共查询到20条相似文献,搜索用时 500 毫秒
1.
Yun Yang Rui Guo Qi Chen Youxun Liu Pengfei Zhang Ziheng Zhang Xi Chen Tianyun Wang 《Biotechnology letters》2018,40(5):789-795
Objective
To promote targeting specificity of anti-CD47 agents, we have constructed a novel bispecific antibody fusion protein against EGFR and CD47, which may minimize the “off-target” effects caused by CD47 expression on red blood cells.Results
The novel bispecific antibody fusion protein, denoted as Bi-SP could simultaneously bind to EGFR and CD47 and exhibited potent phagocytosis-stimulation effects in vitro. Bi-SP treatment with a low dose more effectively inhibited tumor growth than either EGFR-targeting antibody, Pan or the SIRPα variant-Fc (SIRPαV-Fc) in the A431 xenograft tumor model. In addition, the treatment with Bi-SP produced less red blood cell (RBC) losses than the SIRPαV-Fc treatment, suggesting its potential use for minimizing RBC toxicity in therapy.Conclusions
Bi-SP with improved therapeutic index has the potential to treat CD47+ and EGFR+ cancers in clinics.2.
Duanpen Sandee Sumalee Tungpradabkul Manae Tsukio Tadayuki Imanaka Masahiro Takagi 《BMC biotechnology》2002,2(1):16-8
Background
Hep27 monoclonal (Hep27 Mab) is an antibody against hepatocellular carcinoma. Hep27 Mab itself can inhibit the growth of a hepatocellular carcinoma cell line (HCC-S102). We attempted to produce a single-chain fragment (scFv), a small fragment containing an antigen-binding site of Hep27 Mab, by using DNA-recombinant techniques.Results
The sequences encoding the variable regions of heavy (VH) and light (VL) chains of a murine Hep27 Mab were linked together by a linker peptide (Gly4Ser)3 and tagged with a hexa-histidine at the C-terminal; the resultant DNA construct was expressed in E. coli as an insoluble protein. The denatured scFv was refolded and purified by immobilized metal ion affinity chromatography (12 mg/l with a molecular weight of 27 kDa). Hep27scFv exhibited a tumoricidal activity against the HCC-S102 cell as its parental antibody (Hep27 Mab).Conclusion
This scFv may be a potential candidate for a targeting agent in HCC immunodiagnosis or immunotherapy. 相似文献3.
Ming-Derg Lai Meng-Chi Yen Chiu-Mei Lin Cheng-Fen Tu Chun-Chin Wang Pei-Shan Lin Huei-Jiun Yang Chi-Chen Lin 《Genetic vaccines and therapy》2009,7(1):1-13
Background
Tyrosine kinase inhibitor gefitinib is effective against lung cancer cells carrying mutant epidermal growth factor receptor (EGFR); however, it is not effective against lung cancer carrying normal EGFR. The breaking of immune tolerance against self epidermal growth factor receptor with active immunization may be a useful approach for the treatment of EGFR-positive lung tumors. Xenogeneic EGFR gene was demonstrated to induce antigen-specific immune response against EGFR-expressing tumor with intramuscular administration.Methods
In order to enhance the therapeutic effect of xenogeneic EGFR DNA vaccine, the efficacy of altering routes of administration and formulation of plasmid DNA was evaluated on the mouse lung tumor (LL2) naturally overexpressing endogenous EGFR in C57B6 mice. Three different combination forms were studied, including (1) intramuscular administration of non-coating DNA vaccine, (2) gene gun administration of DNA vaccine coated on gold particles, and (3) gene gun administration of non-coating DNA vaccine. LL2-tumor bearing C57B6 mice were immunized four times at weekly intervals with EGFR DNA vaccine.Results
The results indicated that gene gun administration of non-coating xenogenic EGFR DNA vaccine generated the strongest cytotoxicty T lymphocyte activity and best antitumor effects. CD8(+) T cells were essential for anti-tumor immunityas indicated by depletion of lymphocytes in vivo.Conclusion
Thus, our data demonstrate that administration of non-coating xenogenic EGFR DNA vaccine by gene gun may be the preferred method for treating EGFR-positive lung tumor in the future. 相似文献4.
