Biomedical subjects

Dai-Ming Fan

Publications and source records attributed to Dai-Ming Fan.

At least 19 recordsLinked to original sources

PubMed2006

Antisense angiopoietin-1 inhibits tumorigenesis and angiogenesis of gastric cancer.

AIM: To investigate the effect of angiopoietin-1 (Ang-1) on biological behaviors in vitro and tumorigenesis and angiogenesis in vitro of human gastric cancer cells. METHODS: Human full-length Ang-1 gene was cloned from human placental tissues by RT-PCR method. Recombinant human Ang-1 antisense eukaryotic expression vector was constructed by directional cloning, and transfected by lipofectin method into human gastric cancer line SGC7901 with high Ang-1 expression level. Inhibition efficiency was confirmed by semi- quantitative PCR and Western blot method. Cell growth curve and cell cycle were observed with MTT assays and flow cytometry, respectively. Nude mice tumorigenicity test was employed to compare in vitro tumorigenesis of cells with Ang-1 suppression. Microvessel density (MVD) of implanted tumor tissues was analyzed by immunohistochemistry for factor VIII staining. RESULTS: Full-length Ang-1 gene was successfully cloned and stable transfectants were established, namely 7Ang1- for antisenseìand 7901P for empty vector transfected. 7Ang1- cells showed down-regulated Ang-1 expression, while its in vitro proliferation and cell cycle distribution were not significantly changed. In contrast, xenograft of 7Ang1- cells in nude mice had lower volume and weight than those of 7901P after 30 days' implantation (P<0.01, 293.00+/-95.54 mg vs. 624.00+/-77.78 mg) accompanied with less vessel formation with MVD 6.00+/-1.73 compared to 7901P group 8.44+/-1.33 (P<0.01). CONCLUSION: Ang-1 may play an important role in tumorigenesis and angiogenesis of gastric cancer, and targeting its expression may be beneficial for the therapy of gastric cancer.

Angiopoietin-1↗

PubMed2006

Inhibition of gastric cancer cells associated angiogenesis by 15d-prostaglandin J2 through the downregulation of angiopoietin-1.

Peroxisome proliferator-activated receptor gamma (PPARgamma) ligands have been shown to inhibit angiogenesis. We showed that treatment with 15d-PGJ(2), a PPARgamma ligand, downregulate the expressions of angiopoietin-1 (Ang-1) in gastric cancer cells MKN45. The medium of MKN45 cells treated with 15d-PGJ(2) significantly inhibited the migration and tube formation of human umbilical vein endothelial cells (HUVECs). Moreover, Matrigel plug assay revealed that 15d-PGJ(2) reduced in vivo angiogenesis induced by MKN45 cells. These modulations were restored by the addition of recombinant Ang-1. Our findings supported that 15d-PGJ(2) suppressed angiogenesis of gastric cancer cells by downregulation of Ang-1.

Angiogenesis Inhibitors↗

PubMed2005

Helicobacter pylori specific immune response induced by conservative flagellin linear B-cell epitope.

AIM: To testify the immunogenicity of a conservative B-cell linear epitope of Helicobacter pylori (H pylori) flagellin A. METHODS: Different programs were used to analyze the secondary structure, molecular hydropathy, and surface accessibility of H pylori flagellin A. Linear B-cell epitopes were estimated based on the structural and physiochemical information. Analysis of residue divergence was proposed to screen a conservative linear epitope. The 29-peptide (Pep29mer) synthesized by chemical method, including the predicted conservative B-cell epitope and a known K2d compatible T-cell epitope, was used to immunize mice, and then H pylori-specific antibodies were detected by ELISA. RESULTS: Based on the analyses of divergent amino acid residues, structural and physiochemical characteristics, it was strongly suggested that the short fragment NDSDGR was the core of a conservative linear epitope in flagellin A. Animals immunized by Pep29mer acquired efficient immune response. In detail, serum H pylori-specific IgA and IgG1 increased significantly in immunized group, while IgG2a only had an insignificant change. H pylori-specific IgA in gastrointestinal flushing fluid also increased significantly. CONCLUSION: The conservative short fragment NDSDGR is the core of a linear B-cell epitope of flagellin A.

