肿瘤内异质性是肿瘤的一个成熟特征，妨碍了癌症的研究、诊断和治疗。我们先前根据细胞迁移能力对人乳腺癌细胞进行了表型分类。当将这些细胞注射到小鼠体内时，高迁移能力细胞的转移能力较弱，低迁移能力细胞的转移能力更强。本研究旨在确定这些低迁移和高迁移细胞在体外或体内是否相互作用。为了评估癌细胞迁移异质性与转移适应性之间的关系，我们对MDA-MB-231和SUM159PT三阴性乳腺癌细胞进行了表型分类，分成高迁移和低迁移亚群，分别在体外和体内以1:1的混合比例进行转移行为的测定。我们根据需要采用无配对、双尾学生t检验、曼-惠特尼检验、普通单因素方差分析和Kruskal-Wallis H检验进行统计分析，并以p<0.05为显著性水平。当高迁移细胞和低迁移细胞共培养在混合球中时，低迁移细胞的迁移距离比单独培养的低迁移细胞球更远。在混合球中，出现了领导者-追随者行为，高迁移细胞引领低迁移细胞形成迁移束。将高迁移细胞、低迁移细胞或1:1混合亚群的细胞悬液正交注射到小鼠的同位地点，混合细胞悬液和低迁移细胞均显示出明显的远处转移，但高迁移细胞则没有在任何位置观察到明显的转移。值得注意的是，与单独注射亚群相比，注射1:1混合的小鼠中观察到更多明显的远处转移。这项研究表明，低迁移细胞与高迁移细胞以一种共生方式相互作用，导致迁移和转移增加。综上所述，这些发现表明，癌细胞亚群的迁移能力与转移潜力无关，并且高迁移细胞与低迁移细胞之间的合作可以增强整体的转移适应性。 © 2023年。BioMed Central Ltd.,由施普林格自然出版集团的一部分。

Intratumor heterogeneity is a well-established hallmark of cancer that impedes cancer research, diagnosis, and treatment. Previously, we phenotypically sorted human breast cancer cells based on migratory potential. When injected into mice, highly migratory cells were weakly metastatic and weakly migratory cells were highly metastatic. The purpose of this study was to determine whether these weakly and highly migratory cells interact with each other in vitro or in vivo.To assess the relationship between heterogeneity in cancer cell migration and metastatic fitness, MDA-MB-231 and SUM159PT triple negative breast cancer cells were phenotypically sorted into highly migratory and weakly migratory subpopulations and assayed separately and in a 1:1 mixture in vitro and in vivo for metastatic behaviors. Unpaired, two-tailed Student's t-tests, Mann-Whitney tests, ordinary, one-way ANOVAs, and Kruskal-Wallis H tests were performed as appropriate with p < 0.05 as the cutoff for statistical significance.When highly and weakly migratory cells are co-seeded in mixed spheroids, the weakly migratory cells migrated farther than weakly migratory only spheroids. In mixed spheroids, leader-follower behavior occurred with highly migratory cells leading the weakly migratory cells in migration strands. When cell suspensions of highly migratory, weakly migratory, or a 1:1 mixture of both subpopulations were injected orthotopically into mice, both the mixed cell suspensions and weakly migratory cells showed significant distal metastasis, but the highly migratory cells did not metastasize significantly to any location. Notably, significantly more distal metastasis was observed in mice injected with the 1:1 mixture compared to either subpopulation alone.This study suggests that weakly migratory cells interact with highly migratory cells in a commensal fashion resulting in increased migration and metastasis. Together, these findings indicate that cancer cell subpopulation migration ability does not correlate with metastatic potential and that cooperation between highly migratory and weakly migratory subpopulations can enhance overall metastatic fitness.© 2023. BioMed Central Ltd., part of Springer Nature.