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1

A novel zebrafish human tumor xenograft model validated for anti-cancer drug screening.  

PubMed

The development of a relatively simple, reliant and cost-effective animal test will greatly facilitate drug development. In this study, our goal was the establishment of a rapid, simple, sensitive and reproducible zebrafish xenograft model for anti-cancer drug screening. We optimized the conditions for the cancer cell xenograft in terms of injected cell numbers, incubation temperature and time. A range of human carcinoma cell types were stained with a fluorescent dye prior to injection into the fish larvae. Subsequent cancer cell dissemination was observed under fluorescent microscopy. Differences in injected cell numbers were reflected in the rate of dissemination from the xenograft site. Paclitaxel, known as a microtubule stabilizer, dose-dependently inhibited cancer cell dissemination in our zebrafish xenograft model. An anti-migratory drug, LY294002 (phosphatidylinositol 3-kinase inhibitor) also decreased the cancer cell dissemination. Chemical modifications to increase cancer drug pharmacokinetics, such as increased solubility (17-DMAG compared to geldanamycin) could also be assessed in our xenograft model. In addition to testing our new model using known anti-cancer drugs, we carried out further validation by screening a tagged triazine library. Two novel anti-cancer drug candidates were discovered. Therefore, our zebrafish xenograft model provides a vertebrate animal system for the rapid screening and pre-clinical testing of novel anti-cancer agents, prior to the requirement for testing in mammals. Our model system should greatly facilitate drug development for cancer therapy because of its speed, simplicity and reproducibility. PMID:22569777

Jung, Da-Woon; Oh, Eun-Sang; Park, Si-Hwan; Chang, Young-Tae; Kim, Cheol-Hee; Choi, Seok-Yong; Williams, Darren R

2012-05-08

2

A novel xenograft model in zebrafish for high-resolution investigating dynamics of neovascularization in tumors.  

PubMed

Tumor neovascularization is a highly complex process including multiple steps. Understanding this process, especially the initial stage, has been limited by the difficulties of real-time visualizing the neovascularization embedded in tumor tissues in living animal models. In the present study, we have established a xenograft model in zebrafish by implanting mammalian tumor cells into the perivitelline space of 48 hours old Tg(Flk1:EGFP) transgenic zebrafish embryos. With this model, we dynamically visualized the process of tumor neovascularization, with unprecedented high-resolution, including new sprouts from the host vessels and the origination from VEGFR2(+) individual endothelial cells. Moreover, we quantified their contributions during the formation of vascular network in tumor. Real-time observations revealed that angiogenic sprouts in tumors preferred to connect each other to form endothelial loops, and more and more endothelial loops accumulated into the irregular and chaotic vascular network. The over-expression of VEGF165 in tumor cells significantly affected the vascularization in xenografts, not only the number and size of neo-vessels but the abnormalities of tumor vascular architecture. The specific inhibitor of VEGFR2, SU5416, significantly inhibited the vascularization and the growth of melanoma xenografts, but had little affects to normal vessels in zebrafish. Thus, this zebrafish/tumor xenograft model not only provides a unique window to investigate the earliest events of tumoral neoangiogenesis, but is sensitive to be used as an experimental platform to rapidly and visually evaluate functions of angiogenic-related genes. Finally, it also offers an efficient and cost-effective means for the rapid evaluation of anti-angiogenic chemicals. PMID:21765912

Zhao, Chengjian; Wang, Xiaofei; Zhao, Yuwei; Li, Zhimian; Lin, Shuo; Wei, Yuquan; Yang, Hanshuo

2011-07-13

3

Neutrophil-mediated experimental metastasis is enhanced by VEGFR inhibition in a zebrafish xenograft model.  

PubMed

Inhibition of VEGF signalling effectively suppresses localized tumour growth but accelerates tumour invasiveness and micrometastasis by unknown mechanisms. To study the dynamic and reciprocal interactions between tumour cells and their microenvironment during these processes, we established a xenograft model by injecting tumour cells into the blood circulation of transparent zebrafish embryos. This reproducibly results in rapid simultaneous formation of a localized tumour and experimental micrometastasis, allowing time-resolved imaging of both processes at single-cell resolution within 1 week. The tumour vasculature was initiated de novo by remodelling of primitive endothelial cells into a functional network. Roles of myeloid cells in critical tumourigenesis steps such as vascularization and invasion were revealed by genetic and pharmaceutical approaches. We discovered that the physiological migration of neutrophils controlled tumour invasion by conditioning the collagen matrix and forming the metastatic niche, as detected by two-photon confocal microscopy and second harmonic generation. Administration of VEGFR inhibitors blocked tumour vascularization and a localized tumour growth but enhanced migration of neutrophils, which in turn promoted tumour invasion and formation of micrometastasis. This demonstrates the in vivo cooperation between VEGF signalling and myeloid cells in metastasis and provides a new mechanism underlying the recent findings that VEGFR targeting can promote tumour invasiveness. PMID:22374800

He, Shuning; Lamers, Gerda Em; Beenakker, Jan-Willem M; Cui, Chao; Ghotra, Veerander Ps; Danen, Erik Hj; Meijer, Annemarie H; Spaink, Herman P; Snaar-Jagalska, B Ewa

2012-07-03

4

Neutrophil-mediated experimental metastasis is enhanced by VEGFR inhibition in a zebrafish xenograft model  

PubMed Central

Inhibition of VEGF signalling effectively suppresses localized tumour growth but accelerates tumour invasiveness and micrometastasis by unknown mechanisms. To study the dynamic and reciprocal interactions between tumour cells and their microenvironment during these processes, we established a xenograft model by injecting tumour cells into the blood circulation of transparent zebrafish embryos. This reproducibly results in rapid simultaneous formation of a localized tumour and experimental micrometastasis, allowing time-resolved imaging of both processes at single-cell resolution within 1 week. The tumour vasculature was initiated de novo by remodelling of primitive endothelial cells into a functional network. Roles of myeloid cells in critical tumourigenesis steps such as vascularization and invasion were revealed by genetic and pharmaceutical approaches. We discovered that the physiological migration of neutrophils controlled tumour invasion by conditioning the collagen matrix and forming the metastatic niche, as detected by two-photon confocal microscopy and second harmonic generation. Administration of VEGFR inhibitors blocked tumour vascularization and a localized tumour growth but enhanced migration of neutrophils, which in turn promoted tumour invasion and formation of micrometastasis. This demonstrates the in vivo cooperation between VEGF signalling and myeloid cells in metastasis and provides a new mechanism underlying the recent findings that VEGFR targeting can promote tumour invasiveness. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

He, Shuning; Lamers, Gerda EM; Beenakker, Jan-Willem M; Cui, Chao; Ghotra, Veerander PS; Danen, Erik HJ; Meijer, Annemarie H; Spaink, Herman P; Snaar-Jagalska, B Ewa

2012-01-01

5

Zebrafish Models of Rhabdomyosarcoma  

PubMed Central

Rhabdomyosarcoma, an aggressive malignant neoplasm that shows features of skeletal muscle, is the most common soft tissue tumor of childhood. In children, the major subtypes are embryonal and alveolar. Although localized disease responds to a multimodal treatment, the prognosis for patients with high-risk features and metastasis remains dismal. Several in vivo models of rhabdomyosarcoma have been developed in mouse, human xenografts, zebrafish and Drosophila to better understand the underlying mechanisms governing malignancy. The findings so far have indicated the potential role of skeletal muscle precursor cells in malignant transformation. To better understand histogenesis and different aspects of tumorigenesis in rhabdomyosarcoma, we have previously developed a robust zebrafish model of kRAS-induced rhabdomyosarcoma, which shares morphologic and immunophenotypic features with the human counterpart. Cross-species mircroarray comparisons confirm that conserved genetic pathways drive rhabdomyosarcoma growth. The ease for ex vivo manipulation allows development of different transgenic and co-injection strategies to induce tumor formation in zebrafish. In contrast to other vertebrate model systems, the tumor onset in zebrafish is short, allowing for efficient study of different tumor processes including tumor growth, self-renewal, and maintenance.

Chen, Eleanor Y.; Langenau, David M.

2013-01-01

6

Immunocompetent xenograft model  

US Patent & Trademark Office Database

The teachings are directed to an immunocompetent xenograft model. The model comprises an immunodeficient animal modified to have a reconstituted immune system, wherein a xenograft is transplanted in the animal and allowed to establish for an establishment period of at least about 10 days. The xenograft simulates a tissue in a subject in need of a treatment. In these embodiments, the reconstituted immune system is created after the establishment period, and is created by administering a total number of T-cells to the animal. The total number of T-cells consists of a preselected number of responsive T-cells, a preselected number of non-responsive T-cells, and a preselected ratio of responsive T-cells to total T-cells. The preselected number of responsive T-cells simulates a number of responsive T-cells in the subject, and the ratio of the number of responsive T-cells to total T-cells ranges from about 1:100,000 to about 30:100,000.

2012-09-11

7

Modeling withdrawal syndrome in zebrafish.  

PubMed

The zebrafish (Danio rerio) is rapidly becoming a popular model species in behavioral neuroscience research. Zebrafish behavior is robustly affected by environmental and pharmacological manipulations, and can be examined using exploration-based paradigms, paralleled by analysis of endocrine (cortisol) stress responses. Discontinuation of various psychotropic drugs evokes withdrawal in both humans and rodents, characterized by increased anxiety. Sensitivity of zebrafish to drugs of abuse has been recently reported in the literature. Here we examine the effects of ethanol, diazepam, morphine and caffeine withdrawal on zebrafish behavior. Overall, discontinuation of ethanol, diazepam and morphine produced anxiogenic-like behavioral or endocrine responses, demonstrating the utility of zebrafish in translational research of withdrawal syndrome. PMID:20006651

Cachat, Jonathan; Canavello, Peter; Elegante, Marco; Bartels, Brett; Hart, Peter; Bergner, Carisa; Egan, Rupert; Duncan, Ashley; Tien, David; Chung, Amanda; Wong, Keith; Goodspeed, Jason; Tan, Julia; Grimes, Chelsea; Elkhayat, Salem; Suciu, Christopher; Rosenberg, Michael; Chung, Kyung Min; Kadri, Ferdous; Roy, Sudipta; Gaikwad, Siddharth; Stewart, Adam; Zapolsky, Ivan; Gilder, Thomas; Mohnot, Sopan; Beeson, Esther; Amri, Hakima; Zukowska, Zofia; Soignier, R Denis; Kalueff, Allan V

2009-12-16

8

Local regulation of human breast xenograft models  

PubMed Central

Breast cancer studies implant human cancer cells under the renal capsule, subcutaneously, or orthotopically and often use estrogen supplementation and immune suppressants (etoposide) in xenograft mouse models. However, cell behavior is significantly impacted by signals from the local microenvironment. Therefore, we investigated how the combinatorial effect of the location of injection and procedural differences affected xenograft characteristics. Patient-derived breast cancer cells were injected into mouse abdominal or thoracic mammary glands ± estrogen and/or etoposide pretreatment. Abdominal xenografts had increased tumor incidence and volume, and decreased latency (P<0.001) compared to thoracic tumors. No statistically significant difference in tumor volume was found in abdominal xenografts treated ± estrogen or etoposide; however, etoposide suppressed tumor volume in thoracic xenografts (P<0.02). The combination of estrogen and etoposide significantly decreased tumor incidence in both sites. In addition, mice treated ± estradiol were injected orthotopically or subcutaneously with well-characterized breast cancer cell lines (MCF7, ZR75-1, MDA MB-231, or MCF10Ca1h). Orthotopic injection increased tumor volume; growth varied with estrogen supplementation. Location also altered methylation status of several breast cancer-related gene promoters. Lastly, vascularization of orthotopic tumors was significantly enhanced compared to subcutaneous tumors. These data suggest that optimal xenograft success occurs with orthotopic abdominal injections and illustrate molecular details of the compelling influence of the local microenvironment on in vivo models.

Fleming, Jodie M.; Miller, Tyler C.; Meyer, Matthew J.; Ginsburg, Erika; Vonderhaar, Barbara K.

2010-01-01

9

Hooked! Modeling human disease in zebrafish  

PubMed Central

Zebrafish have been widely used as a model system for studying developmental processes, but in the last decade, they have also emerged as a valuable system for modeling human disease. The development and function of zebrafish organs are strikingly similar to those of humans, and the ease of creating mutant or transgenic fish has facilitated the generation of disease models. Here, we highlight the use of zebrafish for defining disease pathways and for discovering new therapies.

Santoriello, Cristina; Zon, Leonard I.

2012-01-01

10

A Novel Zebrafish Xenotransplantation Model for Study of Glioma Stem Cell Invasion  

PubMed Central

Invasion and metastasis of solid tumors are the major causes of death in cancer patients. Cancer stem cells (CSCs) constitute a small fraction of tumor cell population, but play a critical role in tumor invasion and metastasis. The xenograft of tumor cells in immunodeficient mice is one of commonly used in vivo models to study the invasion and metastasis of cancer cells. However, this model is time-consuming and labor intensive. Zebrafish (Danio rerio) and their transparent embryos are emerging as a promising xenograft tumor model system for studies of tumor invasion. In this study, we established a tumor invasion model by using zebrafish embryo xenografted with human glioblastoma cell line U87 and its derived cancer stem cells (CSCs). We found that CSCs-enriched from U87 cells spreaded via the vessels within zebrafish embryos and such cells displayed an extremely high level of invasiveness which was associated with the up-regulated MMP-9 by CSCs. The invasion of glioma CSCs (GSCs) in zebrafish embryos was markedly inhibited by an MMP-9 inhibitor. Thus, our zebrafish embryo model is considered a cost-effective approach tostudies of the mechanisms underlying the invasion of CSCs and suitable for high-throughput screening of novel anti-tumor invasion/metastasis agents.

Yang, Xiao-jun; Cui, Wei; Gu, Ai; Xu, Chuan; Yu, Shi-cang; Li, Ting-ting; Cui, You-hong; Zhang, Xia; Bian, Xiu-wu

2013-01-01

11

Zebrafish muscular disease models towards drug discovery.  

PubMed

Background: Zebrafish is an amenable vertebrate model useful for the study of development and genetics. Small molecule screenings in zebrafish have successfully identified several drugs that affect developmental process. Objective: This review covers the basics of zebrafish muscle system such as muscle development and muscle defects. It also reviews the potential use of zebrafish for chemical screening with regards to muscle disorders. Conclusion: During embryogenesis, zebrafish start to coil their body by contracting trunk muscles 17 h postfertilization, indicating that a motor circuit and skeletal muscle are functionally developed at early stages. Mutagenesis screens in zebrafish have identified many motility mutants that display morphological or functional defects in the CNS, clustering defects of acetylcholine receptors at the neuromuscular junctions or pathological defects of muscles. Most of the muscular mutants are useful as animal models of human muscle disease such as muscle dystrophy. As zebrafish live in water, pharmacological drugs are easily assayable during development, and thus zebrafish may be used to determine novel drugs that mitigate muscle disease. PMID:23485083

Hirata, Hiromi

2009-05-01

12

[Application of zebrafish models in drug screening].  

PubMed

Due to its small size, fast external development, transparent embryos, and amenability to genetic analysis, zebrafish has become an ideal vertebrate animal model. In addition to studies in genetics and developmental biology, zebrafish has also been widely used in human disease modeling and drug screening. As a small whole-organism model, zebrafish can be used to comprehensively test and evaluate the activity and side effect of a compound at the same time, fulfilling high content screening. Recently, new zebrafish disease models and screening technologies have been developed. A number of active compounds were identified and most of them have similar functions in mammal models. One compound prostaglandin E2 has been subjected to clinical trial to test if it can promote the growth of umbilical cord blood units after transplantation. Another compound leflunomide has also been approved in clinical trial to cure melanoma in combination with vemurafenib. These findings demonstrate that zebrafish model is appropriate for drug screening. This review summarizes the unique features of zebrafish model and the recent progresses of zebrafish based drug screening. PMID:23017455

Xin, Sheng-Chang; Zhao, Yan-Qiu; Li, Song; Lin, Shuo; Zhong, Han-Bing

2012-09-01

13

Streptococcus-Zebrafish Model of Bacterial Pathogenesis  

PubMed Central

Due to its small size, rapid generation time, powerful genetic systems, and genomic resources, the zebrafish has emerged as an important model of vertebrate development and human disease. Its well-developed adaptive and innate cellular immune systems make the zebrafish an ideal model for the study of infectious diseases. With a natural and important pathogen of fish, Streptococcus iniae, we have established a streptococcus- zebrafish model of bacterial pathogenesis. Following injection into the dorsal muscle, zebrafish developed a lethal infection, with a 50% lethal dose of 103 CFU, and died within 2 to 3 days. The pathogenesis of infection resembled that of S. iniae in farmed fish populations and that of several important human streptococcal diseases and was characterized by an initial focal necrotic lesion that rapidly progressed to invasion of the pathogen into all major organ systems, including the brain. Zebrafish were also susceptible to infection by the human pathogen Streptococcus pyogenes. However, disease was characterized by a marked absence of inflammation, large numbers of extracellular streptococci in the dorsal muscle, and extensive myonecrosis that occurred far in advance of any systemic invasion. The genetic systems available for streptococci, including a novel method of mutagenesis which targets genes whose products are exported, were used to identify several mutants attenuated for virulence in zebrafish. This combination of a genetically amenable pathogen with a well-defined vertebrate host makes the streptococcus-zebrafish model of bacterial pathogenesis a powerful model for analysis of infectious disease.

Neely, Melody N.; Pfeifer, John D.; Caparon, Michael

2002-01-01

14

Zebrafish models of germ cell tumor.  

PubMed

Germ cell tumors are neoplasms arising from pluripotent germ cells. In humans, these tumors occur in infants, children and young adults. The tumors display a wide range of histologic differentiation states which exhibit different clinical behaviors. Information about the molecular basis of germ cell tumors, and representative animal models of these neoplasms, are lacking. Germline development in zebrafish and humans is broadly conserved, making the fish a useful model to probe the connections between germ cell development and tumorigenesis. Here, we provide an overview of germline development and a brief review of germ cell tumor biology in humans and zebrafish. We also outline some methods for studying the zebrafish germline. PMID:21951524

Neumann, Joanie C; Lillard, Kate; Damoulis, Vanessa; Amatruda, James F

2011-01-01

15

The Zebrafish Model for Liver Carcinogenesis  

Microsoft Academic Search

\\u000a The zebrafish (Danio rerio) has been increasingly recognized as a promising animal model for cancer research. Zebrafish tumors can be generated by treatment\\u000a with chemical carcinogens or by genetic approaches. The liver has been a main target organ for tumorigenesis after carcinogen\\u000a treatment while many other tissue-specific tumors have been generated by tissue-specific expression of proven oncogenes. We\\u000a have used

Zhiyuan Gong; Chor Hui Vivien Koh; Anh Tuan Nguyen; Huiqing Zhan; Zhen Li; Siew Hong Lam; Jan M. Spitsbergen; Alexander Emelyanov; Serguei Parinov

16

Zebrafish myelination: a transparent model for remyelination?  

PubMed Central

There is currently an unmet need for a therapy that promotes the regenerative process of remyelination in central nervous system diseases, notably multiple sclerosis (MS). A high-throughput model is, therefore, required to screen potential therapeutic drugs and to refine genomic and proteomic data from MS lesions. Here, we review the value of the zebrafish (Danio rerio) larva as a model of the developmental process of myelination, describing the powerful applications of zebrafish for genetic manipulation and genetic screens, as well as some of the exciting imaging capabilities of this model. Finally, we discuss how a model of zebrafish myelination can be used as a high-throughput screening model to predict the effect of compounds on remyelination. We conclude that zebrafish provide a highly versatile myelination model. As more complex transgenic zebrafish lines are developed, it might soon be possible to visualise myelination, or even remyelination, in real time. However, experimental outputs must be designed carefully for such visual and temporal techniques.

Buckley, Clare E.; Goldsmith, Paul; Franklin, Robin J. M.

2008-01-01

17

Metastatic behaviour of primary human tumours in a zebrafish xenotransplantation model  

PubMed Central

Background Aberrant regulation of cell migration drives progression of many diseases, including cancer cell invasion and metastasis formation. Analysis of tumour invasion and metastasis in living organisms to date is cumbersome and involves difficult and time consuming investigative techniques. For primary human tumours we establish here a simple, fast, sensitive and cost-effective in vivo model to analyse tumour invasion and metastatic behaviour. Methods We fluorescently labelled small explants from gastrointestinal human tumours and investigated their metastatic behaviour after transplantation into zebrafish embryos and larvae. The transparency of the zebrafish embryos allows to follow invasion, migration and micrometastasis formation in real-time. High resolution imaging was achieved through laser scanning confocal microscopy of live zebrafish. Results In the transparent zebrafish embryos invasion, circulation of tumour cells in blood vessels, migration and micrometastasis formation can be followed in real-time. Xenografts of primary human tumours showed invasiveness and micrometastasis formation within 24 hours after transplantation, which was absent when non-tumour tissue was implanted. Furthermore, primary human tumour cells, when organotopically implanted in the zebrafish liver, demonstrated invasiveness and metastatic behaviour, whereas primary control cells remained in the liver. Pancreatic tumour cells showed no metastatic behaviour when injected into cloche mutant embryos, which lack a functional vasculature. Conclusion Our results show that the zebrafish is a useful in vivo animal model for rapid analysis of invasion and metastatic behaviour of primary human tumour specimen.

2009-01-01

18

Establishment and characterization of a primary human chordoma xenograft model  

PubMed Central

Object Chordomas are rare tumors arising from remnants of the notochord. Because of the challenges in achieving a complete resection, the radioresistant nature of these tumors, and the lack of effective chemotherapeutics, the median survival for patients with chordomas is approximately 6 years. Reproducible preclinical model systems that closely mimic the original patient’s tumor are essential for the development and evaluation of effective therapeutics. Currently, there are only a few established chordoma cell lines and no primary xenograft model. In this study, the authors aimed to develop a primary chordoma xenograft model. Methods The authors implanted independent tumor samples from 2 patients into athymic nude mice. The resulting xenograft line was characterized by histopathological analysis and immunohistochemical staining. The patient’s tumor and serial passages of the xenograft were genomically analyzed using a 660,000 single-nucleotide polymorphism array. Results A serially transplantable xenograft was established from one of the 2 patient samples. Histopathological analysis and immunohistochemical staining for S100 protein, epithelial membrane antigen, and cytokeratin AE1/AE3 of the primary patient sample and the xenografts confirmed that the xenografts were identical to the original chordoma obtained from the patient. Immunohistochemical staining and western blot analysis confirmed the presence of brachyury, a recently described marker of chordomas, in the tumor from the patient and each of the xenografts. Genome-wide variation was assessed between the patient’s tumor and the xenografts and was found to be more than 99.9% concordant. Conclusions To the best of their knowledge, the authors have established the first primary chordoma xenograft that will provide a useful preclinical model for this disease and a platform for therapeutic development.

Siu, I-Mei; Salmasi, Vafi; Orr, Brent A.; Zhao, Qi; Binder, Zev A.; Tran, Christine; Ishii, Masaru; Riggins, Gregory J.; Hann, Christine L.; Gallia, Gary L.

2013-01-01

19

Developing 'integrative' zebrafish models of behavioral and metabolic disorders.  

PubMed

Recently, the pathophysiological overlap between metabolic and mental disorders has received increased recognition. Zebrafish (Danio rerio) are rapidly becoming a popular model organism for translational biomedical research due to their genetic tractability, low cost, quick reproductive cycle, and ease of behavioral, pharmacological or genetic manipulation. High homology to mammalian physiology and the availability of well-developed assays also make the zebrafish an attractive organism for studying human disorders. Zebrafish neurobehavioral and endocrine phenotypes show promise for the use of zebrafish in studies of stress, obesity and related behavioral and metabolic disorders. Here, we discuss the parallels between zebrafish and other model species in stress and obesity physiology, as well as outline the available zebrafish models of weight gain, metabolic deficits, feeding, stress, anxiety and related behavioral disorders. Overall, zebrafish demonstrate a strong potential for modeling human behavioral and metabolic disorders, and their comorbidity. PMID:23948218

Nguyen, Michael; Yang, Ester; Neelkantan, Nikhil; Mikhaylova, Alina; Arnold, Raymond; Poudel, Manoj K; Stewart, Adam Michael; Kalueff, Allan V

2013-08-12

20

The Zebrafish Information Network: the zebrafish model organism database  

PubMed Central

The Zebrafish Information Network (ZFIN; ) is a web based community resource that implements the curation of zebrafish genetic, genomic and developmental data. ZFIN provides an integrated representation of mutants, genes, genetic markers, mapping panels, publications and community resources such as meeting announcements and contact information. Recent enhancements to ZFIN include (i) comprehensive curation of gene expression data from the literature and from directly submitted data, (ii) increased support and annotation of the genome sequence, (iii) expanded use of ontologies to support curation and query forms, (iv) curation of morpholino data from the literature, and (v) increased versatility of gene pages, with new data types, links and analysis tools.

Sprague, Judy; Bayraktaroglu, Leyla; Clements, Dave; Conlin, Tom; Fashena, David; Frazer, Ken; Haendel, Melissa; Howe, Douglas G.; Mani, Prita; Ramachandran, Sridhar; Schaper, Kevin; Segerdell, Erik; Song, Peiran; Sprunger, Brock; Taylor, Sierra; Van Slyke, Ceri E.; Westerfield, Monte

2006-01-01

21

A Model of Bladder Tumor Xenografts in the Nude Rat  

Microsoft Academic Search

PurposeAn in vivo tumor model for the study of human urothelial carcinoma is desirable. Orthotopic xenografts are useful in order to better approximate human tumor cell behavior in situ. A prior model has been described in the nude mouse. However, its small bladder size limits both histologic characterization and the application of intravesical therapeutics. In the absence of preirradiation, orthotopic

Gary S. Oshinsky; Yu Chen; Thomas Jarrett; Ann E. Anderson; Gary H. Weiss

1995-01-01

22

The Zebrafish Information Network: the zebrafish model organism database provides expanded support for genotypes and phenotypes  

PubMed Central

The Zebrafish Information Network (ZFIN, http://zfin.org), the model organism database for zebrafish, provides the central location for curated zebrafish genetic, genomic and developmental data. Extensive data integration of mutant phenotypes, genes, expression patterns, sequences, genetic markers, morpholinos, map positions, publications and community resources facilitates the use of the zebrafish as a model for studying gene function, development, behavior and disease. Access to ZFIN data is provided via web-based query forms and through bulk data files. ZFIN is the definitive source for zebrafish gene and allele nomenclature, the zebrafish anatomical ontology (AO) and for zebrafish gene ontology (GO) annotations. ZFIN plays an active role in the development of cross-species ontologies such as the phenotypic quality ontology (PATO) and the gene ontology (GO). Recent enhancements to ZFIN include (i) a new home page and navigation bar, (ii) expanded support for genotypes and phenotypes, (iii) comprehensive phenotype annotations based on anatomical, phenotypic quality and gene ontologies, (iv) a BLAST server tightly integrated with the ZFIN database via ZFIN-specific datasets, (v) a global site search and (vi) help with hands-on resources.

Sprague, Judy; Bayraktaroglu, Leyla; Bradford, Yvonne; Conlin, Tom; Dunn, Nathan; Fashena, David; Frazer, Ken; Haendel, Melissa; Howe, Douglas G.; Knight, Jonathan; Mani, Prita; Moxon, Sierra A.T.; Pich, Christian; Ramachandran, Sridhar; Schaper, Kevin; Segerdell, Erik; Shao, Xiang; Singer, Amy; Song, Peiran; Sprunger, Brock; Van Slyke, Ceri E.; Westerfield, Monte

2008-01-01

23

The Zebrafish Information Network: the zebrafish model organism database provides expanded support for genotypes and phenotypes.  

PubMed

The Zebrafish Information Network (ZFIN, http://zfin.org), the model organism database for zebrafish, provides the central location for curated zebrafish genetic, genomic and developmental data. Extensive data integration of mutant phenotypes, genes, expression patterns, sequences, genetic markers, morpholinos, map positions, publications and community resources facilitates the use of the zebrafish as a model for studying gene function, development, behavior and disease. Access to ZFIN data is provided via web-based query forms and through bulk data files. ZFIN is the definitive source for zebrafish gene and allele nomenclature, the zebrafish anatomical ontology (AO) and for zebrafish gene ontology (GO) annotations. ZFIN plays an active role in the development of cross-species ontologies such as the phenotypic quality ontology (PATO) and the gene ontology (GO). Recent enhancements to ZFIN include (i) a new home page and navigation bar, (ii) expanded support for genotypes and phenotypes, (iii) comprehensive phenotype annotations based on anatomical, phenotypic quality and gene ontologies, (iv) a BLAST server tightly integrated with the ZFIN database via ZFIN-specific datasets, (v) a global site search and (vi) help with hands-on resources. PMID:17991680

Sprague, Judy; Bayraktaroglu, Leyla; Bradford, Yvonne; Conlin, Tom; Dunn, Nathan; Fashena, David; Frazer, Ken; Haendel, Melissa; Howe, Douglas G; Knight, Jonathan; Mani, Prita; Moxon, Sierra A T; Pich, Christian; Ramachandran, Sridhar; Schaper, Kevin; Segerdell, Erik; Shao, Xiang; Singer, Amy; Song, Peiran; Sprunger, Brock; Van Slyke, Ceri E; Westerfield, Monte

2007-11-08

24

montalcino, a Zebrafish Model for Variegate Porphyria  

PubMed Central

Objective Inherited or acquired mutations in the heme biosynthetic pathway lead to a debilitating class of diseases collectively known as porphyrias, with symptoms that can include anemia, cutaneous photosensitivity, and neurovisceral dysfunction. In a genetic screen for hematopoietic mutants, we isolated a zebrafish mutant, montalcino (mno), which displays hypochromic anemia and porphyria. The objective of this study was to identify the defective gene and characterize the phenotype of the zebrafish mutant. Methods Genetic linkage analysis was utilized to identify the region harboring the mno mutation. Candidate gene analysis together with RT-PCR was utilized to identify the genetic mutation, which was confirmed via allele specific oligo hybridizations. Whole mount in situ hybridizations and 0-dianisidine staining were used to characterize the phenotype of the mno mutant. mRNA and morpholino microinjections were performed to phenocopy and/or rescue the mutant phenotype. Results Homozygous mno mutant embryos have a defect in the protoporphyrinogen oxidase (ppox) gene, which encodes the enzyme that catalyzes the oxidation of protoporphyrinogen. Homozygous mutant embryos are deficient in hemoglobin, and by 36 hpf are visibly anemic and porphyric. The hypochromic anemia of mno embryos was partially rescued by human ppox, providing evidence for the conservation of function between human and zebrafish ppox. Conclusion In humans, mutations in ppox result in variegate porphyria. At present, effective treatment for acute attacks requires the administration intravenous hemin and/or glucose. Thus, mno represents a powerful model for investigation, and a tool for future screens aimed at identifying chemical modifiers of variegate porphyria.

Dooley, Kimberly A.; Fraenkel, Paula G.; Langer, Nathaniel B.; Schmid, Bettina; Davidson, Alan J.; Weber, Gerhard; Chiang, Ken; Foott, Helen; Dwyer, Caitlin; Wingert, Rebecca A.; Zhou, Yi; Paw, Barry H.; Zon, Leonard I.

2008-01-01

25

The Zebrafish Information Network: the zebrafish model organism database.  

PubMed

The Zebrafish Information Network (ZFIN; http://zfin.org) is a web based community resource that implements the curation of zebrafish genetic, genomic and developmental data. ZFIN provides an integrated representation of mutants, genes, genetic markers, mapping panels, publications and community resources such as meeting announcements and contact information. Recent enhancements to ZFIN include (i) comprehensive curation of gene expression data from the literature and from directly submitted data, (ii) increased support and annotation of the genome sequence, (iii) expanded use of ontologies to support curation and query forms, (iv) curation of morpholino data from the literature, and (v) increased versatility of gene pages, with new data types, links and analysis tools. PMID:16381936

Sprague, Judy; Bayraktaroglu, Leyla; Clements, Dave; Conlin, Tom; Fashena, David; Frazer, Ken; Haendel, Melissa; Howe, Douglas G; Mani, Prita; Ramachandran, Sridhar; Schaper, Kevin; Segerdell, Erik; Song, Peiran; Sprunger, Brock; Taylor, Sierra; Van Slyke, Ceri E; Westerfield, Monte

2006-01-01

26

Animal models of human disease: zebrafish swim into view  

Microsoft Academic Search

Despite the pre-eminence of the mouse in modelling human disease, several aspects of murine biology limit its routine use in large-scale genetic and therapeutic screening. Many researchers who are interested in an embryologically and genetically tractable disease model have now turned to zebrafish. Zebrafish biology allows ready access to all developmental stages, and the optical clarity of embryos and larvae

Graham J. Lieschke; Peter D. Currie

2007-01-01

27

Adult zebrafish as a model organism for behavioural genetics.  

PubMed

Recent research has demonstrated the suitability of adult zebrafish to model some aspects of complex behaviour. Studies of reward behaviour, learning and memory, aggression, anxiety and sleep strongly suggest that conserved regulatory processes underlie behaviour in zebrafish and mammals. The isolation and molecular analysis of zebrafish behavioural mutants is now starting, allowing the identification of novel behavioural control genes. As a result of this, studies of adult zebrafish are now helping to uncover the genetic pathways and neural circuits that control vertebrate behaviour. PMID:20678210

Norton, William; Bally-Cuif, Laure

2010-08-02

28

Next-Generation Sequence Analysis of Cancer Xenograft Models  

PubMed Central

Next-generation sequencing (NGS) studies in cancer are limited by the amount, quality and purity of tissue samples. In this situation, primary xenografts have proven useful preclinical models. However, the presence of mouse-derived stromal cells represents a technical challenge to their use in NGS studies. We examined this problem in an established primary xenograft model of small cell lung cancer (SCLC), a malignancy often diagnosed from small biopsy or needle aspirate samples. Using an in silico strategy that assign reads according to species-of-origin, we prospectively compared NGS data from primary xenograft models with matched cell lines and with published datasets. We show here that low-coverage whole-genome analysis demonstrated remarkable concordance between published genome data and internal controls, despite the presence of mouse genomic DNA. Exome capture sequencing revealed that this enrichment procedure was highly species-specific, with less than 4% of reads aligning to the mouse genome. Human-specific expression profiling with RNA-Seq replicated array-based gene expression experiments, whereas mouse-specific transcript profiles correlated with published datasets from human cancer stroma. We conclude that primary xenografts represent a useful platform for complex NGS analysis in cancer research for tumours with limited sample resources, or those with prominent stromal cell populations.

Rossello, Fernando J.; Tothill, Richard W.; Britt, Kara; Marini, Kieren D.; Falzon, Jeanette; Thomas, David M.; Peacock, Craig D.; Marchionni, Luigi; Li, Jason; Bennett, Samara; Tantoso, Erwin; Brown, Tracey; Chan, Philip; Martelotto, Luciano G.; Watkins, D. Neil

2013-01-01

29

Host-Pathogen Interactions Made Transparent with the Zebrafish Model  

PubMed Central

The zebrafish holds much promise as a high-throughput drug screening model for immune-related diseases, including inflammatory and infectious diseases and cancer. This is due to the excellent possibilities for in vivo imaging in combination with advanced tools for genomic and large scale mutant analysis. The context of the embryo’s developing immune system makes it possible to study the contribution of different immune cell types to disease progression. Furthermore, due to the temporal separation of innate immunity from adaptive responses, zebrafish embryos and larvae are particularly useful for dissecting the innate host factors involved in pathology. Recent studies have underscored the remarkable similarity of the zebrafish and human immune systems, which is important for biomedical applications. This review is focused on the use of zebrafish as a model for infectious diseases, with emphasis on bacterial pathogens. Following a brief overview of the zebrafish immune system and the tools and methods used to study host-pathogen interactions in zebrafish, we discuss the current knowledge on receptors and downstream signaling components that are involved in the zebrafish embryo’s innate immune response. We summarize recent insights gained from the use of bacterial infection models, particularly the Mycobacterium marinum model, that illustrate the potential of the zebrafish model for high-throughput antimicrobial drug screening.

Meijer, Annemarie H; Spaink, Herman P

2011-01-01

30

Zebrafish models for the functional genomics of neurogenetic disorders.  

PubMed

In this review, we consider recent work using zebrafish to validate and study the functional consequences of mutations of human genes implicated in a broad range of degenerative and developmental disorders of the brain and spinal cord. Also we present technical considerations for those wishing to study their own genes of interest by taking advantage of this easily manipulated and clinically relevant model organism. Zebrafish permit mutational analyses of genetic function (gain or loss of function) and the rapid validation of human variants as pathological mutations. In particular, neural degeneration can be characterized at genetic, cellular, functional, and behavioral levels. Zebrafish have been used to knock down or express mutations in zebrafish homologs of human genes and to directly express human genes bearing mutations related to neurodegenerative disorders such as spinal muscular atrophy, ataxia, hereditary spastic paraplegia, amyotrophic lateral sclerosis (ALS), epilepsy, Huntington's disease, Parkinson's disease, fronto-temporal dementia, and Alzheimer's disease. More recently, we have been using zebrafish to validate mutations of synaptic genes discovered by large-scale genomic approaches in developmental disorders such as autism, schizophrenia, and non-syndromic mental retardation. Advances in zebrafish genetics such as multigenic analyses and chemical genetics now offer a unique potential for disease research. Thus, zebrafish hold much promise for advancing the functional genomics of human diseases, the understanding of the genetics and cell biology of degenerative and developmental disorders, and the discovery of therapeutics. This article is part of a Special Issue entitled Zebrafish Models of Neurological Diseases. PMID:20887784

Kabashi, Edor; Brustein, Edna; Champagne, Nathalie; Drapeau, Pierre

2010-09-29

31

Murine xenograft model of Spirocerca lupi-associated sarcoma.  

PubMed

Nodular masses and granulomas of the esophagus are among the most frequent lesions caused by Spirocerca lupi, a nematode parasite of dogs, and neoplastic transformation of these granulomas to osteosarcoma or fibrosarcoma has been described. In this study, we developed a xenograft murine model of S. lupi-associated sarcoma. Samples of esophageal fibrosarcoma and osteosarcomas were excised from three dogs diagnosed with spirocercosis. These sarcomas were inoculated into three groups of 6-week-old NOD/SCID mice to create three tumor lines of S. lupi-associated sarcomas. Mice in all groups developed tumors after inoculation, and the cell lines could be further propagated as second-generation xenografts. We successfully established xenograft murine models of three different lines of S. lupi-associated sarcoma that offer readily available sources of these tumors for further experiments. This resource will facilitate studies on the malignant transformation of the granulomas, establishment of efficient chemotherapy and radiotherapy regimens, and identification of diagnostic molecular markers. PMID:16422146

Stettner, Noa; Ranen, Eyal; Dank, Gillian; Lavy, Eran; Aroch, Itamar; Harrus, Shimon; Brenner, Ori; Harmelin, Alon

2005-12-01

32

REVIEW: Zebrafish: A Renewed Model System For Functional Genomics  

NASA Astrophysics Data System (ADS)

In the post genome era, a major goal in molecular biology is to determine the function of the many thousands of genes present in the vertebrate genome. The zebrafish (Danio rerio) provides an almost ideal genetic model to identify the biological roles of these novel genes, in part because their embryos are transparent and develop rapidly. The zebrafish has many advantages over mouse for genome-wide mutagenesis studies, allowing for easier, cheaper and faster functional characterization of novel genes in the vertebrate genome. Many molecular research tools such as chemical mutagenesis, transgenesis, gene trapping, gene knockdown, TILLING, gene targeting, RNAi and chemical genetic screen are now available in zebrafish. Combining all the forward, reverse, and chemical genetic tools, it is expected that zebrafish will make invaluable contribution to vertebrate functional genomics in functional annotation of the genes, modeling human diseases and drug discoveries.

Wen, Xiao-Yan

2008-01-01

33

The emerging use of zebrafish to model metabolic disease.  

PubMed

The zebrafish research community is celebrating! The zebrafish genome has recently been sequenced, the Zebrafish Mutation Project (launched by the Wellcome Trust Sanger Institute) has published the results of its first large-scale ethylnitrosourea (ENU) mutagenesis screen, and a host of new techniques, such as the genome editing technologies TALEN and CRISPR-Cas, are enabling specific mutations to be created in model organisms and investigated in vivo. The zebrafish truly seems to be coming of age. These powerful resources invoke the question of whether zebrafish can be increasingly used to model human disease, particularly common, chronic diseases of metabolism such as obesity and type 2 diabetes. In recent years, there has been considerable success, mainly from genomic approaches, in identifying genetic variants that are associated with these conditions in humans; however, mechanistic insights into the role of implicated disease loci are lacking. In this Review, we highlight some of the advantages and disadvantages of zebrafish to address the organism's utility as a model system for human metabolic diseases. PMID:24046387

Seth, Asha; Stemple, Derek L; Barroso, Inês

34

Osteosarcoma Models: From Cell Lines to Zebrafish  

PubMed Central

High-grade osteosarcoma is an aggressive tumor most commonly affecting adolescents. The early age of onset might suggest genetic predisposition; however, the vast majority of the tumors are sporadic. Early onset, most often lack of a predisposing condition or lesion, only infrequent (<2%) prevalence of inheritance, extensive genomic instability, and a wide histological heterogeneity are just few factors to mention that make osteosarcoma difficult to study. Therefore, it is sensible to design and use models representative of the human disease. Here we summarize multiple osteosarcoma models established in vitro and in vivo, comment on their utilities, and highlight newest achievements, such as the use of zebrafish embryos. We conclude that to gain a better understanding of osteosarcoma, simplification of this extremely complex tumor is needed. Therefore, we parse the osteosarcoma problem into parts and propose adequate models to study them each separately. A better understanding of osteosarcoma provides opportunities for discovering and assaying novel effective treatment strategies. “Sometimes the model is more interesting than the original disease” PJ Hoedemaeker (1937–2007).

Mohseny, Alexander B.; Hogendoorn, Pancras C. W.; Cleton-Jansen, Anne-Marie

2012-01-01

35

ZFIN: enhancements and updates to the Zebrafish Model Organism Database.  

PubMed

ZFIN, the Zebrafish Model Organism Database, http://zfin.org, serves as the central repository and web-based resource for zebrafish genetic, genomic, phenotypic and developmental data. ZFIN manually curates comprehensive data for zebrafish genes, phenotypes, genotypes, gene expression, antibodies, anatomical structures and publications. A wide-ranging collection of web-based search forms and tools facilitates access to integrated views of these data promoting analysis and scientific discovery. Data represented in ZFIN are derived from three primary sources: curation of zebrafish publications, individual research laboratories and collaborations with bioinformatics organizations. Data formats include text, images and graphical representations. ZFIN is a dynamic resource with data added daily as part of our ongoing curation process. Software updates are frequent. Here, we describe recent additions to ZFIN including (i) enhanced access to images, (ii) genomic features, (iii) genome browser, (iv) transcripts, (v) antibodies and (vi) a community wiki for protocols and antibodies. PMID:21036866

Bradford, Yvonne; Conlin, Tom; Dunn, Nathan; Fashena, David; Frazer, Ken; Howe, Douglas G; Knight, Jonathan; Mani, Prita; Martin, Ryan; Moxon, Sierra A T; Paddock, Holly; Pich, Christian; Ramachandran, Sridhar; Ruef, Barbara J; Ruzicka, Leyla; Bauer Schaper, Holle; Schaper, Kevin; Shao, Xiang; Singer, Amy; Sprague, Judy; Sprunger, Brock; Van Slyke, Ceri; Westerfield, Monte

2010-10-29

36

Zebrafish as a model for the study of neutrophil biology.  

PubMed

To understand inflammation and immunity, we need to understand the biology of the neutrophil. Whereas these cells can readily be extracted from peripheral blood, their short lifespan makes genetic manipulations impractical. Murine knockout models have been highly informative, and new imaging techniques are allowing neutrophils to be seen during inflammation in vivo for the first time. However, there is a place for a new model of neutrophil biology, which readily permits imaging of individual neutrophils during inflammation in vivo, combined with the ease of genetic and chemical manipulation. The zebrafish has long been the model of choice for the developmental biology community, and the availability of genomic resources and tools for gene manipulation makes this an attractive model. Zebrafish innate immunity shares many features with mammalian systems, including neutrophils with morphological, biochemical, and functional features, also shared with mammalian neutrophils. Transgenic zebrafish with neutrophils specifically labeled with fluorescent proteins have been generated, and this advance has led to the adoption of zebrafish, alongside existing models, by a number of groups around the world. The use of these models has underpinned a number of key advances in the field, including the identification of a tissue gradient of hydrogen peroxide for neutrophil recruitment following tissue injury and direct evidence for reverse migration as a regulatable mechanism of inflammation resolution. In this review, we discuss the importance of zebrafish models in neutrophil biology and describe how the understanding of neutrophil biology has been advanced by the use of these models. PMID:23463724

Henry, Katherine M; Loynes, Catherine A; Whyte, Moira K B; Renshaw, Stephen A

2013-03-05

37

The developing utility of zebrafish models for cognitive enhancers research.  

PubMed

Whereas cognitive impairment is a common symptom in multiple brain disorders, predictive and high-throughput animal models of cognition and behavior are becoming increasingly important in the field of translational neuroscience research. In particular, reliable models of the cognitive deficits characteristic of numerous neurobehavioral disorders such as Alzheimer's disease and schizophrenia have become a significant focus of investigation. While rodents have traditionally been used to study cognitive phenotypes, zebrafish (Danio rerio) are gaining popularity as an excellent model to complement current translational neuroscience research. Here we discuss recent advances in pharmacological and genetic approaches using zebrafish models to study cognitive impairments and to discover novel cognitive enhancers and neuroprotective mechanisms. PMID:23449968

Stewart, Adam Michael; Kalueff, Allan V

2012-09-01

38

The Developing Utility of Zebrafish Models for Cognitive Enhancers Research  

PubMed Central

Whereas cognitive impairment is a common symptom in multiple brain disorders, predictive and high-throughput animal models of cognition and behavior are becoming increasingly important in the field of translational neuroscience research. In particular, reliable models of the cognitive deficits characteristic of numerous neurobehavioral disorders such as Alzheimer’s disease and schizophrenia have become a significant focus of investigation. While rodents have traditionally been used to study cognitive phenotypes, zebrafish (Danio rerio) are gaining popularity as an excellent model to complement current translational neuroscience research. Here we discuss recent advances in pharmacological and genetic approaches using zebrafish models to study cognitive impairments and to discover novel cognitive enhancers and neuroprotective mechanisms.

Stewart, Adam Michael; Kalueff, Allan V

2012-01-01

39

Graph Theoretical Model of a Sensorimotor Connectome in Zebrafish  

Microsoft Academic Search

Mapping the detailed connectivity patterns (connectomes) of neural circuits is a central goal of neuroscience. The best quantitative approach to analyzing connectome data is still unclear but graph theory has been used with success. We present a graph theoretical model of the posterior lateral line sensorimotor pathway in zebrafish. The model includes 2,616 neurons and 167,114 synaptic connections. Model neurons

Michael Stobb; Joshua M. Peterson; Borbala Mazzag; Ethan Gahtan

2012-01-01

40

Application of zebrafish oculomotor behavior to model human disorders.  

PubMed

To ensure high acuity vision, eye movements have to be controlled with astonishing precision by the oculomotor system. Many human diseases can lead to abnormal eye movements, typically of the involuntary oscillatory eye movements type called nystagmus. Such nystagmus can be congenital (infantile) or acquired later in life. Although the resulting eye movements are well characterized, there is only little information about the underlying etiology. This is in part owing to the lack of appropriate animal models. In this review article, we describe how the zebrafish with its quick maturing visual system can be used to model oculomotor pathologies. We compare the characteristics and assessment of human and zebrafish eye movements. We describe the oculomotor properties of the zebrafish mutant belladonna, which has non-crossing optical fibers, and is a particularly informative model for human oculomotor deficits. This mutant displays a reverse optokinetic response, spontaneous oscillations that closely mimic human congenital nystagmus and abnormal motor behavior linked to circular vection. PMID:21615257

Maurer, Colette M; Huang, Ying-Yu; Neuhauss, Stephan C F

2011-01-01

41

Zebrafish: a model for the study of addiction genetics.  

PubMed

Drug abuse and dependence are multifaceted disorders with complex genetic underpinnings. Identifying specific genetic correlates is challenging and may be more readily accomplished by defining endophenotypes specific for addictive disorders. Symptoms and syndromes, including acute drug response, consumption, preference, and withdrawal, are potential endophenotypes characterizing addiction that have been investigated using model organisms. We present a review of major genes involved in serotonergic, dopaminergic, GABAergic, and adrenoreceptor signaling that are considered to be directly involved in nicotine, opioid, cannabinoid, and ethanol use and dependence. The zebrafish genome encodes likely homologs of the vast majority of these loci. We also review the known expression patterns of these genes in zebrafish. The information presented in this review provides support for the use of zebrafish as a viable model for studying genetic factors related to drug addiction. Expansion of investigations into drug response using model organisms holds the potential to advance our understanding of drug response and addiction in humans. PMID:22207143

Klee, Eric W; Schneider, Henning; Clark, Karl J; Cousin, Margot A; Ebbert, Jon O; Hooten, W Michael; Karpyak, Victor M; Warner, David O; Ekker, Stephen C

2011-12-30

42

Graph Theoretical Model of a Sensorimotor Connectome in Zebrafish  

PubMed Central

Mapping the detailed connectivity patterns (connectomes) of neural circuits is a central goal of neuroscience. The best quantitative approach to analyzing connectome data is still unclear but graph theory has been used with success. We present a graph theoretical model of the posterior lateral line sensorimotor pathway in zebrafish. The model includes 2,616 neurons and 167,114 synaptic connections. Model neurons represent known cell types in zebrafish larvae, and connections were set stochastically following rules based on biological literature. Thus, our model is a uniquely detailed computational representation of a vertebrate connectome. The connectome has low overall connection density, with 2.45% of all possible connections, a value within the physiological range. We used graph theoretical tools to compare the zebrafish connectome graph to small-world, random and structured random graphs of the same size. For each type of graph, 100 randomly generated instantiations were considered. Degree distribution (the number of connections per neuron) varied more in the zebrafish graph than in same size graphs with less biological detail. There was high local clustering and a short average path length between nodes, implying a small-world structure similar to other neural connectomes and complex networks. The graph was found not to be scale-free, in agreement with some other neural connectomes. An experimental lesion was performed that targeted three model brain neurons, including the Mauthner neuron, known to control fast escape turns. The lesion decreased the number of short paths between sensory and motor neurons analogous to the behavioral effects of the same lesion in zebrafish. This model is expandable and can be used to organize and interpret a growing database of information on the zebrafish connectome.

Stobb, Michael; Peterson, Joshua M.; Mazzag, Borbala; Gahtan, Ethan

2012-01-01

43

Zebrafish as a Model System to Screen Radiation Modifiers  

PubMed Central

Zebrafish (Danio rerio) is a bona fide vertebrate model system for understanding human diseases. It allows the transparent visualization of the effects of ionizing radiation and the convenient testing of potential radioprotectors with morpholino-modified oligonucleotides (MO) knockdown. Furthermore, various reverse and forward genetic methods are feasible to decipher novel genetic modifiers of radioprotection. Examined in the review are the radioprotective effects of the proposed radiomodifiers Nanoparticle DF-1 (C-Sixty, Inc., Houston, TX) and Amifostine (WR-2721, Ethyol), the DNA repair proteins Ku80 and ATM, as well as the transplanted hematopoietic stem cells in irradiated zebrafish. The presence of any of these sufficiently rescued the radiation-induced damages in zebrafish, while its absence resulted in mutagenic phenotypes as well as an elevation of time- and dose-dependent radiation-induced apoptosis. Radiosensitizers Flavopiridol and AG1478, both of which block progression into the radioresistant S phase of the cell cycle, have also been examined in zebrafish. Zebrafish has indeed become a favorite model system to test for radiation modifiers that can potentially be used for radiotherapeutic purposes in humans.

Hwang, Misun; Yong, Cha; Moretti, Luigi; Lu, Bo

2007-01-01

44

Distinct phenotypes in zebrafish models of human startle disease.  

PubMed

Startle disease is an inherited neurological disorder that causes affected individuals to suffer noise- or touch-induced non-epileptic seizures, excessive muscle stiffness and neonatal apnea episodes. Mutations known to cause startle disease have been identified in glycine receptor subunit (GLRA1 and GLRB) and glycine transporter (SLC6A5) genes, which serve essential functions at glycinergic synapses. Despite the significant successes in identifying startle disease mutations, many idiopathic cases remain unresolved. Exome sequencing in these individuals will identify new candidate genes. To validate these candidate disease genes, zebrafish is an ideal choice due to rapid knockdown strategies, accessible embryonic stages, and stereotyped behaviors. The only existing zebrafish model of startle disease, bandoneon (beo), harbors point mutations in glrbb (one of two zebrafish orthologs of human GLRB) that cause compromised glycinergic transmission and touch-induced bilateral muscle contractions. In order to further develop zebrafish as a model for startle disease, we sought to identify common phenotypic outcomes of knocking down zebrafish orthologs of two known startle disease genes, GLRA1 and GLRB, using splice site-targeted morpholinos. Although both morphants were expected to result in phenotypes similar to the zebrafish beo mutant, our direct comparison demonstrated that while both glra1 and glrbb morphants exhibited embryonic spasticity, only glrbb morphants exhibited bilateral contractions characteristic of beo mutants. Likewise, zebrafish over-expressing a dominant startle disease mutation (GlyR ?1(R271Q)) exhibited spasticity but not bilateral contractions. Since GlyR ?b can interact with GlyR ? subunits 2-4 in addition to GlyR ?1, loss of the GlyR ?b subunit may produce more severe phenotypes by affecting multiple GlyR subtypes. Indeed, immunohistochemistry of glra1 morphants suggests that in zebrafish, alternate GlyR ? subunits can compensate for the loss of the GlyR ?1 subunit. To address the potential for interplay among GlyR subunits during development, we quantified the expression time-course for genes known to be critical to glycinergic synapse function. We found that GlyR ?2, ?3 and ?4a are expressed in the correct temporal pattern and could compensate for the loss of the GlyR ?1 subunit. Based on our findings, future studies that aim to model candidate startle disease genes in zebrafish should include measures of spasticity and synaptic development. PMID:24029548

Ganser, Lisa R; Yan, Qing; James, Victoria M; Kozol, Robert; Topf, Maya; Harvey, Robert J; Dallman, Julia E

2013-09-09

45

Zebrafish provides a novel model for lymphatic vascular research.  

PubMed

The mammalian lymphatic vasculature has an important function in the maintenance of tissue fluid homeostasis, absorption of dietary lipids, and immune surveillance. The lymphatic vessels are also recruited by many tumors as primary routes for metastasis and mediate immune responses in inflammatory diseases, whereas dysfunction of the lymphatic drainage leads to lymphedema. The characterization of a lymphatic vasculature in zebrafish has made the advantages of this small model organism, the suitability for intravital time-lapse imaging of developmental processes and the amenability for chemical and forward genetic screens, available to lymphatic vascular research. Here we review our current understanding of embryonic lymphangiogenesis in zebrafish, its molecular and anatomical similarities to mammalian lymphatic vascular development, and the possibilities zebrafish offers to complement mouse models and cell culture assays in the lymphangiogenesis field. PMID:21951532

Karpanen, Terhi; Schulte-Merker, Stefan

2011-01-01

46

Zebrafish (Danio rerio) embryos as a model for testing proteratogens.  

PubMed

Zebrafish embryos have been shown to be a useful model for the detection of direct acting teratogens. This communication presents a protocol for a 3-day in vitro zebrafish embryo teratogenicity assay and describes results obtained for 10 proteratogens: 2-acetylaminofluorene, benzo[a]pyrene, aflatoxin B(1), carbamazepine, phenytoin, trimethadione, cyclophosphamide, ifosfamide, tegafur and thio-TEPA. The selection of the test substances accounts for differences in structure, origin, metabolism and water solubility. Apart from 2-acetylaminofluorene, which mainly produces lethal effects, all proteratogens tested were teratogenic in zebrafish embryos exposed for 3 days. The test substances and/or the substance class produced characteristic patterns of fingerprint endpoints. Several substances produced effects that could be identified already at 1 dpf (days post fertilization), whereas the effects of others could only be identified unambiguously after hatching at ? 3 dpf. The LC?? and EC?? values were used to calculate the teratogenicity index (TI) for the different substances, and the EC?? values were related to human plasma concentrations. Results lead to the conclusion that zebrafish embryos are able to activate proteratogenic substances without addition of an exogenous metabolic activation system. Moreover, the teratogenic effects were observed at concentrations relevant to human exposure data. Along with other findings, our results indicate that zebrafish embryos are a useful alternative method for traditional teratogenicity testing with mammalian species. PMID:21237239

Weigt, Stefan; Huebler, Nicole; Strecker, Ruben; Braunbeck, Thomas; Broschard, Thomas H

2011-01-13

47

Progestin-Dependent Progression of Human Breast Tumor Xenografts: A Novel Model for Evaluating Antitumor Therapeutics  

Microsoft Academic Search

Recent clinical trials indicate that synthetic progestins may stimulate progression of breast cancer in postmenopausal women, a result that is consistent with studies in chemically- induced breast cancer models in rodents. However, progestin- dependent progression of breast cancer tumor xenografts has not been shown. This study shows that xenografts obtained from BT-474 and T47-Dhuman breast cancer cells without Matrigel in

Yayun Liang; Cynthia Besch-Williford; Rolf A. Brekken; Salman M. Hyder

2007-01-01

48

Developing an Experimental Model of Vascular Toxicity in Embryonic Zebrafish  

EPA Science Inventory

Developing an Experimental Model of Vascular Toxicity in Embryonic Zebrafish Tamara Tal, Integrated Systems Toxicology Division, U.S. EPA Background: There are tens of thousands of chemicals that have yet to be fully evaluated for their toxicity by validated in vivo testing ...

49

Zebrafish model for allogeneic hematopoietic cell transplantation not requiring preconditioning  

PubMed Central

Recent work on vertebrate hematopoiesis has uncovered the presence of deeply rooted similarities between fish and mammals at molecular and cellular levels. Although small animal models such as zebrafish are ideally suited for genetic and chemical screens, the study of cellular aspects of hematopoietic development in lower vertebrates is severely hampered by the complex nature of their histocompatibility-determining genes. Hence, even when hosts are sublethally irradiated before hematopoietic cell transplantation, stable and long-term reconstitution by allogeneic stem cells often fails. Here, we describe the unexpected observation that transplantation and maintenance of allogeneic hematopoietic stem cells in zebrafish homozygous for the c-mybt25127 allele, carrying a missense mutation (Ile181Asn) in the DNA binding domain can be achieved without prior conditioning. Using this model, we examined several critical parameters of zebrafish hematopoiesis in a near-physiological setting. Limiting dilution analysis suggests that the kidney marrow of adult zebrafish harbors about 10 transplantable hematopoietic stem cells; this tissue also contains thymus-settling precursors that colonize the thymic rudiment within days after transplantation and initiate robust T-cell development. We also demonstrate that c-myb mutants can be stably reconstituted with hematopoietic cells carrying specific genetic defects in lymphocyte development, exemplifying one of the many potential uses of this model in experimental hematology.

Hess, Isabell; Iwanami, Norimasa; Schorpp, Michael; Boehm, Thomas

2013-01-01

50

Development and characterization of a bladder cancer xenograft model using patient-derived tumor tissue.  

PubMed

Most of the cancer xenograft models are derived from tumor cell lines, but they do not sufficiently represent clinical cancer characteristics. Our objective was to develop xenograft models of bladder cancer derived from human tumor tissue and characterize them molecularly as well as histologically. A total of 65 bladder cancer tissues were transplanted to immunodeficient mice. Passagable six cases with clinico-pathologically heterogeneous bladder cancer were selected and their tumor tissues were collected (012T, 025T, 033T, 043T, 048T, and 052T). Xenografts were removed and processed for the following analyses: (i) histologic examination, (ii) short tandem repeat (STR) genotyping, (iii) mutational analysis, and (iv) array-based comparative genomic hybridization (array-CGH). The original tumor tissues (P 0) and xenografts of passage 2 or higher (?P2) were analyzed and compared. As a result, hematoxylin and eosin staining revealed the same histologic architecture and degree of differentiation in the primary and xenograft tumors in all six cases. Xenograft models 043T_P2 and 048T_P2 had completely identical STR profiles to the original samples for all STR loci. The other models had nearly identical STR profiles. On mutational analysis, four out of six xenografts had mutations identical to the original samples for TP53, HRAS, BRAF, and CTNNB1. Array-CGH analysis revealed that all six xenograft models had genomic alterations similar to the original tumor samples. In conclusion, our xenograft bladder cancer model derived from patient tumor tissue is expected to be useful for studying the heterogeneity of the tumor populations in bladder cancer and for evaluating new treatments. PMID:23384396

Park, Bumsoo; Jeong, Byong Chang; Choi, Yoon-La; Kwon, Ghee Young; Lim, Joung Eun; Seo, Seong Il; Jeon, Seong Soo; Lee, Hyun Moo; Choi, Han Yong; Lee, Kyu-Sung

2013-03-24

51

Trolling for the ideal model host: zebrafish take the bait  

PubMed Central

As little as 10 years ago, murine models of infectious disease were the host of choice for analyzing interactions between the pathogen and host during infection. However, not all pathogens can infect mice, nor do they always replicate the clinical syndromes observed in human infections. Furthermore, in the current economic environment, using mammalian models for large-scale screens may be less economically feasible. The emergence of the zebrafish (Danio rerio) as an infectious disease host model, as well as a model for vertebrate immune system development, has provided new information and insights into pathogenesis that, in many instances, would not have been possible using a murine model host. In this article we highlight some of the key findings and the latest techniques along with the many advantages of using the zebrafish host model to gain new insights into pathogenic mechanisms in a live vertebrate host.

