This research was to construct the lentiviral expression vector for anti- p185(erbB2) mouse/human chimeric antibody and to determine the expression of the chimeric antibody gene in 293T cells transfected with this vector. The genes (vL and vH) coding light and heavy chain of variable regions of anti-p185(erbB2) mAb and the constant regions of human IgG1 (kappa and gamma1) were cloned with PCR method. The target genes were assembled by three-primers PCR method to obtain the chimeric light chain (L) and the chimeric heavy chain (H). Both chains inserted into the down stream and upper stream of IRES gene of the plasmid pVAX1/IRES respectively. We digested the plasmid pVAX1/ H-IRES-L with endoenzyme and subcloned H-IRES-L into the lentiviral vector pWPI. The enzyme digestion and sequence analysis showed that the lentiviral expression vector pWPI/H-IRES-L was constructed correctly. Then, it was transfected into 293T cells and after 48h, GFP protein expression in 293T cells were detected by fluorescent microscope and the chimeric antibody expression was detected by RT-PCR and direct ELISA. The results showed that after 293T cells were transfected with recombination plasmid, both light and heavy chains of the chimeric antibody genes could express together. The chimeric antibody expressed could bind to p185(erbB2) specifically. This research may lay a sound foundation for further study of anti-p185(erbB2) engineered antibody.
Animals ; Antibodies, Monoclonal ; biosynthesis ; genetics ; Cell Line ; Chimera ; Cloning, Molecular ; Humans ; Lentivirus ; genetics ; metabolism ; Mice ; Receptor, ErbB-2 ; biosynthesis ; genetics ; immunology ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology ; Transfection

OBJECTIVETo prepare the modified ZHER2V2 affibody with amino-terminal HEHEHE sequence and carboxyl-terminal GGGC sequence by gene recombinant expression,which is the basis for invasive HER2 imaging with affibody.

METHODSThe encoded affibody gene was optimized by codon preference of E. coli with gene designer software. The N-terminal of affibody was fused with HEHEHE sequence,while the C-terminal was fused with GGGC sequence. The synthetic gene was confirmed by Hind 3 endonuclease restriction and gene sequencing. The human epidermal growth factor receptor-2(HER2)affibody gene was sub-cloned into pET22b(+)plasmid and transformed into competent BL21(DE3)bacteria. The expression of modified affibody was induced with isopropyl Β-D-1-thiogalactopyranoside(IPTG)and identified by SDS-PAGE. The affibody was purified by nickel affinity binding and imidazole elution. The purified affibody was labeled with (68)Ga and its affinity was determined by saturation analysis with HER2-positive cells MDA-MB-361.

RESULTSThe affibody gene containing N-terminal HEHEHE and C-terminal GGGC sequences were confirmed by Hind 3 endonuclease restriction and gene sequencing. A newly expressed 8×10(3) protein was expressed from the induced recombinant bacteria identified by SDS-PAGE after sub-cloning HER2 affibody gene into pET22b(+)plasmid,transforming recombinant plasmid into competent BL21(DE3)bacteria and inducing the recombinant bacteria with IPTG. The expressed protein was purified from nickel agarose by 60 mmol/L imidazole eluting. The affinity Kd value of (68)Ga labeled affibody to HER2 positive MDA-MB-361 cells was 1.5 nmol/L.

CONCLUSIONThe affiibody ZHER2V2 containing N-terminal HEHEHE and C-terminal GGGC was successfully prepared by gene optimization,recombinant expression and affinity purification.

Affinity Labels ; isolation & purification ; Escherichia coli ; metabolism ; Gene Expression ; Humans ; Receptor, ErbB-2 ; genetics ; Recombinant Fusion Proteins ; biosynthesis

OBJECTIVETo establish a bioluminescent MDA-MB-231 cell line which can stably express luciferase and green fluorescent protein to allow bioluminescent imaging in nude mouse models bearing human triple-negative breast cancer xenografts.