Amino Acid Sequence↗

PubMed2005

Oral attenuated Salmonella typhimurium vaccine against MG7-Ag mimotope of gastric cancer.

AIM: To develop an oral attenuated Salmonella typhimurium vaccine against gastric cancer and to evaluate its efficacy in mice. METHODS: A complementary sequence of Nco I site and a sequence coding for MG7-Ag mimotope were designed at the 5' terminus of forward primer. Using p1.2 II-HBCAg plasmid as template, PCR was performed to get a fusion gene of the mimotope and a HBcAg gene. The fusion gene was then subcloned into the plasmid pYA3341 complementary to Salmonella typhimurium X4550, and the recombinant plasmid was then transformed into attenuated Salmonella typhimurium X4550. Balb/c mice were orally immunized with the recombinant Salmonella typhimurium X4550. The mice were immunized every 2 wk to reinforce the immunity. At the 6th wk, serum titer of antibody was detected by ELISA, and at the 8th wk, cellular immunity was detected by (51)Cr release test. Ehrlich ascites carcinoma cells expressing MG7-Ag were used in tumor challenge assay as a model to evaluate the protective effect of the vaccine. RESULTS: Serum titer of antibody against MG7-Ag was significantly higher in mice immunized with the vaccine than in control groups (0.9538+/-0.043 vs 0.6531+/-0.018, P<0.01; 0.9538+/-0.043 vs 0.6915+/-0.012, P<0.01), while in vitro (51)Cr release assay of the splenocytes showed no statistical difference in the three groups. Two weeks after tumor challenge, 1 in 5 immunized mice was tumor free, while all the mice in the control group presented tumor. CONCLUSION: Oral attenuated Salmonella typhimurium vaccine against the MG7-Ag mimotope of gastric cancer is immunogenic. It can induce significant humoral immunity against tumors in mice, and has some protective effects.

Administration, Oral↗

PubMed2005

The potent inhibitory effects of cisapride, a specific blocker for human ether-a-go-go-related gene (HERG) channel, on gastric cancer cells.

BACKGROUND: Ion channels may play a role in carcinogenesis. Human ether-a-go-go-related gene (HERG) encoding one of the components of delayed rectifier potassium currents has been indicated to be involved in tumor cell growth and death. Our aim is to investigate the effects of cisapride, a specific blocker for HERG channel, on human gastric cancer cells. METHODS: The effects of cisapride on the proliferation, clonogenicity, cell cycle and apoptosis of gastric cancer cells were evaluated by MTT assay, clonogenicity assay, flow cytometry and transmission electron microscopy. The expression of HERG mRNA and protein in gastric cancer cells and tissues was measured by RT-PCR, Western blot and immunohistochemistry, respectively. RESULTS: HERG mRNA and protein were exclusively expressed in gastric cancer cells. The HERG protein was localized in the cytoplasm and membrane of the gastric cancer cells. The proliferation of gastric cancer cells expressing HERG protein was inhibited in a time- and dose-dependent manner when treated with cisapride (P<0.05). The clonogenicity of gastric cancer cells treated with cisapride (100 nM) was reduced (P<0.05). Flow cytometric analysis indicated that cisapride tends to inhibit gastric cancer cells entering S phase from G(1) phase in the cell cycle (P<0.05). Apoptotic cells were found increased in gastric cancer cells treated with cisapride by both flow cytometry and electron microscopy. CONCLUSIONS: As HERG channel blocker, cisapride, can inhibit the growth of gastric cancer cells by altering distribution of cell cycle and inducing apoptosis so as to be of potential value in the treatment of gastric cancer.

Antineoplastic Agents↗

PubMed2005

A microarray-based gastric carcinoma prewarning system.

