Krywicki R F, Yee D
Department of Medicine, Brooke Army Medical Center, Fort Sam Houston, Texas 78234.
Breast Cancer Res Treat. 1992;22(1):7-19. doi: 10.1007/BF01833329.
The insulin-like growth factors (IGFs) have important roles in normal cellular growth and development. The IGFs have also been implicated in regulation of tumor cell growth. Two ligands, IGF-I and IGF-II, have been identified that are expressed in both fetal and adult tissues. They interact with at least two specific cell surface receptors. The type I IGF receptor is homologous to the insulin receptor in structure and has tyrosine kinase activity. The type II receptor is identical to the mannose-6-phosphate receptor known to be important in the trafficking of lysosomal enzymes; its role in IGF signal transduction is not clear. Furthermore, a hybrid receptor composed of subunits from the insulin receptor and the type I IGF receptor have been identified. In addition to these receptors, six different IGF binding proteins have been identified, which modulate the activity of the IGFs in various ways. Thus, there is great potential for complex interactions between the family members that could ultimately regulate normal and neoplastic cell growth.
胰岛素样生长因子（IGFs）在正常细胞生长和发育中发挥着重要作用。IGFs也与肿瘤细胞生长的调控有关。已鉴定出两种配体，即IGF-I和IGF-II，它们在胎儿和成人组织中均有表达。它们与至少两种特定的细胞表面受体相互作用。I型IGF受体在结构上与胰岛素受体同源，并具有酪氨酸激酶活性。II型受体与已知在溶酶体酶运输中起重要作用的甘露糖-6-磷酸受体相同；其在IGF信号转导中的作用尚不清楚。此外，还鉴定出一种由胰岛素受体和I型IGF受体的亚基组成的杂合受体。除了这些受体外，还鉴定出六种不同的IGF结合蛋白，它们以各种方式调节IGFs的活性。因此，该家族成员之间存在复杂相互作用的巨大潜力，最终可能调节正常细胞和肿瘤细胞的生长。
