The human WRN and BLM RecQ helicases differentially regulate cell proliferation and survival after chemotherapeutic DNA damage.
The human WRN and BLM RecQ helicases differentially regulate cell proliferation and survival after chemotherapeutic DNA damage.
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DOI：
10.1158/0008-5472.can-10-0475
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发表时间：
2010-08-15
期刊：
影响因子：
11.2
通讯作者：
Monnat RJ
中科院分区：
文献类型：
--
作者：
Mao FJ;Sidorova JM;Lauper JM;Emond MJ;Monnat RJ
人类RecQ解旋酶基因WRN和BLM的功能缺失突变分别导致遗传不稳定/癌症易感性综合征Werner综合征和Bloom综合征。为了确定WRN和BLM的共同和独特功能，我们系统地分析了WRN、BLM或两者缺失的等基因细胞系的细胞增殖、细胞存活和基因组损伤。在喜树碱、顺铂、羟基脲或5-氟尿嘧啶治疗前后评估细胞增殖和存活。在复制停止之前和之后，通过流式细胞术定量的γ-H2AX染色来评估基因组损伤。细胞增殖受到WRN和/或BLM消耗程度的强烈影响，BLM比WRN消耗更强烈（p=0.005）。相比之下，WRN/BLM共缺失细胞的增殖与BLM缺失细胞没有差异（p=0.34）。在DNA损伤后，BLM缺失和WRN/BLM共同缺失的细胞的存活率明显受损，而WRN缺失的细胞对DNA损伤表现出明显的敏感性。与WRN-缺失细胞相比，BLM-缺失细胞和WRN/BLM共缺失细胞具有相似的、显著更高的γ-H2AX诱导水平。我们的研究结果为WRN和BLM在化疗DNA损伤或复制停止后决定细胞增殖、细胞存活和基因组损伤中的作用提供了新的信息。我们还提供了WRN和BLM之间功能冗余的新信息。这些结果为进一步将WRN和BLM作为肿瘤化疗反应性的生物标志物提供了强有力的理论依据。
Loss of function mutations in the human RecQ helicase genes WRN and BLM respectively cause the genetic instability/cancer predisposition syndromes Werner syndrome and Bloom syndrome. In order to identify common and unique functions of WRN and BLM, we systematically analyzed cell proliferation, cell survival and genomic damage in isogenic cell lines depleted of WRN, BLM or both proteins. Cell proliferation and survival were assessed prior to and after treatment with camptothecin, cis-Pt, hydroxyurea or 5-fluorouracil. Genomic damage was assessed, prior to and after replication arrest, by γ-H2AX staining quantified at the single cell level by flow cytometry. Cell proliferation was strongly affected by the extent of WRN and/or BLM depletion, and more strongly by BLM than by WRN depletion (p=0.005). The proliferation of WRN/BLM co-depleted cells, in contrast, did not differ from BLM-depleted cells (p=0.34). BLM-depleted and WRN/BLM co-depleted cells had comparably impaired survivals after DNA damage, whereas WRN-depleted cells displayed a distinct pattern of sensitivity to DNA damage. BLM-depleted and WRN/BLM co-depleted cells had similar, significantly higher γ-H2AX induction levels than did WRN-depleted cells. Our results provide new information on the role of WRN and BLM in determining cell proliferation, cell survival and genomic damage after chemotherapeutic DNA damage or replication arrest. We also provide new information on functional redundancy between WRN and BLM. These results provide a strong rationale for further developing WRN and BLM as biomarkers of tumor chemotherapeutic responsiveness.