Nature：科学家找到癌症扩散的新机制

科学家相信他们可能终于找到癌症扩散的原因，这项研究结果对研发癌症治疗法攸关重要。

这项研究已经找出名为“追逐”（chase and run）效应的机制，也就是罹病细胞与健康细胞会在身体各处相互追逐，这项重大突破或许能挽救数以百万计生命。

伦敦大学学院（University College London）研究人员的发现，或许能引导研发出革命性疗法，阻挡追逐效应，让肿瘤待在一个部位。研究人员声称，阻挡“追逐”效应“相对容易”。研究报告现已刊登在了近期出版的《自然-细胞生物学》（Nature Cell Biology）杂志，使用两种胚胎细胞，模拟癌细胞与健康细胞的作用。

这项研究发现的关键在于，首先必须弄清楚癌细胞依附在健康细胞的原因。科学家使用类似的细胞类型并观察细胞行为，模拟体内细胞的互动。

研究人员使用青蛙与斑马鱼的胚胎做研究，他们深信癌细胞依附在健康细胞，以在各处移动的过程，跟人体内的追逐效应类似。

这项研究有助于呈现一些基本生物程序，这在细胞于体内各处移动时发挥作用，但科学家只研究发育中青蛙与斑马鱼胚胎，没有具体研究癌细胞。所以，要见到这类知识能否应用到癌症新疗法上，还有非常漫长的路要走。

Chase-and-run between adjacent cell populations promotes directional collective migration
Abstract
Collective cell migration in morphogenesis and cancer progression often involves the coordination of multiple cell types. How reciprocal interactions between adjacent cell populations lead to new emergent behaviours remains unknown. Here we studied the interaction between neural crest (NC) cells, a highly migratory cell population, and placodal cells, an epithelial tissue that contributes to sensory organs. We found that NC cells chase placodal cells by chemotaxis, and placodal cells run when contacted by NC. Chemotaxis to Sdf1 underlies the chase, and repulsion involving PCP and N-cadherin signalling is responsible for the run. This chase-and-run requires the generation of asymmetric forces, which depend on local inhibition of focal adhesions. The cell interactions described here are essential for correct NC migration and for segregation of placodes in vivo and are likely to represent a general mechanism of coordinated migration.