An epidermal growth factor motif of developmental endothelial locus 1 protein inhibits efficient angiogenesis in explanted squamous cell carcinoma in vivo

ABSTRACT Background: Cancer gene therapy using a nonviral vector is expected to be repeatable, safe, and inexpensive, and to have long-term effectiveness. Gene therapy using the E3 and C1 (E3C1) domain of developmental endothelial locus-1 (Del1) has been shown to improve prognosis in a mouse transplanted tumor model. Objective: In this study, we examined how this treatment affects angiogenesis in mouse transplanted tumors. Materials and methods: Mouse transplanted tumors (SCCKN human squamous carcinoma cell line) were injected locally with a nonviral plasmid vector encoding E3C1 weekly. Histochemical analysis of the transplanted tumors was then performed to assess the effects of E3C1 on prognosis. Results: All mice in the control group had died or reached an endpoint within 39 days. In contrast, one of ten mice in the E3C1 group had died by day 39, and eight of ten had died or reached an endpoint by day 120 (p < 0.01). Enhanced apoptosis in tumor stroma was seen on histochemical analyses, as was inhibited tumor angiogenesis in E3C1-treated mice. In addition, western blot analysis showed decreases in active Notch and HEY1 proteins. Conclusion: These findings indicate that cancer gene therapy using a nonviral vector encoding E3C1 significantly improved life-span by inhibiting tumor angiogenesis. (REV INVEST CLIN. 2021;73(1):39-51)

The anti-tumor effect by adenovirus-mediated ING4 and IL-24 co-expression on hepatocellular carcinoma in vitro / 中华微生物学和免疫学杂志

Objective To construct a recombinant adenoviral vector carrying and co-expressing human inhibitor of growth 4(ING4) and human interleukin-24(IL-24) mediated by poly( A)-Promoter[Ad-ING4-poly(A)-Promoter-IL-24, referred to as Ad-ING4-IL-24] and explore its effect on the growth of HepG-2 human hepatocellular carcinoma cellsin vitro. Methods The poly(A)-Promoter(hEFl-elF4g) (Sal Ⅰ and Not Ⅰ ), ING4 ( Bgl Ⅱ and Sal Ⅰ ), and IL-24 ( Xho Ⅰ and Xba Ⅰ ) fragments were amplified by PCRusing pORF-mbcl-2α, pcDNA3.0-IL-24, and pcDNA3.0-ING4 plasmids as templates and subcloned into pAdTrack-CMV transfer vector to form pAdTrack-CMV-ING4-poly (A)-Promoter-lL-24, respectively. The pAdTrack-CMV-ING4-poly (A)-Promoter-IL-24 transfer vector linearized with Pme Ⅰ digestion and pAdEasy-1 backbone vector was further cotransformed into the bacteria BJ5183 competent cells for homologous recombination. The resultant pAdEasy-l-pAdTrack-CMV-ING4-poly ( A )-Promoter-IL-24 homologous recombinant plasmids were linearized with Pac Ⅰ digestion and transfected into the human embryonic kidney 293 (QBI-293A) cells by liposome, leading to formation of the recombinant adenoviruses Ad-ING4-IL-24co-expressing ING4 and IL-24. The Ad-ING4-IL-24 were amplified in QBI-293A cells and its titer was up to 3.5 × 109 PFU/ml. Adenovirus-mediated ING4 and IL-24 genes expression in HepG-2 cells was examined by RT-PCR and Western blot. The growth-suppressing and apoptosis-inducingg effect of Ad-ING4-IL-24 coexpressing ING4 and IL-24 on HepG-2 human hepatocellular carcinoma cells was assessed by MTT assay and FCM, respectively. Results DNA sequencing showed that the ING4, poly (A)-Promoter, and IL-24 fragments subcloned into pAdTrack-CMV plasmids were completely identical to those reported in GenBank.ING4 and IL-24 gene mediated by adenovirus could both successfully express in HepG-2 cells. Adenovirusmediated ING4 and IL-24 co-expression significantly suppressed HepG-2 hepatocellular carcinoma cell growth and induced cell apoptosis, and the effect of Ad-ING4-IL-24 group was more significant than AdING4 and Ad-IL-24 group. Conclusion The adenoviral vector co-expressing ING4 and IL-24 mediated by poly(A)-Promoter(Ad-ING4-IL-24) was successfully constructed. Ad-ING4-IL-24 had marked anti-tumor effect in suppressing HepG-2 human hepatocellular carcinoma cell growth and inducing cell apoptosis in vitro. Compared with Ad-ING4 and Ad- IL-24, Ad-ING4-IL-24 enhanced anti-tumor effect.

