Targeting Glutaminolysis Shows Efficacy in Both Prednisolone-Sensitive and in Metabolically Rewired Prednisolone-Resistant B-Cell Childhood Acute Lymphoblastic Leukaemia Cells. Targeting Glutaminolysis Shows Efficacy in Both Prednisolone-Sensitive and in Metabolically Rewired Prednisolone-Resistant B-Cell Childhood Acute Lymphoblastic Leukaemia Cells

In spite of the considerable progress in risk stratification and therapeutic regimens in childhood acute lymphoblastic leukaemia (cALL), which has led to cure rates of above 90%, prognosis for patients with relapsed disease remains poor. The main cause of therapy failure is drug resistance, most commonly to glucocorticoids (GCs). While alterations of cell metabolism in cALL are considered a hallmark of this malignancy as well, the molecular differences between prednisolone sensitive and resistant lymphoblasts are not well-studied, thereby precluding the development of novel and targeted therapies. Therefore, the aim of this work was to investigate the biology of matched pairs of cell lines where GCs are effective and such with acquired lack of response to prednisolone. In order to address this, we took advantage of the molecular characterisation of an in vitro model of GC resistance we had previously developed. An integrated transcriptomic and metabolomic analysis revealed alterations in oxidative phosphorylation, glycolysis, amino acid, pyruvate and nucleotide biosynthesis, as well as activation of mTORC1 and MYC signaling, which are also known to control cell metabolism. In attempt to explore the potential therapeutic effect of inhibiting one of the hits from our analysis, we targeted the glutamine-glutamate-α-ketoglutarate axis by three different strategies, all of which impaired mitochondrial respiration and ATP production and induced apoptosis in both GC-sensitive and resistant cell lines. In summary, we report that prednisolone resistance may be accompanied by considerable rewiring of transcriptional and biosynthesis programs. We suggest that targeting glutamine metabolism presents a novel therapeutic approach in cALL. Overall design: Comparing biological triplicates of prednisolone sensitive (Sup-B15) and resistant (Sup-PR) childhood acute lymphoblastic leukaemia cells.

尽管儿童急性淋巴细胞白血病（childhood acute lymphoblastic leukaemia, cALL）的风险分层与治疗方案已取得显著进展，治愈率已突破90%，但复发患者的预后仍不容乐观。治疗失败的主要诱因为药物耐药，其中以糖皮质激素（glucocorticoids, GCs）耐药最为常见。尽管儿童急性淋巴细胞白血病的细胞代谢异常被视为该恶性肿瘤的标志性特征之一，但泼尼松（prednisolone）敏感与耐药淋巴母细胞间的分子差异尚未得到充分解析，这一现状阻碍了新型靶向治疗手段的研发。因此本研究旨在探究两类匹配细胞系的生物学特性：一类为糖皮质激素敏感型，另一类为获得性泼尼松耐药型。为此，我们利用了此前构建的糖皮质激素耐药体外模型的分子表征数据。整合转录组与代谢组分析结果显示，耐药细胞存在氧化磷酸化、糖酵解、氨基酸代谢、丙酮酸代谢及核苷酸生物合成通路的异常，同时伴随mTORC1与MYC信号通路的激活——而这两条通路同样被证实可调控细胞代谢。为探究本研究分析中筛选得到的候选靶点的干预效果，我们通过三种不同策略靶向谷氨酰胺-谷氨酸-α-酮戊二酸轴，结果显示该干预手段可同时损伤糖皮质激素敏感与耐药细胞系的线粒体呼吸与ATP生成，并诱导细胞凋亡。综上，本研究发现泼尼松耐药可能伴随转录程序与生物合成程序的显著重编程。我们提出，靶向谷氨酰胺代谢可为儿童急性淋巴细胞白血病提供全新的治疗策略。总体实验设计：比较泼尼松敏感型（Sup-B15）与耐药型（Sup-PR）儿童急性淋巴细胞白血病细胞的3次生物学重复样本。