Urra Félix A, Córdova-Delgado Miguel, Lapier Michel, Orellana-Manzano Andrea, Acevedo-Arévalo Luis, Pessoa-Mahana Hernán, González-Vivanco Jaime M, Martínez-Cifuentes Maximiliano, Ramírez-Rodríguez Oney, Millas-Vargas Juan Pablo, Weiss-López Boris, Pavani Mario, Ferreira Jorge, Araya-Maturana Ramiro
Programa de Farmacología Molecular y Clínica, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Independencia 1027, Casilla 7, Santiago, Chile.
Departamento de Química Orgánica y Físico-Química, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Casilla 233, Santiago 1, Chile.
Toxicol Appl Pharmacol. 2016 Jan 15;291:46-57. doi: 10.1016/j.taap.2015.12.005. Epub 2015 Dec 19.
Mitochondria participate in several distinctiveness of cancer cell, being a promising target for the design of anti-cancer compounds. Previously, we described that ortho-carbonyl hydroquinone scaffold 14 inhibits the complex I-dependent respiration with selective anti-proliferative effect on mouse mammary adenocarcinoma TA3/Ha cancer cells; however, the structural requirements of this hydroquinone scaffold to affect the oxidative phosphorylation (OXPHOS) of cancer cells have not been studied in detail. Here, we characterize the mitochondrial metabolism of TA3/Ha cancer cells, which exhibit a high oxidative metabolism, and evaluate the effect of small structural changes of the hydroquinone scaffold 14 on the respiration of this cell line. Our results indicate that these structural changes modify the effect on OXPHOS, obtaining compounds with three alternative actions: inhibitors of complex I-dependent respiration, uncoupler of OXPHOS and compounds with both actions. To confirm this, the effect of a bicyclic hydroquinone (9) was evaluated in isolated mitochondria. Hydroquinone 9 increased mitochondrial respiration in state 4o without effects on the ADP-stimulated respiration (state 3ADP), decreasing the complexes I and II-dependent respiratory control ratio. The effect on mitochondrial respiration was reversed by 6-ketocholestanol addition, indicating that this hydroquinone is a protonophoric uncoupling agent. In intact TA3/Ha cells, hydroquinone 9 caused mitochondrial depolarization, decreasing intracellular ATP and NAD(P)H levels and GSH/GSSG ratio, and slightly increasing the ROS levels. Moreover, it exhibited selective NAD(P)H availability-dependent anti-proliferative effect on cancer cells. Therefore, our results indicate that the ortho-carbonyl hydroquinone scaffold offers the possibility to design compounds with specific actions on OXPHOS of cancer cells.
线粒体参与癌细胞的多种特性，是设计抗癌化合物的一个有前景的靶点。此前，我们描述了邻羰基对苯二酚支架14抑制复合体I依赖的呼吸作用，并对小鼠乳腺腺癌TA3/Ha癌细胞具有选择性抗增殖作用；然而，这种对苯二酚支架影响癌细胞氧化磷酸化（OXPHOS）的结构要求尚未得到详细研究。在这里，我们对具有高氧化代谢的TA3/Ha癌细胞的线粒体代谢进行了表征，并评估了对苯二酚支架14的微小结构变化对该细胞系呼吸作用的影响。我们的结果表明，这些结构变化改变了对OXPHOS的影响，得到了具有三种不同作用的化合物：复合体I依赖呼吸作用的抑制剂、OXPHOS的解偶联剂以及兼具这两种作用的化合物。为了证实这一点，我们在分离的线粒体中评估了双环对苯二酚（9）的作用。对苯二酚9增加了状态4o下的线粒体呼吸作用，而对ADP刺激的呼吸作用（状态3ADP）没有影响，降低了复合体I和II依赖的呼吸控制率。添加6-酮胆甾醇可逆转对线粒体呼吸作用的影响，表明这种对苯二酚是一种质子载体解偶联剂。在完整的TA3/Ha细胞中，对苯二酚9导致线粒体去极化，降低细胞内ATP和NAD(P)H水平以及GSH/GSSG比值，并略微增加ROS水平。此外，它对癌细胞表现出选择性依赖NAD(P)H可用性的抗增殖作用。因此，我们的结果表明，邻羰基对苯二酚支架为设计对癌细胞OXPHOS具有特定作用的化合物提供了可能性。
