hTPO和hNIS共转染肺癌细胞系H460介导放射性碘摄取的研究

背景与目的 肺癌严重危害人类生命和健康,目前国内外肺癌的发病率和死亡率仍在不断上升.尤其是非小细胞肺癌(non-small cell lung cacer, NSCLC)治疗效果多年来一直没有显著提高.本研究旨在将人甲状腺过氧化物酶(hTPO)基因及人钠碘转运体(hNIS)基因共转入肺癌细胞系后研究其摄碘能力的变化.方法 克隆,重组,包装并扩增纯化得到重组腺病毒(AdTPO),测定病毒滴度,Western blot检测重组腺病毒的表达.使用脂质体转染法将hNIS基因转染入人肺癌细胞系H460中,经G418抗生素筛选获得稳定表达hNIS的细胞系hNIS-H460,为hNIS-H460组;使用重组腺病毒将hTPO基因转导入hNIS-H460中,使肺癌细胞系获得hTPO基因,为AdTPO-hNIS-H460组;未转入hTPO和hNIS的细胞为对照组(H460).然后进行三组稳定表达细胞系的体外摄125I实验.三组间两两比较用q检验(Newman-Keuls法).结果 AdTPO-hNIS-H460细胞、hNIS-H460细胞和H460细胞所摄取125I分别为(59 637.67±1281.13)、(48622.17±2242.28.)和(1440.17±372.86)计数·min-1.三组间总体具有统计学差异(P＜0.01).AdTPO-hNIS-H460组较对照组(H460)摄125I能力增高约41倍(P＜0.01),hNIS-H460组较对照组(H460)摄碘能力增高约34倍(P＜0.01).AdTPO-hNIS-H460组较hNIS-H460组高约1.2倍(P＜0.01).结论 将hTPO和hNIS基因共转染至肺癌细胞系H460后,可有效提高H460的摄碘能力.     

hNIS基因转导黑色素瘤细胞介导放射性碘摄取的实验研究

目的获取人钠/碘同向转运体(hNIS)基因cDNA,研究其转导黑色素瘤细胞在体外和体内能否介导放射性碘摄取,从而探索该策略用于黑色素瘤放射性碘治疗的可能性.方法运用逆转录聚合酶链反应从人甲状腺组织总RNA中扩增出hNIS基因cDNA,将其克隆至真核载体pc-DNA3中,电转化法分别将重组质粒pc-DNA3-hNIS及空质粒pc-DNA3转导黑色素瘤细胞(B16),分别建立了细胞系B16-A和B16-B.在体外培养条件下检测其对放射性碘的摄取及外流情况.继而将三种细胞系接种C57小鼠行131I显像和肿瘤摄取125I动态定量测定.结果成功克隆到hNIS基因,并建立了能稳定表达hNIS的新型细胞系B16-A.B16-A细胞的摄碘能力较B16细胞高17倍,较B16-B细胞高19倍.碘的外流过程迅速,T1/2eff仅10 min.体内实验发现B16-A细胞所形成肿瘤能摄取放射性碘,腹腔注射125I后1、2、4、12、24 h肿瘤组织的%ID/g平均为12.22.10.91、8.73、1.24、0.19,125I在肿瘤组织内的生物半衰期约为6 h.B16-A细胞系所成肿瘤摄碘量与对照组相比较,P＜0.01,差别具有高度统计意义.结论hNIS基因转导黑色素瘤细胞足以介导放射性碘摄取,但有效半衰期较短,难以产生足够的治疗剂量,有必要进一步研究如何增加放射性碘的摄取量及延长碘在细胞内的滞留时间以提高其放射生物学效应.     

