Department of Hematology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230001, Anhui, China; Blood and Cell Therapy Institute, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230001, Anhui, China; Anhui Provincial Key Laboratory of Blood Research and Applications, Hefei 230001, Anhui, China.
Department of Hematology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230001, Anhui, China; Blood and Cell Therapy Institute, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230001, Anhui, China; Anhui Provincial Key Laboratory of Blood Research and Applications, Hefei 230001, Anhui, China.
Biomed Pharmacother. 2022 Sep;153:113527. doi: 10.1016/j.biopha.2022.113527. Epub 2022 Aug 12.
Around 70 % of patients diagnosed with acute myeloid leukemia (AML) survive less than 5 years due to drug resistance and disease relapse. Consequently, improved clinical treatments are urgently needed. Some but not all AML patients benefit from the combination of the BCL-2 inhibitor Venetoclax with the hypomethylation agent Azacitidine. Here we investigated the utility of employing the cyclin dependent kinase (CDK6) inhibitor Palbociclib to improve the efficacy of Venetoclax/Azacitidine combination therapy. Our analysis of publicly available RNA sequencing datasets showed CDK6 was highly expressed in the major acute forms of leukemia including AML. Consistently, using qPCR and flow cytometry we found that CDK6 was overexpressed in bone marrow mononuclear cells from AML patients compared to healthy controls. Subsequent in vitro testing of Palbociclib, Venetoclax and Azacitidine, alone and in combination against CDK6-overexpressing AML cells lines THP-1 and KG-1 and primary AML cells showed that the Palbociclib/Venetoclax/Azacitidine combination improved treatment efficacy compared to Venetoclax/Azacitidine treatment alone. Additional investigations in a subcutaneous KG-1 mouse model showed similarly the three-drug combination produced the most significant reductions in tumor load together with the least amount of spleen infiltration. We established Palbociclib functioned in combination with Venetoclax/Azacitidine by increasing the rates of apoptosis in AML cells. Further investigations revealed that Palbociclib does not affect BCL-2 activity but downregulated the anti-apoptotic proteins MCL-1 and BCL-X, making AML cells more sensitive to Venetoclax/Azacitidine treatment. Our results propose that the Palbociclib/Venetoclax/Azacitidine regimen warrants further preclinical research for clinical application in AML patients.
约 70%的急性髓系白血病（AML）患者由于耐药性和疾病复发，存活时间不到 5 年。因此，迫切需要改进临床治疗方法。一些但不是所有 AML 患者都从维奈托克（BCL-2 抑制剂）与阿扎胞苷（低甲基化药物）的联合治疗中获益。在这里，我们研究了使用细胞周期蛋白依赖性激酶（CDK）抑制剂帕博西尼（Palbociclib）来提高维奈托克/阿扎胞苷联合治疗效果的效用。我们对公开可用的 RNA 测序数据集的分析表明，CDK6 在包括 AML 在内的主要急性白血病形式中高度表达。一致地，我们使用 qPCR 和流式细胞术发现，与健康对照相比，AML 患者的骨髓单核细胞中 CDK6 过表达。随后，单独和联合使用 Palbociclib、维奈托克和阿扎胞苷对 CDK6 过表达的 AML 细胞系 THP-1 和 KG-1 以及原代 AML 细胞进行的体外测试表明，与维奈托克/阿扎胞苷单独治疗相比，Palbociclib/维奈托克/阿扎胞苷联合治疗提高了治疗效果。在皮下 KG-1 小鼠模型中的进一步研究表明，同样地，三药联合治疗可显著减少肿瘤负荷，同时脾脏浸润最少。我们确定 Palbociclib 通过增加 AML 细胞的凋亡率与维奈托克/阿扎胞苷联合发挥作用。进一步的研究表明，Palbociclib 不会影响 BCL-2 活性，但下调抗凋亡蛋白 MCL-1 和 BCL-X，使 AML 细胞对维奈托克/阿扎胞苷治疗更敏感。我们的研究结果表明，Palbociclib/维奈托克/阿扎胞苷方案值得进一步进行临床前研究，以便在 AML 患者中临床应用。
