Inhibition of KPNB1 Inhibits Proliferation and Promotes Apoptosis of Chronic Myeloid Leukemia Cells Through Regulation of E2F1
Inhibition of KPNB1 Inhibits Proliferation and Promotes Apoptosis of Chronic Myeloid Leukemia Cells Through Regulation of E2F1
复制标题
抑制 KPNB1 通过调节 E2F1 抑制慢性粒细胞白血病细胞增殖并促进细胞凋亡
DOI：
10.2147/ott.s210048
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发表时间：
2019-01-01
影响因子：
4
通讯作者：
Feng, Wenli
中科院分区：
文献类型：
--
作者：
Wang, Teng;Huang, Zhenglan;Feng, Wenli
背景：核转运蛋白-β 1 (KPNB1) 属于核转运蛋白超家族，其功能是从细胞质到细胞核的穿梭蛋白。据报道，在多种癌症中高水平的 KPNB1 可促进细胞增殖并抑制细胞凋亡。然而，KPNB1在慢性粒细胞白血病(CML)中的作用仍不确定。方法：通过Western blotting分析CML患者样本和细胞系中KPNB1的表达水平。采用增殖实验和集落形成实验研究体外KPNB1敲低后CML细胞的增殖情况。接下来，使用蛋白质印迹法评估 KPNB1 对 E2F1 和其他细胞周期调节因子的影响。然后，通过免疫荧光检测E2F1的位置。最后采用流式细胞术检测KPNB1抑制剂进口唑(IPZ)对CML细胞的影响。结果：本研究首次发现KPNB1在CML细胞中过表达。用小干扰 RNA (siRNA) 和 IPZ 靶向 KPNB1 可减少 CML 细胞的增殖并诱导细胞凋亡。还研究了用 siRNA 抑制 KPNB1 后 E2F1 核转运被阻断的潜在机制，表明 KPNB1 过表达介导了 CML 细胞中 E2F1 的过度核转运。此外，E2F1靶分子如c-Myc和KPNA2的表达显着降低。 IPZ将CML细胞阻滞在G2/M期并诱导细胞凋亡。结论：综上所述，我们的结果清楚地表明KPNB1在CML细胞中过度表达并介导E2F1转位到CML细胞核中，从而抑制KPNB1减少CML细胞的增殖并诱导细胞凋亡，这为靶向CML治疗提供了新的见解。
Background: Karyopherin-beta 1 (KPNB1) belongs to the karyopherin superfamily, which functions as shuttling proteins from the cytoplasm to nuclear. A high level of KPNB1 has been reported in various cancers which promotes cell proliferation and inhibits apoptosis. However, the role of KPNB1 in chronic myeloid leukemia (CML) remains uncertain.Methods: Expression level of KPNB1 in CML patient samples and cell lines was analyzed by Western blotting. The proliferation assays and colony formation assay were used to study the CML cell proliferation when KPNB1 knockdown in vitro. Next, Western blotting was used to evaluate the effects of KPNB1 on E2F1 and other cell cycle regulators. Then, the location of E2F1 was detected by immunofluorescence. Finally, flow cytometry was used to detect the effect of KPNB1 inhibitor importazole (IPZ) on CML cells.Results: In this study, we firstly showed that KPNB1 is over-expressed in CML cells. Targeting KPNB1 with small interfering RNA (siRNA) and IPZ reduced proliferation and induced apoptosis of CML cells. The underlying mechanisms were also investigated that E2F1 nuclear transport was blocked after inhibiting KPNB1 with siRNA, suggesting KPNB1 over-expression mediates the excessive nuclear transport of E2F1 in CML cells. Moreover, the expression of the E2F1 targeted molecule such as c-Myc and KPNA2 was markedly reduced. The IPZ arrested CML cells at G2/M phase and induced cell apoptosis.Conclusion: In summary, our results clearly showed that KPNB1 is over-expressed in CML cells and mediates the translocation of E2F1 into the nucleus of CML cells, thereby inhibition of KPNB1 reduced proliferation and induced apoptosis of CML cells which provides new insights for targeted CML therapies.