Patel Jinal A, Rageul Julie, Lo Natalie, Nandi Auntara, Zezelic Camryn, Lee Cynthia T, Khan Arafat, Kim Hyungjin
Department of Pharmacological Sciences, State University of New York at Stony Brook, Stony Brook, NY 11794, United States.
Stony Brook Cancer Center, Renaissance School of Medicine at Stony Brook University, Stony Brook, NY 11794, United States.
Nucleic Acids Res. 2025 Jun 20;53(12). doi: 10.1093/nar/gkaf573.
Exacerbating the DNA replication problems of cancer cells serves as a viable therapeutic approach. Nevertheless, the cytotoxicity of cancer drugs is often hampered by therapy-induced senescence, leading to unfavorable patient outcomes. Here, we employ acute replisome dysfunction in combination with Ataxia telangiectasia and Rad3-related (ATR) inhibition as a strategy to divert senescent cells toward death by triggering DNA replication catastrophe, a form of irreversible replication fork collapse caused by excessive single-stranded DNA (ssDNA) accumulation. RNA-sequencing revealed a distinct set of p53-responsive genes responsible for death. We identify c-Jun N-terminal kinase (JNK) to be essential for augmenting p53-dependent apoptotic programs and inducing pan-nuclear distribution of γH2AX, together constituting a feed-forward loop to drive cell death. Activation of DNA-PKcs initiates the signaling cascade of replication catastrophe, including CHK1-dependent JNK activation, which relies on MRE11 and PARP1 to expand and recognize ssDNA gaps, defining replication-associated gaps as an underlying basis for replication catastrophe. Our study elucidates the dynamic regulation of proximal and distal effectors along the DNA-PKcs/JNK/p53 axis that govern the cell fate decision between senescence and death. We propose that key determinants of replication catastrophe signaling are targetable vulnerabilities that can be exploited to limit senescent cell populations and increase the efficacy of anti-cancer therapies.
加剧癌细胞的DNA复制问题是一种可行的治疗方法。然而，癌症药物的细胞毒性常常受到治疗诱导的衰老的阻碍，导致患者预后不佳。在此，我们采用急性复制体功能障碍并联合抑制共济失调毛细血管扩张症突变基因（ATM）和Rad3相关蛋白（ATR），作为一种策略，通过引发DNA复制灾难（一种由过量单链DNA（ssDNA）积累导致的不可逆复制叉崩溃形式），使衰老细胞走向死亡。RNA测序揭示了一组独特的p53反应基因，这些基因导致细胞死亡。我们确定c-Jun氨基末端激酶（JNK）对于增强p53依赖性凋亡程序和诱导γH2AX的全核分布至关重要，这共同构成了一个前馈环以驱动细胞死亡。DNA依赖蛋白激酶催化亚基（DNA-PKcs）的激活启动了复制灾难的信号级联反应，包括CHK1依赖的JNK激活，这依赖于MRE11和PARP1来扩展和识别ssDNA缺口，将复制相关缺口定义为复制灾难的潜在基础。我们的研究阐明了沿着DNA-PKcs/JNK/p53轴的近端和远端效应器的动态调节，该调节控制着衰老和死亡之间的细胞命运决定。我们提出，复制灾难信号传导的关键决定因素是可靶向的脆弱点，可利用这些脆弱点来限制衰老细胞群体并提高抗癌治疗的疗效。
