The insulin-like growth factor (IGF) system regulates metabolic and mitogenic signaling through an intricate network of related receptors and hormones. IGF-II is one of several hormones within this system that primarily regulates mitogenic functions and is especially important during fetal growth and development. IGF-II is also found to be overexpressed in several cancer types, promoting growth and survival. It is also unique in the IGF system as it acts through both IGF-1R and insulin receptor isoform A (IR-A). Despite this, IGF-II is the least investigated ligand of the IGF system. This review will explore recent developments in IGF-II research including a structure of IGF-II bound to IGF-1R determined using cryo-electron microscopy (cryoEM). Comparisons are made with the structures of insulin and IGF-I bound to their cognate receptors. Finally discussed are outstanding questions in the mechanism of action of IGF-II with the goal of developing antagonists of IGF action in cancer.

中文翻译：

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通过深入了解受体结合和激活来了解IGF-II的作用

胰岛素样生长因子（IGF）系统通过相关受体和激素的复杂网络调节代谢和促有丝分裂信号。IGF-II是该系统中主要调节有丝分裂功能的几种激素之一，在胎儿的生长发育过程中尤其重要。还发现IGF-II在几种癌症类型中过表达，从而促进生长和存活。它在IGF系统中也很独特，因为它通过IGF-1R和胰岛素受体同工型A（IR-A）起作用。尽管如此，IGF-II是IGF系统研究最少的配体。这篇综述将探讨IGF-II研究的最新进展，包括使用低温电子显微镜（cryoEM）确定的与IGF-1R结合的IGF-II结构。将胰岛素和IGF-I与其同源受体结合的结构进行了比较。