Mesenchymal mode of migration participates in pulmonary metastasis of mouse osteosarcoma LM8
Mesenchymal mode of migration participates in pulmonary metastasis of mouse osteosarcoma LM8
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DOI：
10.1007/s10585-010-9352-x
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发表时间：
2010-12-01
影响因子：
4
通讯作者：
Adachi, Souichi
中科院分区：
文献类型：
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作者：
Yui, Yoshihiro;Itoh, Kazuyuki;Adachi, Souichi
由于难治性肺转移，骨肉瘤患者的预后仍然很差。我们先前通过体内筛选，从Dunn小鼠骨肉瘤中建立了高转移性骨肉瘤细胞系LM8。在此，我们旨在阐明与骨肉瘤高转移潜能相关的生物学特性和抑制骨肉瘤肺转移的新靶分子，利用这种同基因自发转移模型。LM8细胞获得成纤维细胞形态，细胞表面有明显的丝状足突。免疫组织化学染色显示LM8细胞与Dunn细胞相比有微弱的应力纤维形成和整合素β1的周边定位，生化分析显示LM8细胞的CDC42活化和粘着斑激酶(FAK)的自动磷酸化。LM8细胞以单细胞迁移模式激活运动。Rho相关激酶(ROCK)抑制剂Y-27632增加了LM8的迁移，而Cdc42沉默则降低了LM8的迁移。我们发现，临床批准的喜树碱类似物伊立替康抑制FAK的迁移、CDC42活性和自磷酸化，并选择性地减弱整合素β1在LM8细胞中的分布。每天口服伊立替康可显著降低同基因C3H小鼠的肺转移率和肺转移率。成纤维细胞的形态和激活的细胞迁移依赖于CDC42而不是Rho-Rock信号通路，这表明LM8以间质方式迁移细胞。这种激活的间充质迁移是LM8细胞肺转移的关键成分。伊立替康除了具有细胞毒作用外，还可抑制间充质迁移，从而有效地预防骨肉瘤的肺转移。
The outcomes of osteosarcoma patients still remain poor because of intractable pulmonary metastasis. We previously established a highly metastatic osteosarcoma cell line, LM8 from Dunn mouse osteosarcoma by in vivo selection. We herein aimed to clarify the characteristic biological features related with high metastatic potential and new target molecules to suppress pulmonary metastasis of osteosarcoma, using this syngeneic spontaneous metastatic model. LM8 cells acquired fibroblastic morphology with striking filopodia on the cell surface. Immunostaining showed faint stress fiber formation and peripherally localized integrin beta 1, and biochemical analyses showed the activated Cdc42 and autophosphorylation of focal adhesion kinase (FAK) in LM8 cells when compared to Dunn cells. LM8 cells had activated motility in single cell migration mode. LM8 migration was increased by a Rho-associated kinase (ROCK) inhibitor, Y-27632, while decreased by Cdc42 silencing using RNA interference system. We found that a clinically approved camptothecin analog, irinotecan suppressed the migration, Cdc42 activity, and autophosphorylation of FAK, and attenuated integrin beta 1 distribution selectively in LM8 cells. Daily oral administration of irinotecan significantly reduced the rate and size of pulmonary metastasis in syngeneic C3H mice. The fibroblastic morphology and activated cell migration with the dependency on Cdc42 but not Rho-ROCK signaling pathway argued that LM8 moved in mesenchymal mode of cell migration. This activated mesenchymal migration was a key component of the pulmonary metastasis of LM8 cells. The inhibition of mesenchymal migration by irinotecan, in addition to its cytotoxic effects, might be effective in preventing pulmonary metastasis of osteosarcoma.