癌症转移是导致癌症相关死亡的主要原因。原发肿瘤在次要部位的播种是一个高度低效的过程，需要对癌细胞的遗传结构进行大量改变。这些改变包括全局基因表达模式的显著改变。MicroRNA是小型非编码蛋白质的RNA，在调节基因表达方面发挥着核心作用。在这里，我们关注癌症转移的microRNA决定因素，并检查转移性癌细胞中的microRNA失调情况。我们以逐步分解的方式分析转移过程，并总结每个步骤中microRNA的参与情况。我们还讨论了不同基于microRNA的策略的优点和局限性，这些策略已经用于在临床前模型中靶向转移。最后，我们强调当前使用microRNA基因治疗靶向晚期或转移性肿瘤的临床试验。

Cancer metastasis is the primary cause of cancer-related deaths. The seeding of primary tumours at a secondary site is a highly inefficient process requiring substantial alterations in the genetic architecture of cancer cells. These alterations include significant changes in global gene expression patterns. MicroRNAs are small, non-protein coding RNAs which play a central role in regulating gene expression. Here, we focus on microRNA determinants of cancer metastasis and examine microRNA dysregulation in metastatic cancer cells. We dissect the metastatic process in a step-wise manner and summarise the involvement of microRNAs at each step. We also discuss the advantages and limitations of different microRNA-based strategies that have been used to target metastasis in pre-clinical models. Finally, we highlight current clinical trials that use microRNA-based therapies to target advanced or metastatic tumours.