Replication-incompetent Adenovirus Vector-mediated MDA-7/IL-24 Selectively Induces Growth Suppression and Apoptosis of Hepatoma Cell Line SMMC-7721 / 华中科技大学学报（医学）（英德文版）

In order to investigate the effect of replication-incompetent adenovirus vector expressing MDA-7/IL-24 on tumor growth and apoptosis of human hepatocellular carcinoma (HCC) cell line SMMC-7721 and normal liver cell line L02, the recombinant replication-incompetent Ad.mda-7 virus vector was constructed and infected into the HCC cell line SMMC-7721 and normal liver cell line L02. RT-PCR was performed to examine the expression of MDA-7 mRNA. The concentrations of MDA-7/IL-4 in culture supernatants were determined by using ELISA. MTT and Hoechst staining assay were applied to observe the inhibitory and killing effects of MDA-7 on the HCC cells. By using flow cytometry, the apoptosis, cell cycle and proliferation of SMMC-7721 and L02 cells were meas- ured. The results showed recombinant replication-incompetent virus expressing MDA-7/IL-24 was constructed successfully, and RT-PCR revealed that it could mediate the high expression of the ex- ogenous gene MDA-7/IL-24 in SMMC-7721 and L02 cells. The expression of MDA-7/IL24 proteins in the culture supernatant was detectable by ELISA. Ad.mda-7 infection induced apoptosis and growth suppression in SMMC-7721 cells and an increased percentage of HCC cells in the G2/M phase of the cell cycle, but not in L02 cells. It was concluded that mda-7/IL-24 gene, mediated with replication-incompetent adenovirus vector, could selectively induce growth suppression and apoptosis in HCC cell line SMMC-7721 but without any toxic side-effect on normal liver line L02.

In Vivo Target RNA Specificity of Trans-Splicing Phenomena by the Group I Intron

The Tetrahymena group I intron has been shown to employ a trans-splicing reaction and has been modified to specifically target and replace human telomerase reverse transcriptase (hTERT) RNA with a suicide gene transcript, resulting in the induction of selective cytotoxicity in cancer cells that express the target RNA, in animal models as well as in cell cultures. In this study, we evaluated the target RNA specificity of trans -splicing phenomena by the group I intron in mice that were intraperitoneally inoculated with hTERT-expressing human cancer cells to validate the anti-cancer therapeutic applicability of the group I intron. To this end, an adenoviral vector that encoded for the hTERT-targeting group I intron was constructed and systemically injected into the animal. 5'-end RACE-PCR and sequencing analyses of the trans-spliced cDNA clones revealed that all of the analyzed products in the tumor tissue of the virus-infected mice resulted from reactions that were generated only with the targeted hTERT RNA. This study implies the in vivo target specificity of the trans - splicing group I intron and hence suggests that RNA replacement via a trans -splicing reaction by the group I intron is a potent anti-cancer genetic approach.

Changing the Composition of Fatty Acids of Cell Membrane Promotes Breast Cancer Cell to Apoptosis / 中国生物工程杂志

Objective: To study expression of the gene of n-6 fatty acid desaturase fat-1 in human breast cancer cell, composition change of fatty acids of cell membrane, and effect of the gene on apoptosis of breast cancer cell. Methods: Construct recombinant adenovirus vector (Ad.GFP.fat-1) containing fat-1 gene, the recombinant adenovirus was produced in 293 package cell, then it infected the breast cancer cells MCF-7; Total RNA of the cells was isolated and hybridized with antisense RNA probe of fat-1 mRNA by Northern to analyze the expression of fat-1 in MCF-7;The effect of fat-1on the proliferation of MCF-7 cell was analyzed by MTT method,apoptosis of the cells were detected by apoptosis kit;Content of n-6 PUFAs/n-3 PUFAs was analyzed by Gas Chromatography. Results: The proposed recombinant virus was got through DNA recombinant technique; fat-1 gene effectively expressed in human breast cancer cell MCF-7; The fat-1 mRNA band appeared 2 days after infection of virus Ad.GFP.fat-1;Compared with the control cell (Ad.GFP), proliferation of MCF-7 cell was markedly inhibited by the gene fat-1( 23%, p

