穿膜融合多肽TAT-N24增强K562细胞对伊马替尼的敏感性

Cell-permeable TAT-N24 Fusion Peptide Enhances Sensitivity of K562 Cells to Imatinib

目的探讨穿膜融合多肽TAT-24增强K562细胞(慢性粒细胞白血病细胞)对伊马替尼敏感性的作用。方法常规培养K562细胞,并分为空白组、伊马替尼组(0.5μmol/L)、DMSO组、TAT-N24(100μg/mL)组、TAT-N24(100μg/mL)+伊马替尼(0.5μmol/L)组进行细胞处理。采用BrdU/PI双掺法检测细胞增殖,AnnexinⅤ/PI法检测细胞凋亡,Western blot检测Bcl-2、Ki-67的表达。结果细胞DNA合成检测显示TAT-N24和伊马替尼对K562细胞的增殖均具有一定的抑制作用(P<0.05),且TAT-N24同伊马替尼联用能够较单用显著抑制K562细胞增殖(P<0.01)。细胞凋亡分析显示,各组凋亡细胞比例分别为:空白组(4.82±0.31)%、DMSO组(4.12±0.47)%、TAT-N24组(5.12±0.45)%、伊马替尼组(9.64±1.07)%、TAT-N24+伊马替尼组(20.43±2.37)%;伊马替尼能够诱导K562细胞凋亡(P<0.05),TAT-N24对K562细胞凋亡无明显影响,但TAT-N24能显著增强伊马替尼对K562细胞凋亡的诱导作用(P<0.01),增强K562细胞对伊马替尼的敏感性。通过对各组细胞Ki-67和Bcl-2蛋白的检测进一步证实,联用TAT-24和伊马替尼能显著降低Bcl-2的表达,增强K562细胞对伊马替尼的敏感性。结论融合多肽TAT-24能够有效增强K562细胞对伊马替尼的敏感性。

Objective To elucidate the effect of cell-permeable TAT-N24fusion peptide on the sensitivity of K562cells(CML cell)to imatinib.Methods K562cells were cultured routinely and divided into blank control group,imatinib(0.5μmol/L)group,DMSO group,TAT-N24(100μg/mL)group and TAT-N24(100μg/mL)+imatinib(0.5μmol/L)group.The cell proliferation,apoptosis and expression levels of Bcl-2and Ki-67were detected by BrdU/PI incorporation assay,AnnexinⅤ/PI method and Western blotting,respectively.Results TAT-N24and imatinib inhibited DNA synthesis of K562cells,but TAT-N24combined with imatinib significantly inhibited proliferation of K562cells.Apoptosis analysis showed the apoptosis rate of cells in each group:(4.82±0.31)%in blank group,(4.12±0.47)%in DMSO group,(5.12±0.45)%in TAT-N24group,(9.64±1.07)%in imatinib group and(20.43±2.37)%in TAT-N24+imatinib group.The results revealed that imatinib significantly induced apoptosis of K562cells(P<0.05),TAT-N24had no significant effect on apoptosis,but TAT-N24significantly enhanced effect of imatinib and induced apoptosis of K562cells.TAT-N24was proved to enhance sensitivity of K562cells to imatinib.Further confirmed by the detection of protein level,TAT-24combined with imatinib significantly reduced the expression of Bcl-2,and enhanced the sensitivity of K562cells to imatinib.Conclusion The fusion peptide TAT-24can effectively enhance the sensitivity of K562cells to imatinib.