OBJECTIVETo develop a new kind of vector system called gene-viral vector, which combines the advantages of gene and virus therapies.

METHODSUsing recombinant technology, an anti-tumor gene was inserted into the genome of replicative virus specific for tumor cells. The cell killing effect, reporter gene expression of the green fluorescence protein, anti-tumor gene expression of mouse interleukin-12 (mIL-12) and replication of virus were observed by the methods of cell pathology, fluorescence microscopy, ELISA and electron microscopy, respectively.

RESULTSA new kind of gene-viral vector system of adenovirus, in which the E1b-55 kD gene was deleted but the E1a gene was preserved, was constructed. The vector system, like the replicative virus ONYX-015, replicated and proliferated in tumor cells but not in normal ones. Our vector had an advantage over ONYX-015 in that it carried different kinds of anti-tumor genes to enhance its therapeutic effect. The reporter gene expression of the green fluorescence protein in tumor cells was much better than the adenovirus vector employed in conventional gene the rapy, and the expression in our vector system was as low as or even less than that in the conventional adenovirus gene therapy system. Similar results were observed in experiments with this vector system carrying the anti-tumor gene mIL-12. Replication and proliferation of the virus carrying the mIL-12 gene in tumor cells were confirmed by electron microscopy.

CONCLUSIONSGene-viral vectors are new vectors with an anti-tumor gene inserted into the genome of replicative virus specific for tumor cells. Because of the specific replication and proliferation of the virus in tumor cells, expression of the anti-tumor gene is increased hundreds to thousands of times. This approach takes full advantages of gene therapy and virus therapy to enhance the effect on the tumor. It overcomes the disadvantages of conventional gene therapy, such as low transfer rate, low gene expression, lack of target tropism, and low anti-tumor activity. We believe that this is a promising means for future tumor treatment.

Adenoviridae ; genetics ; Adenovirus E1A Proteins ; genetics ; Adenovirus E1B Proteins ; genetics ; Genetic Therapy ; methods ; Genetic Vectors ; genetics ; Humans ; Interleukin-12 ; genetics ; Neoplasms ; therapy ; Recombination, Genetic ; Tumor Cells, Cultured ; Virus Replication

OBJECTIVEThe relationship between latent adenovirus infection and airway inflammation have not been well documented. The aim of this study is to illustrate the roles of adenovirus E1A protein on the level of glutathione (GSH) in response to oxidative stress and the effect of the oxidant/antioxidant imbalance upon the transactivation of NF-kappaB triggered by E1A protein.

METHODSRat alveolar epithelial cell stably expressing adenoviral E1A or control plasmid were developed. For isolation of nuclear extracts, 5 x 10(5) cells were plated and grown overnight in 60 mm dishes. Experiments were repeated three times. The cell model of stably expressing adenoviral E1A was stimulated by H2O2. The level of GSH were measured. E1A positive clone was stimulated by LPS or TNF-alpha and treated with L-Buthionine-sulfoximine (BSO). The expression of NF-kappaB was measured by Western blot. Differences between groups were assessed for significance by Student' t test; multiple comparisons by the one-way ANOVA.

RESULTSThere is no difference of GSH level without stimulation between E1A-positive clones and E1A-negative clones. For E1A-positive clones, the level of GSH did not increase in response to H2O2 as E1A-negative clones. The quantitation by densitometry of the NF-kappaB expression in E1A-positive clones were (79.3 +/- 4.6), (80.3 +/- 3.8) respectively without treatment and were (81.8 +/- 3.9) - (89.9 +/- 1.6) and (94.1 +/- 1.9) - (99.8 +/- 1.6) respectively under LPS or TNF-alpha stimulation, which were significantly higher than that of the control group (68.3 +/- 3.8), (69.4 +/- 4.3) respectively without stimulation and (70.1 +/- 2.8) - (80.8 +/- 3.6), (73.4 +/- 4.9) - (83.2 +/- 6.7) respectively under stimulation. The quantitation by densitometry of the NF-kappaB expression in E1A-negative clones were (1.25 +/- 0.18) and (1.69 +/- 0.19) respectively under LPS and TNF-alpha-stimulation and (1.22 +/- 0.16) and (1.75 +/- 0.13) respectively upon treatment for LPS and TNF-alpha with BSO preincubation. There did not show difference upon treatment with LPS or TNF-alpha with or without BSO in E1A-negative cell clone. The quantitation by densitometry of the NF-kappaB expression in E1A-positive clone were (1.75 +/- 0.10) and (2.26 +/- 0.21) respectively upon treatment for LPS and TNF-alpha with BSO preincubation which were significantly higher than that of LPS or TNF-alpha-stimulation alone (1.35 +/- 0.12), (1.80 +/- 0.14) respectively.