AIM: To develop a microarray-based prewarning system consisting of gastric cancer chip, prewarning data and analysis software for early detection of gastric cancer and pre-cancerous lesions. METHODS: Two high-density chips with 8,464 human cDNA sites were used to primarily identify potential genes specific for normal gastric mucosa, pre-cancerous lesion and gastric cancer. The low-density chips, composed of selected genes associated with normal gastric mucosa, precancerous lesion and gastric cancer, were fabricated and used to screen 150 specimens including 60 specimens of gastric cancer, 60 of pre-cancerous tissues and 30 of normal gastric mucosa. CAD software was used to screen out the relevant genes and their critical threshold values of expression levels distinguishing normal mucosa from pre-cancerous lesion and cancer. All data were stored in a computer database to establish a prewarning data library for gastric cancer. Two potential markers brcaa1 and ndr1 were identified by Western blot and immunohistochemistry. RESULTS: A total of 412 genes associated with three stages of gastric cancer development were identified. There were 216 genes displaying higher expression in gastric cancer, 85 genes displaying higher expression in pre-cancerous lesion and 88 genes displaying higher expression in normal gastric mucosa. Also 15 genes associated with metastasis of gastric cancer and 8 genes associated with risk factors were screened out for target genes of diagnosis chip of early gastric cancer. The threshold values of 412 selected genes to distinguish gastric cancer, pre-cancerous lesion from normal gastric mucosa were defined as 6.01+/-2.40, 4.86+/-1.94 and 5.42+/-2.17, respectively. These selected 412 genes and critical threshold values were compiled into an analysis software, which can automatically provide reports by analyzing the results of 412 genes obtained by examining gastric tissues. All data were compiled into a prewarning database for gastric cancer by CGO software. Northern blot and immunohistochemistry analysis confirmed that gene and protein of brcaa1 displayed lower expression in normal gastric mucosa and higher expression in gastric cancer tissues, conversely, ndr1 displayed lower expression in gastric cancer and higher expression in normal gastric mucosa. CONCLUSION: The microarray-based prewarning system for gastric cancer was developed. This system consisted of gastric cancer-associated gene chip, prewarning data and analysis software, which has a high potential for applications in the early detection of gastric cancer. The two potential markers brcaa1 and ndr1 identified may be used to distinguish cancer status fand non-cancer status.

Antigens, Neoplasm↗

PubMed2005

Regulation of apoptosis by the papillomavirus E6 oncogene.

Infection with human papillomaviruses is strongly associated with the development of multiple cancers including esophageal squamous cell carcinoma. The HPV E6 gene is essential for the oncogenic potential of HPV. The regulation of apoptosis by oncogene has been related to carcinogenesis closely; therefore, the modulation of E6 on cellular apoptosis has become a hot research topic recently. Inactivation of the pro-apoptotic tumor suppressor p53 by E6 is an important mechanism by which E6 promotes cell growth; it is expected that inactivation of p53 by E6 should lead to a reduction in cellular apoptosis, numerous studies showed that E6 could in fact sensitize cells to apoptosis. The molecular basis for apoptosis modulation by E6 is poorly understood. In this article, we will present an overview of observations and current understanding of molecular basis for E6-induced apoptosis.

Amino Acid Sequence↗

PubMed2005

Effect of Hewei-Decoction on chronic atrophic gastritis and eradication of Helicobacter pylori.

