D'Hondt V, Caruso M, Bank A
Department of Medicine, Columbia University, College of Physicians and Surgeons, New York, NY 10032, USA.
Hum Gene Ther. 1997 Oct 10;8(15):1745-51. doi: 10.1089/hum.1997.8.15-1745.
Transduction of hematopoietic progenitors with a multidrug resistance gene like mdr-1 or mrp aims to protect bone marrow from toxicity of chemotherapeutic agents. The interest in the use of mrp as an alternative to mdr-1 gene transfer for bone marrow protection lies in its different modulation. Indeed, classical P-gp reversal agents, tested in the clinic to decrease mdr-1 tumor resistance, have little or no effect on MRP function. This would allow, in the same patient, the use of reversal agents to decrease P-gp tumor resistance without reversing bone marrow protection of the transduced hematopoietic cells provided by multidrug resistance-associated protein (MRP). As a first step, we have constructed and tested two different mrp-containing vectors with either the Harvey retroviral long terminal repeat (LTR) or PGK as promoters and generated ecotropic producer cells. We have shown by Southern blot analysis that retroviral supernatant from these producer cells can efficiently transmit the mrp gene to target cells. Mrp expression could be detected by fluorescence-activated cell sorting (FACS) analysis in the producer cells. The transduced cells have increased resistance to doxorubicin, vincristine, and etoposide. Furthermore, chemoprotection of the transduced cells was increased after selection with chemotherapeutic agents in the presence of glutathione, a co-factor for MRP function. These data indicate that mrp retroviral vectors may be useful for chemoprotection and selection.
用多药耐药基因（如mdr-1或mrp）转导造血祖细胞旨在保护骨髓免受化疗药物的毒性作用。将mrp用作mdr-1基因转移的替代方法以保护骨髓，其意义在于它有不同的调节方式。实际上，在临床上用于降低mdr-1肿瘤耐药性的经典P-糖蛋白逆转剂对MRP功能几乎没有影响。这使得在同一患者中，可以使用逆转剂来降低P-糖蛋白肿瘤耐药性，而不会逆转由多药耐药相关蛋白（MRP）提供的转导造血细胞的骨髓保护作用。作为第一步，我们构建并测试了两种不同的含mrp载体，分别以哈维逆转录病毒长末端重复序列（LTR）或磷酸甘油酸激酶（PGK）作为启动子，并产生了嗜亲性包装细胞。我们通过Southern印迹分析表明，这些包装细胞的逆转录病毒上清液可以有效地将mrp基因传递给靶细胞。通过荧光激活细胞分选（FACS）分析可以在包装细胞中检测到Mrp表达。转导的细胞对阿霉素、长春新碱和依托泊苷的耐药性增加。此外，在谷胱甘肽（MRP功能的辅助因子）存在的情况下，用化疗药物进行选择后，转导细胞的化学保护作用增强。这些数据表明，mrp逆转录病毒载体可能对化学保护和选择有用。
