Advances and Applications in Animal Models of Neuroblastoma / 实验动物与比较医学

Neuroblastoma (NB) is one of the most common malignant solid tumors in children, ranks fourth in the incidence of pediatric tumors, and accounts for 15% of pediatric tumor deaths in children in China. Despite the development of new treatment options, the prognosis for high-risk patients is still poor. An animal model that can replicate the tumorigenesis of NB is an important tool for the prevention and treatment of NB. However, there are currently no animal models that can simulate all features of human NB. To provide a reference for the construction of animal models and treatment of NB, this article introduced several animal models of NB that have been extensively researched: the mouse, chick embryo chorioallantoic membrane, and zebrafish models. At the same time, it elaborated on the species, construction methods, characteristics, advantages and disadvantages, and research progress in NB.

A short-term chick embryo in vivo xenograft model to study retinoblastoma cancer stem cells

Purpose: Cancer stem cells (CSCs) reported in various tumors play a crucial role in tumorigenesis and metastasis of retinoblastoma (Rb). Following the efforts to reduce, replace, and refine the use of mammalian models, we aimed to establish a short?term xenograft for Rb to evaluate the CSC properties of CD133? Rb Y79 cells, using the well?established chick embryo chorioallantoic membrane (CE?CAM) assay. Methods: Y79 cells were cultured, labeled with two different dyes (CM?Dil Y79 and enhanced green fluorescent protein (eGFP)) and sorted for CD133? and CD133 + subsets. Two million cells from each of the labeled groups were transplanted onto the abraded CAM on embryonic day 7 (E7). On E14, the tumor nodule formation on CAM and spontaneous metastasis to the embryos were evaluated by confocal microscopy, in vivo imaging, and histology. Results: Y79 cells formed pink–white raised perivascular nodules with feeder vessels on the CAM with both the types of labeled CD133? cells. CD133? cells, when compared to CD133 + cells, demonstrated significantly larger tumor volume (40.45 ± 7.744 mm3 vs 3.478 ± 0.69 mm3, P = 0.0014) and higher fluorescence intensity (CM?Dil: AUF = 6.37 × 107 ± 7.7 × 106 vs 1.08 × 107 ± 1.6 × 106; P < 0.0001; eGFP: AUF = 13.94 × 104 ± 2.54 × 104 vs AUF = 1.39 × 104 ± 0.4 × 104; P = 0.0003). The metastatic potential of CD133? cells was also observed to be higher as noted by in vivo imaging and histopathology. Conclusion: This study highlights that CE?CAM is a feasible alternative nonmammalian model for evaluating tumorigenicity and metastatic potential of Y79 CSCs. Increased tumorigenicity and metastatic potential of CD133? subset of tumor cells substantiate their CSC properties

Effect of draxin knockdown on the projection of 23C10-positive neural fibers in the embryonic chick hindbrain / 解剖学报

[Abstract] Objective To investigate the effects of the downregulation of draxin expression on the projection characteristics of 23C10-positive neural fibers in the chick embryonic hindbrain. Methods The vitro incubation of HH stages 21-22 chick embryonic hindbrain biopsy with alkaline phosphatase (ALP) protein was used as control group. The incubation of HH stages 21-22 chick embryonic hindbrain biopsy with draxin-ALP fusion protein was used as experimental group. The number of embryonic hindbrain for each group was 10. To detect whether 23C10-positive neural fibers could directly bind to draxin protein or not;In ovo electroporation using empty vector in the chick embryonic hindbrain was used as control group. In ovo electroporation with small interfering RNA(siRNA) expressing vector for reducing draxin expression in the chick embryonic hindbrain was used as experimental group. The number of embryonic hindbrain for each group was 18. The effect of the down-regulation of draxin expression and the change of projection characteristics of 23C10-positive neural fibers were observed to check whether the down-regulation of draxin expression would affect the distribution of 23C10-positive fibers. Results Most portion of draxin protein could overlap with 23C10-positive neural fibers in HH stages 21-22 chick embryonic hindbrain biopsies; After expression of the siRNA plasmid against draxin by electroporation, the expression level of draxin protein was significantly reduced, and the distribution of 23C10-positive fibers was scattered in the dorsal hindbrain on the electroporated side at HH stages 25-26 of chick embryos (P < 0. 05) . Conclusion Draxin protein may directly bind to 23C10-positive fibers in hindbrain, and it plays an important regulatory role in the fasciculation of 23C10-positive fibers during chick embryonic development.

