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1

Transforming growth factor-? signalling controls human breast cancer metastasis in a zebrafish xenograft model  

PubMed Central

Introduction The transforming growth factor beta (TGF-?) signalling pathway is known to control human breast cancer invasion and metastasis. We demonstrate that the zebrafish xenograft assay is a robust and dependable animal model for examining the role of pharmacological modulators and genetic perturbation of TGF-? signalling in human breast tumour cells. Methods We injected cancer cells into the embryonic circulation (duct of cuvier) and examined their invasion and metastasis into the avascular collagenous tail. Various aspects of the TGF-? signalling pathway were blocked by chemical inhibition, small interfering RNA (siRNA), or small hairpin RNA (shRNA). Analysis was conducted using fluorescent microscopy. Results Breast cancer cells with different levels of malignancy, according to in vitro and in vivo mouse studies, demonstrated invasive and metastatic properties within the embryonic zebrafish model that nicely correlated with their differential tumourigenicity in mouse models. Interestingly, MCF10A M2 and M4 cells invaded into the caudal hematopoietic tissue and were visible as a cluster of cells, whereas MDA MB 231 cells invaded into the tail fin and were visible as individual cells. Pharmacological inhibition with TGF-? receptor kinase inhibitors or tumour specific Smad4 knockdown disturbed invasion and metastasis in the zebrafish xenograft model and closely mimicked the results we obtained with these cells in a mouse metastasis model. Inhibition of matrix metallo proteinases, which are induced by TGF-? in breast cancer cells, blocked invasion and metastasis of breast cancer cells. Conclusions The zebrafish-embryonic breast cancer xenograft model is applicable for the mechanistic understanding, screening and development of anti-TGF-? drugs for the treatment of metastatic breast cancer in a timely and cost-effective manner.

2013-01-01

2

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

3

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

4

Enrichment of human prostate cancer cells with tumor initiating properties in mouse and zebrafish xenografts by differential adhesion  

PubMed Central

BACKGROUND Prostate tumor-initiating cells (TICs) have intrinsic resistance to current therapies. TICs are commonly isolated by cell sorting or dye exclusion, however, isolating TICs from limited primary prostate cancer (PCa) tissues is inherently inefficient. We adapted the collagen adherence feature to develop a combined immunophenotypic and time-of-adherence assay to identify human prostate TICs. METHODS PCa cells from multiple cell lines and primary tissues were allowed to adhere to several matrix molecules, and fractions of adherent cells were examined for their TIC properties. RESULTS Collagen-I rapidly-adherent PCa cells have significantly higher clonogenic, migration, and invasion abilities, and initiated more tumor xenografts in mice when compared to slowly-adherent and no-adherent cells. To determine the relative frequency of TICs among PCa cell lines and primary PCa cells, we utilized zebrafish xenografts to define the tumor initiation potential of serial dilutions of rapidly-adherent ?2?1hi/CD44hi cells compared to non-adherent cells with ?2?1low/CD44low phenotype. Tumor initiation from rapidly-adherent ?2?1hi/CD44hi TICs harboring the TMPRSS2:ERG fusion generated xenografts comprising of PCa cells expressing Erg, AMACR, and PSA. Moreover, PCa-cell dissemination was consistently observed in the immune-permissive zebrafish microenvironment from as-few-as 3 rapidly-adherent ?2?1hi/CD44hi cells. In zebrafish xenografts, self-renewing prostate TICs comprise 0.02–0.9% of PC3 cells, 0.3–1.3% of DU145 cells, and 0.22–14.3% of primary prostate adenocarcinomas. CONCLUSION Zebrafish PCa xenografts were used to determine that the frequency of prostate TICs varies among PCa cell lines and primary PCa tissues. These data support a paradigm of utilizing zebrafish xenografts to evaluate novel therapies targeting tumor initiating cells in prostate cancer.

Bansal, Nitu; Davis, Stephani; Tereshchenko, Irina; Budak-Alpdogan, Tulin; Zhong, Hua; Stein, Mark N.; Kim, Isaac Yi; DiPaola, Robert S.; Bertino, Joseph R.; Sabaawy, Hatem E.

2014-01-01

5

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

6

Human tumor xenografts as model for drug testing  

Microsoft Academic Search

This paper reviews the history of xenografts, the endpoints commonly used to evaluate response and chemotherapeutic results obtained with serially maintained human tumor xenografts from different laboratories, and discusses the potential clinical relevance of the heterotransplant model for cancer chemotherapy. Specifically, an attempt is made to correlate the published xenograft data with the clinical data. Drug testing with different types

Jürgen Mattern; Mihaly Bak; Eric W. Hahn; Manfred Volm

1988-01-01

7

Mouse Xenograft Model for Mesothelioma  

Cancer.gov

The National Cancer Institute is seeking parties interested in collaborative research to co-develop, evaluate, or commercialize a new mouse model for monoclonal antibodies and immunoconjugates that target malignant mesotheliomas.

8

[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

9

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

10

Zebrafish model for human long QT syndrome  

PubMed Central

Long QT syndrome (LQTS) is a disorder of ventricular repolarization that predisposes affected individuals to lethal cardiac arrhythmias. To date, an appropriate animal model of inherited LQTS does not exist. The zebrafish is a powerful vertebrate model used to dissect molecular pathways of cardiovascular development and disease. Because fundamental electrical properties of the zebrafish heart are remarkably similar to those of the human heart, the zebrafish may be an appropriate model for studying human inherited arrhythmias. Here we describe the molecular, cellular, and electrophysiological basis of a zebrafish mutant characterized by ventricular asystole. Genetic mapping and direct sequencing identify the affected gene as kcnh2, which encodes the channel responsible for the rapidly activating delayed rectifier K+ current (IKr). We show that complete loss of functional IKr in embryonic hearts leads to ventricular cell membrane depolarization, inability to generate action potentials (APs), and disrupted calcium release. A small hyperpolarizing current restores spontaneous APs, implying wild-type function of other ionic currents critical for AP generation. Heterozygous fish manifest overt cellular and electrocardiographic evidence for delayed ventricular repolarization. Our findings provide insight into the pathogenesis of homozygous kcnh2 mutations and expand the use of zebrafish mutants as a model system to study human arrhythmias.

Arnaout, Rima; Ferrer, Tania; Huisken, Jan; Spitzer, Kenneth; Stainier, Didier Y. R.; Tristani-Firouzi, Martin; Chi, Neil C.

2007-01-01

11

Adult zebrafish as a model organism for behavioural genetics  

PubMed Central

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.

2010-01-01

12

Using the zebrafish model for Alzheimer's disease research  

PubMed Central

Rodent models have been extensively used to investigate the cause and mechanisms behind Alzheimer’s disease. Despite many years of intensive research using these models we still lack a detailed understanding of the molecular events that lead to neurodegeneration. Although zebrafish lack the complexity of advanced cognitive behaviors evident in rodent models they have proven to be a very informative model for the study of human diseases. In this review we give an overview of how the zebrafish has been used to study Alzheimer’s disease. Zebrafish possess genes orthologous to those mutated in familial Alzheimer’s disease and research using zebrafish has revealed unique characteristics of these genes that have been difficult to observe in rodent models. The zebrafish is becoming an increasingly popular model for the investigation of Alzheimer’s disease and will complement studies using other models to help complete our understanding of this disease.

Newman, Morgan; Ebrahimie, Esmaeil; Lardelli, Michael

2014-01-01

13

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

14

A xenograft animal model of human arteriovenous malformations  

PubMed Central

Background Arteriovenous malformations (AVMs) are a type of high-flow vascular malformations that most commonly occurs in the head and neck. They are present at birth but are usually clinically asymptomatic until later in life. The pathogenesis of AVMs remains unclear and therapeutic approaches to AVMs are unsatisfied. In order to provide a tool for studying the pathogenesis and therapies of this disease, we established and studied a xenograft animal model of human AVMs. Methods Fresh human AVMs specimens harvested from 4 patients were sectioned (5x5x5 mm) and xenografted subcutaneously in 5 immunologically naïve nude mice (Athymic Nude-Foxn1nu). Each mouse had four pieces specimens in four quadrants along the back. The grafts were observed weekly for volume, color and texture. The grafts were harvested at every 30 days intervals for histologic examination. All grafts (n?=?20) were sectioned and stained for hematoxylin and eosin (H&E). Comparative pathologic evaluation of the grafts and native AVMs were performed by two blinded pathologists. Immunohistochemical examination of human-specific nuclear antigen, vascular endothelial growth factor receptor-2 (VEGFR-2) and Ki-67 was performed. Results Clinical characteristics and pathologic diagnosis of native human derived AVMs were confirmed. 85% (n?=?17) of AVM xenografts survived although the sizes decreased after implantation. Histological examination demonstrated numerous small and medium-size vessels and revealed structural characteristics matching the native AVMs tissue.76.5% (n?=?13) of the surviving xenografts were positive for Ki-67 and human-specific nuclear antigen suggesting survival of the human derived tissue, 52.9% (n?=?9) were positive for VEGFR-2. Conclusions This preliminary xenograft animal model suggests that AVMs can survive in the nude mouse. The presence of human-specific nuclear antigen, VEGFR-2, and Ki-67 demonstrates the stability of native tissue qualities within the xenografts.

2013-01-01

15

Next generation patient-derived prostate cancer xenograft models  

PubMed Central

There is a critical need for more effective therapeutic approaches for prostate cancer. Research in this area, however, has been seriously hampered by a lack of clinically relevant, experimental in vivo models of the disease. This review particularly focuses on the development of prostate cancer xenograft models based on subrenal capsule grafting of patients’ tumor tissue into nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice. This technique allows successful development of transplantable, patient-derived cancer tissue xenograft lines not only from aggressive metastatic, but also from localized prostate cancer tissues. The xenografts have been found to retain key biological properties of the original malignancies, including histopathological and molecular characteristics, tumor heterogeneity, response to androgen ablation and metastatic ability. As such, they are highly clinically relevant and provide valuable tools for studies of prostate cancer progression at cellular and molecular levels, drug screening for personalized cancer therapy and preclinical drug efficacy testing; especially when a panel of models is used to cover a broader spectrum of the disease. These xenograft models could therefore be viewed as next-generation models of prostate cancer.

Lin, Dong; Xue, Hui; Wang, Yuwei; Wu, Rebecca; Watahiki, Akira; Dong, Xin; Cheng, Hongwei; Wyatt, Alexander W; Collins, Colin C; Gout, Peter W; Wang, Yuzhuo

2014-01-01

16

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

17

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

18

Bladder cancer xenografts: a model of tumor cell heterogeneity.  

PubMed

Twenty bladder biopsies from patients with primary transitional cell carcinoma were inoculated into nude mice. To date, eleven of these have grown as primary implants and three serially transplantable xenograft lines (UCRU-BL-12, UCRU-BL-13, UCRU-BL-14) have been established. The histological and ultrastructural features of human transitional cell carcinoma have been maintained in each line. Despite a relatively uniform histological appearance, several indices of occult tumor heterogeneity have been revealed. Immunocytochemical staining was negative for beta-subunit human chorionic gonadotrophin but positive for carcinoembryonic antigen only in areas of squamous differentiation. All three tumors bound peanut lectin. Flow cytometric DNA analysis of UCRU-BL-13 showed multiple aneuploid peaks, separate populations being demonstrated in different xenografts of the same generation. However, the morphologies of these tumors remained identical. On initial implantation UCRU-BL-12 and UCRU-BL-14 were near diploid but aneuploid populations became apparent with increasing passage number. Each xenograft line caused cachexia in the host mice. Treatment with the cisplatin analogue, isopropyl platinum, ameliorated the cachexia displayed by mice carrying UCRU-BL-14 but did not cause tumor regression. UCRU-BL-12, when tested with cisplatin, isopropyl platinum, and carboplatin, showed equivalent growth retardation with each drug. These xenografted human bladder cancers may be useful models for the study of heterogeneity of the tumor populations in bladder cancer and for the evaluation of new approaches to treatment. PMID:2418959

Russell, P J; Raghavan, D; Gregory, P; Philips, J; Wills, E J; Jelbart, M; Wass, J; Zbroja, R A; Vincent, P C

1986-04-01

19

Adult Zebrafish model of streptococcal infection  

PubMed Central

Streptococcal pathogens cause a wide array of clinical syndromes in humans, including invasive systemic infections resulting in high mortality rates. Many of these pathogens are human specific, and therefore difficult to analyze in vivo using typical animal models, as these models rarely replicate what is observed in human infections. This unit describes the use of the zebrafish (Danio rerio) as an animal model for streptococcal infection to analyze multiple disease states. This model closely mimics the necrotizing fasciitis/myositis pathology observed in humans from a Streptococcus pyogenes infection. The use of a zoonotic pathogen, Streptococcus iniae, which replicates systemic infections caused by many streptococcal pathogens, including dissemination to the brain, is also described. Included protocols describe both intraperitoneal and intramuscular infections, as well as methods for histological and quantitative measurements of infection.

Phelps, Hilary A.; Runft, Donna L.

2009-01-01

20

Teratogenic Potential of Antiepileptic Drugs in the Zebrafish Model  

PubMed Central

The zebrafish model is an attractive candidate for screening of developmental toxicity during early drug development. Antiepileptic drugs (AEDs) arouse concern for the risk of teratogenicity, but the data are limited. In this study, we evaluated the teratogenic potential of seven AEDs (carbamazepine (CBZ), ethosuximide (ETX), valproic acid (VPN), lamotrigine (LMT), lacosamide (LCM), levetiracetam (LVT), and topiramate (TPM)) in the zebrafish model. Zebrafish embryos were exposed to AEDs from initiation of gastrula (5.25 hours post-fertilization (hpf)) to termination of hatching (72?hpf) which mimic the mammalian teratogenic experimental design. The lethality and teratogenic index (TI) of AEDs were determined and the TI values of each drug were compared with the US FDA human pregnancy categories. Zebrafish model was useful screening model for teratogenic potential of antiepilepsy drugs and was in concordance with in vivo mammalian data and human clinical data.

Lee, Sung Hak; Kang, Jung Won; Lin, Tao; Lee, Jae Eun; Jin, Dong Il

2013-01-01

21

Fit for consumption: zebrafish as a model for tuberculosis  

PubMed Central

Despite efforts to generate new vaccines and antibiotics for tuberculosis, the disease remains a public health problem worldwide. The zebrafish Danio rerio has emerged as a useful model to investigate mycobacterial pathogenesis and treatment. Infection of zebrafish with Mycobacterium marinum, the closest relative of the Mycobacterium tuberculosis complex, recapitulates many aspects of human tuberculosis. The zebrafish model affords optical transparency, abundant genetic tools and in vivo imaging of the progression of infection. Here, we review how the zebrafish–M. marinum system has been deployed to make novel observations about the role of innate immunity, the tuberculous granuloma, and crucial host and bacterial genes. Finally, we assess how these findings relate to human disease and provide a framework for novel strategies to treat tuberculosis.

Cronan, Mark R.; Tobin, David M.

2014-01-01

22

Zebrafish as a model system to study toxicology.  

PubMed

Monitoring and assessing the effects of contaminants in the aquatic eco-environment is critical in protecting human health and the environment. The zebrafish has been widely used as a prominent model organism in different fields because of its small size, low cost, diverse adaptability, short breeding cycle, high fecundity, and transparent embryos. Recent studies have demonstrated that zebrafish sensitivity can aid in monitoring environmental contaminants, especially with the application of transgenic technology in this area. The present review provides a brief overview of recent studies on wild-type and transgenic zebrafish as a model system to monitor toxic heavy metals, endocrine disruptors, and organic pollutants for toxicology. The authors address the new direction of developing high-throughput detection of genetically modified transparent zebrafish to open a new window for monitoring environmental pollutants. PMID:24307630

Dai, Yu-Jie; Jia, Yong-Fang; Chen, Na; Bian, Wan-Ping; Li, Qin-Kai; Ma, Yan-Bo; Chen, Yan-Ling; Pei, De-Sheng

2014-01-01

23

Use of zebrafish models for the analysis of human disease.  

PubMed

The zebrafish has emerged as a powerful animal model for human diseases. While it has long informed us about the biology of early development, it has recently come into favor for the investigation of clinically relevant problems. Genes conserved from fish to humans can be rapidly analyzed using the zebrafish embryo in what is essentially a transparent in vivo assay. This unit describes methodologies including genetic screening, targeted knockdowns, ectopic overexpression, and transgenesis. PMID:18428328

Zhu, Hao; Zon, Leonard I

2002-11-01

24

Persistent impaired glucose metabolism in a zebrafish hyperglycemia model.  

PubMed

Diabetes mellitus (DM) affects over 10% of the world's population. Hyperglycemia is the main feature for the diagnosis of this disease. The zebrafish (Danio rerio) is an established model organism for the study of various metabolic diseases. In this paper, hyperglycemic zebrafish, when immersed in a 111 mM glucose solution for 14 days, developed increased glycation of proteins from the eyes, decreased mRNA levels of insulin receptors in the muscle, and a reversion of high blood glucose level after treatment with anti-diabetic drugs (glimepiride and metformin) even after 7 days of glucose withdrawal. Additionally, hyperglycemic zebrafish developed an impaired response to exogenous insulin, which was recovered after 7 days of glucose withdrawal. These data suggest that the exposure of adult zebrafish to high glucose concentration is able to induce persistent metabolic changes probably underlined by a hyperinsulinemic state and impaired peripheral glucose metabolism. PMID:24704522

Capiotti, Katiucia Marques; Antonioli, Régis; Kist, Luiza Wilges; Bogo, Maurício Reis; Bonan, Carla Denise; Da Silva, Rosane Souza

2014-05-01

25

Transplantation of cryopreserved human corneas in a xenograft model.  

PubMed

An ideal model to test methods of corneal storage for transplantation would simulate the environment of the grafted human cornea and predict the success of clinical corneal transplants (human to human). In this study, we tested such a model, the corneal xenograft (human to cat). Nine pairs of human corneas were transplanted into both eyes of nine recipient cats. One cornea of each pair was cryopreserved at -196 degrees C in 2.5 M dimethyl sulfoxide while the other was stored in preservative medium at 4 degrees C (control) for 6 +/- 2 (mean +/- SD) days before transplantation. One week after transplantation, the cats were euthanized and the eyes were examined. Three of the grafts (all cryopreserved) were clinical failures and showed no survival of donor corneal endothelial cells on scanning electron microscopy. The remaining six pairs of grafts were examined with a specular microscope and showed endothelial cell losses of 48 +/- 16% in cryopreserved and 8 +/- 16% in control corneas (p < 0.05). This survival is similar to survival in an earlier corneal perfusion model. The nine cryopreserved grafts were thicker than the control grafts, had fewer surviving keratocytes in the central stroma, and had more apoptotic central keratocytes (TUNEL assay). This failure rate in cryopreserved corneas clearly shows that this technique of cryopreservation was not adequate for clinical use. The corneal xenograft model can be used to study cellular survival and apoptosis in vivo after preservation as well as to test new methods of corneal preservation before initiating clinical trials. PMID:12151269

Ohno, Kenji; Nelson, Leif R; Mitooka, Katsuya; Bourne, William M

2002-04-01

26

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

27

Zebrafish: A Model for the Study of Addiction Genetics  

PubMed Central

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.

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

2013-01-01

28

A Human Lung Xenograft Mouse Model of Nipah Virus Infection  

PubMed Central

Nipah virus (NiV) is a member of the genus Henipavirus (family Paramyxoviridae) that causes severe and often lethal respiratory illness and encephalitis in humans with high mortality rates (up to 92%). NiV can cause Acute Lung Injury (ALI) in humans, and human-to-human transmission has been observed in recent outbreaks of NiV. While the exact route of transmission to humans is not known, we have previously shown that NiV can efficiently infect human respiratory epithelial cells. The molecular mechanisms of NiV-associated ALI in the human respiratory tract are unknown. Thus, there is an urgent need for models of henipavirus infection of the human respiratory tract to study the pathogenesis and understand the host responses. Here, we describe a novel human lung xenograft model in mice to study the pathogenesis of NiV. Following transplantation, human fetal lung xenografts rapidly graft and develop mature structures of adult lungs including cartilage, vascular vessels, ciliated pseudostratified columnar epithelium, and primitive “air” spaces filled with mucus and lined by cuboidal to flat epithelium. Following infection, NiV grows to high titers (107 TCID50/gram lung tissue) as early as 3 days post infection (pi). NiV targets both the endothelium as well as respiratory epithelium in the human lung tissues, and results in syncytia formation. NiV infection in the human lung results in the production of several cytokines and chemokines including IL-6, IP-10, eotaxin, G-CSF and GM-CSF on days 5 and 7 pi. In conclusion, this study demonstrates that NiV can replicate to high titers in a novel in vivo model of the human respiratory tract, resulting in a robust inflammatory response, which is known to be associated with ALI. This model will facilitate progress in the fundamental understanding of henipavirus pathogenesis and virus-host interactions; it will also provide biologically relevant models for other respiratory viruses.

Borisevich, Viktoriya; Goez, Yenny; Rockx, Barry

2014-01-01

29

Human Tumor Xenograft Models for Preclinical Assessment of Anticancer Drug Development  

PubMed Central

Xenograft models of human cancer play an important role in the screening and evaluation of candidates for new anticancer agents. The models, which are derived from human tumor cell lines and are classified according to the transplant site, such as ectopic xenograft and orthotopic xenograft, are still utilized to evaluate therapeutic efficacy and toxicity. The metastasis model is modified for the evaluation and prediction of cancer progression. Recently, animal models are made from patient-derived tumor tissue. The patient-derived tumor xenograft models with physiological characters similar to those of patients have been established for personalized medicine. In the discovery of anticancer drugs, standard animal models save time and money and provide evidence to support clinical trials. The current strategy for using xenograft models as an informative tool is introduced.

2014-01-01

30

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

31

Distinct phenotypes in zebrafish models of human startle disease?  

PubMed Central

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 ?1R271Q) 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.

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

2013-01-01

32

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

2013-12-01

33

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

34

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

2011-03-15

35

Credentialing Preclinical Pediatric Xenograft Models Using Gene Expression and Tissue Microarray Analysis  

Microsoft Academic Search

Human tumor xenografts have been used extensively for rapid screening of the efficacy of anticancer drugs for the past 35 years. The selection of appropriate xenograft models for drug testing has been largely empirical and has not incorporated a similarity to the tumor type of origin at the molecular level. This study is the first comprehensive analysis of the tran-

Craig C. Whiteford; Sven Bilke; Braden T. Greer; Till A. Braunschweig; Nicola Cenacchi; Jun S. Wei; Malcolm A. Smith; Peter Houghton; Christopher Morton; C. Patrick Reynolds; Richard Lock; Richard Gorlick; Chand Khanna; Carol J. Thiele; Mikiko Takikita; Daniel Catchpoole; Stephen M. Hewitt; Javed Khan

2007-01-01

36

Zebrafish Models of BCR-ABL-Induced Leukemogenesis.  

National Technical Information Service (NTIS)

We plan to study the consequences of BCR-ABL expression in myeloid cells, using the zebrafish model system. The fundamental genetic mechanisms that control hematopoiesis are well conserved, and many of the genes known to regulate these processes in mammal...

A. T. Look

2005-01-01

37

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 ...

38

The zebrafish as a model to study polycystic liver disease.  

PubMed

In the polycystic liver diseases (PLD), genetic defects initiate the formation of cysts in the liver and kidney. In rodent models of PLD (i.e., the PCK rat and Pkd2(WS25/-) mouse), we have studied hepatorenal cystic disease and therapeutic approaches. In this study, we employed zebrafish injected with morpholinos against genes involved in the PLD, including sec63, prkcsh, and pkd1a. We calculated the liver cystic area, and based on our rodent studies, we exposed the embryos to pasireotide [1??M] or vitamin K3 [100??M] and assessed the endoplasmic reticulum (ER) in cholangiocytes in embryos treated with 4-phenylbutyrate (4-PBA). Our results show that (a) morpholinos against sec63, prkcsh, and pkd1a eliminate expression of the respective proteins; (b) phenotypic body changes included curved tail and the formation of hepatic cysts in zebrafish larvae; (c) exposure of embryos to pasireotide inhibited hepatic cystogenesis in the zebrafish models; and (d) exposure of embryos to 4-PBA resulted in the ER in cholangiocytes resolving from a curved to a smooth appearance. Our results suggest that the zebrafish model of PLD may provide a means to screen drugs that could inhibit hepatic cystogenesis. PMID:23668934

Tietz Bogert, Pamela S; Huang, Bing Q; Gradilone, Sergio A; Masyuk, Tetyana V; Moulder, Gary L; Ekker, Stephen C; Larusso, Nicholas F

2013-06-01

39

The Zebrafish as a Model to Study Polycystic Liver Disease  

PubMed Central

Abstract In the polycystic liver diseases (PLD), genetic defects initiate the formation of cysts in the liver and kidney. In rodent models of PLD (i.e., the PCK rat and Pkd2WS25/? mouse), we have studied hepatorenal cystic disease and therapeutic approaches. In this study, we employed zebrafish injected with morpholinos against genes involved in the PLD, including sec63, prkcsh, and pkd1a. We calculated the liver cystic area, and based on our rodent studies, we exposed the embryos to pasireotide [1??M] or vitamin K3 [100??M] and assessed the endoplasmic reticulum (ER) in cholangiocytes in embryos treated with 4-phenylbutyrate (4-PBA). Our results show that (a) morpholinos against sec63, prkcsh, and pkd1a eliminate expression of the respective proteins; (b) phenotypic body changes included curved tail and the formation of hepatic cysts in zebrafish larvae; (c) exposure of embryos to pasireotide inhibited hepatic cystogenesis in the zebrafish models; and (d) exposure of embryos to 4-PBA resulted in the ER in cholangiocytes resolving from a curved to a smooth appearance. Our results suggest that the zebrafish model of PLD may provide a means to screen drugs that could inhibit hepatic cystogenesis.

Tietz Bogert, Pamela S.; Huang, Bing Q.; Gradilone, Sergio A.; Masyuk, Tetyana V.; Moulder, Gary L.; Ekker, Stephen C.

2013-01-01

40

Modelling of tumour growth and cytotoxic effect of docetaxel in xenografts.  

PubMed

One of the major sources of information on physiological and pathophysiological effects in pre-clinical oncology studies is the xenografted tumour animal model. However, measurement of tumour volume over time potentially masks a range of biological changes that the xenograft is undergoing. In this paper a mechanistic model of tumour growth in xenografts is presented that can be used to investigate the mode of drug action with respect to phenotypic changes. The model encapsulates key histological biomarkers and spatial constraints. The unknown model parameters are first shown to be uniquely identifiable from the proposed experimental studies, and then estimated from the resulting data using the anti-cancer agent docetaxel. PMID:23948442

Evans, Neil D; Dimelow, Richard J; Yates, James W T

2014-05-01

41

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

42

Zebrafish embryos and larvae: a new generation of disease models and drug screens.  

PubMed

Technological innovation has helped the zebrafish embryo gain ground as a disease model and an assay system for drug screening. Here, we review the use of zebrafish embryos and early larvae in applied biomedical research, using selected cases. We look at the use of zebrafish embryos as disease models, taking fetal alcohol syndrome and tuberculosis as examples. We discuss advances in imaging, in culture techniques (including microfluidics), and in drug delivery (including new techniques for the robotic injection of compounds into the egg). The use of zebrafish embryos in early stages of drug safety-screening is discussed. So too are the new behavioral assays that are being adapted from rodent research for use in zebrafish embryos, and which may become relevant in validating the effects of neuroactive compounds such as anxiolytics and antidepressants. Readouts, such as morphological screening and cardiac function, are examined. There are several drawbacks in the zebrafish model. One is its very rapid development, which means that screening with zebrafish is analogous to "screening on a run-away train." Therefore, we argue that zebrafish embryos need to be precisely staged when used in acute assays, so as to ensure a consistent window of developmental exposure. We believe that zebrafish embryo screens can be used in the pre-regulatory phases of drug development, although more validation studies are needed to overcome industry scepticism. Finally, the zebrafish poses no challenge to the position of rodent models: it is complementary to them, especially in early stages of drug research. PMID:21671352

Ali, Shaukat; Champagne, Danielle L; Spaink, Herman P; Richardson, Michael K

2011-06-01

43

Establishment of a xenograft model of human myelodysplastic syndromes  

PubMed Central

Background To understand how myelodysplastic syndrome cells evolve from normal stem cells and gain competitive advantages over normal hematopoiesis, we established a murine xenograft model harboring bone marrow cells from patients with myelodysplastic syndromes or acute myeloid leukemia with myelodysplasia-related changes. Design and Methods Bone marrow CD34+ cells obtained from patients were injected, with or without human mesenchymal stem cells, into the bone marrow of non-obese diabetic/severe combined immunodeficient/IL2R?null hosts. Engraftment and differentiation of cells derived from the patients were investigated by flow cytometry and immunohistochemical analysis. Results Co-injection of patients’ cells and human mesenchymal stem cells led to successful engraftment of patient-derived cells that maintained the immunophenotypes and genomic abnormalities of the original patients. Myelodysplastic syndrome-originated clones differentiated into mature neutrophils, megakaryocytes, and erythroblasts. Two of the samples derived from patients with acute myeloid leukemia with myelodysplasia-related changes were able to sustain neoplastic growth into the next generation while these cells had limited differentiation ability in the murine host. The hematopoiesis of mice engrafted with patients’ cells was significantly suppressed even when human cells accounted for less than 1% of total marrow mononuclear cells. Histological studies revealed invasion of the endosteal surface by patient-derived CD34+ cells and disruption of extracellular matrix architecture, which probably caused inhibition of murine hematopoiesis. Conclusions We established murine models of human myelodysplastic syndromes using cells obtained from patients: the presence of neoplastic cells was associated with the suppression of normal host hematopoiesis. The efficiency of engraftment was related to the presence of an abnormality in chromosome 7.

Muguruma, Yukari; Matsushita, Hiromichi; Yahata, Takashi; Yumino, Shizu; Tanaka, Yumiko; Miyachi, Hayato; Ogawa, Yoshiaki; Kawada, Hiroshi; Ito, Mamoru; Ando, Kiyoshi

2011-01-01

44

Zebrafish: A Model System for the Study of Eye Genetics  

PubMed Central

Over the last decade, the use of the zebrafish as a genetic model has moved beyond the proof-of-concept for the analysis of vertebrate embryonic development to demonstrated utility as a mainstream model organism for the understanding of human disease. The initial identification of a variety of zebrafish mutations affecting the eye and retina, and the subsequent cloning of mutated genes have revealed cellular, molecular and physiological processes fundamental to visual system development. With the increasing development of genetic manipulations, sophisticated techniques for phenotypic characterization, behavioral approaches and screening strategies, the identification of novel genes or novel gene functions will have important implications for our understanding of human eye diseases, pathogenesis, and treatment.

Fadool, James M.; Dowling, John E.

2008-01-01

45

Zebrafish: an in vivo model for nano EHS studies  

PubMed Central

To assure a responsible and sustainable growth of nanotechnology, the environmental health and safety (EHS) aspect of engineered nanomaterials and nano-related products needs to be addressed at a rate commensurate with the expansion of nanotechnology. Zebrafish has been demonstrated as a correlative in vivo vertebrate model for such task, and the current advances of using zebrafish for nano EHS studies are summarized here. In addition to morphological and histopathological observations, the accessibility of gene manipulation would greatly empower such a model for detailed mechanistic studies of any nanoparticles of interest. The potential for establishing high-throughput screening platforms to facilitate the nano EHS studies is highlighted, and a discussion is presented on how toxicogenomics approaches represent a future direction to guide the identification of toxicity pathways.

Zhao, Yan; Nel, Andre E.; Lin, Shuo

2014-01-01

46

Zebrafish as a Novel Vertebrate Model To Dissect Enterococcal Pathogenesis  

PubMed Central

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.

Renshaw, Stephen A.; Ogryzko, Nikolay V.; Foster, Simon J.; Serror, Pascale

2013-01-01

47

Zebrafish as a model for zoonotic aquatic pathogens.  

PubMed

Aquatic habitats harbor a multitude of bacterial species. Many of these bacteria can act as pathogens to aquatic species and/or non-aquatic organisms, including humans, that come into contact with contaminated water sources or colonized aquatic organisms. In many instances, the bacteria are not pathogenic to the aquatic species they colonize and are only considered pathogens when they come into contact with humans. There is a general lack of knowledge about how the environmental lifestyle of these pathogens allows them to persist, replicate and produce the necessary pathogenic mechanisms to successfully transmit to the human host and cause disease. Recently, the zebrafish infectious disease model has emerged as an ideal system for examining aquatic pathogens, both in the aquatic environment and during infection of the human host. This review will focus on how the zebrafish has been used successfully to analyze the pathogenesis of aquatic bacterial pathogens. PMID:24607289

Rowe, Hannah M; Withey, Jeffrey H; Neely, Melody N

2014-09-01

48

Gene Expression Profiles Can Predict Panitumumab Monotherapy Responsiveness in Human Tumor Xenograft Models1  

PubMed Central

Background Epidermal growth factor receptor (EGFR)-targeted agents have demonstrated clinical benefit in patients with cancer. Identifying tissue-of-origin-independent predictive biomarkers is important to optimally treat patients. We sought to identify a gene array profile that could predict responsiveness to panitumumab, a fully human EGFR-binding antibody, using preclinical models of human cancer. Methods Mice bearing 25 different xenograft models were treated twice weekly with panitumumab or immunoglobulin G2 control to determine their responsiveness to panitumumab. Samples from these xenografts and untreated xenografts were arrayed on the Affymetrix human U133A gene chip to identify gene sets predicting responsiveness to panitumumab using univariate and multivariate analyses. The predictive models were validated using the leave-one-group-out (LOO) method. Results Of the 25 xenograft models tested, 12 were responsive and 13 were resistant to panitumumab. Unsupervised analysis demonstrated that the xenograft models clustered by tissue type rather than responsiveness to panitumumab. After normalizing for tissue effects, samples clustered by responsiveness using an unsupervised multidimensional scaling. A multivariate selection algorithm was used to select 13 genes that could stratify xenograft models based on responsiveness after adjustment for tissue effects. The method was validated using the LOO method on a training set of 22 models and confirmed independently on three new models. In contrast, a univariate gene selection method resulted in higher misclassification rates. Conclusion A model was constructed from microarray data that prospectively predict responsiveness to panitumumab in xenograft models. This approach may help identify patients, independent of disease origin, likely to benefit from panitumumab.

Boedigheimer, Michael J; Freeman, Daniel J; Kiaei, Panteha; Damore, Michael A; Radinsky, Robert

2013-01-01

49

Zebrafish: An Emerging Model System for Human Disease and Drug Discovery  

Microsoft Academic Search

In vivo studies represent an essential step in drug development and currently rely largely on mice, yet limitations of mammalian models motivated the search for complementary vertebrate model systems. This review focuses on zebrafish, Danio rerio, as a facile model system to study human disease and drug responses. Zebrafish are particularly suited for this purpose because they represent a vertebrate

G Kari; U Rodeck; A P Dicker

2007-01-01

50

Zebrafish as a model system to study DNA damage and repair.  

PubMed

Zebrafish (Danio rerio) have become a popular vertebrate model to study embryological development, because of unique advantages not found in other model systems. Zebrafish share many gene functions with other vertebrates including humans, making zebrafish a useful system for studying cancer etiology. However, systematic studies of DNA damage and repair pathways using adult or embryonic zebrafish have not been extensively reported. The zebrafish genome contains nearly all the genes involved in different DNA repair pathways in eukaryotes, including direct reversal (DR), mismatch repair (MMR) nucleotide excision repair (NER), base excision repair (BER), homologous recombination (HR), non-homologous end joining (NHEJ) and translesion synthesis (TLS). It also includes the genes of the p53-mediated damage recognition pathway. Therefore, zebrafish provide an ideal model for gaining fundamental insights into mechanisms of DNA damage and repair, especially during embryological development. This review introduces recent work on different DNA damage and repair studies in zebrafish, with special emphasis on the role of BER in zebrafish early embryological development. AP endonuclease 1 (Apex1), a critical protein in the BER pathway, not only regulates BER but also controls cyclic AMP response binding protein (Creb1), which itself regulates ?25% of eukaryotic coding sequences. In addition, Apex1 indirectly regulates levels of p53. As these findings also occur in murine B cells, they illustrate the usefulness of the zebrafish system in elucidating fundamental mechanisms. PMID:23211879

Pei, De-Sheng; Strauss, Phyllis R

2013-01-01

51

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

52

The progress and promise of zebrafish as a model to study mast cells.  

PubMed

Immunological and hematological research using the zebrafish (Danio rerio) has significantly advanced our understanding of blood lineage ontology, cellular functions and mechanisms, and provided opportunities for disease modeling. Mast cells are an immunological cell type involved in innate and adaptive immune systems, hypersensitivity reactions and cancer progression. The application of zebrafish to study mast cell biology exploits the developmental and imaging opportunities inherent in this model system to enable detailed genetic and molecular studies of this lineage outside of traditional mammalian models. In this review, we first place the importance of mast cell research in zebrafish into the context of comparative studies of mast cells in other fish species and highlight its advantages due to superior experimental tractability and direct visualization in transparent embryos. We discuss current and future tools for mast cell research in zebrafish and the notable results of using zebrafish for understanding mast cell fate determination and our development of a systemic mastocytosis model. PMID:24508982

Prykhozhij, Sergey V; Berman, Jason N

2014-09-01

53

Beyond the zebrafish: diverse fish species for modeling human disease  

PubMed Central

ABSTRACT In recent years, zebrafish, and to a lesser extent medaka, have become widely used small animal models for human diseases. These organisms have convincingly demonstrated the usefulness of fish for improving our understanding of the molecular and cellular mechanisms leading to pathological conditions, and for the development of new diagnostic and therapeutic tools. Despite the usefulness of zebrafish and medaka in the investigation of a wide spectrum of traits, there is evidence to suggest that other fish species could be better suited for more targeted questions. With the emergence of new, improved sequencing technologies that enable genomic resources to be generated with increasing efficiency and speed, the potential of non-mainstream fish species as disease models can now be explored. A key feature of these fish species is that the pathological condition that they model is often related to specific evolutionary adaptations. By exploring these adaptations, new disease-causing and disease-modifier genes might be identified; thus, diverse fish species could be exploited to better understand the complexity of disease processes. In addition, non-mainstream fish models could allow us to study the impact of environmental factors, as well as genetic variation, on complex disease phenotypes. This Review will discuss the opportunities that such fish models offer for current and future biomedical research.

Schartl, Manfred

2014-01-01

54

Zebrafish embryos as models for embryotoxic and teratological effects of chemicals  

Microsoft Academic Search

The experimental virtues of the zebrafish embryo such as small size, development outside of the mother, cheap maintenance of the adult made the zebrafish an excellent model for phenotypic genetic and more recently also chemical screens. The availability of a genome sequence and several thousand mutants and transgenic lines together with gene arrays and a broad spectrum of techniques to

Lixin Yang; Nga Yu Ho; Rüdiger Alshut; Jessica Legradi; Carsten Weiss; Markus Reischl; Ralf Mikut; Urban Liebel; Ferenc Müller; Uwe Strähle

2009-01-01

55

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

56

Continuous Local Delivery of Interferon-? Stabilizes Tumor Vasculature in an Orthotopic Glioblastoma Xenograft Resection Model  

PubMed Central

Background High-grade glioblastomas have immature, leaky tumor blood vessels that impede the efficacy of adjuvant therapy. We assessed the ability of human interferon-beta (hIFN-?) delivered locally via gene transfer to effect vascular stabilization in an orthotopic glioblastoma xenograft resection model. Methods Xenografts were established by injecting three grade IV glioblastoma cell lines (GBM6-luc, MT330-luc, and SJG2-luc) into the cerebral cortex of nude rats. Tumors underwent subtotal resection, and then had gel foam containing an adeno-associated virus vector encoding either hIFN-? or green fluorescence protein (GFP, control) placed in the resection cavity. The primary end point was stabilization of tumor vasculature, as evidenced by CD34, ?SMA, and CA IX staining. Overall survival was a secondary endpoint. Results hIFN-? treatment altered the tumor vasculature of GBM6-luc and SJG2-luc xenografts, decreasing the density of endothelial cells, stabilizing vessels with pericytes, and decreasing tumor hypoxia. The mean survival for rats with these tumors was not significantly improved, however. In rats with MT330-luc xenografts, hIFN-? resulted in tumor regression, with a 6-month survival of 55% (INF-? group) and 9% (control group). Conclusion The use of AAV hIFN-? in our orthotopic glioblastoma resection model stabilized tumor vasculature, and dramatically improved survival in rats with MT330 xenografts.

Denbo, Jason W.; Williams, Regan F.; Orr, W. Shannon; Sims, Thomas L.; Ng, Catherine Y.; Zhou, Junfang; Spence, Yunyu; Morton, Christopher L.; Nathwani, Amit C.; Duntsch, Christopher; Pfeffer, Lawrence M.; Davidoff, Andrew M.

2011-01-01

57

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

PubMed Central

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.

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

2013-01-01

58

Neuroprotective effect of zinc chelator DEDTC in a zebrafish (Danio rerio) Model of Hypoxic Brain Injury.  