CONCLUSIONThese results indicate that E1A protein decreased GSH levels in oxidant stress and upregulated NF-kappaB transcription activity. The oxidant/antioxidant imbalance in rat alveolar epithelial cells enhances E1A-modulated transcriptional activation of NF-kappaB. The mechanism underlying transactivation of NF-kappaB involved by E1A may be related to oxidative stress.

Adenovirus E1A Proteins ; genetics ; metabolism ; Animals ; Cell Line ; Epithelial Cells ; metabolism ; NF-kappa B ; genetics ; metabolism ; Oxidative Stress ; Pulmonary Alveoli ; cytology ; Rats ; Transcriptional Activation

OBJECTIVE: To investigate the inhibitive effect of E1A gene carried by PEI-Fe(3)O(4) nanometer particle (NP) on the cell growth of human cervical carcinoma cell in vitro and its mechanism, and to provide the experimental evidence for the feasibility of gene therapy for human cervical carcinoma. METHODS: E1A gene conjugated to PEI-Fe3O4 NP was transfected into human cervical carcinoma cell line Hela. The cell growth curve of Hela was drawn, the doubling time and the number of colony formations on the soft agar were calculated based on the cell count. RT-PCR and Western blot were used to detect the expression of the E1A and HER-2/neu in Hela cells. RESULTS: The cell doubling time of Hela cells transfected with E1A gene (Hela-E1A) was 1.53 times and 1.58 times longer than that of the Hela transfected with blank vector (Hela-vector) and blank Hela control (Hela), respectively. The E1A transfected Hela cells grew slower than those of the control group. The cell colony formation efficiency in the Hela-E1A (6.62%) group was significantly lower than that of Hela (30.48%) and Hela-vector (28.3%) groups (P<0.05). As compared to Hela and Hela-vector, the inhibition rate of Hela-E1A was 78.28% and 76.62% respectively. RT-PCR and Western blot demonstrated that the overexpression of E1A through gene transfection significantly inhibited mRNA and protein expression of HER-2/neu in Hela cells. CONCLUSION E1A gene can suppress the cell growth of human cervical carcinoma cell Hela in vitro. Down-regulated expression of HER-2/neu gene by E1A overexpression in Hela might contribute to the Hela growth inhibitive effect of E1A.
Adenovirus E1A Proteins ; genetics ; Cell Proliferation ; Female ; Gene Expression Regulation, Neoplastic ; Genetic Therapy ; methods ; HeLa Cells ; Humans ; Transfection ; Uterine Cervical Neoplasms ; genetics ; therapy

OBJECTIVETo study the effect of binding activities of the NH(2) terminus of E1A to the proteins regulating cell growth on ras-induced cell senescence and explore the mechanism of E1A-mediated escape from ras-induced senescence by E1A in human fibroblast.

METHODSIn primary human fibroblasts, the proteins regulating cell growth in association with E1A NH(2) terminus, including the Rb family proteins, p300/CBP, and p400, were inactivated or interfered. The effect of alterations in the binding activities of these proteins on cell senescence bypass mediated by E1A was evaluated by cell growth curve.

RESULTSThe Inactivation of Rb family proteins alone was not sufficient to rescue ras-induced cell senescence, whereas inactivation of both the Rb proteins and p300/CBP blocked ras-induced senescence of human fibroblasts.

CONCLUSIONRb and p300/CBP binding activities are both required for E1A to bypass ras-induced senescence in human fibroblasts.

Adenovirus E1A Proteins ; pharmacology ; Cellular Senescence ; drug effects ; Fibroblasts ; cytology ; Humans ; Primary Cell Culture ; Retinoblastoma Protein ; metabolism ; Skin ; cytology ; p300-CBP Transcription Factors ; metabolism ; ras Proteins ; antagonists & inhibitors ; pharmacology

