RET is constitutively activated by novel tandem mutations that alter the active site resulting in multiple endocrine neoplasia type 2B
RET is constitutively activated by novel tandem mutations that alter the active site resulting in multiple endocrine neoplasia type 2B
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DOI：
10.1158/0008-5472.can-06-0884
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发表时间：
2006-10-15
期刊：
影响因子：
11.2
通讯作者：
Ponder, Bruce A. J.
中科院分区：
文献类型：
--
作者：
Cranston, Aaron N.;Carniti, Cristiana;Ponder, Bruce A. J.
RET受体酪氨酸激酶的结构性激活是多发性内分泌肿瘤2型(MEN2)发生和发展的基础，这是一种主要遗传的癌症易感性。重要的是，尽管激酶激活是肿瘤的共同主题，但并不是所有的激活突变在功能上都是相同的。与此一致，我们确定了一名患者具有男性211的典型特征，但缺乏RET的两种经典突变(M918T或A883F)。相反，患者在密码子804和805的顺式基因上存在一对新的生殖线错义突变。我们评估了这些取代在硅胶中的潜在物理化学影响，预测这两种取代单独使用时都是中等有害的，但组合起来则是严重有害的。与这一假设一致，我们表明已鉴定的串联突变(V804M/E805K)具有生物学活性，可以在培养中转化细胞，并且它们的转化能力具有明显的协同作用。此外，V804M/ES05K串联损伤对小分子受体酪氨酸激酶抑制剂PP1具有耐药性，这表明一种不同于经典MEN 213突变的作用模式。为了解决这个问题，我们使用了SOLICO中的同源分子模拟来模拟RET的活性部位。我们预测，RET804构成了一个关键的把关残基，当与RET805结合突变时，会导致铰链区的构象变化，从而将活性位点锁定在ATP水解允许的位置。我们的发现对临床和新型抗癌药物的成功开发都有指导意义。
Constitutive activation of the RET receptor tyrosine kinase underlies the genesis and progression of multiple endocrine neoplasia type 2 (MEN 2), a dominantly inherited cancer predisposition. Importantly, although kinase activation represents a common theme in neoplasias, not all activating mutations are functionally equivalent. Consistent with this, we ascertained a patient with classical features of MEN 211, but lacking either of the classical mutations in RET (M918T or A883F). Instead, the patient harbors a novel pair of germ line missense mutations in cis at codons 804 and 805. We evaluated the potential physiochemical effects of these substitutions in silico, predicting both to be moderately deleterious in isolation, but severely deleterious in combination. Consistent with this postulate, we show that the identified tandem mutations (V804M/E805K) are biologically active, transforming cells in culture and that their transforming capacity in combination is distinctly synergistic. Furthermore, the V804M/ES05K tandem lesion confers resistance to the small molecule receptor tyrosine kinase inhibitor, PP1, suggesting a mode of action distinct from that known for classical MEN 213 mutations. To address this question, we used homology molecular modeling in silico to model the active site of RET. We predict that RET804 constitutes a critical gatekeeper residue that, when mutated in combination with RET805, induces a conformational change in the hinge region that locks the active site in a position permissive for ATP hydrolysis. Our findings have implications both in the clinic and in the successful development of novel kinase-targeted anticancer drugs.