Combined Erlotinib and PF‐03084014 treatment contributes to synthetic lethality in head and neck squamous cell carcinoma 下载免费PDF全文
Yang Zheng Zhao Wang Xu Ding Yibo Dong Wei Zhang Wei Zhang Yi Zhong Wenyi Gu Yunong Wu Xiaomeng Song 《Cell proliferation》2018,51(3)
Objectives
Head and neck squamous cell carcinoma (HNSCC) is characterized by high mortality and low survival rates. As an epidermal growth factor receptor (EGFR) inhibitor, Erlotinib has been approved for treatment of various tumours. PF‐03084014 is a selective inhibitor of Notch1 signalling. This study aimed to explore new approaches for simultaneously targeting EGFR and Notch1 signalling to attenuate tumour growth and improve survival.Materials and methods
Cell proliferation was determined by CCK‐8 assay and Flow cytometry. Cell invasive ability was determined by Transwell assay. Western blot was used to test the expression of Notch1 and EGFR pathway. Cleaved Caspase‐3 staining and TUNEL assay were used to verify the apoptosis through combined treatment.Results
We first confirmed proliferative inhibition and cell death in HNSCC with combined Erlotinib and PF‐03084014 treatment. Moreover, we found PF‐03084014 reversed the increased invasion induced by Erlotinib. In a preclinical therapeutic drug trial in vivo, combined treatment effectively abrogated tumour growth. Most importantly, one mechanism was found that PF‐03084014 alone could activate the PI3K/AKT signalling, the downstream of EGFR signalling, and Erlotinib alone could activate the intracellular domain of Notch1 (NICD), while combined treatment of PF‐03084014 and Erlotinib suppressed the HNSCC growth.Conclusions
These results suggested that concomitant inhibition of the Notch1 and EGFR pathways represented a rational strategy for promoting apoptosis in HNSCC and overcoming treatment resistance.5.
Maria Sandbacka Mervi Halttunen Varpu Jokimaa Kristiina Aittomäki Hannele Laivuori 《Orphanet journal of rare diseases》2011,6(1):1-5
Background
Thymic epithelial tumours (thymoma and carcinoma) are exceptionally rare in children. We describe a national multicentre series with a view to illustrating their clinical behaviour and the results of treatment.Methods
From January 2000 all patients under 18 years of age diagnosed with "rare paediatric tumours" were centrally registered by the Italian centres participating in the TREP project (Tumori Rari in Età Pediatrica [Rare Tumours in Paediatric Age]). The clinical data of children with a thymic epithelial tumour registered as at December 2009 were analyzed for the purposes of the present study.Results
Our series comprised 4 patients with thymoma and 5 with carcinoma (4 males, 5 females; median age 12.4 years). The tumour masses were mainly large, exceeding 5 cm in largest diameter. Based on the Masaoka staging system, 3 patients were stage I, 1 was stage III, 1 was stage IVa and 4 were stage IVb. All 3 patients with stage I thymoma underwent complete tumour resection at diagnosis and were alive 22, 35 and 93 months after surgery. One patient with a thymoma metastasizing to the kidneys died rapidly due to respiratory failure. Thymic carcinomas were much more aggressive, infiltrating nearby organs (in 4 cases) and regional nodes (in 5), and spreading to the bone (in 3) and liver (in 1). All patients received multidrug chemotherapy (platinum derivatives + etoposide or other drugs) with evidence of tumour reduction in 3 cases. Two patients underwent partial tumour resection (after chemo-radiotherapy in one case) and 4 patients were given radiotherapy (45-54 Gy). All patients died of their disease.Conclusions
Children with thymomas completely resected at diagnosis have an excellent prognosis while thymic carcinomas behave aggressively and carry a poor prognosis despite multimodal treatment. 相似文献6.
