特异启动子调控的MDR1和MnSOD基因对骨髓的选择性保护作用  

Selective myelo-protection by MDRl and MnSOD genes regulated by a specific promoter

作　　者：梁利波[1] 马业伟[1] 周小山[1] 杨军[2] 李艳春[1] 王争[1] 周兰萍[1] 章扬培[2] 赵清正[1] 

机构地区：[1]中国医学科学院中国协和医科大学肿瘤医院肿瘤研究所,北京100021 [2]北京军事医学科学院野战输血研究所

出　　处：《中华肿瘤杂志》2003年第1期17-20,共4页Chinese Journal of Oncology

基　　金：国家自然科学基金资助项目(39970818)

摘　　要：目的探讨特异保护骨髓细胞免受抗癌药物及射线损害的新途径。方法 构建了由APN骨髓特异性启动子调控的耐药、耐辐射基因的逆转录病毒载体,导入骨髓母细胞及癌细胞中,用细胞存活实验对耐药耐辐射性能进行观察。分离小鼠骨髓细胞,经转染基因后,再输回到预先用射线处理以破坏骨髓系统的同种受体小鼠体内。经化疗药物或射线处理后,不同时间采血,计算白细胞数,观察在药物或射线照射后导入耐药或耐辐射基因对造血细胞的保护作用。结果 导入MDR1基因的KGla细胞对秋水仙素、足叶乙甙、长春新碱、阿霉素及紫杉醇与对照组相比,各提高了10.6,10.4,11.2,4.2和14.2倍。导入由APN启动子驱动的MnSOD基因,使KGla细胞比对照组对射线(10 Gy)的耐受性提高3.7倍。相反,导入以上两个基因后,肝癌细胞BEL7402的化、放疗耐受性未见明显变化。体内实验表明,转染了MDR1和MnSOD基因的小鼠血液中,白细胞数量明显高于对照组(P<0.01)。结论体外由APN骨髓启动子调控的MDR1和MnSOD基因能特异性地保护骨髓细胞,而对肿瘤细胞无明显影响。体内,在用药物或射线处理动物时能重建造血功能。此研究为肿瘤患者在接受化、放疗时特异性保护骨髓系统,提供了新的思路和依据。Objective To study the specific protection of myeloid cells from chemotherapeutic agents and radiation. Methods The recombinant retroviral vectors containing MDR1 gene and MnSOD gene regulated by APN myeloid promoter were constructed and introduced into myeloblastic cell line KGla and hepatoma cell line BEL7402. The resistance of the cells to antitumor drugs and radiaton were analyzed by cell survival assay. In vivo, the murine bone marrow cells were isolated and infected by the retroviral particles, which were transplanted into recipient mouse treated with paclitaxel or X-ray. The murine white blood cell (WBC) was counted in order to assay the effects of MDR1 or MnSOD gene on hematopoiesis in the course of chemotherapy and radiotherapy. Results The resistance to chemotherapeutic agents such as cochicine, Vp-16, vincristine, doxorubcin and paclitaxel were elevated markedly by 10.6, 10.4, 11.2, 4.2 and 14.2 folds in KGla cell line transduced with MDR1 gene. The resistance to radiation increased 3.7 folds at the dose of 10 Gy compared with parental cells in KGla cell line transduced with MnSOD gene drived by APN promoter. In contrast, the chemosensitivity and the radiosensitivity showed no significant change in BEL 7402 cell line transduced with MDR1 gene and MnSOD gene. In vivo, the WBC counts in the mouse introduced with MDR1 gene or MnSOD gene were higher than those in the control mouse ( P < 0.01) . Conclusion The expression of MDR1 gene and MnSOD gene regulated by APN myeloid promoter is effective on myelo-specific protection without enhancing the resistance of tumor cells in vitro. The hematopoiesis can be reconstituted in vivo during anticancer drug or radiation treatment. This study may provide experimental envidences and new clues for myeloprotection of cancer patients being treated with chemotherapy and/or radiotherapy.

关 键 词：肿瘤 药物治疗 化学治疗 造血功能 骨髓细胞 MDRL基因 MnSOD基因 

分 类 号：R73-36[医药卫生—肿瘤]