Inhibition of MKP-1 expression potentiates JNK related apoptosis in renal cancer cells
Inhibition of MKP-1 expression potentiates JNK related apoptosis in renal cancer cells
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DOI：
10.1097/01.ju.0000124990.37563.00
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发表时间：
2004-08-01
影响因子：
6.6
通讯作者：
Murai, M
中科院分区：
文献类型：
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作者：
Mizuno, R;Oya, M;Murai, M
目的：丝裂原活化蛋白激酶（Mitogen-activated protein kinases，MAPK）包括细胞外信号调节蛋白激酶（extracellular signal-regulated protein kinase，ERK）、c-Jun N-末端激酶（c-Jun N-terminal kinase，JNK）和p38 MAPK（p38）3个亚类。本研究旨在探讨JNK和MAPK磷酸酶-1（MAPK phosphatase-1，MKP-1）在肾癌中的作用。通过阿利兰测定分析茴香霉素（JNK激活剂）和Ro-318220（MKP-1表达抑制剂）的作用。流式细胞术TUNEL法、细胞核形态学改变及DNA片段化检测细胞凋亡。Western blotting.Results：茴香霉素处理的所有细胞株均出现JNK的瞬时激活，但未诱导细胞凋亡。由于我们假设升高的MKP-1表达可能阻止持续的JNK激活，因此使用Ro-318220。当细胞用Ro-318220处理时，Caki-1和KU 20-01细胞中的MKP-1表达降低，但ACHN或769 P细胞中的MKP-1表达不降低。用茴香霉素和Ro-318220联合处理Caki-1和KU 20-01细胞导致MKP-1表达下降，同时伴有持续的JNK激活。结论：肾癌组织中普遍存在的MKP-1表达通过减弱JNK介导的凋亡诱导信号级联反应而促进癌细胞的存活。由于Ro-318220可增强JNK相关凋亡，因此阻断MKP-1表达激活JNK可能是治疗肾癌的有效方法。
Purpose: Mitogen-activated protein kinases (MAPKs) comprise 3 subgroups, that is extracellular signal-regulated protein kinase, c-Jun N-terminal kinase (JNK) and p38 MAPK (p38). In this study we analyzed the role of JNK as well as the expression of MAPK phosphatase-1 (MKP-1) in renal cancers.Materials and Methods: Four renal cell carcinoma (RCC) cell lines were used. The effects of anisomycin (JNK activator) and Ro-318220 (MKP-1 expression inhibitor) were analyzed by alamar blue assay. Apoptosis was determined by flow cytometric TUNEL analysis, nuclear morphological alternations and the detection of DNA fragmentation. Changes in MKP-1 expression as well as the activation of extracellular signal-regulated protein kinases and JNK were analyzed by Western blotting.Results: All cell lines treated with anisomycin resulted in a transient activation of JNK without inducing apoptosis. Since we hypothesized that elevated MKP-1 expression could possibly prevent persistent JNK activation, Ro-318220 was used. When cells were treated with Ro-318220, MKP-1 expression decreased in Caki-1 and KU 20-01 cells but not in ACHN or 769P cells. Combined treatment of Caki-1 and KU 20-01 cells with anisomycin and Ro-318220 resulted in a decrease in MKP-1 expression concomitant with persistent JNK activation. Apoptosis was induced in each cell line.Conclusions: These results suggest that prevalent MKP-1 expression in RCC contributes to cancer cell survival by attenuating an apoptosis inducing signal cascade via JNK. Since Ro-318220 potentiated JNK related apoptosis, JNK activation by blocking MKP-1 expression may be an effective therapeutic approach to RCC.