IMPROVEMENT OF HUMAN ISLET FUNCTION BY ADENO-VIRUS MEDIATED HO-1 GENE TRANSFER

Objective To investigate in vitro heme oxygenase-1 gene (HO-1) delivery to human pancreatic islets by adenovirus vectors. Methods Recombinant adenovirus containing HO-1 or enhanced green fluorescent protein gene(EGFP) was generated by using the AdEasy System. The purified human pancreatic islets were infected with recombinant adenovirus vectors at various multiplicity of infection (MOI). Transduction was confirmed by fluorescence photographs and Western blot. Glucose-stimulated insulin secretion was detected by using Human insulin radioimmunoassay kits and was used to assess the function of human islets infected by recombinant adenovirus.Results Viral titers of Ad-hHO-1 and Ad-EGFP were 1.96×109 and 1.99×109 pfu/mL, respectively. Human pancreatic islets were efficiently infected by recombinant adenovirus vectors in vitro. Transfection of human islets at an MOI of 20 did not inhibit islet function. Recombinant adenovirus mediated HO-1gene transfer significantly improved the islet function of insulin release when simulated by high level glucose. Conclusion Recombinant adenovirus is efficient to deliver exogenous gene into human pancreatic islets in vitro. HO-1 gene transfection can improve human islet function.

The effect of interleukin-6 gene transfer on human cord blood megaka ryopoiesis

Objective:To investigate the effect of IL-6 gene transfe r into human cord blood hematopoietic stem cells on the production of megakaryocy t ic progenitors.Methods:IL-6 gene was transfected into human c o rd blood CD34+ cells using a retrovirus vector with the aid of recombinant fibro nectin fragments in the presence of a cocktail of cytokines (SCF,IL-6,sIL-6R,F L,and TPO).Colony-forming units-megakaryocyte (CFU-MK) assays were performed as IL-6 gene transduced CD34+ cells were incubated alone or in combination with I L -3 or sIL-6R, controlled with neoR gene transduced CD34+ cells.Result s :IL-6 alone or sIL-6R alone stimulated few CFU-MK colonies,the addit ion of sIL-6R to IL-6 gene transduced CD34+ cells significantly enhanced the prod uction of CFU-MK colonies.IL-6 gene transduced CD34+ cells showed a modest syn er gistic effect with IL-3.Conclusion:These results suggest that IL-6 gene transfer may protect patients from chemotherapy-induced thrombocytop en ia.

Effects of adenoviral vector-mediated transduction of human p53,B7-1 and GM-CSF genes on liver cancer cells

The potential efficacy and clinical feasibility of gene therapy for liver cancer were tested through therecombinant adenovirus-mediated (Ad-multigenes ) co-transfer of human wild-type p53, B7-l co-stimulation(CD8o) and granulocyte-macrophage colony-stimulating factor (GM-CSF) genes into human hepatocellular carcinoma cell lines. The treated cells underwent apoptosis with specific DNA fragmentation and became more sensitiveto cisplatin, a chemotherapeutic drug. Their growth was partly inhibited. Efficient proliferation and generation ofCTLs and cytokine production were induced in mixed lymphocytes through tumor cell reaction (MLTR) using peripheral blood T lymphocytes from donors as effector cells and Ad-multigenes or Ad-p53-transfected human hepatocellular carcinoma cells (HepG2 or BEL7402) as stimulator cells. Ad-multigenes-transfected rat carcinosarcomaWalker 256 cells were inoculated subcutaneously into normal rats. Fourteen days later, the activity of spleen cellsin rats inoculated with Ad-multigenes-transduced Walker 256 cells was higher than that in Ad-p53-transducedones. These findings suggest that adenovirus-mediated multigenes p53, B7-1 and GM-CSF can induce apoptosis ofliver cancer cells and initiate a potent antitumor immune response against them.

