5.Cloning and Prokaryotic Expression of Human Recombinant Calreticulin
Chun-Yu CAO ; Yu HAN ; Yan-Lin WANG ;
China Biotechnology 2006;0(04):-
Objective: Clone, express and purify human recombinant calreticulin (CRT). Methods: Human CRT cDNA was amplified from total RNA of human lung cancer cell line A549 cells by RT-PCR. Then, PCR product was subcloned into prokaryotic expression vector pET-15b. After sequencing, this recombinant plasmid was transformed into E.coli. Rossetta. Recombinant CRT was expressed in host cells by IPTG induction. Resulted protein was purified by Ni-NTA resin under denature condition and dialyzed to recover its native structure. SDS-PAGE and Western blot method were used to identify the expression and purification of reconbinant CRT. Results: Human CRT cDNA was cloned from total RNA of A549 cells. CRT prokaryotic expression vector pET-15b-crt was constructed. Reconbinant CRT was induced to express in E.coli and purified by Ni-NTA affinity chromatograph. Conclusion: A method for prokaryotic expression and purification of human recombinant CRT was successfully established. This method laid a foundation for the subsequent CRT research.
6.Therapy of encephalopathy induced by severe dichloroethane poisoning.
Yi-wen JIANG ; Shu-li LIU ; Li LI ; Chun-yan CAO ; Ying SHI
Chinese Journal of Industrial Hygiene and Occupational Diseases 2006;24(8):506-507
Adolescent
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Adult
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Brain Diseases
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chemically induced
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therapy
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Ethylene Dichlorides
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poisoning
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Female
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Humans
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Male
7.Construction of TK Gene-deleted PRV SH StrainContaining a Single LoxP Site
Min-Xiu WANG ; Xin-Ming SU ; Chun-Mei YU ; Rui-Bing CAO ; Pu-Yan CHEN ;
China Biotechnology 2006;0(10):-
Pseudorabies virus (PRV) is a swine herpesvirus of the Alphaherpesvirinae subfamily and a pathogen of swine resulting in devastating disease and economic losses worldwide. Cre/loxP site-specific system has the character of site specific, time specific, tissue specific and high efficiency in recombination, which makes this system universal in vivo and in vitro recombination of bacteria, fungus, plants, insects and mammals. A recombinant PRV which contain a loxP site in TK locus by using Cre/LoxP recombinant system was construsted. A pair of primers were synthesized according to the pEGFP-C1 sequence published on GenBank, and were used to amplify the EGFP gene expression cassette with two loxP sites flanking each side. This target gene was cloned into pSKLR, the resulting transfer vector pSKLR-GFP-loxP was then cotransfected into 293T cells with PRV SH strain genomic DNA. The recombinant virus rPRV1 was selected and purified in TK-143 cells by choosing fluorescent expressing plaques. Cre expression vector pOG231 was cotransfected into 293T cells with rPRV1 genomic DNA. The second recombinant virus rPRV2 was obtained, which contains only one loxP site in TK locus. Sequencing results of rPRV2 TK gene indicated that 34bp loxP site was inserted into rPRV2 genome and there were 270bp deletion in TK gene. PCR amplifying different generations of rPRV2 TK gene showed that the mutant was stable when passages in RK-13 cells. TCID_ 50 assay indicated that rPRV2 grows well on RK-13 cells. The LD_ 50 test results on BALB/C mice suggested that the virulence of rPRV2 was reduced. As a conclusion, the report gene GFP expression cassette was removed successfully from rPRV1 genome and only one LoxP site was leaved in rPRV2 genome by using Cre/LoxP recombinant system.
8.The Structural Identification and Antitumor Activity on MCF-7 Cells of Surfactin from Bacillus subtilis TK-1
Xiao-Hong CAO ; Run-Zhi JIAO ; Chun-Ling WANG ; Le YAN ; Mei-Fang LU ;
China Biotechnology 2006;0(02):-
This thesis aimed at the Bacillus natto TK-1 screened out from Natto.The lipopeptide was purified using Thin-Layer Chromatography(TLC),and investigated its anti-tumor activity.After acid precipitation and methanol extraction,the lipopeptide was separated on TLC.Then the authors get the monomer surfactin which molecular weight is 1036Da through the High performance liquid chromatography(HPLC),electro spray ionization-mass spectrometry(ESI-MS) and infrared(IR).MTT method was implied to testify the anti-tumor activity of the purified sample from TLC.The results indicated a concentration and time-dependent relationships.After 48h,their IC50 were 40 mg/L.The detection with inverted microscope fluorescence microscope displays that the surfactin will cause a series of Morphological changes to the cells.In TUNEL experiment,the authors noticed that surfactin has the ability to induce apoptosis,besides this inhibition shows an obvious time-dependent relationship.
