The destruction box of human Geminin is critical for proliferation and tumor growth in human colon cancer cells
The destruction box of human Geminin is critical for proliferation and tumor growth in human colon cancer cells
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DOI：
10.1038/sj.onc.1206987
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发表时间：
2004-01
期刊：
影响因子：
8
通讯作者：
Kenichi Yoshida;N. Oyaizu;Anindya Dutta;I. Inoue
中科院分区：
文献类型：
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作者：
Kenichi Yoshida;N. Oyaizu;Anindya Dutta;I. Inoue
对人类癌细胞系 HCT116 中内源 Geminin 基因（DNA 复制起始复合物的抑制剂）的破坏盒序列进行域特异性破坏，导致形成在细胞周期 G1 期稳定的蛋白质。尽管异步培养物中 Geminin 的总量没有升高，但 Geminin 的 G1 特异性稳定作用，减少了微型染色体维持复合物的染色质负载，抑制了 DNA 复制，并导致 G1 期细胞的积累。突变的 Geminin 抑制体内致瘤性和体外细胞生长。携带这种突变的细胞无法支持带有 Epstein-Barr 病毒 oriP 复制子的质粒的复制。随着 p53 蛋白及其靶标 p21 蛋白水平的增加，突变细胞中的 DNA 损伤检查点通路被激活。所有这些缺陷都可以通过 Cdt1（一种与 Geminin 结合的复制起始蛋白）的过度表达来弥补。因此，在不增加总蛋白水平的情况下改变人类细胞中内源性 Geminin 的细胞周期依赖性调节会抑制 DNA 复制并抑制肿瘤生长。
A domain-specific disruption was performed on the destruction box sequence of endogenous Geminin gene, an inhibitor of the DNA replication initiation complex, in a human cancer cell line HCT116 resulting in the formation of a protein that was stable in the G1 phase of the cell cycle. Although the total amount of Geminin in asynchronous cultures was not elevated, the G1-specific stabilization of Geminin, diminished chromatin loading of minichromosome maintenance complex, inhibited DNA replication, and resulted in the accumulation of cells in G1. The mutated Geminin suppressed in vivo tumorigenicity and in vitro cell growth. Cells carrying this mutation failed to support the replication of a plasmid bearing the oriP replicator of Epstein–Barr virus. The DNA damage checkpoint pathway was activated in the mutated cells with increased levels of p53 protein and its target, the p21 protein. All these deficits were rescued by overexpression of Cdt1, a replication initiator protein that binds to Geminin. Therefore, alteration of the cell cycle-dependent regulation of endogenous Geminin in human cells without increasing total protein level inhibits DNA replication and suppresses tumor growth.