A selective estrogen receptor-beta agonist causes lesion regression in an experimentally induced model of endometriosis.
BACKGROUND
Endometriosis is a common gynaecological problem of uncertain aetiology. It affects primarily young, reproductive-aged women and can result in chronic pelvic pain and infertility. Current approved therapies have significant side-effects and hysterectomy is employed as a final solution. ERB-041 is a selective estrogen receptor-beta (ERbeta) agonist that has anti-inflammatory activity in preclinical models of arthritis and inflammatory bowel disease, but is inactive in many preclinical models of classic estrogen activity. Because endometriosis is now thought to be, at least in part, an inflammatory disease, we evaluated ERB-041's activity in an experimentally induced model of endometriosis.


METHODS
Athymic nude mice (ovariectomized or intact) were implanted with tissue fragments of normal human endometrium. After establishment of lesions for 11-14 days, mice were treated with ERB-041 for 15-17 days. Upon euthanasia, the number of lesions, their size and location were noted. Five lesions were recovered for RNA analysis.


RESULTS
Across six studies, ERB-041 caused complete lesion regression in 40-75% of the mice studied. The compound appeared to be equally effective in gonad-intact as in ovariectomized mice, and analysed recovered lesions expressed ERalpha but not ERbeta mRNA.


CONCLUSIONS
ERB-041 and possibly other ERbeta selective agonists may be a useful new approach to treating endometriosis.
Harris
Heather A
HA
Women's Health Research Institute, Wyeth Research, Collegeville, PA 19426, USA. harrish@wyeth.com
Bruner-Tran
Kaylon L
KL
Zhang
Xiaochun
X
Osteen
Kevin G
KG
Lyttle
C Richard
CR
D000293:Adolescent; D000328:Adult; D000818:Animals; D001706:Biopsy; D004195:Disease Models, Animal; D004715:Endometriosis / Q000188:drug therapy* / Q000473:pathology; D004717:Endometrium / Q000187:drug effects* / Q000473:pathology; D047629:Estrogen Receptor beta / Q000819:agonists* / Q000235:genetics; D005260:Female; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D008875:Middle Aged; D009924:Organ Culture Techniques; D010052:Ovariectomy; D010080:Oxazoles / Q000737:chemistry / Q000494:pharmacology*; D012333:RNA, Messenger / Q000032:analysis
C478102:ERB 041; D047629:Estrogen Receptor beta; D010080:Oxazoles; D012333:RNA, Messenger