Elevated immunoreactivity against class I histone deacetylases in adenomyosis

Adenomyosis is a common condition with a poorly understood pathogenesis. Recent data suggest that it may be an epigenetic disease. This study investigated the expression and localization of class I histone deacetylases (HDACs) in women with and without adenomyosis.

The ectopic and homologous eutopic endometrium of 50 women with adenomyosis and the endometrium of 18 age- and menstrual phase-matched women without adenomyosis were used for immunohistochemical analysis. Tissue sections were immunostained with HDAC1, -2, and -3. Microscopic evaluation to assess the presence and localization of HDAC1-3 throughout the menstrual cycle in both eutopic endometrial and endometriotic tissues of women with adenomyosis was performed and compared with the normal endometrium.

We found that, compared with the normal endometrium, immunoreactivity against HDAC1 and HDAC3 was higher in both the eutopic and the ectopic endometrium. Increased HDAC2 in the eutopic endometrium was found to be associated with the severity of dysmenorrhea.

Given the potential wide-ranging effect of histone deacetylation on gene expression, these findings suggest that HDACs may be involved in adenomyosis. They also suggest the possibility that HDAC2 may be involved in dysmenorrhea and its severity and that HDACs may be potential therapeutic targets in adenomyosis.