Human epidermal growth factor (hEGF) can be applied in the treatment of surgical trauma (burns, scalds), tissue repair, skin moisturizing, beauty, skincare, etc. However, the low expression and high cost limit the application of hEGF. In order to improve the expression level of hEGF and reduce the production cost, considering the high expression of polyhedrin, this study fused a partial sequence of polyhedrin with hEGF and expressed the fused sequence by using a silkworm baculovirus expression vector system. In view of the small molecular weight of hEGF, we connected hEGF genes in series and optimized the codons to construct multiple fusion expression vectors by fusing different partial sequences of polyhedrin at the N-terminus. The results showed that through the above strategy, the protein expression level of hEGF was significantly increased. The expression vector containing three concatenated hEGF genes with optimized codons and fused with the sequence encoding 25 or 35 residues at the N-terminus of polyhedrin showed the highest expression level.
Humans ; Epidermal Growth Factor/biosynthesis* ; Genetic Vectors/genetics* ; Recombinant Fusion Proteins/biosynthesis* ; Animals ; Bombyx/metabolism* ; Occlusion Body Matrix Proteins/genetics* ; Nucleopolyhedroviruses/genetics* ; Amino Acid Sequence

Epidermal growth factor (EGF) is an epithelial cell growth factor that can stimulate intestinal development, repair the damage of epidermal cells as well as reduce the incidence of pathogen infection and diarrhea. In order to produce a recombinant Lactobacillus plantarum (L. plantarum) expressing porcine epidermal growth factor (pEGF), we constructed a recombinant vector stably expressing pEGF in L. plantarum strains. First, L. plantarum strain Lp-1 was isolated from intestinal contents of piglets. Then the functional domain of pEGF, M6 precursor protein signal peptide (SP) and super strong constitutive promoter (SCP) were connected with the backbone plasmid pIAβ8 to construct the recombinant vector that was transformed into Lp-1 by electroporation. Afterwards, pEGF was expressed in Lp-1 and detected by Tricine-SDS-PAGE and ELISA. After orally irrigated early-weaned BALB/c mice with the recombinant L. plantarum every morning and late afternoon for 10 consecutive days, body weight, villous height and crypt depth in the intestine were measured to examine the influence of the recombinant bacteria on the intestinal development of early-weaned mice in vivo. Finally, the results of our experiments demonstrated that pEGF was successfully expressed in Lp-1 and the molecular weight of pEGF was 6 kDa. In addition, the recombinant pEGF can enhanced the daily gain and exerted significance influence (P < 0.05) to the small intestinal morphology of early-weaned BALB/c mice. In conclusion, pEGF could be expressed in L. plantarum and the recombinant pEGF possesses good biological activity.
Animals ; Electrophoresis, Polyacrylamide Gel ; Epidermal Growth Factor ; biosynthesis ; Genetic Vectors ; Intestines ; microbiology ; Lactobacillus plantarum ; metabolism ; Mice ; Mice, Inbred BALB C ; Plasmids ; Promoter Regions, Genetic ; Protein Precursors ; Protein Sorting Signals ; Recombinant Proteins ; biosynthesis ; Swine

OBJECTIVE: To construct expression vector for the SEA-EGF fusion gene. METHOD: Clone the SEA gene and the EGF gene segment with PCR and RT-PCR independently, and connect this two genes by the bridge PCR. Insert the fusion gene EGF-SEA into the expression vector PET-44. Induced the secretion of the fusion protein SEA-EGF by the antileptic. RESULT: The gene fragment encoding EGF and SEA mature peptide was successfully cloned. The fusion gene EGF-SEA was successfully constructed and was inserted into expression vector. CONCLUSION The new recombinant expression vector for fusion gene EGF-SEA is specific for head and neck cancer, laid the foundation for the further study of fusion protein SEA-EGF targeting immune therapy in head and neck tumors.
Enterotoxins ; genetics ; Epidermal Growth Factor ; genetics ; Genetic Vectors ; Head and Neck Neoplasms ; drug therapy ; Humans ; Molecular Targeted Therapy ; Recombinant Fusion Proteins ; biosynthesis ; genetics