Enhanced Oncolytic Effect and Anti-Tumor Effect of Replication Competent Adenovirus with Double Mutation in E1A & E1B Regions

Gene-modified replication-competent adenoviruses (Ads) are emerging as a promising new modality for the treatment of cancer. We have previously shown that E1B 19kDa and E1B 55kDa gene deleted Ad (Ad-deltaE1B19/55) exhibits improved tumor-specific replication and cell lysis, leading to potent anti-tumor effect. As an additional effort to increase cancer cell-selectivity of replicating adenovirus, we have first generated eleven E1A-mutant Ads (Ad-mt#1~#11) with deletion or substitution in retinoblastoma (Rb) binding sites of E1A. Of these viruses, Ad-mt#7 demonstrated significantly improved cytopathic effect (CPE) and viral replication in a cancer cell-specific manner. To further increase the cancer cell-specific killing effect of Ad-mt#7, both E1B 19kDa and E1B 55kDa genes were deleted, resulting in an Ad-deltaE1Bmt7. As assessed using CPE assay, MTT assay, and immunoblot analysis for Ad fiber expression, Ad-deltaE1Bmt7 exerted markedly enhanced cancer cell-specific killing effect as well as viral replication in comparison to either Ad-mt#7 or Ad-deltaE1B19/55. Furthermore, the growth of established human cervical carcinoma in nude mice was significantly suppressed by intratumoral injection of Ad-deltaE1Bmt7. In summary, we have developed an oncolytic adenovirus with significantly improved therapeutic profiles for cancer treatment.

Development of Hepatoma-Specific Replication Competent Adenovirus

A prerequisite for the development of a cancer cell selective targeting adenovirus is the generation of adenoviral vectors that lack native receptor binding ability and additionally contain domains redirecting the vector to cancer cell specific receptors. Towards this goal, we have generated an E1B 55kDa-deleted oncolytic and coxoackie and adenovirus receptor (CAR)-binding ablated adenovirus, YKL-K420A. This newly engineered adenovirus resulted in a dramatic reduction of transduction efficiency compared to the control adenovirus, YKL-1, in all of the cell lines tested. The malaria circumsporozoite (CS) protein interacts with glycosaminoglycans (GAG) present on the liver cell surface, and plays a prominent role in sporozoite attachment and invasion into hepatocytes. To redirect the CAR binding ablated adenovirus YKL-K420A to hepatocytes, CS protein epitope (EWSPCSVTCGNGIQVRIK) was incorporated onto the C-terminus of the YKL-K420A fiber protein, generating an YKL-K420A-hepa. The In vitro efficacy and specificity of YKL-K420A-hepa was then evaluated by comparing the cytopathic effect in hepatoma and other cancer cells from different origins. In hepatoma cells, YKL-K420A-hepa exerted upto 20-fold higher cytolytic ability compared to the control adenovirus, YKL-1, in hepatoma cell lines. Treatment with YKL-K420A-hepa also significantly suppressed tumor growth in a hepatoma xenograft tumor model when compared to YKL-1. Taken together, these studies demonstrate that the strategy to alter adenovirus tropism may greatly improve adenoviral utilities in gene therapy applications.

Inhibition of Melanoma Cell Lines Using Antisense Sequence Expressing Adenovirus and Cisplatin

PURPOSE: Telomerase is known to play a role of adding repetitive parts to chromosomal ending and to be involved in carcinogenic process through cell immortalization. The purpose of this study is to evaluate that restraining of telomerase activation can have killing effect on cancer cell and enhance susceptibility of cancer cells to anticancer substance. METHODS: The killing effect on melanoma cells was studied by using recombinant adenovirus that makes it possible to inhibit telomerase from getting activated, with such targets as two types of melanoma cell lines. This recombinant adenovirus was used combined with cisplatin, one of the most representative anticancer medicine to evaluate enhancement in susceptibility of cancer cells to anticancer substance. RESULTS: From the result of cytotoxic assay, it is found that melanoma cells have much resistance to cisplatin on the whole. In the case of using Ad-OA of recombinant virus alone, killing effect on melanoma cells was insignificant. On the other hand, when Ad-OA was used in combination with cisplatin, susceptibility of melanoma cell lines to cisplatin was enhanced. CONCLUSIONS: Ad-OA, recombinant adenovirus, could be used as a supplementary medicine in the targeted cancer gene therapy against cancer cell lines resistant to cisplatin.

