PO.MCB01.01 · 分子与细胞生物学
靶向PLK1或WEE1揭示了BRCA1/2野生型、同源重组功能完好的高级别浆液性卵巢癌中的一个治疗弱点
Targeting PLK1 or WEE1 uncovers a therapeutic vulnerability in BRCA1/2 wild-type, homologous recombination-proficient high-grade serous ovarian cancer
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
背景：BRCA1/2野生型（BRCA-WT）且同源重组功能完好（HRP）的高级别浆液性卵巢癌（HGSOC）对铂类药物和PARP抑制剂反应欠佳，且缺乏有效的靶向治疗。我们旨在确定抑制PLK1或WEE1（两种G2/M检查点激酶）能否揭示BRCA-WT/HRP HGSOC中的治疗弱点。
方法：我们在BRCA-WT/HRP（以及BRCA突变型/同源重组缺陷（HRD））卵巢癌模型中评估了PLK1抑制剂volasertib和WEE1抑制剂adavosertib的作用。对细胞活力、细胞周期分布、凋亡标志物和DNA损伤反应进行了定量，包括gammaH2AX、RAD51和53BP1病灶。采用DNA-PKcs抑制或siRNA来评估NHEJ依赖性。抗肿瘤活性在BRCA-WT细胞系来源的异种移植和两个已确认BRCA状态的PDX模型中得到进一步验证。
结果：BRCA-WT细胞对PLK1或WEE1抑制的敏感性显著高于BRCA突变型细胞。在BRCA-WT模型中，volasertib诱导异常纺锤体组装、多倍体化和有丝分裂进程延迟，而adavosertib则废除G2/M检查点并触发过早进入有丝分裂。两种药物均增加DNA损伤并显著减少RAD51病灶，证明了对HR的抑制。尽管观察到NHEJ激活，但不足以补偿受损的HR。相比之下，BRCA突变型细胞反应极小，并表现出组成型高DNA-PKcs表达和持续的53BP1病灶。药理学或遗传学DNA-PKcs抑制可恢复BRCA突变型细胞对PLK1或WEE1抑制的敏感性。在体内，PLK1或WEE1抑制显著减少了BRCA-WT异种移植和BRCA-WT PDX中的肿瘤生长并增加凋亡，而BRCA突变型PDX则反应有限。
结论：BRCA-WT/HRP HGSOC通过破坏HR修复和有丝分裂调控，表现出对PLK1或WEE1抑制的独特易感性，揭示了一种在BRCA突变型/HRD肿瘤中未观察到的基于DNA修复的弱点。这些发现为以生物标志物为导向开发PLK1或WEE1抑制剂作为HRP卵巢癌治疗策略提供了有力依据，而该患者群体存在重大未满足的临床需求。
查看英文原文 English abstract
Background: High-grade serous ovarian cancer (HGSOC) with BRCA1/2 wild-type (BRCA-WT) and homologous recombination proficiency (HRP) responds poorly to platinum agents and PARP inhibitors and lacks effective targeted therapies. We aimed to determine whether inhibition of PLK1 or WEE1, two G2/M checkpoint kinases, could uncover a therapeutic vulnerability in BRCA-WT/HRP HGSOC.
Methods: We evaluated the effects of the PLK1 inhibitor volasertib and the WEE1 inhibitor adavosertib in BRCA-WT/HRP (and BRCA-mutant/HR-deficient (HRD) ovarian cancer models. Cell viability, cell-cycle distribution, apoptosis markers, and DNA damage responses were quantified, including gammaH2AX, RAD51, and 53BP1 foci. DNA-PKcs inhibition or siRNA was used to assess NHEJ dependence. Antitumor activity was further validated in BRCA-WT cell line-derived xenografts and two PDX models with confirmed BRCA status.
Results: BRCA-WT cells demonstrated substantially higher sensitivity to PLK1 or WEE1 inhibition than BRCA-mutant cells. In BRCA-WT models, volasertib induced abnormal spindle assembly, polyploidy, and delayed mitotic progression, whereas adavosertib abrogated the G2/M checkpoint and triggered premature mitotic entry. Both agents increased DNA damage and markedly reduced RAD51 foci, demonstrating HR suppression. Although NHEJ activation was observed, it was insufficient to compensate for impaired HR. In contrast, BRCA-mutant cells showed minimal response and displayed constitutively high DNA-PKcs expression with persistent 53BP1 foci. Pharmacologic or genetic DNA-PKcs inhibition restored sensitivity to PLK1 or WEE1 inhibition in BRCA-mutant cells. In vivo , PLK1 or WEE1 inhibition significantly reduced tumor growth and increased apoptosis in BRCA-WT xenografts and BRCA-WT PDX, whereas BRCA-mutant PDX exhibited limited response.
Conclusion: BRCA-WT/HRP HGSOC exhibits distinct susceptibility to PLK1 or WEE1 inhibition through disruption of HR repair and mitotic regulation, revealing a DNA repair-based vulnerability not observed in BRCA-mutant/HRD tumors. These findings provide a strong rationale for biomarker-guided development of PLK1 or WEE1 inhibitors as therapeutic strategies for HRP ovarian cancers, a patient population with significant unmet clinical needs.
利益披露 Disclosure
A. Kunita,
Konica Minolta, Inc. ).
Q. Xi, None..
M. Kawakami, None.
M. Ogawa,
Konica Minolta, Inc. ).
M. Ka, None.
K. Watanabe,
Konica Minolta, Inc. ).
T. Ushiku, None.
H. Kage,
Konica Minolta, Inc. ).
K. Katayama, None.
K. Oda,
Konica Minolta, Inc. ), Other, Honoraria（lecture fee).
Chugai Pharmaceutical Co., Ltd. Other, Honoraria（lecture fee).
AstraZeneca K.K. ), Other, Honoraria（lecture fee).