重组腺病毒携带钠碘转运体基因介导放射性碘治疗小鼠胶质瘤

目的 验证转染人钠碘转运体基因(hNIS)介导放射性碘治疗肿瘤的有效性.方法 利用重组腺病毒将hNIS基因及人甲状腺过氧化物酶(hTPO)基因转染入人胶质瘤细胞系U251中,使肿瘤细胞获得hNIS和 hTPO基因,然后进行体外摄125I实验、过氯酸盐抑制实验、体外125I反流及内流实验.应用转染hNIS和hTPO基因及未转染hNIS和hTPO基因的细胞株,分别建立荷瘤裸鼠模型,并检测131I对肿瘤的抑制作用.结果 利用腺病毒可以将hNIS和hTPO基因成功转染到U251细胞系中,转染上述基因的肿瘤细胞系可以摄取碘,而且这种摄碘的功能是由hNIS基因所介导的,转染后的hNIS-U251细胞系摄碘能力是U251细胞的121.2倍,hNIS-hTPO-U251细胞系摄碘能力是U251细胞的172.0倍.131I对裸鼠移植瘤的治疗结果表明,在131I作用下,对照组肿瘤均继续迅速生长,而hNIS转染组及hNIS和hTPO共转染组移植瘤体积均有所减小.结论 在肿瘤细胞中转染hNIS和hTPO基因后,可以提高其摄取12I的活性.131I 可以有效杀伤荷瘤裸鼠体内的中瘤细胞.

Abstract：

Objective To explore the possibility of tranfecting hNIS and hTPO genes into gliomas cells by recombinant adenovirus for radioactive iodide treatment. Methods To tranfect hNIS gene into human glioma cell line U251 by recombinant adenovirus.The biological functions of the cells stably expressing hNIS and hTPO genes were assessed by 1251 uptake assay,125I influx-course and 12I-effluxcourse.A glioma model was established with inoculation of the U251 cells in nude mice,and the inhibiting effect of 131 I on the tumor growth was tested in the mouse models. Results The hNIS and hTPO genes were successfully transfected into human gliomas cell line U251 cells by recombinant adenovirus.The radioactive iodide could be intaken by the tumor cells mediated by hNIS gene.The uptake of 125I was higher in cell lines hNIS-U251 and hNIS-hTPO-U251 cells than in cell line U251 cells.The tumor volume of the mice after 131I treatment was significantly decreased in comparison with that before treatment.Conclusion Radioactive 131I treatment after HNIS-based gene transfer can be enhanced and effectively inhibite the tumor growth in nude mice.     

^131I照射对分化型甲状腺癌细胞摄碘水平及NIS mRNA表达的影响

目的：探讨^131I不同时间照射后分化型甲状腺癌细胞摄取放射性碘（^131I）水平的变化以及检测是否影响NIS mRNA表达。方法：分化型乳头状甲状腺癌细胞株（GTHW3）培养在DMEM培养基中,应用同一活度（20μCi）的^131I对培养癌细胞进行不同时间（6h、12h、24h、48h）的照射。γ计数仪测定放射性碘（^131I）摄取率。采用RT—PCR法检测甲状腺癌细胞的NIS mRNA表达。结果：不同时间的放射性^131I照射使甲状腺癌细胞摄取^131I降低;凝胶电泳显示放射性^131I照射24h后GTHW3细胞NIS mRNA表达降低;照射组各时间点的^131I摄取率及24h和48h的NIS mRNA表达与未照射对照组比较均有显著性差异。结论：^131I照射可使DTC细胞的NIS mRNA表达降低,提示^131I照射致DTC细胞失分化及其摄碘能力降低可能与DTC细胞NIS mRNA表达降低有关。     

131I照射对分化型甲状腺癌细胞摄碘水平及NIS mRNA表达的影响

目的:探讨131I不同时间照射后分化型甲状腺癌细胞摄取放射性碘(125I)水平的变化以及检测是否影响NIS mRNA表达.方法:分化型乳头状甲状腺癌细胞株(GTHW3)培养在DMEM培养基中,应用同一活度(20μCi)的131I对培养癌细胞进行不同时间(6h、12h、24h、48h)的照射.γ计数仪测定放射性碘(125I)摄取率.采用RT-PCR法检测甲状腺癌细胞的NIS mRNA表达.结果:不同时间的放射性131I照射使甲状腺癌细胞摄取125I降低;凝胶电泳显示放射性131I照射24h后GTHW3细胞NIS mRNA表达降低;照射组各时间点的125I摄取率及24h和48h的NIS mRNA表达与未照射对照组比较均有显著性差异.结论:131I照射可使DTC细胞的NIS mRNA表达降低,提示131I照射致DTC细胞失分化及其摄碘能力降低可能与DTC细胞NIS mRNA表达降低有关.     