Increased Cytopathic Effect of Replicating Adenovirus Expressing Adenovirus Death Protein / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Replication-competent adenoviruses (Ads) are promising new modalities for the treatment of cancer. Selective replication of a viral agent in tumor may lead to improved efficacy over non-replicating Ads due to viral multiplication, lysis of the infected cancer cell and spread to surrounding cells. In our previous studies it was shown that the E1B 55 kD-deleted Ad (YKL-1) exhibits tumor specific replication and cell lysis, but with reduced cytolytic effects compared to the wild type adenovirus (Int J Cancer 2000;88: 454-463). Thus, improving the potency of oncolytic Ads remains an important goal for cancer gene therapy. To increase the oncolytic ability of YKL-1, an adenovirus death protein (ADP) gene was reintroduced under the control of a CMV or MLP promoter at the E3 region of the YKL-1, generating an YKL-cADP and YKL-mADP, respectively. MATERIALS AND METHODS: The in vitro cytolytic effect of ADP expressing Ads was evaluated by MTT assay, and the induction of apoptosis by ADP expressing Ads was examined by TUNEL analysis. Finally, the antitumor effect of ADP expressing Ads was demonstrated in C33A xenograft tumor model. RESULTS: The YKL-cADP exerted a markedly enhanced cytolytic effect against H460 and SK-Hep1 cancer cell lines. The TUNEL assay indicated that the ADP-mediated cytotoxicity was largely driven by apoptosis. Finally, the YKL-cADP showed a superior antitumor effect than the YKL-1 or YKL-mADP in C33A xenografts. CONCLUSION: These lines of evidence demonstrate that the YKL-cADP induces efficient cell lysis, which is critical for the addition of therapeutic value to replicating Ads in cancer gene therapy.

Effect of Tie-2-siRNA Expression Vector on Human Hepatoma Transplanted Subcutaneously in Nude Mice / 中国普外基础与临床杂志

Objective To explore the effect of Tie-2 small interference RNA(siRNA)treatment in human hepatoma transplanted subcutaneously in nude mice.Methods Tumor cells were implanted in the hind flank of male nude mice of 6 weeks.Tumor-bearing mice were divided into two groups(gene therapy group and control group)and injected intra-tumorally with Tie-2-siRNA/Lipofectamine and saline/Lipofectamine respectively.The tumor volume and weight,serum AFP and microvessel density(MVD)and the histological change of the tumor were tested after gene therapy.Results The growth inhibitory rates in gene therapy group were 26.94%,53.01% and 68.91% on day 4,7 and 10 after gene therapy respectively.The tumor volumes of gene therapy group(118.47,111.57 and 104.59 mm3)were smaller than those of the control group(162.17,237.46 and 336.41 mm3)respectively(P

Construction of Secreting Plasmid for TRAIL and Its Inhibitory Effect on Liver Cancer / 中国普外基础与临床杂志

Objective To construct the eukaryotic expressing plasmid of tumor necrosis factor-related apoptosis-inducing ligand(TRAIL),and study its inhibitory effect on hepatic tumor which implanted subcutaneously in nude BALB/c mice.Methods Total RNA of U937 cell was extracted, and its extracellular domain (114-281aa) was amplified by RT-PCR, then signal peptide was ligated. The recombinant secreting plasmid for TRAIL was constructed successfully which was confirmed by enzyme cleavage identification and sequencing identification. Liver cancer cell (strain No.7402) was implanted subcutaneously in 32 nude BALB/c mice. These mice were randomly divided into two groups: study group and control group. The mice in study group received muscular injection of plasmids for transfection, and the mice in control group received the injection of normal saline at the same time. The size of implanted tumors were measured continuously till the day of sacrificing, tumor cell apoptosis effect was examined by TUNEL method. Results In study group,tumor volume was smaller than that in control group and the blue-purple apoptosis cells were observed under microscope. Conclusion TRAIL plasmid can induce apoptosis of liver cancer cell and can inhibit the growth of liver tumor.

Application and Prospection of RNAi in Colorectal Cancer Gene Therapy / 中国普外基础与临床杂志

Objective To explore the application of RNA interference(RNAi) in colorectal cancer gene therapy.Methods The related literatures in recent years were reviewed.Results RNAi causes a high effective and distinctive degradation of mRNA homologous in sequence to the dsRNA.This new technology has been successfully applied to research the genesis and the growth of colorectal cancer.Conclusion RNAi has been a new focus in gene therapy for colorectal cancer.

