Flex-Hets differentially normal cells by directly induce apoptosis in cancer over targeting mitochondria
Flex-Hets differentially normal cells by directly induce apoptosis in cancer over targeting mitochondria
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DOI：
10.1158/1535-7163.mct-06-0279
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发表时间：
2007-06-01
影响因子：
5.7
通讯作者：
Benbrook, Doris
中科院分区：
文献类型：
--
作者：
Liu, Tongzu;Hannafon, Bethany;Benbrook, Doris
Flex-Het药物在多种类型的癌细胞中诱导凋亡，对正常细胞几乎没有影响。这种凋亡通过伴随活性氧（ROS）产生的内在线粒体途径发生。本研究的目的是确定线粒体的直接或间接靶向是否是癌症和正常细胞对Flex-Hets的不同敏感性的原因。线粒体的影响和凋亡的测定使用JC-1和Annexin V-FITC染料与流式细胞术。Western blot检测Bcl-2、Bcl-x（L）、Bax的表达。Flex-Hets在卵巢癌细胞系中诱导线粒体肿胀和凋亡，但在各种正常细胞培养物中（包括人卵巢表面上皮细胞）几乎没有影响。对线粒体内膜（IMM）电位的影响是可变的，在正常细胞中没有发生。两种不同的抗氧化剂，以淬灭细胞内和线粒体ROS的浓度给药，并没有改变Flex-Het诱导的线粒体肿胀，IMM电位的损失，或凋亡。用放线菌酮抑制蛋白质合成也不能阻止Flex-Het线粒体或细胞凋亡效应。Bcl-2和Bcl-x（L）水平在卵巢癌细胞系中降低，但在正常培养中升高，而Bax表达不受Flex-Hets处理的影响。总之，ROS似乎是线粒体肿胀的结果，而不是原因。Flex-Hets对癌细胞与正常细胞凋亡的差异诱导涉及直接靶向与Bcl-2蛋白平衡改变相关的线粒体。这种机制不需要IMM电位、ROS产生或蛋白质合成。
Flex-Het drugs induce apoptosis in multiple types of cancer cells, with little effect on normal cells. This apoptosis occurs through the intrinsic mitochondrial pathway accompanied by generation of reactive oxygen species (ROS). The objective of this study was to determine if direct or indirect targeting of mitochondria is responsible for the differential sensitivities of cancer and normal cells to Flex-Hets. Mitochondrial effects and apoptosis were measured using JC-1 and Annexin V-FITC dyes with flow cytometry. Bcl-2, Bcl-x(L), and Bax were measured by Western blot. Flex-Hets induced mitochondrial swelling and apoptosis in ovarian cancer cell lines but had minimal to no effects in a variety of normal cell cultures, including human ovarian surface epithelium. Effects on inner mitochondrial membrane (IMM) potential were variable and did not occur in normal cells. Two different antioxidants, administered at concentrations shown to quench intracellular and mitochondrial ROS, did not alter Flex-Het-induced mitochondrial swelling, loss of IMM potential, or apoptosis. Inhibition of protein synthesis with cycloheximide also did not prevent Flex-Het mitochondrial or apoptosis effects. Bcl-2 and Bcl-x(L) levels were decreased in an ovarian cancer cell line but increased in a normal culture, whereas Bax expression was unaffected by Flex-Hets treatment. In conclusion, ROS seems to be a consequence rather than a cause of mitochondrial swelling. The differential induction of apoptosis in cancer versus normal cells by Flex-Hets involves direct targeting of mitochondria associated with alterations in the balance of Bcl-2 proteins. This mechanism does not require IMM potential, ROS generation, or protein synthesis.