Gain-of-function mutations of platelet-derived growth factor receptor α gene in gastrointestinal stromal tumors
Gain-of-function mutations of platelet-derived growth factor receptor α gene in gastrointestinal stromal tumors
复制标题
DOI：
10.1016/s0016-5085(03)01046-1
复制
发表时间：
2003-09-01
期刊：
影响因子：
29.4
通讯作者：
Kitamura, Y
中科院分区：
文献类型：
--
作者：
Hirota, S;Ohashi, A;Kitamura, Y
背景和目标：大多数胃肠道间质瘤（GISTS）存在c-kit受体酪氨酸激酶（KIT）基因的功能获得性突变，但也有部分GISTS不存在。我们调查了没有KIT突变的GISTS的原因。因为GISTS明显表达血小板衍生生长因子受体（PDGFR）α，我们检查了没有KIT突变的GISTS是否有PDGFR等突变。方法：在有或无KIT突变的GISTS中测定PDGFR α cDNA全编码区序列。将突变体PDGFR α cDNA转染到293 T人胚肾细胞中，并检查PDGFR α的自磷酸化。通过氚胸苷掺入法估计稳定转染突变型PDGFR α cDNA的Ba/F3小鼠淋巴细胞的增殖。将野生型KIT cDNA与突变型PDGFR α cDNA共转染，并通过抗KIT抗体进行免疫沉淀。检查了甲磺酸伊马替尼对活化的PDGFR α的抑制作用。结果如下：我们在8例无KIT突变的GISTS中的5例中发现了2种PDGFR α组成型激活突变，即瓦尔-561突变为Asp或Asp-842突变为瓦尔，但在10例有KIT突变的GISTS中未发现。每个突变的稳定转染诱导Ba/F3细胞的自主增殖。组成性激活的突变体PDGFR α结合并激活共转染的野生型KIT。甲磺酸伊马替尼可有效抑制PDGFR α由瓦尔-561转化为Asp的组成性激活，但仅微弱抑制PDGFR α由Asp-842转化为瓦尔的组成性激活，即使在10 μ mol/L浓度下。结论：PDGFR α的功能获得性突变似乎在无KIT突变的GISTS的发生中起重要作用。
Background & Aims: Most gastrointestinal stromal tumors (GISTS) have gain-of-function mutations of c-kit receptor tyrosine kinase (KIT) gene, but some GISTS do not. We investigated the cause of GISTS without KIT mutations. Because GISTS apparently expressed plate let-derived growth factor receptor (PDGFR) alpha, we examined whether GISTs without KIT mutations had a mutation of PDGFR et. Methods: Whole coding region of PDGFR alpha complementary DNA (cDNA) was sequenced in GISTS with or without KIT mutations. Mutant PDGFR alpha cDNA was transfected into 293T human embryonic kidney cells, and autophosphorylation of PDGFR alpha was examined. Proliferation of Ba/F3 murine lymphoid cells stably transfected with mutant PDGFR alpha cDNA was estimated by tritium thymidine incorporation. Wild-type KIT cDNA was cotransfected with mutant PDGFR alpha cDNA, and immunoprecipitation by anti-KIT antibody was performed. Inhibitory effect of Imatinib mesylate on activated PDGFR alpha was examined. Results: We found 2 types of constitutively activated mutations of PDGFR alpha, Val-561 to Asp or Asp-842 to Val, in 5 of 8 GISTS without KIT mutations but not in :10 GISTS with KIT mutations. Stable transfection of each mutation induced autonomous proliferation of Ba/F3 cells. Constitutively activated mutant PDGFR alpha bound and activated the cotransfected wild-type KIT. The constitutive activation of PDGFR alpha with Val-561 to Asp was inhibited effectively by Imatinib mesylate but that of PDGFR alpha with Asp-842 to Val was inhibited only weakly, even at the concentration of 10 mumol/L. Conclusions: The gain-of-function mutations of PDGFR alpha appear to play an important role in development of GISTS without KIT mutations.