PubMed

A study was conducted using zebrafish as a model of hypoxic brain injury to investigate the potential neuroprotective effects of zinc (Zn(2+)) chelation. The accumulation of intracellular Zn(2+) is a significant causal factor of the neuronal injury, and has been implicated in cell death followed by ischemic stroke. In this study, the zebrafish was placed in the hypoxia chamber with an extremely low level of dissolved oxygen (less than 0.8?mg/L), which is similar to the conditions in a complete global ischemic stroke. Approximately 50% of zebrafish died after a short period (?11?min) of hypoxic treatment, suggesting that this is a responsive model system for use in evaluating treatments for hypoxic brain damage. The application of DEDTC reduced intracellular Zn(2+) accumulation and produced a concentration-dependent effect by increasing the survival rate of zebrafish. Zn(2+) chelation also enhanced zebrafish tolerance for hypoxia. When the brain damages were evaluated with TTC staining, the zebrafish that were treated with DEDTC in hypoxic treatment yielded the improvement of TTC staining that was similar to the healthy zebrafish brain. The results support that rising intracellular Zn(2+) plays a critical role in the neuronal damages, and demonstrate the protective effects of Zn(2+) chelation in hypoxic-ischemic brain injury in zebrafish. PMID:23461417

Yu, Xinge; Li, Yang V

2013-03-01

59

A multi-scale model for correlation in B cell VDJ usage of zebrafish  

NASA Astrophysics Data System (ADS)

The zebrafish (Danio rerio) is one of the model animals used for the study of immunology because the dynamics in the adaptive immune system of zebrafish are similar to that in higher animals. In this work, we built a multi-scale model to simulate the dynamics of B cells in the primary and secondary immune responses of zebrafish. We use this model to explain the reported correlation between VDJ usage of B cell repertoires in individual zebrafish. We use a delay ordinary differential equation (ODE) system to model the immune responses in the 6-month lifespan of a zebrafish. This mean field theory gives the number of high-affinity B cells as a function of time during an infection. The sequences of those B cells are then taken from a distribution calculated by a 'microscopic' random energy model. This generalized NK model shows that mature B cells specific to one antigen largely possess a single VDJ recombination. The model allows first-principle calculation of the probability, p, that two zebrafish responding to the same antigen will select the same VDJ recombination. This probability p increases with the B cell population size and the B cell selection intensity. The probability p decreases with the B cell hypermutation rate. The multi-scale model predicts correlations in the immune system of the zebrafish that are highly similar to that from experiment.

Pan, Keyao; Deem, Michael W.

2011-10-01

60

The zebrafish as a vertebrate model of functional aging and very gradual senescence.  

PubMed

The zebrafish (Danio rerio) has been developed as a powerful model for genetic studies in developmental biology, which also gives insights into several diseases of adult humans such as cardiovascular disease and cancer. Because aging processes affect these and many other human diseases, it is important to compare zebrafish and other mammalian aging. However, the aging process of zebrafish remains largely unexplored, and little is known about its functional aging and senescence. In a survey of aging in zebrafish, we detected senescence-associated beta-galactosidase activity in skin and oxidized protein accumulation in muscle. However, we did not observe lipofuscin granules ('aging pigments'), which commonly accumulate in postmitotic cells of other vertebrates. This absence of lipofuscins may be consistent with the existence of continuously proliferating myocytes that incorporated BrdU in muscle tissues of aged zebrafish. Moreover, we demonstrated that zebrafish have constitutively abundant telomerase activity in somatic tissues from embryos to aged adults. Although some stress-associated markers are upregulated and minor histological changes are observed during the aging process of zebrafish, our studies together with other evidence of remarkable reproductive and regenerative abilities suggest that zebrafish show very gradual or sub-negligible senescence in vivo. PMID:12855287

Kishi, Shuji; Uchiyama, Junzo; Baughman, Anne M; Goto, Tadateru; Lin, Mao C; Tsai, Stephanie B

2003-07-01

61

The Visual System of Zebrafish and its Use to Model Human Ocular Diseases  

PubMed Central

Free swimming zebrafish larvae depend mainly on their sense of vision to evade predation and to catch prey. Hence there is strong selective pressure on the fast maturation of visual function and indeed the visual system already supports a number of visually-driven behaviors in the newly hatched larvae. The ability to exploit the genetic and embryonic accessibility of the zebrafish in combination with a behavioral assessment of visual system function has made the zebrafish a popular model to study vision and its diseases. Here, we review the anatomy, physiology and development of the zebrafish eye as the basis to relate the contributions of the zebrafish to our understanding of human ocular diseases.

Gestri, Gaia; Link, Brian A; Neuhauss, Stephan CF

2011-01-01

62

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

63

Effect of Estrogen on Progression of Human Proliferative Breast Cancer Disease in a Xenograft Model.  

National Technical Information Service (NTIS)

We have utilized the T24-lla-ras transfected MCPi0A xenograft model of early human breast cancer progression to a) determine whether the observed epidemiologic link between estrogen and increased risk of breast cancer indeed reflect a direct growth promot...

P. V. Shekhar

1997-01-01

64

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

2012-04-01

65

Zebrafish ? As an Integrative Model for Twenty-first Century Toxicity Testing  

EPA Science Inventory

The zebrafish embryo is a useful small model for investigating vertebrate development because of its transparency, low cost, transgenic and morpholino capabilities, conservation of cell signaling, and concordance with mammalian developmental phenotypes. From these advantages, the...

66

Human Breast Fibroblasts Inhibit Growth of the MCF10AT Xenograft Model of Proliferative Breast Disease  

PubMed Central

Stromal fibroblasts are important for normal breast homeostasis and regulation of epithelial growth; however, this regulatory function is altered during carcinogenesis. To study the role of fibroblasts in the development of breast cancer, fibroblasts derived from normal breast (NAFs) were incorporated into the MCF10AT xenograft model of progressive proliferative breast disease. The persistence of human NAFs in xenografts was established by intracellular labeling and tyramide-coupled fluorescent in situ hybridization. Overall, the number of MCF10AT epithelial structures was decreased, and the rate of epithelial cell apoptosis was increased in xenografts containing NAFs. However, these changes were primarily in low-grade epithelial structures, corresponding to normal or mildly hyperplastic ductal epithelium. The level and rate of apoptosis of high-grade epithelial structures, corresponding to in situ and invasive carcinoma, were not consistently altered by NAFs. In addition, there was variability in the growth-inhibitory capacity of NAFs derived from different individuals. NAFs induced changes in the morphology of high-grade MCF10AT structures and in xenograft stroma, including the composition of extracellular matrix, and increased angiogenesis and lymphocytic infiltration. These findings imply that NAFs can inhibit the growth of normal and hyperplastic epi-thelium but are less able to regulate the more transformed epithelial cells that arise during carcino-genesis.

Sadlonova, Andrea; Mukherjee, Shibani; Bowe, Damon B.; Gault, Sandra R.; Dumas, Nicole A.; Van Tine, Brian A.; Frolova, Natalya; Page, Grier P.; Welch, Danny R.; Novak, Lea; Frost, Andra R.

2007-01-01

67

Hypoxia-Induced Retinal Angiogenesis in Zebrafish as a Model to Study Retinopathy  

Microsoft Academic Search

Mechanistic understanding and defining novel therapeutic targets of diabetic retinopathy and age-related macular degeneration (AMD) have been hampered by a lack of appropriate adult animal models. Here we describe a simple and highly reproducible adult fli-EGFP transgenic zebrafish model to study retinal angiogenesis. The retinal vasculature in the adult zebrafish is highly organized and hypoxia-induced neovascularization occurs in a predictable

Renhai Cao; Lasse Dahl Ejby Jensen; Iris Söll; Giselbert Hauptmann; Yihai Cao; Arnold Schwartz

2008-01-01

68

Effect of Various Antiepileptic Drugs in Zebrafish PTZ-Seizure Model  

PubMed Central

Recently zebrafish larvae have emerged as a high-throughput model for screening pharmacological activities. The present study was undertaken to investigate the effect of established anticonvulsants, such as valproic acid, carbamazepine, gabapentin, diazepam, lacosamide and pregabalin against pentylenetetrazole (6 mM) seizures in adult zebrafish. Different phases of seizures (increase swim activity, rapid whirlpool-like circling swim behaviour and brief clonus-like seizures leading to loss of posture) were elicited in zebrafish on exposure for 15 min to 6 mM pentylenetetrazole. The exposure of zebrafish to an increasing concentration of the anticonvulsants alongside 6 mM pentylenetetrazole showed concentration-dependent elevation of seizure latency against pentylenetetrazole-induced seizures except for pregabalin, which failed to produce any anticonvulsant activity in zebrafish. Moreover the proconvulsant activity of caffeine was also evaluated using suboptimal concentration (4 mM) of pentylenetetrazole in adult zebrafish. Decrease in seizure latency of different phases of seizures was observed with increasing concentration of caffeine compared with its respective control group. In view of the above findings, the results of the present study suggested that adult zebrafish produce the expected anticonvulsive and proconvulsive effects and could potentially be used as a screen in future epilepsy research.

Gupta, P.; Khobragade, S. B.; Shingatgeri, V. M.

2014-01-01

69

Effect of Various Antiepileptic Drugs in Zebrafish PTZ-Seizure Model.  

PubMed

Recently zebrafish larvae have emerged as a high-throughput model for screening pharmacological activities. The present study was undertaken to investigate the effect of established anticonvulsants, such as valproic acid, carbamazepine, gabapentin, diazepam, lacosamide and pregabalin against pentylenetetrazole (6 mM) seizures in adult zebrafish. Different phases of seizures (increase swim activity, rapid whirlpool-like circling swim behaviour and brief clonus-like seizures leading to loss of posture) were elicited in zebrafish on exposure for 15 min to 6 mM pentylenetetrazole. The exposure of zebrafish to an increasing concentration of the anticonvulsants alongside 6 mM pentylenetetrazole showed concentration-dependent elevation of seizure latency against pentylenetetrazole-induced seizures except for pregabalin, which failed to produce any anticonvulsant activity in zebrafish. Moreover the proconvulsant activity of caffeine was also evaluated using suboptimal concentration (4 mM) of pentylenetetrazole in adult zebrafish. Decrease in seizure latency of different phases of seizures was observed with increasing concentration of caffeine compared with its respective control group. In view of the above findings, the results of the present study suggested that adult zebrafish produce the expected anticonvulsive and proconvulsive effects and could potentially be used as a screen in future epilepsy research. PMID:24843189

Gupta, P; Khobragade, S B; Shingatgeri, V M

2014-03-01

70

Joint longitudinal and survival-cure models in tumour xenograft experiments.  

PubMed

In tumour xenograft experiments, treatment regimens are administered, and the tumour volume of each individual is measured repeatedly over time. Survival data are recorded because of the death of some individuals during the observation period. Also, cure data are observed because of a portion of individuals who are completely cured in the experiments. When modelling these data, certain constraints have to be imposed on the parameters in the models to account for the intrinsic growth of the tumour in the absence of treatment. Also, the likely inherent association of longitudinal and survival-cure data has to be taken into account in order to obtain unbiased estimators of parameters. In this paper, we propose such models for the joint modelling of longitudinal and survival-cure data arising in xenograft experiments. Estimators of parameters in the joint models are obtained using a Markov chain Monte Carlo approach. Real data analysis of a xenograft experiment is carried out, and simulation studies are also conducted, showing that the proposed joint modelling approach outperforms the separate modelling methods in the sense of mean squared errors. Copyright © 2014 John Wiley & Sons, Ltd. PMID:24753021

Pan, Jianxin; Bao, Yanchun; Dai, Hongsheng; Fang, Hong-Bin

2014-08-15

71

Human skeletal muscle xenograft as a new preclinical model for muscle disorders.  

PubMed

Development of novel therapeutics requires good animal models of disease. Disorders for which good animal models do not exist have very few drugs in development or clinical trial. Even where there are accepted, albeit imperfect models, the leap from promising preclinical drug results to positive clinical trials commonly fails, including in disorders of skeletal muscle. The main alternative model for early drug development, tissue culture, lacks both the architecture and, usually, the metabolic fidelity of the normal tissue in vivo. Herein, we demonstrate the feasibility and validity of human to mouse xenografts as a preclinical model of myopathy. Human skeletal muscle biopsies transplanted into the anterior tibial compartment of the hindlimbs of NOD-Rag1(null) IL2r?(null) immunodeficient host mice regenerate new vascularized and innervated myofibers from human myogenic precursor cells. The grafts exhibit contractile and calcium release behavior, characteristic of functional muscle tissue. The validity of the human graft as a model of facioscapulohumeral muscular dystrophy is demonstrated in disease biomarker studies, showing that gene expression profiles of xenografts mirror those of the fresh donor biopsies. These findings illustrate the value of a new experimental model of muscle disease, the human muscle xenograft in mice, as a feasible and valid preclinical tool to better investigate the pathogenesis of human genetic myopathies and to more accurately predict their response to novel therapeutics. PMID:24452336

Zhang, Yuanfan; King, Oliver D; Rahimov, Fedik; Jones, Takako I; Ward, Christopher W; Kerr, Jaclyn P; Liu, Naili; Emerson, Charles P; Kunkel, Louis M; Partridge, Terence A; Wagner, Kathryn R

2014-06-15

72

Studies on sensitivity of zebrafish as a model organism for Parkinson's disease: Comparison with rat model  

PubMed Central

Objective: To determine the utility of zebra fish as an animal model for Parkinson's disease (PD) in comparison with rat model. Materials and Methods: MTT assay was performed on rat and zebrafish brain synaptosomal fractions using rotenone as a neurotoxic agent. Quercetin and resveratrol were used as standards to compare anti-apoptotic activity in both organisms. Catalepsy was induced in zebrafish by exposing them to haloperidol (9 ?M) solution. Drug-treated groups were exposed to bromocriptine and pramipexole, 30 min prior to haloperidol exposure at the dose of 2, 5, and 10 ?g/mL. Swimming speed, time spent in the bottom of the tank, and complete cataleptic time were evaluated to assess behavioral changes. In rats, catalepsy was induced using haloperidol (1.25 mg/kg i.p.). Drug-treated groups received bromocriptine (2.5 mg/kg.) and pramipexole (1 mg/kg) orally. Bar test, block test, and locomotor activity were carried out to assess behavioral changes. Results: Resveratrol and quercetin showed comparable inhibition of apoptosis in rats and zebrafish. In anti-cataleptic study, bromocriptine and pramipexole-treated groups showed significant difference (P < 0.05) in behavioral parameters as compared to haloperidol control group in both the experimental organisms. Results obtained from fish model were in correlation with rat model. Conclusion: Findings of the present study revealed that zebrafish model is highly sensitive and can be used for basic screening of drugs against PD.

Makhija, Dinesh T.; Jagtap, Aarti G.

2014-01-01

73

Modeling pegylated liposomal doxorubicin-induced hand-foot syndrome and intestinal mucositis in zebrafish  

PubMed Central

Pegylated liposomal doxorubicin (PLD) has been widely used to treat cancer. The adverse effects of PLD noted in clinical practice, especially hand-foot syndrome (HFS), are regarded as unique, and the management methods for them remain limited. This study was aimed at developing a feasible experimental model for translational medicine to solve this clinical issue by using skin fluorescent transgenic zebrafish. We established an optimal protocol for the administration of Lipo-Dox™, a PLD in current clinical use, to the Tg(k18:dsred) zebrafish line expressing red fluorescence in keratinocytes. We made use of bodyweight, survival rate, gross observation, flssuorescent microscopic assessment, and pathological examination of the zebrafish to assess this model. The consecutive administration protocol of PLD resulted in growth retardation of the zebrafish embryo and survival impairment, indicating establishment of a significant toxicity. We observed fin necrosis and keratinocyte dissociation phenotypes in the PLD-treated fish after consecutive administration. The skin toxicity induced by the Lipo-Dox injection was subsequently reversible, which might be compatible with a clinical course of skin recovery after discontinuation of Lipo-Dox administration. Furthermore, we found that the number of intestinal goblet cells, an important marker of intestinal inflammation, in the Lipo-Dox-injected zebrafish was markedly increased, accompanied by impaired mucosal integrity. The intestinal inflammation induced by Lipo-Dox resembled the intestinal mucositis the clinical patients suffered from after the administration of PLD. In conclusion, we established a zebrafish model for PLD-induced HFS. The intestinal mucositis simultaneously noted in the PLD-treated zebrafish validated the similarity of clinical courses after administration of PLD. This model is easily assessable, efficient, and worthy for use in developing a new therapeutic protocol for prevention or treatment of HFS as well as intestinal mucositis. Further clinical investigations to validate the correlation between human and zebrafish data are warranted.

Chen, Yau-Hung; Lee, Ya-Ting; Wen, Chi-Chung; Chen, Yun-Chen; Chen, Yu-Jen

2014-01-01

74

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

Microsoft Academic Search

BackgroundIn 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

Shaukat Ali; Harald G. J. Van Mil; Michael K. Richardson; Ferenc Mueller

2011-01-01

75

Microbial fingerprinting detects intestinal microbiota dysbiosis in Zebrafish models with chemically-induced enterocolitis  

PubMed Central

Background Inflammatory bowel disease (IBD) involves a breakdown in interactions between the host immune response and the resident commensal microbiota. Recent studies have suggested gut physiology and pathology relevant to human IBD can be rapidly modeled in zebrafish larvae. The aim of this study was to investigate the dysbiosis of intestinal microbiota in zebrafish models with IBD-like enterocolitis using culture-independent techniques. Results IBD-like enterocolitis was induced by exposing larval zebrafish to trinitrobenzenesulfonic acid (TNBS). Pathology was assessed by histology and immunofluorescence. Changes in intestinal microbiota were evaluated by denaturing gradient gel electrophoresis (DGGE) and the predominant bacterial composition was determined with DNA sequencing and BLAST and confirmed by real-time polymerase chain reaction. Larval zebrafish exposed to TNBS displayed intestinal-fold architecture disruption and inflammation reminiscent of human IBD. In this study, we defined a reduced biodiversity of gut bacterial community in TNBS-induced coliitis. The intestinal microbiota dysbiosis in zebrafish larvae with IBD-like colitis was characterized by an increased proportion of Proteobacteria (especially Burkholderia) and a decreased of Firmicutes(Lactobacillus group), which were significantly correlated with enterocolitis severity(Pearson correlation p < 0.01). Conclusions This is the first description of intestinal microbiota dysbiosis in zebrafish IBD-like models, and these changes correlate with TNBS-induced enterocolitis. Prevention or reversal of this dysbiosis may be a viable option for reducing the incidence and severity of human IBD.

2013-01-01

76

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

77

Simultaneous analysis of tumor and stromal gene expression profiles from xenograft models.  

PubMed

Identifying the gene expression alterations that occur in both the tumor and stroma is essential to understanding tumor biology. We have developed a dual-species microarray analysis method that allows the dissection of both tumor and stromal gene expression profiles from xenograft models, based on limited interspecies cross-hybridization on Illumina gene expression beadchips. This methodology allows for simultaneous genome-wide analysis of gene expression profiles of both tumor cells and the associated stromal tissue. PMID:21947683

Iorns, Elizabeth; Clarke, Jennifer; Ward, Toby; Dean, Sonja; Lippman, Marc

2012-01-01

78

The T61 human breast cancer xenograft: An experimental model of estrogen therapy of breast cancer  

Microsoft Academic Search

Summary Endocrine therapy is one of the principal treatment modalities of breast cancer, both in an adjuvant setting and in advanced disease. The T61 breast cancer xenograft described here provides an experimental model of the effects of estrogen treatment at a molecular level. T61 is an estrogen receptor positive tumor which was originally derived from a T1N0M0 invasive ductal cancer

Nils Briinner I; Mogens Spang-Thomsen; Kevin Cullen

1996-01-01

79

The zebrafish swimbladder: A simple model for lung elastin injury and repair.  

PubMed

In this communication we offer data to suggest that the zebrafish swimbladder may provide a simple model of elastin injury and repair which is amenable to genetic analysis and pertinent to lung physiology. In situ hybridization of zebrafish embryos illustrated that elastin gene expression is evident in the developing gut tract prior to swimbladder morphogenesis. Northern blot analysis demonstrated that the major zebrafish elastin mRNA is 2.0 kb which is significantly smaller than its higher vertebrate counterpart. Amino acid analysis of alkali-resistant protein from the anterior chamber of the adult zebrafish swimbladder showed a composition similar to higher vertebrate elastins including significant amounts of desmosine crosslinks. Electron microscopic investigations of the swimbladder wall indicate a simple structure with an inner layer of elastin fibers. Elastase delivery to the swimbladder in vitro resulted in significant fragmentation of elastin in the anterior chamber providing an environment for studying elastin repair within the tissue. PMID:10761635

Perrin, S; Rich, C B; Morris, S M; Stone, P J; Foster, J A

1999-01-01

80

A model 450 million years in the making: zebrafish and vertebrate immunity  

PubMed Central

Since its first splash 30 years ago, the use of the zebrafish model has been extended from a tool for genetic dissection of early vertebrate development to the functional interrogation of organogenesis and disease processes such as infection and cancer. In particular, there is recent and growing attention in the scientific community directed at the immune systems of zebrafish. This development is based on the ability to image cell movements and organogenesis in an entire vertebrate organism, complemented by increasing recognition that zebrafish and vertebrate immunity have many aspects in common. Here, we review zebrafish immunity with a particular focus on recent studies that exploit the unique genetic and in vivo imaging advantages available for this organism. These unique advantages are driving forward our study of vertebrate immunity in general, with important consequences for the understanding of mammalian immune function and its role in disease pathogenesis.

Renshaw, Stephen A.; Trede, Nikolaus S.

2012-01-01

81

Gastric Penetration of Amoxicillin in a Human Helicobacter pylori-Infected Xenograft Model  

PubMed Central

The delivery of antibiotics into Helicobacter pylori-infected human stomachs is still poorly understood. Human embryonic gastric xenografts in nude mice have recently been proposed as a new model for the study of H. pylori infection. Using this model, we compared the penetration of amoxicillin, after intraperitoneal administration of a dose of 20 mg/kg of body weight, into the gastric mucosae of infected and uninfected xenografts. The concentrations of this drug in serum and superficial gastric mucosae were determined at 20 min and 1 and 3 h after injection. Ten mice with H. pylori-infected grafts (n = 5) or uninfected grafts (n = 5) were studied. Mucosal samples were obtained by cryomicrotomy. The concentrations in serum were similar to those obtained in the serum of humans after oral administration of 1 g of amoxicillin. The mean area under the tissue concentration-versus-time curve from 0 to 3 h obtained for mice with infected grafts was significantly higher than that obtained for the animals with uninfected grafts (P = 0.01). These results suggest that the penetration of amoxicillin into the superficial gastric mucosa may be substantially increased in the case of H. pylori infection. Thus, human xenografts in nude mice represent a new, well-standardized model for investigation of systemic delivery of drugs into H. pylori-infected gastric mucosa.

Lozniewski, Alain; Duprez, Adrien; Renault, Corinne; Muhale, Filipe; Conroy, Marie-Christine; Weber, Michele; Le Faou, Alain; Jehl, Francois

1999-01-01

82

A model for experimental interstitial radiotherapy using intracerebral D-54MG glioma xenografts in athymic mice.  

PubMed

Due to its constant glial morphology and small variability as to tumor location and growth characteristics, the intracerebral D-54MG tumor xenograft provides the predictability and reproducibility needed by models for the study of stereotactic interstitial radiotherapy. Development and results of experimental brachytherapy in an intracerebral human gliomas derived xenograft tumor model are reported. Tumor homogenate prepared from homogenized subcutaneous D-54MG xenografts was inoculated into the frontal lobe of athymic BALB/c mice (nu/nu genotype). The D-54MG glioma xenografts grew at the site of inoculation without intraventricular or subarachnoid spread. The increase of median survival (IMS) was 58.33% for the highest dose (9370 cGy) and 33.3% for the intermediate dose (5654 cGy). In both experiments the survival prolongation was statistically significant (p < 0.05) as calculated by the Log Rank Rest for Kaplan Meier Survival Distributions. In the low dose group (3159 cGy) only a small and not significant IMS was achieved (16.67%). The results of the present investigation demonstrate the accuracy of the stereotactic operative procedure and the efficacy of experimental intracerebral interstitial radiotherapy with I 125 seeds. Using a constant dose rate, experimental interstitial brachytherapy in brain-tumor bearing nude mice was shown to result in a dose dependant survival prolongation for the treated animals. The model may help to optimize the rational basis of clinical brain tumor therapy and is well suited to simulate dose and dose rate related therapeutic effects. PMID:8927242

Lippitz, B E

1995-01-01

83

The chick chorioallantoic membrane as an in vivo xenograft model for Burkitt lymphoma  

PubMed Central

Background Burkitt lymphoma (BL) is an aggressive malignancy that arises from B-cells and belongs to the group of Non-Hodgkin lymphomas (NHL). Due to the lack of appropriate in vivo models NHL research is mainly performed in vitro. Here, we studied the use of the chick chorioallantoic membrane (CAM) for the generation of human BL xenograft tumors, which we compared with known characteristics of the human disease. Methods In order to generate experimental BL tumors, we inoculated human BL2B95 and BL2-GFP cells on the CAM. BL2B95 xenograft-tumors were grown for seven days and subsequently analyzed with transmission electron and immunofluorescence microscopy, as well as histological staining approaches. BL2-GFP cells were studied at regular intervals up to seven days, and their metastatic behavior was visualized with intravital immunofluorescence techniques. Results Xenografted BL2B95 cells formed solid tumors in the CAM model with a Ki67-index greater than 90%, preservation of typical tumor markers (CD10, CD19, CD20), a ‘starry sky’ morphology, production of agyrophilic fibers in the stroma, formation of blood and lymphatic vessels and lymphogenic dissemination of BL2B95 to distant sites. We identified macrophages, lymphocytes and heterophilic granulocytes (chick homolog of neutrophils) as the most abundant immune cells in the experimental tumors. BL2-GFP cells could be traced in real-time during their distribution in the CAM, and the first signs for their dissemination were visible after 2-3 days. Conclusions We show that xenografted BL2B95 cells generate tumors in the CAM with a high degree of cellular, molecular and proliferative concord with the human disease, supporting the application of the CAM model for NHL research with a focus on tumor-stroma interactions. Additionally we report that BL2-GFP cells, grafted on the CAM of ex ovo cultured chick embryos, provide a powerful tool to study lymphogenic dissemination in real-time.

2014-01-01

84

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

85

Preclinical antitumor activity of the diindolylmethane formulation in xenograft mouse model of prostate cancer.  

PubMed

Aim: Preclinical study of the specific anticancer pharmacological activity of the formulation containing active substance 3,3?-diindolylmethane (DIM), cod liver oil, polysorbate 80 and ?-tocopherol acetate (vitamin E), in vivo in a xenograft animal model of LNCaP. Materials and Methods: The DIM, cod liver oil, polysorbate 80 and ?-tocopherol acetate (vitamin E) formulation was intragastrically administered to BALB/c-nude (nu/nu) mice during 33 days post inoculation at the dose of 133 mg/kg/day. Antitumor activity of the test drug was estimated by the rate of tumor growth inhibition (T/C% - treated versus control), dividing the tumor volumes from treatment groups with the control groups. Results: Statistically significant tumor xenograft regressions have been shown in group which received the DIM, cod liver oil, polysorbate 80 and ?-tocopherol acetate (vitamin E) on the 37(th) day of observation post inoculation. The highest antitumor activity was achieved on the 39(th) day (T/C = 16,8%). Therapeutic effect lasts for 6 days after the end of therapy period. Conclusion: Our findings demonstrate inhibitory effect of the formulation on tumor development in the xenograft animal model due to the tumor growth rate reduction. PMID:24980762

Kiselev, V I; Drukh, V M; Muyzhnek, E L; Kuznetsov, I N; Pchelintseva, O I; Paltsev, M A

2014-06-01

86

A New Xenograft Model of Primary Central Nervous System Lymphoma  

Microsoft Academic Search

The management of primary lymphoma of the central nervous system (PCNSL) remains controversial and patients' outcome dismal. In order to investigate new selective therapeutic strategies in a controlled system, a reproducible model of PCNSL in nude rats was developed and characterized. Human B lymphoma cells (BL2) were implanted in the brain frontal area in New Zealand nude rats through a

Marco Saini; Mattia Bellinzona; Wiebke Weichhold; Madjid Samii

1999-01-01

87

Establishment of Patient-Derived Non ^ Small Cell Lung Cancer Xenografts as Models for the Identification of Predictive Biomarkers  

Microsoft Academic Search

Purpose: It was the aim of our study to establish an extensive panel of non-small cell lung cancer (NSCLC) xenograft models useful for the testing of novel compounds and for the identification of biomarkers. Experimental Design: Starting from102surgical NSCLC specimens, which were obtained from primarily diagnosed patients with early-stage tumors (T2\\/T3), 25 transplantable xenografts were established and used for further

Iduna Fichtner; Jana Rolff; Richie Soong; Jens Hoffmann; Stefanie Hammer; Anette Sommer; Michael Becker; Johannes Merk

2008-01-01

88

Unpredictable chronic stress model in zebrafish (Danio rerio): behavioral and physiological responses.  

PubMed

Zebrafish (Danio rerio) have emerged as a promising model organism to study development, toxicology, pharmacology, and neuroscience, among other areas. Despite the increasing number of studies using zebrafish, behavioral studies with this species are still elementary when compared to rodents. The aim of this study was to develop a model of unpredictable chronic stress (UCS) in zebrafish. We evaluated the effects of UCS protocol during 7 or 14 days on behavioral and physiological parameters. The effects of stress were evaluated in relation to anxiety and exploratory behavior, memory, expression of corticotrophin-releasing factor (CRF) and glucocorticoid receptor (GR), and cortisol levels. As expected, UCS protocol increased the anxiety levels, impaired cognitive function, and increased CRF while decreased GR expression. Moreover, zebrafish submitted to 7 or 14 days of UCS protocol presented increased cortisol levels. The protocol developed here is a complementary model for studying the neurobiology and the effects of chronic stress in behavioral and physiological parameters. In addition, this protocol is less time consuming than standard rodent models commonly used to study chronic stress. These results confirm UCS in zebrafish as an adequate model to preclinical studies of stress, although further studies are warranted to determine its predictive validity. PMID:21187119

Piato, Ângelo L; Capiotti, Katiucia M; Tamborski, Angélica R; Oses, Jean P; Barcellos, Leonardo J G; Bogo, Maurício R; Lara, Diogo R; Vianna, Monica R; Bonan, Carla D

2011-03-30

89

Synchronized oscillations in a mathematical model of segmentation in zebrafish  

NASA Astrophysics Data System (ADS)

Somitogenesis is a process for the development of somites which are transient, segmental structures that lie along the anterior-posterior axis of vertebrate embryos. The pattern of somites is governed by the segmentation clock and its timing is controlled by the clock genes which undergo synchronous oscillation over adjacent cells in the posterior presomitic mesoderm (PSM). In this paper, we analyze a mathematical model which depicts the kinetics of the zebrafish segmentation clock genes subject to direct autorepression by their own products under time delay, and cell-to-cell interaction through Delta-Notch signalling. Our goal is to elucidate how synchronous oscillations are generated for the cells in the posterior PSM, and how oscillations are arrested for the cells in the anterior PSM. For this system of delayed equations, an iteration technique is employed to derive the global convergence to the synchronous equilibrium, which corresponds to the oscillation-arrested. By applying the delay Hopf bifurcation theory and the center manifold theorem, we derive the criteria for the existence of stable synchronous oscillations for the cells at the tail bud of the PSM. Our analysis provides the basic parameter ranges and delay magnitudes for stable synchronous, asynchronous oscillation and oscillation-arrested. We exhibit how synchronous oscillations are affected by the degradation rates and delays. Extended from the analytic theory, further numerical findings linked to the segmentation process are presented.

Liao, Kang-Ling; Shih, Chih-Wen; Tseng, Jui-Pin

2012-04-01

90

A renewable tissue resource of phenotypically stable, biologically and ethnically diverse, patient-derived human breast cancer xenograft models.  

PubMed

Breast cancer research is hampered by difficulties in obtaining and studying primary human breast tissue, and by the lack of in vivo preclinical models that reflect patient tumor biology accurately. To overcome these limitations, we propagated a cohort of human breast tumors grown in the epithelium-free mammary fat pad of severe combined immunodeficient (SCID)/Beige and nonobese diabetic (NOD)/SCID/IL-2?-receptor null (NSG) mice under a series of transplant conditions. Both models yielded stably transplantable xenografts at comparably high rates (?21% and ?19%, respectively). Of the conditions tested, xenograft take rate was highest in the presence of a low-dose estradiol pellet. Overall, 32 stably transplantable xenograft lines were established, representing 25 unique patients. Most tumors yielding xenografts were "triple-negative" [estrogen receptor (ER)-progesterone receptor (PR)-HER2+; n = 19]. However, we established lines from 3 ER-PR-HER2+ tumors, one ER+PR-HER2-, one ER+PR+HER2-, and one "triple-positive" (ER+PR+HER2+) tumor. Serially passaged xenografts show biologic consistency with the tumor of origin, are phenotypically stable across multiple transplant generations at the histologic, transcriptomic, proteomic, and genomic levels, and show comparable treatment responses as those observed clinically. Xenografts representing 12 patients, including 2 ER+ lines, showed metastasis to the mouse lung. These models thus serve as a renewable, quality-controlled tissue resource for preclinical studies investigating treatment response and metastasis. PMID:23737486

Zhang, Xiaomei; Claerhout, Sofie; Prat, Aleix; Dobrolecki, Lacey E; Petrovic, Ivana; Lai, Qing; Landis, Melissa D; Wiechmann, Lisa; Schiff, Rachel; Giuliano, Mario; Wong, Helen; Fuqua, Suzanne W; Contreras, Alejandro; Gutierrez, Carolina; Huang, Jian; Mao, Sufeng; Pavlick, Anne C; Froehlich, Amber M; Wu, Meng-Fen; Tsimelzon, Anna; Hilsenbeck, Susan G; Chen, Edward S; Zuloaga, Pavel; Shaw, Chad A; Rimawi, Mothaffar F; Perou, Charles M; Mills, Gordon B; Chang, Jenny C; Lewis, Michael T

2013-08-01

91

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

92

Cisplatin plus paclitaxel and maintenance of bevacizumab on tumour progression, dissemination, and survival of ovarian carcinoma xenograft models  

PubMed Central

Background: Bevacizumab is being incorporated as first-line therapy with standard-of-care chemotherapy on epithelial ovarian carcinoma (EOC). We investigated bevacizumab combined with chemotherapy on tumour progression and mouse survival in EOC xenograft models. Methods: Bevacizumab was administered concomitantly with cisplatin plus paclitaxel (DDP+PTX), continued after induction (maintenance) or started after chemotherapy. The effect on tumour progression was monitored by bioluminescence imaging (BLI) (1A9-luc xenograft). Tumour dissemination into the peritoneal organs and ascites formation (HOC22 xenograft) was evaluated by histological analysis at the end of treatment (interim) and at euthanasia (survival). The effects on overall survival (OS) were investigated in both EOC models. Results: Bevacizumab with PTX+DDP delayed tumour progression in mice bearing EOC xenografts. OS was significantly extended, with complete responses, by bevacizumab continued after stopping chemotherapy in the HOC22 xenograft. Bevacizumab alone inhibited ascites formation, with only limited effect on tumour burden, but combined with PTX+DDP reduced ascites and metastases. Bevacizumab started after induction with PTX+DDP and maintained was equally effective on tumour progression and survival on 1A9-luc xenograft. Conclusion: Bevacizumab combined with chemotherapy not only affected tumour progression, but when administered as maintenance regimen significantly prolonged survival, reducing ascites, and tumour dissemination. We believe our findings are consistent with the clinical results and shed light on the potential effects of this kind of treatment on tumour progression.

Oliva, P; Decio, A; Castiglioni, V; Bassi, A; Pesenti, E; Cesca, M; Scanziani, E; Belotti, D; Giavazzi, R

2012-01-01

93

Zebrafish as a model to understand autophagy and its role in neurological disease?  

PubMed Central

In the past decade, the zebrafish (Danio rerio) has become a popular model system for the study of vertebrate development, since the embryos and larvae of this species are small, transparent and undergo rapid development ex utero, allowing in vivo analysis of embryogenesis and organogenesis. These characteristics can also be exploited by researchers interested in signaling pathways and disease processes and, accordingly, there is a growing literature on the use of zebrafish to model human disease. This model holds great potential for exploring how autophagy, an evolutionarily conserved mechanism for protein degradation, influences the pathogeneses of a range of different human diseases and for the evaluation of this pathway as a potential therapeutic strategy. Here we summarize what is known about the regulation of autophagy in eukaryotic cells and its role in neurodegenerative disease and highlight how research using zebrafish has helped further our understanding of these processes.

Fleming, Angeleen; Rubinsztein, David C.

2011-01-01

94

Protective effect of fucoidan against AAPH-induced oxidative stress in zebrafish model.  

PubMed

Fucoidan, extracted from Ecklonia cava, has been extensively studied because of its wide biological activities. However, antioxidative activities have not been yet examined. Therefore we evaluated in vitro and in vivo studies on antioxidative activities of E. cava fucoidan (ECF). ECF exhibited more prominent effects in peroxyl radical scavenging activity, compared to the other scavenging activities. Thus, ECF was further evaluated for its protective ability against 2,2'-azobis dihydrochloride induced oxidative stress in Vero cells and ECF strongly reduced the AAPH-induced oxidative damage through scavenging intracellular reactive oxygen species. Furthermore, we evaluated protective effect of ECF against AAPH-induced oxidative stress in zebrafish model. ECF significantly reduced ROS generation, lipid peroxidation and cell death in zebrafish model. These findings indicate that ECF has antioxidant activities in vitro Vero cells and in vivo zebrafish model, even though ECF is not a polyphenol or flavonoid compound and does not contain benzene rings or conjugated structures. PMID:24507271

Kim, Eun-A; Lee, Seung-Hong; Ko, Chang-ik; Cha, Seon-Heui; Kang, Min-Cheol; Kang, Sung-Myung; Ko, Seok-Chun; Lee, Won-Woo; Ko, Ju-Young; Lee, Ji-Hyeok; Kang, Nalae; Oh, Jae-Young; Ahn, Ginnae; Jee, Young Heun; Jeon, You-Jin

2014-02-15

95

The role of the DNA damage response in zebrafish and cellular models of Diamond Blackfan anemia  

PubMed Central

Ribosomal biogenesis involves the processing of pre-ribosomal RNA. A deficiency of some ribosomal proteins (RPs) impairs processing and causes Diamond Blackfan anemia (DBA), which is associated with anemia, congenital malformations and cancer. p53 mediates many features of DBA, but the mechanism of p53 activation remains unclear. Another hallmark of DBA is the upregulation of adenosine deaminase (ADA), indicating changes in nucleotide metabolism. In RP-deficient zebrafish, we found activation of both nucleotide catabolism and biosynthesis, which is consistent with the need to break and replace the faulty ribosomal RNA. We also found upregulation of deoxynucleotide triphosphate (dNTP) synthesis – a typical response to replication stress and DNA damage. Both RP-deficient zebrafish and human hematopoietic cells showed activation of the ATR/ATM-CHK1/CHK2/p53 pathway. Other features of RP deficiency included an imbalanced dNTP pool, ATP depletion and AMPK activation. Replication stress and DNA damage in cultured cells in non-DBA models can be decreased by exogenous nucleosides. Therefore, we treated RP-deficient zebrafish embryos with exogenous nucleosides and observed decreased activation of p53 and AMPK, reduced apoptosis, and rescue of hematopoiesis. Our data suggest that the DNA damage response contributes to p53 activation in cellular and zebrafish models of DBA. Furthermore, the rescue of RP-deficient zebrafish with exogenous nucleosides suggests that nucleoside supplements could be beneficial in the treatment of DBA.

Danilova, Nadia; Bibikova, Elena; Covey, Todd M.; Nathanson, David; Dimitrova, Elizabeth; Konto, Yoan; Lindgren, Anne; Glader, Bertil; Radu, Caius G.; Sakamoto, Kathleen M.; Lin, Shuo

2014-01-01

96

The role of the DNA damage response in zebrafish and cellular models of Diamond Blackfan anemia.  

