Functional inactivation of pRB results in aneuploid mammalian cells after release from a mitotic block
Functional inactivation of pRB results in aneuploid mammalian cells after release from a mitotic block
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DOI：
10.1038/sj.neo.7900256
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发表时间：
2002-09-01
期刊：
影响因子：
4.8
通讯作者：
Di Leonardo, A
中科院分区：
文献类型：
--
作者：
Lentini, L;Pipitone, L;Di Leonardo, A
在肿瘤和早期癌症中观察到的广泛的染色体不稳定性表明非整倍体可能是细胞转化和肿瘤起始的先决条件。肿瘤抑制基因和有丝分裂检查点基因的缺陷可能是非整倍体表型的候选者。通过使用流式细胞术，细胞遗传学和免疫细胞化学技术，我们调查是否pRB缺陷可以驱动永久非整倍体在正常的人类和小鼠成纤维细胞后，有丝分裂检查点的挑战微管不稳定的药物。小鼠和人的pRB缺陷的原代成纤维细胞，从有丝分裂块释放后，在增殖的非整倍体细胞具有额外的中心体。非整倍体pRB缺陷细胞在相同克隆的细胞中显示染色体数目的升高的变异。此外，这些细胞获得了以不依赖贴壁的方式生长的能力，其程度与肿瘤细胞相同，这表明非整倍性是细胞转化中的初始突变步骤。正常小鼠胚胎成纤维细胞（MEFs）在秋水仙胺处理后，Rb基因外显子19侧翼含有LoxP位点，并在G2/M期被阻滞，中心体重复。然而，这些细胞逃脱了逮捕，并成为非整倍体pRB消融CRE重组酶，这表明pRB作为一个主要组成部分的检查点，控制细胞倍性。
The widespread chromosome instability observed in tumors and in early stage carcinomas suggests that aneuploidy could be a prerequisite for cellular transformation and tumor initiation. Defects in tumor suppressors and genes that are part of mitotic checkpoints are likely candidates for the aneuploid phenotype. By using flow cytometric, cytogenetic, and immunocytochemistry techniques we investigated whether pRB deficiency could drive perpetual aneuploidy in normal human and mouse fibroblasts after mitotic checkpoint challenge by microtubule-destabilizing drugs. Both mouse and human pRB-deficient primary fibroblasts resulted, upon release from a mitotic block, in proliferating aneuploid cells possessing supernumerary centrosomes. Aneuploid pRB-deficient cells show an elevated variation in chromosome numbers among cells of the same clone. In addition, these cells acquired the capability to grow in an anchorage-independent way at the same extent as tumor cells did suggesting aneuploidy as an initial mutational step in cell transformation. Normal Mouse Embryonic Fibroblasts (MEFs) harboring LoxP sites flanking exon 19 of the Rb gene arrested in G2/M with duplicated centrosomes after colcemid treatment. However, these cells escaped the arrest and became aneuploid upon pRB ablation by CRE recombinase, suggesting pRB as a major component of a checkpoint that controls cellular ploidy.