CENPA overexpression promotes genome instability in pRb-depleted human cells.
CENPA overexpression promotes genome instability in pRb-depleted human cells.
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DOI：
10.1186/1476-4598-8-119
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发表时间：
2009-12-10
期刊：
影响因子：
37.3
通讯作者：
Di Leonardo A
中科院分区：
文献类型：
--
作者：
Amato A;Schillaci T;Lentini L;Di Leonardo A
非整倍体是大多数人类癌症的一个标志，它是染色体不稳定性的结果，并且常常与中心体扩增相关。视网膜母细胞瘤蛋白（pRb）的功能失活已被表明是促进染色体不稳定性以及中心体扩增的一个原因。然而，潜在的分子机制仍有待阐明。
在此我们表明，在野生型和p53基因敲除的HCT116细胞中pRb的缺失都与多极纺锤体、后期桥、滞后染色体以及含有完整染色体的微核的存在相关。此外，由pRb急性缺失导致的非整倍体不受p53缺失的影响。
实时定量逆转录聚合酶链反应显示，pRb的缺失改变了参与中心体复制、动粒组装以及纺锤体组装检查点（SAC）的基因的表达。然而，尽管MAD2上调，pRb缺失的细胞似乎具有功能性的SAC，因为它们在经过有丝分裂毒物处理后会在有丝分裂期停滞。此外，pRb缺失的HCT116细胞显示出BRCA1的过表达，这似乎是MAD2上调的原因。
通过RNA干扰对CENPA进行转录后沉默，使得CENP - A蛋白水平与对照细胞中的水平相似，这大大减少了pRb缺失细胞中的非整倍体细胞数量。
总之，我们的研究结果表明了pRb急性缺失的一个新方面，即它主要通过诱导CENPA过表达来促进非整倍体，而CENPA过表达反过来可能通过影响纺锤体微管与动粒的正确附着而诱导微核。
Aneuploidy is a hallmark of most human cancers that arises as a consequence of chromosomal instability and it is frequently associated with centrosome amplification. Functional inactivation of the Retinoblastoma protein (pRb) has been indicated as a cause promoting chromosomal instability as well centrosome amplification. However, the underlying molecular mechanism still remains to be clarified. Here we show that pRb depletion both in wild type and p53 knockout HCT116 cells was associated with the presence of multipolar spindles, anaphase bridges, lagging chromosomes and micronuclei harbouring whole chromosomes. In addition aneuploidy caused by pRb acute loss was not affected by p53 loss. Quantitative real-time RT-PCR showed that pRB depletion altered expression of genes involved in centrosome duplication, kinetochore assembly and in the Spindle Assembly Checkpoint (SAC). However, despite MAD2 up-regulation pRb-depleted cells seemed to have a functional SAC since they arrested in mitosis after treatments with mitotic poisons. Moreover pRb-depleted HCT116 cells showed BRCA1 overexpression that seemed responsible for MAD2 up-regulation. Post-transcriptional silencing of CENPA by RNA interference, resulting in CENP-A protein levels similar to those present in control cells greatly reduced aneuploid cell numbers in pRb-depleted cells. Altogether our findings indicate a novel aspect of pRb acute loss that promotes aneuploidy mainly by inducing CENPA overexpression that in turn might induce micronuclei by affecting the correct attachment of spindle microtubules to kinetochores.
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影响因子：
--
作者：
Amato A;Lentini L;Schillaci T;Iovino F;Di Leonardo A
通讯作者：
Di Leonardo A
影响因子：
64.8
作者：
Cahill, DP;Lengauer, C;Vogelstein, B
通讯作者：
Vogelstein, B
DOI：
10.1006/bbrc.1997.7378
发表时间：
1997-10-20
影响因子：
3.1
作者：
Mundt, KE;Golsteyn, RM;Nigg, EA
通讯作者：
Nigg, EA
影响因子：
5.3
作者：
Oikawa, T;Okuda, M;Fukasawa, K
通讯作者：
Fukasawa, K
影响因子：
9.7
作者：
Lentini, Laura;Iovino, Flora;Di Leonardo, Aldo
通讯作者：
Di Leonardo, Aldo