Stimulatory effects of retinoic acid on tumor growth and serum insulin-like growth factor-1 in rats bearing estrogen-responsive pituitary tumor MtT/Se.
MtT/Se is one of 4 cell lines derived from an estrogen-dependent pituitary tumor, MtT/F84. The main difference between these tumor types is that MtT/F84 secretes both growth hormone (GH) and prolactin (PRL) whereas MtT/Se secretes only GH. MtT/Se grew slowly in ovariectomized (ovex) rats, but tumor growth was much faster in estrogen-treated ovex rats. Effects of dietary retinoic acid (RA) on tumor growth, serum GH and insulin-like growth factor-1 (IGF-1) levels were examined in ovex rats. Latency of tumor growth was shortened, and tumor take and weight were promoted by all-trans RA both in the presence and absence of exogenous estrogen. Serum GH and IGF-1 levels became increased in tumor-bearing rats whereas PRL levels remained unchanged. Serum IGF-1 levels exhibited a good correlation with tumor weights (r = 0.84). Our results suggest a close relationship between increase of tumor weight and stimulation of serum IGF-1 level by RA in tumor-bearing rats.
Roy
B
B
Department of Cancer Research, Hiroshima University.
Ogundigie
P O
PO
Fujimoto
N
N
Ito
A
A
D000818:Animals; D002455:Cell Division / Q000187:drug effects; D003600:Cytosol / Q000378:metabolism; D004967:Estrogens; D005260:Female; D013006:Growth Hormone / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000187:drug effects* / Q000378:metabolism; D009376:Neoplasms, Hormone-Dependent / Q000097:blood / Q000188:drug therapy / Q000473:pathology*; D010911:Pituitary Neoplasms / Q000097:blood / Q000188:drug therapy / Q000473:pathology*; D011388:Prolactin / Q000097:blood; D051381:Rats; D011960:Receptors, Estrogen / Q000378:metabolism; D013268:Stimulation, Chemical; D014212:Tretinoin / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
D004967:Estrogens; D011960:Receptors, Estrogen; D014212:Tretinoin; D007334:Insulin-Like Growth Factor I; D011388:Prolactin; D013006:Growth Hormone