Allen, Jonathan P; Neely, Melody N

2010-01-01

52

Generation of a transgenic zebrafish model of Tauopathy using a novel promoter element derived from the zebrafish eno2 gene  

PubMed Central

The aim of this study was to isolate cis-acting regulatory elements for the generation of transgenic zebrafish models of neurodegeneration. Zebrafish enolase-2 (eno2) showed neuronal expression increasing from 24 to 72 h post-fertilization (hpf) and persisting through adulthood. A 12 kb eno2 genomic fragment, extending from 8 kb upstream of exon 1 to exon 2, encompassing intron 1, was sufficient to drive neuronal reporter gene expression in vivo over a similar time course. Five independent lines of stable Tg(eno2 : GFP) zebrafish expressed GFP widely in neurons, including populations with relevance to neurodegeneration, such as cholinergic neurons, dopaminergic neurons and cerebellar Purkinje cells. We replaced the exon 2-GFP fusion gene with a cDNA encoding the 4-repeat isoform of the human microtubule-associated protein Tau. The first intron of eno2 was spliced with high fidelity and efficiency from the chimeric eno2-Tau transcript. Tau was expressed at ?8-fold higher levels in Tg(eno2 : Tau) zebrafish brain than normal human brain, and localized to axons, neuropil and ectopic neuronal somatic accumulations resembling neurofibrillary tangles. The 12 kb eno2 promoter drives high-level transgene expression in differentiated neurons throughout the CNS of stable transgenic zebrafish. This regulatory element will be useful for the construction of transgenic zebrafish models of neurodegeneration.

Bai, Qing; Garver, Jessica A.; Hukriede, Neil A.; Burton, Edward A.

2007-01-01

53

Drug screening in a zebrafish model of Duchenne muscular dystrophy  

PubMed Central

Two known zebrafish dystrophin mutants, sapje and sapje-like (sapc/100), represent excellent small-animal models of human muscular dystrophy. Using these dystrophin-null zebrafish, we have screened the Prestwick chemical library for small molecules that modulate the muscle phenotype in these fish. With a quick and easy birefringence assay, we have identified seven small molecules that influence muscle pathology in dystrophin-null zebrafish without restoration of dystrophin expression. Three of seven candidate chemicals restored normal birefringence and increased survival of dystrophin-null fish. One chemical, aminophylline, which is known to be a nonselective phosphodiesterase (PDE) inhibitor, had the greatest ability to restore normal muscle structure and up-regulate the cAMP-dependent PKA pathway in treated dystrophin-deficient fish. Moreover, other PDE inhibitors also reduced the percentage of affected sapje fish. The identification of compounds, especially PDE inhibitors, that moderate the muscle phenotype in these dystrophin-null zebrafish validates the screening protocol described here and may lead to candidate molecules to be used as therapeutic interventions in human muscular dystrophy.

Kawahara, Genri; Karpf, Jeremy A.; Myers, Jennifer A.; Alexander, Matthew S.; Guyon, Jeffrey R.; Kunkel, Louis M.

2011-01-01

54

Neuronal regeneration in a zebrafish model of adult brain injury.  

PubMed

Neural stem cells in the subventricular zone (SVZ) of the adult mammalian forebrain are a potential source of neurons for neural tissue repair after brain insults such as ischemic stroke and traumatic brain injury (TBI). Recent studies show that neurogenesis in the ventricular zone (VZ) of the adult zebrafish telencephalon has features in common with neurogenesis in the adult mammalian SVZ. Here, we established a zebrafish model to study injury-induced neurogenesis in the adult brain. We show that the adult zebrafish brain possesses a remarkable capacity for neuronal regeneration. Telencephalon injury prompted the proliferation of neuronal precursor cells (NPCs) in the VZ of the injured hemisphere, compared with in the contralateral hemisphere. The distribution of NPCs, viewed by BrdU labeling and ngn1-promoter-driven GFP, suggested that they migrated laterally and reached the injury site via the subpallium and pallium. The number of NPCs reaching the injury site significantly decreased when the fish were treated with an inhibitor of ?-secretase, a component of the Notch signaling pathway, suggesting that injury-induced neurogenesis mechanisms are at least partly conserved between fish and mammals. The injury-induced NPCs differentiated into mature neurons in the regions surrounding the injury site within a week after the injury. Most of these cells expressed T-box brain protein (Tbr1), suggesting they had adopted the normal neuronal fate in this region. These results suggest that the telencephalic VZ contributes to neural tissue recovery following telencephalic injury in the adult zebrafish, and that the adult zebrafish is a useful model for regenerative medicine. PMID:22028327

Kishimoto, Norihito; Shimizu, Kohei; Sawamoto, Kazunobu

2011-10-25

55

Embryonic Senescence and Laminopathies in a Progeroid Zebrafish Model  

Microsoft Academic Search

BackgroundMutations that disrupt the conversion of prelamin A to mature lamin A cause the rare genetic disorder Hutchinson-Gilford progeria syndrome and a group of laminopathies. Our understanding of how A-type lamins function in vivo during early vertebrate development through aging remains limited, and would benefit from a suitable experimental model. The zebrafish has proven to be a tractable model organism

Eriko Koshimizu; Shintaro Imamura; Jie Qi; Jamal Toure; Delgado M. Valdez; Christopher E. Carr; Jun-Ichi Hanai; Shuji Kishi; Alfred Lewin

2011-01-01

56

Zebrafish as a novel vertebrate model to dissect enterococcal pathogenesis.  

PubMed

Enterococcus faecalis is an opportunistic pathogen responsible for a wide range of life-threatening nosocomial infections, such as septicemia, peritonitis, and endocarditis. E. faecalis infections are associated with a high mortality and substantial health care costs and cause therapeutic problems due to the intrinsic resistance of this bacterium to antibiotics. Several factors contributing to E. faecalis virulence have been identified. Due to the variety of infections caused by this organism, numerous animal models have been used to mimic E. faecalis infections, but none of them is considered ideal for monitoring pathogenesis. Here, we studied for the first time E. faecalis pathogenesis in zebrafish larvae. Using model strains, chosen isogenic mutants, and fluorescent derivatives expressing green fluorescent protein (GFP), we analyzed both lethality and bacterial dissemination in infected larvae. Genetically engineered immunocompromised zebrafish allowed the identification of two critical steps for successful establishment of disease: (i) host phagocytosis evasion mediated by the Epa rhamnopolysaccharide and (ii) tissue damage mediated by the quorum-sensing Fsr regulon. Our results reveal that the zebrafish is a novel, powerful model for studying E. faecalis pathogenesis, enabling us to dissect the mechanism of enterococcal virulence. PMID:24002065

Prajsnar, Tomasz K; Renshaw, Stephen A; Ogryzko, Nikolay V; Foster, Simon J; Serror, Pascale; Mesnage, Stéphane

2013-09-03

57

Computational Graph Theoretical Model of the Zebrafish Sensorimotor Pathway  

NASA Astrophysics Data System (ADS)

Mapping the detailed connectivity patterns of neural circuits is a central goal of neuroscience and has been the focus of extensive current research [4, 3]. The best quantitative approach to analyze the acquired data is still unclear but graph theory has been used with success [3, 1]. We present a graph theoretical model with vertices and edges representing neurons and synaptic connections, respectively. Our system is the zebrafish posterior lateral line sensorimotor pathway. The goal of our analysis is to elucidate mechanisms of information processing in this neural pathway by comparing the mathematical properties of its graph to those of other, previously described graphs. We create a zebrafish model based on currently known anatomical data. The degree distributions and small-world measures of this model is compared to small-world, random and 3-compartment random graphs of the same size (with over 2500 nodes and 160,000 connections). We find that the zebrafish graph shows small-worldness similar to other neural networks and does not have a scale-free distribution of connections.

Peterson, Joshua M.; Stobb, Michael; Mazzag, Bori; Gahtan, Ethan

2011-11-01

58

An adult zebrafish model for preclinical tuberculosis vaccine development.  

PubMed

Tuberculosis remains a major global health challenge despite extensive vaccination schemes with the current live vaccine, Bacillus Calmette-Guérin. Tuberculosis vaccine research has been hampered by a scarcity of animal models which replicate human disease and are suitable for large-scale studies. We have shown recently that Mycobacterium marinum, a close relative of Mycobacterium tuberculosis, causes an infection resembling human tuberculosis in adult zebrafish (Danio rerio). In the present study we use this model to show that BCG vaccination as well as DNA vaccination with selected mycobacterial antigens (Ag85B, CFP-10 and ESAT-6) protects adult zebrafish from mycobacterial infection. Using a low-dose (?20-30 bacteria) intraperitoneal M. marinum infection, both the number of granulomas and the amount of infected organs were reduced in the DNA vaccinated fish. Likewise, when infecting with a lethal infection dose (?20,000-27,000 bacteria), vaccination significantly reduced both mortality and bacterial counts in a manner dependent on the adaptive immune response. Protective effects of vaccination were associated with enhanced expression of interferon gamma. Our results indicate that the zebrafish is a promising new model for preclinical tuberculosis vaccine research. PMID:24055305

Oksanen, Kaisa E; Halfpenny, Nicholas J A; Sherwood, Eleanor; Harjula, Sanna-Kaisa E; Hammarén, Milka M; Ahava, Maarit J; Pajula, Elina T; Lahtinen, Marika J; Parikka, Mataleena; Rämet, Mika

2013-09-20

59

Zebrafish as potential model for developmental neurotoxicity testing: a mini review.  

PubMed

The zebrafish is a powerful toxicity model; biochemical assays can be combined with observations at a structural and functional level within one individual. This mini review summarises the potency of zebrafish as a model for developmental neurotoxicity screening, and its possibilities to investigate working mechanisms of toxicants. The use of zebrafish in toxicity research can ultimately lead to the refinement or reduction of animal use. PMID:22971930

de Esch, Celine; Slieker, Roderick; Wolterbeek, André; Woutersen, Ruud; de Groot, Didima

2012-09-03

60

The zebrafish: scalable in vivo modeling for systems biology  

PubMed Central

The zebrafish offers a scalable vertebrate model for many areas of biologic investigation. There is substantial conservation of genetic and genomic features and, at a higher order, conservation of intermolecular networks, as well as physiologic systems and phenotypes. We highlight recent work demonstrating the extent of this homology, and efforts to develop high-throughput phenotyping strategies suited to genetic or chemical screening on a scale compatible with in vivo validation for systems biology. We discuss the implications of these approaches for functional annotation of the genome, elucidation of multicellular processes in vivo, and mechanistic exploration of hypotheses generated by a broad range of ‘unbiased’ ‘omic technologies such as expression profiling and genome-wide association. Finally, we outline potential strategies for the application of the zebrafish to the systematic study of phenotypic architecture, disease heterogeneity and drug responses.

Deo, Rahul C.; MacRae, Calum A.

2011-01-01

61

Genetically Engineered Cancer Models, But Not Xenografts, Faithfully Predict Anticancer Drug Exposure in Melanoma Tumors  

PubMed Central

Background. Rodent studies are a vital step in the development of novel anticancer therapeutics and are used in pharmacokinetic (PK), toxicology, and efficacy studies. Traditionally, anticancer drug development has relied on xenograft implantation of human cancer cell lines in immunocompromised mice for efficacy screening of a candidate compound. The usefulness of xenograft models for efficacy testing, however, has been questioned, whereas genetically engineered mouse models (GEMMs) and orthotopic syngeneic transplants (OSTs) may offer some advantages for efficacy assessment. A critical factor influencing the predictability of rodent tumor models is drug PKs, but a comprehensive comparison of plasma and tumor PK parameters among xenograft models, OSTs, GEMMs, and human patients has not been performed. Methods. In this work, we evaluated the plasma and tumor dispositions of an antimelanoma agent, carboplatin, in patients with cutaneous melanoma compared with four different murine melanoma models (one GEMM, one human cell line xenograft, and two OSTs). Results. Using microdialysis to sample carboplatin tumor disposition, we found that OSTs and xenografts were poor predictors of drug exposure in human tumors, whereas the GEMM model exhibited PK parameters similar to those seen in human tumors. Conclusions. The tumor PKs of carboplatin in a GEMM of melanoma more closely resembles the tumor disposition in patients with melanoma than transplanted tumor models. GEMMs show promise in becoming an improved prediction model for intratumoral PKs and response in patients with solid tumors.

Combest, Austin J.; Roberts, Patrick J.; Dillon, Patrick M.; Sandison, Katie; Hanna, Suzan K.; Ross, Charlene; Habibi, Sohrab; Zamboni, Beth; Muller, Markus; Brunner, Martin; Sharpless, Norman E.

2012-01-01

62

Toxicity of silver nanoparticles in zebrafish models  

NASA Astrophysics Data System (ADS)

This study was initiated to enhance our insight on the health and environmental impact of silver nanoparticles (Ag-np). Using starch and bovine serum albumin (BSA) as capping agents, silver nanoparticles were synthesized to study their deleterious effects and distribution pattern in zebrafish embryos (Danio rerio). Toxicological endpoints like mortality, hatching, pericardial edema and heart rate were recorded. A concentration-dependent increase in mortality and hatching delay was observed in Ag-np treated embryos. Additionally, nanoparticle treatments resulted in concentration-dependent toxicity, typified by phenotypes that had abnormal body axes, twisted notochord, slow blood flow, pericardial edema and cardiac arrhythmia. Ag+ ions and stabilizing agents showed no significant defects in developing embryos. Transmission electron microscopy (TEM) of the embryos demonstrated that nanoparticles were distributed in the brain, heart, yolk and blood of embryos as evident from the electron-dispersive x-ray analysis (EDS). Furthermore, the acridine orange staining showed an increased apoptosis in Ag-np treated embryos. These results suggest that silver nanoparticles induce a dose-dependent toxicity in embryos, which hinders normal development.

Asharani, P. V.; Lian Wu, Yi; Gong, Zhiyuan; Valiyaveettil, Suresh

2008-06-01

63

Pharmacogenomic considerations of xenograft mouse models of acute leukemia.  

PubMed

The use of combination chemotherapy to cure acute lymphoblastic leukemia in children and acute myeloid leukemia in adults emerged for acute myeloid leukemia in the 1960s and for acute lymphoblastic leukemia in the 1980s as a paradigm for curing any disseminated cancer. This article summarizes recent developments and considerations in the use of acute leukemia xenografts established in immunodeficient mice to elucidate the genetic and genomic basis of acute leukemia pathogenesis and treatment response. PMID:23171339

Guihard, Soizic; Peyrouze, Pauline; Cheok, Meyling H

2012-11-01

64

VEGF induces angiogenesis in a zebrafish embryo glioma model established by transplantation of human glioma cells.  

PubMed

Zebrafish (Danio rerio) is becoming an increasingly popular vertebrate cancer model. In this study, we established a xenotransplanted zebrafish embryo glioma model to further investigate the molecular mechanisms of tumor angiogenesis. We find that the glioma cell line U87 can survive, proliferate and induce additional SIV branches in zebrafish embryos. In addition, by the means of in situ hybridization and quantitive RT-PCR analyses we find that the transplanted U87 cells can induce the ectopic zebrafish vascular endothelial growth factor A (VEGF A) and its receptor VEGFR2/KDR mRNA expression and increase their expression levels, resulting in additional SIV branches. PMID:22711017

Li, Dong; Li, Xiang-Pen; Wang, Hong-Xuan; Shen, Qing-Yu; Li, Xiang-Ping; Wen, Lu; Qin, Xiu-Jiao; Jia, Qiu-Li; Kung, Hsiang-Fu; Peng, Ying

2012-06-12

65

Low dose estrogen supplementation reduces mortality of mice in estrogen-dependent human tumor xenograft model.  

PubMed

Breast cancer is one of the most frequent female cancers in the Western world. Perturbation of estrogen levels by hormone replacement therapy or pregnancy is associated with a variety of diseases, including breast cancer. Estrogen supplementation is required to establish appropriate animal models for estrogen-related diseases. In this report, we demonstrated that supplementation with high doses of 17beta-estradiol results in deaths in estrogen-dependent MCF-7 tumor xenograft model. Renal damage and bladder stone formation was implicated as a major cause of death. The mortality rate was significantly reduced when mice received a low dose of 17beta-estradiol. We also confirmed that low dose of 17beta-estradiol supplementation can support the growth of tumors in MCF-7 tumor xenograft model. These results suggest that low dose estrogen supplementation may be more appropriate in estrogen-dependent tumor xenograft models. PMID:19122299

Kang, Jong Soon; Kang, Moo Rim; Han, Sang-Bae; Yoon, Won Kee; Kim, Jang Hyun; Lee, Taek Chang; Lee, Chang Woo; Lee, Ki Hoon; Lee, Kiho; Park, Song-Kyu; Kim, Hwan Mook

2009-01-01

66

Personalized primary tumor xenograft model established for the pre-clinical trial to guide postoperative chemotherapy.  

PubMed

Despite of the fact that a large amount of therapeutic agents have been developed for cancer treatment, we are still sometimes in a dilemma of choosing a most effective regimen for individual. With the reference of several recent researches, positive clinical correlations have been identified with primary tumor xenografts models, but limitations in existed models reveals a need for improvement. Over the past decade, conceptual progress has been made that tumors had increasingly been recognized as organs in which ostensibly normal cells as well as cancer cells participate actively in tumorigenesis by creating the "tumor microenvironment". Herein, we propose a hypothesis based on this novel conception that if transplanted as an organ, tumor implantation in nude mice would conserve most approximated biological traits with improved success rate, which make personalized tumor xenograft model practical for pre-clinical trials as substitutes for each patient. In our pilot study, intact tumor bloc was applied in implantation to evaluate this notion. As a result, 107 xenografts from all 20 patients of gastric cancer were transplanted successfully. Pathological comparison confirmed that no differences between xenografts and primary tumors while the therapeutic response to two chemotherapeutic agents, docetaxel and pemetrexed, exhibited differently. In conclusion, applying personalized primary tumor xenograft model derived from freshly excised tumor in pre-clinic trails would potentially lead to a more effective customized chemotherapy. PMID:23010155

Han, Chenglong; Shen, Jie; Wang, Hao; Yu, Lixia; Qian, Xiaoping; Liu, Baorui; Guan, Wenxian

2012-09-22

67

A two-scale model for correlation between B cell VDJ usage in zebrafish  

NASA Astrophysics Data System (ADS)

The zebrafish (Danio rerio) is one of the model animals for study of immunology. The dynamics of the adaptive immune system in zebrafish is similar to that in higher animals. In this work, we built a two-scale model to simulate the dynamics of B cells in primary and secondary immune reactions in zebrafish and to explain the reported correlation between VDJ usage of B cell repertoires in distinct zebrafish. The first scale of the model consists of a generalized NK model to simulate the B cell maturation process in the 10-day primary immune response. The second scale uses a delay ordinary differential equation system to model the immune responses in the 6-month lifespan of zebrafish. The generalized NK model shows that mature B cells specific to one antigen mostly possess a single VDJ recombination. The probability that mature B cells in two zebrafish have the same VDJ recombination increases with the B cell population size or the B cell selection intensity and decreases with the B cell hypermutation rate. The ODE model shows a distribution of correlation in the VDJ usage of the B cell repertoires in two six-month-old zebrafish that is highly similar to that from experiment. This work presents a simple theory to explain the experimentally observed correlation in VDJ usage of distinct zebrafish B cell repertoires after an immune response.

Pan, Keyao; Deem, Michael

2011-03-01

68

A zebrafish model of diabetes mellitus and metabolic memory.  

PubMed

Diabetes mellitus currently affects 346 million individuals and this is projected to increase to 400 million by 2030. Evidence from both the laboratory and large scale clinical trials has revealed that diabetic complications progress unimpeded via the phenomenon of metabolic memory even when glycemic control is pharmaceutically achieved. Gene expression can be stably altered through epigenetic changes which not only allow cells and organisms to quickly respond to changing environmental stimuli but also confer the ability of the cell to "memorize" these encounters once the stimulus is removed. As such, the roles that these mechanisms play in the metabolic memory phenomenon are currently being examined. We have recently reported the development of a zebrafish model of type I diabetes mellitus and characterized this model to show that diabetic zebrafish not only display the known secondary complications including the changes associated with diabetic retinopathy, diabetic nephropathy and impaired wound healing but also exhibit impaired caudal fin regeneration. This model is unique in that the zebrafish is capable to regenerate its damaged pancreas and restore a euglycemic state similar to what would be expected in post-transplant human patients. Moreover, multiple rounds of caudal fin amputation allow for the separation and study of pure epigenetic effects in an in vivo system without potential complicating factors from the previous diabetic state. Although euglycemia is achieved following pancreatic regeneration, the diabetic secondary complication of fin regeneration and skin wound healing persists indefinitely. In the case of impaired fin regeneration, this pathology is retained even after multiple rounds of fin regeneration in the daughter fin tissues. These observations point to an underlying epigenetic process existing in the metabolic memory state. Here we present the methods needed to successfully generate the diabetic and metabolic memory groups of fish and discuss the advantages of this model. PMID:23485929

Intine, Robert V; Olsen, Ansgar S; Sarras, Michael P

2013-02-28

69

Toward developmental models of psychiatric disorders in zebrafish.  

PubMed

Psychiatric disorders are a diverse set of diseases that affect all aspects of mental function including social interaction, thinking, feeling, and mood. Although psychiatric disorders place a large economic burden on society, the drugs available to treat them are often palliative with variable efficacy and intolerable side-effects. The development of novel drugs has been hindered by a lack of knowledge about the etiology of these diseases. It is thus necessary to further investigate psychiatric disorders using a combination of human molecular genetics, gene-by-environment studies, in vitro pharmacological and biochemistry experiments, animal models, and investigation of the non-biological basis of these diseases, such as environmental effects. Many psychiatric disorders, including autism spectrum disorder, attention-deficit/hyperactivity disorder, mental retardation, and schizophrenia can be triggered by alterations to neural development. The zebrafish is a popular model for developmental biology that is increasingly used to study human disease. Recent work has extended this approach to examine psychiatric disorders as well. However, since psychiatric disorders affect complex mental functions that might be human specific, it is not possible to fully model them in fish. In this review, I will propose that the suitability of zebrafish for developmental studies, and the genetic tools available to manipulate them, provide a powerful model to study the roles of genes that are linked to psychiatric disorders during neural development. The relative speed and ease of conducting experiments in zebrafish can be used to address two areas of future research: the contribution of environmental factors to disease onset, and screening for novel therapeutic compounds. PMID:23637652

Norton, William H J

2013-04-26

70

Toward developmental models of psychiatric disorders in zebrafish  

PubMed Central

Psychiatric disorders are a diverse set of diseases that affect all aspects of mental function including social interaction, thinking, feeling, and mood. Although psychiatric disorders place a large economic burden on society, the drugs available to treat them are often palliative with variable efficacy and intolerable side-effects. The development of novel drugs has been hindered by a lack of knowledge about the etiology of these diseases. It is thus necessary to further investigate psychiatric disorders using a combination of human molecular genetics, gene-by-environment studies, in vitro pharmacological and biochemistry experiments, animal models, and investigation of the non-biological basis of these diseases, such as environmental effects. Many psychiatric disorders, including autism spectrum disorder, attention-deficit/hyperactivity disorder, mental retardation, and schizophrenia can be triggered by alterations to neural development. The zebrafish is a popular model for developmental biology that is increasingly used to study human disease. Recent work has extended this approach to examine psychiatric disorders as well. However, since psychiatric disorders affect complex mental functions that might be human specific, it is not possible to fully model them in fish. In this review, I will propose that the suitability of zebrafish for developmental studies, and the genetic tools available to manipulate them, provide a powerful model to study the roles of genes that are linked to psychiatric disorders during neural development. The relative speed and ease of conducting experiments in zebrafish can be used to address two areas of future research: the contribution of environmental factors to disease onset, and screening for novel therapeutic compounds.

Norton, William H. J.

2013-01-01

71

Parkin Is Protective against Proteotoxic Stress in a Transgenic Zebrafish Model  

PubMed Central

Background Mutations in the gene encoding the E3 ubiquitin ligase parkin (PARK2) are responsible for the majority of autosomal recessive parkinsonism. Similarly to other knockout mouse models of PD-associated genes, parkin knockout mice do not show a substantial neuropathological or behavioral phenotype, while loss of parkin in Drosophila melanogaster leads to a severe phenotype, including reduced lifespan, apoptotic flight muscle degeneration and male sterility. In order to study the function of parkin in more detail and to address possible differences in its role in different species, we chose Danio rerio as a different vertebrate model system. Methodology/Principal Findings We first cloned zebrafish parkin to compare its biochemical and functional aspects with that of human parkin. By using an antisense knockdown strategy we generated a zebrafish model of parkin deficiency (knockdown efficiency between 50% and 60%) and found that the transient knockdown of parkin does not cause morphological or behavioral alterations. Specifically, we did not observe a loss of dopaminergic neurons in parkin-deficient zebrafish. In addition, we established transgenic zebrafish lines stably expressing parkin by using a Gal4/UAS-based bidirectional expression system. While parkin-deficient zebrafish are more vulnerable to proteotoxicity, increased parkin expression protected transgenic zebrafish from cell death induced by proteotoxic stress. Conclusions/Significance Similarly to human parkin, zebrafish parkin is a stress-responsive protein which protects cells from stress-induced cell death. Our transgenic zebrafish model is a novel tool to characterize the protective capacity of parkin in vivo.

Paquet, Dominik; van Bebber, Frauke; Haass, Christian; Tatzelt, Jorg; Schmid, Bettina; Winklhofer, Konstanze F.

2010-01-01

72

On the diabetic menu: Zebrafish as a model for pancreas development and function  

PubMed Central

Summary Development of the vertebrate pancreas is a complex stepwise process comprising regionalization, cell differentiation, and morphogenesis. Studies in zebrafish are contributing to an emerging picture of pancreas development in which extrinsic signaling molecules influence intrinsic transcriptional programs to allow ultimate differentiation of specific pancreatic cell types. Zebrafish experiments have revealed roles for several signaling molecules in aspects of this process; for example our own work has shown that Retinoic Acid signals specify the pre-pancreatic endoderm. Time-lapse imaging of live zebrafish embryos has started to provide detailed information about early pancreas morphogenesis. In addition to modeling embryonic development, the zebrafish has recently begun to be used as a model for pancreas regeneration studies. Here we review the significant progress in these areas and consider the future potential of zebrafish as a diabetes research model.

Kinkel, Mary D.; Prince, Victoria E.

2009-01-01

73

A preclinical xenograft model of prostate cancer using human tumors.  

PubMed

Most cases of prostate cancer are now diagnosed as moderate-grade localized disease. These tumor specimens are important tools in the discovery and translation of prostate cancer research; however, unlike more advanced tumors, they are notoriously difficult to grow in the laboratory. We developed a system for efficiently xenografting localized human prostate cancer tissue, and we adapted this protocol to study the interactions between the specific subsets of epithelial and stromal cells. Fresh prostate tissues or isolated epithelial cells are recombined with mouse seminal vesicle mesenchyme (SVM) and grafted under the renal capsule of immunodeficient mice for optimum growth and survival. Alternatively, mouse mesenchyme can be replaced with human prostate fibroblasts in order to determine their contribution to tumor progression. Grafts can be grown for several months to determine the effectiveness of novel therapeutic compounds when administered to host mice, thereby paving the way for personalizing the treatment of individual prostate cancers. PMID:23558784

Lawrence, Mitchell G; Taylor, Renea A; Toivanen, Roxanne; Pedersen, John; Norden, Sam; Pook, David W; Frydenberg, Mark; Papargiris, Melissa M; Niranjan, Birunthi; Richards, Michelle G; Wang, Hong; Collins, Anne T; Maitland, Norman J; Risbridger, Gail P

2013-04-04

74

Progestin-dependent progression of human breast tumor xenografts: a novel model for evaluating antitumor therapeutics.  

PubMed

Recent clinical trials indicate that synthetic progestins may stimulate progression of breast cancer in postmenopausal women, a result that is consistent with studies in chemically-induced breast cancer models in rodents. However, progestin-dependent progression of breast cancer tumor xenografts has not been shown. This study shows that xenografts obtained from BT-474 and T47-D human breast cancer cells without Matrigel in estrogen-supplemented nude mice begin to regress within days after tumor cell inoculation. However, their growth is resumed if animals are supplemented with progesterone. The antiprogestin RU-486 blocks progestin stimulation of growth, indicating involvement of progesterone receptors. Exposure of xenografts to medroxyprogesterone acetate, a synthetic progestin used in postmenopausal hormone replacement therapy and oral contraception, also stimulates growth of regressing xenograft tumors. Tumor progression is dependent on expression of vascular endothelial growth factor (VEGF); growth of progestin-dependent tumors is blocked by inhibiting synthesis of VEGF or VEGF activity using a monoclonal anti-VEGF antibody (2C3) or by treatment with PRIMA-1, a small-molecule compound that reactivates mutant p53 into a functional protein and blocks VEGF production. These results suggest a possible model system for screening potential therapeutic agents for their ability to prevent or inhibit progestin-dependent human breast tumors. Such a model could potentially be used to screen for safer antiprogestins, antiangiogenic agents, or for compounds that reactivate mutant p53 and prevent progestin-dependent progression of breast disease. PMID:17942925

Liang, Yayun; Besch-Williford, Cynthia; Brekken, Rolf A; Hyder, Salman M

2007-10-15

75

Subcutaneous passage increases cell aggressiveness in a xenograft model of diffuse large B cell lymphoma.  

PubMed

Xenograft models of human diffuse large B cell lymphoma (DLBCL) are widely used to test new drugs against this neoplasia. Most of them, however, are subcutaneous xenografts that do not show a disseminated disease as it is found in the human neoplasia. In this paper, we aimed to develop a disseminated xenograft model of DLBCL by performing a subcutaneous passage of DLBCL cells before their intravenous injection in mice. WSU-DLCL-2 (WSU) cells were injected into both flanks of NOD/SCID mice. The subcutaneous tumours were disaggregated and a cell suspension (WSU-SC) was obtained. Two groups of 10 NOD/SCID mice were intravenously injected with WSU-SC or WSU cells. All mice injected with WSU-SC cells developed lymphoma in 32-47 days and showed lymph node and bone marrow infiltration. WSU-SC cells showed a significantly higher engraftment rate and faster dissemination than WSU cells after intravenous injection in mice. When molecularly compared, WSU-SC cells showed higher expression levels of FAK, p130Cas and phosphorylated AKT than WSU cells. The subcutaneous passage enhanced the engraftment and the metastatic capacity of WSU cells, allowing the generation of a rapid and disseminated DLBCL xenograft model. The aggressive behaviour of WSU-SC cells was associated with increased p130Cas and FAK expression and AKT activation. PMID:22262061

Bosch, Rosa; Moreno, María José; Dieguez-Gonzalez, Rebeca; Céspedes, María Virtudes; Gallardo, Alberto; Nomdedeu, Josep; Pavón, Miguel Angel; Espinosa, Iñigo; Mangues, Maria Antònia; Sierra, Jorge; Casanova, Isolda; Mangues, Ramon

2012-01-20

76

Efficacy of Weekly Docetaxel and Bevacizumab in Mesenchymal Chondrosarcoma: A New Theranostic Method Combining Xenografted Biopsies with a Mathematical Model  

Microsoft Academic Search

The paucity of clinical treatment data on rare tumors, such as mesenchymal chondrosarcoma (MCS), emphasizes the need in theranostic tools for these diseases. We put forward and validated a new theranostic method, combining tumor xenografts and mathematical models, and used it to suggest an improved treatment schedule for a particular MCS patient. Growth curves and gene expression analysis of xenografts,

Boris Gorelik; Irit Ziv; Revital Shohat; Michael Wick; W. David Hankins; David Sidransky; Zvia Agur

2008-01-01

77

Atransgenic zebrafish model of neutrophilic inflammation  

Microsoft Academic Search

We have established an in vivo model for genetic analysis of the inflammatory re- sponse by generating a transgenic ze- brafish line that expresses GFP under the neutrophil-specific myeloperoxidase pro- moter. We show that inflammation is in- duced after transection of the tail of ze- brafish larvae and that this inflammation subsequently resolves over a similar time course to mammalian

Stephen A. Renshaw; Catherine A. Loynes; Daniel M. I. Trushell; Stone Elworthy; Philip W. Ingham; Moira K. B. Whyte

78

Establishment of a PDTT xenograft model of gastric carcinoma and its application in personalized therapeutic regimen selection.  

PubMed

Background/Aims: Lack of appropriate tumor models that reliably predict response to anticancer agents remains a major deficiency in the clinical practice of personalized cancer therapy. The aim of our study was to establish a patient-derived tumor tissue (PDTT) xenograft model of gastric carcinoma for personalized cancer therapeutic regimen selection and testing of novel molecularly targeted agents. Methodology: Patient-derived tumor tissue of primary gastric carcinoma was used to create the xenograft model. After 11 weeks, xenografts were harvested for serial transplantation. H&E staining, immunohistochemical staining and Western blotting were used to determine biological stability of the xenograft during serial transplantation compared with the original tumor tissue. Drug sensitivities of the xenograft to bevacizumab (Avastin), FP3 and cetuximab were evaluated. PMID:21940303

Jin, Ketao; He, Kuifeng; Han, Na; Li, Guangliang; Wang, Haohao; Xu, Zhenzhen; Jiang, Haiping; Zhang, Jing; Teng, Lisong

2011-07-15

79

Can zebrafish be used as animal model to study Alzheimer's disease?  

PubMed Central

Zebrafish is rapidly emerging as a promising model organism to study various central nervous system (CNS) disorders, including Alzheimer’s disease (AD). AD is the main cause of dementia in the human population and there is an urgency to understand the causes of this neurodegenerative disease. In this respect, the development of new animal models to study the underlying neurodegenerative mechanisms of AD is an urgent need. In this review we analyze the current situation in the use of zebrafish as a model for AD, discussing the reasons to use this experimental paradigm in CNS investigation and analyzing the several strategies adopted to induce an AD-like pathology in zebrafish. We discuss the strategies of performing interventions to cause damage in the zebrafish brain by altering the major neurotransmitter systems (such as cholinergic, glutamatergic or GABAergic circuits). We also analyze the several transgenic zebrafish constructed for the AD study, discussing both the familial-AD models based on APP processing pathway (APP and presenilins) and in the TAU hyperphosphorylation, together with the genes involved in sporadic-AD, as apolipoprotein E. We conclude that zebrafish is in a preliminary stage of development in the AD field, and that the transgenic animals must be improved to use this fish as an optimal model for AD research. Furthermore, a deeper knowledge of the zebrafish brain and a better characterization of the injury caused by alterations in the major neurotransmitter systems are needed.

Santana, Soraya; Rico, Eduardo P; Burgos, Javier S

2012-01-01

80

Zebrafish as a model for normal and malignant hematopoiesis  

PubMed Central

Zebrafish studies in the past two decades have made major contributions to our understanding of hematopoiesis and its associated disorders. The zebrafish has proven to be a powerful organism for studies in this area owing to its amenability to large-scale genetic and chemical screening. In addition, the externally fertilized and transparent embryos allow convenient genetic manipulation and in vivo imaging of normal and aberrant hematopoiesis. This review discusses available methods for studying hematopoiesis in zebrafish, summarizes key recent advances in this area, and highlights the current and potential contributions of zebrafish to the discovery and development of drugs to treat human blood disorders.

Jing, Lili; Zon, Leonard I.

2011-01-01

81

Prolongation of xenograft survival after combination therapy with 15-deoxyspergualin and total-lymphoid irradiation in the hamster-to-rat cardiac xenograft model.  

PubMed

Adequate immunosuppression remains a major obstacle to successful xenotransplantation, with early xenograft rejection appearing to be mediated by humoral factors. Total-lymphoid irradiation (TLI) and 15-deoxyspergualin (DOSP) have been shown to be effective immunosuppressive agents in allografs. In this study, TLI alone and in combination with DOSP and cyclosporine were evaluated in the hamster-to-rat heterotopic cardiac xenograft model. The animals were divided into four groups: group 1--control (n = 9); group 2--TLI alone, administered pretransplant at 125 cGy/day, four days per week, for three weeks (n = 12); group 3--TLI plus CsA at 10 mg/kg/day (n = 17); and group 4--TLI plus DOSP at 2.5 mg/kg/day (n = 10). Tissue sections were taken from rejected xenografts in all treatment groups for histological examination. Complement-dependent cytotoxicity assays were performed on the control group and also the TLI-DOSP group. The control animals were found to have a mean graft survival of 3.2 +/- 0.4 days. TLI alone (5.8 +/- 0.7 days) did not significantly improve graft survival in comparison with the control group. Combination of TLI with DOSP (26.3 +/- 5.9 days) results in significantly improved survival (P less than 0.05) in comparison with the control, TLI alone, and combination of TLI and CsA (13.6 +/- 8.6 days). Complement-dependent cytotoxicity assays revealed that control groups have low rat antihamster lymphocytotoxic antibody titer (1/1-1/10) prior to xenografting, and that these antibody titers show a precipitous rise to a level of 1/640-1/1280 by day 3, the time at which rejection occurred. This correlates with the histological findings of the rejected hearts showing a severe humoral type of rejection and no evidence of cellular rejection. In contrast, animals in the TLI-DOSP group had markedly lowered rat antihamster lymphocytotoxic antibody titers (1/20-1/40) on day 3, and these titers only increased to 1/160 at time of rejection. This correlates with the histological findings of a lesser degree of humoral rejection in the TLI-DOSP group. Combination therapy with TLI and DOSP results in a marked increase of survival in xenografts in this model not seen with any other drug combination studied in over 500 xenografts in our laboratory. This study indicates that TLI combined with DOSP results in prolonged suppression of the antixenograft antibody response. This combination of agents appears to have the potential to prevent early xenograft rejection. PMID:1733081

Marchman, W; Araneda, D; DeMasi, R; Taylor, D; Larkin, E; Alqaisi, M; Thomas, F

1992-01-01

82

The Zebrafish Embryo as a Dynamic Model of Anoxia Tolerance  

PubMed Central

Developing organisms depend upon a delicate balance in the supply and demand of energy to adapt to variable oxygen availability, though the essential mechanisms determining such adaptation remain elusive. In this study we examine reversible anoxic arrest and dynamic bioenergetic transitions during zebrafish development. Our data reveal that the duration of anoxic viability corresponds to the developmental stage and anaerobic metabolic rate. Diverse chemical inhibitors of mitochondrial oxidative phosphorylation induce a similar arrest in normoxic embryos, suggesting a pathway responsive to perturbations in aerobic energy production rather than molecular oxygen. Consistent with this concept, arrest is accompanied by rapid activation of the energy-sensing AMP-activated protein kinase pathway, demonstrating a potential link between the sensing of energy status and adaptation to oxygen availability. These observations permit mechanistic insight into energy homeostasis during development that now enable genetic and small molecule screens in this vertebrate model of anoxia tolerance.

Mendelsohn, Bryce A.; Kassebaum, Bethany L.; Gitlin, Jonathan D.

2010-01-01

83

Screening for melanoma modifiers using a zebrafish autochthonous tumor model.  

PubMed

Genomic studies of human cancers have yielded a wealth of information about genes that are altered in tumors. A challenge arising from these studies is that many genes are altered, and it can be difficult to distinguish genetic alterations that drove tumorigenesis from that those arose incidentally during transformation. To draw this distinction it is beneficial to have an assay that can quantitatively measure the effect of an altered gene on tumor initiation and other processes that enable tumors to persist and disseminate. Here we present a rapid means to screen large numbers of candidate melanoma modifiers in zebrafish using an autochthonous tumor model that encompasses steps required for melanoma initiation and maintenance. A key reagent in this assay is the miniCoopR vector, which couples a wild-type copy of the mitfa melanocyte specification factor to a Gateway recombination cassette into which candidate melanoma genes can be recombined. The miniCoopR vector has a mitfa rescuing minigene which contains the promoter, open reading frame and 3'-untranslated region of the wild-type mitfa gene. It allows us to make constructs using full-length open reading frames of candidate melanoma modifiers. These individual clones can then be injected into single cell Tg(mitfa:BRAF(V600E));p53(lf);mitfa(lf)zebrafish embryos. The miniCoopR vector gets integrated by Tol2-mediated transgenesis and rescues melanocytes. Because they are physically coupled to the mitfa rescuing minigene, candidate genes are expressed in rescued melanocytes, some of which will transform and develop into tumors. The effect of a candidate gene on melanoma initiation and melanoma cell properties can be measured using melanoma-free survival curves, invasion assays, antibody staining and transplantation assays. PMID:23183931

Iyengar, Sharanya; Houvras, Yariv; Ceol, Craig J

2012-11-13

84

Zebrafish as a potential model organism for drug test against hepatitis C virus.  

PubMed

Screening and evaluating anti- hepatitis C virus (HCV) drugs in vivo is difficult worldwide, mainly because of the lack of suitable small animal models. We investigate whether zebrafish could be a model organism for HCV replication. To achieve NS5B-dependent replication an HCV sub-replicon was designed and created with two vectors, one with HCV ns5b and fluorescent rfp genes, and the other containing HCV's 5'UTR, core, 3'UTR and fluorescent gfp genes. The vectors containing sub-replicons were co-injected into zebrafish zygotes. The sub-replicon amplified in liver showing a significant expression of HCV core RNA and protein. The sub-replicon amplification caused no abnormality in development and growth of zebrafish larvae, but induced gene expression change similar to that in human hepatocytes. As the amplified core fluorescence in live zebrafish was detectable microscopically, it rendered us an advantage to select those with replicating sub-replicon for drug experiments. Ribavirin and oxymatrine, two known anti-HCV drugs, inhibited sub-replicon amplification in this model showing reduced levels of HCV core RNA and protein. Technically, this method had a good reproducibility and is easy to operate. Thus, zebrafish might be a model organism to host HCV, and this zebrafish/HCV (sub-replicon) system could be an animal model for anti-HCV drug screening and evaluation. PMID:21857967

Ding, Cun-Bao; Zhang, Jing-Pu; Zhao, Ye; Peng, Zong-Gen; Song, Dan-Qing; Jiang, Jian-Dong

2011-08-08

85

Hematein, a casein kinase II inhibitor, inhibits lung cancer tumor growth in a murine xenograft model.  

PubMed

Casein kinase II (CK2) inhibitors suppress cancer cell growth. In this study, we examined the inhibitory effects of a novel CK2 inhibitor, hematein, on tumor growth in a murine xenograft model. We found that in lung cancer cells, hematein inhibited cancer cell growth, Akt/PKB Ser129 phosphorylation, the Wnt/TCF pathway and increased apoptosis. In a murine xenograft model of lung cancer, hematein inhibited tumor growth without significant toxicity to the mice tested. Molecular docking showed that hematein binds to CK2? in durable binding sites. Collectively, our results suggest that hematein is an allosteric inhibitor of protein kinase CK2 and has antitumor activity to lung cancer. PMID:24008396

Hung, Ming-Szu; Xu, Zhidong; Chen, Yu; Smith, Emmanuel; Mao, Jian-Hua; Hsieh, David; Lin, Yu-Ching; Yang, Cheng-Ta; Jablons, David M; You, Liang

2013-09-04

86

Establishment of multi-site infection model in zebrafish larvae for studying Staphylococcus aureus infectious disease.  

PubMed

Zebrafish (Danio rerio) is an ideal model for studying the mechanism of infectious disease and the interaction between host and pathogen. As a teleost, zebrafish has developed a complete immune system which is similar to mammals. Moreover, the easy acquirement of large amounts of transparent embryos makes it a good candidate for gene manipulation and drug screening. In a zebrafish infection model, all of the site, timing, and dose of the bacteria microinjection into the embryo are important factors that determine the bacterial infection of host. Here, we established a multi-site infection model in zebrafish larvae of 36 hours post-fertilization (hpf) by microinjecting wild-type or GFP-expressing Staphylococcus aereus (S. aureus) with gradient burdens into different embryo sites including the pericardial cavity (PC), eye, the fourth hindbrain ventricle (4V), yolk circulation valley (YCV), caudal vein (CV), yolk body (YB), and Duct of Cuvier (DC) to resemble human infectious disease. With the combination of GFP-expressing S. aureus and transgenic zebrafish Tg (coro1a: eGFP; lyz: Dsred) and Tg (lyz: Dsred) lines whose macrophages or neutrophils are fluorescent labeled, we observed the dynamic process of bacterial infection by in vivo multicolored confocal fluorescence imaging. Analyses of zebrafish embryo survival, bacterial proliferation and myeloid cells phagocytosis show that the site- and dose-dependent differences exist in infection of different bacterial entry routes. This work provides a consideration for the future study of pathogenesis and host resistance through selection of multi-site infection model. More interaction mechanisms between pathogenic bacteria virulence factors and the immune responses of zebrafish could be determined through zebrafish multi-site infection model. PMID:23021551

Li, Ya-juan; Hu, Bing

2012-08-23

87

Antitumor activity of erlotinib in combination with capecitabine in human tumor xenograft models  

Microsoft Academic Search

Purpose: To examine the antitumor activity and tolerability of a combination comprising erlotinib and capecitabine in human colorectal,\\u000a breast and epidermal cancer xenograft models. Further aims of the study were to examine the effects of single-agent erlotinib\\u000a therapy on tumor growth, and on thymidine phosphorylase (TP) and dihydropyrimidine dehydrogenase (DPD) levels, (enzymes which\\u000a activate and deactivate capecitabine, respectively) in tumor

Kaori F.-Ouchi; Mieko Yanagisawa; Fumiko Sekiguchi; Yutaka Tanaka

2006-01-01

88

Androgen-dependent and -independent Human Prostate Xenograft Tumors as Models for Drug Activity Evaluation1  

Microsoft Academic Search

The present study evaluated three human prostate xenogran tumors (CWR22, CWR22R, and CWR91) as models for drug activity evaluation. The chemosensitivity and the expression of several proteins (i.e.. p-glyco- protein or Pgp, prostate specific antigen or PSA, p53, and Bcl-2) in xenograft tumors were compared with those in patient tumors obtained through radical prostatectomy (n = 26). CWR22 is androgen-dependent,

Chiung-Tong Chen; Yuebo Gan; M. Guillaume Wientjes

1998-01-01

89

In Vivo Bioluminescence Imaging of Murine Xenograft Cancer Models with a Red-shifted Thermostable Luciferase  

Microsoft Academic Search

Purpose  Conventional in vivo bioluminescence imaging using wild-type green-emitting luciferase is limited by absorption and scattering of the bioluminescent\\u000a signal through tissues. Imaging methods using a red-shifted thermostable luciferase from Photinus pyralis were optimized to improve the sensitivity and image resolution. In vivo bioluminescence imaging performance of red- and green-emitting luciferases were compared in two different xenograft mouse\\u000a models for cancer.

Laura Mezzanotte; Raffaella Fazzina; Elisa Michelini; Roberto Tonelli; Andrea Pession; Bruce Branchini; Aldo Roda

2010-01-01

90

Large-Scale Assessment of the Zebrafish Embryo as a Possible Predictive Model in Toxicity Testing  

PubMed Central

Background In the drug discovery pipeline, safety pharmacology is a major issue. The zebrafish has been proposed as a model that can bridge the gap in this field between cell assays (which are cost-effective, but low in data content) and rodent assays (which are high in data content, but less cost-efficient). However, zebrafish assays are only likely to be useful if they can be shown to have high predictive power. We examined this issue by assaying 60 water-soluble compounds representing a range of chemical classes and toxicological mechanisms. Methodology/Principal Findings Over 20,000 wild-type zebrafish embryos (including controls) were cultured individually in defined buffer in 96-well plates. Embryos were exposed for a 96 hour period starting at 24 hours post fertilization. A logarithmic concentration series was used for range-finding, followed by a narrower geometric series for LC50 determination. Zebrafish embryo LC50 (log mmol/L), and published data on rodent LD50 (log mmol/kg), were found to be strongly correlated (using Kendall's rank correlation tau and Pearson's product-moment correlation). The slope of the regression line for the full set of compounds was 0.73403. However, we found that the slope was strongly influenced by compound class. Thus, while most compounds had a similar toxicity level in both species, some compounds were markedly more toxic in zebrafish than in rodents, or vice versa. Conclusions For the substances examined here, in aggregate, the zebrafish embryo model has good predictivity for toxicity in rodents. However, the correlation between zebrafish and rodent toxicity varies considerably between individual compounds and compound class. We discuss the strengths and limitations of the zebrafish model in light of these findings.

Ali, Shaukat; van Mil, Harald G. J.; Richardson, Michael K.

2011-01-01

91

Therapeutic activity of two xanthones in a xenograft murine model of human chronic lymphocytic leukemia  

PubMed Central

Background We previously reported that allanxanthone C and macluraxanthone, two xanthones purified from Guttiferae trees, display in vitro antiproliferative and proapoptotic activities in leukemic cells from chronic lymphocytic leukemia (CLL) and leukemia B cell lines. Results Here, we investigated the in vivo therapeutic effects of the two xanthones in a xenograft murine model of human CLL, developed by engrafting CD5-transfected chronic leukemia B cells into SCID mice. Treatment of the animals with five daily injections of either allanxanthone C or macluraxanthone resulted in a significant prolongation of their survival as compared to control animals injected with the solvent alone (p = 0.0006 and p = 0.0141, respectively). The same treatment of mice which were not xenografted induced no mortality. Conclusion These data show for the first time the in vivo antileukemic activities of two plant-derived xanthones, and confirm their potential interest for CLL therapy.

2010-01-01

92

Chemotherapeutic treatment of xenograft Spirocerca lupi-associated sarcoma in a murine model.  

PubMed

To date, data are not available concerning the effectiveness of chemotherapy in the treatment of Spirocerca lupi-associated esophageal sarcomas. In the present study, we compared the effectiveness of 4 chemotherapeutic agents against S. lupi-associated osteosarcoma, using a xenograft murine model created in our lab. Samples of xenografted osteosarcoma were inoculated subcutaneously into 5 groups (n = 10 each) of 6-wk-old male and female NOD/SCID mice. Tumor-bearing mice were divided into treatment and control groups. The treatment groups were injected with either pegylated liposomal doxorubicin (6 mg/kg, intravenously, n = 9), doxorubicin (6 mg/kg, intravenously, n = 8), carboplatin (60 mg/kg, intraperitoneally, repeated twice at 1-wk intervals for a total of 2 doses, n = 9), or cisplatin (6 mg/kg, intraperitoneally, n = 8). The control group was injected with buffered saline (n = 9). Tumor size was determined by caliper measurements. Compared with the control group, the pegylated liposomal doxorubicin- and doxorubicin-treated groups, but not the carboplatin or cisplatin groups, showed significant inhibition of tumor growth. Our results indicate that doxorubicin-based drugs are effective against S. lupi-associated sarcomas in a mouse xenograft model. Because it is less toxic than doxorubicin, pegylated liposomal doxorubicin is likely the drug of choice for treatment of S. lupi-associated sarcomas. We suggest that combination of doxorubicin or its pegylated form with surgical excision will improve the prognosis of dogs with this disease. PMID:17605341

Stettner, Noa; Ranen, Eyal; Dank, Gillian; Lavy, Eran; Brenner, Ori; Harmelin, Alon

2007-06-01

93

Primary esophageal and gastro-esophageal junction cancer xenograft models: clinicopathological features and engraftment.  

PubMed

There are very few xenograft models available for the study of esophageal (E) and gastro-esophageal junction (GEJ) cancer. Using a NOD/SCID model, we implanted 90 primary E and GEJ tumors resected from patients and six endoscopic biopsy specimens. Of 69 resected tumors with histologically confirmed viable adenocarcinoma or squamous cell carcinoma, 22 (32%) was engrafted. One of 11 tumors, considered to have had a complete pathological response to neo-adjuvant chemo-radiation, also engrafted. Of the 23 patients whose tumors were engrafted, 65% were male; 30% were early stage while 70% were late stage; 22% received neo-adjuvant chemo-radiation; 61% were GEJ cancers. Engraftment occurred in 18/54 (33%) adenocarcinomas and 5/16 (31%) squamous cell carcinomas. Small endoscopic biopsy tissue had a 50% (3/6) engraftment rate. Of the factors analyzed, pretreatment with chemo-radiation and well/moderate differentiation showed significantly lower correlation with engraftment (P<0.05). In the subset of patients who did not receive neo-adjuvant chemo-radiation, 18/41 (44%) engrafted compared with those with pretreatment where 5/29 (17%, P=0.02) engrafted. Primary xenograft lines may be continued through 4-12 passages. Xenografts maintained similar histology and morphological characteristics with only minor variations even after multiple passaging in most instances. PMID:23399854

Dodbiba, Lorin; Teichman, Jennifer; Fleet, Andrew; Thai, Henry; Sun, Bin; Panchal, Devang; Patel, Devalben; Tse, Alvina; Chen, Zhuo; Faluyi, Olusola O; Renouf, Daniel J; Girgis, Hala; Bandarchi, Bizhan; Schwock, Joerg; Xu, Wei; Bristow, Robert G; Tsao, Ming-Sound; Darling, Gail E; Ailles, Laurie E; El-Zimaity, Hala; Liu, Geoffrey

2013-02-11

94

Mouse Xenograft Models for Drug Discovery in Pancreatic Cancer  

Microsoft Academic Search

\\u000a It is estimated that the development of a new anticancer agent costs US $800–1,000 million and takes over a decade between\\u000a conception and approval. However, 90% of novel antineoplastic drugs fail in the clinic despite evidence of antitumor efficacy\\u000a in classical preclinical models. This raises serious concerns whether such models are predictive of drug efficacy in humans,\\u000a supporting the development of

Belen Rubio-Viqueira; Manuel Hidalgo

95

Impaired neural development in a zebrafish model for Lowe syndrome.  

PubMed

Lowe syndrome, which is characterized by defects in the central nervous system, eyes and kidneys, is caused by mutation of the phosphoinositide 5-phosphatase OCRL1. The mechanisms by which loss of OCRL1 leads to the phenotypic manifestations of Lowe syndrome are currently unclear, in part, owing to the lack of an animal model that recapitulates the disease phenotype. Here, we describe a zebrafish model for Lowe syndrome using stable and transient suppression of OCRL1 expression. Deficiency of OCRL1, which is enriched in the brain, leads to neurological defects similar to those reported in Lowe syndrome patients, namely increased susceptibility to heat-induced seizures and cystic brain lesions. In OCRL1-deficient embryos, Akt signalling is reduced and there is both increased apoptosis and reduced proliferation, most strikingly in the neural tissue. Rescue experiments indicate that catalytic activity and binding to the vesicle coat protein clathrin are essential for OCRL1 function in these processes. Our results indicate a novel role for OCRL1 in neural development, and support a model whereby dysregulation of phosphoinositide metabolism and clathrin-mediated membrane traffic leads to the neurological symptoms of Lowe syndrome. PMID:22210625

Ramirez, Irene Barinaga-Rementeria; Pietka, Grzegorz; Jones, David R; Divecha, Nullin; Alia, A; Baraban, Scott C; Hurlstone, Adam F L; Lowe, Martin

2011-12-30

96

Impaired neural development in a zebrafish model for Lowe syndrome  

PubMed Central

Lowe syndrome, which is characterized by defects in the central nervous system, eyes and kidneys, is caused by mutation of the phosphoinositide 5-phosphatase OCRL1. The mechanisms by which loss of OCRL1 leads to the phenotypic manifestations of Lowe syndrome are currently unclear, in part, owing to the lack of an animal model that recapitulates the disease phenotype. Here, we describe a zebrafish model for Lowe syndrome using stable and transient suppression of OCRL1 expression. Deficiency of OCRL1, which is enriched in the brain, leads to neurological defects similar to those reported in Lowe syndrome patients, namely increased susceptibility to heat-induced seizures and cystic brain lesions. In OCRL1-deficient embryos, Akt signalling is reduced and there is both increased apoptosis and reduced proliferation, most strikingly in the neural tissue. Rescue experiments indicate that catalytic activity and binding to the vesicle coat protein clathrin are essential for OCRL1 function in these processes. Our results indicate a novel role for OCRL1 in neural development, and support a model whereby dysregulation of phosphoinositide metabolism and clathrin-mediated membrane traffic leads to the neurological symptoms of Lowe syndrome.

Ramirez, Irene Barinaga-Rementeria; Pietka, Grzegorz; Jones, David R.; Divecha, Nullin; Alia, A.; Baraban, Scott C.; Hurlstone, Adam F. L.; Lowe, Martin

2012-01-01

97

Orthotopic human melanoma xenograft model systems for studies of tumour angiogenesis, pathophysiology, treatment sensitivity and metastatic pattern.  

PubMed Central

Adequate tumour models are a prerequisite in experimental cancer research. The purpose of the present work was to establish and assess the validity of four new orthotopic human melanoma xenograft model systems (A-07, D-12, R-18, U-25). Permanent cell lines were established in monolayer culture from subcutaneous metastases of four different melanoma patients by using an in vivo-in vitro procedure, and cells from these lines were inoculated intradermally in Balb/c nu/nu mice to form tumours. Individual xenografted tumours of the same line differed substantially in growth and pathophysiological parameters, probably as a consequence of differences between inoculation sites in host factors which influence tumour angiogenesis. Nevertheless, xenografted tumours of different lines showed distinctly different biological characteristics. Several biological characteristics of the donor patients' tumours were retained in the xenografted tumours, including angiogenic potential; growth, histopathological and pathophysiological parameters; and sensitivity to radiation, heat and dacarbazine treatment. Moreover, the organ-specific metastatic pattern of the xenografted tumours reflected the pattern of distant metastases in the donor patients. The organs of preference for distant metastases were lungs (A-07, D-12), lymph nodes (R-18) and brain (U-25). R-18 lymph node metastases and U-25 brain metastases developed in the absence of lung involvement. The four orthotopic human melanoma xenograft model systems show great promise for future studies of tumour angiogenesis, pathophysiology, treatment sensitivity and metastatic pattern. Images Figure 1 Figure 4 Figure 5 Figure 7

Rofstad, E. K.

1994-01-01

98

Modeling Human Choroidal Melanoma Xenograft Growth in Immunocompromised Rodents to Assess Treatment Efficacy  

PubMed Central

Purpose. To evaluate potential treatments of primary uveal melanoma in rodent xenograft models, it is necessary to track individual tumor growth during treatment. Previously, high-frequency ultrasound (HF-US) was used to measure tumor volume in nude rats for up to 2 weeks. This study tests the hypothesis that HF-US can be used to repeatedly measure tumor volume for at least a month in both nude rat and severe combined immunodeficiency (SCID) mouse xenograft models of human uveal melanoma, with the goal of modeling tumor growth to evaluate treatment efficacy. Methods. C918 human uveal melanoma spheroids were implanted in the choroids of six nude rats and six severe combined immunodeficiency mice. OCM-1 human uveal melanoma spheroids were implanted in six nude rats. Every 4–7 days thereafter for up to 5 weeks, HF-US images of the tumor-bearing eye were captured every 100 or 250 ?m. Tumor areas were measured on each image and integrated to calculate volume. Tumor growth was modeled using a logistic curve, and parameters characterizing growth, including the time to reach a target volume (tT), were evaluated as potential measures of treatment efficacy. Results. Tumor volume could be measured for up to 5 weeks in all models, and the logistic curve described the growth well. The parameter tT was shown to be a suitable endpoint to evaluate treatments. Conclusions. HF-US is a practical method to track uveal melanoma growth in the same nude rat or SCID mouse for up to a month. Such growth data can be used to evaluate treatments in these xenograft models.

Braun, Rod D.; Vistisen, Kerry S.

2012-01-01

99

Assessing the impact of thermal acclimation on physiological condition in the zebrafish model.  

PubMed

The zebrafish has become a valuable vertebrate model organism in a wide range of scientific disciplines, but current information concerning the physiological temperature response of adult zebrafish is rather scarce. In this study, zebrafish were experimentally acclimated for 28 days to 18, 26 or 34 °C and a suite of non-invasive and invasive methods was applied to determine the thermal dependence of zebrafish physiological condition. With decreasing temperature, the metabolic rate of zebrafish decreased, as shown by the decreasing oxygen uptake and ammonia excretion rates, limiting the critical swimming speed, probably due to a decreased muscle fibre power output. In response to exercise, fuel stores were mobilized to the liver as shown by the increased hepatosomatic index, liver total absolute energetic value and liver carbohydrate concentration but due to the low metabolic rate they could not be adequately addressed to power swimming activity at 18 °C. Conversely, the increased metabolic performance at high temperature came with an increased metabolic cost resulting in decreased energy status reflected particularly well by the non-invasive condition factor and invasive measures of carcass protein concentration, carcass total absolute energetic value and liver carbohydrate concentration. We showed that the combined measurement of the relative condition factor and critical swimming speed is a powerful non-invasive tool for long-term follow-up studies. Invasive methods were redundant for measuring general energy status but they provided detailed information concerning metabolic reorganization. With this study we proved that the usefulness of the zebrafish as a model organism can easily be expanded to include physiological studies and we provided a reference dataset for the selection of measures of physiological responses for future studies using the zebrafish. PMID:22872185

Vergauwen, Lucia; Knapen, Dries; Hagenaars, An; De Boeck, Gudrun; Blust, Ronny

2012-08-08

100

Novel Insights into the Genetic Controls of Primitive and Definitive Hematopoiesis from Zebrafish Models  

PubMed Central

Hematopoiesis is a dynamic process where initiation and maintenance of hematopoietic stem cells, as well as their differentiation into erythroid, myeloid and lymphoid lineages, are tightly regulated by a network of transcription factors. Understanding the genetic controls of hematopoiesis is crucial as perturbations in hematopoiesis lead to diseases such as anemia, thrombocytopenia, or cancers, including leukemias and lymphomas. Animal models, particularly conventional and conditional knockout mice, have played major roles in our understanding of the genetic controls of hematopoiesis. However, knockout mice for most of the hematopoietic transcription factors are embryonic lethal, thus precluding the analysis of their roles during the transition from embryonic to adult hematopoiesis. Zebrafish are an ideal model organism to determine the function of a gene during embryonic-to-adult transition of hematopoiesis since bloodless zebrafish embryos can develop normally into early larval stage by obtaining oxygen through diffusion. In this review, we discuss the current status of the ontogeny and regulation of hematopoiesis in zebrafish. By providing specific examples of zebrafish morphants and mutants, we have highlighted the contributions of the zebrafish model to our overall understanding of the roles of transcription factors in regulation of primitive and definitive hematopoiesis.

