Inhibition of breast cancer cell growth in vitro by a tyrosine kinase inhibitor.

摘要: Abstract Human breast cancer cell proliferation is regulated by growth factors that bind to receptors with intrinsic tyrosine kinase (TK) activity, including the epidermal factor (EGF) receptor. To determine whether inhibition of receptor TK activity inhibits tumor growth, we studied effects a inhibitor, RG-13022, on cultured human cells. RG-13022 represents class compounds which have been shown inhibit preferentially EGF in cell-free system and also EGF-stimulated significantly inhibited autophosphorylation its two lines abundant, although not amplified, content (MDA-231 T47D). DNA synthesis T47D MCF-7 cells reversible dose-dependent manner. Inhibition was observed at 0.1 µm, it maximal 10 µm. The effect rapid (within 3 h), persisted for 18 h, partially reversed 24 h 1 At 5 more than 50 h. Inhibitory were panel estrogen receptor-positive receptor-negative lines. only EGF-induced but stimulated insulin, insulin-like I, II, or transforming α. totally blocked estrogen-stimulated phosphorylation receptor, as well estrogen-induced proliferation, suggesting functioning pathways are required action. inhibitor potent hormonally cancer. Tyrosine inhibitors potential providing new strategy “endocrine therapy”