Elevation of insulin-like growth factor-binding protein-1 mRNA expression following hormone replacement therapy.
The purpose of this study was to investigate the possible regulatory roles of insulin-like growth factors (IGF) and IGF binding protein-1 (IGFBP-1) on postmenopausal endometrium in women undergoing hormone replacement therapy (HRT). Endometrial tissues and blood samples were collected from 25 postmenopausal women with abnormal uterine bleeding before and after HRT. As a control, blood and endometrial samples were also obtained at mid-luteal phase (days 18-23 of the menstrual cycle) from 10 women with benign uterine leiomyoma during surgical intervention. Expression of mRNA for IGF-I, IGF-II, type 1-IGF receptor, IGFBP-1, oestrogen receptor (ER) and progesterone receptor (PR) in the endometrium was explored by a semiquantitative reverse transcription-polymerase chain reaction (RT-PCR). Serum concentrations of IGFBP-1, oestradiol, progesterone, follicle stimulating hormone (FSH) and sex hormone-binding globulin (SHBG) were also determined. In the endometrium obtained from postmenopausal women with abnormal uterine bleeding (before HRT), expression of IGFBP-1 was undetectable, whereas PR expression was abundant. HRT significantly up-regulated expression of IGFBP-1 but down-regulated PR. Moderate expression of IGF-I, IGF-II, type 1-IGF receptor and ER was identified in the postmenopausal endometrium before HRT. HRT significantly down-regulated IGF-I, up-regulated IGF-II, but had no effects on expression of type 1-IGF receptor and ER. In conclusion, up-regulation of IGFBP-1 collaboratively with down-regulation of IGF-I may account for the protective effect of progesterone in HRT on the endometrium.
Wang
H S
HS
Department of Obstetrics & Gynecology, Chang-Gung Medical College, Chang-Gung Memorial Hospital, Lin-Kou Medical Center, Taipei, Taiwan, Republic of China.
Wang
T H
TH
Soong
Y K
YK
D004717:Endometrium / Q000737:chemistry* / Q000502:physiology; D004958:Estradiol / Q000097:blood; D015914:Estrogen Replacement Therapy; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000097:blood / Q000235:genetics*; D007334:Insulin-Like Growth Factor I / Q000235:genetics; D007335:Insulin-Like Growth Factor II / Q000235:genetics; D008875:Middle Aged; D017698:Postmenopause; D011374:Progesterone / Q000097:blood; D012333:RNA, Messenger / Q000032:analysis*; D017526:Receptor, IGF Type 1 / Q000235:genetics; D011960:Receptors, Estrogen / Q000235:genetics; D011980:Receptors, Progesterone / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012738:Sex Hormone-Binding Globulin / Q000378:metabolism
D018970:Insulin-Like Growth Factor Binding Protein 1; D012333:RNA, Messenger; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D012738:Sex Hormone-Binding Globulin; D011374:Progesterone; D004958:Estradiol; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; D005640:Follicle Stimulating Hormone; D017526:Receptor, IGF Type 1