No abstract available.
Ovarian Neoplasms* ; Transfection*

A site-directed mutant DNA fragment was synthesized and transfected into clinical Neisseria gonorrhoeae (NG) stains to construct the transformants that contained the corresponding mutagenesis of regulation region of mtrR gene. According to the technique of gene splicing by overlap extension (SOEing), a DNA segment with specific mutagenesis was constructed by two-step polymerase chain reaction (PCR). The mutation fragments EF could be used for the next experiment in which the mutation NG strains were induced. By comparing the recombinant EF fragments to the corresponding DNA fragments of clinical NG strains, 2 of these were not compatible completely. The results of sequencing revealed that there was a 9 bp deletion between the 45 to 54 inverted repeat sequence localized within the mtrR promoter. It can be confirmed that the fragments EF are the specifically designed mutant fragments.
Bacterial Proteins/*genetics ; DNA Fragmentation ; DNA, Bacterial/genetics ; Mutagenesis, Site-Directed ; Neisseria gonorrhoeae/*genetics ; Neisseria gonorrhoeae/metabolism ; Recombination, Genetic ; Repressor Proteins/*genetics ; Sequence Deletion ; Transfection ; Transformation, Bacterial

OBJECTIVETo construct COL1A1-targeted short hairpin RNA (shRNA) vector with pSilencer 4.1-CMV neo siRNA expression vector and to evaluate its effect on proliferation and migration of gastric cancer BGC-823 cells in vitro.

METHODSThree COL1A1-shRNA plasmids (COL1A1-shRNA-1, COL1A1-shRNA-2, COL1A1-shRNA-3), targeting different sites of COL1A1 gene, were constructed using pSilencer 4.1-CMV neo siRNA expression vector and transfected into gastric cancer BGC-823 cells. Real time quantitative RT-PCR and Western blot were performed to detect expression levels of COL1A1. MTT and Transwell migration assays were employed to evaluate the effects of COL1A1 gene silence on cell proliferation and migration.

RESULTThree recombinant plasmids targeting COL1A1 were constructed successfully. The expressions of COL1A1 in BGC-823 cells, including mRNA and protein levels, were significantly inhibited by the COL1A1-shRNA transfectants, which resulted in a clear reduction of cell proliferation and migration capacity.

CONCLUSIONThe COL1A1-shRNA can effectively knock down gene expression and inhibit proliferation and migration of gastric cancer BGC-823 cells.

Cell Line, Tumor ; Cell Proliferation ; Collagen Type I ; genetics ; metabolism ; Genetic Vectors ; Humans ; Plasmids ; genetics ; RNA, Messenger ; genetics ; RNA, Small Interfering ; genetics ; Stomach Neoplasms ; pathology ; Transfection ; Transformation, Bacterial

OBJECTIVETo observe the therapeutic effect of CDglyTK gene mediated by synthetic radiation-inducible promoter in the treatment of Tca8113 cells.

METHODSCDglyTK gene in pCEA-CDglyTK was subcloned into pcDNA3.1 (+) to construct plasmid pcDNA3.1 (+)-CDglyTK, and then the synthetic radiation-inducible promoter in pMD18 -T -E was inserted into pcDNA3.1 (+) -CDglyTK to construct plasmid pcDNA3.1 (+ )/E -CDglyTK. The recombinant plasmid was transfected into Tca8113 cells by lipofectamine, and then exposed to 3 Gy irradiation. Cytotoxicity was evaluated by MTT. The expression of CDglyTK gene was detected by RT-PCR. The apoptosis and proliferation were examined by flow cytomtery.

RESULTSThe plasmid pcDNA3.1 (+)/E-CDglyTK was constructed successfully. The comparative survival rate of Tca8113 cells was markedly decreased by induction irradiation. Up-regulation of CDglyTK expression was found in Tca8113 cells exposed to irradiation. The apoptosis index (AI) of Tca8113 cells exposed to irradiation was higher than that of Tca8113 cells without irradiation, the other way round, the proliferation index (PI) of Tca8113 cells exposed to irradiation was lower than that of Tca8113 cells without irradiation.

CONCLUSIONThe synthetic radiation-inducible promoter can be served as a molecular switch to improve the expression of CDglyTK gene in Tca8113 cells, and low dose induction radiation can significantly improve the therapeutic efficiency.

Apoptosis ; Humans ; Plasmids ; Promoter Regions, Genetic ; Transfection

OBJECTIVETo construct a eukaryotic vector which could express bone morphogenetic protein-7 (bmp-7) in MC3T3-E1.

METHODSBone morphogenetic protein-7 gene was obtained by RT-PCR from human embryo kidney. And after sequencing and electrophoresis the obtained aim DNA fragment was inserted into eukaryotic expression plasmid pcDNA3.1 (+) by using restricted endonuclease and ligase. The DNA sequence of the newly-constructed plamids was proved right by the gene technic company. And then the new plasmids containing right sequence aim gene were transfected into MC3T3-E1 cells by Lipofectamine 2000. 72 h after transfecting, RT-PCR was performed to show the transfected cells containing the aim gene, and the whole protein of the transfected cells were gathered and used as samples in the next Western blot to test the expression of bmp-7 gene.

