病毒唑通过抑制eIF4F翻译起始复合物 功能发挥抗白血病的作用
Ribavirin plays a the anti-leukemia role in chronic myeloid leukemia by inhibiting the activity of eIF4F translation initiation complexes
目的：研究病毒唑单药及与伊马替尼联合抗慢性粒细胞白血病（CML）的效应及作用机制。方法：以人CML细胞株K562及原代白血病细胞为研究模型，采用MTT药物敏感试验检测病毒唑、伊马替尼单药及两药联合对K562细胞抑制增殖的作用； Western Blot方法分析药物对细胞mTOR/4EBP1/eIF4E信号通路关键点蛋白磷酸化表达水平的影响；7-甲基鸟嘌呤帽亲和分析法分析药物对eIF4F起始复合物中4EBP1、eIF4E、eIF4G表达的影响。结果：1. MTT结果显示病毒唑、伊马替尼单药对K562细胞株的IC50值分别为92.2μM和0.145μM，而伊马替尼与20μM的病毒唑联合作用使伊马替尼的IC50值下降到了0.077μM，计算其50%抑制率时的协同指数（CI值）是0.74，表明两药存在协同作用。2. Western Blot结果显示病毒唑下调K562细胞株mTOR/4EBP1/eIF4E信号通路关键蛋白mTOR、4EBP1、eIF4E磷酸化水平；与伊马替尼联合，上述信号通路关键蛋白的磷酸化水平均进一步下调。3. 病毒唑联合伊马替尼联合明显下调CML患者原代细胞上述信号通路蛋白磷酸化水平。4. 7-甲基鸟嘌呤帽亲和分析结果显示病毒唑增加K562细胞株eIF4E与4EBP1的结合，减少与eIF4G的结合，抑制eIF4F翻译起始复合物的形成，与伊马替尼联合后表现出协同抑制eIF4F组装的作用。结论：病毒唑通过抑制mTOR/4EBP1/eIF4E信号通路活性，抑制eIF4F翻译起始复合物形成而抑制CML细胞的增殖，伊马替尼与病毒唑联合有协同抗CML作用。
Objective: To investigate the anti-leukemia effect and mechanism of ribavirin alone or ribavirin plus imatinib in chronic myeloid leukemia (CML). Methods: The CML cell line K562 was treated with ribavirin alone or in combination with imatinib, cell proliferation was evaluated by using the MTT assay. The phosphorylative and total expression of the key proteins of mTOR/4EBP1/eIF4E signaling pathway were assessed by western blot analysis. The assembly of eIF4F translation initiation complex was examined with 7-Methyl-guanosine cap af?nity assay. Results: 1. The MTT assay showed that ribavirin or imatinib alone had anti-proliferation effect on K562 cell line, the IC50 values of ribavirin and imatinib against to K562 cell line was 92.2μM and 0.145μM. Combined with 20μM of ribavirin, the IC50 values of imatinib decreased to 0.077μM, the combination index (CI) was 0.74, which indicated the combination of imatinib and ribavirin had synergistic anti-leukemia effect. 2. Ribavirin down-regulated the phosphorylation levels of mTOR, 4EBP1, eIF4E proteins in the mTOR/4EBP1/eIF4E signaling pathway. The combination of ribavirin with imatinib down-regulated the phosphorylation level of these proteins more significantly than that with ribavirin alone. 3. Similarly, the combination of ribavirin and imatinib down-regulated the phosphorylation level of these proteins more significantly than that with ribavirin alone in CML patient primary cells. 4. 7-Methyl-guanosine cap af?nity assay showed that ribavirin could increase the combination of eIF4E and 4EBP1, decrease the combination of eIF4E and eIF4G in K562 cell line, therefore, inhibit the assembly of eIF4F translation initiation complex. When combined with imatinib, inhibition effect on assembly of eIF4F translation initiation complex was more obvious. Conclusions These studies demonstrated that ribavirin down-regulated the phosphorylation level of mTOR/4EBP1/eIF4E signaling pathway and inhibited the assembly of eIF4F translation initiation complexes. The combination of ribavirin with imatinib enhanced anti-leukemic role in chronic myeloid leukemia.
龚玉萍、石芳芳
基础医学药学肿瘤学
慢性粒细胞白血病病毒唑eIF4F翻译起始复合物mTOR/4EBP1/ eIF4E信号通路伊马替尼
chronic myeloid leukemiaribavirineIF4F complexmTOR/4EBP1/eIF4E signaling pathwayimatinib
龚玉萍,石芳芳.病毒唑通过抑制eIF4F翻译起始复合物 功能发挥抗白血病的作用[EB/OL].(2016-09-02)[2025-08-03].http://www.paper.edu.cn/releasepaper/content/201609-26.点此复制
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