Development of a Conditional Replication Competent Adenovirus, Controlled by the Human Telomerase Promoter (hTERT) / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: This study has been planned to generate a replication-competent adenovirus which replicates in a cancer cell-specific manner, thus minimizing the side effects and toxicity of cancer gene therapy. MATERIALS AND METHODS: we have generated an E1B 19 kD attenuated recombinant adenoviruses, Ad-TERT-delta19 and Ad-mTERT-delta19, which encode E1A gene driven by the wild type hTERT and modified m-hTERT promoter containing additional c-myc and Sp1 binding sites in the backbone of Ad-deltaE1B19. The in vitro efficacy and specificity of the hTERT and m-hTERT promoter have been evaluated by the comparison of viral replication and cytopathic effect in cancer cells and normal cell lines. To assess anti-tumor effect and safety of hTERT or m-hTERT promoter driven replication competent adenoviruses, tumor regression after subcutaneous injection in subcutaneous C33A xenografts and lacZ expression after systemic injection in organs were examined. RESULTS: The activation of hTERT or m-hTERT promoter was significantly up-regulated only in hTERT-positive cells, but not in hTERT-negative cells. Moreover, the activity of m-hTERT promoter was substantially increased in hTERT-positive cancer cells, but not in hTERT-negative cells. While Ad-TERT-delta19 replicated in and induced cytopathic effect in cancer and in some normal cell lines, Ad-mTERT-delta19 enhanced viral replication and cytopathic effect in cancer cells only. Furthermore, the growth of established human cervical carcinoma in nude mice was significantly suppressed by intratumoral injection of Ad-mTERT-delta19. CONCLUSIONS: The use of m-hTERT promoter is not only useful in the regulation of therapeutic gene expression but also that replication-competent oncolytic adenovirus under the control of m-hTERT promoter may be a new promising tool for the treatment of human malignancies.

Evaluation of E1B-mutant Replicating Adenoviruses for Cancer Gene Therapy / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Gene-attenuated replication-competent adenoviruses are emerging as a promising new modality for the treatment of cancer. In an effort to continually improve upon cancer gene therapy, we have modified gene- attenuated replication-competent adenoviruses so as to cause them to replicate efficiently and lyse the infected cancer cells more effectively. MATERIALS AND METHODS: We modified the E1 region of the adenovirus (Ad) systematically, generating Ad-deltaE1B19, Ad-deltaE1B55, Ad-deltaE1B19/55, and Ad-WT. The cytopathic effects (CPE) and viral replication of these four gene modified adenoviruses were compared, and the morphology and DNA fragmentation of the infected cells was evaluated. RESULTS: Among the constructed adenoviruses, E1B 19kD-inactivated adenovirus (Ad-deltaE1B19) was the most potent, inducing the largest-sized plaques and markedCPE. Moreover, cells infected with Ad-deltaE1B19 showed complete cell lysis with disintegrated cellular structure whereas cells infected with Ad-WT maintained intact cellular and nuclear membrane with properly structured organelles. TUNEL assay was also used to monitor DNA integrity, and a more profound induction of apoptosis was observed in the Ad-deltaE1B19 infected cells in comparison to wild type adenovirus infected cells. CONCLUSION: We demonstrate that the inactivation of the E1B19kD gene in a replicating adenovirus leads to increased CPE, rapid viral release, improved cell-to-cell viral spread and increased induction of apoptosis.

Efficacy of cisplatin against human ovarian cancer cells when combined with p53 gene therapy / 中国免疫学杂志

Objective:To explore the effects of wild type p53 gene on biologic behavior of human ovarian cancer cell line SKOV 3 and the efficacy of cisplatin against the cancer cells when combined with p53 gene therapy.Methods:A human wild type p53 gene recombinant eukaryotic expression vector was introduced by lipofectin mediated gene transfection into SKOV 3 cells which does not express endogenous p53.The clones obtained were observed for their biological behavior and the colony formation when exposed to cisplatin.Results:The exogenous wild type p53 gene expressed stably in the cells.The growth rate and colony formation of these transfected cells were suppressed significantly by exogenous p53 gene and the percentage of phase G 1 cells increased.There was an increasement in the sensitivity to cisplatin of the transfected cells.Conclusion:Exogenous wild type p53 gene can suppress the growth of human ovarian cancer cells and increase the efficacy of cisplatin against the cells.