9.Preparation and Biological Activity of Poly (?-glutamic acid)-D-galactose-esterifiable Derivative Cisplatin Complex Compound
Xiao-Hong CAO ; Le YAN ; Chun-Ling WANG ; Run-Zhi JIAO ; Mei-Fang LU ;
China Biotechnology 2006;0(03):-
The study was to develop cis-dichlorodiammineplatinum(DDP)-loaded formulations using a novel type of self-assembled compound composed of block copolymers synthesized by poly(?-glutamic acid)(?-PGA).For the potential of targeting liver cancer cells,D-galactose was conjugated on the prepared ?-PGA.In vitro,DDP can be released from the resulting conjugate in PBS:there was a burst release during the first 8 h,then followed by sustained release.DDP could be easily incorporated into poly(?-glutamic acid)-D-galactose esterifiable derivative through a covalent bond.The yield of DDP incorporation into the esterifiable derivative was 9.4%~10.2%.In vitro experiments conclusively established that the poly(?-glutamic acid)-D-galactose esterifiable derivative-Cisplatin Complex Compound(?-D+-DDP)was much less toxic to normal cell lines than DDP only.The surviving rate of cells treated with ?-D+-DDP compound is higher than those treated with free DDP.Also it has obvious antitumor efficiency on human liver tumor BEL-7402 cells.HE staining indicated that the ?-D+-DDP compound make the BEL-7402 apoptosis.These results indicated that the conjugation of DDP to the esterifiable derivative reduced its cytotoxicity activity,but retains its antitumor activity in vitro.In conclusion,the ?-D+-DDP compound could be used as a potential clinic antitumor drug.The ?-PGA obtained by fermentation can be used as a valuable drug carrier system.
10.Preparation and Liver-Targeted Activity of Poly (?-glutamic acid)-D-Galactose-Esterifiable Derivative Cisplatin Complex Compound
Le YAN ; Xiao-Hong CAO ; Chun-Ling WANG ; Run-Zhi JIAO ;
China Biotechnology 2006;0(05):-
DDP could be easily incorporated into poly (?-glutamic acid)-D-galactose esterifiable derivative through a covalent bond. The yield of DDP incorporation into the ?-PGA was 9.4%~10.2%. The DDP was released in the initial 8h in a burst manner,and thereafter in a sustained manner. The results that the conjugation of DDP to poly (?-glutamic acid)-D-galactose esterifiable derivative not only reduced the toxicity of the DDP but also enhanced antitumor activity and the targeting ability. The vivo experiments conclusively established that the ?-D+-DDP compound was much less toxic to animals than DDP alone. A direct evaluation showed that mice treated with ?-D+-DDP compound at a dose of 7.5 mg/kg displayed significant tumor regression. Furthermore,the implanted solid tumors disappeared completely from 35% of the H22 tumor-bearing mice after ?-D+-DDP compound administration. The aforementioned results of biodistributions of the prepared ?-D+-DDP compound in various organs in normal mice demonstrated that the ?-D+-DDP compound had a specific interaction with liver's parenchymal cells and H22 hepatocellular carcinoma tumor cells via ligand receptor recognition. In conclusion,the results indicated that the ?-D+-DDP compound prepared can effectively target the site of hepatoma tumor via the recognition and significantly reduce its size. The ?-D+-DDP compound was less toxic than the free DDP,and could effectively reduce xenografted H22 hepatocellular carcinoma cells in KM mice and prolong the survival of KM mice grafted with H22 hepatocellular carcinoma tumor cells. Therefore,the prepared ?-D+-DDP compound may be used as a potential drug delivery system for the targeted delivery to liver cancers or other liver diseases.