PubMed

Ribosomal biogenesis involves the processing of pre-ribosomal RNA. A deficiency of some ribosomal proteins (RPs) impairs processing and causes Diamond Blackfan anemia (DBA), which is associated with anemia, congenital malformations and cancer. p53 mediates many features of DBA, but the mechanism of p53 activation remains unclear. Another hallmark of DBA is the upregulation of adenosine deaminase (ADA), indicating changes in nucleotide metabolism. In RP-deficient zebrafish, we found activation of both nucleotide catabolism and biosynthesis, which is consistent with the need to break and replace the faulty ribosomal RNA. We also found upregulation of deoxynucleotide triphosphate (dNTP) synthesis - a typical response to replication stress and DNA damage. Both RP-deficient zebrafish and human hematopoietic cells showed activation of the ATR/ATM-CHK1/CHK2/p53 pathway. Other features of RP deficiency included an imbalanced dNTP pool, ATP depletion and AMPK activation. Replication stress and DNA damage in cultured cells in non-DBA models can be decreased by exogenous nucleosides. Therefore, we treated RP-deficient zebrafish embryos with exogenous nucleosides and observed decreased activation of p53 and AMPK, reduced apoptosis, and rescue of hematopoiesis. Our data suggest that the DNA damage response contributes to p53 activation in cellular and zebrafish models of DBA. Furthermore, the rescue of RP-deficient zebrafish with exogenous nucleosides suggests that nucleoside supplements could be beneficial in the treatment of DBA. PMID:24812435

Danilova, Nadia; Bibikova, Elena; Covey, Todd M; Nathanson, David; Dimitrova, Elizabeth; Konto, Yoan; Lindgren, Anne; Glader, Bertil; Radu, Caius G; Sakamoto, Kathleen M; Lin, Shuo

2014-07-01

97

A Primary Xenograft Model of Small Cell Lung Cancer Reveals Irreversible Changes in Gene Expression Imposed by Culture In-Vitro  

PubMed Central

Traditional approaches to the preclinical investigation of cancer therapies rely on the use of established cell lines maintained in serum-based growth media. This is particularly true of small cell lung cancer (SCLC), where surgically resected tissue is rarely available. Recent attention has focused on the need for better models that preserve the integrity of cancer stem cell populations, as well as three-dimensional tumor-stromal interactions. Here we describe a primary xenograft model of SCLC in which endobronchial tumor specimens obtained from chemo-naive patients are serially propagated in vivo in immunodeficient mice. In parallel, cell lines grown in conventional tissue culture conditions were derived from each xenograft line, passaged for 6 months, and then re-implanted to generate secondary xenografts. Using the Affymetrix platform, we analyzed gene expression in primary xenograft, xenograft-derived cell line, and secondary xenograft, and compared these data to similar analyses of unrelated primary SCLC samples and laboratory models. When compared to normal lung, primary tumors, xenografts and cell lines displayed a gene expression signature specific for SCLC. Comparison of gene expression within the xenograft model identified a group of tumor-specific genes expressed in primary SCLC and xenografts that was lost during the transition to tissue culture, and that was not regained when the tumors were re-established as secondary xenografts. Such changes in gene expression may be a common feature of many cancer cell culture systems, with functional implications for the use of such models for preclinical drug development.

Daniel, Vincent C.; Marchionni, Luigi; Hierman, Jared S.; Rhodes, Jonathan T.; Devereux, Wendy L.; Rudin, Charles M.; Yung, Rex; Parmigani, Giovanni; Dorsch, Marion; Peacock, Craig D.; Watkins, D. Neil

2009-01-01

98

Evaluation of the retinoids with cisplatin and vincristine in xenograft models of neuroblastoma.  

PubMed

Retinoids have been studied for the treatment of children with neuroblastoma for >25 years. Posttransplant administration of isotretinoin is standard of care for children with high-risk neuroblastoma, whereas fenretinide remains investigational. Previous preclinical studies have evaluated the interaction of retinoids and cytotoxic agents with conflicting results. We evaluated the schedule-dependent interaction of the cytotoxic agents, vincristine and cisplatin, with the retinoids, isotretinoin and fenretinide, in xenograft models of neuroblastoma. Concomitant administration of isotretinoin or fenretinide with the cytotoxic agents did not result in any clear potentiation of cytotoxicity. PMID:23669732

Norris, Robin E; Nguyen, Vu T; Adamson, Peter C

2014-01-01

99

Zebrafish models in cardiac development and congenital heart birth defects  

PubMed Central

The zebrafish has become an ideal vertebrate animal system for investigating cardiac development due to its genetic tractability, external fertilization, early optical clarity and ability to survive without a functional cardiovascular system during development. In particular, recent advances in imaging techniques and the creation of zebrafish transgenics now permit the in vivo analysis of the dynamic cellular events that transpire during cardiac morphogenesis. As a result, the combination of these salient features provides detailed insight as to how specific genes may influence cardiac development at the cellular level. In this review, we will highlight how the zebrafish has been utilized to elucidate not only the underlying mechanisms of cardiac development and human congenital heart diseases (CHDs), but also potential pathways that may modulate cardiac regeneration. Thus, we have organized this review based on the major categories of CHDs – structural heart, functional heart, and vascular/great vessel defects, and will conclude with how the zebrafish may be further used to contribute to our understanding of specific human CHDs in the future.

Tu, Shu; Chi, Neil C.

2014-01-01

100

Global gene expression profiling confirms the molecular fidelity of primary tumor-based orthotopic xenograft mouse models of medulloblastoma.  

PubMed

We previously showed that primary tumor-based orthotopic xenograft mouse models of medulloblastoma replicated the histopathological phenotypes of patients' original tumors. Here, we performed global gene expression profiling of 11 patient-specific xenograft models to further determine whether the xenograft tumors were molecularly accurate during serial subtransplantations in mouse brains and whether they represented all the molecular subtypes of medulloblastoma that were recently described. Analysis of the transcriptomes of 9 pairs of matched passage I xenografts and patients' tumors revealed high correlation coefficients (r(2) > 0.95 in 5 models, > 0.9 in 3 models, and > 0.85 in 1 model) and only identified 69 genes in which expressions were altered (FDR = 0.0023). Subsequent pair-wise comparisons between passage I, III, and V xenografts from the 11 models further showed that no dramatic alterations were introduced (r(2) > 0.9 in 8 models and > 0.8 in 3 models). The genetic abnormalities of each model were then identified through comparison with control RNAs from 5 normal cerebella and 2 fetal brains. Hierarchical clustering using 3 previously published molecular signatures showed that our models span the whole spectrum of molecular subtypes, including SHH (n = 2), WNT (n = 2), and the most recently identified group C (n = 4) and group D (n = 3). In conclusion, we demonstrated that the 11 orthotopic medulloblastoma xenograft models were molecularly faithful to the primary tumors, and our comprehensive collection of molecularly distinct animal models should serve as a valuable resource for the development of new targeted therapies for medulloblastoma. PMID:22459127

Zhao, Xiumei; Liu, Zhigang; Yu, Litian; Zhang, Yujing; Baxter, Patricia; Voicu, Horatiu; Gurusiddappa, Sivashankarappa; Luan, Joseph; Su, Jack M; Leung, Hon-chiu Eastwood; Li, Xiao-Nan

2012-05-01

101

Global gene expression profiling confirms the molecular fidelity of primary tumor-based orthotopic xenograft mouse models of medulloblastoma  

PubMed Central

We previously showed that primary tumor-based orthotopic xenograft mouse models of medulloblastoma replicated the histopathological phenotypes of patients' original tumors. Here, we performed global gene expression profiling of 11 patient-specific xenograft models to further determine whether the xenograft tumors were molecularly accurate during serial subtransplantations in mouse brains and whether they represented all the molecular subtypes of medulloblastoma that were recently described. Analysis of the transcriptomes of 9 pairs of matched passage I xenografts and patients' tumors revealed high correlation coefficients (r2 > 0.95 in 5 models, > 0.9 in 3 models, and > 0.85 in 1 model) and only identified 69 genes in which expressions were altered (FDR = 0.0023). Subsequent pair-wise comparisons between passage I, III, and V xenografts from the 11 models further showed that no dramatic alterations were introduced (r2 > 0.9 in 8 models and > 0.8 in 3 models). The genetic abnormalities of each model were then identified through comparison with control RNAs from 5 normal cerebella and 2 fetal brains. Hierarchical clustering using 3 previously published molecular signatures showed that our models span the whole spectrum of molecular subtypes, including SHH (n = 2), WNT (n = 2), and the most recently identified group C (n = 4) and group D (n = 3). In conclusion, we demonstrated that the 11 orthotopic medulloblastoma xenograft models were molecularly faithful to the primary tumors, and our comprehensive collection of molecularly distinct animal models should serve as a valuable resource for the development of new targeted therapies for medulloblastoma.

Zhao, Xiumei; Liu, Zhigang; Yu, Litian; Zhang, Yujing; Baxter, Patricia; Voicu, Horatiu; Gurusiddappa, Sivashankarappa; Luan, Joseph; Su, Jack M.; Leung, Hon-chiu Eastwood; Li, Xiao-Nan

2012-01-01

102

Molecular characterization of patient-derived human pancreatic tumor xenograft models for preclinical and translational development of cancer therapeutics.  

PubMed

Preclinical evaluation of novel cancer agents requires models that accurately reflect the biology and molecular characteristics of human tumors. Molecular profiles of eight pancreatic ductal adenocarcinoma patient tumors were compared to corresponding passages of xenografts obtained by grafting tumor fragments into immunocompromised mice. Molecular characterization was performed by copy number analysis, gene expression and microRNA microarrays, mutation analysis, short tandem repeat (STR) profiling, and immunohistochemistry. Xenografts were found to be highly representative of their respective tumors, with a high degree of genetic stability observed by STR profiling and mutation analysis. Copy number variation (CNV) profiles of early and late xenograft passages were similar, with recurrent losses on chromosomes 1p, 3p, 4q, 6, 8p, 9, 10, 11q, 12p, 15q, 17, 18, 20p, and 21 and gains on 1q, 5p, 8q, 11q, 12q, 13q, 19q, and 20q. Pearson correlations of gene expression profiles of tumors and xenograft passages were above 0.88 for all models. Gene expression patterns between early and late passage xenografts were highly stable for each individual model. Changes observed in xenograft passages largely corresponded to human stromal compartment genes and inflammatory processes. While some differences exist between the primary tumors and corresponding xenografts, the molecular profiles remain stable after extensive passaging. Evidence for stability in molecular characteristics after several rounds of passaging lends confidence to clinical relevance and allows for expansion of models to generate the requisite number of animals required for cohorts used in drug screening and development studies. PMID:24204193

Mattie, Mike; Christensen, Ashley; Chang, Mi Sook; Yeh, William; Said, Suzanne; Shostak, Yuriy; Capo, Linnette; Verlinsky, Alla; An, Zili; Joseph, Ingrid; Zhang, Yi; Kumar-Ganesan, Sathish; Morrison, Karen; Stover, David; Challita-Eid, Pia

2013-10-01

103

Molecular Characterization of Patient-Derived Human Pancreatic Tumor Xenograft Models for Preclinical and Translational Development of Cancer Therapeutics12  

PubMed Central

Preclinical evaluation of novel cancer agents requires models that accurately reflect the biology and molecular characteristics of human tumors. Molecular profiles of eight pancreatic ductal adenocarcinoma patient tumors were compared to corresponding passages of xenografts obtained by grafting tumor fragments into immunocompromised mice. Molecular characterization was performed by copy number analysis, gene expression and microRNA microarrays, mutation analysis, short tandem repeat (STR) profiling, and immunohistochemistry. Xenografts were found to be highly representative of their respective tumors, with a high degree of genetic stability observed by STR profiling and mutation analysis. Copy number variation (CNV) profiles of early and late xenograft passages were similar, with recurrent losses on chromosomes 1p, 3p, 4q, 6, 8p, 9, 10, 11q, 12p, 15q, 17, 18, 20p, and 21 and gains on 1q, 5p, 8q, 11q, 12q, 13q, 19q, and 20q. Pearson correlations of gene expression profiles of tumors and xenograft passages were above 0.88 for all models. Gene expression patterns between early and late passage xenografts were highly stable for each individual model. Changes observed in xenograft passages largely corresponded to human stromal compartment genes and inflammatory processes. While some differences exist between the primary tumors and corresponding xenografts, the molecular profiles remain stable after extensive passaging. Evidence for stability in molecular characteristics after several rounds of passaging lends confidence to clinical relevance and allows for expansion of models to generate the requisite number of animals required for cohorts used in drug screening and development studies.

Mattie, Mike; Christensen, Ashley; Chang, Mi Sook; Yeh, William; Said, Suzanne; Shostak, Yuriy; Capo, Linnette; Verlinsky, Alla; An, Zili; Joseph, Ingrid; Zhang, Yi; Kumar-Ganesan, Sathish; Morrison, Karen; Stover, David; Challita-Eid, Pia

2013-01-01

104

Zebrafish (Danio rerio) as a model for the study of aging and exercise: physical ability and trainability decrease with age.  

PubMed

A rapidly aging global population has motivated the development and use of models for human aging. Studies on aging have shown parallels between zebrafish and humans at the internal organization level; however, few parallels have been studied at the whole-organism level. Furthermore, the effectiveness of exercise as a method to mitigate the effects of aging has not been studied in zebrafish. We investigated the effects of aging and intermittent exercise on swimming performance, kinematics and behavior. Young, middle-aged and old zebrafish (20-29, 36-48 and 60-71% of average lifespan, respectively) were exercised to exhaustion in endurance and sprint swimming tests once a week for four weeks. Both endurance and sprint performance decreased with increased age. Swimming performance improved with exercise training in young and middle-aged zebrafish, but not in old zebrafish. Tail-beat amplitude, which is akin to stride length in humans, increased for all age groups with training. Zebrafish turning frequency, which is an indicator of routine activity, decreased with age but showed no change with exercise. In sum, our results show that zebrafish exhibit a decline in whole-organism performance and trainability with age. These findings closely resemble the senescence-related declines in physical ability experienced by humans and mammalian aging models and therefore support the use of zebrafish as a model for human exercise and aging. PMID:24316042

Gilbert, Matthew J H; Zerulla, Tanja C; Tierney, Keith B

2014-02-01

105

A single intravenous injection of oncolytic picornavirus SVV-001 eliminates medulloblastomas in primary tumor-based orthotopic xenograft mouse models  

PubMed Central

Difficulties of drug delivery across the blood–brain barrier (BBB) and failure to eliminate cancer stem cells (CSCs) are believed to be the major causes of tumor recurrences in children with medulloblastoma (MB). Seneca Valley virus-001 (SVV-001) is a naturally occurring oncolytic picornavirus that can be systemically administered. Here, we report its antitumor activities against MB cells in a panel of 10 primary tumor-based orthotopic xenograft mouse models. We found that SVV-001 killed the primary cultured xenograft cells, infected and replicated in tumor cells expressing CSC surface marker CD133, and eliminated tumor cells capable of forming neurospheres in vitro in 5 of the 10 xenograft models. We confirmed that SVV-001 could pass through BBB in vivo. A single i.v. injection of SVV-001 in 2 anaplastic MB models led to widespread infection of the preformed intracerebellar (ICb) xenografts, resulting in significant increase in survival (2.2–5.9-fold) in both models and complete elimination of ICb xenografts in 8 of the 10 long-term survivors. Mechanistically, we showed that the intracellular replication of SVV-001 is mediated through a subverted autophagy that is different from the bona fide autophagic process induced by rapamycin. Our data suggest that SVV-001 is well suited for MB treatment. This work expands the current views in the oncolytic therapy field regarding the utility of oncolytic viruses in simultaneous targeting of stem and nonstem tumor cells.

Yu, Litian; Baxter, Patricia A.; Zhao, Xiumei; Liu, Zhigang; Wadhwa, Lalita; Zhang, Yujing; Su, Jack MF; Tan, Xiaojie; Yang, Jianhua; Adesina, Adekunle; Perlaky, Lazlo; Hurwitz, Mary; Idamakanti, Neeraja; Police, Seshidhar Reddy; Hallenbeck, Paul L.; Blaney, Susan M.; Chintagumpala, Murali; Hurwitz, Richard L.; Li, Xiao-Nan

2011-01-01

106

Validation of the Zebrafish Pentylenetetrazol Seizure Model: Locomotor versus Electrographic Responses to Antiepileptic Drugs  

PubMed Central

Zebrafish have recently emerged as an attractive in vivo model for epilepsy. Seven-day-old zebrafish larvae exposed to the GABAA antagonist pentylenetetrazol (PTZ) exhibit increased locomotor activity, seizure-like behavior, and epileptiform electrographic activity. A previous study showed that 12 out of 13 antiepileptic drugs (AEDs) suppressed PTZ-mediated increases in larval movement, indicating the potential utility of zebrafish as a high-throughput in vivo model for AED discovery. However, a question remained as to whether an AED-induced decrease in locomotion is truly indicative of anticonvulsant activity, as some drugs may impair larval movement through other mechanisms such as general toxicity or sedation. We therefore carried out a study in PTZ-treated zebrafish larvae, to directly compare the ability of AEDs to inhibit seizure-like behavioral manifestations with their capacity to suppress epileptiform electrographic activity. We re-tested the 13 AEDs of which 12 were previously reported to inhibit convulsions in the larval movement tracking assay, administering concentrations that did not, on their own, impair locomotion. In parallel, we carried out open-field recordings on larval brains after treatment with each AED. For the majority of AEDs we obtained the same response in both the behavioral and electrographic assays. Overall our data correlate well with those reported in the literature for acute rodent PTZ tests, indicating that the larval zebrafish brain is more discriminatory than previously thought in its response to AEDs with different modes of action. Our results underscore the validity of using the zebrafish larval locomotor assay as a rapid first-pass screening tool in assessing the anticonvulsant and/or proconvulsant activity of compounds, but also highlight the importance of performing adequate validation when using in vivo models.

Buenafe, Olivia E. M.; Clinckers, Ralph; Smolders, Ilse; de Witte, Peter A. M.; Crawford, Alexander D.; Esguerra, Camila V.

2013-01-01

107

The Nordic countries meeting on the zebrafish as a model for development and disease 2012.  

PubMed

The first Nordic Countries Meeting on the Zebrafish as a Model for Development and Disease took place at Karolinska Institutet in Stockholm, November 21-23, 2012. The meeting gathered 130 scientists, students, and company representatives from Iceland, Finland, Norway, Denmark, and Sweden, as well as invited guests and keynote speakers from England, Scotland, Germany, Poland, The Netherlands, Singapore, Japan, and the United States. Presentations covered a wide range of topics, including developmental biology, genetics, evolutionary biology, toxicology, behavioral studies, and disease mechanisms. The need for formal guidance and training in zebrafish housing, husbandry, and health monitoring was recognized, and the meeting expressed its support for the joint working group of the FELASA/COST action BM0804 EuFishBioMed. The decision was made to turn the Nordic meeting into an annual event and create a Nordic network of zebrafish researchers. PMID:23590403

Andersson Lendahl, Monika; Zetterberg, Henrik

2013-03-01

108

Global Metabolomics Reveals Urinary Biomarkers of Breast Cancer in a MCF-7 Xenograft Mouse Model  

PubMed Central

Global metabolomics analysis has the potential to uncover novel metabolic pathways that are differentially regulated during carcinogenesis, aiding in biomarker discovery for early diagnosis and remission monitoring. Metabolomics studies with human samples can be problematic due to high inter-individual variation; however xenografts of human cancers in mice offer a well-controlled model system. Urine was collected from a xenograft mouse model of MCF-7 breast cancer and analyzed by mass spectrometry-based metabolomics to identify metabolites associated with cancer progression. Over 10 weeks, 24 h urine was collected weekly from control mice, mice dosed with estradiol cypionate (1 mg/mL), mice inoculated with MCF-7 cells (1 × 107) and estradiol cypionate (1 mg/mL), and mice dosed with MCF-7 cells (1 × 107) only (n = 10/group). Mice that received both estradiol cypionate and MCF-7 cells developed tumors from four weeks after inoculation. Five urinary metabolites were identified that were associated with breast cancer; enterolactone glucuronide, coumaric acid sulfate, capric acid glucuronide, an unknown metabolite, and a novel mammalian metabolite, “taurosebacic acid”. These metabolites revealed a correlation between tumor growth, fatty acid synthesis, and potential anti-proliferative effects of gut microbiota-metabolized food derivatives. These biomarkers may be of value for early diagnosis of cancer, monitoring of cancer therapeutics, and may also lead to future mechanistic studies.

Johnson, Caroline H.; Manna, Soumen K.; Krausz, Kristopher W.; Bonzo, Jessica A.; Divelbiss, Raymond D.; Hollingshead, Melinda G.; Gonzalez, Frank J.

2013-01-01

109

Small-sample inference for incomplete longitudinal data with truncation and censoring in tumor xenograft models.  

PubMed

In cancer drug development, demonstrating activity in xenograft models, where mice are grafted with human cancer cells, is an important step in bringing a promising compound to humans. A key outcome variable is the tumor volume measured in a given period of time for groups of mice given different doses of a single or combination anticancer regimen. However, a mouse may die before the end of a study or may be sacrificed when its tumor volume quadruples, and its tumor may be suppressed for some time and then grow back. Thus, incomplete repeated measurements arise. The incompleteness or missingness is also caused by drastic tumor shrinkage (<0.01 cm3) or random truncation. Because of the small sample sizes in these models, asymptotic inferences are usually not appropriate. We propose two parametric test procedures based on the EM algorithm and the Bayesian method to compare treatment effects among different groups while accounting for informative censoring. A real xenograft study on a new antitumor agent, temozolomide, combined with irinotecan is analyzed using the proposed methods. PMID:12229996

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

2002-09-01

110

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

2012-05-01

111

A murine xenograft model for a transmissible cancer in Tasmanian devils.  

PubMed

The number of Tasmanian devils in the wild is rapidly declining owing to a transmissible cancer, devil facial tumor disease (DFTD). Although progress has been made to understand the spread of this disease, crucial research on the pathogenesis of DFTD has been limited because of the threatened status of the host species. Here, the authors describe the development of a NOD/SCID (nonobese diabetic / severe combined immunodeficiency) mouse model that reproduces DFTD and provides a much-needed model to undertake studies into this intriguing transmissible cancer. Histologically, the DFTD produced in NOD/SCID mice (xenografted DFTD) was indistinguishable from the DFTD identified in Tasmanian devils. At the protein level, all xenografted DFTD tumors expressed periaxin, a marker that confirmed the diagnosis of DFTD. The karyotype of DFTD in NOD/SCID mice reproduced similar chromosomal alterations as seen in diseased devils. Furthermore, each NOD/SCID mouse inoculated with cultured DFTD tumor cells developed tumors, whereas DFTD did not develop in any of the inoculated immune-competent BALB/c mice. PMID:20861503

Kreiss, A; Tovar, C; Obendorf, D L; Dun, K; Woods, G M

2011-03-01

112

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

113

Translating Discovery in Zebrafish Pancreatic Development to Human Pancreatic Cancer: Biomarkers, Targets, Pathogenesis, and Therapeutics  

PubMed Central

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.

Kazi, Abid A.; Yee, Rosemary K.

2013-01-01

114

Antitumor activity of chemoendocrine therapy in premenopausal and postmenopausal models with human breast cancer xenografts.  

PubMed

We examined the efficacy of chemoendocrine therapy using capecitabine as a chemotherapeutic agent in premenopausal and postmenopausal models with estrogen receptor (ER)-positive human breast cancer xenografts. Tamoxifen and letrozole were used as endocrine therapeutic agents for premenopausal and postmenopausal models, respectively. The antitumor activity of capecitabine in combination was significantly superior to either monotherapy treatment in both premenopausal (p<0.01) and postmenopausal (p<0.05) models. No increase in toxicity in terms of body weight loss was observed during treatment in either of the xenograft models. In the premenopausal model, the level of thymidine phosphorylase (TP), a key enzyme generating 5-FU from capecitabine, was upregulated (p<0.05) in tumors by tamoxifen but not by letrozole treatment in the postmenopausal model. The combination of 5'-deoxy-5-fluorouridine (5'-DFUR; an intermediate of capecitabine) with 4-hydroxytamoxifen (4-OHT; an active form of tamoxifen) or letrozole was also evaluated in vitro by using estrogen-responsive element (ERE) reporter gene assays aimed to model premenopausal and postmenopausal breast cancer. Both combinations decreased the number of estrogen-responding cells in a concentration-dependent manner and further analysis by isobolograms revealed a synergistic effect of the combination of 5'-DFUR with 4-OHT, and at least an additive effect of the combination of 5'-DFUR with letrozole. These results suggest that chemoendocrine therapy using capecitabine may be a useful treatment modality for patients with hormone-receptor-positive breast cancer, regardless of the menopausal status and should be explored in clinical trials. PMID:22076074

Kataoka, Motoyuki; Yamaguchi, Yuri; Moriya, Yoichiro; Sawada, Noriaki; Yasuno, Hideyuki; Kondoh, Kumiko; Evans, Dean B; Mori, Kazushige; Hayashi, Shin-Ichi

2012-02-01

115

Predictive Markers of Efficacy for an Angiopoietin-2 Targeting Therapeutic in Xenograft Models  

PubMed Central

The clinical efficacy of anti-angiogenic therapies has been difficult to predict, and biomarkers that can predict responsiveness are sorely needed in this era of personalized medicine. CVX-060 is an angiopoietin-2 (Ang2) targeting therapeutic, consisting of two peptides that bind Ang2 with high affinity and specificity, covalently fused to a scaffold antibody. In order to optimize the use of this compound in the clinic the construction of a predictive model is described, based on the efficacy of CVX-060 in 13 cell line and 2 patient-derived xenograft models. Pretreatment size tumors from each of the models were profiled for the levels of 27 protein markers of angiogenesis, SNP haplotype in 5 angiogenesis genes, and somatic mutation status for 11 genes implicated in tumor growth and/or vascularization. CVX-060 efficacy was determined as tumor growth inhibition (TGI%) at termination of each study. A predictive statistical model was constructed based on the correlation of these efficacy data with the marker profiles, and the model was subsequently tested by prospective analysis in 11 additional models. The results reveal a range of CVX-060 efficacy in xenograft models of diverse tissue types (0-64% TGI, median = 27%) and define a subset of 3 proteins (Ang1, EGF, Emmprin), the levels of which may be predictive of TGI by Ang2 blockade. The direction of the associations is such that better efficacy correlates with high levels of target and low levels of compensatory/antagonizing molecules. This effort has revealed a set of candidate predictive markers for CVX-060 efficacy that will be further evaluated in ongoing clinical trials.

Triana-Baltzer, Gallen; Pavlicek, Adam; Goulart, Ariadne; Huang, Hanhua; Pirie-Shepherd, Steven; Levin, Nancy

2013-01-01

116

Effect of cyclooxygenase inhibitors in a xenograft model of canine mammary tumours.  

PubMed

Inhibition of cyclooxygenase-2 (COX-2) represents a possible avenue for the prevention and/or treatment of some cancers. Our goal was to compare the effect of a selective inhibitor of COX-2, deracoxib, and a COX-1 and -2 inhibitor, piroxicam, on the growth of canine mammary tumours in a murine model. CMT-9 was used to induce xenografts in nude mice. Mice were treated with piroxicam (0.6 mg kg(-1)), deracoxib (6 mg kg(-1)) or a control solution. Tumour volumes between 0 and 24 days post-treatment showed no significant difference between all groups. A second series of experiments was performed with a higher dose of piroxicam (0.9 mg kg(-1)). Tumour volumes between 14 and 21 days post-treatment were significantly smaller in piroxicam-treated mice compared with controls. These results demonstrate that COX inhibition reduced the growth of canine mammary cancer xenografts in mice, suggesting that COX inhibitors could have a positive effect in dogs. PMID:21848619

Sonzogni-Desautels, K; Knapp, D W; Sartin, E; Doré, M

2011-09-01

117

Hypoxia is not required for human endometrial breakdown or repair in a xenograft model of menstruation.  

PubMed

Menstrual endometrial breakdown induced by estradiol and progesterone withdrawal is regularly attributed to vasospasm of spiral arteries causing ischemia and hypoxia. We investigated whether hypoxia actually occurred in an in vivo model of menstruation. Three complementary approaches were used to look for signs of hypoxia in fragments of human functionalis xenografted to ovariectomized immunodeficient mice bearing pellets-releasing estradiol and progesterone, and then deprived of ovarian steroids. Hormone withdrawal 21 d after grafting induced menstrual breakdown and MMP expression within 4 d. Local partial oxygen pressure (pO2) was measured by electron paramagnetic resonance using implanted lithium phtalocyanine crystals. In mice with hormone maintenance until sacrifice, pO2 was low one week after grafting (14.8±3.4 mmHg) but increased twofold from the second week when tissue was largely revascularized. After 3 wk, pO2 was not modified by hormone withdrawal but was slightly increased on hormone reimpregnation 4 d after removal (34.7±6.1 mmHg) by comparison with hormone maintenance (27.1±8.6 mmHg). These results were confirmed using fluorescence quenching-based OxyLite measurements. In a further search for signs of hypoxia, we did not find significant HIF1-? immunostaining, nor pimonidazole adducts after hormone withdrawal. We conclude that hypoxia is not needed to trigger menstrual-like tissue breakdown or repair in human endometrial xenograft. PMID:23729593

Coudyzer, Pauline; Lemoine, Pascale; Jordan, Bénédicte F; Gallez, Bernard; Galant, Christine; Nisolle, Michelle; Courtoy, Pierre J; Henriet, Patrick; Marbaix, Etienne

2013-09-01

118

Curcumin induces apoptosis and inhibits growth of human Burkitt's lymphoma in xenograft mouse model.  

PubMed

Curcumin, a natural compound extracted from rhizomes of curcuma Curcuma species, has been shown to possess potent anti-inflammatory, anti-tumor and anti-oxidative properties. However, the mechanism of action of the compound remains poorly understood. In this report, we have analyzed the effects of curcumin on the cell proliferation of Burkitt's lymphoma Raji cells. The results demonstrated that curcumin could effectively inhibit the growth of Raji cells in a dose- and time-dependent manner. Further studies indicated that curcumin treatment resulted in apoptosis of cells. Biochemical analysis showed that the expression of Bax, Bid and cytochrome C were up-regulated, while the expression of oncogene c-Myc was down regulated after curcumin treatment. Furthermore, poly (ADP-ribose) polymerase (PARP) cleavage was induced by the compound. Interestingly, the antiapoptotic Bcl-2 expression was not significantly changed in Raji cells after curcumin treatment. These results suggested that the mechanism of action of curcumin was to induce mitochondrial damage and therefore led to Raji cell apoptosis. We further investigated the in vivo effects of curcumin on the growth of xenograft tumors in nude mice. The results showed that curcumin could effectively inhibit tumor growth in the xenograft mouse model. The overall results showed that curcumin could suppress the growth of Burkitt's lymphoma cells in both in vitro and in vitro systems. PMID:19326074

Li, Zai-xin; Ouyang, Ke-qing; Jiang, Xv; Wang, Dong; Hu, Yinghe

2009-03-31

119

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

120

A zebrafish model of chordoma initiated by notochord-driven expression of HRASV12.  

PubMed

Chordoma is a malignant tumor thought to arise from remnants of the embryonic notochord, with its origin in the bones of the axial skeleton. Surgical resection is the standard treatment, usually in combination with radiation therapy, but neither chemotherapeutic nor targeted therapeutic approaches have demonstrated success. No animal model and only few chordoma cell lines are available for preclinical drug testing, and, although no druggable genetic drivers have been identified, activation of EGFR and downstream AKT-PI3K pathways have been described. Here, we report a zebrafish model of chordoma, based on stable transgene-driven expression of HRASV12 in notochord cells during development. Extensive intra-notochordal tumor formation is evident within days of transgene expression, ultimately leading to larval death. The zebrafish tumors share characteristics of human chordoma as demonstrated by immunohistochemistry and electron microscopy. The mTORC1 inhibitor rapamycin, which has some demonstrated activity in a chordoma cell line, delays the onset of tumor formation in our zebrafish model, and improves survival of tumor-bearing fish. Consequently, the HRASV12-driven zebrafish model of chordoma could enable high-throughput screening of potential therapeutic agents for the treatment of this refractory cancer. PMID:24311731

Burger, Alexa; Vasilyev, Aleksandr; Tomar, Ritu; Selig, Martin K; Nielsen, G Petur; Peterson, Randall T; Drummond, Iain A; Haber, Daniel A

2014-07-01

121

A zebrafish model of chordoma initiated by notochord-driven expression of HRASV12  

PubMed Central

Chordoma is a malignant tumor thought to arise from remnants of the embryonic notochord, with its origin in the bones of the axial skeleton. Surgical resection is the standard treatment, usually in combination with radiation therapy, but neither chemotherapeutic nor targeted therapeutic approaches have demonstrated success. No animal model and only few chordoma cell lines are available for preclinical drug testing, and, although no druggable genetic drivers have been identified, activation of EGFR and downstream AKT-PI3K pathways have been described. Here, we report a zebrafish model of chordoma, based on stable transgene-driven expression of HRASV12 in notochord cells during development. Extensive intra-notochordal tumor formation is evident within days of transgene expression, ultimately leading to larval death. The zebrafish tumors share characteristics of human chordoma as demonstrated by immunohistochemistry and electron microscopy. The mTORC1 inhibitor rapamycin, which has some demonstrated activity in a chordoma cell line, delays the onset of tumor formation in our zebrafish model, and improves survival of tumor-bearing fish. Consequently, the HRASV12-driven zebrafish model of chordoma could enable high-throughput screening of potential therapeutic agents for the treatment of this refractory cancer.

Burger, Alexa; Vasilyev, Aleksandr; Tomar, Ritu; Selig, Martin K.; Nielsen, G. Petur; Peterson, Randall T.; Drummond, Iain A.; Haber, Daniel A.

2014-01-01

122

The use of xenograft models for the selection of cancer treatments with the EGFR as an example  

Microsoft Academic Search

Mouse models of cancer have consistently been used to qualify new anti-cancer drugs for development of human clinical trials. The most used models are xenografts of human tumors grown subcutaneously in immunodeficient mice such as athymic (nude) or severe combined immune deficient (SCID) mice. However, the number of anti-cancer agents that fail in the clinic far outweighs those considered effective,

Teresa Troiani; Clorinda Schettino; Erika Martinelli; Floriana Morgillo; Giampaolo Tortora; Fortunato Ciardiello

2008-01-01

123

Developmental Roles of D-bifunctional Protein-A Zebrafish Model of Peroxisome Dysfunction  

PubMed Central

The peroxisome is an intracellular organelle that responds dynamically to environmental changes. Various model organisms have been used to study the roles of peroxisomal proteins in maintaining cellular homeostasis. By taking advantage of the zebrafish model whose early stage of embryogenesis is dependent on yolk components, we examined the developmental roles of the D-bifunctional protein (Dbp), an essential enzyme in the peroxisomal ?-oxidation. The knockdown of dbp in zebrafish phenocopied clinical manifestations of its deficiency in human, including defective craniofacial morphogenesis, growth retardation, and abnormal neuronal development. Overexpression of murine Dbp rescued the morphological phenotypes induced by dbp knockdown, indicative of conserved roles of Dbp during zebrafish and mammalian development. Knockdown of dbp impaired normal development of blood, blood vessels, and most strikingly, endoderm-derived organs including the liver and pancreas - a phenotype not reported elsewhere in connection with peroxisome dysfunction. Taken together, our results demonstrate for the first time that zebrafish might be a useful model animal to study the role of peroxisomes during vertebrate development.

Kim, Yong-Il; Bhandari, Sushil; Lee, Joon No; Yoo, Kyeong-Won; Kim, Se-Jin; Oh, Gi-Su; Kim, Hyung-Jin; Cho, Meyoung; Kwak, Jong-Young; So, Hong-Seob; Park, Raekil; Choe, Seong-Kyu

2014-01-01

124

Analyzing autophagy in zebrafish.  

PubMed

The transparency, external development and simple drug administration of zebrafish embryos makes them a useful model for studying autophagy during embryonic development in vivo. Cloning of zebrafish lc3 and generation of a transgenic GFP-Lc3 fish line provide excellent tools to monitor autophagy in this organism. ( 1) This protocol discusses several convenient autophagy assays in zebrafish, including immunoblotting of Lc3 lipidation, microscopy imaging of GFP-Lc3 and lysosomal staining. PMID:20495344

He, Congcong; Klionsky, Daniel J

2010-07-01

125

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

2013-07-01

126

New Model Systems to Illuminate Thyroid Organogenesis. Part I: An Update on the Zebrafish Toolbox  

PubMed Central

Thyroid dysgenesis (TD) resulting from defects during embryonic thyroid development represents a major cause of congenital hypothyroidism. The pathogenetic mechanisms of TD in human newborns, however, are still poorly understood and disease-causing genetic variants have been identified in only a small percentage of TD cases. This limited understanding of the pathogenesis of TD is partly due to a lack of knowledge on how intrinsic factors and extrinsic signalling cues orchestrate the differentiation of thyroid follicular cells and the morphogenesis of thyroid tissue. Recently, embryonic stem cells and zebrafish embryos emerged as novel model systems that allow for innovative experimental approaches in order to decipher cellular and molecular mechanisms of thyroid development and to unravel pathogenic mechanisms of TD. Zebrafish embryos offer several salient properties for studies on thyroid organogenesis including rapid and external development, optical transparency, ease of breeding, relative short generation time and amenability for genome editing. In this review, we will highlight recent advances in the zebrafish toolkit to visualize cellular dynamics of organ development and discuss specific prospects of the zebrafish model for studies on vertebrate thyroid development and human congenital thyroid diseases.

Opitz, Robert; Antonica, Francesco; Costagliola, Sabine

2013-01-01

127

Analysis of Blood Coagulation in the Zebrafish  

Microsoft Academic Search

The zebrafish (Danio rerio) is a unique animal model in which saturation mutagenesis has been used to identify genes involved in vertebrate development. The relevance of the zebrafish as a genetic model for hemostasis depends, in large part, on the degree of similarity between the zebrafish and mammalian systems. The diminutive size of the zebrafish poses technical problems for analysis

Pudur Jagadeeswaran

1999-01-01

128

Establishment and Characterization of the First Pediatric Adrenocortical Carcinoma Xenograft Model Identifies Topotecan as a Potential Chemotherapeutic Agent  

PubMed Central

Purpose Pediatric adrenocortical carcinoma (ACC) is a rare and highly aggressive malignancy. Conventional chemotherapeutic agents have shown limited utility and are largely ineffective in treating children with advanced ACC. The lack of cell lines and animal models of pediatric ACC has hampered the development of new therapies. Here we report the establishment of the first pediatric ACC xenograft model and the characterization of its sensitivity to selected chemotherapeutic agents. Experimental Design A tumor from an 11-year-old boy with previously untreated ACC was established as a subcutaneous xenograft in immunocompromised CB17 scid?/? mice. The patient harbored a germline TP53 G245C mutation, and the primary tumor showed loss of heterozygosity with retention of the mutated TP53 allele. Histopathology, DNA fingerprinting, gene expression profiling, and biochemical analyses of the xenograft were performed and compared with the primary tumor and normal adrenal cortex. The second endpoint was to assess the preliminary antitumor activity of selected chemotherapeutic agents. Results The xenograft maintained the histopathologic and molecular features of the primary tumor. Screening the xenograft for drug responsiveness showed cisplatin had a potent antitumor effect. However, etoposide, doxorubicin, and a panel of other common cancer drugs had little or no antitumor activity, with the exception of topotecan, which was found to significantly inhibit tumor growth. Consistent with these preclinical findings, topotecan as a single agent in a child with relapsed ACC resulted in disease stabilization. Conclusion Our study established a novel TP53-associated pediatric ACC xenograft and identified topotecan as a potentially effective agent for treating children with this disease.

Pinto, Emilia M.; Morton, Christopher; Rodriguez-Galindo, Carlos; McGregor, Lisa; Davidoff, Andrew M.; Mercer, Kimberly; Debelenko, Larisa V.; Billups, Catherine; Ribeiro, Raul C.; Zambetti, Gerard P.

2013-01-01

129

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

130

NAD+ biosynthesis ameliorates a zebrafish model of muscular dystrophy.  

PubMed

Muscular dystrophies are common, currently incurable diseases. A subset of dystrophies result from genetic disruptions in complexes that attach muscle fibers to their surrounding extracellular matrix microenvironment. Cell-matrix adhesions are exquisite sensors of physiological conditions and mediate responses that allow cells to adapt to changing conditions. Thus, one approach towards finding targets for future therapeutic applications is to identify cell adhesion pathways that mediate these dynamic, adaptive responses in vivo. We find that nicotinamide riboside kinase 2b-mediated NAD+ biosynthesis, which functions as a small molecule agonist of muscle fiber-extracellular matrix adhesion, corrects dystrophic phenotypes in zebrafish lacking either a primary component of the dystrophin-glycoprotein complex or integrin alpha7. Exogenous NAD+ or a vitamin precursor to NAD+ reduces muscle fiber degeneration and results in significantly faster escape responses in dystrophic embryos. Overexpression of paxillin, a cell adhesion protein downstream of NAD+ in this novel cell adhesion pathway, reduces muscle degeneration in zebrafish with intact integrin receptors but does not improve motility. Activation of this pathway significantly increases organization of laminin, a major component of the extracellular matrix basement membrane. Our results indicate that the primary protective effects of NAD+ result from changes to the basement membrane, as a wild-type basement membrane is sufficient to increase resilience of dystrophic muscle fibers to damage. The surprising result that NAD+ supplementation ameliorates dystrophy in dystrophin-glycoprotein complex- or integrin alpha7-deficient zebrafish suggests the existence of an additional laminin receptor complex that anchors muscle fibers to the basement membrane. We find that integrin alpha6 participates in this pathway, but either integrin alpha7 or the dystrophin-glycoprotein complex is required in conjunction with integrin alpha6 to reduce muscle degeneration. Taken together, these results define a novel cell adhesion pathway that may have future therapeutic relevance for a broad spectrum of muscular dystrophies. PMID:23109907

Goody, Michelle F; Kelly, Meghan W; Reynolds, Christine J; Khalil, Andre; Crawford, Bryan D; Henry, Clarissa A

2012-01-01

131

NAD+ Biosynthesis Ameliorates a Zebrafish Model of Muscular Dystrophy  

PubMed Central

Muscular dystrophies are common, currently incurable diseases. A subset of dystrophies result from genetic disruptions in complexes that attach muscle fibers to their surrounding extracellular matrix microenvironment. Cell-matrix adhesions are exquisite sensors of physiological conditions and mediate responses that allow cells to adapt to changing conditions. Thus, one approach towards finding targets for future therapeutic applications is to identify cell adhesion pathways that mediate these dynamic, adaptive responses in vivo. We find that nicotinamide riboside kinase 2b-mediated NAD+ biosynthesis, which functions as a small molecule agonist of muscle fiber-extracellular matrix adhesion, corrects dystrophic phenotypes in zebrafish lacking either a primary component of the dystrophin-glycoprotein complex or integrin alpha7. Exogenous NAD+ or a vitamin precursor to NAD+ reduces muscle fiber degeneration and results in significantly faster escape responses in dystrophic embryos. Overexpression of paxillin, a cell adhesion protein downstream of NAD+ in this novel cell adhesion pathway, reduces muscle degeneration in zebrafish with intact integrin receptors but does not improve motility. Activation of this pathway significantly increases organization of laminin, a major component of the extracellular matrix basement membrane. Our results indicate that the primary protective effects of NAD+ result from changes to the basement membrane, as a wild-type basement membrane is sufficient to increase resilience of dystrophic muscle fibers to damage. The surprising result that NAD+ supplementation ameliorates dystrophy in dystrophin-glycoprotein complex– or integrin alpha7–deficient zebrafish suggests the existence of an additional laminin receptor complex that anchors muscle fibers to the basement membrane. We find that integrin alpha6 participates in this pathway, but either integrin alpha7 or the dystrophin-glycoprotein complex is required in conjunction with integrin alpha6 to reduce muscle degeneration. Taken together, these results define a novel cell adhesion pathway that may have future therapeutic relevance for a broad spectrum of muscular dystrophies.

