多药耐药基因在人骨髓CD34^+细胞中的表达及对化疗药物的耐受性

Chemoprotective role of multiple drug resistance gene over expression in human bone marrow CD34^+ cells

目的 探讨人多药耐药 (MDR1)基因过表达能否提高骨髓造血干 /祖细胞对化疗药物的耐受性。方法 应用免疫磁性分选系统 (miniMACS)体外分离、纯化骨髓CD34+ 细胞并进行扩增 ;采用脂质体介导的基因转移方法 ,将人MDR1基因转染骨髓CD34+ 细胞 ,并运用流式细胞术检测基因转导前后造血干 /祖细胞中MDR1基因的编码产物 Pl70糖蛋白表达和功能变化。MTT法检测基因转导前后造血干 /祖细胞对化疗药物耐受性的改变。结果 MDR1基因转导后 4 8h骨髓造血干 /祖细胞Pl70抗原表达为 (2 3 6± 2 34) % ,明显高于转导前 (11 2± 2 2 ) % (P <0 0 1)。P170的功能活性被Rh 12 3的摄取和排除试验证实。转基因后细胞表现为典型的多药耐药表型 ,对P170谱的多种化疗药的耐受性提高了约 2～ 8倍 ,对非P170谱的顺铂、氨甲喋呤耐受性没有改变。结论 人多药耐药基因能提高骨髓造血干 /祖细胞对多种化疗药物的耐受性 ,表现为典型的多药耐药表型。

Objective To explore whether over expression of multiple drug resistance (MDR1) gene in human normal bone marrow hematopoietic stem/progenitor cells (HPCs) could increase resistance of HPCs to cytotoxic drugs Methods Bone marrow CD34 + cells were enriched with magnetic cell sorting system (MACS) Then liposome mediated MDR1 gene was transferred into bone marrow CD34 + cells The fluorescence activated cell sorter (FACS) was used to evaluate the expression and function of P170 encoded by MDR1 gene MTT assay was used to evaluate the difference of drug tolerance in transduced and non transduced cells Results The amount of P170 in non transduced CD34 + cells was (11 2±2 2)%, but up to (23 6±2 34)% after gene transduction for 48 h ( P <0 0l) The function of P170 was confirmed by the accumulation and extrusion of Rh 123 The transduced cells showed a classical MDR type The resistance factor of the transduced CD34 +cells to cytotoxic drugs was about 2～8 times as much as that of the control Conclusion The over expression of P170 could increase the resistance of HPCs to MDR type cytotoxic agents