Expression of human yrdC gene promotes proliferation of gastric carcinoma cells

Objective： The aim of the research was to study the function of human yrdC gene in the gastric carcinoma cells. Methods： Human yrdC gene was isolated from human spleen tissue by RT-PCR. Anti-human yrdC monoclonal antibody was prepared by hybridoma cell technique. Recombinant adenovirus Ad.yrdC carrying yrdC gene was constructed by using the AdEasy adenoviral vector system. Recombinant adenovirus Ad.yrdCshRNA mediated yrdCshRNA was prepared by RNA interference technology. Gastric adenocarcinoma BGC-823 cells of moderate differentiation were transfected and absorbance of the transfected cells was calculated at 490 nm by methyl thiazolyl tetrazolium （MTT） method. Results： A value of the transfected Ad.yrdC group was significantly greater than that of the non-transfected and transfected Ad.Null groups, and A value of Ad.yrdCshRNA group was significantly lower than that of the non-transfected and transfected Ad.Null groups. Conclusion： Expression of yrdC gene has a function of promoting the proliferation of gastric carcinoma cells.

Construction of human eukaryotic expression plasmid vascular endothelial growth factor 165 and its expression in transfected vascular smooth muscles

BACKGROUND: The highly specific vascular endothelialgrowth factor (VEGF) induces the growth of vascular en-dothelial cell. This study was to construct the eukaryoticexpression plasmid of vascular endothelial growth factorl65(VEGF165) and observe its expression in vascular smoothmuscles (VSMCs).METHODS: The primers were designed and synthesizedaccording to the gene sequences of human VEGF165. TheVEGF165 gene was obtained from umbilic artery tissue bythe method of RT-PCR, then it was cloned to eukaryoticexpression plasmid pBudCE4.1 by recombination strategy.The eukaryotic expression plasmid named pBudCE4.1/VEGF165 was identified by restriction enzyme digestion,and was sequenced. The pBudCE4.1/VEGF165 was trans-fected into VSMCs by using lipofection. The VEGF165 ex-pression of mRNA and protein was detected by RT-PCRand Western blot respectively.RESULTS: VEGF165 was shown about 576bp by RT-PCR.Sequencing revealed the amplified VEGF165 gene was iden-tical with that in the GeneBank. Restrictive enzyme (HindBam HI) digestion analysis showed that recombinantexpression plasmid pBudCE4. l/tVEGF165 had been con-structed successfully. The expression of VEGF165 at mRNAand protein levels in the transformed VSMCs had beendemonstrated by RT-PCR and Western blot.CONCLUSIONS: The recombinant eukaryotic expressionplasmid pBudCE4.1/VEGF165 has been successfully con-structed and expressed in transformed VSMCs. The presentstudy has laid a foundation for VEGF165 gene therapy ofvascular stenosis in the transplant organ.

CONSTRUCTION AND EXPRESSION OF THE REPLICATION-DEFI-CIENT ADENONIRUS VECTOR OF HUMAN GM-CSF

The full-length cDNA encoding human Granulocyte macrophage colony stimulating factor (GM CSF) was cloned by RT PCR, placed under the control of CMV promoter, and inserted into adenovirus vector of E1 substitution type, pAx1cw. Subsequently, the cassette cosmid was cotransfected into 293 cells together with EcoT22I digested Ad5 TPC, and the replication deficient recombinant adenoviruses(Ad) of human GM CSF were generated efficiently by homologous recombination, with the titers of 1.51×10 9pfu/ml. 48 hours after infection with prepared human GM CSF recombinant adenoviruses in vitro, HeLa cells and primary human skin fibroblasts expressed high levels of human GM CSF (80～400ng/ 10 6cells/24hr). These suggest that the recombinant Ad of human GM CSF prepared by COS/TPC method is effective in mediating GM CSF gene transfer and might be used in cancer gene therapy.

