Long-term activation of SAPK/JNK, p38 kinase and Fas-L expression by cisplatin is attenuated in human carcinoma cells that acquired drug resistance
Long-term activation of SAPK/JNK, p38 kinase and Fas-L expression by cisplatin is attenuated in human carcinoma cells that acquired drug resistance
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DOI：
10.1002/ijc.20522
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发表时间：
2004-12-20
影响因子：
6.4
通讯作者：
Kaina, B
中科院分区：
文献类型：
--
作者：
Brozovic, A;Fritz, G;Kaina, B
肿瘤细胞长期暴露于顺铂（cDDP）会产生对cDDP的耐药性，这影响肿瘤治疗。为阐明获得性cDDP耐药（ACR）的机制，我们将经慢性cDDP处理后获得ACR的HeLa细胞与其亲代细胞株进行比较。我们发现ACR是由于诱导凋亡水平较低所致。此外，经cDDP处理后，Fas、Bax和Bid的水平保持不变，而Bcl - 2和磷酸化Bad（p - Bad）在处理后的后期（120小时）降低。在早期，与耐药细胞相比，敏感细胞中Fas配体（fas - L）的表达显著增强，并在凋亡开始前一直保持上调。因此，Fas系统的激活至关重要，这与在敏感细胞中cDDP激活caspase - 8以及caspase - 9和 - 3的发现相符。cDDP以剂量依赖的方式激发应激活化蛋白激酶/c - Jun N末端激酶（SAPK/JNK）和p38激酶的激活，ACR细胞中的激活水平明显低于敏感的亲代细胞株。通过报告基因检测发现，cDDP诱导c - Jun和AP - 1活性，而在ACR细胞中该活性再次减弱。时间进程分析显示，SAPK/JNK和p38激酶活性持续上调（暴露后>72小时），敏感细胞中的活性水平远高于ACR细胞。分别通过JNK抑制剂II和SB 203580抑制JNK或p38激酶，可减弱cDDP诱导的凋亡，这支持了JNK和p38激酶在cDDP反应中的作用。由于几种独立衍生的cDDP耐药细胞系显示出MAPK信号减弱，持续的SAPK/JNK和p38激酶激活可能是cDDP诱导细胞死亡的一种普遍机制。ACR细胞显示出较低水平的DNA损伤，表明长期刺激SAPK/JNK和p38激酶是由未修复的cDDP诱导的DNA损伤所触发的。（C）2004威利 - 利斯公司
Tumor cells chronically exposed to cisplatin (cDDP) acquire cDDP resistance that impacts tumor therapy. To elucidate the mechanism of acquired cDDP resistance (ACR), we compared HeLa cells that gained ACR upon chronic cDDP treatment with the parental strain. We show that ACR is due to a lower level of induced apoptosis. Further, upon cDDP treatment, the levels of Fas, Bax and Bid remained unchanged, whereas Bcl-2 and p-Bad were reduced at late times (120 hr) after treatment. At early times, Fas ligand (fas-L) expression was significantly enhanced in sensitive compared to resistant cells and remained upregulated up to the onset of apoptosis. Thus, activation of the Fas system is critical, which is in line with the finding that in sensitive cells, caspase-8 along with caspase-9 and -3 were activated by cDDP. cDDP provoked the activation of stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK) and p38 kinase dose-dependently, with significantly lower levels in ACR cells than in the sensitive parental line. cDDP induces c-Jun and AP-1 activity, as measured by a reporter gene assay, which was again attenuated in ACR cells. Time course analysis revealed that SAPK/JNK and p38 kinase activity was sustained upregulated (> 72 hr postexposure), which occurred at much higher level in sensitive than in ACR cells. Inhibition of either JNK or p38 kinase (by JNK inhibitor II and SB 203580, respectively) attenuated cDDP-induced apoptosis, supporting the role of JNK and p38 kinase in the cDDP response. Since several independently derived cDDP-resistant cell lines displayed attenuated MAPK signaling, sustained SAPK/JNK and p38 kinase activation may be a general mechanism of cDDP-induced cell death. ACR cells displayed a reduced level of DNA damage, indicating long-term stimulation of SAPK/JNK and p38 kinase is triggered by nonrepaired cDDP-induced DNA lesions. (C) 2004 Wiley-Liss, Inc.