METHODSThe lentivirus carrying luc2, eGFP and neo fusion genes were packaged in 293T cells via calcium phosphate co-precipitation. Human triple-negative breast cancer cell line MDA-MB-231 was infected by the lentivirus, and the positive cell clones were tested for eGFP and luc2 expressions by fluorescence microscopy and Xenogen IVIS200 bioluminescent imaging system, respectively. MTT assay, transwell invasion assay and wound healing assay were performed to evaluate the changes in the proliferation, invasion and migration abilities of the infected cells. The cells were then orthotopically implanted into the right second mammary fat pat of female BALB/c nude mice. The tumor growth was monitored by the in vivo imaging system every week, and the tumor tissues were harvested to evaluate the in vivo stability and tumorigenicity of the modified cells using cryosection and HE staining.

RESULTSThe lentivirus-infected MDA-MB-231cells could stably express luc2 and eGFP, and the luciferase activity reached 9689 phontons/s/per cell. No significant changes occurred in the biological activities of the lentivirus-infected MDA-MB-231 cells. We successfully established the nude mouse model bearing orthotopically implanted human triple-negative breast cancer cells.

CONCLUSIONThe modified MDA-MB-231 cell line can be detected sensitively at the primary implantation site and distant metastasis site in nude mice, which provides a convenient and sensitive platform for the research of metastatic mechanism and new antitumor drugs of human triple-negative breast cancer. The combination of eGFP and luc2 is superior to single reporter gene.

Animals ; Brain Neoplasms ; secondary ; Breast Neoplasms ; genetics ; metabolism ; pathology ; Cell Line, Tumor ; Disease Models, Animal ; Female ; Genes, Reporter ; Green Fluorescent Proteins ; biosynthesis ; genetics ; Humans ; Lentivirus ; genetics ; metabolism ; Luciferases ; biosynthesis ; genetics ; Luminescent Measurements ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Neoplasm Invasiveness ; Neoplasm Transplantation ; Receptor, ErbB-2 ; metabolism ; Receptors, Estrogen ; metabolism ; Receptors, Progesterone ; metabolism

To produce many epitopes of peptide mut, different tandem repeats containing HER-2 mimetic peptide mut were constructed and expressed. The oligonucleotide coding mut sequence was inserted into pET28a(+) to construct the prokaryotic recombinant plasmid pET28a-mutl. The mut coding sequence was repeatedly inserted into the vector in tandem to obtain a series of plasmids pET28a-mut2, pET28a-mut4, pET28a-mut8 and pET28a-mut16. The plasmids were transformed into E. coli. BL21 and induced by IPTG. The recombinant proteins were expressed in E. coli. The binding analysis verified that the interaction between the tandem peptides mut and Herceptin was increased. In conclusion, the tandem peptides consisted of many antigen epitopes, and laid the foundation for the further study of HER-2 peptide vaccine for biotherapy of cancer with HER-2 overexpression.
Breast Neoplasms ; metabolism ; Cancer Vaccines ; biosynthesis ; immunology ; Epitopes ; Escherichia coli ; genetics ; metabolism ; Female ; Gene Expression ; Humans ; Peptides ; genetics ; immunology ; metabolism ; Receptor, ErbB-2 ; biosynthesis ; chemistry ; genetics ; Recombinant Proteins ; biosynthesis ; genetics ; immunology

OBJECTIVETo evaluate the immunostimulatory capacity of human peripheral blood dendritic cells (DCs) with Her2/neu gene transfection mediated by adeno-associated virus.