Microbubble-enhanced ultrasound exposure improves gene transfer in vascular endothelial cells

AIM： To explore the effects of ultrasound exposure combined with microbubble contrast agent （SonoVue） on the permeability of the cellular membrane and on the expression of plasrnid DNA encoding enhanced green fluorescent protein （pEGFP） transfer into human umbilical vein endothelial cells （HUVECs）. METHODS： HUVECs with fluorescein isothiocyanatedextran （FD500） and HUVECs with pEGFP were exposed to continuous wave （1.9 MHz, 80.0 mW/cm^2） for 5 min, with or without a SonoVue. The percentage of FD500 taken by the HUVECs and the transient expression rate of pEGFP in the HUVECs were examined by fluorescence microscopy and flow cytornetry, respectively. RESULTS： The percentage of FDS00-positive HUVECs in the group of ultrasound exposure combined with SonoVue was significantly higher than that of the group of ultrasound exposure alone （24.0%± 5.5% vs 66.6% ± 4.1%, P 〈 0.001）. Compared with the group of ultrasound exposure alone, the transfection expression rate of pEGFP in HUVECs was markedly increased with the addition of SonoVue （16.1% ± 1.9% vs 1.5% ± 0.2%, P 〈 0.001）. No statistical significant difference was observed in the HUVECs survival rates between the ultrasound group with and without the addition of SonoVue （94.1% ± 2.3% vs 91.1% ± 4.1% ）. CONCLUSION： The cell membrane permeability of HUVECs and the transfection efficiency of pEGFP into HUVECs exposed to ultrasound are significantly increased after addition of an ultrasound contrast agent without obvious damage to the survival of HUVECs. This non- invasive gene transfer method may be a useful tool for clinical gene therapy of hepatic tumors.

Adenoviral-mediated Hath1-EGFP gene transfer into guinea pig cochlea through intact round window membrane

Objective To study expression of adenoviral-mediated Hath1-EGFP gene in the guinea pig cochlea after transfer through intact round window membrane(RWM), and to assess its effects on hearing. Methods Twenty adult guinea pigs were used, of which: 12 were surgically inoculated with Ad-Hath1-EGFP in the bony groove of round window niche, and 8 with artificial perilymph. Auditory brainstem response(ABR) thresholds were determined in all animals before and 5 days after surgery. On post-surgery day 5 and day 14, animals were sacrificed and whole mounts of cochlea and frozen sections were examined. Results ABR tests showed no significant change of hearing after the surgery. Strong fluorescence staining in the cochleae was seen in Ad-Hath1-EGFP groups. The highest levels of gene expression were seen in the post-surgery day 5 group with little decrease on post-surgery day 14.The contralateral cochlea and those in the control groups were free of fluorescence staining. Conclusion The transgenic Hath1-EGFP can be effectively delivered into the inner ear through intact RWM, in an atraumatic manner.

Amelioration of carbon tetrachloride-induced cirrhosis and portal hypertension in rat using adenoviral gene transfer of Akt