RESULTSDNA sequencing indicated the sequence of the obtained bmp-7 was identical to the reported ones in GeneBank. The electrophoretic map of the products of RT-PCR and restriction enzyme digestion played another evidence that the newly-constructed plasmids were bmp-7/pcDNA3.1(+). The results of Western blot showed that the transfected cells could express BMP-7.

CONCLUSIONThe construction of a eukaryotic vector which could express BMP-7 in MC3T3-E1 was successful.

Bone and Bones ; Genetic Vectors ; Humans ; Plasmids ; Transfection

TGF-p receptor mutation is now considered as one of the carcinogenic process of many tumors. To evaluate whether there is an abnormality in TGF-p type II receptor in osteosarcoma cell lines, we performed Northern analysis, cross-linking assay, luciferase activity and TGF-p growth inhibition assay in four osteosarcoma cell lines: G292, U202, HOS and SaOS. We also transfected the tumor cells with normal TGF-p type II receptor sequence to find if there is a possibility of gene therapy in osteosarcoma. In Northern analysis, Type II receptor expressions were decreased at SaOS, U202 and HOS cell lines. In cross-linking assay, all four cell lines didnt show type II receptor at their cell surface. The growth of these tumor cells were not suppressed by TGF-p. From these findings, we concluded that the normal production of TGF-p type II receptor was impaired in osteosarcoma. The transfection of these tumor cells with normal type II receptor sequence restored growth inhibition by TGF-p. This means even though TGF-p type II receptor is abnormal in osteosarcoma, we can restore its function by transfection of normal sequence. We think that the TGF-p type Il receptor gene therapy can be one of the treatment method for osteosarcoma in the future.
Cell Line* ; Genetic Therapy ; Luciferases ; Osteosarcoma* ; Transfection

To construct a eukaryotic expression plasmid containing the luciferase reporter gene (Fluc) to quickly detect apoptosis. Four amino acids, Asp-Glu-Val-Asp (DEVD), the recognize motif of Caspase-3, were introduced into the middle of the Fluc-C and N fragment. Meanwhile, four amino acids, Asp-Glu-Val-Gly (DEVG), were selected as a negative control. Subsequently, the recombinant gene was cloned into the N and C terminal end of the split intein, and named as pFluc-DEVD and pFluc-DEVG. Then the plasmids were transfected into cells and renilla luciferase was co-transfected in each sample as an internal control for transfection efficiency. Then the apoptosis level was detected by the double luciferase reporter gene and the Western blotting analysis. The results showed that when apoptosis occurred, the content of firefly luciferase expressed in the pFluc-DEVD plasmid transfected group was about 3 times higher than pFluc-DEVG plasmid transfected group. Furthermore, Western blotting detection indicated that the Fluc level was significantly increased in pFluc-DEVD transfected group when pre-treated by apoptosis stimulants. The activation degree of Caspase-3 was closely related to the expression of Fluc, and had a significant statistical difference. These results confirmed that firefly luciferase protein expressed by pFluc-DEVD plasmid can be cleaved by the intracellular Caspase-3 enzyme, and this plasmid can accurately reflect the cell apoptosis level, which provides a useful method for quantitative detection of apoptosis.
Apoptosis ; Genes, Reporter ; Luciferases, Firefly ; Transfection

