nm23H1 is involved in tumor invasion by regulating rho family GTPases

nm23H1通过调节rho家族GTP酶参与肿瘤侵袭

• 批准号: 14570183
• 负责人: TANAKA Masamitsu
• 金额: $ 2.37万
• 依托单位: National Cancer Center (2003)Hamamatsu University School of Medicine (2002)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14570183/
• 关键词: Tiam1; nm23; Eph; ephrin; Rac1; 低分子量G蛋白質

To know the effect of nm23H1 on the invasion and metastasis of Tiam1-expressing tumor cells, we have established a cell line "BW5147 nm23H1 Tet-ON cell". In this cell line, Tiam1 is stably overexpressed and nm23H1 is inducibly expressed by the addition of doxycycline. The expression of nm23H1 inhibited Tiam1-induced Rac1 activation, membrane ruffling and the formation of lamellipodia of BW5147 nm23H1 Tet-ON cell, By the analysis using Boyden chambers, we found that the migration and invasion of BW5147 cells were inhibited by the overexpression of nm23H1. On the other hand, nm23H1 mutant which lacks the ability of binding to Tiam1 had no effect to inhibit Tiam1-induced Rac1 activation and cell migration. The effect of nm23H1 on Tiam1 expressing tumors was also examined in vivo by feeding doxycycline-containing foods to the mice inoculated BW5147 nm23H1 Tet-ON cells. However we currently do not success to reduce the size of implanted tumor of BW5147 nm23H1 Tet-ON cells because of the modest expression level of nm23H1 in those tumors. On the other hand, we have identified EphA2 tyrosine kinase receptor and ephrin-B1 ligand as stimulators of Tiam1. Interaction of Tiam1 with EphA2 or ephrin-B1 activates Rac1 leading to the induction of neurite outgrowth of cortical neurons and neuroblastoma cells. Because the activation of Tiam1/Rac1 stimulates the cell motility of tumor cells, the results suggest the induction of nm23H1 expression may effectively inhibit the invasion of tumors, which express both Tiam1 and EphA2 or ephrin-B1.

为了了解nm23H1对Tiam1表达肿瘤细胞侵袭和转移的影响，我们建立了细胞系“BW5147 nm23H1 Tet-ON细胞”。在该细胞系中，Tiam1 稳定过表达，nm23H1 通过添加强力霉素诱导表达。 nm23H1的表达抑制了Tiam1诱导的BW5147 nm23H1 Tet-ON细胞的Rac1激活、膜皱起和板状伪足的形成，通过Boyden小室分析，我们发现nm23H1的过表达抑制了BW5147细胞的迁移和侵袭。 。另一方面，缺乏与Tiam1结合能力的nm23H1突变体没有抑制Tiam1诱导的Rac1激活和细胞迁移的作用。还通过给接种 BW5147 nm23H1 Tet-ON 细胞的小鼠喂食含有多西环素的食物，在体内检查了 nm23H1 对表达 Tiam1 的肿瘤的影响。然而，我们目前未能成功减少 BW5147 nm23H1 Tet-ON 细胞植入肿瘤的大小，因为这些肿瘤中 nm23H1 的表达水平较低。另一方面，我们已经确定 EphA2 酪氨酸激酶受体和 ephrin-B1 配体作为 Tiam1 的刺激剂。 Tiam1 与 EphA2 或 ephrin-B1 的相互作用会激活 Rac1，从而诱导皮质神经元和神经母细胞瘤细胞的神经突生长。由于Tiam1/Rac1的激活会刺激肿瘤细胞的细胞运动，因此结果表明诱导nm23H1表达可以有效抑制同时表达Tiam1和EphA2或ephrin-B1的肿瘤的侵袭。

项目成果

Masamitsu Tanaka: "Association of disheveiled with Eph-tyrosine kinase receptor and ephrin mediates cell repulsion"EMBO Journal. 22. 847-858 (2003)

Masamitsu Tanaka：“Eph-酪氨酸激酶受体和肝配蛋白介导细胞排斥的关联”EMBO 杂志。

Masamitsu Tanaka et al.: "Association of Dishevelled with Eph-tyrosine kinase receptor and ephrin mediates cell repulsion"EMBO J.. 22. 847-858 (2003)

Masamitsu Tanaka 等：“Disheveled 与 Eph-酪氨酸激酶受体和肝配蛋白介导细胞排斥的关联”EMBO J.. 22. 847-858 (2003)

Yoshirou Otsuki: "Guanine nucleotide exchange factor, Tiam1,directly binds to c-Myc and interferes with c-Myc mediated apoptosis in Rat1 fibroblasts"J Biological Chemistry. 278. 5132-5140 (2003)

Yoshirou Otsuki：“鸟嘌呤核苷酸交换因子 Tiam1 直接与 c-Myc 结合并干扰 c-Myc 介导的 Rat1 成纤维细胞凋亡”J Biological Chemistry。

Masamitsu Tanaka et al.: "Tiam1 mediates neurite outgrowth induced by ephrin-B1 and EphA2."EMBO J.. 23. 1075-1088 (2004)

Masamitsu Tanaka 等人：“Tiam1 介导 ephrin-B1 和 EphA2 诱导的神经突生长。”EMBO J.. 23. 1075-1088 (2004)