AIM: To demonstrate the effect of Hewei-Decoction (Decoction for regulating the stomach) on chronic atrophic gastritis (CAG) and eradication of Helicobacter pylori. METHODS: Ninety patients with CAG entering the investigation were divided into six differentiation syndromes, based on their major symptoms and signs. Hewei-Decoction was taken by all the patients orally for 4 or 8 wk. The efficacy was assessed by both the composite accumulation of reduced scores of major symptoms and the eradication of H pylori. chi(2) test was used to compare the efficacy between H pylori-positive and negative cases, and to disclose the relationship between efficacy and eradication of H pylori. RESULTS: In patients with six different syndrome types, the efficacy of Hewei-Decoction was 91.67% (11/12), 92.86% (13/14), 97.22% (35/36), 87.50% (14/16), 75.00% (6/8), 75.00% (3/4) respectively. The rate of highly efficacious was 58.33% (7/12), 50.00% (7/14), 77.78% (28/36), 62.50% (10/16), 12.50% (1/8) and 25.00% (1/4), respectively. The total efficacy was 91.11% (82/90), and the rate of highly efficacious was 60.00% (54/90). The eradication rate of H pylori was 67.86% (38/56). The therapeutic effect of Hewei-Decoction was better in H pylori positive cases than that in H pylori-negative cases with the total effect of 96.43% vs 82.35% (P<0.05). In 56 H pylori positive cases, the therapeutic effect was better in H pylori eradicated cases than that in H pylori- existent cases with the total effect of 97.37% vs 72.22% (P<0.01). CONCLUSION: Hewei-Decoction is effective in most cases of all the syndrome types. The results indicate that eradication of H pylori is one of the important mechanisms for alleviation of symptoms and signs. Also, the decoction is efficacious in H pylori-negative cases.

Administration, Oral↗

PubMed2004

Inhibition of gastric cancer-associated angiogenesis by antisense COX-2 transfectants.

We characterized the effects of selective Cox-2 inhibition on the angiogenesis gastric cancer cell line SGC7901 by stable transfection of antisense Cox-2 cDNA (Cox-2-AS) or pharmacological inhibition by selective cox-2 inhibitor (NS398). The conditioned media obtained from SGC7901 treated with Cox-2-AS or NS398 suppressed the proliferation, migration and tube formation of human umbilical vein endothelial cells. Moreover, both treatments inhibited in vivo angiogenesis. These inhibitions could be partially reversed by the addition of PGE2. Our findings support that selective inhibition of Cox-2 alone plays an instrumental role on gastric cancer associated angiogenesis.

Cyclooxygenase 2↗

PubMed2004

Chinese literature associated with diagnosis of Helicobacter pylori.

AIM: To synthetically analyze and probe into the diagnosis of H pylori infection, we followed the principles of evidence-based medicine. METHODS: A total of 22 papers of prevalence survey and case-control studies were selected for studying about diadynamic methods. Using meta-analysis, we analyzed the different diadynamic methods of H pylori in China. RESULTS: Through meta-analysis, among the five diadynamic methods, the accuracy of polymerase chain reaction (PCR) was the highest (98.47%) and PCR was the most sensitive method (Sp: 99.03%). CONCLUSION: Among the five diadynamic methods, the accuracy of PCR is the highest and PCR is the most sensitive method to diagnose the infection of H pylori.

Asian People↗

PubMed2004

Clinical experience with molecular adsorbent recirculating system (MARS) in patients with drug-induced liver failure.

The molecular adsorbent recirculating system (MARS) is a novel extracorporeal technique for liver support. We report the clinical results in a group of fourteen patients with drug-induced liver failure. Fourteen patients, aged 22-83 years, with acute or subacute liver failure [mean Child-Turcotte-Pugh (CTP) score 11 (range 8-15)] due to the intake of various drugs (diet pill overdose-2; Chinese traditional medicine (CTM)-4; antibiotic, paracetamol, tuberculostatic, or vasodilator abuse-8) were treated with one to seven sessions of MARS. Beneficial effects such as the improvement of encephalopathy and prothrombin activity, as well as a reduction of bilirubin and ammonia were recorded during MARS treatments. Thirteen out of fourteen patients survived the hospitalization (93%), and two of the discharged patients died during the follow-up of 6-12 months. The overall survival rate was about 79%. MARS therapy can contribute to the improved treatment of drug-induced liver failure patients.

Adult↗

PubMed2003

Angiostatin up-regulation in gastric cancer cell SGC7901 inhibits tumorigenesis in nude mice.