Zoran Jeknić Stevan Jeknić Slađana Jevremović Angelina Subotić Tony H. H. Chen 《Plant cell reports》2014,33(8):1307-1321
Key message
Genetic modulation of the carotenogenesis in I. germanica ‘Fire Bride’ by ectopic expression of a crtB gene causes several flower parts to develop novel orange and pink colors.Abstract
Flower color in tall bearded irises (Iris germanica L.) is determined by two distinct biochemical pathways; the carotenoid pathway, which imparts yellow, orange and pink hues and the anthocyanin pathway, which produces blue, violet and maroon flowers. Red-flowered I. germanica do not exist in nature and conventional breeding methods have thus far failed to produce them. With a goal of developing iris cultivars with red flowers, we transformed a pink iris I. germanica, ‘Fire Bride’, with a bacterial phytoene synthase gene (crtB) from Pantoea agglomerans under the control of the promoter region of a gene for capsanthin–capsorubin synthase from Lilium lancifolium (Llccs). This approach aimed to increase the flux of metabolites into the carotenoid biosynthetic pathway and lead to elevated levels of lycopene and darker pink or red flowers. Iris callus tissue ectopically expressing the crtB gene exhibited a color change from yellow to pink-orange and red, due to accumulation of lycopene. Transgenic iris plants, regenerated from the crtB-transgenic calli, showed prominent color changes in the ovaries (green to orange), flower stalk (green to orange), and anthers (white to pink), while the standards and falls showed no significant differences in color when compared to control plants. HPLC and UHPLC analysis confirmed that the color changes were primarily due to the accumulation of lycopene. In this study, we showed that ectopic expression of a crtB can be used to successfully alter the color of certain flower parts in I. germanica ‘Fire Bride’ and produce new flower traits. 相似文献7.
8.
Eva Jordan Laila Al-Halabi Thomas Schirrmann Michael Hust Stefan Dübel 《Microbial cell factories》2007,6(1):1-7
Background
The demand on antigen binding reagents in research, diagnostics and therapy raises questions for novel antibody formats as well as appropriate production systems. Recently, the novel single chain Fab (scFab) antibody format combining properties of single chain Fv (scFv) and Fab fragments was produced in the Gram-negative bacterium Escherichia coli. In this study we evaluated the Gram-positive bacterium Bacillus megaterium for the recombinant production of scFab and scFvs in comparison to E. coli.Results
The lysozyme specific D1.3 scFab was produced in B. megaterium and E. coli. The total yield of the scFab after purification obtained from the periplasmic fraction and culture supernatant of E. coli was slightly higher than that obtained from culture supernatant of B. megaterium. However, the yield of functional scFab determined by analyzing the antigen binding activity was equally in both production systems. Furthermore, a scFv fragment with specificity for the human C reactive protein was produced in B. megaterium. The total yield of the anti-CRP scFv produced in B. megaterium was slightly lower compared to E. coli, whereas the specific activity of the purified scFvs produced in B. megaterium was higher compared to E. coli.Conclusion
B. megaterium allows the secretory production of antibody fragments including the novel scFab antibody format. The yield and quality of functional antibody fragment is comparable to the periplasmic production in E. coli. 相似文献9.
