Aberrant methylation at HOXA10 may be responsible for its aberrant expression in the endometrium of patients with endometriosis.
OBJECTIVE
HOXA10, expressed in endometrium, plays an important role in uterine receptivity at the time of implantation. In the endometrium of women with endometriosis, its expression is reduced. The aim of this study was to determine whether the observed aberrant expression of HOXA10 is caused by aberrant methylation of the gene.


METHODS
Endometrial tissues were collected from 6 women with laparoscopically confirmed endometriosis, and 4 women who underwent tubal ligation and were confirmed to have no endometriosis. In addition, menstrual blood from 5 women with no gynecologic complaints was collected and also used as controls. Methylation-specific polymerase chain reaction (PCR) and bisulfite sequencing were performed in 3 fragments in 2 regions of HOXA10 to detect difference in methylation patterns. Real-time reverse transcriptase (RT)-PCR was also performed to measure expression levels of HOXA10 in select cases and controls.


RESULTS
In all 3 fragments, there were highly statistically significant differences in methylation patterns between women with endometriosis and those without endometriosis. The expression level of HOXA10 was lower in women with endometriosis than those without, as previously reported.


CONCLUSIONS
There is aberrant methylation in the endometrium of women with endometriosis compared with those without endometriosis. The aberrant methylation at HOXA10 may be responsible for the aberrant gene expression in the endometrium of women with endometriosis. This finding suggests that endometriosis may also be an epigenetic disease.
Wu
Yan
Y
Department of Pediatrics, Medical College of Wisconsin, Milwaikee 53226-0509, USA.
Halverson
Gloria
G
Basir
Zainab
Z
Strawn
Estil
E
Yan
Pearlly
P
Guo
Sun-Wei
SW
D001483:Base Sequence; D019175:DNA Methylation; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D004715:Endometriosis / Q000235:genetics*; D004717:Endometrium / Q000378:metabolism*; D044127:Epigenesis, Genetic; D005260:Female; D000080905:Homeobox A10 Proteins; D018398:Homeodomain Proteins; D006801:Humans; D016133:Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction
D004268:DNA-Binding Proteins; D000080905:Homeobox A10 Proteins; D018398:Homeodomain Proteins; C069634:HOXA10 protein, human