Study of viral vector for mutagenesis in tumor genetherapy / 中国免疫学杂志

Objective:To observe mutagenesis of retrovirus and adenovirus as transgenic vector,and provide safe clinic evidence for transgenic tumor cell as tumor vaccin.Methods:Cells were cultured together with virus.Then,DNA and supernatant were carried on an in vestigation in mutagenesis by means of laboratory technique about genetic toxicology.Results:The result indicated that DNA and supernatant of transgenic cell had no mutagenesis through test both In vivo and in vitroConclusion:The virus modified had no mutagenesis as transgenic vector.

Comparison of Efficiency of Infection of Human Cancer Cell Lines Via Retroviral Vector System / 대한암학회지

PURPOSE: There are several reasons why retroviruses are useful as vectors for gene therapy. However, retroviral vectors also have some limitations. Research in retroviral-mediated gene transfer has struggled with low titer and transduction efficiency on certain human target cells even with the addition of polycations to enhance transduction. Efficient in vivo gene transfer with retroviral vectors will require the availability of large amounts of vector at titers higher than generally possible by most current methods. Therefore, transduction efficiency of various human cell types with retroviral vector system is very important in human gene therapy. In an effort to test the transduction efficiency of a retrovial vector in the human cancer cell lines, a retroviral vector was infected into various human cancer cell lines. MATERIALS AND METHODS: We generated retrovirus producing cell lines through transfection or infection of amphotropic packaging cell line PA317 with ecotropic retroviruses encoding bacterial lacZ gene. The amphotropic retrovirus vector was used to transduce various human cancer cell lines. RESULTS: Of eight randomly chosen G418-resistant clones generated by transfection, only two clone produced the vector at up to >10 (6) cfu/ml, while one of five clones generated by infection yielded higher-titer virus in the absence of helper virus, up to 1 X 10 (7) cfu/ml, than the transfected clones. Transduction with supernatant derived from a PA317 producer cell line has resulted in transduction levels from 1% to 15%, 5- to 60-fold lower than those analyzed in NIH3T3 cells. CONCLUSION: These findings suggest that new improved gene transfer method into human cancer cells using retroviruses is required for efficient in vivo cancer gene therapy.

Production of IL-12 from gene modified human dermal fibroblasts: A preclinical study for IL-12 cancer gene therapy

Cytokine has been used as an immune stimulator and administered to patients for a treatment of cancer. Interleukin-12 (IL-12) is a potent cytokine which acts through a variety of functions including interferon-gamma production and cytotoxic T-cell activation. Considering the toxicity of high dose systemic IL-12 administration into human, local administration of low dose IL-12 can be a more efficient strategy. In ex vivo therapy, human dermal fibroblast has been considered as a useful vehicle for transferring genes, Here we show that human dermal fibroblast transduced with retrovirus containing IL-12 gene can be manipulated to produce reasonable amount of IL-12 protein. Human dermal fibroblast was isolated from freshly harvested skin specimens by collagenase digestion, grown in primary cultures, and transduced with a retroviral vector containing genes for human IL-12 and a selectable marker Neo(R). Following selection in G418, IL-12 producing fibroblasts were tested for secreted IL-12 level by ELISA. Six specimens of human skin were processed to obtain fibroblasts. ELISA results show that 40-150 units of IL-12 was produced for 24 h from 1x10(6) cells of transduced and selected fibroblast cultures. The primary cultures were maintained for up to nine passages about 108 days. The mean +/- overall time for obtaining enough number of cells was 49 +/- 2 days. The fibroblasts continued to produce IL-12 in culture for 90 days. These preliminary results can be used for the design of ex vivo gene therapy clinical trial using human dermal fibroblast.

Mutagenesis of Transgenic Human Lung Adenocarcinoma Cell Line SPC-A-1/IL-2 / 中国肿瘤生物治疗杂志

Objective: To investigate the safety of transgenic human lung adenocarcinoma cell line SPC-A-1/IL-2 as tumor vaccine. Methods: IL-2 gene was introduced into human lung adenocarcinoma cell line SPC-A-1 and was expressed stably on the basis of the construction of retroviral packing cell line PA317/pLIL-2SN.The mutagenesis of both the DNA and supernatant of SPC-A-1/IL-2 in the and in vitro was tested by means of genetic toxicological techniques.Results:The result indicated that mutagenesis of both the DNA and the supernatant of transgenic cell SPC-A-1/IL-2 was not observed. Conclusion: The initial experiment suggested that the application of transgenic cell SPC-A-l/IL-2 as tumor vaccine was bisically safe and reliable.