Lingbo Zhang Kezheng Wang Falin Zhao Weiping Hu Junjie Chen Gregory M. Lanza Baozhong Shen Bin Zhang 《PloS one》2012,7(9)
Background
The effectiveness of near-infrared imaging (NIR) interrogation of epidermal growth factor receptor (EGFR) expression as a sensitive biomarker of oral squamous cell carcinoma (OSCC) response to arsenic trioxide therapy was studied in mice.Material and Methods
A431 OSCC in vitro were exposed to 0 µM, 0.5 µM, 2.5 µM, or 5 µM of As2O3 for 0 h, 24 h, 48 h and 72 h. Confocal microscopy and flow cytometry confirmed EGFR expression and demonstrated a sensitivity dose-related signal decline with As2O3 treatment. Next, mice with pharynx-implanted A431 cells received As2O3 i.p. every 48 h at 0.0, 0.5, 2.5, or 5 mg/kg/day (n = 6/group) from day 0 to 10. An intravenous NIR probe, EGF-Cy5.5, was injected at baseline and on days 4, 8, and 12 for dynamic NIR imaging. Tumor volume and body weights were measured three times weekly.Results
In vitro, A431 EGFR expression was well appreciated in the controls and decreased (p<0.05) with increasing As2O3 dose and treatment duration. In vivo EGFR NIR tumor signal intensity decreased (p<0.05) in As2O3 treated groups versus controls from days 4 to 12, consistent with increasing dosage. Tumor volume diminished in a dose-related manner while body weight was unaffected. Immunohistochemical staining of excised tumors confirmed that EGFR expression was reduced by As2O3 treatment in a dose responsive pattern.Conclusion
This study demonstrates for the first time that OSCC can be interrogated in vivo by NIR molecular imaging of the EGFR and that this biomarker is effective for the longitudinal assessment of OSCC response to As2O3 treatment. 相似文献10.
F Finetti E Terzuoli E Bocci I Coletta L Polenzani G Mangano MA Alisi N Cazzolla A Giachetti M Ziche S Donnini 《PloS one》2012,7(7):e40576
Background
Blockade of Prostaglandin (PG) E2 production via deletion of microsomal Prostaglandin E synthase-1 (mPGES-1) gene reduces tumor cell proliferation in vitro and in vivo on xenograft tumors. So far the therapeutic potential of the pharmacological inhibition of mPGES-1 has not been elucidated. PGE2 promotes epithelial tumor progression via multiple signaling pathways including the epidermal growth factor receptor (EGFR) signaling pathway.Methodology/Principal Findings
Here we evaluated the antitumor activity of AF3485, a compound of a novel family of human mPGES-1 inhibitors, in vitro and in vivo, in mice bearing human A431 xenografts overexpressing EGFR. Treatment of the human cell line A431 with interleukin-1beta (IL-1β) increased mPGES-1 expression, PGE2 production and induced EGFR phosphorylation, and vascular endothelial growth factor (VEGF) and fibroblast growth factor-2 (FGF-2) expression. AF3485 reduced PGE2 production, both in quiescent and in cells stimulated by IL-1β. AF3485 abolished IL-1β-induced activation of the EGFR, decreasing VEGF and FGF-2 expression, and tumor-mediated endothelial tube formation. In vivo, in A431 xenograft, AF3485, administered sub-chronically, decreased tumor growth, an effect related to inhibition of EGFR signalling, and to tumor microvessel rarefaction. In fact, we observed a decrease of EGFR phosphorylation, and VEGF and FGF-2 expression in tumours explanted from treated mice.Conclusion
Our work demonstrates that the pharmacological inhibition of mPGES-1 reduces squamous carcinoma growth by suppressing PGE2 mediated-EGFR signalling and by impairing tumor associated angiogenesis. These results underscore the potential of mPGES-1 inhibitors as agents capable of controlling tumor growth. 相似文献11.
Chih-Yueh Liu Chang-Ching Weng Chih-Hsiang Lin Chiou-Ying Yang Kwok-Kong Tony Mong Yaw-Kuen Li 《Biotechnology letters》2017,39(3):407-413
Objectives
A Neissaria bacterial pilus sugar, bacillosamine, was synthesized and, for the first time, used as a probe to screen a single-chain variable fragment (scFv).Results
Four Neisseria, Neisseria gonorrhoeae, Neisseria meningitidis, Neisseria sicca and Neisseria subflava, and two negative controls, Streptococcus pneumoniae and Escherichia coli, were tested through ELISA, immunostaining and gold nanoparticle immunological assay. All results indicated that the selected scFv is feasible for the specific detection of Neisseria species via the recognition of bacillosamine.Conclusions
The recombinant scFv could detect Neisseria strains at 106 CFU/ml.12.
