Induction of p21CIP1/Waf1 and activation of p34cdc2 involved in retinoic acid-induced apoptosis in human hepatoma Hep3B cells
Induction of p21CIP1/Waf1 and activation of p34cdc2 involved in retinoic acid-induced apoptosis in human hepatoma Hep3B cells
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DOI：
10.1006/excr.1999.4397
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发表时间：
1999-04-10
影响因子：
3.7
通讯作者：
Yin, SC
中科院分区：
文献类型：
--
作者：
Hsu, SL;Chen, MC;Yin, SC
检测维甲酸(RA)对人肝癌细胞株Hep3B的生物活性。在无血清条件下，RA诱导的人肝癌细胞株Hep3B细胞在无血清条件下，24 h内S/M期比例升高，有丝分裂指数增加，继而发生细胞凋亡，同时伴有P53非依赖性的内源性p21(Cipi/Waf1)蛋白表达上调、p34(Cdc2)蛋白激活、Rb2蛋白水平和磷酸化水平增加。此外，维甲酸对BclX-L、BclX-S、细胞周期蛋白A、B、D1、D3、E及Rbl的表达无明显影响，但可明显下调CDK2的活性，减少CDK4的表达，并可轻微延缓p27(Kip1)的表达。奥洛莫辛是一种有效的p34(Cdc2)和cdk2抑制剂，有效地阻断了RA介导的p34(Cdc2)激酶的激活，并阻止了RA诱导的细胞凋亡。此外，p21(CIP2/Waf1)和p34(Cdc2)的反义寡核苷酸可显著挽救RA诱导的细胞凋亡。我们的研究结果表明，p21(CIP2/Waf1)的过表达可能不是RA诱导人肝癌细胞Hep3B凋亡所必需的唯一调控因子。RA处理导致Rb2过度磷酸化，p34(Cdc2)激酶激活与有丝分裂进程异常一致，随后出现异常核。这种异常的细胞周期进程似乎是RA诱导细胞死亡所必需的。这些结果表明，细胞周期调节因子p21(CIP2/Waf1)和p34(Cdc2)的不适当调控与Bax的诱导有关，并参与了RA对Hep3B细胞的死亡和凋亡。(C)1999年学术出版社。
The biological activity of retinoic acid (RA) was examined in human hepatoma Hep3B cells, Under serum-deprived conditions, RA induced S/M-phase elevation and mitotic index increase within 24 h, followed by apoptosis, This RA-induced apoptosis was accompanied by p53-independent up-regulation of endogenous p21(CIPI/Waf1) proteins, as well as activation of p34(cdc2) kinase, and increase of Rb2 protein level and phosphorylation pattern. In addition, RA had no effect on the levels of Bcl-X-L; Bcl-X-S; cyclins A, B, D1, D3, or E; or Rbl expression but markedly downmodulated Cdk2 kinase activity and reduced Cdk4 expression, RA also slightly delayed p27(Kip1) expression. Olomoucine, a potent p34(cdc2) and Cdk2 inhibitor, effectively blocked RA-mediated p34(cdc2) kinase activation and prevented RA-induced apoptosis. Furthermore, antisense oligonucleotide complementary to p21(CIP2/Waf1) and p34(cdc2) mRNA significantly rescued RA-induced apoptosis. Our data indicate that p21(CIP2/Waf1) overexpression may not be the only regulatory factor necessary for RA-induced apoptosis in human hepatoma Hep3B cells. RA treatment leads to Rb2 hyperphosphorylation, and p34(cdc2) kinase activation is coincident with an aberrant mitotic progression, followed by appearance of abnormal nucleus. This aberrant cell cycle progression appeared requisite for RA-induced cell death. These findings suggest that inappropriate regulation of the cell cycle regulators p21(CIP2/Waf1) and p34(cdc2) is coupled with induction of Bax and involved in cell death with apoptosis when Hep3B cells are exposed to RA. (C) 1999 Academic Press.