hNIS/TK基因共转染介导131I/GCV对肝癌细胞株的毒性作用

背景与目的:与传统的单纯疱疹病毒胸苷激酶(herpes simplex virus thymidine kinase,HSV-TK)/丙氧鸟苷(ganciclovir,GCV)肿瘤自杀系统相比,人钠/碘同向转运体(human sodium-iodide symporter,hNIS)是近年来发现的新型治疗基因.然而,两者的疗效尚需进一步提高.本研究旨在探索hNIS介导的放射性核素体系与HSV-TK/GCV自杀基因体系对肝癌细胞的联合毒性作用.方法:构建EF1-a启动子调控下的hNIS的表达载体与CMV启动子调控下的GFP和HSV-TK共表达载体,慢病毒包装后转染肝癌细胞HepG2,荧光显微镜下观察重组肿瘤细胞HepG2/NTG荧光蛋白的表达;采用RT-PCR技术进一步检测目的基因hNIS和HSV-TK的表达情况;MTT检测GCV对HepG2/NTG的杀伤作用;摄碘试验及流出试验评价HepG2/NTG对碘的摄取及滞留情况;最后通过克隆形成实验评价GCV和131I对HepG2/NTG的单独及联合杀伤作用.结果:RT-PCR技术、荧光显像证实hNIS、GFP和HSV-TK基因在肝癌细胞中成功表达;与对照组相比,HepG2/NTG的摄碘高出76倍,20 min摄碘率最高,其后表现出碘外流,有效半衰期不到10 min,同时这种碘摄取能被NaClO4特异性抑制.GCV或131I对HepG2/NTG的毒性作用呈现剂量依赖性:50μg/mL GCV作用72 h后,实验组细胞的存活率仅为(33.98±2.71)%;放射性浓度为7.4MBq/mL的131I处理7 h后,细胞的存活率仅为(41.17±0.72)%;GCV和131I联合作用后,细胞的存活率仅为(8.55±1.22)%,较单一药物作用细胞存活率下降了6倍.结论:131I/GCV对重组肝癌细胞产生显著的毒性作用,提示慢病毒介导hNIS/TK基因共转染介导肿瘤的放射化学治疗是可行的.     

放射性^131I照射与分化型甲状腺癌细胞摄碘（^125I）率关系的实验研究

目的：探讨分化型甲状腺癌培养细胞接受放射性碘（^131I）照射剂量与摄取放射性碘间的相关性,为放射性碘去除治疗甲状腺癌提供新的思路.方法：设两个实验组,对分化型甲状腺癌细胞进行培养,其一应用同一活度（20μCi）的放射性^131I对培养细胞进行不同时间的照射,另组应用不同活度的放射性^131I对培养细胞进行相同时间（12h）的照射,分别测定两组甲状腺癌细胞摄取放射性^125I水平.结果：不同活度或不同时间的放射性^131I照射使甲状腺癌细胞摄取碘的水平降低,受照射组与未照射对照组细胞摄碘率比较有显著性差异（P＜0.01）.结论：放射性^131I照射可以使分化型甲状腺癌细胞摄碘率显著降低.     

放射性碘-131在荷乳腺癌裸鼠体内分布与显像的实验研究

背景与目的近年发现约85%的雌激素受体阳性乳腺癌及其转移组织细胞表面存在大量碘转运体(sodium/iodidesymporter,NIS),可主动将血液中的碘转运到乳腺癌组织,其碘浓度远高于其他组织。本实验观察放射性131I在乳腺癌荷瘤裸鼠体内生物分布及核素显像,探讨131I对雌激素受体阳性乳腺癌的特异性亲和作用。方法制备MCF-7/ER(+)与MCF-7/ER(-)人乳腺癌裸鼠模型,当肿瘤长至0.8～1.0cm时腹腔注射131I37～55.5MBq,分别于注射后6、12、24h处死裸鼠,取血标本和心、肺、肝、肾、胃、小肠、肌肉、肿瘤组织,分别测量每克组织每分钟的放射性计数,计算每克组织摄取的放射性占总注入量的百分比(%ID/g)及肿瘤与非肿瘤组织之比(T/NT)。同时于不同时段对裸鼠行核素显像,观察131I在裸鼠体内的分布。结果注射131I后6hMCF-7/ER(+)组裸鼠肿瘤组织放射性浓度已较高,与MCF-7/ER(-)组相比有显著性差异(P<0.05),甲状腺、血液、肝脏、胃、肾放射性浓度也相对较高。12h时MCF-7/ER(+)组血、心、肺、小肠、肌肉的T/NT分别为2.39、3.06、3.94、7.69、7.60,24h时分别为5.15、5.47、5.29、11.44、10.99,而12h时放射性较高的肝、肾、胃T/NT也达到1.82、2.65、2.60。显像结果示12h时MCF-7/ER(+)裸鼠肿瘤部位可看到明显的放射性浓聚灶,24h仍可清     