Pharmacologically targeting molecular motor promotes mitochondrial fission for anti-cancer

Mitochondrial shape rapidly changes by dynamic balance of fusion and fission to adjust to constantly changing energy demands of cancer cells. Mitochondrial dynamics balance is exactly regulated by molecular motor consisted of myosin and actin cytoskeleton proteins. Thus, targeting myosin-actin molecular motor is considered as a promising strategy for anti-cancer. In this study, we performed a proof-of-concept study with a natural-derived small-molecule J13 to test the feasibility of anti-cancer therapeutics

Anticataractogenic effect of betaine in chick embryo hydrocortisone-induced cataract model

Background & objectives: Cataract is one of the leading causes of blindness in the world. The aim of the present study was to investigate anticataractogenic effect of betaine in chick embryo hydrocortisone (HC)-induced cataract model. Methods: The study included 60 fertilized eggs divided into six groups each having 10 eggs: one group treated with only HC (HC group); three treated with both HC and different doses of betaine (HC/B 1.00, HC/B 0.50 and HC/B 0.25 groups) and two non-HC groups treated with only phosphate-buffered saline (PBS group) or betaine (B group). After the injections, lenses of the embryos were removed and classified into five stages according to the lens opacification. The amounts of reduced glutathione (GSH) in the removed lenses were measured. Results: All the lenses in non-HC-treated groups were clear, whereas in the HC-treated group, 90 per cent of the lenses had cataract (stages 4 and 5). The mean score of lens opacity was significantly lower in all HC/B groups compared to HC group (2.4-3.5 vs. 4.4, P<0.05). Among HC/B groups, the HC/B 0.25 group had significantly lower mean score of lens opacity compared to remaining HC/B groups treated with higher doses of betaine. In addition, the mean reduced GSH level was significantly higher in HC/B 0.25 group compared to HC, HC/B 1.00 and HC/B 0.50 groups (P<0.001). Interpretation & conclusions: The present results show beneficial anti-cataract and anti-oxidant effects of 0.25 ?mol/egg betaine on HC-induced cataract in the chick embryo.

The novel model: Experimental optical coherence tomography–guided anterior segment imaging chick embryo model

Purpose: The aim of this study was to present an experimental optical coherence tomography (OCT)–guided anterior segment (AS) imaging chick embryo model. Through this model, we aimed to reveal similarities and differences between human cornea, AS tissues, and chick embryo tissues by quantitative image analysis. Methods: Ex vivo, the chick embryos' globes were determined by detailed AS camera of spectral-domain (SD)-OCT in 10 fertilized specific pathogen-free eggs on the 20th day. Quantitative image analysis of anterior chamber tissues was performed with SD-OCT in detail. After imaging, cross sections of the chick embryo globes containing cornea with anterior chamber were histologically examined and compared with human tissues. The similarities of our model with data in the human cornea and AS studies in the literature were compared. Results: SD-OCT imaging was able to successfully delineate the AS tissues of chick embryos such as the cornea, iris, lens, pupil, conjunctiva, ciliary body, anterior chamber, and lens. Quantitative semi-automated measurements showed the following: mean central corneal thickness: 213.4 ± 7.05 ?m (197–223 ?m), mean anterior chamber depth: 878.9 ± 41.74 (804–919 ?m), mean anterior chamber area: 2.43 ± 0.16 mm2 (2.17–2.73 mm2), mean corneoscleral junction (limbal) thickness: 322.8 ± 20.05 ?m (289–360 ?m), and mean iris thickness: 230.4 ± 13.27 ?m (203–245 ?m). In addition, detailed histological comparisons of the AS tissues with human tissues were evaluated to be very similar. Conclusion: In conclusion, this chick embryo model mimics human tissues and it can be considered as a platform for the study of teratogen-induced malformations and AS dysgenesis during gestation of AS tissues. In addition, this study demonstrates the feasibility of SD-OCT in the quantitative assessment of AS structures in chick embryo model.