Sood, Raman; Liu, Paul

2012-01-01

101

Hematopoietic stem cells, hematopoiesis and disease: lessons from the zebrafish model  

PubMed Central

The zebrafish model is rapidly gaining prominence in the study of development, hematopoiesis, and disease. The zebrafish provides distinct advantages over other vertebrate models during early embryonic development by producing transparent, externally fertilized embryos. Embryonic zebrafish are easily visualized and manipulated through microinjection, chemical treatment, and mutagenesis. These procedures have contributed to large-scale chemical, suppressor, and genetic screens to identify hematopoietic gene mutations. Genomic conservation and local synteny between the human and zebrafish genomes make genome-scale and epigenetic analysis of these mutations (by microarray, chromatin immunoprecipitation sequencing, and RNA sequencing procedures) powerful methods for translational research and medical discovery. In addition, large-scale screening techniques have resulted in the identification of several small molecules capable of rescuing hematopoietic defects and inhibiting disease. Here, we discuss the contributions of the zebrafish model to the understanding of hematopoiesis, hematopoietic stem cell development, and disease-related discovery. We also highlight the recent discovery of small molecules with clinical promise, such as dimethyl prostaglandin E2, 3F8, and thiazole-carboxamide 10A.

2011-01-01

102

Kinetics of Neuroendocrine Differentiation in an Androgen-Dependent Human Prostate Xenograft Model  

Microsoft Academic Search

It was previously shown in the PC-295 xenograft that the number of\\u000a chromogranin A (CgA)-positive neuroendocrine (NE) cells increased after\\u000a androgen withdrawal. NE cells did not proliferate and differentiated from\\u000a G0-phase-arrested cells. Here we further characterized NE differentiation,\\u000a androgen receptor status, and apoptosis-associated Bcl-2 expression in the\\u000a PC-295 model after androgen withdrawal to assess the origin of NE cells.\\u000a PC-295

Johan Jongsma; Monique H. Oomen; Marinus A. Noordzij; Wytske M. Van Weerden; Gerard J. M. Martens; Theodorus H. van der Kwast; Fritz H. Schröder; Gert J. van Steenbrugge

1999-01-01

103

A preclinical xenograft model identifies castration-tolerant cancer-repopulating cells in localized prostate tumors.  

PubMed

A lack of clinically relevant experimental models of human prostate cancer hampers evaluation of potential therapeutic agents. Currently, androgen deprivation therapy is the gold standard treatment for advanced prostate cancer, but inevitably, a subpopulation of cancer cells survives and repopulates the tumor. Tumor cells that survive androgen withdrawal are critical therapeutic targets for more effective treatments, but current model systems cannot determine when they arise in disease progression and are unable to recapitulate variable patient response to treatment. A model system was developed in which stromal-supported xenografts from multiple patients with early-stage localized disease can be tested for response to castration. The histopathology of these xenografts mimicked the original tumors, and short-term host castration resulted in reduced proliferation and increased apoptosis in tumor cells. After 4 weeks of castration, residual populations of quiescent, stem-like tumor cells remained. Without subsequent treatment, these residual cells displayed regenerative potential, because testosterone readministration resulted in emergence of rapidly proliferating tumors. Therefore, this model may be useful for revealing potential cellular targets in prostate cancer, which exist before the onset of aggressive incurable disease. Specific eradication of these regenerative tumor cells that survive castration could then confer survival benefits for patients. PMID:23720582

Toivanen, Roxanne; Frydenberg, Mark; Murphy, Declan; Pedersen, John; Ryan, Andrew; Pook, David; Berman, David M; Taylor, Renea A; Risbridger, Gail P

2013-05-29

104

Primary Xenografts of Human Prostate Tissue as a Model to Study Angiogenesis Induced by Reactive Stroma  

PubMed Central

Characterization of the mechanism(s) of androgen-driven human angiogenesis could have significant implications for modeling new forms of anti-angiogenic therapies for CaP and for developing targeted adjuvant therapies to improve efficacy of androgen-deprivation therapy. However, models of angiogenesis by human endothelial cells localized within an intact human prostate tissue architecture are until now extremely limited. This report characterizes the burst of angiogenesis by endogenous human blood vessels in primary xenografts of fresh surgical specimens of benign prostate or prostate cancer (CaP) tissue that occurs between Days 6–14 after transplantation into SCID mice pre-implanted with testosterone pellets. The wave of human angiogenesis was preceded by androgen-mediated up-regulation of VEGF-A expression in the stromal compartment. The neo-vessel network anastomosed to the host mouse vascular system between Days 6–10 post-transplantation, the angiogenic response ceased by Day 15, and by Day 30 the vasculature had matured and stabilized, as indicated by a lack of leakage of serum components into the interstitial tissue space and by association of nascent endothelial cells with mural cells/pericytes. The angiogenic wave was concurrent with the appearance of a reactive stroma phenotype, as determined by staining for ?-SMA, Vimentin, Tenascin, Calponin, Desmin and Masson's trichrome, but the reactive stroma phenotype appeared to be largely independent of androgen availability. Transplantation-induced angiogenesis by endogenous human endothelial cells present in primary xenografts of benign and malignant human prostate tissue was preceded by induction of androgen-driven expression of VEGF by the prostate stroma, and was concurrent with and the appearance of a reactive stroma phenotype. Androgen-modulated expression of VEGF-A appeared to be a causal regulator of angiogenesis, and possibly of stromal activation, in human prostate xenografts.

Montecinos, Viviana P.; Godoy, Alejandro; Hinklin, Jennifer; Vethanayagam, R. Robert; Smith, Gary J.

2012-01-01

105

Novel use of zebrafish as a vertebrate model to screen radiation protectors and sensitizers  

SciTech Connect

Purpose: Zebrafish (Danio rerio) embryos provide a unique vertebrate model to screen therapeutic agents easily and rapidly because of their relatively close genetic relationship to humans, ready abundance and accessibility, short embryonal development, and optical clarity. To validate zebrafish embryos as a screen for radiation modifiers, we evaluated the effects of ionizing radiation in combination with a known radioprotector (free radical scavenger Amifostine) or radiosensitizing agent (tyrosine kinase inhibitor AG1478). Methods and materials: Viable zebrafish embryos were exposed to 0-10 Gy single-fraction 250 kVp X-rays with or without either Amifostine (0-4 mM) or AG1478 (0-10 {mu}M) at defined developmental stages from 1-24 h postfertilization (hpf). Embryos were examined for morphologic abnormalities and viability until 144 hpf. Results: Radiation alone produced a time- and dose-dependent perturbation of normal embryonic development and survival with maximal sensitivity at doses {>=}4 Gy delivered before 4 hpf. Amifostine markedly attenuated this effect, whereas AG1478 enhanced teratogenicity and lethality, particularly at therapeutically relevant (2-6 Gy) radiation doses. Conclusions: Collectively, these data validate the use of zebrafish as a vertebrate model to assess the effect of radiation alone or with radiation response modulators. Zebrafish embryos may thus provide a rapid, facile system to screen novel agents ultimately intended for human use in the context of therapeutic or accidental radiation exposure.

McAleer, Mary Frances [Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, PA (United States)]. E-mail: adam.dicker@mail.tju.edu; Davidson, Christian [Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, PA (United States); Davidson, William Robert [Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, PA (United States); Yentzer, Brad [Department of Dermatology, Thomas Jefferson University, Philadelphia, PA (United States); Farber, Steven A. [Department of Microbiology and Immunology, Thomas Jefferson University, Philadelphia, PA (United States); Rodeck, Ulrich [Department of Dermatology, Thomas Jefferson University, Philadelphia, PA (United States); Dicker, Adam P. [Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, PA (United States)

2005-01-01

106

Limb Regeneration is Impaired in an Adult Zebrafish Model of Diabetes Mellitus  

PubMed Central

The zebrafish (Danio Rerio) is an established model organism for the study of developmental processes, human disease and tissue regeneration. We report that limb regeneration is severely impaired in our newly developed adult zebrafish model of type I diabetes. Intraperitoneal streptozocin injection of adult, wild type zebrafish results in a sustained hyperglycemic state as determined by elevated fasting blood glucose values and increased glycation of serum protein. Serum insulin levels are also decreased and pancreas immunohistochemisty revealed a lesser amount of insulin signal in hyperglycemic fish. Additionally, the diabetic complications of retinal thinning and glomerular basement membrane thickening (early signs of retinopathy and nephropathy) resulting from the hyperglycemic state were evident in streptozocin injected fish at three weeks. Most significantly, limb regeneration, following caudal fin amputation, is severely impaired in diabetic zebrafish. Nonspecific toxic effects outside the pancreas were not found to contribute to impaired limb regeneration. This experimental system using adult zebrafish facilitates a broad spectrum of genetic and molecular approaches to study regeneration in the diabetic background.

Olsen, Ansgar S.; Sarras, Michael P.; Intine, Robert V.

2010-01-01

107

Dietary Strontium Increases Bone Mineral Density in Intact Zebrafish (Danio rerio): A Potential Model System for Bone Research  

PubMed Central

Abstract Zebrafish (Danio rerio) skeletal bone possesses properties similar to human bone, which suggests that they may be used as a model to study mineralization characteristics of the human Haversian system, as well as human bone diseases. One prerequisite for the use of zebrafish as an alternative osteoporotic bone model is to determine whether their bone displays functional plasticity similar to that observed in other bone models. Strontium citrate was supplemented into a laboratory-prepared diet (45% crude protein) to produce dietary strontium levels of 0%, 0.63%, 1.26%, 1.89%, and 2.43% and fed ad libitum twice daily for 12 weeks to 28-day-old intact zebrafish. Length was determined at 4-week intervals, and both weight and length were recorded at 12 weeks. At 12 weeks, seven zebrafish from each dietary level were analyzed for total bone mineral density by microcomputed tomography. Dietary strontium citrate supplementation significantly (p?zebrafish whole-body and spinal column bone mineral density. In addition, trace amounts of strontium were incorporated into the scale matrix in those zebrafish that consumed strontium-supplemented diets. These findings suggest that zebrafish bone displays plasticity similar to that reported for other bone models (i.e., rat, mouse, and monkey) that received supplements of strontium compounds and zebrafish should be viewed as an increasingly valuable bone model.

Padgett-Vasquez, Steve; Garris, Heath W.; Nagy, Tim R.; D'Abramo, Louis R.; Watts, Stephen A.

2010-01-01

108

Monitoring Serial Changes in Circulating Human Breast Cancer Cells in Mruine Xenograft Models  

PubMed Central

Circulating tumor cells (CTC) are emerging as a powerful prognostic and predictive biomarker in several types of cancer, including breast, colon, and prostate. Studies of CTC in metastasis and further development of CTC as a biomarker in cancer have been limited by the inability to repetitively monitor CTC in mouse models of cancer. We have validated a method to enumerate CTC in blood samples obtained from living mice using a modified version of an in vitro diagnostic system for quantifying CTC in patients. Different routes of blood collection were tested to identify a method to reproducibly recover CTC from tumor-bearing mice without interference from contaminating normal murine epithelial cells. CTC are present in blood samples from mice bearing orthotopic xenografts of several different breast cancer cell lines and primary breast cancer cells from patient biopsies. We also show that this technology can be used for serial monitoring of CTC in mouse xenograft models of human breast cancer. These results establish a new method for studying CTC in mouse models of epithelial cancer, providing the foundation for studies of molecular regulation of CTC in cancer and CTC as biomarker for therapeutic efficacy.

Eliane, Jean-Pierre; Repollet, Madeline; Luker, Kathryn E.; Brown, Martha; Rae, James M.; Dontu, Gabriela; Schott, Anne F.; Wicha, Max; Doyle, Gerald V.; Hayes, Daniel F.; Luker, Gary D.

2009-01-01

109

Repeated-measures models with constrained parameters for incomplete data in tumour xenograft experiments.  

PubMed

In cancer drug development, xenograft experiments (models) where mice are grafted with human cancer cells are used to elucidate the mechanism of action and/or to assess efficacy of a promising compound. Demonstrated activity in this model is an important step to bring a promising compound to humans. A key outcome variable in these experiments is tumour volumes measured over a period of time, while mice are treated with an anticancer agent following certain schedules. However, a mouse may die during the experiment or may be sacrificed when its tumour volume quadruples and then incomplete repeated measurements arise. The incompleteness or missingness is also caused by drastic tumour shrinkage (<0.01 cm3) or random truncation. In addition, if no treatment were given to the tumour-bearing mice, the tumours would keep growing until the mice die or are sacrificed. This intrinsic growth of tumour in the absence of treatment constrains the parameters in the regression and causes further difficulties in statistical analysis. We develop a maximum likelihood method based on the expectation/conditional maximization (ECM) algorithm to estimate the dose-response relationship while accounting for the informative censoring and the constraints of model parameters. A real xenograft study on a new anti-tumour agent temozolomide combined with irinotecan is analysed using the proposed method. PMID:15523707

Tan, Ming; Fang, Hong-Bin; Tian, Guo-Liang; Houghton, Peter J

2005-01-15

110

Zebrafish Provides a Novel Model for Lymphatic Vascular Research  

Microsoft Academic Search

The mammalian lymphatic vasculature has an important function in the maintenance of tissue fluid homeostasis, absorption of dietary lipids, and immune surveillance. The lymphatic vessels are also recruited by many tumors as primary routes for metastasis and mediate immune responses in inflammatory diseases, whereas dysfunction of the lymphatic drainage leads to lymphedema. The characterization of a lymphatic vasculature in zebrafish

Terhi Karpanen; Stefan Schulte-Merker

2011-01-01

111

Use of zebrafish as a model to understand mechanisms of addiction and complex neurobehavioral phenotypes  

PubMed Central

Despite massive research efforts the exact pathogenesis and pathophysiology of addiction and neuropsychiatric disorders such as anxiety, schizophrenia and autism remains largely unknown. Animal models can serve as tools to understand the etiology and pathogenesis of these disorders. In recent years researchers are turning to zebrafish as it allows easy access to all developmental stages and imaging of pathological processes as well as automated behavioral quantification coupled with large scale screening and mutagenesis strategies. This review summarizes studies conducted over the last few years which demonstrate the relevance of the zebrafish model to human diseases including addiction and neuropsychiatric disorders.

Mathur, Priya; Guo, Su

2010-01-01

112

Establishment of canine hemangiosarcoma xenograft models expressing endothelial growth factors, their receptors, and angiogenesis-associated homeobox genes  

PubMed Central

Background Human hemangiosarcoma (HSA) tends to have a poor prognosis; its tumorigenesis has not been elucidated, as there is a dearth of HSA clinical specimens and no experimental model for HSA. However, the incidence of spontaneous HSA is relatively high in canines; therefore, canine HSA has been useful in the study of human HSA. Recently, the production of angiogenic growth factors and their receptors in human and canine HSA has been reported. Moreover, the growth-factor environment of HSA is very similar to that of pathophysiological angiogenesis, which some homeobox genes regulate in the transcription of angiogenic molecules. In the present study, we established 6 xenograft canine HSA tumors and detected the expression of growth factors, their receptors, and angiogenic homeobox genes. Methods Six primary canine HSAs were xenografted to nude mice subcutaneously and serially transplanted. Subsequently, the expressions of vascular endothelial growth factor (VEGF)-A, basic fibroblast growth factors (bFGF), flt-1 and flk-1 (receptors of VEGF-A), FGFR-1, and angiogenic homeobox genes HoxA9, HoxB3, HoxB7, HoxD3, Pbx1, and Meis1 were investigated in original and xenograft tumors by histopathology, immunostaining, and reverse transcription polymerase chain reaction (RT-PCR), using canine-specific primer sets. Results Histopathologically, xenograft tumors comprised a proliferation of neoplastic cells that were varied in shape, from spindle-shaped and polygonal to ovoid; some vascular-like structures and vascular clefts of channels were observed, similar to those in the original tumors. The expression of endothelial markers (CD31 and vWF) was detected in xenograft tumors by immunohistochemistry and RT-PCR. Moreover, the expression of VEGF-A, bFGF, flt-1, flk-1, FGFR-1, HoxA9, HoxB3, HoxB7, HoxD3, Pbx1, and Meis1 was detected in xenograft tumors. Interestingly, expressions of bFGF tended to be higher in 3 of the xenograft HSA tumors than in the other tumors. Conclusion We established 6 xenograft canine HSA tumors in nude mice and found that the expressions of angiogenic growth factors and their receptors in xenograft HSAs were similar to those in spontaneous HSA. Furthermore, we detected the expression of angiogenic homeobox genes; therefore, xenograft models may be useful in analyzing malignant growth in HSA.

2009-01-01

113

Research on segmentation of dorsal diencephalon and ventral midbrain of zebrafish embryo based on active contour model.  

PubMed

Zebrafish is a valuable vertebrate model in life science research. In the zebrafish research, segmentation of zebrafish embryo images is a prerequisite for subsequent processing and analysis. Specifically, shape analysis of zebrafish's two important organs, the dorsal diencephalon and the ventral midbrain, is significant for studying the mutants caused by gene expression. Nevertheless, due to non-uniform intensity distribution and weak boundaries in dorsal diencephalon and ventral midbrain microscopic images, classical segmentation methods are unable to determine the precise boundaries. In this paper, a novel segmentation technique for zebrafish embryo images is proposed based on active contour model, which includes region based active contour model and geodesic active contour. Finally, the effectiveness of this approach is confirmed by the experimental results that the agreement between the algorithm and manual segmentation is more than 90%. PMID:22436295

Wu, Tao; Lu, Jianfeng; Lu, Yanting; Yang, Jingyu

2012-03-21

114

An experimental xenograft mouse model of diffuse pontine glioma designed for therapeutic testing.  

PubMed

The prognosis for diffuse infiltrating pontine gliomas (DIPG) remains extremely poor, with the majority of patients surviving less than 2 years. Here, we have adapted standard xenograft techniques to study glioma growth in the mouse brainstem, and have utilized the mouse model for studying a relevant therapeutic for treating DIPGs. bioluminescence imaging monitoring revealed a progressive increase in signal following the injection of either of two tumor cell types into the brainstem. Mice with orthotopic GS2 tumors, and receiving a single 100 mg/kg dose of temozolomide showed a lengthy period of decreased tumor luminescence, with substantially increased survival relative to untreated mice (P < 0.001). A small molecule inhibitor that targets cdk4/6 was used to test AM-38 brainstem xenograft response to treatment. Drug treatment resulted in delayed tumor growth, and significantly extended survival. Our results demonstrate the feasibility of using an orthotopic brainstem tumor model in athymic mice, and for application to testing therapeutic agents in treating DIPG. PMID:22231932

Aoki, Yasuyuki; Hashizume, Rintaro; Ozawa, Tomoko; Banerjee, Anu; Prados, Michael; James, C David; Gupta, Nalin

2012-01-10

115

The State of the Art of the Zebrafish Model for Toxicology and Toxicologic Pathology Research--Advantages and Current Limitations  

PubMed Central

The zebrafish (Danio rerio) is now the pre-eminent vertebrate model system for clarification of the roles of specific genes and signaling pathways in development. The zebrafish genome will be completely sequenced within the next 1–2 years. Together with the substantial historical database regarding basic developmental biology, toxicology, and gene transfer, the rich foundation of molecular genetic and genomic data makes zebrafish a powerful model system for clarifying mechanisms in toxicity. In contrast to the highly advanced knowledge base on molecular developmental genetics in zebrafish, our database regarding infectious and noninfectious diseases and pathologic lesions in zebrafish lags far behind the information available on most other domestic mammalian and avian species, particularly rodents. Currently, minimal data are available regarding spontaneous neoplasm rates or spontaneous aging lesions in any of the commonly used wild-type or mutant lines of zebrafish. Therefore, to fully utilize the potential of zebrafish as an animal model for understanding human development, disease, and toxicology we must greatly advance our knowledge on zebrafish diseases and pathology.

Spitsbergen, Jan M.; Kent, Michael L.

2007-01-01

116

Zebrafish: An in vivo model for the study of neurological diseases  

PubMed Central

As the population ages, there is a growing need for effective therapies for the treatment of neurological diseases. A limited number of therapeutics are currently available to improve cognitive function and research is limited by the need for in vivo models. Zebrafish have recently become a focus of neurobehavioral studies since larvae display neuropathological and behavioral phenotypes that are quantifiable and relate to those seen in man. Due to the small size of Zebrafish larvae, assays can be undertaken in 96 well plates and as the larvae can live in as little as 200 ?l of fluid, only a few milligrams of compound are needed for screening. Thus in vivo analysis of the effects of compounds can be undertaken at much earlier stages in the drug discovery process. This review will look at the utility of the zebrafish in the study of neurological diseases and its role in improving the throughput of candidate compounds in in vivo screens.

Best, J D; Alderton, Wendy K

2008-01-01

117

Magnetic resonance imaging of metastases in xenograft mouse models of cancer.  

PubMed

Magnetic resonance imaging (MRI) of small animals has emerged as a valuable tool to noninvasively monitor tumor growth in mouse models of cancer. However, imaging of metastases in mouse models is difficult due to the need for high spatial resolution. We have demonstrated MRI of metastases in the liver, brain, adrenal glands, and lymph nodes in different xenograft mouse models of cancer. MRI of mice was performed with a clinical 3.0 T magnetic resonance scanner and a commercially available small-animal receiver coil. The imaging protocol consisted of T1- and T2-weighted fat-saturated spin echo sequences with a spatial resolution of 200 ?m × 200 ?m × 500 ?m. Total acquisition time was 30 min per mouse. The technique allowed for repetitive examinations of larger animal cohorts to observe the development of metastases. PMID:24092443

Peldschus, Kersten; Ittrich, Harald

2014-01-01

118

A zebrafish transgenic model of Ewing's sarcoma reveals conserved mediators of EWS-FLI1 tumorigenesis  

PubMed Central

SUMMARY Ewing’s sarcoma, a malignant bone tumor of children and young adults, is a member of the small-round-blue-cell tumor family. Ewing’s sarcoma family tumors (ESFTs), which include peripheral primitive neuroectodermal tumors (PNETs), are characterized by chromosomal translocations that generate fusions between the EWS gene and ETS-family transcription factors, most commonly FLI1. The EWS-FLI1 fusion oncoprotein represents an attractive therapeutic target for treatment of Ewing’s sarcoma. The cell of origin of ESFT and the molecular mechanisms by which EWS-FLI1 mediates tumorigenesis remain unknown, and few animal models of Ewing’s sarcoma exist. Here, we report the use of zebrafish as a vertebrate model of EWS-FLI1 function and tumorigenesis. Mosaic expression of the human EWS-FLI1 fusion protein in zebrafish caused the development of tumors with histology strongly resembling that of human Ewing’s sarcoma. The incidence of tumors increased in a p53 mutant background, suggesting that the p53 pathway suppresses EWS-FLI1-driven tumorigenesis. Gene expression profiling of the zebrafish tumors defined a set of genes that might be regulated by EWS-FLI1, including the zebrafish ortholog of a crucial EWS-FLI1 target gene in humans. Stable zebrafish transgenic lines expressing EWS-FLI1 under the control of the heat-shock promoter exhibit altered embryonic development and defective convergence and extension, suggesting that EWS-FLI1 interacts with conserved developmental pathways. These results indicate that functional targets of EWS-FLI1 that mediate tumorigenesis are conserved from zebrafish to human and provide a novel context in which to study the function of this fusion oncogene.

Leacock, Stefanie W.; Basse, Audrey N.; Chandler, Garvin L.; Kirk, Anne M.; Rakheja, Dinesh; Amatruda, James F.

2012-01-01

119

Translating discovery in zebrafish pancreatic development to human pancreatic cancer: biomarkers, targets, pathogenesis, and therapeutics.  

PubMed

Abstract Experimental studies in the zebrafish have greatly facilitated understanding of genetic regulation of the early developmental events in the pancreas. Various approaches using forward and reverse genetics, chemical genetics, and transgenesis in zebrafish have demonstrated generally conserved regulatory roles of mammalian genes and discovered novel genetic pathways in exocrine pancreatic development. Accumulating evidence has supported the use of zebrafish as a model of human malignant diseases, including pancreatic cancer. Studies have shown that the genetic regulators of exocrine pancreatic development in zebrafish can be translated into potential clinical biomarkers and therapeutic targets in human pancreatic adenocarcinoma. Transgenic zebrafish expressing oncogenic K-ras and zebrafish tumor xenograft model have emerged as valuable tools for dissecting the pathogenetic mechanisms of pancreatic cancer and for drug discovery and toxicology. Future analysis of the pancreas in zebrafish will continue to advance understanding of the genetic regulation and biological mechanisms during organogenesis. Results of those studies are expected to provide new insights into how aberrant developmental pathways contribute to formation and growth of pancreatic neoplasia, and hopefully generate valid biomarkers and targets as well as effective and safe therapeutics in pancreatic cancer. PMID:23682805

Yee, Nelson S; Kazi, Abid A; Yee, Rosemary K

2013-05-17

120

REVIEW Zebrafish in Context: Uses of a Laboratory Model in Comparative Studies  

Microsoft Academic Search

With the recent interest in the reintegration of evolutionary and developmental biology has come a growing need for understanding the phylogenetic relations and degree of generality of the model organisms upon which we rely so heavily. In vertebrate biology the zebrafish Danio rerio has become a paradigmatic system for studies at levels of organization from molecular to interspecific. Studies of

Brian D. Metscher; Per Erik Ahlberg

121

Zebrafish fetal alcohol syndrome model: effects of ethanol are rescued by retinoic acid supplement  

Microsoft Academic Search

This study was designed to develop a zebrafish experimental model to examine defects in retinoic acid (RA) signaling caused by embryonic ethanol exposure. RA deficiency may be a causative factor leading to a spectrum of birth defects classified as fetal alcohol spectrum disorder (FASD). Experimental support for this hypothesis using Xenopus showed that effects of treatment with ethanol could be

James A. Marrs; Sherry G. Clendenon; Don R. Ratcliffe; Stephen M. Fielding; Qin Liu; William F. Bosron

2010-01-01

122

Zebrafish models of the immune response: taking it on the ChIn  

Microsoft Academic Search

ABSTRACT: The zebrafish is proving to be an extremely versatile new experimental model for unraveling the mysteries of innate immunity and has considerable promise as a system for the identification of novel modulators of this crucial biological process. A rate-limiting factor, however, is the mechanical stimulus required to induce the inflammatory response. A new chemically induced inflammation assay ('ChIn' assay)

Stephen A Renshaw; Philip W Ingham

2010-01-01

123

Physeal Bystander Effects in Rhabdomyosarcoma Radiotherapy: Experiments in a New Xenograft Model  

PubMed Central

Radiotherapy used in the treatment of pediatric musculoskeletal sarcomas may result in crippling defects of skeletal growth. Several radioprotective strategies have shown potential for preserving function of the irradiated epiphysis but have not been evaluated in a tumor-bearing animal model. We developed two bioluminescent human rhabdomyosarcoma cell lines that were used to establish xenograft tumors in skeletally immature mice. Bioluminescence imaging and radiography allowed serial evaluation of tumor growth and tibial elongation following localized radiotherapy. High-dose (10?Gy) radiotherapy significantly reduced tumor growth velocity and prolonged the median survival of tumor-bearing mice but also resulted in a significant 3.3% shortening of the irradiated limb. Exposure to a lower, 2?Gy dose resulted in 4.1% decrease in limb length but did not extend survival. This new model provides a clinically relevant means to test the efficacy and safety of novel radioprotectant and radiorecovery strategies for use in this context.

Horton, Jason A.; Strauss, Judith A.; Allen, Matthew J.; Damron, Timothy A.

2011-01-01

124

Stromal cell-derived factor-1 and hematopoietic cell homing in an adult zebrafish model of hematopoietic cell transplantation  

PubMed Central

In mammals, stromal cell–derived factor-1 (SDF-1) promotes hematopoietic cell mobilization and migration. Although the zebrafish, Danio rerio, is an emerging model for studying hematopoietic cell transplantation (HCT), the role of SDF-1 in the adult zebrafish has yet to be determined. We sought to characterize sdf-1 expression and function in the adult zebrafish in the context of HCT. In situ hybridization of adult zebrafish organs shows sdf-1 expression in kidney tubules, gills, and skin. Radiation up-regulates sdf-1 expression in kidney to nearly 4-fold after 40 Gy. Assays indicate that zebrafish hematopoietic cells migrate toward sdf-1, with a migration ratio approaching 1.5 in vitro. A sdf-1a:DsRed2 transgenic zebrafish allows in vivo detection of sdf-1a expression in the adult zebrafish. Matings with transgenic reporters localized sdf-1a expression to the putative hematopoietic cell niche in proximal and distal renal tubules and collecting ducts. Importantly, transplant of hematopoietic cells into myelosuppressed recipients indicated migration of hematopoietic cells to sdf-1a–expressing sites in the kidney and skin. We conclude that sdf-1 expression and function in the adult zebrafish have important similarities to mammals, and this sdf-1 transgenic vertebrate will be useful in characterizing the hematopoietic cell niche and its interactions with hematopoietic cells.

Glass, Tiffany J.; Patrinostro, Xiaobai; Tolar, Jakub; Bowman, Teresa V.; Zon, Leonard I.; Blazar, Bruce R.

2011-01-01

125

Assessing teratogenic changes in a zebrafish model of fetal alcohol exposure.  

PubMed

Fetal alcohol syndrome (FAS) is a severe manifestation of embryonic exposure to ethanol. It presents with characteristic defects to the face and organs, including mental retardation due to disordered and damaged brain development. Fetal alcohol spectrum disorder (FASD) is a term used to cover a continuum of birth defects that occur due to maternal alcohol consumption, and occurs in approximately 4% of children born in the United States. With 50% of child-bearing age women reporting consumption of alcohol, and half of all pregnancies being unplanned, unintentional exposure is a continuing issue. In order to best understand the damage produced by ethanol, plus produce a model with which to test potential interventions, we developed a model of developmental ethanol exposure using the zebrafish embryo. Zebrafish are ideal for this kind of teratogen study. Each pair lays hundreds of eggs, which can then be collected without harming the adult fish. The zebrafish embryo is transparent and can be readily imaged with any number of stains. Analysis of these embryos after exposure to ethanol at different doses and times of duration and application shows that the gross developmental defects produced by ethanol are consistent with the human birth defect. Described here are the basic techniques used to study and manipulate the zebrafish FAS model. PMID:22453686

Loucks, Evyn; Ahlgren, Sara

2012-03-20

126

Identification of Clostridium difficile toxin B cardiotoxicity using a zebrafish embryo model of intoxication.  

PubMed

Clostridium difficile toxin B (TcdB) has been studied extensively by using cell-free systems and tissue culture, but, like many bacterial toxins, the in vivo targets of TcdB are unknown and have been difficult to elucidate with traditional animal models. In the current study, the transparent Danio rerio (zebrafish) embryo was used as a model for imaging of in vivo TcdB localization and organ-specific damage in real time. At 24 h after treatment, TcdB was found to localize at the pericardial region, and zebrafish exhibited the first signs of cardiovascular damage, including a 90% reduction in systemic blood flow and a 20% reduction in heart rate. Within 72 h of exposure to TcdB, the ventricle chamber of the heart became deformed and was unable to contract or pump blood, and the fish exhibited extensive pericardial edema. In line with the observed defects in ventricle contraction, TcdB was found to directly disrupt coordinated contractility and rhythmicity in primary cardiomyocytes. Furthermore, using a caspase-3 inhibitor, we were able to block TcdB-related cardiovascular damage and prevent zebrafish death. These findings present an insight into the in vivo targets of TcdB, as well as demonstrate the strength of the zebrafish embryo as a tractable model for identification of in vivo targets of bacterial toxins and evaluation of novel candidate therapeutics. PMID:16966605

Hamm, Elaine E; Voth, Daniel E; Ballard, Jimmy D

2006-09-11

127

Enterohemorrhagic Escherichia coli induce attaching and effacing lesions and hemorrhagic colitis in human and bovine intestinal xenograft models.  

PubMed

Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is an important cause of diarrhea, hemorrhagic colitis and hemolytic uremic syndrome in humans worldwide. The two major virulence determinants of EHEC are the Shiga toxins (Stx) and the type III secretion system (T3SS), including the injected effectors. Lack of a good model system hinders the study of EHEC virulence. Here, we investigated whether bovine and human intestinal xenografts in SCID mice can be useful for studying EHEC and host tissue interactions. Fully developed, germ-free human and bovine small intestine and colon were established by subcutaneous transplantation of human and bovine fetal gut into SCID mice. Xenografts were allowed to develop for 3-4 months and thereafter were infected by direct intraluminal inoculation of Stx-negative derivatives of EHEC O157:H7, strain EDL933. The small intestine and colon xenografts closely mimicked the respective native tissues. Upon infection, EHEC induced formation of typical attaching and effacing lesions and tissue damage that resembled hemorrhagic colitis in colon xenografts. By contrast, xenografts infected with an EHEC mutant deficient in T3SS remained undamaged. Furthermore, EHEC did not attach to or damage the epithelium of small intestinal tissue, and these xenografts remained intact. EHEC damaged the colon in a T3SS-dependent manner, and this model is therefore useful for studying the molecular details of EHEC interactions with live human and bovine intestinal tissue. Furthermore, we demonstrate that Stx and gut microflora are not essential for EHEC virulence in the human gut. PMID:20959635

Golan, Lilach; Gonen, Erez; Yagel, Simcha; Rosenshine, Ilan; Shpigel, Nahum Y

2010-10-19

128

Enterohemorrhagic Escherichia coli induce attaching and effacing lesions and hemorrhagic colitis in human and bovine intestinal xenograft models  

PubMed Central

SUMMARY Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is an important cause of diarrhea, hemorrhagic colitis and hemolytic uremic syndrome in humans worldwide. The two major virulence determinants of EHEC are the Shiga toxins (Stx) and the type III secretion system (T3SS), including the injected effectors. Lack of a good model system hinders the study of EHEC virulence. Here, we investigated whether bovine and human intestinal xenografts in SCID mice can be useful for studying EHEC and host tissue interactions. Fully developed, germ-free human and bovine small intestine and colon were established by subcutaneous transplantation of human and bovine fetal gut into SCID mice. Xenografts were allowed to develop for 3–4 months and thereafter were infected by direct intraluminal inoculation of Stx-negative derivatives of EHEC O157:H7, strain EDL933. The small intestine and colon xenografts closely mimicked the respective native tissues. Upon infection, EHEC induced formation of typical attaching and effacing lesions and tissue damage that resembled hemorrhagic colitis in colon xenografts. By contrast, xenografts infected with an EHEC mutant deficient in T3SS remained undamaged. Furthermore, EHEC did not attach to or damage the epithelium of small intestinal tissue, and these xenografts remained intact. EHEC damaged the colon in a T3SS-dependent manner, and this model is therefore useful for studying the molecular details of EHEC interactions with live human and bovine intestinal tissue. Furthermore, we demonstrate that Stx and gut microflora are not essential for EHEC virulence in the human gut.

Golan, Lilach; Gonen, Erez; Yagel, Simcha; Rosenshine, Ilan; Shpigel, Nahum Y.

2011-01-01

129

Zebrafish as a model to study peripheral thyroid hormone metabolism in vertebrate development.  

PubMed

To unravel the role of thyroid hormones (THs) in vertebrate development it is important to have suitable animal models to study the mechanisms regulating TH availability and activity. Zebrafish (Danio rerio), with its rapidly and externally developing transparent embryo has been a widely used model in developmental biology for some time. To date many of the components of the zebrafish thyroid axis have been identified, including the TH transporters MCT8, MCT10 and OATP1C1, the deiodinases D1, D2 and D3, and the receptors TR? and TR?. Their structure and function closely resemble those of higher vertebrates. Interestingly, due to a whole genome duplication in the early evolution of ray-finned fishes, zebrafish possess two genes for D3 (dio3 and dio3a) and for TR? (thraa and thrab). Transcripts of all identified genes are present during embryonic development and several of them show dynamic spatio-temporal distribution patterns. Transient morpholino-knockdown of D2, D3 or MCT8 expression clearly disturbs embryonic development, confirming the importance of each of these regulators during early life stages. The recently available tools for targeted stable gene knockout will further increase the value of zebrafish to study the role of peripheral TH metabolism in pre- and post-hatch/post-natal vertebrate development. PMID:23603432

Heijlen, Marjolein; Houbrechts, Anne M; Darras, Veerle M

2013-04-19

130

Stab wound injury of the zebrafish telencephalon: a model for comparative analysis of reactive gliosis.  

PubMed

Reactive glia, including astroglia and oligodendrocyte progenitors (OPCs) are at the core of the reaction to injury in the mammalian brain with initially beneficial and later partially adverse functions such as scar formation. Given the different glial composition in the adult zebrafish brain with radial ependymoglia but no parenchymal astrocytes, we examined the glial response to an invasive stab wound injury model in the adult zebrafish telencephalon. Strikingly, already a few days after injury the wound was closed without any scar tissue. Similar to mammals, microglia cells reacted first and accumulated close to the injury site, while neither GFAP+ radial ependymoglia nor adult OPCs were recruited to the injury site. Moreover, OPCs failed to increase their proliferation after this injury, while the number of proliferating GFAP+ glia was increased until 7 days after injury. Importantly, neurogenesis was also increased after injury, generating additional neurons recruited to the parenchyma which survived for several months. Thus, these data suggest that the specific glial environment in the adult zebrafish telencephalon is not only permissive for long-term neuronal survival, but avoids scar formation. Invasive injury in the adult zebrafish telencephalon may therefore provide a useful model to untangle the molecular mechanisms involved in these beneficial glial reactions. PMID:22105794

Baumgart, Emily Violette; Barbosa, Joana S; Bally-Cuif, Laure; Götz, Magdalena; Ninkovic, Jovica

2011-11-21

131

A Novel Ovarian Xenografting Model to Characterize the Impact of Chemotherapy Agents on Human Primordial Follicle Reserve  

Microsoft Academic Search

Many chemotherapeutic agents, especially of the alkylating family, alter fertility in premenopausal females. However, it is not practically possible to quantify and characterize the impact of cancer drugs on ovarian reserve in a clinical setting. Thus, our specific aim was to develop a xenograft model to characterize the in vivo impact of chemotherapy agents on human ovary. Ovarian pieces from

Ozgur Oktem; Kutluk Oktay

2007-01-01

132

Efficacy of Liposomes and Hyperthermia in a Human Tumor Xenograft Model: Importance of Triggered Drug Release1  

Microsoft Academic Search

The tumor drug concentrations, drug distributions, and therapeutic efficacies achieved by three fundamentally different liposomes, nonther- mosensitive liposome (NTSL), traditional thermosensitive liposome (TTSL), and low temperature sensitive liposome (LTSL); free doxorubicin (DOX); and saline in combination with hyperthermia (HT) were directly compared in a human tumor xenograft model. NTSL is a nonthermosen- sitive liposome in the physiological temperature range, TTSL

Garheng Kong; Gopal Anyarambhatla; William P. Petros; Rod D. Braun; O. Michael Colvin; David Needham; Mark W. Dewhirst

2000-01-01

133

A nanoemulsion formulation of dacarbazine reduces tumor size in a xenograft mouse epidermoid carcinoma model compared to dacarbazine suspension  

Microsoft Academic Search

Dacarbazine (DAC) is an anticancer drug that has been used to treat various types of cancers. The aim of the current study was to test whether there is an increased efficacy of DAC as a nanoemulsion on reducing tumor size in an epidermoid carcinoma xenograft mouse model. Tumors were induced in 5-week-old nude mice by subcutaneous injection. The mice were

Srikanth Kakumanu; Jean Bosco Tagne; Thomas A. Wilson; Robert J. Nicolosi

2011-01-01

134

Anticancer effect of arsenic trioxide on cholangiocarcinoma: in vitro experiments and in vivo xenograft mouse model.  

PubMed

The purpose of our study was to investigate anticancer activity of arsenic trioxide (As2O3) on cholangiocarcinoma through in vitro and in vivo experiments using human cholangiocarcinoma cancer cells (CC-t6 cells) and a nude mouse model. The effect of As2O3 on CC-t6 cell survival was determined in vitro using MTT assay. Analysis of cell cycle phase distribution and quantification of apoptosis/necrosis, which were achieved by flow cytometry, were performed in order to understand the mechanism of As2O3. In vivo experiment was performed to assess the effectiveness of local injection of As2O3 on tumor inhibition by comparing the following three groups each consisting of five nude mouse xenograft models: high dose As2O3 (5 mg/kg), low dose As2O3 (1 mg/kg), and saline. In MTT assay, As2O3 inhibited the growth of CC-t6 cells more effectively than cisplatin or adriamycin at concentrations between 1 and 100 ?M for most time points between 24 and 72 h (p < 0.05). With increased concentration of As2O3, there was dose-dependent increase in G 0/G 1 phase and dose-dependent decrease in S phase. As2O3-mediated inhibition of cell viability was achieved via induction of apoptosis and necrosis in a dose-dependent manner. Injection of As2O3 into CC-t6-induced tumors in nude mice inhibited the growth of subcutaneous tumor xenografts. As2O3 treatment dose-dependently inhibited the proliferation of CC-t6 cells via G 0/G 1 phase arrest and retarded tumor growth in nude mice, suggesting that As2O3 may be effective in the treatment of cholangiocarcinoma. PMID:23467906

Kim, Eun-Young; Lee, Sang Soo; Shin, Ji Hoon; Kim, Soo Hyun; Shin, Dong-Ho; Baek, Seung Yon

2013-03-01

135

CysLT1R Antagonists Inhibit Tumor Growth in a Xenograft Model of Colon Cancer.  

PubMed

The expression of the inflammatory G-protein coupled receptor CysLT1R has been shown to be upregulated in colon cancer patients and associated with poor prognosis. The present study investigated the correlation between CysLT1R and colon cancer development in vivo using CysLT1R antagonists (ZM198,615 or Montelukast) and the nude mouse xenograft model. Two drug administration regimens were established. The first regimen was established to investigate the importance of CysLT1R in tumor initiation. Nude mice were inoculated with 50 µM CysLT1R antagonist-pretreated HCT-116 colon cancer cells and received continued treatment (5 mg/kg/day, intraperitoneally). The second regimen aimed to address the role of CysLT1R in tumor progression. Nude mice were inoculated with non-pretreated HCT-116 cells and did not receive CysLT1R antagonist treatment until recordable tumor appearance. Both regimens resulted in significantly reduced tumor size, attributed to changes in proliferation and apoptosis as determined by reduced Ki-67 levels and increased levels of p21(WAF/Cip1) (P<0.01), cleaved caspase 3, and the caspase-cleaved product of cytokeratin 18. Decreased levels of VEGF (P<0.01) and reduced vessel size (P<0.05) were also observed, the latter only in the ZM198,615-pretreatment group. Furthermore, we performed a series of in vitro studies using the colon cancer cell line HCT-116 and CysLT1R antagonists. In addition to significant reductions in cell proliferation, adhesion and colony formation, we observed induction of cell cycle arrest and apoptosis in a dose-dependent manner. The ability of Montelukast to inhibit growth of human colon cancer xenograft was further validated by using two additional colon cancer cell lines, SW-480 and HT-29. Our results demonstrate that CysLT1R antagonists inhibit growth of colon cancer xenografts primarily by reducing proliferation and inducing apoptosis of the tumor cells. PMID:24039952

Savari, Sayeh; Liu, Minghui; Zhang, Yuan; Sime, Wondossen; Sjölander, Anita

2013-09-05

136

Gene-specific differential response to anti-apoptotic therapies in zebrafish models of ocular coloboma  

PubMed Central

Purpose We recently demonstrated that molecular therapy using aminoglycosides can overcome the underlying genetic defect in two zebrafish models of ocular coloboma and showed abnormal cell death to be a key feature associated with the optic fissure closure defects. In further studies to identify molecular therapies for this common congenital malformation, we now examine the effects of anti-apoptotic compounds in zebrafish models of ocular coloboma in vivo. Methods Two ocular coloboma zebrafish lines (pax2.1/noitu29a and lamb1/gupm189) were exposed to diferuloylmethane (curcumin) or benzyloxycarbonyl-Val-Ala-Asp(Ome)-fluoromethylketone (zVAD-fmk; a pan-caspase inhibitor) for up to 8 days post-fertilization. The effects of these compounds were assessed by morphology, histology, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining and western blot analysis. Results The size of the coloboma in gup zebrafish mutants treated with diferuloylmethane was greatly reduced. In treated mutants a reduction in TUNEL staining and a 67% decrease in activated caspase-3 protein were observed. The release of cytochrome c from the mitochondria into the cytosol was reduced fourfold by in vivo diferuloylmethane treatment, suggesting that the drug was acting to inhibit the intrinsic apoptotic pathway. Inhibition of caspases directly with zVAD-fmk also resulted in a similar reduction in coloboma phenotype. Treatment with either diferuloylmethane or zVAD-fmk resulted in a statistically significant 1.4 fold increase in length of survival of these mutant zebrafish (p<0.001), which normally succumb to the lethal genetic mutation. In contrast, the coloboma phenotype in noi zebrafish mutants did not respond to either diferuloylmethane or zVAD-fmk exposure, even though inhibition of apoptotic cell death was observed by a reduction in TUNEL staining. Conclusions The differential sensitivity to anti-apoptotic agents in lamb1-deficient and pax2.1-deficient zebrafish models, suggests that apoptotic cell death is not a final common pathway in all ocular coloboma genotypes. When considering anti-cell death therapies for ocular colobomatous defects attention should be paid to the genotype under investigation.

Moosajee, Mariya; Shan, Xianghong; Gregory-Evans, Kevin

2011-01-01

137

Calculated and TLD-based absorbed dose estimates for I-131-labeled 3F8 monoclonal antibody in a human neuroblastoma xenograft nude mouse model  

Microsoft Academic Search

Preclinical evaluation of the therapeutic potential of radiolabeled antibodies is commonly performed in a xenografted nude mouse model. To assess therapeutic efficacy it is important to estimate the absorbed dose to the tumor and normal tissues of the nude mouse. The current study was designed to accurately measure radiation does to human neuroblastoma xenografts and normal organs in nude mice

Omer Ugur; Andrew M. Scott; Lale Kostakoglu; T. Edmond Hui; Mary E. Masterson; Robert Febo; George Sgouros; Eddie Rosa; Bipin M. Mehta; Darrell R. Fisher; Nai-Kong V. Cheung; Steven M. Larson

1995-01-01

138

Adult zebrafish as a model system for cutaneous wound-healing research.  

PubMed

Upon injury, the skin must quickly regenerate to regain its barrier function. In mammals, wound healing is rapid and scar free during embryogenesis, whereas in adults it involves multiple steps including blood clotting, inflammation, re-epithelialization, vascularization, and granulation tissue formation and maturation, resulting in a scar. We have established a rapid and robust method to introduce full-thickness wounds onto the flank of adult zebrafish, and show that apart from external fibrin clot formation, all steps of adult mammalian wound repair also exist in zebrafish. Wound re-epithelialization is extremely rapid and initiates with no apparent lag phase, subsequently followed by the immigration of inflammatory cells and the formation of granulation tissue, consisting of macrophages, fibroblasts, blood vessels, and collagen. The granulation tissue later regresses, resulting in minimal scar formation. Studies after chemical treatment or with transgenic fish further suggest that wound re-epithelialization occurs independently of inflammation and fibroblast growth factor signaling, whereas both are essential for fibroblast recruitment and granulation tissue formation. Together, these results demonstrate that major steps and principles of cutaneous wound healing are conserved among adult mammals and adult zebrafish, making zebrafish a valuable model for studying vertebrate skin repair. PMID:23325040

Richardson, Rebecca; Slanchev, Krasimir; Kraus, Christopher; Knyphausen, Philipp; Eming, Sabine; Hammerschmidt, Matthias

2013-01-16

139

Survivin Antisense Oligonucleotides Effectively Radiosensitize Colorectal Cancer Cells in Both Tissue Culture and Murine Xenograft Models  

SciTech Connect

Purpose: Survivin shows a radiation resistance factor in colorectal cancer. In the present study, we determined whether survivin messenger RNA levels in patients with rectal cancer predict tumor response after neoadjuvant radiochemotherapy and whether inhibition of survivin by the use of antisense oligonucleotides (ASOs) enhances radiation responses. Methods and Materials: SW480 colorectal carcinoma cells were transfected with survivin ASO (LY2181308) and irradiated with doses ranging from 0-8 Gy. Survivin expression, cell-cycle distribution, {gamma}H2AX fluorescence, and induction of apoptosis were monitored by means of immunoblotting, flow cytometry, and caspase 3/7 activity. Clonogenic survival was determined by using a colony-forming assay. An SW480 xenograft model was used to investigate the effect of survivin attenuation and irradiation on tumor growth. Furthermore, survivin messenger RNA levels were studied in patient biopsy specimens by using Affymetrix microarray analysis. Results: In the translational study of 20 patients with rectal cancer, increased survivin levels were associated with significantly greater risk of local tumor recurrence (p = 0.009). Treatment of SW480 cells with survivin ASOs and irradiation resulted in an increased percentage of apoptotic cells, caspase 3/7 activity, fraction of cells in the G{sub 2}/M phase, and H2AX phosphorylation. Clonogenic survival decreased compared with control-treated cells. Furthermore, treatment of SW480 xenografts with survivin ASOs and irradiation resulted in a significant delay in tumor growth. Conclusion: Survivin appears to be a molecular biomarker in patients with rectal cancer. Furthermore, in vitro and in vivo data suggest a potential role of survivin as a molecular target to improve treatment response to radiotherapy in patients with rectal cancer.

Roedel, Franz [Department of Radiation Therapy and Oncology, University of Frankfurt/Main, Frankfurt (Germany)], E-mail: franz.roedel@kgu.de; Frey, Benjamin [Department of Radiation Oncology, University of Erlangen, Erlangen (Germany); Leitmann, Werner M.S. [Lilly Deutschland GmbH, Bad Homburg (Germany); Capalbo, Gianni; Weiss, Christian; Roedel, Claus [Department of Radiation Therapy and Oncology, University of Frankfurt/Main, Frankfurt (Germany)

2008-05-01

140

Human Xenografts Are Not Rejected in a Naturally Occurring Immunodeficient Porcine Line: A Human Tumor Model in Pigs  

PubMed Central

Abstract Animal models for cancer therapy are invaluable for preclinical testing of potential cancer treatments; however, therapies tested in such models often fail to translate into clinical settings. Therefore, a better preclinical model for cancer treatment testing is needed. Here we demonstrate that an immunodeficient line of pigs can host and support the growth of xenografted human tumors and has the potential to be an effective animal model for cancer therapy. Wild-type and immunodeficient pigs were injected subcutaneously in the left ear with human melanoma cells (A375SM cells) and in the right ear with human pancreatic carcinoma cells (PANC-1). All immunodeficient pigs developed tumors that were verified by histology and immunohistochemistry. Nonaffected littermates did not develop tumors. Immunodeficient pigs, which do not reject xenografted human tumors, have the potential to become an extremely useful animal model for cancer therapy because of their similarity in size, anatomy, and physiology to humans.

Basel, Matthew T.; Balivada, Sivasai; Beck, Amanda P.; Kerrigan, Maureen A.; Pyle, Marla M.; Dekkers, Jack C.M.; Wyatt, Carol R.; Rowland, Robert R.R.; Anderson, David E.; Bossmann, Stefan H.

2012-01-01

141

Establishment, Maintenance and in vitro and in vivo Applications of Primary Human Glioblastoma Multiforme (GBM) Xenograft Models for Translational Biology Studies and Drug Discovery  

PubMed Central

Development of clinically relevant tumor model systems for glioblastoma multiforme (GBM) is important for advancement of basic and translational biology. One model that has gained wide acceptance in the neuro-oncology community is the primary xenograft model. This model entails the engraftment of patient tumor specimens into the flank of nude mice and subsequent serial passage of these tumors in the flank of mice. These tumors then can be used to establish short-term explant cultures or intracranial xenografts. The focus of this manuscript is to review the procedures associated with the establishment, maintenance and utilization of a primary GBM xenograft panel.

Carlson, Brett L.; Pokorny, Jenny L.; Schroeder, Mark A.; Sarkaria, Jann N.

2011-01-01

142

Model of human transitional cell carcinoma: tumor xenografts in upper urinary tract of nude rat.  

PubMed

An in vivo model for the study of human transitional cell carcinoma (TCC) in the urinary tract is desirable. Orthotopic xenografts are useful in order to approximate better the behavior of human tumor cells in situ. Prior models have been described in the urinary bladder of the nude mouse and rat. We have developed the first model of implantation of human TCC in the upper urinary tract of an experimental animal. The kidneys of homozygous nude rats 4 weeks of age were inoculated with 1-5 x 10(6) cells of the RT4 well-differentiated papillary human TCC line through bilateral flank incisions, with transparenchymal injection of tumor cells into either the collecting system (renal pelvis) or the parenchyma. The overall implantation rate was 92% (54/59 kidneys). However, implantation into the collecting system occurred in only 45% (18/45) of the group. Ligation of the ureter prior to inoculation to produce urine stasis improved the mucosal implantation rate. Despite suspect urine cytology findings in the renal pelvis injection group, no distal seeding of the urinary tract was seen. Intraparenchymal tumor growth was less differentiated and had a higher fraction of mitotic cells than mucosal tumors. Vascular and lymphatic invasion were commonly seen; however, distant metastasis was not observed. This model will prove useful in determining the role of seeding in recurrent disease and in developing less invasive modalities for the treatment of upper tract TCC. PMID:7780425

Jarrett, T W; Chen, Y; Anderson, A E; Oshinsky, G; Smith, A D; Weiss, G H

1995-02-01

143

Neutrophil migration: moving from zebrafish models to human autoimmunity.  

PubMed

There has been a resurgence of interest in the neutrophil's role in autoimmune disease. Classically considered an early responder that dies at the site of inflammation, new findings using live imaging of embryonic zebrafish and other modalities suggest that neutrophils can reverse migrate away from sites of inflammation. These 'inflammation-sensitized' neutrophils, as well as the neutrophil extracellular traps and other products made by neutrophils in general, may have many implications for autoimmunity. Here, we review what is known about the role of neutrophils in three different autoimmune diseases: rheumatoid arthritis, systemic lupus erythematosus, and small vessel vasculitis. We then highlight recent findings related to several cytoskeletal regulators that guide neutrophil recruitment including Lyn, Rac2, and SHIP. Finally, we discuss how our improved understanding of the molecules that control neutrophil chemotaxis may impact our knowledge of autoimmunity. PMID:24117827

Shelef, Miriam A; Tauzin, Sebastien; Huttenlocher, Anna

2013-11-01

144

A novel zebrafish embryo xenotransplantation model to study primary human fibroblast motility in health and disease.  

PubMed

Fibroblasts have a central role in the maintenance of tissue homeostasis and repair after injury. Currently, there are no tractable, cost-effective model systems for studying the biology of human fibroblasts in vivo. Here we demonstrate that primary human fibroblasts survive transplantation into zebrafish embryos. Transplanted cells migrate and proliferate, but do not integrate into host tissues. We used this system to study the intrinsic motility of lung fibroblasts from a prototype fibrotic lung disease, idiopathic pulmonary fibrosis (IPF). IPF fibroblasts displayed a significantly higher level of motility than did fibroblasts from nonfibrotic lungs. This is the first in vivo examination of primary human lung fibroblast motility in health and disease using zebrafish models. PMID:22356695

Benyumov, Alexey O; Hergert, Polla; Herrera, Jeremy; Peterson, Mark; Henke, Craig; Bitterman, Peter B

2012-02-22

145

neb: a zebrafish model of nemaline myopathy due to nebulin mutation  

PubMed Central

SUMMARY Nemaline myopathy is one of the most common and severe non-dystrophic muscle diseases of childhood. Patients typically present in infancy with hypotonia, weakness, delayed motor development, and bulbar and respiratory difficulties. Mutations in six different genes are associated with nemaline myopathy, with nebulin mutations being the most common. No treatments or disease-modifying therapies have been identified for this disease. One of the major barriers to treatment development is the lack of models amenable to rapid and coordinated testing of potential therapeutic strategies. To overcome this barrier, we have characterized the first zebrafish model of nemaline myopathy. This model, termed neb, harbors a recessive mutation in the nebulin gene that results in decreased Nebulin protein levels, a severe motor phenotype and premature lethality. In addition to impaired motor function, neb zebrafish exhibit many of the features associated with human nemaline myopathy. These include impaired force generation, altered thin filament length and the presence of specific histopathological changes, including the formation of nemaline bodies. In summary, neb zebrafish mirror the genetic, clinical and pathological aspects of nemaline myopathy due to NEB mutation, and thus are an excellent model for future therapy development for this devastating disorder.

Telfer, William R.; Nelson, Darcee D.; Waugh, Trent; Brooks, Susan V.; Dowling, James J.

2012-01-01

146

Antitumor activity of celastrol nanoparticles in a xenograft retinoblastoma tumor model  

PubMed Central

Background Celastrol, a Chinese herbal medicine, has shown antitumor activity against various tumor cell lines. However, the effect of celastrol on retinoblastoma has not yet been analyzed. Additionally, the poor water solubility of celastrol restricts further therapeutic applications. The goal of this study was to evaluate the effect of celastrol nanoparticles (CNPs) on retinoblastoma and to investigate the potential mechanisms involved. Methods Celastrol-loaded poly(ethylene glycol)-block-poly(?-caprolactone) nanopolymeric micelles were developed to improve the hydrophilicity of celastrol. The 2-(2-methoxy-4- nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulf-ophenyl)-2H tetrazolium monosodium salt (WST-8) assay was used to determine the inhibitory effect of CNPs on SO-Rb 50 cell proliferation in vitro. Immunofluorescence was used to evaluate the apoptotic effect of CNPs on nuclear morphology, and flow cytometry was used to quantify cellular apoptosis. The expression of Bcl-2, Bax, NF-?B p65, and phospo-NF-?B p65 proteins was assessed by Western blotting. A human retinoblastoma xenograft model was used to evaluate the inhibitory effects of CNPs on retinoblastoma in NOD-SCID mice. Hematoxylin and eosin staining was used to assess the apoptotic effects of CNPs on retinoblastoma. Results CNPs inhibit the proliferation of SO-Rb 50 cells in a dose- and time-dependent manner with an IC50 of 17.733 ?g/mL (celastrol-loading content: 7.36%) after exposure to CNPs for 48 hours. CNPs induce apoptosis in SO-Rb 50 cells in a dose-dependent manner. The expression of Bcl-2, NF-?B p65, and phospo-NF-?B p65 proteins decreased after exposure to CNPs 54.4 ?g/mL for 48 hours. Additionally, the Bax/Bcl-2 ratio increased, whereas the expression of Bax itself was not significantly altered. CNPs inhibit the growth of retinoblastoma and induce apoptosis in retinoblastoma cells in mice. Conclusion CNPs inhibit the growth of retinoblastoma in mouse xenograft model by inducing apoptosis in SO-Rb 50 cells, which may be related to the increased Bax/Bcl-2 ratio and the inhibition of NF-?B. CNPs may represent a potential alternative treatment for retinoblastoma.

Li, Zhanrong; Wu, Xianghua; Li, Jingguo; Yao, Lin; Sun, Limei; Shi, Yingying; Zhang, Wenxin; Lin, Jianxian; Liang, Dan; Li, Yongping

2012-01-01

147

Zebrafish as an alternative model for hypoxic-ischemic brain damage  

PubMed Central

Acute cerebral ischemia is one of the leading causes of mortality and chronic disability. Animal models provide an essential tool for understanding the complex cellular and molecular pathophysiology of hypoxic-ischemia and for testing novel neuroprotective drugs in the pre-clinical setting. In this study we tested zebrafish as a novel model for hypoxic-ischemic brain damage. We built an air-proof chamber where water inside had a low oxygen concentration (0.6-0.8 mg/L) proximate to complete hypoxia. Each zebrafish was placed individually in the hypoxia chamber and was subjected to hypoxia treatment until it became motionless, lying on its side on the bottom of the chamber (time to hypoxia = 679.52 ± 90 seconds, mean ± SD, n =23), followed by transferring into a recovery beaker. Overall, 60.87% of subjects did not recover from hypoxia while 39% survived. The size and distribution of brain injury were determined by triphenyltetrazolium chloride (TTC) staining. Bilateral, moderate to complete TTC decoloration or demarcation of the infarct after 10 minutes of hypoxic treatment was clearly visible in the optic tectum of the optic lobe. The size of the infarct expanded to the deep structure of the optic lobe with longer hypoxic treatments. The zebrafish that survived hypoxia experienced initial twitching followed by unbalanced erratic movements until they regained coordinated, balanced swimming ability. These data indicate that zebrafish are susceptible to hypoxic attack and suggest that the model we present in this study can be used as an alternative model to evaluate hypoxia-induced brain damage.

Yu, Xinge; Li, Yang V

2011-01-01

148

Characterization of novel genomic alterations and therapeutic approaches using acute megakaryoblastic leukemia xenograft models.  

