IL—6基因转染的骨髓基质细胞系对骨髓移植小鼠造血功能恢复？…

目的：探讨白细胞介素６（ＩＬ－６）基因转染的骨髓基质细胞系ＱＸＭＳＣ１ＩＬ－６对骨髓移植后造血功能的重建作用。方法：将骨髓造血细胞和骨髓基质细胞系一起经尾静脉注射给同系小鼠，建立骨髓移植（ＢＭＴ）模型。小鼠的造血功能用脾结节（ＣＦＵ－Ｓ）、粒－单系祖细胞（ＣＦＵ－ＧＭ）、红系祖细胞（ＣＦＵ－Ｅ、ＢＦＵ－Ｅ）测定及外周血各项血液学指标来确定。结果：ＷＸＭＳＣ１ＩＬ－６转基因骨髓基质细胞可明显增强ＢＭ     

人多药耐药基因-1及二氢叶酸还原酶基因共转导小鼠造血细胞

耐药基因转导骨髓细胞对化疗病人造血系统的保护作用已受到人们的重视.本研究利用多药耐药基因-1(mdr-1)及二氢叶酸还原酶(dhfr)双基因转染小鼠骨髓细胞,观察造血细胞对两种耐药谱化疗药物的抵抗能力.结果表明,所用逆转录病毒载体转染率达到15%左右,转基因骨髓细胞CFU-GM对taxo1及MTX的耐药能力明显增强,说明外源基因在造血祖细胞中的正确表达;转基因骨髓细胞回输给同系小鼠7个月后,FCM技术仍可检测到外周血白细胞gp170的表达,且其基因组DNA中可检测到mdr-1及dhfr基因特异序列,表明两种基因可能已稳定整合至造血干/祖细胞中.上述结果为以骨髓细胞为靶体的耐药基因治疗提供了有用的实验室资料.     

突变的人DHFR肿瘤耐药基因转导脐血干细胞的体外实验研究

目的探讨突变的人二氢叶酸还原酶（ｍＤＨＦＲ）耐药基因在人造血干细胞中抗甲氨蝶呤（ＭＴＸ）的效应。方法应用免疫磁珠分选系统（ＭＡＣＳ）分离纯化脐血ＣＤ３４＋细胞后，用含ｍＤＨＦＲ的逆转录病毒上清转染脐血ＣＤ３４＋细胞，采用造血干细胞集落形成实验进行转导后细胞抗ＭＴＸ分析。结果应用ＭＡＣＳ能高度纯化人ＣＤ３４＋细胞，使分选后的脐血ＣＤ３４＋细胞的纯度平均达９０％，回收率为７１．１％。在ＭＴＸ浓度为２０ｎｍｏｌ／Ｌ的条件下培养１４天，转导ｍＤＨＦＲ耐药基因的脐血干细胞集落形成数明显高于对照组（Ｐ＜０．０１），同时对ＭＴＸ的抗性提高了约２倍。结论突变的人ＤＨＦＲ耐药基因能提高人的造血干细胞对化疗药物ＭＴＸ的抗性。     

白血病患者WT1基因的表达及其临床意义

目的：探讨ＷＴ１基因在白血病细胞中的表达及其临床意义。方法：应用逆转录－聚合酶链反应（ＲＴ－ＰＣＲ）法测定Ｋ５６２、ＨＬ－６０、ＴＦ－１及Ｕ９３７四株白血病细胞系，４５例白血病患者，１５名正常人外周血及１０例非血液病患者正常骨髓细胞ＷＴ１基因的表达。结果：Ｋ５６２、ＨＬ－６０及ＴＦ－１三株白血病细胞系均高度表达ＷＴ１，而Ｕ９３７细胞系未测到ＷＴ１。急性髓系白血病（ＡＭＬ）２５例中２１例、急性淋巴细胞白血病（ＡＬＬ）１１例中８例、慢性粒细胞白血病（ＣＭＬ）急性变者２例、慢性及加速期ＣＭＬ患者７例中１例ＷＴ１表达阳性。１５名正常人外周血及１０例非血液病患者正常骨髓细胞ＷＴ１基因表达阴性。结论：ＷＴ１基因在大多数急性白血病中表达，与白血病的病程发展可能有关，可作为检测白血病微量残留病的特异性标记。     