Sally Nordlund Andersen Dorte Bodin Dresbøll Kristian Thorup-Kristensen 《Plant and Soil》2014,378(1-2):59-72
Aims
To investigate root competition in a legume/non-legume mixture, and how root growth of the legume is affected by the competition at increasing nitrogen (N) supply.Methods
Red beet (Beta vulgaris L.) and red clover (Trifolium pratense L.) were grown in transparent rhizotron tubes either in mixture or as sole crop at N supplies of 0, 75 or 150 kg ha-1. The root growth was evaluated by the root intensity on the rhizotron surface, root depth and plant uptake of 15N injected into the soil at the deeper part of the red clover root system.Results
Competition with red beet decreased clover root intensity in deeper soil layers compared to clover grown as sole crop. The difference between clover in sole crop and in mixture was not evident at the highest N supply because the root growth of clover in sole crop appeared to be lowered at high N level. Increased N supply increased the dominance of red beet, but generally did not alter the root growth and distribution of the two species grown in mixture.Conclusions
Clover root growth and rooting depth were inhibited by competition with red beet but the effect was not enhanced by increased N supply; hence the increased dominance of red beet at higher N level was likely due to its increased growth and competitiveness for other soil resources. 相似文献13.
Luigi Boni Angelo Benevento Gianlorenzo Dionigi Francesca Rovera Mario Diurni Renzo Dionigi 《World journal of surgical oncology》2005,3(1):1-7
Background
Parathyroid carcinoma is a rare malignancy, with an incidence of 0.5 to 4% of all cases of primary hyperparathyroidism. Surgery is the only curative treatment.Case presentation
We report the case of a 66-year-old man referred for a large suspicious substernal goitre associated with severe hypercalcemia due to hyperparathyroidism. After normalization of serum calcium levels, patient underwent surgery. The voluminous cervicomediastinal firm mass could not be removed through the cervical incision; therefore a cervicothoracic approach was employed. Histopathology revealed a giant parathyroid cancer of 450 grams. A review of the literature was also undertaken to summarize the current treatment approaches for this rare malignancy.Conclusion
Parathyroid cancer is usually not recognized either preoperatively or intra-operatively. En bloc resection of the tumour with the adjacent tissue is the treatment of choice and it is very important to avoid the rupture of the capsule during operation. Neither tumour size, nor the lymph node status appears to play a role in prognosis. The management of parathyroid carcinoma is a challenge even for experienced surgeons. 相似文献14.
15.
Witlox MA Van Beusechem VW Grill J Haisma HJ Schaap G Bras J Van Diest P De Gast A Curiel DT Pinedo HM Gerritsen WR Wuisman PI 《The journal of gene medicine》2002,4(5):510-516
Background
Despite improvements in the treatment of osteosarcoma (OS) there are still too many patients who cannot benefit from current treatment modalities. Therefore, new therapeutic approaches are warranted. Here we explore the efficacy of targeted adenoviral based suicide gene therapy.Methods and results
Immunohistochemistry and FACS analysis detected low or absent expression levels of the primary adenovirus receptor CAR on human primary OS and human OS cell lines. These results predict a low infection efficiency and thus a reduced therapeutic effect. Targeting the adenoviruses to another receptor highly expressed on OS could overcome this limitation. We found epidermal growth factor receptor (EGFR) to be widely expressed on primary OS. Immunohistochemistry on primary tumor samples and FACS analysis on primary short‐term cultures and four OS cell lines showed that EGFR was consistently expressed. The recombinant bispecific single‐chain antibody 425‐s11 redirects adenoviral vectors towards the EGFR. Adenovirus transduction experiments in the presence or absence of 425‐s11 showed significantly enhanced gene transfer with the targeted adenoviral vector compared with the native vector (OS cell lines 2.5 to 7.2 times enhanced gene transfer and OS primary short term cultures 1.7 to 10 times enhanced gene transfer). On this basis, targeted suicide gene therapy experiments with AdCMVHSV‐TK in combination with ganciclovir were performed. These experiments demonstrated up to 3.5‐fold enhanced kill of OS cell lines and primary short‐term cultures by the EGFR targeted vector.Conclusions
Suicide gene therapy with adenovirus targeted towards EGFR may have favorable therapeutic characteristics for future gene therapy applications in OS. Copyright © 2002 John Wiley & Sons, Ltd.16.
