Fiskus Warren, Mill Christopher P, Bose Prithviraj, Masarova Lucia, Pemmaraju Naveen, Dunbar Andrew, Birdwell Christine E, Davis John A, Das Kaberi, Hou Hanxi, Manshouri Taghi, Jain Antrix, Malovannaya Anna, Philip Kevin, Alhamadani Noor, Matthews Alicia, Lin Katie, Flores Lauren B, Loghavi Sanam, DiNardo Courtney, Su Xiaoping, Rampal Raajit K, Bhalla Kapil N
Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX.
Department of Hematopoietic Biology and Malignancy, The University of Texas MD Anderson Cancer Center, Houston, TX.
Blood. 2025 Feb 6;145(6):612-624. doi: 10.1182/blood.2024026388.
Rising blast percentage or secondary acute myeloid leukemia (sAML) transformation in myeloproliferative neoplasms (MPNs) leads to JAK1/2 inhibitor (JAKi) therapy resistance and poor survival. Here, we demonstrate that treatment with the CDK7 inhibitor (CDK7i) SY-5609 depletes phenotypically characterized post-MPN sAML stem/progenitor cells. In cultured post-MPN sAML SET2, HEL and patient-derived (PD) post-MPN sAML cells, SY-5609 treatment inhibited growth and induced lethality while sparing normal cells. RNA-sequencing analysis after SY-5609 treatment reduced mRNA expression of MYC, MYB, CDK4/6, PIM1, and CCND1 but increased expression of CDKN1A and BCL2L1. Mass spectrometry of SY-5609-treated MPN-sAML cells also reduced c-Myc, c-Myb, PIM1, and CDK4/6 but increased p21, caspase-9, and BAD protein levels. CRISPR-mediated CDK7 depletion also reduced cell viability of HEL cells. Cytometry by time of flight (CyTOF) analysis of SY-5609-treated PD post-MPN sAML stem/progenitor cells showed reduced c-Myc, CDK6, and PU.1 but increased protein levels of CD11b, p21, and cleaved caspase-3. Cotreatment with SY-5609 and ruxolitinib was synergistically lethal in HEL, SET2, and PD post-MPN sAML cells. A CRISPR screen in sAML cells revealed BRD4, CBP, and p300 as codependencies with CDK7i. Accordingly, cotreatment with SY-5609 and the bromodomain and extra-terminal protein inhibitor (BETi) OTX015 or pelabresib or the CBP/p300 inhibitor GNE-049 was synergistically lethal in MPN-sAML cells (including those exhibiting TP53 loss). Finally, in the HEL-Luc/GFP xenograft model, compared with each agent alone, cotreatment with SY-5609 and OTX015 reduced sAML burden and improved survival without host toxicity. These findings demonstrate promising preclinical activity of CDK7i-based combinations with BETi or CBP/p300 inhibitor against advanced MPNs, including post-MPN sAML.
骨髓增殖性肿瘤（MPN）中 blast 百分比升高或继发性急性髓系白血病（sAML）转化会导致 JAK1/2 抑制剂（JAKi）治疗耐药和生存期缩短。在此，我们证明 CDK7 抑制剂（CDK7i）SY-5609 治疗可消耗具有表型特征的 MPN 后 sAML 干/祖细胞。在培养的 MPN 后 sAML SET2、HEL 细胞以及患者来源（PD）的 MPN 后 sAML 细胞中，SY-5609 治疗抑制细胞生长并诱导细胞死亡，同时对正常细胞无影响。SY-5609 治疗后的 RNA 测序分析降低了 MYC、MYB、CDK4/6、PIM1 和 CCND1 的 mRNA 表达，但增加了 CDKN1A 和 BCL2L1 的表达。对 SY-5609 处理的 MPN-sAML 细胞进行质谱分析也降低了 c-Myc、c-Myb、PIM1 和 CDK4/6 的水平，但增加了 p21、caspase-9 和 BAD 的蛋白水平。CRISPR 介导的 CDK7 缺失也降低了 HEL 细胞的活力。对 SY-5609 处理的 PD MPN 后 sAML 干/祖细胞进行飞行时间流式细胞术（CyTOF）分析显示，c-Myc、CDK6 和 PU.1 水平降低，但 CD11b、p21 和裂解的 caspase-3 的蛋白水平增加。SY-5609 与鲁索替尼联合治疗对 HEL、SET2 和 PD MPN 后 sAML 细胞具有协同致死作用。在 sAML 细胞中进行的 CRISPR 筛选显示 BRD4、CBP 和 p300 是与 CDK7i 相互依赖的基因。因此，SY-5609 与溴结构域和额外末端蛋白抑制剂（BETi）OTX015 或派拉布瑞西或 CBP/p300 抑制剂 GNE-049 联合治疗对 MPN-sAML 细胞（包括那些 TP53 缺失的细胞）具有协同致死作用。最后，在 HEL-Luc/GFP 异种移植模型中，与单独使用每种药物相比，SY-5609 与 OTX015 联合治疗可降低 sAML 负担并改善生存期，且无宿主毒性。这些发现表明基于 CDK7i 与 BETi 或 CBP/p300 抑制剂的联合治疗对晚期 MPN，包括 MPN 后 sAML，具有有前景的临床前活性。
