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

Adenocarcinoma ; genetics ; Adult ; Aged ; Female ; Humans ; Lung Neoplasms ; genetics ; Male ; Middle Aged ; Mutation ; Receptor, Epidermal Growth Factor ; genetics

A DNA fragment encoding extracellular domain of mouse epidermal growth factor receptor (EGFR) was obtained by PCR from a previous recombinant plasmid. The DNA fragment was then ligated into prokaryotic expression vector, and expressed in Escherichia Coli. The recombinant protein was purified under denature conditions by affinity chromatography, and refolded with gradient dialysis. The recombinant protein could produce antibodies to recognize extracellular domain and full-length of mouse EGFR, and form homodimer in the presence of EGF detected by western blot analysis. These findings provide evidence that the renatured recombinant extracellular domain of mouse epidermal growth factor receptor is immunogenetic and may be important for further application of this protein in functional and immunological research.
Animals ; Escherichia coli ; genetics ; metabolism ; Genetic Vectors ; Mice ; Plasmids ; Receptor, Epidermal Growth Factor ; biosynthesis ; chemistry ; genetics ; isolation & purification ; Transfection

OBJECTIVETo investigate the effects of leucine-rich repeats and immunoglobulin-like domains 3 (LRIG3) on the biological activity of glioblastoma cell line GL15.

METHODSGlioblastoma GL15 cells were cultured and transfected with LRIG3-EGFP plasmid. The location of LRIG3 in GL15 cells was observed with confocal microscopy. The proliferation and invasiveness of GL15 cells were detected with methyl thiazolyl tetrazolium (MTT) and Transwell methods respectively; the expression of epidermal growth factor receptor (EGFR) and LRIG3 mRNA and protein were detected with reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot respectively.

RESULTAfter transfection with the plasmid LRIG-EGFP, LRIG3 fusion protein was found in cytoplasm of GL15 cells and cell proliferative and invasiveness were reduced. The expression of EGFR and LRIG3 varied with the duration of EGF treatment (100 ng/ml): the expression of EGFR decreased while the expression of LRIG3 increased as time prolonged.

CONCLUSIONLRIG3 can inhibit the proliferation and invasiveness of glioblastoma cells and may be used as a target gene in gene therapy of glioblastoma.

Brain Neoplasms ; pathology ; Cell Proliferation ; Epidermal Growth Factor ; genetics ; Glioblastoma ; pathology ; Humans ; Membrane Proteins ; genetics ; metabolism ; Neoplasm Invasiveness ; Plasmids ; genetics ; RNA, Messenger ; genetics ; metabolism ; Receptor, Epidermal Growth Factor ; genetics ; metabolism ; Recombinant Fusion Proteins ; genetics ; metabolism ; Transfection ; Tumor Cells, Cultured

Breast Neoplasms ; metabolism ; Female ; Humans ; Multidrug Resistance-Associated Proteins ; genetics ; metabolism ; Receptor, Epidermal Growth Factor ; metabolism ; Receptors, Progesterone ; metabolism

OBJECTIVETo summary the recent advances in molecular research of glioblastoma (GBM) and current trends in personalized therapy of this disease.

DATA SOURCESData cited in this review were obtained mainly from PubMed in English up to 2015, with keywords "molecular", "genetics", "GBM", "isocitrate dehydrogenase", "telomerase reverse transcriptase", "epidermal growth factor receptor", "PTPRZ1-MET", and "clinical treatment".

STUDY SELECTIONArticles regarding the morphological pathology of GBM, the epidemiology of GBM, genetic alteration of GBM, and the development of treatment for GBM patients were identified, retrieved, and reviewed.

RESULTSThere is a large amount of data supporting the view that these recurrent genetic aberrations occur in a specific context of cellular origin, co-oncogenic hits and are present in distinct patient populations. Primary and secondary GBMs are distinct disease entities that affect different age groups of patients and develop through distinct genetic aberrations. These differences are important, especially because they may affect sensitivity to radio- and chemo-therapy and should thus be considered in the identification of targets for novel therapeutic approaches.

CONCLUSIONThis review highlights the molecular and genetic alterations of GBM, indicating that they are of potential value in the diagnosis and treatment for patients with GBM.

Brain Neoplasms ; genetics ; pathology ; Glioblastoma ; genetics ; pathology ; Humans ; Isocitrate Dehydrogenase ; genetics ; Mutation ; PTEN Phosphohydrolase ; genetics ; Receptor, Epidermal Growth Factor ; genetics ; Telomerase ; genetics

OBJECTIVETo probe the mechanism of electroacupuncture at points "Weibingfang" in treatment of acute gastric mucosal lesion.

METHODSForty Wistar rats of sanitary degree were randomly divided into 4 groups, normal group, model group, sham-model group and Weibingfang group, 10 rats in each group. The acute gastric mucosal lesion model was made by intragastric perfusion of anhydrous alcohol. The Weibingfang group were treated by electroacupuncture at "Neiguan" (PC 6), "Zhongwan" (CV 12) and "Zusanli" (ST 36) with sparse-dense wave, frequency of 10-30 Hz, current intensity of 2 mA, for 20 min. One hour after the treatment, the blood from the abdominal aorta and the gastric mucosa tissue were taken, and serum epidermal growth factor (EGF) level and epidermic growth factor receptor mRNA (EGFR mRNA) expression in the gastric mucosa were detected with enzyme linked immunosorbent assay (ELISA) and reverse transcriptase-polymerase chain reaction (RT-PCR) respectively.

