胆固醇对K562及耐药株K562G细胞增殖及伊马替尼敏感性的影响

Effects of Cholesterol on the Proliferation and Imatinib Sensitivity of Chronic Leukemia Cell Line K562 and Imatinib-Resistance Cell Line K562G

目的:探讨胆固醇对K562及耐药株K562G细胞增殖及伊马替尼(Imatinib,IM)敏感性的影响。方法:通过qRT-PCR方法检测K562和K562G细胞的胆固醇代谢途径相关蛋白的表达;以不同药物组合处理K562细胞、K562G细胞,采用CCK-8方法检测细胞增殖情况。结果:耐药K562G细胞胆固醇合成酶(人角鲨烯单加氧酶SQLE,细胞色素P450酶家族51亚家族A1 CYP51A1,固醇C5去饱和酶SC5D)表达下降、而低密度脂蛋白受体LDLR、固醇酰基转移酶SOAT1、ATP结合盒转运体A1 ABCA1表达量增加;0.5μg/m L、0.75μg/m L胆固醇处理K562细胞,其增殖率比对照组K562细胞分别增加(9.51±2.84)%和(19.88±3.00)%;使用阿托伐他汀(20μM)、GW3965 (20μM)、MβCD (10 m M)降低K562G细胞胆固醇使其增殖抑制率分别为(50.73±2.34)%,(49.42±1.13)%,(76.54±1.48)%;两种浓度胆固醇使IM处理的K562细胞增殖抑制率分别减少51.59%及53.80%;MβCD联合IM使K562及K562G细胞存活率分别降低至6.89%及23.34%。结论:IM抵抗的K562G细胞与IM敏感的K562细胞相比胆固醇代谢增强;增加胆固醇能够促进K562细胞增殖,降低细胞对IM的敏感性;MβCD可能通过降低胆固醇增强K562、K562G细胞对IM敏感性。

Objective: To investigate the effects of cholesterol on the proliferation and Imatinib(IM) sensitivity of K562 and K562 G cells. Methods: The expression of cholesterol metabolism-related enzymes in K562 and K562 G cells were detected by qRT-PCR.K562 and K562 G cells were treated with different drug combinations, and the cell proliferation was detected by CCK-8 method. Results:The expression of cholesterol synthesis-related enzymes(human squalene monooxygenase SQLE, cytochrome P450 family 51 subfamily A1 CYP51 A1, sterol C5 desaturase SC5 D) in K562 G cells were significantly decreased, while the expression of low-density lipoprotein receptor LDLR, sterol acyltransferase SOAT1, ATP binding box transporter A1 ABCA1 were significantly increased. The proliferation rates of K562 cells treated with 0.5 μg/m L and 0.75 μg/m L cholesterol were increased respectively by(9.51±2.84)% and(19.88± 3.00)%compared with the control group. The inhibition rate of K562 G cells was lowered by using Atorvastatin(20 μM), GW3965(20 μM) and MβCD(10 m M), respectively(50.73±2.34)%,(49.42±1.13)% and(76.54±1.48)%. The two concentrations of cholesterol reduced the inhibition rate of K562 cells treated with IM before by 51.59 % and 53.80 %, respectively. The combination of MβCD and IM reduced the survival rate of K562 and K526 G cells to 6.89 % and 23.34 %, respectively. Conclusion: The cholesterol metabolism of K562 G cells is increased compared with that of K562 cells. Increasing cholesterol can promote the proliferation of K562 cells and reduce their sensitivity to IM. MβCD may increase the sensitivity of K562 and K562 G cells to IM by lowering cholesterol.