多药耐药基因在骨髓移植模型中的表达

目的 探讨多药耐药基因（mdrl)在骨髓移植小鼠模型中表达情况，及转染mdrl的骨髓细胞对化疗中骨髓保护的可行性。方法 以小鼠骨髓细胞为靶细胞，通过逆转录病毒介导，将mdrl转入骨髓细胞，通过将转染基因的骨髓细胞回输同种小鼠体内的骨髓移植动物模型，观察不同时期移植小鼠骨髓细胞中mdrl的表达及功能，结果 （1）成功地将mdrl导入小鼠骨髓细胞中，转染率达到35%；（2）采用程序性移植方法成功建立了mdrl转基因鼠骨髓移植模型；（3）mdrl在移植小鼠细胞内稳定，有效地表达，观察1-5个月mdrl转染的细胞在受体鼠骨髓单个核细胞中所占比例分别为8.0%，8.0%,7.5%,4.0%,3.0%;(4)mdrl转染的骨髓细胞在化疗中有明显的骨髓保护作用。结论 从一个侧面证实了通过mdrl转染骨髓细胞在化疗中进行骨髓保护是一种长期，稳定，有效的方法。     

人GM—CSF基因转染小鼠肝癌细胞及其致瘤性研究

为建立以腺病毒为载体的ＧＭ－ＣＳＦ基因转染瘤苗，并研究其体内抗肿瘤作用，应用携带有人ＧＭ－ＣＳＦ基因的重组腺病毒（Ｒ－Ａｄ５）载体转染ＢＡＬＢ／ｃ小鼠肝癌细胞株（Ｈ２２），体外应用酶联免疫吸附试验（ＥＬＩＳＡ法），检测ＧＭ－ＣＳＦ表达水平，以ＧＭ－ＣＳＦ基因转染的Ｈ２２细胞进行致瘤性研究。结果：（１）重组腺病毒载体能成功地介导ＧＭ－ＣＳＦ基因转染Ｈ２２细胞并能持续有效表达２６￣３１天，瘤苗的辐照处     

HSV-tk/GCV自杀基因疗法及其影响树突状细胞功能的实验研究

目的 研究单纯疱疹病毒－胸苷激酶／更昔洛韦（ＨＳＶ－ｔｋ／ＧＣＶ）自杀基因系统的特性,探讨转ＨＳＶ－ｔｋ基因后,肿瘤细胞被更昔洛韦（Ｇａｎｃｉｃｌｏｖｉｒ,ＧＣＶ）杀伤时的凋亡现象及对树突状细胞功能的影响。方法 以逆转录病毒法将ＨＳＶ－ｔｋ基因转人乳腺癌细胞株ＭＣＦ－７中,以Ｓｏｕｔｈｅｒｎ ｂｌｏｔ法对肿瘤细胞基因组ＤＮＡ中ｔｋ基因的整合进行鉴定,以流式细胞仪及电镜观察ＧＣＶ杀伤ＭＣＦ－７／ｔｋ细胞时的凋亡现象,由脐血ＣＤ３４＾＋细胞诱生树突状细胞,以＾３Ｈ－ＴｄＲ掺入法检测树突状细胞刺激同种异体Ｔ淋巴细胞增殖的能力。结果 以逆转录病毒法成功地将ＨＳＶ－ｔｋ基因转入ＭＣＦ－７细胞中,转染ｔｋ基因的ＭＣＦ－７细胞能被ＧＣＶ有效杀伤并存在凋亡现象,凋亡率可达３１．３％;由脐血ＣＤ３４＾＋细胞在ＧＭ－ＣＳＦ、ＴＮＦ     

内在核糖体进入位点控制多药耐药基因mdr1表达的研究

目的：观察内在核糖体进入位点（ＩＲＥＳ）控制多药耐药基因ｍｄｒ１的表达能力。方法：以帽依赖性Ｈａｍｄｒ１载体为对照，利用ｐＳＸＬＣ／ｐＨａ系统构建依赖脑心肌炎病毒ＩＲＥＳ翻译的逆转录病毒载体ＨａＩＲＥＳｍｄｒ１（ＨａＩｍｄｒ１），脂质体转染法导入鼠源包装细胞ＧＰ＋Ｅ８６并获得长春新碱耐药细胞；用聚合酶链反应（ＰＣＲ）与流式细胞术（ＦＣＭ）检测ｍｄｒ１基因的转移与表达。结果：病毒生产细胞ＧＰ＋Ｅ８６／ＨａＩｍｄｒ１上清中逆转录病毒的滴度为２．０×１０５ｃｆｕ／ｍｌ，对长春新碱、柔红霉素与紫杉醇产生交叉耐药（２４～５２倍），而且具有多药耐药表型。ＰＣＲ证实ｍｄｒ１基因已稳定整合至ＧＰ＋Ｅ８６／ＨａＩｍｄｒ１细胞基因组；ＦＣＭ分析表明ＩＲＥＳ能引导ｍｄｒ１基因翻译成Ｐ糖蛋白而高效表达，程度略低于Ｈａｍｄｒ１对照。结论：ＩＲＥＳ可引导ｍｄｒ１基因进行有效的帽非依赖性翻译，ｍｄｒ１基因在双顺反子载体中可作为显性选择性基因用于基因治疗。     