RESULTSThere were significant differences in blood EGF level (41.62 +/- 12.58) ng/L and EGFR mRNA expression (0.78 +/- 0.03) in the model group were significantly different from [(60.37 +/- 12.01) ng/L and 0.55 +/- 0.04] in the normal group and [(61.21 +/- 13.46) ng/L and 0.53 +/- 0.05] in the sham-model group (P < 0.05); after electroacupuncture, blood EGF level (70.59 +/- 10.14) ng/L increased and the EGFR mRNA expression (1.18 +/- 0.02) in the gastric mucosa was up-regulated with a significant differences as compared with those in the model group (P < 0.05).

CONCLUSIONPoint "Weibingfang" can promote proliferation, differentiation and migration of the gastric mucosal epidermic cells to repair the gastric mucosal lesion.

Acupuncture Points ; Animals ; Electroacupuncture ; Epidermal Growth Factor ; blood ; genetics ; Female ; Gastric Mucosa ; metabolism ; Gene Expression ; Humans ; Male ; RNA, Messenger ; genetics ; metabolism ; Random Allocation ; Rats ; Rats, Wistar ; Receptor, Epidermal Growth Factor ; genetics ; metabolism ; Stomach Diseases ; genetics ; metabolism ; therapy

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

BACKGROUNDEpidermal growth factor receptor (EGFR) mutations in lung carcinomas can make the disease more responsive to the treatment with tyrosine kinase inhibitors. We aimed to evaluate the prevalence of EGFR mutations in a large series of lung carcinomas.

METHODSWe examined 1195 consecutive lung cancer patients for EGFR mutations in exons 18, 19, and 21 using direct sequencing of polymerase chain reaction products. A detailed smoking history was obtained. Patients were categorized as never smokers (< 100 lifetime cigarettes), former smokers (quit > 1 year ago), or current smokers (quit < 1 year ago).

RESULTSThere were EGFR mutations in 9 (4.5%) of 201 squamous carcinomas, in 1 (2%) of 50 large cell carcinomas, and in 1 (2.3%) of 44 small cell carcinomas that were investigated. Three hundred and twenty-seven mutations were found in the series of 858 adenocarcinomas (38.1%). Among 858 lung adenocarcinomas, we detected EGFR mutations in 250 (48.6%) of 514 never smokers, 39 (33.9%) of 115 former smokers, and 38 (16.6%) of 229 current smokers. Significantly fewer EGFR mutations were found in people who smoked for more than 15 pack-years (P = 0.0002) or stopped smoking less than 15 years ago (P = 0.033) compared with individuals who never smoked.

CONCLUSIONSAdenocarcinoma is the most frequent EGFR mutation pathologic type in lung cancer. The likelihood of EGFR mutations in exons 18, 19 and 21 decreases as the number of pack-years increases. Mutations were less common in people who smoked for more than 15 pack-years or who stopped smoking cigarettes less than 15 years ago. These data can assist clinicians in assessing the likelihood of exons 18, 19, or 21 EGFR mutations in Chinese patients with lung cancer when mutational analysis is not feasible.

Adenocarcinoma ; genetics ; DNA Mutational Analysis ; Exons ; genetics ; Female ; Humans ; Lung Neoplasms ; genetics ; Male ; Mutation ; Polymerase Chain Reaction ; Receptor, Epidermal Growth Factor ; genetics ; Smoking ; adverse effects

The human epidermal growth factor receptor (EGFR) extracellular region (residues 1-621) consists of four subdomains, i.e. L1, S1, L2, and S2. The L2 domain (EGFR-L2) is composed of residues 311-479 and plays a major role in ligand-binding. Due to the high content of cysteine residues (42 cysteines) in the S1 and S2 domains, it is quite difficulty to get a correctly refolded product of the complete EGFR extracellular domain. In contrast, only 4 cysteine residues are present in EGFR-L2 domain. The aim of the present study is to prepare a soluble EGFR-L2 domain from the recombinant protein inclusion body overexpressed in Escherichia coli (E. coli). DNA fragment encoding EGFR-L2 containing a polyhistidine-tag at the carboxyl terminus was amplified by PCR from the cDNA of EGFR extracellular region, and was inserted into pET-3c to construct the prokaryotic expression vector. The target protein was highly expressed in E. coli BL21 (DE3) strain and was only present in the inclusion body as revealed by immunoblotting analysis. No soluble product could be refolded through dilution or stepwise dialysis strategies. However, on-column refolding of denatured EGFR-L2 bound to Ni2+ -NTA produced a soluble one. Furthermore,the soluble EGFR-L2 was simultaneously purified to high purity (>95%) through eluting from the same Ni2+ -NTA column with a linear imidazole gradient. The refolded EGFR-L2 had specific binding activity with the cognate ligand EGF, although its affinity was low. These results suggest that a polyhistidine-tag fused with a recombinant protein facilitate not only the purification but also the renaturation of the target product through on-column refolding. Besides, this refolding strategy may be suitable for the preparation of those recombinant proteins which are hard to refold through conventional approaches.
Escherichia coli ; genetics ; metabolism ; Humans ; Inclusion Bodies ; genetics ; metabolism ; Protein Folding ; Receptor, Epidermal Growth Factor ; biosynthesis ; genetics ; isolation & purification ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; isolation & purification