AIM:To investigate whether a virus constitutively expressing active Akt is useful to prevent cirrhosis induced by carbon tetrachloride(CCl4).METHODS:Using cre-loxp technique,we created an Ad-myr-HA-Akt virus,in which Akt is labeled by a HA tag and its expression is driven by myr promoter.Further,through measuring enzyme levels and histological structure,we determined the efficacy of this Ad-myrHA-Akt virus in inhibiting the development of cirrhosis induced by CCl4in rats.Lastly,using western blotting,we examined the expression levels and/or phosphorylation status of Akt,apoptotic mediators,endothelial nitric oxide synthase(eNOS),and markers for hepatic stellate cells activation to understand the underlying mechanisms of protective role of this virus.RESULTS:The Ad-myr-HA-Akt virus was confirmed using polymerase chain reaction amplification of inserted Akt gene and sequencing for full length of inserted fragment,which was consistent with the sequence reported in the GenBank.The concentrations of Admyr-HA-Akt and adenoviral enhanced green fluorescent protein(Ad-EGFP)virus used in the current study were5.5×1011vp/mL.The portal vein diameter,peak velocity of blood flow,portal blood flow and congestion index were significantly increased in untreated,saline and Ad-EGFP cirrhosis groups when compared to normal control after the virus was introduced to animal through tail veil injection.In contrast,these parameters in the Akt cirrhosis group were comparable to normal control group.Compared to the normal control,the liver function(Alanine aminotransferase,Aspartate aminotransferase and Albumin)was significantly impaired in the untreated,saline and Ad-EGFP cirrhosis groups.The Akt cirrhosis group showed significant improvement of liver function when compared to the untreated,saline and Ad-EGFP cirrhosis groups.The Hyp level and portal vein pressure in Akt cirrhosis groups were also significantly lower than other cirrhosis groups.The results of HE and Van Gieson staining indicated that Akt group has better preservation of histological structure and less fibrosis than other cirrhosis groups.The percentage of apoptotic cell was greatly less in Akt cirrhosis group than in other cirrhosis groups.Akt group showed positive HA tag and an increased level of phosphorylated Akt as well as decreased levels of Fas.In contrast,Caspase-3 and Caspase-9 levels in Akt group were significantly lower than other cirrhosis groups.Noticeable decrease of DR5 andα-SMA and increase of phosphorylated eNOS were observed in the Akt group when compared to other cirrhosis groups.The NO level in liver was significantly higher in Akt group than other cirrhosis groups,which was consistent with the level of phosphorylated eNOS in these groups.CONCLUSION:This study suggest that Ad-myr-HA-Akt virus is a useful tool to prevent CCl4-induced cirrhosis in rat model and Akt pathway may be a therapeutic target for human cirrhosis.

Increasing drug resistance in human lung cancer cells by mutant-type p53 gene mediated by retrovirus

Human mutant-type (mt) p53 cDNA was synthesized and cloned from human lung cancer cell line GL containing mt-p53 gene by using polymerase chain reaction (PCR). It was confirmed that the mt-p53 cDNA con-tained the complete coding sequence of p53 gene but mutated at codon 245 (G→T) and resulted in glycine to cysteine by sequencing analysis. The retroviral vector pD53M of the mt-p53 was constructed and introduced into the drug-sen-sitive human lung cancer cells GAO in which p53 gene did not mutate. The transfected GAO cells strongly expressed mutant-type p53 protein by immunohistochemistry, showing that pD53M vector could steadily express in GAO cells. The drug resistance to several anticancer agents of GAO cells infected by pD53M increased in varying degrees, with the highest increase of 4-fold, in vitro and in vivo. By quantitative PCR and flow cytometry (FCM) analyses, the expression of MDR1 gene and the activity of P-glycoprotein (Pgp) did not increase, the expression of MRP gene and the activity of multidrug resistance-related protein (Mrp) increased slightly. These results indicated that the drug re-sistance associated with mt-p53 gene might be somewhat correlated with MRP/Mrp but not with MDR1/Pgp. It was possible to modify the tumor drug resistance by changing status of p53 gene.

