RNAi mediated acute depletion of retinoblastoma protein (pRb) promotes aneuploidy in human primary cells via micronuclei formation.
RNAi mediated acute depletion of retinoblastoma protein (pRb) promotes aneuploidy in human primary cells via micronuclei formation.
复制标题
DOI：
10.1186/1471-2121-10-79
复制
发表时间：
2009-11-02
期刊：
影响因子：
--
通讯作者：
Di Leonardo A
中科院分区：
文献类型：
--
作者：
Amato A;Lentini L;Schillaci T;Iovino F;Di Leonardo A
染色体数目或结构的改变以及额外的中心体和多极有丝分裂在人类肿瘤中是常见的。因此，中心体扩增和有丝分裂检查点功能障碍被认为是染色体不稳定的可能原因。视网膜母细胞瘤肿瘤抑制因子(Rb)参与调节DNA合成和中心体复制的同步性，并参与一些有丝分裂基因的转录调控。为研究pRb急性缺失对人成纤维细胞染色体稳定性的影响，将人pRb特异性siRNA瞬时导入原代人成纤维细胞。急性pRB缺失的成纤维细胞表现出细胞周期进程、中心体稳态、动粒和有丝分裂检查点蛋白所必需的基因表达的变化。尽管纺锤体装配检查点(SAC)相关基因的表达发生了变化，但在PRB耗尽的成纤维细胞中，该检查点似乎功能正常。特别是，Aurora-A和PLK1的过度表达表明这两个基因可能在观察到的基因组不稳定性中发挥了作用。然而，当它们在pRb缺失的成纤维细胞中转录后沉默时，我们没有观察到非整倍体细胞数量的减少。这一发现表明，这两个基因的过度表达并不是Rb急性丢失引发的基因组不稳定的原因，尽管它影响了细胞的增殖。急性pRb缺失的人成纤维细胞除了存在额外的着丝粒和非整倍体外，还存在含有整个染色体的微核。在这里，我们第一次展示了RB的急性丢失触发了人类原代成纤维细胞的中心体放大和非整倍体。总之，我们的结果表明，pRb缺失的原代人成纤维细胞具有完整的纺锤体检查点，微核可能是由错误连接的动粒引起的，这反过来又触发了染色体分离错误，这是导致pRb严重缺失的原代人成纤维细胞非整倍体的原因。
Changes in chromosome number or structure as well as supernumerary centrosomes and multipolar mitoses are commonly observed in human tumors. Thus, centrosome amplification and mitotic checkpoint dysfunctions are believed possible causes of chromosomal instability. The Retinoblastoma tumor suppressor (RB) participates in the regulation of synchrony between DNA synthesis and centrosome duplication and it is involved in transcription regulation of some mitotic genes. Primary human fibroblasts were transfected transiently with short interfering RNA (siRNA) specific for human pRb to investigate the effects of pRb acute loss on chromosomal stability. Acutely pRb-depleted fibroblasts showed altered expression of genes necessary for cell cycle progression, centrosome homeostasis, kinetochore and mitotic checkpoint proteins. Despite altered expression of genes involved in the Spindle Assembly Checkpoint (SAC) the checkpoint seemed to function properly in pRb-depleted fibroblasts. In particular AURORA-A and PLK1 overexpression suggested that these two genes might have a role in the observed genomic instability. However, when they were post-transcriptionally silenced in pRb-depleted fibroblasts we did not observe reduction in the number of aneuploid cells. This finding suggests that overexpression of these two genes did not contribute to genomic instability triggered by RB acute loss although it affected cell proliferation. Acutely pRb-depleted human fibroblasts showed the presence of micronuclei containing whole chromosomes besides the presence of supernumerary centrosomes and aneuploidy. Here we show for the first time that RB acute loss triggers centrosome amplification and aneuploidy in human primary fibroblasts. Altogether, our results suggest that pRb-depleted primary human fibroblasts possess an intact spindle checkpoint and that micronuclei, likely caused by mis-attached kinetochores that in turn trigger chromosome segregation errors, are responsible for aneuploidy in primary human fibroblasts where pRb is acutely depleted.
登录
查看更多内容
影响因子：
64.8
作者：
Cahill, DP;Lengauer, C;Vogelstein, B
通讯作者：
Vogelstein, B
影响因子：
9.7
作者：
Lentini, Laura;Iovino, Flora;Di Leonardo, Aldo
通讯作者：
Di Leonardo, Aldo
影响因子：
64.5
作者：
Jallepalli, PV;Waizenegger, IC;Lengauer, C
通讯作者：
Lengauer, C
影响因子：
64.8
作者：
Macurek, Libor;Lindqvist, Arne;Medema, Rene H.
通讯作者：
Medema, Rene H.
DOI：
10.1073/pnas.032479999
发表时间：
2002-02-19
影响因子：
11.1
作者：
Lingle, WL;Barrett, SL;Salisbury, JL
通讯作者：
Salisbury, JL