5-Bromo-2-deoxyuridine activates DNA damage signalling responses and induces a senescence-like phenotype in p16-null lung cancer cells
5-Bromo-2-deoxyuridine activates DNA damage signalling responses and induces a senescence-like phenotype in p16-null lung cancer cells
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DOI：
10.1097/cad.0b013e32825209f6
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发表时间：
2007-10-01
影响因子：
2.3
通讯作者：
O'Dea, Shirley
中科院分区：
文献类型：
--
作者：
Masterson, Joanne C.;O'Dea, Shirley
5-Bromo-2-deoxyuridine (BrdU) 是一种胸苷类似物，可掺入复制 DNA 中。尽管最初被设计为化疗剂，但人们早已知道亚致死浓度的 BrdU 会改变多种细胞类型的生长和表型。然而，这些 BrdU 介导的作用背后的机制仍然未知。我们通过检查 DNA 损伤反应、细胞周期效应和表型变化来表征 BrdU 对 A549 肺癌细胞的影响。 A549 细胞表达野生型 p53，但 p16 缺失。亚致死浓度的 BrdU 会在这些细胞中引起 DNA 损伤反应，涉及 Chk1、Chk2 和 p53 的激活。在治疗群体中，增大的细胞核和多核细胞的数量明显增加。发生细胞周期抑制，导致 S、G(2)/M 和 Go 期细胞的增殖和积累减少。 BrdU 诱导 p21 表达的早期抑制，这与增殖细胞核抗原的核定位相一致。随后，与对照细胞相比，p21 水平增加，而增殖细胞核抗原水平降低。 p27 和 p57 表达也发生上调。暴露于 BrdU 的第 7 天，处理过的细胞获得衰老样表型，细胞大小、颗粒度和 β-半乳糖苷酶活性均有所增加。我们得出的结论是，BrdU 会在 A549 细胞中诱导 DNA 损伤反应，从而导致增殖有丝分裂退出减少和类似于衰老的表型变化。 (c) 2007 年利平科特威廉姆斯和威尔金斯。
5-Bromo-2-deoxyuridine (BrdU) is a thymidine analogue that is incorporated into replicating DNA. Although originally designed as a chemotherapeutic agent, sublethal concentrations of BrdU have long been known to alter the growth and phenotype of a wide range of cell types. Mechanisms underlying these BrdU-mediated effects remain unknown, however. We have characterized the effects of BrdU on A549 lung cancer cells by examining DNA damage responses, cell cycle effects and phenotypic changes. A549 cells express wild-type p53, but are p16-null. Sublethal concentrations of BrdU evoke a DNA damage response in these cells that involves the activation of Chk1, Chk2 and p53. Increased numbers of enlarged nuclei and multinucleated cells are evident in the treated populations. Cell cycle inhibition occurs, resulting in reduced proliferation and accumulation of cells in the S, G(2)/M and Go phases. BrdU induces an early inhibition of p21 expression that coincides with nuclear localization of proliferating cell nuclear antigen. Subsequently, p21 levels increase, whereas proliferating cell nuclear antigen levels decrease compared with control cells. Upregulation of p27 and p57 expression also occurs. By day 7 of exposure to BrdU, treated cells acquire a senescent-like phenotype with an increase in cell size, granularity and beta-galactosiclase activity. We conclude that BrdU induces a DNA damage response in A549 cells, which results in reduced proliferation mitotic exit and phenotypic changes that resemble senescence. (c) 2007 Lippincott Williams & Wilkins.