Elucidation of Tumor Resistance Mechanisms in Tuberous Sclerosis Complex-Associated Renal Angiomyolipoma for the Design of Novel Nanotherapies

摘要 大多数结节性硬化症(TSC)患者发展为良性肾肿瘤，称为肾脏 血管肌脂肪瘤(AML)，可导致肾功能不全和自发性危及生命的出血。这个 AML的主要治疗方法是依维莫司，一种雷帕霉素类似的激酶mTOR抑制剂，具有细胞抑制活性， 只能部分缩小肿瘤的大小。随着时间的推移，AML变得稳定，肿瘤的再生长通常发生在 治疗因副作用而中断。因此，迫切需要阐明其发病机制。 肿瘤抗药性为开发更有效的治疗方法提供了可能。 在过去的20多年里，对急性髓细胞白血病进行实验性总结的努力都失败了，排除了对急性髓细胞白血病的研究 生物学。为了解决这个问题，我们使用了基因工程患者来源的诱导多能干细胞。 细胞(IPSCs)产生AML类器官。携带双等位基因失活的IPSCs产生的有机化合物 TSC2基因座的突变(即TSC2-/-)真实地概括了人类的关键解剖学和分子特征 肾脏AML(Hernandez Jor等人报道)。纳特社区。2021年11月11日；12(1)：6496)。其中一些功能 包括共表达平滑肌和黑素细胞标志物的肌黑素样细胞的存在， 与肾脏AML共有的信号通路的转录激活。TSC2-/-AML的移植 免疫缺陷啮齿动物肾脏中的有机类物质导致完全血管化的人AML异种移植 机理研究和体内药物测试。使用这些新工具，我们发现了潜在的 P21CIP1和bcl2凋亡调节剂抑制AML细胞耐药机制的研究 由野猪引起的死亡。我们的体内实验也表明，通过纳米载体传递药物可能 提高抗肿瘤治疗的效果，同时减少对其他组织的不良影响。这样做的目的是 建议阐明p21CIP1和bcl-2蛋白驱动的抗凋亡机制，以促进肿瘤的发展 结合bcl2蛋白抑制剂药物和拉帕洛格的新的抗肿瘤疗法，可以联合使用 组织靶向纳米粒子。我们的长期目标是为急性髓细胞白血病设计新的治疗方法，提高疗效 和专一性。中心假说是p21CIP1和bcl-2所驱动的抗凋亡机制 凋亡抑制物可维持AML细胞存活，促进肿瘤对雷帕洛格治疗的耐药性。我们的三个 目的：目的1：探讨肾性AML中p21CIP1介导的肿瘤耐药的抗凋亡机制； 目的2：阐明IGFBP2在稳定p21CIP1促进AML细胞存活中的作用；目的3：研究IGFBP2在AML细胞存活中的作用 BCL-2蛋白通过药物阻断BH3结构域相互作用对AML细胞存活的影响 总的来说，这些研究将为急性髓系白血病的发病机制提供亟需的洞察，并将评估 Bcl2抑制剂单独或联合雷帕洛格治疗急性髓系白血病靶向纳米粒的疗效。

Summary A majority of patients with Tuberous Sclerosis Complex (TSC) develop benign kidney tumors known as renal angiomyolipoma (AML) that can cause renal insufficiency and spontaneous life-threatening hemorrhages. The main therapy for AML is everolimus, a rapamycin analog inhibitor of the kinase mTOR with cytostatic activity that only partially reduces tumor size. AMLs become stable over time, and tumor re-growth is often occurs after treatment is interrupted due to side effects. Therefore, there is an urgent need to elucidate mechanisms of tumor resistance for the development of more efficacious therapies. Efforts to recapitulate AML experimentally have failed for the past 20+ years, precluding the study of AML biology. To address this problem, we have used genetically engineered patient-derived induced pluripotent stem cells (iPSCs) to generate AML organoids. Organoids generated from iPSCs carrying biallelic inactivating mutations in the TSC2 locus (i.e. TSC2-/-) faithfully recapitulated key anatomical and molecular features of human kidney AML (reported in Hernandez JOR et al. Nat Commun. 2021 Nov 11;12(1):6496). Some of those features included the presence of myomelanocytic AML-like cells co-expressing smooth muscle and melanocyte markers, and the transcriptional activation of signaling pathways shared with kidney AML. Transplantation of TSC2-/- AML organoids into the kidneys of immunodeficient rodents resulted in fully vascularized human AML xenografts for mechanistic studies and for drug testing testing in vivo. Using these novel tools we identified potential mechanisms of tumor resistance driven by p21CIP1 and by BCL-2 apoptosis modulators, preventing AML cell death induced by rapalogs. Our in vivo experiments also indicated that drug delivery via nanocarriers may increase the efficacy of anti-tumor therapy while reducing undesired effects in other tissues. The objective of this proposal is to elucidate anti-apoptotic mechanisms driven by p21CIP1 and BCL-2 proteins for the development of novel anti-tumor therapies combining BCL-2 protein inhibitor drugs and rapalogs, that can be co-delivered using tissue-targeting nanoparticles. Our long-term goal is to design new therapies for AML with increased efficacy and specificity. The central hypothesis is that antiapoptotic mechanisms driven by p21CIP1 and BCL-2 apoptosis inhibitors sustain AML cell survival promoting tumor resistance to rapalog therapy. Our three aims are: Aim 1: To investigate anti-apoptotic mechanisms of tumor resistance driven by p21CIP1 in renal AML; Aim 2: To elucidate the role of IGFBP2 in stabilizing p21CIP1 promoting AML cell survival; Aim 3: To study the contribution of BCL-2 proteins to AML cell survival through pharmacologic blockage of BH3 domain interaction. Collectively, these studies will provide much needed insight into the mechanisms of AML and will assess the efficacy of BCL-2 inhibitor therapy alone or in combination with rapalogs in AML-targeting nanoparticles.