Goody, Michelle F.; Kelly, Meghan W.; Reynolds, Christine J.; Khalil, Andre; Crawford, Bryan D.; Henry, Clarissa A.

2012-01-01

132

Inflammation precedes the development of human malignant mesotheliomas in a SCID mouse xenograft model  

PubMed Central

Asbestos fibers cause chronic inflammation that may be critical to the development of malignant mesothelioma (MM). Two human MM cell lines (Hmeso, PPM Mill) were used in a SCID mouse xenograft model to assess time-dependent patterns of inflammation and tumor formation. After intraperitoneal (IP) injection of MM cells, mice were euthanized at 7, 14, and 30 days, and peritoneal lavage fluid (PLF) was examined for immune cell profiles and human and mouse cytokines. Increases in human MM-derived IL-6, IL-8, bFGF, and VEGF were observed in mice at 7 days postinjection of either MM line, and a striking neutrophilia was observed at all time points. Free-floating tumor spheroids developed in mice at 14 days, and both spheroids and adherent MM tumor masses occurred in all mice at 30 days. Results suggest that inflammation and cytokine production precede and may be critical to the development of MMs.

Hillegass, Jedd M.; Shukla, Arti; Lathrop, Sherrill A.; MacPherson, Maximilian B.; Beuschel, Stacie L.; Butnor, Kelly J.; Testa, Joseph R.; Pass, Harvey I.; Carbone, Michele; Steele, Chad; Mossman, Brooke T.

2010-01-01

133

Human polyethylene granuloma tissues inhibit bone healing in a novel xenograft animal model.  

PubMed

During revision of a conventional polyethylene joint replacement, surgeons usually remove the source of osteolysis (polyethylene) but cannot always remove all of the polyethylene granuloma tissues. We developed a human/rat xenograft model to investigate the effects of polyethylene granuloma tissues on bone healing. Human osteoarthritic and periprosthetic tissues collected during primary and revision hip arthroplasty surgeries were transplanted into the distal femora of athymic nude rats. After 3 weeks in vivo, there was a significant difference in the bone volume fraction (Vf ) between empty, primary, and revision defects (p?=?0.02), with a lower Vf in defects with revision granuloma tissues compared to defects with primary osteoarthritic tissues. Polyethylene granuloma tissues in trabecular bone defects inhibited bone healing. Therefore, debridement around a metal-on-polyethylene hip replacement may shorten the time it takes to achieve secondary stability around a revision hip replacement. PMID:24619566

Esposito, Christina I; Oliver, Rema A; Campbell, Patricia A; Yu, Yan; Walter, William L; Walter, William K; Walsh, William R

2014-06-01

134

A larval zebrafish model of bipolar disorder as a screening platform for neuro-therapeutics.  

PubMed

Modelling neurological diseases has proven extraordinarily difficult due to the phenotypic complexity of each disorder. The zebrafish has become a useful model system with which to study abnormal neurological and behavioural activity and holds promise as a model of human disease. While most of the disease modelling using zebrafish has made use of adults, larvae hold tremendous promise for the high-throughput screening of potential therapeutics. The further development of larval disease models will strengthen their ability to contribute to the drug screening process. Here we have used zebrafish larvae to model the symptoms of bipolar disorder by treating larvae with sub-convulsive concentrations of the GABA antagonist pentylenetetrazol (PTZ). A number of therapeutics that act on different targets, in addition to those that have been used to treat bipolar disorder, were tested against this model to assess its predictive value. Carbamazepine, valproic acid, baclofen and honokiol, were found to oppose various aspects of the PTZ-induced changes in activity. Lidocaine and haloperidol exacerbated the PTZ-induced activity changes and sulpiride had no effect. By comparing the degree of phenotypic rescue with the mechanism of action of each therapeutic we have shown that the low-concentration PTZ model can produce a number of intermediate phenotypes that model symptoms of bipolar disorder, may be useful in modelling other disease states, and will help predict the efficacy of novel therapeutics. PMID:22677277

Ellis, Lee David; Soanes, Kelly Howard

2012-08-01

135

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

2013-06-01

136

Oncolytic HSV and Erlotinib Inhibit Tumor Growth and Angiogenesis in a Novel Malignant Peripheral Nerve Sheath Tumor Xenograft Model  

Microsoft Academic Search

Malignant peripheral nerve sheath tumors (MPNSTs), driven in part by hyperactive Ras and epidermal growth factor receptor (EGFR) signaling, are often incurable. Testing of therapeutics for MPNST has been hampered by lack of adequate xenograft models. We previously documented that human MPNST cells are permissive for lytic infection by oncolytic herpes simplex viruses (oHSV). Herein we developed and characterized a

Yonatan Y Mahller; Sachin S Vaikunth; Mark A Currier; Shyra J Miller; Maria C Ripberger; Ya-Hsuan Hsu; Ruty Mehrian-Shai; Margaret H Collins; Timothy M Crombleholme; Nancy Ratner; Timothy P Cripe

2007-01-01

137

Exisulind (sulindac sulfone) suppresses growth of human prostate cancer in a nude mouse xenograft model by increasing apoptosis  

Microsoft Academic Search

Objectives. Recent studies have shown that Exisulind, a sulfone metabolite of the nonsteroidal anti-inflammatory drug (NSAID) sulindac, has inhibitory activity in vitro with cultured human prostate cancer cells. To determine whether this effect might be pharmacologically relevant in vivo, we tested whether Exisulind therapy could suppress the growth of human prostate cancer cells in a nude mouse xenograft model.Methods. Thirty

Erik T Goluboff; Ahmad Shabsigh; James A Saidi; I. Bernard Weinstein; Nandita Mitra; Daniel Heitjan; Gary A Piazza; Rifat Pamukcu; Ralph Buttyan; Carl A Olsson

1999-01-01

138

Oncolytic HSV and erlotinib inhibit tumor growth and angiogenesis in a novel malignant peripheral nerve sheath tumor xenograft model.  

PubMed

Malignant peripheral nerve sheath tumors (MPNSTs), driven in part by hyperactive Ras and epidermal growth factor receptor (EGFR) signaling, are often incurable. Testing of therapeutics for MPNST has been hampered by lack of adequate xenograft models. We previously documented that human MPNST cells are permissive for lytic infection by oncolytic herpes simplex viruses (oHSV). Herein we developed and characterized a xenograft model of human MPNST and evaluated the antitumor effects of oHSV mutants (G207 and hrR3) and the EGFR inhibitor, erlotinib. Additive cytotoxicity of these agents was found in human MPNST cell lines, suggesting that EGFR signaling is not critical for virus replication. Mice bearing human MPNST tumors treated with G207 or hrR3 by intraperitoneal or intratumoral injection showed tumor-selective virus biodistribution, virus replication, and reduced tumor burden. oHSV injection demonstrated more dramatic antitumor activity than erlotinib. Combination therapies showed a trend toward an increased antiproliferative effect. Both oHSV and erlotinib were antiangiogenic as measured by proangiogenic gene expression, effect on endothelial cells and xenograft vessel density. Overall, oHSVs showed highly potent antitumor effects against MPNST xenografts, an effect not diminished by EGFR inhibition. Our data suggest that inclusion of MPNSTs in clinical trials of oHSV is warranted. PMID:17235305

Mahller, Yonatan Y; Vaikunth, Sachin S; Currier, Mark A; Miller, Shyra J; Ripberger, Maria C; Hsu, Ya-Hsuan; Mehrian-Shai, Ruty; Collins, Margaret H; Crombleholme, Timothy M; Ratner, Nancy; Cripe, Timothy P

2007-02-01

139

Zebrafish models in translational research: tipping the scales toward advancements in human health  

PubMed Central

Advances in genomics and next-generation sequencing have provided clinical researchers with unprecedented opportunities to understand the molecular basis of human genetic disorders. This abundance of information places new requirements on traditional disease models, which have the potential to be used to confirm newly identified pathogenic mutations and test the efficacy of emerging therapies. The unique attributes of zebrafish are being increasingly leveraged to create functional disease models, facilitate drug discovery, and provide critical scientific bases for the development of new clinical tools for the diagnosis and treatment of human disease. In this short review and the accompanying poster, we highlight a few illustrative examples of the applications of the zebrafish model to the study of human health and disease.

Phillips, Jennifer B.; Westerfield, Monte

2014-01-01

140

Human Embryonic Gastric Xenografts in Nude Mice: a New Model of Helicobacter pylori Infection  

PubMed Central

In vitro or animal models have been used to investigate the pathogenesis of Helicobacter pylori infection. However, extrapolation to humans of results obtained with these heterologous models remains difficult. We have developed a new model for the study of H. pylori infection that uses human entire embryonic stomachs engrafted in nude mice. At 80 days after implantation, 22 of these xenografts, which exhibited a mature gastric epithelium, were inoculated with 107 to 108 CFU of either H. pylori LB1, a freshly isolated H. pylori strain (n = 12), or H. pylori ATCC 49503 (n = 10). After 12-week examination, H. pylori LB1 persistently colonized the antrum of all inoculated grafts, as assessed by culture (mucus and mucosa), immunohistochemistry (mucosa), and a rapid urease test (mucus). H. pylori ATCC 49503, either before or after in vivo passage, permitted only a transient 2-week colonization in one of the five inoculated grafts in both groups. Colonization was always associated with an increase of gastric juice pH. A mild neutrophil infiltration of the gastric mucosa was noted solely in infected grafts. Transmission electron microscopy showed adherence of H. pylori organisms to epithelial cell surface. In six animals, intracytoplasmic location of this bacterium was observed in the antrum or the fundus. These results allow us to propose this model as a new ex vivo model for the study of specific H. pylori-gastric cell interactions.

Lozniewski, Alain; Muhale, Filipe; Hatier, Renee; Marais, Armelle; Conroy, Marie-Christine; Edert, Danielle; le Faou, Alain; Weber, Michele; Duprez, Adrien

1999-01-01

141

A transgenic zebrafish liver tumor model with inducible Myc expression reveals conserved Myc signatures with mammalian liver tumors  

PubMed Central

SUMMARY Myc is a pleiotropic transcription factor that is involved in many cellular activities relevant to carcinogenesis, including hepatocarcinogenesis. The zebrafish has been increasingly used to model human diseases and it is particularly valuable in helping to identify common and conserved molecular mechanisms in vertebrates. Here we generated a liver tumor model in transgenic zebrafish by liver-specific expression of mouse Myc using a Tet-On system. Dosage-dependent induction of Myc expression specifically in the liver was observed in our Myc transgenic zebrafish, TO(Myc), and the elevated Myc expression caused liver hyperplasia, which progressed to hepatocellular adenoma and carcinoma with prolonged induction. Next generation sequencing-based transcriptomic analyses indicated that ribosome proteins were overwhelmingly upregulated in the Myc-induced liver tumors. Cross-species analyses showed that the zebrafish Myc model correlated well with Myc transgenic mouse models for liver cancers. The Myc-induced zebrafish liver tumors also possessed molecular signatures highly similar to human those of hepatocellular carcinoma. Finally, we found that a small Myc target gene set of 16 genes could be used to identify liver tumors due to Myc upregulation. Thus, our zebrafish model demonstrated the conserved role of Myc in promoting hepatocarcinogenesis in all vertebrate species.

Li, Zhen; Zheng, Weiling; Wang, Zhengyuan; Zeng, Zhiqiang; Zhan, Huiqing; Li, Caixia; Zhou, Li; Yan, Chuan; Spitsbergen, Jan M.; Gong, Zhiyuan

2013-01-01

142

Pharmacokinetic Modeling of an Induction Regimen for In Vivo Combined Testing of Novel Drugs against Pediatric Acute Lymphoblastic Leukemia Xenografts  

PubMed Central

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 to predict synergy/antagonism with established therapy is an essential attribute. In this study, we report optimization of an induction-type regimen by combining VCR, dexamethasone (DEX) and ASP (VXL) against ALL xenograft models established from patient biopsies in immune-deficient mice. We demonstrate that the VXL combination was synergistic in vitro against leukemia cell lines as well as in vivo against ALL xenografts. In vivo, VXL treatment caused delays in progression of individual xenografts ranging from 22 to >146 days. The median progression delay of xenografts derived from long-term surviving patients was 2-fold greater than that of xenografts derived from patients who died of their disease. Pharmacokinetic analysis revealed that systemic DEX exposure in mice increased 2-fold when administered in combination with VCR and ASP, consistent with clinical findings, which may contribute to the observed synergy between the 3 drugs. Finally, as proof-of-principle we tested the in vivo efficacy of combining VXL with either the Bcl-2/Bcl-xL/Bcl-w inhibitor, ABT-737, or arsenic trioxide to provide evidence of a robust in vivo platform to prioritize new drugs for clinical trials in children with relapsed/refractory ALL.

Kang, Min H.; Liem, Natalia L. M.; Carol, Hernan; Boehm, Ingrid; Groepper, Daniel; Reynolds, C. Patrick; Stewart, Clinton F.; Lock, Richard B.

2012-01-01

143

Neutrophil migration; moving from zebrafish models to human autoimmunity  

PubMed Central

Summary 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 (NETs) 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.

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

2014-01-01

144

Murine genetically engineered and human xenograft models of chronic lymphocytic leukemia.  

PubMed

Chronic lymphocytic leukemia (CLL) is a genetically complex disease, with multiple factors having an impact on onset, progression, and response to therapy. Genetic differences/abnormalities have been found in hematopoietic stem cells from patients, as well as in B lymphocytes of individuals with monoclonal B-cell lymphocytosis who may develop the disease. Furthermore, after the onset of CLL, additional genetic alterations occur over time, often causing disease worsening and altering patient outcomes. Therefore, being able to genetically engineer mouse models that mimic CLL or at least certain aspects of the disease will help us understand disease mechanisms and improve treatments. This notwithstanding, because neither the genetic aberrations responsible for leukemogenesis and progression nor the promoting factors that support these are likely identical in character or influences for all patients, genetically engineered mouse models will only completely mimic CLL when all of these factors are precisely defined. In addition, multiple genetically engineered models may be required because of the heterogeneity in susceptibility genes among patients that can have an effect on genetic and environmental characteristics influencing disease development and outcome. For these reasons, we review the major murine genetically engineered and human xenograft models in use at the present time, aiming to report the advantages and disadvantages of each. PMID:25048783

Chen, Shih-Shih; Chiorazzi, Nicholas

2014-07-01

145

The bone-healing effect of a xenograft in a rat calvarial defect model.  

PubMed

Bone grafts have been widely used to fill osseous defects in medicine, dentistry, and periodontology. The purpose of this study was to investigate the effects of a xenograft (Unilab Surgibone) on experimentally created parietal bone defects in rats. To this end, 14 rats were employed in the present study and in each of them, 5-mm-diameter defects were created on the parietal bone. The right defect sites were filled with the xenograft material, while the left sites were used as control. After 30 days, the rats were sacrificed and tissue samples were retrieved from the defect sites of the cranium. Dense collagenous tissue was observed in the control area, whereas the xenograft particles were surrounded by a fibrous tissue layer at the implantation site. Based on the findings obtained, it could be concluded that the investigated xenograft seemed biocompatible and could be proposed as a potential material for filling osseous defects. PMID:19721275

Develioglu, Hakan; Unver Saraydin, Serpil; Kartal, Unal

2009-07-01

146

Xenografting as a Tool to Preserve Endangered Species: Outcomes and Challenges in Model Systems  

PubMed Central

The use of testis tissue xenografting as a valuable tool to rescue endangered and genetically valuable individuals that die young or otherwise fail to produce sperm has been the subject of much interest. Although the technique has been successfully applied to a wide variety of species, little is known about what determines the outcome. Furthermore, to improve the applicability of xenografting, new methods to preserve and transport testis tissue from valuable animals are emerging. However, one major issue remains: the application of xenografting implies the development of subsequent ART techniques to produce offspring from the recovered material. This paper focuses on these three aspects of testis tissue xenografting as a tool for rescuing endangered and valuable genetic pools.

Mota, Paula C.; Ramalho-Santos, Joao; Schlatt, Stefan

2011-01-01

147

Patient-Derived Xenograft Models to Improve Targeted Therapy in Epithelial Ovarian Cancer Treatment  

PubMed Central

Despite increasing evidence that precision therapy targeted to the molecular drivers of a cancer has the potential to improve clinical outcomes, high-grade epithelial ovarian cancer (OC) patients are currently treated without consideration of molecular phenotype, and predictive biomarkers that could better inform treatment remain unknown. Delivery of precision therapy requires improved integration of laboratory-based models and cutting-edge clinical research, with pre-clinical models predicting patient subsets that will benefit from a particular targeted therapeutic. Patient-derived xenografts (PDXs) are renewable tumor models engrafted in mice, generated from fresh human tumors without prior in vitro exposure. PDX models allow an invaluable assessment of tumor evolution and adaptive response to therapy. PDX models have been applied to pre-clinical drug testing and biomarker identification in a number of cancers including ovarian, pancreatic, breast, and prostate cancers. These models have been shown to be biologically stable and accurately reflect the patient tumor with regards to histopathology, gene expression, genetic mutations, and therapeutic response. However, pre-clinical analyses of molecularly annotated PDX models derived from high-grade serous ovarian cancer (HG-SOC) remain limited. In vivo response to conventional and/or targeted therapeutics has only been described for very small numbers of individual HG-SOC PDX in conjunction with sparse molecular annotation and patient outcome data. Recently, two consecutive panels of epithelial OC PDX correlate in vivo platinum response with molecular aberrations and source patient clinical outcomes. These studies underpin the value of PDX models to better direct chemotherapy and predict response to targeted therapy. Tumor heterogeneity, before and following treatment, as well as the importance of multiple molecular aberrations per individual tumor underscore some of the important issues addressed in PDX models.

Scott, Clare L.; Becker, Marc A.; Haluska, Paul; Samimi, Goli

2013-01-01

148

Xmrk, Kras and Myc Transgenic Zebrafish Liver Cancer Models Share Molecular Signatures with Subsets of Human Hepatocellular Carcinoma  

PubMed Central

Previously three oncogene transgenic zebrafish lines with inducible expression of xmrk, kras or Myc in the liver have been generated and these transgenic lines develop oncogene-addicted liver tumors upon chemical induction. In the current study, comparative transcriptomic approaches were used to examine the correlation of the three induced transgenic liver cancers with human liver cancers. RNA profiles from the three zebrafish tumors indicated relatively small overlaps of significantly deregulated genes and biological pathways. Nevertheless, the three transgenic tumor signatures all showed significant correlation with advanced or very advanced human hepatocellular carcinoma (HCC). Interestingly, molecular signature from each oncogene-induced zebrafish liver tumor correlated with only a small subset of human HCC samples (24–29%) and there were conserved up-regulated pathways between the zebrafish and correlated human HCC subgroup. The three zebrafish liver cancer models together represented nearly half (47.2%) of human HCCs while some human HCCs showed significant correlation with more than one signature defined from the three oncogene-addicted zebrafish tumors. In contrast, commonly deregulated genes (21 up and 16 down) in the three zebrafish tumor models generally showed accordant deregulation in the majority of human HCCs, suggesting that these genes might be more consistently deregulated in a broad range of human HCCs with different molecular mechanisms and thus serve as common diagnosis markers and therapeutic targets. Thus, these transgenic zebrafish models with well-defined oncogene-induced tumors are valuable tools for molecular classification of human HCCs and for understanding of molecular drivers in hepatocarcinogenesis in each human HCC subgroup.

Zheng, Weiling; Li, Zhen; Nguyen, Anh Tuan; Li, Caixia; Emelyanov, Alexander; Gong, Zhiyuan

2014-01-01

149

How mitochondrial dysfunction affects zebrafish development and cardiovascular function: an in vivo model for testing mitochondria-targeted drugs  

PubMed Central

Background and Purpose Mitochondria are a drug target in mitochondrial dysfunction diseases and in antiparasitic chemotherapy. While zebrafish is increasingly used as a biomedical model, its potential for mitochondrial research remains relatively unexplored. Here, we perform the first systematic analysis of how mitochondrial respiratory chain inhibitors affect zebrafish development and cardiovascular function, and assess multiple quinones, including ubiquinone mimetics idebenone and decylubiquinone, and the antimalarial atovaquone. Experimental Approach Zebrafish (Danio rerio) embryos were chronically and acutely exposed to mitochondrial inhibitors and quinone analogues. Concentration-response curves, developmental and cardiovascular phenotyping were performed together with sequence analysis of inhibitor-binding mitochondrial subunits in zebrafish versus mouse, human and parasites. Phenotype rescuing was assessed in co-exposure assays. Key Results Complex I and II inhibitors induced developmental abnormalities, but their submaximal toxicity was not additive, suggesting active alternative pathways for complex III feeding. Complex III inhibitors evoked a direct normal-to-dead transition. ATP synthase inhibition arrested gastrulation. Menadione induced hypochromic anaemia when transiently present following primitive erythropoiesis. Atovaquone was over 1000-fold less lethal in zebrafish than reported for Plasmodium falciparum, and its toxicity partly rescued by the ubiquinone precursor 4-hydroxybenzoate. Idebenone and decylubiquinone delayed rotenone- but not myxothiazol- or antimycin-evoked cardiac dysfunction. Conclusion and Implications This study characterizes pharmacologically induced mitochondrial dysfunction phenotypes in zebrafish, laying the foundation for comparison with future studies addressing mitochondrial dysfunction in this model organism. It has relevant implications for interpreting zebrafish disease models linked to complex I/II inhibition. Further, it evidences zebrafish's potential for in vivo efficacy or toxicity screening of ubiquinone analogues or antiparasitic mitochondria-targeted drugs.

Pinho, Brigida R; Santos, Miguel M; Fonseca-Silva, Anabela; Valentao, Patricia; Andrade, Paula B; Oliveira, Jorge M A

2013-01-01

150

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

151

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

PubMed Central

Studying genetics of development with small model organisms such as 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 human as well as potential drug screens. There have been sweeping developments of microfabrication and microfluidic technologies for manipulating and imaging small objects, which allow high-throughput quantitative biological studies. Here, we review recent progress on these microfluidic tools and project future directions in these fields.

Hwang, Hyundoo

2013-01-01

152

In Vivo Single-Molecule Microscopy Using the Zebrafish Model System  

Microsoft Academic Search

\\u000a In recent years, several groups have succeeded in extending single-molecule microscopy technology to the level of a living\\u000a vertebrate organism using the zebrafish embryo as a model system. In this chapter an overview will be presented of these studies\\u000a and three lines of research will be discussed. First, work will be presented in which fluorescent proteins have been imaged\\u000a at

Marcel J. M. Schaaf; Thomas S. Schmidt

153

Establishment and characterization of esophageal squamous cell carcinoma patient-derived xenograft mouse models for preclinical drug discovery.  

PubMed

The purpose of this study was to establish and characterize patient-derived esophageal squamous cell carcinoma xenograft (PDECX) mice for utilization in antitumor drug discovery. A total of 96 esophageal squamous cell carcinoma (ESCC) tissues from Chinese patients were transplanted subcutaneously into immunodeficient mice. Histology, EGFR, K-ras, B-raf, and PIK3CA mutations, and HER2 gene amplifications were analyzed in both patient tumors and mouse xenograft tissues using immunohistochemistry, mutant-enriched liquid chip sequencing and fluorescence in situ hybridization assays, respectively. Furthermore, in vivo efficacy studies using five PDECX mice harboring a variety of genetic aberrations were performed using the chemotherapy agents 5-fluorouracil (5-FU) and cisplatin. Thirty-seven PDECX mouse models were successfully established in immunodeficient mice. Pathological analysis revealed similar histological architecture and degrees of differentiation between patient ESCC and xenografted tumors. No mutations were identified in EGFR, K-ras, and B-raf genes in either xenograft models or patient ESCC tissues. In contrast, PIK3CA gene mutations were detected in 12.5% (12/96) ESCC patients and 18.9% (7/37) PDECX models. Interestingly, patient ESCC tissues exhibiting HER2 overexpression or gene amplification were unable to survive in immunodeficient mice. Further analysis showed that PDECX models carrying HER2 2+ expression had no response to 5-FU/cisplatin, compared with HER2-negative models. In conclusion, a panel of PDECX mouse models, which include PIK3CA mutant and HER2-positive models, was established and characterized thus mimicking the current clinical genetic setting of esophageal carcinoma. The sensitivity of HER2-negative ESCC models to chemotherapy supports stratification approaches in the treatment of esophageal carcinoma patients and warrants further investigation of the impact of PI3KCA on treatment response. PMID:24999713

Zhang, Jingchuan; Jiang, Dongxian; Li, Xiaojing; Lv, Jing; Xie, Liang; Zheng, Li; Gavine, Paul R; Hu, Qin; Shi, Yuan; Tan, Lijie; Ge, Di; Xu, Songtao; Li, Leon; Zhu, Lifang; Hou, Yingyong; Wang, Qun

2014-08-01

154

Hypoxia-Induced Retinal Angiogenesis in Zebrafish as a Model to Study Retinopathy  

PubMed Central

Mechanistic understanding and defining novel therapeutic targets of diabetic retinopathy and age-related macular degeneration (AMD) have been hampered by a lack of appropriate adult animal models. Here we describe a simple and highly reproducible adult fli-EGFP transgenic zebrafish model to study retinal angiogenesis. The retinal vasculature in the adult zebrafish is highly organized and hypoxia-induced neovascularization occurs in a predictable area of capillary plexuses. New retinal vessels and vascular sprouts can be accurately measured and quantified. Orally active anti-VEGF agents including sunitinib and ZM323881 effectively block hypoxia-induced retinal neovascularization. Intriguingly, blockage of the Notch signaling pathway by the inhibitor DAPT under hypoxia, results in a high density of arterial sprouting in all optical arteries. The Notch suppression-induced arterial sprouting is dependent on tissue hypoxia. However, in the presence of DAPT substantial endothelial tip cell formation was detected only in optic capillary plexuses under normoxia. These findings suggest that hypoxia shifts the vascular targets of Notch inhibitors. Our findings for the first time show a clinically relevant retinal angiogenesis model in adult zebrafish, which might serve as a platform for studying mechanisms of retinal angiogenesis, for defining novel therapeutic targets, and for screening of novel antiangiogenic drugs.

Soll, Iris; Hauptmann, Giselbert; Cao, Yihai

2008-01-01

155

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

156

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

SciTech Connect

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 imaging as a surrogate measure of response was assessed. Methods and Materials: Different orthotopic pancreatic cancer xenograft models (AsPC-1 and Panc-1) were used to represent the range of pathophysiology observed in human beings. Identical dose escalation studies (10, 20, and 40J/cm) using interstitial verteporfin PDT were performed, and magnetic resonance 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 affect the optimal PDT treatment regimen, with faster-growing tumors being relatively easier to treat. This highlights the fact that therapy in human beings shows a heterogeneous range of outcomes, and suggests a need for careful individualized treatment outcomes assessment in clinical work.

Samkoe, Kimberley S., E-mail: samkoe@dartmouth.ed [Thayer School of Engineering, Dartmouth College, Hanover, NH (United States); Chen, Alina [Thayer School of Engineering, Dartmouth College, Hanover, NH (United States); Rizvi, Imran [Thayer School of Engineering, Dartmouth College, Hanover, NH (United States); Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA (United States); O'Hara, Julia A. [Thayer School of Engineering, Dartmouth College, Hanover, NH (United States); Hoopes, P. Jack [Thayer School of Engineering, Dartmouth College, Hanover, NH (United States); Department of Surgery, Dartmouth Medical School, Hanover, NH (United States); Pereira, Stephen P. [Institute of Hepatology, University College London Medical School, London (United Kingdom); Hasan, Tayyaba [Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA (United States); Pogue, Brian W. [Thayer School of Engineering, Dartmouth College, Hanover, NH (United States); Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA (United States); Department of Surgery, Dartmouth Medical School, Hanover, NH (United States)

2010-01-15

157

Cyclophosphamide Enhances Human Tumor Growth in Nude Rat Xenografted Tumor Models1  

PubMed Central

Abstract The effect of the immunomodulatory chemotherapeutic agent cyclophosphamide (CTX) on tumor growth was investigated in primary and metastatic intracerebral and subcutaneous rat xenograft models. Nude rats were treated with CTX (100 mg/kg, intraperitoneally) 24 hours before human ovarian carcinoma (SKOV3), small cell lung carcinoma (LX-1 SCLC), and glioma (UW28, U87MG, and U251) tumor cells were inoculated subcutaneously, intraperitoneally, or in the right cerebral hemisphere or were infused into the right internal carotid artery. Tumor development was monitored and recorded. Potential mechanisms were further investigated. Only animals that received both CTX and Matrigel showed consistent growth of subcutaneous tumors. Cyclophosphamide pretreatment increased the percentage (83.3% vs 0%) of animals showing intraperitoneal tumors. In intracerebral implantation tumor models, CTX pretreatment increased the tumor volume and the percentage of animals showing tumors. Cyclophosphamide increased lung carcinoma bone and facial metastases after intra-arterial injection, and 20% of animals showed brain metastases. Cyclophosphamide transiently decreased nude rat white blood cell counts and glutathione concentration, whereas serum vascular endothelial growth factor was significantly elevated. Cyclophosphamide also increased CD31 reactivity, a marker of vascular endothelium, and macrophage (CD68-positive) infiltration into glioma cell-inoculated rat brains. Cyclophosphamide may enhance primary and metastatic tumor growth through multiple mechanisms, including immune modulation, decreased response to oxidative stress, increased tumor vascularization, and increased macrophage infiltration. These findings may be clinically relevant because chemotherapy may predispose human cancer subjects to tumor growth in the brain or other tissues.

Wu, Yingjen Jeffrey; Muldoon, Leslie L.; Dickey, Dana Thomas; Lewin, Seth J.; Varallyay, Csanad G.; Neuwelt, Edward A.

2009-01-01

158

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

159

Modeling pancreatic cancer in vivo: from xenograft and carcinogen-induced systems to genetically engineered mice.  

PubMed

In the last 10 years, there has been a relative explosion of new rodent systems that recapitulate both genetic and cellular lesions that lead to the development of pancreatic cancer. These models now need to be considered when selecting an appropriate in vivo system to study disease etiology, cell signaling, and drug development. The majority of these evaluations have used transplantation of cancer cells and the use of carcinogens, which still maintain their value when investigating human cancer and epigenetic contributors. Xenograft models utilize cultured or primary pancreatic cancer cells that are placed under the skin or implanted within the pancreas of immunocompromised mice. Carcinogen-induced systems rely on administration of certain chemicals to generate cellular changes that rapidly lead to pancreatic cancer. Genetically modified mice are more advanced in their design in that relevant genetic mutations can be inserted into mouse genomic DNA in both a conditional and inducible manner. Generation of mice that develop spontaneous pancreatic cancer from a targeted genetic mutation is a valuable research tool, considering the broad spectrum of genes and cell targets that can be used, producing a variety of neoplastic lesions and cancer that can reflect many aspects of human pancreatic ductal adenocarcinoma. PMID:20335777

Ding, Yongzeng; Cravero, John D; Adrian, Kevin; Grippo, Paul

2010-04-01

160

Use of TSH?:EGFP transgenic zebrafish as a rapid in vivo model for assessing thyroid-disrupting chemicals  

SciTech Connect

Accumulating evidence indicates that a wide range of chemicals have the ability to interfere with the hypothalamic–pituitary–thyroid (HPT) axis. Novel endpoints should be evaluated in addition to existing methods in order to effectively assess the effects of these chemicals on the HPT axis. Thyroid-stimulating hormone subunit ? (TSH?) plays central regulatory roles in the HPT system. We identified the regulatory region that determines the expression level of zebrafish TSH? in the anterior pituitary. In the transgenic zebrafish with EGFP driven by the TSH? promoter, the similar responsive patterns between the expression levels of TSH?:EGFP and endogenous TSH? mRNA in the pituitary are observed following treatments with goitrogen chemicals and exogenous thyroid hormones (THs). These results suggest that the TSH?:EGFP transgenic reporter zebrafish may be a useful alternative in vivo model for the assessment of chemicals interfering with the HPT system. Highlights: ? The promoter of zebrafish TSH? gene has been identified. ? The stable TSH?:EGFP transgenic zebrafish reporter germline has been generated. ? The EGFP in the transgenic fish recapitulated the pattern of pituitary TSH? mRNA. ? The transgenic zebrafish may be an in vivo model for EDC assessment.

Ji, Cheng [Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei (China) [Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei (China); Graduate University of Chinese Academy of Sciences, Beijing (China); Jin, Xia; He, Jiangyan [Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei (China)] [Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei (China); Yin, Zhan, E-mail: zyin@ihb.ac.cn [Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei (China)] [Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei (China)

2012-07-15

161

Nilotinib potentiates anticancer drug sensitivity in murine ABCB1-, ABCG2-, and ABCC10-multidrug resistance xenograft models  

PubMed Central

A panel of clinically used tyrosine kinase inhibitors was compared and nilotinib was found to most potently sensitize specific anticancer agents by blocking the functions of ABCB1/P-glycoprotein, ABCG2/BCRP and ABCC10/MRP7 transporters involved in multi-drug resistance. Nilotinib appreciably enhanced the antitumor response of 1) paclitaxel in the ABCB1- and novel ABCC10-xenograft models, and 2) doxorubicin in a novel ABCG2-xenograft model. With no apparent toxicity observed in the above models, nilotinib attenuated tumor growth synergistically and increased paclitaxel concentrations in ABCB1-overexpressing tumors. The beneficial actions of nilotinib warrant consideration as viable combinations in the clinic with agents that suffer from MDR-mediated insensitivity.

Tiwari, Amit K.; Sodani, Kamlesh; Dai, Chun-ling; Abuznait, Alaa H.; Singh, Satyakam; Xiao, Zhi-Jie; Patel, Atish; Talele, Tanaji T.; Fu, Liwu; Kaddoumi, Amal; Gallo, James M.; Chen, Zhe-Sheng

2012-01-01

162

Macrophage-pathogen interactions in infectious diseases: new therapeutic insights from the zebrafish host model  

PubMed Central

Studying macrophage biology in the context of a whole living organism provides unique possibilities to understand the contribution of this extremely dynamic cell subset in the reaction to infections, and has revealed the relevance of cellular and molecular processes that are fundamental to the cell-mediated innate immune response. In particular, various recently established zebrafish infectious disease models are contributing substantially to our understanding of the mechanisms by which different pathogens interact with macrophages and evade host innate immunity. Transgenic zebrafish lines with fluorescently labeled macrophages and other leukocyte populations enable non-invasive imaging at the optically transparent early life stages. Furthermore, there is a continuously expanding availability of vital reporters for subcellular compartments and for probing activation of immune defense mechanisms. These are powerful tools to visualize the activity of phagocytic cells in real time and shed light on the intriguing paradoxical roles of these cells in both limiting infection and supporting the dissemination of intracellular pathogens. This Review will discuss how several bacterial and fungal infection models in zebrafish embryos have led to new insights into the dynamic molecular and cellular mechanisms at play when pathogens encounter host macrophages. We also describe how these insights are inspiring novel therapeutic strategies for infectious disease treatment.

Torraca, Vincenzo; Masud, Samrah; Spaink, Herman P.; Meijer, Annemarie H.

2014-01-01

163

Modelling the binding affinity of steroids to zebrafish sex hormone-binding globulin.  

PubMed

The circulating endogenous steroids are transported in the bloodstream. These are bound to a highly specific sex hormone-binding globulin (SHBG) and in lower affinity to proteins such as the corticosteroid-binding protein and albumin in vertebrates, including fish. It is generally believed that the glycoprotein SHBG protects these steroids from rapid metabolic degradation and thus intervenes in its availability at the target tissues. Endocrine disrupters binding to SHBG affect the normal activity of natural steroids. Since xenobiotics are primarily released in the aquatic environment, there is a need to evaluate the binding affinity of xenosteroid mimics on fish SHBG, especially in zebrafish (Danio rerio), a small freshwater fish originating in India and widely employed in ecotoxicology, toxicology, and genetics. In this context, a zebrafish SHBG (zfSHBG) homology model was developed using the human SHBG (hSHBG) receptor structure as template. It was shown that interactions with amino acids Ser-36, Asp-59 and Thr-54 were important for binding affinity. A ligand-based pharmacophore model was also developed for both zfSHBG and hSHBG inhibitors that differentiated binders from non-binders, but also demonstrated structural requirements for zfSHBG and hSHBG ligands. The study provides insights into the mechanism of action of endocrine disruptors in zebrafish as well as providing a useful tool for identifying anthropogenic compounds inhibiting zfSHBG. PMID:24874994

Saxena, A K; Devillers, J; Pery, A R R; Beaudouin, R; Balaramnavar, V M; Ahmed, S

2014-05-01

164

Modeling mixtures of thyroid gland function disruptors in a vertebrate alternative model, the zebrafish eleutheroembryo.  

PubMed

Maternal thyroxine (T4) plays an essential role in fetal brain development, and even mild and transitory deficits in free-T4 in pregnant women can produce irreversible neurological effects in their offspring. Women of childbearing age are daily exposed to mixtures of chemicals disrupting the thyroid gland function (TGFDs) through the diet, drinking water, air and pharmaceuticals, which has raised the highest concern for the potential additive or synergic effects on the development of mild hypothyroxinemia during early pregnancy. Recently we demonstrated that zebrafish eleutheroembryos provide a suitable alternative model for screening chemicals impairing the thyroid hormone synthesis. The present study used the intrafollicular T4-content (IT4C) of zebrafish eleutheroembryos as integrative endpoint for testing the hypotheses that the effect of mixtures of TGFDs with a similar mode of action [inhibition of thyroid peroxidase (TPO)] was well predicted by a concentration addition concept (CA) model, whereas the response addition concept (RA) model predicted better the effect of dissimilarly acting binary mixtures of TGFDs [TPO-inhibitors and sodium-iodide symporter (NIS)-inhibitors]. However, CA model provided better prediction of joint effects than RA in five out of the six tested mixtures. The exception being the mixture MMI (TPO-inhibitor)-KClO4 (NIS-inhibitor) dosed at a fixed ratio of EC10 that provided similar CA and RA predictions and hence it was difficult to get any conclusive result. There results support the phenomenological similarity criterion stating that the concept of concentration addition could be extended to mixture constituents having common apical endpoints or common adverse outcomes. PMID:23562343

Thienpont, Benedicte; Barata, Carlos; Raldúa, Demetrio

2013-06-01

165

Resolution of psoriasis upon blockade of IL-15 biological activity in a xenograft mouse model  

PubMed Central

Psoriasis is a chronic inflammatory disease of the skin characterized by epidermal hyperplasia, dermal angiogenesis, infiltration of activated T cells, and increased cytokine levels. One of these cytokines, IL-15, triggers inflammatory cell recruitment, angiogenesis, and production of other inflammatory cytokines, including IFN-?, TNF-?, and IL-17, which are all upregulated in psoriatic lesions. To investigate the role of IL-15 in psoriasis, we generated mAb’s using human immunoglobulin-transgenic mice. One of the IL-15–specific antibodies we generated, 146B7, did not compete with IL-15 for binding to its receptor but potently interfered with the assembly of the IL-15 receptor ?, ?, ? complex. This antibody effectively blocked IL-15–induced T cell proliferation and monocyte TNF-? release in vitro. In a human psoriasis xenograft model, antibody 146B7 reduced the severity of psoriasis, as measured by epidermal thickness, grade of parakeratosis, and numbers of inflammatory cells and cycling keratinocytes. These results obtained with this IL-15–specific mAb support an important role for IL-15 in the pathogenesis of psoriasis.

Villadsen, Louise S.; Schuurman, Janine; Beurskens, Frank; Dam, Tomas N.; Dagnaes-Hansen, Frederik; Skov, Lone; Rygaard, J?rgen; Voorhorst-Ogink, Marleen M.; Gerritsen, Arnout F.; van Dijk, Marc A.; Parren, Paul W.H.I.; Baadsgaard, Ole; van de Winkel, Jan G.J.

