■B细胞急性淋巴细胞白血病(B-ALL)是影响儿童的最常见的恶性肿瘤。虽然大多数B-ALL患者(90%)成功康复,早期复发的B-ALL病例继续表现出较高的死亡率.MZ1,一种新的溴结构域和末端外(BET)蛋白抑制剂,已证明对血液恶性肿瘤具有有效的抗肿瘤活性。这项研究的目的是检查MZ1在B-ALL治疗中的作用和治疗潜力。
■为了确定MZ1的基本机制,对B-ALL细胞系进行了一系列体外测定,包括细胞计数试剂盒8(CCK8)测定,碘化丙啶(PI)染色,和膜联蛋白V/PI染色。采用蛋白质印迹和定量实时聚合酶链反应(qRT-PCR)检测蛋白质和mRNA表达水平。转录组RNA测序(RNA-seq)用于筛选MZ1的靶基因,并采用慢病毒转染来建立稳定表达/敲低的细胞系。
■已观察到MZ1诱导含溴结构域4(BRD4)的降解,含溴结构域3(BRD3),B-ALL细胞株中的含溴结构域2(BRD2),导致体外抑制细胞生长,诱导细胞凋亡和周期阻滞。这些发现表明,MZ1对B-ALL的两种不同的分子亚型表现出细胞毒性作用。即697(TCF3/PBX1)和RS4;11(MLL-AF4)B-ALL细胞系。此外,RNA测序分析显示MZ1显著下调细胞周期蛋白D3(CCND3)基因在B-ALL细胞系中的表达,反过来促进细胞凋亡,细胞周期受阻,并引起细胞增殖抑制。
■我们的结果表明MZ1具有潜在的抗B-ALL作用,可能是一个新的治疗靶点。
UNASSIGNED: B-cell acute lymphoblastic leukemia (B-ALL) is the most prevalent malignant tumor affecting children. While the majority of B-ALL patients (90%) experience successful recovery, early relapse cases of B-ALL continue to exhibit high mortality rates.
MZ1, a novel inhibitor of Bromodomains and extra-terminal (BET) proteins, has demonstrated potent antitumor activity against hematological malignancies. The objective of this study was to examine the role and therapeutic potential of
MZ1 in the treatment of B-ALL.
UNASSIGNED: In order to ascertain the fundamental mechanism of
MZ1, a sequence of in vitro assays was conducted on B-ALL cell lines, encompassing Cell Counting Kit 8 (CCK8) assay, Propidium iodide (PI) staining, and Annexin V/PI staining. Western blotting and quantitative real-time polymerase chain reaction (qRT-PCR) were employed to examine protein and mRNA expression levels. Transcriptomic RNA sequencing (RNA-seq) was utilized to screen the target genes of
MZ1, and lentiviral transfection was employed to establish stably-expressing/knockdown cell lines.
UNASSIGNED: MZ1 has been observed to induce the degradation of Bromodomain Containing 4 (BRD4), Bromodomain Containing 3 (BRD3), and Bromodomain Containing 2 (BRD2) in B-ALL cell strains, leading to inhibited cell growth and induction of cell apoptosis and cycle arrest in vitro. These findings suggest that MZ1 exhibits cytotoxic effects on two distinct molecular subtypes of B-ALL, namely 697 (TCF3/PBX1) and RS4;11 (MLL-AF4) B-ALL cell lines. Additionally, RNA-sequencing analysis revealed that
MZ1 significantly downregulated the expression of Cyclin D3 (CCND3) gene in B-ALL cell lines, which in turn promoted cell apoptosis, blocked cell cycle, and caused cell proliferation inhibition.
UNASSIGNED: Our results suggest that MZ1 has potential anti-B-ALL effects and might be a novel therapeutic target.