Dale Rein Idun, Solberg Landsverk Kirsti, Micci Francesca, Patzke Sebastian, Stokke Trond
a Group for Molecular Radiation Biology ; Department of Radiation Biology ; The Norwegian Radium Hospital ; Oslo , Norway.
b Section of Cancer Cytogenetics, Institute for Medical Informatics, The Norwegian Radium Hospital ; Oslo , Norway.
Cell Cycle. 2015;14(20):3248-60. doi: 10.1080/15384101.2015.1085137.
PARP inhibitors have been approved for treatment of tumors with mutations in or loss of BRCA1/2. The molecular mechanisms and particularly the cellular phenotypes resulting in synthetic lethality are not well understood and varying clinical responses have been observed. We have investigated the dose- and time-dependency of cell growth, cell death and cell cycle traverse of 4 malignant lymphocyte cell lines treated with the PARP inhibitor Olaparib. PARP inhibition induced a severe growth inhibition in this cell line panel and increased the levels of phosphorylated H2AX-associated DNA damage in S phase. Repair of the remaining replication related damage caused a G2 phase delay before entry into mitosis. The G2 delay, and the growth inhibition, was more pronounced in the absence of functional ATM. Further, Olaparib treated Reh and Granta-519 cells died by apoptosis, while U698 and JVM-2 cells proceeded through mitosis with aberrant chromosomes, skipped cytokinesis, and eventually died by necrosis. The TP53-deficient U698 cells went through several rounds of DNA replication and mitosis without cytokinesis, ending up as multinucleated cells with DNA contents of up to 16c before dying. In summary, we report here for the first time cell cycle-resolved DNA damage induction, and cell line-dependent differences in the mode of cell death caused by PARP inhibition.
聚（ADP - 核糖）聚合酶（PARP）抑制剂已被批准用于治疗具有BRCA1/2突变或缺失的肿瘤。导致合成致死性的分子机制，尤其是细胞表型，目前尚不清楚，并且已观察到不同的临床反应。我们研究了用PARP抑制剂奥拉帕尼处理的4种恶性淋巴细胞系的细胞生长、细胞死亡和细胞周期进程的剂量和时间依赖性。PARP抑制在该细胞系组中诱导了严重的生长抑制，并增加了S期磷酸化H2AX相关DNA损伤的水平。对剩余复制相关损伤的修复导致进入有丝分裂前的G2期延迟。在缺乏功能性ATM的情况下，G2期延迟和生长抑制更为明显。此外，奥拉帕尼处理的Reh和Granta - 519细胞通过凋亡死亡，而U698和JVM - 2细胞经历有丝分裂，染色体异常，跳过胞质分裂，最终坏死死亡。TP53缺陷的U698细胞在没有胞质分裂的情况下经历了几轮DNA复制和有丝分裂，最终成为多核细胞，其DNA含量高达16c，然后死亡。总之，我们首次在此报告了细胞周期解析的DNA损伤诱导以及PARP抑制引起的细胞死亡模式的细胞系依赖性差异。