PubMed

Acute megakaryoblastic leukemia (AMKL) is a heterogeneous disease generally associated with poor prognosis. Gene expression profiles indicate the existence of distinct molecular subgroups, and several genetic alterations have been characterized in the past years, including the t(1;22)(p13;q13) and the trisomy 21 associated with GATA1 mutations. However, the majority of patients do not present with known mutations, and the limited access to primary patient leukemic cells impedes the efficient development of novel therapeutic strategies. In this study, using a xenotransplantation approach, we have modeled human pediatric AMKL in immunodeficient mice. Analysis of high-throughput RNA sequencing identified recurrent fusion genes defining new molecular subgroups. One subgroup of patients presented with MLL or NUP98 fusion genes leading to up-regulation of the HOX A cluster genes. A novel CBFA2T3-GLIS2 fusion gene resulting from a cryptic inversion of chromosome 16 was identified in another subgroup of 31% of non-Down syndrome AMKL and strongly associated with a gene expression signature of Hedgehog pathway activation. These molecular data provide useful markers for the diagnosis and follow up of patients. Finally, we show that AMKL xenograft models constitute a relevant in vivo preclinical screening platform to validate the efficacy of novel therapies such as Aurora A kinase inhibitors. PMID:23045605

Thiollier, Clarisse; Lopez, Cécile K; Gerby, Bastien; Ignacimouttou, Cathy; Poglio, Sandrine; Duffourd, Yannis; Guégan, Justine; Rivera-Munoz, Paola; Bluteau, Olivier; Mabialah, Vinciane; Diop, M'boyba; Wen, Qiang; Petit, Arnaud; Bauchet, Anne-Laure; Reinhardt, Dirk; Bornhauser, Beat; Gautheret, Daniel; Lecluse, Yann; Landman-Parker, Judith; Radford, Isabelle; Vainchenker, William; Dastugue, Nicole; de Botton, Stéphane; Dessen, Philippe; Bourquin, Jean-Pierre; Crispino, John D; Ballerini, Paola; Bernard, Olivier A; Pflumio, Françoise; Mercher, Thomas

2012-10-08

149

Characterization of novel genomic alterations and therapeutic approaches using acute megakaryoblastic leukemia xenograft models  

PubMed Central

Acute megakaryoblastic leukemia (AMKL) is a heterogeneous disease generally associated with poor prognosis. Gene expression profiles indicate the existence of distinct molecular subgroups, and several genetic alterations have been characterized in the past years, including the t(1;22)(p13;q13) and the trisomy 21 associated with GATA1 mutations. However, the majority of patients do not present with known mutations, and the limited access to primary patient leukemic cells impedes the efficient development of novel therapeutic strategies. In this study, using a xenotransplantation approach, we have modeled human pediatric AMKL in immunodeficient mice. Analysis of high-throughput RNA sequencing identified recurrent fusion genes defining new molecular subgroups. One subgroup of patients presented with MLL or NUP98 fusion genes leading to up-regulation of the HOX A cluster genes. A novel CBFA2T3-GLIS2 fusion gene resulting from a cryptic inversion of chromosome 16 was identified in another subgroup of 31% of non–Down syndrome AMKL and strongly associated with a gene expression signature of Hedgehog pathway activation. These molecular data provide useful markers for the diagnosis and follow up of patients. Finally, we show that AMKL xenograft models constitute a relevant in vivo preclinical screening platform to validate the efficacy of novel therapies such as Aurora A kinase inhibitors.

Thiollier, Clarisse; Lopez, Cecile K.; Gerby, Bastien; Ignacimouttou, Cathy; Poglio, Sandrine; Duffourd, Yannis; Guegan, Justine; Rivera-Munoz, Paola; Bluteau, Olivier; Mabialah, Vinciane; Diop, M'Boyba; Wen, Qiang; Petit, Arnaud; Bauchet, Anne-Laure; Reinhardt, Dirk; Bornhauser, Beat; Gautheret, Daniel; Lecluse, Yann; Landman-Parker, Judith; Radford, Isabelle; Vainchenker, William; Dastugue, Nicole; de Botton, Stephane; Dessen, Philippe; Bourquin, Jean-Pierre; Crispino, John D.; Ballerini, Paola; Bernard, Olivier A.; Pflumio, Francoise

2012-01-01

150

Imaging Tumor Variation in Response to Photodynamic Therapy in Pancreas Cancer Xenograft Models  

PubMed Central

Purpose A treatment monitoring study investigated the differential effects of orthotopic pancreatic cancer models in response to interstitial photodynamic therapy (PDT), and the validity of using magnetic resonance (MR) imaging as a surrogate measure of response was assessed. Methods and Materials Different orthotopic pancreas cancer xenograft models (AsPC-1 and Panc-1) were used to represent the range of pathophysiology observed in humans. Identical dose escalation studies (10, 20 and 40 J/cm) using interstitial verteporfin PDT were performed and MR imaging with T2-weighted and T1-weighted contrast were used to monitor the total tumor volume and the vascular perfusion volume, respectively. Results There was a significant amount of necrosis in the slower growing Panc-1 tumor using high light dose, although complete necrosis was not observed. Lower doses were required for the same level of tumor kill in the faster growing AsPC-1 cell line. Conclusions The tumor growth rate and vascular pattern of the tumor affects the optimal PDT treatment regime, with faster growing tumors being relatively easier to treat. This highlights the fact that therapy in humans will show a heterogeneous range of outcomes, and suggests a need for careful individualized treatment outcomes assessment in clinical work.

Samkoe, Kimberley S.; Chen, Alina; Rizvi, Imran; O'Hara, Julia A.; Hoopes, P. Jack; Pereira, Stephen P.; Hasan, Tayyaba; Pogue, Brian W.

2009-01-01

151

Chemotherapeutic Effect of Calcidiol Derivative B3CD in a Neuroblastoma Xenograft Model  

PubMed Central

Bromoacetoxy-calcidiol (B3CD), a pro-apoptotic and cytotoxic agent in neuroblastoma (NB) cell lines, displayed therapeutic potential in vivo as an anti-cancer drug in a NB xenograft mouse model. Tumors of all animals treated intraperitoneally with B3CD went into regression within 10–30 days of treatment, while tumors in control animals grew aggressively. The response mechanisms of NB cells to B3CD in vitro were studied and included differential targeting of cell cycle key regulators p21 and cyclin D1 on the transcriptional and expression level leading to arrest in G0/G1 phase. In contrast to the effect in ovarian cancer cells, B3CD-induced cell death in SMS-KCNR NB cells was only marginally mediated by the p38 MAPK signaling pathway. Signaling induced by exogenous recombinant EGF lead to a partial restoration of the negative effects of B3CD on SMS-KCNR cell proliferation and survival. Upon combinational treatment of SMS-KCNR cells with B3CD and recombinant EGF, the EGF receptor (EGF-R) was highly activated. We suggest future studies to include analysis of the effects of B3CD in combination therapy with pharmacological inhibitors of cell cycle regulators or with EGF-R targeting inhibitors, -toxins or -antibodies in vitro and their translation into in vivo models of tumor development.

Lange, Thilo Sascha; Zou, Yongping; Singh, Rakesh K.; Kim, Kyu Kwang; Kristjansdottir, Katrin; Saulnier Sholler, Giselle L.; Brard, Laurent

2010-01-01

152

Establishing Zebrafish as a Novel Exercise Model: Swimming Economy, Swimming-Enhanced Growth and Muscle Growth Marker Gene Expression  

PubMed Central

Background Zebrafish has been largely accepted as a vertebrate multidisciplinary model but its usefulness as a model for exercise physiology has been hampered by the scarce knowledge on its swimming economy, optimal swimming speeds and cost of transport. Therefore, we have performed individual and group-wise swimming experiments to quantify swimming economy and to demonstrate the exercise effects on growth in adult zebrafish. Methodology/Principal Findings Individual zebrafish (n?=?10) were able to swim at a critical swimming speed (Ucrit) of 0.548±0.007 m s?1 or 18.0 standard body lengths (BL) s?1. The optimal swimming speed (Uopt) at which energetic efficiency is highest was 0.396±0.019 m s?1 (13.0 BL s?1) corresponding to 72.26±0.29% of Ucrit. The cost of transport at optimal swimming speed (COTopt) was 25.23±4.03 µmol g?1 m?1. A group-wise experiment was conducted with zebrafish (n?=?83) swimming at Uopt for 6 h day?1 for 5 days week?1 for 4 weeks vs. zebrafish (n?=?84) that rested during this period. Swimming zebrafish increased their total body length by 5.6% and body weight by 41.1% as compared to resting fish. For the first time, a highly significant exercise-induced growth is demonstrated in adult zebrafish. Expression analysis of a set of muscle growth marker genes revealed clear regulatory roles in relation to swimming-enhanced growth for genes such as growth hormone receptor b (ghrb), insulin-like growth factor 1 receptor a (igf1ra), troponin C (stnnc), slow myosin heavy chain 1 (smyhc1), troponin I2 (tnni2), myosin heavy polypeptide 2 (myhz2) and myostatin (mstnb). Conclusions/Significance From the results of our study we can conclude that zebrafish can be used as an exercise model for enhanced growth, with implications in basic, biomedical and applied sciences, such as aquaculture.

Rovira, Mireia; Brittijn, Sebastiaan A.; Burgerhout, Erik; van den Thillart, Guido E. E. J. M.; Spaink, Herman P.; Planas, Josep V.

2010-01-01

153

Anti-inflammatory effect of fucoidan extracted from Ecklonia cava in zebrafish model.  

PubMed

Fucoidan extracted from Ecklonia cava had strong anti-inflammatory activities. However, the direct effects of fucoidan of E. cava on anti-inflammatory activities in vivo model remained to be determined. Therefore, the present study was designed to assess in vivo anti-inflammatory effect of fucoidan extracted from E. cava (ECF) using tail-cutting-induced and lipopolysaccharide (LPS)-stimulated zebrafish model. Treating zebrafish model with tail-cutting and LPS-treatment significantly increased the ROS and NO level. However, ECF inhibited this tail-cutting-induced and LPS-stimulated ROS and NO generation. These results show that ECF alleviated inflammation by inhibiting the ROS and NO generation induced by tail-cutting and LPS-treatment. In addition, ECF has a protective effect against the toxicity induced by LPS exposure in zebrafish embryos. This outcome could explain the potential anti-inflammatory activity of ECF, which might have a beneficial effect during the treatment of inflammatory diseases. PMID:23218269

Lee, Seung-Hong; Ko, Chang-Ik; Jee, Youngheun; Jeong, Yoonhwa; Kim, Misook; Kim, Jin-Soo; Jeon, You-Jin

2012-10-02

154

Whole plant based treatment of hypercholesterolemia with Crataegus laevigata in a zebrafish model  

PubMed Central

Background Consumers are increasingly turning to plant-based complementary and alternative medicines to treat hypercholesterolemia. Many of these treatments are untested and their efficacy is unknown. This multitude of potential remedies necessitates a model system amenable to testing large numbers of organisms that maintains similarity to humans in both mode of drug administration and overall physiology. Here we develop the larval zebrafish (4–30?days post fertilization) as a vertebrate model of dietary plant-based treatment of hypercholesterolemia and test the effects of Crataegus laevigata in this model. Methods Larval zebrafish were fed high cholesterol diets infused with fluorescent sterols and phytomedicines. Plants were ground with mortar and pestle into a fine powder before addition to food. Fluorescent sterols were utilized to optically quantify relative difference in intravascular cholesterol levels between groups of fish. We utilized the Zeiss 7-Live Duo high-speed confocal platform in order to both quantify intravascular sterol fluorescence and to capture video of the heart beat for determination of cardiac output. Results In this investigation we developed and utilized a larval zebrafish model to investigate dietary plant-based intervention of the pathophysiology of hypercholesterolemia. We found BODIPY-cholesterol effectively labels diet-introduced intravascular cholesterol levels (P?zebrafish cardiac output declines as cholesterol dose increases (difference between 0.1% and 8% (w/w) high cholesterol diet-treated cardiac output significant at P?model, we found hawthorn leaves and flowers significantly reduce intravascular cholesterol levels (P?zebrafish has the potential to become a powerful model to test plant based dietary intervention of hypercholesterolemia. Using this model we have shown that hawthorn leaves and flowers have the potential to affect cardiac output as well as intravascular cholesterol levels. Further, our observation that hawthorn leaves and flowers interact with cholesterol to impact cardiac output indicates that the physiological effects of hawthorn may depend on diet.

2012-01-01

155

Monitoring the development of xenograft triple-negative breast cancer models using diffusion-weighted magnetic resonance imaging.  

PubMed

Evaluations of tumor growth rates and molecular biomarkers are traditionally used to assess new mouse models of human breast cancers. This study investigated the utility of diffusion weighted (DW)-magnetic resonance imaging (MRI) for evaluating cellular proliferation of new tumor models of triple-negative breast cancer, which may augment traditional analysis methods. Eleven human breast cancer cell lines were used to develop xenograft tumors in severe combined immunodeficient mice, with two of these cell lines exhibiting sufficient growth to be serially passaged. DW-MRI was performed to measure the distributions of the apparent diffusion coefficient (ADC) in these two tumor xenograft models, which showed a correlation with tumor growth rates and doubling times during each passage. The distributions of the ADC values were also correlated with expression of Ki67, a biomarker of cell proliferation, and hypoxia inducible factor (HIF)-1? and vascular endothelial growth factor receptor-2 (VEGFR2), which are essential proteins involved in regulating aerobic glycolysis and angiogenesis that support tumor cell proliferation. Although phosphatase and tensin homolog (PTEN) levels were different between the two xenograft models, AKT levels did not differ nor did they correlate with tumor growth. This last result demonstrates the complexity of signaling protein pathways and the difficulty in interpreting the effects of protein expression on tumor cell proliferation. In contrast, DW-MRI may be a more direct assessment of tumor growth and cancer cell proliferation. PMID:23239438

Stephen, Renu M; Pagel, Mark D; Brown, Kathy; Baker, Amanda F; Meuillet, Emmanuelle J; Gillies, Robert J

2012-11-01

156

Intravenous injection of hybrid liposomes suppresses the liver metastases in xenograft mouse models of colorectal cancer in vivo.  

PubMed

Therapeutic effects of hybrid liposomes (HL) composed of l-?-dimyristoylphosphatidylcholine (DMPC) and polyoxyethylene(25) dodecyl ether (C(12)(EO)(25)) on the metastasis of human colon carcinoma (HCT116) cells were examined in vivo. Remarkably high therapeutic effects were obtained in the xenograft mouse models of colorectal cancer (CRC) liver metastases after treatment with HL-25 on the basis of relative liver weight and histological analysis of the liver tissue sections of mouse models with HE staining, and TUNEL staining for detection of apoptotic cells. The survival effects of HL-25 were obtained using xenograft mouse models of CRC liver metastases. Furthermore, with regard to pharmacokinetics, the accumulation of fluorescent labeled HL-25 was observed in the liver tissue of xenograft mouse models of CRC liver metastases for 24 h after the intravenous injection of fluorescent labeled HL-25. Therapeutic effects of HL without any drugs on the liver metastasis of human CRC were revealed for the first time in vivo. PMID:23059544

Ichihara, Hideaki; Hino, Motoki; Umebayashi, Masayo; Matsumoto, Yoko; Ueoka, Ryuichi

2012-09-07

157

Imaging of 186Re-liposome therapy in ovarian cancer xenograft model of peritoneal carcinomatosis.  

PubMed

This study determined the biodistribution of rhenium-186 ((186)Re) encapsulated in biotin-liposomes containing patent blue dye, injected intraperitoneally (IP) with avidin in an OVCAR-3 ovarian cancer xenograft model and evaluated tumor response of this therapy with fluorine-18-fluorodeoxyglucose ((18)F-FDG) microPET imaging. Treated rats (n = 8) received an IP injection of (186)Re-blue-biotin-liposomes (1000 MBq/kg) 30 min before an IP injection of avidin (5 mg), whereas control rats (n = 4) received a sham IP injection of saline. Scintigraphic images showed that (186)Re-blue-biotin liposomes/avidin were retained in the peritoneal cavity with 18% of the original activity remaining after 5 days. From 1 to 4 weeks post-treatment, peritoneal (18)F-FDG standard uptake values decreased 30% in treatment group, yet increased 44% in control group. Total number of cells in ascites was significantly higher in control versus treatment group. Omental fat in control rats had numerous tumor cells compared with treated rats. Results show the potential for (186)Re-blue-biotin-liposome/avidin system in treating advanced ovarian cancer involving peritoneal carcinomatosis. PMID:18686134

Zavaleta, Cristina L; Goins, Beth A; Bao, Ande; McManus, Linda M; McMahan, C Alex; Phillips, William T

2008-08-01

158

Inhibition of estrogen-dependent tumorigenesis by the thyroid hormone receptor ? in xenograft models.  

PubMed

Association studies suggest that thyroid hormone receptor ? (TR?) could function as a tumor suppressor in breast cancer development, but unequivocal evidence is still lacking. To understand the role of TR? in breast tumor development, we adopted the gain-of-function approach by stably expressing the THRB gene in a human breast cancer cell line, MCF-7 (MCF-7-TR?). Parental MCF-7 cells express the estrogen receptor, but not TRs. MCF-7 cells, stably expressing only the selectable marker, the Neo gene, were also generated as control for comparison (MCF-7-Neo cells). Cell-based studies indicate that the estrogen (E2)-dependent growth of MCF-7 cells was inhibited by the expression of TR? in the presence of the thyroid hormone (T3). In a xenograft mouse model, large tumors rapidly developed after inoculation of MCF-7-Neo cells in athymic mice. In contrast, markedly smaller tumors (98% smaller) were found when MCF-7-TR? cells were inoculated in athymic mice, indicating that TR? inhibited the E2-dependent tumor growth of MCF-7 cells. Further detailed molecular analysis showed that TR? acted to activate apoptosis and decrease proliferation of tumor cells, resulting in inhibition of tumor growth. The TR?-mediated inhibition of tumor growth was elucidated via down-regulation of the JAK-STAT-cyclin D pathways. This in vivo evidence shows that TR? could act as a tumor suppressor in breast tumorigenesis. The present study provides new insights into the role of TR in breast cancer. PMID:23841029

Park, Jeong Won; Zhao, Li; Cheng, Sheue-Yann

2013-06-20

159

Mitochondrially targeted wild-type p53 induces apoptosis in a solid human tumor xenograft model.  

PubMed

Classic but also novel roles of p53 are becoming increasingly well characterized. We previously showed that ex vivo retroviral transfer of mitochondrially targeted wild type p53 (mitop53) in the Emu-myc mouse lymphoma model efficiently induces tumor cell killing in vivo. In an effort to further explore the therapeutic potential of mitop53 for its pro-apoptotic effect in solid tumors, we generated replication-deficient recombinant human Adenovirus type 5 vectors. We show here that adenoviral delivery of mitop53 by intratumoral injection into HCT116 human colon carcinoma xenograft tumors in nude mice is surprisingly effective, resulting in tumor cell death of comparable potency to conventional p53. These apoptotic effects in vivo were confirmed by Ad5-mitop53 mediated cell death of HCT116 cells in culture. Together, these data provide encouragement to further explore the potential for novel mitop53 proteins in cancer therapy to execute the shortest known circuitry of p53 death signaling. PMID:18719383

Palacios, Gustavo; Crawford, Howard C; Vaseva, Angelina; Moll, Ute M

2008-08-07

160

Molecular imaging of fibrin in a breast cancer xenograft mouse model  

PubMed Central

Rationale and objectives Fibrin deposition has been indicated within the stroma of a majority of solid tumors. Here we assess the feasibility of using the established fibrin-specific probe EP-2104R for the noninvasive imaging of fibrin in the context of breast cancer. Methods EP-2104R, untargeted Gd-DTPA and a newly synthesized non-fibrin binding control linear peptide (CLP) were compared using steady-state and dynamic contrast enhanced MR imaging in a breast cancer xenograft mouse model at 9.4T. Results EP-2104R transiently enhanced both the tumor core and periphery, but only the enhancement in the tumor periphery persisted even 90 min after EP-2104R administration. However, untargeted Gd-DTPA and CLP are not retained in the tumor periphery. The half-life of EP-2104R in the tumor periphery (103±18 min) is significantly longer (p<0.05) than either Gd-DTPA (29.6±2.4 min) or CLP (42.4±1.5 min), but the rate of clearance is similar for all the three probes from the tumor core. The presence of high concentrations of fibrin in the tumor periphery was corroborated using immuno-histochemistry with a fibrin-specific antibody. Conclusions The persistent enhancement observed in the tumor periphery with EP-2104R is likely a result of its fibrin-specific binding rather than its size and demonstrates the feasibility of EP-2104R for molecular imaging of fibrin in tumor stroma.

Uppal, Ritika; Medarova, Zdravka; Farrar, Christian T.; Dai, Guangping; Moore, Anna; Caravan, Peter

2013-01-01

161

Captopril inhibits tumour growth in a xenograft model of human renal cell carcinoma.  

PubMed Central

The effect of captopril on tumour growth was examined in a xenograft model of human renal cell carcinoma (RCC). Inoculation of the human RCC cell line SN12K-1 (10(6) cells) under the left kidney capsule of severe combined immunodeficient (SCID) mice resulted in the growth of large tumours, with an increase in weight of the inoculated kidney of 3.69+/-1.63-fold (mean+/-s.d.) when compared with the contralateral normal kidney. In mice treated with captopril (19 mg kg(-1) day(-1) or 94 mg kg(-1) day(-1) administered in the drinking water), there was a significant dose-related reduction in tumour development; the tumour bearing kidneys weighed 1.9+/-0.42 and 1.55+/-0.42 times the normal kidneys, respectively (P< 0.05 compared with untreated animals). In vitro, captopril at clinically achievable doses (0.1-10 microM) had no significant effect on the incorporation of [3H]thymidine into SN12K-1 cells. Thus, this highly significant attenuation by captopril of in vivo tumour growth does not appear to be due to a direct effect on the proliferation of the tumour cells. Further studies are required to determine the mechanism of inhibition of tumour growth by captopril, in particular to evaluate the role of angiotensin II in this process. Images Figure 1

Hii, S. I.; Nicol, D. L.; Gotley, D. C.; Thompson, L. C.; Green, M. K.; Jonsson, J. R.

1998-01-01

162

Efficacy of combined axitinib with dacarbazine in a B16F1 melanoma xenograft model  

PubMed Central

In this study, we evaluated the efficacy and intestinal side effects of the selective inhibitor of vascular endothelial growth factor (VEGF) receptors, axitinib and/or dacarbazine (DTIC), in a B16F1 melanoma xenograft model. C57BL/6 mice were subcutaneously inoculated with B16F1 melanoma cells. The study was randomized into four groups receiving either 0.5% carboxyl methylcellulose, DTIC, axitinib or a combination of DTIC and axitinib. When the experimental period was complete, the tumor tissues from each mouse were excised, photographed and weighed. The tumor and intestinal tissues were harvested with 4% paraformaldehyde, and paraffin-embedded sections were prepared for hematoxylin and eosin staining, immunohistochemical staining (with antibody specific to proliferating cell nuclear antibody) and terminal deoxynucleotidyl-transferase-mediated dUTP nick end labeling assays. The expression of the VEGF and matrix metalloproteinase 9 genes was analyzed using real-time polymerase chain reaction. No significant benefit to treatment with a combination of axitinib and DTIC, as opposed to axitinib alone, was observed; however, the combined treatment did not enhance the level of enteritis compared with that observed in the axitinb group. In addition, axitinib, as a single agent, demonstrated an improved treatment efficacy compared with DTIC. Therefore, axitinib represents a potential novel, efficient and safe anticancer agent, suggesting a possible use for this schedule in treating melanomas that are less sensitive to DTIC.

ZHANG, XIAO-HUA; QIAO, EN-QI; GAO, ZHENZHEN; YUAN, HUA-QING; CAI, PEI-FEN; LI, XIAO-MIN; GU, YAN-HONG

2013-01-01

163

Characterization and investigation of zebrafish models of filamin-related myofibrillar myopathy.  

PubMed

Myofibrillar myopathies are a group of muscle disorders characterized by the disintegration of skeletal muscle fibers and formation of sarcomeric protein aggregates. All the proteins known to be involved in myofibrillar myopathies localize to a region of the sarcomere known as the Z-disk, the site at which defects are first observed. Given the common cellular phenotype observed in this group of disorders, it is thought that there is a common mechanism of pathology. Mutations in filamin C, which has several proposed roles in the development and function of skeletal muscle, can result in filamin-related myofibrillar myopathy. The lack of a suitable animal model system has limited investigation into the mechanism of pathology in this disease and the role of filamin C in muscle development. Here, we characterize stretched out (sot), a zebrafish filamin Cb mutant, together with targeted knockdown of zebrafish filamin Ca, revealing fiber dissolution and formation of protein aggregates strikingly similar to those seen in filamin-related myofibrillar myopathies. Through knockdown of both zebrafish filamin C homologues, we demonstrate that filamin C is not required for fiber specification and that fiber damage is a consequence of muscle activity. The remarkable similarities in the myopathology between our models and filamin-related myofibrillar myopathy makes them suitable for the study of these diseases and provides unique opportunities for the investigation of the function of filamin C in muscle and development of therapies. PMID:22706277

Ruparelia, Avnika A; Zhao, Mo; Currie, Peter D; Bryson-Richardson, Robert J

2012-06-16

164

Behavioral and Synaptic Circuit Features in a Zebrafish Model of Fragile X Syndrome  

PubMed Central

Fragile X syndrome (FXS) is the most frequent inherited form of human mental retardation. It is characterized by cognitive impairment and physical and behavioral problems and is caused by the silencing of fmr1 transcription and the absence of the fmr1 protein (FMRP). Recently, animal models of FXS have greatly facilitated the investigation of the molecular and cellular mechanisms of this loss-of-function disorder. The present study was aimed to further characterize the role of FMRP in behavior and synaptic function by using fmr1 knockout zebrafish. In adult zebrafish, we found that fmr1 knockout produces the anxiolytic-like responses of increased exploratory behavior in light/dark and open-field tests and avoidance learning impairment. Furthermore, electrophysiological recordings from telencephalic slice preparations of knockout fish displayed markedly reduced long-term potentiation and enhanced long-term depression compared to wild-type fish; however, basal glutamatergic transmission and presynaptic function at the lateral (Dl) and medial (Dm) division of the dorsal telencephalon synapse remained normal. Taken together, our study not only evaluates the mechanism of FRMP but also suggests that zebrafish have valuable potential as a complementary vertebrate model in studying the molecular pathogenesis of human fragile X syndrome.

Ng, Ming-Chong; Yang, Yi-Ling; Lu, Kwok-Tung

2013-01-01

165

Embryonic fate map of first pharyngeal arch structures in the sox10: kaede zebrafish transgenic model.  

PubMed

Cranial neural crest cells follow stereotypic patterns of migration to form craniofacial structures. The zebrafish is a powerful vertebrate genetic model where transgenics with reporter proteins under the transcriptional regulation of lineage-specific promoters can be generated. Numerous studies demonstrate that the zebrafish ethmoid plate is embryologically analogous to the mammalian palate. A fate map correlating embryonic cranial neural crest to defined jaw structures would provide a useful context for the morphogenetic analysis of craniofacial development. To that end, the sox10:kaede transgenic was generated, where sox10 provides lineage restriction to the neural crest. Specific regions of neural crest were labeled at the 10-somite stage by photoconversion of the kaede reporter protein. Lineage analysis was carried out during pharyngeal development in wild-type animals, after miR140 injection, and after estradiol treatment. At the 10-somite stage, cranial neural crest cells anterior of the eye contributed to the median ethmoid plate, whereas cells medial to the eye formed the lateral ethmoid plate and trabeculae and a posterior population formed the mandible. miR-140 overexpression and estradiol inhibition of Hedgehog signaling resulted in cleft development, with failed migration of the anterior cell population to form the median ethmoid plate. The sox10:kaede transgenic line provides a useful tool for neural crest lineage analysis. These studies illustrate the advantages of the zebrafish model for application in morphogenetic studies of vertebrate craniofacial development. PMID:22948622

Dougherty, Max; Kamel, George; Shubinets, Valeriy; Hickey, Graham; Grimaldi, Michael; Liao, Eric C

2012-09-01

166

A new inducible RNAi xenograft model for assessing the staged tumor response to mTOR silencing  

Microsoft Academic Search

Human xenograft tumor models are widely used for efficacy evaluation of potential cancer targets. siRNA is usually stably introduced into tumor cells prior to transplantation. However, silencing of the cancer therapeutic target usually results in reduced cell growth\\/survival in vitro and\\/or failure to establish tumors in vivo, thus hindering tumor response-based efficacy evaluation. The present study explored a new tumor

Ning Ke; Demin Zhou; Jon E. Chatterton; Guohong Liu; John Chionis; Jing Zhang; Lindsey Tsugawa; Rebecca Lynn; Dehua Yu; Bernd Meyhack; Flossie Wong-Staal; Qi-Xiang Li

2006-01-01

167

Using a Xenograft Model of Human Breast Cancer Metastasis to Find Genes Associated with Clinically Aggressive Disease  

Microsoft Academic Search

Metastasis is the primary cause of death from breast cancer. A xenograft model was used to identify genes potentially involved with metastasis, comparing expression in the poorly metastatic GI101A human breast cancer cell line and a highly metastatic variant, GILM2. cDNA microarray analyses of these isogenic variants were done using 16K Operon 70-mer oligonucleotide microarray slides. Differentially expressed genes were

Harriet M. Kluger; Dina Chelouche Lev; Yuval Kluger; Mary M. McCarthy; Galina Kiriakova; Robert L. Camp; David L. Rimm

2005-01-01

168

Transcriptome analysis of anti-fatty liver action by Campari tomato using a zebrafish diet-induced obesity model  

PubMed Central

Background High dietary intake of vegetable products is beneficial against obesity and its related diseases such as dyslipidemia, nonalcoholic fatty liver disease, and cancer. We previously developed a diet-induced obesity model of zebrafish (DIO-zebrafish) that develops visceral adiposity, dyslipidemia, and liver steatosis. Zebrafish is a polyphagous animal; thus we hypothesized that DIO-zebrafish could be used for transcriptome analysis of anti-obesity effects of vegetables. Results Each vegetable exhibited different effects against obesity. We focused on "Campari" tomato, which suppressed increase of body weight, plasma TG, and lipid droplets in livers of DIO-zebrafish. Campari tomato decreased srebf1 mRNA by increase of foxo1 gene expression, which may depend on high contents of ?-carotene in this strain. Conclusions Campari tomato ameliorates diet-induced obesity, especially dyslipidemia and liver steatosis via downregulation of gene expression related to lipogenesis. DIO-zebrafish can discriminate the anti-obesity effects of different strains of vegetables, and will become a powerful tool to assess outcomes and find novel mechanisms of anti-obesity effects of natural products.

2011-01-01

169

Aggressiveness of human melanoma xenograft models is promoted by aneuploidy-driven gene expression deregulation.  

PubMed

Melanoma is a devastating skin cancer characterized by distinct biological subtypes. Besides frequent mutations in growth- and survival-promoting genes like BRAF and NRAS, melanomas additionally harbor complex non-random genomic alterations. Using an integrative approach, we have analysed genomic and gene expression changes in human melanoma cell lines (N=32) derived from primary tumors and various metastatic sites and investigated the relation to local growth aggressiveness as xenografts in immuno-compromised mice (N=22). Although the vast majority >90% of melanoma models harbored mutations in either BRAF or NRAS, significant differences in subcutaneous growth aggressiveness became obvious. Unsupervised clustering revealed that genomic alterations rather than gene expression data reflected this aggressive phenotype, while no association with histology, stage or metastatic site of the original melanoma was found. Genomic clustering allowed separation of melanoma models into two subgroups with differing local growth aggressiveness in vivo. Regarding genes expressed at significantly altered levels between these subgroups, a surprising correlation with the respective gene doses (>85% accordance) was found. Genes deregulated at the DNA and mRNA level included well-known cancer genes partly already linked to melanoma (RAS genes, PTEN, AURKA, MAPK inhibitors Sprouty/Spred), but also novel candidates like SIPA1 (a Rap1GAP). Pathway mining further supported deregulation of Rap1 signaling in the aggressive subgroup e.g. by additional repression of two Rap1GEFs. Accordingly, siRNA-mediated down-regulation of SIPA1 exerted significant effects on clonogenicity, adherence and migration in aggressive melanoma models. Together our data suggest that an aneuploidy-driven gene expression deregulation drives local aggressiveness in human melanoma. PMID:22535842

Mathieu, Véronique; Pirker, Christine; Schmidt, Wolfgang M; Spiegl-Kreinecker, Sabine; Lötsch, Daniela; Heffeter, Petra; Hegedus, Balazs; Grusch, Michael; Kiss, Robert; Berger, Walter

2012-04-01

170

Identification of compounds with anti-convulsant properties in a zebrafish model of epileptic seizures.  

PubMed

The availability of animal models of epileptic seizures provides opportunities to identify novel anticonvulsants for the treatment of people with epilepsy. We found that exposure of 2-day-old zebrafish embryos to the convulsant agent pentylenetetrazole (PTZ) rapidly induces the expression of synaptic-activity-regulated genes in the CNS, and elicited vigorous episodes of calcium (Ca(2+)) flux in muscle cells as well as intense locomotor activity. We then screened a library of ?2000 known bioactive small molecules and identified 46 compounds that suppressed PTZ-inducedtranscription of the synaptic-activity-regulated gene fos in 2-day-old (2 dpf) zebrafish embryos. Further analysis of a subset of these compounds, which included compounds with known and newly identified anticonvulsant properties, revealed that they exhibited concentration-dependent inhibition of both locomotor activity and PTZ-induced fos transcription, confirming their anticonvulsant characteristics. We conclude that this in situ hybridisation assay for fos transcription in the zebrafish embryonic CNS is a robust, high-throughput in vivo indicator of the neural response to convulsant treatment and lends itself well to chemical screening applications. Moreover, our results demonstrate that suppression of PTZ-induced fos expression provides a sensitive means of identifying compounds with anticonvulsant activities. PMID:22730455

Baxendale, Sarah; Holdsworth, Celia J; Meza Santoscoy, Paola L; Harrison, Michael R M; Fox, James; Parkin, Caroline A; Ingham, Philip W; Cunliffe, Vincent T

2012-06-21

171

Zebrafish eleutheroembryos provide a suitable vertebrate model for screening chemicals that impair thyroid hormone synthesis.  

PubMed

Thyroxine-immunofluorescence quantitative disruption test (TIQDT) was designed to provide a simple, rapid, alternative bioassay for assessing the potential of chemical pollutants and drugs to disrupt thyroid gland function. This study demonstrated that zebrafish eleutheroembryos provided a suitable vertebrate model, not only for screening the potential thyroid disrupting effect of molecules, but also for estimating the potential hazards associated with exposure to chemicals directly impairing thyroxine (T4) synthesis. Amitrole, potassium perchlorate, potassium thiocyanate, methimazole (MMI), phloroglucinol, 6-propyl-2-thiouracil, ethylenethiourea, benzophenone-2, resorcinol, pyrazole, sulfamethoxazole, sodium bromide, mancozeb, and genistein were classified as thyroid gland function disruptors. Concordance between TIQDT on zebrafish and mammalian published data was very high and the physiological relevance of T4-intrafollicular content was clearly higher than regulation at the transcriptional level of tg or slc5a5. Moreover, concentration-response analysis provided information about the thyroid disrupting potency and hazard of selected positive compounds. Finally, the effect of perchlorate, but not MMI, was completely rescued by low-micromolar amounts of iodide. TIQDT performed on zebrafish eleutheroembryos is an alternative whole-organism screening assay that provides relevant information for environmental and human risk assessments. PMID:21800831

Thienpont, Benedicte; Tingaud-Sequeira, Angèle; Prats, Eva; Barata, Carlos; Babin, Patrick J; Raldúa, Demetrio

2011-08-09

172

Immunologically untreated fresh xenograft implantation in a pig-to-goat model.  

PubMed

Immunologically untreated frozen-stored xenografts show controlled rejection and repair due to reduced cellularity in our previous study. To clarify the issue, we compared results obtained using fresh and frozen-stored xenografts. Porcine pulmonary valved conduits were prepared without immunologic treatment and implanted in the right ventricular outflow tract of goats under cardiopulmonary bypass immediately after harvest without frozen storage (the fresh group) or after frozen storage (-70 degrees C for 3 - 7 days) (the frozen group). Four goats were assigned to be raised for 3 (N = 1) or 6 (N = 3) months postoperatively in each group. One goat in the frozen group assigned for the 6-month observation expired at 2 months postoperatively because of thrombotic occlusion of the pulmonary valve. The other goats survived until the scheduled sacrifice. According to echocardiographic findings, one animal sacrificed at 3 months in the frozen group showed more than a moderate degree of pulmonary regurgitation, but all animals in the fresh group showed less than a mild degree. On gross examination, leaflets were slightly better preserved in the fresh group and aneurysmal dilatation of the pulmonary artery was observed at 3 months only in the frozen group. Microscopically, pulmonary arteries showed less severe degenerative changes in the fresh group. Moreover, in the fresh group, viable donor valve cells were still present until 3 months postoperatively (though it disappeared at 6 months postoperatively) and a linear endothelial lining of viable host cells was prominent on all leaflets, whereas this was not the case in the frozen group. In conclusion, fresh xenografts preserved cellular viability and showed fewer degenerative changes than frozen-stored xenografts. Thus, immunologically untreated fresh xenografts could provide a potential valve substitute with distinctive advantages in terms of self-healing potential as compared with frozen-stored xenografts. PMID:18959669

Sung, Kiick; Kim, Won Gon; Seo, Jung Wook

2008-10-01

173

Noninvasive estimation of tumour viability in a xenograft model of human neuroblastoma with proton magnetic resonance spectroscopy (1H MRS)  

PubMed Central

The aim of the study was to evaluate proton magnetic resonance spectroscopy (1H MRS) for noninvasive biological characterisation of neuroblastoma xenografts in vivo. For designing the experiments, human neuroblastoma xenografts growing subcutaneously in nude rats were analysed in vivo with 1H MRS and magnetic resonance imaging at 4.7?T. The effects of spontaneous tumour growth and antiangiogenesis treatment, respectively, on spectral characteristics were evaluated. The spectroscopic findings were compared to tumour morphology, proliferation and viable tumour tissue fraction. The results showed that signals from choline (Cho)-containing compounds and mobile lipids (MLs) dominated the spectra. The individual ML/Cho ratios for both treated and untreated tumours were positively correlated with tumour volume (P<0.05). There was an inverse correlation between the ML/Cho ratio and the viable tumour fraction (r=?0.86, P<0.001). Higher ML/Cho ratios concomitant with pronounced histological changes were seen in spectra from tumours treated with the antiangiogenic drug TNP-470, compared to untreated control tumours (P<0.05). In conclusion, the ML/Cho ratio obtained in vivo by 1H MRS enabled accurate assessment of the viable tumour fraction in a human neuroblastoma xenograft model. 1H MRS also revealed early metabolic effects of antiangiogenesis treatment. 1H MRS could prove useful as a tool to monitor experimental therapy in preclinical models of neuroblastoma, and possibly also in children.

Lindskog, M; Kogner, P; Ponthan, F; Schweinhardt, P; Sandstedt, B; Heiden, T; Helms, G; Spenger, C

2003-01-01

174

Exploring alternative models of rostral-caudal patterning in the zebrafish neurectoderm with computer simulations.  

PubMed

The StarLogo and NetLogo programming environments allow developmental biologists to build computer models of cell-cell interactions in an epithelium and visualize emergent properties of hypothetical genetic regulatory networks operating in the cells. These environments were used to explore alternative models that show how a posteriorizing morphogen gradient might define gene-expression domains along the rostral-caudal axis in the zebrafish neurectoderm. The models illustrate how a hypothetical genetic network based on auto-activation and cross-repression could lead to establishment of discrete non-overlapping gene-expression domains. PMID:15261658

Chitnis, Ajay B; Itoh, Motoyuki

2004-08-01

175

Microfluidic tools for developmental studies of small model organisms--nematodes, fruit flies, and zebrafish.  

PubMed

Studying the genetics of development with small model organisms such as the zebrafish (Danio Rerio), the fruit fly (Drosophila melanogaster), and the soil-dwelling nematode (Caenorhabditis elegans), provide unique opportunities for understanding related processes and diseases in humans. These model organisms also have potential for use in drug discovery and toxicity-screening applications. There have been sweeping developments in microfabrication and microfluidic technologies for manipulating and imaging small objects, including small model organisms, which allow high-throughput quantitative biological studies. Here, we review recent progress in microfluidic tools able to manipulate small organisms and project future directions and applications of these techniques and technologies. PMID:23161817

Hwang, Hyundoo; Lu, Hang

2012-11-19

176

Combination of Vandetanib, Radiotherapy, and Irinotecan in the LoVo Human Colorectal Cancer Xenograft Model  

SciTech Connect

Purpose: The tumor growth kinetics of the human LoVo colorectal xenograft model was assessed in response to vandetanib, an orally available receptor tyrosine kinase inhibitor, radiotherapy (RT), or irinotecan (CPT-11), as single therapies and in combination. Methods and Materials: LoVo cells were injected subcutaneously into the right hind limb (5x10{sup 6} cells in 100muL phosphate-buffered saline) of athymic NCR NUM mice and tumors were grown to a volume of 200-300 mm{sup 3} before treatment. Vandetanib was administered at 50 mg/kg daily orally for 14 days starting on Day 1. RT was given as three fractions (3x3 Gy) on Days 1, 2, and 3. CPT-11 was given at 15 mg/kg intraperitoneally on Days 1 and 3. Tumor volumes were measured on a daily basis and calculated by measuring tumor diameters with digital calipers in two orthogonal dimensions. Results: All three single treatments (vandetanib, CPT-11, and radiation) significantly slowed LoVo colorectal tumor growth. Vandetanib significantly increased the antitumor effects of CPT-11 and radiation when given in combination with either of these treatments. These treatment combinations resulted in a slow tumor growth rate during the 2 weeks of vandetanib administration. The triple combination of vandetanib, CPT-11, and radiation produced the most marked improvement in response as observed by measurable shrinkage of tumors during the first week of treatment. Conclusions: The tumor growth delay kinetics observed in this study of the LoVo colorectal model suggest concurrent and sustained post-sequencing of vandetanib with cytotoxic therapy may be beneficial in tumors of this type.

Wachsberger, Phyllis, E-mail: Phyllis.wachsberger@jeffersonhospital.or [Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, PA (United States); Burd, Randy [Department of Nutritional Sciences, University of Arizona, Tucson, AZ (United States); Ryan, Anderson [AstraZeneca Pharmaceuticals, Alderley Park, Macclesfield (United Kingdom); Daskalakis, Constantine [Department of Pharmacology and Experimental Therapeutics, Thomas Jefferson University, Philadelphia, PA (United States); Dicker, Adam P. [Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, PA (United States)

2009-11-01

177

A Novel, Diffusely Infiltrative Xenograft Model of Human Anaplastic Oligodendroglioma with Mutations in FUBP1, CIC, and IDH1  

PubMed Central

Oligodendroglioma poses a biological conundrum for malignant adult human gliomas: it is a tumor type that is universally incurable for patients, and yet, only a few of the human tumors have been established as cell populations in vitro or as intracranial xenografts in vivo. Their survival, thus, may emerge only within a specific environmental context. To determine the fate of human oligodendroglioma in an experimental model, we studied the development of an anaplastic tumor after intracranial implantation into enhanced green fluorescent protein (eGFP) positive NOD/SCID mice. Remarkably after nearly nine months, the tumor not only engrafted, but it also retained classic histological and genetic features of human oligodendroglioma, in particular cells with a clear cytoplasm, showing an infiltrative growth pattern, and harboring mutations of IDH1 (R132H) and of the tumor suppressor genes, FUBP1 and CIC. The xenografts were highly invasive, exhibiting a distinct migration and growth pattern around neurons, especially in the hippocampus, and following white matter tracts of the corpus callosum with tumor cells accumulating around established vasculature. Although tumors exhibited a high growth fraction in vivo, neither cells from the original patient tumor nor the xenograft exhibited significant growth in vitro over a six-month period. This glioma xenograft is the first to display a pure oligodendroglioma histology and expression of R132H. The unexpected property, that the cells fail to grow in vitro even after passage through the mouse, allows us to uniquely investigate the relationship of this oligodendroglioma with the in vivo microenvironment.

Valenzuela, Jaime Alberto Campos; Balss, Jorg; Wang, Jian; Schubert, Manja; Sakariassen, Per ?ystein; Sundstr?m, Terje; Torsvik, Anja; Aarhus, Mads; Mahesparan, Rupavathana; von Deimling, Andreas; Kaderali, Lars; Niclou, Simone P.; Schrock, Evelin; Bjerkvig, Rolf; Nigro, Janice M.

2013-01-01

178

Targeting JAK1/2 and mTOR in murine xenograft models of Ph-like acute lymphoblastic leukemia  

PubMed Central

CRLF2 rearrangements, JAK1/2 point mutations, and JAK2 fusion genes have been identified in Philadelphia chromosome (Ph)–like acute lymphoblastic leukemia (ALL), a recently described subtype of pediatric high-risk B-precursor ALL (B-ALL) which exhibits a gene expression profile similar to Ph-positive ALL and has a poor prognosis. Hyperactive JAK/STAT and PI3K/mammalian target of rapamycin (mTOR) signaling is common in this high-risk subset. We, therefore, investigated the efficacy of the JAK inhibitor ruxolitinib and the mTOR inhibitor rapamycin in xenograft models of 8 pediatric B-ALL cases with and without CRLF2 and JAK genomic lesions. Ruxolitinib treatment yielded significantly lower peripheral blast counts compared with vehicle (P < .05) in 6 of 8 human leukemia xenografts and lower splenic blast counts (P < .05) in 8 of 8 samples. Enhanced responses to ruxolitinib were observed in samples harboring JAK-activating lesions and higher levels of STAT5 phosphorylation. Rapamycin controlled leukemia burden in all 8 B-ALL samples. Survival analysis of 2 representative B-ALL xenografts demonstrated prolonged survival with rapamycin treatment compared with vehicle (P < .01). These data demonstrate preclinical in vivo efficacy of ruxolitinib and rapamycin in this high-risk B-ALL subtype, for which novel treatments are urgently needed, and highlight the therapeutic potential of targeted kinase inhibition in Ph-like ALL.

Maude, Shannon L.; Tasian, Sarah K.; Vincent, Tiffaney; Hall, Junior W.; Sheen, Cecilia; Roberts, Kathryn G.; Seif, Alix E.; Barrett, David M.; Chen, I-Ming; Collins, J. Racquel; Mullighan, Charles G.; Hunger, Stephen P.; Harvey, Richard C.; Willman, Cheryl L.; Fridman, Jordan S.; Loh, Mignon L.; Grupp, Stephan A.

2012-01-01

179

siRNA targeting Livin decreases tumor in a xenograft model for colon cancer  

PubMed Central

AIM: To evaluate the effect of silencing Livin gene expression with siRNA to apoptosis and proliferation in a colon cancer cell line. METHODS: To investigate the anticancer effect of silencing Livin gene expression, we established an siRNA transfected cell line using the HCT116 colon cancer cell line. After confirming the successful transfection, MTT assay, flow cytometry and annexin V staining were employed to evaluate the antiapoptotic effect. To confirm the in vivo effect of Livin-siRNA, different doses of Livin-siRNA were injected into xenografted tumors in BALB/c nude mice model. RESULTS: Livin expression was dramatically decreased after siRNA transfection, especially at 25 ?mol/L of siRNA, but this suppression was not dose-dependent. The cell count at 18 h after transfection was significantly reduced as compared with controls (P < 0.01), but tended not to decrease proportionally depending on transfected dose or time. MTT assay revealed that silencing the Livin gene suppressed cellular proliferation at 18 h after transfection (P = 0.04); however, the inhibitory effect disappeared thereafter. Also, there was no significant difference in cellular proliferation depending on siRNA dose. The rate of apoptosis also increased with silencing of the Livin gene. In vivo, the tumor size significantly decreased after Livin-siRNA injection at 20 ?mol/L concentration (P = 0.03). There were no significant body weight changes of mice after siRNA injection. Histologic examination revealed no significant toxic reaction in kidney, liver and brain of mice. CONCLUSION: siRNA-mediated downregulation of Livin expression can induce apoptosis in colon cancer in vitro and in vivo, which suggests the possibility of new cancer therapeutics using siRNA.

Oh, Bo-Young; Lee, Ryung-Ah; Kim, Kwang Ho

2011-01-01

180

Carbohydrate restriction and lactate transporter inhibition in a mouse xenograft model of human prostate cancer  

PubMed Central

OBJECTIVES To determine if a no-carbohydrate ketogenic diet (NCKD) and lactate transporter inhibition can exert a synergistic effect on delaying prostate tumour growth in a xenograft mouse model of human prostate cancer. MATERIALS AND METHODS 120 nude athymic male mice (aged 6–8 weeks) were injected s.c. in the flank with 1.0 x 105 LAPC-4 prostate cancer cells. Mice were randomized to one of four treatment groups: Western diet (WD, 35% fat, 16% protein, 49% carbohydrate) and vehicle (Veh) treatment; WD and mono-carboxylate transporter-1 (MCT1) inhibition via ?-cyano-4-hydroxycinnamate (CHC) delivered through a mini osmotic pump; NCKD (84% fat, 16% protein, 0% carbohydrate) plus Veh ; or NCKD and MCT1 inhibition. Mice were fed and weighed three times per week and feed was adjusted to maintain similar body weights. Tumour size was measured twice weekly and the combined effect of treatment was tested via Kruskal – Wallis analysis of all four groups. Independent effects of treatment (NCKD vs. WD and CHC vs. Veh) on tumour volume were tested using linear regression analysis. All mice were killed on Day 53 (conclusion of pump ejection), and serum and tumour sections were analysed for various markers. Again, combined and independent effects of treatment were tested using Kruskal – Wallis and linear regression analysis, respectively. RESULTS There were no significant differences in tumour volumes among the four groups (P=0.09). When testing the independent effects of treatment, NCKD was significantly associated with lower tumour volumes at the end of the experiment (P=0.026), while CHC administration was not (P=0.981). However, CHC was associated with increased necrotic fraction (P<0.001). CONCLUSIONS Differences in tumour volumes were observed only in comparisons between mice fed a NCKD and mice fed a WD. MCT1 inhibition did not have a significant effect on tumour volume, although it was associated with increased necrotic fraction.

Kim, Howard S.; Masko, Elizabeth M.; Poulton, Susan L.; Kennedy, Kelly M.; Pizzo, Salvatore V.; Dewhirst, Mark W.; Freedland, Stephen J.

2012-01-01

181

Characterization of childhood acute lymphoblastic leukemia xenograft models for the preclinical evaluation of new therapies  

Microsoft Academic Search

Continuous xenografts from 10 children with acute lymphoblastic leukemia (ALL) were established in nonobese diabetic\\/severe combined immunodeficient (NOD\\/SCID) mice. Relative to primary engrafted cells, negligible changes in growth rates and im- munophenotype were observed at second and third passage. Analysis of clonal anti- gen receptor gene rearrangements in 2 xeno- grafts from patients at diagnosis showed that the pattern of

Natalia L. M. Liem; Rachael A. Papa; Christopher G. Milross; Michael A. Schmid; Mayamin Tajbakhsh; Seoyeon Choi; Carole D. Ramirez; Alison M. Rice; Michelle Haber; Murray D. Norris; Karen L. MacKenzie; Richard B. Lock

2004-01-01

182

Establishment of a rhabdomyosarcoma xenograft model in human-adapted mice.  

PubMed

The outcome of patients with advanced stage rhabdomyosarcoma (RMS) is still sobering. This outcome has not improved through conservative treatments. Therefore, novel treatment approaches such as immunotherapy need to be evaluated in human-adapted animal models. The aim of this study was to develop a humanized mouse model of childhood RMS as a basis for the study of immunotherapeutic approaches. Therefore, NOD/LtSz-scid IL2rgammanull-mice were used for all the experiments (n=19). The animals underwent sublethal irradiation on days 1 and 2 (1 x 300 cGy). After irradiation, the transplantation of human CD34+-cells (1,000,000 cells per animal i.v.) was carried out. Five animals served as the control and did not undergo stem cell transplantation. The engraftment of human cells was assessed in peripheral blood on days 21 and 55 by FACS analysis. Eight weeks after transplantation, the subcutaneous xenotransplantation of human alveolar and embryonal RMS cell lines was carried out. Tumor growth was monitored and tumors were resected 93 days after CD34+-transplantation. The tumor specimens were evaluated histologically. The successful engraftment of human cells with the establishment of a human immune system was observed in 12 out of 14 animals. B and T cells were mostly detected in the peripheral blood. There were only a few monocytes and almost no natural killer cells. The xenotransplantation of alveolar RMS resulting in subcutaneous tumor growth was feasible in 7 animals. The xenotransplantation of embryonal RMS was performed in 5 animals and led to tumor growth in 1 animal. A histological work up showed either alveolar or embryonal RMS cells with central necrosis. This is the first time a xenotransplantation model of human RMS has been developed in a humanized mouse model. The establishment of subcutaneous tumor xenografts was more effective in the alveolar subtype. This model offers a basic tool for further analyzing novel immunotherapeutic approaches in RMS, and could possibly be used in other solid pediatric tumors. PMID:20811690

Seitz, Guido; Pfeiffer, Matthias; Fuchs, Jörg; Warmann, Steven W; Leuschner, Ivo; Vokuhl, Christian; Lang, Peter; Handgretinger, Rupert; Armeanu-Ebinger, Sorin

2010-10-01

183

The Zebrafish Brain in Research and Teaching: A Simple in Vivo and in Vitro Model for the Study of Spontaneous Neural Activity  

ERIC Educational Resources Information Center

|Recently, the zebrafish ("Danio rerio") has been established as a key animal model in neuroscience. Behavioral, genetic, and immunohistochemical techniques have been used to describe the connectivity of diverse neural circuits. However, few studies have used zebrafish to understand the function of cerebral structures or to study neural circuits.…

Vargas, R.; Johannesdottir, I. P.; Sigurgeirsson, B.; Porsteinsson, H.; Karlsson, K. AE.

2011-01-01

184

Drift-Diffusion Analysis of Neutrophil Migration during Inflammation Resolution in a Zebrafish Model  

PubMed Central

Neutrophils must be removed from inflammatory sites for inflammation to resolve. Recent work in zebrafish has shown neutrophils can migrate away from inflammatory sites, as well as die in situ. The signals regulating the process of reverse migration are of considerable interest, but remain unknown. We wished to study the behaviour of neutrophils during reverse migration, to see whether they moved away from inflamed sites in a directed fashion in the same way as they are recruited or whether the inherent random component of their migration was enough to account for this behaviour. Using neutrophil-driven photoconvertible Kaede protein in transgenic zebrafish larvae, we were able to specifically label neutrophils at an inflammatory site generated by tailfin transection. The locations of these neutrophils over time were observed and fitted using regression methods with two separate models: pure-diffusion and drift-diffusion equations. While a model hypothesis test (the F-test) suggested that the datapoints could be fitted by the drift-diffusion model, implying a fugetaxis process, dynamic simulation of the models suggested that migration of neutrophils away from a wound is better described by a zero-drift, “diffusion” process. This has implications for understanding the mechanisms of reverse migration and, by extension, neutrophil retention at inflammatory sites.

Holmes, Geoffrey R.; Dixon, Giles; Anderson, Sean R.; Reyes-Aldasoro, Constantino Carlos; Elks, Philip M.; Billings, Stephen A.; Whyte, Moira K. B.; Kadirkamanathan, Visakan; Renshaw, Stephen A.

2012-01-01

185

Drift-Diffusion Analysis of Neutrophil Migration during Inflammation Resolution in a Zebrafish Model.  

PubMed

Neutrophils must be removed from inflammatory sites for inflammation to resolve. Recent work in zebrafish has shown neutrophils can migrate away from inflammatory sites, as well as die in situ. The signals regulating the process of reverse migration are of considerable interest, but remain unknown. We wished to study the behaviour of neutrophils during reverse migration, to see whether they moved away from inflamed sites in a directed fashion in the same way as they are recruited or whether the inherent random component of their migration was enough to account for this behaviour. Using neutrophil-driven photoconvertible Kaede protein in transgenic zebrafish larvae, we were able to specifically label neutrophils at an inflammatory site generated by tailfin transection. The locations of these neutrophils over time were observed and fitted using regression methods with two separate models: pure-diffusion and drift-diffusion equations. While a model hypothesis test (the F-test) suggested that the datapoints could be fitted by the drift-diffusion model, implying a fugetaxis process, dynamic simulation of the models suggested that migration of neutrophils away from a wound is better described by a zero-drift, "diffusion" process. This has implications for understanding the mechanisms of reverse migration and, by extension, neutrophil retention at inflammatory sites. PMID:22899935

Holmes, Geoffrey R; Dixon, Giles; Anderson, Sean R; Reyes-Aldasoro, Constantino Carlos; Elks, Philip M; Billings, Stephen A; Whyte, Moira K B; Kadirkamanathan, Visakan; Renshaw, Stephen A

2012-07-29

186

Cellular differentiation in primary cell cultures from single zebrafish embryos as a model for the study of myogenesis.  

PubMed

Culturing cells in vitro can produce a uniform population for the study of cellular differentiation, which is especially useful for the quantification of gene expression or the observation of subcellular structures. In zebrafish, a handful of immortalized cell lines have been used for these purposes, despite being heavily selected by passaging. Methods for primary cell culture of zebrafish embryonic blastomeres have been previously reported, but require combining a large number of genetically heterogeneous embryos, meaning that subsequent cell cultures are not clonal. Without genetically uniform cultures, this model system cannot exploit the wealth of available embryonic lethal mutants in zebrafish. We therefore describe methods for the generation of zebrafish embryonic blastomere cell cultures from single genetically characterized embryos. We examined myogenic differentiation and gene expression in single-embryo cultures from early wild-type embryos, as well as embryos containing an embryonic lethal mutation of unc45b, a myosin chaperone known to be required for sarcomere organization during myogenesis. We also demonstrated the practical usefulness of this technique by experimentally manipulating expression of specific genes in individual embryos before cell culture using standard tools of zebrafish biology such as morpholino-oligonucleotide gene knockdown and transgene-mediated gene expression. PMID:20936983

Myhre, J Layne; Pilgrim, David B

2010-09-01

187

Xenograft and genetically engineered mouse model systems of osteosarcoma and Ewing's sarcoma: tumor models for cancer drug discovery.  

PubMed

Introduction: There are > 75 histological types of solid tumors that are classified into two major groups: bone and soft-tissue sarcomas. These diseases are more prevalent in children, and pediatric sarcomas tend to be highly aggressive and rapidly progressive. Sarcomas in adults may follow a more indolent course, but aggressive tumors are also common. Sarcomas that are metastatic at diagnosis, or recurrent following therapy, remain refractory to current treatment options with dismal overall survival rates. A major focus of clinical trials, for patients with sarcoma, is to identify novel and more effective therapeutic strategies targeted to genomic or proteomic aberrations specific to the malignant cells. Critical to the understanding of the potential for targeted therapies are models of disease that are representative of clinical disease and predictive of relevant clinical responses. Areas covered: In this article, the authors discuss the use of mouse xenograft models and genetically engineered mice in cancer drug discovery. The authors provide a special focus on models for the two most common bone sarcomas: osteosarcoma (OS) and Ewing's sarcoma (ES). Expert opinion: Predicting whether a new anticancer agent will have a positive therapeutic index in patients with OS and ES remains a challenge. The use of mouse sarcoma models for understanding the mechanisms involved in the response of tumors to new treatments is an important step in the process of drug discovery and the development of clinically relevant therapeutic strategies for these diseases. PMID:23844615

Sampson, Valerie B; Kamara, Davida F; Kolb, E Anders

2013-07-12

188

Unique and potent effects of acute ibogaine on zebrafish: the developing utility of novel aquatic models for hallucinogenic drug research.  

PubMed

An indole alkaloid, ibogaine is the principal psychoactive component of the iboga plant, used by indigenous peoples in West Africa for centuries. Modulating multiple neurotransmitter systems, the drug is a potent hallucinogen in humans, although its psychotropic effects remain poorly understood. Expanding the range of model species is an important strategy for translational neuroscience research. Here we exposed adult zebrafish (Danio rerio) to 10 and 20mg/L of ibogaine, testing them in the novel tank, light-dark box, open field, mirror stimulation, social preference and shoaling tests. In the novel tank test, the zebrafish natural diving response (geotaxis) was reversed by ibogaine, inducing initial top swimming followed by bottom dwelling. Ibogaine also attenuated the innate preference for dark environments (scototaxis) in the light-dark box test. While it did not exert overt locomotor or thigmotaxic responses in the open field test, the drug altered spatiotemporal exploration of novel environment, inducing clear preference of some areas over others. Ibogaine also promoted 'mirror' exploration in the mirror stimulation test, disrupted group cohesion in the shoaling test, and evoked strong coloration responses due to melanophore aggregation, but did not alter brain c-fos expression or whole-body cortisol levels. Overall, our results support the complex pharmacological profile of ibogaine and its high sensitivity in zebrafish models, dose-dependently affecting multiple behavioral domains. While future investigations in zebrafish may help elucidate the mechanisms underlying these unique behavioral effects, our study strongly supports the developing utility of aquatic models in hallucinogenic drug research. High sensitivity of three-dimensional phenotyping approaches applied here to behavioral effects of ibogaine in zebrafish provides further evidence of how 3D reconstructions of zebrafish swimming paths may be useful for high-throughput pharmacological screening. PMID:22974549

Cachat, Jonathan; Kyzar, Evan J; Collins, Christopher; Gaikwad, Siddharth; Green, Jeremy; Roth, Andrew; El-Ounsi, Mohamed; Davis, Ari; Pham, Mimi; Landsman, Samuel; Stewart, Adam Michael; Kalueff, Allan V

2012-09-04

189

A transgenic zebrafish model of a human cardiac sodium channel mutation exhibits bradycardia, conduction-system abnormalities and early death.  

