzed by RT‑qPCR and western blotting to determine the association between these members and EMT in adenomyosis. The results of the present study revealed that FAK was upregulated and the expression levels of EMT‑associated molecules were altered in adenomyosis. Silencing FAK expression inhibited adenomyosis cell migration in vitro and the expression of EMT‑promoting molecules, suggesting that the FAK/PI3K/AKT signaling pathway may participate in the EMT of endometrial cells in adenomyosis. In conclusion, FAK may regulate EMT in adenomyosis, and this process may be associated with the PI3K/AKT signaling pathway.