Ravagnan L, Marzo I, Costantini P, Susin S A, Zamzami N, Petit P X, Hirsch F, Goulbern M, Poupon M F, Miccoli L, Xie Z, Reed J C, Kroemer G
Centre National de la Recherche Scientifique, Unité Propre de Recherche 420, Villejuif, France.
Oncogene. 1999 Apr 22;18(16):2537-46. doi: 10.1038/sj.onc.1202625.
The molecular mode of action of lonidamine, a therapeutic agent employed in cancer chemotherapy, has been elusive. Here we provide evidence that lonidamine (LND) acts on mitochondria to induce apoptosis. LND provokes a disruption of the mitochondrial transmembrane potential which precedes signs of nuclear apoptosis and cytolysis. The mitochondrial and cytocidal effects of LND are not prevented by inhibitors of caspases or of mRNA or protein synthesis. However, they are prevented by transfection-enforced overexpression of Bcl-2, an oncoprotein which inhibits apoptosis by stabilizing the mitochondrial membrane barrier function. Accordingly, the cell death-inducing effect of LND is amplified by simultaneous addition of PK11195, an isoquinoline ligand of the peripheral benzodiazepine receptor which antagonizes the cytoprotective effect of Bcl-2. When added to isolated nuclei, LND fails to provoke DNA degradation unless mitochondria are added simultaneously. In isolated mitochondria, LND causes the dissipation of the mitochondrial inner transmembrane potential and the release of apoptogenic factors capable of inducing nuclear apoptosis in vitro. Thus the mitochondrion is the subcellular target of LND. All effects of LND on isolated mitochondria are counteracted by cyclosporin A, an inhibitor of the mitochondrial PT pore. We therefore tested the effect of LND on the purified PT pore reconstituted into liposomes. LND permeabilizes liposomal membranes containing the PT pore. This effect is prevented by addition of recombinant Bcl-2 protein but not by a mutant Bcl-2 protein that has lost its apoptosis-inhibitory function. Altogether these data indicate that LND represents a novel type of anti-cancer agent which induces apoptosis via a direct effect on the mitochondrial PT pore.
氯尼达明是一种用于癌症化疗的治疗药物，其分子作用模式一直难以捉摸。在此，我们提供证据表明氯尼达明（LND）作用于线粒体以诱导细胞凋亡。LND引发线粒体跨膜电位的破坏，这先于核凋亡和细胞溶解的迹象出现。LND的线粒体和细胞杀伤作用不受半胱天冬酶抑制剂或mRNA或蛋白质合成抑制剂的影响。然而，通过转染强制过表达Bcl-2可阻止这些作用，Bcl-2是一种癌蛋白，通过稳定线粒体膜屏障功能来抑制细胞凋亡。因此，同时添加PK11195可增强LND的细胞死亡诱导作用，PK11195是外周苯二氮䓬受体的异喹啉配体，可拮抗Bcl-2的细胞保护作用。当添加到分离的细胞核中时，除非同时添加线粒体，否则LND不会引发DNA降解。在分离的线粒体中，LND导致线粒体内膜跨膜电位的消散，并释放能够在体外诱导核凋亡的凋亡因子。因此，线粒体是LND的亚细胞靶点。LND对分离线粒体的所有作用均被线粒体通透性转换孔（PT孔）抑制剂环孢素A抵消。因此，我们测试了LND对重组到脂质体中的纯化PT孔的作用。LND可使含有PT孔的脂质体膜通透性增加。添加重组Bcl-2蛋白可阻止这种作用，但失去凋亡抑制功能的突变型Bcl-2蛋白则不能。总之，这些数据表明LND是一种新型抗癌药物，通过直接作用于线粒体PT孔诱导细胞凋亡。
