JZL184, an inhibitor of monoacylglycerol lipase (MAGL) and thus of the degradation of the endocannabinoid 2-arachidonoylglycerol (2-AG), mediates various anticancer effects in preclinical studies. However, studies on the effect of this or other MAGL inhibitors under hypoxia, an important factor in tumor biology and response to cancer therapy, have not yet been performed in cancer cells. In the present study, the impact of the conditioned media (CM) of A549 and H358 lung cancer cells incubated with JZL184 under hypoxic conditions on the angiogenic properties of human umbilical vein endothelial cells (HUVECs) was investigated. Treatment of HUVECs with CM derived from cancer cells cultured for 48 h under hypoxic conditions was associated with a substantial increase in migration and tube formation compared with unconditioned medium, which was inhibited when cancer cells were incubated with JZL184. In this process, JZL184 led to a significant increase in 2-AG levels in both cell lines. Analysis of a panel of proangiogenic factors revealed inhibition of hypoxia-induced vascular endothelial growth factor (VEGF) expression by JZL184. Antiangiogenic and VEGF-lowering effects were also demonstrated for the MAGL inhibitor MJN110. Receptor antagonist experiments suggest partial involvement of the cannabinoid receptors CB1 and CB2 in the antiangiogenic and VEGF-lowering effects induced by JZL184. The functional importance of VEGF for angiogenesis in the selected system is supported by observations showing inhibition of VEGF receptor 2 (VEGFR2) phosphorylation in HUVECs by CM from hypoxic cancer cells treated with JZL184 or when hypoxic cancer cell-derived CM was spiked with a neutralizing VEGF antibody. On the other hand, JZL184 did not exert a direct effect on VEGFR2 activation induced by recombinant VEGF, so there seems to be no downstream effect on already released VEGF. In conclusion, these results reveal a novel mechanism of antiangiogenic action of JZL184 under conditions of hypoxic tumor–endothelial communication.

中文翻译：

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JZL184 通过抑制缺氧肺癌细胞中 VEGF 表达对内皮细胞的抗血管生成作用

JZL184 是一种单酰基甘油脂肪酶 (MAGL) 抑制剂，从而抑制内源性大麻素 2-花生四烯酰甘油 (2-AG) 的降解，在临床前研究中介导多种抗癌作用。然而，尚未在癌细胞中进行有关这种或其他 MAGL 抑制剂在缺氧条件下的影响的研究，缺氧是肿瘤生物学和癌症治疗反应的重要因素。在本研究中，研究了在缺氧条件下与 JZL184 一起孵育的 A549 和 H358 肺癌细胞的条件培养基 (CM) 对人脐静脉内皮细胞 (HUVEC) 血管生成特性的影响。与未条件培养基相比，用源自在低氧条件下培养 48 小时的癌细胞的 CM 处理 HUVEC 与迁移和管形成的显着增加相关，而当癌细胞与 JZL184 一起孵育时，迁移和管形成会受到抑制。在此过程中，JZL184 导致两种细胞系中 2-AG 水平显着增加。对一组促血管生成因子的分析表明，JZL184 可抑制缺氧诱导的血管内皮生长因子 (VEGF) 表达。MAGL 抑制剂 MJN110 还具有抗血管生成和降低 VEGF 的作用。受体拮抗剂实验表明大麻素受体 CB1 和 CB2 部分参与了 JZL184 诱导的抗血管生成和 VEGF 降低作用。VEGF 对所选系统中血管生成的功能重要性得到了观察结果的支持，该观察结果显示，来自用 JZL184 处理的缺氧癌细胞的 CM 或当缺氧癌细胞衍生的 CM 中掺有中和 VEGF 时，对 HUVEC 中 VEGF 受体 2 (VEGFR2) 磷酸化的抑制抗体。另一方面，JZL184对重组VEGF诱导的VEGFR2激活没有直接影响，因此似乎对已经释放的VEGF没有下游影响。总之，这些结果揭示了 JZL184 在缺氧肿瘤-内皮通讯条件下抗血管生成作用的新机制。