致癌性ras-p21信号通路上的Jun氨基末端激酶（JNK）诱导卵母细胞成熟依赖于raf-MEK信号转导通路。

Induction of oocyte maturation by jun-N-terminal kinase (JNK) on the oncogenic ras-p21 pathway is dependent on the raf-MEK signal transduction pathway.

作者信息

Chie L, Amar S, Kung H F, Lin M C, Chen H, Chung D L, Adler V, Ronai Z, Friedman F K, Robinson R C, Kovac C, Brandt-Rauf P W, Yamaizumi Z, Michl J, Pincus M R

机构信息

Department of Biology, Long Island University, Brooklyn, NY 11201, USA.

出版信息

Cancer Chemother Pharmacol. 2000;45(6):441-9. doi: 10.1007/s002800051017.

DOI:10.1007/s002800051017

PMID:10854130

Abstract

PURPOSE

We have previously found that microinjection of activated MEK (mitogen activated kinase kinase) and ERK (mitogen-activated protein; MAP kinase) fails to induce oocyte maturation, but that maturation, induced by oncogenic ras-p21 and insulin-activated cell ras-p21, is blocked by peptides from the ras-binding domain of raf. We also found that jun kinase (JNK), on the stress-activated protein (SAP) pathway, which is critical to the oncogenic ras-p21 signal transduction pathway, is a strong inducer of oocyte maturation. Our purpose in this study was to determine the role of the raf-MEK-MAP kinase pathway in oocyte maturation and how it interacts with JNK from the SAP pathway.

METHODS

We microinjected raf dominant negative mutant mRNA (DN-raf) and the MEK-specific phosphatase, MKP-T4, either together with oncogenic p21 or c-raf mRNA, into oocytes or into oocytes incubated with insulin to determine the effects of these raf-MEK-MAP kinase pathway inhibitors.

RESULTS

We found that oocyte maturation induced by both oncogenic and activated normal p21 is inhibited by both DN-raf and by MKP-T4. The latter more strongly blocks the oncogenic pathway. Also an mRNA encoding a constitutively activated MEK strongly induces oocyte maturation that is not inhibited by DN-raf or by MKP-T4. Surprisingly, we found that oocyte maturation induced by JNK is blocked both by DN-raf and MKP-T4. Furthermore, we discovered that c-raf induces oocyte maturation that is inhibited by glutathione-S-transferase (GST), which we have found to be a potent and selective inhibitor of JNK.

CONCLUSION

We conclude that there is a strong reciprocal interaction between the SAP pathway involving JNK and the raf-MEK-MAP kinase pathway and that oncogenic ras-p21 can be preferentially inhibited by MEK inhibitors. The results imply that blockade of both MEK and JNK-oncogenic ras-p21 interactions may constitute selective synergistic combination chemotherapy against oncogenic ras-induced tumors.

摘要

目的

我们之前发现，显微注射活化的MEK（丝裂原活化激酶激酶）和ERK（丝裂原活化蛋白；MAP激酶）不能诱导卵母细胞成熟，但是由致癌性ras-p21和胰岛素激活的细胞ras-p21诱导的成熟会被来自raf的ras结合结构域的肽所阻断。我们还发现，应激激活蛋白（SAP）途径上的Jun激酶（JNK）对致癌性ras-p21信号转导途径至关重要，是卵母细胞成熟的强诱导剂。我们在本研究中的目的是确定raf-MEK-MAP激酶途径在卵母细胞成熟中的作用以及它如何与SAP途径中的JNK相互作用。

方法

我们将raf显性负性突变体mRNA（DN-raf）和MEK特异性磷酸酶MKP-T4与致癌性p21或c-raf mRNA一起显微注射到卵母细胞中，或者注射到与胰岛素一起孵育的卵母细胞中，以确定这些raf-MEK-MAP激酶途径抑制剂的作用。

结果

我们发现，致癌性和活化的正常p21诱导的卵母细胞成熟均被DN-raf和MKP-T4抑制。后者更强烈地阻断致癌途径。此外，编码组成型活化MEK的mRNA强烈诱导卵母细胞成熟，且不受DN-raf或MKP-T4抑制。令人惊讶的是，我们发现JNK诱导的卵母细胞成熟被DN-raf和MKP-T4均阻断。此外，我们发现c-raf诱导的卵母细胞成熟被谷胱甘肽-S-转移酶（GST）抑制，我们发现GST是JNK的一种有效且选择性的抑制剂。