JAK3 is predominantly expressed in hematopoietic cells and has been a promising therapeutic target for the treatment of B-cell lymphoma. In this study, a new class of thieno[3,2-d]pyrimidines harboring acrylamide pharmacophore were synthesized as potent covalent JAK3 inhibitors (IC50 < 10 nM). Among them, 9a and 9 g displayed the strongest inhibitory potency against JAK3 kinase activity, with IC50 values of 1.9 nM and 1.8 nM, respectively. Furthermore, compared with the reference agents, Spebrutinib and Ibrutinib, 9a not only demonstrated enhanced antiproliferative activity against B lymphoma cells, but also showed very weak proliferative inhibition against normal peripheral blood mononuclear cells (PBMCs) at a concentration of 20 μM. Analysis of the mechanism revealed that 9a could induce the obvious apoptosis in B lymphoma cells and prevent JAK3-STAT3 cascade as well as BTK pathway. Taken together, 9a may be served as a potential new JAK3 inhibitor for the treatment of B-cell lymphoma.

中文翻译：

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基于噻吩并[3,2-d]嘧啶骨架的JAK3抑制剂：设计，合成和生物活性评估，用于治疗B细胞淋巴瘤。

JAK3主要在造血细胞中表达，并已成为治疗B细胞淋巴瘤的有希望的治疗靶标。在这项研究中，合成了一类新型的带有丙烯酰胺药效基团的噻吩并[3,2-d]嘧啶类化合物，作为有效的共价JAK3抑制剂（IC50 <10 nM）。其中，9a和9 g表现出对JAK3激酶活性最强的抑制力，IC50值分别为1.9 nM和1.8 nM。此外，与参考药物Spebrutinib和Ibrutinib相比，9a不仅显示出对B淋巴瘤细胞增强的抗增殖活性，而且在浓度为20μM时，对正常外周血单核细胞（PBMC）的增殖抑制作用非常弱。机理分析表明，9a可以诱导B淋巴瘤细胞明显凋亡，并阻止JAK3-STAT3级联和BTK通路。综上所述，9a可以作为潜在的新型JAK3抑制剂用于治疗B细胞淋巴瘤。