King David, Southgate Harriet E D, Roetschke Saskia, Gravells Polly, Fields Leona, Watson Jessica B, Chen Lindi, Chapman Devon, Harrison Daniel, Yeomanson Daniel, Curtin Nicola J, Tweddle Deborah A, Bryant Helen E
Academic Unit of Molecular Oncology, Department of Oncology and Metabolism, Sheffield Institute for Nucleic Acids (SInFoNiA), University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK.
Wolfson Childhood Cancer Research Centre, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE1 7RU, UK.
Cancers (Basel). 2021 Dec 10;13(24):6215. doi: 10.3390/cancers13246215.
Despite intensive high-dose multimodal therapy, high-risk neuroblastoma (NB) confers a less than 50% survival rate. This study investigates the role of replication stress in sensitivity to inhibition of Ataxia telangiectasia and Rad3-related (ATR) in pre-clinical models of high-risk NB. Amplification of the oncogene always imparts high-risk disease and occurs in 25% of all NB. Here, we show that MYCN-induced replication stress directly increases sensitivity to the ATR inhibitors VE-821 and AZD6738. PARP inhibition with Olaparib also results in replication stress and ATR activation, and sensitises NB cells to ATR inhibition independently of status, with synergistic levels of cell death seen in MYCN expressing ATR- and PARP-inhibited cells. Mechanistically, we demonstrate that ATR inhibition increases the number of persistent stalled and collapsed replication forks, exacerbating replication stress. It also abrogates S and G2 cell cycle checkpoints leading to death during mitosis in cells treated with an ATR inhibitor combined with PARP inhibition. In summary, increased replication stress through high MYCN expression, PARP inhibition or chemotherapeutic agents results in sensitivity to ATR inhibition. Our findings provide a mechanistic rationale for the inclusion of ATR and PARP inhibitors as a potential treatment strategy for high-risk NB.
尽管采用了强化大剂量多模式疗法，但高危神经母细胞瘤（NB）的生存率仍低于50%。本研究在高危NB临床前模型中，研究了复制应激在对共济失调毛细血管扩张症和Rad3相关蛋白（ATR）抑制敏感性中的作用。癌基因的扩增总是导致高危疾病，在所有NB中发生率为25%。在此，我们表明MYCN诱导的复制应激直接增加了对ATR抑制剂VE-821和AZD6738的敏感性。用奥拉帕尼抑制PARP也会导致复制应激和ATR激活，并使NB细胞对ATR抑制敏感，与状态无关，在表达MYCN的ATR和PARP抑制细胞中可见协同水平的细胞死亡。从机制上讲，我们证明ATR抑制增加了持续停滞和崩溃的复制叉数量，加剧了复制应激。它还消除了S期和G2期细胞周期检查点，导致在用ATR抑制剂联合PARP抑制处理的细胞有丝分裂期间死亡。总之，通过高表达MYCN、抑制PARP或使用化疗药物增加复制应激会导致对ATR抑制敏感。我们的研究结果为将ATR和PARP抑制剂作为高危NB的潜在治疗策略提供了机制依据。