OBJECTIVE: To explore the effects of the rat FVIII light chain (rLC) on the activity of human FVIII heavy chain hHC745 and hHC1690. METHODS: hHC745, hHC1690, human FVIII light chain (hLC) and rLC were cloned into adeno-associated virus serotype 8 (AAV8) expression vectors with CB promoter (ubiquitous expression), respectively, and transfected into 293T cells using a dual-chain strategy of co-expression of HC and LC. The cultured cell supernatant was collected at 48 hours after transfection. The plasmids (pAAV8-CB-hHC745, pAAV8-CB-hHC1690, pAAV8-CB-hLC and pAAV8-CB-rLC) were hydrodynamically injected into hemophilia A (HA) mice via lateral tail vein. Forty-eight hours after injection, the peripheral blood of the mice was collected through retroorbital venous plexus and the plasma was obtained by centrifugation. The activity of FVIII was detected by activated partial thromboplastin time (aPTT) assay, and the antigen expression level of FVIII was determined by enzyme-linked immunosorbent assay (ELISA). The specific activity of FVIII was calculated based on the activity and the antigen expression level. RESULTS: In 293T cells, the coagulation activity of FVIII was significantly enhanced when hHC745 and hHC1690 combined with rLC compared with them combined with hLC. The FVIII activity of hHC745+rLC was about 4.6 times higher than that of hHC745+hLC, while hHC1690+rLC was about 2.9 times higher than that of hHC1690+hLC. The data from ELISA showed that there was no significant difference in FVIII antigen expression when hHC745 and hHC1690 combined with rLC and hLC. The specific activity of hHC745+rLC increased to about 4.1 times compared with hHC745+hLC, while that of hHC1690+rLC increased to about 2.8 times compared with hHC1690+hLC. In HA mice administrated with hydrodynamic injection, the FVIII activity of hHC745+rLC and hHC1960+rLC was significantly higher than that of hHC745+hLC and hHC1690+hLC at comparable expression level. The FVIII activity of hHC745+rLC was significantly higher than that of hHC745+hLC, increasing to about 5.1 times, while, that of hHC1690+rLC increasing to about 2.1 times than hHC1690+hLC. ELISA results also showed that there was no significant difference in FVIII antigen expression when hHC745 and hHC1690 combined with rLC and hLC. The specific activity of hHC745+rLC increased to about 4.2 times compared with hHC745+hLC, while that of hHC1690+rLC increased to about 1.8 times compared with hHC1690+hLC. In addition, the activity of hHC1690 combined with rLC was significantly higher than that of hHC745 combined with rLC. CONCLUSION rLC can significantly enhance the coagulation activity of FVIII when co-expressed with hHC of different length including hHC745 and hHC1690.
Rats ; Humans ; Mice ; Animals ; Dependovirus/genetics* ; Transfection

OBJECTIVETo observe the effect of recombinant adenovirus Ad-ING4 on K562 cells.

METHODSHuman ING4 recombinant transfer vector pAdTrack-CMV-ING4 was constructed by enzyme digest and ligation of human ING4 gene which was obtained through site specific point mutation of mouse ING4. The vector was co-transduced into BJ5183 E. coli with pAdEasy-1. The new recombinant adenovirus vector pAdEasy-1-pAdTrack-CMV-hING4 was transfected into QBI-293A cells. To obtain the ING4 recombined adenovirus (Ad-ING4). Ad-ING4 was used to infect K562 cells. The effect on K562 cells of ING4 was tested by LSCM FCM and immunohistochemistry.

RESULTSHuman ING4 recombinant adenovirus vector was constructed successfully, and high titre ING4 recombinant adenovirus (Ad-ING4) was obtained. ING4 can down-regulate the expression of bcl-2 and up-regulate expression of bax. The apoptosis of K562 cells induced by ING4 was proved by LSCM FCM and immunohistochemistry. The apoptosis rate was 19.7% (after 72h), which displayed significant difference compared with that of control groups (P < 0.01).

CONCLUSIONAd-ING4 can inhibit the growth of K562 cells and induce the cells apoptosis. The human ING4 recombinant adenoviral vector constructed might provide an approach to the target therapy of tumors.

Adenoviridae ; genetics ; Animals ; Apoptosis ; genetics ; Base Sequence ; Carrier Proteins ; genetics ; Cell Cycle Proteins ; genetics ; Cell Proliferation ; Genetic Vectors ; Homeodomain Proteins ; genetics ; Humans ; K562 Cells ; Mice ; Molecular Sequence Data ; Mutagenesis, Site-Directed ; Plasmids ; genetics ; Transfection ; Transformation, Bacterial ; Tumor Suppressor Proteins ; genetics

OBJECTIVETo study the interaction between ShcD and TrkC and to reveal the molecular mechanism of the downstream signal transduction of TrkC.

METHODSYeast two-hybrid assay was used. The intracellular domains of TrkC and TrkC mutants were cloned into pAS2-1, and ShcD and its four domains (CH2, PTB, CH1, and SH2 domains) were cloned into pACT2 vector respectively. The constructs were separately cotransformed into yeast. beta-galactosidase activity was measured to detect their interactions. TrkC was cloned into pmRFP (carrying red fluorescent protein), and ShcD was cloned into pEGFP (carrying green fluorescent protein). pmRFP-TrkC and pEGFP-ShcD were co-transfected into 293T cells, and then the cells were fixed and subjected to confocal analysis to study their subcellular localization.

RESULTSShcD interacted with TrkC but not with kinase dead mutant TrkCM1(K572A). Both PTB and SH2 domains were capable of binding to TrkC, and PTB domain bound NPQY motif of TrkC. ShcD colocalized with TrkC throughout the cytoplasm and in the plasma membrane in 293T cells.

CONCLUSIONShcD binds to TrkC in a kinase-activity-dependent manner through its PTB and SH2 domains.

Adaptor Proteins, Signal Transducing ; genetics ; metabolism ; Binding Sites ; Cells, Cultured ; Genetic Vectors ; Humans ; Plasmids ; genetics ; Protein Binding ; Receptor, trkC ; genetics ; metabolism ; Shc Signaling Adaptor Proteins ; genetics ; metabolism ; Transfection ; Transformation, Bacterial ; Two-Hybrid System Techniques ; src Homology Domains ; genetics