Kurayoshi Kenta, Takase Yusuke, Ueno Masaya, Ohta Kumiko, Fuse Kyoko, Ikeda Shuji, Watanabe Takayoshi, Nishida Yuki, Horike Shin-Ichi, Hosomichi Kazuyoshi, Ishikawa Yuichi, Tadokoro Yuko, Kobayashi Masahiko, Kasahara Atsuko, Jing Yongwei, Shoulkamy Mahmoud I, Meguro-Horike Makiko, Kojima Kensuke, Kiyoi Hitoshi, Sugiyama Hiroshi, Nagase Hiroki, Tajima Atsushi, Hirao Atsushi
Division of Molecular Genetics, Cancer Research Institute, Kanazawa University, Kakuma-machi, Kanazawa, 920-1192, Japan.
Division of Molecular Genetics, WPI Nano Life Science Institute (WPI-Nano LSI), Kanazawa University, Kakuma-machi, Kanazawa, 920-1192, Japan.
Cell Death Dis. 2023 Sep 29;14(9):642. doi: 10.1038/s41419-023-06168-2.
Differentiation therapy has been proposed as a promising therapeutic strategy for acute myeloid leukemia (AML); thus, the development of more versatile methodologies that are applicable to a wide range of AML subtypes is desired. Although the FOXOs transcription factor represents a promising drug target for differentiation therapy, the efficacy of FOXO inhibitors is limited in vivo. Here, we show that pharmacological inhibition of a common cis-regulatory element of forkhead box O (FOXO) family members successfully induced cell differentiation in various AML cell lines. Through gene expression profiling and differentiation marker-based CRISPR/Cas9 screening, we identified TRIB1, a complement of the COP1 ubiquitin ligase complex, as a functional FOXO downstream gene maintaining an undifferentiated status. TRIB1 is direct target of FOXO3 and the FOXO-binding cis-regulatory element in the TRIB1 promoter, referred to as the FOXO-responsive element in the TRIB1 promoter (FRE-T), played a critical role in differentiation blockade. Thus, we designed a DNA-binding pharmacological inhibitor of the FOXO-FRE-T interface using pyrrole-imidazole polyamides (PIPs) that specifically bind to FRE-T (FRE-PIPs). The FRE-PIPs conjugated to chlorambucil (FRE-chb) inhibited transcription of TRIB1, causing differentiation in various AML cell lines. FRE-chb suppressed the formation of colonies derived from AML cell lines but not from normal counterparts. Administration of FRE-chb inhibited tumor progression in vivo without remarkable adverse effects. In conclusion, targeting cis-regulatory elements of the FOXO family is a promising therapeutic strategy that induces AML cell differentiation.
分化疗法已被提议作为急性髓系白血病（AML）的一种有前景的治疗策略；因此，人们期望开发出更通用的方法，适用于广泛的AML亚型。尽管FOXOs转录因子是分化疗法中一个有前景的药物靶点，但FOXO抑制剂在体内的疗效有限。在此，我们表明对叉头框O（FOXO）家族成员的一个常见顺式调控元件进行药理学抑制可成功诱导多种AML细胞系的细胞分化。通过基因表达谱分析和基于分化标志物的CRISPR/Cas9筛选，我们鉴定出TRIB1，它是COP1泛素连接酶复合物的一个补充成分，作为维持未分化状态的功能性FOXO下游基因。TRIB1是FOXO3的直接靶点，TRIB1启动子中的FOXO结合顺式调控元件，即TRIB1启动子中的FOXO反应元件（FRE-T），在分化阻滞中起关键作用。因此，我们使用特异性结合FRE-T的吡咯-咪唑聚酰胺（PIPs）设计了一种FOXO-FRE-T界面的DNA结合药理学抑制剂（FRE-PIPs）。与苯丁酸氮芥偶联的FRE-PIPs（FRE-chb）抑制TRIB1的转录，导致多种AML细胞系分化。FRE-chb抑制AML细胞系来源的集落形成，但不抑制正常细胞系的集落形成。给予FRE-chb可在体内抑制肿瘤进展且无明显不良反应。总之，靶向FOXO家族的顺式调控元件是一种诱导AML细胞分化的有前景的治疗策略。
