低浓度双硫仑/铜抑制骨髓MSCs内NF-κB通路逆转急性B淋巴细胞白血病耐药机理研究

骨髓微环境与白血病耐药相关，MSCs是骨髓微环境中重要的基质细胞。最近发现B-ALL细胞表面VLA-4和MSCs表面VCAM-1结合活化B-ALL细胞NF-κB通路诱导耐药；同时激活MSCs内NF-κB通路，上调MSCs的 VCAM-1，进一步增强MSCs和ALL细胞相互作用形成正反馈机制诱导耐药。我们最近研究发现低浓度双硫仑/铜能够逆转MSCs诱导的 B-ALL细胞对化疗药物耐药，但是具体机制不明。我们前期研究示双硫仑/铜能抑制白血病细胞NF-κB通路。因此，我们提出低浓度双硫仑/铜通过抑制MSCs内NF-κB通路下调其VCAM-1逆转B-ALL耐药的假说。本项目拟在细胞株、原代B-ALL细胞与MSCs共培养及人源化B-ALL移植鼠模型中，采用免疫印迹、流式细胞分析等方法从体内、外研究低浓度双硫仑/铜逆转耐药的作用及机理，为难治复发B-ALL治疗策略提供新的理论依据。

Chemotherapy resistance in acute lymphoblastic leukemia (ALL) may be mediated by increased interaction between leukemic blasts and the bone marrow mesenchymal stem cells (MSCs). Co-culture of MSCs with ALL cells activated nuclear factor (NF)- κB signaling pathway , the interaction between vascular cell adhesion molecule 1 (VCAM-1) and very late antigen-4 (VLA-4) played an integral role in the activation of NF-κB in MSCs and leukemic cells. And reciprocal NF-κB activation in MSCs and leukemia cells is essential for promoting chemoresistance in ALL cells. We recently found low dose of disulfiram/Cu could reverse MSCs induced chemoresistance of B-ALL cells to cytarabine, Yet the underlying mechanisms associated with this effect remain unclear. We have previously demonstrated disulfiram/Cu targets ALL cells in vitro and in vivo by inhibition of NF-κB pathway. We speculate disulfiram/Cu may reverse chemoresistance of ALL cells to Ara-C by inhibition of NF-κB pathway in MSCs and downregulate VCAM-1 expression. In the present study, we further investigate whether low dose of disulfiram/Cu could reverse MSCs induced chemoresistance in B-ALL cell lines, primary B-ALL cells and in patient-derived xenograft (PDX) humanized mouse models. Westernblot, EMSA, Immunohistochemistry as well as flow cytometry will also be employed to explore the underlying mechanisms.