The expression of insulin-like growth factor and its binding protein mRNA in the endometrium of postmenopausal patients with breast cancer receiving tamoxifen.
BACKGROUND
Insulin-like growth factor I (IGF-I) is known to mediate estrogen effect in the uterus, whereas IGF binding proteins (IGFBPs) modulate the biologic effects of IGF-I. Tamoxifen may act via the IGF-IGFBP system in the postmenopausal endometrium.


METHODS
Endometrial samples were collected from 16 postmenopausal women with breast cancer of whom 9 received tamoxifen and the remaining 7 received no hormonal treatment. The expression of messenger RNA for IGF-I, IGF-II, and the IGFBPs 1-6 was studied using dot blot and Northern blot techniques.


RESULTS
Expression of mRNA for IGF-I, IGFBP-2, -3, -4, and -6 was present in endometrial specimens. The expression of IGF-I mRNA was similar in the tamoxifen-treated and control patients, whereas mRNA expression for IGF-II was not detected. The expression of IGFBP-2 and -4 mRNA predominated in the endometrium of patients who received tamoxifen.


CONCLUSIONS
These findings demonstrate that the IGF-IGFBP system is present in the postmenopausal endometrium and may be modulated by tamoxifen.
Laatikainen
T J
TJ
Department of Obstetrics and Gynecology, University of Oulu, Finland.
Tomás
E I
EI
Voutilainen
R J
RJ
D000368:Aged; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D015152:Blotting, Northern; D001943:Breast Neoplasms / Q000737:chemistry* / Q000188:drug therapy*; D003430:Cross-Sectional Studies; D004717:Endometrium / Q000737:chemistry*; D004965:Estrogen Antagonists / Q000627:therapeutic use*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D018969:Insulin-Like Growth Factor Binding Proteins / Q000032:analysis* / Q000235:genetics; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D007335:Insulin-Like Growth Factor II / Q000032:analysis; D008875:Middle Aged; D017698:Postmenopause; D012333:RNA, Messenger / Q000032:analysis; D013002:Somatomedins / Q000032:analysis* / Q000235:genetics; D013629:Tamoxifen / Q000627:therapeutic use*
D018931:Antineoplastic Agents, Hormonal; D004965:Estrogen Antagonists; D018969:Insulin-Like Growth Factor Binding Proteins; D012333:RNA, Messenger; D013002:Somatomedins; D013629:Tamoxifen; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II