Chatterjee Megha, Gu Franklin, Samanta Susmita, Rasaily Uttam, Thota Sai Manohar, Varghese Dana, Qiu Yunping, Fordwuo Lynette Ewura Esi, Villanueva Hugo, McKenna Mary Kathryn, Park Jun Hyoung, Zhang Weijie, Tian Lin, Yu Liqun, Piyarathna Badrajee, Gao Yang, Simons Brian Wesley, Jung Sung Yun, Karanam Balasubramanyam, Putluri Vasanta, Chandandeep Nagi, Mohamed Nada, Asirvatham Jaya Ruth, Jebakumar Deborah, Rao Arundati, Gutierrez Carolina, Omilian Angela R, Morrison Carl, Das Gokul M, Ambrosone Christine, Seeley Erin H, Kaipparettu Benny Abraham, Kurland Irwin J, Putluri Nagireddy, Elkhanany Ahmed, Davis Andrew A, Zhu Qian, Zhang Xiang H-F, Sreekumar Arun
Department of Molecular and Cell Biology, Baylor College of Medicine, Houston, TX 77030, USA.
Verna & Marrs McLean Dept. of Biochemistry & Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA.
bioRxiv. 2026 Jan 30:2026.01.28.702389. doi: 10.64898/2026.01.28.702389.
Compared to other subtypes of breast cancer, triple-negative breast cancers (TNBC) have fewer treatment options and exhibit a worse prognosis. Through integrated transcriptomic, metabolomic, immunohistochemical, spatial, and clinical analyses, we identify the mitochondrial enzyme, α-aminoadipate aminotransferase (AADAT) as a previously unrecognized metabolic immune checkpoint in TNBC. mRNA and protein were significantly upregulated in human TNBC, and high AADAT expression was associated with reduced intra-tumoral CD8 T-cell density and inferior survival. Genetic silencing of in orthotopic murine TNBC models curtailed primary tumor growth and distant metastasis in a CD8 T-cell-dependent manner, enhanced effector T-cell activation, and sensitized tumors to dual PD-1/CTLA-4 blockade. Mechanistically, unbiased metabolomics showed increased malate levels after knockdown. Additionally, 4-hydroxyphenylpyruvate, an essential precursor for coenzyme Q(CoQ) biosynthesis, decreased following knockdown, suggesting an impaired mitochondrial electron transport chain. CoQ supplementation restored metabolic balance and reversed malate accumulation caused by knockdown, indicating that AADAT helps maintain CoQ-supported redox homeostasis, thereby preventing malate buildup and export. Notably, malate addition directly boosted CD8 T-cell oxidative metabolism, increased the NAD/NADH ratio and reactive oxygen species, and augmented TNF-α and IFN-γ production. In vivo, malate supplementation in drinking water phenocopied AADAT knockdown, restored the response to paclitaxel plus anti-PD-1 therapy in multiple independent syngeneic TNBC models with de novo or acquired resistance to immunotherapy, reduced tumor burden, and prolonged survival. In patient cohorts, higher spatially clustered intra-tumoral malate is associated with co-localization of functional CD8 T cells, decreased exhausted T-cell neighborhoods, and superior post-chemotherapy outcomes. These data position AADAT as a central metabolic orchestrator of immune escape in TNBC and nominate oral malate as a readily translatable adjuvant to reverse chemo-immunotherapy resistance in TNBC.
与其他亚型的乳腺癌相比，三阴性乳腺癌（TNBC）的治疗选择较少，预后较差。通过整合转录组学、代谢组学、免疫组织化学、空间分析和临床分析，我们确定线粒体酶α-氨基己二酸转氨酶（AADAT）是TNBC中一种先前未被认识的代谢免疫检查点。AADAT的mRNA和蛋白在人类TNBC中显著上调，高AADAT表达与肿瘤内CD8 T细胞密度降低和较差的生存率相关。在原位小鼠TNBC模型中，AADAT基因沉默以CD8 T细胞依赖的方式抑制原发性肿瘤生长和远处转移，增强效应T细胞活化，并使肿瘤对双重PD-1/CTLA-4阻断敏感。从机制上讲，非靶向代谢组学显示AADAT基因敲低后苹果酸水平升高。此外，辅酶Q（CoQ）生物合成的必需前体4-羟基苯丙酮酸在AADAT基因敲低后减少，表明线粒体电子传递链受损。补充CoQ可恢复代谢平衡，并逆转AADAT基因敲低导致的苹果酸积累，表明AADAT有助于维持CoQ支持的氧化还原稳态，从而防止苹果酸积累和输出。值得注意的是，添加苹果酸直接促进CD8 T细胞的氧化代谢，增加NAD/NADH比值和活性氧，并增强TNF-α和IFN-γ的产生。在体内，饮用水中补充苹果酸模拟了AADAT基因敲低的效果，恢复了多个对免疫疗法具有原发性或获得性耐药性的独立同基因TNBC模型对紫杉醇加抗PD-1疗法的反应，减轻了肿瘤负担，并延长了生存期。在患者队列中，肿瘤内空间聚集的苹果酸水平较高与功能性CD8 T细胞的共定位、耗尽T细胞区域减少以及化疗后更好的结果相关。这些数据将AADAT定位为TNBC免疫逃逸的核心代谢协调因子，并将口服苹果酸提名为一种易于转化的佐剂，以逆转TNBC中的化学免疫疗法耐药性。
