RN7SK（7SK）是一种高度保守的非编码RNA，通过与少数蛋白质相互作用来作为转录调节因子。尽管越来越多的证据支持7SK相互作用蛋白质的促癌作用，但仅有少数报告涉及7SK和癌症之间的直接联系。为了测试通过过表达7SK来假定抑制癌症的作用，研究了外泌体7SK传递对癌症表型的影响。人间充质干细胞衍生的外泌体被装载了7SK（Exo-7SK）。MDA-MB-231三阴性乳腺癌细胞株经过Exo-7sk处理。通过qPCR评估7SK的表达水平。通过MTT和Annexin V/PI的测定方法以及qPCR评估细胞凋亡调节基因，评估了细胞的活力。通过生长曲线分析，集落形成和细胞周期分析评估了细胞增殖。通过转移和入侵测定以及基因调节上皮-间充质转化（EMT）的qPCR评估评估TNBCs的攻击性。此外，使用裸鼠异种移植模型评估了肿瘤形成能力。将MDA-MB-231细胞处理为Exo-7SK导致7SK的高效过表达。表达调节凋亡基因的转录水平；降低增殖率；降低迁移和侵入；调节EMT调节基因的转录；降低体内肿瘤形成能力。最后，Exo-7SK降低了HMGA1 mRNA水平，HMGA1是与主要基因调节和促癌作用相关联的7SK相互作用蛋白质，以及其生物信息学选定的促癌靶基因。总的来说，我们的研究结果表明，Exo-7SK通过下调HMGA1来抑制癌症表型，为这一概念的验证提供了证据。版权所有©2023。Elsevier Inc.出版。

RN7SK (7SK), a highly conserved non-coding RNA, serves as a transcription regulator via interaction with a few proteins. Despite increasing evidences which support the cancer-promoting roles of 7SK-interacting proteins, limited reports address the direct link between 7SK and cancer. To test the hypothetic suppression of cancer by overexpression of 7SK, the effects of exosomal 7SK delivery on cancer phenotypes were studied.Exosomes derived from human mesenchymal stem cells were loaded with 7SK (Exo-7SK). MDA-MB-231, triple negative breast cancer (TNBC), cell line was treated with Exo-7sk. Expression levels of 7SK were evaluated by qPCR. Cell viability was assessed via MTT and Annexin V/PI assays as well as qPCR assessment of apoptosis-regulating genes. Cell proliferation was evaluated by growth curve analysis, colony formation and cell cycle assays. Aggressiveness of TNBCs was evaluated via transwell migration and invasion assays and qPCR assessment of genes regulating epithelial to mesenchymal transition (EMT). Moreover, tumor formation ability was assessed using a nude mice xenograft model.Treatment of MDA-MB-231 cells with Exo-7SK resulted in efficient overexpression of 7SK; reduced viability; altered transcription levels of apoptosis-regulating genes; reduced proliferation; reduced migration and invasion; altered transcription of EMT-regulating genes; and reduced in vivo tumor formation ability. Finally, Exo-7SK reduced mRNA levels of HMGA1, a 7SK interacting protein with master gene regulatory and cancer promoting roles, and its bioinformatically-selected cancer promoting target genes.Altogether, as a proof of the concept, our findings suggest that exosomal delivery of 7SK may suppress cancer phenotypes via downregulation of HMGA1.Copyright © 2023. Published by Elsevier Inc.