血浆miR-140表达水平与地西他滨治疗疗效的关系及其机制研究

Relation of miR-140 Expression Level with Therapeutic Effect of Decitabine and Its Mechanism

目的:探讨血浆miR-140表达水平与地西他滨化疗疗效的关系及其具体分子机制是否与对Toll样受体-4(TLR4)表达的调控有关。方法:急性髓系白血病(acute myeloid leukaemia,AML)病人47例,分别用地西他滨联合化疗方案治疗(22例)和用传统治疗方案治疗(25例),比较2组病人临床疗效,采用实时荧光定量PCR(real-time PCR)检测病人血浆miR-140的表达水平。以地西他滨、miR-140 mimic、miR-140 inhibitor处理体外培养的AML细胞株HL-60,应用real-time PCR及Western blot分别检测HL-60中miR-140、TLR4、NF-κB的mRNA及蛋白表达水平。结果:与传统治疗方案相比,地西他滨联合化疗组显示出较优的临床有效性(P<0.05);2组病人治疗后血浆miR-140的水平均明显升高,且相对于标准化疗方案治疗组而言,地西他滨联合化疗组病人治疗后血浆miR-140水平升高得更为显著(P<0.05)。在体外培养的HL-60中,0.3μmol/L的地西他滨能够显著地抑制细胞的增殖活性,同时伴有miR-140的显著上调及TLR-4、NF-κB表达的下调,预先以200 nmol/L的niR-140 inhibitor处理HL-60可部分逆转地西他滨的这些作用(P<0.05)。结论:地西他滨诱导的血浆miR-140高表达可能与其化疗疗效相关,miR-140/TLR4/NF-κB通路可能部分介导了地西他滨的药理作用。

Objective:To investigate the relationship of miR-140 expression level with the therapeutic effect of decitabine,and to explore whether the molecular mechanism is dependent on the regulation of TLR4 expression.Methods:Forty-seven patients with acute myeloid leukaemia(AML)were enrolled in our study and divided into decitabine combination treatment group(22 cases)and traditional treatment group(25 cases).The clinical efficacy was compared between these two groups.Real-time PCR was used to determine the plasma level of miR-140 in AML patients.Decitabine,miR-140 mimic and miR140 inhibitor were used to treat AML HL-60 cells in vitro,the real-time PCR and Western blot were used to detect the expressions of miR-140,TLR4 and NF-κB at both mRNA and protein levels.Results:Compared with traditional treatment group,decitabine combination treatment group showed more significant clinical efficacy.Plasma miR-140 level in both 2 treatment groups both decreased,but the plasma miR-140 level was higher in decitabine combination treatment group as compared with traditional treatment group.Experiment in vitro showed that 0.3μmol/L decitabine significantly inhibited the HL-60 cell proliferation accompanied by up-regulation of miR-140 expression and down-regulation of expression of TLR4 and NF-κB.These effects induced by decitabine were partly reversed by pretreating the cells with 200 nmol/L miR-140 inhibitor.Conclusion:Decitabine-induced up-regulation of miR-140 expression may be related with its chemotherapeutic effects,and miR-140/TLR4/NF-κB pathway may partly mediate the pharmacologic action of decitabine.