Effect of tumor cell glutamine metabolism on anti-tumor immunity in TNBC

项目摘要/摘要 乳腺癌是西方女性最常见的恶性肿瘤。虽然佐剂和 分子靶向治疗显著改善某些分子亚型患者的存活率 在乳腺癌中，三阴性/基底细胞样乳腺癌(TNBC)的预后仍然严峻， 由于缺乏致癌驱动因素的识别。在寻找癌症易损性方面， 发现TNBC特别依赖谷氨酰胺代谢，这可能是由于上调- 谷氨酰胺转运体ASCT2/SLC1A5和谷氨酰胺酶GLS的调节 谷氨酰胺消费的限速步骤。尽管人们对谷氨酰胺分解感兴趣 在TNBC中，谷氨酰胺代谢的全局抑制将如何影响TBC的免疫细胞尚不清楚 肿瘤微环境，特别是考虑到快速增殖的肿瘤浸润性 淋巴细胞(TIL)需要谷氨酰胺分解来为细胞生长提供大分子。 具体地说，肿瘤细胞和TIL之间对谷氨酰胺的竞争还没有 到目前为止已经研究过了，但很可能对抗肿瘤免疫很重要。 我们已经生成了初步数据，提供了GLS基因敲除的证据，特别是在 肿瘤细胞增加肿瘤间质液中的谷氨酰胺浓度并增强 细胞毒CD8 T淋巴细胞活性。上述作用在免疫缺陷患者中被取消。 这表明获得性免疫起着至关重要的作用。此外，药理学 抑制谷氨酰胺转运体ASCT2选择性靶向肿瘤细胞 TIL函数。基于这些发现，我们假设(1)肿瘤细胞在竞争中胜过TIL 谷氨酰胺在抑制抗肿瘤的同时维持其增殖计划 免疫反应，以及(2)选择性靶向肿瘤细胞的谷氨酰胺代谢增强 抗肿瘤免疫。为了验证这些假设，我们将首先测试谷氨酰胺竞争 肿瘤细胞和TIL以及这种竞争如何影响肿瘤的生长、转移和抗肿瘤 免疫反应(目标1)。我们还将具体定义GLS丢失的代谢变化 MALDI显像团原位检测肿瘤细胞对T细胞募集和活化的影响 光谱分析(目标2)。最后，我们将评估谷氨酰胺的体内药理靶向性。 转运蛋白和谷氨酰胺酶治疗TNBC(目标3)。该项目的成功将说明 肿瘤之间是否存在对谷氨酰胺的代谢竞争是一个长期存在的问题 细胞和浸润性淋巴细胞，并利用这些知识开发新的治疗方法 谷氨酰胺成瘾癌症的治疗策略。

PROJECT SUMMARY/ ABSTRACT Breast cancer is the most common malignancy among western women. Although adjuvant and molecularly targeted therapies significantly improve patient survival in some molecular subtypes of breast cancer, the prognosis of triple-negative/basal-like breast cancer (TNBC) remains grim, due to lack of identification of oncogenic drivers. In searching of cancer vulnerability, it was discovered that TNBC is especially dependent on glutamine metabolism, likely due to up- regulation of the glutamine transporter, ASCT2/SLC1A5, and glutaminase, GLS, representing the rate-limiting steps in glutamine consumption. Despite the interest in targeting glutaminolysis in TNBC, it is unclear how global inhibition of glutamine metabolism will affect immune cells in the tumor microenvironment, particularly given that rapidly proliferating tumor infiltrating lymphocytes (TILs) require glutaminolysis to supply macromolecules for cell growth. Specifically, the competition between tumor cells and TILs for glutamine has not been investigated thus far, but is likely to be important for anti-tumor immunity. We have generated preliminary data providing evidence that knockout of GLS specifically in tumor cells increases glutamine concentration in the tumor interstitial fluid and enhances cytotoxic CD8 T lymphocyte activities. The above effects are abrogated in immune-deficient mice, suggesting that adaptive immunity plays a critical role. In addition, pharmacologic inhibition of the glutamine transporter, ASCT2, selectively targeting tumor cells while enhancing TIL function. Based on these findings, we hypothesize that (1) tumor cells outcompete TILs for glutamine to sustain their proliferative programs while simultaneously suppressing antitumor immune response, and (2) selectively targeting glutamine metabolism in tumor cells enhances antitumor immunity. To test these hypotheses, we will first test glutamine competition between tumor cells and TILs and how this competition affects tumor growth, metastasis, and anti-tumor immune responses (Aim 1). We will also define how metabolic changes in GLS loss specifically in tumor cells impact T cell recruitment and activation in situ by MALDI-imaging mass spectrometry (Aim 2). Finally, we will evaluate in vivo pharmacological targeting of glutamine transporter and glutaminase for treating TNBC (Aim 3). The success of the project will elucidate a long-standing issue whether there is a metabolic competition for glutamine between tumor cells and infiltrating lymphocytes, and leverage the knowledge for developing new therapeutic strategies for treatment of glutamine-addicted cancer.