PubMed

The recent exponential increase in human genetic studies due to the advances of next generation sequencing has generated unprecedented numbers of new gene variants. Determining which of these are causative of human disease is a major challenge. In-vitro studies and murine models have been used to study inherited cardiac arrhythmias but have several limitations. Zebrafish models provide an attractive alternative for modeling human heart disease due to similarities in cardiac electrophysiology and contraction, together with ease of genetic manipulation, external development and optical transparency. Although zebrafish cardiac mutants and morphants have been widely used to study loss and knockdown of zebrafish gene function, the phenotypic effects of human dominant-negative gene mutations expressed in transgenic zebrafish have not been evaluated. The aim of this study was to generate and characterize a transgenic zebrafish arrhythmia model harboring the pathogenic human cardiac sodium channel mutation SCN5A-D1275N, that has been robustly associated with a range of cardiac phenotypes, including conduction disease, sinus node dysfunction, atrial and ventricular arrhythmias, and dilated cardiomyopathy in humans and in mice. Stable transgenic fish with cardiac expression of human SCN5A were generated using Tol2-mediated transgenesis and cardiac phenotypes were analyzed using video microscopy and ECG. Here we show that transgenic zebrafish expressing the SCN5A-D1275N mutation, but not wild-type SCN5A, exhibit bradycardia, conduction-system abnormalities and premature death. We furthermore show that SCN5A-WT, and to a lesser degree SCN5A-D1275N, are able to compensate the loss of endogenous zebrafish cardiac sodium channels, indicating that the basic pathways, through which SCN5A acts, are conserved in teleosts. This proof-of-principle study suggests that zebrafish may be highly useful in vivo models to differentiate functional from benign human genetic variants in cardiac ion channel genes in a time- and cost-efficient manner. This article is part of a Special Issue entitled "Na(+) Regulation in Cardiac Myocytes". PMID:23791817

Huttner, Inken G; Trivedi, Gunjan; Jacoby, Arie; Mann, Stefan A; Vandenberg, Jamie I; Fatkin, Diane

2013-06-19

190

Estrogen prevents cardiac and vascular failure in the 'listless' zebrafish (Danio rerio) developmental model.  

PubMed

The presence of a robust estrogen (E2) response system throughout heart and blood vessel tissues of vertebrates, including humans, has led to the speculation that this ubiquitous hormone may play a prominent role in the health and maintenance of the adult cardiovascular system (CVS). We previously established an embryonic zebrafish model called 'listless', which results from the inhibition of E2 synthesis by treatment with aromatase enzyme inhibitors (AI). These fish have outward symptoms similar to the human condition of congestive heart failure and tamponade. E2 replacement therapy (1) reduced the severity of cardiac sac abnormalities, (2) protected heart function, (3) prevented reduction in heart size, and (4) reduced blood vessel deterioration. Nitric oxide may be a critical downstream mediator of these events. We also demonstrate that removal of fluid around the heart increases survival of AI-treated fish. These results strongly indicate the importance of E2 in the developing CVS of the zebrafish and offer a potential model for the study of its role in CVS development, maintenance, and disease conditions. PMID:23631900

Allgood, Ottie E; Hamad, Alia; Fox, Joshua; Defrank, Anna; Gilley, Ryan; Dawson, Frederick; Sykes, Benjamin; Underwood, Tarenne J; Naylor, Rachel C; Briggs, Ashley A; Lassiter, Christopher S; Bell, Wade E; Turner, James E

2013-04-28

191

Polymethoxy-1-alkenes from Aphanizomenon ovalisporum Inhibit Vertebrate Development in the Zebrafish (Danio rerio) Embryo Model  

PubMed Central

Cyanobacteria are recognized producers of a wide array of toxic or otherwise bioactive secondary metabolites. The present study utilized the zebrafish (Danio rerio) embryo as an aquatic animal model of vertebrate development to identify, purify and characterize lipophilic inhibitors of development (i.e., developmental toxins) from an isolate of the freshwater cyanobacterial species, Aphanizomenon ovalisporum.Bioassay-guided fractionation led to the purification, and subsequent chemical characterization, of an apparent homologous series of isotactic polymethoxy-1-alkenes (1–6), including three congeners (4–6) previously identified from the strain, and two variants previously identified from other species (2 and 3), as well as one apparently novel member of the series (1). Five of the PMAs in the series (1–5) were purified in sufficient quantity for comparative toxicological characterization, and toxicity in the zebrafish embryo model was found to generally correlate with relative chain length and/or methoxylation. Moreover, exposure of embryos to a combination of variants indicates an apparent synergistic interaction between the congeners. Although PMAs have been identified previously in cyanobacteria, this is the first report of their apparent toxicity. These results, along with the previously reported presence of the PMAs from several cyanobacterial species, suggest a possibly widespread distribution of the PMAs as toxic secondary metabolites and warrants further chemical and toxicological investigation.

Jaja-Chimedza, Asha; Gantar, Miroslav; Gibbs, Patrick D. L.; Schmale, Michael C.; Berry, John P.

2012-01-01

192

A model of glucose-6-phosphate dehydrogenase deficiency in the zebrafish.  

PubMed

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common genetic defect and enzymopathy worldwide, affecting approximately 400 million people and causing acute hemolysis in persons exposed to prooxidant compounds such as menthol, naphthalene, antimalarial drugs, and fava beans. Mouse models have not been useful because of a lack of significant response to oxidative challenge. We turned to zebrafish (Danio rerio) embryos, which develop ex utero and are transparent, allowing visualization of hemolysis. We designed morpholinos to zebrafish g6pd that were effective in reducing gene expression as shown by Western blot and G6PD enzyme activity, resulting in a brisk hemolysis and pericardial edema secondary to anemia. Titration of the g6pd knockdown allowed us to generate embryos that displayed no overt phenotype until exposed to the prooxidant compounds 1-naphthol, menthol, or primaquine, after which they developed hemolysis and pericardial edema within 48-72 hours. We were also able to show that g6pd morphants displayed significant levels of increased oxidative stress compared with controls. We anticipate that this will be a useful model of G6PD deficiency to study hemolysis as well as oxidative stress that occurs after exposure to prooxidants, similar to what occurs in G6PD-deficient persons. PMID:23603363

Patrinostro, Xiaobai; Carter, Michelle L; Kramer, Ashley C; Lund, Troy C

2013-04-16

193

Human primary ductal carcinoma in situ (DCIS) subtype-specific pathology is preserved in a mouse intraductal (MIND) xenograft model  

PubMed Central

Ductal carcinoma in situ (DCIS) is a non-obligate precursor of invasive breast cancer. The current recognition that DCIS lesions exhibit inter- and intra-lesion diversity suggests that the process of evolution to invasive breast cancer is more complex than previously recognized. Here we demonstrate the reproducible growth of primary DCIS cells derived from patient’s surgical and biopsy samples by the mouse intraductal (MIND) model. MIND involves injection of cells into the NOD-SCID IL2Rgammanull (NSG) mouse mammary ducts. Twelve (8 unique and 4 repeats) DCIS and 2 atypical hyperplasia specimens, heterogeneous with respect to biomarker expression and histology, were injected into 48 mouse mammary glands and analyzed for successful xenotransplantation. Overall, 14/34 and 11/14 of MIND xenotransplanted glands contained human DCIS and atypical hyperplastic cells, respectively, after 8 weeks, which formed single and multi-layered epithelium inside the ducts, and were heterogeneous with respect to expression of human cytokeratins, estrogen receptor ? (ER), and HER2. ER protein expression was recapitulated in MIND xenografts at ratios similar to the corresponding patient biopsies. In both patient biopsies and corresponding MIND xenografts HER2 protein expression and nuclear HER2 gene over-expression was restricted to the DCIS lesions and were not found in the surrounding stroma or normal ducts. The xenografted DCIS lesions recapitulate the pathology and heterogeneity of human disease thus providing a powerful tool for the characterization of the distinct cellular and molecular basis of inter- and intra-tumoral heterogeneity and the processes of DCIS to early invasive breast cancer progression.

Valdez, Kelli Elizabeth; Fang, Fan; Smith, William; Allred, D. Craig; Medina, Daniel; Behbod, Fariba

2012-01-01

194

S-Allylcysteine inhibits tumour progression and the epithelial-mesenchymal transition in a mouse xenograft model of oral cancer.  

PubMed

Oral cancer is prevalent worldwide. Studies have indicated that an increase in the osteopontin (OPN) plasma level is correlated with the progression of oral cancer. Our previous report showed that the aqueous garlic extract S-allylcysteine (SAC) inhibited the epithelial-mesenchymal transition (EMT) of human oral cancer CAL-27 cells in vitro. Therefore, the present study investigated whether SAC consumption would help prevent tumour growth and progression, including the EMT, in a mouse xenograft model of oral cancer. The results demonstrated that SAC dose-dependently inhibited the growth of oral cancer in tumour-bearing mice. The histopathological and immunohistochemical staining results indicated that SAC was able to effectively suppress the tumour growth and progression of oral cancer in vivo. The chemopreventive effect of SAC was associated with the suppression of carcinogenesis factors such as N-methylpurine DNA glycosylase and OPN. SAC significantly suppressed the phosphorylation of Akt, mammalian target of rapamycin, inhibitor of ?B? and extracellular signal-regulated kinase 1/2 in tumour tissues. The results demonstrated that the SAC-mediated suppression of cyclin D1 protein was associated with an augmented expression of the cell-cycle inhibitor p16(Ink4). Furthermore, SAC inhibited the expression of cyclo-oxygenase-2, vimentin and NF-?B p65 (RelA). These results show that SAC has potential as an agent against tumour growth and the progression of oral cancer in a mouse xenograft model. PMID:22011514

Pai, Man-Hui; Kuo, Yueh-Hsiung; Chiang, En-Pei Isabel; Tang, Feng-Yao

2011-10-20

195

Acute stress disrupts performance of zebrafish in the cued and spatial memory tests: the utility of fish models to study stress-memory interplay.  

PubMed

The zebrafish (Danio rerio) has emerged as a promising model organism for affective or cognitive neuroscience research, and may be useful to study the interplay between memory and anxiety-related states. To assess the effects of acute psychological stress on spatial and cued memory, adult zebrafish were trained in an aquatic plus-maze for 14 days using food bait as a reward. Two ecologically relevant stressors (alarm pheromone or Indian leaf fish exposure) were applied to acutely stress zebrafish immediately prior to the final (testing) trial. Overall, acute single inescapable stress markedly impaired spatial and cued memory in zebrafish plus-maze test, reducing the number of correct arm entries and time spent in the target arm. This observation parallels rodent and clinical literature on memory-impairing effects of acute stress, strongly supporting the utility of zebrafish in neurobehavioral research. PMID:21545830

Gaikwad, Siddharth; Stewart, Adam; Hart, Peter; Wong, Keith; Piet, Valerie; Cachat, Jonathan; Kalueff, Allan V

2011-05-03

196

Therapeutic Antibodies Targeting CSF1 Impede Macrophage Recruitment in a Xenograft Model of Tenosynovial Giant Cell Tumor  

PubMed Central

Tenosynovial giant cell tumor is a neoplastic disease of joints that can cause severe morbidity. Recurrences are common following local therapy, and no effective medical therapy currently exists. Recent work has demonstrated that all cases overexpress macrophage colony-stimulating factor (CSF1), usually as a consequence of an activating gene translocation, resulting in an influx of macrophages that form the bulk of the tumor. New anti-CSF1 drugs have been developed; however there are no preclinical models suitable for evaluation of drug benefits in this disease. In this paper, we describe a novel renal subcapsular xenograft model of tenosynovial giant cell tumor. Using this model, we demonstrate that an anti-CSF1 monoclonal antibody significantly inhibits host macrophage infiltration into this tumor. The results from this model support clinical trials of equivalent humanized agents and anti-CSF1R small molecule drugs in cases of tenosynovial giant cell tumor refractory to conventional local therapy.

Cheng, Hongwei; Clarkson, Paul W.; Gao, Dongxia; Pacheco, Marina; Wang, Yuzhuo; Nielsen, Torsten O.

2010-01-01

197

Prey capture in zebrafish larvae serves as a model to study cognitive functions.  

PubMed

Prey capture in zebrafish larvae is an innate behavior which can be observed as early as 4~days postfertilization, the day when they start to swim. This simple behavior apparently involves several neural processes including visual perception, recognition, decision-making, and motor control, and, therefore, serves as a good model system to study cognitive functions underlying natural behaviors in vertebrates. Recent progresses in imaging techniques provided us with a unique opportunity to image neuronal activity in the brain of an intact fish in real-time while the fish perceives a natural prey, paramecium. By expanding this approach, it would be possible to image entire brain areas at a single-cell resolution in real-time during prey capture, and identify neuronal circuits important for cognitive functions. Further, activation or inhibition of those neuronal circuits with recently developed optogenetic tools or neurotoxins should shed light on their roles. Thus, we will be able to explore the prey capture in zebrafish larvae more thoroughly at cellular levels, which should establish a basis of understanding of the cognitive function in vertebrates. PMID:23781176

Muto, Akira; Kawakami, Koichi

2013-06-11

198

Assaying hematopoiesis using zebrafish.  

PubMed

The zebrafish has become a commonly used model for studying hematopoiesis as a result of its unique attributes. Zebrafish are highly suitable for large-scale genetic and chemical screens compared to other vertebrate systems. It is now possible to analyze hematopoietic lineages in zebrafish and validate cell function via transplantation assays. Here, we review advancements over the past decade in forward genetic screens, chemical screens, fluorescence-activated cell sorting analysis, and transplantation assays. Integrating these approaches enables new chemical and genetic screens that assay cell function within the hematopoietic system. Studies in zebrafish will continue to contribute and expand our knowledge about hematopoiesis, and develop novel treatments for clinical applications. PMID:23916372

Boatman, Sonja; Barrett, Francesca; Satishchandran, Sruthi; Jing, Lili; Shestopalov, Ilya; Zon, Leonard I

2013-08-02

199

Validation of visualized transgenic zebrafish as a high throughput model to assay bradycardia related cardio toxicity risk candidates.  

PubMed

Drug-induced QT prolongation usually leads to torsade de pointes (TdP), thus for drugs in the early phase of development this risk should be evaluated. In the present study, we demonstrated a visualized transgenic zebrafish as an in vivo high-throughput model to assay the risk of drug-induced QT prolongation. Zebrafish larvae 48 h post-fertilization expressing green fluorescent protein in myocardium were incubated with compounds reported to induce QT prolongation or block the human ether-a-go-go-related gene (hERG) K? current. The compounds sotalol, indapaminde, erythromycin, ofoxacin, levofloxacin, sparfloxacin and roxithromycin were additionally administrated by microinjection into the larvae yolk sac. The ventricle heart rate was recorded using the automatic monitoring system after incubation or microinjection. As a result, 14 out of 16 compounds inducing dog QT prolongation caused bradycardia in zebrafish. A similar result was observed with 21 out of 26 compounds which block hERG current. Among the 30 compounds which induced human QT prolongation, 25 caused bradycardia in this model. Thus, the risk of compounds causing bradycardia in this transgenic zebrafish correlated with that causing QT prolongation and hERG K? current blockage in established models. The tendency that high logP values lead to high risk of QT prolongation in this model was indicated, and non-sensitivity of this model to antibacterial agents was revealed. These data suggest application of this transgenic zebrafish as a high-throughput model to screen QT prolongation-related cardio toxicity of the drug candidates. PMID:22744888

Wen, Dingsheng; Liu, Aiming; Chen, Feng; Yang, Julin; Dai, Renke

2012-06-29

200

The Zebrafish as a New Model for the In Vivo Study of Shigella flexneri Interaction with Phagocytes and Bacterial Autophagy.  

PubMed

Autophagy, an ancient and highly conserved intracellular degradation process, is viewed as a critical component of innate immunity because of its ability to deliver cytosolic bacteria to the lysosome. However, the role of bacterial autophagy in vivo remains poorly understood. The zebrafish (Danio rerio) has emerged as a vertebrate model for the study of infections because it is optically accessible at the larval stages when the innate immune system is already functional. Here, we have characterized the susceptibility of zebrafish larvae to Shigella flexneri, a paradigm for bacterial autophagy, and have used this model to study Shigella-phagocyte interactions in vivo. Depending on the dose, S. flexneri injected in zebrafish larvae were either cleared in a few days or resulted in a progressive and ultimately fatal infection. Using high resolution live imaging, we found that S. flexneri were rapidly engulfed by macrophages and neutrophils; moreover we discovered a scavenger role for neutrophils in eliminating infected dead macrophages and non-immune cell types that failed to control Shigella infection. We observed that intracellular S. flexneri could escape to the cytosol, induce septin caging and be targeted to autophagy in vivo. Depletion of p62 (sequestosome 1 or SQSTM1), an adaptor protein critical for bacterial autophagy in vitro, significantly increased bacterial burden and host susceptibility to infection. These results show the zebrafish larva as a new model for the study of S. flexneri interaction with phagocytes, and the manipulation of autophagy for anti-bacterial therapy in vivo. PMID:24039575

Mostowy, Serge; Boucontet, Laurent; Mazon Moya, Maria J; Sirianni, Andrea; Boudinot, Pierre; Hollinshead, Michael; Cossart, Pascale; Herbomel, Philippe; Levraud, Jean-Pierre; Colucci-Guyon, Emma

2013-09-05

201

The Zebrafish as a New Model for the In Vivo Study of Shigella flexneri Interaction with Phagocytes and Bacterial Autophagy  

PubMed Central

Autophagy, an ancient and highly conserved intracellular degradation process, is viewed as a critical component of innate immunity because of its ability to deliver cytosolic bacteria to the lysosome. However, the role of bacterial autophagy in vivo remains poorly understood. The zebrafish (Danio rerio) has emerged as a vertebrate model for the study of infections because it is optically accessible at the larval stages when the innate immune system is already functional. Here, we have characterized the susceptibility of zebrafish larvae to Shigella flexneri, a paradigm for bacterial autophagy, and have used this model to study Shigella-phagocyte interactions in vivo. Depending on the dose, S. flexneri injected in zebrafish larvae were either cleared in a few days or resulted in a progressive and ultimately fatal infection. Using high resolution live imaging, we found that S. flexneri were rapidly engulfed by macrophages and neutrophils; moreover we discovered a scavenger role for neutrophils in eliminating infected dead macrophages and non-immune cell types that failed to control Shigella infection. We observed that intracellular S. flexneri could escape to the cytosol, induce septin caging and be targeted to autophagy in vivo. Depletion of p62 (sequestosome 1 or SQSTM1), an adaptor protein critical for bacterial autophagy in vitro, significantly increased bacterial burden and host susceptibility to infection. These results show the zebrafish larva as a new model for the study of S. flexneri interaction with phagocytes, and the manipulation of autophagy for anti-bacterial therapy in vivo.

Mostowy, Serge; Boucontet, Laurent; Mazon Moya, Maria J.; Sirianni, Andrea; Boudinot, Pierre; Hollinshead, Michael; Cossart, Pascale; Herbomel, Philippe; Levraud, Jean-Pierre; Colucci-Guyon, Emma

2013-01-01

202

Muscle diseases in the zebrafish.  

PubMed

Animal models in biomedical research are important for understanding the pathological mechanisms of human diseases at a molecular and cellular level. Several aspects of mammalian animals, however, may limit their use in modelling neuromuscular disorders. Many attributes of zebrafish (Danio rerio) are complementary to mammalian experimental systems, establishing the zebrafish as a powerful model organism in disease biology. This review focuses on a number of key studies using the zebrafish to model hereditary muscle diseases with additional emphasis on recent advances in zebrafish functional genomics and drug discovery. Increasing research in zebrafish disease models, combined with knowledge from mammalian models, will bring novel insights into the disease pathogenesis of neuromuscular disorders, as well as facilitate the development of effective therapeutic strategies. PMID:22647769

Lin, Yung-Yao

2012-05-28

203

From Omics to Drug Metabolism and High Content Screen of Natural Product in Zebrafish: A New Model for Discovery of Neuroactive Compound  

PubMed Central

The zebrafish (Danio rerio) has recently become a common model in the fields of genetics, environmental science, toxicology, and especially drug screening. Zebrafish has emerged as a biomedically relevant model for in vivo high content drug screening and the simultaneous determination of multiple efficacy parameters, including behaviour, selectivity, and toxicity in the content of the whole organism. A zebrafish behavioural assay has been demonstrated as a novel, rapid, and high-throughput approach to the discovery of neuroactive, psychoactive, and memory-modulating compounds. Recent studies found a functional similarity of drug metabolism systems in zebrafish and mammals, providing a clue with why some compounds are active in zebrafish in vivo but not in vitro, as well as providing grounds for the rationales supporting the use of a zebrafish screen to identify prodrugs. Here, we discuss the advantages of the zebrafish model for evaluating drug metabolism and the mode of pharmacological action with the emerging omics approaches. Why this model is suitable for identifying lead compounds from natural products for therapy of disorders with multifactorial etiopathogenesis and imbalance of angiogenesis, such as Parkinson's disease, epilepsy, cardiotoxicity, cerebral hemorrhage, dyslipidemia, and hyperlipidemia, is addressed.

Hung, Ming Wai; Zhang, Zai Jun; Li, Shang; Lei, Benson; Yuan, Shuai; Cui, Guo Zhen; Man Hoi, Pui; Chan, Kelvin; Lee, Simon Ming Yuen

2012-01-01

204

Stereotactic intracranial implantation and in vivo bioluminescent imaging of tumor xenografts in a mouse model system of glioblastoma multiforme.  

PubMed

Glioblastoma multiforme (GBM) is a high-grade primary brain cancer with a median survival of only 14.6 months in humans despite standard tri-modality treatment consisting of surgical resection, post-operative radiation therapy and temozolomide chemotherapy. New therapeutic approaches are clearly needed to improve patient survival and quality of life. The development of more effective treatment strategies would be aided by animal models of GBM that recapitulate human disease yet allow serial imaging to monitor tumor growth and treatment response. In this paper, we describe our technique for the precise stereotactic implantation of bio-imageable GBM cancer cells into the brains of nude mice resulting in tumor xenografts that recapitulate key clinical features of GBM. This method yields tumors that are reproducible and are located in precise anatomic locations while allowing in vivo bioluminescent imaging to serially monitor intracranial xenograft growth and response to treatments. This method is also well-tolerated by the animals with low perioperative morbidity and mortality. PMID:23051742

Baumann, Brian C; Dorsey, Jay F; Benci, Joseph L; Joh, Daniel Y; Kao, Gary D

2012-09-25

205

Vascular Development in the Zebrafish  

PubMed Central

The zebrafish has emerged as an excellent vertebrate model system for studying blood and lymphatic vascular development. The small size, external and rapid development, and optical transparency of zebrafish embryos are some of the advantages the zebrafish model system offers. Multiple well-established techniques have been developed for imaging and functionally manipulating vascular tissues in zebrafish embryos, expanding on and amplifying these basic advantages and accelerating use of this model system for studying vascular development. In the past decade, studies performed using zebrafish as a model system have provided many novel insights into vascular development. In this article we discuss the amenability of this model system for studying blood vessel development and review contributions made by this system to our understanding of vascular development.

Gore, Aniket V.; Monzo, Kathryn; Cha, Young R.; Pan, Weijun; Weinstein, Brant M.

2012-01-01

206

Gavaging adult zebrafish.  

PubMed

The zebrafish has become an important in vivo model in biomedical research. Effective methods must be developed and utilized to deliver compounds or agents in solutions for scientific research. Current methods for administering compounds orally to adult zebrafish are inaccurate due to variability in voluntary consumption by the fish. A gavage procedure was developed to deliver precise quantities of infectious agents to zebrafish for study in biomedical research. Adult zebrafish over 6 months of age were anesthetized with 150 mg/L of buffered MS-222 and gavaged with 5 ?l of solution using flexible catheter implantation tubing attached to a cut 22-G needle tip. The flexible tubing was lowered into the oral cavity of the zebrafish until the tip of the tubing extended past the gills (approximately 1 cm). The solution was then injected slowly into the intestinal tract. This method was effective 88% of the time, with fish recovering uneventfully. This procedure is also efficient as one person can gavage 20-30 fish in one hour. This method can be used to precisely administer agents for infectious diseases studies, or studies of other compounds in adult zebrafish. PMID:23962977

Collymore, Chereen; Rasmussen, Skye; Tolwani, Ravi J

2013-08-11

207

Natural killer cell lines preferentially kill clonogenic multiple myeloma cells and decrease myeloma engraftment in a bioluminescent xenograft mouse model  

PubMed Central

Background Novel therapies capable of targeting drug resistant clonogenic MM cells are required for more effective treatment of multiple myeloma. This study investigates the cytotoxicity of natural killer cell lines against bulk and clonogenic multiple myeloma and evaluates the tumor burden after NK cell therapy in a bioluminescent xenograft mouse model. Design and Methods The cytotoxicity of natural killer cell lines was evaluated against bulk multiple myeloma cell lines using chromium release and flow cytometry cytotoxicity assays. Selected activating receptors on natural killer cells were blocked to determine their role in multiple myeloma recognition. Growth inhibition of clonogenic multiple myeloma cells was assessed in a methylcellulose clonogenic assay in combination with secondary replating to evaluate the self-renewal of residual progenitors after natural killer cell treatment. A bioluminescent mouse model was developed using the human U266 cell line transduced to express green fluorescent protein and luciferase (U266eGFPluc) to monitor disease progression in vivo and assess bone marrow engraftment after intravenous NK-92 cell therapy. Results Three multiple myeloma cell lines were sensitive to NK-92 and KHYG-1 cytotoxicity mediated by NKp30, NKp46, NKG2D and DNAM-1 activating receptors. NK-92 and KHYG-1 demonstrated 2- to 3-fold greater inhibition of clonogenic multiple myeloma growth, compared with killing of the bulk tumor population. In addition, the residual colonies after treatment formed significantly fewer colonies compared to the control in a secondary replating for a cumulative clonogenic inhibition of 89–99% at the 20:1 effector to target ratio. Multiple myeloma tumor burden was reduced by NK-92 in a xenograft mouse model as measured by bioluminescence imaging and reduction in bone marrow engraftment of U266eGFPluc cells by flow cytometry. Conclusions This study demonstrates that NK-92 and KHYG-1 are capable of killing clonogenic and bulk multiple myeloma cells. In addition, multiple myeloma tumor burden in a xenograft mouse model was reduced by intravenous NK-92 cell therapy. Since multiple myeloma colony frequency correlates with survival, our observations have important clinical implications and suggest that clinical studies of NK cell lines to treat MM are warranted.

Swift, Brenna E.; Williams, Brent A.; Kosaka, Yoko; Wang, Xing-Hua; Medin, Jeffrey A.; Viswanathan, Sowmya; Martinez-Lopez, Joaquin; Keating, Armand

2012-01-01

208

Antitumor activity of motesanib alone and in combination with cisplatin or docetaxel in multiple human non-small-cell lung cancer xenograft models  

PubMed Central

Background Non–small-cell lung cancer (NSCLC) is categorized into various histologic subtypes that play an important role in prognosis and treatment outcome. We investigated the antitumor activity of motesanib, a selective antagonist of vascular endothelial growth factor receptors (VEGFR) 1, 2, and 3, platelet-derived growth factor receptor, and Kit, alone and combined with chemotherapy in five human NSCLC xenograft models (A549, Calu-6, NCI-H358, NCI-H1299, and NCI-H1650) containing diverse genetic mutations. Results Motesanib as a single agent dose-dependently inhibited tumor xenograft growth compared with vehicle in all five of the models (P?xenografts compared with either single agent alone (P?xenografts compared with either single agent alone (P?xenografts, motesanib with and without cisplatin significantly decreased tumor blood vessel area (P?xenograft models containing diverse genetic mutations, and that it had enhanced activity when combined with cisplatin or docetaxel. These effects appeared to be mediated primarily by antiangiogenic mechanisms.

2012-01-01

209

Emerging applications of zebrafish as a model organism to study oxidative mechanisms and their role in inflammation and vascular accumulation of oxidized lipids  

PubMed Central

With the advent of genetic engineering, zebrafish (Danio rerio) were recognized as an attractive model organism to study many biological processes. Remarkably, the small size and optical transparency of zebrafish larvae enable high-resolution imaging of live animals. Zebrafish respond to various environmental and pathological factors with robust oxidative stress. In this article, we provide an overview of molecular mechanisms involved in oxidative stress and antioxidant response in zebrafish. Existing applications of generically-encoded fluorescent sensors allow imaging, in real time, production of H2O2 and studying its involvement in inflammatory responses, as well as activation of oxidation-sensitive transcription factors HIF and NRF2. Oxidative stress, combined with hypelipidemia, leads to oxidation of lipoproteins, the process that contributes significantly to development of human atherosclerosis. Recent work found that feeding zebrafish a high-cholesterol diet results in hypercholesterolemia, vascular lipid accumulation and extreme lipoprotein oxidation. Generation of a transgenic zebrafish expressing a GFP-tagged human antibody to malondialdehyde (MDA)-modified LDL makes possible in vivo visualization of MDA epitopes in the vascular wall and testing the efficacy of antioxidants and dietary interventions. Thus, using zebrafish as a model organism provides important advantages in studying the role of ROS and lipid oxidation in basic biologic and pathologic processes.

Fang, Longhou; Miller, Yury I.

2012-01-01

210

Pdgfra protects against ethanol-induced craniofacial defects in a zebrafish model of FASD.  

PubMed

Human birth defects are highly variable and this phenotypic variability can be influenced by both the environment and genetics. However, the synergistic interactions between these two variables are not well understood. Fetal alcohol spectrum disorders (FASD) is the umbrella term used to describe the wide range of deleterious outcomes following prenatal alcohol exposure. Although FASD are caused by prenatal ethanol exposure, FASD are thought to be genetically modulated, although the genes regulating sensitivity to ethanol teratogenesis are largely unknown. To identify potential ethanol-sensitive genes, we tested five known craniofacial mutants for ethanol sensitivity: cyp26b1, gata3, pdgfra, smad5 and smoothened. We found that only platelet-derived growth factor receptor alpha (pdgfra) interacted with ethanol during zebrafish craniofacial development. Analysis of the PDGF family in a human FASD genome-wide dataset links PDGFRA to craniofacial phenotypes in FASD, prompting a mechanistic understanding of this interaction. In zebrafish, untreated pdgfra mutants have cleft palate due to defective neural crest cell migration, whereas pdgfra heterozygotes develop normally. Ethanol-exposed pdgfra mutants have profound craniofacial defects that include the loss of the palatal skeleton and hypoplasia of the pharyngeal skeleton. Furthermore, ethanol treatment revealed latent haploinsufficiency, causing palatal defects in ?62% of pdgfra heterozygotes. Neural crest apoptosis partially underlies these ethanol-induced defects in pdgfra mutants, demonstrating a protective role for Pdgfra. This protective role is mediated by the PI3K/mTOR pathway. Collectively, our results suggest a model where combined genetic and environmental inhibition of PI3K/mTOR signaling leads to variability within FASD. PMID:23861062

McCarthy, Neil; Wetherill, Leah; Lovely, C Ben; Swartz, Mary E; Foroud, Tatiana M; Eberhart, Johann K

2013-08-01

211

The Zebrafish- Danio rerio - Is a Useful Model for Measuring the Effects of Small-molecule Mitigators of Late Effects of Ionizing Irradiation  

PubMed Central

Background/Aim Use of zebrafish models may decrease the cost of screening new irradiation protectors and mitigators. Materials and Methods Zebrafish (Danio rerio) models were tested for screening water-soluble radiation protectors and mitigators. Irradiation of embryos and monitoring survival, and measuring fibrosis of the caudal musculature of adults allowed for testing of acute and late effects, respectively. Results Incubation of zebrafish embryos either before or after irradiation in ethyl pyruvate (1 mM) increased survival. Irradiation of adults to 15 to 75 Gy, delivered in single-fraction at 13 Gy/min, showed dose-dependent fibrosis at 30 days, quantitated as physiological decrease in swimming tail movement, and histopathological detection of collagen deposition in the dorsal musculature. Continuous administration of small-molecule radioprotector drugs in the water after irradiation reduced both acute and chronic injuries. Conclusion The zebrafish is cost-effective for screening new radiation countermeasures.

EPPERLY, MICHAEL W.; BAHARY, NATHAN; QUADER, MUBINA; DEWALD, VALERIE; GREENBERGER, JOEL S.

2013-01-01

212

A Novel Synthetic Smoothened Antagonist Transiently Inhibits Pancreatic Adenocarcinoma Xenografts in a Mouse Model  

PubMed Central

Background Hedgehog (Hh) signaling is over-activated in several solid tumors where it plays a central role in cell growth, stroma recruitment and tumor progression. In the Hh signaling pathway, the Smoothened (SMO) receptor comprises a primary drug target with experimental small molecule SMO antagonists currently being evaluated in clinical trials. Principal Findings Using Shh-Light II (Shh-L2) and alkaline phosphatase (AP) based screening formats on a “focused diversity” library we identified a novel small molecule inhibitor of the Hh pathway, MS-0022 (2-bromo-N-(4-(8-methylimidazo[1,2-a]pyridin-2-yl)phenyl)benzamide). MS-0022 showed effective Hh signaling pathway inhibition at the level of SMO in the low nM range, and Hh pathway inhibition downstream of Suppressor of fused (SUFU) in the low µM range. MS-0022 reduced growth in the tumor cell lines PANC-1, SUIT-2, PC-3 and FEMX in vitro. MS-0022 treatment led to a transient delay of tumor growth that correlated with a reduction of stromal Gli1 levels in SUIT-2 xenografts in vivo. Significance We document the in vitro and in vivo efficacy and bioavailability of a novel small molecule SMO antagonist, MS-0022. Although MS-0022 primarily interferes with Hh signaling at the level of SMO, it also has a downstream inhibitory effect and leads to a stronger reduction of growth in several tumor cell lines when compared to related SMO antagonists.

Strand, Martin F.; Wilson, Steven R.; Dembinski, Jennifer L.; Holsworth, Daniel D.; Khvat, Alexander; Okun, Ilya; Petersen, Dirk; Krauss, Stefan

2011-01-01

213

Deferoxamine Iron Chelation Increases ?-aminolevulinic Acid Induced Protoporphyrin IX in Xenograft Glioma Model  

PubMed Central

Exogenous administration of ?-aminolevulinic acid (?-ALA) leads to selective accumulation of protoporphyrin IX (PpIX) in brain tumors, and has shown promising results in increasing extent of resection in fluorescence-guided resection (FGR) of brain tumors. However, this approach still suffers from heterogeneous staining and so some tumor margins may go undetected because of this variation in PpIX production. The aim of this study was to test the hypothesis that iron chelation therapy could increase the level of fluorescence in malignant glioma tumors. Mice implanted with xenograft U251-GFP glioma tumor cells were given a 200-mg/kg dose of deferoxamine (DFO), once a day for three days prior to ?-ALA administration. The PpIX fluorescence observed in the tumor regions was 1.9 times the background in animal group without DFO, and 2.9 times the background on average, in the DFO pre-treated group. A 50% increase in PpIX fluorescence contrast in the DFO group was observed relative to the control group (t-test p-value = 0.0020). These results indicate that iron chelation therapy could significantly increase ?-ALA induced PpIX fluorescence in malignant gliomas, pointing to a potential role of iron chelation therapy for more effective FGR of brain tumors.

Valdes, Pablo A.; Samkoe, Kimberley; O'Hara, Julia A.; Roberts, David W.; Paulsen, Keith D.; Pogue, Brian W.

2009-01-01

214

Recombinant Human Endostatin Normalizes Tumor Vasculature and Enhances Radiation Response in Xenografted Human Nasopharyngeal Carcinoma Models  

PubMed Central

Background Hypoxic tumor cells can reduce the efficacy of radiation. Antiangiogenic therapy may transiently “normalize” the tumor vasculature to make it more efficient for oxygen delivery. The aim of this study is to investigate whether the recombinant human endostatin (endostar) can create a “vascular normalization window” to alleviate hypoxia and enhance the inhibitory effects of radiation therapy in human nasopharyngeal carcinoma (NPC) in mice. Methodology/Principal Findings Transient changes in morphology of tumor vasculature and hypoxic tumor cell fraction in response to endostar were detected in mice bearing CNE-2 and 5–8F human NPC xenografts. Various treatment schedules were tested to assess the influence of endostar on the effect of radiation therapy. Several important factors relevant to the angiogenesis were identified through immunohistochemical staining. During endostar treatment, tumor vascularity decreased, while the basement membrane and pericyte coverage associated with endothelial cells increased, which supported the idea of vessel normalization. Hypoxic tumor cell fraction also decreased after the treatment. The transient modulation of tumor physiology caused by endostar improved the effect of radiation treatment compared with other treatment schedules. The expressions of vascular endothelial growth factor (VEGF), matrix metalloproteinase-2 (MMP-2), MMP-9, and MMP-14 decreased, while the level of pigment epithelium-derived factor (PEDF) increased. Conclusions Endostar normalized tumor vasculature, which alleviated hypoxia and significantly sensitized the function of radiation in anti-tumor in human NPC. The results provide an important experimental basis for combining endostar with radiation therapy in human NPC.

Chen, Yuanyuan; Li, Qiang; Zuo, Yufang; Chen, Jing; Hu, Xiao; Zhou, Qichao; Wang, Yan; Ma, Honglian; Bao, Yong; Chen, Ming

2012-01-01

215

Adenovirus-mediated expression of mutated forkhead human transcription like-1 suppresses tumor growth in a mouse melanoma xenograft model.  

PubMed

Melanoma is generally resistant to chemotherapy, which may be related to defects in death receptor signaling and to defects in induction of apoptosis. Forkhead family transcription factors induce the expression of death receptor ligands such as Fas ligand (Fas-L) resulting in apoptosis. We therefore investigated whether a triple mutant form of forkhead transcription factor FKHRL1 (FKHRL1/TM) can enhance Fas-L mediated-apoptosis in melanoma cells. Two melanoma cells A2058 or DM6 were tested for their sensitivity to agonistic anti-Fas antibody (CH-11); adenovirus expressing FKHRL1/TM (Ad-FKHRL1/TM) was assessed for its capability to induce activation of the caspase pathway; the role of Fas-L in the Ad-FKHRL1/TM mediated-cell death was also assessed in vitro. Ad-FKHRL1/TM antitumor activity in vivo was also evaluated in a mouse melanoma xenograft model. We found that DM6 melanoma cells were more resistant to Fas/Fas-L-mediated apoptosis induced by agonistic anti-Fas antibody than A2058 melanoma cells. Ectopic expression of FKHRL1/TM in melanoma cells upregulated Fas-L expression, decreased procaspase-8 levels, and significantly increased Fas/FasL-mediated cell death in both cells lines; this induced cell death was partially blocked by a Fas/Fas-L antagonist. Importantly, Ad-FKHRL1/TM treatment of subcutaneous melanoma xenografts in mice resulted in approximately 70% decrease in tumor size compared with controls. These data indicate that overexpression of FKHRL1/TM can induce the Fas-L pathway in melanoma cells. Ad-FKHRL1/TM therefore might represent a promising vector for melanoma treatment. PMID:22892845

Gomez-Gutierrez, Jorge G; Egger, Michael E; Hao, Hongying; Zhou, Heshan Sam; McMasters, Kelly M

2012-08-15

216

Targeting Tumor Vasculature Endothelial Cells and Tumor Cells for Immunotherapy of Human Melanoma in a Mouse Xenograft Model  

NASA Astrophysics Data System (ADS)

An immunotherapy treatment for cancer that targets both the tumor vasculature and tumor cells has shown promising results in a severe combined immunodeficient mouse xenograft model of human melanoma. The treatment involves systemic delivery of an immunoconjugate molecule composed of a tumor-targeting domain conjugated to the Fc effector domain of human IgG1. The effector domain induces a cytolytic immune response against the targeted cells by natural killer cells and complement. Two types of targeting domains were used. One targeting domain is a human single-chain Fv molecule that binds to a chondroitin sulfate proteoglycan expressed on the surface of most human melanoma cells. Another targeting domain is factor VII (fVII), a zymogen that binds with high specificity and affinity to the transmembrane receptor tissue factor (TF) to initiate the blood coagulation cascade. TF is expressed by endothelial cells lining the tumor vasculature but not the normal vasculature, and also by many types of tumor cells including melanoma. Because the binding of a fVII immunoconjugate to TF might cause disseminated intravascular coagulation, the active site of fVII was mutated to inhibit coagulation without affecting the affinity for TF. The immunoconjugates were encoded as secreted molecules in a replication-defective adenovirus vector, which was injected into the tail vein of severe combined immunodeficient mice. The results demonstrate that a mutated fVII immunoconjugate, administered separately or together with a single-chain Fv immunoconjugate that binds to the tumor cells, can inhibit the growth or cause regression of an established human tumor xenograft. This procedure could be effective in treating a broad spectrum of human solid tumors that express TF on vascular endothelial cells and tumor cells.

Hu, Zhiwei; Sun, Ying; Garen, Alan

1999-07-01

217

Humanised xenograft models of bone metastasis revisited: novel insights into species-specific mechanisms of cancer cell osteotropism.  

PubMed

The determinants and key mechanisms of cancer cell osteotropism have not been identified, mainly due to the lack of reproducible animal models representing the biological, genetic and clinical features seen in humans. An ideal model should be capable of recapitulating as many steps of the metastatic cascade as possible, thus facilitating the development of prognostic markers and novel therapeutic strategies. Most animal models of bone metastasis still have to be derived experimentally as most syngeneic and transgeneic approaches do not provide a robust skeletal phenotype and do not recapitulate the biological processes seen in humans. The xenotransplantation of human cancer cells or tumour tissue into immunocompromised murine hosts provides the possibility to simulate early and late stages of the human disease. Human bone or tissue-engineered human bone constructs can be implanted into the animal to recapitulate more subtle, species-specific aspects of the mutual interaction between human cancer cells and the human bone microenvironment. Moreover, the replication of the entire "organ" bone makes it possible to analyse the interaction between cancer cells and the haematopoietic niche and to confer at least a partial human immunity to the murine host. This process of humanisation is facilitated by novel immunocompromised mouse strains that allow a high engraftment rate of human cells or tissue. These humanised xenograft models provide an important research tool to study human biological processes of bone metastasis. PMID:23657538

Holzapfel, Boris Michael; Thibaudeau, Laure; Hesami, Parisa; Taubenberger, Anna; Holzapfel, Nina Pauline; Mayer-Wagner, Susanne; Power, Carl; Clements, Judith; Russell, Pamela; Hutmacher, Dietmar Werner

2013-06-01

218

Zebrafish models for ectopic mineralization disorders: practical issues from morpholino design to post-injection observations.  

PubMed

Zebrafish (ZF, Danio rerio) has emerged as an important and popular model species to study different human diseases. Key regulators of skeletal development and calcium metabolism are highly conserved between mammals and ZF. The corresponding orthologs share significant sequence similarities and an overlap in expression patterns when compared to mammals, making ZF a potential model for the study of mineralization-related disorders and soft tissue mineralization. To characterize the function of early mineralization-related genes in ZF, these genes can be knocked down by injecting morpholinos into early stage embryos. Validation of the morpholino needs to be performed and the concern of aspecific effects can be addressed by applying one or more independent techniques to knock down the gene of interest. Post-injection assessment of early mineralization defects can be done using general light microscopy, calcein staining, Alizarin red staining, Alizarin red-Alcian blue double staining, and by the use of transgenic lines. Examination of general molecular defects can be done by performing protein and gene expression analysis, and more specific processes can be explored by investigating ectopic mineralization-related mechanisms such as apoptosis and mitochondrial dysfunction. In this paper, we will discuss all details about the aforementioned techniques; shared knowledge will be very useful for the future investigation of ZF models for ectopic mineralization disorders and to understand the underlying pathways involved in soft tissue calcification. PMID:23760765

Hosen, Mohammad Jakir; Vanakker, Olivier M; Willaert, Andy; Huysseune, Ann; Coucke, Paul; De Paepe, Anne

2013-05-08

219

Oculomotor instabilities in zebrafish mutant belladonna: a behavioral model for congenital nystagmus caused by axonal misrouting.  

PubMed

A large fraction of homozygous zebrafish mutant belladonna (bel) larvae display a reversed optokinetic response (OKR) that correlates with failure of the retinal ganglion cells to cross the midline and form the optic chiasm. Some of these achiasmatic mutants display strong spontaneous eye oscillations (SOs) in the absence of motion in the surround. The presentation of a stationary grating was necessary and sufficient to evoke SO. Both OKR reversal and SO depend on vision and are contrast sensitive. We built a quantitative model derived from bel fwd (forward) eye behaviors. To mimic the achiasmatic condition, we reversed the sign of the retinal slip velocity in the model, thereby successfully reproducing both reversed OKR and SO. On the basis of the OKR data, and with the support of the quantitative model, we hypothesize that the reversed OKR and the SO can be completely attributed to RGC misrouting. The strong resemblance between the SO and congenital nystagmus (CN) seen in humans with defective retinotectal projections implies that CN, of so far unknown etiology, may be directly caused by a projection defect. PMID:17005851

Huang, Ying-Yu; Rinner, Oliver; Hedinger, Patrik; Liu, Shih-Chii; Neuhauss, Stephan C F

2006-09-27

220

The Fimbriae of Enteroaggregative Escherichia coli Induce Epithelial Inflammation In Vitro and in a Human Intestinal Xenograft Model  

PubMed Central

Background.Enteroaggregative Escherichia coli (EAEC) are increasingly recognized as an important agent of inflammatory and often persistent diarrhea. Although previous studies report on the inflammatory aspects of EAEC pathogenesis, the mechanisms by which EAEC trigger these events are not well understood. Methods.EAEC strains harboring mutations in known EAEC virulence determinants were tested in an in vitro model of transepithelial migration of polymorphonuclear neutrophils (PMNs) and in human intestinal xenografts in severe-combined immunodeficient (SCID-HU-INT) mice, a novel model for studying EAEC disease in vivo. Results.Expression of aggregative adherence fimbriae (AAFs), the principal adhesins of EAEC, was required for EAEC-induced PMN transepithelial migration in vitro. Moreover, constructed plasmids encoding AAF gene clusters demonstrated that the AAF adhesins are sufficient for triggering this event in a nonpathogenic E. coli background. Furthermore, with use of the SCID-HU-INT mouse model, severe tissue damage and infiltration of inflammatory cells was observed in the human tissue after EAEC infection. These pathological marks were strongly related to AAF expression, thus clearly confirming our in vitro findings. Conclusions.The present work establishes EAEC as an important inflammatory pathogen and the AAF adhesins as inducers of potentially detrimental immune responses.

Boll, Erik J.; Struve, Carsten; Sander, Anja; Demma, Zachary; Nataro, James P.; McCormick, Beth A.; Krogfelt, Karen A.

2012-01-01

221

Distinct neuroblastoma-associated alterations of PHOX2B impair sympathetic neuronal differentiation in zebrafish models.  

PubMed

Heterozygous germline mutations and deletions in PHOX2B, a key regulator of autonomic neuron development, predispose to neuroblastoma, a tumor of the peripheral sympathetic nervous system. To gain insight into the oncogenic mechanisms engaged by these changes, we used zebrafish models to study the functional consequences of aberrant PHOX2B expression in the cells of the developing sympathetic nervous system. Allelic deficiency, modeled by phox2b morpholino knockdown, led to a decrease in the terminal differentiation markers th and dbh in sympathetic ganglion cells. The same effect was seen on overexpression of two distinct neuroblastoma-associated frameshift mutations, 676delG and K155X - but not the R100L missense mutation - in the presence of endogenous Phox2b, pointing to their dominant-negative effects. We demonstrate that Phox2b is capable of regulating itself as well as ascl1, and that phox2b deficiency uncouples this autoregulatory mechanism, leading to inhibition of sympathetic neuron differentiation. This effect on terminal differentiation is associated with an increased number of phox2b(+), ascl1(+), elavl3(-) cells that respond poorly to retinoic acid. These findings suggest that a reduced dosage of PHOX2B during development, through either a heterozygous deletion or dominant-negative mutation, imposes a block in the differentiation of sympathetic neuronal precursors, resulting in a cell population that is likely to be susceptible to secondary transforming events. PMID:23754957

Pei, Desheng; Luther, William; Wang, Wenchao; Paw, Barry H; Stewart, Rodney A; George, Rani E

2013-06-06

222

Metallofullerene-based Nanoplatform for Brain Tumor Brachytherapy and Longitudinal Imaging in a Murine Orthotopic Xenograft Model  

PubMed Central

Purpose: To demonstrate in an orthotopic xenograft brain tumor model that a functionalized metallofullerene (f-Gd3N@C80) can enable longitudinal tumor imaging and, when radiolabeled with lutetium 177 (177Lu) and tetraazacyclododecane tetraacetic acid (DOTA) (177Lu-DOTA-f-Gd3N@C80), provide an anchor to deliver effective brachytherapy. Materials and Methods: All experiments involving the use of mice were carried out in accordance with protocols approved by the institutional animal care and use committee. Human glioblastoma U87MG cells were implanted by using stereotactic procedures into the brains of 37 female athymic nude-Foxn1nu mice and allowed to develop into a tumor for 8 days. T1- and T2-weighted magnetic resonance (MR) imaging was performed in five mice. Biodistribution studies were performed in 12 mice at four time points over 7 days to evaluate gadolinium content. Survival studies involved 20 mice that received infusion of a nanoplatform by means of convection-enhanced delivery (CED) 8 days after tumor implantation. Mice in survival studies were divided into two groups: one comprised untreated mice that received f-Gd3N@C80 alone and the other comprised mice treated with brachytherapy that received 1.11 MBq of 177Lu-DOTA-f-Gd3N@C80. Survival data were evaluated by using Kaplan-Meier statistical methods. Results: MR imaging showed extended tumor retention (25.6% ± 1.2 of the infused dose at 52 days, confirmed with biodistribution studies) of the f-Gd3N@C80 nanoplatform, which enabled longitudinal imaging. Successful coupling of 177Lu to the f-Gd3N@C80 surface was achieved by using a bifunctional macrocyclic chelator. The extended tumor retention allowed for effective brachytherapy, as indicated by extended survival time (>2.5 times that of the untreated group) and histologic signs of radiation-induced tumor damage. Conclusion: The authors have developed a multimodal nanoplatform and have demonstrated longitudinal tumor imaging, prolonged intratumoral probe retention, biodistribution, and extended survival in an orthotopic xenograft brain tumor model. © RSNA, 2011 Supplemental material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11102569/-/DC1

Shultz, Michael D.; Wilson, John D.; Fuller, Christine E.; Zhang, Jianyuan; Dorn, Harry C.

2011-01-01

223

Enhanced anti-tumor and anti-angiogenic effects of metronomic cyclophosphamide combined with Endostar in a xenograft model of human lung cancer  

PubMed Central

Standard chemotherapy for advanced NSCLC has reached a therapeutic plateau. More effective strategies must be explored. The purpose of this study was to evaluate the role of metronomic chemotherapy combined with an angiogenesis inhibitor in non-small cell lung cancer (NSCLC). A total of 114 BALB/c nude mice were inoculated subcutaneously with human NSCLC cells (A549), and when xenograft tumors were palpable, mice were randomly injected with saline as controls (Ctrl), or treated with metronomic cyclophosphamide (MET CPA), recombinant human endostatin, Endostar (Endo), MET CPA combined with Endostar (MET CPA + Endo) or maximum tolerance dose of CPA (MTD CPA), respectively. The growth of xenograft tumors and mouse survival were monitored. The frequency of peripheral blood circulating endothelial cells (CECs), microvessel density (MVD) and pericyte coverage was determined using flow cytometry and immunofluorescence staining. In comparison with the controls, treatment with either drug significantly inhibited the growth of xenograft tumors in mice. Treatment with MET CPA or Endostar, but not with MTD CPA, significantly reduced the frequency of peripheral blood total and viable CECs and the value of MVD. Endostar also considerably reduced pericyte coverage in xenograft tumors. Moreover, MET CPA combined with Endostar further reduced the frequency of peripheral blood CECs, the value of MVD, and pericyte coverage, with concomitant delay in tumor growth and extension of mouse survival. Our results indicate that MET CPA combined with Endostar results in enhanced anti-tumor and anti-angiogenic effects in a xenograft model of human lung cancer. Combined therapy with metronomic chemotherapy and an angiogenesis inhibitor may serve as a promising treatment strategy for patients with advanced NSCLC.

WANG, RUI; QIN, SHUKUI; CHEN, YUQING; LI, YUMEI; CHEN, CHANGJIE; WANG, ZISHU; ZHENG, RONGSHENG; WU, QIONG

2012-01-01

224

Investigating the role of CD38 and functionally related molecular risk factors in the CLL NOD/SCID xenograft model.  

PubMed

We explored the role of CD38 and functionally associated molecular risk factors in a recently described chronic lymphocytic leukemia (CLL) nonobese diabetic/ severe combined immunodeficient xenograft model. Intravenous injection of peripheral blood mononuclear cells from 73 patients with CLL into 244 mice resulted in robust engraftment of leukemic cells into the murine spleens detected 4 wks after transplantation. Leukemic cell engraftment correlated significantly (P < 0.05) with markers reflecting disease activity, e.g., Binet stage and lymphocyte doubling time, and the expression of molecular risk factors including CD38, CD49d, ZAP-70, and IgVH mutational status. Increased engraftment levels of CD38+ as compared to CD38- CLL cells could be attributed, in part, to leukemic cell proliferation as evidenced by combined immunostaining of murine spleen sections for Ki-67 and CD20. In short-term (24 h) homing assays, CD38+ CLL cells migrated more efficiently to the bone marrow of the recipient animals than their CD38- counterparts. Finally, CD38 expression by the leukemic cells was found to be dynamic in that it was regulated not only by elements of the murine microenvironment but also by co-engrafting non-malignant human T cells. This model could be useful for evaluating the biological basis of CLL growth in the context of the hematopoietic microenvironment as well as preclinical testing of novel compounds. PMID:21692849

Aydin, Semra; Grabellus, Florian; Eisele, Lewin; Möllmann, Michael; Hanoun, Maher; Ebeling, Peter; Moritz, Thomas; Carpinteiro, Alexander; Nückel, Holger; Sak, Ali; Göthert, Joachim R; Dührsen, Ulrich; Dürig, Jan

2011-07-01

225

Nilotinib and Imatinib Are Comparably Effective in Reducing Growth of Human Eosinophil Leukemia Cells in a Newly Established Xenograft Model  

PubMed Central

We developed a xenograft model of human Chronic Eosinophilic Leukemia (CEL) to study disease progression and remission-induction under therapy with tyrosine kinase inhibitors using imatinib and nilotinib as examples. The FIP1L1/PDGFRA+ human CEL cell lineEOL-1 was injected intravenously into scid mice, and MR imaging and FACS analysis of mouse blood samples were performed to monitor disease development and the effects of imatinib and nilotinib. Organ infiltration was analyzed in detail by immunohistochemistry after sacrifice. All animals developed CEL and within one week of therapy, complete remissions were seen with both imatinib and nilotinib, resulting in reduced total tumor volumes by MR-imaging and almost complete disappearance of EOL-1 cells in the peripheral blood and in tissues. The new model system is feasible for the evaluation of new tyrosine kinase inhibitors and our data suggest that nilotinib may be a valuable additional targeted drug active in patients with FIP1L1/PDGFRA+ CEL.

Salamon, Johannes; Thamer, Mohammed; Herrmann, Harald; Valent, Peter; Schumacher, Udo; Ullrich, Sebastian

2012-01-01

226

Nilotinib and imatinib are comparably effective in reducing growth of human eosinophil leukemia cells in a newly established xenograft model.  

PubMed

We developed a xenograft model of human Chronic Eosinophilic Leukemia (CEL) to study disease progression and remission-induction under therapy with tyrosine kinase inhibitors using imatinib and nilotinib as examples. The FIP1L1/PDGFRA+ human CEL cell lineEOL-1 was injected intravenously into scid mice, and MR imaging and FACS analysis of mouse blood samples were performed to monitor disease development and the effects of imatinib and nilotinib. Organ infiltration was analyzed in detail by immunohistochemistry after sacrifice. All animals developed CEL and within one week of therapy, complete remissions were seen with both imatinib and nilotinib, resulting in reduced total tumor volumes by MR-imaging and almost complete disappearance of EOL-1 cells in the peripheral blood and in tissues. The new model system is feasible for the evaluation of new tyrosine kinase inhibitors and our data suggest that nilotinib may be a valuable additional targeted drug active in patients with FIP1L1/PDGFRA+ CEL. PMID:22348015

Wicklein, Daniel; Ramos Leal, Nuno; Salamon, Johannes; Thamer, Mohammed; Herrmann, Harald; Valent, Peter; Schumacher, Udo; Ullrich, Sebastian

2012-02-14

227

Characterization of antiestrogenic activity of the Chinese herb, prunella vulgaris, using in vitro and in vivo (Mouse Xenograft) models.  

PubMed

Prunella vulgaris (PV), a commonly used Chinese herb, also known as Self-heal, has a wide range of reported medicinal activities. By screening multiple herbs using the endometrial cancer cell line, ECC-1, and an alkaline phosphatase detection assay, we found that PV displayed significant antiestrogenic activity. We investigated the possible usefulness of antiestrogenic activity using both in vitro and in vivo models of endometrial function. Using the well-differentiated, hormone-responsive endometrial cell line, ECC-1, PV extract, at concentrations that were not toxic to the cells, significantly reduced alkaline phosphatase activity and cell proliferation in response to estrogen in a dose-dependent manner. The expression of CYR61, an estrogen-induced protein, was blocked in ECC-1 cells by both the antiestrogen ICI 182,780 and PV extract. Interestingly, PV extract did not appear to directly inhibit estrogen signaling. Rather, we found that its activities were probably related to an ability to function as an aryl hydrocarbon receptor (AHR) agonist in ECC-1 cells. In support of this hypothesis, we noted that PV induced CYP1A1, CYP1B1, and AHR repressor expression in a dose-dependent manner--responses that were blocked by small interfering RNA treatment to reduce AHR and specific AHR antagonists. Ovariectomized immunodeficient RAG-2/gamma(c) knockout mice implanted with human endometrial xenografts developed implants only when treated with estrogen. Mice treated with estrogen and PV tea in their drinking water had fewer and smaller xenograft implants compared with their estrogen-treated counterparts that drank only water (P < 0.05). Analysis of the resulting implants by immunohistochemistry demonstrated persistent estrogen receptor (ER), but reduced proliferation and CYR61 expression. Mouse uterine tissue weight in PV-treated mice was not different from controls, and cycle fecundity of intact C57 female mice was unaffected by PV tea treatment. PV, or Self-heal, exhibits significant antiestrogenic properties, both in vitro and in vivo. This activity is likely due to the ability of PV-activated AHR to interfere with estrogen. This herb may be useful as an adjunct for the treatment of estrogen-dependent processes like endometriosis and breast and uterine cancers. Full characterization of this herb will likely provide new insights into the crosstalk between AHR and ESR1, with potential for therapeutic applications in women. PMID:18923163

Collins, Nancy H; Lessey, Elizabeth C; DuSell, Carolyn D; McDonnell, Donald P; Fowler, Lindsay; Palomino, Wilder A; Illera, Maria J; Yu, Xianzhong; Mo, Bilan; Houwing, Angela M; Lessey, Bruce A

2008-10-15

228

Analysis of Movement Behavior of Zebrafish (DANIO RERIO) Under Chemical Stress Using Hidden Markov Model  

NASA Astrophysics Data System (ADS)

Based on computer vision techniques, the movement tracks of an indicator species (zebrafish) were continuously observed in two dimensions before and after the treatments with a toxic chemical (formaldehyde, 2.5 ppm). Behavioral patterns based on the shape of movement segments were regarded as states, while linear and angular speeds measured from the movement segments were used as observed events for training with a hidden Markov model (HMM). The state sequences were estimated by HMM based on transition and emission probability matrices, and observed events. The movement tracks were further reconstructed based on behavior state sequences generated by HMM. Subsequently, permutation entropy and fractal dimension were calculated to monitor behavioral changes before and after the treatments. Both parameters based on the real and reconstructed data significantly decreased after the treatments, and individual variability was minimized with the parameters obtained from the reconstructed tracks. The parameter extraction based on optimal state sequence by HMM was suitable for resolving the problem of variability in behavioral data, and would be an effective means of monitoring chemical stress in the environment.

Li, Yan; Lee, Jang-Myung; Chon, Tae-Soo; Liu, Yuedan; Kim, Hungsoo; Bae, Mi-Jung; Park, Young-Seuk

2013-01-01

229

Rargb regulates organ laterality in a zebrafish model of right atrial isomerism.  

PubMed

Developmental signals determine organ morphology and position during embryogenesis. To discover novel modifiers of liver development, we performed a chemical genetic screen in zebrafish and identified retinoic acid as a positive regulator of hepatogenesis. Knockdown of the four RA receptors revealed that all receptors affect liver formation, however specific receptors exert differential effects. Rargb knockdown results in bilateral livers but does not impact organ size, revealing a unique role for Rargb in conferring left-right positional information. Bilateral populations of hepatoblasts are detectable in rargb morphants, indicating Rargb acts during hepatic specification to position the liver, and primitive endoderm is competent to form liver on both sides. Hearts remain at the midline and gut looping is perturbed in rargb morphants, suggesting Rargb affects lateral plate mesoderm migration. Overexpression of Bmp during somitogenesis similarly results in bilateral livers and midline hearts, and inhibition of Bmp signaling rescues the rargb morphant phenotype, indicating Rargb functions upstream of Bmp to regulate organ sidedness. Loss of rargb causes biliary and organ laterality defects as well as asplenia, paralleling symptoms of the human condition right atrial isomerism. Our findings uncover a novel role for RA in regulating organ laterality and provide an animal model of one form of human heterotaxia. PMID:22982668

Garnaas, Maija K; Cutting, Claire C; Meyers, Alison; Kelsey, Peter B; Harris, James M; North, Trista E; Goessling, Wolfram

2012-09-13

230

snow white, a Zebrafish Model of Hermansky-Pudlak Syndrome Type 5.  

