Venetoclax (VEN)和阿扎胞苷(AZA)的联合治疗已成为75岁或以上或不能接受强化化疗的急性髓系白血病（AML）患者的标准护理方案。尽管最初有希望，但联合治疗的抗药性是一个问题，VEN+AZA复发/难治患者的预后不佳。为了更好地了解抗药机制，我们开发了VEN+AZA耐药的AML细胞系MV4-11/VEN+AZA-R和ML-2/VEN+AZA-R，相对于母细胞系，这两株细胞显示出>300倍的持续抗药性。我们证明这些细胞具有独特的代谢特征，包括显著增加的胞苷三磷酸（CTP）和脱氧胞苷三磷酸（dCTP）水平，脂肪酸和氨基酸代谢的改变以及对糖酵解的利用和依赖性增加。此外，与母细胞相比，抗药细胞中脂肪酸转运蛋白CD36的表达增加。使用2-脱氧-D-葡萄糖抑制糖酵解重新使抗药细胞对VEN+AZA敏感。此外，VEN+AZA-R细胞中抗凋亡蛋白Mcl-1水平升高，而促凋亡蛋白Bax水平降低。Mcl-1过表达或Bax沉默导致对VEN+AZA的抗药性。我们的结果揭示了VEN+AZA抗药性的分子机制，有助于开发新的治疗方法来克服AML患者的抗药性。版权所有 © 2023 Elsevier公司发表。

The combination of venetoclax (VEN) and azacitidine (AZA) has become the standard of care for acute myeloid leukemia (AML) patients who are ≥75 years or unfit for intensive chemotherapy. Though initially promising, resistance to the combination therapy is an issue and VEN+AZA-relapsed/refractory patients have dismal outcomes. To better understand the mechanisms of resistance, we developed VEN+AZA-resistant AML cell lines, MV4-11/VEN+AZA-R and ML-2/VEN+AZA-R, which show >300-fold persistent resistance compared to the parental lines. We demonstrate that these cells have unique metabolic profiles, including significantly increased levels of cytidine triphosphate (CTP) and deoxycytidine triphosphate (dCTP), changes in fatty acid and amino acid metabolism and increased utilization and reliance on glycolysis. Furthermore, fatty acid transporter CD36 is increased in the resistant cells compared to the parental cells. Inhibition of glycolysis with 2-Deoxy-D-glucose re-sensitized the resistant cells to VEN+AZA. In addition, the VEN+AZA-R cells have increased levels of the antiapoptotic protein Mcl-1 and decreased levels of the pro-apoptotic protein Bax. Overexpression of Mcl-1 or knockdown of Bax result in resistance to VEN+AZA. Our results provide insight into the molecular mechanisms contributing to VEN+AZA resistance and assist in the development of novel therapeutics to overcome this resistance in AML patients.Copyright © 2023. Published by Elsevier Inc.