Estrogen receptor alpha and beta in uterine fibroids: a basis for altered estrogen responsiveness.
OBJECTIVE
To investigate the relative expression and the DNA-binding status of estrogen receptors alpha and beta in fibroids and normal myometrial tissue to explore the molecular basis of altered estrogen responsiveness of leiomyomas.


METHODS
Biopsy samples from uterine fibroids and adjacent normal myometrial tissue at the follicular phase of the menstrual cycle.


METHODS
Aretaieio University Hospital and the National Hellenic Research Foundation, Athens, Greece.


METHODS
Thirty-five patients who underwent hysterectomy or myomectomy because of myoma symptoms.


METHODS
None.


METHODS
Deoxyribonucleic acid-binding status of estrogen receptors alpha and beta.


RESULTS
The level of messenger RNA expression of estrogen receptor alpha and beta and the level of estrogen receptor as a whole are increased on average to a similar extent in leiomyomas compared with normal myometrium. Occasionally, however, estrogen receptor alpha is disproportionately increased in leiomyomas, and this appears to increase the amount of estrogen receptor alpha that binds to the estrogen-responsive element of estrogen target genes as homodimer rather than as heterodimer with estrogen receptor beta.


CONCLUSIONS
The estrogen receptor alpha-to-estrogen receptor beta expression ratio rather than the individual expression levels determines the fraction of DNA-binding homodimers of estrogen receptor alpha and possibly the growth potential of myomas.
Bakas
Panagiotis
P
2nd Department of Obstetrics and Gynaecology, Aretaieio Hospital, University of Athens, Athens, Greece.
Liapis
Angelos
A
Vlahopoulos
Spiros
S
Giner
Maria
M
Logotheti
Stella
S
Creatsas
Georgios
G
Meligova
Aggeliki K
AK
Alexis
Michael N
MN
Zoumpourlis
Vassilis
V
D000328:Adult; D004247:DNA / Q000378:metabolism; D019281:Dimerization; D047628:Estrogen Receptor alpha / Q000235:genetics / Q000378:metabolism*; D047629:Estrogen Receptor beta / Q000235:genetics / Q000378:metabolism*; D004967:Estrogens / Q000378:metabolism*; D005260:Female; D005498:Follicular Phase / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007889:Leiomyoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D008875:Middle Aged; D009215:Myometrium / Q000378:metabolism* / Q000503:physiopathology; D012333:RNA, Messenger / Q000032:analysis; D014594:Uterine Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology
D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D004967:Estrogens; D012333:RNA, Messenger; D004247:DNA