2003-01-01

166

Hepatic vitamin A preloading reduces colorectal cancer metastatic multiplicity in a mouse xenograft model  

PubMed Central

Previous research in our laboratory showed that retinol inhibited all-trans retinoic acid (ATRA)-resistant human colon cancer cell invasion via a retinoic acid receptor (RAR)-independent mechanism in vitro. The objective of the current study was to determine if dietary vitamin A supplementation inhibited metastasis of ATRA-resistant colon cancer cells in a nude mouse xenograft model. Female nude mice (BALB/cAnNCr-nu/nu, n=14 per group) consumed a control diet (2400 IU retinyl palmitate/kg diet) or a vitamin A supplemented diet (200,000 IU retinyl palmitate/kg diet) for one month prior to tumor cell injection to preload the liver with vitamin A. HCT-116, ATRA-resistant, human colon cancer cells were intrasplenically injected. Mice continued to consume their respective diets for 5 wks following surgery. Consumption of supplemental vitamin A decreased hepatic metastatic multiplicity to 17% of control. Hepatic and splenic retinol and retinyl ester concentrations were significantly higher in the mice supplemented with vitamin A when compared to mice consuming the control diet. Supplemental vitamin A did not decrease body weight, feed intake or cause toxicity. Thus, supplemental dietary vitamin A may decrease the overall number of hepatic metastasis resulting from colon cancer.

Park, Eun Young; Pinali, Daniel; Lindley, Krista; Lane, Michelle A.

2013-01-01

167

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

PubMed Central

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.

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

2013-01-01

168

Xenografts in pharmacologically immunosuppressed mice as a model to test the chemotherapeutic sensitivity of human tumors.  

PubMed

A human tumor xenograft model using pharmacologically immunosuppressed mice was assessed for its suitability to test preclinically the sensitivity of colorectal carcinomas, bone sarcomas and melanomas against anticancer agents. Besides ionizing radiation, 14 cytotoxic drugs including 5-fluorouracil (5-FU), dimethylmyleran (DMM), cytosine arabinoside, cyclophosphamide, melphalan, BCNU, mitomycin C, adriamycin, bleomycin, etoposide, vinblastine, cisplatin, procarbazine and DTIC were assayed. Ionizing radiation, 5-FU and DMM were also applied at lethal doses followed by bone-marrow rescue heavy therapy. Four colon carcinomas responded poorly to most of the agents but one tumor displayed marked sensitivity to BCNU. Lethal doses of radiation, 5-FU and DMM could also show considerable activity. High sensitivity was shown by a Ewing sarcoma to DMM and cyclophosphamide and by an osteosarcoma to the latter drug. No strong effects were seen against melanomas. Lethal doses of DMM induced the best regression of one colon carcinoma. In general, the superiority of heavy therapy for solid human tumors compared to maximally tolerated doses was demonstrated. Individual carcinomas of the same type displayed different drug sensitivity. PMID:3455687

Floersheim, G L; Bieri, A; Chiodetti, N

1986-01-15

169

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

170

Nanoelectroablation of Human Pancreatic Carcinoma in a Murine Xenograft Model without Recurrence  

PubMed Central

We have identified an effective nanoelectroablation therapy for treating pancreatic carcinoma in a murine xenograft model. This therapy initiates apoptosis in a nonthermal manner by applying low energy electric pulses 100 ns long and 30 kV/cm in amplitude to the tumor. We first identified the minimum pulse number required for complete ablation by treating 30 tumors. We found that the minimum number of pulses required to ablate the tumor with a single treatment is between 250 and 500 pulses. We settled on a single application of either 500 or 1000 pulses to treat pancreatic carcinomas in 19 NIH-III mice. Seventeen of the 19 treated tumors exhibited complete regression without recurrence. Three mice died of unknown causes within 3 months after treatment but 16 lived for 270–302 days at which time we sacrificed them for histological analysis. In the 17 untreated controls, the tumor grew so large that we had to sacrifice all of them within 4 months.

Nuccitelli, Richard; Huynh, Joanne; Lui, Kaying; Wood, Ryan; Kreis, Mark; Athos, Brian; Nuccitelli, Pamela

2012-01-01

171

Establishment of a Lung Metastatic Breast Tumor Xenograft Model in Nude Rats  

PubMed Central

Objective Larger animal models provide relevant tumor burden in the development of advanced clinical imaging methods for non-invasive cancer detection and diagnosis, and are especially valuable for studying metastatic disease. Most available experimental models, however, are based on immune-compromised mice. To lay the foundation for studying spontaneous metastasis using non-invasive magnetic resonance imaging (MRI), this study aims to establish a highly metastatic breast cancer xenograft model in nude rats. Materials and Methods A highly metastatic variant of human adenocarcinoma MDA-MB-231 known as LM2 was inoculated into nude rats. Orthotopic and subcutaneous (flank) sites were compared, with half of the orthotopic injections guided by ultrasound imaging. MRI with gadolinium contrast administration was performed weekly beginning on Day 6 and ending on Day 104. Excised tumors were assessed on histology using hematoxylin and eosin and CD34. Fisher's exact test was used to compare successful tumor induction amongst different inoculation methods. Results Primary LM2 tumors were established orthotopically in all cases under ultrasound-guided injection, and none otherwise (p?=?0.0028). Contrast-enhanced MRI revealed rapidly progressing tumors that reached critical size (15 mm diameter) in 2 to 3 weeks after inoculation. MRI and histology findings were consistent: LM2 tumors were characterized by low vascularity confined to the tumor rim and large necrotic cores with increasing interstitial fluid pressure. Conclusions The metastatic LM2 breast tumor model was successfully established in the mammary fat pads of nude rats, using ultrasound needle guidance as a non-invasive alternative to surgery. This platform lays the foundation for future development and application of MRI to study spontaneous metastasis and different stages throughout the metastatic cascade.

Nofiele, Joris Tchouala; Cheng, Hai-Ling Margaret

2014-01-01

172

An orthotopic xenograft model of intraneural NF1 MPNST suggests a potential association between steroid hormones and tumor cell proliferation  

Microsoft Academic Search

Malignant peripheral nerve sheath tumors (MPNST) are the most aggressive cancers associated with neurofibromatosis type 1 (NF1). Here we report a practical and reproducible model of intraneural NF1 MPNST, by orthotopic xenograft of an immortal human NF1 tumor-derived Schwann cell line into the sciatic nerves of female scid mice. Intraneural injection of the cell line sNF96.2 consistently produced MPNST-like tumors

George Q Perrin; Hua Li; Lauren Fishbein; Susanne A Thomson; Min S Hwang; Mark T Scarborough; Anthony T Yachnis; Margaret R Wallace; Thomas H Mareci; David Muir

2007-01-01

173

Mind the fish: zebrafish as a model in cognitive social neuroscience  

PubMed Central

Understanding how the brain implements social behavior on one hand, and how social processes feedback on the brain to promote fine-tuning of behavioral output according to changes in the social environment is a major challenge in contemporary neuroscience. A critical step to take this challenge successfully is finding the appropriate level of analysis when relating social to biological phenomena. Given the enormous complexity of both the neural networks of the brain and social systems, the use of a cognitive level of analysis (in an information processing perspective) is proposed here as an explanatory interface between brain and behavior. A conceptual framework for a cognitive approach to comparative social neuroscience is proposed, consisting of the following steps to be taken across different species with varying social systems: (1) identification of the functional building blocks of social skills; (2) identification of the cognitive mechanisms underlying the previously identified social skills; and (3) mapping these information processing mechanisms onto the brain. Teleost fish are presented here as a group of choice to develop this approach, given the diversity of social systems present in closely related species that allows for planned phylogenetic comparisons, and the availability of neurogenetic tools that allows the visualization and manipulation of selected neural circuits in model species such as the zebrafish. Finally, the state-of-the art of zebrafish social cognition and of the tools available to map social cognitive abilities to neural circuits in zebrafish are reviewed.

Oliveira, Rui F.

2013-01-01

174

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

2012-11-01

175

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

PubMed Central

SUMMARY 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 (Ca2+) 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.

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

2012-01-01

176

Zebrafish as a model organism to evaluate drugs potentially able to modulate sirtuin expression.  

PubMed

Sirtuins comprise a unique class of NAD(+)-dependent deacetylases that are key regulators of many physiological processes. They appear to be a potential target set of enzymes for treatment of age-associated diseases and have attracted interest in many research areas involving chemical and cellular investigations to understand them and discover potential ligands. For molecular screening, a cost-effective, easily manipulated, and consolidated model organism is needed, and the zebrafish fits these requirements perfectly. Here, we report the identification of sirtuin-related genes and their expression patterns in nine tissues of adult zebrafish. The investigation identified eight sirtuin-related genes, and their phylogenetic analysis resulted in seven well-resolved terminal clades, corresponding to each sirtuin (SIRT1, 2, 4-7) and two SIRT3 paralogs. Each gene showed a unique expression profile, illustrating a wide tissue distribution of sirtuins in zebrafish. SIRT1, SIRT3, SIRT5, and SIRT6 genes were expressed in all tissues, and SIRT1 exhibited the highest level of expression in all organs. A modulation experiment was performed using resveratrol, and results confirmed to the predicted scenario: altered sirtuin expression levels. Drugs based on sirtuin modulators may be tested using this system and could lead us to more selective and powerful therapies for age-related disorders. PMID:21413868

Pereira, Talita Carneiro Brandão; Rico, Eduardo Pacheco; Rosemberg, Denis Broock; Schirmer, Helena; Dias, Renato Dutra; Souto, André Arigony; Bonan, Carla Denise; Bogo, Maurício Reis

2011-03-01

177

Spotlight on Zebrafish: Translational Impact  

PubMed Central

In recent years, the zebrafish has emerged as an increasingly prominent model in biomedical research. To showcase the translational impact of the model across multiple disease areas, Disease Models & Mechanisms has compiled a Special Issue that includes thought-provoking reviews, original research reporting new and important insights into disease mechanisms, and novel resources that expand the zebrafish toolkit. This Editorial provides a summary of the issue’s contents, highlighting the diversity of zebrafish disease models and their clinical applications.

Patton, E. Elizabeth; Dhillon, Paraminder; Amatruda, James F.; Ramakrishnan, Lalita

2014-01-01

178

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

179

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

PubMed Central

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.

Schmidt, Wolfgang M.; Spiegl-Kreinecker, Sabine; Lotsch, Daniela; Heffeter, Petra; Hegedus, Balazs; Grusch, Michael; Kiss, Robert; Berger, Walter

2012-01-01

180

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

181

Zebrafish provide a sensitive model of persisting neurobehavioral effects of developmental chlorpyrifos exposure: Comparison with nicotine and pilocarpine effects and relationship to dopamine deficits  

Microsoft Academic Search

Chlorpyrifos (CPF) an organophosphate pesticide causes persisting behavioral dysfunction in rat models when exposure is during early development. In earlier work zebrafish were used as a complementary model to study mechanisms of CPF-induced neurotoxicity induced during early development. We found that developmental (first five days after fertilization) chlorpyrifos exposure significantly impaired learning in zebrafish. However, this testing was time and

Donnie Eddins; Daniel Cerutti; Paul Williams; Elwood Linney; Edward D. Levin

2010-01-01

182

Differential antitumor activity of aflibercept and bevacizumab in patient-derived xenograft models of colorectal cancer.  

PubMed

The recombinant fusion protein aflibercept (ziv-aflibercept in the United States) binds VEGF-A, VEGF-B, and placental growth factor (PlGF). The monoclonal antibody bevacizumab binds VEGF-A. Recent studies hypothesized that dual targeting of VEGF/PlGF is more beneficial than targeting either ligand. We compared activity of aflibercept versus bevacizumab in 48 patient-derived xenograft (PDX) colorectal cancer models. Nude mice engrafted subcutaneously with PDX colorectal cancer tumors received biweekly aflibercept, bevacizumab, or vehicle injections. Differential activity between aflibercept and bevacizumab, determined by mouse (m), human (h), VEGF-A, and PlGF levels in untreated tumors, was measured. Aflibercept induced complete tumor stasis in 31 of 48 models and bevacizumab in 2 of 48. Based on statistical analysis, aflibercept was more active than bevacizumab in 39 of 48 models; in 9 of 39 of these models, bevacizumab was considered inactive. In 9 of 48 remaining models, aflibercept and bevacizumab had similar activity. Tumor levels of hVEGF-A (range 776-56,039 pg/mg total protein) were ?16- to 1,777-fold greater than mVEGF-A (range 8-159 pg/mg total protein). Tumor levels of mPlGF (range 104-1,837 pg/mg total protein) were higher than hPlGF (range 0-543 pg/mg total protein) in 47 of 48 models. Tumor cells were the major source of VEGF; PlGF was primarily produced by tumor stroma. Because tumor levels of hVEGF-A were far greater than mVEGF-A, bevacizumab's inability to bind mVEGF-A is unlikely to explain higher and more consistent aflibercept activity. Neutralizing PlGF and VEGFR-1 activation may be a factor and should be investigated in future studies. In these colorectal cancer PDX models, aflibercept demonstrated greater antitumor activity than bevacizumab. Mol Cancer Ther; 13(6); 1636-44. ©2014 AACR. PMID:24688047

Chiron, Marielle; Bagley, Rebecca G; Pollard, Jack; Mankoo, Parminder K; Henry, Christophe; Vincent, Loïc; Geslin, Catherine; Baltes, Nina; Bergstrom, Donald A

2014-06-01

183

Larval zebrafish as a model for glucose metabolism: expression of phosphoenolpyruvate carboxykinase as a marker for exposure to anti-diabetic compounds.  

PubMed

The zebrafish model system is one of the most widely used animal models for developmental research and it is now becoming an attractive model for drug discovery and toxicological screening. The completion of sequencing the zebrafish genome and the availability of full-length cDNAs and DNA microarrays for expression analysis, in addition to techniques for generating transgenic lines and targeted mutations, have made the zebrafish model even more attractive to researchers. Recent data indicate that the regulation of glucose metabolism in zebrafish, through the production of insulin, is similar to mammalian models, and many of the genes involved in regulating blood glucose levels have been identified in zebrafish. The data presented here show that adult zebrafish respond to anti-diabetic drugs similarly to mammalian models, by reducing blood glucose levels. Furthermore, we show that the expression of phosphoenolpyruvate carboxykinase (PEPCK), which catalyzes a rate-limiting step in gluconeogenesis and is transcriptionally regulated by glucagon and insulin, is regulated in larval zebrafish similarly to that seen in mammalian systems, and changes in PEPCK expression can be obtained through real-time PCR analysis of whole larval RNA. Taken together, these data suggest that larval zebrafish may be an appropriate model for the examination of glucose metabolism, using PEPCK as an indicator of blood glucose levels. PMID:17446233

Elo, B; Villano, C M; Govorko, D; White, L A

2007-04-01

184

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

185

Endogenous retrovirus induces leukemia in a xenograft mouse model for primary myelofibrosis.  

PubMed

The compound immunodeficiencies in nonobese diabetic (NOD) inbred mice homozygous for the Prkdc(scid) and Il2rg(null) alleles (NSG mice) permit engraftment of a wide-range of primary human cells, enabling sophisticated modeling of human disease. In studies designed to define neoplastic stem cells of primary myelofibrosis (PMF), a myeloproliferative neoplasm characterized by profound disruption of the hematopoietic microenvironment, we observed a high frequency of acute myeloid leukemia (AML) in NSG mice. AML was of mouse origin, confined to PMF-xenografted mice, and contained multiple clonal integrations of ecotropic murine leukemia virus (E-MuLV). Significantly, MuLV replication was not only observed in diseased mice, but also in nontreated NSG controls. Furthermore, in addition to the single ecotropic endogenous retrovirus (eERV) located on chromosome 11 (Emv30) in the NOD genome, multiple de novo germ-line eERV integrations were observed in mice from each of four independent NSG mouse colonies. Analysis confirmed that E-MuLV originated from the Emv30 provirus and that recombination events were not necessary for virus replication or AML induction. Pathogenicity is thus likely attributable to PMF-mediated paracrine stimulation of mouse myeloid cells, which serve as targets for retroviral infection and transformation, as evidenced by integration into the Evi1 locus, a hotspot for retroviral-induced myeloid leukemia. This study thus corroborates a role of paracrine stimulation in PMF disease progression, underlines the importance of target cell type and numbers in MuLV-induced disease, and mandates awareness of replicating MuLV in NOD immunodeficient mice, which can significantly influence experimental results and their interpretation. PMID:24912157

Triviai, Ioanna; Ziegler, Marion; Bergholz, Ulla; Oler, Andrew J; Stübig, Thomas; Prassolov, Vladimir; Fehse, Boris; Kozak, Christine A; Kröger, Nicolaus; Stocking, Carol

2014-06-10

186

Preclinical evaluation of transcriptional targeting strategy for human hepatocellular carcinoma in an orthotopic xenograft mouse model.  

PubMed

Gene regulation of many key cell-cycle players in S-, G(2) phase, and mitosis results from transcriptional repression in their respective promoter regions during the G(0) and G(1) phases of cell cycle. Within these promoter regions are phylogenetically conserved sequences known as the cell-cycle-dependent element (CDE) and cell-cycle genes homology regions (CHR) sites. Thus, we hypothesize that transcriptional regulation of cell-cycle regulation via the CDE/CHR region together with liver-specific apolipoprotein E (apoE)-hAAT promoter could bring about a selective transgene expression in proliferating human hepatocellular carcinoma. We show that the newly generated vector AH-6CC-L2C could mediate hepatocyte-targeted luciferase gene expression in tumor cells and freshly isolated short-term hepatocellular carcinoma cultures from patient biopsy. In contrast, normal murine and human hepatocytes infected with AH-6CC-L2C expressed minimal or low luciferase activities. In the presence of prodrug 5-fluorocytosine (5-FC), AH-6CC-L2C effectively suppressed the growth of orthotopic hepatocellular carcinoma patient-derived xenograft mouse model via the expression of yeast cytosine deaminase (yCD) that converts 5-FC to anticancer metabolite 5-fluoruracil. More importantly, we show that combination treatment of AH-6CC-L2C with an EZH2 inhibitor, DZNep, that targets EpCAM-positive hepatocellular carcinoma, can bring about a greater therapeutic efficacy compared with a single treatment of virus or inhibitor. Our study showed that targeting proliferating human hepatocellular carcinoma cells through the transcriptional control of therapeutic gene could represent a feasible approach against hepatocellular carcinoma. PMID:23720769

Sia, Kian Chuan; Huynh, Hung; Chung, Alexander Yaw Fui; Ooi, London Lucien Peng Jin; Lim, Kiat Hon; Hui, Kam Man; Lam, Paula Yeng Po

2013-08-01

187

DMU-212 inhibits tumor growth in xenograft model of human ovarian cancer.  

PubMed

DMU-212 has been shown to evoke a mitochondrial apoptotic pathway in transformed fibroblasts and breast cancer. However, recently published data indicated the ability of DMU-212 to evoke apoptosis in both mitochondria- and receptor-mediated manner in two ovarian cancer cell lines, namely A-2780 and SKOV-3, which showed varied sensitivity to the compound tested. The pronounced cytotoxic effects of DMU-212 observed in A-2780 cells were related to the execution of extracellular apoptosis pathway and cell cycle arrest in G2/M phase. In view of the great anticancer potential of DMU-212 against A-2780 cell line, the aim of the current study was to assess antiproliferative activity of DMU-212 in xenograft model of ovarian cancer. To evaluate in vitro metabolic properties of cells that were to be injected into SCID mice, uptake and decline of DMU-212 in A-2780 ovarian cancer cell line was investigated. It was found that the concentration of the test compound in A-2780 cells was growing within first eight hours, and then the gradual decline was observed. A-2780 cells stably transfected with pcDNA3.1/Zeo(-)-Luc vector were subcutaneously inoculated into the right flanks of SCID mice. After seven days of the treatment with DMU-212 (50mg/kg b.w), tumor growth appeared to be suppressed in the animals treated with the compound tested. At day 14 of the experiment, tumor burden in mice treated with DMU-212 was significantly lower, as compared to untreated controls. Our findings suggest that DMU-212 might be considered as a potential anticancer agent used in ovarian cancer therapy. PMID:24768110

Piotrowska, Hanna; Myszkowski, Krzysztof; Abraszek, Joanna; Kwiatkowska-Borowczyk, Eliza; Amarowicz, Ryszard; Murias, Marek; Wierzchowski, Marcin; Jodynis-Liebert, Jadwiga

2014-05-01

188

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

189

Novel Dedifferentiated Liposarcoma Xenograft Models Reveal PTEN Down-Regulation as a Malignant Signature and Response to PI3K Pathway Inhibition  

PubMed Central

Liposarcoma is a type of soft tissue sarcoma that exhibits poor survival and a high recurrence rate. Treatment is generally limited to surgery and radiation, which emphasizes the need for better understanding of this disease. Because very few in vivo and in vitro models can reproducibly recapitulate the human disease, we generated several xenograft models from surgically resected human dedifferentiated liposarcoma. All xenografts recapitulated morphological and gene expression characteristics of the patient tumors after continuous in vivo passages. Importantly, xenograftability was directly correlated with disease-specific survival of liposarcoma patients. Thus, the ability for the tumor of a patient to engraft may help identify those patients who will benefit from more aggressive treatment regimens. Gene expression analyses highlighted the association between xenograftability and a unique gene expression signature, including down-regulated PTEN tumor-suppressor gene expression and a progenitor-like phenotype. When treated with the PI3K/AKT/mTOR pathway inhibitor rapamycin alone or in combination with the multikinase inhibitor sorafenib, all xenografts responded with increased lipid content and a more differentiated gene expression profile. These human xenograft models may facilitate liposarcoma research and accelerate the generation of readily translatable preclinical data that could ultimately influence patient care.

Smith, Kathleen B.; Tran, Linh M.; Tam, Brenna M.; Shurell, Elizabeth M.; Li, Yunfeng; Braas, Daniel; Tap, William D.; Christofk, Heather R.; Dry, Sarah M.; Eilber, Fritz C.; Wu, Hong

2014-01-01

190

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

191

FishNet: an online database of zebrafish anatomy  

Microsoft Academic Search

BACKGROUND: Over the last two decades, zebrafish have been established as a genetically versatile model system for investigating many different aspects of vertebrate developmental biology. With the credentials of zebrafish as a developmental model now well recognized, the emerging new opportunity is the wider application of zebrafish biology to aspects of human disease modelling. This rapidly increasing use of zebrafish

Robert J Bryson-Richardson; Silke Berger; Thomas F Schilling; Thomas E Hall; Nicholas J Cole; Abigail J Gibson; James Sharpe; Peter D Currie

2007-01-01

192

Changes in ovarian tumor cell number, tumor vasculature, and T cell function monitored in vivo using a novel xenograft model  

PubMed Central

Despite an initial response to chemotherapy, most patients with ovarian cancer eventually progress and succumb to their disease. Understanding why effector T cells that are known to infiltrate the tumor do not eradicate the disease after cytoreduction is critically important to the development of novel therapeutic strategies to augment tumor immunity and improve patient outcomes. Such studies have been hampered by the lack of a suitable in vivo model. We report here a simple and reliable model system in which ovarian tumor cell aggregates implanted intraperitoneally into severely immunodeficient NSG mice establish tumor microenvironments within the omentum. The rapid establishment of tumor xenografts within this small anatomically well-defined site enables the recovery, characterization, and quantification of tumor and tumor-associated T cells. We validate here the ability of the omental tumor xenograft (OTX) model to quantify changes in tumor cell number in response to therapy, to quantify changes in the tumor vasculature, and to demonstrate and study the immunosuppressive effects of the tumor microenvironment. Using the OTX model, we show that the tumor-associated T cells originally present within the tumor tissues are anergic and that fully functional autologous T cells injected into tumor-bearing mice localize within the tumor xenograft. The transferred T cells remain functional for up to 3 days within the tumor microenvironment but become unresponsive to activation after 7 days. The OTX model provides for the first time the opportunity to study in vivo the cellular and molecular events contributing to the arrest in T cell function in human ovarian tumors.

Yokota, Sandra J.; Facciponte, John G.; Kelleher, Raymond J.; Shultz, Leonard D.; Loyall, Jenni L.; Parsons, Robert R.; Odunsi, Kunle; Frelinger, John G.; Lord, Edith M.; Gerber, Scott A.; Balu-Iyer, Sathy V.; Bankert, Richard B.

2013-01-01

193

An inducible krasV12 transgenic zebrafish model for liver tumorigenesis and chemical drug screening  

PubMed Central

SUMMARY Because Ras signaling is frequently activated by major hepatocellular carcinoma etiological factors, a transgenic zebrafish constitutively expressing the krasV12 oncogene in the liver was previously generated by our laboratory. Although this model depicted and uncovered the conservation between zebrafish and human liver tumorigenesis, the low tumor incidence and early mortality limit its use for further studies of tumor progression and inhibition. Here, we employed a mifepristone-inducible transgenic system to achieve inducible krasV12 expression in the liver. The system consisted of two transgenic lines: the liver-driver line had a liver-specific fabp10 promoter to produce the LexPR chimeric transactivator, and the Ras-effector line contained a LexA-binding site to control EGFP-krasV12 expression. In double-transgenic zebrafish (driver-effector) embryos and adults, we demonstrated mifepristone-inducible EGFP-krasV12 expression in the liver. Robust and homogeneous liver tumors developed in 100% of double-transgenic fish after 1 month of induction and the tumors progressed from hyperplasia by 1 week post-treatment (wpt) to carcinoma by 4 wpt. Strikingly, liver tumorigenesis was found to be ‘addicted’ to Ras signaling for tumor maintenance, because mifepristone withdrawal led to tumor regression via cell death in transgenic fish. We further demonstrated the potential use of the transparent EGFP-krasV12 larvae in inhibitor treatments to suppress Ras-driven liver tumorigenesis by targeting its downstream effectors, including the Raf-MEK-ERK and PI3K-AKT-mTOR pathways. Collectively, this mifepristone-inducible and reversible krasV12 transgenic system offers a novel model for understanding hepatocarcinogenesis and a high-throughput screening platform for anti-cancer drugs.

Nguyen, Anh Tuan; Emelyanov, Alexander; Koh, Chor Hui Vivien; Spitsbergen, Jan M.; Parinov, Serguei; Gong, Zhiyuan

2012-01-01

194

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

2012-01-01

195

Anterior Gradient-3: a novel biomarker for ovarian cancer that mediates cisplatin resistance in xenograft models.  

PubMed

The Anterior Gradient (AGR) genes AGR2 and AGR3 are part of the Protein Disulfide Isomerase (PDI) family and harbour core thioredoxin folds (CxxS motifs) that have the potential to regulate protein folding and maturation. A number of proteomics and transcriptomics screens in the fields of limb regeneration, cancer cell metastasis, pro-oncogenic oestrogen-signalling, and p53 regulation have identified AGR2 as a novel component of these signalling pathways. Curiously, despite the fact that the AGR2 and AGR3 genes are contiguous on chromosome 7p21.1-3, the AGR3 protein has rarely been identified in such OMICs screens along with AGR2 protein. Therefore there is little information on how AGR3 protein is expressed in normal and diseased states. A panel of three monoclonal antibodies was generated towards AGR3 protein for identifying novel clinical models that can be used to define whether AGR3 protein could play a positive or negative role in human cancer development. One monoclonal antibody was AGR3-specific and bound a linear epitope that could be defined using both pep-scan and phage-peptide library screening. Using this monoclonal antibody, endogenous AGR3 protein expression was shown to be cytosolic in four human ovarian cancer subtypes; serous, endometrioid, clear cell, and mucinous. Mucinous ovarian cancers produced the highest number of AGR3 positive cells. AGR3 expression is coupled to AGR2 expression only in mucinous ovarian cancers, whereas AGR3 and AGR2 expressions are uncoupled in the other three types of ovarian cancer. AGR3 expression in ovarian cancer is independent of oestrogen-receptor expression, which is distinct from the oestrogen-receptor dependent expression of AGR3 in breast cancers. Isogenic cancer cell models were created that over-express AGR3 and these demonstrated that AGR3 mediates cisplatin-resistance in mouse xenografts. These data indicate that AGR3 is over-expressed by a hormone (oestrogen-receptor ?)-independent mechanism and identify a novel protein-folding associated pathway that could mediate resistance to DNA-damaging agents in human cancers. PMID:22361111

Gray, Terry A; MacLaine, Nicola J; Michie, Caroline O; Bouchalova, Pavla; Murray, Euan; Howie, Jacqueline; Hrstka, Roman; Maslon, Magdalena M; Nenutil, Rudolf; Vojtesek, Borek; Langdon, Simon; Hayward, Larry; Gourley, Charlie; Hupp, Ted R

2012-04-30

196

Immunohistopathological and neuroimaging characterization of murine orthotopic xenograft models of glioblastoma multiforme recapitulating the most salient features of human disease.  

PubMed

Tumorigenesis in human glioblastoma multiforme (GBM) is driven by several genetic abnormalities with disruption of important molecular pathways, such as p53/MDM2/p14ARF and EGFR/PTEN/Akt/mTOR. The malignant progression of human GBM is also primarily associated with a peculiar multistep pathophysiological process characterized by intratumoral ischemic necrosis (i.e. pseudopalisading necrosis) and activation of the hypoxia-inducible factor (HIF)-1alpha pathway with consequent peritumoral microvascular proliferation and infiltrative behaviour. Predictable preclinical animal models of GBM should recapitulate the main pathobiological hallmarks of the human disease. In this study we describe two murine orthotopic xenograft models using U87MG and U251 human cell lines. Ten Balb/c nude male mice were orthotopically implanted with either U87MG (5 mice) or U251 (5 mice) cell lines. Intracranial tumor growth was monitored through Magnetic Resonance Imaging (MRI). Immunohistopathological examination of the whole cranium was performed 30 days after implantation. U251 orthotopic xenografts recapitulated the salient pathobiological features described for human GBM, including invasive behaviour, wide areas of pseudopalisading necrosis, florid peripheral angiogenesis, GFAP and vimentin expression, nonfunctional p53 expression, striking active-caspase-3 and HIF-1alpha expression along pseudopalisades. U87MG orthotopic xenografts proved to be very dissimilar from human GBM, showing expansile growth, occasional necrotic foci without pseudopalisades, intratumoral lacunar pattern of angiogenesis, lack of GFAP expression, functional p53 expression and inconsistent HIF-1alpha expression. Expression of pAkt was upregulated in both models. The results obtained suggest that the U251 orthotopic model may be proposed as a predictive and reliable tool in preclinical studies since it recapitulates the most salient pathobiological features reported for human GBM. PMID:19475534

Radaelli, E; Ceruti, R; Patton, V; Russo, M; Degrassi, A; Croci, V; Caprera, F; Stortini, G; Scanziani, E; Pesenti, E; Alzani, R

2009-07-01

197

SKI606, a Src\\/Abl Inhibitor with In vivo Activity in Colon Tumor Xenograft Models  

Microsoft Academic Search

Src up-regulation is a common event in human cancers. In colorectal cancer, increased Src levels are an indicator of poor prognosis, and progression to metastatic disease is associated with substantial increases in Src activity. Therefore, we examined the activity of SKI-606, a potent inhibitor of Src and Abl kinases, against colon tumor lines in vitro and in s.c. tumor xenograft

Jennifer M. Golas; Judy Lucas; Carlo Etienne; Jonathan Golas; Carolyn Discafani; Latha Sridharan; Erwin Boghaert; Kim Arndt; Fei Ye; Diane H. Boschelli; Fangbiao Li; Craig Titsch; Christine Huselton; Inder Chaudhary; Frank Boschelli

2005-01-01

198

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

2013-01-01

199

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

2013-08-01

200

Defining Hepatic Dysfunction Parameters in Two Models of Fatty Liver Disease in Zebrafish Larvae  

PubMed Central

Abstract Fatty liver disease in humans can progress from steatosis to hepatocellular injury, fibrosis, cirrhosis, and liver failure. We developed a series of straightforward assays to determine whether zebrafish larvae with either tunicamycin- or ethanol-induced steatosis develop hepatic dysfunction. We found altered expression of genes involved in acute phase response and hepatic function, and impaired hepatocyte secretion and disruption of canaliculi in both models, but glycogen deficiency in hepatocytes and dilation of hepatic vasculature occurred only in ethanol-treated larvae. Hepatic stellate cells (HSCs) become activated during liver injury and HSC numbers increased in both models. Whether the excess lipids in hepatocytes are a direct cause of hepatocyte dysfunction in fatty liver disease has not been defined. We prevented ethanol-induced steatosis by blocking activation of the sterol response element binding proteins (Srebps) using gonzombtps1 mutants and scap morphants and found that hepatocyte dysfunction persisted even in the absence of lipid accumulation. This suggests that lipotoxicity is not the primary cause of hepatic injury in these models of fatty liver disease. This study provides a panel of parameters to assess liver disease that can be easily applied to zebrafish mutants, transgenics, and for drug screening in which liver function is an important consideration.

Howarth, Deanna L.; Yin, Chunyue; Yeh, Karen

2013-01-01

201

Transcriptional changes and developmental abnormalities in a zebrafish model of myotonic dystrophy type 1  

PubMed Central

Myotonic dystrophy type I (DM1) is a multi-system, autosomal dominant disorder caused by expansion of a CTG repeat sequence in the 3?UTR of the DMPK gene. The size of the repeat sequence correlates with age at onset and disease severity, with large repeats leading to congenital forms of DM1 associated with hypotonia and intellectual disability. In models of adult DM1, expanded CUG repeats lead to an RNA toxic gain of function, mediated at least in part by sequestering specific RNA splicing proteins, most notably muscleblind-related (MBNL) proteins. However, the impact of CUG RNA repeat expression on early developmental processes is not well understood. To better understand early developmental processes in DM1, we utilized the zebrafish, Danio rerio, as a model system. Direct injection of (CUG)91 repeat-containing mRNA into single-cell embryos induces toxicity in the nervous system and muscle during early development. These effects manifest as abnormal morphology, behavioral abnormalities and broad transcriptional changes, as shown by cDNA microarray analysis. Co-injection of zebrafish mbnl2 RNA suppresses (CUG)91 RNA toxicity and reverses the associated behavioral and transcriptional abnormalities. Taken together, these findings suggest that early expression of exogenously transcribed CUG repeat RNA can disrupt normal muscle and nervous system development and provides a new model for DM1 research that is amenable to small-molecule therapeutic development.

Todd, Peter K.; Ackall, Feras Y.; Hur, Junguk; Sharma, Kush; Paulson, Henry L.; Dowling, James J.

2014-01-01

202

The genetic heterogeneity and mutational burden of engineered melanomas in zebrafish models  

PubMed Central

Background Melanoma is the most deadly form of skin cancer. Expression of oncogenic BRAF or NRAS, which are frequently mutated in human melanomas, promote the formation of nevi but are not sufficient for tumorigenesis. Even with germline mutated p53, these engineered melanomas present with variable onset and pathology, implicating additional somatic mutations in a multi-hit tumorigenic process. Results To decipher the genetics of these melanomas, we sequence the protein coding exons of 53 primary melanomas generated from several BRAFV600E or NRASQ61K driven transgenic zebrafish lines. We find that engineered zebrafish melanomas show an overall low mutation burden, which has a strong, inverse association with the number of initiating germline drivers. Although tumors reveal distinct mutation spectrums, they show mostly C?>?T transitions without UV light exposure, and enrichment of mutations in melanogenesis, p53 and MAPK signaling. Importantly, a recurrent amplification occurring with pre-configured drivers BRAFV600E and p53-/- suggests a novel path of BRAF cooperativity through the protein kinase A pathway. Conclusion This is the first analysis of a melanoma mutational landscape in the absence of UV light, where tumors manifest with remarkably low mutation burden and high heterogeneity. Genotype specific amplification of protein kinase A in cooperation with BRAF and p53 mutation suggests the involvement of melanogenesis in these tumors. This work is important for defining the spectrum of events in BRAF or NRAS driven melanoma in the absence of UV light, and for informed exploitation of models such as transgenic zebrafish to better understand mechanisms leading to human melanoma formation.

2013-01-01

203

A zebrafish model for uremic toxicity: role of the complement pathway.  

PubMed

Many organic solutes accumulate in end-stage renal disease (ESRD) and some are poorly removed with urea-based prescriptions for hemodialysis. However, their toxicities have been difficult to assess. We have employed an animal model, the zebrafish embryo, to test the toxicity of uremic serum compared to control. Serum was obtained from stable ESRD patients predialysis or from normal subjects. Zebrafish embryos 24 h postfertilization were exposed to experimental media at a water:human serum ratio of 3:1. Those exposed to serum from uremic subjects had significantly reduced survival at 8 h (19 ± 18 vs. 94 ± 6%, p < 0.05, uremic serum vs. control, respectively). Embryos exposed to serum from ESRD subjects fractionated at 50 kDa showed significantly greater toxicity with the larger molecular weight fraction (83 ± 11 vs. 7 ± 17% survival, p < 0.05, <50 vs. >50 kDa, respectively). Heating serum abrogated its toxicity. EDTA, a potent inhibitor of complement by virtue of calcium chelation, reduced the toxicity of uremic serum compared to untreated uremic serum (96 ± 5 vs. 28 ± 20% survival, p < 0.016, chelated vs. nonchelated serum, respectively). Anti-factor B, a specific inhibitor of the alternative complement pathway, reduced the toxicity of uremic serum, compared to untreated uremic serum (98 ± 6 vs. 3 ± 9% survival, p < 0.016, anti-factor B treated vs. nontreated, respectively). Uremic serum is thus more toxic to zebrafish embryos than normal serum. Furthermore, this toxicity is associated with a fraction of large size, is inactivated by heat, and is reduced by both specific and nonspecific inhibitors of complement activation. Together these data lend support to the hypothesis that at least some uremic toxicities may be mediated by complement. PMID:23689420

Berman, Nathaniel; Lectura, Melisa; Thurman, Joshua M; Reinecke, James; Raff, Amanda C; Melamed, Michal L; Quan, Zhe; Evans, Todd; Meyer, Timothy W; Hostetter, Thomas H

2013-01-01

204

Human proangiogenic circulating hematopoietic stem and progenitor cells promote tumor growth in an orthotopic melanoma xenograft model.  

PubMed

We previously identified a distinct population of human circulating hematopoietic stem and progenitor cells (CHSPCs; CD14(-)glyA(-)CD34(+)AC133(+/-)CD45(dim)CD31(+) cells) in the peripheral blood (PB) and bone marrow, and their frequency in the PB can correlate with disease state. The proangiogenic subset (pCHSPC) play a role in regulating tumor progression, for we previously demonstrated a statistically significant increase in C32 melanoma growth in NOD.Cg-Prkdc (scid) (NOD/SCID) injected with human pCHSPCs (p < 0.001). We now provide further evidence that pCHSPCs possess proangiogenic properties. In vitro bio-plex cytokine analyses and tube forming assays indicate that pCHSPCs secrete a proangiogenic profile and promote vessel formation respectively. We also developed a humanized bone marrow-melanoma orthotopic model to explore in vivo the biological significance of the pCHSPC population. Growth of melanoma xenografts increased more rapidly at 3-4 weeks post-tumor implantation in mice previously transplanted with human CD34(+) cells compared to control mice. Increases in pCHSPCs in PB correlated with increases in tumor growth. Additionally, to determine if we could prevent the appearance of pCHSPCs in the PB, mice with humanized bone marrow-melanoma xenografts were administered Interferon ?-2b, which is used clinically for treatment of melanoma. The mobilization of the pCHSPCs was decreased in the mice with the humanized bone marrow-melanoma xenografts. Taken together, these data indicate that pCHSPCs play a functional role in tumor growth. The novel in vivo model described here can be utilized to further validate pCHSPCs as a biomarker of tumor progression. The model can also be used to screen and optimize anticancer/anti-angiogenic therapies in a humanized system. PMID:23877751

Mund, Julie A; Shannon, Harlan; Sinn, Anthony L; Cai, Shanbao; Wang, Haiyan; Pradhan, Kamnesh R; Pollok, Karen E; Case, Jamie

2013-10-01

205

Influence of tumour size on uptake of111In-DTPA-labelled pegylated liposomes in a human tumour xenograft model  

Microsoft Academic Search

The relationship between tumour size and uptake of111In-DTPA-labelled pegylated liposomes has been examined in a human head and neck cancer xenograft model in nude mice. The mean tumour uptake of111In-labelled pegylated liposomes at 24 hours was 7.2 ± 6.6% ID\\/g. Liposome uptake for tumours 1.0 g was 15.1 ± 10.8, 5.9 ± 2.2 and 3.0 ± 1.3% ID\\/g, respectively. An

K J Harrington; G Rowlinson-Busza; K N Syrigos; R M Abra; P S Uster; A M Peters; J S W Stewart

2000-01-01

206

Zebrafish as a model system for environmental health studies in the grade 9-12 classroom.  