GENE TRANSFER INTO PORCINE MYOCARDIUM VIA PERICARDIAL CAVITY BY HOMEMADE EASY PUNCTURE DEVICE

Objective To explore the feasibility and safety of gene transfer into porcine myocardium via the pericardial cavity by a homemade easy device. Methods Replication-deficient recombinant adenoviral vector carrying LacZ report gene (Ad-LacZ) was constructed by the calcium phosphate precipitation method. Twelve healthy Chinese mini-swine were randomly divided into experimental group (n=6) and control group (n=6). Acute myocardial infarction (AMI) model was established by balloon occlusion of the distal part of D1 branch of left anterior descending (LAD) artery, at the same time the intra-pericardial cavity injections were performed through the small incision of the abdominal wall below the xyphoid appendix using a homemade device. Then gene transfer was performed using a central venous catheter. The pericardium was pretreated with injection of a mixture of collagenase (1 200 U) and hyaluronidase (3 000 U) in both groups. Then 2.0×109 plaque formation unit (PFU) Ad-LacZ was injected into the pericardial cavity in experimental group, while 1 mL of normal saline was injected in the control group. The β-galactosidase activity detection and X-gal staining of the ischemic myocardium were performed on the 3rd, 7th, and 28th day after injection. Results The LAD artery was occluded completely and infarction and ischemia were detected by histological assessment. In experimental group, the X-gal staining positive cells and β-galactosidase activity quantification were detectable on the 3rd day after injection, increased markedly on the 7th day, and then declined on the 28th day. The transfer efficiencies indicated by the positive myocardial cells were 16.7%, 45.6%, 22.8% on the 3rd, 7th, 28th day, respectively. In control group, no positive cells and β-galactosidase activity were observed. Conclusion Adenovirus can be transferred into ischemic myocardium and express target gene in the AMI model for four weeks with the homemade easy device via pericardial cavity pretreated by collagenase and hyaluronidase.

Effects of kallikrein gene transfer on penumbral microvascular proliferation and on regional cerebral blood flow following cerebral ischemia/reperfusion injury

BACKGROUND： Recent findings have demonstrated that the kallikrein-kinin system （KKS） participates in the pathological process of cerebral ischemia/reperfusion injury. Kallikrein gene transfer exhibits neural protective effects following cerebral infarction. OBJECTIVE： To observe the effects of kallikrein gene transfer on vascular proliferation in the peripheral infarct focus and on regional cerebral blood flow （rCBF） following cerebral ischemia/reperfusion injury. DESIGN, TIME AND SETTING： The completely randomized, controlled experiment was performed at the Lin Baixin Laboratory Center, the Second Affiliated Hospital of Sun Yat-sun University between September 2007 and April 2008. MATERIALS： pUCI9-HTK plasmid was constructed and maintained in the Laboratory for Neurology, the Second Affiliated Hospital of Sun Yat-sen University, China. Mouse anti-human kallikrein 1 monoclonal antibody was purchased from R＆D Systems, USA. METHODS Ninety healthy, male, Sprague Dawley rats were used. Middle cerebral artery occlusion （MCAO） was established in all rats to induce cerebral ischemia/reperfusion injury. Following MCAO establishment, all rats were randomly divided into three groups （n = 30）： blank control, saline, and pAdCMV-HTK. The saline and pAdCMV-HTK groups were stereotactically micro-injected with 5μL of physiological saline or with pAdCMV-HTK [multiplicity of infection （MOI） = 20], respectively, into the ischemic penumbra. In the blank control group, only sham injection was performed. MAIN OUTCOME MEASURES： At 12, 24, and 72 hours after treatment, cerebral infarction volume was measured by 2, 3, 5-triphenyltetrazolium chloride （TTC） staining. Exogenous HTK expression, as well as regional vascular endothelial growth factor （VEGF） expression, was detected by immunohistochemistry. rCBF was examined by 14C-iodoantipyrine micro tracing. In addition, neurological severity score （NSS） was performed. Higher scores indicated more severe neurological deficits. RESULTS： NSS results demonstrated that compared with the saline and the blank control groups, the pAdCMV-HTK group exhibited lower NSSs 24 hours after pAdCMV-HTK injection （P 〈 0.05）. The NSSs were further decreased after 72 hours （P 〈 0.01）. Cerebral infarction volume at 24 hours, and in particular at 72 hours after treatment, was significantly reduced in the pAdCMV-HTK group compared with the blank control and saline groups （P 〈 0.05）. The rCBF in the area surrounding the infarction lesion was slightly decreased in all groups compared with the contralateral area. At 24 and 72 hours following treatment, the rCBF in the peripheral infarction lesion was significantly elevated in the pAdCMV-HTK group compared with the blank control and saline groups （P 〈 0.05）. Immunohistochemistry results revealed that VEGF-positive cells were primarily found in the cortex and in some white matter surrounding the cerebral infarction lesion. In addition, the expression of VEGF in the pAdCMV-HTK group was significantly higher compared with that in the blank control and saline groups at 12, 24, and 72 hours following treatment （P 〈 0.05）. CONCLUSION： Following cerebral ischemia/reperfusion, kallikrein gene transfer can promote vascular proliferation in the brain tissue surrounding the infarction lesion, improve rCBF, and reduce infarction volume, thereby exhibiting protective effects to attenuate neurological deficits.

