Expression of sex hormone-binding globulin, oxytocin receptor, caveolin-1 and p21 in leiomyoma.
BACKGROUND
Interaction of sex hormone-binding globulin (SHBG) and oxytocin (OT) is among the factors that control smooth muscle proliferation and tumor growth through the oxytocin receptor (OTR). Also, a close functional interaction of OTR and caveolin-1 has been shown to modulate cell growth and proliferation.


METHODS
We studied surgical samples from 23 leiomyoma patients (aged 33-66 years) with immunocytochemistry. Specimens from five patients (34-76 years), who had hysterectomy for other reasons, served as controls. Tissue samples were cut into serial 1-microm thick sections for co-localization of SHBG, OTR, proliferation marker p21 and caveolin-1.


RESULTS
SHBG was found in smooth muscle cells in all samples. OTR staining occurred in most of these cells in myomas, while controls contained only scattered cells positive for OTR. There were no apparent differences in immunostaining for p21, while immunoreactivity for caveolin-1 was observed in most cells in myomas and in only few cells in controls. Caveolin-1 was mostly co-localized with SHBG and OTR in myoma samples whereas controls showed this co-localization only occasionally.


CONCLUSIONS
Our observations indicate an interaction of SHBG and OTR, associated with caveolin-1, which may account in part for known non-genomic actions of ovarian steroids. Growth of leiomyomas may be linked to these mechanisms.
Sendemir
Aynur
A
Department of Obstetrics and Gynecology, Helios Klinikum Erfurt, Erfurt, Germany.
Sendemir
Erdogan
E
Kosmehl
Hartmuth
H
Jirikowski
Gustav F
GF
D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D051242:Caveolin 1 / Q000378:metabolism*; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D018231:Leiomyomatosis / Q000378:metabolism*; D008875:Middle Aged; D009215:Myometrium / Q000378:metabolism; D010121:Oxytocin / Q000378:metabolism; D018045:Receptors, Oxytocin / Q000378:metabolism*; D012738:Sex Hormone-Binding Globulin / Q000378:metabolism*; D014594:Uterine Neoplasms / Q000378:metabolism*
C493956:CDKN1A protein, human; D051242:Caveolin 1; D050759:Cyclin-Dependent Kinase Inhibitor p21; D018045:Receptors, Oxytocin; D012738:Sex Hormone-Binding Globulin; D010121:Oxytocin