Amino acid transporter SLC38A5 as a drug target for TNBC: Evaluation with genetic and pharmacologic approaches

氨基酸转运蛋白 SLC38A5 作为 TNBC 的药物靶点：用遗传和药理学方法进行评估

• 批准号: 10576760
• 负责人: VADIVEL GANAPATHY
• 金额: $ 21.46万
• 依托单位: TEXAS TECH UNIVERSITY HEALTH SCIS CENTER
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-12-16 至 2024-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10576760
• 关键词: Amino Acid Transporter; Amino Acids; Anthelmintics; Attention; Automobile Driving; Biochemical Pathway; Breast Cancer Cell; Breast Cancer cell line; Cancer Cell Growth; Carbon; Cell Line; Cell Proliferation; Cells; Clinical Trials; Coupled; DNA Methylation; Data; Drug Targeting; Epigenetic Process; Essential Amino Acids; Estrogen receptor positive; Evaluation; FDA approved; Future; Genetic; Genetic Transcription; Glutamine; Glycine; Goals; Growth; Growth and Development function; Human; In Vitro; Knockout Mice; Logic; Lysine; Malignant Neoplasms; Mammary Neoplasms; Mediating; Metabolic Pathway; Metabolism; Methionine; Methylation; Molecular; Mus; Normal Cell; Nude Mice; Pathway interactions; Pharmaceutical Preparations; Pre-Clinical Model; Proliferating; Protein Biosynthesis; Purines; Pyrimidine; Role; Serine; Specificity; System; Testing; Therapeutic; Up-Regulation; WNT Signaling Pathway; Xenograft procedure; addiction; amino acid metabolism; anti-cancer; cancer cell; cancer therapy; carcinogenesis; chemotherapy; drug repurposing; druggable target; in vivo; inhibitor; malignant breast neoplasm; meter; mouse model; neoplastic cell; novel; nucleotide metabolism; patient derived xenograft model; pharmacologic; pre-clinical; small hairpin RNA; targeted treatment; tool; triple-negative invasive breast carcinoma; tumor; tumor growth; uptake

Amino acid metabolism in tumor cells is very different from that in normal cells. The tumor-specific metabolic pathway “glutaminolysis” focuses on glutamine. Recently, another fundamental pathway was discovered for cancer cell proliferation: the “serine-glycine-methionine-one-carbon” pathway. Tumor cells upregulate specific amino acid transporters to satisfy their increased need for glutamine, glycine, serine, and methionine to fuel these pathways. Blocking the entry of these amino acids into tumor cells has potential for cancer therapy. Recently, we provided evidence for this approach by identifying SLC6A14, an amino acid transporter with broad specificity, that is induced in ER-positive (ER+) breast cancer (BC) and by showing that blockade of this transporter reduces ER+ BC. But, SLC6A14 is not expressed in triple-negative breast cancer (TNBC). TNBC must rely upon a different transporter as a “fix” to its “addiction” to glutamine/serine/glycine/methionine. We have now identified this transporter as SLC38A5, a Na+-coupled uptake system exclusively for these four amino acids. SLC38A5 is upregulated in TNBC by WNT/DVL1. Furthermore, SLC38A5 promotes macropinocytosis, a unique feature essential for tumor growth. Here we will show that SLC38A5 drives the glutamine- and one-carbon metabolic pathways in TNBC and evaluate in preclinical models the potential of this transporter as a logical drug target for TNBC. We have identified the FDA-approved drug niclosamide as a potent inhibitor of SLC38A5 function and expression. This drug can be used pharmacologically to interrogate the role of SLC38A5 in TNBC. We also have Slc38a5-null mice as a genetic tool for these studies. Hypothesis: SLC38A5 drives the glutamine-dependent and one-carbon metabolic pathways in TNBC; as such, pharmacologic inhibition or genetic deletion of SLC38A5 will block TNBC. We will test this hypothesis with two aims: (Aim 1) Demonstrate that SLC38A5 is obligatory for glutaminolysis and one-carbon metabolic pathway to promote cell proliferation and remodeling of the epigenetic landscape in TNBC cells and elucidate the molecular mechanisms by which WNT/DVL1 induces SLC38A5 in these cells. Here we will use classical as well as patient-derived xenograft TNBC cell lines. (Aim 2) Evaluate the impact of SLC38A5 loss on tumor growth in mouse models of TNBC using Slc38a5-/- mice and niclosamide as a proof-of-concept for future use of this transporter as a selective drug target for TNBC. Here we will use xenografts of human TNBC cell lines in nude mice to evaluate the anticancer efficacy of niclosamide, and also compare the development/growth of spontaneous mammary tumors in a TNBC mouse model [C3(1)-TAg mouse] with and without niclosamide treatment (pharmacologic) and on Slc38a5+/+ and Slc38a5-/- backgrounds (genetic). Impact: With no known targeted therapy, chemotherapy is the only option for TNBC. Establishment of SLC38A5 as a drug target would aid future use of pharmacologics (e.g., niclosamide) to block its expression and transport function as a targeted therapy for TNBC, either as a monotherapy or in combination with standard chemotherapeutics.