PubMed

Hermansky-Pudlak Syndrome (HPS) is a set of genetically heterogeneous diseases caused by mutations in one of nine known HPS genes. HPS patients display oculocutaneous hypopigmentation and bleeding diathesis and, depending on the disease subtype, pulmonary fibrosis, congenital nystagmus, reduced visual acuity, and platelet aggregation deficiency. Mouse models for all known HPS subtypes have contributed greatly to our understanding of the disease, but many of the molecular and cellular mechanisms underlying HPS remain unknown. Here, we characterize ocular defects in the zebrafish (Danio rerio) mutant snow white (snw), which possesses a recessive, missense mutation in hps5 (hps5(I76N)). Melanosome biogenesis is disrupted in snw/hps5 mutants, resulting in hypopigmentation, a significant decrease in the number, size, and maturity of melanosomes, and the presence of ectopic multi-melanosome clusters throughout the mutant retina and choroid. snw/hps5(I76N) is the first Hps5 mutation identified within the N-terminal WD40 repeat protein-protein binding domain. Through in vitro coexpression assays, we demonstrate that Hps5(I76N) retains the ability to bind its protein complex partners, Hps3 and Hps6. Furthermore, while Hps5 and Hps6 stabilize each other's expression, this stabilization is disrupted by Hps5(I76N). The snw/hps5(I76N) mutant provides a valuable resource for structure-function analyses of Hps5 and enables further elucidation of the molecular and cellular mechanisms underlying HPS. PMID:23893484

Daly, Christina M S; Willer, Jason; Gregg, Ronald; Gross, Jeffrey M

2013-07-26

231

Microcephaly models in the developing zebrafish retinal neuroepithelium point to an underlying defect in metaphase progression.  

PubMed

Autosomal recessive primary microcephaly (MCPH) is a congenital disorder characterized by significantly reduced brain size and mental retardation. Nine genes are currently known to be associated with the condition, all of which encode centrosomal or spindle pole proteins. MCPH is associated with a reduction in proliferation of neural progenitors during fetal development. The cellular mechanisms underlying the proliferation defect, however, are not fully understood. The zebrafish retinal neuroepithelium provides an ideal system to investigate this question. Mutant or morpholino-mediated knockdown of three known MCPH genes (stil, aspm and wdr62) and a fourth centrosomal gene, odf2, which is linked to several MCPH proteins, results in a marked reduction in head and eye size. Imaging studies reveal a dramatic rise in the fraction of proliferating cells in mitosis in all cases, and time-lapse microscopy points to a failure of progression through prometaphase. There was also increased apoptosis in all the MCPH models but this appears to be secondary to the mitotic defect as we frequently saw mitotically arrested cells disappear, and knocking down p53 apoptosis did not rescue the mitotic phenotype, either in whole retinas or clones. PMID:24153002

Novorol, Claire; Burkhardt, Janina; Wood, Kirstin J; Iqbal, Anila; Roque, Claudio; Coutts, Nicola; Almeida, Alexandra D; He, Jie; Wilkinson, Christopher J; Harris, William A

2013-10-23

232

Investigation of proNT/NMN secretion from small cell lung carcinoma cells using a mouse xenograft model.  

PubMed

Proneurotensin/neuromedin N (proNT/NMN), the precursor of neurotensin (NT) and neuromedin N (NMN), is produced by cancer tissues derived from the pancreas and colon. NT stimulates tumor growth and proliferation through its receptors; however, little is known about the precursor molecule in cancer tissues. We previously demonstrated that proNT/NMN is secreted from small cell lung carcinoma (SCLC) cell lines in serum-free conditioned medium, but not from non-small cell lung carcinoma (NSCLC) cell lines. It was suggested that this precursor may serve as a tumor marker for SCLC. In this study, we established in vivo xenograft models to evaluate the possibility of proNT/NMN as a specific tumor marker. SBC3 cells, derived from human SCLC, were inoculated into mice, and the proNT/NMN levels in plasma and tumor tissues were detected using specific antibodies. In contrast to control mouse plasma, the proNT/NMN levels in tumor-bearing mice increased as the tumors grew, and the elevated plasma proNT/NMN levels were decreased by tumor resection. Moreover, proNT/NMN was expressed in SBC3 tumors, suggesting that proNT/NMN was secreted into blood from the tumor, and this secretion may be specific to SCLC. PMID:22825476

Wakabayashi-Nakao, Kanako; Maruyama, Koji; Ishii, Hidee; Muramatsu, Koji; Hatakeyama, Keiichi; Ohshima, Keiichi; Ogura, Shun-Ichiro; Nakajima, Takashi; Yamaguchi, Ken; Mochizuki, Tohru

2012-07-23

233

Targeting FGF19 inhibits tumor growth in colon cancer xenograft and FGF19 transgenic hepatocellular carcinoma models.  

PubMed

Although fibroblast growth factor 19 (FGF19) can promote liver carcinogenesis in mice its involvement in human cancer is not well characterized. Here we report that FGF19 and its cognate receptor FGF receptor 4 (FGFR4) are coexpressed in primary human liver, lung and colon tumors and in a subset of human colon cancer cell lines. To test the importance of FGF19 for tumor growth, we developed an anti-FGF19 monoclonal antibody that selectively blocks the interaction of FGF19 with FGFR4. This antibody abolished FGF19-mediated activity in vitro and inhibited growth of colon tumor xenografts in vivo and effectively prevented hepatocellular carcinomas in FGF19 transgenic mice. The efficacy of the antibody in these models was linked to inhibition of FGF19-dependent activation of FGFR4, FRS2, ERK and beta-catenin. These findings suggest that the inactivation of FGF19 could be beneficial for the treatment of colon cancer, liver cancer and other malignancies involving interaction of FGF19 and FGFR4. PMID:17599042

Desnoyers, L R; Pai, R; Ferrando, R E; Hötzel, K; Le, T; Ross, J; Carano, R; D'Souza, A; Qing, J; Mohtashemi, I; Ashkenazi, A; French, D M

2007-06-25

234

Imatinib mesylate (Glivec) inhibits Schwann cell viability and reduces the size of human plexiform neurofibroma in a xenograft model.  

PubMed

Plexiform neurofibromas (PNF), one of the major features of neurofibromatosis type 1 (NF1), are characterized by complex cellular composition and mostly slow but variable growth patterns. In this study, we examined the effect of imatinib mesylate, a receptor tyrosine kinase inhibitor, on PNF-derived Schwann cells and PNF tumour growth in vitro and in vivo. In vitro, PNF-derived primary Schwann cells express platelet-derived growth factors receptors (PDGFR) alpha and beta, both targets of imatinib, and cell viability was reduced by imatinib mesylate, with 50% inhibition concentration (IC(50)) of 10 microM. For in vivo studies, PNF tumour fragments xenografted onto the sciatic nerve of athymic nude mice were first characterized. The tumours persisted for at least 63 days and maintained typical characteristics of PNFs such as complex cellular composition, low proliferation rate and angiogenesis. A transient enlargement of the graft size was due to inflammation by host cells. Treatment with imatinib mesylate at a daily dose of 75 mg/kg for 4 weeks reduced the graft size by an average of 80% (n = 8), significantly different from the original sizes within the group and from sizes of the grafts in 11 untreated mice in the control group (P < 0.001). We demonstrated that grafting human PNF tumour fragments into nude mice provides an adequate in vivo model for drug testing. Our results provide in vivo and in vitro evidence for efficacy of imatinib mesylate for PNF. PMID:19921098

Demestre, Maria; Herzberg, Jan; Holtkamp, Nikola; Hagel, Christian; Reuss, David; Friedrich, Reinhard E; Kluwe, Lan; Von Deimling, Andreas; Mautner, Victor-F; Kurtz, Andreas

2009-11-17

235

Carbon nanotube lipid drug approach for targeted delivery of a chemotherapy drug in a human breast cancer xenograft animal model.  

PubMed

Carbon nanotube (CNT) possesses excellent properties as a drug carrier. To overcome the challenge of drug functionalization with CNT, we have developed a lipid-drug approach for efficient drug loading onto CNT, in which a long chain lipid molecule is conjugated to the drug molecule so that the lipid-drug can be loaded directly onto CNT through binding of the lipid 'tail' in the drug molecule to CNT surfaces via hydrophobic interactions. In a proof-of-concept study, drug paclitaxel (PTX) was conjugated with a non-toxic lipid molecule docosanol for functionalization with CNT. Folic acid was also conjugated to CNT for targeted drug delivery. High level of drug loading onto SWNT could be achieved by lipid-drug approach. Conjugation of FA to SWNT-lipid-PTX led to an increase in cell penetration capacity, and the targeted SWNT-lipid-PTX showed much improved drug efficacy in vitro in comparison to free drug Taxol and non-targeted SWNT-lipid-PTX at 48 h (78.5% vs. 31.6% and 59.1% in cytotoxicity respectively, p < 0.01). In vivo analysis using a human breast cancer xenograft mice model also confirmed the improved drug efficacy. The targeted SWNT-lipid-PTX was found non-toxic as evaluated by biochemical analysis using blood samples, and by histological analysis of major organs. PMID:24060420

Shao, Wei; Paul, Arghya; Zhao, Bin; Lee, Crystal; Rodes, Laetitia; Prakash, Satya

2013-09-20

236

Selectin-deficiency reduces the number of spontaneous metastases in a xenograft model of human breast cancer.  

PubMed

Metastasis formation is a complex process still poorly understood. Previous work in a colon cancer xenograft model showed that E(ndothelial) and P(latelet) selectins mediate spontaneous metastasis to the lungs. To investigate the functional role of selectins in breast cancer, human DU4475 breast cancer cells were injected subcutaneously into pfp-/-rag2-/- mice and in all their selectin-deficient variants (EP-/-, E-/- and P-/-). Pfp-/-rag2-/- mice as well as all their selectin-deficient variants developed primary tumours and spontaneous metastases. Compared with the wild-type mice, disseminated tumours cells were significantly lower (74% reduction, P=0.046) in the bone marrow of selectin-deficient mice. Pfp-/-rag2-/- mice developed significantly higher numbers of lung metastases (6644.83±741.77) than the E-/- (4053.33±112.58; P=0.002) and the EP-/- pfp-/-rag2-/- mice (4665.65±754.50; P<0.001). The results indicate that E- and P-selectins play a role in spontaneous metastasis formation both into bone marrow and lungs. However, spontaneous metastasis was not completely abrogated, hence additional cell adhesion molecules must be involved in the metastatic spread. PMID:22366582

Stübke, Katrin; Wicklein, Daniel; Herich, Lena; Schumacher, Udo; Nehmann, Nina

2012-02-23

237

Zebrafish: a model animal for analyzing the impact of environmental pollutants on muscle and brain mitochondrial bioenergetics.  

PubMed

Mercury, anthropogenic release of uranium (U), and nanoparticles constitute hazardous environmental pollutants able to accumulate along the aquatic food chain with severe risk for animal and human health. The impact of such pollutants on living organisms has been up to now approached by classical toxicology in which huge doses of toxic compounds, environmentally irrelevant, are displayed through routes that never occur in the lifespan of organisms (for instance injecting a bolus of mercury to an animal although the main route is through prey and fish eating). We wanted to address the effect of such pollutants on the muscle and brain mitochondrial bioenergetics under realistic conditions, at unprecedented low doses, using an aquatic model animal, the zebrafish Danio rerio. We developed an original method to measure brain mitochondrial respiration: a single brain was put in 1.5 mL conical tube containing a respiratory buffer. Brains were gently homogenized by 13 strokes with a conical plastic pestle, and the homogenates were immediately used for respiration measurements. Skinned muscle fibers were prepared by saponin permeabilization. Zebrafish were contaminated with food containing 13 ?g of methylmercury (MeHg)/g, an environmentally relevant dose. In permeabilized muscle fibers, we observed a strong inhibition of both state 3 mitochondrial respiration and cytochrome c oxidase activity after 49 days of MeHg exposure. We measured a dramatic decrease in the rate of ATP release by skinned muscle fibers. Contrarily to muscles, brain mitochondrial respiration was not modified by MeHg exposure although brain accumulated twice as much MeHg than muscles. When zebrafish were exposed to 30 ?g/L of waterborne U, the basal mitochondrial respiratory control ratio was decreased in muscles after 28 days of exposure. This was due to an increase of the inner mitochondrial membrane permeability. The impact of a daily ration of food containing gold nanoparticles of two sizes (12 and 50 nm) was investigated at a very low dose for 60 days (40 ng gold/fish/day). Mitochondrial dysfunctions appeared in brain and muscle for both tested sizes. In conclusion, at low environmental doses, dietary or waterborne heavy metals impinged on zebrafish tissue mitochondrial respiration. Due to its incredible simplicity avoiding tedious and time-consuming mitochondria isolation, our one-pot method allowing brain respiratory analysis should give colleagues the incentive to use zebrafish brain as a model in bioenergetics. This article is part of a Directed Issue entitled: Bioenergetic dysfunction, adaptation and therapy. PMID:22842533

Bourdineaud, Jean-Paul; Rossignol, R; Brèthes, D

2012-07-27

238

Enhanced Antitumor Activity of SarCNU in Comparison to BCNU in an Extraneuronal Monoamine Transporter Positive Human Glioma Xenograft Model  

Microsoft Academic Search

A novel analogue of nitrosoureas, 2-chloroethyl-3-sarcosinamide-1-nitrosourea (SarCNU), has demonstrated increased anticancer effects in vitro and in vivo. Our previous work suggested that SarCNU enters cells via the extraneuronal monoamine transporter (EMT), that contributes to its enhanced cytotoxicity. In the present study, comparative activities of SarCNU and 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) were evaluated in an EMT positive human glioma xenograft model. Athymic nude

Zhong-Ping Chen; Gang Wang; Qiang Huang; Zhi-Fang Sun; Li-Ying Zhou; An-Dong Wang; Lawrence C. Panasci

1999-01-01

239

FR255734, a Humanized, Fc-Silent, Anti-CD28 Antibody, Improves Psoriasis in the SCID Mouse-Psoriasis Xenograft Model  

Microsoft Academic Search

In psoriasis, CD28\\/B7 costimulatory molecules are well characterized. Here, using the severe combined immunodeficient (SCID) mouse-psoriasis xenograft model, we report therapeutic efficacy of a humanized anti-CD28 monoclonal antibody (FR255734; Astellas Pharmaceuticals Inc., Tokyo, Japan). Transplanted psoriasis plaques on the SCID mouse were treated weekly for 4 weeks with intraperitoneal injections of FR255734 at 10, 3, and 1-mg kg?1 doses. Groups

Siba P Raychaudhuri; Smriti Kundu-Raychaudhuri; Kouichi Tamura; Taro Masunaga; Kaori Kubo; Kaori Hanaoka; Wen-Yue Jiang; Leonore A Herzenberg; Leonard A Herzenberg

2008-01-01

240

Three-dimensional MR mapping of angiogenesis with  5 1(   3)-targeted theranostic nanoparticles in the MDA-MB-435 xenograft mouse model  

Microsoft Academic Search

Our objectives were 1) to characterize angiogenesis in the MDA-MB-435 xenograft mouse model with three-dimensional (3D) MR molecular im- aging using 51(RGD)- or irrelevant RGS-targeted paramagnetic nanoparticles and 2) to use MR molecu- lar imaging to assess the antiangiogenic effectiveness of 51(3)- vs. 3-targeted fumagillin (50 g\\/kg) nanoparticles. Tumor-bearing mice were imaged with MR before and after administration of either

Anne H. Schmieder; Shelton D. Caruthers; Huiying Zhang; Todd A. Williams; J. David Robertson; Samuel A. Wickline; Gregory M. Lanza

2008-01-01

241

A Novel Nonobese Diabetic\\/Severe Combined Immunodeficient Xenograft Model for Chronic Lymphocytic Leukemia Reflects Important Clinical Characteristics of the Disease  

Microsoft Academic Search

We here describe a novel xenograft model of chronic lymphocytic leukemia (CLL) generated by infusion of human primary CLL cells into immunodeficient nonobese\\/severe combined immunodeficient (NOD\\/SCID) mice. Combined i.v. and i.p. injection of peripheral blood mononuclear cells (PBMC) from 39 patients with CLL resulted in highly reproducible splenic (37 of 39) and peritoneal (35 of 39) engraftment, which remained stable

Jan Durig; Peter Ebeling; Florian Grabellus; Ursula R. Sorg; Michael Mollmann; Philipp Schutt; Joachim Gothert; Ludger Sellmann; Siegfried Seeber; Michael Flasshove; Ulrich Duhrsen; Thomas Moritz

242

Zebrafish orthologs of human muscular dystrophy genes  

PubMed Central

Background Human muscular dystrophies are a heterogeneous group of genetic disorders which cause decreased muscle strength and often result in premature death. There is no known cure for muscular dystrophy, nor have all causative genes been identified. Recent work in the small vertebrate zebrafish Danio rerio suggests that mutation or misregulation of zebrafish dystrophy orthologs can also cause muscular degeneration phenotypes in fish. To aid in the identification of new causative genes, this study identifies and maps zebrafish orthologs for all known human muscular dystrophy genes. Results Zebrafish sequence databases were queried for transcripts orthologous to human dystrophy-causing genes, identifying transcripts for 28 out of 29 genes of interest. In addition, the genomic locations of all 29 genes have been found, allowing rapid candidate gene discovery during genetic mapping of zebrafish dystrophy mutants. 19 genes show conservation of syntenic relationships with humans and at least two genes appear to be duplicated in zebrafish. Significant sequence coverage on one or more BAC clone(s) was also identified for 24 of the genes to provide better local sequence information and easy updating of genomic locations as the zebrafish genome assembly continues to evolve. Conclusion This resource supports zebrafish as a dystrophy model, suggesting maintenance of all known dystrophy-associated genes in the zebrafish genome. Coupled with the ability to conduct genetic screens and small molecule screens, zebrafish are thus an attractive model organism for isolating new dystrophy-causing genes/pathways and for use in high-throughput therapeutic discovery.

Steffen, Leta S; Guyon, Jeffrey R; Vogel, Emily D; Beltre, Rosanna; Pusack, Timothy J; Zhou, Yi; Zon, Leonard I; Kunkel, Louis M

2007-01-01

243

Inhibition of tumor growth and histopathological changes following treatment with a chemokine receptor CXCR4 antagonist in a prostate cancer xenograft model  

PubMed Central

The stromal derived factor-1 (SDF-1)/CXCR4 axis is associated with tumor aggressiveness and metastasis in prostate cancer. The present study aimed to explore the potential therapeutic effects of a CXCR4 antagonist in prostate cancer. The effect of SDF-1 and a CXCR4-specific antagonist, AMD3100, on human prostate cancer PC-3 cell proliferation and protein kinase B (Akt) signaling was assessed. Moreover, a PC-3 tumor xenograft model was used to evaluate the effect of AMD3100 on tumor growth and to identify the histopathological changes and immunohistochemical differences between AMD3100-treated and untreated groups. Cell proliferation was not significantly affected by SDF-1 or AMD3100 treatment in vitro. Western blot analysis revealed that SDF-1 stimulation enhanced the expression of phosphorylated Akt in the PC-3 cells, but that the SDF-1-induced expression of phosphorylated Akt was abrogated in the AMD3100-treated PC-3 cells. In the PC-3 tumor xenograft model, AMD3100 significantly inhibited tumor growth, while AMD3100-treated PC-3 tumors had lower levels of microvessel formation and a lower immunoreactivity for the proliferation marker Ki-67 and the anti-apoptotic marker Bcl-2 compared to control tumors in vivo. The CXCR4-specific antagonist inhibits SDF-1-induced CXCR4/Akt signal transduction, and effectively suppresses tumor growth in the PC-3 xenograft model. The present study indicates that CXCR4 targeting may represent a novel strategy for the treatment of castration-resistant prostate cancer (CRPC).

CHO, KANG SU; YOON, SO JUNG; LEE, JOO YONG; CHO, NAM HOON; CHOI, YOUNG DEUK; SONG, YUN SEOB; HONG, SUNG JOON

2013-01-01

244

Host immune response and acute disease in a zebrafish model of francisella pathogenesis  

USGS Publications Warehouse

Members of the bacterial genus Francisella are highly virulent and infectious pathogens. New models to study Francisella pathogenesis in evolutionarily distinct species are needed to provide comparative insight, as the mechanisms of host resistance and pathogen virulence are not well understood. We took advantage of the recent discovery of a novel species of Francisella to establish a zebrafish/Francisella comparative model of pathogenesis and host immune response. Adult zebraflsh were susceptible to acute Francisella-induced disease and suffered mortality in a dose-dependent manner. Using immunohistochemical analysis, we localized bacterial antigens primarily to lymphoid tissues and livers of zebraflsh following infection by intraperitoneal injection, which corresponded to regions of local cellular necrosis. Francisella sp. bacteria replicated rapidly in these tissues beginning 12 h postinfection, and bacterial titers rose steadily, leveled off, and then decreased by 7 days postinfection. Zebraflsh mounted a significant tissue-specific proinflammatory response to infection as measured by the upregulation of interleukin-l?? (IL-1??), gamma interferon, and tumor necrosis factor alpha mRNA beginning by 6 h postinfection and persisting for up to 7 days postinfection. In addition, exposure of zebraflsh to heat-killed bacteria demonstrated that the significant induction of IL-?? was highly specific to live bacteria. Taken together, the pathology and immune response to acute Francisella infection in zebraflsh share many features with those in mammals, highlighting the usefulness of this new model system for addressing both general and specific questions about Francisella host-pathogen interactions via an evolutionary approach. Copyright ?? 2009, American Society for Microbiology. All Rights Reserved.

Vojtech, L. N.; Sanders, G. E.; Conway, C.; Ostland, V.; Hansen, J. D.

2009-01-01

245

Validation of a mouse xenograft model system for gene expression analysis of human acute lymphoblastic leukaemia  

Microsoft Academic Search

BACKGROUND: Pre-clinical models that effectively recapitulate human disease are critical for expanding our knowledge of cancer biology and drug resistance mechanisms. For haematological malignancies, the non-obese diabetic\\/severe combined immunodeficient (NOD\\/SCID) mouse is one of the most successful models to study paediatric acute lymphoblastic leukaemia (ALL). However, for this model to be effective for studying engraftment and therapy responses at the

Amy L Samuels; Violet K Peeva; Rachael A Papa; Marin J Firth; Richard W Francis; Alex H Beesley; Richard B Lock; Ursula R Kees

2010-01-01

246

Lack of long-lasting effects of mitotane adjuvant therapy in a mouse xenograft model of adrenocortical carcinoma.  

PubMed

Mitotane is a widely used drug in the therapy of adrenocortical carcinoma (ACC). It is important to set up preclinical protocols to study the possible synergistic effects of its association with new drugs for ACC therapy. We assessed the efficacy of different routes of administration of mitotane (i.p. and oral) in inhibiting growth of H295R ACC cell xenografts in an adjuvant setting. Both formulations of mitotane could inhibit H295R xenografts growth only at short times after carcinoma cells inoculation, even though plasma mitotane levels approached or fell within the therapeutic range in humans. Our results show that mitotane adjuvant therapy is inadequate to antagonize long-term growth of H295R cancer cells xenografts and that care should then be taken in the design of preclinical protocols to evaluate the performance of new drugs in association with mitotane. PMID:23906534

Doghman, Mabrouka; Lalli, Enzo

2013-07-30

247

Delayed xenograft rejection  

Microsoft Academic Search

Despite considerable progress in understanding the mechanisms of discordant xenograft rejection, and overcoming hyperacute rejection through targeting of complement or antibody, vascularized xenografts are typically rejected within days. Here, Fritz Bach and colleagues discuss the importance of endothelial cell activation, platelet aggregation and other aspects of thrombosis, as well as the contribution of host natural killer cell and monocyte activation

Fritz H. Bach; Hans Winkler; Christiane Ferran; Wayne W. Hancock; Simon C. Robson

1996-01-01

248

Studying rod photoreceptor development in zebrafish  

PubMed Central

The zebrafish has rapidly become a favored model vertebrate organism, well suited for studies of developmental processes using large-scale genetic screens. In particular, zebrafish morphological and behavioral genetic screens have led to the identification of genes important for development of the retinal photoreceptors. This may help clarify the genetic mechanisms underlying human photoreceptor development and dysfunction in retinal diseases. In this review, we present the advantages of zebrafish as a vertebrate model organism, summarize retinal and photoreceptor cell development in zebrafish, with emphasis on the rod photoreceptors, and describe zebrafish visual behaviors that can be used for genetic screens. We then describe some of the photoreceptor cell mutants that have been isolated in morphological and behavioral screens and discuss the limitations of current screening methods for uncovering mutations that specifically affect rod function. Finally, we present some alternative strategies to target the rod developmental pathway in zebrafish.

Morris, A.C.; Fadool, J.M.

2009-01-01

249

Differential expression of FGF family members in a progestin-dependent BT-474 human breast cancer xenograft model.  

PubMed

Members of the fibroblast growth factor (FGF) family have been associated with tumor progression and angiogenesis, though the mechanism through which they affect the progression of breast cancer remains elusive. We recently showed that progestins increase the production of the potent angiogenic factor VEGF in an in vivo BT-474 human breast cancer cell-derived xenograft model. In this study we sought to determine the effect of progesterone (P) on regulation of specific FGF family members (FGF-2, FGF-4 and FGF-8) in the same model. Using immunohistochemistry we found that treatment with P significantly reduced FGF-2 and FGF-8 levels, while modestly increasing the levels of FGF-4 in tumors collected at the termination of the study or soon after P treatment began. The in vivo observations with FGF-2 were confirmed in cultured BT-474 cells, though the P-mediated reduction in FGF-2 was not blocked by the anti-progestin RU-486, suggesting that classical progesterone receptors (PR) are not involved in FGF-2 down-regulation. Also, P did not affect levels of FGF-2 mRNA in BT-474 cells, indicating that P exerts its effects on FGF-2 post-transcriptionally. Our observations suggest that the in vivo stimulation of BT-474 cell growth by P is associated with down-regulation of FGF-2 and FGF-8. Furthermore, since FGF-4 levels increased during P-treatment, FGF-4 may be required for tumor growth and maintenance and might therefore be a potential therapeutic target through which to suppress P-dependent tumor growth. PMID:22237711

López Pérez, Franklin R; Liang, Yayun; Besch-Williford, Cynthia L; Mafuvadze, Benford; Hyder, Salman M

2012-03-01

250

Rapamycin targeting mTOR and hedgehog signaling pathways blocks human rhabdomyosarcoma growth in xenograft murine model.  

PubMed

Rhabdomyosarcomas (RMS) represent the most common childhood soft-tissue sarcoma. Over the past few decades outcomes for low and intermediate risk RMS patients have slowly improved while patients with metastatic or relapsed RMS still face a grim prognosis. New chemotherapeutic agents or combinations of chemotherapies have largely failed to improve the outcome. Based on the identification of novel molecular targets, potential therapeutic approaches in RMS may offer a decreased reliance on conventional chemotherapy. Thus, identification of effective therapeutic agents that specifically target relevant pathways may be particularly beneficial for patients with metastatic and refractory RMS. The PI3K/AKT/mTOR pathway has been found to be a potentially attractive target in RMS therapy. In this study, we provide evidence that rapamycin (sirolimus) abrogates growth of RMS development in a RMS xenograft mouse model. As compared to a vehicle-treated control group, more than 95% inhibition in tumor growth was observed in mice receiving parenteral administration of rapamycin. The residual tumors in rapamycin-treated group showed significant reduction in the expression of biomarkers indicative of proliferation and tumor invasiveness. These tumors also showed enhanced apoptosis. Interestingly, the mechanism by which rapamycin diminished RMS tumor growth involved simultaneous inhibition of mTOR and hedgehog (Hh) pathways. Diminution in these pathways in this model of RMS also inhibited epithelial mesenchymal transition (EMT) which then dampened the invasiveness of these tumors. Our data provide bases for using rapamycin either alone or in combination with traditional chemotherapeutic drugs to block the pathogenesis of high risk RMS. PMID:23665330

Kaylani, Samer Z; Xu, Jianmin; Srivastava, Ritesh K; Kopelovich, Levy; Pressey, Joseph G; Athar, Mohammad

2013-05-09

251

Evaluation of the NOD/SCID xenograft model for glucocorticoid-regulated gene expression in childhood B-cell precursor acute lymphoblastic leukemia  

PubMed Central

Background Glucocorticoids such as prednisolone and dexamethasone are critical drugs used in multi-agent chemotherapy protocols used to treat acute lymphoblastic leukemia (ALL), and response to glucocorticoids is highly predictive of outcome. The NOD/SCID xenograft mouse model of ALL is a clinically relevant model in which the mice develop a systemic leukemia which retains the fundamental biological characteristics of the original disease. Here we report a study evaluating the NOD/SCID xenograft mouse model to investigate glucocorticoid-induced gene expression. Cells from a glucocorticoid-sensitive xenograft derived from a child with B-cell precursor ALL were inoculated into NOD/SCID mice. When highly engrafted the mice were randomized into groups of 4 to receive dexamethasone 15 mg/kg by intraperitoneal injection or vehicle control. Leukemia cells were harvested from mice spleens at 0, 8, 24 or 48 hours thereafter, and gene expression analyzed on Illumina WG-6_V3 chips, comparing all groups to time 0 hours. Results The 8 hour dexamethasone-treated timepoint had the highest number of significantly differentially expressed genes, with fewer observed at the 24 and 48 hour timepoints, and with minimal changes seen across the time-matched controls. When compared to publicly available datasets of glucocorticoid-induced gene expression from an in vitro cell line study and from an in vivo study of patients with ALL, at the level of pathways, expression changes in the 8 hour xenograft samples showed a similar response to patients treated with glucocorticoids. Replicate analysis revealed that at the 8 hour timepoint, a dataset with high signal and differential expression, using data from 3 replicates instead of 4 resulted in excellent recovery scores of > 0.9. However at other timepoints with less signal very poor recovery scores were obtained with 3 replicates. Conclusions The NOD/SCID xenograft mouse model provides a reproducible experimental system in which to investigate clinically-relevant mechanisms of drug-induced gene regulation in ALL; the 8 hour timepoint provides the highest number of significantly differentially expressed genes; time-matched controls are redundant and excellent recovery scores can be obtained with 3 replicates.

2011-01-01

252

Ethanol exposure alters zebrafish development: A novel model of fetal alcohol syndrome  

Microsoft Academic Search

Prenatal exposure to alcohol has been shown to produce the overt physical and behavioral symptoms known as fetal alcohol syndrome (FAS) in humans. Also, it is believed that low concentrations and\\/or short durations of alcohol exposure can produce more subtle effects. The purpose of this study was to investigate the effects of embryonic ethanol exposure on the zebrafish (Danio rerio)

Joseph Bilotta; Jalynn A. Barnett; Laura Hancock; Shannon Saszik

2004-01-01

253

A combined targeted/phenotypic approach for the identification of new antiangiogenics agents active on a zebrafish model: from in silico screening to cyclodextrin formulation.  

PubMed

A combined targeted/phenotypic approach for the rapid identification of novel antiangiogenics with in vivo efficacy is herein reported. Considering the important role played by the tyrosine kinase c-Src in the regulation of tumour angiogenesis, we submitted our in-house library of c-Src inhibitors to a sequential screening approach: in silico screening on VEGFR2, in vitro screening on HUVEC cells, ADME profiling, formulation and in vivo testing on a zebrafish model. A promising antiangiogenic candidate able to interfere with the vascular growth of a zebrafish model at low micromolar concentration was thus identified. PMID:22853993

Radi, Marco; Evensen, Lasse; Dreassi, Elena; Zamperini, Claudio; Caporicci, Marialessandra; Falchi, Federico; Musumeci, Francesca; Schenone, Silvia; Lorens, James B; Botta, Maurizio

2012-07-13

254

Utilization of Quantitative In Vivo Pharmacology Approaches to Assess Combination Effects of Everolimus and Irinotecan in Mouse Xenograft Models of Colorectal Cancer  

PubMed Central

Purpose The PI3K/AKT/mTOR pathway is frequently dysregulated in cancers and inhibition of mTOR has demonstrated the ability to modulate pro-survival pathways. As such, we sought to determine the ability of the mTOR inhibitor everolimus to potentiate the antitumor effects of irinotecan in colorectal cancer (CRC). Experimental Design The combinatorial effects of everolimus and irinotecan were evaluated in vitro and in vivo in CRC cell lines harboring commonly found mutations in PIK3CA, KRAS and/or BRAF. Pharmacokinetically-directed dosing protocols of everolimus and irinotecan were established and used to assess the in vivo antitumor effects of the agents. At the end of treatment, 3–6 tumors per treatment arm were harvested for biomarker analysis by NMR metabolomics. Results Everolimus and irinotecan/SN38 demonstrated synergistic anti-proliferative effects in multiple CRC cell lines in vitro. Combination effects of everolimus and irinotecan were determined in CRC xenograft models using clinically-relevant dosing protocols. Everolimus demonstrated significant tumor growth inhibition alone and when combined with irinotecan in HT29 and HCT116 tumor xenografts. Metabolomic analysis showed that HT29 tumors were more metabolically responsive than HCT116 tumors. Everolimus caused a decrease in glycolysis in both tumor types whilst irinotecan treatment resulted in a profound accumulation of lipids in HT29 tumors indicating a cytotoxic effect. Conclusions Quantitative analysis of tumor growth and metabolomic data showed that the combination of everolimus and irinotecan was more beneficial in the BRAF/PIK3CA mutant HT29 tumor xenografts, which had an additive effect, than the KRAS/PIK3CA mutant HCT116 tumor xenografts, which had a less than additive effect.

Bradshaw-Pierce, Erica L.; Pitts, Todd M.; Kulikowski, Gillian; Selby, Heather; Merz, Andrea L.; Gustafson, Daniel L.; Serkova, Natalie J.; Eckhardt, S. Gail; Weekes, Colin D.

2013-01-01

255

5-fluorouracil enhances the antitumor effect of sorafenib and sunitinib in a xenograft model of human renal cell carcinoma  

PubMed Central

Sorafenib and sunitinib are multi-kinase inhibitors with antitumor activity in patients with advanced renal cell carcinoma (RCC). Several studies have evaluated the effect of sorafenib/sunitinib in combination with chemotherapeutic agents in different types of tumor. However, few studies have addressed the activity of fluorinated pyrimidine in combination with sorafenib/sunitinib. In this study, we examined the potential of combination therapy with 5FU and sorafenib/sunitinib in human RCC cell lines. Three human RCC cell lines, ACHN, Caki-1 and Caki-2, were used to assess sensitivity to 5-fluorouracil (5FU), sorafenib and sunitinib alone or in combination using an in vitro cell survival assay. Caki-2 cells demonstrated significantly higher resistance to 5FU and sorafenib as compared to ACHN and Caki-1. Additive antitumor effects of the combination therapy were observed in the in vitro study. There was a tendency for a positive correlation between the sensitivity to sunitinib and platelet-derived growth factor ? (PDGFR-?) expression levels, which were examined by reverse transcription polymerase chain reaction. Caki-1 xenograft models were prepared by inoculating cells subcutaneously into nude mice, which were divided randomly into six groups: control, 5FU (8 mg/kg/day, intraperitoneally), sorafenib (15 mg/kg/day, orally), sunitinib (20 mg/kg/day, orally), and 5FU with sorafenib or sunitinib. The treatments were administered on 5 days each week, and tumor growth was monitored for 42 days following inoculation of cells. Synergistic antitumor effects of the combination therapy were observed in an in vivo study. The resected tumors were evaluated using the Ki-67 labeling index and microvessel density. Both the Ki-67 labeling index and microvessel density were decreased in tumors treated with the combination therapy compared to those treated with sorafenib/sunitinib alone. These findings suggest that the combination therapy of 5FU with sorafenib/sunitinib may be an effective therapeutic modality for advanced RCC patients.

MIYAKE, MAKITO; ANAI, SATOSHI; FUJIMOTO, KIYOHIDE; OHNISHI, SAYURI; KUWADA, MASAOMI; NAKAI, YASUSHI; INOUE, TAKESHI; TOMIOKA, ATSUSHI; TANAKA, NOBUMICHI; HIRAO, YOSHIHIKO

2012-01-01

256

Naltrindole inhibits human multiple myeloma cell proliferation in vitro and in a murine xenograft model in vivo.  

PubMed

It has been demonstrated previously that immune cell activation and proliferation were sensitive to the effects of naltrindole, a nonpeptidic ?-opioid receptor-selective antagonist; therefore, we hypothesized that human multiple myeloma (MM) would be a valuable model for studying potential antineoplastic properties of naltrindole. [(3)H]naltrindole exhibited saturable, low-affinity binding to intact human MM cells; however, the pharmacological profile of the binding site differed considerably from the properties of ?-, ?-, and ?-opioid receptors, and opioid receptor mRNA was not detected in MM cells by reverse transcriptase-polymerase chain reaction. Naltrindole inhibited the proliferation of cultured human U266 MM cells in a time- and dose-dependent manner with an EC(50) of 16 ?M. The naltrindole-induced inhibition of U266 cell proliferation was not blocked by a 10-fold molar excess of naltrexone, a nonselective opioid antagonist. Additive inhibition of MM cell proliferation was observed when using a combination of naltrindole with the histone deacetylase inhibitor sodium valproate, the proteasome inhibitor bortezomib, the glucocorticoid receptor agonist dexamethasone, and the HMG CoA reductase inhibitor simvastatin. Treatment of U266 cells with naltrindole significantly decreased the level of the active, phosphorylated form of the kinases, extracellular signal-regulated kinase and Akt, which may be related to its antiproliferative activity. The antiproliferative activity of naltrindole toward MM cells was maintained in cocultures of MM and bone marrow-derived stromal cells, mimicking the bone marrow microenvironment. In vivo, naltrindole significantly decreased tumor cell volumes in human MM cell xenografts in severe combined immunodeficient mice. We hypothesize that naltrindole inhibits the proliferation of MM cells through a nonopioid receptor-dependent mechanism. PMID:22537770

Mundra, Jyoti Joshi; Terskiy, Alexandra; Howells, Richard D

2012-04-26

257

Naltrindole Inhibits Human Multiple Myeloma Cell Proliferation In Vitro and in a Murine Xenograft Model In Vivo  

PubMed Central

It has been demonstrated previously that immune cell activation and proliferation were sensitive to the effects of naltrindole, a nonpeptidic ?-opioid receptor-selective antagonist; therefore, we hypothesized that human multiple myeloma (MM) would be a valuable model for studying potential antineoplastic properties of naltrindole. [3H]naltrindole exhibited saturable, low-affinity binding to intact human MM cells; however, the pharmacological profile of the binding site differed considerably from the properties of ?-, ?-, and ?-opioid receptors, and opioid receptor mRNA was not detected in MM cells by reverse transcriptase-polymerase chain reaction. Naltrindole inhibited the proliferation of cultured human U266 MM cells in a time- and dose-dependent manner with an EC50 of 16 ?M. The naltrindole-induced inhibition of U266 cell proliferation was not blocked by a 10-fold molar excess of naltrexone, a nonselective opioid antagonist. Additive inhibition of MM cell proliferation was observed when using a combination of naltrindole with the histone deacetylase inhibitor sodium valproate, the proteasome inhibitor bortezomib, the glucocorticoid receptor agonist dexamethasone, and the HMG CoA reductase inhibitor simvastatin. Treatment of U266 cells with naltrindole significantly decreased the level of the active, phosphorylated form of the kinases, extracellular signal-regulated kinase and Akt, which may be related to its antiproliferative activity. The antiproliferative activity of naltrindole toward MM cells was maintained in cocultures of MM and bone marrow-derived stromal cells, mimicking the bone marrow microenvironment. In vivo, naltrindole significantly decreased tumor cell volumes in human MM cell xenografts in severe combined immunodeficient mice. We hypothesize that naltrindole inhibits the proliferation of MM cells through a nonopioid receptor-dependent mechanism.

Mundra, Jyoti Joshi; Terskiy, Alexandra

2012-01-01

258

Antitumor activity of Endostar combined with radiation against human nasopharyngeal carcinoma in mouse xenograft models  

PubMed Central

Radiation treatment for nasopharyngeal carcinoma (NPC) is common and effective. However, local recurrence occurs frequently. Endostar, a novel recombinant human endostatin, is an antiangiogenic drug with a potent antitumor effect. The present study aimed to observe and explore the radiosensitization effects of Endostar on NPC and its underlying mechanism. The NPC subcutaneous transplantation tumor animal model was established to evaluate the antitumor activity of Endostar combined with radiation (Endostar + radiation) treatment compared with monotherapy (Endostar or radiation). Tumor growth and tumor weight were measured to evaluate the antitumor effect. The level of vascular endothelial growth factor (VEGF) and microvessel density (MVD) were measured using immunohistochemical staining of the tumor tissues. Significant antitumor activity was found in the Endostar + radiation group. The tumor inhibition rates of Endostar, radiation and Endostar + radiation were 27.12, 60.45 and 86.11%, respectively. The VEGF levels in the tumor tissue in the Endostar + radiation group were lower than those in the radiation and control groups. The MVD in the tumor tissues in the Endostar + radiation group was 12.2±2.5, lower than that in the Endostar (29.3±3.4), radiation (23.5±3.6) and control (44.7±5.1) groups. These results suggest that Endostar increases the radiation sensitivity of NPC-transplanted tumors in nude mice by lowering VEGF expression. In this study, the NPC animal model was established, which reflects the efficacy of clinical combination therapies and the combination of Endostar and radiation. The mechanisms of the combination therapies should be further investigated using this model.

ZHOU, JUYING; WANG, LILI; XU, XIAOTING; TU, YU; QIN, SONGBING; YIN, YUZHEN

2012-01-01

259

Kidney Development and Disease in the Zebrafish  

Microsoft Academic Search

Unraveling the molecular pathogenesis of human disease presents many experimental challenges, not the least of which is that experiments on humans are generally frowned upon. Model organisms, including the zebrafish, allow for experimental analysis of gene function and the detailed characterization of disease processes. Zebrafish have matured as a vertebrate model organism now that genetic tools for targeted \\

Iain A. Drummond

2005-01-01

260

The in ovo CAM-assay as a xenograft model for sarcoma.  

PubMed

Sarcoma is a very rare disease that is heterogeneous in nature, all hampering the development of new therapies. Sarcoma patients are ideal candidates for personalized medicine after stratification, explaining the current interest in developing a reproducible and low-cost xenotransplant model for this disease. The chick chorioallantoic membrane is a natural immunodeficient host capable of sustaining grafted tissues and cells without species-specific restrictions. In addition, it is easily accessed, manipulated and imaged using optical and fluorescence stereomicroscopy. Histology further allows detailed analysis of heterotypic cellular interactions. This protocol describes in detail the in ovo grafting of the chorioallantoic membrane with fresh sarcoma-derived tumor tissues, their single cell suspensions, and permanent and transient fluorescently labeled established sarcoma cell lines (Saos-2 and SW1353). The chick survival rates are up to 75%. The model is used to study graft- (viability, Ki67 proliferation index, necrosis, infiltration) and host (fibroblast infiltration, vascular ingrowth) behavior. For localized grafting of single cell suspensions, ECM gel provides significant advantages over inert containment materials. The Ki67 proliferation index is related to the distance of the cells from the surface of the CAM and the duration of application on the CAM, the latter determining a time frame for the addition of therapeutic products. PMID:23892612

Sys, Gwen M L; Lapeire, Lore; Stevens, Nikita; Favoreel, Herman; Forsyth, Ramses; Bracke, Marc; De Wever, Olivier

2013-07-17

261

Knockdown of fbxl10/kdm2bb rescues chd7 morphant phenotype in a zebrafish model of CHARGE syndrome.  

PubMed

CHARGE syndrome is a sporadic autosomal-dominant genetic disorder characterized by a complex array of birth defects so named for its cardinal features of ocular coloboma, heart defects, choanal atresia, growth retardation, genital abnormalities, and ear abnormalities. Approximately two-thirds of individuals clinically diagnosed with CHARGE syndrome have heterozygous loss-of-function mutations in the gene encoding chromodomain helicase DNA-binding protein 7 (CHD7), an ATP-dependent chromatin remodeler. To examine the role of Chd7 in development, a zebrafish model was generated through morpholino (MO)-mediated targeting of the zebrafish chd7 transcript. High doses of chd7 MO induce lethality early in embryonic development. However, low dose-injected embryos are viable, and by 4 days post-fertilization, morphant fish display multiple defects in organ systems analogous to those affected in humans with CHARGE syndrome. The chd7 morphants show elevated expression of several potent cell-cycle inhibitors including ink4ab (p16/p15), p21 and p27, accompanied by reduced cell proliferation. We also show that Chd7 is required for proper organization of neural crest-derived craniofacial cartilage structures. Strikingly, MO-mediated knockdown of the jumonji domain-containing histone demethylase fbxl10/kdm2bb, a repressor of ribosomal RNA (rRNA) genes, rescues cell proliferation and cartilage defects in chd7 morphant embryos and can lead to complete rescue of the CHARGE syndrome phenotype. These results indicate that CHARGE-like phenotypes in zebrafish can be mitigated through modulation of fbxl10 levels and implicate FBXL10 as a possible therapeutic target in CHARGE syndrome. PMID:23920116

Balow, Stephanie A; Pierce, Lain X; Zentner, Gabriel E; Conrad, Patricia A; Davis, Stephani; Sabaawy, Hatem E; McDermott, Brian M; Scacheri, Peter C

2013-08-03

262

Zebrafish (Danio rerio) as a screen for attenuation of Lancefield group C streptococci and a model for streptococcal pathogenesis.  

PubMed

Group C streptococci are highly contagious pyogenic bacteria responsible for respiratory tract, lymph node, urogenital tract, and wound infections. Wild-type strains of Streptococcus equi ssp equi (S. equi) and Streptococcus equi ssp zooepidemicus (S. zoo) as well as a commercially available modified live vaccine strain of S. equi were evaluated for virulence in zebrafish. Survival times, histologic lesions, and relative gene expression were compared among groups. Based on the intramuscular route of infection, significantly shorter survival times were observed in fish infected with wild-type strain when compared to modified live vaccine and S. zoo strains. Histologically, S. zoo-infected fish demonstrated a marked increase in inflammatory infiltrates (predominantly macrophages) at the site of infection, as well as increased cellularity in the spleen and renal interstitium. In contrast, minimal cellular immune response was observed in S. equi-injected fish with local tissue necrosis and edema predominating. Based on whole comparative genomic hybridization, increased transcription of positive acute-phase proteins, coagulation factors, and antimicrobial peptides were observed in S. equi-injected fish relative to S. zoo-injected fish, while mediators of cellular inflammation, including CXC chemokines and granulin, were upregulated in S. zoo-injected fish relative to S. equi-injected fish. In a screen of 11 clinical isolates, S. equi strains with a single nucleotide deletion in the upstream region of szp, a known virulence factor of streptococci, were found to be significantly attenuated in zebrafish. These collective findings underscore the value of the zebrafish as a model of streptococcal pathogenesis. PMID:21997564

Borst, L B; Patterson, S K; Lanka, S; Suyemoto, M M; Maddox, C W

2011-10-12

263

Tumor endothelin-1 enhances metastatic colonization of the lung in mouse xenograft models of bladder cancer  

PubMed Central

Many patients with advanced bladder cancer develop lethal metastases to the lung. The vasoconstricting protein endothelin-1 (ET-1) has been implicated in this process, although the mechanism(s) by which it promotes metastasis remains unclear. Here, we have evaluated whether tumor ET-1 expression can serve as a biomarker for lung metastasis and whether it is required for metastatic disease. Evaluation of ET-1 mRNA and protein expression in four patient cohorts revealed that levels of ET-1 are higher in patients with muscle-invasive bladder cancers, which are associated with higher incidence of metastasis, and that high ET-1 levels are associated with decreased disease-specific survival. Consistent with its proinflammatory activity, we found that tumor-derived ET-1 acts through endothelin-1 receptor A (ETAR) to enhance migration and invasion of both tumor cells and macrophages and induces expression of inflammatory cytokines and proteases. Using human and mouse cancer cells depleted of ET-1 and pharmacologic blockade of ET receptors in lung metastasis models, we found that tumor ET-1 expression and ETAR activity are necessary for metastatic lung colonization and that this process is preceded by and dependent on macrophage infiltration of the lung. In contrast, tumor ET-1 expression and ETAR activity appeared less important in established primary or metastatic tumor growth. These findings strongly suggest that ETAR inhibitors might be more effective as adjuvant therapeutic agents than as initial treatment for advanced primary or metastatic disease.

Said, Neveen; Smith, Steven; Sanchez-Carbayo, Marta; Theodorescu, Dan

2010-01-01

264

Raloxifene inhibits tumor growth and lymph node metastasis in a xenograft model of metastatic mammary cancer  

PubMed Central

Background The effects of raloxifene, a novel selective estrogen receptor modulator, were studied in a mouse metastatic mammary cancer model expressing cytoplasmic ER?. Methods Mammary tumors, induced by inoculation of syngeneic BALB/c mice with BJMC3879luc2 cells, were subsequently treated with raloxifene at 0, 18 and 27 mg/kg/day using mini-osmotic pumps. Results In vitro study demonstrated that the ER? in BJMC3879luc2 cells was smaller (between 50 and 64 kDa) than the normal-sized ER? (66 kDa) and showed cytoplasmic localization. A statistically significant but weak estradiol response was observed in this cell line. When BJMC3879luc2 tumors were implanted into mice, the ER? mRNA levels were significantly higher in females than in males. In vitro studies showed that raloxifene induced mitochondria-mediated apoptosis and cell-cycle arrest in the G1-phase and a decrease in the cell population in the S-phase. In animal experiments, tumor volumes were significantly suppressed in the raloxifene-treated groups. The multiplicity of lymph node metastasis was significantly decreased in the 27 mg/kg group. Levels of apoptosis were significantly increased in the raloxifene-treated groups, whereas the levels of DNA synthesis were significantly decreased in these groups. No differences in microvessel density in tumors were observed between the control and raloxifene-treated groups. The numbers of dilated lymphatic vessels containing intraluminal tumor cells were significantly reduced in mammary tumors in the raloxifene-treated groups. The levels of ER? mRNA in mammary tumors tended to be decreased in the raloxifene-treated groups. Conclusion These results suggest that the antimetastatic activity of raloxifene in mammary cancer expressing cytoplasmic ER? may be a crucial finding with clinical applications and that raloxifene may be useful as an adjuvant therapy and for the chemoprevention of breast cancer development.

2010-01-01

265

Osteopontin Regulates Epithelial Mesenchymal Transition-Associated Growth of Hepatocellular Cancer in a Mouse Xenograft Model  

PubMed Central

Objective To determine the efficacy of osteopontin (OPN) targeting in hepatocellular cancer (HCC). Summary/Background OPN is associated with HCC growth and metastasis and represents a unique therapeutic target. Methods OPN and EMT markers, ?-smooth muscle actin (SMA), vimentin and tenascin-c, were measured in archived human HCC tissues from metastatic (n=4) and non-metastatic (n=4) settings. Additional studies utilized human Sk-Hep-1 (high OPN expression) and Hep3b (low OPN expression) HCC cells. An RNA aptamer (APT) that avidly binds (Kd=18 nM; t 1/2=7 hrs) and ablates OPN binding was developed. Adhesion, migration/invasion, and EMT markers were determined with APT or a mutant control aptamer (Mu-APT). RFP-Luc-Sk-Hep-1 were implanted into NOD-scid mice livers and followed using bioluminescence imaging. After verification of tumor growth, at week 3, APT (0.5 mg/kg; n=4) or Mu-APT (0.5 mg/kg; n=4) was injected Q48h. When mice were sacrificed at week 8, tumor cells were re-isolated and assayed for EMT markers. Results OPN and EMT markers were significantly increased in the metastatic cohort. APT inhibited Sk-Hep-1 adhesion and migration/invasion by 5- and 4-fold, respectively. APT significantly decreased EMT protein markers, SMA, vimentin and tenascin-c. In contrast, APT did not alter Hep3B adhesion, or migration/invasion. EMT markers were slightly decreased. In the in vivo model, at weeks 6-8, APT inhibited HCC growth by >10-fold. SMA, vimentin and tenascin-c mRNAs were decreased by 60%, 40% and 49% in RFP+ Sk-Hep-1 recovered by FACS. (p<0.04 vs Mu-APT for all) Conclusions APT targeting of OPN significantly decreases EMT and tumor growth of HCC.

Bhattacharya, Syamal D; Mi, Zhiyong; Kim, Victoria M.; Guo, Hongtao; Talbot, Lindsay J.; Kuo, Paul C

2011-01-01

266

Irradiation-Dependent Effects on Tumor Perfusion and Endogenous and Exogenous Hypoxia Markers in an A549 Xenograft Model  

Microsoft Academic Search

Purpose: Hypoxia is a major determinant of tumor radiosensitivity, and microenvironmental changes in response to ionizing radiation (IR) are often heterogenous. We analyzed IR-dependent changes in hypoxia and perfusion in A549 human lung adenocarcinoma xenografts. Materials and Methods: Immunohistological analysis of two exogenously added chemical hypoxic markers, pimonidazole and CCI-103F, and of the endogenous marker Glut-1 was performed time dependently

Emmanouil Fokas; Jörg Hänze; Florentine Kamlah; Bastian G. Eul; Nico Lang; Boris Keil; Johannes T. Heverhagen; Rita Engenhart-Cabillic; Hanxiang An; Frank Rose

2010-01-01

267

Combined Bcl-2/mTOR Inhibition Leads to Enhanced Radiosensitization via Induction of Apoptosis and Autophagy in Non-Small-Cell Lung Tumor Xenograft Model  

PubMed Central

Purpose Radiotherapy has a central role in the treatment of non-small-cell lung cancer. Effectiveness of this modality, however, is often limited as resistance results from defects in cell death. Experimental Design We investigated whether simultaneous upregulation of apoptosis, via Bcl-2 inhibitor ABT-737, and autophagy, via mTOR inhibitor rapamycin, can be used to enhance radiosensitivity of H460 cells in vitro and growth delay in a xenograft model. Results In vitro studies confirmed that ABT-737 and rapamycin induce apoptosis and autophagy, respectively. ABT-737 induced cleaved caspase-3, a marker of apoptosis, and rapamycin correlated with an increase in punctate localization of GFP-LC3, characteristic of autophagy. The combination ABT-737/rapamycin markedly enhanced sensitivity of H460 cells to radiation (DER=2.47, p=0.002) in clonogenic assay. In addition, the combination ABT-737/rapamycin/radiation showed a dramatic tumor growth delay in a mouse xenograft model. In vivo immunohistochemistry staining showed that combination therapy yielded over a 100% increase in caspase-3 activity (apoptosis) and a 6-fold decrease in p62 protein level (indicative of autophagic flux) as compared to radiation alone control group. Moreover, cell proliferation (Ki67 staining) was reduced by 77% (p=0.001) and vascular density (vWF staining) by 67.5% (p=0.09) compared to radiation alone. Additional in vitro studies in human umbilical endothelial cells indicated that combined therapy also significantly decrease tubule formation. Conclusion These results suggest that concurrent induction of apoptosis and autophagy enhances radiation therapy both in vitro and in lung cancer xenograft models. Further investigations are warranted to assess the clinical potential of such strategy in lung cancer patients.

Kim, Kwang Woon; Moretti, Luigi; Mitchell, Lauren Rhea; Jung, Dae Kwang; Lu, Bo

2009-01-01

268

Downregulation of matrix metalloprotease-9 and urokinase plasminogen activator by TX-1877 results in decreased tumor growth and metastasis on xenograft model of rectal cancer  

Microsoft Academic Search

Purpose  It is well known that hypoxic milieu is the primary cancer environment. Therefore, tumor hypoxia is considered to be a potential\\u000a therapeutic target. In the present study, we investigated the antitumor and antimetastatic effect of hypoxic cell radiosensitizer,\\u000a TX-1877 on xenograft model of rectal cancer.\\u000a \\u000a \\u000a \\u000a Methods  Nude mice bearing subcutaneously or orthotopically implanted human colon cancer cell lines HCT-116 and HT-29

Kotaro Miyake; Mitsuo Shimada; Masanori Nishioka; Koji Sugimoto; Erdenebulgan Batmunkh; Yoshihiro Uto; Hideko Nagasawa; Hitoshi Hori

2009-01-01

269

Ahsa1 and Hsp90 activity confers more severe craniofacial phenotypes in a zebrafish model of hypoparathyroidism, sensorineural deafness and renal dysplasia (HDR).  

PubMed

The severity of most human birth defects is highly variable. Our ability to diagnose, treat and prevent defects relies on our understanding of this variability. Mutation of the transcription factor GATA3 in humans causes the highly variable hypoparathyroidism, sensorineural deafness and renal dysplasia (HDR) syndrome. Although named for a triad of defects, individuals with HDR can also exhibit craniofacial defects. Through a forward genetic screen for craniofacial mutants, we isolated a zebrafish mutant in which the first cysteine of the second zinc finger of Gata3 is mutated. Because mutation of the homologous cysteine causes HDR in humans, these zebrafish mutants could be a quick and effective animal model for understanding the role of gata3 in the HDR disease spectrum. We demonstrate that, unexpectedly, the chaperone proteins Ahsa1 and Hsp90 promote severe craniofacial phenotypes in our zebrafish model of HDR syndrome. The strengths of the zebrafish system, including rapid development, genetic tractability and live imaging, make this an important model for variability. PMID:23720234

Sheehan-Rooney, Kelly; Swartz, Mary E; Zhao, Feng; Liu, Dong; Eberhart, Johann K

2013-05-29

270

Ahsa1 and Hsp90 activity confers more severe craniofacial phenotypes in a zebrafish model of hypoparathyroidism, sensorineural deafness and renal dysplasia (HDR)  

PubMed Central

SUMMARY The severity of most human birth defects is highly variable. Our ability to diagnose, treat and prevent defects relies on our understanding of this variability. Mutation of the transcription factor GATA3 in humans causes the highly variable hypoparathyroidism, sensorineural deafness and renal dysplasia (HDR) syndrome. Although named for a triad of defects, individuals with HDR can also exhibit craniofacial defects. Through a forward genetic screen for craniofacial mutants, we isolated a zebrafish mutant in which the first cysteine of the second zinc finger of Gata3 is mutated. Because mutation of the homologous cysteine causes HDR in humans, these zebrafish mutants could be a quick and effective animal model for understanding the role of gata3 in the HDR disease spectrum. We demonstrate that, unexpectedly, the chaperone proteins Ahsa1 and Hsp90 promote severe craniofacial phenotypes in our zebrafish model of HDR syndrome. The strengths of the zebrafish system, including rapid development, genetic tractability and live imaging, make this an important model for variability.

Sheehan-Rooney, Kelly; Swartz, Mary E.; Zhao, Feng; Liu, Dong; Eberhart, Johann K.

2013-01-01

271

Zebrafish Thrombocytes: Functions and Origins  

PubMed Central

Platelets play an important role in mammalian hemostasis. Thrombocytes of early vertebrates are functionally equivalent to mammalian platelets. A substantial amount of research has been done to study platelet function in humans as well as in animal models. However, to date only limited functional genomic studies of platelets have been performed but are low throughput and are not cost-effective. Keeping this in mind we introduced zebrafish, a vertebrate genetic model to study platelet function. We characterized zebrafish thrombocytes and established functional assays study not only their hemostatic function but to also their production. We identified a few genes which play a role in their function and production. Since we introduced the zebrafish model for the study of hemostasis and thrombosis, other groups have adapted this model to study genes that are associated with thrombocyte function and a few novel genes have also been identified. Furthermore, transgenic zebrafish with GFP-tagged thrombocytes have been developed which helped to study the production of thrombocytes and their precursors as well as their functional roles not only in hemostasis but also hematopoiesis. This paper integrates the information available on zebrafish thrombocyte function and its formation.

Khandekar, Gauri; Kim, Seongcheol; Jagadeeswaran, Pudur

2012-01-01

272

Expression of heme oxygenase-1 can determine cardiac xenograft survival  

Microsoft Academic Search

The rejection of concordant xenografts, such as mouse-to-rat cardiac xenografts, is very similar to the delayed rejection of porcine-to-primate discordant xenografts. In concordant models, this type of rejection is prevented by brief complement inhibition by cobra venom factor (CVF) and sustained T-cell immunosuppression by cyclosporin A (CyA) (refs. 7, 8, 9, 10). Mouse hearts that survive indefinitely in rats treated

M. P. Soares; Y. Lin; J. Anrather; E. Csizmadia; K. Takigami; K. Sato; S. T. Grey; R. B. Colvin; A. M. Choi; K. D. Poss; F. H. Bach

1998-01-01

273

The utility of the zebrafish model in conditioned place preference to assess the rewarding effects of drugs.  

PubMed

Substance abuse is a significant public health concern both domestically and worldwide. The persistent use of substances regardless of aversive consequences forces the user to give higher priority to the drug than to normal activities and obligations. The harmful and hazardous use of psychoactive substances can lead to a dependence syndrome. In this regard, the genetic and neurobiological underpinnings of reward-seeking behavior need to be fully understood in order to develop effective pharmacotherapies and other methods of treatment. Animal models are often implemented in preclinical screening for testing the efficacy of novel treatments. Several paradigms exist that model various facets of addiction including sensitization, tolerance, withdrawal, drug seeking, extinction, and relapse. Self-administration and, most notably, conditioned place preference (CPP) are relatively simple tests that serve as indicators of the aforementioned aspects of addiction by means of behavioral quantification. CPP is a commonly used technique to evaluate the motivational effects of compounds and experiences that have been associated with a positive or negative reward, which capitalizes on the basic principles of Pavlovian conditioning. During training, the unconditioned stimulus is consistently paired with a neutral set of environmental stimuli, which obtain, during conditioning, secondary motivational properties that elicit approach behavior in the absence of the unconditioned stimulus. For over 50 years, rodents have been the primary test subjects. However, the zebrafish (Danio rerio) is gaining favor as a valuable model organism in the fields of biology, genetics, and behavioral neuroscience. This paper presents a discussion on the merits, advantages, and limitations of the zebrafish model and its utility in relation to CPP. PMID:23811781

Collier, Adam D; Echevarria, David J

2013-09-01

274

Tumor accumulation of NIR fluorescent PEG-PLA nanoparticles: impact of particle size and human xenograft tumor model.  