METHODSThe HLA genotypes of the breast cancer cells SK-BR-3 and MCF7 were determined, and the mononuclear cells from healthy donors with matching HLA genotype were isolated by Ficoll-Hypaque density gradient separation. The isolated cells were divided into two groups with or without transfection with the recombinant virus harboring Her2/neu gene. The cells were cultured for 7 days in RPMI 1640 medium supplemented with 10% AB human serum, GM-CSF, interleukin-4 (IL-4) and tumor necrosis factor-alpha (TNF-alpha). The mature DCs were then harvested from the cell culture and their phenotypes were identified using flow cytometry. MTT assay was employed to examine the specific killing activity of the T cells induced by the DCs.

RESULTSThe DCs transfected with the recombinant adeno-associated virus expressed CD1a, CD86 and CD83 at the rate of 98.10%, 99.42%, and 84.59%, and those without the viral transfection expressed the markers at the rate 92.69%, 98.07%, and 82.72%, respectively, showing no obvious differences in the phenotypes of the two DCs. The transfected DCs, however, showed markedly higher expression rates of CD40 and CD80 than the non-transfected DCs (61.02% vs 36.19%, and 97.61% vs 55.5%, respectively). The DCs, irrespective of the transfection, showed comparable capacities in stimulating T cell proliferation. The transfected DCs exhibited the capacity of inducing the T cells to specifically kill the target tumor cells, with the highest killing rate of (39.7-/+7.2)%.

CONCLUSIONThe immunostimulatory capacity of human peripheral blood DCs are enhanced by Her2/neu gene transfection mediated by adeno-associated virus.

Breast Neoplasms ; pathology ; Cell Line, Tumor ; Cells, Cultured ; Dendritic Cells ; cytology ; immunology ; metabolism ; Dependovirus ; genetics ; metabolism ; Genes, erbB-2 ; genetics ; Genetic Vectors ; Granulocyte-Macrophage Colony-Stimulating Factor ; pharmacology ; Humans ; Leukocytes, Mononuclear ; cytology ; Receptor, ErbB-2 ; biosynthesis ; genetics ; Recombinant Proteins ; genetics ; immunology ; metabolism ; Transfection

OBJECTIVETo construct a plasmid carrying small interfering RNA (siRNA) targeting human C-erbB2 gene (pGenesil- erbB2) and test its effect on Her-2 expression at the post-transcriptional level in human colon cancer cell lines HT-29 cells that highly express erbB2.

METHODSA HT-29 cell line that highly expressed CerbB-2 was selected using immunohistochemical method. The double-stranded siRNA targeting human CerbB-2 cDNA and the negative control fragment were cloned into pGenesil-1 vector, and after identification and sequence analysis, the constructed pGenesil-erbB2 plasmid was transfected into the selected HT-29 cell line.

RESULTSThe pGenesil-erbB2 plasmid was successfully constructed and stably transferred into HT-29 cells. The transfection resulted in significant inhibition of Her-2 protein expression in the HT-29 cells, as shown by Western blotting.

CONCLUSIONThe pGenesil-erbB plasmid we constructed can be stably transfected into HT-29 cells to inhibit the expression of Her-2 protein, and can be useful in further studies of increasing the radiosensitivity of HT-29 cell lines.

Base Sequence ; Genes, erbB-2 ; genetics ; HT29 Cells ; Humans ; Molecular Sequence Data ; Plasmids ; genetics ; RNA Interference ; RNA, Small Interfering ; Receptor, ErbB-2 ; biosynthesis ; genetics ; Transfection