PubMed

Abstract Developing zebrafish embryos were used as a model system for high school students to conduct scientific investigations that reveal features of normal development and to test how different environmental toxicants impact the developmental process. The primary goal of the module was to engage students from a wide range of socio-economic backgrounds, with particular focus on underserved inner-city high schools, in inquiry-based learning and hands-on experimentation. In addition, the module served as a platform for both teachers and students to design additional inquiry-based experiments. In this module, students spawned adult zebrafish to generate developing embryos, exposed the embryos to various toxicants, then gathered, and analyzed data obtained from control and experimental embryos. The module provided a flexible, experimental framework for students to test the effects of numerous environmental toxicants, such as ethanol, caffeine, and nicotine, on the development of a model vertebrate organism. Students also observed the effects of dose on experimental outcomes. From observations of the effects of the chemical agents on vertebrate embryos, students drew conclusions on how these chemicals could impact human development and health. Results of pre-tests and post-tests completed by participating students indicate statistically significant changes in awareness of the impact of environmental agents on fish and human beings In addition, the program's evaluator concluded that participation in the module resulted in significant changes in the attitude of students and teachers toward science in general and environmental health in particular. PMID:24941301

Tomasiewicz, Henry G; Hesselbach, Renee; Carvan, Michael John; Goldberg, Barbara; Berg, Craig A; Petering, David H

2014-08-01

207

Polymethoxy-1-alkenes from Aphanizomenon ovalisporum inhibit vertebrate development in the zebrafish (Danio rerio) embryo model.  

PubMed

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. PMID:23170087

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

2012-10-01

208

MYBPC1 mutations impair skeletal muscle function in zebrafish models of arthrogryposis.  

PubMed

Myosin-binding protein C1 (MYBPC1) is an abundant skeletal muscle protein that is expressed predominantly in slow-twitch muscle fibers. Human MYBPC1 mutations are associated with distal arthrogryposis type 1 and lethal congenital contracture syndrome type 4. As MYBPC1 function is incompletely understood, the mechanism by which human mutations result in contractures is unknown. Here, we demonstrate using antisense morpholino knockdown, that mybpc1 is required for embryonic motor activity and survival in a zebrafish model of arthrogryposis. Mybpc1 morphant embryos have severe body curvature, cardiac edema, impaired motor excitation and are delayed in hatching. Myofibril organization is selectively impaired in slow skeletal muscle and sarcomere numbers are greatly reduced in mybpc1 knockdown embryos, although electron microscopy reveals normal sarcomere structure. To evaluate the effects of human distal arthrogryposis mutations, mybpc1 mRNAs containing the corresponding human W236R and Y856H MYBPC1 mutations were injected into embryos. Dominant-negative effects of these mutations were suggested by the resultant mild bent body curvature, decreased motor activity, as well as impaired overall survival compared with overexpression of wild-type RNA. These results demonstrate a critical role for mybpc1 in slow skeletal muscle development and establish zebrafish as a tractable model of human distal arthrogryposis. PMID:23873045

Ha, Kyungsoo; Buchan, Jillian G; Alvarado, David M; McCall, Kevin; Vydyanath, Anupama; Luther, Pradeep K; Goldsmith, Matthew I; Dobbs, Matthew B; Gurnett, Christina A

2013-12-15

209

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

210

Identification of a new modulator of the intercalated disc in a zebrafish model of arrhythmogenic cardiomyopathy.  

PubMed

Arrhythmogenic cardiomyopathy (ACM) is characterized by frequent cardiac arrhythmias. To elucidate the underlying mechanisms and discover potential chemical modifiers, we created a zebrafish model of ACM with cardiac myocyte-specific expression of the human 2057del2 mutation in the gene encoding plakoglobin. A high-throughput screen identified SB216763 as a suppressor of the disease phenotype. Early SB216763 therapy prevented heart failure and reduced mortality in the fish model. Zebrafish ventricular myocytes that expressed 2057del2 plakoglobin exhibited 70 to 80% reductions in INa and IK1 current densities, which were normalized by SB216763. Neonatal rat ventricular myocytes that expressed 2057del2 plakoglobin recapitulated pathobiological features seen in patients with ACM, all of which were reversed or prevented by SB216763. The reverse remodeling observed with SB216763 involved marked subcellular redistribution of plakoglobin, connexin 43, and Nav1.5, but without changes in their total cellular content, implicating a defect in protein trafficking to intercalated discs. In further support of this mechanism, we observed SB216763-reversible, abnormal subcellular distribution of SAP97 (a protein known to mediate forward trafficking of Nav1.5 and Kir2.1) in rat cardiac myocytes expressing 2057del2 plakoglobin and in cardiac myocytes derived from induced pluripotent stem cells from two ACM probands with plakophilin-2 mutations. These observations pinpoint aberrant trafficking of intercalated disc proteins as a central mechanism in ACM myocyte injury and electrical abnormalities. PMID:24920660

Asimaki, Angeliki; Kapoor, Sudhir; Plovie, Eva; Karin Arndt, Anne; Adams, Edward; Liu, ZhenZhen; James, Cynthia A; Judge, Daniel P; Calkins, Hugh; Churko, Jared; Wu, Joseph C; MacRae, Calum A; Kléber, André G; Saffitz, Jeffrey E

2014-06-11

211

Pseudotyped AAV Vector-Mediated Gene Transfer in a Human Fetal Trachea Xenograft Model: Implications for In Utero Gene Therapy for Cystic Fibrosis  

PubMed Central

Background Lung disease including airway infection and inflammation currently causes the majority of morbidities and mortalities associated with cystic fibrosis (CF), making the airway epithelium and the submucosal glands (SMG) novel target cells for gene therapy in CF. These target cells are relatively inaccessible to postnatal gene transfer limiting the success of gene therapy. Our previous work in a human-fetal trachea xenograft model suggests the potential benefit for treating CF in utero. In this study, we aim to validate adeno-associated virus serotype 2 (AAV2) gene transfer in a human fetal trachea xenograft model and to compare transduction efficiencies of pseudotyping AAV2 vectors in fetal xenografts and postnatal xenograft controls. Methodology/Principal Findings Human fetal trachea or postnatal bronchus controls were xenografted onto immunocompromised SCID mice for a four-week engraftment period. After injection of AAV2/2, 2/1, 2/5, 2/7 or 2/8 with a LacZ reporter into both types of xenografts, we analyzed for transgene expression in the respiratory epithelium and SMGs. At 1 month, transduction by AAV2/2 and AAV2/8 in respiratory epithelium and SMG cells was significantly greater than that of AAV2/1, 2/5, and 2/7 in xenograft tracheas. Efficiency in SMG transduction was significantly greater in AAV2/8 than AAV2/2. At 3 months, AAV2/2 and AAV2/8 transgene expression was >99% of respiratory epithelium and SMG. At 1 month, transduction efficiency of AAV2/2 and AAV2/8 was significantly less in adult postnatal bronchial xenografts than in fetal tracheal xenografts. Conclusions/Significance Based on the effectiveness of AAV vectors in SMG transduction, our findings suggest the potential utility of pseudotyped AAV vectors for treatment of cystic fibrosis. The human fetal trachea xenograft model may serve as an effective tool for further development of fetal gene therapy strategies for the in utero treatment of cystic fibrosis.

Leung, Alice; Katz, Anna B.; Lim, Foong-Yen; Habli, Mounira; Jones, Helen N.; Wilson, James M.; Crombleholme, Timothy M.

2012-01-01

212

The interferon response is involved in nervous necrosis virus acute and persistent infection in zebrafish infection model  

Microsoft Academic Search

Betanodavirus, a small positive-sense bipartite RNA virus notoriously affecting marine aquaculture worldwide has been extensively studied in vitro. However, impending studies in elucidating virus–host interactions have been limiting due to the lack of appropriate animal disease models. Therefore, in this study, we have attempted to successfully establish NNV infection in zebrafish (Danio rerio) showing typical NNV symptoms and which could

Ming-Wei Lu; Yung-Mei Chao; Tz-Chun Guo; Nina Santi; Øystein Evensen; Siti Khadijah Kasani; Jiann-Ruey Hong; Jen-Leih Wu

2008-01-01

213

Developing a Zebrafish Model of NF1 for Structure-Function Analysis and Identification of Modifier Genes.  

National Technical Information Service (NTIS)

The primary goal of this project is to develop a zebrafish model of the autosomal dominant genetic disorder type I neurofibromatosis (NF1). This disorder is very common, affecting approximately 1 in 3000 live births, and results from mutations in the NF1 ...

J. A. Epstein

2010-01-01

214

MEDI3617, a human anti-angiopoietin 2 monoclonal antibody, inhibits angiogenesis and tumor growth in human tumor xenograft models.  

PubMed

Angiopoietin 2 (Ang2) is an important regulator of angiogenesis, blood vessel maturation and integrity of the vascular endothelium. The correlation between the dynamic expression of Ang2 in tumors with regions of high angiogenic activity and a poor prognosis in many tumor types makes Ang2 an ideal drug target. We have generated MEDI3617, a human anti-Ang2 monoclonal antibody that neutralizes Ang2 by preventing its binding to the Tie2 receptor in vitro, and inhibits angiogenesis and tumor growth in vivo. Treatment of mice with MEDI3617 resulted in inhibition of angiogenesis in several mouse models including: FGF2-induced angiogenesis in a basement extract plug model, tumor and retinal angiogenesis. In xenograft tumor models, treatment with MEDI3617 resulted in a reduction in tumor angiogenesis and an increase in tumor hypoxia. The administration of MEDI3617 as a single agent to mice bearing human tumor xenografts resulted in tumor growth inhibition against a broad spectrum of tumor types. Combining MEDI3617 with chemotherapy or bevacizumab resulted in a delay in tumor growth and no body weight loss was observed in the combination groups. These results, combined with pharmacodynamic studies, demonstrate that treatment of tumor-bearing mice with MEDI3617 significantly inhibited tumor growth as a single agent by blocking tumor angiogenesis. Together, these data show that MEDI3617 is a robust antiangiogenic agent and support the clinical evaluation and biomarker development of MEDI3617 in cancer patients. PMID:22327175

Leow, Ching Ching; Coffman, Karen; Inigo, Ivan; Breen, Shannon; Czapiga, Meggan; Soukharev, Serguei; Gingles, Neill; Peterson, Norman; Fazenbaker, Christine; Woods, Rob; Jallal, Bahija; Ricketts, Sally-Ann; Lavallee, Theresa; Coats, Steve; Chang, Yong

2012-05-01

215

Zebrafish and medaka: model organisms for a comparative developmental approach of brain asymmetry  

PubMed Central

Comparison between related species is a successful approach to uncover conserved and divergent principles of development. Here, we studied the pattern of epithalamic asymmetry in zebrafish (Danio rerio) and medaka (Oryzias latipes), two related teleost species with 115–200?Myr of independent evolution. We found that these species share a strikingly conserved overall pattern of asymmetry in the parapineal–habenular–interpeduncular system. Nodal signalling exhibits comparable spatial and temporal asymmetric expressions in the presumptive epithalamus preceding the development of morphological asymmetries. Neuroanatomical asymmetries consist of left-sided asymmetric positioning and connectivity of the parapineal organ, enlargement of neuropil in the left habenula compared with the right habenula and segregation of left–right habenular efferents along the dorsoventral axis of the interpeduncular nucleus. Despite the overall conservation of asymmetry, we observed heterotopic changes in the topology of parapineal efferent connectivity, heterochronic shifts in the timing of developmental events underlying the establishment of asymmetry and divergent degrees of canalization of embryo laterality. We offer new tools for developmental time comparison among species and propose, for each of these transformations, novel hypotheses of ontogenic mechanisms that explain interspecies variations that can be tested experimentally. Together, these findings highlight the usefulness of zebrafish and medaka as comparative models to study the developmental mechanisms of epithalamic asymmetry in vertebrates.

Signore, Iskra A.; Guerrero, Nestor; Loosli, Felix; Colombo, Alicia; Villalon, Aldo; Wittbrodt, Joachim; Concha, Miguel L.

2008-01-01

216

Mariner is defective in myosin VIIA: a zebrafish model for human hereditary deafness.  

PubMed

The zebrafish (Danio rerio) possesses two mechanosensory organs believed to be homologous to each other: the inner ear, which is responsible for the senses of audition and equilibrium, and the lateral line organ, which is involved in the detection of water movements. Eight zebrafish circler or auditory/vestibular mutants appear to have defects specific to sensory hair cell function. The circler genes may therefore encode components of the mechanotransduction apparatus and/or be the orthologous counterparts of the genes underlying human hereditary deafness. In this report, we show that the phenotype of the circler mutant, mariner, is due to mutations in the gene encoding Myosin VIIA, an unconventional myosin which is expressed in sensory hair cells and is responsible for various types of hearing disorder in humans, namely Usher 1B syndrome, DFNB2 and DFNA11. Our analysis of the fine structure of hair bundles in the mariner mutants suggests that a missense mutation within the C-terminal FERM domain of the tail of Myosin VIIA has the potential to dissociate the two different functions of the protein in hair bundle integrity and apical endocytosis. Notably, mariner sensory hair cells display morphological and functional defects that are similar to those present in mouse shaker-1 hair cells which are defective in Myosin VIIA. Thus, this study demonstrates the striking conservation of the function of Myosin VIIA throughout vertebrate evolution and establishes mariner as the first fish model for human hereditary deafness. PMID:10958658

Ernest, S; Rauch, G J; Haffter, P; Geisler, R; Petit, C; Nicolson, T

2000-09-01

217

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

PubMed Central

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.

Muto, Akira; Kawakami, Koichi

2013-01-01

218

Heritable T Cell Malignancy Models Established in a Zebrafish Phenotypic Screen  

PubMed Central

T cell neoplasias are common in pediatric oncology, and include acute lymphoblastic leukemia (T-ALL) and lymphoblastic lymphoma (T-LBL). These cancers have worse prognoses than their B cell counterparts, and their treatments carry significant morbidity. While many pediatric malignancies have characteristic translocations, most T lymphocyte-derived diseases lack cytogenetic hallmarks. Lacking these informative lesions, insight into their molecular pathogenesis is less complete. Although dysregulation of the NOTCH1 pathway occurs in a substantial fraction of cases, many other genetic lesions of T cell malignancy have not yet been determined. To address this deficiency, we pioneered a phenotype-driven forward-genetic screen in zebrafish (Danio rerio). Using transgenic fish with T lymphocyte-specific expression of enhanced green fluorescent protein (EGFP), we performed chemical mutagenesis, screened animals for GFP+ tumors, and identified multiple lines with a heritable predisposition to T cell malignancy. In each line, patterns of infiltration and morphologic appearance resembled human T-ALL and T-LBL. T cell receptor analyses confirmed their clonality. Malignancies were transplantable and contained leukemia-initiating cells (LIC), like their human correlates. In summary, we have identified multiple zebrafish mutants that recapitulate human T cell neoplasia and show heritable transmission. These vertebrate models provide new genetic platforms for the study of these important human cancers.

Frazer, J. Kimble; Meeker, Nathan; Rudner, Lynnie; Bradley, Diana F.; Smith, Alexandra C. H.; Demarest, Bradley; Joshi, Deepa; Locke, Erin E.; Hutchinson, Sarah A.; Tripp, Sheryl; Perkins, Sherrie L.; Trede, Nikolaus S.

2009-01-01

219

Evaluation of MGMT Promoter Methylation Status and Correlation with Temozolomide Response in Orthotopic Glioblastoma Xenograft Model  

PubMed Central

CpG methylation within the O6-methylguanine-DNA-methyltransferase (MGMT) promoter is associated with enhanced survival of glioblastoma multiforme (GBM) patients treated with temozolomide (TMZ). Although MGMT promoter is methylated in ~50% of GBM, several studies have reported a lack of correlation between MGMT methylation and protein expression levels and consequently inaccurate discrimination of TMZ sensitive and resistant patients. To understand the limitations of currently used assays, TMZ responsiveness of 13 GBM xenograft lines was correlated with MGMT protein expression and MGMT promoter methylation determined by 1) standard methylation-specific polymerase chain reaction (MS-PCR), 2) quantitative MS-PCR (qMS-PCR) and 3) bisulfite sequencing. For each xenograft line, mice with established intracranial xenografts were treated with vehicle control or TMZ (66 mg/kg × 5 days), and TMZ response was defined as relative prolongation in median survival for TMZ-treated vs. control-treated mice. The relative survival benefit with TMZ was inversely related to MGMT protein expression (r= ?0.75; p=0.003) and directly correlated with qMS-PCR (r=0.72; p=0.006). There was a direct correlation between MGMT methylation signal by qMS-PCR and the number of methylated CpG sites within the region amplified by MS-PCR (r =0.78, p=0.002). However, bisulfite sequencing revealed heterogeneity in the extent of CpG methylation in those tumors with a robust qMS-PCR signal. Three of the 4 GBM lines with a qMS-PCR signal greater than 10% had at least 1 unmethylated CpG site, while only one line was fully methylated at all 12 CpG sites. These data highlight one potential limitation of the evaluation of MGMT methylation by MS-PCR assay and suggest that more detailed evaluation of methylation at individual CpG sites relative to TMZ response may be worth pursuing.

Kitange, Gaspar J.; Carlson, Brett L.; Mladek, Ann C.; Decker, Paul A.; Schroeder, Mark A.; Wu, Wenting; Grogan, Patrick T.; Giannini, Caterina; Ballman, Karla V.; Buckner, Jan C.; James, C. David; Sarkaria, Jann N.

2009-01-01

220

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

2012-10-01

221

INDUCED AND SPONTANEOUS NEOPLASIA IN ZEBRAFISH.  

EPA Science Inventory

To address the potential of zebrafish as a cancer model, it is important to determine the susceptibility of zebrafish to tumors, and to compare zebrafish tumors with human tumors. To determine whether the commonly-used germ line mutagen, ethylnitrosourea (ENU) induces tumors, we ...

222

Combined immunohistochemical and autoradiographic analyses of antigen/antibody interactions in tumor xenograft models.  

PubMed

A study was conducted to establish optimal conditions which would allow for the simultaneous localization of a carcinoma antigen and its complementary radiolabeled antibody. Immunoperoxidase staining was used to identify the tumor distribution of antigen, while tissue localization of the radiolabeled antibody was identified by autoradiography. The tumor associated glycoprotein-72 (TAG-72) antigen and the high affinity murine monoclonal antibody, CC49 IgG were used as the model antigen/antibody pair. Athymic female mice bearing either CX-1 or LS-174T human colorectal adenocarcinoma xenografts were used as animal/tumor test systems. Experimental mice each received a bolus intravenous injection of the CC49 antibody which was labeled with 125I (specific activity, 0.17 to 0.26 microCi/microgram). Control mice were given a bolus injection of MOPC-21 IgG monoclonal antibody (tumor irrelevant antibody) which was also radiolabeled with 125I (specific activity, 0.24 to 0.35 microCi/microgram). At 24 hours postinjection, all tumors removed, counted for radioactivity, and fixed in formalin. The avidin/biotin immunoperoxidase complex technique was used to identify TAG-72 antigenic sites on slide-mounted tissue sections. Nonradiolabeled CC49 IgG (0.5 micrograms/ml) was used as the specific antigen binding primary antibody in the immunostaining procedures. Nonradiolabeled MOPC-21 IgG (0.5 micrograms/ml) served as the negative control. Immunohistochemically stained tissue sections were coated with photographic emulsion and processed for autoradiographic localization of 125I-CC49 or 125I-MOPC-21. After an optimal exposure time of 6 days, slides were processed and examined under a light microscope. Results of the biolocalization experiment revealed that the % of injected dose/gram of 125I-CC49 in both LS-174T and CX-1 tumors (30.4 +/- 5.2% and 20.6 +/- 5.4%, respectively) were significantly greater (p greater than 0.01) than those for 125I-MOPC-21 (4.9 +/- 0.5% and 5.1 +/- 0.7%, respectively). In both tumor lines from mice injected with 125I-CC49, dense clusters of silver grains were found over those regions which were positive for TAG-72 immunoreactivity. These dual-labeled structures were also found in contact with, or in close proximity to the microvasculature. Tumors from mice which were injected with the control radioconjugate showed a random distribution of silver grains within stromal tissue but no specific localization to TAG-72 positive regions. We conclude that intravenously administered 125I-CC49 IgG localizes specifically to antigen-containing sites in the LS-174T and CX-1 tumor models. The methods described herein should serve as useful tools for the direct study of antigen-antibody interactions in tumor biology. PMID:2072661

DePalatis, L R; Johnson, K A; Kaplan, D A

1991-07-01

223

Rapamycin increases neuroblastoma xenograft and host stromal derived osteoprotegerin inhibiting osteolytic bone disease in a bone metastasis model  

PubMed Central

Purpose Osteoprotegerin (OPG) is a decoy receptor for the Receptor of NF-?B (RANK) ligand that can inhibit osteoclastogenesis. Previous studies have suggested that Mammalian Target of Rapamycin (mTOR) inhibition upregulates OPG production. We tested the hypothesis that the mTOR inhibitor rapamycin could inhibit neuroblastoma bone metastases through its action on OPG. Experimental Design An orthotopic model of bone metastasis was established. Mice with established disease were subsequently treated with rapamycin (5 mg/kg IP daily) or vehicle control (DMSO 1:1000). X-rays were obtained twice a week to detect pathologic fractures. Serum OPG levels were measured by ELISA after two weeks of treatment. Results Mice with bone disease receiving rapamycin had increased serum levels of OPG in the CHLA-20 mice compared to controls (36.89 pg/mL±3.90 vs 18.4 pg/mL±1.67, p=0.004) and NB1691 tumor-bearing groups (46.03±2.67 pg/mL vs 17.96±1.84 pg/mL, p=0.001), and a significantly longer median time to pathologic fractures with CHLA-20 (103 days vs 74.5 days, p=0.014) and NB1691 xenografts. Conclusion In a xenograft model, increased OPG expression correlated with a delay to pathologic fracture suggesting a potential role for mTOR inhibitors in the treatment of neuroblastoma bone metastases.

Hartwich, Joseph E.; Orr, W. Shannon; Ng, Catherine Y.; Spence, Yunyu; McLaughlin, Jillian M.; Furman, Wayne L.; McGregor, Lisa M.; Davidoff, Andrew M.

2013-01-01

224

Activin type IB receptor signaling in prostate cancer cells promotes lymph node metastasis in a xenograft model  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer ActRIB signaling induces Snail and S100A4 expressions in prostate cancer cells. Black-Right-Pointing-Pointer The prostate cancer cell lines expressing an active form of ActRIB were established. Black-Right-Pointing-Pointer ActRIB signaling promotes EMT and lymph node metastasis in xenograft model. -- Abstract: Activin, a member of the transforming growth factor-{beta} family, has been known to be a growth and differentiating factor. Despite its pluripotent effects, the roles of activin signaling in prostate cancer pathogenesis are still unclear. In this study, we established several cell lines that express a constitutive active form of activin type IB receptor (ActRIBCA) in human prostate cancer cells, ALVA41 (ALVA-ActRIBCA). There was no apparent change in the proliferation of ALVA-ActRIBCA cells in vitro; however, their migratory ability was significantly enhanced. In a xenograft model, histological analysis revealed that the expression of Snail, a cell-adhesion-suppressing transcription factor, was dramatically increased in ALVA-ActRIBCA tumors, indicating epithelial mesenchymal transition (EMT). Finally, mice bearing ALVA-ActRIBCA cells developed multiple lymph node metastases. In this study, we demonstrated that ActRIBCA signaling can promote cell migration in prostate cancer cells via a network of signaling molecules that work together to trigger the process of EMT, and thereby aid in the aggressiveness and progression of prostate cancers.

Nomura, Masatoshi, E-mail: nomura@med.kyushu-u.ac.jp [Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan)] [Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Tanaka, Kimitaka; Wang, Lixiang; Goto, Yutaka; Mukasa, Chizu; Ashida, Kenji; Takayanagi, Ryoichi [Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan)] [Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan)

2013-01-04

225

Complement system in zebrafish.  

PubMed

Zebrafish is recently emerging as a model species for the study of immunology and human diseases. Complement system is the humoral backbone of the innate immune defense, and our knowledge as such in zebrafish has dramatically increased in the recent years. This review summarizes the current research progress of zebrafish complement system. The global searching for complement components in genome database, together with published data, has unveiled the existence of all the orthologues of mammalian complement components identified thus far, including the complement regulatory proteins and complement receptors, in zebrafish. Interestingly, zebrafish complement components also display some distinctive features, such as prominent levels of extrahepatic expression and isotypic diversity of the complement components. Future studies should focus on the following issues that would be of special importance for understanding the physiological role of complement components in zebrafish: conclusive identification of complement genes, especially those with isotypic diversity; analysis and elucidation of function and mechanism of complement components; modulation of innate and adaptive immune response by complement system; and unconventional roles of complement-triggered pathways. PMID:24462834

Zhang, Shicui; Cui, Pengfei

2014-09-01

226

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

227

From omics to drug metabolism and high content screen of natural product in zebrafish: a new model for discovery of neuroactive compound.  

PubMed

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. PMID:22919414

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

228

Kindlin-1 mutant zebrafish as an in vivo model system to study adhesion mechanisms in the epidermis.  

PubMed

From a forward genetic screen for epidermal defects in zebrafish, we identified a loss-of-function mutation in Kindlin-1, an essential regulator of integrin function. The mutation generates a premature stop codon, deleting the integrin-binding site. The mutant zebrafish develops cell-matrix and cell-cell adhesion defects in the basal epidermis leading to progressive fin rupturing, and was therefore designated rupturing-of-fins (rof). Similar defects were observed in the epidermis of Kindler syndrome patients, carrying a loss-of-function mutation in kindlin-1. Mutational analysis and rescue experiments in zebrafish revealed that residues K610, W612, and I647 in the F3 domain are essential for Kindlin-1 function in vivo, and that Kindlin-2 can functionally compensate for the loss of Kindlin-1. The fin phenotype of rof/kindlin-1 mutants resembles that of badfin mutants, carrying a mutation in integrin ?3. We show here that this mutation impairs the biosynthesis of integrin ?3?1 and causes cell-matrix and cell-cell defects in vivo. Whereas both Integrin-linked kinase (Ilk) and Kindlin-1 cooperate with Integrin ?3?1 to resist trauma-induced epidermal defects, Kindlin-1 and Ilk, surprisingly, do not act synergistically but in parallel. Thus, the rof/kindlin-1 mutant zebrafish provides a unique model system to study epidermal adhesion mechanisms in vivo. PMID:23549420

Postel, Ruben; Margadant, Coert; Fischer, Boris; Kreft, Maaike; Janssen, Hans; Secades, Pablo; Zambruno, Giovanna; Sonnenberg, Arnoud

2013-09-01

229

CWR22: androgen-dependent xenograft model derived from a primary human prostatic carcinoma.  

PubMed

The long-term propagation of primary human prostate cancer (PCA) in vivo or in vitro has been rare. Most such PCAs are phenotypically different from most PCAs in humans; i.e., they make little prostate specific antigen and respond little, if at all, to androgen deprivation. A serially transplantable, primary human PCA, designated CWR22, exhibits a clonal cytogenetic aberration, causes high elevations of prostate specific antigen in the peripheral blood of nude mice, and is unusually responsive to androgen deprivation as compared with other xenografts. Studies of mRNA from CWR22 have demonstrated the expression of prostate specific antigen and the epidermal growth factor receptor family including erbB1/epidermal growth factor receptor, erbB2/neu, and erbB3, but not erbB4. A ligand for these receptors, the neu differentiation factor, is also expressed. PMID:7525052

Wainstein, M A; He, F; Robinson, D; Kung, H J; Schwartz, S; Giaconia, J M; Edgehouse, N L; Pretlow, T P; Bodner, D R; Kursh, E D

1994-12-01

230

Distinct choline metabolic profiles are associated with differences in gene expression for basal-like and luminal-like breast cancer xenograft models  

PubMed Central

Background Increased concentrations of choline-containing compounds are frequently observed in breast carcinomas, and may serve as biomarkers for both diagnostic and treatment monitoring purposes. However, underlying mechanisms for the abnormal choline metabolism are poorly understood. Methods The concentrations of choline-derived metabolites were determined in xenografted primary human breast carcinomas, representing basal-like and luminal-like subtypes. Quantification of metabolites in fresh frozen tissue was performed using high-resolution magic angle spinning magnetic resonance spectroscopy (HR MAS MRS). The expression of genes involved in phosphatidylcholine (PtdCho) metabolism was retrieved from whole genome expression microarray analyses. The metabolite profiles from xenografts were compared with profiles from human breast cancer, sampled from patients with estrogen/progesterone receptor positive (ER+/PgR+) or triple negative (ER-/PgR-/HER2-) breast cancer. Results In basal-like xenografts, glycerophosphocholine (GPC) concentrations were higher than phosphocholine (PCho) concentrations, whereas this pattern was reversed in luminal-like xenografts. These differences may be explained by lower choline kinase (CHKA, CHKB) expression as well as higher PtdCho degradation mediated by higher expression of phospholipase A2 group 4A (PLA2G4A) and phospholipase B1 (PLB1) in the basal-like model. The glycine concentration was higher in the basal-like model. Although glycine could be derived from energy metabolism pathways, the gene expression data suggested a metabolic shift from PtdCho synthesis to glycine formation in basal-like xenografts. In agreement with results from the xenograft models, tissue samples from triple negative breast carcinomas had higher GPC/PCho ratio than samples from ER+/PgR+ carcinomas, suggesting that the choline metabolism in the experimental models is representative for luminal-like and basal-like human breast cancer. Conclusions The differences in choline metabolite concentrations corresponded well with differences in gene expression, demonstrating distinct metabolic profiles in the xenograft models representing basal-like and luminal-like breast cancer. The same characteristics of choline metabolite profiles were also observed in patient material from ER+/PgR+ and triple-negative breast cancer, suggesting that the xenografts are relevant model systems for studies of choline metabolism in luminal-like and basal-like breast cancer.

2010-01-01

231

Zebrafish as a model to assess cancer heterogeneity, progression and relapse  

PubMed Central

Clonal evolution is the process by which genetic and epigenetic diversity is created within malignant tumor cells. This process culminates in a heterogeneous tumor, consisting of multiple subpopulations of cancer cells that often do not contain the same underlying mutations. Continuous selective pressure permits outgrowth of clones that harbor lesions that are capable of enhancing disease progression, including those that contribute to therapy resistance, metastasis and relapse. Clonal evolution and the resulting intratumoral heterogeneity pose a substantial challenge to biomarker identification, personalized cancer therapies and the discovery of underlying driver mutations in cancer. The purpose of this Review is to highlight the unique strengths of zebrafish cancer models in assessing the roles that intratumoral heterogeneity and clonal evolution play in cancer, including transgenesis, imaging technologies, high-throughput cell transplantation approaches and in vivo single-cell functional assays.

Blackburn, Jessica S.; Langenau, David M.

2014-01-01

232

Assessment of the In vivo Antitumor Effects of ENMD-2076, a Novel Multitargeted Kinase Inhibitor, against Primary and Cell Line-Derived Human Colorectal Cancer Xenograft Models  

PubMed Central

Purpose This in vivo study was designed to investigate the efficacy of ENMD-2076, a small-molecule kinase inhibitor with activity against the Aurora kinases A and B, and several other tyrosine kinases linked to cancer, including vascular endothelial growth factor receptor 2, cKit, and fibroblast growth factor receptor 1, against murine xenograft models of human colorectal cancer (CRC). Experimental Design HT-29 CRC cell line xenografts were treated with either vehicle or ENMD-2076 (100 or 200 mg/kg) orally daily for 28 days. Tumor growth inhibition, dynamic contrast-enhanced magnetic resonance imaging, and 18FDG-positron emission tomography were conducted to assess the anti-proliferative, antiangiogenic, and antimetabolic responses, respectively. Effects on proliferation were also analyzed by immunohistochemical methods. Additionally, three patient-derived xenografts from primary and metastatic sites were treated with ENMD-2076 (100 mg/kg) and assessed for tumor growth inhibition. Results In the HT-29 xenograft model, ENMD-2076 induced initial tumor growth inhibition followed by regression. Treatment was associated with significant tumor blanching, indicating a loss of vascularity and substantial reductions in tumor vascular permeability and perfusion as measured by dynamic contrast-enhanced magnetic resonance imaging. Positron emission tomography scanning showed significant decreases in 18FDG uptake at days 3 and 21 of treatment, which was associated with a marked reduction in proliferation as assessed by Ki-67. All three of the patient-derived xenografts tested were sensitive to treatment with ENMD 2076 as measured by tumor growth inhibition. Conclusions ENMD-2076 showed robust antitumor activity against cell line and patient-derived xenograft models of CRC that is detectable by functional imaging, supporting clinical investigation of this agent in CRC.

Serkova, Natalie J.; Hasebroock, Kendra M.; Pitts, Todd M.; Diamond, Jennifer R.; Fletcher, Graham C.; Bray, Mark R.; Eckhardt, S. Gail

2014-01-01

233

A novel patient-derived intra-femoral xenograft model of bone metastatic prostate cancer that recapitulates mixed osteolytic and osteoblastic lesions  

PubMed Central

Prostate cancer metastasizes to bone in the majority of patients with advanced disease leading to painfully debilitating fractures, spinal compression and rapid decline. In addition, prostate cancer bone metastases often become resistant to standard therapies including androgen deprivation, radiation and chemotherapy. There are currently few models to elucidate mechanisms of interaction between the bone microenvironment and prostate cancer. It is, thus, essential to develop new patient-derived, orthotopic models. Here we report the development and characterization of PCSD1 (Prostate Cancer San Diego 1), a novel patient-derived intra-femoral xenograft model of prostate bone metastatic cancer that recapitulates mixed osteolytic and osteoblastic lesions. Methods A femoral bone metastasis of prostate cancer was removed during hemiarthroplasty and transplanted into Rag2-/-;?c-/- mice either intra-femorally or sub-cutaneously. Xenograft tumors that developed were analyzed for prostate cancer biomarker expression using RT-PCR and immunohistochemistry. Osteoblastic, osteolytic and mixed lesion formation was measured using micro-computed tomography (microCT). Results PCSD1 cells isolated directly from the patient formed tumors in all mice that were transplanted intra-femorally or sub-cutaneously into Rag2-/-;?c-/- mice. Xenograft tumors expressed human prostate specific antigen (PSA) in RT-PCR and immunohistochemical analyses. PCSD1 tumors also expressed AR, NKX3.1, Keratins 8 and 18, and AMACR. Histologic and microCT analyses revealed that intra-femoral PCSD1 xenograft tumors formed mixed osteolytic and osteoblastic lesions. PCSD1 tumors have been serially passaged in mice as xenografts intra-femorally or sub-cutaneously as well as grown in culture. Conclusions PCSD1 xenografts tumors were characterized as advanced, luminal epithelial prostate cancer from a bone metastasis using RT-PCR and immunohistochemical biomarker analyses. PCSD1 intra-femoral xenografts formed mixed osteoblastic/osteolytic lesions that closely resembled the bone lesions in the patient. PCSD1 is a new primary prostate cancer bone metastasis-derived xenograft model to study metastatic disease in the bone and to develop novel therapies for inhibiting prostate cancer growth in the bone-niche.

2011-01-01

234

Co-treatment with arsenic trioxide and ganciclovir reduces tumor volume in a murine xenograft model of nasopharyngeal carcinoma  

PubMed Central

We have previously shown that disruption of promyelocytic leukemia nuclear bodies (PML NBs) is sufficient to activate the EBV lytic cycle thus making infected cells susceptible to ganciclovir (GCV) mediated killing in vitro. Here we show that co-administration of GCV and arsenic trioxide (ATO), a PML NB disruptor, reduces tumor volume in a xenograft model of nasopharyngeal carcinoma utilizing CNE1 cells. When administered at pharmacologic levels, both GCV and ATO reduced tumor growth while co-treatment with GCV?+?ATO resulted in a diminution of tumor volume. Treatment with GCV or ATO individually resulted in an increased number of apoptotic cells while co-treatment with GCV?+?ATO synergistically induced apoptosis. Treatment with ATO or co-treatment with GCV?+?ATO resulted in expression of EBV lytic proteins. These data suggest that co-treatment with GCV?+?ATO may provide an effective treatment for nasopharyngeal carcinoma patients.

2013-01-01

235

Zebrafish von Willebrand Factor  

PubMed Central

von Willebrand factor (vWF) is a large protein involved in primary hemostasis. A dysfunction in this protein or an insufficient production of the protein leads to improper platelet adhesion/aggregation, resulting in a bleeding phenotype known as von Willebrand disease (vWD). To gain a better understanding of vWF interactions in vivo, the use of zebrafish as a model is ideal because of the transparency of the embryos and larvae. In this article, we examined the presence and function of vWF in hemostasis of zebrafish utilizing a variety of molecular methods. Using RT-PCR and antibody staining, we have shown that vWF mRNA is present in thrombocytes. Through antibody staining, we demonstrated vWF is synthesized in blood vessels. The role of zebrafish vWF in hemostasis was established through knockdown methods using vWF morpholino (vWF MO) antisense oligonucleotides. Embryos injected with vWF MO at the one to four cell stages resulted in a bleeding phenotype. Injection of embryos with vWF MO also caused an increase in time to occlusion within arteries in larvae upon laser induced injury. We then used vWF-specific Vivo-Morpholinos (VMO) to induce vWF knockdown in adult zebrafish by targeting the exon homologous to the human exon 28 of the vWF gene. The reduced ristocetin-mediated agglutination of thrombocytes in a plate tilting assay, using blood from adult zebrafish injected with VMO, provided evidence that vWF is involved in the hemostatic process. We also administered desmopressin acetate to larvae and adults which resulted in enhanced aggregation/agglutination of thrombocytes. Zebrafish genome database analysis revealed the presence of GPIb? gene. It also revealed the exon of zebrafish vWF gene corresponding to exon 28 of human vWF gen is highly similar to the exon 28 of human vWF gene, except that it has an insertion that leads to a translated peptide sequence that separates the two A domains coded by this exon. This exon is also conserved in other fishes. In summary, we established that zebrafish vWF has a role similar to that of vWF found in humans, thus, making zebrafish a useful model for studying the cell biology of vWF in vivo.

Carrillo, Maira; Kim, Seongcheol; Rajpurohit, Surendra Kumar; Kulkarni, Vrinda; Jagadeeswaran, Pudur

2010-01-01

236

Zebrafish von Willebrand factor.  

PubMed

von Willebrand factor (vWF) is a large protein involved in primary hemostasis. A dysfunction in this protein or an insufficient production of the protein leads to improper platelet adhesion/aggregation, resulting in a bleeding phenotype known as von Willebrand disease (vWD). To gain a better understanding of vWF interactions in vivo, the use of zebrafish as a model is ideal because of the transparency of the embryos and larvae. In this article, we examined the presence and function of vWF in hemostasis of zebrafish utilizing a variety of molecular methods. Using RT-PCR and antibody staining, we have shown that vWF mRNA is present in thrombocytes. Through antibody staining, we demonstrated vWF is synthesized in blood vessels. The role of zebrafish vWF in hemostasis was established through knockdown methods using vWF morpholino (vWF MO) antisense oligonucleotides. Embryos injected with vWF MO at the one to four cell stages resulted in a bleeding phenotype. Injection of embryos with vWF MO also caused an increase in time to occlusion within arteries in larvae upon laser induced injury. We then used vWF-specific Vivo-morpholinos (VMO) to induce vWF knockdown in adult zebrafish by targeting the exon homologous to the human exon 28 of the vWF gene. The reduced ristocetin-mediated agglutination of thrombocytes in a plate tilting assay, using blood from adult zebrafish injected with VMO, provided evidence that vWF is involved in the hemostatic process. We also administered desmopressin acetate to larvae and adults which resulted in enhanced aggregation/agglutination of thrombocytes. Zebrafish genome database analysis revealed the presence of GPIb? gene. It also revealed the exon of zebrafish vWF gene corresponding to exon 28 of human vWF gene is highly similar to the exon 28 of human vWF gene, except that it has an insertion that leads to a translated peptide sequence that separates the two A domains coded by this exon. This exon is also conserved in other fishes. In summary, we established that zebrafish vWF has a role similar to that of vWF found in humans, thus, making zebrafish a useful model for studying the cell biology of vWF in vivo. PMID:21035359

Carrillo, Maira; Kim, Seongcheol; Rajpurohit, Surendra Kumar; Kulkarni, Vrinda; Jagadeeswaran, Pudur

2010-12-15

237

A novel anti-tumor inhibitor identified by virtual screen with PLK1 structure and zebrafish assay.  

PubMed

Polo-like kinase 1 (PLK1), one of the key regulators of mitosis, is a target for cancer therapy due to its abnormally high activity in several tumors. Plk1 is highly conserved and shares a nearly identical 3-D structure between zebrafish and humans. The initial 10 mitoses of zebrafish embryonic cleavages occur every?30 minutes, and therefore provide a rapid assay to evaluate mitosis inhibitors including those targeting Plk1. To increase efficiency and specificity, we first performed a computational virtual screen of?60000 compounds against the human Plk1 3-D structure docked to both its kinase and Polo box domain. 370 candidates with the top free-energy scores were subjected to zebrafish assay and 3 were shown to inhibit cell division. Compared to general screen for compounds inhibiting zebrafish embryonic cleavage, computation increased the efficiency by 11 folds. One of the 3 compounds, named I2, was further demonstrated to effectively inhibit multiple tumor cell proliferation in vitro and PC3 prostate cancer growth in Xenograft mouse model in vivo. Furthermore, I2 inhibited Plk1 enzyme activity in a dose dependent manner. The IC50 values of I2 in these assays are compatible to those of ON-01910, a Plk1 inhibitor currently in Phase III clinic trials. Our studies demonstrate that zebrafish assays coupled with computational screening significantly improves the efficiency of identifying specific regulators of biological targets. The PLK1 inhibitor I2, and its analogs, may have potential in cancer therapeutics. PMID:23658603

Lu, Jing; Xin, Shengchang; Meng, Huan; Veldman, Matt; Schoenfeld, David; Che, Chao; Yan, Ruibin; Zhong, Hanbing; Li, Song; Lin, Shuo

2013-01-01

238

Apoptotic activity and antitumor efficacy of PEGylated TNF-related apoptosis-inducing ligand (TRAIL) in a Mia Paca-2 cell-xenografted mouse model.  

