Investigating the role of autophagy in Tak1 null prostate cancer and TRAIL sensitivity

 描述(申请人提供)自噬是一种保守的细胞生存途径，对正常的细胞功能至关重要，但它与许多疾病有关，包括癌症的发生。 进展，以及改变时对治疗的反应。越来越多的证据表明，某些类型的肿瘤以肿瘤抑制基因缺失为特征，在应激和饥饿期间高度依赖自噬生存。Cramer实验室证实MAP3K7/Tak1是一种肿瘤抑制基因，在30%-40%的前列腺癌中被发现缺失，并与较差的无病生存率有关。前列腺癌是美国最常见的男性癌症，也是癌症相关死亡的第二大原因。此外，克雷默实验室还发现了一种特别侵袭性的前列腺癌亚型，其特征是Tak1和CHD1的缺失。Tak1也被证明可以激活自噬，但还没有确定CHD1和自噬之间的直接联系。有趣的是，Tak1缺失已经被证明可以引起对肿瘤坏死因子相关的凋亡诱导配体(TRAIL)治疗的强大的细胞死亡反应，这在我的初步数据中显示为通过坏死性下垂而不是典型的细胞凋亡。此外，我的数据显示，自噬在调节细胞死亡方面发挥了作用。当TRAIL刺激时，Tak1的缺失如何导致如此显著的细胞死亡尚不完全清楚，还需要进一步研究其与自噬的关系。目前在前列腺癌中存在少量的基因靶向突变，对常见突变如何在疾病进展或治疗结果中相互作用知之甚少。识别和理解生存所需的靶向信号通路，例如自噬的Tak1，将允许更适当和直接的治疗。此外，确定Tak1和CHD1的协调缺失在侵袭性前列腺癌中的作用将使我们能够阐明它们在改变自噬通量和 实现量身定做的治疗。自噬如何通过Tak1的缺失通过坏死性下垂调节细胞死亡的机制，以及Tak1细胞如何对TRAIL敏感，将在该提案中进行评估，并可能解释导致靶向治疗的途径之间先前未知的联系。在这项研究中，我打算研究Tak1缺失在自噬中的作用，以及它与痕迹敏感性的关系。我将使用组织重组来确定在CHD1缺失的背景下，Tak1细胞中改变的自噬如何改变前列腺癌的发展、进展和治疗反应。使用shRNA、sgRNA和自噬的化学修饰剂，我将使Tak1基因缺失的小鼠前列腺细胞对抗癌治疗，特别是TRAIL敏感。如果Tak1缺失细胞通过自噬在体内实现对TRAIL的增敏 抑制剂，它将证明Tak1是前列腺癌的一个可选标记物。因此，如果成功，含有Tak1和CHD1缺失的前列腺癌亚型患者将有针对性的治疗选择，TRAIL和自噬抑制剂，增加那些将受益的人的结果，并避免对那些不会受益的人进行不必要的和潜在的有害治疗。

 DESCRIPTION (provided by applicant) Autophagy is a conserved cell survival pathway that is crucial to proper cell function, yet it is implicated in many diseases including cancer initiation, progression, and response to therapy when altered. Gathering evidence shows that there are certain tumor types characterized by tumor suppressor loss that are highly dependent on autophagy for survival during stress and starvation. The Cramer lab validated MAP3K7/Tak1 as a tumor suppressor gene which is found to be deleted in 30-40% of prostate tumors and is associated with poor disease-free survival. Prostate cancer is the most commonly diagnosed cancer in the United States in men, and the second leading cause of cancer related deaths. Further, the Cramer lab also identified a particularly aggressive subtype of prostate cancer that is characterized by loss of both Tak1 and CHD1. Tak1 has also been shown to activate autophagy, but no direct link between CHD1 and autophagy has been determined. Interestingly, Tak1 loss has been shown to cause a robust cell death response to treatment with TNF-related apoptosis inducing ligand (TRAIL) that is shown in my preliminary data as through necroptosis and NOT canonical apoptosis. Further, my data show that autophagy plays a role in modulating this cell death. It is not fully understood how the loss of Tak1 causes such pronounced cell death when stimulated with TRAIL, and further research into its connection with autophagy is needed. There currently is a small number of genetically targetable mutations in prostate cancer, with little understanding of how common mutations cooperate in the progression of the disease or therapy outcome. Identification and understanding of targetable signaling pathways that are needed for survival, such as Tak1 with autophagy, will allow for more appropriate and direct therapies. Furthermore, identifying the role of coordinate loss of Tak1 and CHD1 in regard to aggressive prostate cancer will allow us to elucidate their role in altering autophagic flux and enable tailored treatments. The mechanism of how autophagy regulates cell death through necroptosis with loss of Tak1 and how Tak1 cells are sensitized to TRAIL will be evaluated in this proposal and could explain a previously unknown connection between pathways leading to targetable therapeutics. In this research proposal, I intend to examine the role of Tak1 loss on autophagy and how it relates to TRAIL sensitivity. I will use tissue recombination to determine how altered autophagy in Tak1 cells, in the context of CHD1 loss, modifies prostate cancer development, progression, and treatment response. Using shRNA, sgRNA, and chemical modifiers of autophagy, I will sensitize Tak1 null mouse prostate cells to anti- cancer therapies, specifically TRAIL. If sensitization of Tak1 null cells to TRAIL is achieved in vivo with autophagy inhibitors, it will demonstrate Tak1 as a selectable marker in prostate cancer. Thus, if successful, patients with the subtype of prostate cancers containing Tak1 and CHD1 loss would have targeted treatment options, TRAIL and autophagy inhibitors, increasing results in those who would benefit and avoiding unnecessary and potentially harmful treatments for those who would not.