We constructed the recombinant adenovirus vector expressing IL-24 and E1A (Ad-IL-24-E1A) and investigated the inhibition of Ad-IL-24-E1A on SMMC-7721 hepatocellular carcinoma in vitro. We amplified IL-24 gene by PCR using pAdTrack-IL-24 as template. The IL-24 gene was cloned into pAdTrack-IRES at the Bgl II and Sal I site to form pAdTrack-IL-24-IRES. E1A digested from pAdTrack-E1A was cloned into the pAdTrack-IL-24-IRES at the Xho I and EcoR V site to form the pAdTrack-IL-24-IRES-E1A. We co-transformed both pAdTrack-IL-24-IRES-E1A and pAdeasy-1 digested by Pme I and packaged to obtain Ad-IL-24-E1A. Ad-IL-24-E1A at 50 MOI infected SMMC-7721 cells. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay determined cell proliferation. Flow cytometry detected Cell apoptosis. The apoptotic rate of SMMC-7721 cells was 52% 48 h after infection with Ad-IL-24-E1A. The result showed that the growth of SMMC-7721 cells was significantly inhibited by Ad-IL-24-E1A at the MOI of 50.
Adenoviridae ; genetics ; metabolism ; Adenovirus E1A Proteins ; biosynthesis ; genetics ; Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Carcinoma, Hepatocellular ; pathology ; Cell Line, Tumor ; Cell Proliferation ; Genetic Vectors ; genetics ; Humans ; Interleukins ; biosynthesis ; genetics ; Liver Neoplasms ; pathology ; Recombinant Proteins ; biosynthesis ; genetics ; pharmacology

BACKGROUNDThe expression of therapeutic gene and its anti-tumor effects will be augmented and a synergism of oncolytic virus with the therapeutic gene is speculated. This study was undertaken to assess the anti-tumor effects of a novel gene-viral therapeutic system CNHK300-mEndostatin (CNHK300-mE) in hepatocellular carcinoma (HCC).

METHODSA novel gene-viral therapeutic system named CNHK300-mE was constructed using the human telomerase reverse transcriptase (hTERT) promoter to drive the expression of the adenovirus E1A gene and cloning the therapeutic gene mouse endostatin into the adenovirus genome. By the tissue culture infectious dose 50 (TCID50) method and cytoviability assay, the replicative and cytolytic capabilities of CNHK300-mE in two HCC lines (HepGII and Hep3B) and one normal cell line (MRC-5) were analyzed, and the transgene expressions of mouse endostatin in vitro and in vivo were detected by Western blotting and ELISA assay. Tumor growth suppression and anti-angiogenesis effects in vivo were investigated using nude mice xenografts model derived from SMMC-7721 HCC cells.

RESULTSThe 3296-fold replicating capacity of CNHK300-mE in HCC cell lines versus in the normal cell line at 96 hours post infection and the 25-fold effective dose for killing 50% cells (ED50) in the normal cell line versus HCC cell lines, which were both superior to ONYX-015, were observed. Tumor growth suppression of CNHK300-mE superior to either Ad-mE or ONYX-015 was demonstrated (P < 0.01) and the anti-angiogenic effects in vivo superior to Ad-mE were also observed with immunohistochemical staining of von Willebrand factor. In comparison with non-replicative adenovirus Ad-mE, the transgene expression of mE mediated by CNHK300-mE was significantly higher in vitro (P < 0.005) and in vivo (P < 0.05).

CONCLUSIONBeing capable of replicating in and lysing the telomerase-positive HCC cells and mediating effective expression of the therapeutic gene in vitro and in vivo, the novel gene-viral therapeutic system CNHK300-mE is potentially effective in the treatment of HCC.

Adenoviridae ; genetics ; Adenovirus E1A Proteins ; genetics ; Animals ; Blotting, Western ; Enzyme-Linked Immunosorbent Assay ; Genetic Therapy ; Humans ; Liver Neoplasms, Experimental ; therapy ; Mice ; Mice, Inbred BALB C ; Neoplasm Transplantation ; Transplantation, Heterologous ; Virus Replication

OBJECTIVETo investigate the role of human adenovirus type 5 (Ad5) early-region 1A (E1A) in premature senescence of human fibroblasts induced by Ras activation.

METHODSHuman fibroblasts were cotransduced with E1A, E1A1-143, or their vector (BP) and Ha-RasV12 or its vector (WH). The growth curves and percentages of the apoptotic cells were determined.

RESULTSExpression of E1A or Ha-RasV12 in human fibroblasts significantly inhibited the cell growth. Transduction of Ha-RasV12 along with E1A or E1A 1-143 into human fibroblast cells resulted in active and rapid cell proliferation.

CONCLUSIONE1A can rescue human fibroblasts from Ras-induced premature senescence, and the senescence bypassing activity of E1A resides in its NH2 terminus.

