RIZ1表达对髓性白血病细胞株凋亡的影响

Apoptotic effect of RIZ1 expression on human myeloid leukemic cell lines

背景与目的RIZ1是近年来发现的抑癌基因,在多种实体瘤如乳腺癌、肝癌和胃癌中RIZI均表达下降或无表达。本研究探讨了RIZ1转录对髓性白血病细胞凋亡的作用。方法采用RT-PCR法检测5种髓性白血病细胞株即AML193、KG-1、KG-1a、K562、Ery-1中RIZ1mRNA转录状况。将含RIZ1全长cDNA的重组质粒pRIZ1RH转入该基因表达缺乏的细胞株中,以制备强制性基因表达细胞模型。细胞株导入单纯载体(pcDNA3.1)作为对照。于基因导入后24h应用FCM细胞凋亡率。结果该5种细胞株中,AML193与K562呈RIZ1mRNA无转录或低转录,但导入pRIZ1RH24h后则出现转录或转录明显增加,且测得该两细胞株凋亡率分别为(22.7±0.7)%、(28.6±1.2)%,均高于相应对照组[分别为(11.7±1.6)%、(9.0±0.8)%],差异均有显著性(P<0.01)。结论RIZ1的转录能够诱导AML193和K562髓性白血病细胞株凋亡,提示该基因可作为其失活的髓性白血病患者之基因疗法的重要靶分子。

Background and purpose： Few reports demonstrate the relation between the expression of RIZ1 which has been found to be a tumor suppressor gene recently and leukemia. This study investigated the effect of RIZ1 expression on the apoptosis of human myeloid leukemic cell lines. Methods： The expression of RIZ1 mRNA was observed in human myeloid leukemic cell lines AML193, KG-1, KG-1a, K562 and Ery-1 by reverse transcription polymerase chain reaction assay. RIZ1 was forced to express in the expression-lacking cell lines by transfecting pRIZ1 RH containing full length of RIZ1 cDNA to the cell lines. As controls, the cell lines were transfected with pcDNA3. 1. The apoptotic cells were determined by using the annexin V/propidium iodide stain 23, h after transfection. Results： Among the 5 cell lines, no expression of RIZ1 mRNA had been detected in AML193 and low expression in K562. The forced expression could be found in both cell lines 24h after transfection of pRIZ1 RH, accompanied by obviously increased apoptotic rates which were （22.7 ± 0.7）% in AML193 and （28.6±1.2）% in K562 compared to controls （11.7% ±1.6% and 9.0%±0.8%, respectively） （P 〈0.01）. Conclusions： The expression of RIZ1 can induce almptosis in human myeloid leukemic cell lines AML193 and K562, suggesting that RIZ1 may be an important molecular target for the gene therapeutics in the patients of myeloid leukemia lacking of RIZ1 expression.