Wang Ji-Shi, Chai Bai-Sheng, Fang Qin, He Ying-Ying, Chen Cheng, Yang Chang
Department of Hematology, Affiliated Hospital of Gui Yang Medical College, Guiyang 550004, China.
Zhonghua Xue Ye Xue Za Zhi. 2011 Jun;32(6):388-91.
To investigate the effect of heme oxygenase-1 (HO-1) expression on cell growth and apoptosis in imatinib resistant chronic myeloid leukemia (CML) cells (K562/A02-IM), and explore the relationship between HO-1 gene and CML.
The expression of HO-1 in 20 drug-resistant CML patients was detected by RT-PCR. Different concentrations of hemin were used to induce HO-1 expression of K562/A02-IM, HO-1 expression at different time was detected by RT-PCR and Western blot analysis. Cell apoptosis was detected by Annexin V/PI staining, and MTT assay was used to detect viability of K562/A02-IM cells after induction or inhibition of HO-1 gene by hemin and zinc protoporphyrin (ZPP).
RT-PCR showed that HO-1 was expressed in the bone marrow mononuclear cells (BMMNCs). When treated with hemin at different concentrations (0, 10, 20, 40 µmol/L) for 16 h, the expression of HO-1 in K562/A02-IM was increased in a dose-dependent manner, and peaked at 20 µmol/L of hemin for 16 h. The apoptosis rates were (17.61 ± 0.01)%, (12.13 ± 0.11)%, (7.94 ± 0.03)% and (4.62 ± 0.15)% at 0,10, 20 and 40 µmol/L of hemin respectively for 16 h and were (14.7 ± 0.05)%, (8.1 ± 0.07)% and (16.3 ± 0.13)% at 20 µmol/L of hemin treatment for 8,16, and 24 h respectively. Hemin induced apoptosis of K562/A02-IM cells in a dose-dependent manner. The expression of HO-1 was induced in K562/A02-IM cells in a dose-dependent manner, and the survival of K562/A02-IM cells was significantly increased as compared to that of control group. When HO-1 was inhibited by ZPP, the cells survival was sharply decreased compared to that of the control group (P < 0.05).
HO-1 was expressed in the BMMNCs. It is a kind of molecules whose expression can be induced and can promote the growth of drug-resistant cells. Inhibition of HO-1 expression probably be used for the treatment of drug-resistant CML.
探讨血红素加氧酶-1（HO-1）表达对伊马替尼耐药的慢性髓性白血病（CML）细胞（K562/A02-IM）生长及凋亡的影响，探讨HO-1基因与CML的关系。
采用RT-PCR检测20例耐药CML患者HO-1的表达。用不同浓度的血红素诱导K562/A02-IM细胞HO-1表达，采用RT-PCR和Western blot分析检测不同时间HO-1的表达。采用Annexin V/PI染色检测细胞凋亡，用MTT法检测血红素及锌原卟啉（ZPP）诱导或抑制HO-1基因后K562/A02-IM细胞的活力。
RT-PCR显示HO-1在骨髓单个核细胞（BMMNCs）中表达。用不同浓度（0、10、20、40 μmol/L）血红素处理16 h，K562/A02-IM细胞中HO-1的表达呈剂量依赖性增加，在20 μmol/L血红素处理16 h时达到峰值。16 h时，0、10、20和40 μmol/L血红素处理组的凋亡率分别为（17.61±0.01）%、（12.13±0.11）%、（7.94±0.03）%和（4.62±0.15）%；20 μmol/L血红素处理8、16和24 h时的凋亡率分别为（14.7±0.05）%、（8.1±0.07）%和（16.3±0.13）%。血红素呈剂量依赖性诱导K562/A02-IM细胞凋亡。K562/A02-IM细胞中HO-1的表达呈剂量依赖性诱导，与对照组相比，K562/A02-IM细胞的存活率显著增加。当HO-1被ZPP抑制时，与对照组相比细胞存活率急剧下降（P<0.05）。
HO-1在BMMNCs中表达。它是一种其表达可被诱导且能促进耐药细胞生长的分子。抑制HO-1表达可能用于耐药CML的治疗。