异基因骨髓移植后早期输注供者白细胞治疗复发性急性白血病一例

最近,我所收治１例对ＢＵＣＹ２［加用环己亚硝脲（ＣＣＮＵ）与足叶乙甙（Ｖｐ１６）］预处理方案耐药的复发性急性白血病（ＡＬ）患者,在异基因骨髓移植（ａｌｌｏＢＭＴ）后早期进行２次供者白细胞输注（ＤＬＩ）治疗获完全缓解及骨髓植活,报道如下。病例和方法１患者,男,２８岁。１９９７年３月在当地医院诊断为急性髓系白血病（ＡＭＬＭ４型）,经ＤＡ方案（柔红霉素＋阿糖胞苷）、ＨＡ方案（三尖杉酯碱＋阿糖胞苷）及ＨＡＣ方案（ＨＡ＋环磷酰胺）各２个疗程诱导化疗,未缓解。同年９月转入我所。经骨髓细胞形态学、细胞化学…     

急性早幼粒细胞白血病基因分析

目的：分析急性早幼粒细胞白血病（ＡＰＬ）患者经全反式维甲酸（ＡＴＲＡ）联合细胞毒药物及异基因骨髓移植（ａｌｏ－ＢＭＴ）治疗后融合基因的变化。方法：采用逆转录－多聚酶链反应（ＲＴ－ＰＣＲ）对２２例ＡＰＬ患者治疗前后ＲＡＲα／ＰＭＬ融合基因进行检测。其中１２例患者为单纯化疗，１０例接受了ａｌｏ－ＢＭＴ，９例患者于第１次完全缓解（ＣＲ１）期、１例于第１次复发（ＲＲ１）期接受了ａｌｏ－ＢＭＴ。结果：单纯维甲酸诱导完全缓解时，７５％ＡＰＬ患者融合基因仍然阳性；继用强化疗后８３％患者融合基因转为阴性，ＲＴ－ＰＣＲ转阴时间为发病后１～３９个月；ａｌｏ－ＢＭＴ后４个月内及４个月后，分别有６２．５％及８５．７％患者融合基因转阴。结论：化疗及ＢＭＴ均可使患者融合基因转阴，ａｌｏ－ＢＭＴ似乎能更快地清除体内白血病细胞     

Gene therapy for breast cancer

Gene therapy for advanced breast cancer is expected to be useful therapeutic approach. Strategies in ongoing clinical protocols can be divided into four: (1) suppression of oncogenes or transduction of tumor suppressor genes; (2) enhancement of immunological response; (3) transduction of suicide genes; (4) protection of bone marrow using drug resistance gene. We have started clinical study of multidrug resistance (mdr1) gene therapy. Advanced breast cancer patients received high dose chemotherapy and autologous peripheral blood stem cell transplantation (PBSCT) with mdr1-transduced hematopoietic cells, and then were treated with docetaxel. 2 patients have been treated so far, and in vivo enrichment of mdr1-transduced cells with docetaxel treatment was seen. Both patients are in complete remission and have no apparent adverse effect from mdr1 gene transduction.     

提高多药耐药基因导入人CD_(34)~ 细胞转导效率的探讨

目的　探讨逆转录病毒介导的多药耐药基因 (mdr1)导入人CD34 细胞的影响因素 ,以提高基因转导效率。方法　用流式细胞术 (FCM)检测不同组合细胞因子及人骨髓基质细胞 细胞因子支持的基因转导效率 ;用造血祖细胞集落培养观察耐药性 ;用FCM检测不同浓度紫杉醇素对基因转导细胞的作用。结果　细胞因子SCF Flt配体 (FL) IL 3组合支持的基因转导效率高于其它组合 (SCF IL 6 IL 3,SCF IL 6 IL 3 Tpo ,SCF IL 3)。骨髓基质细胞 细胞因子 (SCF FL IL 3)支持的基因转导效率 (2 0 .5 % )又高于单纯用该组细胞因子的转导效率 (15 .2 % ) ,并且前者形成的抗性集落形成细胞数多于后者。在 10ng ml紫杉醇作用下基因转导CD34 细胞的阳性率可达 38.5 %。结论　骨髓基质细胞 细胞因子 (SCF FL IL 3)对基因转导有较强的促进作用 ;一定浓度的紫杉醇具有富集基因转导细胞的作用     

