Abstract
We consider the hypothesis that estrogen control of hormone dependent breast cancer is mediated by autocrine and paracrine growth factors secreted by the breast cancer cells themselves. Though we show direct, unmediated effects of estrogen on specific cell functions, we also provide evidence that human breast cancer cells secrete a collection of growth factors (IGF-I, TGFα, TGFβ, a PDGF-like competency factor, and at least one new epithelial colony stimulating factor). Some of these are estrogen-regulated in hormone dependent cells, and are constitutively increased in cells which acquire independence either spontaneously or by ras transfection. Collectively, the secreted growth factors are capable of promoting tumor formation by MCF-7 cells in nude mice, though not to the same extent as estrogens. There would seem to be potential for clinical intervention in the autocrine and paracrine control of breast cancer cells, including some cells which are no longer dependent on estrogens.
Original language | English (US) |
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Pages (from-to) | 59-70 |
Number of pages | 12 |
Journal | Breast cancer research and treatment |
Volume | 7 |
Issue number | 2 |
DOIs | |
State | Published - Jun 1 1986 |
Keywords
- antiestrogen
- autocrine growth factors
- EGF
- hormone dependence
- IGF-I
- paracrine growth factors
- PDGF
- TGFα
- TGFβ
ASJC Scopus subject areas
- Oncology
- Cancer Research