我国人类基因专利现状分析与对策建议

专利保护对于人类基因技术发展至关重要。我国人类基因专利申请呈现持续增长趋势,但现有专利分析存在数据过时、检索策略不精确和数据未降噪等问题,阻碍了对人类基因专利现状的理解及相关政策和产业战略的制定。通过优化检索策略,对合享数据库中2010年至2022年间人类基因专利申请数据进行检索、降噪和分析,发现申请数量迅速增长,主要申请者为高等教育机构和科研院所,技术领域集中,专利权利要求范围较窄,专利价值普遍不高,转让活动较少。为推进知识产权强国战略和人类基因产业发展,建议加强知识产权保护,支持研发,促进资源共享;完善法律法规,加强执法力度;提升创新意识,加强技术交流;培养基因科学与知识产权法律人才,提高公众认识。

Current gene therapy for stomach carcinoma

Gastric cancer is common in China [1-42],and its early diagnosis and treatment in advanced stage are difficult [31-50].In recent years ,gene study in cancer is a hotspot ,and great progress has been achieved [41-80] .Cancer gene therapy has shifted from the imagination into the laboratory and clinical trials.

High expression of human clotting factor IX cDNA in myoblasts C2C12 cells and C3H mice

Mouse myoblast C2C12 cell was used as target cell for gene transfer study of human clotting factor IX (hFIX) cDNA. In addition to the previously constructed retroviral vectors XLIX, LNCIX and GINaCIX, GlNaMCIX with hFIX driven by muscle creatine kinase (MCK) enhancer and human cytomegalovirus (CMV) was constructed, based on the retroviral vector GINa. These four retroviral vectors were used to transduce mouse my-oblasts C2C12. With ELISA assays, it has been found that the expression levels of human clotting factor IX detected in those transduced C2C12 cells are GlNaMCIX>GlNaCIX> LNCIX>XLIX. Mixed colonal cells transduced with GlNaMCIX expressed hFIX protein at the level of 640 ng/106 cell every 24 h. The modified C2C12 cells transduced with GlNaMCIX were implanted into skeletal muscle of the hindlegs of C3H mice; a stable expression of hFIX was detected and lasted for 35 d, with a maximum level of 206 ng/mL plasma. The regulation of hFIX cDNA expression in myoblasts was discussed and it was strongly suggested that a myoblast-mediated gene delivery system had the poten-tial to be optimized as a safe and effective therapeutic modality for hemophilia B.

Adenoviral-mediated localized CTLA-4Ig gene expression induces long-term allograft pancreas survival and donor-specific immune tolerance in rats

T cell activation following alloantigen recognition plays a critical role in the development of the rejection in all solid organ, tissue and cell transplantation. A recombinant molecule, cytotoxic T lymphocyte antigen 4 antibody （CTLA-4Ig）, is known to induce to T-cell into ＂anergy＂ by blocking the costimulatory B7-CD28 interaction. Either systemic or localized administration of CTLA-Ig has been shown to prolong allograft survival and induce donor-specific tolerance in some transplant models. In this study, we characterized the expression and immunosuppressive effectiveness of adenoviral-mediated CTLA-4Ig gene transfer. We demonstrated transduction of the allografts with AdCTLA-4Ig resulted in localized expression, permanent graft survival and stable donor-specific tolerance. In addition, by performing simultaneous dual-organ through a local expression of CTLA-4Ig via adenoviral-mediated transplantation, we targeted on immunosuppression gene transfer into pancreatic allografts.

