未来转移的器官不是循环肿瘤细胞的被动接受者，而是在转移扩散发生之前就被原发肿瘤选择性地、主动地修饰。肿瘤通过调节远处器官来创造微环境，在肿瘤细胞到达之前促进其生存和增殖，从而建立转移前生态位，从而精心策划转移前程序。原发性肿瘤来源的外泌体调节这些转移前的微环境，产生有利于肿瘤细胞归巢和扩张的宽松环境。此外，microRNA 已成为外泌体货物的关键组成部分，不仅可以诱导转移前生态位的形成，还可以为特定继发性肿瘤群体的到达和定植做好准备。在此背景下，本综述致力于阐明肿瘤源性外泌体 microRNA 对其个体化转移前生态位起源的影响，以期确定特异性癌症转移的新方法并利用这种现象进行癌症免疫治疗。© 2024。作者。

Organs of future metastasis are not passive receivers of circulating tumor cells, but are instead selectively and actively modified by the primary tumor before metastatic spread has even occurred. Tumors orchestrate a pre-metastatic program by conditioning distant organs to create microenvironments that foster the survival and proliferation of tumor cells before their arrival, thereby establishing pre-metastatic niches. Primary tumor-derived exosomes modulate these pre-metastatic niches, generating a permissive environment that facilitates the homing and expansion of tumor cells. Moreover, microRNAs have emerged as a key component of exosomal cargo, serving not only to induce the formation of pre-metastatic niches but also to prime these sites for the arrival and colonization of specific secondary tumor populations. Against this backdrop, this review endeavors to elucidate the impact of tumor-derived exosomal microRNAs on the genesis of their individualized pre-metastatic niches, with a view towards identifying novel means of specifying cancer metastasis and exploiting this phenomenon for cancer immunotherapy.© 2024. The Author(s).