Adenovirus E1A Proteins ; genetics ; metabolism ; Apoptosis ; genetics ; physiology ; Cell Transformation, Neoplastic ; genetics ; metabolism ; Cells, Cultured ; Cellular Senescence ; genetics ; physiology ; Fibroblasts ; cytology ; metabolism ; Genes, ras ; physiology ; Humans ; Skin ; cytology ; Transfection

The E1A gene was obtained by PCR with QBI-293A cell genome DNA as template. After enzyme digestion, the E1A gene was ligated to transfer vector pAdTrack-CMV. The positive clone pAdTrack-CMV-E1A were lineared by PmeI and co-transformed with pAdEasy-1 in BJ5183 E. coli. The recombinant adenovirus vector pAdEasy-1-pAdTrack-CMV-E1A were digested by PacI and transfected into QBI-293A cells with liposomes. The oncolytic recombinant adenovirus Ad-E1A was obtained after 7 days. The results showed that this oncolytic adenovirus Ad-E1A can replicate in ECV304 cells and inhibit growth of ECV304 cell. In addition, it also decreased the secretion of VEGF and expression of NF-kappaB of ECV304 cells, indicating that Ad-E1A have potential of inhibition of tumor metastasis.
Adenoviridae ; genetics ; physiology ; Adenovirus E1A Proteins ; biosynthesis ; genetics ; Cell Proliferation ; Cells, Cultured ; Endothelial Cells ; cytology ; metabolism ; Humans ; Oncolytic Virotherapy ; Oncolytic Viruses ; genetics ; physiology ; Promoter Regions, Genetic ; Umbilical Veins ; cytology ; metabolism

OBJECTIVETo develop a novel vector system, which combines the advantages of the gene therapy, antiangiogenic therapy and virus therapy, and to observe its effect on lung cancer.

METHODSHuman angiostatin gene hA(k1-5) was inserted into the genome of the replicative virus specific for the tumor cells by virus recombination technology. The expression of hA(k1-5), its effect on tumor growth in vitro and in vivo were studied.

RESULTSA new kind of gene-viral vector system, designated as CNHK200-hA(k1-5), in which the E1b55 000 gene was deleted but the E1a gene of adenovirus preserved, was constructed. The novel vector system possessed the same property as the replicative virus ONYX-015, which replicates in p53- tumor cells but not in normal cells, thus specifically kills tumor cells. In vitro, CNHK200-hA and Ad-hA both could kill A549 tumor cells but the latter needed 100 times more MOI to achieve the same amplitude of cell killing. In vivo, the therapeutic effect of CNHK200-hA on human lung cancer A549 xenograft in nude mice was significantly better than that of Ad-hA and that of tumor-replicative virus ONYX-015.

CONCLUSIONCNHK200-hA(k1-5), a novel vector is constructed in which the angiostatin gene is inserted into the genome of the replicative adenovirus cytotoxic to p53-negative tumor cells. It has the advantages of specific tumor targeting, high level gene expression in tumor cells, and potent tumoricidal activity.

Adenoviridae ; genetics ; Adenovirus E1A Proteins ; genetics ; Angiostatins ; biosynthesis ; genetics ; physiology ; Animals ; Cell Line, Tumor ; Cell Survival ; drug effects ; Female ; Genetic Therapy ; Genetic Vectors ; Humans ; Lung Neoplasms ; metabolism ; pathology ; therapy ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Neoplasm Transplantation ; Transfection

OBJECTIVE: To explore the molecular mechanism of proliferation inhibition of human breast cancer cell MCF-7 regulated by E1A gene. METHODS: E1A gene was transfected into MCF-7 cells by liposome reagents. RT-PCR and Western blot were used to detect E1A mRNA and protein expression and HER-2 mRNA in MCF-7. The proliferation and colony formation of MCF-7 were measured by 3-(4,5-dinmethylthiahiazo-z-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and soft agar formation assay. The apoptosis of MCF-7 cells regulated by E1A expression was examined by flow cytometry. RESULTS: E1A was not endogenously expressed in MCF-7. E1A expression in MCF-7 could significantly decrease HER-2 mRNA and protein expression. Flow cytometry indicated that the apoptosis of MCF-7 could be induced by E1A. Meanwhile, E1A gene could significantly inhibit MCF-7 proliferation and colony formation in soft agar. CONCLUSION E1A gene can decrease HER-2 expression and induce the apoptosis of human breast cancer cell MCF-7, and inhibit the proliferation and colony formation of MCF-7.
Adenovirus E1A Proteins ; biosynthesis ; genetics ; Apoptosis ; genetics ; Breast Neoplasms ; genetics ; metabolism ; Cell Proliferation ; Female ; Genes, erbB-2 ; genetics ; Humans ; RNA, Messenger ; biosynthesis ; genetics ; Receptor, ErbB-2 ; biosynthesis ; genetics ; Transfection ; Tumor Cells, Cultured