Evidence of an EGF/TGE-alpha--independent pathway for estrogen-regulated cell proliferation.
To elucidate the relationship between epidermal growth factor (EGF)/transforming growth factor (TGF-alpha) and estradiol-17 beta (E) in cell proliferation, we examined their effects on the breast cancer cell line, CAMA-1. While E was able to consistently induce cell proliferation under a variety of experimental conditions, EGF/TGF-alpha was without effect. Despite the presence of the receptor (EGFR) gene, mature EGFR protein and mRNA were not detected by radioreceptor assay, 35S Met-labelling, and the Intron Differential RNA/PCR method under conditions in which cells remain responsive to E. Furthermore, TGF-alpha is not an autocrine factor in CAMA-1 cells. We demonstrated unequivocally that EGF/TGF-alpha interaction with EGFR is not an obligatory event in mediating estrogen-stimulated cell proliferation.
Department of Obstetrics and Gynecology, University of Minnesota, Minneapolis 55455.
B S
BS
Leung
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Stout
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Zhou
H J
HJ
Ji
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Zhang
H T
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Leung
D001483:Base Sequence; D015139:Blotting, Southern; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D002455:Cell Division / Q000187:drug effects; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D066246:ErbB Receptors / Q000032:analysis / Q000235:genetics; D004958:Estradiol / Q000494:pharmacology*; D015870:Gene Expression; D006801:Humans; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D012334:RNA, Neoplasm / Q000032:analysis / Q000235:genetics; D016211:Transforming Growth Factor alpha / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
D012333:RNA, Messenger; D012334:RNA, Neoplasm; D016211:Transforming Growth Factor alpha; D004958:Estradiol; D004815:Epidermal Growth Factor; D066246:ErbB Receptors