Disruption of mitochondrial function selectively targets tumour cells that are dependent on oxidative phosphorylation. However, due to their high energy demands, cardiac cells are disproportionately targeted by mitochondrial toxins resulting in a loss of cardiac function. An analysis of the effects of mubritinib on cardiac cells showed that this drug did not inhibit HER2 as reported, but directly inhibits mitochondrial respiratory complex I, reducing cardiac-cell beat rate, with prolonged exposure resulting in cell death. We used a library of chemical variants of mubritinib and showed that modifying the 1H-1,2,3-triazole altered complex I inhibition, identifying the heterocyclic 1,3-nitrogen motif as the toxicophore. The same toxicophore is present in a second anti-cancer therapeutic carboxyamidotriazole (CAI) and we demonstrate that CAI also functions through complex I inhibition, mediated by the toxicophore. Complex I inhibition is directly linked to anti-cancer cell activity, with toxicophore modification ablating the desired effects of these compounds on cancer cell proliferation and apoptosis.
线粒体功能的破坏会选择性地针对依赖氧化磷酸化的肿瘤细胞。然而,由于心脏细胞对能量的需求很高,它们不成比例地成为线粒体毒素的目标,导致心脏功能丧失。对姆布利替尼对心脏细胞影响的分析表明,这种药物并不像报道的那样抑制HER2,而是直接抑制线粒体呼吸复合体I,降低心脏细胞的搏动率,长期接触会导致细胞死亡。我们使用了一个 mubritinib 化学变体库,结果表明对 1H-1,2,3-三唑进行修饰可改变复合体 I 的抑制作用,并确定杂环 1,3- 氮基团为毒性分子。在第二种抗癌疗法羧基氨基三唑(CAI)中也存在相同的毒性团,我们证明 CAI 也是通过毒性团介导的复合物 I 抑制作用发挥作用的。复合体 I 抑制作用与抗癌细胞活性直接相关,而毒性团的修饰会削弱这些化合物对癌细胞增殖和凋亡的预期作用。