AIM: To explore the influence of angiostatin up-regulation on the biologic behavior of gastric cancer cells in vitro and in vivo, and the potential of angiostatin gene therapy in the treatment of human gastric cancer. METHODS: Mouse angiostatin cDNA was subcloned into the eukaryotic expression vector pcDNA3.1(+) and identified by restriction endonucleases digestion and sequencing. The recombinant vector pcDNA3.1(+)-angio was transfected into human gastric cancer cells SGC7901 with liposome and paralleled with the vector control and the mock control. Angiostatin transcription and protein expression were examined by RT-PCR and Western blot in the stable cell lines selected by G418. Cell proliferation and growth in vitro of the three groups were observed respectively under microscope, cell number counting and FACS. The cells overexpressing angiostatin, vector transfected and untreated were respectively implanted subcutaneously into nude mice. After 30 days the size of tumors formed was measured, and microvessel density count (MVD) in the tumor tissues was assessed by immunohistochemistry with the primary anti-vWF antibody. RESULTS: The recombinant vector pcDNA3.1(+)-angio was confirmed with the correct sequence of mouse angiostatin under the promoter CMV. After 30 d of transfection and selection with G418, macroscopic resistant cell clones were formed in the experimental group transfected with pcDNA 3.1(+)-angio and the vector control. But no untreated cells survived in the mock control. Angiostatin mRNA transcription and protein expression were detected in the experimental group. No significant differences were observed among the three groups in cell morphology, cell growth curves and cell cycle phase distributions in vitro. However, in nude mice model, markedly inhibited tumorigenesis and slowed tumor expansion were observed in the experimental group as compared with the controls, which was paralleled with decreased microvessel density in and around tumor tissues (P<0.05). CONCLUSION: Angiostatin does not directly inhibit human gastric cancer cell proliferation and growth in vitro, but exerts its anti-tumor functions through antiangiogenesis in a paracrine way in vivo.

Angiogenesis Inhibitors↗

PubMed2003

Effect of ZNRD1 gene antisense RNA on drug resistant gastric cancer cells.

AIM: To investigate the expression level of ZNRD1 gene in gastric cancer cells SGC7901 and gastric cancer MDR (multidrug resistant) cells SGC7901/VCR, and to observe the drug sensitizing and proliferation effect of ZNRD1 antisense nucleic acid transduction on SGC7901/VCR cells. METHODS: Amplification of sequences encoding ZNRD1 from SGC7901/VCR cDNA by PCR. The levels of ZNRD1 mRNA expression were demonstrated using semiquantitative reverse transcription polymerase chain reaction (RT-PCR). Eukaryotic expression vector pcDNA3.1-anti ZNRD1 was constructed and transfected into SGC7901/VCR cells by lipofectamine. Immunochemical method was used to detect the expression of protein in SGC7901/VCR cells and transfectants. The cell cycle alteration and the intracellular adriamycin (ADM) accumulation were observed by FACS. Growth curve and drug sensitization of cells for vincristine (VCR) were analyzed with MTT assay. RESULTS: We cloned the open reading frame of full-length ZNRD1. The expression of ZNRD1 showed higher in SGC7901/VCR than in SGC7901 cells. The antisense ZNRD1 drug-resistant clones were selected after gene transfection. Immunochemical results showed that the expression level of ZNRD1 protein was lower in anti ZNRD1-SGC7901/VCR cells than that in non-transfectants. Comparing to SGC7901/VCR and pcDNA3.1-SGC7901/VCR, anti ZNRD1-SGC7901/VCR showed gradually accumulated in G(1) phase, with a concomitant decrease of cell population in S phase. FACS also suggested intracellular ADM accumulation increased 2fold in SGC7901/VCR cells after transfected with antisense ZNRD1. MTT assay showed that transfectants cells proliferation was lagged and more sensitive to VCR than non-transfectants. CONCLUSION: ZNRD1 gene displayed highly expression in VCR resistant gastric cancer cells. Expression of ZNRD1 protein was effectively blocked in anti ZNRD1-SGC7901/VCR cells by gene transfection. ZNRD1 antisense nucleic acid transfection sensitized drug resistant gastric cancer cells to VCR, increased ADM accumulation and inhibited the cells proliferation. ZNRD1 antisense RNA transduction could reverse the MDR of human drug-resistant gastric cancer cell SGC7901/VCR to a degree.

