Growth regulation of human breast carcinoma occurs through regulated growth factor secretion.
We describe studies on human breast cancer in which it is shown that specific growth factors (IGF-I, TGF alpha, PDGF) are secreted by human breast cancer cells and likely to be involved in tumor growth and progression. These activities are regulated by estradiol in hormone-dependent breast cancer and secreted constitutively by hormone-independent cells. These growth factor activities can induce the growth of hormone-dependent cells in vivo in athymic nude mice. Hormone-dependent breast cancer cells also secrete TGF beta, a growth-inhibitory substance, when treated with antiestrogens. TGF beta functions as a negative autocrine growth regulator and is responsible for some of the growth-inhibitory effects of antiestrogens.
Lippman
M E
ME
Medical Breast Cancer Section, National Cancer Institute, Bethesda, Maryland 20892.
Dickson
R B
RB
Gelmann
E P
EP
Rosen
N
N
Knabbe
C
C
Bates
S
S
Bronzert
D
D
Huff
K
K
Kasid
A
A
D000818:Animals; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism*; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D006133:Growth Substances / Q000096:biosynthesis* / Q000494:pharmacology; D006801:Humans; D008325:Mammary Neoplasms, Experimental / Q000378:metabolism; D051379:Mice; D008819:Mice, Nude; D014407:Tumor Cells, Cultured
D004967:Estrogens; D006133:Growth Substances