PubMed

Cancer therapies are often terminated due to serious side effects of the drugs. The cause is the nonspecific distribution of chemotherapeutic agents to both cancerous and normal cells. Therefore, drug carriers which deliver their toxic cargo specific to cancer cells are needed. Size is one key parameter for the nanoparticle accumulation in tumor tissues. In the present study the influence of the size of biodegradable nanoparticles was investigated in detail, combining in vivo and ex vivo analysis with comprehensive particle size characterizations. Polyethylene glycol-polyesters poly(lactide) block polymers were synthesized and used for the production of three defined, stable, and nontoxic near-infrared (NIR) dye-loaded nanoparticle batches. Size analysis based on asymmetrical field flow field fractionation coupled with multiangle laser light scattering and photon correlation spectroscopy (PCS) revealed narrow size distribution and permitted accurate size evaluations. Furthermore, this study demonstrates the constraints of particle size data only obtained by PCS. By the multispectral analysis of the Maestro in vivo imaging system the in vivo fate of the nanoparticles next to their accumulation in special red fluorescent DsRed2 expressing HT29 xenografts could be followed. This simultaneous imaging in addition to confocal microscopy studies revealed information about the accumulation characteristics of nanoparticles inside the tumor tissues. This knowledge was further combined with extended size-dependent fluorescence imaging studies at two different xenograft tumor types, the HT29 (colorectal carcinoma) and the A2780 (ovarian carcinoma) cell lines. The combination of two different size measurement methods allowed the characterization of the dependence of nanoparticle accumulation in the tumor on even rather small differences in the nanoparticle size. While two nanoparticle batches (111 and 141 nm in diameter) accumulated efficiently in the human xenograft tumor tissue, the slightly bigger nanoparticles (diameter 166 nm) were rapidly eliminated by the liver. PMID:21970766

Schädlich, Andreas; Caysa, Henrike; Mueller, Thomas; Tenambergen, Frederike; Rose, Cornelia; Göpferich, Achim; Kuntsche, Judith; Mäder, Karsten

2011-10-10

275

Decorin Protein Core Affects the Global Gene Expression Profile of the Tumor Microenvironment in a Triple-Negative Orthotopic Breast Carcinoma Xenograft Model  

PubMed Central

Decorin, a member of the small leucine-rich proteoglycan gene family, exists and functions wholly within the tumor microenvironment to suppress tumorigenesis by directly targeting and antagonizing multiple receptor tyrosine kinases, such as the EGFR and Met. This leads to potent and sustained signal attenuation, growth arrest, and angiostasis. We thus sought to evaluate the tumoricidal benefits of systemic decorin on a triple-negative orthotopic breast carcinoma xenograft model. To this end, we employed a novel high-density mixed expression array capable of differentiating and simultaneously measuring gene signatures of both Mus musculus (stromal) and Homo sapiens (epithelial) tissue origins. We found that decorin protein core modulated the differential expression of 374 genes within the stromal compartment of the tumor xenograft. Further, our top gene ontology classes strongly suggests an unexpected and preferential role for decorin protein core to inhibit genes necessary for immunomodulatory responses while simultaneously inducing expression of those possessing cellular adhesion and tumor suppressive gene properties. Rigorous verification of the top scoring candidates led to the discovery of three genes heretofore unlinked to malignant breast cancer that were reproducibly found to be induced in several models of tumor stroma. Collectively, our data provide highly novel and unexpected stromal gene signatures as a direct function of systemic administration of decorin protein core and reveals a fundamental basis of action for decorin to modulate the tumor stroma as a biological mechanism for the ascribed anti-tumorigenic properties.

Owens, Rick T.; Iniguez, Leonardo A.; Purkins, George; Vadigepalli, Rajanikanth; Evans, Barry; Schaefer, Liliana; Peiper, Stephen C.; Wang, Zi-Xuan; Iozzo, Renato V.

2012-01-01

276

Anti-CD45 pretargeted radioimmunotherapy using bismuth-213: high rates of complete remission and long-term survival in a mouse myeloid leukemia xenograft model  

PubMed Central

Pretargeted radioimmunotherapy (PRIT) using an anti-CD45 antibody (Ab)–streptavidin (SA) conjugate and DOTA-biotin labeled with ?-emitting radionuclides has been explored as a strategy to decrease relapse and toxicity. ?-emitting radionuclides exhibit high cytotoxicity coupled with a short path length, potentially increasing the therapeutic index and making them an attractive alternative to ?-emitting radionuclides for patients with acute myeloid leukemia. Accordingly, we have used 213Bi in mice with human leukemia xenografts. Results demonstrated excellent localization of 213Bi-DOTA-biotin to tumors with minimal uptake into normal organs. After 10 minutes, 4.5% ± 1.1% of the injected dose of 213Bi was delivered per gram of tumor. ?-imaging demonstrated uniform radionuclide distribution within tumor tissue 45 minutes after 213Bi-DOTA-biotin injection. Radiation absorbed doses were similar to those observed using a ?-emitting radionuclide (90Y) in the same model. We conducted therapy experiments in a xenograft model using a single-dose of 213Bi-DOTA-biotin given 24 hours after anti-CD45 Ab-SA conjugate. Among mice treated with anti-CD45 Ab-SA conjugate followed by 800 ?Ci of 213Bi- or 90Y-DOTA-biotin, 80% and 20%, respectively, survived leukemia-free for more than 100 days with minimal toxicity. These data suggest that anti-CD45 PRIT using an ?-emitting radionuclide may be highly effective and minimally toxic for treatment of acute myeloid leukemia.

Kenoyer, Aimee L.; Back, Tom; Hamlin, Donald K.; Wilbur, D. Scott; Fisher, Darrell R.; Park, Steven I.; Frayo, Shani; Axtman, Amanda; Orgun, Nural; Orozco, Johnnie; Shenoi, Jaideep; Lin, Yukang; Gopal, Ajay K.; Green, Damian J.; Appelbaum, Frederick R.; Press, Oliver W.

2011-01-01

277

Inhibition of Tumor Growth in a Mouse Xenograft Model by the Humanized Anti-HGF Monoclonal Antibody YYB-101 Produced in a Large-Scale CHO Cell Culture.  

PubMed

The humanized anti-hepatocyte growth factor (HGF) monoclonal antibody (mAb) YYB-101 is a promising therapeutic candidate for treating various cancers. In this study, we developed a bioprocess for large-scale production of YYB-101 and evaluated its therapeutic potential for tumor treatment using a xenograft mouse model. By screening diverse chemically defined basal media formulations and by assessing the effects of various feed supplements and feeding schedules on cell growth and antibody production, we established an optimal medium and feeding method to produce 757 mg/l of YYB-101 in flask cultures, representing a 7.5-fold increase in titer compared with that obtained under non-optimized conditions. The optimal dissolved oxygen concentration for antibody production was 70% pO2. A pH shift from 7.2 to 7.0, rather than controlled pH of either 7.0 or 7.2, resulted in productivity improvement in 5 L and 200 L bioreactors, yielding 737 and 830 mg/ml of YYB-101, respectively. The YYB-101 mAb highly purified by affinity chromatography using a Protein A column and two-step ion exchange chromatography effectively neutralized HGF in a cell-based assay and showed potent tumor suppression activity in a mouse xenograft model established with human glioblastoma cells. PMID:23851271

Song, Seong-Won; Lee, Song-Jae; Kim, Chang-Young; Song, Jae-Kyung; Jung, Eui-Jung; Choi, Yong Bock; Min, Sung-Won; Oh, Jong-Won

2013-09-28

278

Functional activity of the membrane-associated complement inhibitor CD59 in a pig-to-human in vitro model for hyperacute xenograft rejection.  

PubMed Central

Hyperacute rejection triggered by activation of the recipient's complement system represents the major barrier to successful xenotransplantation. Transfer of human membrane-associated complement regulators to donor organs has been suggested as one strategy to interfere with complement-mediated hyperacute xenograft rejection. Pigs are discussed as potential organ donors. We therefore investigated a putative protective function of the membrane-bound complement inhibitor CD59 in a pig-to-human in vitro model of hyperacute xenograft rejection. Aortic porcine endothelial cells were transfected with human CD59 cDNA. Expression of human CD59 was demonstrated by cytofluorimetric and RNA analysis. Removal of CD59 from the cell surface by phosphatidylinositol-specific phospholipase C (PI-PLC) demonstrated its production as a glycosyl phosphatidylinositol (GPI)-anchored protein. Functional activity of the transfected CD59 was tested by a lactate dehydrogenase (LDH) release assay for complement-mediated lysis. Porcine endothelial cells expressing human CD59 were significantly protected from lysis by human serum complement compared with CD59- cells. The protective effect was abolished by preincubating the cells with anti-CD59 antibodies or PI-PLC. We calculated by Scatchard analysis that the established CD59+ cell line expressed a CD59 level comparable to that of human endothelial cells. Our results recommend the production of pigs transgenic for CD59. Images Fig. 3

Heckl-Ostreicher, B; Binder, R; Kirschfink, M

1995-01-01

279

Zebrafish in hematology: sushi or science?  

PubMed Central

After a decade of the “modern era” of zebrafish hematology research, what have been their major contributions to hematology and what challenges does the model face? This review argues that, in hematology, zebrafish have demonstrated their suitability, are proving their utility, have supplied timely and novel discoveries, and are poised for further significant contributions. It presents an overview of the anatomy, physiology, and genetics of zebrafish hematopoiesis underpinning their use in hematology research. Whereas reverse genetic techniques enable functional studies of particular genes of interest, forward genetics remains zebrafish's particular strength. Mutants with diverse and interesting hematopoietic defects are emerging from multiple genetic screens. Some mutants model hereditary blood diseases, occasionally leading to disease genes first; others provide insights into developmental hematology. Models of malignant hematologic disorders provide tools for drug-target and pharmaceutics discovery. Numerous transgenic zebrafish with fluorescently marked blood cells enable live-cell imaging of inflammatory responses and host-pathogen interactions previously inaccessible to direct observation in vivo, revealing unexpected aspects of leukocyte behavior. Zebrafish disease models almost uniquely provide a basis for efficient whole animal chemical library screens for new therapeutics. Despite some limitations and challenges, their successes and discovery potential mean that zebrafish are here to stay in hematology research.

Carradice, Duncan

2008-01-01

280

Discriminating Different Cancer Cells Using a Zebrafish in Vivo Assay  

PubMed Central

Despite the expanded understanding of tumor angiogenesis phenomenon and how it impacts cancer treatment outcomes, we have yet to develop a robust assay that can quickly, easily, and quantitatively measure tumor-induced angiogenesis. Since the zebrafish/tumor xenograft represents an emerging tool in this regard, the present study strives to capitalize on the ease, effectiveness, and the adaptability of this model to quantify tumor angiogenesis. In order to test a range of responses, we chose two different tumorigenic cell lines, the human non-small cell lung carcinoma (H1299) and the mouse lung adenocarcinoma (CL13). Non-tumorigenic 3T3-L1 cells served as negative control. The cells were grafted near to the perivitelline space of the zebrafish embryos and the angiogenic response was analyzed using whole-mount alkaline phosphatase (AP) vessel staining and fluorescence microscopy. Angiogenic activity was scored based on the length and number of the newly formed ectopic vessels and the percentage of embryos with ectopic vessels. At 2 day-post-implantation, we detected a significant increase in the length and number of ectopic vessels with H1299 cell implantation compared to CL13 cell transplantation, both are higher than 3T3-L1 control. We also observed a significantly higher percentage of embryos with ectopic vessels with H1299 and CL13 transplantation compared to the 3T3-L1 control, but this parameter is not as robust and reliable as measuring the length and number of ectopic vessels. Furthermore, the systemic exposure of zebrafish embryos to an anti-angiogenesis drug (PTK 787, inhibitor of vascular endothelial growth factor receptor tyrosine kinase) inhibited tumor-induced angiogenesis, suggesting that the assay can be used to evaluate anti-angiogenic drugs. This study implicates the feasibility of using zebrafish xenotransplantation to perform quantitative measurement of the angiogenic activity of cancer cells which can be further extended to measure cancer cell metastasis. This assay represents not only the useful test for patient diagnosis, but also has the potential for evaluating anti-cancer drugs treatment.

Moshal, Karni S.; Ferri-Lagneau, Karine F.; Haider, Jamil; Pardhanani, Pooja; Leung, TinChung

2011-01-01

281

In vivo Electroporation of Morpholinos into the Adult Zebrafish Retina  

PubMed Central

Many devastating inherited eye diseases result in progressive and irreversible blindness because humans cannot regenerate dying or diseased retinal neurons. In contrast, the adult zebrafish retina possesses the robust ability to spontaneously regenerate any neuronal class that is lost in a variety of different retinal damage models, including retinal puncture, chemical ablation, concentrated high temperature, and intense light treatment 1-8. Our lab extensively characterized regeneration of photoreceptors following constant intense light treatment and inner retinal neurons after intravitreal ouabain injection 2, 5, 9. In all cases, resident Müller glia re-enter the cell cycle to produce neuronal progenitors, which continue to proliferate and migrate to the proper retinal layer, where they differentiate into the deficient neurons. We characterized five different stages during regeneration of the light-damaged retina that were highlighted by specific cellular responses. We identified several differentially expressed genes at each stage of retinal regeneration by mRNA microarray analysis 10. Many of these genes are also critical for ocular development. To test the role of each candidate gene/protein during retinal regeneration, we needed to develop a method to conditionally limit the expression of a candidate protein only at times during regeneration of the adult retina. Morpholino oligos are widely used to study loss of function of specific proteins during the development of zebrafish, Xenopus, chick, mouse, and tumors in human xenografts 11-14. These modified oligos basepair with complementary RNA sequence to either block the splicing or translation of the target RNA. Morpholinos are stable in the cell and can eliminate or "knockdown" protein expression for three to five days 12. Here, we describe a method to efficiently knockdown target protein expression in the adult zebrafish retina. This method employs lissamine-tagged antisense morpholinos that are injected into the vitreous of the adult zebrafish eye. Using electrode forceps, the morpholino is then electroporated into all the cell types of the dorsal and central retina. Lissamine provides the charge on the morpholino for electroporation and can be visualized to assess the presence of the morpholino in the retinal cells. Conditional knockdown in the retina can be used to examine the role of specific proteins at different times during regeneration. Additionally, this approach can be used to study the role of specific proteins in the undamaged retina, in such processes as visual transduction and visual processing in second order neurons.

Thummel, Ryan; Bailey, Travis J.; Hyde, David R.

2011-01-01

282

Current Status of Sperm Cryopreservation in Biomedical Research Fish Models: Zebrafish, Medaka, and Xiphophorus*  

PubMed Central

Aquarium fishes are becoming increasingly important because of their value in biomedical research and the ornamental fish trade, and because many have become threatened or endangered in the wild. This review summarizes the current status of sperm cryopreservation in three fishes widely used in biomedical research: zebrafish, medaka, and live-bearing fishes of the genus Xiphophorus, and will focus on the needs and opportunities for future research and application of cryopreservation in aquarium fish. First, we summarize the basic biological characteristics regarding natural habitat, testis structure, spermatogenesis, sperm morphology, and sperm physiology. Second, we compare protocol development of sperm cryopreservation. Third, we emphasize the importance of artificial fertilization in sperm cryopreservation to evaluate the viability of thawed sperm. We conclude with a look to future research directions for sperm cryopreservation and the application of this technique in aquarium species.

Yang, Huiping; Tiersch, Terrence R.

2009-01-01

283

Evaluation of the anti-inflammatory effect of chalcone and chalcone analogues in a zebrafish model.  

PubMed

The aim of this study was to investigate novel chalcones with potent anti-inflammatory activities in vivo. Chalcone and two chalcone analogues (compound 5 and 9) were evaluated using a caudal fin-wounded transgenic zebrafish line "Tg(mpx:gfp)" to visualize the effect of neutrophil recruitment dynamically. Results showed that treatment with compound 9 not only affected wound-induced neutrophil recruitment, but also affected Mpx enzymatic activity. Moreover, protein expression levels of pro-inflammatory factors (Mpx, NF?B, and TNF?) were also regulated by compound 9. Taken together, our results provide in vivo evidence of the anti-inflammatory effects of synthesized chalcone analogues on wound-induced inflammation. PMID:23385341

Chen, Yau-Hung; Wang, Wei-Hua; Wang, Yun-Hsin; Lin, Zi-Yu; Wen, Chi-Chung; Chern, Ching-Yuh

2013-02-05

284

Navigation by environmental geometry: the use of zebrafish as a model.  

PubMed

Sensitivity to environmental shape in spatial navigation has been found, at both behavioural and neural levels, in virtually every species tested, starting early in development. Moreover, evidence that genetic deletions can cause selective deficits in such navigation behaviours suggests a genetic basis to navigation by environmental geometry. Nevertheless, the geometric computations underlying navigation have not been specified in any species. The present study teases apart the geometric components within the traditionally used rectangular enclosure and finds that zebrafish selectively represent distance and directional relationships between extended boundary surfaces. Similar behavioural results in geometric navigation tasks with human children provide prima facie evidence for similar underlying cognitive computations and open new doors for probing the genetic foundations that give rise to these computations. PMID:23788708

Lee, Sang Ah; Vallortigara, Giorgio; Flore, Michele; Spelke, Elizabeth S; Sovrano, Valeria A

2013-06-20

285

Functional Ginger Extracts from Supercritical Fluid Carbon Dioxide Extraction via In Vitro and In Vivo Assays: Antioxidation, Antimicroorganism, and Mice Xenografts Models  

PubMed Central

Supercritical fluid carbon dioxide extraction technology was developed to gain the active components from a Taiwan native plant, Zingiber officinale (ginger). We studied the biological effects of ginger extracts via multiple assays and demonstrated the biofunctions in each platform. Investigations of ginger extracts indicated antioxidative properties in dose-dependant manners on radical scavenging activities, reducing powers and metal chelating powers. We found that ginger extracts processed moderate scavenging values, middle metal chelating levels, and slight ferric reducing powers. The antibacterial susceptibility of ginger extracts on Staphylococcus aureus, Streptococcus sobrinus, S. mutans, and Escherichia coli was determined with the broth microdilution method technique. The ginger extracts had operative antimicroorganism potentials against both Gram-positive and Gram-negative bacteria. We further discovered the strong inhibitions of ginger extracts on lethal carcinogenic melanoma through in vivo xenograft model. To sum up, the data confirmed the possible applications as medical cosmetology agents, pharmaceutical antibiotics, and food supplements.

Lee, Chih-Chen; Chiou, Li-Yu; Wang, Jheng-Yang; Chou, Sin-You; Lan, John Chi-Wei; Huang, Tsi-Shu; Huang, Kuo-Chuan

2013-01-01

286

Functional Ginger Extracts from Supercritical Fluid Carbon Dioxide Extraction via In Vitro and In Vivo Assays: Antioxidation, Antimicroorganism, and Mice Xenografts Models.  

PubMed

Supercritical fluid carbon dioxide extraction technology was developed to gain the active components from a Taiwan native plant, Zingiber officinale (ginger). We studied the biological effects of ginger extracts via multiple assays and demonstrated the biofunctions in each platform. Investigations of ginger extracts indicated antioxidative properties in dose-dependant manners on radical scavenging activities, reducing powers and metal chelating powers. We found that ginger extracts processed moderate scavenging values, middle metal chelating levels, and slight ferric reducing powers. The antibacterial susceptibility of ginger extracts on Staphylococcus aureus, Streptococcus sobrinus, S. mutans, and Escherichia coli was determined with the broth microdilution method technique. The ginger extracts had operative antimicroorganism potentials against both Gram-positive and Gram-negative bacteria. We further discovered the strong inhibitions of ginger extracts on lethal carcinogenic melanoma through in vivo xenograft model. To sum up, the data confirmed the possible applications as medical cosmetology agents, pharmaceutical antibiotics, and food supplements. PMID:23983624

Lee, Chih-Chen; Chiou, Li-Yu; Wang, Jheng-Yang; Chou, Sin-You; Lan, John Chi-Wei; Huang, Tsi-Shu; Huang, Kuo-Chuan; Wang, Hui-Min

2013-07-29

287

Anti-CD45 Pretargeted Radioimmunotherapy using Bismuth-213: High Rates of Complete Remission and Long-Term Survival in a Mouse Myeloid Leukemia Xenograft Model  

SciTech Connect

Pretargeted radioimmunotherapy (PRIT) using an anti-CD45 antibody (Ab)-streptavidin (SA) conjugate and DOTA-biotin labeled with beta-emitting radionuclides has been explored as a strategy to decrease relapse and toxicity. Alpha-emitting radionuclides exhibit high cytotoxicity coupled with a short path-length, potentially increasing the therapeutic index and making them an attractive alternative to beta-emitting radionuclides for patients with Acute Myeloid Leukemia (AML). Accordingly, we have used 213Bi in mice with human leukemia xenografts. Results demonstrated excellent localization of 213Bi-DOTA-biotin to tumors with minimal uptake into normal organs. After 10 minutes, 4.5 ± 1.1% of the injected dose of 213Bi was delivered per gram of tumor. Alpha imaging demonstrated uniform radionuclide distribution within tumor tissue 45 minutes after 213Bi-DOTA-biotin injection. Radiation absorbed doses were similar to those observed using a beta-emitting radionuclide (90Y) in the same model. We conducted therapy experiments in a xenograft model using a single-dose of 213Bi-DOTA-biotin given 24 hours after anti-CD45 Ab-SA conjugate. Among mice treated with anti-CD45 Ab-SA conjugate followed by 800 ?Ci of 213Bi- or 90Y-DOTA-biotin, 80% and 20%, respectively, survived leukemia-free for >100 days with minimal toxicity. These data suggest that anti-CD45 PRIT using an alpha-emitting radionuclide may be highly effective and minimally toxic for treatment of AML.

Pagel, John M.; Kenoyer, Aimee L.; Back, Tom; Hamlin, Donald K.; Wilbur, D. Scott; Fisher, Darrell R.; Park, Steven I.; Frayo, Shani; Axtman, Amanda; Orgun, Nural; Orozoco, Johnnie; Shenoi, Jaideep; Lin, Yukang; Gopal, Ajay K.; Green, Damian J.; Appelbaum, Frederick R.; Press, Oliver W.

2011-07-21

288

A novel zebrafish model of hyperthermia-induced seizures reveals a role for TRPV4 channels and NMDA-type glutamate receptors  

PubMed Central

Febrile seizures are the most common seizure type in children under the age of five, but mechanisms underlying seizure generation in vivo remain unclear. Animal models to address this issue primarily focus on immature rodents heated indirectly using a controlled water bath or air blower. Here we describe an in vivo model of hyperthermia-induced seizures in larval zebrafish aged 3 to 7 days post-fertilization (dpf). Bath controlled changes in temperature are rapid and reversible in this model. Acute electrographic seizures following transient hyperthermia showed age-dependence, strain independence, and absence of mortality. Electrographic seizures recorded in the larval zebrafish forebrain were blocked by adding antagonists to the transient receptor potential vanilloid (TRPV4) channel or N-methyl-d-aspartate (NMDA) glutamate receptor to the bathing medium. Application of GABA, GABA re-uptake inhibitors, or TRPV1 antagonist had no effect on hyperthermic seizures. Expression of vanilloid channel and glutamate receptor mRNA was confirmed by quantitative PCR analysis at each developmental stage in larval zebrafish. Taken together, our findings suggest a role of heat-activation of TRPV4 channels and enhanced NMDA receptor-mediated glutamatergic transmission in hyperthermia-induced seizures.

Hunt, Robert F.; Hortopan, Gabriela A.; Gillespie, Anna; Baraban, Scott C.

2012-01-01

289

Biodistribution and Safety Assessment of Bladder Cancer Specific Recombinant Oncolytic Adenovirus in Subcutaneous Xenografts Tumor Model in Nude Mice  

PubMed Central

Background The previous works about safety evaluation for constructed bladder tissue specific adenovirus are poorly documented. Thus, we investigated the biodistribution and body toxicity of bladder specific oncolytic adenovirus Ad-PSCAE-UPII-E1A (APU-E1A) and Ad-PSCAE-UPII-E1A-AR (APU-E1A-AR), providing meaningful information prior to embarking on human clinical trials. Materials and Method Conditionally replicate recombinant adenovirus (CRADs) APU-E1A, APU-EIA-AR were constructed with bladder tissue specific Uroplakin II (UP II) promoter to induce the expression of Ad5E1A gene and E1A-AR fusing gene, and PSCAE was inserted at upstream of promoter to enhance the function of promoter. Based on the cytopathic and anti-tumor effect of bladder cancer, these CRADs were intratumorally injected into subcutaneous xenografts tumor in nude mice. We then determined the toxicity through general health and behavioral assessment, hepatic and hematological toxicity evaluation, macroscopic and microscopic postmortem analyses. The spread of the transgene E1A of adenovirus was detected with RT-PCR and Western blot. Virus replication and distribution were examined with APU-LUC administration and Luciferase Assay. Results General assessment and body weight of the animals did not reveal any alteration in general behavior. The hematological alterations of groups which were injected with 5×108 pfu or higher dose (5×109 pfu) of APU-E1A and APU-E1A-AR showed no difference in comparison with PBS group, and only slight increased transaminases in contrast to PBS group at 5×109 pfu of APU-E1A and APU-E1A-AR were observed. E1A transgene did not disseminate to organs outside of xenograft tumor. Virus replication was not detected in other organs beside tumor according to Luciferase Assay. Conclusions Our study showed that recombinant adenovirus APU-E1A-AR and APU-E1A appear safe with 5×107 pfu and 5×108 pfu intratumorally injection in mice, without any discernable effects on general health and behavior.

Wang, Fang; Wang, Zhiping; Tian, Hongwei; Qi, Meijiao; Zhai, Zhenxing; Li, Shuwen; Li, Renju; Zhang, Hongjuan; Wang, Wenyun; Fu, Shenjun; Lu, Jianzhong; Rodriguez, Ronald; Guo, Yinglu; Zhou, Liqun

2012-01-01

290

Biodistribution and pharmacokinetics of a telodendrimer micellar paclitaxel nanoformulation in a mouse xenograft model of ovarian cancer  

PubMed Central

Background A multifunctional telodendrimer-based micelle system was characterized for delivery of imaging and chemotherapy agents to mouse tumor xenografts. Previous optical imaging studies demonstrated qualitatively that these classes of nanoparticles, called nanomicelles, preferentially accumulate at tumor sites in mice. The research reported herein describes the detailed quantitative imaging and biodistribution profiling of nanomicelles loaded with a cargo of paclitaxel. Methods The telodendrimer was covalently labeled with 125I and the nanomicelles were loaded with 14C-paclitaxel, which allowed measurement of pharmacokinetics and biodistribution in the mice using microSPECT/CT imaging and liquid scintillation counting, respectively. Results The radio imaging data showed preferential accumulation of nanomicelles at the tumor site along with a slower clearance rate than paclitaxel formulated in Cremophor EL (Taxol®). Liquid scintillation counting confirmed that 14C-labeled paclitaxel sequestered in nanomicelles had increased uptake by tumor tissue and slower pharmacokinetics than Taxol. Conclusion Overall, the results indicate that nanomicelle-formulated paclitaxel is a potentially superior formulation compared with Taxol in terms of water solubility, pharmacokinetics, and tumor accumulation, and may be clinically useful for both tumor imaging and improved chemotherapy applications.

Xiao, Wenwu; Luo, Juntao; Jain, Teesta; Riggs, John W; Tseng, Harry P; Henderson, Paul T; Cherry, Simon R; Rowland, Douglas; Lam, Kit S

2012-01-01

291

Combination of angiogenesis inhibitors increases the anti-tumor efficacy of photodynamic therapy in a human bladder tumor xenograft model  

NASA Astrophysics Data System (ADS)

Photodynamic therapy (PDT) is a standard treatment for various malignant and non-malignant conditions. Though therapeutic responses are encouraging, recurrences have been noted, as one of the limitations of PDT is treatment-induced hypoxia that triggers angiogenesis. The present study evaluates the use of angiogenic inhibitors Avastin, that targets vascular endothelial growth factor (VEGF) and Erbitux that targets epidermal growth factor receptor (EGFR) with PDT in an in vivo bladder carcinoma xenograft. Tumor bearing mice were assigned to 6 different categories: control, PDT only, Avastin + Erbitux, PDT + Avastin, PDT + Erbitux and PDT + Avastin and Erbitux. Treated and control tumors were monitored for recurrence for up to 90 days. VEGF and EGFR expression was detected in the tumor tissue. Migratory assay was performed to establish the inhibitory effect of the angiogenesis agents. Using confocal laser endomicroscopy, the tumor microvasculature was assessed. Tumors treated with the combination therapy of PDT + inhibitors showed significantly greater response compared to control and PDT only treated group. Combination therapy treated tumors also showed the most post-treatment damage with reduced tumor vasculature. These results demonstrate that the combination of PDT with inhibitors that target different angiogenesis pathways can improve tumor control.

Bhuvaneswari, Ramaswamy; Gan, Yik Yuen; Thong, Patricia S. P.; Chin, William Wei L.; Soo, Khee Chee; Olivo, Malini

2009-06-01

292

Low-dose mistletoe lectin-I reduces melanoma growth and spread in a scid mouse xenograft model  

PubMed Central

This study investigates the effects of mistletoe lectin-I (ML-I) on melanoma growth and spread in vivo. The human melanoma cell line MV3 was xenografted into severe combined immunodeficient mice and vehicle solution or purified ML-I was administered at 30, 150 and 500?ng per kg body weight (20 mice per group) daily. After 19 days, mice were killed, primary tumours (PTs) and lungs were dissected out, and tumour weights, number of lung metastases (LMs), number of tumour-infiltrating dendritic cells (DCs), and apoptosis rates in the melanoma cells and in the DCs were assessed. A 35% reduction of PT weight (P=0.03) and a 55% decrease in number of LMs (P=0.016) were evident for low-dose ML-I (30?ng?kg?1) treatment but not for higher doses. Mistletoe lectin-I increased apoptosis rates in the melanoma cells of PTs at all doses, while no induction of apoptosis was noted in the LMs. Low-dose ML-I significantly increased the number of DCs infiltrating the PTs (P<0.0001) and protected DCs against apoptosis, while higher doses induced apoptosis in the DCs (P<0.01). Our results demonstrate that low-dose ML-I reduced melanoma growth and number of metastases in vivo, primarily due to immunomodulatory effects.

Thies, A; Dautel, P; Meyer, A; Pfuller, U; Schumacher, U

2007-01-01

293

Silencing of APE1 Enhances Sensitivity of Human Hepatocellular Carcinoma Cells to Radiotherapy In Vitro and in a Xenograft Model  

PubMed Central

Resistance to radiotherapy is a key limitation for the treatment of human hepatocellular carcinoma (HCC). To overcome this problem, we investigated the correlation between radioresistance and the human apurinic/apyrimidinic endonuclease (APE1), a bifunctional protein, which plays an important role in DNA repair and redox regulation activity of transcription factors. In the present study, we examined the radiosensitivity profiles of three human HCC cell lines, HepG2, Hep3B, and MHCC97L, using the adenoviral vector Ad5/F35-mediated APE1 siRNA (Ad5/F35-siAPE1). The p53 mutant cell lines MHCC97L showed radioresistance, compared with HepG2 and Hep3B cells. APE1 was strongly expressed in MHCC97L cells and was induced by irradiation in a dose-dependent manner, and Ad5/F35-siAPE1 effectively inhibited irradiation-induced APE1 and p53 expression. Moreover, silencing of APE1 significantly potentiated the growth inhibition and apoptosis induction by irradiation in all tested human HCC cell lines. In addition, Ad5/F35-siAPE1 significantly enhanced inhibition of tumor growth and potentiated cell apoptosis by irradiation both in HepG2 and MHCC97L xenografts. In conclusion, down regulation of APE1 could enhance sensitivity of human HCC cells to radiotherapy in vitro and in vivo.

Cun, Yanping; Dai, Nan; Xiong, Chengjie; Li, Mengxia; Sui, Jiangdong; Qian, Chengyuan; Li, Zheng; Wang, Dong

2013-01-01

294

Thymoquinone Inhibits Tumor Growth and Induces Apoptosis in a Breast Cancer Xenograft Mouse Model: The Role of p38 MAPK and ROS.  

PubMed

Due to narrow therapeutic window of cancer therapeutic agents and the development of resistance against these agents, there is a need to discover novel agents to treat breast cancer. The antitumor activities of thymoquinone (TQ), a compound isolated from Nigella sativa oil, were investigated in breast carcinoma in vitro and in vivo. Cell responses after TQ treatment were assessed by using different assays including MTT assay, annexin V-propidium iodide staining, Mitosox staining and Western blot. The antitumor effect was studied by breast tumor xenograft mouse model, and the tumor tissues were examined by histology and immunohistochemistry. The level of anti-oxidant enzymes/molecules in mouse liver tissues was measured by commercial kits. Here, we show that TQ induced p38 phosphorylation and ROS production in breast cancer cells. These inductions were found to be responsible for TQ's anti-proliferative and pro-apoptotic effects. Moreover, TQ-induced ROS production regulated p38 phosphorylation but not vice versa. TQ treatment was found to suppress the tumor growth and this effect was further enhanced by combination with doxorubicin. TQ also inhibited the protein expression of anti-apoptotic genes, such as XIAP, survivin, Bcl-xL and Bcl-2, in breast cancer cells and breast tumor xenograft. Reduced Ki67 and increased TUNEL staining were observed in TQ-treated tumors. TQ was also found to increase the level of catalase, superoxide dismutase and glutathione in mouse liver tissues. Overall, our results demonstrated that the anti-proliferative and pro-apoptotic effects of TQ in breast cancer are mediated through p38 phosphorylation via ROS generation. PMID:24098377

Woo, Chern Chiuh; Hsu, Annie; Kumar, Alan Prem; Sethi, Gautam; Tan, Kwong Huat Benny

2013-10-02

295

(212)Pb-radioimmunotherapy induces G(2) cell-cycle arrest and delays DNA damage repair in tumor xenografts in a model for disseminated intraperitoneal disease.  

PubMed

In preclinical studies, targeted radioimmunotherapy using (212)Pb-TCMC-trastuzumab as an in vivo generator of the high-energy ?-particle emitting radionuclide (212)Bi is proving an efficacious modality for the treatment of disseminated peritoneal cancers. To elucidate mechanisms associated with this therapy, mice bearing human colon cancer LS-174T intraperitoneal xenografts were treated with (212)Pb-TCMC-trastuzumab and compared with the nonspecific control (212)Pb-TCMC-HuIgG, unlabeled trastuzumab, and HuIgG, as well as untreated controls. (212)Pb-TCMC-trastuzumab treatment induced significantly more apoptosis and DNA double-strand breaks (DSB) at 24 hours. Rad51 protein expression was downregulated, indicating delayed DNA double-strand damage repair compared with (212)Pb-TCMC-HuIgG, the nonspecific control. (212)Pb-TCMC-trastuzumab treatment also caused G(2)-M arrest, depression of the S phase fraction, and depressed DNA synthesis that persisted beyond 120 hours. In contrast, the effects produced by (212)Pb-TCMC-HuIgG seemed to rebound by 120 hours. In addition, (212)Pb-TCMC-trastuzumab treatment delayed open chromatin structure and expression of p21 until 72 hours, suggesting a correlation between induction of p21 protein and modification in chromatin structure of p21 in response to (212)Pb-TCMC-trastuzumab treatment. Taken together, increased DNA DSBs, impaired DNA damage repair, persistent G(2)-M arrest, and chromatin remodeling were associated with (212)Pb-TCMC-trastuzumab treatment and may explain its increased cell killing efficacy in the LS-174T intraperitoneal xenograft model for disseminated intraperitoneal disease. PMID:22238365

Yong, Kwon Joong; Milenic, Diane E; Baidoo, Kwamena E; Brechbiel, Martin W

2012-01-11

296

212Pb-Radioimmunotherapy induces G2 cell cycle arrest and delays DNA damage repair in tumor xenografts in a model for disseminated intraperitoneal disease  

PubMed Central

In pre-clinical studies, targeted radioimmunotherapy using 212Pb-TCMC-trastuzumab as an in vivo generator of the high energy ?-particle emitting radionuclide 212Bi is proving an efficacious modality for the treatment of disseminated peritoneal cancers. To elucidate mechanisms associated with this therapy, mice bearing human colon cancer LS-174T i.p. xenografts were treated with 212Pb-TCMC-trastuzumab and compared to the non-specific control 212Pb-TCMC-HuIgG, unlabeled trastuzumab, and HuIgG, as well as untreated controls. 212Pb-TCMC-trastuzumab treatment induced significantly more apoptosis and DNA double stranded breaks (DSBs) at 24 h. Rad51 protein expression was down-regulated, indicating delayed DNA double strand damage repair compared to 212Pb-TCMC-HuIgG, the non-specific control. 212Pb-TCMC-trastuzumab treatment also caused G2/M arrest, depression of the S phase fraction and depressed DNA synthesis that persisted beyond 120 h. In contrast, the effects produced by 212Pb-TCMC-HuIgG appeared to rebound by 120 h. In addition, 212Pb-TCMC-trastuzumab treatment delayed open chromatin structure and expression of p21 until 72 h, suggesting a correlation between induction of p21 protein and modification in chromatin structure of p21 in response to 212Pb-TCMC-trastuzumab treatment. Taken together, increased DNA DSBs, impaired DNA damage repair, persistent G2/M arrest, and chromatin remodeling were associated with 212Pb-TCMC-trastuzumab treatment and may explain its increased cell killing efficacy in the LS-174T i.p. xenograft model for disseminated intraperitoneal disease.

Yong, Kwon J.; Milenic, Diane E.; Baidoo, Kwamena E.; Brechbiel, Martin W.

2012-01-01

297

Thymoquinone Inhibits Tumor Growth and Induces Apoptosis in a Breast Cancer Xenograft Mouse Model: The Role of p38 MAPK and ROS  

PubMed Central

Due to narrow therapeutic window of cancer therapeutic agents and the development of resistance against these agents, there is a need to discover novel agents to treat breast cancer. The antitumor activities of thymoquinone (TQ), a compound isolated from Nigella sativa oil, were investigated in breast carcinoma in vitro and in vivo. Cell responses after TQ treatment were assessed by using different assays including MTT assay, annexin V-propidium iodide staining, Mitosox staining and Western blot. The antitumor effect was studied by breast tumor xenograft mouse model, and the tumor tissues were examined by histology and immunohistochemistry. The level of anti-oxidant enzymes/molecules in mouse liver tissues was measured by commercial kits. Here, we show that TQ induced p38 phosphorylation and ROS production in breast cancer cells. These inductions were found to be responsible for TQ’s anti-proliferative and pro-apoptotic effects. Moreover, TQ-induced ROS production regulated p38 phosphorylation but not vice versa. TQ treatment was found to suppress the tumor growth and this effect was further enhanced by combination with doxorubicin. TQ also inhibited the protein expression of anti-apoptotic genes, such as XIAP, survivin, Bcl-xL and Bcl-2, in breast cancer cells and breast tumor xenograft. Reduced Ki67 and increased TUNEL staining were observed in TQ-treated tumors. TQ was also found to increase the level of catalase, superoxide dismutase and glutathione in mouse liver tissues. Overall, our results demonstrated that the anti-proliferative and pro-apoptotic effects of TQ in breast cancer are mediated through p38 phosphorylation via ROS generation.

Woo, Chern Chiuh; Hsu, Annie; Kumar, Alan Prem; Sethi, Gautam; Tan, Kwong Huat Benny

2013-01-01

298

River waters induced neurotoxicity in an embryo-larval zebrafish model.  

PubMed

Some investigations have revealed an increased release of psychoactive drugs into the aquatic environments near big cities. However, despite the alert generated by the presence of such neurotoxic compounds, there is a lack of studies evaluating the impact on living organisms. One solution consists in the development of bioassays able to address specific risks, such as neurotoxicity, but on the other hand suitable to assess complex matrices like river samples. The objective of this work was to assess surface water toxicity by means of a zebrafish embryo-larval combined toxicity assay, which is based on a variety of toxicological endpoints, especially those related to neurodevelopment. For such a purpose, we selected the Tagus River in which a previous monitoring study revealed the presence of psychoactive drugs. Results showed that most of the toxicological endpoints evaluated remained unaltered in the exposed embryos, except for the tail length that was larger in the exposed larvae, and the locomotor activity in the 6-day larvae, which was decreased in four groups of exposure (n=5 sampling points). In the absence of systemic toxicity, changes in larval locomotion are indicative of neurotoxicity. This result suggests that the Tagus River can convey neurotoxic compounds at levels that may represent an early and specific threat over the aquatic species of vertebrates, what can have dramatic consequences under the ecological point of view. PMID:22906717

García-Cambero, Jesús Pablo; Catalá, Myriam; Valcárcel, Yolanda

2012-08-18

299

Functional modeling in zebrafish demonstrates that the atrial-fibrillation-associated gene GREM2 regulates cardiac laterality, cardiomyocyte differentiation and atrial rhythm  

PubMed Central

SUMMARY Atrial fibrillation (AF) is the most common cardiac arrhythmia and carries a significant risk of stroke and heart failure. The molecular etiologies of AF are poorly understood, leaving patients with limited therapeutic options. AF has been recognized as an inherited disease in almost 30% of patient cases. However, few genetic loci have been identified and the mechanisms linking genetic variants to AF susceptibility remain unclear. By sequencing 193 probands with lone AF, we identified a Q76E variant within the coding sequence of the bone morphogenetic protein (BMP) antagonist gremlin-2 (GREM2) that increases its inhibitory activity. Functional modeling in zebrafish revealed that, through regulation of BMP signaling, GREM2 is required for cardiac laterality and atrial differentiation during embryonic development. GREM2 overactivity results in slower cardiac contraction rates in zebrafish, and induction of previously identified AF candidate genes encoding connexin-40, sarcolipin and atrial natriuretic peptide in differentiated mouse embryonic stem cells. By live heart imaging in zebrafish overexpressing wild-type or variant GREM2, we found abnormal contraction velocity specifically in atrial cardiomyocytes. These results implicate, for the first time, regulators of BMP signaling in human AF, providing mechanistic insights into the pathogenesis of the disease and identifying potential new therapeutic targets.

Muller, Iris I.; Melville, David B.; Tanwar, Vineeta; Rybski, Witold M.; Mukherjee, Amrita; Shoemaker, M. Benjamin; Wang, Wan-Der; Schoenhard, John A.; Roden, Dan M.; Darbar, Dawood; Knapik, Ela W.; Hatzopoulos, Antonis K.

2013-01-01

300

Irradiation-Dependent Effects on Tumor Perfusion and Endogenous and Exogenous Hypoxia Markers in an A549 Xenograft Model  

SciTech Connect

Purpose: Hypoxia is a major determinant of tumor radiosensitivity, and microenvironmental changes in response to ionizing radiation (IR) are often heterogenous. We analyzed IR-dependent changes in hypoxia and perfusion in A549 human lung adenocarcinoma xenografts. Materials and Methods: Immunohistological analysis of two exogenously added chemical hypoxic markers, pimonidazole and CCI-103F, and of the endogenous marker Glut-1 was performed time dependently after IR. Tumor vessels and apoptosis were analyzed using CD31 and caspase-3 antibodies. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and fluorescent beads (Hoechst 33342) were used to monitor vascular perfusion. Results: CCI-103F signals measuring the fraction of hypoxic areas after IR were significantly decreased by approximately 50% when compared with pimonidazole signals, representing the fraction of hypoxic areas from the same tumors before IR. Interestingly, Glut-1 signals were significantly decreased at early time point (6.5 h) after IR returning to the initial levels at 30.5 h. Vascular density showed no difference between irradiated and control groups, whereas apoptosis was significantly induced at 10.5 h post-IR. DCE-MRI indicated increased perfusion 1 h post-IR. Conclusions: The discrepancy between the hypoxic fractions of CCI-103F and Glut-1 forces us to consider the possibility that both markers reflect different metabolic alterations of tumor microenvironment. The reliability of endogenous markers such as Glut-1 to measure reoxygenation in irradiated tumors needs further consideration. Monitoring tumor microvascular response to IR by DCE-MRI and measuring tumor volume alterations should be encouraged.

Fokas, Emmanouil, E-mail: emmanouil.fokas@yahoo.d [Department of Radiotherapy and Radiation Oncology, Medical Faculty of Philipps University, Marburg (Germany); Haenze, Joerg [Department of Internal Medicine, Justus Liebig University, Giessen (Germany); Kamlah, Florentine [Department of Radiotherapy and Radiation Oncology, Medical Faculty of Philipps University, Marburg (Germany); Eul, Bastian G.; Lang, Nico [Department of Internal Medicine, Justus Liebig University, Giessen (Germany); Keil, Boris; Heverhagen, Johannes T. [Department of Radiology, Medical Faculty of Philipps University, Marburg (Germany); Engenhart-Cabillic, Rita; An Hanxiang [Department of Radiotherapy and Radiation Oncology, Medical Faculty of Philipps University, Marburg (Germany); Rose, Frank, E-mail: rosef@med.uni-marburg.d [Department of Radiotherapy and Radiation Oncology, Medical Faculty of Philipps University, Marburg (Germany)

2010-08-01

301

Increased intratumoral fluorothymidine uptake levels following multikinase inhibitor sorafenib treatment in a human renal cell carcinoma xenograft model  

PubMed Central

An early identification of the tumor response to sorafenib treatment is indispensable for selecting optimal personalized treatment strategies. However, at present, no reliable predictors are clinically available. 18F-fluorothymidine (18F-FLT) positron emission tomography (PET) is used to assess tumor proliferation, since the FLT uptake level reflects thymidine kinase-1 (TK-1) activity. Thus, the present study determined whether FLT was able to evaluate the early tumor response to sorafenib treatment in a human renal cell carcinoma (RCC; A498) xenograft in comparison with the tumor proliferation marker, Ki-67. Mice bearing A498 tumors were assigned to the control and sorafenib-treated groups and the tumor volume was measured every day. [Methyl-3H(N)]-3?-fluoro-3?-deoxythymidine (3H-FLT) was injected 2 h prior to the sacrifice of the mice on days three and seven following the treatment. 3H-FLT autoradiography (ARG) and Ki-67 immunohistochemistry (IHC) were performed using adjacent tumor sections. In the visual assessment, the intratumoral 3H-FLT uptake level diffusely increased following the treatment, while no significant changes were observed in Ki-67 IHC. The intratumoral 3H-FLT uptake levels significantly increased by 2.7- and 2.6-fold on days three and seven following the treatment, while the tumor volume and Ki-67 index did not significantly change. Thus, an increased FLT uptake level was demonstrated following the treatment, which may indicate the suppression of thymidylate synthase (TS) and the compensatory upregulation of TK-1 activity by sorafenib.

MURAKAMI, MASAHIRO; ZHAO, SONGJI; ZHAO, YAN; YU, WENWEN; FATEMA, CHOWDHURY NUSRAT; NISHIJIMA, KEN-ICHI; YAMASAKI, MASAHIRO; TAKIGUCHI, MITSUYOSHI; TAMAKI, NAGARA; KUGE, YUJI

2013-01-01

302

Small Molecule Suppressors of Drosophila Kinesin Deficiency Rescue Motor Axon Development in a Zebrafish Model of Spinal Muscular Atrophy  

PubMed Central

Proximal spinal muscular atrophy (SMA) is the most common inherited motor neuropathy and the leading hereditary cause of infant mortality. Currently there is no effective treatment for the disease, reflecting a need for pharmacologic interventions that restore performance of dysfunctional motor neurons or suppress the consequences of their dysfunction. In a series of assays relevant to motor neuron biology, we explored the activities of a collection of tetrahydroindoles that were reported to alter the metabolism of amyloid precursor protein (APP). In Drosophila larvae the compounds suppressed aberrant larval locomotion due to mutations in the Khc and Klc genes, which respectively encode the heavy and light chains of kinesin-1. A representative compound of this class also suppressed the appearance of axonal swellings (alternatively termed axonal spheroids or neuritic beads) in the segmental nerves of the kinesin-deficient Drosophila larvae. Given the importance of kinesin-dependent transport for extension and maintenance of axons and their growth cones, three members of the class were tested for neurotrophic effects on isolated rat spinal motor neurons. Each compound stimulated neurite outgrowth. In addition, consistent with SMA being an axonopathy of motor neurons, the three axonotrophic compounds rescued motor axon development in a zebrafish model of SMA. The results introduce a collection of small molecules as pharmacologic suppressors of SMA-associated phenotypes and nominate specific members of the collection for development as candidate SMA therapeutics. More generally, the results reinforce the perception of SMA as an axonopathy and suggest novel approaches to treating the disease.

Gassman, Andrew; Hao, Le T.; Bhoite, Leena; Bradford, Chad L.; Chien, Chi-Bin; Beattie, Christine E.; Manfredi, John P.

2013-01-01

303

Modelling of human Wiskott-Aldrich syndrome protein mutants in zebrafish larvae using in vivo live imaging  

PubMed Central

Summary Wiskott–Aldrich syndrome (WAS) and X-linked neutropenia (XLN) are immunodeficiencies in which the function of several haematopoietic cell lineages is perturbed as a result of mutations in the actin regulator WASp. From in vitro cell biology experiments, and biochemical and structural approaches, we know much about the functional domains of WASp and how WASp might regulate the dynamic actin cytoskeleton downstream of activators such as Cdc42, but in vivo experiments are much more challenging. In patients, there is a correlation between clinical disease and genotype, with severe reductions in WASp expression or function associating with complex multilineage immunodeficiency, whereas specific mutations that cause constitutive activation of WASp result in congenital neutropenia. Here, we take advantage of the genetic tractability and translucency of zebrafish larvae to first characterise how a null mutant in zfWASp influences the behaviour of neutrophils and macrophages in response to tissue damage and to clearance of infections. We then use this mutant background to study how leukocyte lineage-specific transgenic replacement with human WASp variants (including normal wild type and point mutations that either fail to bind Cdc42 or cannot be phosphorylated, and a constitutively active mutant equivalent to that seen in XLN patients) alter the capacity for generation of neutrophils, their chemotactic response to wounds and the phagocytic clearance capacity of macrophages. This model provides a unique insight into WASp-related immunodeficiency at both a cellular and whole organism level.

Jones, Rebecca A.; Feng, Yi; Worth, Austen J.; Thrasher, Adrian J.; Burns, Siobhan O.; Martin, Paul

2013-01-01

304

Small molecule suppressors of Drosophila Kinesin deficiency rescue motor axon development in a zebrafish model of spinal muscular atrophy.  

PubMed

Proximal spinal muscular atrophy (SMA) is the most common inherited motor neuropathy and the leading hereditary cause of infant mortality. Currently there is no effective treatment for the disease, reflecting a need for pharmacologic interventions that restore performance of dysfunctional motor neurons or suppress the consequences of their dysfunction. In a series of assays relevant to motor neuron biology, we explored the activities of a collection of tetrahydroindoles that were reported to alter the metabolism of amyloid precursor protein (APP). In Drosophila larvae the compounds suppressed aberrant larval locomotion due to mutations in the Khc and Klc genes, which respectively encode the heavy and light chains of kinesin-1. A representative compound of this class also suppressed the appearance of axonal swellings (alternatively termed axonal spheroids or neuritic beads) in the segmental nerves of the kinesin-deficient Drosophila larvae. Given the importance of kinesin-dependent transport for extension and maintenance of axons and their growth cones, three members of the class were tested for neurotrophic effects on isolated rat spinal motor neurons. Each compound stimulated neurite outgrowth. In addition, consistent with SMA being an axonopathy of motor neurons, the three axonotrophic compounds rescued motor axon development in a zebrafish model of SMA. The results introduce a collection of small molecules as pharmacologic suppressors of SMA-associated phenotypes and nominate specific members of the collection for development as candidate SMA therapeutics. More generally, the results reinforce the perception of SMA as an axonopathy and suggest novel approaches to treating the disease. PMID:24023935

Gassman, Andrew; Hao, Le T; Bhoite, Leena; Bradford, Chad L; Chien, Chi-Bin; Beattie, Christine E; Manfredi, John P

2013-09-04

305

Zebrafish assays of ciliopathies.  

PubMed

In light of the growing list of human disorders associated with their dysfunction, primary cilia have recently come to attention as being important regulators of developmental signaling pathways and downstream processes. These organelles, present on nearly every vertebrate cell type, are highly conserved structures allowing for study across a range of species. Zebrafish, in particular, have emerged as useful organisms in which to explore the consequences of ciliary dysfunction and to model human ciliopathies. Here, we present a range of useful techniques that allow for investigation of various aspects of ciliary function. The described assays capitalize on the hallmark gastrulation defects associated with ciliary defects as well as relative ease of visualization of cilia in whole-mount embryos. Further, we describe our recently developed assay for querying functionality of human gene variants in live developing embryos. Finally, a current catalog of known zebrafish ciliary mutant lines is included. The techniques presented here provide a basic toolkit for in vivo investigation of both the biological and genetic mechanisms underlying a growing class of human diseases. PMID:21951534

Zaghloul, Norann A; Katsanis, Nicholas

2011-01-01

306

Analyzing habituation responses to novelty in zebrafish (Danio rerio).  

PubMed

Analysis of habituation is widely used to characterize animal cognitive phenotypes and their modulation. Although zebrafish (Danio rerio) are increasingly utilized in neurobehavioral research, their habituation responses have not been extensively investigated. Utilizing the novel tank test, we examine intra- and inter-session habituation and demonstrate robust habituation responses in adult zebrafish. Analyzing the intra-session habituation to novelty further, we also show that selected anxiogenic drugs (caffeine, pentylenetetrazole), as well as stress-inducing alarm pheromone, attenuated zebrafish habituation. Some acute anxiolytic agents, such as morphine and ethanol, while predictably reducing zebrafish anxiety, had no effects on habituation. Chronic ethanol and fluoxetine treatments improved intra-session habituation in zebrafish. In general, our study parallels literature on rodent habituation responses to novelty, and reconfirms zebrafish as a promising model for cognitive neurobehavioral research. PMID:20035794

Wong, Keith; Elegante, Marco; Bartels, Brett; Elkhayat, Salem; Tien, David; Roy, Sudipta; Goodspeed, Jason; Suciu, Chris; Tan, Julia; Grimes, Chelsea; Chung, Amanda; Rosenberg, Michael; Gaikwad, Siddharth; Denmark, Ashley; Jackson, Andrew; Kadri, Ferdous; Chung, Kyung Min; Stewart, Adam; Gilder, Tom; Beeson, Esther; Zapolsky, Ivan; Wu, Nadine; Cachat, Jonathan; Kalueff, Allan V

2009-12-23

307

The role of estrogen in the developmental appearance of sensory-motor behaviors in the zebrafish (Danio rerio): the characterization of the "listless" model.  

PubMed

The brain is a steroidogenic organ and is thus dependent on estrogen for many aspects of its development and maintenance in both males and females. The purpose of this study was to develop a model to investigate the effect of estrogen on zebrafish sensory-motor (S-M) maturation through mechanisms found in the central nervous (CNS) and peripheral nervous (PNS) systems. In these experiments the aromatase inhibitor (AI), 4-hydroxy androstenedione (4-OH-A), which blocks estrogen synthesis, was used to diminish estrogen's effects on zebrafish CNS and PNS development. During these various treatments the zebrafish were analyzed for neurological deficits, including tactile response, swimming movements, vestibular behavior, pectoral fin and eye movements. Over a three to five day time period (48-168 h post fertilization), in response to AI treatment, none of these S-M behaviors were developmentally expressed creating a "listless" or non-responding condition. Furthermore, when the AI was removed from the treatment medium the S-M behaviors were fully expressed over a two to three day time period. Most importantly, when estrogen was added at the same time as the AI in a co-treatment paradigm, normal developmental appearance of S-M behaviors was rescued in all neurological parameters measured. Furthermore, the addition of estrogen alone after AI washout accelerated the recovery of the tactile response during the first 24 h of treatment. Treatment of developing zebrafish with the selective estrogen receptor blocker ICI 182,780 mimicked the deficit in S-M behaviors caused by AI treatment. This deficit was overcome by low concentrations of estrogen in a co-treatment paradigm with high ICI levels indicating the possibility of a non-genomic mechanism for estrogen's actions on the developmental expression of these S-M behaviors. Eventually, AI exposed fish died of cardiac arrest 4 to 5 days after the start of treatment; however, AI/estrogen co-treatment allowed for 90-100% survival and the maintenance of normal heart rates during this time period. In conclusion, these studies have demonstrated that the presence of estrogen in the early developing zebrafish embryo is necessary for the proper developmental expression of critical nervous system S-M behaviors necessary for survival, as well as the health of the cardiovascular system. These studies also establish a unique "listless" model for further analysis of estrogen's role in the development of brain, brainstem, and spinal cord circuitry related to the maturation of these behavioral and cardiovascular phenomena. PMID:18586226

Nelson, Bryan P; Henriet, Russ P; Holt, Andrew W; Bopp, Katherine C; Houser, Alexander P; Allgood, Ottie E; Turner, James E

2008-05-28

308

Zebrafish genomics comes of age.  

PubMed

Abstract The ZF-HEALTH/EuFishBiomed workshop on "Genomics and High-throughput Sequencing Technologies with the Zebrafish Model" took place in December 2012 in Cambridge, United Kingdom. The organisers, Fiona Wardle and Ferenc Müller, brought together developmental biologists, geneticists, and bioinformaticians from Europe and the rest of the world to share findings and insights about the latest genomic capabilities and applications in this popular model organism. PMID:23745762

Tan, Haihan; Zsigmond, Aron

2013-06-08

309

Building an asymmetric brain: development of the zebrafish epithalamus  

PubMed Central

The human brain exhibits notable asymmetries. Little is known about these symmetry deviations, however scientists are beginning to understand them by employing the lateralized zebrafish epithalamus as a model. The zebrafish epithalamus consists of the pineal and parapineal organs and paired habenular nuclei located bilaterally to the pineal complex. While zebrafish pineal and parapineal organs arise from a common population of cells, parapineal cells undergo a separate program that allows them to migrate left of the pineal anlage. Studying the processes that lead to brain laterality in zebrafish will allow a better understanding of how human brain laterality is established.

Snelson, Corey D.; Gamse, Joshua T.

2009-01-01

310

Zebrafish screen identifies novel compound with selective toxicity against leukemia  

PubMed Central

To detect targeted antileukemia agents we have designed a novel, high-content in vivo screen using genetically engineered, T-cell reporting zebrafish. We exploited the developmental similarities between normal and malignant T lymphoblasts to screen a small molecule library for activity against immature T cells with a simple visual readout in zebrafish larvae. After screening 26 400 molecules, we identified Lenaldekar (LDK), a compound that eliminates immature T cells in developing zebrafish without affecting the cell cycle in other cell types. LDK is well tolerated in vertebrates and induces long-term remission in adult zebrafish with cMYC-induced T-cell acute lymphoblastic leukemia (T-ALL). LDK causes dephosphorylation of members of the PI3 kinase/AKT/mTOR pathway and delays sensitive cells in late mitosis. Among human cancers, LDK selectively affects survival of hematopoietic malignancy lines and primary leukemias, including therapy-refractory B-ALL and chronic myelogenous leukemia samples, and inhibits growth of human T-ALL xenografts. This work demonstrates the utility of our method using zebrafish for antineoplastic candidate drug identification and suggests a new approach for targeted leukemia therapy. Although our efforts focused on leukemia therapy, this screening approach has broad implications as it can be translated to other cancer types involving malignant degeneration of developmentally arrested cells.

Ridges, Suzanne; Heaton, Will L.; Joshi, Deepa; Choi, Henry; Eiring, Anna; Batchelor, Lance; Choudhry, Priya; Manos, Elizabeth J.; Sofla, Hossein; Sanati, Ali; Welborn, Seth; Agarwal, Archana; Spangrude, Gerald J.; Miles, Rodney R.; Cox, James E.; Frazer, J. Kimble; Deininger, Michael; Balan, Kaveri; Sigman, Matthew; Muschen, Markus; Perova, Tatiana; Johnson, Radia; Montpellier, Bertrand; Guidos, Cynthia J.; Jones, David A.

2012-01-01

311

Zebrafish in The Wild: A Review of Natural History And New Notes from The Field  

Microsoft Academic Search

The zebrafish, Danio rerio, has emerged as a major model organism for biomedical research, yet little is known about its natural history. We review the literature pertaining to the geographic range, biotic and abiotic habitats, and life cycle of the zebrafish. We also report our own field study to document several aspects of zebrafish nat- ural history across sites in

Raymond E. Engeszer; Larissa B. Patterson; Andrew A. Rao; David M. Parichy

2007-01-01

312

Polygenic Sex Determination System in Zebrafish  

PubMed Central

Background Despite the popularity of zebrafish as a research model, its sex determination (SD) mechanism is still unknown. Most cytogenetic studies failed to find dimorphic sex chromosomes and no primary sex determining switch has been identified even though the assembly of zebrafish genome sequence is near to completion and a high resolution genetic map is available. Recent publications suggest that environmental factors within the natural range have minimal impact on sex ratios of zebrafish populations. The primary aim of this study is to find out more about how sex is determined in zebrafish. Methodology/Principal Findings Using classical breeding experiments, we found that sex ratios across families were wide ranging (4.8% to 97.3% males). On the other hand, repeated single pair crossings produced broods of very similar sex ratios, indicating that parental genotypes have a role in the sex ratio of the offspring. Variation among family sex ratios was reduced after selection for breeding pairs with predominantly male or female offspring, another indication that zebrafish sex is regulated genetically. Further examinations by a PCR-based “blind assay" and array comparative genomic hybridization both failed to find universal sex-linked differences between the male and female genomes. Together with the ability to increase the sex bias of lines by selective breeding, these data suggest that zebrafish is unlikely to utilize a chromosomal sex determination (CSD) system. Conclusions/Significance Taken together, our study suggests that zebrafish sex is genetically determined with limited, secondary influences from the environment. As we have not found any sign for CSD in the species, we propose that the zebrafish has a polygenic sex determination system.

