Exosomes mediated crosstalk between tumor cells and other stromal cells including tumor associated macrophages plays an essential role in reprogramming tumor microenvironment (TME) to facilitate tumor progression. However, the mechanism of tumor derived exosomes promotes bladder cancer progression have not been defined. Exosomes were extracted from bladder cancer cells MB49 conditioned medium by ultracentrifugation. The effects of MB49-derived exosomes on macrophages polarization were analyzed by qPCR, flow cytometry, and Western blot. The immunosuppressive phenotype and function of MB49-derived exosomes stimulated macrophages were verified by tumor xenograft assays and T cell co-culture experiments. Exosomal miRNAs were analyzed by microarray to identify potential targets regulating macrophage polarization. MB49-derived exosomes could be ingested by macrophages, consequently promoting macrophages immunosuppressive polarization. Mechanically, the MB49-derived exosomes induced macrophage M2 polarization was mediated by down-regulation of PTEN and activation of AKT/STAT3/6 signaling. Moreover, hindrance of the generation or secretion of exosomes by GW4869 inhibited macrophages differentiation into immunosuppressive phenotype and function, thereby suppressed tumor growth in a mouse subcutaneous tumor model. Our study confirmed the contribution of bladder cancer derived exosomes on the establishment of immunosuppressive TME and provided a potential therapeutic target for bladder cancer treatment.

中文翻译：

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癌症衍生的外泌体诱导巨噬细胞免疫抑制极化以促进膀胱癌进展

外泌体介导的肿瘤细胞与包括肿瘤相关巨噬细胞在内的其他基质细胞之间的串扰在重编程肿瘤微环境 (TME) 以促进肿瘤进展方面发挥着重要作用。然而，肿瘤来源的外泌体促进膀胱癌进展的机制尚未明确。通过超速离心从膀胱癌细胞 MB49 条件培养基中提取外泌体。通过 qPCR、流式细胞术和蛋白质印迹分析 MB49 衍生的外泌体对巨噬细胞极化的影响。MB49衍生的外泌体刺激巨噬细胞的免疫抑制表型和功能通过肿瘤异种移植物测定和T细胞共培养实验得到验证。通过微阵列分析外泌体 miRNA，以确定调节巨噬细胞极化的潜在靶标。MB49衍生的外泌体可以被巨噬细胞摄取，从而促进巨噬细胞免疫抑制极化。机械地，MB49 衍生的外泌体诱导巨噬细胞 M2 极化是由 PTEN 的下调和 AKT/STAT3/6 信号的激活介导的。此外，GW4869 阻碍外泌体的产生或分泌抑制巨噬细胞分化为免疫抑制表型和功能，从而抑制小鼠皮下肿瘤模型中的肿瘤生长。我们的研究证实了膀胱癌衍生的外泌体对建立免疫抑制 TME 的贡献，并为膀胱癌的治疗提供了潜在的治疗靶点。MB49衍生的外泌体诱导巨噬细胞M2极化是由PTEN的下调和AKT/STAT3/6信号的激活介导的。此外，GW4869 阻碍外泌体的产生或分泌抑制巨噬细胞分化为免疫抑制表型和功能，从而抑制小鼠皮下肿瘤模型中的肿瘤生长。我们的研究证实了膀胱癌衍生的外泌体对建立免疫抑制 TME 的贡献，并为膀胱癌的治疗提供了潜在的治疗靶点。MB49衍生的外泌体诱导巨噬细胞M2极化是由PTEN的下调和AKT/STAT3/6信号的激活介导的。此外，GW4869 阻碍外泌体的产生或分泌抑制巨噬细胞分化为免疫抑制表型和功能，从而抑制小鼠皮下肿瘤模型中的肿瘤生长。我们的研究证实了膀胱癌衍生的外泌体对建立免疫抑制 TME 的贡献，并为膀胱癌的治疗提供了潜在的治疗靶点。从而抑制小鼠皮下肿瘤模型中的肿瘤生长。我们的研究证实了膀胱癌衍生的外泌体对建立免疫抑制 TME 的贡献，并为膀胱癌的治疗提供了潜在的治疗靶点。从而抑制小鼠皮下肿瘤模型中的肿瘤生长。我们的研究证实了膀胱癌衍生的外泌体对建立免疫抑制 TME 的贡献，并为膀胱癌的治疗提供了潜在的治疗靶点。