Induction of p16Ink4a-dependent senescence through exogenous signals

通过外源信号诱导 p16Ink4a 依赖性衰老

• 批准号: 280452905
• 负责人: Professor Dr. Martin Röcken
• 金额: --
• 依托单位: Universitäts-Hautklinik
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/280452905?language=en
• 关键词: Induction; p16Ink4a; dependent; senescence; through

Data from our laboratory have shown that simultaneous activation of the interferon (IFN) and of the tumor necrosis factor (TNF)-signaling pathways results in a stable cell cycle arrest in a broad range of tumor cells. This cytokine-induced cell cycle arrest strictly depends on the Cdk4/6 inhibitor p16INK4a and shows all characteristic features of cellular senescence (CIS). As TNF is too toxic for systemic applications, here we asked whether molecules of the TNF-signaling pathway could be targeted. Combing such molecules with IFN may allow establishing an efficient cancer therapy. Based on the data gained during the first funding period, this application has three related projects: (I) Searching for molecules that induce senescence in cancer cells when combined with IFN, we identified JunB as a key messenger important for the regulation of senescence and synthetic lethality in response to IFN. We have constructed tumor cells that overexpress JunB. Surprisingly, CIS can be induced in JunB-overexpressing cells with IFN alone. Thus JunB overexpression can replace the TNF required for CIS. This opens not only the approach for a druggable molecule. More interestingly, our data strongly suggest that JunB is a tunable molecule that ultimately determines whether an IFN signal leads to survival, senescence or apoptosis. (II) Searching for druggable molecules that can induce apoptosis in senescent cancer cells (senolysis) we found that combining IFN with HDAC inhibitors can induce senolysis. A key molecule that seems to be critical for the induction of senolysis was DNA-methyl transferase 1 (DNMT1). We will now exactly analyze the role of DNMT1 in CIS and senolysis by establishing knock-out cells (DNMT10/0) and especially also tumor cells with constitutive DNMT1-expression (DNMT1CONST). Intraperitoneal application of (DNMT10/0) or of (DNMT1CONST) tumor cells, followed by treatment with IFN with HDAC inhibitors will unravel whether DNMT1 is the postulated key messenger required for cancer immune control by HDAC inhibitors, when combined with IFN. (III) A key question concerns the natural clearance mechanisms of senescent cancer cells, and the biological meaning of this clearance. Here we identified TRAIL and iNOS as natural signals capable of inducing senolysis in vitro; moreover, we found that senolysis is needed to clear senescent cancer cells by macrophages or dendritic cells. It will now be important to identify the role of TRAIL and iNOS in inducing senolysis in vivo, and the need of these molecules for the in vivo-clearance of senescent cancers.Together, the data will explain how the immune system promotes synthetic lethality in cancers and how this can be exploited to clear cancers, when combined with either senescence-inducing molecules or drugs targeting cancer drivers, when oncogene-induced senescence fails.

来自我们实验室的数据表明，干扰素（IFN）和肿瘤坏死因子（TNF）信号通路的同时激活导致在广泛的肿瘤细胞中稳定的细胞周期停滞。这种由尼古丁诱导的细胞周期阻滞严格依赖于Cdk 4/6抑制剂p16 INK 4a，并显示出细胞衰老（CIS）的所有特征。由于TNF对全身应用毒性太大，因此我们询问是否可以靶向TNF信号通路的分子。将这些分子与IFN结合可以建立有效的癌症治疗。基于在第一个资助期获得的数据，该申请有三个相关项目：（I）寻找与IFN结合时诱导癌细胞衰老的分子，我们确定JunB是一种对衰老和响应IFN的合成致死性的调节重要的关键信使。我们构建了过表达JunB的肿瘤细胞。令人惊讶的是，CIS可以在JunB过表达细胞中单独用IFN诱导。因此，JunB过表达可以取代CIS所需的TNF。这不仅为可药用分子开辟了途径。更有趣的是，我们的数据强烈表明JunB是一种可调分子，最终决定IFN信号是否导致生存，衰老或凋亡。(II)寻找可以诱导衰老癌细胞凋亡的药物分子（衰老溶解），我们发现IFN与HDAC抑制剂组合可以诱导衰老溶解。一个关键的分子，似乎是关键的诱导senolysis是DNA甲基转移酶1（DNMT 1）。我们现在将通过建立敲除细胞（DNMT 10/0）以及特别是具有组成性DNMT 1表达的肿瘤细胞（DNMT 1CONST）来准确分析DNMT 1在CIS和衰老溶解中的作用。腹膜内应用（DNMT 10/0）或（DNMT 1CONST）肿瘤细胞，然后用IFN和HDAC抑制剂治疗，将阐明DNMT 1是否是HDAC抑制剂与IFN联合时癌症免疫控制所需的假定关键信使。(III)一个关键问题是衰老癌细胞的自然清除机制，以及这种清除的生物学意义。在这里，我们确定了TRAIL和iNOS作为能够在体外诱导衰老的天然信号;此外，我们发现，衰老需要通过巨噬细胞或树突状细胞来清除衰老的癌细胞。现在，重要的是要确定TRAIL和iNOS在体内诱导衰老过程中的作用，以及这些分子在体内清除衰老癌症的必要性。这些数据将共同解释免疫系统如何促进癌症的合成致死性，以及如何利用这一点来清除癌症，当与衰老诱导分子或靶向癌症驱动因子的药物结合时，当癌基因诱导的衰老失败时。