The protein production system using a baculovirus Antheraea pernyi nucleopolyhedrovirus (AnpeNPV) as a gene expression vector and its host insect as a natural bioreactor was successful established and its excellent performance in the protein production has been demonstrated. In this paper, the system is used to produce recombinant human epidermal growth factor (rhEGF), which have been widely used in medical and cosmetic treatment. A recombinant AnpehEGF virus has been constructed by replacing the viral polyhedrin gene with the rhEGF gene, and then injected it to Samia cynthia ricini pupae. Amplification and expression of rhEGF gene in the pupae was clearly detected by PCR, Western blot and ELISA analyses. These analyses have also revealed that rhEGF in the pupae was significantly increased at 6 days post-infection, and reached maximum level at the 12th day. The concentrations of rhEGF were 19.77, 24.90, 618.59 and 1 952.46 ng/g pupae at 3, 6, 9 and 12 days post-infection, respectively. However, the rhEGF concentration reduced at later stage (days 15). The rhEGF in the pupae could be purified using ammonium sulfate precipitation and Ni-NTA agrose affinity chromatography. Results demonstrate that Samia cynthia ricini pupae can be used as a bioreactor to produce rhEGF and, if successfully improved, will be a novel method of rhEGF production with lower cost and more efficient.
Amino Acid Sequence ; Animals ; Bombyx ; genetics ; metabolism ; Epidermal Growth Factor ; biosynthesis ; genetics ; Genetic Vectors ; genetics ; Humans ; Molecular Sequence Data ; Nucleopolyhedrovirus ; genetics ; Recombinant Proteins ; biosynthesis ; genetics

Transglutaminase 2 (TG2), a cross-linking enzyme, is involved in drug resistance and in the constitutive activation of nuclear factor kappa B (NF-kappaB). We investigated the association of non-small cell lung cancer (NSCLC) treatment efficacy with TG2 and NF-kappaB expression in 120 patients: 102 with adenocarcinoma and 18 with other histologic types. All patients underwent surgery; 88 received adjuvant chemotherapy, with 28 receiving platinum-based doublet chemotherapy as first-line treatment and 29 receiving epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) therapy. Patients' TG2 and NF-kappaB expression values were calculated semiquantitatively. The median TG2 value was 50 (range, 0-300) and the median NF-kappaB value was 20 (range, 0-240). Disease-free survival did not differ between the low- and high-TG2 groups. Among patients who received palliative platinum-based doublet chemotherapy, progression free survival (PFS) was longer in the low-TG2 group than in the high-TG2 group (11.0 vs. 7.0 months; P=0.330). Among those who received EGFR-TKI therapy, PFS was also longer in the low-TG2 group than in the high-TG 2 group (11.0 vs. 2.0 months; P=0.013). Similarly, in EGFR wild-type patients treated with EGFR-TKI, PFS was longer in patients with low TG2 expression (9.0 vs. 2.0 months; P=0.013). TG2 expression levels can predict PFS in patients with NSCLC treated with EGFR-TKI.
Adenocarcinoma/*drug therapy/mortality/surgery ; Adult ; Aged ; Aged, 80 and over ; Antineoplastic Agents/therapeutic use ; Carcinoma, Non-Small-Cell Lung/*drug therapy/mortality/surgery ; Disease-Free Survival ; Female ; GTP-Binding Proteins/*biosynthesis ; Humans ; Lung Neoplasms/*drug therapy/mortality/surgery ; Male ; Middle Aged ; NF-kappa B/biosynthesis ; Protein Kinase Inhibitors/therapeutic use ; Receptor, Epidermal Growth Factor/*antagonists & inhibitors/genetics ; Transglutaminases/*biosynthesis ; Treatment Outcome

Bispecific antibodies have been exploited as both cancer immunodiagnostics and cancer therapeutics, which have shown promises in clinical trials in cancer imaging and therapy. To improve the anti-tumor effect, an scDb (bispecific single-chain diabody) was constructed from the variable domain genes of two scFvs (single-chain variable fragment antibodies) directed against human EGFR (epidermal growth factor receptor) and VEGFR2 (vascular endothelial growth factor receptor 2) extracellular domains. The anti-EGFR/ anti-KDR scDb was constructed into pHEN2 plasmid and expressed in Escherichia coli HB2151 host. After purification by one-step affinity chromatography of IMAC, scDb protein was characterized by Western blotting. The yield of scDb protein was 570 microg per liter medium. scDb bound to EGFR as efficiently as the parental antibody scFv-E10, while a little bit weaker than the parental antibody scFv-AK404R when bound to KDR. In conclusion, the scDb protein could bind both EGFR and KDR specifically and could be applied for further anti-tumor research.
Antibodies, Bispecific ; biosynthesis ; genetics ; Escherichia coli ; metabolism ; Humans ; Plasmids ; Protein Binding ; Receptor, Epidermal Growth Factor ; immunology ; Single-Chain Antibodies ; biosynthesis ; genetics ; Vascular Endothelial Growth Factor Receptor-2 ; immunology

