背景：血小板在止血、凝血以及肿瘤发生过程中起着重要作用。血小板与循环肿瘤细胞（CTCs）之间的相互作用可能造成多种促癌效应，包括促进肿瘤生长、上皮间质转化（EMT）、转移性细胞存活、粘附、阻滞以及可能的前转移巢和转移形成。与CTCs的相互作用可能会改变血小板的转录组。然而，由于CTCs是罕见的事件，CTCs与血小板之间的相互作用仍知之甚少。在这里，我们使用我们已建立的结肠癌CTC系列在体外研究结肠癌CTC-血小板相互作用及其对这两种细胞类型行为/表型的影响。方法：我们将来自健康供体的血小板暴露于凝血酶（阳性对照）或来自一位结肠癌患者的三个CTC系列的培养基，然后通过显微镜和流式细胞术监测形态和蛋白质表达的变化。然后，通过RNA测序分析间接共培养（有Transwell插入物存在）的三个CTC系列中血小板的转录组。我们还通过逆转录定量PCR定量血小板与CTCs直接共培养（无Transwell插入物）后与EMT和癌症发展相关的基因的表达。结果：我们观察到血小板在暴露于CTC培养基和间接共培养（分泌物）后发生形态和转录组的变化。此外，与血小板共培养的CTCs中涉及EMT的基因的表达水平（p < 0.05）降低，但涉及间充质标记物（FN1和SNAI2）的基因的表达水平未受影响。癌症侵袭相关基因（MYC、VEGFB、IL33、PTGS2和PTGER2）的表达水平增加。结论：我们首次使用我们独特的结肠CTC系列研究了CTC-血小板相互作用。与CTC的培养基的孵育导致血小板聚集和激活，支持他们的相互作用可能有助于在血液中保持CTC的完整性。此外，与血小板的共培养影响了CTCs中多个参与侵袭和EMT维持的基因的表达。 版权所有©2023年Eslami-S、Cortés-Hernández、Glogovitis、Antunes-Ferreira、D’Ambrosi、Kurma、Garima、Cayrefourcq、Best、Koppers-Lalic、Wurdinger和Alix-Panabières。

Background: Platelets are active players in hemostasis, coagulation and also tumorigenesis. The cross-talk between platelets and circulating tumor cells (CTCs) may have various pro-cancer effects, including promoting tumor growth, epithelial-mesenchymal transition (EMT), metastatic cell survival, adhesion, arrest and also pre-metastatic niche and metastasis formation. Interaction with CTCs might alter the platelet transcriptome. However, as CTCs are rare events, the cross-talk between CTCs and platelets is poorly understood. Here, we used our established colon CTC lines to investigate the colon CTC-platelet cross-talk in vitro and its impact on the behavior/phenotype of both cell types. Methods: We exposed platelets isolated from healthy donors to thrombin (positive control) or to conditioned medium from three CTC lines from one patient with colon cancer and then we monitored the morphological and protein expression changes by microscopy and flow cytometry. We then analyzed the transcriptome by RNA-sequencing of platelets indirectly (presence of a Transwell insert) co-cultured with the three CTC lines. We also quantified by reverse transcription-quantitative PCR the expression of genes related to EMT and cancer development in CTCs after direct co-culture (no Transwell insert) with platelets. Results: We observed morphological and transcriptomic changes in platelets upon exposure to CTC conditioned medium and indirect co-culture (secretome). Moreover, the expression levels of genes involved in EMT (p < 0.05) were decreased in CTCs co-cultured with platelets, but not of genes encoding mesenchymal markers (FN1 and SNAI2). The expression levels of genes involved in cancer invasiveness (MYC, VEGFB, IL33, PTGS2, and PTGER2) were increased. Conclusion: For the first time, we studied the CTC-platelet cross-talk using our unique colon CTC lines. Incubation with CTC conditioned medium led to platelet aggregation and activation, supporting the hypothesis that their interaction may contribute to preserve CTC integrity during their journey in the bloodstream. Moreover, co-culture with platelets influenced the expression of several genes involved in invasiveness and EMT maintenance in CTCs.Copyright © 2023 Eslami-S, Cortés-Hernández, Glogovitis, Antunes-Ferreira, D’Ambrosi, Kurma, Garima, Cayrefourcq, Best, Koppers-Lalic, Wurdinger and Alix-Panabières.