REQUIMTE/LAQV, Laboratório de Farmacognosia, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, R. Jorge Viterbo Ferreira, nº 228, 4050-313 Porto, Portugal.
REQUIMTE/LAQV, Laboratório de Farmacognosia, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, R. Jorge Viterbo Ferreira, nº 228, 4050-313 Porto, Portugal.
Phytomedicine. 2019 Oct;63:153017. doi: 10.1016/j.phymed.2019.153017. Epub 2019 Jul 4.
The roots and tubers of several species of the Cyperus genus are used in several parts of the world as foodstuffs and beverages. The genus is rich in several classes of quinones, however their biological properties have not been studied before.
We evaluated the anticancer effect of several benzoquinones isolated from the genus and described their mechanism of action towards cancer cells.
The most potent molecules were selected according to their effect upon cell viability. The mechanism of cell death was studied by using pharmacological inhibitors of caspases, caspase-3/4/9 activity assays, annexin-V/7-AAD by flow cytometry and intracellular reactive oxygen species and calcium levels through fluorescence spectroscopy. Elucidation of the involvement of distinct branches of the ER stress pathway was pursued by RT-PCR and WB for mRNA and protein expression levels, respectively, as well as pharmacological inhibitors. Proteasome inhibitory activity was assessed by using purified 20S catalytic subunit with the fluorogenic substrate Suc-Leu-Leu-Val-Tyr-AMC.
Cytotoxicity studies against cancer cell lines showed that the human gastric cancer cell line AGS was the most susceptible, the most potent molecule, hydroxycyperaquinone, exhibiting an IC close to 1 µM. Morphological and biochemical traits suggested that a process of regulated cell death was taking place, which was shown to be intrinsic pathway-independent. Results indicated that benzoquinones exert their toxicity by triggering ER stress, as shown by increased expression of CHOP (mRNA and protein levels), intracellular reactive oxygen species, changes in calcium dynamics and caspase-4 activation. Proteasome inhibition by these molecules is described for the first time.
Hydroxycyperaquinone is a novel sub-micromolar inhibitor of the 20S catalytic core of the 26S proteasome, causing cell death via IRE1α-independent/PERK-dependent pathways in stomach cancer cells. Its presence in products consumed orally may be of relevance for gastric tumors.
在世界上的一些地方，香蒲属的几种植物的根和块茎被用作食物和饮料。该属富含几类醌类化合物，但它们的生物学特性尚未被研究过。
我们评估了从该属中分离出的几种苯醌的抗癌作用，并描述了它们对癌细胞的作用机制。
根据对细胞活力的影响选择最有效的分子。通过使用半胱天冬酶的药理学抑制剂、caspase-3/4/9 活性测定、流式细胞术的 Annexin-V/7-AAD 以及通过荧光光谱法测定细胞内活性氧和钙水平来研究细胞死亡的机制。通过 RT-PCR 和 WB 分别检测 mRNA 和蛋白质表达水平，以及药理学抑制剂，阐明 ER 应激途径不同分支的参与情况。用荧光底物 Suc-Leu-Leu-Val-Tyr-AMC 评估蛋白酶体抑制活性。
对癌细胞系的细胞毒性研究表明，人胃癌细胞系 AGS 最敏感，最有效的分子羟基香蒲醌的 IC 接近 1 µM。形态和生化特征表明，发生了一种受调控的细胞死亡过程，该过程被证明与内在途径无关。结果表明，苯醌通过触发内质网应激发挥其毒性作用，这表现为 CHOP（mRNA 和蛋白水平）表达增加、细胞内活性氧增加、钙动力学变化和 caspase-4 激活。这些分子对蛋白酶体的抑制作用是首次被描述的。
羟基香蒲醌是 26S 蛋白酶体 20S 催化核心的新型亚微摩尔抑制剂，通过 IRE1α 非依赖性/PERK 依赖性途径在胃癌细胞中引起细胞死亡。它在口服摄入的产品中的存在可能与胃肿瘤有关。