Epidermal growth factor receptor (EGFR) and its ligands (EGF and TGFalpha) are over-expressed in a variety of tumors. Immunization EGF-carrier protein inhibits tumor growth through abrogating binding of EGF to EGFR. Here, a chimeric protein of EGF and TGFalpha (E5T) was genetically fused to Staphylococcal enterotoxin A (SEA), a bacterial superantigenic protein which promotes humoral B cell response through enhancement of Ag-specific CD4 T cells activity. The resulted fusion proteins were expressed in Escherichia coli and purified though metal chelating affinity chromatography. Immunization of E5T-mSEA fusion protein in mice induced production of high titers antibodies, which recognize both EGF and TGFalpha. Anti- E5T-mSEA serum at dilution of 1:10 significantly inhibited growth of A431 cell lines but had little effect on 293T cell lines.
Amino Acid Sequence ; Animals ; Cancer Vaccines ; biosynthesis ; immunology ; Cell Line, Tumor ; Enterotoxins ; biosynthesis ; genetics ; Epidermal Growth Factor ; biosynthesis ; genetics ; Escherichia coli ; genetics ; metabolism ; Humans ; Immunization ; Mice ; Mice, Inbred C57BL ; Molecular Sequence Data ; Random Allocation ; Receptor, Epidermal Growth Factor ; antagonists & inhibitors ; immunology ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology ; Transforming Growth Factor alpha ; biosynthesis ; genetics

The epithelial growth factor receptor interference (EGFRi) was obtained by synthetic primers. Overlapping PCR was used to produce EGFRi-IL-24 fusion gene, which is linked by Gly4Ser3. After sequence analysis, EGFRi-IL-24 was cloned into expression vector pPIC9k; EGFRi-IL-24/pPIC9k was linearized with SacI,and then transformed to electroporated pastoris GS115. Subsequently, positive clone was selected by G418 and PCR, and its phenotype was determined by SDS-PAGE and MTT assay. The results demonstrated that EGFRi-IL-24 protein was expressed and shown to have the potential for use in researches of its biological function and in clinical application.
Antineoplastic Agents ; pharmacology ; Genetic Vectors ; genetics ; Humans ; Interleukins ; biosynthesis ; genetics ; Pichia ; genetics ; metabolism ; Receptor, Epidermal Growth Factor ; antagonists & inhibitors ; biosynthesis ; genetics ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; pharmacology

BACKGROUND/AIMS: Mutations of the epidermal growth factor receptor (EGFR) and Kirsten rat sarcoma viral oncogene (KRAS) are important in the pathogenesis of lung cancer, and recent reports have revealed racial and geographical differences in mutation expression. METHODS: This study was conducted to investigate the prevalence of EGFR and KRAS mutations and their correlation with clinical variables in Korean patients with adenocarcinoma of the lung. Formalin-fixed adenocarcinoma specimens from 104 randomly selected patients diagnosed at Kosin University Gospel Hospital from October 1996 to January 2005 were used for the study. RESULTS: We found a high prevalence of EGFR mutations and a low prevalence of KRAS mutations. EGFR mutations were present in 24% (25 of 104) of the samples: one mutation in exon 18, 13 in exon 19, one in exon 20, and 10 in exon 21. The presence of an EGFR mutation was not associated with gender, smoking history, histological grade, age, bronchioalveolar components, or cancer stage in patients with adenocarcinoma of the lung. CONCLUSIONS: Mutations of KRAS were present in 9.6% (9 of 94) of the samples: eight in codon 12 and one in codon 13. EGFR mutations were never found in tumors with KRAS mutations, suggesting a mutually exclusive relationship.
Adenocarcinoma/*genetics/metabolism/mortality ; Adult ; Aged ; DNA, Neoplasm/*genetics ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; Korea/epidemiology ; Lung Neoplasms/*genetics/metabolism/mortality ; Male ; Middle Aged ; *Mutation ; Polymerase Chain Reaction ; Prognosis ; Proto-Oncogene Proteins/biosynthesis/*genetics ; Receptor, Epidermal Growth Factor/biosynthesis/*genetics ; Retrospective Studies ; Survival Rate ; ras Proteins/biosynthesis/*genetics

Animals ; Carcinoma, Non-Small-Cell Lung ; genetics ; metabolism ; Humans ; Lung Neoplasms ; genetics ; metabolism ; Molecular Imaging ; Mutation ; Positron-Emission Tomography ; RNA, Messenger ; metabolism ; Receptor, Epidermal Growth Factor ; biosynthesis ; genetics