BLRD Merit Review Research Career Scientist (RCS) Award (IK6)

项目摘要/摘要 我的研究项目的目标是阐明肿瘤血管生成的分子机制， 癌症新陈代谢和抗肿瘤免疫，并将我们的发现转化为 癌症治疗。在此RCS获奖期内，我将继续：(1)针对mTOR信令 肺癌亚型中对当前靶向治疗无效的途径。我们 先前证明了mTOR是“旁路”激酶下游的公共信令节点， 靶向mTOR在多种耐药环境中是一种很有前途的方法。里克托 MTORC2是一种独特的成分，在大约13%的肺癌中通常被扩增。 虽然mTOR激酶抑制剂同时抑制mTORC1和mTORC2，但选择性抑制mTORC2 具有不干扰依赖于mTORC1的负反馈环路和mTORC1- 介导抑制突变型RAS肿瘤的巨噬细胞吞噬作用。我们发现了点突变 破坏mLST8-mTOR结合特别地破坏mTORC2的稳定性而不影响mTORC1， 指出了一种可行的抑制剂设计策略。我们将继续严格了解 MTORC2基因在靶向治疗无效的肺癌亚型中的作用 治疗，并进一步研究是否可以使用靶向mLST8来选择性地抑制mTORC2。 (2)确定小剂量mTORC1抑制剂在肿瘤正常化中的治疗潜力 血管和募集抗肿瘤淋巴细胞。我的实验室开创性地研究了mTORC1和 肿瘤血管中mTORC2的表达。我们发现淋巴细胞浸润显著增加。 内皮特异性Raptor缺失(mTORC1失活)的肿瘤。虽然是标准的 高剂量的Rapalog可以抑制免疫功能，我们发现一种低、相对免疫的- 节省剂量的维罗莫司(RAD001)，一种mTORC1抑制剂，归一化肿瘤血管和 增强的肿瘤浸润性淋巴细胞。临床前动物研究的有希望的结果将设定 启动临床试验以改进免疫疗法的阶段。(3)EphA2 RTK在谷氨酰胺中的作用 代谢与抗肿瘤免疫。我们的意外发现，ePhin-A1/EphA2 信号轴调节癌细胞中的脂质堆积使我们系统地研究了 EPhin-A1/EphA2在肿瘤代谢中的作用全球新陈代谢图谱显示， 谷氨酰胺分解增加，这是一种关键的代谢途径，产生脂肪生成的中间产物， 在EPhin-A1基因敲除或EphA2过表达肿瘤细胞中。对机制的研究导致了我们 发现EphA2 RTK通过上调谷氨酰胺促进谷氨酰胺代谢 转运蛋白ASCT2(由SLC1A5编码)和谷氨酰胺酶GLS通过转录激活 共激活剂YAP和TAZ。然而，敲除肿瘤细胞中的GLS可以增强抗肿瘤免疫。 我们将继续剖析肿瘤细胞特异性缺失的GLS对 免疫细胞。此外，我们将测试和比较谷氨酰胺通路抑制剂(V-9302)或 谷氨酰胺酶(CB-839)对其抑制肿瘤细胞和抗肿瘤淋巴细胞作用的比较。 意义：这些项目的成功将对退伍军人具有巨大的翻译潜力 通过确定对肺癌耐药的亚型的新治疗靶点 目前的靶向治疗，以及通过肿瘤血液正常化加强免疫治疗 血管和肿瘤代谢的抑制。

Project Summary/Abstract The goals of my research programs are to elucidate molecular mechanisms of tumor angiogenesis, cancer metabolism, and anti-tumor immunity, and to translate our discoveries towards improved cancer therapy. During this RCS award period I will continue to: (1) Targeting mTOR signaling pathways in lung cancer subtypes that are refractory to current targeted therapies. We demonstrated previously that mTOR is a common signaling node downstream of “bypass” kinases, and targeting mTOR represents a promising approach in multiple settings of drug resistance. Rictor, a unique components of mTORC2, is commonly amplified in approximately 13% of lung cancer. While mTOR kinase inhibitors inhibit both mTORC1 and mTORC2, selective inhibition of mTORC2 has the advantage of not perturbing the mTORC1-dependent negative feedback loops and mTORC1- mediated inhibition of macropinocytosis in mutant Ras tumors. We found that point mutations disrupting mLST8-mTOR binding specifically destabilize mTORC2 without affecting mTORC1, pointing to a viable strategy for inhibitor design. We will continue to gain a rigorous understanding of the contribution of mTORC2 to subtypes of lung cancer that are currently refractory to targeted therapies, and to further investigate if targeting mLST8 can be used to selectively inhibit mTORC2. (2) Determine the therapeutic potential of low dose mTORC1 inhibitors in normalizing tumor blood vessels and recruiting anti-tumor lymphocytes. My lab pioneered studies of mTORC1 and mTORC2 in tumor blood vessels. We discovered that lymphocyte infiltration increased significantly in the tumors with endothelial-specific deletion of Raptor (mTORC1 inactivation). Although standard high doses of Rapalogs can inhibit immune function, we discovered that a low, relatively immune- sparing dose of everolimus (RAD001), an mTORC1 inhibitor, normalized tumor blood vessels and enhanced tumor infiltrating lymphocytes. Promising results of pre-clinical animal studies will set the stage for initiating a clinical trial to improve immunotherapy. (3) Role of EphA2 RTK in glutamine metabolism and anti-tumor immunity. Our serendipitous discovery that the ephrin-A1/EphA2 signaling axis regulates lipid accumulation in cancer cells has led us systematically to investigate the role of ephrin-A1/EphA2 in tumor metabolism. Global metabolic profiling revealed a significant increase in glutaminolysis, a critical metabolic pathway that generates intermediates for lipogenesis, in ephrin-A1 knockout or EphA2 overexpressing tumor cells. Investigation of mechanisms led us to discover that EphA2 RTK promotes glutamine metabolism by upregulation of the glutamine transporter ASCT2 (encoded by SLC1A5) and glutaminase GLS via activation of the transcription coactivators YAP and TAZ. Knockout of GLS in tumor cells, however, increases anti-tumor immunity. We will continue to dissect the effects and mechanisms by which tumor cell-specific loss of GLS on immune cells. Further, we will test and compare inhibitors of glutamine access (V-9302) or glutaminase (CB-839) on their effects in inhibiting tumor cells versus anti-tumor lymphocytes. Significance: Success of these projects will have significant translational potential for the veteran populations, by identifying new therapeutic targets for lung cancer subtypes that are refractory to current targeted therapies, and by enhancing immunotherapies via normalization of tumor blood vessels and inhibition of tumor metabolism.