IDH1在急性髓细胞白血病耐药中的作用及microRNA调控机制研究

Drug resistance of leukemia cells is one of the main problem for improvement of treatment reaction. Our previous study found that AML patients with high expression of IDH1 are associated with poor prognosis, high IDH1 expression is significantly associated with low expression of the miR-181 in AML patients. In addition, we also found that miR-181 underexpression and overexpression of IDH1 with respect to mRNA and protein were detected in drug resistance HL-60/ADR cell lines. So it is reasonable to infer that IDH1 expression which regulated by miR-181 associate with drug resistance. The objectives of this study is as follows: (1)We will detect drug sensitivity, miR-181 and IDH1 expression of AML patients with drug resistance. (2) Transfecting miR-181 mimic and inhibitor to inhibit or increas the expression of miR-181 in HL-60/ADR, while detecting expression of IDH1, drug resistance and expression of its associated signaling pathway to further clarify the regulatory mechanism. (3) Validate miR-181 regulation IDH1 mechanisms in tumor-bearing animal models. The significance of this study may find new mechanism to drug resistance, which would generate new knowledge of the platform to surveil the drug resistance and target treatment of AML.

化疗耐药是当前制约AML临床疗效进一步提高的主要因素之一。我们前期研究发现IDH1基因高表达是AML的独立预后不良因素之一, IDH1基因高表达AML患者miR-181低表达，多药耐药细胞株HL-60/ADR的IDH1 mRNA和蛋白质高表达，而miR-181低表达。因此，我们推测IDH1和miR-181与多药耐药有关。本研究拟通过（1）检测AML耐药患者骨髓中的IDH1和miR-181表达与药物敏感性。（2）转染miR-181 mimic或inhibitor增强或抑制miR-181表达，观察细胞中IDH1的表达和耐药情况，并检测其相关的信号通路的表达，进一步阐明调控机制。（3) 在动物荷瘤模型中验证miR-181调控IDH1的机制。本研究有望发现AML耐药的新机制，为临床耐药的监测和靶向治疗提供科学依据。

化疗耐药是制约AML疗效的主要因素之一。我们研究发现IDH1基因高表达是AML的独立预后不良因素之一, 高表达者预后差。IDH1基因高表达AML患者miR-181低表达，多药耐药细胞株HL-60/ADR的IDH1 mRNA和蛋白质高表达，而miR-181低表达。因此，我们推测IDH1和miR-181与多药耐药有关。沉默耐药细胞株HL-60/ADR的IDH1基因后发现其诱导细胞凋亡，增加对阿霉素的敏感性，逆转耐药。我们检测AML患者IDH1、miR-181b、miR-181d和miR-4286的表达情况，分析IDH1表达与miR-181b、miR-181d和miR-4286相关性，结果显示：IDH1表达与miR-181b和miR-181d呈负相关。而miR-4286与IDH1mRNA表达呈正相关相关。检测初发和复发AML患者 miR181a、miR181b和miR181d表达情况并分析，结果显示：初发AML患者miR181a、miR181b和miR181d表达高，而复发后AML患者miR181a、miR181b和miR181d的表达低，差异具有统计学意义，p值均小于0.05。HL-60/ADR细胞株转染miR181的 mimic后抑制PI3K-AKT信号通路，导细胞凋亡，增加对阿霉素的敏感性。本课题从不同视角阐明AML耐药的机制，为临床耐药的监测和靶向治疗提供科学依据。. 在完成国家自然基金任务的前提下，我们观察了miR181a和miR362-5p在AML中的作用，结果表明：miRNA-181a高表达组患者患者HGB、完全缓解率高、NPM1野生型比例均较低表达组高, miRNA-181a高表达是独立于临床指标和高频基因突变的预后良好的标志物，miRNA-181a表达水平可作为CN-AML预后的重要指标。miR-362-5p高表达见于老年患者，在单因素分析中，总体生存率低。miR-362-5p的独立预后价值在与白细胞、染色体和基因突变进行多因素分析时仍然存在。 此外，miR-362-5p的预后价值也在验证组CN-AML患者中得到验证。miR-362-5p高表达的CN-AML患者预后差。