显微手术切除联合瘤腔植入缓释氟尿嘧啶和^125I治疗胶质瘤的临床观察

目的：探讨外科显微手术切除联合瘤床内植入5-氟尿嘧啶（5-FU）多聚缓释体局部化疗和125I局部放疗治疗胶质瘤的疗效。方法：65例胶质瘤行开颅显微手术切除,术中瘤床周围植入5-FU多聚缓释体和125I粒子,术后每3个月立体定向引导再次植入1～2次。观察疗效和瘤周水肿情况及不良反应。结果：术后1周内头痛明显,脑脊液白细胞不同程度的升高,瘤周水肿较单纯手术明显,经治疗所有患者都顺利出院。随访6个月～5年,39例患者获完全随访;患者生存36例。结论：手术切除肿瘤联合瘤床内植入缓释5-FU多聚缓释体局部化疗和125I局部放疗,是治疗胶质瘤的一种有效地方法。     

全反式维甲酸对甲状腺癌细胞NIS基因表达及吸碘能力影响的实验研究

目的：探讨全反式维甲酸（ATRA）对甲状腺癌细胞株钠/碘同向转运体（NIS）基因表达、吸碘能力的影响,为ATRA用于放射性碘治疗甲状腺癌提供理论依据。方法：分别以不同浓度（10^-7mol/L、10^-6mol/L、10^-5mol/L、10^-4mol/L）的ATRA处理体外培养的甲状腺癌细胞株（FTC-133）,48h后利用半定量RT-PCR检测细胞NISmRNA表达,γ-计数仪检测细胞吸碘能力。结果：ARTA浓度在（0～10%-5）mol/L范围内,细胞NIS基因表达及吸碘能力随ARTA剂量的增加而增加（P〈0.05）。当ARTA浓度达10%-4mol/L时,增加与前一浓度相比无统计学意义（P〉0.05）。结论：ATRA可上调甲状腺癌FTC-133细胞NIS基因表达,增强其吸碘能力,而且这种作用在一定浓度范围内具有剂量依赖性。     

Transfection of the Human Sodium/Iodide Symporter （NIS） Gene with Liposomes and the Expression of the NIS Protein in Human Lung A549 Cancer Cells

OBJECTIVE To examine the possibility of human sodium iodide symporter （hNIS） protein expression in lung cancer cells. METHODS Human lung A549 cancer cells were thawed and cultured in vitro. The cells were divided into an experimental group transfected with a recombinant pcDNA3-hNIS plasmid and a control group transfected only with a pcDNA3 plasmid. The recombinant plasmid vector encoding the hNIS gene （pcDNA3-hNIS） was amplified, purified and identified. The hNIS gene was followed by DNA sequencing. A Western blot and an immunohistochemical assay were applied to detect the hNIS protein expression in the transfected human lung A549 cancer cells. RESULTS Restriction enzyme digestion and DNA sequencing results showed the size and direction of the inserted gene in the recombinant pcD- NA3-hNIS plasmid was correct. The Western blot method and immunohistochemical analysis showed a positive NIS protein expression in the experimental group. The NIS protein was detected mainly in the cell membranes showing a positive rate up to 70.6% with no expression of the NIS protein in the control group. There was a significant difference between two groups （P=0.000）. CONCLUSION The hNIS gene was transfected effectively into human lung A549 cancer cells mediated by Lipofectamine 2000, and was expressed with its protein in vitro.     

Endogenous expression of the sodium iodide symporter mediates uptake of iodide in murine models of colorectal carcinoma