In vitro study of morphological changes of the cultured otocyst isolated from the chick embryo / Estudio in vitro de los cambios morfológicos del otocisto cultivado aislado del embrión de pollo

The aim of this study was to observe morphological changes of the cultured otocysts isolated from various stages of the chick embryo. Isolated otocysts were dissected from embryonic day, E2.5-4.5 of incubation (HH stage 16-26) according to stages of developing inner ear. Morphology of the chick otocyst exhibited an ovoid shape. The width and height of the otocyst were 0.2 mm and 0.3 mm, respectively. Elongation of a tube-like structure, the endolymphatic duct, was found at the dorsal aspect of the otocyst. The cultured otocyst is lined by the otic epithelium and surrounding periotic mesenchymal cells started to migrate outwards the lateral aspect of such epithelium. Notably, the acoustic-vestibular ganglion (AVG) was observed at the ventrolateral aspect of the otocyst. Appearance of AVG in vitro can be applied for studying chemical-induced ototoxicity and sensorineural hearing loss. It was concluded that the organ-cultured otocyst of the chick embryo could be used as a model to study sensory organ development of avian inner ear.

El objetivo de este estudio fue observar los cambios morfológicos de otocistos cultivados aislados en las diversas etapas del desarrollo del embrión de pollo. Otocistos aislados fueron obtenidos de embriones día, E2.5-4.5 de incubación (HH etapa 16-26) de acuerdo a las etapas de desarrollo del oído interno. El otocisto de pollo presentó una morfología ovoide. El ancho y la altura del otocisto fue de 0,2 mm y 0,3 mm, respectivamente. En la cara dorsal del otocisto se visualizó el alargamiento de una estructura similar a un tubo, el conducto endolinfático. El otocisto cultivado está revestido por epitelio ótico y células mesenquimatosas perióticas que comienzan a migrar hacia el exterior de la cara lateral en búsqueda del epitelio. En particular, el ganglio acústico-vestibular (GAV) fue observado en la parte ventrolateral del otocisto. La aparición de GAV in vitro puede ser aplicado para el estudio de la ototoxicidad inducida por productos químicos y la pérdida de audición neurosensorial. Se concluyó que el otocisto cultivado de embrión de pollo podría ser utilizado como un modelo para estudiar el desarrollo de órganos sensoriales del oído interno aviar.

Effect of angiogenesis on Solanine and VEGF antibody in chicken embryo transplantation model of human colon cancer cells / 重庆医学

Objective To establish model of the chicken embryo transplantation of human colon cancer cells ,and investigate the effect of Solanine、VEGF antibody and Solanine combined with VEGF antibody on human colon cancer cells induce tumor angio‐genesis and tumor proliferation .Methods The model of the chicken embryo transplantation of human colon cancer HT‐29 cells were divided into three experimental group and control group .We added to the chick embryo chorioallantoic membrane with Sola‐nine、VEGF antibody and Solanine+ VEGF antibody mixture ,PBS was added to the control group .Then we analysed picture through the stereomicroscope and IPP 6 .0 image analysis software ,using immunohistochemistry envision method to detect of CD34 antigen and ki‐67 antigen ,and observing effect of Solanine group ,VEGF antibody group ,Solanine+ VEGF antibody group and the effect on the tumor angiogenesis and tumor proliferation .Results The tumor angiogenesis ,CD34 antigen and ki‐67 antigen of Sola‐nine+VEGF antibody group were significantly better than those of VEGF antibody group and Solanine group(P<0 .01);VEGF antibody group had statistical significant difference with Solanine group(P<0 .01);the effect of other three groups were better than that of the control group(P<0 .01) .Conclusion Solanine、VEGF antibody and Solanine combined with VEGF antibody could in‐hibit tumor angiogenesis and tumor proliferation of human colon cancer cell line HT‐29 to induce .It provides a new way for anti‐an‐giogenes .

