雷帕霉素逆转急性淋巴细胞白血病CEM-C1细胞对糖皮质激素耐药的研究

目的探讨雷帕霉素是否可以逆转地塞米松(DEX)耐药的急性T淋巴细胞白血病(T-ALL)细胞株CEM-C1细胞的GC耐药性。方法以儿童T-ALL GC耐药株CEM-C1和GC敏感株CEM-C7为研究对象,MTT法检测不同浓度(1 000 ng/ml、100 ng/ml、10 ng/ml、1 ng/ml和0.1 ng/ml)雷帕霉素及其联合1μmol/L地塞米松(DEX)作用后对细胞增殖的影响;细胞离心甩片瑞氏染色法观察细胞形态学变化;Annexin V/PI染色法检测对细胞凋亡的影响;PI染色法检测细胞周期改变。结果①不同浓度雷帕霉素作用于CEM-C1和CEM-C7细胞,对细胞生长的抑制作用均呈时间和浓度依赖性,联合应用1μmol/L DEX后,这一生长抑制作用显著增强,24 h IC50约为100 ng/ml。②以终浓度100 ng/ml雷帕霉素作用于CEM-C1和CEM-C7细胞18、24及48 h,细胞形态学与对照相比均无明显变化;Annexin V-PI双染流式细胞术检测均未见明显凋亡;细胞周期测定发现两种细胞均阻滞于G1期,S期细胞比例均明显降低。③以终浓度100 ng/ml雷帕霉素联合1μmol/L DEX作用于CEM-C1细胞后,瑞氏染色发现CEM-C1细胞于24 h出现细胞核改变,48 h出现明显凋亡;Annexin V/PI双染细胞凋亡检测显示细胞凋亡率较单用雷帕霉素及DEX时显著增加,18 h时早期凋亡细胞开始增多,24 h时最为明显;细胞周期测定显示S期细胞比率较单用雷帕霉素时显著降低,而G1期细胞显著增多。结论雷帕霉素能够逆转CEM-C1细胞对GC的耐药性,其机制有待进一步深入研究。

Rapamycin reverses glucocorticoid resistance in human T-cell acute lymphoblastic leukemia CEM-C1 cells

Objective Glucocorticoids(GC) specifically induce apoptosis in malignant lymphoblasts and are thus pivotal in the treatment of acute lymphoblastic leukemia(ALL).However,GC-resistance is a therapeutic problem with an unclear molecular mechanism.Whether dexamethasone(DEX) combined with rapamycin could inhibit the growth and in-duce the apoptosis in GC resistant CEM-C1 cells was explored in this study.Methods Childhood T-ALL GC-resistant cell line CEM-C1 and GC-sensitive cell line CEM-C7 were cultured in vitro...