Autophagy regulation of prostate tumor development

 描述（由申请人提供）：自噬在癌症发生、进展和对治疗的反应中很重要。虽然我们已经在临床上尝试靶向自噬，但目前还没有办法确定将或不会从自噬抑制中受益的肿瘤，并且不知道由不同致癌驱动突变驱动的肿瘤是否会从自噬抑制中受益。 对自噬抑制的反应不同。由于不同的肿瘤驱动因子对自噬具有相反的作用（例如，突变型RAS被认为促进自噬，而PTEN的缺失激活了应该抑制自噬的经典PIK 3C途径），因此具有不同驱动因子的肿瘤可能在其自噬依赖性方面不同，从而对自噬抑制的反应不同。在使用常规（尽管是最先进的）基因工程小鼠（GEM）模型的动物模型中，越来越多的证据表明RAS驱动的肿瘤受益于自噬抑制。然而，与制备这种GEM相关的时间和成本使得测试多种临床相关的肿瘤驱动因子与多种自噬调节因子的头对头沿着非常困难和昂贵。在这个试点项目中，我们的目标是开发 这是一种新的方法，它将使我们能够直接评估通过靶向不同的自噬调节剂和由五种不同的临床相关前列腺肿瘤驱动因子驱动的肿瘤细胞来抑制自噬的效果，并在体外和体内癌症发展和进展期间这样做。我们将通过利用Cramer实验室开创的一种新方法来实现这一目标，该方法使用工程纯化的前列腺干细胞与泌尿生殖间充质重组来生长组织重组体，这些重组体模拟正常前列腺组织或由特定肿瘤驱动因素（RAS激活，PTEN丢失等）驱动的侵袭性肿瘤。我们将联合收割机与Thorburn实验室的新方法相结合，以靶向和评估自噬，使我们能够测试抑制三种基本自噬调节剂的效果，这些调节剂控制肿瘤细胞自噬过程中的不同步骤，这些肿瘤细胞由五种不同的肿瘤驱动剂组合驱动，所有这些肿瘤驱动剂都与侵袭性人类前列腺癌相关，并预测对自噬具有不同的，有时是相反的影响。我们将进行体外和体内分析，以验证我们的中心假设：不同的肿瘤驱动因素导致肿瘤细胞表现出不同程度的 在体外对自噬依赖性有反应，在体内对自噬抑制有反应。我们这样做有两个目标：1。确定特定的肿瘤驱动致癌突变对体外自噬和自噬依赖性的影响。和2.在不同致癌突变/驱动因素的背景下，确定自噬在体内前列腺肿瘤发展和进展中的作用。这个高风险/高回报的项目将确定我们的方法是否可行，从而使我们知道如何进行更大的研究项目，以确定这些作用的重要性和机制，并评估肿瘤突变的分析是否可以用于选择癌症最有可能对自噬抑制治疗有反应的患者。我们相信这些高风险但潜在高回报的特点，以及根据所获得的结果确定明确前进方向的能力，使该项目成为R21机制的理想选择。

 DESCRIPTION (provided by applicant): Autophagy is important in cancer development, progression and response to therapy. Although we are already trying to target autophagy in the clinic, there is currently no way to identify the tumors that will or will not benefit from autophay inhibition and it is unknown if tumors that are driven by different oncogenic driver mutations will differ in their response to autophagy inhibition or not. Because different tumor drivers have opposing effects on autophagy (e.g. mutant RAS is thought to promote autophagy while loss of PTEN activates the canonical PIK3C pathway which should inhibit autophagy), it is likely that tumors with different drivers will differ in their autophagy dependency and thus respond differently to autophagy inhibition. In animal models using conventional (albeit state of the art) genetically engineered mouse (GEM) models, accumulating evidence suggests that RAS-driven tumors benefit from autophagy inhibition. However the time and cost associated with making such GEMs makes testing multiple clinically relevant tumor drivers head to head along with multiple autophagy regulators very difficult and expensive. In this pilot project we aim to develop a new approach that will allow us to directly assess the effects of inhibiting autophagy by targeting different autophagy regulators and in tumor cells driven by five different clinically relevant prostate tumor drivers and to do so both in vitro and during cancer development and progression in vivo. We will do this by capitalizing on a novel approach pioneered by the Cramer lab that uses engineered purified prostate stem cells recombined with urogenital mesenchyme to grow tissue recombinants that mimic normal prostate tissue or aggressive tumors driven by specific tumor drivers (RAS activation, PTEN loss etc.). We will combine this new approach with new methods from the Thorburn lab to target and assess autophagy, allowing us to test the effects of inhibiting three essential autophagy regulators that control distinct steps in the autophagy process in tumor cells driven by five different combinations of tumor drivers all associated with aggressive human prostate cancer and predicted to have different and sometimes opposing effects on autophagy. We will perform both in vitro and in vivo analysis to test our central hypothesis: different tumor drivers cause tumor cells to display different degrees of autophagy dependence in vitro and respond to autophagy inhibition in vivo. We will do this with two aims: 1. Determine the effects of specific tumor-driving oncogenic mutations on autophagy and autophagy-dependence in vitro. And 2. Determine the role of autophagy in prostate tumor development & progression in vivo in the context of different oncogenic mutations/drivers. This high risk/ high return project will establish if our approach is feasible o not and thus allow us to know how to proceed with a larger research project to determine the importance and mechanism of these effects and assess whether analysis of tumor mutations can be used to select patients whose cancer is most likely to respond to autophagy inhibition therapy. We believe these characteristics of high risk but potential for high return with the abiliy to identify a clear way forward based on the results obtained makes this project ideal for the R21 mechanism.