Diminished functional role and altered localization of SHP2 in non-small cell lung cancer cells with EGFR-activating mutations.
Diminished functional role and altered localization of SHP2 in non-small cell lung cancer cells with EGFR-activating mutations.
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DOI：
10.1038/onc.2012.240
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发表时间：
2013-05-02
期刊：
影响因子：
8
通讯作者：
Lazzara, M. J.
中科院分区：
文献类型：
--
作者：
Furcht, C. M.;Rojas, A. R. Munoz;Nihalani, D.;Lazzara, M. J.
携带表皮生长因子受体（EGFR）激活突变的非小细胞肺癌（NSCLC）细胞倾向于显示几种生存信号通路的活性升高。令人惊讶的是，这些突变还与ERK和SHP 2磷酸化的减少相关，SHP 2是大多数受体酪氨酸激酶下游的ERK完全激活所需的蛋白质酪氨酸磷酸酶。由于ERK活性影响细胞对EGFR抑制的反应，因此改变的SHP 2功能可能在EGFR突变见证的对吉非替尼的显著反应中发挥作用。在这里，我们证明了受损的SHP 2磷酸化与表达突变型与野生型EGFR的NSCLC细胞中SHP 2功能减弱相关。在表达野生型EGFR的NSCLC细胞中，SHP2敲低降低了ERK磷酸化，基本上和对吉非替尼的反应，并增加了细胞对吉非替尼的敏感性。在表达EGFR突变体的细胞中，SHP 2敲低的这些作用不太显著，但组成型活性SHP 2的表达降低了细胞对吉非替尼的敏感性。在表达EGFR突变体的细胞中，不进行有效的配体介导的内吞作用，SHP 2基本上与GAB1和EGFR相关，并且SHP 2在膜组分中的存在依赖于EGFR活性。而EGF促进了更均匀的细胞内分布的最初集中在细胞中表达野生型EGFR的SHP 2，SHP 2是基本均匀分布，并没有重新分配在EGF与EGFR突变的细胞。因此，EGFR突变可能促进质膜上的一部分SHP 2与促进SHP 2活性的衔接子的结合。与此一致，从EGFR突变细胞免疫沉淀的SHP 2是活性的，EGF治疗没有改变这种活性。总之，我们的数据表明，在EGFR突变的细胞中，一部分SHP 2被隔离在质膜上，阻碍了SHP 2促进ERK活性的能力，并将SHP 2确定为NSCLC中EGFR共抑制的潜在靶点。
Non-small cell lung cancer (NSCLC) cells harboring activating mutations of the epidermal growth factor receptor (EGFR) tend to display elevated activity of several survival signaling pathways. Surprisingly, these mutations also correlate with reduced phosphorylation of ERK and SHP2, a protein tyrosine phosphatase required for complete ERK activation downstream of most receptor tyrosine kinases. Since ERK activity influences cellular response to EGFR inhibition, altered SHP2 function could play a role in the striking response to gefitinib witnessed with EGFR mutation. Here, we demonstrate that impaired SHP2 phosphorylation correlates with diminished SHP2 function in NSCLC cells expressing mutant, versus wild-type, EGFR. In NSCLC cells expressing wild-type EGFR, SHP2 knockdown decreased ERK phosphorylation, basally and in response to gefitinib, and increased cellular sensitivity to gefitinib. In cells expressing EGFR mutants, these effects of SHP2 knockdown were less substantial, but expression of constitutively active SHP2 reduced cellular sensitivity to gefitinib. In cells expressing EGFR mutants, which do not undergo efficient ligand-mediated endocytosis, SHP2 was basally associated with GAB1 and EGFR, and SHP2′s presence in membrane fractions was dependent on EGFR activity. Whereas EGF promoted a more uniform intracellular distribution of initially centrally localized SHP2 in cells expressing wild-type EGFR, SHP2 was basally evenly distributed and did not redistribute in response to EGF in cells with EGFR mutation. Thus, EGFR mutation may promote association of a fraction of SHP2 at the plasma membrane with adapters which promote SHP2 activity. Consistent with this, SHP2 immunoprecipitated from cells with EGFR mutation was active, and EGF treatment did not change this activity. Overall, our data suggest that a fraction of SHP2 is sequestered at the plasma membrane in cells with EGFR mutation in a way that impedes SHP2′s ability to promote ERK activity and identify SHP2 as a potential target for co-inhibition with EGFR in NSCLC.
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影响因子：
11.2
作者：
Lazzara MJ;Lane K;Chan R;Jasper PJ;Yaffe MB;Sorger PK;Jacks T;Neel BG;Lauffenburger DA
通讯作者：
Lauffenburger DA
影响因子：
158.5
作者：
Lynch, TJ;Bell, DW;Haber, DA
通讯作者：
Haber, DA
影响因子：
4.8
作者：
Wickrema, A;Uddin, S;Platanias, LC
通讯作者：
Platanias, LC
影响因子：
5.3
作者：
Shi, ZQ;Yu, DH;Feng, GS
通讯作者：
Feng, GS
影响因子：
14.8
作者：
Paulsen, Candice E.;Truong, Thu H.;Garcia, Francisco J.;Homann, Arne;Gupta, Vinayak;Leonard, Stephen E.;Carroll, Kate S.
通讯作者：
Carroll, Kate S.