Antineoplastic Agents↗

PubMed2003

Development of an oral DNA vaccine against MG7-Ag of gastric cancer using attenuated salmonella typhimurium as carrier.

AIM: To develop an oral DNA vaccine against gastric cancer and evaluate its efficacy in mice. METHODS: The genes of the MG7-Ag mimotope and a universal Th epitope (Pan-DR epitope, PADRE) were included in the PCR primers. By PCR, the fusion gene of the two epitopes was amplified. The fusion gene was confirmed by sequencing and was then cloned into pcDNA3.1(+) plasmid. The pcDNA3.1 (+)-MG7/PADRE was used to transfect an attenuated Salmonella typhimurium. C57BL/6 mice were orally immunized with 1X10(8) cfu Salmonella transfectants. Salmonella harboring the empty pcDNA3.1(+) plasmid and phosphate buffer saline (PBS) were used as negative controls. At the 6th week, serum titer of MG7-Ag specific antibody was detected by ELISA. At the 8th week cellular immunity was detected by an unprimed proliferation test of the spleenocytes by using a ((3)H)-thymidine incorporation assay. Ehrlich ascites carcinoma cells expressing MG7-Ag were used as a model in tumor challenge assay to evaluate the protective effect of the vaccine. RESULTS: Serum titer of antibody against MG7-Ag was significantly higher in mice immunized with the vaccine than that in control groups (0.841 vs 0.347, P<0.01; 0.841 vs 0.298, P<0.01), while in vitro unprimed proliferation assay of the spleenocytes showed no statistical difference between those three groups. Two weeks after tumor challenge, 2 in 7 immunized mice were tumor free, while all the mice in the control groups showed tumor formation. CONCLUSION: Oral DNA vaccine against the MG7-Ag momitope of gastric cancer is immunogenic. It can induce significant humoral immunity against tumor in mice, and the vaccine has partially protective effects.

Administration, Oral↗

PubMed2003

Screening and identification of mimotope of gastric cancer associated antigen MGb1-Ag.

AIM: Using a monoclonal antibody against gastric cancer antigen named MGb1 to screen a phage-displayed random peptide library fused with coat protein pIII in order to get some information on mimotopes. METHODS: Through affinity enrichment and ELISA screening, positive clones of phages were amplified. 10 phage clones were selected after three rounds of biopanning and the ability of specific binding of the positive phage clones to MGb1-Ab were detected by ELISA assay (DNA sequencing was performed and the amino acid sequences were deduced) By blocking test, specificity of the mimic phage epitopes was identified. RESULTS: There were approximately 200 times of enrichment about the titer of bound phages after three rounds of biopanning procedures. DNA of 10 phage clones after the third biopanning was assayed and the result showed that the positive clones had a specific binding activity to MGb1-Ab and a weak ability of binding to control mAb or to mouse IgG. DNA sequencing of 10 phage clones was performed and the amino acid sequences were deduced. According to the homology of the amino acid sequences of the displayed peptides, most of the phage clones had motifs of H(x)Q or L(x)S. And these 10 phage clones could also partly inhibit the binding of MGb1-Ab to gastric cancer cell KATO-III. The percentage of blocking was from (21.0+/-1.6) % to (39.0+/-2.7) %. CONCLUSION: Motifs of H(x)Q and L(x)S selected and identified show a high homology in the mimic epitopes of gastric cancer associated antigen. There may be one or more clones which can act as candidates of tumor vaccines.

Animals↗

PubMed2003

Apoptosis-inducing effect of recombinant Caspase-3 expressed by constructed eukaryotic vector on gastric cancer cell line SGC7901.