PubMed

The purpose of this study was to demonstrate the apoptotic activity and antitumor effect of PEGylated tumor necrosis factor-related apoptosis-inducing ligand (PEG-TRAIL) in pancreatic carcinoma Mia Paca-2 cells and in Mia Paca-2 cell-xenografted mice. PEG-TRAIL was prepared using mPEG-aldehyde (Mw 5 kDa). The apoptosis induced by PEG-TRAIL in Mia Paca-2 cells and in the tumors of Mia Paca-2 cell-xenografted mice was quantified by FACS analysis and using a TUNEL assay. Mia Paca-2 cell-xenografted BALB/c nu/nu mice were administered intratumoral injections of PEG-TRAIL (50 ?g/mouse/injection) every 3 days from day 0 (~4 weeks after xenografting) to day 15. Tumor volumes were measured every 3 days from day 0 to day 27. PEG-TRAIL displayed obvious apoptotic activity in Mia Paca-2 cells; the FACS signal was shifted to the apoptotic area and the cells exhibited green fluorescence indicating apoptosis in the TUNEL assay. Furthermore, PEG-TRAIL was found to suppress tumors in Mia Paca-2 cell-xenografted mice (tumor volumes: 183.9±134.1 for PEG-TRAIL vs. 1827.3±264.5 mm(3) for saline control). In addition, in vivo TUNEL assays of tumor tissues showed that the antitumor effect of PEG-TRAIL was due apoptosis. Our findings provide clear in vivo evidence of the antitumor potential of PEG-TRAIL in a Mia Paca-2 cell-xenografted mouse model based of pancreatic cancer. PMID:24268811

Byeon, Hyeong Jun; Choi, Seong Ho; Choi, Ji Su; Kim, Tae Hyung; Lee, Eun Seong; Lee, Kang Choon; Youn, Yu Seok

2014-02-01

239

Targeting plasminogen activator inhibitor-1 inhibits angiogenesis and tumor growth in a human cancer xenograft model.  

PubMed

Cancers of the urinary bladder result in aggressive and highly angiogenic tumors for which standard treatments have only limited success. Patients with advanced disease have a 5-year survival rate of less than 20%, and no new anticancer agent has been successfully introduced into the clinic armamentarium for the treatment of bladder cancer in more than 20 years. Investigations have identified plasminogen activator inhibitor-1 (PAI-1), a serine protease inhibitor, as being highly expressed in several malignancies, including bladder cancer, in which high expression is associated with a poor prognosis. In this study, we evaluated PAI-1 as a potential therapeutic target for bladder cancer. PAI-1 expression was manipulated in a panel of cell lines and functional inhibition was achieved using the small molecule tiplaxtinin. Reduction or inhibition of PAI-1 resulted in the reduction of cellular proliferation, cell adhesion, and colony formation, and the induction of apoptosis and anoikis in vitro. Treatment of T24 xenografts with tiplaxtinin resulted in inhibition of angiogenesis and induction of apoptosis, leading to a significant reduction in tumor growth. Similar results were obtained through evaluation of the human cervical cancer HeLa cell line, showing that PAI-1-mediated effects are not restricted to tumor cells of bladder origin. Collectively, these data show that targeting PAI-1 may be beneficial and support the notion that novel drugs such as tiplaxtinin could be investigated as anticancer agents. PMID:24072883

Gomes-Giacoia, Evan; Miyake, Makito; Goodison, Steve; Rosser, Charles J

2013-12-01

240

Contributing Factors of Temozolomide Resistance in MCF-7 Tumor Xenograft Models  

PubMed Central

Vasculature mediated drug resistance in tumors was studied in female SCID mice bearing wild type MCF-7 and adriamycin resistant MCF-7/ADR xenograft using temozolomide (TMZ). A strong tumor growth inhibitory effect of TMZ treatment was observed in MCF-7 tumors during the initial treatment phase with subsequent relapse, but not in MCF-7/ADR tumors. Non-invasive MRI measurements of tumor vascular volume and vascular permeability-surface area product (PS) demonstrated significant reduction of PS in long-term treated MCF-7, but not in MCF-7/ADR tumors. O6-Methylguanine-DNA methyltransferase (MGMT) mRNA, and VEGF expression was analyzed using real-time RT-PCR and ELISA, respectively. No significant changes in MGMT mRNA and VEGF expression were observed in either MCF-7 or MCF-7/ADR tumors. However, in vitro incubation of MCF-7 cells with TMZ did induce the expression of MGMT mRNA. In addition, p53 and p21 levels were scored by immunoblotting. Exposure of cells to TMZ did not affect either the p21 or the p53 expression in both MCF-7 and MCF-7/ADR cells. The absence of these molecular responses to TMZ treatment in MCF-7 tumors in vivo supports the possibility that the onset of cancer drug resistance is associated with reduced PS, which can decrease delivery of the drug to cancer cells.

Kato, Yoshinori; Okollie, Baasil; Raman, Venu; Vesuna, Farhad; Zhao, Ming; Baker, Sharyn D.; Bhujwalla, Zaver M.; Artemov, Dmitri

2007-01-01

241

Effect of melatonin on tumor growth and angiogenesis in xenograft model of breast cancer.  

PubMed

As neovascularization is essential for tumor growth and metastasis, controlling angiogenesis is a promising tactic in limiting cancer progression. Melatonin has been studied for their inhibitory properties on angiogenesis in cancer. We performed an in vivo study to evaluate the effects of melatonin treatment on angiogenesis in breast cancer. Cell viability was measured by MTT assay after melatonin treatment in triple-negative breast cancer cells (MDA-MB-231). After, cells were implanted in athymic nude mice and treated with melatonin or vehicle daily, administered intraperitoneally 1 hour before turning the room light off. Volume of the tumors was measured weekly with a digital caliper and at the end of treatments animals underwent single photon emission computed tomography (SPECT) with Technetium-99m tagged vascular endothelial growth factor (VEGF) C to detect in vivo angiogenesis. In addition, expression of pro-angiogenic/growth factors in the tumor extracts was evaluated by membrane antibody array and collected tumor tissues were analyzed with histochemical staining. Melatonin in vitro treatment (1 mM) decreased cell viability (p<0.05). The breast cancer xenografts nude mice treated with melatonin showed reduced tumor size and cell proliferation (Ki-67) compared to control animals after 21 days of treatment (p<0.05). Expression of VEGF receptor 2 decreased significantly in the treated animals compared to that of control when determined by immunohistochemistry (p<0.05) but the changes were not significant on SPECT (p>0.05) images. In addition, there was a decrease of micro-vessel density (Von Willebrand Factor) in melatonin treated mice (p<0.05). However, semiquantitative densitometry analysis of membrane array indicated increased expression of epidermal growth factor receptor and insulin-like growth factor 1 in treated tumors compared to vehicle treated tumors (p<0.05). In conclusion, melatonin treatment showed effectiveness in reducing tumor growth and cell proliferation, as well as in the inhibition of angiogenesis. PMID:24416386

Jardim-Perassi, Bruna Victorasso; Arbab, Ali S; Ferreira, Lívia Carvalho; Borin, Thaiz Ferraz; Varma, Nadimpalli R S; Iskander, A S M; Shankar, Adarsh; Ali, Meser M; de Campos Zuccari, Debora Aparecida Pires

2014-01-01

242

Zebrafish Models for Ectopic Mineralization Disorders: Practical Issues from Morpholino Design to Post-Injection Observations  

PubMed Central

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.

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

2013-01-01

243

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

2013-01-01

244

Evolutionary conservation of TFIIH subunits: implications for the use of zebrafish as a model to study TFIIH function and regulation.  

PubMed

Transcriptional factor IIH (TFIIH) is involved in cell cycle regulation, nucleotide excision repair, and gene transcription. Mutations in three of its subunits, XPB, XPD, and TTDA, lead to human recessive genetic disorders such as trichothiodystrophy and xeroderma pigmentosum, the latter of which is sometimes associated with Cockayne's syndrome. In the present study, we investigate the sequence conservation of TFIIH subunits among several teleost fish species and compare their characteristics and putative regulation by transcription factors to those of human and zebrafish. We report the following findings: (i) comparisons among protein sequences revealed a high sequence identity for each TFIIH subunit analysed; (ii) among transcription factors identified as putative regulators, OCT1 and AP1 have the highest binding-site frequencies in the promoters of TFIIH genes, and (iii) TFIIH genes have alternatively spliced isoforms. Finally, we compared the protein primary structure in human and zebrafish of XPD and XPB - two important ATP-dependent helicases that catalyse the unwinding of the DNA duplex at promoters during transcription - highlighting the conservation of domain regions such as the helicase domains. Our study suggests that zebrafish, a widely used model for many human diseases, could also act as an important model to study the function of TFIIH complex in repair and transcription regulation in humans. PMID:24731924

Silva, I A L; Cox, C J; Leite, R B; Cancela, M L; Conceição, N

2014-01-01

245

Cre/lox-regulated transgenic zebrafish model with conditional myc-induced T cell acute lymphoblastic leukemia.  

PubMed

We have created a stable transgenic rag2-EGFP-mMyc zebrafish line that develops GFP-labeled T cell acute lymphoblastic leukemia (T-ALL), allowing visualization of the onset and spread of this disease. Here, we show that leukemias from this transgenic line are highly penetrant and render animals moribund by 80.7 +/- 17.6 days of life (+/-1 SD, range = 50-158 days). These T cell leukemias are clonally aneuploid, can be transplanted into irradiated recipient fish, and express the zebrafish orthologues of the human T-ALL oncogenes tal1/scl and lmo2, thus providing an animal model for the most prevalent molecular subgroup of human T-ALL. Because T-ALL develops very rapidly in rag2-EGFP-mMyc transgenic fish (in which "mMyc" represents mouse c-Myc), this line can only be maintained by in vitro fertilization. Thus, we have created a conditional transgene in which the EGFP-mMyc oncogene is preceded by a loxed dsRED2 gene and have generated stable rag2-loxP-dsRED2-loxP-EGFP-mMyc transgenic zebrafish lines, which have red fluorescent thymocytes and do not develop leukemia. Transgenic progeny from one of these lines can be induced to develop T-ALL by injecting Cre RNA into one-cell-stage embryos, demonstrating the utility of the Cre/lox system in the zebrafish and providing an essential step in preparing this model for chemical and genetic screens designed to identify modifiers of Myc-induced T-ALL. PMID:15827121

Langenau, David M; Feng, Hui; Berghmans, Stephane; Kanki, John P; Kutok, Jeffery L; Look, A Thomas

2005-04-26

246

Hydrogel-Based 3D Model of Patient-Derived Prostate Xenograft Tumors Suitable for Drug Screening.  

PubMed

The lack of effective therapies for bone metastatic prostate cancer (PCa) underscores the need for accurate models of the disease to enable the discovery of new therapeutic targets and to test drug sensitivities of individual tumors. To this end, the patient-derived xenograft (PDX) PCa model using immunocompromised mice was established to model the disease with greater fidelity than is possible with currently employed cell lines grown on tissue culture plastic. However, poorly adherent PDX tumor cells exhibit low viability in standard culture, making it difficult to manipulate these cells for subsequent controlled mechanistic studies. To overcome this challenge, we encapsulated PDX tumor cells within a three-dimensional hyaluronan-based hydrogel and demonstrated that the hydrogel maintains PDX cell viability with continued native androgen receptor expression. Furthermore, a differential sensitivity to docetaxel, a chemotherapeutic drug, was observed as compared to a traditional PCa cell line. These findings underscore the potential impact of this novel 3D PDX PCa model as a diagnostic platform for rapid drug evaluation and ultimately push personalized medicine toward clinical reality. PMID:24779589

Fong, Eliza L S; Martinez, Mariane; Yang, Jun; Mikos, Antonios G; Navone, Nora M; Harrington, Daniel A; Farach-Carson, Mary C

2014-07-01

247

Novel zebrafish model reveals a critical role for mapk in lymphangiogenesis  

PubMed Central

Purpose Lymphatic disorders are poorly understood with few animal models. We designed a novel assay to measure lymphatic development using transgenic zebrafish with fluorescently labeled endothelial cells. Two major branches of the vascular endothelial growth factor receptor (VEGFR) signaling pathway were examined: the MAPK and PI3K pathways. Methods Direct visualization of lymphatic development was performed in control embryos or under chemical inhibition. Treatment involved a 6-hour pulse of inhibitor at 3 days post fertilization (dpf). Fish were analyzed for the presence of the TD at 4 dpf (n > 100 specimens). Results TD formation was prevented using selective inhibitors against kinases (MAPK, PI3K/TOR, or VEGFR). These kinases were important for TD formation, as the lymphatic vessel failed to form in a majority of treated animals. Remarkably, MAPK pathway inhibition most robustly reduced lymphangiogenesis, demonstrated by a lack of lymphatic endothelial cells. Conclusion We conclude that MAPK pathway function downstream of the VEGFRs is crucial at the early stages of TD development. This study provides a novel animal model and a potential target pathway for further investigation. We suggest further examination of MAPK pathway deregulation as a potential mechanism underlying lymphatic disease in humans.

Fevurly, R. Dawn; Hasso, Sean; Fye, Alexander; Fishman, Steven J.; Chan, Joanne

2013-01-01

248

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

2013-06-01

249

Prolonged sulforaphane treatment does not enhance tumorigenesis in oncogenic K-ras and xenograft mouse models of lung cancer  

PubMed Central

Background: Sulforaphane (SFN), an activator of nuclear factor erythroid-2 related factor 2 (Nrf2), is a promising chemopreventive agent which is undergoing clinical trial for several diseases. Studies have indicated that there is gain of Nrf2 function in lung cancer and other solid tumors because of mutations in the inhibitor Kelch-like ECH-associated protein 1 (Keap1). More recently, several oncogenes have been shown to activate Nrf2 signaling as the main prosurvival pathway mediating ROS detoxification, senescence evasion, and neoplastic transformation. Thus, it is important to determine if there is any risk of enhanced lung tumorigenesis associated with prolonged administration of SFN using mouse models of cancer. Materials and Methods: We evaluated the effect of prolonged SFN treatment on oncogenic K-ras (K-rasLSL-G12D)-driven lung tumorigenesis. One week post mutant-K-ras expression, mice were treated with SFN (0.5 mg, 5 d/wk) for 3 months by means of a nebulizer. Fourteen weeks after mutant K-ras expression (K-rasLSL-G12D), mice were sacrificed, and lung sections were screened for neoplastic foci. Expression of Nrf2-dependent genes was measured using real time RT-PCR. We also determined the effect of prolonged SFN treatment on the growth of preclinical xenograft models using human A549 (with mutant K-ras and Keap1 allele) and H1975 [with mutant epidermal growth factor receptor (EGFR) allele] nonsmall cell lung cancer cells. Results: Systemic SFN administration did not promote the growth of K-rasLSL-G12D-induced lung tumors and had no significant effect on the growth of A549 and H1975 established tumor xenografts in nude mice. Interestingly, localized delivery of SFN significantly attenuated the growth of A549 tumors in nude mice, suggesting an Nrf2-independent antitumorigenic activity of SFN. Conclusions: Our results demonstrate that prolonged SFN treatment does not promote lung tumorigenesis in various mouse models of lung cancer.

Kombairaju, Ponvijay; Ma, Jinfang; Thimmulappa, Rajesh K; Yan, Shengbin G; Gabrielson, Edward; Singh, Anju; Biswal, Shyam

2012-01-01

250

Development of an ErbB-overexpressing A-431 Optical Reporting Tumor Xenograft Model to Assess Targeted Photodynamic Therapy Regimens  

PubMed Central

To better assess the efficacy of erbB-targeted therapies, it would help to have optical reporting human tumor xenograft models that abundantly express erbB receptors. A-431 cells have frequently been used in erbB1-targeting studies, but a well-characterized optical reporting version of the cell line has not been readily available. In this study, optical reporting A-431 clones were developed that express both a fluorescent protein reporter (green, GFP; or red, RFP) and a bioluminescent reporter, firefly luciferase. Reporter genes were transduced into cells using commercial lentiviral vectors, and clonal selection was carried out using a series of procedures. A number of clones were isolated for further characterization. A GFP/luciferase clone, A-431/D4, and an RFP/luciferase clone, A-431/G4, were obtained that exhibit erbB1 expression levels and tumor growth kinetics similar to the parental cells. To demonstrate the utility of the optical reporting clones, A-431/G4 tumors were grown subcutaneously in nude mice and treated with vascular-targeted photodynamic therapy (PDT), which targets the angiogenic consequences of erbB signaling. The A-431/G4 tumor model permitted highly sensitive longitudinal monitoring of PDT treatment response using optical imaging. A-431/D4 and A-431/G4 optical reporting tumor models should also prove useful for assessing therapies that directly target the erbB1 receptor.

Savellano, Mark D.; Owusu-Brackett, Nicci; Son, Ji; Callier, Thierri; Savellano, Dagmar Hogemann

2010-01-01

251

Intravital fluorescence imaging of small interfering RNA-mediated gene repression in a dual reporter melanoma xenograft model.  

PubMed

Development of RNA interference (RNAi)-based therapeutics has been hampered by the lack of effective and efficient means of delivery. Reliable model systems for screening and optimizing delivery of RNAi-based agents in vivo are crucial for preclinical research aimed at advancing nucleic acid-based therapies. We describe here a dual fluorescent reporter xenograft melanoma model prepared by intradermal injection of human A375 melanoma cells expressing tandem tomato fluorescent protein (tdTFP) containing a small interfering RNA (siRNA) target site as well as enhanced green fluorescent protein (EGFP), which is used as a normalization control. Intratumoral injection of a siRNA specific to the incorporated siRNA target site, complexed with a cationic lipid that has been optimized for in vivo delivery, resulted in 65%±11% knockdown of tdTFP relative to EGFP quantified by in vivo imaging and 68%±10% by reverse transcription-quantitative polymerase chain reaction. No effect was observed with nonspecific control siRNA treatment. This model provides a platform on which siRNA delivery technologies can be screened and optimized in vivo. PMID:23098239

Hickerson, Robyn P; Gonzalez-Gonzalez, Emilio; Vlassov, Alexander V; Li, Mu; Lara, Maria Fernanda; Contag, Christopher H; Kaspar, Roger L

2012-12-01

252

Laser-targeted ablation of the zebrafish embryonic ventricle: A novel model of cardiac injury and repair????  

PubMed Central

Background While the adult zebrafish (Danio rerio) heart demonstrates a remarkable capacity for self-renewal following apical resection little is known about the response to injury in the embryonic heart. Methods Injury to the beating zebrafish embryo heart was induced by laser using a transgenic zebrafish expressing cardiomyocyte specific green fluorescent protein. Changes in ejection fraction (EF), heart rate (HR), and caudal vein blood flow (CVBF) assessed by video capture techniques were assessed at 2, 24 and 48 h post-laser. Change in total and mitotic ventricular cardiomyocyte number following laser injury was also assessed by counting respectively DAPI (VCt) and Phospho-histone H3 (VCm) positive nuclei in isolated hearts using confocal microscopy. Results Laser injury to the ventricle resulted in bradycardia and mild bleeding into the pericardium. At 2 h post-laser injury, there was a significant reduction in cardiac performance in lasered-hearts compared with controls (HR 117 ± 11 vs 167 ± 9 bpm, p ? 0.001; EF 14.1 ± 1.8 vs 20.1 ± 1.3%, p ? 0.001; CVBF 103 ± 15 vs 316 ± 13?ms? 1, p ? 0.001, respectively). Isolated hearts showed a significant reduction in VCt at 2 h post-laser compared to controls (195 ± 15 vs 238 ± 15, p ? 0.05). Histology showed necrosis and apoptosis (TUNEL assay) at the site of laser injury. At 24 h post-laser cardiac performance and VCt had recovered fully to control levels. Pretreatment with the cell-cycle inhibitor, aphidicolin, significantly inhibited functional recovery of the ventricle accompanied by a significant inhibition of cardiomyocyte proliferation. Conclusions Laser-targeted injury of the zebrafish embryonic heart is a novel and reproducible model of cardiac injury and repair suitable for pharmacological and molecular studies.

Matrone, Gianfranco; Taylor, Jonathan M.; Wilson, Kathryn S.; Baily, James; Love, Gordon D.; Girkin, John M.; Mullins, John J.; Tucker, Carl S.; Denvir, Martin A.

2013-01-01

253

Novel Mouse Xenograft Models Reveal a Critical Role of CD4+ T Cells in the Proliferation of EBV-Infected T and NK Cells  

Microsoft Academic Search

Epstein-Barr virus (EBV), a ubiquitous B-lymphotropic herpesvirus, ectopically infects T or NK cells to cause severe diseases of unknown pathogenesis, including chronic active EBV infection (CAEBV) and EBV-associated hemophagocytic lymphohistiocytosis (EBV-HLH). We developed xenograft models of CAEBV and EBV-HLH by transplanting patients' PBMC to immunodeficient mice of the NOD\\/Shi-scid\\/IL-2R?null strain. In these models, EBV-infected T, NK, or B cells proliferated

Ken-Ichi Imadome; Misako Yajima; Ayako Arai; Atsuko Nakazawa; Fuyuko Kawano; Sayumi Ichikawa; Norio Shimizu; Naoki Yamamoto; Tomohiro Morio; Shouichi Ohga; Hiroyuki Nakamura; Mamoru Ito; Osamu Miura; Jun Komano; Shigeyoshi Fujiwara

2011-01-01

254

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

255

Optimizing lutetium 177-anti-carbonic anhydrase IX radioimmunotherapy in an intraperitoneal clear cell renal cell carcinoma xenograft model.  

PubMed

A new approach in the treatment of clear cell renal carcinoma (ccRCC) is radioimmunotherapy (RIT) using anti-carbonic anhydrase IX (CAIX) antibody G250. To investigate the potential of RIT with lutetium 177 (177Lu)-labeled G250, we conducted a protein dose escalation study and subsequently an RIT study in mice with intraperitoneally growing ccRCC lesions. Mice with intraperitoneal xenografts were injected with 1, 3, 10, 30, or 100 ?g of G250 labeled with 10 MBq indium 111 (111In) to determine the optimal protein dose. The optimal protein dose determined with imaging and biodistribution studies was used in a subsequent RIT experiment in three groups of 10 mice with intraperitoneal SK-RC-52 tumors. One group received 13 MBq 177Lu-DOTA-G250, a control group received 13 MBq nonspecific 177Lu-MOPC21, and the second control group was not treated and received 20 MBq 111In-DOTA-G250. The optimal G250 protein dose to target ccRCC in this model was 10 ?g G250. Treatment with 13 MBq 177Lu-DOTA-G250 was well tolerated and resulted in significantly prolonged median survival (139 days) compared to controls (49-53 days, p ?=? .015), indicating that RIT has potential in this metastatic ccRCC model. PMID:24824962

Muselaers, Constantijn H J; Oosterwijk, Egbert; Bos, Desirée L; Oyen, Wim J G; Mulders, Peter F A; Boerman, Otto C

2014-06-01

256

Optimizing Lutetium 177-Anti-Carbonic Anhydrase IX Radioimmunotherapy in an Intraperitoneal Clear Cell Renal Cell Carcinoma Xenograft Model.  

PubMed

AbstractA new approach in the treatment of clear cell renal carcinoma (ccRCC) is radioimmunotherapy (RIT) using anti-carbonic anhydrase IX (CAIX) antibody G250. To investigate the potential of RIT with lutetium 177 (177Lu)-labeled G250, we conducted a protein dose escalation study and subsequently an RIT study in mice with intraperitoneally growing ccRCC lesions. Mice with intraperitoneal xenografts were injected with 1, 3, 10, 30, or 100 ?g of G250 labeled with 10 MBq indium 111 (111In) to determine the optimal protein dose. The optimal protein dose determined with imaging and biodistribution studies was used in a subsequent RIT experiment in three groups of 10 mice with intraperitoneal SK-RC-52 tumors. One group received 13 MBq 177Lu-DOTA-G250, a control group received 13 MBq nonspecific 177Lu-MOPC21, and the second control group was not treated and received 20 MBq 111In-DOTA-G250. The optimal G250 protein dose to target ccRCC in this model was 10 ?g G250. Treatment with 13 MBq 177Lu-DOTA-G250 was well tolerated and resulted in significantly prolonged median survival (139 days) compared to controls (49-53 days, p ?=? .015), indicating that RIT has potential in this metastatic ccRCC model. PMID:24742401

Muselaers, Constantijn H J; Oosterwijk, Egbert; Bos, Desirée L; Oyen, Wim J G; Mulders, Peter F A; Boerman, Otto C

2014-04-01

257

Neural and Synaptic Defects in slytherin, a Zebrafish Model for Human Congenital Disorders of Glycosylation  

PubMed Central

Congenital disorder of glycosylation type IIc (CDG IIc) is characterized by mental retardation, slowed growth and severe immunodeficiency, attributed to the lack of fucosylated glycoproteins. While impaired Notch signaling has been implicated in some aspects of CDG IIc pathogenesis, the molecular and cellular mechanisms remain poorly understood. We have identified a zebrafish mutant slytherin (srn), which harbors a missense point mutation in GDP-mannose 4,6 dehydratase (GMDS), the rate-limiting enzyme in protein fucosylation, including that of Notch. Here we report that some of the mechanisms underlying the neural phenotypes in srn and in CGD IIc are Notch-dependent, while others are Notch-independent. We show, for the first time in a vertebrate in vivo, that defects in protein fucosylation leads to defects in neuronal differentiation, maintenance, axon branching, and synapse formation. Srn is thus a useful and important vertebrate model for human CDG IIc that has provided new insights into the neural phenotypes that are hallmarks of the human disorder and has also highlighted the role of protein fucosylation in neural development.

Song, Yuanquan; Willer, Jason R.; Scherer, Paul C.; Panzer, Jessica A.; Kugath, Amy; Skordalakes, Emmanuel; Gregg, Ronald G.; Willer, Gregory B.; Balice-Gordon, Rita J.

2010-01-01

258

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

259

Neural and Synaptic Defects in slytherin a Zebrafish Model for Human Congenital Disorders of Glycosylation  

SciTech Connect

Congenital disorder of glycosylation type IIc (CDG IIc) is characterized by mental retardation, slowed growth and severe immunodeficiency, attributed to the lack of fucosylated glycoproteins. While impaired Notch signaling has been implicated in some aspects of CDG IIc pathogenesis, the molecular and cellular mechanisms remain poorly understood. We have identified a zebrafish mutant slytherin (srn), which harbors a missense point mutation in GDP-mannose 4,6 dehydratase (GMDS), the rate-limiting enzyme in protein fucosylation, including that of Notch. Here we report that some of the mechanisms underlying the neural phenotypes in srn and in CGD IIc are Notch-dependent, while others are Notch-independent. We show, for the first time in a vertebrate in vivo, that defects in protein fucosylation leads to defects in neuronal differentiation, maintenance, axon branching, and synapse formation. Srn is thus a useful and important vertebrate model for human CDG IIc that has provided new insights into the neural phenotypes that are hallmarks of the human disorder and has also highlighted the role of protein fucosylation in neural development.

Y Song; J Willer; P Scherer; J Panzer; A Kugath; E Skordalakes; R Gregg; G Willer; R Balice-Gordon

2011-12-31

260

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

261

Novel Vitamin K analogs suppress seizures in zebrafish and mouse models of epilepsy.  

PubMed

Epilepsy is a debilitating disease affecting 1-2% of the world's population. Despite this high prevalence, 30% of patients suffering from epilepsy are not successfully managed by current medication suggesting a critical need for new anti-epileptic drugs (AEDs). In an effort to discover new therapeutics for the management of epilepsy, we began our study by screening drugs that, like some currently used AEDs, inhibit histone deacetylases (HDACs) using a well-established larval zebrafish model. In this model, 7-day post fertilization (dpf) larvae are treated with the widely used seizure-inducing compound pentylenetetrazol (PTZ) which stimulates a rapid increase in swimming behavior previously determined to be a measurable manifestation of seizures. In our first screen, we tested a number of different HDAC inhibitors and found that one, 2-benzamido-1 4-naphthoquinone (NQN1), significantly decreased swim activity to levels equal to that of valproic acid, 2-n-propylpentanoic acid (VPA). We continued to screen structurally related compounds including Vitamin K3 (VK3) and a number of novel Vitamin K (VK) analogs. We found that VK3 was a robust inhibitor of the PTZ-induced swim activity, as were several of our novel compounds. Three of these compounds were subsequently tested on mouse seizure models at the National Institute of Neurological Disorders and Stroke (NINDS) Anticonvulsant Screening Program. Compound 2h reduced seizures particularly well in the minimal clonic seizure (6Hz) and corneal-kindled mouse models of epilepsy, with no observable toxicity. As VK3 affects mitochondrial function, we tested the effects of our compounds on mitochondrial respiration and ATP production in a mouse hippocampal cell line. We demonstrate that these compounds affect ATP metabolism and increase total cellular ATP. Our data indicate the potential utility of these and other VK analogs for the prevention of seizures and suggest the potential mechanism for this protection may lie in the ability of these compounds to affect energy production. PMID:24291671

Rahn, J J; Bestman, J E; Josey, B J; Inks, E S; Stackley, K D; Rogers, C E; Chou, C J; Chan, S S L

2014-02-14

262

Enhanced Antitumor Efficacy and Reduced Systemic Toxicity of Sulfatide-Containing Nanoliposomal Doxorubicin in a Xenograft Model of Colorectal Cancer  

PubMed Central

Sulfatide is a glycosphingolipid known to interact with several extracellular matrix proteins, such as tenascin-C which is overexpressed in many types of cancer including that of the colon. In view of the limited success of chemotherapy in colorectal cancer and high toxicity of doxorubicin (DOX), a sulfatide-containing liposome (SCL) encapsulation approach was taken to overcome these barriers. This study assessed the in vitro cytotoxicity, biodistribution, therapeutic efficacy and systemic toxicity in vivo of sulfatide-containing liposomal doxorubicin (SCL-DOX) using human colonic adenocarcinoma HT-29 xenograft as the experimental model. In vitro, SCL-DOX was shown to be delivered into the nuclei and displayed prolonged retention compared with the free DOX. The use of this nanodrug delivery system to deliver DOX for treatment of tumor-bearing mice produced a much improved therapeutic efficacy in terms of tumor growth suppression and extended survival in contrast to the free drug. Furthermore, treatment of tumor-bearing mice with SCL-DOX resulted in a lower DOX uptake in the principal sites of toxicity of the free drug, namely the heart and skin, as well as reduced myelosuppression and diminished cardiotoxicity. Such natural lipid-guided nanodrug delivery systems may represent a new strategy for the development of effective anticancer chemotherapeutics targeting the tumor microenvironment for both primary tumor and micrometastases.

Lin, Jia; Yu, Yan; Shigdar, Sarah; Fang, Ding Zhi; Du, Jun Rong; Wei, Ming Q.; Danks, Andrew; Liu, Ke; Duan, Wei

2012-01-01

263

Antitumor activity of [Pt(O,O'-acac)(?-acac)(DMS)] in mouse xenograft model of breast cancer  

PubMed Central

The higher and selective cytotoxicity of [Pt(O,O?-acac)(?-acac)(DMS)] toward cancer cell in both immortalized cell lines and in breast cancer cells in primary cultures, stimulated a pre-clinical study so as to evaluate its therapeutic potential in vivo. The efficacy of [Pt(O,O?-acac)(?-acac)(DMS)] was assessed using a xenograft model of breast cancer developed by injection of MCF-7 cells in the flank of BALB/c nude mice. Treatment of solid tumor-bearing mice with [Pt(O,O?-acac)(?-acac)(DMS)] induced up to 50% reduction of tumor mass compared with an average 10% inhibition recorded in cisplatin-treated animals. Thus, chemotherapy with [Pt(O,O?-acac)(?-acac)(DMS)] was much more effective than cisplatin. We also demonstrated enhanced in vivo pharmacokinetics, biodistribution and tolerability of [Pt(O,O?-acac)(?-acac)(DMS)] when compared with cisplatin administered in Wistar rats. Pharmacokinetics studies with [Pt(O,O?-acac)(?-acac)(DMS)] revealed prolonged Pt persistence in systemic blood circulation and decreased nefrotoxicity and hepatotoxicity, major target sites of cisplatin toxicity. Overall, [Pt(O,O?-acac)(?-acac)(DMS)] turned out to be extremely promising in terms of greater in vivo anticancer activity, reduced nephrotoxicity and acute toxicity compared with cisplatin.

Muscella, A; Vetrugno, C; Migoni, D; Biagioni, F; Fanizzi, F P; Fornai, F; De Pascali, S A; Marsigliante, S

2014-01-01

264

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

2013-12-01

265

Functional aging and gradual senescence in zebrafish.  

PubMed

Zebrafish (Danio rerio) has been recognized as a powerful model for genetic studies in developmental biology. Recently, the zebrafish system also has given insights into several human diseases such as neurodegenerative, hematopoietic, and cardiovascular disease, and cancer. Because aging processes affect these and various other human disorders, it is important to compare zebrafish and mammalian senescence. However, the aging process of zebrafish remains largely unexplored, and little is known about functional aging and senescence in zebrafish. In our initial studies to assess aging phenotypes in zebrafish, we have identified several potential aging biomarkers in an ongoing search for suitable ones on zebrafish aging. In aging zebrafish, we detected senescence-associated beta-galactosidase activity in skin and oxidized protein accumulation in muscle. On the other hand, we did not observe lipofuscin granules (aging pigments), which accumulate in postmitotic cells, in muscle of zebrafish with advancing age. Consistently, there were continuously proliferating myocytes that incorporated BrdU in muscle tissues of the aged fish. Moreover, we demonstrated that zebrafish have constitutively abundant telomerase activity in adult somatic tissues implicating unlimited replicative ability of cells throughout their lives. Although some stress-associated markers are upregulated and minor histological changes are observed during the aging process of zebrafish, our studies together with other evidence of remarkable reproductive and regenerative abilities suggest that zebrafish show very gradual senescence. By using those biological and biochemical aging markers already characterized in normal zebrafish, transgenic fish analyses and genetic mutant fish screens can be readily performed. These efforts will help to elucidate the role and molecular mechanisms of common or different pathways of aging among vertebrates from fish to humans and also will contribute to the discovery of potential drugs applicable to age-associated diseases in the future. PMID:15247079

Kishi, Shuji

2004-06-01

266

Ovarian Tumor Attachment, Invasion, and Vascularization Reflect Unique Microenvironments in the Peritoneum: Insights from Xenograft and Mathematical Models  

PubMed Central

Ovarian cancer relapse is often characterized by metastatic spread throughout the peritoneal cavity with tumors attached to multiple organs. In this study, interaction of ovarian cancer cells with the peritoneal tumor microenvironment was evaluated in a xenograft model based on intraperitoneal injection of fluorescent SKOV3.ip1 ovarian cancer cells. Intra-vital microscopy of mixed GFP-red fluorescent protein (RFP) cell populations injected into the peritoneum demonstrated that cancer cells aggregate and attach as mixed spheroids, emphasizing the importance of homotypic adhesion in tumor formation. Electron microscopy provided high resolution structural information about local attachment sites. Experimental measurements from the mouse model were used to build a three-dimensional cellular Potts ovarian tumor model (OvTM) that examines ovarian cancer cell attachment, chemotaxis, growth, and vascularization. OvTM simulations provide insight into the relative influence of cancer cell–cell adhesion, oxygen availability, and local architecture on tumor growth and morphology. Notably, tumors on the mesentery, omentum, or spleen readily invade the “open” architecture, while tumors attached to the gut encounter barriers that restrict invasion and instead rapidly expand into the peritoneal space. Simulations suggest that rapid neovascularization of SKOV3.ip1 tumors is triggered by constitutive release of angiogenic factors in the absence of hypoxia. This research highlights the importance of cellular adhesion and tumor microenvironment in the seeding of secondary ovarian tumors on diverse organs within the peritoneal cavity. Results of the OvTM simulations indicate that invasion is strongly influenced by features underlying the mesothelial lining at different sites, but is also affected by local production of chemotactic factors. The integrated in vivo mouse model and computer simulations provide a unique platform for evaluating targeted therapies for ovarian cancer relapse.

Steinkamp, Mara P.; Winner, Kimberly Kanigel; Davies, Suzy; Muller, Carolyn; Zhang, Yong; Hoffman, Robert M.; Shirinifard, Abbas; Moses, Melanie; Jiang, Yi; Wilson, Bridget S.

2013-01-01

267

Ovarian tumor attachment, invasion, and vascularization reflect unique microenvironments in the peritoneum: insights from xenograft and mathematical models.  

PubMed

Ovarian cancer relapse is often characterized by metastatic spread throughout the peritoneal cavity with tumors attached to multiple organs. In this study, interaction of ovarian cancer cells with the peritoneal tumor microenvironment was evaluated in a xenograft model based on intraperitoneal injection of fluorescent SKOV3.ip1 ovarian cancer cells. Intra-vital microscopy of mixed GFP-red fluorescent protein (RFP) cell populations injected into the peritoneum demonstrated that cancer cells aggregate and attach as mixed spheroids, emphasizing the importance of homotypic adhesion in tumor formation. Electron microscopy provided high resolution structural information about local attachment sites. Experimental measurements from the mouse model were used to build a three-dimensional cellular Potts ovarian tumor model (OvTM) that examines ovarian cancer cell attachment, chemotaxis, growth, and vascularization. OvTM simulations provide insight into the relative influence of cancer cell-cell adhesion, oxygen availability, and local architecture on tumor growth and morphology. Notably, tumors on the mesentery, omentum, or spleen readily invade the "open" architecture, while tumors attached to the gut encounter barriers that restrict invasion and instead rapidly expand into the peritoneal space. Simulations suggest that rapid neovascularization of SKOV3.ip1 tumors is triggered by constitutive release of angiogenic factors in the absence of hypoxia. This research highlights the importance of cellular adhesion and tumor microenvironment in the seeding of secondary ovarian tumors on diverse organs within the peritoneal cavity. Results of the OvTM simulations indicate that invasion is strongly influenced by features underlying the mesothelial lining at different sites, but is also affected by local production of chemotactic factors. The integrated in vivo mouse model and computer simulations provide a unique platform for evaluating targeted therapies for ovarian cancer relapse. PMID:23730620

Steinkamp, Mara P; Winner, Kimberly Kanigel; Davies, Suzy; Muller, Carolyn; Zhang, Yong; Hoffman, Robert M; Shirinifard, Abbas; Moses, Melanie; Jiang, Yi; Wilson, Bridget S

2013-01-01

268

A clinically relevant orthotopic xenograft model of ependymoma that maintains the genomic signature of the primary tumor and preserves cancer stem cells in vivo  

PubMed Central

Limited availability of in vitro and in vivo model systems has hampered efforts to understand tumor biology and test novel therapies for ependymoma, the third most common malignant brain tumor that occurs in children. To develop clinically relevant animal models of ependymoma, we directly injected a fresh surgical specimen from a 9-year-old patient into the right cerebrum of RAG2/severe complex immune deficiency (SCID) mice. All five mice receiving the initial transplantation of the patient tumor developed intracerebral xenografts, which have since been serially subtransplanted in vivo in mouse brains for 4 generations and can be cryopreserved for long-term maintenance of tumorigenicity. The xenograft tumors shared nearly identical histopathological features with the original tumors, harbored 8 structural chromosomal abnormalities as detected with spectral karyotyping, maintained gene expression profiles resembling that of the original patient tumor with the preservation of multiple key genetic abnormalities commonly found in human ependymomas, and contained a small population (<2.2%) of CD133+ stem cells that can form neurospheres and display multipotent capabilities in vitro. The permanent cell line (BXD-1425EPN), which was derived from a passage II xenograft tumor and has been passaged in vitro more than 70 times, expressed similar differentiation markers of the xenograft tumors, maintained identical chromosomal abnormalities, and formed tumors in the brains of SCID mice. In conclusion, direct injection of primary ependymoma tumor cells played an important role in the generation of a clinically relevant mouse model IC-1425EPN and a novel cell line, BXD-1425EPN. This cell line and model will facilitate the biological studies and preclinical drug screenings for pediatric ependymomas.

Yu, Litian; Baxter, Patricia A.; Voicu, Horatiu; Gurusiddappa, Sivashankarappa; Zhao, Yijue; Adesina, Adekunle; Man, Tsz-Kwong; Shu, Qin; Zhang, Yu-Jing; Zhao, Xiu-Mei; Su, Jack M.; Perlaky, Lazlo; Dauser, Robert; Chintagumpala, Murali; Lau, Ching C.; Blaney, Susan M.; Rao, Pulivarthi H.; Leung, Hon-chiu Eastwood; Li, Xiao-Nan

2010-01-01

269

A clinically relevant orthotopic xenograft model of ependymoma that maintains the genomic signature of the primary tumor and preserves cancer stem cells in vivo.  