Innervation of the chick embryo cornea during development / 中华实验眼科杂志

Background To understand the distribution and development of corneal nerve in animal or human has an important significance for clinical and basic research of corneal diseases.At present,some studies on cornea nerve development and location have been performed.However,the quantified study on innervation and distribution of corneal nerve fibers as embryonic development has not been reported.Objective This study attempted to understand the distribution of corneal nerve fibers in the development of chick embryo,and to evaluate the changes of the length and density of corneal nerve fibers with aging of chick embryo.Methods Whole chick corneas with limbus were obtained from chick embryo aged 6-20 days (E6-E20),and corneal nerve fiber was labeled using immunofluorescence technique by anti-neuron-specific β-Ⅲ tubulin antibody.The corneas were radially cut into 4 parts,and the integrate corneal flat mounts were prepared with the upward epithelium and mounting with anti-fade fluorescent quenching buffer glycerin containing DAPI.Fluorescence microscope was used to capture the nerve fiber images in cornea,and cornea area and the number of nerve fiber bundles were exhibited by using Photoshop CS4.Cornea nerve fiber density and total length were measured by Imaris x64 7.4.2 software.Results Total cornea flat mounts showed that the nerve bundles grew from temporal scleral forward cornea limbus at E6-E8,and the nerve fibers formed the ring surrounding by limbus during E9-E10.Then the fibers extended forward the central cornea in E11 to E15 and developed into nerve fiber plexus on the whole cornea in E16 to E20.During the period of E6-E20,the corneal surface area,the length and density of corneal nerve fibers were gradually increased with the aging of chick embryo,showing statistically significant differences among different time points (F =127.007,227.051,67.748,all at P＜0.01).The increase of the corneal area of the chick embryo presented a strong positive correlation with the extending of length of the corneal nerve fiber (r =0.863,P＜0.01).Chick corneal nerve fiber bundle appeared at E13,with a number of (59.00 ± 1.14)/mm2 and then increased to a peak of (576.75 ±29.16)/mm2 at E 18 and reduced to (299.67± 25.46)/mm2 at E20,with a significant difference among them (F =13.759,P=0.000).Conclusions Corneal nerve starts to develop in E9 of chick embryo,and the corneal surface area,the total length of the corneal nerve fibers and the density rapidly increase concurrently with the development of chick embryo.

Effect of sorafenib combined with thalidomide on angiogenesis in chick chorioallantoic membrane / 临床肝胆病杂志

ObjectiveTo investigate the effect of sorafenib and/or thalidomide on angiogenesis in chick chorioallantoic membrane (CAM). MethodsWhite eggs incubated for 7 days were used to establish a CAM model. The model eggs were randomly divided blank control group, sorafenib group, thalidomide group, and sorafenib/thalidomide group. After treatment, each egg was incubated for another 2 days. The CAM samples were collected and fixed to take their pictures under a microscope, and the vascular coverage of each sample was calculated. Comparison between these groups was made by analysis of variance, and comparison between each two groups was made by SNK-q test. ResultsThe thalidomide group or sorafenib group had significantly lower vascular coverage than the blank control group (30.2%±2.9% or 26.5%±2.1% vs 38.3%±2.7%, P＜0.05). The sorafenib/thalidomide group had significantly lower vascular coverage than the thalidomide group or sorafenib group (12.6%±1.5% vs 30.2%±2.9% or 26.5%±2.1%, P＜0.05). ConclusionBoth sorafenib and thalidomide have a good anti-angiogenic effect on CAM, but a combination of the two drugs shows better efficacy.

In vitro and in silico antidiabetic activity of pyran ester derivative isolated from Tragia cannabina

Objective: To investigate the in vitro antidiabetic effects of isolated 4-Oxo-4H-pyran-2,6-dicarboxylic acid bis-[6-methyl-heptyl] ester from the chloroform extract of root of Tragia cannabina (T. cannabina) and AMP kinase activation property of the isolated compound.Methods:chromatographed over silica gel 60-120 mesh of column length 100 cm and diameter 3 cm. Elution was carried out with solvents and solvent mixtures of increasing polarities. Then the chloroform extract was used for isolation. In vitro antidiabetic activity was performed with fertile eggs of White Leghorn chicks by induction of diabetes by streptozotocin.Results:The roots of T. cannabina were collected and extracted with ethanol [95% v/v] then formation of hydrogen bond and consuming less binding energy, which is good when compared to orientation of standard drug metformin. In in vitro antidiabetic evaluation by streptozotocin treated chick embryo the administration of isolated compound at a doses of 0.5 mg/egg and 1 mg/egg produced a significant reduction in the blood glucose levels in a dose dependant manner (P<0.01). The blood glucose level of diabetic control was (244.20±12.64) mg/dL, whereas it was (207.40±2.43) mg/dL (P<0.001) for isolated compound 0.5 mg/egg and 174.800±2.410 mg/dL (P<0.001) for 1 mg/ egg of the isolated compound.Conclusions:The significant glucose levels were reduced (P<0.01) after administration of the The isolated pyran ester binds very efficiently within the active pocket of AMPK with the pyran ester isolated from T. cannabina to streptozotocin treated chick embryo.

