虽然分子靶点，如HER2、TP53和PIK3CA，在食管癌中得到广泛研究，但其中很少有成功应用于临床治疗的。因此，发现新颖的可操作靶点和抑制剂至关重要。真核翻译延伸因子2（eEF2）据报道在各种癌症中高表达。然而，它对癌症的维持和进展的贡献尚未完全阐明。本研究利用组织芯片评估了eEF2蛋白在食管鳞状细胞癌中的表达和临床意义。接下来，我们进行了敲低、过表达、RNA结合蛋白免疫沉淀（RIP）序列和新生蛋白合成分析，探讨了eEF2的分子功能。此外，我们利用化合物筛选、表面等离子共振（SPR）、等温滴定量热（ITC）分析、细胞增殖和患者来源的异种移植（PDX）小鼠模型，发现了eEF2抑制剂，并评估其对食管鳞状细胞癌生长的影响。我们发现，在食管鳞状细胞癌中高表达eEF2，并与患者预后呈负相关。敲低eEF2抑制了食管鳞状细胞癌的细胞增殖和集落形成。eEF2与拓扑异构酶II（TOP1）和拓扑异构酶II（TOP2）mRNA结合，并增强TOP1和TOP2的蛋白生物合成。我们还发现桃仙丹素是eEF2的一种新型抑制剂，并且桃仙丹素在体内外都抑制了食管鳞状细胞癌的生长。我们的研究表明，桃仙丹素通过靶向eEF2和调控下游TOP1和TOP2生物合成来抑制食管鳞状细胞癌的生长。eEF2可作为潜在的治疗靶点，在进一步的临床研究中提供支持。©2023.作者

Although molecular targets such as HER2, TP53 and PIK3CA have been widely studied in esophageal cancer, few of them were successfully applied for clinical treatment. Therefore, it is urgent to discover novel actionable targets and inhibitors. Eukaryotic translational elongation factor 2 (eEF2) is reported to be highly expressed in various cancers. However, its contribution to the maintenance and progression of cancer has not been fully clarified.In the present study, we utilized tissue array to evaluate eEF2 protein expression and clinical significance in esophageal squamous cell carcinoma (ESCC). Next, we performed knockdown, overexpression, RNA-binding protein immunoprecipitation (RIP) sequence, and nascent protein synthesis assays to explore the molecular function of eEF2. Furthermore, we utilized compound screening, Surface Plasmon Resonance (SPR), Isothermal Titration Calorimetry (ITC) assay, cell proliferation and Patient derived xenograft (PDX) mouse model assays to discover an eEF2 inhibitor and assess its effects on ESCC growth.We found that eEF2 were highly expressed in ESCC and negatively associated with the prognosis of ESCC patients. Knocking down of eEF2 suppressed the cell proliferation and colony formation of ESCC. eEF2 bond with the mRNA of Topoisomerase II (TOP1) and Topoisomerase II (TOP2) and enhanced the protein biosynthesis of TOP1 and TOP2. We also identified Toosendanin was a novel inhibitor of eEF2 and Toosendanin inhibited the growth of ESCC in vitro and in vivo.Our findings show that Toosendanin treatment suppresses ESCC growth through targeting eEF2 and regulating downstream TOP1 and TOP2 biosynthesis. eEF2 could be supplied as a potential therapeutic target in the further clinical studies.© 2023. The Author(s).