Kam Angel Y F, Piryani Sadhna O, McCall Chad M, Park Hee Su, Rizzieri David A, Doan Phuong L
Division of Hematologic Malignancies and Cellular Therapy, Duke University, Durham, North Carolina.
Department of Pathology, Duke University, Durham, North Carolina.
Clin Cancer Res. 2019 Jul 1;25(13):4155-4167. doi: 10.1158/1078-0432.CCR-18-3517. Epub 2019 Apr 5.
Myelodysplastic syndrome (MDS) is associated with a dysregulated innate immune system. The purpose of this study was to determine whether modulation of the innate immune system via high mobility group box-1 (HMGB1) could reduce cell viability in MDS.
We quantified HMGB1 in an MDS cell line MDS-L and in primary MDS cells compared with nonmalignant hematopoietic cells. We performed loss-of-function studies of HMGB1 using pooled siRNAs and a small-molecule inhibitor sivelestat compared with standard chemotherapy. We measured levels of engraftment of MDS-L cells in NOD-scidIL2Rg (NSG) mice following treatment with sivelestat. Mechanistically, we interrogated cell survival pathways and 45 targets within the NFκB pathway using both protein analysis and a proteome profiler array.
We discovered that HMGB1 had increased expression in both MDS-L cells and in primary CD34 MDS cells compared with healthy CD34 hematopoietic cells. Sivelestat impaired MDS cell expansion, increased cellular death, and spared healthy hematopoietic cells. MDS-L marrow engraftment is reduced significantly at 17 weeks following treatment with sivelestat compared with control mice. Treatment of CD34 MDS cells with sivelestat and azacitidine or decitabine was additive to increase apoptotic cell death compared with chemotherapy alone. Sivelestat promoted apoptosis with increased expression of PUMA, activated caspase 3, and increased DNA double-strand breaks. Inhibition of HMGB1 reduced levels of Toll-like receptors (TLR) and suppressed activation of NFκB in MDS-L cells.
Inhibition of HMGB1 could promote MDS cell death and alter innate immune responses via suppression of NFκB pathways.
骨髓增生异常综合征（MDS）与先天免疫系统失调有关。本研究的目的是确定通过高迁移率族蛋白B1（HMGB1）调节先天免疫系统是否能降低MDS中的细胞活力。
我们将MDS细胞系MDS-L和原发性MDS细胞中的HMGB1含量与非恶性造血细胞进行了量化比较。与标准化疗相比，我们使用汇集的小干扰RNA和小分子抑制剂西维来司他对HMGB1进行了功能丧失研究。在用西维来司他治疗后，我们测量了NOD-scidIL2Rg（NSG）小鼠中MDS-L细胞的植入水平。从机制上，我们使用蛋白质分析和蛋白质组分析阵列研究了细胞存活途径和NFκB途径中的45个靶点。
我们发现，与健康的CD34造血细胞相比，HMGB1在MDS-L细胞和原发性CD34 MDS细胞中的表达均增加。西维来司他损害了MDS细胞的扩增，增加了细胞死亡，并使健康的造血细胞免受影响。与对照小鼠相比，在用西维来司他治疗17周后，MDS-L骨髓植入显著减少。与单独化疗相比，用西维来司他和阿扎胞苷或地西他滨治疗CD34 MDS细胞可增加凋亡细胞死亡。西维来司他通过增加PUMA的表达、激活的半胱天冬酶3和增加DNA双链断裂来促进细胞凋亡。抑制HMGB1可降低MDS-L细胞中Toll样受体（TLR）的水平并抑制NFκB的激活。
抑制HMGB1可通过抑制NFκB途径促进MDS细胞死亡并改变先天免疫反应。
