PO.CL06.03 · 临床研究
CDK7抑制通过染色质重编程减轻MYC-MB中的AZD1775耐药
CDK7 inhibition mitigates AZD1775 resistance via chromatin reprogramming in MYC-MB
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
髓母细胞瘤(MB)是儿童最常见的恶性脑肿瘤,约占儿童脑肿瘤的20%。MB是一种异质性疾病,其临床结局在很大程度上受分子亚组的影响。其中,以MYC扩增为特征的Group 3型MB预后最差,具有很高的转移和复发倾向。我们既往的研究确定WEE1是MB细胞存活的关键调控因子,并发现Myc驱动的MB对WEE1抑制剂AZD1775尤为敏感。尽管AZD1775已显示出疗效,尤其是在与基因毒性药物联用时,但对小分子抑制剂的耐药往往会出现,从而限制其治疗潜力。CDK7是一种通过磷酸化RNA Pol II的C端结构域来启动转录所必需的激酶,在Myc驱动的恶性肿瘤中发挥关键作用,并常在超级增强子(super-enhancer)处富集。AZD1775耐药细胞经历染色质重组,建立替代性顺式作用元件,促进DNA修复和增殖基因的转录,从而规避治疗。我们假设靶向CDK7介导的转录重编程能够克服AZD1775耐药。使用CDK7抑制剂THZ1,我们对DNA修复蛋白进行了western blot分析,观察到ATM通路激活(DNA损伤反应的关键组成部分)受到抑制。在亲本细胞系和AZD1775耐药细胞系中进行的增殖实验表明,AZD1775与THZ1联用可显著抑制细胞生长。这些发现提示,THZ1可能逆转适应性染色质重组,使耐药的MB细胞对AZD1775重新敏感,并增强整体治疗反应。未来的研究将探讨CDK7抑制剂与其他表观遗传调节剂联用的潜力,以进一步破坏耐药机制并改善侵袭性MB亚型(尤其是Group 3型MB)的治疗结局。该方法为克服治疗耐药和推进髓母细胞瘤的精准医学提供了一条有前景的途径。
查看英文原文 English abstract
Medulloblastoma (MB) is the most common malignant brain tumor in children, comprising ~20% of pediatric brain tumors. MB is a heterogeneous disease, with clinical outcomes heavily influenced by molecular subgroups. Among these, Group 3 MB, characterized by MYC amplification, exhibits the poorest prognosis, with a high propensity for metastasis and recurrence. Our previous research identified WEE1 as a critical regulator of MB cell survival and found that Myc-driven MB is particularly sensitive to the WEE1 inhibitor AZD1775. Although AZD1775 has demonstrated efficacy, especially when combined with genotoxic agents, resistance to small molecule inhibitors often emerges, limiting its therapeutic potential.CDK7, a kinase essential for transcriptional initiation via phosphorylation of RNA Pol II's C-terminal domain, plays a critical role in Myc-driven malignancies and is frequently enriched at super-enhancers. AZD1775-resistant cells undergo chromatin reorganization to establish alternate cis-acting elements that promote transcription of DNA repair and proliferation genes, circumventing treatment. We hypothesized that targeting CDK7-mediated transcriptional reprogramming could overcome AZD1775 resistance.Using the CDK7 inhibitor THZ1, we performed western blot analysis of DNA repair proteins and observed inhibition of ATM pathway activation, a key component of the DNA damage response. Proliferation assays in both parental and AZD1775-resistant cell lines demonstrated that combining AZD1775 with THZ1 significantly suppressed cell growth. These findings suggest that THZ1 may reverse adaptive chromatin reorganization, sensitizing resistant MB cells to AZD1775 and enhancing the overall therapeutic response.Future studies will investigate the potential of combining CDK7 inhibitors with other epigenetic modulators to further disrupt resistance mechanisms and improve treatment outcomes in aggressive MB subtypes, particularly Group 3 MB. This approach offers a promising avenue for overcoming therapeutic resistance and advancing precision medicine in medulloblastoma.
利益披露 Disclosure
K. Smart, None..
B. Veo, None..
R. Vibhakar, None.