Therapeutic antibody targeting of individual Notch receptors
Therapeutic antibody targeting of individual Notch receptors
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DOI：
10.1038/nature08878
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发表时间：
2010-04-15
期刊：
影响因子：
64.8
通讯作者：
Siebel, Christian W.
中科院分区：
文献类型：
--
作者：
Wu, Yan;Cain-Hom, Carol;Siebel, Christian W.
Notch家族的四种受体是广泛表达的跨膜蛋白，其作为哺乳动物细胞通过其进行通信以调节细胞命运和生长的关键管道发挥作用（1，2）。配体结合引发受体负调控区（NRR）的构象变化，使ADAM蛋白酶在质膜位点裂解（3，4），否则该位点隐藏在静止的NRR中5，6。随后由c-分泌酶复合物催化的膜内蛋白水解释放细胞内结构域（ICD）以启动下游Notch转录程序。通过每个受体的异常信号传导与许多疾病有关，特别是癌症（7），使Notch途径成为新药的引人注目的目标。尽管γ-分泌酶抑制剂（GSI）已进入临床（8），但GSI无法区分单个Notch受体，抑制其他信号传导途径（9）并导致肠毒性（10），这归因于Notch 1和2的双重抑制（参考文献11）。为了阐明Notch 1和Notch 2的离散功能并开发降低肠毒性的临床相关抑制剂，我们使用噬菌体展示技术产生高度特异性的抗体，这些抗体特异性地拮抗每个受体，但与人类和小鼠序列交叉反应，从而能够区分Notch 1与Notch 2在人类患者和啮齿动物模型中的功能。我们的共晶结构表明，抑制机制依赖于稳定NRR静止。在临床前模型中，选择性阻断Notch 1通过两种机制抑制肿瘤生长：抑制癌细胞生长和血管生成失调。尽管Notch 1加Notch 2的抑制引起严重的肠毒性，但单独抑制任一受体可减少或避免这种作用，表明优于泛Notch抑制剂的明显优势。我们的研究强调了旁系同源物特异性拮抗剂在解剖不同Notch受体对分化和疾病的贡献方面的价值，并揭示了独立靶向Notch 1和Notch 2的治疗前景。
The four receptors of the Notch family are widely expressed transmembrane proteins that function as key conduits through which mammalian cells communicate to regulate cell fate and growth(1,2). Ligand binding triggers a conformational change in the receptor negative regulatory region (NRR) that enables ADAM protease cleavage(3,4) at a juxtamembrane site that otherwise lies buried within the quiescent NRR5,6. Subsequent intramembrane proteolysis catalysed by the c-secretase complex liberates the intracellular domain (ICD) to initiate the downstream Notch transcriptional program. Aberrant signalling through each receptor has been linked to numerous diseases, particularly cancer(7), making the Notch pathway a compelling target for new drugs. Although gamma-secretase inhibitors (GSIs) have progressed into the clinic(8), GSIs fail to distinguish individual Notch receptors, inhibit other signalling pathways(9) and cause intestinal toxicity(10), attributed to dual inhibition of Notch1 and 2 (ref. 11). To elucidate the discrete functions of Notch1 and Notch2 and develop clinically relevant inhibitors that reduce intestinal toxicity, we used phage display technology to generate highly specialized antibodies that specifically antagonize each receptor paralogue and yet cross-react with the human and mouse sequences, enabling the discrimination of Notch1 versus Notch2 function in human patients and rodent models. Our co-crystal structure shows that the inhibitory mechanism relies on stabilizing NRR quiescence. Selective blocking of Notch1 inhibits tumour growth in pre-clinical models through two mechanisms: inhibition of cancer cell growth and deregulation of angiogenesis. Whereas inhibition of Notch1 plus Notch2 causes severe intestinal toxicity, inhibition of either receptor alone reduces or avoids this effect, demonstrating a clear advantage over pan-Notch inhibitors. Our studies emphasize the value of paralogue-specific antagonists in dissecting the contributions of distinct Notch receptors to differentiation and disease and reveal the therapeutic promise in targeting Notch1 and Notch2 independently.