INSERM UMR-S 769, LabEx LERMIT, Université Paris-Sud 11, 5 rue J B Clement, Chatenay-Malabry, France.
Biochem Pharmacol. 2012 May 1;83(9):1172-82. doi: 10.1016/j.bcp.2012.01.017. Epub 2012 Jan 21.
A major clinical problem regarding antitumoral treatment with DNA cross-linking agents such as cisplatin (Cisp), mechlorethamine (HN2) or its derivative melphalan (MLP) is intrinsic or acquired resistance to therapy, which frequently results from a resistance to apoptosis induction. In this study, aimed to identify novel sensitizing targets to DNA cross-linker-induced cell death, we demonstrated that MLP, Cisp and HN2 induce mitochondrial permeability transition pore (PTP)-mediated apoptosis in cervical and colon carcinoma cells. This apoptotic pathway is characterized by dissipation of the mitochondrial membrane potential, production of ROS, mitochondrial translocation of Bax, release of apoptogenic factors, caspase activation and nuclear alterations. The opening of PTP and subsequent apoptosis was reduced in Bax deficient cells and in cells with elevated Bcl-2 level, but not in cells invalidated for Bak. We further showed that, among the pro-apoptotic PTP regulators tested (VDAC1, creatine kinase, ANT1 and ANT3), exogenous overexpression of VDAC1 was the most effective in enhancing Cisp- and MLP-induced apoptosis. In addition, pharmacologically induced up-regulation of VDAC1 by the chemotherapeutic agent arsenic trioxide (As(2)O(3)) greatly sensitized HeLa cells to Cisp and MLP treatment. These data indicate that increased expression of VDAC1 appears as a promising strategy to improve DNA cross-linker-induced chemotherapy.
一种主要的临床问题是关于使用 DNA 交联剂（如顺铂（Cisp）、盐酸氮芥（HN2）或其衍生物美法仑（MLP））进行抗肿瘤治疗，其存在内在或获得性耐药性，这通常是由于对细胞凋亡诱导的耐药性所致。在这项研究中，旨在确定新型增敏靶点以诱导 DNA 交联剂诱导的细胞死亡，我们证明 MLP、Cisp 和 HN2 诱导宫颈和结肠癌细胞中线粒体通透性转换孔（PTP）介导的细胞凋亡。这种凋亡途径的特征是线粒体膜电位耗散、ROS 产生、Bax 线粒体易位、促凋亡因子释放、半胱天冬酶激活和核改变。Bax 缺陷细胞和 Bcl-2 水平升高的细胞中 PTP 的开放和随后的凋亡减少，但 Bak 无效的细胞中则不会减少。我们进一步表明，在测试的促凋亡 PTP 调节剂中（VDAC1、肌酸激酶、ANT1 和 ANT3），外源性过表达 VDAC1 最有效地增强 Cisp 和 MLP 诱导的细胞凋亡。此外，化疗药物三氧化二砷（As(2)O(3)）通过药理途径诱导 VDAC1 的上调，极大地增强了 HeLa 细胞对 Cisp 和 MLP 治疗的敏感性。这些数据表明，增加 VDAC1 的表达似乎是提高 DNA 交联剂诱导化疗效果的一种有前途的策略。
