In Vitro expression levels of cell-cycle checkpoint proteins are associated with cellular DNA repair capacity in peripheral blood lymphocytes:: A multivariate analysis
In Vitro expression levels of cell-cycle checkpoint proteins are associated with cellular DNA repair capacity in peripheral blood lymphocytes:: A multivariate analysis
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DOI：
10.1021/pr060655k
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发表时间：
2007-01-01
影响因子：
4.4
通讯作者：
Wei, Qingyi
中科院分区：
文献类型：
--
作者：
Fan, You-Hong;Hu, Zhibin;Wei, Qingyi
DNA修复应该发生在细胞感觉到DNA损伤信号并经历细胞周期停滞以提供足够的时间进行DNA修复之后，并且外周淋巴细胞中的次优DNA修复能力（DRC）已被建议作为癌症易感性标志物。许多研究表明，DNA损伤传感，细胞周期检查点和DNA修复之间的功能联系。我们假设，在体外细胞周期检查点相关蛋白的表达水平在刺激淋巴细胞预测DRC水平。为了验证这一假设，我们进行了DRC的宿主细胞再激活试验，通过从120个正常供体的刺激外周血淋巴细胞与瞬时表达质粒被苯并[a]芘二醇环氧化物（BPDE）破坏。使用反相蛋白裂解物微阵列测定法评估相同细胞的8个细胞周期检查点相关基因的蛋白表达诱导。在校正年龄、性别、胚化率和样本储存时间的多变量线性回归分析中，DRC与由BPDE加合物诱导的细胞周期检查点相关蛋白表达水平之间的关联对于p27、CCND1、ATM和MDM 2具有统计学显著性（P分别为0.00、0.03、0.03和0.03），p73和p21为临界值（P分别为0.07和0.09），但p53和p16未为临界值（P分别为0.13和0.18）。由于所有这八种蛋白的相对表达水平高度相关，我们进一步进行了主成分分析，并确定ATM是DRC最重要的预测因子，其次是MDM2和p27。我们的研究结果提供了基于人群的体外证据，证明细胞周期检查点相关蛋白在调节DNA修复中发挥重要作用，至少在未受影响的人外周血淋巴细胞中。进一步的研究是必要的，以调查这些蛋白质的表达水平在癌症易感性的个体间差异的作用。
DNA repair should occur after cells sense DNA damage signals and undergo cell-cycle arrest to provide sufficient time for DNA repair, and suboptimal DNA repair capacity (DRC) in peripheral lymphocytes has been suggested as a cancer susceptibility marker. Numerous studies showed a functional link between DNA damage sensing, cell-cycle checkpoint, and DNA repair. We hypothesized that in vitro cell-cycle checkpoint-related protein expression levels in stimulated lymphocytes predict DRC levels. To test this hypothesis, we performed the host-cell reactivation assay for DRC by transfecting stimulated peripheral blood lymphocytes from 120 normal donors with transient expression plasmids damaged by benzo[a]pyrene diol epoxide (BPDE). The same cells were assessed for protein expression induction of eight cell-cycle checkpoint-related genes using the reverse-phase protein lysate microarray assay. In multivariate linear regression analysis adjusting for age, sex, blastogenic rate, and sample storage duration, the association between DRC and expression levels of cell-cycle checkpoint-related proteins induced by BPDE-adducts was statistically significant for p27, CCND1, ATM, and MDM2 (P = 0.00, 0.03, 0.03, and 0.03, respectively), borderline for p73 and p21 (P = 0.07 and 0.09, respectively), but not for p53 and p16 (P = 0.13 and 0.18, respectively). Because the relative expression levels of all these eight proteins were highly correlated, we further performed the principal component analysis and identified ATM as the most important predictor of DRC, followed by MDM2 and p27. Our results provide population-based in vitro evidence demonstrating that cell-cycle checkpoint-related proteins play essential roles in regulating DNA repair, at least in unaffected human peripheral blood lymphocytes. Further studies are warranted to investigate the role of interindividual variation in the expression levels of these proteins in cancer susceptibility.