ZD6474对伊马替尼耐药的K562细胞增殖的影响  

Effect of ZD6474 on the proliferation of imatinib-resistant K562 cells

作　　者：嘉红云[1] 吴晓蔓[1] 王忠英[1] 邓小燕[1] 林桢[1] 冯桂玲[1] 黄文林[2] 

机构地区：[1]广州医学院第二附属医院检验科,510260 [2]中山大学肿瘤防治中心

出　　处：《中华血液学杂志》2010年第6期371-375,共5页Chinese Journal of Hematology

摘　　要：目的 探讨酪氨酸激酶抑制剂ZD6474（Vandetanib）对K562细胞及其衍生的伊马替尼耐药的K562/G细胞的增殖抑制作用及其分子机制.方法 通过逐渐增加药物浓度的方法诱导伊马替尼耐药的K562/G细胞株,采用Western blot方法检测耐药细胞株中明显变化的分子.WST方法检测伊马替尼和ZD6474对细胞增殖的影响,流式细胞术检测药物对细胞周期的影响.采用RT-PCR、Western blot和体外Src激酶卣接测定的方法研究ZD6474作用的分子机制.结果 伊马替尼对K562细胞的IC50值为（0.28 4-0.04）μmol/L,而对K562/G细胞的IC50值为（15.80±0.93）μmol/L,K562/G细胞的耐药倍数为56倍,Western blot结果提示其耐药机制与磷酸化Src激酶（p-Src）的表达增强,Bcl-2和磷酸化STAT3（p-STAT3）的表达升高有关.ZD6474呈剂量依赖的方式抑制K562和K562/G细胞增殖,48 h的IC50值分别为1.61 μmol/L和3.18 μmol/L.ZD6474作用24 h,可以显著诱导细胞周期阻滞和细胞凋亡.分子机制研究显示,ZD6474显著抑制Src激酶活性,上调Bax/Bcl-2的比例,以及下调p-STAT3表达.结论 ZD6474可以有效抑制伊马替尼耐药的K562/G和亲本K562细胞增殖,诱导凋亡.其机制与ZD6474显著抑制Src激酶活性有关.Objective To investigate the effect of tyrosine kinase inhibitor ZD6474（Vandetanib）on the proliferative inhibition of K562 cells and its derived imatinib-resistant K562/G cells and its mechanism.Methods Imatinib-resistant K562/G cells were obtained by culturing cells in gradually increasing concentrations of imatinib.The changed factors related to drug-resistance were tested by Western blot.ZD6474 and imatinib affected K562/G and parental K562 cells proliferation were analyzed by WST assay.Flow cytometry was used to analyze cell cycle.Direct inhibition of Src activity by ZD6474 was measured by a coiorimetric ELISA assay with recombinant human Src kinase.Results 10 μmol/L imatinib failed to inhibit K562/G cells proliferation or induce cell cycle arrest.Compared with that in parental K562 cells,there were marked high levels of p-Src and Src protein in K562/G cells.The expression of Bcl-2 and P-STAT3 also increased in K562/G cells.After 48 hours incubation,the IC50 values of ZD6474 in K562 and K562/G ceHs were 1.61μmol/L and 3.18μmol/L,respectively.ZD6474 treatment caused accumulation of cells in the G0/G1 fraction and cell apoptosis in K562 and K562/G cells.ZD6474 decreased the expression of P-Src and Src at posttranscriptional level.Moreover,ZD6474 increased the ratio of Bax/Bcl-2 and decreased the expression of PSTAT3 at the same concentration for inducing apoptosis.Conclusions ZD6474 is effective in inhibiting the proliferation of imatinib-resistant K562/G cells and parental K562 cells.and induces their apoptasis by significant inhibition of Src kinase activity.Our study provides a reliable experimental basis for chronic myeloid leukemia treatment with ZD6474.

关 键 词：K562细胞 耐药 伊马替尼 酪氨酸激酶抑制剂 细胞增殖 

分 类 号：R965[医药卫生—药理学]