Ribo-lite, a method defining paired transcriptome (RNA-seq) and translatome (Ribo-seq) at low input on AML cells from mice treated with 5+3 or vehicle and fed standard amino acids (AA) or branched chain amino acid (BCAA) free diets.

Acute Myeloid Leukemia (AML) commonly relapses after initial chemotherapy response. We assessed metabolic adaptations in chemoresistant cells in vivo before overt relapse, identifying altered branched-chain amino acid (BCAA) levels in patient-derived xenografts (PDX) and immunophenotypically identified leukemia stem cells from AML patients. Notably, this was associated with increased BCAA transporter expression with low BCAA catabolism. Restricting of BCAAs further reduced chemoresistant AML cells but relapse still occurred. Among the persisting cells we found an unexpected increase in protein production. This was accompanied by elevated translation of 2-oxoglutarate-and-iron-dependent oxygenase 1 (OGFOD1), a known ribosomal dioxygenase that adjusts the fidelity of tRNA anticodon pairing with coding mRNA1–3 and upregulates protein synthesis in AML driving disease aggressiveness. Inhibiting OGFOD1 impaired translation processing, decreased protein synthesis and improved animal survival even with chemoresistant AML through regulation of protein synthesis. Leukemic cells can therefore persist despite the stress of chemotherapy and nutrient deprivation through adaptive control of translation while sparing normal hematopoiesis. Targeting OGFOD1 may offer a distinctive, translation modifying means of reducing the chemopersisting cells that drive relapse. Overall design: Mice were fed branched chain amino acid (BCAA) free or standard amino acid (AA) diet to determine effects in gene expression and translated mRNAs using Riboseq, following 5+3 (cytarabine and doxorubicin) chemotherapy

急性髓系白血病（Acute Myeloid Leukemia, AML）在初次化疗应答后常出现复发。本研究在显性复发前，于体内评估了化疗耐药细胞的代谢适应特征，并在患者来源异种移植瘤（patient-derived xenografts, PDX）以及从AML患者体内免疫表型鉴定得到的白血病干细胞中，检测到支链氨基酸（branched-chain amino acid, BCAA）水平发生异常改变。值得注意的是，该异常改变与支链氨基酸转运蛋白表达上调、支链氨基酸分解代谢减弱密切相关。对支链氨基酸进行饮食限制可进一步减少化疗耐药的AML细胞，但肿瘤复发仍会发生。在存活下来的耐药细胞中，我们意外发现蛋白质合成水平显著上调，该现象伴随2-氧代戊二酸和铁依赖性加氧酶1（2-oxoglutarate-and-iron-dependent oxygenase 1, OGFOD1）的翻译水平升高——该蛋白是一种已被证实的核糖体加氧酶，可调节tRNA反密码子与编码mRNA的配对保真度[1-3]，并在AML中通过上调蛋白质合成促进疾病侵袭性。抑制OGFOD1可损害翻译过程、降低蛋白质合成水平，即使在存在化疗耐药AML的小鼠模型中，也可通过调控蛋白质合成改善动物生存率。因此，白血病细胞可通过适应性调控翻译过程，在化疗应激与营养剥夺的双重压力下持续存活，同时不会损害正常造血功能。靶向OGFOD1或许可提供一种独特的翻译修饰策略，以减少驱动肿瘤复发的化疗耐受持续存活细胞。实验整体设计：将小鼠分为两组，分别喂食无支链氨基酸饮食与标准氨基酸饮食，在接受5+3化疗方案（阿糖胞苷联合多柔比星）治疗后，利用核糖体测序（Riboseq）检测两组小鼠的基因表达与翻译中mRNA的变化情况。