AIM: To investigate the apoptosis-inducing effect of Caspases-3 expressed by constructed eukaryotic vector on gastric cancer cell line SGC7901. METHODS: PCR was employed to amplify the sequences of both small and large subunits of Caspases-3. Its products were separately cloned into the Sma I site of pBluescript KS(+) to generate both plasmids pBS/SS and pBS/LS. The small subunit fragment was excised from plasmid pBS/SS with BamH I and then inserted into the BamH I site of plasmid pBS/LS preceding that of the large subunit to yield plasmid pBS/Rev-Caspase-3. Rev-Caspase-3 cDNA was excised with Kpn I+Xba I and then subcloned into plasmid pcDNA3.1 (+) to construct Rev-Caspase-3 eukaryotic expression vector pcDNA/Rev-Caspase-3, which was used to transiently transfect SGC7901 cell line. Cell count, MTT assay and electron microscopy were used to confirm the antiproliferation and apoptosis-inducing effect of Rev-Caspase-3 expression on gastric cancer cells. RESULTS: Plasmid pBS/Rev-Caspase-3 and eukaryotic expression vector pcDNA/Rev-Caspase-3 were successfully constructed. SGC7901 cells were transiently transfected by either pcDNA/Rev-Caspase-3 or pcDNA3.1 (+) for 24, 48, 72, and 96 h respectively. Cell growth was measured by cell count and MTT assay. In cell count assay, the cell numbers were 1.8 X 10(6), 1.55 X 10(6), 2.0 X 10(6), and 3.1 X 10(6) in the experimental group and 2.5 X 10(6), 3.1 X 10(6), 4.0 X 10(6), and 5.7 X 10(6) in the control group at 24, 48, 72 and 96 h respectively. The growth of SGC7901 cells was suppressed by Rev-Caspase-3 in a time-dependent manner (P<0.05). The results of MTT assay were similar to that of cell count (P<0.05). The characteristics of apoptosis such as chromatin condensation, crescent formation and margination were seen and more obvious with time in the given-experimental period in the experimental group, but not easily observed in the control group. CONCLUSION: The expression of Rev-Caspase-3 by the constructed eukaryotic vector can significantly induce apoptosis of gastric cancer cell line SGC7901, which may exhibit a potential way in gastric cancer gene therapy.

Apoptosis↗

PubMed2003

Selection and identification of mimic epitopes for gastric cancer-associated antigen MG7 Ag.

Phage display technology is now well established as an important experimental approach in designing new reagents for diagnosis of diseases and development of novel vaccines. Aiming at identifying possible immunogenic mimotopes of gastric cancer-associated antigen, we used a monoclonal antibody against gastric cancer, named monoclonal antibody MG7, to screen two phage-displayed nanopeptide libraries. All selected phages were used to immunize BALB/c mice separately. By immunohistochemical staining the tissue sections with the immunized mice sera, we identified one phage that induced gastric cancer-specific antibody response. Consistent with our reported results before, we demonstrate that specific immunogenic epitopes can be isolated by screening phage-displayed library even when natural antigens are not readily available.

Animals↗

PubMed2003

[Cloning of human testicular carcinoma antigen MAGE-E1 gene and its expression in E.coli].

AIM: To clone and express the testicular carcinoma antigen MAGE-E1 gene in E.coli. METHODS: The cDNA encoding human MAGE-E1 gene was amplified by RT-PCR from human glioma cell line BT-325, then the MAGE-E1 gene was inserted into plasmid pGEM-T easy. After sequencing, the MAGE-E1 was cloned into the prokaryotic expression vector pGEX-4T-2 to construct the recombinant expression vector pGEX-4T-2-MAGE-E1 which was used to transform E.coli. RESULTS: The expressed product reached the highest level at 5 h after IPTG induction. SDS-PAGE and scanning analysis of gel density indicated that the expressed protein was about M(r) 41 000 and account for 35% of the total bacterial protein. CONCLUSION: The high efficient expression of the MAGE-E1 gene fragment lays the foundation for further preparing antibody against MAGE-E1 protein and the tumor vaccine for glioma immunotherapy.

Cloning, Molecular↗