The Jun kinase stress-activated protein kinase pathway functions to regulate DNA repair and inhibition of the pathway sensitizes tumor cells to cisplatin
The Jun kinase stress-activated protein kinase pathway functions to regulate DNA repair and inhibition of the pathway sensitizes tumor cells to cisplatin
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DOI：
10.1074/jbc.272.22.14041
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发表时间：
1997-05-30
影响因子：
4.8
通讯作者：
Mercola, D
中科院分区：
文献类型：
--
作者：
Potapova, O;Haghighi, A;Mercola, D
我们研究了Jun/应激激活蛋白激酶（JNK/SAPK）通路在T98 G胶质母细胞瘤细胞DNA修复和顺铂耐药中的作用。JUN/SAPK被DNA损伤激活，并磷酸化c-Jun N-末端结构域中的丝氨酸63和73，已知这会增加其反式激活特性。我们表明，用顺铂而不是反式铂异构体处理T98 G胶质母细胞瘤细胞，激活JNK/SAPK约10倍，T98 G细胞对顺铂高度耐药（IC 50 = 140 +/-13 μ M），修饰为表达不可磷酸化的显性负性c-Jun（称为dnJun），在用顺铂而不是transplatin处理后表现出活力降低，与表达的dnJun水平成比例（r（Pearson）= 0.98），导致IC 50降低7倍。在U87细胞、PC-3细胞和MCF-7细胞以及经修饰以表达TAM-67（一种已知的c-Jun功能抑制剂）的T98 G细胞中观察到类似的作用。相反，在修饰为表达野生型c-Jun的细胞中没有观察到致敏作用。此外，通过定量聚合酶链反应-终止测定，我们表明表达dnJun的细胞在顺铂加合物的修复中受到抑制（p = 0.55），而在亲本细胞中修复是容易检测到的（p = 0.003）。这些观察结果表明，JNK/SAPK途径被顺铂诱导的DNA损伤激活，并且这种反应是顺铂治疗后DNA修复和活力所必需的。基因毒性应激后DNA修复的调节可能是JNK/SAPK途径的正常生理作用。
We have studied the role of Jun/stress-activated protein kinase (JNK/SAPK) pathway in DNA repair and cisplatin resistance in T98G glioblastoma cells. JUN/SAPK is activated by DNA damage and phosphorylates serines 63 and 73 in the N-terminal domain of c-Jun, which is known to increase its transactivation properties, We show that treatment of T98G glioblastoma cells with cisplatin but not the transplatin isomer activates JNK/SAPK about 10-fold, T98G cells, which are highly resistent to cisplatin (IC50 = 140 +/- 13 mu M), modified to express a nonphosphorylatable dominant negative c-Jun (termed dnJun) exhibit decreased viability following treatment with cisplatin, but not transplatin, in proportion (r(Pearson) = 0.98) to the level of dnJun expressed leading to a 7-fold decreased IC50. Similar effects are observed in U87 cells, PC-3 cells, and MCF-7 cells, as well as in T98G cells modified to express TAM-67, a known inhibitor of c-Jun function. In contrast, no sensitization effect was observed in cells modified to express wildtype c-Jun, Furthermore, through quantitative polymerase chain reaction-stop assays, we show that dnJun expressing cells were inhibited in repair of cisplatin adducts (p = 0.55), whereas repair is readily detectable (p = 0.003) in parental cells. These observations indicate that the JNK/SAPK pathway is activated by cisplatin-induced DNA damage and that this response is required for DNA repair and viability following cisplatin treatment, Regulation of DNA repair following genotoxic stress may be a normal physiological role of the JNK/SAPK pathway.