17.
18.
Aims
The aim of this study was to examine the effect of plant species differing in functional and phylogenetic traits on the decomposition processes of leaf litter in a grassland of Japanese pampas grass (Miscanthus sinensis) and adjacent forests of Japanese red pine (Pinus densiflora) and Japanese oak (Quercus crispula), representing sequential stages of secondary succession.Methods
The litterbag experiments were carried out for 3 years in a temperate region of central Japan.Results
The decomposition constant (Olson’s k) was 0.49, 0.39, and 0.56/year for grass, pine, and oak, respectively. Nitrogen mass decreased in grass leaf litter during decomposition, whereas the absolute amount of nitrogen increased in leaf litter of pine and oak during the first year. Holocellulose in grass leaf litter decomposed selectively over acid-unhydrolyzable residues more markedly than in leaf litter of pine and oak. 13C nuclear magnetic resonance analysis also revealed a decrease in the relative area of O-alkyl-C in grass.Conclusions
The different decomposition among the three litter species implied that the secondary succession from grassland to pine forest and from pine to oak forests could decrease and increase, respectively, the rate of accumulation and turnover of organic materials and N in soils. 相似文献19.
Jana Zimmermann Isolde Saalbach Doreen Jahn Martin Giersberg Sigrun Haehnel Julia Wedel Jeanette Macek Karen Zoufal Gerhard Glünder Dieter Falkenburg Sergey M Kipriyanov 《BMC biotechnology》2009,9(1):1-22
Background
Coccidiosis caused by protozoans of genus Eimeria is a chicken parasitic disease of great economical importance. Conventional disease control strategies depend on vaccination and prophylactic use of anticoccidial drugs. Alternative solution to prevent and treat coccidiosis could be provided by passive immunization using orally delivered neutralizing antibodies. We investigated the possibility to mitigate the parasitic infection by feeding poultry with antibody expressing transgenic crop seeds.Results
Using the phage display antibody library, we generated a panel of anti-Eimeria scFv antibody fragments with high sporozoite-neutralizing activity. These antibodies were expressed either transiently in agrobacteria-infiltrated tobacco leaves or stably in seeds of transgenic pea plants. Comparison of the scFv antibodies purified either from tobacco leaves or from the pea seeds demonstrated no difference in their antigen-binding activity and molecular form compositions. Force-feeding experiments demonstrated that oral delivery of flour prepared from the transgenic pea seeds had higher parasite neutralizing activity in vivo than the purified antibody fragments isolated from tobacco. The pea seed content was found to protect antibodies against degradation by gastrointestinal proteases (>100-fold gain in stability). Ad libitum feeding of chickens demonstrated that the transgenic seeds were well consumed and not shunned. Furthermore, feeding poultry with shred prepared from the antibody expressing pea seeds led to significant mitigation of infection caused both by high and low challenge doses of Eimeria oocysts.Conclusion
The results suggest that our strategy offers a general approach to control parasitic infections in production animals using cost-effective antibody expression in crop seeds affordable for the animal health market. 相似文献20.
Sara A Collins Alexandra Buhles Martina F Scallan Patrick T Harrison Deirdre M O'Hanlon Gerald C O'Sullivan Mark Tangney 《Genetic vaccines and therapy》2010,8(1):1-13