转mdr1基因诱导CIK细胞耐药并保持肿瘤杀伤活性

目的　将多药耐药基因 (mdr1)转入细胞因子诱导的杀伤 (cytokine inducedkiller,CIK)细胞 ,观察其是否产生耐药性并且保持肿瘤杀伤活性。方法　用IFN γ ,CD3单抗 ,IL 2 ,IL 1等细胞因子体外诱导外周血单个核细胞获得CIK细胞。采用电穿孔方法将mdr1基因表达质粒pHamdr转入CIK细胞。转染后 72h提取细胞总RNA ,DNA酶消化残留质粒DNA后进行RT PCR ,鉴定mdr1基因表达 ;流式细胞仪检测细胞膜耐药蛋白 (P gp)表达。四唑蓝比色法 (MTT)检测转基因后CIK细胞对阿霉素和秋水仙碱的耐药性 ;同时检测转染前后CIK细胞对MCF7细胞 (人类乳腺癌细胞系 )的杀伤活性变化。结果　转染mdr1后的CIK细胞mdr1mRNA阳性 ,P gp阳性的CIK细胞为 2 1%～ 37% (平均 2 7% )。转染后CIK细胞获得了多药耐药性 ,对阿霉素的IC50 值较转染前升高了 2 2 .3～ 4 5 .8倍 ,对秋水仙碱的IC50 值升高了 6 .7～ 11.35倍。转染前后CIK细胞对MCF7肿瘤细胞的杀伤活性无明显变化 (P >0 0 5 )。结论　CIK细胞转入mdr1基因后获得了多药耐药性 ,转染后的CIK细胞仍然保持原有的肿瘤细胞杀伤活性。     

Retrovirus-mediated gene transfer of the human multidrug resistance-associated protein into hematopoietic cells protects mice from chemotherapy-induced leukopenia

Utilization of chemotherapy for the treatment of tumors is mainly limited by its hematological toxicity. Because of the low-level expression of drug resistance genes, transduction of hematopoietic progenitors with multidrug resistance 1 (MDR1) or multidrug resistance-associated protein (MRP) genes should provide protection from chemotherapeutic agent toxicity. Successful transfer of drug resistance genes into hematopoietic cells may allow the administration of higher doses of chemotherapy and, thus, increase regression of chemosensitive tumors. The interest in the use of MRP as an alternative to MDR1 for bone marrow protection lies in its different modulation. This would allow, in the same patient, the use of MDR1 reversal agents to decrease MDR1 tumor resistance without reversing bone marrow (BM) protection of the MRP-transduced hematopoietic cells, since MRP expression is not reversed by these agents. We have constructed MRP-containing retroviral vectors using the phosphoglycerate kinase promoter and generated ecotropic producer cells. Lethally irradiated mice were engrafted with BM cells transduced by coculture with MRP producer cells. Evidence of long-term (9 months) gene transfer was provided by PCR of peripheral blood from MRP-transduced mice. Southern blot analysis confirmed the integrity of the provirus in the MRP-transduced mice. Long-term MRP expression (>5 months) was detected by RT-PCR and fluorescence-activated cell sorting of blood from living mice. High-level expression of MRP in murine hematopoietic cells reduces doxorubicin-induced leukopenia and mortality. Furthermore, we show in vivo selection of MRP-transduced cells following doxorubicin administration, with better and more significant chemoprotection after the second chemotherapy cycle. These data indicate that MRP retroviral gene transfer may be useful for chemoprotection and selection.     

提高多药耐药基因导入人CD34^＋细胞转导效率的探讨

目的 探讨逆转录病毒介导的多药耐药基因导入人ＣＤ３４＾＋细胞的影响因素,以提高基因转导效率。方法 用流式细胞术（ＦＣＭ）检测不同组合细胞因子及人骨髓基质细胞＋细胞因子支持的基因转导效率;用造血祖细胞集落培养观察耐药性;用ＦＣＭ检测不同浓度柴杉醇素对基因转导细胞的作用。     

