Cheng Jian, Wang Ting, Chen Bao-An, Ding Jia-Hua, Gao Chong, Xia Guo-Hua, Bao Wen, Song Hui-Hui, Xu Wen-Lin, Shen Hui-Ling
Department of Hematology, Zhongda Hospital, Southeast University Medical College, Nanjing, Jiangso Province, China.
Zhongguo Shi Yan Xue Ye Xue Za Zhi. 2011 Apr;19(2):337-41.
Iron is an essential element for cell growing including tumor cells. This study was purposed to explore the effect of desferrioxamine (DFO) on cell line K562/A02 and its mechanism. K562/A02 cells were cultured with different concentrations of DFO. The inhibitory effects of adriamycin (ADM) used alone or combined with DFO on the proliferation of K562/A02 was evaluated by MTT assay. The apoptosis rate of K562/A02 cells after treatment with 0, 12.5, 25 and 50 µmol/L DFO alone or in combination with 1 mg/L ADM were analyzed by flow cytometry. ADM accumulation in K562/A02 cells after treatment with different concentrations of 0, 12.5, 25 and 50 µmol/L DFO were also analyzed by flow cytometry. The levels of BAX/BCL-2 and MDR1 mRNA were determined by RT-PCR, and then the protein level of P-glycoprotein (P-gp) was detected by Western blot. The results showed that the IC(50) of ADM for K562 and K562/A02 cells were (1.46 ± 0.07) mg/L and (40.98 ± 3.05) mg/L respectively. The resistance of K562/A02 cells to ADM was 28.06 times as that of K562 cells. After treatment of K562/A02 cell with DFO of 12.5, 25 and 50 µmol/L for 48 hours, the resistance of K562/A02 cells to ADM were increased by 24.95, 16.11 and 9.99 times respectively. When K562/A02 cells were incubated with different concentrations of DFO of 12.5, 25, 50 µmol/L for 48 hours, the apoptosis rat were (3.50 ± 0.30)%, (7.27 ± 0.32)% and (12.53 ± 1.21)% respectively. After co-culture with DFO and ADM for 48 hours, apoptosis rate were (6.13 ± 0.29)%, (9.57 ± 0.40)% and (18.97 ± 1.10)% respectively. The above apoptosis rates was much higher than that of control group (p < 0.05) and they were dose-dependent. In comparison between DFO + ADM group and DFO group, there was no significant difference (p > 0.05). Expression rate of BAX/BCL-2 increased. The levels of MDR1 mRNA reduced. Furthermore, expression of P-gp also decreased in K562/A02 cells. It is concluded that iron increase can promote K562/A02 cells growth and inhibit their apoptosis. Otherwise, iron-deprivation can induce K562/A02 cells apoptosis. DFO disturbs the iron metabolism and inhibits DNA synthesis of K562/A02 cells. This action of DFO may enhance the susceptibility of K562/A02 cells to apoptosis induced by chemotherapeutic drugs. The iron-deprivation may play a role in the treatment of leukemia with combination of DFO with other anticancer agents.
铁是包括肿瘤细胞在内的细胞生长所必需的元素。本研究旨在探讨去铁胺（DFO）对K562/A02细胞系的作用及其机制。用不同浓度的DFO培养K562/A02细胞。采用MTT法评价阿霉素（ADM）单独或与DFO联合使用对K562/A02细胞增殖的抑制作用。采用流式细胞术分析单独使用0、12.5、25和50 μmol/L DFO或与1 mg/L ADM联合处理后K562/A02细胞的凋亡率。采用流式细胞术分析用不同浓度0、12.5、25和50 μmol/L DFO处理后K562/A02细胞中ADM的蓄积情况。采用RT-PCR检测BAX/BCL-2和MDR1 mRNA水平，然后用Western blot检测P-糖蛋白（P-gp）的蛋白水平。结果显示，ADM对K562和K562/A02细胞的IC(50)分别为(1.46±0.07)mg/L和(40.98±3.05)mg/L。K562/A02细胞对ADM的耐药性是K562细胞的28.06倍。用12.5、25和50 μmol/L DFO处理K562/A02细胞48小时后，K562/A02细胞对ADM的耐药性分别增加了24.95、16.11和9.99倍。当K562/A02细胞用12.5、25、50 μmol/L不同浓度的DFO孵育48小时时，凋亡率分别为(3.50±0.30)%、(7.27±0.32)%和(12.53±1.21)%。与DFO和ADM共培养48小时后，凋亡率分别为(6.13±0.29)%、(9.57±0.40)%和(18.97±1.10)%。上述凋亡率均显著高于对照组（p<0.05），且呈剂量依赖性。DFO+ADM组与DFO组比较，差异无统计学意义（p>0.05）。BAX/BCL-2表达率升高。MDR1 mRNA水平降低。此外，K562/A