We studied the aggregation of a recombinant engineering antibody (chA21). Anti-ErbB2 antibody chA21 was produced by fusing single-chain Fv (scFv) with human IgG1 Fc fragment, and it was proved to be a drug candidate for cancer therapy. We characterized the aggregation of chA21 by high performance sized-exclusive chromatography (HPSEC), dynamic light scattering (DLS), SDS-PAGE, indirect ELISA assay, and compared the influence of temperature and additive on the level of aggregation and binding activity. Conformation changes of different levels of aggregation were also analyzed via circular dichroism (CD). Finally, we analyzed which part of chA21 was involved in aggregation by cleaving it into scFv and Fc fragments. The results showed that chA21 could form aggregates in the storage solution. The aggregates interacted through non-covalent bonds and remained binding activity. Temperature and additive could slightly affect the level of aggregation and binding activity, while the conformations of chA21 were stable. Aggregation propensity of scFv fragment was almost same as chA21, indicating that scFv may be the major part to form the aggregates. The research on aggregation may be helpful to develop a suitable formulation for chA21 clinical application as well as provide direction for future antibody design and reconstruction.
Antibodies ; chemistry ; metabolism ; Humans ; Immunoglobulin Fc Fragments ; chemistry ; metabolism ; Immunoglobulin Variable Region ; chemistry ; metabolism ; Protein Conformation ; Protein Engineering ; methods ; Receptor Aggregation ; immunology ; Receptor, ErbB-2 ; chemistry ; immunology ; Recombinant Proteins ; biosynthesis ; chemistry ; genetics ; immunology

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

This study is to investigate the roles of neuregulin receptor ErbB2 and protein kinase B (PKB) in pacing-induced heart failure of rhesus monkey. Rapid pacing was used to induce heart failure in rhesus monkey. Aorta intubatton was used to perform hemodynamic measurements, 17 days after pacing. N-Terminal pro-brain natriuretic peptide (BNP), one of the most important molecular marker of heart failure, was also measured by the method of electrochemical luminescence immunoassay. The mRNA expressions of ErbB2, PKB and Bcl-xl were detected in the left ventricular free walls by RT-PCR method. The expressions of phospho-PKB and Bcl-xl on protein level were also detected by Western blotting. The contractibility of cardiac muscle decreased significantly, which consisted with the increase of BNP. Compared with control group, the mRNA expressions of ErbB2, PKB and Bcl-xl were depressed, and similar results were also found in the protein expression analysis of phospho-PKB and Bcl-xl. The expressions of ErbB2, PKB and Bcl-xl were down-regulated during heart failure in rhesus monkey which suggested the important roles of ErbB2 receptor and PKB in the mechanism of heart failure.
Animals ; Apoptosis ; Cardiac Pacing, Artificial ; adverse effects ; Heart Failure ; etiology ; metabolism ; physiopathology ; Macaca mulatta ; Male ; Myocardial Contraction ; Myocardium ; metabolism ; pathology ; Natriuretic Peptide, Brain ; blood ; Phosphorylation ; Proto-Oncogene Proteins c-akt ; biosynthesis ; genetics ; metabolism ; RNA, Messenger ; metabolism ; Random Allocation ; Receptor, ErbB-2 ; biosynthesis ; genetics ; Signal Transduction ; bcl-X Protein ; biosynthesis ; genetics

OBJECTIVETo detect HER-2/neu expression in prostate cancer tissues of both androgen dependent and independent groups and to evaluate the role of HER-2/neu in androgen independent prostate cancer.

METHODSImmunohistochemical assay was used in the detection of HER-2/neu in the prostate cancer samples from 30 cases of androgen dependent cancer and 24 cases of androgen independent cancer. The correlation was analyzed between HER-2/neu over-expression and the tumor's clinical stage and Gleason score.

RESULTSThe rates of HER-2/neu over-expression were 10% and 33% in the androgen dependent group and the androgen independent group, significantly higher in the Gleason score >7 group and the clinical stage > T2 group than in the -7 group and the > T2 group (14.29% vs. 26.92%, 34.62% vs. 7.14%, P < 0.01).

CONCLUSIONThe rate of HER-2/neu over-expression is high in androgen independent prostate cancer and is correlated with the tumor stage and Gleason score.

Androgens ; physiology ; Humans ; Immunohistochemistry ; Male ; Neoplasm Staging ; Neoplasms, Hormone-Dependent ; metabolism ; pathology ; Prostatic Neoplasms ; metabolism ; pathology ; Receptor, ErbB-2 ; biosynthesis