The sodium iodide symporter (NIS) mediates iodide uptake into the thyroid. Because of this mechanism, differentiated thyroid cancer is susceptible for radioiodine therapy. Functional NIS expression in extrathyroidal tumors has been reported mainly in breast cancer. We screened colorectal tumors for NIS expression and investigated the mechanisms regulating NIS activity. Cell lines were screened for iodide uptake in vitro and NIS expression was evaluated by real‐time RT‐PCR, immunocytochemistry and immunoblotting. Iodide and pertechnetate uptake were evaluated in allograft tumors by biodistribution studies and scintigraphy. Tumors of transgenic mouse models for colorectal cancer harboring mutations in the oncogenes KRAS, β‐catenin or the tumor‐suppressor gene adenomatous‐polyposis coli (APC) were screened for NIS expression by RT‐PCR. In vitro, functional NIS activity was detected in murine CMT93 rectal carcinoma cells and NIS expression was verified on mRNA and protein level. Inhibition of tyrosine kinases increased iodide uptake. Inhibition of tyrosine phosphatases decreased iodide uptake. In vivo, functional NIS expression was preserved in CMT93 tumors and tumor uptake could be enhanced by treatment of mice with tyrosine kinase inhibitors. In transgenic murine models of colorectal cancer, 14% of endogenous tumors expressed elevated levels of NIS mRNA. We conclude that NIS is functionally expressed in a subset of murine colorectal tumors and its activity is regulated by tyrosine phosphorylation. Therefore, with specific tyrosine kinase inhibition, these tumors might be susceptible for radioiodine treatment. Further studies are justified to identify the specific pathways regulating NIS activity and to transfer these findings to human cell lines and tissues. © 2009 UICC     

A novel oncolytic viral therapy and imaging technique for gastric cancer using a genetically engineered vaccinia virus carrying the human sodium iodide symporter

Background

Gastric cancers have poor overall survival despite recent advancements in early detection methods, endoscopic resection techniques, and chemotherapy treatments. Vaccinia viral therapy has had promising therapeutic potential for various cancers and has a great safety profile. We investigated the therapeutic efficacy of a novel genetically-engineered vaccinia virus carrying the human sodium iodide symporter (hNIS) gene, GLV-1 h153, on gastric cancers and its potential utility for imaging with ^99mTc pertechnetate scintigraphy and ¹²⁴I positron emission tomography (PET).

Methods

GLV-1 h153 was tested against five human gastric cancer cell lines using cytotoxicity and standard viral plaque assays. In vivo, subcutaneous flank tumors were generated in nude mice with human gastric cancer cells, MKN-74. Tumors were subsequently injected with either GLV-1 h153 or PBS and followed for tumor growth. ^99mTc pertechnetate scintigraphy and ¹²⁴I microPET imaging were performed.

Results

GFP expression, a surrogate for viral infectivity, confirmed viral infection by 24 hours. At a multiplicity of infection (MOI) of 1, GLV-1 h153 achieved > 90% cytotoxicity in MNK-74, OCUM-2MD3, and AGS over 9 days, and >70% cytotoxicity in MNK- 45 and TMK-1. In vivo, GLV-1 h153 was effective in treating xenografts (p < 0.001) after 2 weeks of treatment. GLV-1 h153-infected tumors were readily imaged by ^99mTc pertechnetate scintigraphy and ¹²⁴I microPET imaging 2 days after treatment.

Conclusions

GLV-1 h153 is an effective oncolytic virus expressing the hNIS protein that can efficiently regress gastric tumors and allow deep-tissue imaging. These data encourages its continued investigation in clinical settings.     

Human sodium iodide symporter gene adjunctive radiotherapy to enhance the preventive effect of hMUC1 DNA vaccine

We demonstrate the use of combination therapy to overcome the limitations of cancer DNA vaccines by adding radioiodine gene therapy in an animal cancer model. We established a stable cell line (CT26/hMUC1-hNIS-Fluc: CMNF) expressing the hMUC1, hNIS and Fluc genes using a retro- and lentivirus system. The survival rates (%) of CMNF cells were determined using clonogenic assays after (131)I treatment. After i.m. immunization to 4 groups of Balb/c mice (pcDNA3.1, pcDNA3.1+(131)I, pcDNA3-hMUC1+PBS and pcDNA3-hMUC1+(131)I groups) with pcDNA3-hMUC1 or pcDNA3.1 once a week for 2 weeks, 1 x 10(5) CMNF cells were injected s.c. into the right thighs of mice in each group. Twenty-one days after tumor transplantation, (131)I was administered i.p. to the pcDNA3.1+(131)I and pcDNA3-hMUC1+ (131)I groups. Tumor progression was monitored in the 4 groups by bioluminescent and scintigraphic imaging and by taking caliper measurements. Tumor masses were extracted and weighted at 39 days post-tumor challenge. We confirmed that CMNF cells highly express hMUC1, hNIS and Fluc by FACS, (125)I uptake, and luciferase assay. The survival rates of CMNF were markedly reduced to (14.6 +/- 1.5)% after (131)I treatment compared with the survival rates of parental cells (p < 0.001). Tumor growth inhibition was significant only in the pcDNA3-hMUC1+ (131)I group at 39 days post challenge. Tumor masses in pcDNA3-hMUC1+ (131)I group were smaller than those of the other groups. This study shows that the weak preventive effects of cancer DNA vaccine can be overcome by radioiodine gene therapy utilizing sodium iodide symporter.     

