The mechanism for tumor angiogenesis in hepatocellular carcinoma : focused on the signal transduction pathway by Flt-1

肝细胞癌肿瘤血管生成机制：聚焦Flt-1信号转导通路

• 批准号: 11670498
• 负责人: ITO Nobuyuki
• 金额: $ 1.92万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11670498/
• 关键词: angiogenesis; Flt-1; Grap; signal transduction; endothelial cel; hepatocellular carcinom; SH2蛋白

We identified four tyrosine-phosphorylation sites on VEGF receptor-1 (Flt-1). PLC-γ, SHP-2, Grb2, Crk and Nck bind to Flt-1 in a phosphoyrosine-dependent manner. The analysis using mutant receptor-expressing cells indicates that the phosphorylation of Tyr1213 and Tyr1333 is essential for VEGF-induced endothelial cell growth. VEGF-induced signal was enhanced by coexpressing Flt-1 and another VEGF receptor, KDR.Heparin modulates the VEGF-induced signaling by enhancing PLC-γ phosphorylation.We also identified a novel molecule that binds to Tyr1213 in a phosphotyrosine-dependent manner. Molecular cloning revealed this 27 kDa molecule has a high homology with human Grap (Grb2-related adaptor protein), indicating that this molecule was a mouse Grap. Grap has been shown to be expressed exclusively in hematopoietic cells. However, all kinds of endothelial cells we examined expressed Grap by RT-PCR, indicating the importance of this molecule in endothelial cell growth. In vitro studies showed that the SH3 domain of Grap binds c-Cb1 and Sos-1. Down stream of this signal transduction pathway should be further investigated.

我们确定了四个酪氨酸磷酸化位点的血管内皮生长因子受体-1（Flt-1）。PLC-γ、SHP-2、Grb2、Crk和Nck以磷酸酪氨酸依赖性方式与Flt-1结合。使用突变体受体表达细胞的分析表明，Tyr1213和Tyr1333的磷酸化对于VEGF诱导的内皮细胞生长是必需的。共表达Flt-1和另一种VEGF受体KDR可增强VEGF诱导的信号传导，肝素可通过增强PLC-γ磷酸化来调节VEGF诱导的信号传导，我们还鉴定了一种以磷酸酪氨酸依赖方式与Tyr1213结合的新分子。分子克隆结果表明，该分子与人Grb 2相关衔接蛋白（Grb 2-related adaptor protein，Grp）具有很高的同源性，表明该分子为小鼠Grp。已显示Grap仅在造血细胞中表达。然而，通过RT-PCR，我们检测的所有类型的内皮细胞都表达Grap，表明该分子在内皮细胞生长中的重要性。体外研究表明，葡萄糖的SH3结构域结合c-Cb1和Sos-1。该信号转导通路的下游应进一步研究。

项目成果

J.H.Qi,N.Ito, et al.: "Tyrosine phosphatase SHP-2 is involved in regulation of platelet-derived growth factor-induced migration"Journal of Biological Chemistry. 274. 14455-14463 (1999)

J.H.Qi，N.Ito 等人：“酪氨酸磷酸酶 SHP-2 参与调节血小板衍生生长因子诱导的迁移”生物化学杂志。

T.Kitada,S.Kawata, et al.: "The addition of bisecting N-acetylglucosamine residues to E-cadherin down-regulate the tyrosine phosphorylation of β-catenin"Journal of Biological Chemistry. 276. 475-480 (2001)

T.Kitada、S.Kawata 等人：“E-钙粘蛋白中添加平分 N-乙酰葡糖胺残基可下调 β-连环蛋白的酪氨酸磷酸化”《生物化学杂志》276. 475-480 (2001)。

Ito N., Claesson-Welsh L.: "Dual effects of heparin on VEGF receptor-1 and transduction of biological responses."Angiogenesis. 3. 159-166 (1999)

Ito N.，Claesson-Welsh L.：“肝素对 VEGF 受体 1 和生物反应转导的双重作用。”血管生成。

K.Huang,N.Ito, et al.: "Signaling properties of VEGF receptor-1 and -2 homo-and heterodimers"The Internationl Journal of Biochemistry & Cell Biology. (in press). (2001)

K.Huang、N.Ito 等人：“VEGF 受体-1 和 -2 同二聚体和异二聚体的信号特性”国际生物化学杂志

Kitada T., Miyoshi E., Noda K., Higashiyama S., Ihara H., Matsuura N., Hayashi N., Kawata S., Matsuzawa Y., Taniguchi N.: "The addition of bisecting N-acetylglucosamine residues to E-cadherin down-regulates the tyrosine phosphorylation of β-catenin."J.Bio

Kitada T.、Miyoshi E.、Noda K.、Higashiyama S.、Ihara H.、Matsuura N.、Hayashi N.、Kawata S.、Matsuzawa Y.、Taniguchi N.：“将二等分的 N-乙酰氨基葡萄糖残基添加到E-钙粘蛋白下调 β-连环蛋白的酪氨酸磷酸化。”J.Bio