新型逆转录病毒载体介导的人多药耐药基因转移小鼠造血干／祖细胞

为探讨逆转录病毒介导的外源基因转导对骨髓造血重建的影响,我们以人多药耐药基因(mdr-1)为报告基因,采用包含Friend脾灶形成病毒(spleen focus-forming vims)和鼠胚胎干细胞病毒序列的新型逆转录病毒载体SF-MDR,以病毒包装细胞与小鼠造血细胞体外共培养法进行基因转染,并对基因转导后造血细胞的体外耐药能力及体内造血重建能力进行了观测。结果表明,该载体可有效地介导mdr-1基因转导,明显提高小鼠骨髓造血细胞对秋水仙素及紫杉醇的耐受能力,对细胞体内造血重建能力没有影响,体内移植8个月后经紫杉醇体内筛选,7/7的小鼠可于外周血细胞基因组DNA中检出外源mdr-1基因的存在。     

mdr-1和DHFR双基因共转染人CD34+细胞拓宽造血细胞耐药谱的体外研究

目的　探讨将多药耐药基因 (mdr 1)和二氢叶酸还原酶基因 (DHFR)同时导入人CD3 4 细胞 ,以拓宽造血细胞耐药谱 ,改善骨髓耐受联合化疗的可行性。方法　将以造血细胞中高表达的逆转录病毒载体FMCF为基本结构骨架 ,通过引入IRES序列构建获得含mdr 1和DHFR(L2 2Y)双耐药基因的逆转录病毒载体pSF DIM ,通过脂质体介导包装 ,单嗜性和双嗜性包装细胞上清交叉感染提高病毒滴度。低温离心病毒上清转染人脐血CD3 4 细胞 ,用流式细胞仪检测P gp的表达 ,基因组PCR检测外源性耐药基因的整合 ,CFU GM培养观察耐药性变化。结果　逆转录病毒载体pSF DIM转导人脐血CD3 4 细胞后 ,P gp的表达较未转基因组增加了 10 .98% ;基因组PCR同时检测到两种外源性耐药基因的整合 ;与未转基因组比较 ,在 48nmol/L甲氨蝶呤和 10ng/ml及 12ng/ml紫杉醇 (商品名Taxol)浓度水平 ,CFU GM集落形成显著增加 (P <0 .0 5 )。结论　重组双耐药基因逆转录病毒载体pSF DIM可以有效介导mdr 1和DHFR双耐药基因进入人脐血CD3 4 细胞并且获得共表达 ,拓宽了造血细胞耐药谱     

Drug selection of MDR1-transduced hematopoietic cells ex vivo increases transgene expression and chemoresistance in reconstituted bone marrow in mice

The MDR1 (multidrug resistance) gene, transferred to hematopoietic cells, is expected to protect them from anticancer chemotherapy and may serve as a selectable marker, restoring gene expression in vivo. Appropriate selection strategies, however, need to be established. To investigate whether preselection ex vivo affects chemoresistance, murine bone marrow cells were retrovirally transduced with high-titer or, as a model for suboptimal gene expression, low-titer retroviruses and exposed to daunomycin or colchicine for 48-96 h. Selection significantly increased chemoresistance of clonogenic progenitor cells. In tissue culture, the entire target population was rendered highly drug resistant after MDR1 transfer with high-titer viruses. If transduction was performed under suboptimal conditions, drug selection increased the frequency of chemoresistant colonies up to 40% over the number of unselected cells. Colchicine and daunomycin were equally efficient in increasing drug resistance ex vivo, but colchicine-preselected cells rescued lethally irradiated mice under conditions where daunomycin-selected bone marrow cells failed to do so. Hence, while hematopoietic cells can be protected by MDR1, the selection strategy is critical for repopulation of bone marrow with transduced cells. Preselection in culture before transplantation significantly increased P-gp expression and chemoresistance in vivo in mice reconstituted with transduced bone marrow cells. This study may help to facilitate the use of MDR1 as a selectable marker in gene therapy of the hematopoietic system. Gene Therapy (2000) 7, 348-358.     

Gene therapy for relapsed breast cancer

Gene therapy for advanced breast cancer is anticipated to be a useful therapeutic approach. Strategies in ongoing clinical protocols can be divided into four groups: (1) suppression of oncogenes or transfer of tumor-suppressor genes: (2) enhancement of immunological response: (3) transfer of suicide genes: (4) protection of bone marrow using drug resistance genes. We have started a clinical study of multidrug resistance (MDR1) gene therapy. Patients received high dose chemotherapy and autologous peripheral blood stem cell transplantation (PBSCT) with MDR1-transduced hematopoietic cells, and then were treated with docetaxel. Three patients have been treated so far, and in vivo enrichment of MDR1-transduced cells with docetaxel treatment has been seen. There has been no apparent adverse effect from the MDR1 gene transfer.