Targeting the Metabolic Regulator SIRT5 in Acute Myeloid Leukemia

R01CA254354支持的针对急性髓系白血病(AML)代谢调节基因SIRT5的研究 我们已经报道了赖氨酸脱酰酶SIRT5是AML中的一个可药物代谢靶点(Yanet al.血样 癌症迪斯科。2021年；2(3)：266-287)。我们新的初步数据表明，SIRT5的作用可能扩展到 急性淋巴细胞白血病(ALL)，包括复发/难治(R/R)ALL。ALL是最常见的癌症 在孩子们身上。在9岁达到高峰后，发病率开始下降，但在30岁后稳步上升。多数 所有病例均来源于B淋巴样前体细胞(B-ALL)，但15%来自T细胞(T-ALL)。咄咄逼人 化疗极大地改善了儿童的预后，但往往以长期功能障碍为代价 减损。相比之下，成年人的长期存活率为50%，这反映了高危基因类型和更高的治疗水平。 相关死亡率。针对B细胞抗原的嵌合抗原受体(CAR)T细胞在以下亚群中有效 R/R B-ALL，但由于靶抗原丢失，经常会产生耐药性。RR T-ALL的抢救疗法是 所有存活，并减少幸存者的功能损害。虽然ALL在基因上是不同的，但大多数情况下 在B细胞或T细胞前体水平上表现出分化障碍。有证据表明，能源限制 在B细胞前体细胞经历体细胞过度突变时，为恶性转化创造了障碍 抗体多样化。B系转录因子的突变失活使这种代谢刹车失效 并允许bcr-abl1等癌基因的恶性转化。类似的机制也可能在T T细胞受体多样化过程中的细胞前体。我们发现SIRT5是急性髓系白血病的关键调控因子 新陈代谢和已报道的代谢重新编程和恶性转化之间的相互作用， 我们问SIRT5依赖是否延伸到所有人。我们发现许多所有的细胞系，包括耐药的 对SIRT5基因敲除(KD)很敏感，这促使我们假设SIRT5是维持 所有的新陈代谢。我们的目标是：(1)确定SIRT5中断对所有细胞系和原代细胞的影响 并与全球能量新陈代谢的变化相关。我们将使用shRNA、CRISPR/Cas9和Small 破坏所有细胞中SIRT5的分子抑制剂，将对生长和活力的影响与能量变化相关 并测试干扰SIRT5是否与其他ALL疗法具有协同作用。(2)识别SIRT5- 总之，SIRT5依赖的调控途径和生物标志物。我们将让所有细胞接受RNA和 DNA测序和代谢组谱以及与SIRT5依赖相关的身份特征。(3) 在小鼠模型中确定SIRT5干扰是否减轻白血病负担并提高存活率 最重要的是。我们将在遗传ALL模型和患者来源的异种移植中测试SIRT5中断的效果。 代谢可塑性限制了抑制单个代谢途径的效果。绕过新陈代谢 可塑性和避免治疗逃逸，我们将目标SIRT5作为所有新陈代谢的主控制器。如果成功 我们的研究将建立SIRT5作为RR ALL的治疗靶点。

Supported by R01CA254354: Targeting the Metabolic Regulator SIRT5 in Acute Myeloid Leukemia (AML) we have reported that the lysine deacylase SIRT5 is a druggable metabolic target in AML (Yan et al. Blood Cancer Discov. 2021;2(3):266-287). Our new preliminary data suggest that the role of SIRT5 may extend to acute lymphoblastic leukemia (ALL), including relapsed/refractory (R/R) ALL. ALL is the most common cancer in children. After a peak at age 9, incidence initially declines, but then rises steadily after the age of 30. Most ALL cases originate from B-lymphoid precursor cells (B-ALL), but 15% are of T cell origin (T-ALL). Aggressive chemotherapy has greatly improved outcome in children, but often at the expense of long-term functional impairment. In contrast, long-term survival in adults is <50%, reflecting high-risk genotypes and higher treatment- related mortality. Chimeric antigen receptor (CAR) T cells targeting B cell antigens are effective in a subset of R/R B-ALL, but resistance often develops due to loss of the target antigen. Salvage therapies for RR T-ALL are ALL survival and reduce functional impairment in survivors. While ALL is genetically heterogeneous, most cases exhibit a differentiation block at the level of a B or T cell precursor. There is evidence that energy restriction creates a barrier to malignant transformation as B cell precursors undergo somatic hypermutation during antibody diversification. Mutational inactivation of B lineage transcription factors disables this metabolic brake and allows malignant transformation by oncogenes such as BCR-ABL1. Similar mechanisms may operate in T cell precursors during T cell receptor diversification. Our discovery that SIRT5 is a key regulator of AML metabolism and the reported interplay between metabolic reprogramming and malignant transformation in ALL, we asked whether SIRT5 dependence extends to ALL. We find that many ALL cell lines, including drug-resistant lines, are sensitive to SIRT5 knockdown (KD), prompting us to hypothesize that SIRT5 is required for maintaining ALL metabolism. Our Aims are: (1) Determine the effects of SIRT5 disruption on ALL cell lines and primary cells and correlate with global changes in energy metabolism. We will use shRNA, CRISPR/Cas9 and small molecule inhibitors to disrupt SIRT5 in ALL cells, correlate effects on growth and viability with changes in energy metabolism, and test whether disrupting SIRT5 is synergistic with other ALL therapeutics. (2) Identify SIRT5- regulated pathways and biomarkers of SIRT5 dependency in ALL. We will subject ALL cells to RNA and DNA sequencing and metabolomic profiling and identity features associated with SIRT5 dependency. (3) Determine whether SIRT5 disruption reduces leukemia burden and improves survival in mouse models of ALL. We will test the effect of SIRT5 disruption in genetic ALL models and patient-derived xenografts. Metabolic plasticity limits the efficacy of inhibiting individual metabolic pathways. To circumvent metabolic plasticity and avoid therapy escape, we will target SIRT5 as a master controller of ALL metabolism. If successful our studies will establish SIRT5 as a therapy target in RR ALL.