Regulation of insulin-like growth factors by antiestrogen.
Regulation of insulin-like growth factors by antiestrogen.
复制标题
抗雌激素对胰岛素样生长因子的调节。
DOI：
10.1007/bf00689681
复制
发表时间：
1994
影响因子：
3.8
通讯作者：
Kiang,DT
中科院分区：
文献类型：
--
作者：
Winston,R;Kao,PC;Kiang,DT
Insulin-like growth factors are potent mitogens for breast cancer cell proliferation. This effect is modulated by the cirulatory and extracellular IGFBPs as well as by the affinity of ligand binding receptors on the target cells. Antiestrogens have been shown to reduce both circulatory and microenvironmental IGF levels and thus suppress the IGF-I-induced growth of both ER-positive and ER-negative breast cancer cells. However, the effects of antiestrogens in down regulation of type I IGF receptor and in altering the autophosphorylation tyrosine kinase activity of EGF receptors are mainly observed in ER-positive cells. Furthermore, alteration of IGFBP by antiestrogens such as a marked increase of IGFBP-I production have been shown to inhibit the proliferative effect of IGF-I on ER-positive, but stimulate this effect, on ER-negative cells. Such differential effects from IGF receptor and IGFBP may explain the clinical outcome that tumor regression from antiestrogens is mainly observed in ER-positive type. This assumption based on IGF regulation alone is certainly an oversimplistic view amid the complexity of autocrine, paracrine, and endocrine functions.
