Exosomal pyruvate kinase isoenzyme type M2 (PKM2) has been found to play a key role in the progression of human hepatocarcinoma. However, exosomal PKM2 (especially plasma‑derived exosomal PKM2), in patients with oesophageal squamous cell carcinoma (ESCC) has not been well defined. In the present study, plasma‑derived exosomes were isolated from healthy controls and patients with ESCC, and identified by transmission electronic microscopy, western blotting, nano‑flow cytometry, nanoparticle tracking and phagocytosis analysis; exosomal PKM2 was detected by western blotting and ELISA. In addition, changes in cellular proliferation and motility in recipient cells (Eca109) were assessed using Cell Counting Kit‑8, colony formation, wound‑healing and Transwell assays. The PKM2 content was higher in exosomes from patients with ESCC than in those from healthy donors. Furthermore, exosomes from patients with ESCC enhanced the proliferation and motility of ESCC cells in vitro. Notably, PKM2 was found to be transferred by exosomes, and was able to act by activating STAT3. To verify the association between PKM2 and STAT3, immunohistochemistry was employed to analyse the protein levels of PKM2 and pSTAT3^Tyr705. These data revealed that PKM2 and pSTAT3^Tyr705 were upregulated and associated with overall survival in patients with ESCC. Therefore, the present study highlights that exosomes from patients with ESCC enhance the migration and invasiveness of ESCC cells by transferring PKM2.

中文翻译：

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血浆来源的外泌体丙酮酸激酶同工酶 M2 型可加速食管鳞状细胞癌细胞的增殖和运动。


外泌体丙酮酸激酶同工酶 M2 型（PKM2）已被发现在人类肝癌的进展中发挥关键作用。然而，食管鳞状细胞癌（ESCC）患者中的外泌体 PKM2（尤其是血浆来源的外泌体 PKM2）尚未明确定义。在本研究中，从健康对照和食管鳞癌患者中分离出血浆来源的外泌体，并通过透射电子显微镜、蛋白质印迹、纳米流式细胞术、纳米颗粒追踪和吞噬分析进行鉴定；通过蛋白质印迹和ELISA检测外泌体PKM2。此外，还使用 ​​Cell Counting Kit-8、集落形成、伤口愈合和 Transwell 检测评估了受体细胞 (Eca109) 的细胞增殖和运动性变化。 ESCC 患者的外泌体中 PKM2 含量高于健康供体的外泌体。此外，来自食管鳞癌患者的外泌体在体外增强了食管鳞癌细胞的增殖和运动能力。值得注意的是，PKM2被发现是通过外泌体转移的，并且能够通过激活STAT3来发挥作用。为了验证 PKM2 和 STAT3 之间的关联，采用免疫组织化学分析 PKM2 和 pSTAT3 ^Tyr705的蛋白水平。这些数据显示 PKM2 和 pSTAT3 ^Tyr705上调并与 ESCC 患者的总生存期相关。因此，本研究强调来自 ESCC 患者的外泌体通过转移 PKM2 增强 ESCC 细胞的迁移和侵袭能力。