[Expression of prolactin, TGF alpha and TGF beta 1 genes in estrogen-induced eutopic and ectopic pituitary prolactin-secreting tumors of rats].
The Sprague-Dawley (SD) rat bearing a heteroplasted pituitary underneath renal capsule was used to observe differential expression of prolactin (PRL), transforming growth factor alpha (TGF alpha) and transforming growth factor beta 1 (TGF beta 1) genes during the formation of pituitary prolactin-secreting tumor (prolactinoma) induced by 17 beta-estradiol (E2). Our results indicated that in both eutopic and ectopic pituitaries disconnected from hypothalamus formed simultaneously PRL-secreting tumors after the rats treated with E2 for 120 days in vivo, which was accompanied by overexpression of PRL gene (P < 0.05-0.01). The PRL mRNA level was higher in eutopic prolactinoma than that in ectopic prolactinoma (P < 0.05). Overexpression of TGF alpha and TGF beta 1 genes were also detected in eutopic prolactinoma. However, the expression of TGF alpha and TGF beta 1 genes in ectopic prolactinoma was similar to that in normal pituitary. It is suggested that TGF alpha and TGF beta 1 may be involved in prolactinoma tumorigenesis of eutopic pituitary. However, the mechanism mediating eutopic and ectopic prolactin-secreting tumor formation seems different.
Wu
X M
XM
Department of Physiology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing 100005.
Xu
J P
JP
Zhang
R
R
Xu
R K
RK
D000818:Animals; D004958:Estradiol; D015870:Gene Expression; D008297:Male; D009368:Neoplasm Transplantation; D010911:Pituitary Neoplasms / Q000139:chemically induced / Q000378:metabolism*; D011388:Prolactin / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D015175:Prolactinoma / Q000139:chemically induced / Q000378:metabolism*; D012313:RNA / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D013370:Subrenal Capsule Assay; D016211:Transforming Growth Factor alpha / Q000096:biosynthesis / Q000235:genetics; D016212:Transforming Growth Factor beta / Q000096:biosynthesis* / Q000235:genetics; D053773:Transforming Growth Factor beta1
C508962:Tgfb1 protein, rat; D016211:Transforming Growth Factor alpha; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D004958:Estradiol; D012313:RNA; D011388:Prolactin