Monitoring adenoviral based gene delivery in rat glioma by molecular imaging

AIM: To determine whether endothelial progenitor cells (EPCs) can be used as delivery vehicle for adenoviral vectors and imaging probes for gene therapy in glioblastoma.METHODS: To use cord blood derived EPCs as delivery vehicle for adenoviral vectors and imaging probes for glioma gene therapy, a rat model of human glioma was made by implanting U251 cells orthotopically. EPCs were transfected with an adenovirus (AD5/carrying hNIS gene) and labeled with iron oxide and inoculated them directly into the tumor 14 d following implantation of U251 cells. Magnetic resonance imaging (MRI) was used to in vivo track the migration of EPCs in the tumor. The expression of gene products was determined by in vivo Tc-99m single photon emission computed tomography (SPECT). The findings were validated with immunohistochemistry (IHC).RESULTS: EPCs were successfully transfected with the adenoviral vectors carrying hNIS which was proved by significantly (P < 0.05) higher uptake of Tc-99m in transfected cells. Viability of EPCs following transfection and iron labeling was not altered. In vivo imaging showed the presence of iron positive cells and the expression of transgene (hNIS) product on MRI and SPECT, respectively, all over the tumors following administration of transfected and iron labeled EPCs in the tumors. IHC confirmed the distribution of EPC around the tumor away from the injection site and also showed transgene expression in the tumor. The results indicated the EPCs’ ability to deliver adenoviral vectors into the glioma upon intratumor injection.CONCLUSION: EPCs can be used as vehicle to deliver adenoviral vector to glioma and also act as imaging probe at the same time.     

Ectopic expression of the thyroperoxidase gene augments radioiodide uptake and retention mediated by the sodium iodide symporter in non-small cell lung cancer

Radioiodide is an effective therapy for thyroid cancer. This treatment modality exploits the thyroid-specific expression of the sodium iodide symporter (NIS) gene, which allows rapid internalization of iodide into thyroid cells. To test whether a similar treatment strategy could be exploited in nonthyroid malignancies, we transfected non-small cell lung cancer (NSCLC) cell lines with the NIS gene. Although the expression of NIS allowed significant radioiodide uptake in the transfected NSCLC cell lines, rapid radioiodide efflux limited tumor cell killing. Because thyroperoxidase (TPO) catalyzes iodination of proteins and subsequently causes iodide retention within thyroid cells, we hypothesized that coexpression of both NIS and TPO genes would overcome this deficiency. Our results show that transfection of NSCLC cells with both human NIS and TPO genes resulted in an increase in radioiodide uptake and retention and enhanced tumor cell apoptosis. These findings suggest that single gene therapy with only the NIS gene may have limited efficacy because of rapid efflux of radioiodide. In contrast, the combination of NIS and TPO gene transfer, with resulting TPO-mediated organification and intracellular retention of radioiodide, may lead to more effective tumor cell death. Thus, TPO could be used as a therapeutic strategy to enhance the NIS-based radioiodide concentrator gene therapy for locally advanced lung cancer.     

IL-4基因治疗脑胶质瘤的实验研究

目的 探索一条细胞因子ＩＬ－４基因治疗脑胶质瘤的新途径。方法 用脂质体转染的方法,以重组逆转录病毒做载本,将目的基因鼠ＩＬ－４基因转入包装细胞和大鼠Ｃ６胶质瘤细胞,通过Ｇ４１８抗性筛选,得到分泌ＩＬ－４的细胞株Ψ２ ＩＬ－４和Ｃ６ＩＬ－４。Ｅｌｉｓａ法检测病毒上清中ＩＬ－的含量,通过Ｓｏｕｔｈｅｒｎ ｂｏｌｔ 和Ｄｏｔ ｂｌｏｔ证明ＩＬ－４基因的整合和表达。体外观察并比较了野生型和转基因瘤细胞的细