Aberrant expression of the RON receptor tyrosine kinase, a cell surface protein, is a pathogenic feature in pancreatic cancer, which renders it a drug target for targeted therapy. Nevertheless, development of therapeutics targeting RON for pancreatic cancer therapy is hampered due to the lack of full addiction by pancreatic cancer cells to RON signaling for growth and survival. Here we describe a novel strategy using anti-RON antibody-directed drug delivery in the form of an antibody–drug conjugate for inhibition and/or eradication of pancreatic cancers. Monoclonal antibody Zt/g4 specific to the RON Sema domain was selected as the drug carrier based on its ability to induce robust RON internalization. Conjugation of Zt/g4 with monomethyl auristatin E, designated as Zt/g4-MMAE, was achieved through a protease-sensitive dipeptide linker to reach a drug to antibody ratio of 3.29:1. Zt/g4-MMAE was stable in human plasma with a dissociation rate less than 4% within a 10 day period. In vitro, Zt/g4-MMAE rapidly induced RON internalization, resulting in cell cycle arrest followed by massive cell death. The maximal effect was seen in pancreatic cancer cells with more than 10 000 receptor molecules per cell. Zt/g4-MMAE also synergized in vitro with chemotherapeutics including gemcitabine, 5-fluorouracil, and oxaliplatin to further reduce PDAC cell viability. In vivo, Zt/g4-MMAE exerts a long-lasting activity, which not only inhibited but also eradicated pancreatic xenograft tumors. These finding indicate that Zt/g4-directed drug delivery is highly effective for eradicating pancreatic tumors. Thus, Zt/g4-MMAE is a novel biotherapeutic with potential for therapy of RON-expressing pancreatic malignancies.

中文翻译：

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抗-RON抗体-药物结合物Zt / g4-MMAE对胰腺癌过表达RON受体酪氨酸激酶靶向治疗的临床前疗效

RON受体酪氨酸激酶（一种细胞表面蛋白）的异常表达是胰腺癌的致病特征，使其成为靶向治疗的药物靶标。然而，由于胰腺癌细胞缺乏针对RON信号的生长和存活的完全成瘾性，阻碍了针对RON进行胰腺癌治疗的疗法的开发。在这里，我们描述了一种使用抗-RON抗体定向药物以抗体-药物偶联物的形式抑制和/或根除胰腺癌的新策略。基于RON Sema域特异的单克隆抗体Zt / g4，基于其诱导强大的RON内部化的能力，被选作药物载体。Zt / g4与单甲基澳瑞他汀E（称为Zt / g4-MMAE）的缀合，通过蛋白酶敏感的二肽接头实现的“药物/抗体”比达到3.29：1。Zt / g4-MMAE在人血浆中稳定，在10天的时间内解离率小于4％。在体外，Zt / g4-MMAE迅速诱导RON内在化，导致细胞周期停滞，随后大量细胞死亡。在每个细胞具有超过10 000个受体分子的胰腺癌细胞中看到了最大的作用。Zt / g4-MMAE还与包括吉西他滨，5-氟尿嘧啶和奥沙利铂的化学疗法在体外协同作用，以进一步降低PDAC细胞的活力。在体内，Zt / g4-MMAE具有持久的活性，不仅可以抑制而且可以根除胰腺异种移植肿瘤。这些发现表明，Zt / g4指导的药物递送对于根除胰腺肿瘤是高度有效的。因此，