Liew, Woei Chang; Bartfai, Richard; Lim, Zijie; Sreenivasan, Rajini; Siegfried, Kellee R.; Orban, Laszlo

2012-01-01

313

Aromatase Inhibitors and Xenograft Studies  

PubMed Central

Aromatase inhibitors (AIs) have become the front-line choice for treatment of ER+ breast cancer. Nevertheless, although patients are responsive initially, they may acquire resistance and become unresponsive to further treatment. In addition, approximately 25% of breast cancers do not express the estrogen receptor (ER?) and consequently, are innately resistant to endocrine therapy. We have investigated the mechanisms associated with this lack of treatment response using xenograft models. We found that in cells and tumors that acquired resistance to the AI letrozole therapy, expression of the ER was reduced whereas growth factor signally was enhanced, including a marked increase in HER2 expression. Treatment with trastuzumab (HER2 antibody) resulted in a significant down-regulation of HER2 and p-MAPK as well as restoration of ER? expression. Thus, when trastuzumab was added to letrozole treatment at the time of tumor progression, there was significantly prolonged tumor suppression compared to trastuzumab or letrozole alone. This suggests that inhibition of both HER2 and ER? signaling pathways are required for overcoming resistance and restoring treatment sensitivity. ER negative tumors are innately resistant to endocrine therapy. Repression of the ER? has been found to be due to epigenetic modifications such as increased methylation and histone deacetylation. We found that entinostat (ENT), a histone deacetylase inhibitor (HDACi), activated not only expression of ER? but also aromatase in MDA-MB-231 ER-negative breast cancer cells, resulting in their ability to respond to estrogen and letrozole. Treatment with ENT in combination with letrozole significantly reduced tumor growth rate in xenografts compared to control tumors (p <0.001). ENT plus letrozole treatment also prevented the colonization and growth of MDA-MB-231 cells in the lung with a significant reduction (p<0.03) in both visible and microscopic foci. These results provide a strong indication for possible use of AIs in combination with HDAC inhibitors for the treatment of ER-negative breast cancer.

Chumsri, Saranya; Sabnis, Gauri J; Howes, Timothy; Brodie, Angela MH

2011-01-01

314

Ontogeny and nutritional control of adipogenesis in zebrafish (Danio rerio)  

PubMed Central

The global obesity epidemic demands an improved understanding of the developmental and environmental factors regulating fat storage. Adipocytes serve as major sites of fat storage and as regulators of energy balance and inflammation. The optical transparency of developing zebrafish provides new opportunities to investigate mechanisms governing adipocyte biology, however zebrafish adipocytes remain uncharacterized. We have developed methods for visualizing zebrafish adipocytes in vivo by labeling neutral lipid droplets with Nile Red. Our results establish that neutral lipid droplets first accumulate in visceral adipocytes during larval stages and increase in number and distribution as zebrafish grow. We show that the cellular anatomy of zebrafish adipocytes is similar to mammalian white adipocytes and identify peroxisome-proliferator activated receptor ? and fatty acid binding protein 11a as markers of the zebrafish adipocyte lineage. By monitoring adipocyte development prior to neutral lipid deposition, we find that the first visceral preadipocytes appear in association with the pancreas shortly after initiation of exogenous nutrition. Zebrafish reared in the absence of food fail to form visceral preadipocytes, indicating that exogenous nutrition is required for adipocyte development. These results reveal homologies between zebrafish and mammalian adipocytes and establish the zebrafish as a new model for adipocyte research.

Flynn, Edward J.; Trent, Chad M.; Rawls, John F.

2009-01-01

315

FR255734, a humanized, Fc-Silent, Anti-CD28 antibody, improves psoriasis in the SCID mouse-psoriasis xenograft model.  

PubMed

In psoriasis, CD28/B7 costimulatory molecules are well characterized. Here, using the severe combined immunodeficient (SCID) mouse-psoriasis xenograft model, we report therapeutic efficacy of a humanized anti-CD28 monoclonal antibody (FR255734; Astellas Pharmaceuticals Inc., Tokyo, Japan). Transplanted psoriasis plaques on the SCID mouse were treated weekly for 4 weeks with intraperitoneal injections of FR255734 at 10, 3, and 1-mg kg(-1) doses. Groups treated with doses of 10 and 3 mg kg(-1) had significant thinning of the epidermis and reduced HLA-DR-positive lymphocytic infiltrates. The length of the rete pegs changed from 415.2+/-59.6 to 231.4+/-40.4 microm (P<0.005) in the 10-mg kg(-1) group, and from 323.4+/-69.6 to 237.5+/-73.6 microm in the 3-mg kg(-1) group (P=0.002). Positive controls treated with CTLA4-Ig and cyclosporine had significant histological improvement, whereas plaques treated with saline and isotype controls (human and mouse IgG2) remained unchanged. In vitro studies have shown that FR255734 effectively blocked T-cell proliferation and proinflammatory cytokine production. These observations warrant studies to evaluate the efficacy of FR255734 in human autoimmune diseases. PMID:18337836

Raychaudhuri, Siba P; Kundu-Raychaudhuri, Smriti; Tamura, Kouichi; Masunaga, Taro; Kubo, Kaori; Hanaoka, Kaori; Jiang, Wen-Yue; Herzenberg, Leonore A; Herzenberg, Leonard A

2008-03-13

316

Microtubule-associated protein tau facilitates the targeted killing of proliferating cancer cells in vitro and in a xenograft mouse tumour model in vivo.  

PubMed

Background:Antibody drug conjugates (ADCs) and immunotoxins (ITs) are promising anticancer immunotherapeutics. Despite their encouraging performance in clinical trials, both ADCs and ITs often suffer from disadvantages such as stoichiometrically undefined chemical linkage of the cytotoxic payload (ADCs) and the potential immunogenicity of toxins derived from bacteria and plants (ITs).Methods:Human microtubule-associated protein tau (MAP) was cloned in-frame with human EGF, expressed in E. coli and purified by standard chromatographic methods. The in vitro activity was confirmed by flow cytometry, cell viability assays and tubulin polymerisation assay. The in vivo efficacy was demonstrated using noninvasive far-red in vivo imaging.Results:The EGF-MAP selectively induced apoptosis in EGFR-overexpressing proliferating cancer cells through stabilisation of microtubules. Nonproliferating cells were not affected, demonstrating superior selectivity of EGF-MAP for cancer cells. The EGF-MAP was well tolerated at high doses in mice compared with the ETA'-based control. The in vivo efficacy of EGF-MAP was demonstrated in a tumour xenograft mouse model.Conclusion:Our data indicate the general mechanism of action for a new class of human immunotherapeutic reagents suitable for the treatment of cancer. This approach combines the binding specificity of targeting ligands with the selective cytotoxicity of MAP towards proliferating cells. PMID:23942071

Hristodorov, D; Mladenov, R; Pardo, A; Pham, A-T; Huhn, M; Fischer, R; Thepen, T; Barth, S

2013-08-13

317

Efficacy and toxicity of a CD22-targeted antibody-saporin conjugate in a xenograft model of non-Hodgkin's lymphoma  

PubMed Central

Antibody drug conjugates (ADCs) can deliver potent drugs to cancer cells by employing the specificity of monoclonal antibodies (mAbs). ADCs have demonstrated significant anticancer activity and, in 2011, brentuximab vedotin has been approved by the FDA for the treatment of Hodgkin's and anaplastic large cell lymphomas. CD22 is an ideal target for ADC against B-cell malignancies because of its lineage-specific expression and rapid internalization upon antibody binding. In this study, we evaluated the anti-CD22 mAb HB22.7 as a vehicle for the targeted delivery of the potent toxin saporin (SAP). In vitro, HB22.7-SAP was cytotoxic against a panel of non-Hodgkin's lymphoma (NHL) cell lines representing the most common types of the disease. Moreover, in a xenograft model of NHL, HB22.7-SAP significantly inhibited the growth of established lesions and completely prevented tumor development when treatment was initiated within 24 h from tumor-cell inoculation. HB22.7-SAP had no significant in vivo toxicity. In conclusion, HB22.7 constitutes a potential platform for CD22-targeted ADCs.

Kato, Jason; O'Donnell, Robert T.; Abuhay, Mastewal; Tuscano, Joseph M.

2012-01-01

318

Efficacy and toxicity of a CD22-targeted antibody-saporin conjugate in a xenograft model of non-Hodgkin's lymphoma.  

PubMed

Antibody drug conjugates (ADCs) can deliver potent drugs to cancer cells by employing the specificity of monoclonal antibodies (mAbs). ADCs have demonstrated significant anticancer activity and, in 2011, brentuximab vedotin has been approved by the FDA for the treatment of Hodgkin's and anaplastic large cell lymphomas. CD22 is an ideal target for ADC against B-cell malignancies because of its lineage-specific expression and rapid internalization upon antibody binding. In this study, we evaluated the anti-CD22 mAb HB22.7 as a vehicle for the targeted delivery of the potent toxin saporin (SAP). In vitro, HB22.7-SAP was cytotoxic against a panel of non-Hodgkin's lymphoma (NHL) cell lines representing the most common types of the disease. Moreover, in a xenograft model of NHL, HB22.7-SAP significantly inhibited the growth of established lesions and completely prevented tumor development when treatment was initiated within 24 h from tumor-cell inoculation. HB22.7-SAP had no significant in vivo toxicity. In conclusion, HB22.7 constitutes a potential platform for CD22-targeted ADCs. PMID:23264893

Kato, Jason; O'Donnell, Robert T; Abuhay, Mastewal; Tuscano, Joseph M

2012-12-01

319

Systemic siRNA Delivery via Peptide-Tagged Polymeric Nanoparticles, Targeting PLK1 Gene in a Mouse Xenograft Model of Colorectal Cancer  

PubMed Central

Polymeric nanoparticles were developed from a series of chemical reactions using chitosan, polyethylene glycol, and a cell-targeting peptide (CP15). The nanoparticles were complexed with PLK1-siRNA. The optimal siRNA loading was achieved at an N?:?P ratio of 129.2 yielding a nanoparticle size of >200?nm. These nanoparticles were delivered intraperitoneally and tested for efficient delivery, cytotoxicity, and biodistribution in a mouse xenograft model of colorectal cancer. Both unmodified and modified chitosan nanoparticles showed enhanced accumulation at the tumor site. However, the modified chitosan nanoparticles showed considerably, less distribution in other organs. The relative gene expression as evaluated showed efficient delivery of PLK1-siRNA (0.5?mg/kg) with 50.7 ± 19.5% knockdown (P = 0.031) of PLK1 gene. The in vivo data reveals no systemic toxicity in the animals, when tested for systemic inflammation and liver toxicity. These results indicate a potential of using peptide-tagged nanoparticles for systemic delivery of siRNA at the targeted tumor site.

Malhotra, Meenakshi; Tomaro-Duchesneau, Catherine; Saha, Shyamali; Prakash, Satya

2013-01-01

320

Selective Small Molecule Stat3 Inhibitor Reduces Breast Cancer Tumor-Initiating Cells and Improves Recurrence Free Survival in a Human-Xenograft Model  

PubMed Central

Metastasis and disease relapse are hypothesized to result from tumor initiating cells (TICs). Previously, we have defined a CD44+/CD24?/low mammosphere-forming tumorigenic 493-gene signature in breast cancer. Stat3 was identified as a critical node in self-renewal based on an ongoing lentiviral shRNA screen being conducted in two breast cancer cell lines SUM159 and BT549. In corroborating work, targeting the SH2 domain of Stat3 with a novel small molecule decreased the percentage of cells expressing TIC markers (CD44+/CD24?/low and ALDH+) and mammosphere formation in p-Stat3 overexpressing human breast cancer xenografts in SCID-beige mice. Importantly, we observed a four-fold improvement in the 30-day recurrence-free survival relative to docetaxel alone with the addition of the Stat3 inhibitor in the chemoresistant tumor model. Thus, these findings provide a strong impetus for the development of selective Stat3 inhibitors in order to improve survival in patients with p-Stat3 overexpressing tumors.

Dave, Bhuvanesh; Landis, Melissa D.; Dobrolecki, Lacey E.; Wu, Meng-Fen; Zhang, Xiaomei; Westbrook, Thomas F.; Hilsenbeck, Susan G.; Liu, Dan; Lewis, Michael T.; Tweardy, David J.; Chang, Jenny C.

2012-01-01

321

The utility of fecal corticosterone metabolites and animal welfare assessment protocols as predictive parameters of tumor development and animal welfare in a murine xenograft model.  

PubMed

The aim of the present study was to evaluate the utility of various non-invasive parameters for the prediction of tumor development and animal welfare in a murine xenograft model in male C.B-17 SCID (C.B-Igh-1(b)/IcrTac-Prkdc(scid)) mice. The study showed that body weight, food and water consumption, and an animal welfare assessment (AWA) protocol revealed marked differences between control and cancer lines as the size of the tumor increased. However, only the AWA protocol was effective in predicting the tumor size and the level of fecal corticosterone metabolites (FCM). FCM levels were, however, negatively-correlated to the AWA score, and the tumor size, both when evaluated on a given day and when accumulated over the entire period. In conclusion, the present study demonstrated that body weight and food and water consumption were negatively-affected as tumor developed but only the animal welfare protocol could be used to predict tumor size. PMID:23422477

Jacobsen, Kirsten Rosenmaj; Jørgensen, Pernille; Pipper, Christian Bressen; Steffensen, Astrid Margrethe; Hau, Jann; Abelson, Klas S P

322

Suppression of tumor growth in xenograft model mice by small interfering RNA targeting osteopontin delivery using biocompatible poly(amino ester).  

PubMed

Gene therapy using small interfering RNA (siRNA) is a novel strategy for effective anticancer therapies. However, low gene transfection efficiency and technical difficulties linked to siRNA delivery limit their practical application for gene delivery. Therefore, development of effective siRNA carriers is required. Overexpression of osteopontin (OPN) and its association with tumorigenesis has been reported in a majority of breast cancers. In this study, we used siRNA against OPN (siOPN) and investigated the possible OPN-dependent signaling pathway and the potential use of poly(amino ester) (PAE) based on glycerol propoxylate triacrylate (GPT) and spermine (SPE) for siRNA delivery. The GPT-SPE could effectively condense siRNA and protect the siRNA from RNaseA enzyme degradation. GPT-SPE/siRNA complexes showed good intracellular uptake and high gene silencing efficiency in vitro. Furthermore, in the breast cancer xenograft model, intratumoral injection of GPT-SPE/siOPN significantly inhibited tumor growth. These results demonstrated that silencing of OPN effectively suppressed the growth of breast cancer cells and further suggested that delivery of siRNA using GPT-SPE may act as an effective gene carrier for cancer therapy. PMID:22531848

Minai-Tehrani, Arash; Jiang, Hu-Lin; Kim, You-Kyoung; Chung, Youn-Sun; Yu, Kyeong-Nam; Kim, Ji-Eun; Shin, Ji-Young; Hong, Seong-Ho; Lee, Jae-Ho; Kim, Hye-Joon; Chang, Seung-Hee; Park, Sungjin; Kang, Bit Na; Cho, Chong-Su; Cho, Myung-Haing

2012-04-15

323

Designing Zebrafish Chemical Screens  

Microsoft Academic Search

The zebrafish is proving to be highly amenable to in vivo small molecule screening. With a growing number of screens successfully completed, a rich interface is being created between disciplines that have historically used zebrafish (e.g., embryology and genetics) and disciplines focused on small molecules (e.g., chemistry and pharmacology). Navigating this interface requires consideration of the unique demands of conducting

Randall T. Peterson; Mark C. Fishman

2011-01-01

324

Transgenic zebrafish model to study translational control mediated by upstream open reading frame of human chop gene.  

PubMed

Upstream open reading frame (uORF)-mediated translational inhibition is important in controlling key regulatory genes expression. However, understanding the underlying molecular mechanism of such uORF-mediated control system in vivo is challenging in the absence of an animal model. Therefore, we generated a zebrafish transgenic line, termed huORFZ, harboring a construct in which the uORF sequence from human CCAAT/enhancer-binding protein homologous protein gene (huORF(chop)) is added to the leader of GFP and is driven by a cytomegalovirus promoter. The translation of transgenic huORF(chop)-gfp mRNA was absolutely inhibited by the huORF(chop) cassette in huORFZ embryos during normal conditions, but the downstream GFP was only apparent when the huORFZ embryos were treated with endoplasmic reticulum (ER) stresses. Interestingly, the number and location of GFP-responsive embryonic cells were dependent on the developmental stage and type of ER stresses encountered. These results indicate that the translation of the huORF(chop)-tag downstream reporter gene is controlled in the huORFZ line. Moreover, using cell sorting and microarray analysis of huORFZ embryos, we identified such putative factors as Nrg/ErbB, PI3K and hsp90, which are involved in huORF(chop)-mediated translational control under heat-shock stress. Therefore, using the huORFZ embryos allows us to study the regulatory network involved in human uORF(chop)-mediated translational inhibition. PMID:21873270

Lee, Hung-Chieh; Chen, Yi-Jiun; Liu, Yu-Wei; Lin, Kai-Yen; Chen, Shaio-Wen; Lin, Cheng-Yung; Lu, Yi-Chin; Hsu, Pei-Chun; Lee, Sheng-Chung; Tsai, Huai-Jen

2011-08-25

325

Developmental effects of simulated microgravity on zebrafish, (Danio rerio)  

Microsoft Academic Search

Zebrafish are widely used model vertebrates in research and recently this species has been used to study the effects of microgravity on fundamental biological processes. In this study we used a NASA-designed rotating wall vessel (RWV) to investigate the effects of simulated microgravity (SMG) on zebrafish development up to 14 days post fertilization (dpf). At developmental stages beyond the 3-4

Matthew Stoyek; Sara Edsall; Tamara Franz-Odendaal; Frank Smith; Roger Croll

2010-01-01

326

Cell cultures from zebrafish embryos and adult tissues  

Microsoft Academic Search

Summary The zebrafish is increasingly popular as a nonmammalian model for studies of vertebrate developmental biology, genetics, and toxicology. The availability of cell culture systems makes it possible to address many basic questions using in vitro approaches. Here we describe materials and procedures for initiating cell cultures from zebrafish early (blastula- and gastrula-stage) diploid and haploid embryos and adult tissues

C. Samuel Bradford; Le Sun; Paul Collodi; David W. Barnes

1994-01-01

327

Fgf21 is essential for haematopoiesis in zebrafish  

Microsoft Academic Search

Fibroblast growth factors (Fgfs) function as key secreted signalling molecules in many developmental events. The zebrafish is a powerful model system for the investigation of embryonic vertebrate haematopoiesis. Although the effects of Fgf signalling on haematopoiesis in vitro have been reported, the functions of Fgf signalling in haematopoiesis in vivo remain to be explained. We identified Fgf21 in zebrafish embryos.

Hajime Yamauchi; Yuhei Hotta; Morichika Konishi; Ayumi Miyake; Atsuo Kawahara; Nobuyuki Itoh

2006-01-01

328

The social zebrafish: Behavioral responses to conspecific, heterospecific, and computer animated fish  

PubMed Central

Zebrafish has been in the forefront of developmental biology and genetics, but only recently has interest in their behavior increased. Zebrafish are small and prolific, which lends this species to high throughput screening applications. A typical feature of zebrafish is its propensity to aggregate in groups, a behavior known as shoaling. Thus zebrafish has been proposed as a possible model organism appropriate for the analysis of the genetics of vertebrate social behavior. However, shoaling behavior is not well characterized in zebrafish. Here, using a recently developed software application, we first investigate how zebrafish respond to conspecific and heterospecific fish species that differ in coloration and/or shoaling tendencies. We found that zebrafish shoaled with their own species but not with two heterospecific species, one of which was a shoaling the other a non-shoaling species. In addition, we have started the analysis of visual stimuli that zebrafish may utilize to determine whether to shoal with a fish or not. We systematically modified the color, the location, the pattern, and the body shape of computer animated zebrafish images and presented them to experimental zebrafish. The subjects responded differentially to some of these stimuli showing preference for yellow and avoidance of elongated zebrafish images. Our results suggest that computerized stimulus presentation and automated behavioral quantification of zebrafish responses are feasible, which in turn implies that high throughput forward genetic mutation or drug screening will be possible in the analysis of social behavior with this model organism.

Saverino, Cristina; Gerlai, Robert

2008-01-01

329

Stressing Zebrafish for Behavioral Genetics  

PubMed Central

Synopsis The stress response is a normal reaction to a real or perceived threat. However, stress response systems that are overwhelmed or out of balance can increase both the incidence and severity of diseases including addiction and mood and anxiety disorders. Using an animal model with both genetic diversity and large family size can help discover the specific genetic and environmental contributions to these behavioral diseases. The stress response has been studied extensively in teleosts because of their importance in food production. The zebrafish (Danio rerio) is a major model organism with a strong record for use in developmental biology, genetic screening, and genomic studies. More recently, the stress response of larval and adult zebrafish has been documented. High-throughput automated tracking systems make possible behavioral readouts of the stress response in zebrafish. This non-invasive measure of the stress response can be combined with mutagenesis methods to dissect the genes involved in complex stress response behaviors in vertebrates. Understanding the genetic and epigenetic basis for the stress response in vertebrates will help to develop advanced screening and therapies for stress-aggravated diseases like addiction and mood and anxiety disorders.

Clark, Karl J.; Boczek, Nicole J.; Ekker, Stephen C.

2012-01-01

330

Forebrain electrophysiological recording in larval zebrafish.  

PubMed

Epilepsy affects nearly 3 million people in the United States and up to 50 million people worldwide. Defined as the occurrence of spontaneous unprovoked seizures, epilepsy can be acquired as a result of an insult to the brain or a genetic mutation. Efforts to model seizures in animals have primarily utilized acquired insults (convulsant drugs, stimulation or brain injury) and genetic manipulations (antisense knockdown, homologous recombination or transgenesis) in rodents. Zebrafish are a vertebrate model system that could provide a valuable alternative to rodent-based epilepsy research. Zebrafish are used extensively in the study of vertebrate genetics or development, exhibit a high degree of genetic similarity to mammals and express homologs for ~85% of known human single-gene epilepsy mutations. Because of their small size (4-6 mm in length), zebrafish larvae can be maintained in fluid volumes as low as 100 ?l during early development and arrayed in multi-well plates. Reagents can be added directly to the solution in which embryos develop, simplifying drug administration and enabling rapid in vivo screening of test compounds. Synthetic oligonucleotides (morpholinos), mutagenesis, zinc finger nuclease and transgenic approaches can be used to rapidly generate gene knockdown or mutation in zebrafish. These properties afford zebrafish studies an unprecedented statistical power analysis advantage over rodents in the study of neurological disorders such as epilepsy. Because the "gold standard" for epilepsy research is to monitor and analyze the abnormal electrical discharges that originate in a central brain structure (i.e., seizures), a method to efficiently record brain activity in larval zebrafish is described here. This method is an adaptation of conventional extracellular recording techniques and allows for stable long-term monitoring of brain activity in intact zebrafish larvae. Sample recordings are shown for acute seizures induced by bath application of convulsant drugs and spontaneous seizures recorded in a genetically modified fish. PMID:23380808

Baraban, Scott C

2013-01-24

331

Examination of a Palatogenic Gene Program in Zebrafish  

PubMed Central

Human palatal clefting is debilitating and difficult to rectify surgically. Animal models enhance our understanding of palatogenesis and are essential in strategies designed to ameliorate palatal malformations in humans. Recent studies have shown that the zebrafish palate, or anterior neurocranium, is under similar genetic control to the amniote palatal skeleton. We extensively analyzed palatogenesis in zebrafish to determine the similarity of gene expression and function across vertebrates. By 36 hpf palatogenic cranial neural crest cells reside in homologous regions of the developing face compared to amniote species. Transcription factors and signaling molecules regulating mouse palatogenesis are expressed in similar domains during palatogenesis in zebrafish. Functional investigation of a subset of these genes, fgf10a, tgfb2, pax9 and smad5 revealed their necessity in zebrafish palatogenesis. Collectively, these results suggest that the gene regulatory networks regulating palatogenesis may be conserved across vertebrate species, demonstrating the utility of zebrafish as a model for palatogenesis.

Swartz, Mary E.; Sheehan-Rooney, Kelly; Dixon, Michael J.; Eberhart, Johann K.

2011-01-01

332

Preclinical Activity of the Type II CD20 Antibody GA101 (Obinutuzumab) Compared with Rituximab and Ofatumumab In Vitro and in Xenograft Models.  

PubMed

We report the first preclinical in vitro and in vivo comparison of GA101 (obinutuzumab), a novel glycoengineered type II CD20 monoclonal antibody, with rituximab and ofatumumab, the two currently approved type I CD20 antibodies. The three antibodies were compared in assays measuring direct cell death (AnnexinV/PI staining and time-lapse microscopy), complement-dependent cytotoxicity (CDC), antibody-dependent cell-mediated cytotoxicity (ADCC), antibody-dependent cell-mediated phagocytosis (ADCP), and internalization. The models used for the comparison of their activity in vivo were SU-DHL4 and RL xenografts. GA101 was found to be superior to rituximab and ofatumumab in the induction of direct cell death (independent of mechanical manipulation required for cell aggregate disruption formed by antibody treatment), whereas it was 10 to 1,000 times less potent in mediating CDC. GA101 showed superior activity to rituximab and ofatumumab in ADCC and whole-blood B-cell depletion assays, and was comparable with these two in ADCP. GA101 also showed slower internalization rate upon binding to CD20 than rituximab and ofatumumab. In vivo, GA101 induced a strong antitumor effect, including complete tumor remission in the SU-DHL4 model and overall superior efficacy compared with both rituximab and ofatumumab. When rituximab-pretreated animals were used, second-line treatment with GA101 was still able to control tumor progression, whereas tumors escaped rituximab treatment. Taken together, the preclinical data show that the glyoengineered type II CD20 antibody GA101 is differentiated from the two approved type I CD20 antibodies rituximab and ofatumumab by its overall preclinical activity, further supporting its clinical investigation. Mol Cancer Ther; 12(10); 2031-42. ©2013 AACR. PMID:23873847

Herter, Sylvia; Herting, Frank; Mundigl, Olaf; Waldhauer, Inja; Weinzierl, Tina; Fauti, Tanja; Muth, Gunter; Ziegler-Landesberger, Doris; Van Puijenbroek, Erwin; Lang, Sabine; Duong, Minh Ngoc; Reslan, Lina; Gerdes, Christian A; Friess, Thomas; Baer, Ute; Burtscher, Helmut; Weidner, Michael; Dumontet, Charles; Umana, Pablo; Niederfellner, Gerhard; Bacac, Marina; Klein, Christian

2013-07-19

333

Harnessing Autopsied DIPG Tumor Tissues for Orthotopic Xenograft Model Development in the Brain Stems of SCID Mice.  

National Technical Information Service (NTIS)

Diffuse intrinsic pontine glioma (DIPG) remains the most lethal childhood cancer. The slow progress in biological study and preclinical drug development is caused by the lack of fresh tumor tissues and clinically relevant animal models. The objective of o...

X. Li

2012-01-01

334

Pharmacokinetic Modeling of an Induction Regimen for In Vivo Combined Testing of Novel Drugs against Pediatric Acute Lymphoblastic Leukemia Xenografts  

Microsoft Academic Search

Current regimens for induction therapy of pediatric acute lymphoblastic leukemia (ALL), or for re-induction post relapse, use a combination of vincristine (VCR), a glucocorticoid, and l-asparaginase (ASP) with or without an anthracycline. With cure rates now approximately 80%, robust pre-clinical models are necessary to prioritize active new drugs for clinical trials in relapsed\\/refractory patients, and the ability of these models

Barbara Szymanska; Urszula Wilczynska-Kalak; Min H. Kang; Natalia L. M. Liem; Hernan Carol; Ingrid Boehm; Daniel Groepper; C. Patrick Reynolds; Clinton F. Stewart; Richard B. Lock

2012-01-01

335

Successful high-resolution animal positron emission tomography of human Ewing tumours and their metastases in a murine xenograft model  

Microsoft Academic Search

Purpose  As primary osseous metastasis is the main adverse prognostic factor in patients with Ewing tumours, a NOD\\/scid mouse model for human Ewing tumour metastases has been established to examine the mechanisms of metastasis. The aim of this\\u000a study was to evaluate the feasibility of diagnostic molecular imaging by small animal PET in this mouse model.\\u000a \\u000a \\u000a \\u000a Methods  Human Ewing tumour cells were

Christiane Franzius; Marc Hotfilder; Christopher Poremba; Sven Hermann; Klaus Schäfers; Helmut Erich Gabbert; Heribert Jürgens; Otmar Schober; Michael Schäfers; Josef Vormoor

2006-01-01

336

Characterization of behavioral and endocrine effects of LSD on zebrafish.  

PubMed

Lysergic acid diethylamide (LSD) is a potent hallucinogenic drug that strongly affects animal and human behavior. Although adult zebrafish (Danio rerio) are emerging as a promising neurobehavioral model, the effects of LSD on zebrafish have not been investigated previously. Several behavioral paradigms (the novel tank, observation cylinder, light-dark box, open field, T-maze, social preference and shoaling tests), as well as modern video-tracking tools and whole-body cortisol assay were used to characterize the effects of acute LSD in zebrafish. While lower doses (5-100 microg/L) did not affect zebrafish behavior, 250 microg/L LSD increased top dwelling and reduced freezing in the novel tank and observation cylinder tests, also affecting spatiotemporal patterns of activity (as assessed by 3D reconstruction of zebrafish traces and ethograms). LSD evoked mild thigmotaxis in the open field test, increased light behavior in the light-dark test, reduced the number of arm entries and freezing in the T-maze and social preference test, without affecting social preference. In contrast, LSD affected zebrafish shoaling (increasing the inter-fish distance in a group), and elevated whole-body cortisol levels. Overall, our findings show sensitivity of zebrafish to LSD action, and support the use of zebrafish models to study hallucinogenic drugs of abuse. PMID:20561961

Grossman, Leah; Utterback, Eli; Stewart, Adam; Gaikwad, Siddharth; Chung, Kyung Min; Suciu, Christopher; Wong, Keith; Elegante, Marco; Elkhayat, Salem; Tan, Julia; Gilder, Thomas; Wu, Nadine; Dileo, John; Cachat, Jonathan; Kalueff, Allan V

2010-06-01

337

Regular care and maintenance of a zebrafish (Danio rerio) laboratory: an introduction.  

PubMed

This protocol describes regular care and maintenance of a zebrafish laboratory. Zebrafish are now gaining popularity in genetics, pharmacological and behavioural research. As a vertebrate, zebrafish share considerable genetic sequence similarity with humans and are being used as an animal model for various human disease conditions. The advantages of zebrafish in comparison to other common vertebrate models include high fecundity, low maintenance cost, transparent embryos, and rapid development. Due to the spur of interest in zebrafish research, the need to establish and maintain a productive zebrafish housing facility is also increasing. Although literature is available for the maintenance of a zebrafish laboratory, a concise video protocol is lacking. This video illustrates the protocol for regular housing, feeding, breeding and raising of zebrafish larvae. This process will help researchers to understand the natural behaviour and optimal conditions of zebrafish husbandry and hence troubleshoot experimental issues that originate from the fish husbandry conditions. This protocol will be of immense help to researchers planning to establish a zebrafish laboratory, and also to graduate students who are intending to use zebrafish as an animal model. PMID:23183629

Avdesh, Avdesh; Chen, Mengqi; Martin-Iverson, Mathew T; Mondal, Alinda; Ong, Daniel; Rainey-Smith, Stephanie; Taddei, Kevin; Lardelli, Michael; Groth, David M; Verdile, Giuseppe; Martins, Ralph N

2012-11-18

338

FXR Controls the Tumor Suppressor NDRG2 and FXR Agonists Reduce Liver Tumor Growth and Metastasis in an Orthotopic Mouse Xenograft Model  

PubMed Central

The farnesoid X receptor (FXR) is expressed predominantly in tissues exposed to high levels of bile acids and controls bile acid and lipid homeostasis. FXR?/? mice develop hepatocellular carcinoma (HCC) and show an increased prevalence for intestinal malignancies, suggesting a role of FXR as a tumor suppressor in enterohepatic tissues. The N-myc downstream-regulated gene 2 (NDRG2) has been recognized as a tumor suppressor gene, which is downregulated in human hepatocellular carcinoma, colorectal carcinoma and many other malignancies. We show reduced NDRG2 mRNA in livers of FXR?/? mice compared to wild type mice and both, FXR and NDRG2 mRNAs, are reduced in human HCC compared to normal liver. Gene reporter assays and Chromatin Immunoprecipitation data support that FXR directly controls NDRG2 transcription via IR1-type element(s) identified in the first introns of the human, mouse and rat NDRG2 genes. NDRG2 mRNA was induced by non-steroidal FXR agonists in livers of mice and the magnitude of induction of NDRG2 mRNA in three different human hepatoma cell lines was increased when ectopically expressing human FXR. Growth and metastasis of SK-Hep-1 cells was strongly reduced by non-steroidal FXR agonists in an orthotopic liver xenograft tumor model. Ectopic expression of FXR in SK-Hep1 cells reduced tumor growth and metastasis potential of corresponding cells and increased the anti-tumor efficacy of FXR agonists, which may be partly mediated via increased NDRG2 expression. FXR agonists may show a potential in the prevention and/or treatment of human hepatocellular carcinoma, a devastating malignancy with increasing prevalence and limited therapeutic options.

Deuschle, Ulrich; Schuler, Julia; Schulz, Andreas; Schluter, Thomas; Kinzel, Olaf; Abel, Ulrich; Kremoser, Claus

2012-01-01

339

Dependence of Wilms tumor cells on signaling through insulin-like growth factor 1 in an orthotopic xenograft model targetable by specific receptor inhibition.  

PubMed

We have previously demonstrated an increased DNA copy number and expression of IGF1R to be associated with poor outcome in Wilms tumors. We have now tested whether inhibiting this receptor may be a useful therapeutic strategy by using a panel of Wilms tumor cell lines. Both genetic and pharmacological targeting resulted in inhibition of downstream signaling through PI3 and MAP kinases, G(1) cell cycle arrest, and cell death, with drug efficacy dependent on the levels of phosphorylated IGF1R. These effects were further associated with specific gene expression signatures reflecting pathway inhibition, and conferred synergistic chemosensitisation to doxorubicin and topotecan. In the in vivo setting, s.c. xenografts of WiT49 cells resembled malignant rhabdoid tumors rather than Wilms tumors. Treatment with an IGF1R inhibitor (NVP-AEW541) showed no discernable antitumor activity and no downstream pathway inactivation. By contrast, Wilms tumor cells established orthotopically within the kidney were histologically accurate and exhibited significantly elevated insulin-like growth factor-mediated signaling, and growth was significantly reduced on treatment with NVP-AEW541 in parallel with signaling pathway ablation. As a result of the paracrine effects of enhanced IGF2 expression in Wilms tumor, this disease may be acutely dependent on signaling through the IGF1 receptor, and thus treatment strategies aimed at its inhibition may be useful in the clinic. Such efficacy may be missed if only standard ectopic models are considered as a result of an imperfect recapitulation of the specific tumor microenvironment. PMID:22529373

Bielen, Aleksandra; Box, Gary; Perryman, Lara; Bjerke, Lynn; Popov, Sergey; Jamin, Yann; Jury, Alexa; Valenti, Melanie; Brandon, Alexis de Haven; Martins, Vanessa; Romanet, Vincent; Jeay, Sebastien; Raynaud, Florence I; Hofmann, Francesco; Robinson, Simon P; Eccles, Suzanne A; Jones, Chris

2012-04-23

340

FXR controls the tumor suppressor NDRG2 and FXR agonists reduce liver tumor growth and metastasis in an orthotopic mouse xenograft model.  

PubMed

The farnesoid X receptor (FXR) is expressed predominantly in tissues exposed to high levels of bile acids and controls bile acid and lipid homeostasis. FXR(-/-) mice develop hepatocellular carcinoma (HCC) and show an increased prevalence for intestinal malignancies, suggesting a role of FXR as a tumor suppressor in enterohepatic tissues. The N-myc downstream-regulated gene 2 (NDRG2) has been recognized as a tumor suppressor gene, which is downregulated in human hepatocellular carcinoma, colorectal carcinoma and many other malignancies.We show reduced NDRG2 mRNA in livers of FXR(-/-) mice compared to wild type mice and both, FXR and NDRG2 mRNAs, are reduced in human HCC compared to normal liver. Gene reporter assays and Chromatin Immunoprecipitation data support that FXR directly controls NDRG2 transcription via IR1-type element(s) identified in the first introns of the human, mouse and rat NDRG2 genes. NDRG2 mRNA was induced by non-steroidal FXR agonists in livers of mice and the magnitude of induction of NDRG2 mRNA in three different human hepatoma cell lines was increased when ectopically expressing human FXR. Growth and metastasis of SK-Hep-1 cells was strongly reduced by non-steroidal FXR agonists in an orthotopic liver xenograft tumor model. Ectopic expression of FXR in SK-Hep1 cells reduced tumor growth and metastasis potential of corresponding cells and increased the anti-tumor efficacy of FXR agonists, which may be partly mediated via increased NDRG2 expression. FXR agonists may show a potential in the prevention and/or treatment of human hepatocellular carcinoma, a devastating malignancy with increasing prevalence and limited therapeutic options. PMID:23056173

Deuschle, Ulrich; Schüler, Julia; Schulz, Andreas; Schlüter, Thomas; Kinzel, Olaf; Abel, Ulrich; Kremoser, Claus

2012-10-09

341

Targeted delivery of a peripheral benzodiazepine receptor ligand-gemcitabine conjugate to brain tumors in a xenograft model  

Microsoft Academic Search

Purpose: Peripheral benzodiazepine receptors (PBRs) are overexpressed in brain tumors compared to normal brain, and could serve as a target to selectively increase anticancer drug delivery through a PBR ligand-drug conjugate system. We have previously synthesized PBR ligand-gemcitabine conjugates based on the model PBR ligand, PK11195. The goal of the current study was to examine this new drug delivery strategy

Ping Guo; Jianguo Ma; Shaolan Li; Zhiwei Guo; Andrea L. Adams; James M. Gallo

2001-01-01

342

Neurogenesis in zebrafish - from embryo to adult  

PubMed Central

Neurogenesis in the developing central nervous system consists of the induction and proliferation of neural progenitor cells and their subsequent differentiation into mature neurons. External as well as internal cues orchestrate neurogenesis in a precise temporal and spatial way. In the last 20 years, the zebrafish has proven to be an excellent model organism to study neurogenesis in the embryo. Recently, this vertebrate has also become a model for the investigation of adult neurogenesis and neural regeneration. Here, we summarize the contributions of zebrafish in neural development and adult neurogenesis.

2013-01-01

343

Myelopoiesis and Myeloid Leukaemogenesis in the Zebrafish  

PubMed Central

Over the past ten years, studies using the zebrafish model have contributed to our understanding of vertebrate haematopoiesis, myelopoiesis, and myeloid leukaemogenesis. Novel insights into the conservation of haematopoietic lineages and improvements in our capacity to identify, isolate, and culture such haematopoietic cells continue to enhance our ability to use this simple organism to address disease biology. Coupled with the strengths of the zebrafish embryo to dissect developmental myelopoiesis and the continually expanding repertoire of models of myeloid malignancies, this versatile organism has established its niche as a valuable tool to address key questions in the field of myelopoiesis and myeloid leukaemogenesis. In this paper, we address the recent advances and future directions in the field of myelopoiesis and leukaemogenesis using the zebrafish system.

Forrester, A. Michael; Berman, Jason N.; Payne, Elspeth M.

2012-01-01

344

Zebrafish cell clocks feel the heat and see the light!  

PubMed

The zebrafish has rapidly become established as one of the most valuable vertebrate models for studying circadian clock function. A major initial attraction was its utility in large-scale genetic screens. It subsequently emerged that most zebrafish cells possess circadian clocks that can be entrained directly by exposure to temperature or light dark cycles, a property shared by several zebrafish cell lines. This is not the case for mammals, where the retina is the primary source of light input to the clock. Furthermore, mammalian cell culture clocks can only be entrained by acute culture treatments such as serum shocks. Thus, the zebrafish is proving invaluable to study light and temperature input to the vertebrate clock. In addition, the accessibility of its early developmental stages has placed the zebrafish at the forefront of studies aimed at understanding how the circadian clock is established during embryogenesis. PMID:18248192

Vallone, Daniela; Lahiri, Kajori; Dickmeis, Thomas; Foulkes, Nicholas S

2005-01-01

345

Development of sensory systems in zebrafish (Danio rerio).  

PubMed

Zebrafish possess all of the classic sensory modalities: taste, tactile, smell, balance, vision, and hearing. For each sensory system, this article provides a brief overview of the system in the adult zebrafish followed by a more detailed overview of the development of the system. By far the majority of studies performed in each of the sensory systems of the zebrafish have involved some aspect of molecular biology or genetics. Although molecular biology and genetics are not major foci of the paper, brief discussions of some of the mutant strains of zebrafish that have developmental defects in each specific sensory system are included. The development of the sensory systems is only a small sampling of the work being done using zebrafish and provides a mere glimpse of the potential of this model for the study of vertebrate development, physiology, and human disease. PMID:11581521

Moorman, S J

2001-01-01

346

Intravenous Microinjections of Zebrafish Larvae to Study Acute Kidney Injury  

PubMed Central

In this video article we describe a zebrafish model of AKI using gentamicin as the nephrotoxicant. The technique consists of intravenous microinjections on 2 dpf zebrafish. This technique represents an efficient and rapid method to deliver soluble substances into the bloodstream of zebrafish larvae, allowing for the injection of 15-20 fish per hour. In addition to AKI studies, this microinjection technique can also be used for other types of experimental studies such as angiography. We provide a detailed protocol of the technique from equipment required to visual measures of decreased kidney function. In addition, we also demonstrate the process of fixation, whole mount immunohistochemistry with a kidney tubule marker, plastic embedding and sectioning of the larval zebrafish. We demonstrate that zebrafish larvae injected with gentamicin show morphological features consistent with AKI: edema, loss of cell polarity in proximal tubular epithelial cells, and morphological disruption of the tubule.

Cianciolo Cosentino, Chiara; Roman, Beth L.; Drummond, Iain A.; Hukriede, Neil A.

2010-01-01

347

Transgenesis in zebrafish with the tol2 transposon system.  

PubMed

The zebrafish (Danio rerio) is a useful model for genetic studies of vertebrate development. Its embryos are transparent and develop rapidly outside the mother, making it feasible to visualize and manipulate specific cell types in the living animal. Zebrafish is well suited for transgenic manipulation since it is relatively easy to collect large numbers of embryos from adult fish. Several approaches have been developed for introducing transgenes into the zebrafish germline, from the injection of naked DNA to transposon-mediated integration. In particular, the Tol2 transposable element has been shown to create insertions in the zebrafish genome very efficiently. By using Tol2, gene trap and enhancer trap vectors containing the GFP reporter gene or yeast transcription activator Gal4 gene have been developed. Here we outline methodology for creating transgenic zebrafish using Tol2 vectors, and their applications to visualization and manipulation of specific tissues or cells in vivo and for functional studies of vertebrate neural circuits. PMID:19504063

Suster, Maximiliano L; Kikuta, Hiroshi; Urasaki, Akihiro; Asakawa, Kazuhide; Kawakami, Koichi

2009-01-01

348

Dissection of the Adult Zebrafish Kidney  

PubMed Central

Researchers working in the burgeoning field of adult stem cell biology seek to understand the signals that regulate the behavior and function of stem cells during normal homeostasis and disease states. The understanding of adult stem cells has broad reaching implications for the future of regenerative medicine1. For example, better knowledge about adult stem cell biology can facilitate the design of therapeutic strategies in which organs are triggered to heal themselves or even the creation of methods for growing organs in vitro that can be transplanted into humans1. The zebrafish has become a powerful animal model for the study of vertebrate cell biology2. There has been extensive documentation and analysis of embryonic development in the zebrafish3. Only recently have scientists sought to document adult anatomy and surgical dissection techniques4, as there has been a progressive movement within the zebrafish community to broaden the applications of this research organism to adult studies. For example, there are expanding interests in using zebrafish to investigate the biology of adult stem cell populations and make sophisticated adult models of diseases such as cancer5. Historically, isolation of the zebrafish adult kidney has been instrumental for studying hematopoiesis, as the kidney is the anatomical location of blood cell production in fish6,7. The kidney is composed of nephron functional units found in arborized arrangements, surrounded by hematopoietic tissue that is dispersed throughout the intervening spaces. The hematopoietic component consists of hematopoietic stem cells (HSCs) and their progeny that inhabit the kidney until they terminally differentiate8. In addition, it is now appreciated that a group of renal stem/progenitor cells (RPCs) also inhabit the zebrafish kidney organ and enable both kidney regeneration and growth, as observed in other fish species9-11. In light of this new discovery, the zebrafish kidney is one organ that houses the location of two exciting opportunities for adult stem cell biology studies. It is clear that many outstanding questions could be well served with this experimental system. To encourage expansion of this field, it is beneficial to document detailed methods of visualizing and then isolating the adult zebrafish kidney organ. This protocol details our procedure for dissection of the adult kidney from both unfixed and fixed animals. Dissection of the kidney organ can be used to isolate and characterize hematopoietic and renal stem cells and their offspring using established techniques such as histology, fluorescence activated cell sorting (FACS)11,12, expression profiling13,14, and transplantation11,15. We hope that dissemination of this protocol will provide researchers with the knowledge to implement broader use of zebrafish studies that ultimately can be translated for human application.

Wingert, Rebecca A.

2011-01-01

349

Control of optical contrast using gold nanoshells for optical coherence tomography imaging of mouse xenograft tumor model in vivo  

NASA Astrophysics Data System (ADS)

The control of image contrast is essential toward optimizing a contrast enhancement procedure in optical coherence tomography (OCT). In this study, the in vivo control of optical contrast in a mouse tumor model with gold nanoshells as a contrast agent is examined. Gold nanoshells are administered into mice, with the injected dosage and particle surface parameters varied and its concentration in the tumor under each condition is determined using a noninvasive theoretical OCT modeling technique. The results show that too high a concentration of gold nanoshells in the tumor only enhances the OCT signal near the tissue surface, while significantly attenuating the signal deeper into the tissue. With an appropriate dosage, IV delivery of gold nanoshells allows a moderate concentration of 6.2×109 particles/ml in tumor to achieve a good OCT signal enhancement with minimal signal attenuation with depth. An increase in the IV dosage of gold nanoshells reveals a corresponding nonlinear increase in their tumor concentration, as well as a nonlinear reduction in the fractional concentration of injected gold nanoshells. Furthermore, this fractional concentration is improved with the use of antiepodermal growth factor receptor (EGFR) surface functionalization, which also reduces the time required for tumor delivery from 6 to 2 h.

Kah, James Chen Yong; Olivo, Malini; Chow, Tzu Hao; Song, Kin San; Koh, Karen Zhen Yu; Mhaisalkar, Subodh; Sheppard, Colin James Richard

2009-09-01

350

Therapeutic effect of human iPS-cell-derived myeloid cells expressing IFN-? against peritoneally disseminated cancer in xenograft models.  

PubMed

We recently developed a method to generate myeloid cells with proliferation capacity from human iPS cells. iPS-ML (iPS-cell-derived myeloid/macrophage line), generated by introducing proliferation and anti-senescence factors into iPS-cell-derived myeloid cells, grew continuously in an M-CSF-dependent manner. A large number of cells exhibiting macrophage-like properties can be readily obtained by using this technology. In the current study, we evaluated the possible application of iPS-ML in anti-cancer therapy. We established a model of peritoneally disseminated gastric cancer by intraperitoneally injecting NUGC-4 human gastric cancer cells into SCID mice. When iPS-ML were injected intraperitoneally into the mice with pre-established peritoneal NUGC-4 tumors, iPS-ML massively accumulated and infiltrated into the tumor tissues. iPS-ML expressing IFN-? (iPS-ML/IFN-?) significantly inhibited the intra-peritoneal growth of NUGC-4 cancer. Furthermore, iPS-ML/IFN-? also inhibited the growth of human pancreatic cancer MIAPaCa-2 in a similar model. iPS-ML are therefore a promising treatment agent for peritoneally disseminated cancers, for which no standard treatment is currently available. PMID:23826321

Koba, Chihiro; Haruta, Miwa; Matsunaga, Yusuke; Matsumura, Keiko; Haga, Eriko; Sasaki, Yuko; Ikeda, Tokunori; Takamatsu, Koutaro; Nishimura, Yasuharu; Senju, Satoru

2013-06-24

351

PhagoSight: an open-source MATLAB® package for the analysis of fluorescent neutrophil and macrophage migration in a zebrafish model.  

PubMed

Neutrophil migration in zebrafish larvae is increasingly used as a model to study the response of these leukocytes to different determinants of the cellular inflammatory response. However, it remains challenging to extract comprehensive information describing the behaviour of neutrophils from the multi-dimensional data sets acquired with widefield or confocal microscopes. Here, we describe PhagoSight, an open-source software package for the segmentation, tracking and visualisation of migrating phagocytes in three dimensions. The algorithms in PhagoSight extract a large number of measurements that summarise the behaviour of neutrophils, but that could potentially be applied to any moving fluorescent cells. To derive a useful panel of variables quantifying aspects of neutrophil migratory behaviour, and to demonstrate the utility of PhagoSight, we evaluated changes in the volume of migrating neutrophils. Cell volume increased as neutrophils migrated towards the wound region of injured zebrafish. PhagoSight is openly available as MATLAB® m-files under the GNU General Public License. Synthetic data sets and a comprehensive user manual are available from http://www.phagosight.org. PMID:24023630

Henry, Katherine M; Pase, Luke; Ramos-Lopez, Carlos Fernando; Lieschke, Graham J; Renshaw, Stephen A; Reyes-Aldasoro, Constantino Carlos

2013-08-30

352

Assessing the efficacy of the hedgehog pathway inhibitor vitamin D3 in a murine xenograft model for pancreatic cancer.  

PubMed

The developmental Hedgehog (Hh) pathway has been shown to cause malignancies in the adult organism, specifically in the proximal gastrointestinal tract. Previous studies have used the Hh-inhibitory alkaloid cyclopamine to treat Hh-dependent tumor growth. The present study aimed to determine the efficacy and specificity of the recently discovered endogenous inhibitor of the Hh pathway, vitamin D3, on inhibition of pancreatic adenocarcinoma cell growth in vitro and in vivo. Vitamin D3 was found to inhibit cell growth specifically through inactivation of Smo and the downstream Hh pathway, rather than activation of the vitamin D3 receptor. However, in in vivo models vitamin D3 was not found to be effective against tumor cell growth. PMID:20495364

Brüggemann, Lois W; Queiroz, Karla C S; Zamani, Khatera; van Straaten, Amber; Spek, C Arnold; Bijlsma, Maarten F

2010-07-26

353

GFAP transgenic zebrafish  

Microsoft Academic Search

We have generated transgenic zebrafish that express green fluorescent protein (GFP) in glial cells driven by the zebrafish glial fibrillary acidic protein (GFAP) regulatory elements. Transgenic lines Tg(gfap:GFP) were generated from three founders; the results presented here are from the mi2001 line. GFP expression was first visible in the living embryo at the tail bud-stage, then in the developing brain

Rebecca L. Bernardos; Pamela A. Raymond

2006-01-01

354

Cationic microRNA-delivering nanovectors with bifunctional peptides for efficient treatment of PANC-1 xenograft model.  

PubMed

Therapeutic strategies based on modulation of microRNA activity possess much promise in cancer therapy, but the in vivo delivery of microRNA to target sites and its penetration into tumor tissues remain great challenge. In this work, miR-34a-delivering therapeutic nanocomplexes with a tumor-targeting and -penetrating bifunctional CC9 peptide were proposed for efficient treatment of pancreatic cancers. In vitro study indicated that the nanoparticle-based miR-34a delivery systems could effectively facilitate cellular uptake and greatly up-regulate the mRNA level of miR-34a in PANC-1 cell lines. The up-regulation of miR-34a remarkably induced cell cycle arrest and apoptosis, suppressed the tumor cell migration and inhibited the target gene expressions such as E2F3, Bcl-2, c-myc and cyclin D1. More importantly, the in vivo systemic administration of the developed targeting miR-34a delivery systems in a pancreatic cancer model significantly inhibited tumor growth and induced cancer cell apoptosis. Such bifunctional peptide-conjugated miRNA-delivering nanocomplexes should have great potential applications in cancer therapy. PMID:23298779

Hu, Q L; Jiang, Q Y; Jin, X; Shen, J; Wang, K; Li, Y B; Xu, F J; Tang, G P; Li, Z H

2013-01-05

355

Cryo-image Analysis of Tumor Cell Migration, Invasion, and Dispersal in a Mouse Xenograft Model of Human Glioblastoma Multiforme  

PubMed Central

Purpose The goals of this study were to create cryo-imaging methods to quantify characteristics (size, dispersal, and blood vessel density) of mouse orthotopic models of glioblastoma multiforme (GBM) and to enable studies of tumor biology, targeted imaging agents, and theranostic nanoparticles. Procedures Green fluorescent protein-labeled, human glioma LN-229 cells were implanted into mouse brain. At 20–38 days, cryo-imaging gave whole brain, 4-GB, 3D microscopic images of bright field anatomy, including vasculature, and fluorescent tumor. Image analysis/visualization methods were developed. Results Vessel visualization and segmentation methods successfully enabled analyses. The main tumor mass volume, the number of dispersed clusters, the number of cells/cluster, and the percent dispersed volume all increase with age of the tumor. Histograms of dispersal distance give a mean and median of 63 and 56 ?m, respectively, averaged over all brains. Dispersal distance tends to increase with age of the tumors. Dispersal tends to occur along blood vessels. Blood vessel density did not appear to increase in and around the tumor with this cell line. Conclusion Cryo-imaging and software allow, for the first time, 3D, whole brain, microscopic characterization of a tumor from a particular cell line. LN-229 exhibits considerable dispersal along blood vessels, a characteristic of human tumors that limits treatment success.

Qutaish, Mohammed Q.; Sullivant, Kristin E.; Burden-Gulley, Susan M.; Lu, Hong; Roy, Debashish; Wang, Jing; Basilion, James P.; Brady-Kalnay, Susann M.; Wilson, David L.

2012-01-01

356

Adoptively transferred human lung tumor specific cytotoxic T cells can control autologous tumor growth and shape tumor phenotype in a SCID mouse xenograft model  

PubMed Central

Background The anti-tumor efficacy of human immune effector cells, such as cytolytic T lymphocytes (CTLs), has been difficult to study in lung cancer patients in the clinical setting. Improved experimental models for the study of lung tumor-immune cell interaction as well as for evaluating the efficacy of adoptive transfer of immune effector cells are needed. Methods To address questions related to the in vivo interaction of human lung tumor cells and immune effector cells, we obtained an HLA class I + lung tumor cell line from a fresh surgical specimen, and using the infiltrating immune cells, isolated and characterized tumor antigen-specific, CD8+ CTLs. We then established a SCID mouse-human tumor xenograft model with the tumor cell line and used it to study the function of the autologous CTLs provided via adoptive transfer. Results The tumor antigen specific CTLs isolated from the tumor were found to have an activated memory phenotype and able to kill tumor cells in an antigen specific manner in vitro. Additionally, the tumor antigen-specific CTLs were fully capable of homing to and killing autologous tumors in vivo, and expressing IFN-?, each in an antigen-dependent manner. A single injection of these CTLs was able to provide significant but temporary control of the growth of autologous tumors in vivo without the need for IL-2. The timing of injection of CTLs played an essential role in the outcome of tumor growth control. Moreover, immunohistochemical analysis of surviving tumor cells following CTL treatment indicated that the surviving tumor cells expressed reduced MHC class I antigens on their surface. Conclusion These studies confirm and extend previous studies and provide additional information regarding the characteristics of CTLs which can be found within a patient's tumor. Moreover, the in vivo model described here provides a unique window for observing events that may also occur in patients undergoing adoptive cellular immunotherapy as effector cells seek and destroy areas of tumor growth and for testing strategies to improve clinical effectiveness.

Oflazoglu, Ezogelin; Elliott, Mark; Takita, Hiroshi; Ferrone, Soldano; Henderson, Robert A; Repasky, Elizabeth A

2007-01-01

357

Anti-metastatic potential of human V?1(+) ?? T cells in an orthotopic mouse xenograft model of colon carcinoma.  

PubMed

The role of human intraepithelial V?1(+) ?? T cell cytotoxic effectors in the immune surveillance against metastatic colon cancer has never been addressed, despite their reported capacity to infiltrate colon carcinomas and to kill colonic cancer cells in vitro. We previously showed that V?1(+) ?? T cells are enriched in blood in response to cytomegalovirus (CMV) infection, and that such increase may be protective against epithelial cancers. The objective of the present study was to investigate whether CMV-induced V?1(+) ?? T lymphocytes could inhibit the propagation of human colon tumors in vivo, in order to evaluate their immunotherapeutic potential in this context. Even though metastases are an important cause of death in various cancers including colorectal cancer (CRC), the anti-metastatic effect of immune effectors has been poorly analyzed. To this purpose, we set up a reliable model of metastatic colon cancer through orthotopic implantation of luciferase-expressing human HT29 cells in immunodeficient mice. Using bioluminescence imaging to follow the outcome of colonic cancer cells, we showed that a systemic treatment with CMV-induced V?1(+) ?? T cells could not only inhibit primary colon tumor growth but also the emergence of secondary tumor foci in the lungs and liver. Finally, our data lead to propose that V?1(+) ?? T lymphocytes may directly influence the appearance of metastases independently from their control of primary tumor size. These findings, which extend our previous work, pave the road for the potential manipulation of V?1(+) ?? T lymphocytes in novel anti-CRC immunotherapeutic protocols. PMID:23619975

Devaud, Christel; Rousseau, Benoît; Netzer, Sonia; Pitard, Vincent; Paroissin, Christian; Khairallah, Camille; Costet, Pierre; Moreau, Jean-François; Couillaud, Franck; Dechanet-Merville, Julie; Capone, Myriam

2013-04-26

358

Ultrasound Bio-Microscopic Image Segmentation for Evaluation of Zebrafish Cardiac Function  

PubMed Central

Zebrafish can fully regenerate their myocardium after ventricular resection without evidence of scars. This extraordinary regenerative ability provides an excellent model system to study the activation of the regenerative potential for human heart tissue. In addition to the morphology, it is vital to understand the cardiac function of zebrafish. To characterize adult zebrafish cardiac function, an ultrasound biomicroscope (UBM) was customized for real-time imaging of the zebrafish heart (about 1 mm in diameter) at a resolution of around 37 µm. Moreover, we developed an image segmentation algorithm to track the cardiac boundary and measure the dynamic size of the zebrafish heart for further quantification of zebrafish cardiac function. The effectiveness and accuracy of the proposed segmentation algorithm were verified on a tissue-mimicking phantom and in vivo zebrafish echocardiography. The quantitative evaluation demonstrated that the accuracy of the proposed algorithm is comparable to the manual delineation by experts.

Zhou, Xiaowei; Sun, Lei; Yu, Yanyan; Qiu, Weibao; Lien, Ching-Ling; Shung, K. Kirk; Yu, Weichuan

2013-01-01

359

Evaluating dynamic contrast-enhanced and photoacoustic CT to assess intra-tumor heterogeneity in xenograft mouse models  

NASA Astrophysics Data System (ADS)

Purpose: To evaluate photoacoustic CT spectroscopy (PCT-S) and dynamic contrast-enhanced CT (DCE-CT) ability to measure parameters - oxygen saturation and vascular physiology - associated with the intra-tumor oxygenation status. Material and Methods: Breast (VEGF165 enhance MCF-7) and ovarian (SKOV3x) cancer cells were implanted into the fat pads and flanks of immune deficient mice and allowed to grow to a diameter of 8-15 mm. CT was used to determine physiological parameters by acquiring a sequence of scans over a 10 minute period after an i.v. injection of a radio-opaque contrast agent (Isovue). These time-dependent contrast-enhanced curves were fit to a two-compartmental model determining tumor perfusion, fractional plasma volume, permeability-surface area produce, and fractional interstitial volume on a voxel-by-voxel basis. After which, the tumors were imaged using photoacoustic CT (Optosonics, Inc., Indianapolis, IN 46202). The near infrared spectra (700-910 nm) within the vasculature was fit to linear combination of measured oxy- and deoxy-hemoglobin blood samples to obtain oxygen saturation levels (SaO2). Results: The PCT-S scanner was first calibrated using different samples of oxygenated blood, from which a statistical error ranging from 2.5-6.5% was measured and a plot of the hemoglobin dissociation curve was consistent with empirical formula. In vivo determination of tumor vasculature SaO2 levels were measurably tracked, and spatially correlated to the periphery of the tumor. Tumor depend variations in SaO2 - 0.32 (ovarian) and 0.60 (breast) - and in vascular physiology - perfusion, 1.03 and 0.063 mL/min/mL, and fractional plasma volume, 0.20 and 0.07 - were observed. Conclusion: Combined, PCT-S and CED-CT has the potential to measure intra-tumor levels of tumor oxygen saturation and vascular physiology, key parameters associated with hypoxia.

Stantz, Keith M.; Liu, Bo; Cao, Minsong; Reinecke, Dan; Dzemidzic, Mario; Liang, Yun; Kruger, Robert

2006-03-01

360

Neutrophil Reverse Migration Becomes Transparent with Zebrafish  

PubMed Central

The precise control of neutrophil-mediated inflammation is critical for both host defense and the prevention of immunopathology. In vivo imaging studies in zebrafish, and more recently in mice, have made the novel observation that neutrophils leave a site of inflammation through a process called neutrophil reverse migration. The application of advanced imaging techniques to the genetically tractable, optically transparent zebrafish larvae was critical for these advances. Still, the mechanisms underlying neutrophil reverse migration and its effects on the resolution or priming of immune responses remain unclear. Here, we review the current knowledge of neutrophil reverse migration, its potential roles in host immunity, and the live imaging tools that make zebrafish a valuable model for increasing our knowledge of neutrophil behavior in vivo.

Starnes, Taylor W.; Huttenlocher, Anna

2012-01-01

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