肿瘤细胞的氨基酸代谢与正常细胞有很大不同。肿瘤特异性代谢 途径“谷氨酰胺分解”集中于谷氨酰胺。最近，另一种基本途径被发现， 癌细胞增殖：“丝氨酸-甘氨酸-甲硫氨酸-一碳”途径。肿瘤细胞上调 特异性氨基酸转运蛋白，以满足其对谷氨酰胺、甘氨酸、丝氨酸和甲硫氨酸增加的需求 为这些通路提供燃料。阻断这些氨基酸进入肿瘤细胞有致癌的可能 疗法最近，我们通过鉴定氨基酸转运蛋白SLC 6A 14为这种方法提供了证据， 具有广泛的特异性，在ER阳性（ER+）乳腺癌（BC）中诱导，并通过显示阻断 减少ER+ BC。但是，SLC 6A 14在三阴性乳腺癌（TNBC）中不表达。 TNBC必须依赖于不同的转运蛋白作为其对谷氨酰胺/丝氨酸/甘氨酸/甲硫氨酸的“成瘾”的“修复”。 我们现在已经确定这种转运蛋白为SLC 38 A5，这是一种专门针对这四种蛋白的Na+偶联摄取系统。 个氨基酸SLC 38 A5在TNBC中被WNT/DVL 1上调。此外，SLC 38 A5促进 巨胞饮作用是肿瘤生长所必需的独特特征。在这里，我们将展示SLC 38 A5驱动 谷氨酰胺和一碳代谢途径，并在临床前模型中评估 这种转运蛋白作为TNBC的合理药物靶点。我们已经确定了FDA批准的药物氯硝柳胺， SLC 38 A5功能和表达的有效抑制剂。这种药可以用来审问 SLC 38 A5在TNBC中的作用。我们也有Slc 38 a5-null小鼠作为这些研究的遗传工具。 假设：SLC 38 A5驱动TNBC中的谷氨酰胺依赖性和一碳代谢途径; 这种SLC 38 A5药理学抑制或基因缺失将阻断TNBC。我们将检验这一假设 有两个目的：（目的1）证明SLC 38 A5是必不可少的β-氨基分解和一碳代谢 在TNBC细胞中促进细胞增殖和表观遗传景观重塑的途径，并阐明 WNT/DVL 1在这些细胞中诱导SLC 38 A5的分子机制。在这里，我们将使用古典 以及患者来源的异种移植TNBC细胞系。(Aim 2）评估SLC 38 A5缺失对肿瘤的影响 使用Slc 38 a5-/-小鼠和氯硝柳胺作为未来使用的概念验证的TNBC小鼠模型中的生长 作为TNBC的选择性药物靶点。在这里，我们将使用人类TNBC细胞系的异种移植物 在裸鼠中评估氯硝柳胺的抗癌功效，并且还比较在裸鼠中的发育/生长。 TNBC小鼠模型[C3（1）-TAg小鼠]中存在和不存在氯硝柳胺的自发性乳腺肿瘤 治疗（药理学）和Slc 38 a5 +/+和Slc 38 a5-/-背景（遗传学）。影响：未知 作为靶向治疗，化疗是TNBC的唯一选择。SLC 38 A5作为药物靶点的建立 将有助于药理学的未来使用（例如，氯硝柳胺）以阻止其表达和转运功能 作为单一疗法或与标准化疗剂组合，用于TNBC的靶向治疗。