Reversing intrinsic cancer cell resistance to alkylating agents by histone deacetylase inhibition

通过组蛋白脱乙酰酶抑制逆转癌细胞对烷化剂的内在耐药性

• 批准号: 214657440
• 负责人: Dr. Wynand P. Roos
• 金额: --
• 依托单位: Institut für Toxikologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/214657440?language=en
• 关键词: Reversing; intrinsic; cancer; cell; resistance

Alkylating agents are ideal for the study of DNA damage triggered cell death, as the DNA lesions responsible for activating cell death along with the activated repair and damage response pathways have been elucidated in detail. This knowledge does, however, not explain why glioma cells differ so significantly in their survival following the induction of critical DNA lesions compared to non-transformed cells. The answer to this may be found in the histone deacetylase (HDAC) dependent deregulation of components of the DNA damage response, death execution and/or DNA repair pathways. As deregulation of the class I HDACs HDAC1 and HDAC3 do occur during the malignant transformation of glioblastoma, HDAC1 and HDAC3 may lead to anticancer drug resistance. However, whether or not the inhibition of class I HDACs has any effect on the intrinsic alkylating agent sensitivity of glioma cells is still a matter of debate. During the previous DFG funding period, I addressed the influence of class I HDACs on melanoma resistance. The data showed that HDAC2 stimulates the expression of the homologous recombination repair protein RAD51 and the Fanconi anaemia protein FANCD2, which causes resistance in melanomas to alkylating agents (Krumm et al. 2016, Roos and Krumm 2016). This resistance could be overcome by small molecule inhibition of class I HDACs. For gliomas, my preliminary data show that the inhibition of HDAC1 and HDAC2 with Entinostat (MS-275) sensitises glioma cells to alkylating agents, although the mechanism of sensitization differs from the mechanism we reported for melanoma cells. The preliminary data, in gliomas, points to a possible mechanism where overexpressed HDAC1 and/or HDAC3 causes resistance to the alkylating agent temozolomide (TMZ), due to the stimulation of a prolonged TMZ-induced DNA damage response. This causes the TMZ exposed glioma cells to enter a senescence-like state that protects them from initiating apoptosis. Upon co-treatment with the HDACi MS-275 and TMZ, the TMZ-induced DNA damage response is downregulated, gliomas no longer enter this senescence-like state and they become apoptotic. In this DFG-grant, I wish to focus on the mechanism of HDAC1/2/3 mediated resistance of glioma cells to alkylating agents and address the following specific questions. (1) Which of the class I HDACs causes the resistance of gliomas to alkylating agents? (2) What roles do HDAC1/2/3 play in the aberrant activation of the TMZ-triggered DNA damage response in glioma? Here the roles of HDAC1/2/3 on the histone acetyltransferase TIP60, the phosphatases PP2A and WIP1 as well as the epigenetic marks H3K56Ac and H4K91Ac will be addressed. (3) What roles do HDAC1/2/3 play in alkylating agent triggered senescence?

烷化剂是研究DNA损伤引发的细胞死亡的理想药物，因为已经详细阐明了负责激活细胞死亡的DNA损伤沿着激活的修复和损伤反应途径。然而，这些知识并不能解释为什么神经胶质瘤细胞在诱导关键DNA损伤后的存活率与非转化细胞相比如此显著不同。这个问题的答案可以在DNA损伤反应、死亡执行和/或DNA修复途径的组分的组蛋白脱乙酰酶（HDAC）依赖性失调中找到。由于I类HDAC HDAC 1和HDAC 3的失调确实发生在胶质母细胞瘤的恶性转化期间，HDAC 1和HDAC 3可能导致抗癌药物抗性。然而，I类HDAC的抑制是否对神经胶质瘤细胞的内在烷化剂敏感性有任何影响仍然是一个争论的问题。在之前的DFG资助期间，我讨论了I类HDAC对黑色素瘤耐药性的影响。数据显示，HDAC 2刺激同源重组修复蛋白RAD 51和范可尼贫血蛋白FANCD 2的表达，导致黑色素瘤对烷化剂产生耐药性（Krumm et al. 2016，鲁什and Krumm 2016）。这种抗性可以通过I类HDAC的小分子抑制来克服。对于神经胶质瘤，我的初步数据表明，恩替司他（MS-275）抑制HDAC 1和HDAC 2使神经胶质瘤细胞对烷化剂敏感，尽管致敏机制与我们报道的黑色素瘤细胞的机制不同。在神经胶质瘤中的初步数据指出了一种可能的机制，其中过度表达的HDAC 1和/或HDAC 3导致对烷化剂替莫唑胺（TMZ）的抗性，这是由于长期TMZ诱导的DNA损伤反应的刺激。这导致TMZ暴露的胶质瘤细胞进入衰老样状态，保护它们免于启动凋亡。在用HDACi MS-275和TMZ共同处理后，TMZ诱导的DNA损伤反应下调，胶质瘤不再进入这种衰老样状态，并且它们变得凋亡。在这个DFG的资助，我希望集中在HDAC 1/2/3介导的胶质瘤细胞对烷化剂的耐药性的机制，并解决以下具体问题。(1)哪一种I类HDAC导致胶质瘤对烷化剂产生耐药性？(2)HDAC 1/2/3在胶质瘤中TMZ触发的DNA损伤反应的异常激活中起什么作用？在这里，HDAC 1/2/3对组蛋白乙酰转移酶TIP 60，磷酸酶PP 2A和WIP 1以及表观遗传标记H3 K56 Ac和H4 K91 Ac的作用将得到解决。(3)HDAC 1/2/3在烷化剂引发的衰老中起什么作用？