In vitro and in silico antidiabetic activity of pyran ester derivative isolated from Tragia cannabina

<p><b>OBJECTIVE</b>To investigate the in vitro antidiabetic effects of isolated 4-Oxo-4H-pyran-2,6-dicarboxylic acid bis-[6-methyl-heptyl] ester from the chloroform extract of root of Tragia cannabina (T. cannabina) and AMP kinase activation property of the isolated compound.</p><p><b>METHODS</b>The roots of T. cannabina were collected and extracted with ethanol [95% v/v] then chromatographed over silica gel 60-120 mesh of column length 100 cm and diameter 3 cm. Elution was carried out with solvents and solvent mixtures of increasing polarities. Then the chloroform extract was used for isolation. In vitro antidiabetic activity was performed with fertile eggs of White Leghorn chicks by induction of diabetes by streptozotocin.</p><p><b>RESULTS</b>The isolated pyran ester binds very efficiently within the active pocket of AMPK with the formation of hydrogen bond and consuming less binding energy, which is good when compared to orientation of standard drug metformin. In in vitro antidiabetic evaluation by streptozotocin treated chick embryo the administration of isolated compound at a doses of 0.5 mg/egg and 1 mg/egg produced a significant reduction in the blood glucose levels in a dose dependant manner (P<0.01). The blood glucose level of diabetic control was (244.20±12.64) mg/dL, whereas it was (207.40±2.43) mg/dL (P<0.001) for isolated compound 0.5 mg/egg and 174.800±2.410 mg/dL (P<0.001) for 1 mg/ egg of the isolated compound.</p><p><b>CONCLUSIONS</b>The significant glucose levels were reduced (P<0.01) after administration of the pyran ester isolated from T. cannabina to streptozotocin treated chick embryo.</p>

Behavior of the P1.HTR mastocytoma cell line implanted in the chorioallantoic membrane of chick embryos

The P1.HTR cell line includes highly transfectable cells derived from P815 mastocytoma cells originating from mouse breast tissue. Despite its widespread use in immunogenic studies, no data are available about the behavior of P1.HTR cells in the chick embryo chorioallantoic membrane model. The objective of the present investigation was to study the effects of P1.HTR cells implanted on the chorioallantoic membrane of chick embryos. We inoculated P1.HTR cells into the previously prepared chick embryo chorioallantoic membrane and observed the early and late effects of these cells by stereomicroscopy, histochemistry and immunohistochemistry. A highly angiotropic and angiogenic effect occurred early after inoculation and a tumorigenic potential with the development of mastocytoma keeping well mast cells immunophenotype was detected later during the development. The P1.HTR mastocytoma cell line is a good tool for the development of the chick embryo chorioallantoic membrane mastocytoma model and also for other studies concerning the involvement of blood vessels. The chick embryo chorioallantoic membrane model of mastocytoma retains the mast cell immunophenotype under experimental conditions and could be used as an experimental tool for in vivo preliminary testing of antitumor and antivascular drugs.

The study of the transverse sections of 7-10 somite chick embryos by the scanning electron microscopy and compared with the classical light microscopy.

Objective: To comparatively study the use of scanning electron microscopy and conventional light microscopy of the transverse sections of the 7-10 somite staged chick embryos as model for the study of development of human embryo. Methods: Conventional light microscopy and scanning electron microscopy had been applied as tools for the study of the chick embryos. Results: The results showed that scanning electron micrographs gave the clearer different views of chick embryo transverse sections as compared with the conventional light microscopy. Conclusion: From this study it was clearly shown that the three dimensional images obtained from scanning electron microscope could give comprehensive view of chick embryo specimens. Hence this should be the good alternative way for Embryology study.

Role of N-cadherin in cranial neural crest delamination during chick embryogenesis / 中国病理生理杂志

AIM: To investigate the role of N-cadherin in the delamination of neural crest cells. METHODS: The normal expression of N-cadherin in neural tube was identified using in situ hybridization. The cells with N-cadherin over expression were obtained by transfection of wild-type N-cadherin (wt-N-cadherin) ,and the cells with N-cadherin silencing expression were obtained by transfection of dominant-negative N-cadherin (dn-N-cadherin). The migration of cranial neural crest cells was determined by the technique of immunohistochemistry. RESULTS: Either overexpression or down-regulation of N-cadherin significantly affected the migration of cranial neural crest cells. CONCLUSION: Delamination and migration of the cranial neural crest cells rely on the relative N-cadherin expression in the neural tube during neurulation.

