Purpose: Acute myeloid leukemia (AML) is a complex malignancy characterized by the clonal expansion of immature myeloid precursors. The standard treatment for newly diagnosed AML is chemotherapy consisting of cytosine arabinoside (Ara-C) and anthracyclines with disappointing clinical outcomes and severe adverse effects, such as symptomatic bradycardia, neurotoxicity. Thus, it is promising to treat AML through combination drug therapy to reduce the adverse effects of chemotherapeutics. In our recent published PNAS paper, we reported that NK-1R antagonists, both Aprepitant and SR140333, induce apoptosis of myeloid leukemia cells by inducing oxidative stress through mitochondrial calcium overload. We, therefore, tested the hypothesis of the combination Ara-C with NK-1R antagonist could enhance the efficacy of Ara-C.
Methods: MTT assay was employed to detect the cell proliferation. Flow cytometry was applied to detect the cell cycle and necrosis. PI uptake and LDH release assay were used to detect the disintegration of the plasma membrane. Xenograft model was constructed to explore the effect of combination Ara-C with Aprepitant in vivo.
Results: Our results showed that Aprepitant sensitizes HL60 cells to the cytotoxic effects of Ara-C more than 5-fold by enhancing G0/G1 cell cycle arrest and necrosis in vitro. Furthermore, Nec-1, a specific inhibitor of necroptosis, could recover the cell proliferative viability significantly. Attractively, once every 2-days regimen of Ara-C (5 mg/kg) and Aprepitant (10 mg/kg) via in situ injection dramatically reduced the tumor volume from 2175.0 ± 341.9 mm³ in the vehicle group to 828.4 ± 232.4 mm³ in the combination group without obvious toxicity in human myeloid leukemia xenograft mice.
Conclusion: Taken together, reduced dose of Ara-C combination with moderate Aprepitant provides more effective therapeutical methods for AML treatment in vitro and in vivo with the elimination of the toxicity of Ara-C, which may pay new avenue for the usage of the routine chemotherapy drug Ara-C with low dose to enhance efficacy and reduce toxicity in clinical practice.

Keywords: neurokinin receptor antagonist, cytosine arabinoside, combined chemotherapy, acute myeloid leukemia


中文翻译：

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Aprepitant 在体外和体内使急性髓细胞白血病细胞对胞嘧啶阿拉伯糖苷的细胞毒性作用敏感。

目的：急性髓细胞白血病（AML）是一种复杂的恶性肿瘤，其特征是未成熟髓细胞前体细胞的克隆扩增。新诊断的 AML 的标准治疗是由阿糖胞苷 (Ara-C) 和蒽环类药物组成的化学疗法，具有令人失望的临床结果和严重的不良反应，例如症状性心动过缓、神经毒性。因此，有希望通过联合药物治疗来治疗 AML，以减少化疗药物的副作用。在我们最近发表的 PNAS 论文中，我们报道了 NK-1R 拮抗剂，包括 Aprepitant 和 SR140333，通过线粒体钙超载诱导氧化应激来诱导髓性白血病细胞凋亡。因此，我们测试了 Ara-C 与 NK-1R 拮抗剂的组合可以增强 Ara-C 功效的假设。
方法：采用MTT法检测细胞增殖情况。流式细胞仪用于检测细胞周期和坏死。PI摄取和LDH释放测定用于检测质膜的崩解。构建异种移植模型以探索Ara-C与阿瑞匹坦联合在体内的作用。
结果：我们的研究结果表明，Aprepitant 通过增强体外 G0/G1 细胞周期停滞和坏死，使 HL60 细胞对 Ara-C 的细胞毒作用敏感 5 倍以上。此外，坏死性凋亡的特异性抑制剂 Nec-1 可以显着恢复细胞增殖活力。吸引人的是，通过原位注射每 2 天一次的 Ara-C (5 mg/kg) 和 Aprepitant (10 mg/kg) 方案将肿瘤体积从 2175.0 ± 341.9 mm ^{3显着减少}载体组为828.4±232.4 mm ³，联合组对人髓性白血病异种移植小鼠无明显毒性。
结_化疗药物Ara-C在临床实践中以低剂量增强疗效并降低毒性。

关键词：神经激肽受体拮抗剂，阿糖胞苷，联合化疗，急性髓系白血病