Adult ; Aged ; Carcinoma, Hepatocellular ; metabolism ; Female ; Humans ; Liver Neoplasms ; metabolism ; Male ; Middle Aged ; RNA, Messenger ; biosynthesis ; genetics ; Receptor, ErbB-2 ; biosynthesis ; genetics ; Receptor, ErbB-3 ; biosynthesis ; genetics

To purify the extracellular domain of HER2 in vitro and improve its prokaryotic expression abundance, the cDNA fragment encoding extracellular domain of HER2 was obtained by PCR and cloned into the expression vector pGEX-6P-1. After transforming it into Escherichia coli BL21, we instituted an investigation of different inducing conditions to try out the optimal condition for expressing soluble fusion protein. As for insoluble inclusion bodies, they were dissolved in 8 M Urea and refolded in refolding buffer. The soluble protein and the refolded protein were purified with Glutathione Sepharose 4B, respectively. The results showed that both the soluble and insoluble protein existed in Escherichia coli, but the majority was insoluble. It is beneficial to the expression of soluble fusion protein by induction at lower temperature (30 degrees C) and higher optical density (A600= 1.8) with the use of certain additive in medium. By purification of the supernatant of the lysate and refolded protein, the yield of the fusion protein was about 1.23 mg per liter culture. As a result, we have obtained the maximum soluble extracellular domain of HER2 protein, and thus have laid a foundation for further work on functional study and antibody preparation for HER2.
Cloning, Molecular ; Escherichia coli ; genetics ; Genes, erbB-2 ; genetics ; Humans ; Prokaryotic Cells ; metabolism ; Protein Folding ; Receptor, ErbB-2 ; biosynthesis ; genetics ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; isolation & purification

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

In order to explore a potential indicator of predicting the occurrence and development of gestational trophoblastic tumor, the expression of c-erbB2 oncogene in human normal placenta, hydatidiform mole and choriocarcinoma was investigated. The expression of c-erbB2 was detected immunohistochemically by monoclonal antibody against the gene on the formalin-fixed paraffin sections of 21 hydatidiform moles, 21 invasive moles, 20 choriocarcinomas and 30 normal placentas. Results showed that the expression level of c-erbB2 was significantly higher in gestational trophoblastic tumor than in hydatidiform mole and normal placenta of midterm and term pregnancy (P < 0.05), while there was no significant difference between patients with gestational trophoblastic tumor of stage III, IV and those of stage I, II. It was demonstrated that overexpression of c-erbB2 may closely associated with malignant transformation of hydatidiform mole, not only providing important insight into pathogenesis of gestational trophoblastic tumor, but also having an important significance for the early diagnosis and early treatment of gestational trophoblastic tumor.
Biomarkers, Tumor ; Choriocarcinoma ; metabolism ; Female ; Genes, erbB-2 ; Humans ; Hydatidiform Mole ; metabolism ; Hydatidiform Mole, Invasive ; metabolism ; Placenta ; metabolism ; Pregnancy ; Receptor, ErbB-2 ; biosynthesis ; genetics ; Uterine Neoplasms ; metabolism

OBJECTIVETo detect the expressions of human epidermal growth factor receptor 2 (Her-2), epidermal growth factor receptor (EGFR), presenilin 2 (PS-2) and estrogen receptor (ER) in breast cancer and discuss their clinical implications.

METHODSThe expressions of Her-2, EGFR, PS-2 and ER were measured immunohistochemically in 108 patients with breast cancer.

RESULTSThe positive expression rates of Her-2, EGFR, PS-2 and ER were 37.0%, 40.7%, 57.4% and 53.7% respectively in the breast cancer patients. The expression of Her-2 was not correlated with EGFR, but inversely correlated with PS-2 and ER. The expressions of Her-2 and EGFR, PS-2, ER were correlated with the histological grades (P<0.05), and Her-2, EGFR and ER expressions with lymph node metastasis (P<0.05). The expressions of Her-2, EGFR, PS-2 and ER did not correlate to the pathological types, patient's age and tumor size (P>0.05).

CONCLUSIONExpressions of Her-2 and EGFR often suggests an unfavorable prognosis while expressions of PS-2 and ER suggest a more favorable one. Expressions of Her-2, EGFR, PS-2 and ER are useful prognostic factors in breast cancer patients.

Adult ; Aged ; Biomarkers, Tumor ; biosynthesis ; Breast Neoplasms ; metabolism ; pathology ; Carcinoma, Ductal, Breast ; metabolism ; pathology ; Female ; Humans ; Immunohistochemistry ; Middle Aged ; Presenilin-2 ; biosynthesis ; Prognosis ; Receptor, Epidermal Growth Factor ; biosynthesis ; Receptor, ErbB-2 ; biosynthesis ; Receptors, Estrogen ; biosynthesis

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 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

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 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 study the growth regulation pathway and the mechanism of acquired resistance to tamoxifen (TAM) in breast cancer cells.

METHODSTAM was used to induce wild-type MCF-7 human breast cancer cell line and establish a tamoxifen-resistant (TAM-R) cell line. RT-PCR, Western blot and immuocytochemical techniques were used to detect and compare mRNA and protein of c-erbB1, cerbB2, c-erbB3, c-erbB4 in wild-type MCF-7 and TAM-R MCF-7 cell lines.

RESULTSCompared with wild-type MCF-7 cells, the mRNA of c-erbB1 increased 6 times (P < 0.05) and the protein 3 times higher (P < 0.05), and the mRNA of c-erbB2 increased 3 times (P < 0.05) and the protein 1.5 times higher (P < 0.05) in TAM-R MCF-7 cells. However, comparable levels of c-erbB3 mRNA and protein were expressed in both cell lines. c-erbB4 could not be detected. Under basic conditions, phosphorylated c-erbB1/c-erbB2 and c-erbB1/c-erbB3 heterodimers but not c-erbB2/c-erbB3 receptor heterodimers were detected in TAM-R cells in association with increased level of phosphorylated MAPK.

CONCLUSIONOur findings demonstrated that the development of TAM-resistance in MCF-7 cells is related with the autocrine release and action of an c-erbB1-specific ligand inducing preferential c-erbB1/c-erbB2 dimerization and downstream activation of the MAPK pathway.

Antineoplastic Agents, Hormonal ; pharmacology ; Blotting, Western ; Breast Neoplasms ; genetics ; metabolism ; pathology ; Cell Line, Tumor ; Drug Resistance, Neoplasm ; Female ; Gene Expression Regulation, Neoplastic ; drug effects ; Humans ; Immunohistochemistry ; Mitogen-Activated Protein Kinases ; metabolism ; Phosphorylation ; drug effects ; RNA, Messenger ; biosynthesis ; genetics ; Receptor, Epidermal Growth Factor ; biosynthesis ; genetics ; Receptor, ErbB-2 ; biosynthesis ; genetics ; Receptor, ErbB-3 ; biosynthesis ; genetics ; Receptor, ErbB-4 ; Reverse Transcriptase Polymerase Chain Reaction ; Tamoxifen ; pharmacology