Inorganic lead (Pb)- and mercury (Hg)-induced neuronal cell death involves cytoskeletal reorganization / 한국실험동물학회지

Inorganic lead and mercury are widely spread xenobiotic neurotoxicants threatening public health. The exposure to inorganic lead and mercury results in adverse effects of poisoning including IQ deficit and peripheral neuropathy. Additionally, inorganic neurotoxicants have even more serious impact on earlier stages of embryonic development. This study was therefore initiated in order to determine the cytotoxic effects of lead and mercury in earlier developmental stages of chick embryo. Administration of inorganic lead and mercury into the chick embryo resulted in the prolonged accumulation of inorganics in the neonatal brain, with detrimental cytotoxicity on neuronal cells. Subsequent studies demonstrated that exposure of chick embryo to inorganic lead and mercury resulted in the reorganization of cytoskeletal proteins in the neonatal brain. These results therefore suggest that inorganics-mediated cytoskeletal reorganization of the structural proteins, resulting in neurocytotoxicity, is one of the underlying mechanisms by which inorganics transfer deleterious effects on central nervous system.

Effect of Strychinine, a Glycine Inhibitor, on the Programmed Cell Death of Motoneurons during the Chick Development

In this study, we report that the treatment of strychinine (STR), an inhibitor of glycine receptor, induced premature onset of programmed cell death (PCD) of developing chick motoneurons (MNs). Treatment of STR on E4 chick embryo increased the apoptosis of MN on E5 when MN PCD does not occur normally. On the other hand, treatment of STR from E3 or E5 for 24 hours did not significantly influence the extent of MN PCD, indicating that the STR effect is developmental stage-specific. However, the expression of glycine receptor isoform was low on E3-4, and other glycine receptor antagonists did not exhibit PCD-promoting activity, suggesting that the STR action on PCD is not related to the glycine receptor activation. Identification of the target molecule for STR action may provide novel mechanism how the onset of developmental PCD is regulated.

Portulaca oleracea L. extract ameliorates the cisplatin-induced toxicity in chick embryonic liver.

Cisplatin, a cytotoxic agent used in treating cancer, at high doses induces hepatotoxicity. In this study, we investigated the protective role of aqueous extract of aerial parts of Portulaca oleracea L. (Po) against cisplatin-induced hepatotoxicity in chick embryonic liver. A group of 12 day old chick embryos, acclimatized to laboratory conditions were treated with a single dose of cisplatin (100 µg), while another group received Po extract at different doses (1 and 3 mg) 6 h prior to cisplatin treatment. The biochemical parameters were estimated after 24 and 72 h of incubation. A dose-dependent increase in biochemical parameters, such as alanine transaminase, aspartate transaminase, alkaline phosphatase, lactate dehydrogenase, malondialdehyde levels and a decrease in antioxidant enzymes levels like superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione-s-transferase and reduced glutathione were observed in cisplatin-treated animals, indicating a definite damage to the liver tissue. Pre-treatment with Po extract was found to provide significant protection against cisplatin-induced hepatotoxicity, as evident by the recovered levels of the altered changes in the measured biochemical parameters.

Modulation of cell surface architecture in gastrulating chick embryo in response to altered fibroblast growth factor (FGF) signaling.

Gastrulation is a fundamental process that results in formation of the three germ layers in an embryo. It involves highly coordinated cell migration. Cell to cell communication through cell surface and the surrounding molecular environment governs cell migration. In the present work, cell surface features, which are indicative of the migratory status of a cell, of an early gastrulating chick embryo were studied using scanning electron microscopy. The distinct ultrastructural features of cells located in the various regions of the epiblast are described. Differences in the surface features of cells from distinct embryonic regions indicate differences in their migratory capacities. Further, the dynamic nature of these cell surface features by their response to altered fibroblast growth factor (FGF) signaling, experimentally created by using either excess FGF or inhibition of FGF signaling are demonstrated.

Optimization of recombinant human endostatin refolding / 基础医学与临床

Objective To optimize the conditions for enhancing the refolding of a novel recombinant human(rh)endostatin and test the biological activities of refolded endostatin.Methods The partial purified inclusion bodies of rh-endostatin were dissolved with 6 mol/L guanidine-HCl followed by combination of dilution and dialysis of the dissolved endostatin.The refolded endostatin was then purified by cation-exchange chromatography.The biological activities of purified rh-endostatin were assessed by endostatin-specific monoclonal antibody and chick embryo chorioallantoic membrane assay.Results A 46% refolding yield was achieved after optimizing the refolding conditions.The purified endostatin reacted with specific anti-endostatin monoclonal antibody and showed significant inhibition of angiogenesis in chick embryo ehorioallantoic membrane assay.Conclusion The method of highest refolding yield of human endostatin was developed.This optimized method significantly promotes the application of this novel human endostatin to preclinical and clinical studies.