Inhibition of nuclear factor κB chemosensitizes non-small cell lung cancer through cytochrome c release and caspase activation
Inhibition of nuclear factor κB chemosensitizes non-small cell lung cancer through cytochrome c release and caspase activation
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DOI：
10.1067/mtc.2002.118684
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发表时间：
2002-02-01
影响因子：
6
通讯作者：
Mayo, MW
中科院分区：
文献类型：
--
作者：
Jones, DR;Broad, RM;Mayo, MW
目的：虽然我们之前已经证明抑制核因子kappaB使非小细胞肺癌细胞对化疗介导的细胞死亡敏感，但介导这一过程的凋亡途径尚不清楚。本研究的目的是确定非小细胞肺癌细胞中核因子kappaB抑制后的化学敏感性是否为线粒体和caspase介导的过程，是否依赖于核因子kappaB转录活性。方法：先前描述的h157非小细胞肺癌细胞用吉西他滨处理，并测定DNA片段。荧光法测定细胞质提取物中Caspase 3、6、7、8和9的活性。测定线粒体通透性指数和胞浆细胞色素c水平。将caspase抑制剂Boc-D以及核因子kappaB调控的基因产物Al、c-IAP-2和Bcl-X-L添加到缺乏核因子kappaB的H157细胞中，并评估其凋亡程度。所有实验均为三次重复，通过方差分析确定数据的显著性。结果：缺乏功能性核因子kappaB （H157I）的非小细胞肺癌细胞在化疗后比载体对照细胞（H157V）发生更多的凋亡。化疗后H157I细胞线粒体通透性指数和细胞色素c释放增加。H157I细胞也比对照细胞有更多的caspase 3和9的激活。抑制caspase活性或转染核因子kappab调控。核因子kappaB抑制后的产物挽救了细胞的死亡。结论：抑制核因子kappaB在非小细胞肺癌细胞中的化学增敏作用是通过增加细胞色素c的释放和4 - caspase 3和9的激活来实现的。除化疗外，抑制核因子kappaB或其基因产物作为晚期非小细胞肺癌患者的治疗策略值得进一步研究。
Objective: Although we have previously shown that inhibition of nuclear factor kappaB sensitizes non-small cell lung cancer cells to chemotherapy-mediated cell death, the apoptotic pathways mediating this process are unknown. The purpose of this study was to determine whether chemosensitivity after the inhibition of nuclear factor kappaB in non-small cell lung cancer cells is a mitochondrial and caspase-mediated process and whether it is dependent on nuclear factor kappaB transcriptional activity.Methods: Previously described H 157 non-small cell lung cancer cells were treated with gemcitabine, and DNA fragmentation was determined. Caspase 3, 6, 7, 8, and 9 activity in cytoplasmic extracts was determined fluorometrically. The mitochondrial permeability index and cytosolic cytochrome c levels were also determined. The caspase inhibitor Boc-D, as well as nuclear factor kappaB-regulated gene products Al, c-IAP-2, and Bcl-X-L, were added to H157 cells lacking nuclear factor kappaB and the degree of apoptosis assessed. All experiments were performed in triplicate, and data significance was determined by means of analysis of variance.Results: Non-small cell lung cancer cells lacking functional nuclear factor kappaB (H157I) underwent more apoptosis after chemotherapy than vector control cells (H157V). There was an increase in the mitochondrial permeability index and cytochrome c release after chemotherapy in the H157I cells. H157I cells also had more activation of caspases 3 and 9 than control cells. Inhibition of caspase activity or transfection with nuclear factor kappaB-regulated. gone products rescued cell cl death after the inhibition of nuclear factor kappaB.Conclusion: Chemosensitization by means of inhibition of nuclear factor kappaB in non-small cell lung cancer cells occurs through increased cytochrome c release and 4 caspase 3 and 9 activation. Inhibition of nuclear factor kappaB or its gene products in addition to chemotherapy warrants further study as a treatment strategy in patients with advanced-stage non-small cell lung cancer.