High expression of human clotting factor IX cDNA in the bone marrow stroma cells of hemophilia B patient

Hemophilia B, a serious bleeding disorder, is an inherited X chromosome-linked diseasecaused by the deficiency or inactiveness of human clotting factor IX (FIX). The conven-tional clinical treatment of plasma infusion is expensive and associated with a high risk

Construction and high expression of retroviral vector with human clotting factor IX cDNA in vitro

The construction of the high liter and highly expressed safety retroviral vector carrying human clotting factor IX cDNA is reported. Retroviral vectors LNCTX, LIXSN and LCTXSN, driven by hCMV, LTR and hCMV combined with LTR promoter respectively, were constructed, based on the retroviral vector LNL6, and transferred into packaging cell line PA317 with electroporalion. Human dolling factor IX was delected in the cultured cells transduced with LNCIX and LIXSN but not in the cells transduced with LCIXSN. The viral titer of PA317/LNC1X was 800000 CFU per mL. With ELISA detection, it was found that the cells transduced with this vector can express human clotting factor IX at the level of 3.3μg per 106 cells in 24 h in human fibrosarcoma cells HT-1080 and 2.5μg per 106 cells in 24 h in hemophilia B patients' skin fibroblast HSF cells, and more than 80% of them were biologically active. The viral liter and expression of human FIX were increased, and the construction of retroviral vector backbone was improved and the safety was guaranteed as compared to those vectors used previously. These vectors may produce a sufficient quantily of factor IX proteins to cause the phenotypic modification for hemophilia B patients.

Long-Term Expression of Human Factor Ⅸ cDNA in Rabbits

In this study, rabbits were used as a model for gene therapy for hemophilia B, Human factor Ⅸ cDNA was transferred to cultured normal rabbit skin fibroblasts (RSF) by a recombinant plasmid (pCMVIX) or retrovirus(XL-IX or N2CMVIX) constructed in our laboratoy. Infected fibroblasts capable of synthesizing and secreting high levels of biologically active human factor Ⅸ protein were selected and embedded in a collagen matrix. The latter was surgically implanted into rabbits as autografts or allografts. Human factor Ⅸ protein was detected in the plasma of all the grafted rabbits, and its expression has been maintained for more than 10 months at the time of writing. In addition, we have improved and simplified the method of implantation from surgically grafting the tissue-like matrix to the injection of the infected cell-collagen mixture subcutaneously. Using the latter method, human factor Ⅸ in rabbits injected with RSF-N2CMVIX reached a peak of 480 ng/ml plasma, and its expression has continued for more than 3 months at the time of writing. We suggest that the simplified method of transplantation by subcutaneous injection would offer an effective and acceptable approach to somatic cell gene therapy and may be practical for human trials.

腺病毒介导PDCD5基因转移促进依托泊甙诱导的K562细胞凋亡

本研究观察程序性细胞死亡5基因(programmed cell death 5,PDCD5)重组腺病毒转染K562细胞后对化疗药物依托泊甙的增敏作用。利用AdMaxTM腺病毒载体包装系统,通过同源重组方法构建Ad-PDCD5重组腺病毒及对照腺病毒Ad-null及Ad-eGFP;用不同感染复数将Ad-eGFP、Ad-null或Ad-PDCD5转染人白血病细胞系,实时定量PCR检测PDCD5mRNA的相对表达水平;利用MTT法及Annexin-V-FITC/PI双染色流式细胞术观察依托泊甙对转染后K562细胞增殖与凋亡的影响。结果表明:Ad-eGFP腺病毒对白血病细胞系K562、Jurkat及CEM的转染效率可达60%-86%。Ad-PDCD5重组腺病毒能梯度增加K562细胞PDCD5 mRNA的相对表达水平,腺病毒介导的PDCD5基因转移促进依托泊甙诱导的K562细胞凋亡。结论:PDCD5重组腺病毒可能成为化疗药物的增敏剂。