Retinoic acid and estrogen modulation of insulin-like growth factor binding protein-4 gene expression and the estrogen receptor status of human breast carcinoma cells.
Retinoic acid (RA) and estrogen modulation of insulin like-growth factor binding protein-4 (IGFBP-4) gene expression was investigated in a number of human breast carcinoma (HBC) cell lines. Our results indicate that RA and/or estrogen modulation of IGFBP-4 mRNA levels appear to correlate with the ER-status of HBC cell lines. RA and estrogen enhanced IGFBP-4 mRNA levels in ER-positive MCF-7, RRO-I and ZR-75 cell lines and the effect of both of these agents in combination was additive. Although both individually also enhanced IGFBP-4 mRNA levels in ER-positive T47D cells, their effect in combination was antagonistic in this cell line. Transfection of human ER into ER-negative MDA-MB-231 cells conferred RA and estrogen the ability to enhance IGFBP-4 mRNA but both agents failed to concomitantly modulate IGFBP-4 levels in the CM suggesting a dual regulation by these agents at transcription/post-transcription and translation/secretion levels.
Sheikh
M S
MS
Department of Medicine, University of Maryland School of Medicine, Baltimore.
Shao
Z M
ZM
Hussain
A
A
Chen
J C
JC
Roberts
C T
CT
LeRoith
D
D
Fontana
J A
JA
D015152:Blotting, Northern; D001943:Breast Neoplasms; D002352:Carrier Proteins / Q000096:biosynthesis*; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D015870:Gene Expression / Q000187:drug effects*; D006801:Humans; D018974:Insulin-Like Growth Factor Binding Protein 4; D011061:Poly A / Q000302:isolation & purification / Q000378:metabolism; D012313:RNA / Q000302:isolation & purification / Q000378:metabolism; D012333:RNA, Messenger / Q000302:isolation & purification / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000187:drug effects / Q000378:metabolism; D014162:Transfection; D014212:Tretinoin / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
D002352:Carrier Proteins; D004967:Estrogens; D018974:Insulin-Like Growth Factor Binding Protein 4; D012333:RNA, Messenger; D011960:Receptors, Estrogen; D011994:Recombinant Proteins; D011061:Poly A; D014212:Tretinoin; D012313:RNA