Women's Malignancies Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD, USA.
Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD, USA.
Cancer Treat Rev. 2018 Dec;71:1-7. doi: 10.1016/j.ctrv.2018.09.003. Epub 2018 Sep 11.
Poly(ADP-ribose) polymerase (PARP) inhibition serves as a potent therapeutic option eliciting synthetic lethality in cancers harboring homologous recombination (HR) repair defects, such as BRCA mutations. However, the development of resistance to PARP inhibitors (PARPis) poses a clinical challenge. Restoration of HR competency is one of the many molecular factors contributing to PARPi resistance. Combination therapy with cell cycle checkpoint (ATR, CHK1, and WEE1) inhibitors is being investigated clinically in many cancers, particularly in ovarian cancer, to enhance the efficacy and circumvent resistance to PARPis. Ideally, inhibition of ATR, CHK1 and WEE1 proteins will abrogate G2 arrest and subsequent DNA repair via restored HR in PARPi-treated cells. Replication fork stabilization has recently been identified as a potential compensatory PARPi resistance mechanism, found in the absence of restored HR. ATR, CHK1, and WEE1 each possess different roles in replication fork stabilization, providing different mechanisms to consider when developing combination therapies to avoid continued development of drug resistance. This review examines the impact of ATR, CHK1, and WEE1 on replication fork stabilization. We also address the therapeutic potential for combining PARPis with cell cycle inhibitors and the possible consequence of combination therapies which do not adequately address both restored HR and replication fork stabilization as PARPi resistance mechanisms.
聚(ADP-核糖)聚合酶(PARP)抑制剂在同源重组(HR)修复缺陷的癌症中具有合成致死作用,如 BRCA 突变,因此成为一种有效的治疗选择。然而,PARP 抑制剂(PARPi)耐药性的发展是临床面临的挑战之一。恢复 HR 能力是导致 PARPi 耐药的众多分子因素之一。细胞周期检查点(ATR、CHK1 和 WEE1)抑制剂联合治疗正在许多癌症中进行临床研究,特别是在卵巢癌中,以提高疗效并避免对 PARPi 的耐药性。理想情况下,ATR、CHK1 和 WEE1 蛋白的抑制将通过恢复 PARPi 处理细胞中的 HR 来消除 G2 阻滞和随后的 DNA 修复。最近发现,在没有恢复 HR 的情况下,复制叉稳定化是一种潜在的代偿性 PARPi 耐药机制。ATR、CHK1 和 WEE1 在复制叉稳定化中各自具有不同的作用,为避免继续产生耐药性,在开发联合治疗时需要考虑不同的机制。这篇综述探讨了 ATR、CHK1 和 WEE1 对复制叉稳定化的影响。我们还讨论了将 PARPi 与细胞周期抑制剂联合应用的治疗潜力,以及那些不能充分解决 HR 恢复和复制叉稳定化作为 PARPi 耐药机制的联合治疗的可能后果。