目的： 探讨靶向干扰细胞因子诱导凋亡抑制因子1 （cytokine induced apoptosis inhibitor 1，CIAPIN1）基因表达后慢性 粒细胞性白血病K562细胞对伊马替尼的敏感性。 方法 ：构建靶向CIAPIN1基因的shRNA干扰载体；使用实时定量PCR、West- ern blotting以及免疫荧光评价CIAPIN1-shRNA组（CIAPIN1-shRNA转染）和scramble-shRNA组（scramble-shRNA转染K562细 胞）干扰效率；伊马替尼（imatinib）处理两组K562细胞后，MTT法检测其增殖能力，集落形成实验检测细胞克隆形成能力，流式细 胞术和Western blotting检测细胞周期、凋亡及凋亡相关蛋白的变化。 结果： shRNA干扰可有效抑制CIAPIN1表达，CIAPIN1- shRNA组的CIAPIN1 mRNA表达量为scramble-shRNA组的(29.74±4.03)%、CIAPIN1蛋白表达量前者为后者的(21.57±2.18)%。 CIAPIN1表达下调能显著抑制伊马替尼对K562细胞的增殖和克隆形成，CIAPIN1-shRNA+imatinib组的细胞克隆形成数为 （15.60±1.03）个/视野，克隆半径为（2.63±0.55）μm，均小于scramble-shRNA+imatinib组（P<0.05或P<0.01）。CIAPIN1-shRNA+ imatinib组的细胞G1期细胞比例比scramble-shRNA+imatinib组明显增多，S期细胞比例较scramble-shRNA+imatinib组明显减少 （均P<0.01）。CIAPIN1-shRNA+imatinib组K562细胞凋亡率明显增加（P<0.01）。敲除CIAPIN1能抑制细胞周期相关蛋白Cyclin D1、Bcl-xl、Bcl-2、Mcl-1表达，诱导细胞内细胞凋亡相关蛋白p21、Bid、Bim表达，且与伊马替尼具有协同作用。 结论： CIAPIN1表 达下调可明显提高K562细胞对伊马替尼的敏感性，该作用主要通过阻滞K562细胞周期及诱导凋亡相关蛋白表达实现。

Objective: To investigate the biological effects and the related mechanisms of cytokine induced apoptosis inhibitor 1 (CIAPIN1) on the sensitivity of K562 chronic myeloid leukemia cells to imatinib. Methods: Specific short hairpin RNA (shRNA) inter- ference vectors targeting CIAPIN1 (CIAPIN1-shRNA) were constructed. Interference efficiency of interference group (K562 cells trans- fected with CIAPIN1-shRNA) and control group (K562 cells transfected with scramble-shRNA) was evaluated using Real-time PCR, Western blotting and immunofluorescence staining. The interference group and control group were treated by 2 μmol/L imatinib. Cell viability was detected using MTT assay. Colony formation ability was detected using cell colony forming experiment. Cell cycle and apoptosis was detected using Flow cytometry and Western blotting. Results: CIAPIN1 expression was decreased effectively by specific shRNA targeting CIAPIN1. The CIAPIN1 mRNA content in CIAPIN1-shRNA group accounted (29.74±4.03)% of scramble-shRNA group, while the CIAPIN1 protein content in CIAPIN1-shRNA group accounted (21.57±2.18)% of scramble-shRNA group. CIAPIN1 knock-down significantly enhanced the inhibitory activity of imatinib on proliferation and colony forming ability of K562 cells. The col-ony number and radius of the CIAPIN1-shRNA+imatinib group was (15.60±1.03) and (2.63±0.55) μm, which were all less than those of the scramble-shRNA+imatinib group. The knock down also increased the activity of imatinib to block the cell cycle at G1 phase and to promot apoptosis of cells. The cell ratio at G1 phase of the CIAPIN1-shRNA+imatinib group was obviously increased while the ratio at S phase was obviously decreased compared with those of scramble-shRNA+imatinib group. Hoechst33258 staining and flow cytome- try showed that the proportion of apoptotic K562 cells in the CIAPIN1-shRNA+imatinib group increased. The results of Western blot- ting showed that CIAPIN1 knock-down not only up-regulated the expressions of apoptosis related proteins (p21, Bid and Bim), but also repressed expressions of cell cycle related proteins (Cyclin D1, Bcl-xl, Bcl-2 and Mcl-1), which had synergistic effects with imatinib. Conclusion: CIAPIN1 knock-down significantly sensitized K562 cells to imatinib treatment, and the mechanism might be related with cell cycle arrest and expression of apoptosis-associated proteins.

国家自然科学基金资助项目（No. 81541093）；山东省自然科学基金项目资助（No. ZR2015HL075）；山东省高等学校科研计划项目资 助（No. J17KA252）；山东省医药卫生科技发展计划项目资助（No. 2015WS0056）；潍坊市科学技术发展计划项目资助（No. 2014WS048）。