Division of Medicine, Department of Hematology, Oncology and Palliative Medicine, University of Rostock, 18057 Rostock, Germany.
Department of Cell Physiology and Biophysics, Institute of Cell Biology and Biophysics, Leibniz University Hannover, 30419 Hannover, Germany.
Int J Mol Sci. 2021 Jan 8;22(2):592. doi: 10.3390/ijms22020592.
Impaired B-cell receptor (BCR) function has been associated with the progress of several B-cell malignancies. The spleen tyrosine kinase (SYK) represents a potential therapeutic target in a subset of B-cell neoplasias. In precursor B-acute lymphoblastic leukemia (B-ALL), the pathogenic role and therapeutic potential of SYK is still controversially discussed. We evaluate the application of the SYK inhibitor entospletinib (Ento) in pre- and pro-B-ALL cell lines, characterizing the biologic and molecular effects.
SYK expression was characterized in pre-B-ALL (NALM-6) and pro-B-ALL cell lines (SEM and RS4;11). The cell lines were exposed to different Ento concentrations and the cell biological response analyzed by proliferation, metabolic activity, apoptosis induction, cell-cycle distribution and morphology. BCR pathway gene expression and protein modulations were further characterized.
Ento significantly induced anti-proliferative and pro-apoptotic effects in NALM-6 and SEM, while barely affecting RS4;11. Targeted RNAseq revealed pronounced gene expression modulation only in NALM-6, while Western Blot analyses demonstrated that vital downstream effector proteins, such as pAKT, pERK, pGSK3β, p53 and BCL-6, were affected by Ento exposure in the inhibitor-sensitive cell lines.
Different acting modes of Ento, independent of pre-BCR dependency, were characterized, unexpected in SEM. Accordingly, SYK classifies as a potential target structure in a subset of pro-B-ALLs.
B 细胞受体（BCR）功能障碍与几种 B 细胞恶性肿瘤的进展有关。脾脏酪氨酸激酶（SYK）是一组 B 细胞肿瘤潜在的治疗靶点。在前体 B 急性淋巴细胞白血病（B-ALL）中，SYK 的致病作用和治疗潜力仍存在争议。我们评估了 SYK 抑制剂 entospletinib（Ento）在前体 B-ALL 和前 B-ALL 细胞系中的应用，对其生物学和分子效应进行了特征描述。
在前 B-ALL（NALM-6）和前 B-ALL 细胞系（SEM 和 RS4;11）中对 SYK 表达进行了特征描述。细胞系暴露于不同的 Ento 浓度下，通过增殖、代谢活性、凋亡诱导、细胞周期分布和形态学来分析细胞生物学反应。进一步分析 BCR 途径基因表达和蛋白修饰。
Ento 显著诱导 NALM-6 和 SEM 中的抗增殖和促凋亡作用，而对 RS4;11 的影响很小。靶向 RNAseq 仅在 NALM-6 中显示出明显的基因表达调节，而 Western Blot 分析表明，在抑制剂敏感的细胞系中，重要的下游效应蛋白，如 pAKT、pERK、pGSK3β、p53 和 BCL-6，受 Ento 暴露的影响。
Ento 的作用模式不同，与前 BCR 依赖性无关，在 SEM 中出乎意料。因此，SYK 被归类为一组前 B-ALL 中的潜在靶标结构。
