Progression of epithelial cancers predominantly proceeds by collective invasion of cell groups with coordinated cell–cell junctions and multicellular cytoskeletal activity. Collectively invading breast cancer cells express the gap junction protein connexin-43 (Cx43), yet whether Cx43 regulates collective invasion remains unclear. We here show that Cx43 mediates gap-junctional coupling between collectively invading breast cancer cells and, via hemichannels, adenosine nucleotide/nucleoside release into the extracellular space. Using molecular interference and rescue strategies, we identify that Cx43 hemichannel function, but not intercellular communication, induces leader cell activity and collective migration through the engagement of the adenosine receptor 1 (ADORA1) and AKT signaling. Accordingly, pharmacological inhibition of ADORA1 or AKT signaling caused leader cell collapse and halted collective invasion. ADORA1 inhibition further reduced local invasion of orthotopic mammary tumors in vivo, and joint up-regulation of Cx43 and ADORA1 in breast cancer patients correlated with decreased relapse-free survival. This identifies autocrine purinergic signaling, through Cx43 hemichannels, as a critical pathway in leader cell function and collective invasion.

中文翻译：

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自分泌嘌呤能环通过连接蛋白 43 半通道诱导的集体入侵

上皮癌的进展主要是通过具有协调的细胞-细胞连接和多细胞细胞骨架活性的细胞群的集体侵袭来进行的。集体侵袭的乳腺癌细胞表达间隙连接蛋白 connexin-43 (Cx43)，但 Cx43 是否调节集体侵袭仍不清楚。我们在这里表明，Cx43 介导集体入侵的乳腺癌细胞之间的间隙连接耦合，并通过半通道将腺苷核苷酸/核苷释放到细胞外空间。利用分子干扰和救援策略，我们发现 Cx43 半通道功能（而非细胞间通讯）通过腺苷受体 1 (ADORA1) 和 AKT 信号传导的参与诱导前导细胞活动和集体迁移。因此，ADORA1 或 AKT 信号传导的药理学抑制导致前导细胞崩溃并停止集体入侵。ADORA1 抑制进一步减少了体内原位乳腺肿瘤的局部侵袭，乳腺癌患者中 Cx43 和 ADORA1 的联合上调与无复发生存率降低相关。这表明通过 Cx43 半通道的自分泌嘌呤能信号传导是前导细胞功能和集体入侵的关键途径。