PubMed

Limited availability of in vitro and in vivo model systems has hampered efforts to understand tumor biology and test novel therapies for ependymoma, the third most common malignant brain tumor that occurs in children. To develop clinically relevant animal models of ependymoma, we directly injected a fresh surgical specimen from a 9-year-old patient into the right cerebrum of RAG2/severe complex immune deficiency (SCID) mice. All five mice receiving the initial transplantation of the patient tumor developed intracerebral xenografts, which have since been serially subtransplanted in vivo in mouse brains for 4 generations and can be cryopreserved for long-term maintenance of tumorigenicity. The xenograft tumors shared nearly identical histopathological features with the original tumors, harbored 8 structural chromosomal abnormalities as detected with spectral karyotyping, maintained gene expression profiles resembling that of the original patient tumor with the preservation of multiple key genetic abnormalities commonly found in human ependymomas, and contained a small population (<2.2%) of CD133(+) stem cells that can form neurospheres and display multipotent capabilities in vitro. The permanent cell line (BXD-1425EPN), which was derived from a passage II xenograft tumor and has been passaged in vitro more than 70 times, expressed similar differentiation markers of the xenograft tumors, maintained identical chromosomal abnormalities, and formed tumors in the brains of SCID mice. In conclusion, direct injection of primary ependymoma tumor cells played an important role in the generation of a clinically relevant mouse model IC-1425EPN and a novel cell line, BXD-1425EPN. This cell line and model will facilitate the biological studies and preclinical drug screenings for pediatric ependymomas. PMID:20511191

Yu, Litian; Baxter, Patricia A; Voicu, Horatiu; Gurusiddappa, Sivashankarappa; Zhao, Yijue; Adesina, Adekunle; Man, Tsz-Kwong; Shu, Qin; Zhang, Yu-Jing; Zhao, Xiu-Mei; Su, Jack M; Perlaky, Lazlo; Dauser, Robert; Chintagumpala, Murali; Lau, Ching C; Blaney, Susan M; Rao, Pulivarthi H; Leung, Hon-Chiu Eastwood; Li, Xiao-Nan

2010-06-01

270

Orthotopic glioblastoma stem-like cell xenograft model in mice to evaluate intra-arterial delivery of bevacizumab: from bedside to bench.  

PubMed

Bevacizumab (BV), a humanized monocolonal antibody directed against vascular endothelial growth factor (VEGF), is a standard intravenous (IV) treatment for recurrent glioblastoma multiforme (GBM), that has been introduced recently as an intra-arterial (IA) treatment modality in humans. Since preclinical models have not been reported, we sought to develop a tumor stem cell (TSC) xenograft model to investigate IA BV delivery in vivo. Firefly luciferase transduced patient TSC were injected into the cortex of 35 nude mice. Tumor growth was monitored weekly using bioluminescence imaging. Mice were treated with either intraperitoneal (IP) or IA BV, with or without blood-brain barrier disruption (BBBD), or with IP saline injection (controls). Tumor tissue was analyzed using immunohistochemistry and western blot techniques. Tumor formation occurred in 31 of 35 (89%) mice with a significant signal increase over time (p=0.018). Post mortem histology revealed an infiltrative growth of TSC xenografts in a similar pattern compared to the primary human GBM. Tumor tissue analyzed at 24 hours after treatment revealed that IA BV treatment with BBBD led to a significantly higher intratumoral BV concentration compared to IA BV alone, IP BV or controls (p<0.05). Thus, we have developed a TSC-based xenograft mouse model that allows us to study IA chemotherapy. However, further studies are needed to analyze the treatment effects after IA BV to assess tumor progression and overall animal survival. PMID:22985932

Burkhardt, Jan-Karl; Hofstetter, Christoph P; Santillan, Alejandro; Shin, Benjamin J; Foley, Conor P; Ballon, Douglas J; Pierre Gobin, Y; Boockvar, John A

2012-11-01

271

Circulating tumor cells as a biomarker of response to treatment in patient-derived xenograft mouse models of pancreatic adenocarcinoma.  

PubMed

Circulating tumor cells (CTCs) are cells shed from solid tumors into circulation and have been shown to be prognostic in the setting of metastatic disease. These cells are obtained through a routine blood draw and may serve as an easily accessible marker for monitoring treatment effectiveness. Because of the rapid progression of pancreatic ductal adenocarcinoma (PDAC), early insight into treatment effectiveness may allow for necessary and timely changes in treatment regimens. The objective of this study was to evaluate CTC burden as a biomarker of response to treatment with a oral phosphatidylinositol-3-kinase inhibitor, BKM120, in patient-derived xenograft (PDX) mouse models of PDAC. PDX mice were randomized to receive vehicle or BKM120 treatment for 28 days and CTCs were enumerated from whole blood before and after treatment using a microfluidic chip that selected for EpCAM (epithelial cell adhesion molecule) positive cells. This microfluidic device allowed for the release of captured CTCs and enumeration of these cells via their electrical impedance signatures. Median CTC counts significantly decreased in the BKM120 group from pre- to post-treatment (26.61 to 2.21 CTCs/250 µL, p?=?0.0207) while no significant change was observed in the vehicle group (23.26 to 11.89 CTCs/250 µL, p?=?0.8081). This reduction in CTC burden in the treatment group correlated with tumor growth inhibition indicating CTC burden is a promising biomarker of response to treatment in preclinical models. Mutant enriched sequencing of isolated CTCs confirmed that they harbored KRAS G12V mutations, identical to the matched tumors. In the long-term, PDX mice are a useful preclinical model for furthering our understanding of CTCs. Clinically, mutational analysis of CTCs and serial monitoring of CTC burden may be used as a minimally invasive approach to predict and monitor treatment response to guide therapeutic regimens. PMID:24586805

Torphy, Robert J; Tignanelli, Christopher J; Kamande, Joyce W; Moffitt, Richard A; Herrera Loeza, Silvia G; Soper, Steven A; Yeh, Jen Jen

2014-01-01

272

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

2013-12-01

273

Axon degeneration and PGC-1?-mediated protection in a zebrafish model of ?-synuclein toxicity.  

PubMed

?-synuclein (aSyn) expression is implicated in neurodegenerative processes, including Parkinson's disease (PD) and dementia with Lewy bodies (DLB). In animal models of these diseases, axon pathology often precedes cell death, raising the question of whether aSyn has compartment-specific toxic effects that could require early and/or independent therapeutic intervention. The relevance of axonal pathology to degeneration can only be addressed through longitudinal, in vivo monitoring of different neuronal compartments. With current imaging methods, dopaminergic neurons do not readily lend themselves to such a task in any vertebrate system. We therefore expressed human wild-type aSyn in zebrafish peripheral sensory neurons, which project elaborate superficial axons that can be continuously imaged in vivo. Axonal outgrowth was normal in these neurons but, by 2 days post-fertilization (dpf), many aSyn-expressing axons became dystrophic, with focal varicosities or diffuse beading. Approximately 20% of aSyn-expressing cells died by 3 dpf. Time-lapse imaging revealed that focal axonal swelling, but not overt fragmentation, usually preceded cell death. Co-expressing aSyn with a mitochondrial reporter revealed deficits in mitochondrial transport and morphology even when axons appeared overtly normal. The axon-protective protein Wallerian degeneration slow (WldS) delayed axon degeneration but not cell death caused by aSyn. By contrast, the transcriptional coactivator PGC-1?, which has roles in the regulation of mitochondrial biogenesis and reactive-oxygen-species detoxification, abrogated aSyn toxicity in both the axon and the cell body. The rapid onset of axonal pathology in this system, and the relatively moderate degree of cell death, provide a new model for the study of aSyn toxicity and protection. Moreover, the accessibility of peripheral sensory axons will allow effects of aSyn to be studied in different neuronal compartments and might have utility in screening for novel disease-modifying compounds. PMID:24626988

O'Donnell, Kelley C; Lulla, Aaron; Stahl, Mark C; Wheat, Nickolas D; Bronstein, Jeff M; Sagasti, Alvaro

2014-05-01

274

Axon degeneration and PGC-1?-mediated protection in a zebrafish model of ?-synuclein toxicity  

PubMed Central

?-synuclein (aSyn) expression is implicated in neurodegenerative processes, including Parkinson’s disease (PD) and dementia with Lewy bodies (DLB). In animal models of these diseases, axon pathology often precedes cell death, raising the question of whether aSyn has compartment-specific toxic effects that could require early and/or independent therapeutic intervention. The relevance of axonal pathology to degeneration can only be addressed through longitudinal, in vivo monitoring of different neuronal compartments. With current imaging methods, dopaminergic neurons do not readily lend themselves to such a task in any vertebrate system. We therefore expressed human wild-type aSyn in zebrafish peripheral sensory neurons, which project elaborate superficial axons that can be continuously imaged in vivo. Axonal outgrowth was normal in these neurons but, by 2 days post-fertilization (dpf), many aSyn-expressing axons became dystrophic, with focal varicosities or diffuse beading. Approximately 20% of aSyn-expressing cells died by 3 dpf. Time-lapse imaging revealed that focal axonal swelling, but not overt fragmentation, usually preceded cell death. Co-expressing aSyn with a mitochondrial reporter revealed deficits in mitochondrial transport and morphology even when axons appeared overtly normal. The axon-protective protein Wallerian degeneration slow (WldS) delayed axon degeneration but not cell death caused by aSyn. By contrast, the transcriptional coactivator PGC-1?, which has roles in the regulation of mitochondrial biogenesis and reactive-oxygen-species detoxification, abrogated aSyn toxicity in both the axon and the cell body. The rapid onset of axonal pathology in this system, and the relatively moderate degree of cell death, provide a new model for the study of aSyn toxicity and protection. Moreover, the accessibility of peripheral sensory axons will allow effects of aSyn to be studied in different neuronal compartments and might have utility in screening for novel disease-modifying compounds.

O'Donnell, Kelley C.; Lulla, Aaron; Stahl, Mark C.; Wheat, Nickolas D.; Bronstein, Jeff M.; Sagasti, Alvaro

2014-01-01

275

Evaluation of spontaneous propulsive movement as a screening tool to detect rescue of Parkinsonism phenotypes in zebrafish models.  

PubMed

Zebrafish models of human neuropsychiatric diseases offer opportunities to identify novel therapeutic targets and treatments through phenotype-based genetic or chemical modifier screens. In order to develop an assay to detect rescue of zebrafish models of Parkinsonism, we characterized spontaneous zebrafish larval motor behavior from 3 to 9 days post fertilization in a microtiter plate format suitable for screening, and clarified the role of dopaminergic signaling in its regulation. The proportion of time that larvae spent moving increased progressively between 3 and 9 dpf, whereas their active velocity decreased between 5 and 6 dpf as sporadic burst movements gave way to a more mature beat-and-glide pattern. Spontaneous movement varied between larvae and during the course of recordings as a result of intrinsic larval factors including genetic background. Variability decreased with age, such that small differences between groups of larvae exposed to different experimental conditions could be detected robustly by 6 to 7 dpf. Suppression of endogenous dopaminergic signaling by exposure to MPP(+), haloperidol or chlorpromazine reduced mean velocity by decreasing the frequency with which spontaneous movements were initiated, but did not alter active velocity. The variability of mean velocity assays could be reduced by analyzing groups of larvae for each data point, yielding acceptable screening window coefficients; the sample size required in each group was determined by the magnitude of the motor phenotype in different models. For chlorpromazine exposure, samples of four larvae allowed robust separation of treated and untreated data points (Z=0.42), whereas the milder impairment provoked by MPP(+) necessitated groups of eight larvae in order to provide a useful discovery assay (Z=0.13). Quantification of spontaneous larval movement offers a simple method to determine functional integrity of motor systems, and may be a useful tool to isolate novel molecular modulators of Parkinsonism phenotypes. PMID:21669287

Farrell, Thomas C; Cario, Clinton L; Milanese, Chiara; Vogt, Andreas; Jeong, Jong-Hyeon; Burton, Edward A

2011-10-01

276

Evaluation of spontaneous propulsive movement as a screening tool to detect rescue of Parkinsonism phenotypes in zebrafish models  

PubMed Central

Zebrafish models of human neuropsychiatric diseases offer opportunities to identify novel therapeutic targets and treatments through phenotype-based genetic or chemical modifier screens. In order to develop an assay to detect rescue of zebrafish models of Parkinsonism, we characterized spontaneous zebrafish larval motor behavior from 3 to 9 days post fertilization in a microtiter plate format suitable for screening, and clarified the role of dopaminergic signaling in its regulation. The proportion of time that larvae spent moving increased progressively between 3 and 9 dpf, whereas their active velocity decreased between 5 and 6 dpf as sporadic burst movements gave way to a more mature beat-and-glide pattern. Spontaneous movement varied between larvae and during the course of recordings as a result of intrinsic larval factors including genetic background. Variability decreased with age, such that small differences between groups of larvae exposed to different experimental conditions could be detected robustly by 6 to 7 dpf. Suppression of endogenous dopaminergic signaling by exposure to MPP+, haloperidol or chlorpromazine reduced mean velocity by decreasing the frequency with which spontaneous movements were initiated, but did not alter active velocity. The variability of mean velocity assays could be reduced by analyzing groups of larvae for each data point, yielding acceptable screening window coefficients; the sample size required in each group was determined by the magnitude of the motor phenotype in different models. For chlorpromazine exposure, samples of four larvae allowed robust separation of treated and untreated data points (Z=0.42), whereas the milder impairment provoked by MPP+ necessitated groups of eight larvae in order to provide a useful discovery assay (Z=0.13). Quantification of spontaneous larval movement offers a simple method to determine functional integrity of motor systems, and may be a useful tool to isolate novel molecular modulators of Parkinsonism phenotypes.

Farrell, Thomas C.; Cario, Clinton L.; Milanese, Chiara; Vogt, Andreas; Jeong, Jong-Hyeon; Burton, Edward A.

2011-01-01

277

Endotoxin molecule lipopolysaccharide-induced zebrafish inflammation model: a novel screening method for anti-inflammatory drugs.  

PubMed

Lipopolysaccharide (LPS), an endotoxin molecule, has been used to induce inflammatory responses. In this study, LPS was used to establish an in vivo inflammation model in zebrafish for drug screening. We present an experimental method that conveniently and rapidly assesses the anti-inflammatory properties of drugs. The yolks of 3-day post-fertilization (dpf) larvae were injected with 0.5 mg/mL LPS to induce fatal inflammation. After LPS stimulation, macrophages were tracked by NR and SB staining and neutrophil migration was observed using the MPO:GFP line. Larval mortality was used as the primary end-point. Expression levels of key cytokines involved in the inflammatory response including IL-1?, IL-6, and TNF-?, were measured using quantitative reverse transcription polymerase chain reaction (RT-PCR). Macrophages and neutrophils were both recruited to the LPS-injected site during the inflammatory response. Mortality was increased by LPS in a dose-dependent manner within 48 h. Analyses of IL-1?, IL-6, and TNF-? expression levels revealed the upregulation of the inflammatory response in the LPS-injected larvae. Further, the anti-inflammatory activity of chlorogenic acid (CA) was evaluated in this zebrafish model to screen for anti-inflammatory drugs. A preliminary result showed that CA revealed a similar effect as the corticosteroid dexamethasone (DEX), which was used as a positive control, by inhibiting macrophage and neutrophil recruitment to the LPS site and improving survival. Our results suggest that this zebrafish screening model could be applied to study inflammation-mediated diseases. Moreover, the Traditional Chinese Medicine CA displays potential anti-inflammatory activity. PMID:24566310

Yang, Li-Ling; Wang, Guo-Quan; Yang, Li-Mei; Huang, Zhi-Bing; Zhang, Wen-Qing; Yu, Lin-Zhong

2014-01-01

278

Increased Plasma Colloid Osmotic Pressure Facilitates the Uptake of Therapeutic Macromolecules in a Xenograft Tumor Model1  

PubMed Central

Elevated tumor interstitial fluid pressure (TIFP) is a characteristic of most solid tumors. Clinically, TIFP may hamper the uptake of chemotherapeutic drugs into the tumor tissue reducing their therapeutic efficacy. In this study, a means of modulating TIFP to increase the flux of macromolecules into tumor tissue is presented, which is based on the rationale that elevated plasma colloid osmotic pressure (COP) pulls water from tumor interstitium lowering the TIFP. Concentrated human serum albumin (20% HSA), used as an agent to enhance COP, reduced the TIFP time-dependently from 8 to 2 mm Hg in human tumor xenograft models bearing A431 epidermoid vulva carcinomas. To evaluate whether this reduction facilitates the uptake of macromolecules, the intratumoral distribution of fluorescently conjugated dextrans (2.5 mg/ml) and cetuximab (2.0 mg/ml) was probed using novel time domain nearinfrared fluorescence imaging. This method permitted discrimination and semiquantification of tumor-accumulated conjugate from background and unspecific probe fluorescence. The coadministration of 20% HSA together with either dextrans or cetuximab was found to lower the TIFP significantly and increase the concentration of the substances within the tumor tissue in comparison to control tumors. Furthermore, combined administration of 20% HSA plus cetuximab reduced the tumor growth significantly in comparison to standard cetuximab treatment. These data demonstrate that increased COP lowers the TIFP within hours and increases the uptake of therapeutic macromolecules into the tumor interstitium leading to reduced tumor growth. This model represents a novel approach to facilitate the delivery of therapeutics into tumor tissue, particularly monoclonal antibodies.

Hofmann, Matthias; McCormack, Emmet; Mujic, Maja; Rossberg, Maila; Bernd, August; Bereiter-Hahn, Jurgen; Gjertsen, Bj?rn Tore; Wiig, Helge; Kippenberger, Stefan

2009-01-01

279

Viral Diseases in Zebrafish: What Is Known and Unknown  

PubMed Central

Naturally occurring viral infections have the potential to introduce confounding variability that leads to invalid and misinterpreted data. Whereas the viral diseases of research rodents are well characterized and closely monitored, no naturally occurring viral infections have been characterized for the laboratory zebrafish (Danio rerio), an increasingly important biomedical research model. Despite the ignorance about naturally occurring zebrafish viruses, zebrafish models are rapidly expanding in areas of biomedical research where the confounding effects of unknown infectious agents present a serious concern. In addition, many zebrafish research colonies remain linked to the ornamental (pet) zebrafish trade, which can contribute to the introduction of new pathogens into research colonies, whereas mice used for research are purpose bred, with no introduction of new mice from the pet industry. Identification, characterization, and monitoring of naturally occurring viruses in zebrafish are crucial to the improvement of zebrafish health, the reduction of unwanted variability, and the continued development of the zebrafish as a model organism. This article addresses the importance of identifying and characterizing the viral diseases of zebrafish as the scope of zebrafish models expands into new research areas and also briefly addresses zebrafish susceptibility to experimental viral infection and the utility of the zebrafish as an infection and immunology model.

Crim, Marcus J.; Riley, Lela K.

2013-01-01

280

Long-term effects of ionizing radiation on gene expression in a zebrafish model.  

PubMed

Understanding how initial radiation injury translates into long-term effects is an important problem in radiation biology. Here, we define a set of changes in the transcription profile that are associated with the long-term response to radiation exposure. The study was performed in vivo using zebrafish, an established radiobiological model organism. To study the long-term response, 24 hour post-fertilization embryos were exposed to 0.1 Gy (low dose) or 1.0 Gy (moderate dose) of whole-body gamma radiation and allowed to develop for 16 weeks. Liver mRNA profiles were then analyzed using the Affymetrix microarray platform, with validation by quantitative PCR. As a basis for comparison, 16-week old adults were exposed at the same doses and analyzed after 4 hours. Statistical analysis was performed in a way to minimize the effects of multiple comparisons. The responses to these two treatment regimes differed greatly: 360 probe sets were associated primarily with the long-term response, whereas a different 2062 probe sets were associated primarily with the response when adults of the same age were irradiated 4 hours before exposure. Surprisingly, a ten-fold difference in radiation dose (0.1 versus 1.0 Gy) had little effect. Analysis at the gene and pathway level indicated that the long-term response includes the induction of cytokine and inflammatory regulators and transcription and growth factors. The acute response includes the induction of p53 target genes and modulation of the hypoxia-induced transcription factor-C/EBP axis. Results help define genes and pathways affected in the long-term, low and moderate dose radiation response and differentiate them from those affected in an acute response in the same tissue. PMID:23936019

Jaafar, Lahcen; Podolsky, Robert H; Dynan, William S

2013-01-01

281

Podocyte Developmental Defects Caused by Adriamycin in Zebrafish Embryos and Larvae: A Novel Model of Glomerular Damage  

PubMed Central

The zebrafish pronephros is gaining popularity in the nephrology community, because embryos are easy to cultivate in multiwell plates, allowing large number of experiments to be conducted in an in vivo model. In a few days, glomeruli reach complete development, with a structure that is similar to that of the mammalian counterpart, showing a fenestrated endothelium and a basement membrane covered by the multiple ramifications of mature podocytes. As a further advantage, zebrafish embryos are permeable to low molecular compounds, and this explains their extensive use in drug efficacy and toxicity experiments. Here we show that low concentrations of adriamycin (i.e. 10 and 20 µM), when dissolved in the medium of zebrafish embryos at 9 hours post-fertilization and removed after 48 hours (57 hpf), alter the development of podocytes with subsequent functional impairment, demonstrated by onset of pericardial edema and reduction of expression of the podocyte proteins nephrin and wt1. Podocyte damage is morphologically confirmed by electron microscopy and functionally supported by increased clearance of microinjected 70 kDa fluorescent dextran. Importantly, besides pericardial edema and glomerular damage, which persist and worsen after adriamycin removal from the medium, larvae exposed to adriamycin 10 and 20 µM do not show any myocardiocyte alterations nor vascular changes. The only extra-renal effect is a transient delay of cartilage formation that rapidly recovers once adriamycin is removed. In summary, this low dose adriamycin model can be applied to analyze podocyte developmental defects, such as those observed in congenital nephrotic syndrome, and can be taken in consideration for pharmacological studies of severe early podocyte injury.

Zennaro, Cristina; Mariotti, Massimo; Carraro, Michele; Pasqualetti, Sara; Corbelli, Alessandro; Armelloni, Silvia; Li, Min; Ikehata, Masami; Clai, Milan; Artero, Mary; Messa, Piergiorgio; Boscutti, Giuliano; Rastaldi, Maria Pia

2014-01-01

282

Excessive activity of cathepsin K is associated with cartilage defects in a zebrafish model of mucolipidosis II  

PubMed Central

SUMMARY The severe pediatric disorder mucolipidosis II (ML-II; also known as I-cell disease) is caused by defects in mannose 6-phosphate (Man-6-P) biosynthesis. Patients with ML-II exhibit multiple developmental defects, including skeletal, craniofacial and joint abnormalities. To date, the molecular mechanisms that underlie these clinical manifestations are poorly understood. Taking advantage of a zebrafish model of ML-II, we previously showed that the cartilage morphogenesis defects in this model are associated with altered chondrocyte differentiation and excessive deposition of type II collagen, indicating that aspects of development that rely on proper extracellular matrix homeostasis are sensitive to decreases in Man-6-P biosynthesis. To further investigate the molecular bases for the cartilage phenotypes, we analyzed the transcript abundance of several genes in chondrocyte-enriched cell populations isolated from wild-type and ML-II zebrafish embryos. Increased levels of cathepsin and matrix metalloproteinase (MMP) transcripts were noted in ML-II cell populations. This increase in transcript abundance corresponded with elevated and sustained activity of several cathepsins (K, L and S) and MMP-13 during early development. Unlike MMP-13, for which higher levels of protein were detected, the sustained activity of cathepsin K at later stages seemed to result from its abnormal processing and activation. Inhibition of cathepsin K activity by pharmacological or genetic means not only reduced the activity of this enzyme but led to a broad reduction in additional protease activity, significant correction of the cartilage morphogenesis phenotype and reduced type II collagen staining in ML-II embryos. Our findings suggest a central role for excessive cathepsin K activity in the developmental aspects of ML-II cartilage pathogenesis and highlight the utility of the zebrafish system to address the biochemical underpinnings of metabolic disease.

Petrey, Aaron C.; Flanagan-Steet, Heather; Johnson, Steven; Fan, Xiang; De la Rosa, Mitche; Haskins, Mark E.; Nairn, Alison V.; Moremen, Kelley W.; Steet, Richard

2012-01-01

283

A novel cell line and xenograft model of ampulla of Vater adenocarcinoma  

Microsoft Academic Search

Ampulla of Vater cancers (AVC) are of clinical relevance, as they represent more than one-third of patients undergoing surgery for pancreaticoduodenal malignancies and have a better prognosis than periampullary cancers of pancreaticobiliary origin. The availability of cellular models is crucial to perform cell biology and pharmacological studies and clarify the relationship between AVC and pancreatic and biliary cancers. Numerous cell

Claudio Sorio; Patrick S. Moore; MariaGrazia Ennas; Cristina Tecchio; Antonio Bonora; Silvia Sartoris; Piera Balzarini; Piergiovanni Grigolato; Aldo Scarpa

2004-01-01

284

Characteristics of Rod Regeneration in a Novel Zebrafish Retinal Degeneration Model Using N-Methyl-N-Nitrosourea (MNU)  

PubMed Central

Primary loss of photoreceptors caused by diseases such as retinitis pigmentosa is one of the main causes of blindness worldwide. To study such diseases, rodent models of N-methyl-N-nitrosourea (MNU)-induced retinal degeneration are widely used. As zebrafish (Danio rerio) are a popular model system for visual research that offers persistent retinal neurogenesis throughout the lifetime and retinal regeneration after severe damage, we have established a novel MNU-induced model in this species. Histology with staining for apoptosis (TUNEL), proliferation (PCNA), activated Müller glial cells (GFAP), rods (rhodopsin) and cones (zpr-1) were performed. A characteristic sequence of retinal changes was found. First, apoptosis of rod photoreceptors occurred 3 days after MNU treatment and resulted in a loss of rod cells. Consequently, proliferation started in the inner nuclear layer (INL) with a maximum at day 8, whereas in the outer nuclear layer (ONL) a maximum was observed at day 15. The proliferation in the ONL persisted to the end of the follow-up (3 months), interestingly, without ongoing rod cell death. We demonstrate that rod degeneration is a sufficient trigger for the induction of Müller glial cell activation, even if only a minimal number of rod cells undergo cell death. In conclusion, the use of MNU is a simple and feasible model for rod photoreceptor degeneration in the zebrafish that offers new insights into rod regeneration.

Tappeiner, Christoph; Balmer, Jasmin; Iglicki, Matias; Schuerch, Kaspar; Jazwinska, Anna; Enzmann, Volker; Tschopp, Markus

2013-01-01

285

The zebrafish ( Danio rerio) embryo as a model system for identification and characterization of developmental toxins from marine and freshwater microalgae  

Microsoft Academic Search

The zebrafish (Danio rerio) embryo has emerged as an important model of vertebrate development. As such, this model system is finding utility in the investigation of toxic agents that inhibit, or otherwise interfere with, developmental processes (i.e. developmental toxins), including compounds that have potential relevance to both human and environmental health, as well as biomedicine. Recently, this system has been

John P. Berry; Miroslav Gantar; Patrick D. L. Gibbs; Michael C. Schmale

2007-01-01

286

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

287

FDG small animal PET permits early detection of malignant cells in a xenograft murine model  

Microsoft Academic Search

Purpose  The administration of new anticancer drugs in animal models is the first step from in vitro to in vivo pre-clinical protocols.\\u000a At this stage it is crucial to ensure that cells are in the logarithmic phase of growth and to avoid vascular impairment,\\u000a which can cause inhomogeneous distribution of the drug within the tumour and thus lead to bias in

Cristina Nanni; Korinne Di Leo; Roberto Tonelli; Cinzia Pettinato; Domenico Rubello; Antonello Spinelli; Silvia Trespidi; Valentina Ambrosini; Paolo Castellucci; Mohsen Farsad; Roberto Franchi; Andrea Pession; Stefano Fanti

2007-01-01

288

Antibody-directed neutralization of annexin II (ANX II) inhibits neoangiogenesis and human breast tumor growth in a xenograft model.  

PubMed

Activation of the fibrinolytic pathway has long been associated with human breast cancer. Plasmin is the major end product of the fibrinolytic pathway and is critical for normal physiological functions. The mechanism by which plasmin is generated in breast cancer is not yet fully described. We previously identified annexin II (ANX II), a fibrinolytic receptor, in human breast tumor tissue samples and observed a strong positive correlation with advanced stage cancer (Sharma et al., 2006a). We further demonstrated that tissue plasminogen activator (tPA) binds to ANX II in invasive breast cancer MDA-MB231cells, which leads to plasmin generation (Sharma et al., 2010). We hypothesize that ANX II-dependent plasmin generation in breast tumor is necessary to trigger the switch to neoangiogenesis, thereby stimulating a more aggressive cancer phenotype. Our immunohistochemical studies of human breast tumor tissues provide compelling evidence of a strong positive correlation between ANX II expression and neoangiogenesis, and suggest that ANX II is a potential target to slow or inhibit breast tumor growth by inhibiting neoangiogenesis. We now report that administration of anti-ANX II antibody potently inhibits the growth of human breast tumor in a xenograft model. Inhibition of tumor growth is at least partly due to attenuation of neoangiogenic activity within the tumor. In vitro studies demonstrate that anti-ANX II antibody inhibits angiogenesis on three dimensional matrigel cultures by eliciting endothelial cell (EC) death likely due to apoptosis. Taken together, these data suggest that selective disruption of the fibrinolytic activity of ANX II may provide a novel strategy for specific inhibition of neoangiogenesis in human breast cancer. PMID:22044461

Sharma, Meena; Blackman, Marc R; Sharma, Mahesh C

2012-02-01

289

Early development of hearing in zebrafish.  

PubMed

The zebrafish (Danio rerio) has become a valuable vertebrate model for human hearing and balance disorders because it combines powerful genetics, excellent embryology, and exceptional in vivo visualization in one organism. In this study, we investigated auditory function of zebrafish at early developmental stages using the microphonic potential method. This is the first study to report ontogeny of response of hair cells in any fish during the first week post fertilization. The right ear of each zebrafish embedded in agarose was linearly stimulated with a glass probe that was driven by a calibrated piezoelectric actuator. Using beveled micropipettes filled with standard fish saline, extracellular microphonic potentials were recorded from hair cells in the inner ear of zebrafish embryos or larvae in response to 20, 50, 100, and 200-Hz stimulation. Saccular hair cells expressing green fluorescent protein of the transgenic zebrafish from 2 to 7 days post fertilization (dpf) were visualized and quantified using confocal microscopy. The otic vesicles' areas, otoliths' areas, and saccular hair cell count and density increased linearly with age and standard body length. Microphonic responses increased monotonically with stimulus intensity, stimulus frequency, and age of zebrafish. Microphonic threshold at 200 Hz gradually decreased with zebrafish age. The increases in microphonic response and sensitivity correlate with the increases in number and density of hair cells in the saccule. These results enhance our knowledge of early development of auditory function in zebrafish and provide the control data that can be used to evaluate hearing of young zebrafish morphants or mutants. PMID:23575600

Lu, Zhongmin; DeSmidt, Alexandra A

2013-08-01

290

Establishment of IPC 227 cells as human xenografts in rabbits: a model of uveal melanoma.  

PubMed

This study was designed in order to evaluate the feasibility of establishing an animal model of human uveal melanoma. IPC227, a cell line established from the biopsy of a patient with a spindle cell ciliary body melanoma, was transplanted into the anterior chamber of the eye in immunosuppressed New Zealand rabbits. In a second step, a tumour fragment from the anterior chamber was implanted transclerally into the posterior choroid. Complete ophthalmological examinations were then performed on the animals. Characteristic growth patterns were noted depending on the location of implantation. In the anterior chamber, diffuse, flat, heavily pigmented tumours appeared 8 days after the injection of the cell suspension that covered the iris and the angle by day 25, with a success rate of 100%. Nodular, lightly pigmented tumours were obtained 6-7 weeks after subchoroidal implantation, with a 25% success rate. Clinical examination, including fundus photography, ultrasound and magnetic resonance imaging, demonstrated the same characteristics as those of human uveal melanoma, confirming the value of this model for the evaluation of new therapeutic and diagnostic methods in the management of uveal melanoma. PMID:11095405

Bonicel, P; Michelot, J; Bacin, F; Papon, J; Kemeny, J L; Moins, N; Morvan, D; Madelmont, J C

2000-10-01

291

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

2013-01-01

292

A zebrafish model for Waardenburg syndrome type IV reveals diverse roles for Sox10 in the otic vesicle  

PubMed Central

SUMMARY In humans, mutations in the SOX10 gene are a cause of the auditory-pigmentary disorder Waardenburg syndrome type IV (WS4) and related variants. SOX10 encodes an Sry-related HMG box protein essential for the development of the neural crest; deafness in WS4 and other Waardenburg syndromes is usually attributed to loss of neural-crest-derived melanocytes in the stria vascularis of the cochlea. However, SOX10 is strongly expressed in the developing otic vesicle and so direct roles for SOX10 in the otic epithelium might also be important. Here, we examine the otic phenotype of zebrafish sox10 mutants, a model for WS4. As a cochlea is not present in the fish ear, the severe otic phenotype in these mutants cannot be attributed to effects on this tissue. In zebrafish sox10 mutants, we see abnormalities in all otic placodal derivatives. Gene expression studies indicate deregulated expression of several otic genes, including fgf8, in sox10 mutants. Using a combination of mutant and morphant data, we show that the three sox genes belonging to group E (sox9a, sox9b and sox10) provide a link between otic induction pathways and subsequent otic patterning: they act redundantly to maintain sox10 expression throughout otic tissue and to restrict fgf8 expression to anterior macula regions. Single-cell labelling experiments indicate a small and transient neural crest contribution to the zebrafish ear during normal development, but this is unlikely to account for the strong defects seen in the sox10 mutant. We discuss the implication that the deafness in WS4 patients with SOX10 mutations might reflect a haploinsufficiency for SOX10 in the otic epithelium, resulting in patterning and functional abnormalities in the inner ear.

Dutton, Kirsten; Abbas, Leila; Spencer, Joanne; Brannon, Claire; Mowbray, Catriona; Nikaido, Masataka; Kelsh, Robert N.; Whitfield, Tanya T.

2009-01-01

293

Pharmacokinetic and pharmacodynamic modeling of hedgehog inhibitor TAK-441 for the inhibition of Gli1 messenger RNA expression and antitumor efficacy in xenografted tumor model mice.  

PubMed

6-Ethyl-N-[1-(hydroxyacetyl)piperidin-4-yl]-1-methyl-4-oxo-5-(2-oxo-2-phenylethyl)-3-(2,2,2-trifluoroethoxy)-4,5-dihydro-1H-pyrrolo[3,2-c]pyridine-2-carboxamide (TAK-441) is a potent, selective hedgehog signaling pathway inhibitor that binds to Smo and is being developed for the treatment of cancer. The objectives of these studies were to explore the possibility of establishing of a link between the pharmacokinetics of TAK-441 and the responses of Gli1 mRNA in tumor-associated stromal or skin cells and the antitumor effect of hedgehog inhibition. To this end, we built pharmacokinetic and pharmacodynamic models that describe the relationship of the concentrations of TAK-441 plasma to the responses of Gli1 mRNA in the tumor (target) and skin (surrogate) and to tumor growth inhibition in mice bearing xenografts of human pancreatic tumors (PAN-04). The responses of Gli1 mRNA and tumor growth were described by an indirect response model and an exponential tumor growth model, respectively. The IC50 values for Gli1 mRNA inhibition in the tumor and skin by TAK-441 were estimated to be 0.0457 and 0.113 ?g/ml, respectively. The IC90 value for tumor growth inhibition was estimated to be 0.68 ?g/ml. These results suggest that a >83% inhibition of Gli1 mRNA expression in the skin or a >94% inhibition of Gli1 mRNA expression in the tumor would be required to sufficiently inhibit (>90%) hedgehog-related tumor growth in the xenografted model mice. We conclude that Gli1 mRNA expression in the tumor and skin could be a useful biomarker for predicting the antitumor effect of hedgehog inhibitors. PMID:23298863

Kogame, Akifumi; Tagawa, Yoshihiko; Shibata, Sachio; Tojo, Hideaki; Miyamoto, Maki; Tohyama, Kimio; Kondo, Takahiro; Prakash, Shimoga; Shyu, Wen Chyi; Asahi, Satoru

2013-04-01

294

Effect of Citrus bergamia juice on human neuroblastoma cells in vitro and in metastatic xenograft models.  

PubMed

Neuroblastoma is the most common extracranial pediatric solid tumor with poor prognosis in children with disseminated stage of disease. A number of studies show that molecules largely distributed in commonly consumed fruits and vegetables may have anti-tumor activity. In this study we evaluate the effect of Citrus bergamia (bergamot) juice (BJ) in vitro and in a spontaneous metastatic neuroblastoma SCID mouse model. Qualitative and quantitative characterizations of BJ flavonoid fractions were performed by RP-HPLC/PDA/MS. We show that BJ significantly affects SK-N-SH and LAN-1 cell proliferation in vitro, but fails to reduce primary tumor weight in vivo. Moreover, BJ reduced cell adhesiveness and invasion of LAN-1 and SK-N-SH cells in vitro and the number of pulmonary metastases under consideration of the number of tumor cells in the blood in mice inoculated with LAN-1 cells in vivo. These effects without any apparent sign of systemic toxicity confirm the potential clinical interest of BJ and lay the basis for further investigation in cancer. PMID:24594241

Navarra, M; Ursino, M R; Ferlazzo, N; Russo, M; Schumacher, U; Valentiner, U

2014-06-01

295

Uptake of verteporfin by orthotopic xenograft pancreas models with different levels of aggression  

NASA Astrophysics Data System (ADS)

Pancreatic cancer is an aggressive disease with a poor prognosis, usually treated with chemoradiation therapy. Interstitial photodynamic therapy is a potentially effective adjuvant treatment that is under development. In the current study, two orthotopic pancreatic cancer models (AsPC-1 and Panc-1), have been characterized with respect to growth rates, morphology and liposomal drug (Verteporfin) uptake and distribution in SCID mice. Fluorescence of Verteporfin was measured in liver and tumor in vivo using a PDT fluorescence dosimeter with measurements taken before and up to one hour after tail vein injection. Fluorescence reached a plateau by about 15 minutes and did not decrease over the first hour. At time points from 15 minutes to 24 hrs, the internal organs (kidney, spleen, pancreas, tumor, muscle, lung, liver, and skin were excised and scanned on a Typhoon imager. The ratio of fluorescence in tumor versus normal tissues was analyzed with image processing, calculated at each time point and compared to in vivo results. Tissue distribution of Verteporfin in relation to functional vasculature marked by DiOc7 was carried out on frozen sections. Final analysis will result in determination of the ideal time point to administer light to achieve maximum tumor destruction while preserving normal tissue.

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

2009-06-01

296

Human intestinal epithelial cells produce proinflammatory cytokines in response to infection in a SCID mouse-human intestinal xenograft model of amebiasis.  

PubMed Central

The protozoan parasite Entamoeba histolytica causes amebic dysentery and amebic liver abscess, diseases associated with significant morbidity and mortality worldwide. E. histolytica infection appears to involve the initial attachment of amebic trophozoites to intestinal epithelial cells, followed by lysis of these cells and subsequent invasion into the submucosa. A recent in vitro study (L. Eckmann, S. L. Reed, J. R. Smith, and M. F. Kagnoff, J. Clin. Invest. 96:1269-1279, 1995) demonstrated that incubation of E. histolytica trophozoites with epithelial cell lines results in epithelial cell production of inflammatory cytokines, including interleukin-1 (IL-1) and IL-8, suggesting that intestinal epithelial cell production of cytokines might play a role in the inflammatory response and tissue damage seen in intestinal amebiasis. To determine whether intestinal epithelial cell production of IL-1 and IL-8 occurs in response to E. histolytica infection in vivo and as an approach to studying the specific interactions between amebic trophozoites and human intestine, we used a SCID mouse-human intestinal xenograft (SCID-HU-INT) model of disease, where human intestinal xenografts were infected with virulent E. histolytica trophozoites. Infection of xenografts with E. histolytica trophozoites resulted in extensive tissue damage, which was associated with the development of an early inflammatory response composed primarily of neutrophils. Using oligonucleotide primers that specifically amplify human IL-1beta and IL-8, we could demonstrate by reverse transcription PCR that mRNA for both IL-1beta and IL-8 is produced by human intestinal xenografts in response to amebic infection. The increase in human intestinal IL-1beta and IL-8 in response to invasive amebiasis was confirmed by enzyme-linked immunosorbent assays specific for human IL-1beta and IL-8. Using immunohistochemistry, we confirmed that human intestinal epithelial cells were the source of IL-8 in infected xenografts and established that IL-8 production can occur at sites distal to areas of intestinal mucosal damage. These results demonstrate that human intestinal epithelial cells can produce inflammatory cytokines in response to infection in vivo and establish the SCID-HU-INT model as a system for studying the interactions between E. histolytica and human intestine.

Seydel, K B; Li, E; Swanson, P E; Stanley, S L

1997-01-01

297

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

298

Evaluation of Zebrafish Danio rerio as a Model for Enteric Septicemia of Catfish (ESC)  

Microsoft Academic Search

Zebrafish (also known as zebra danio) Danio rerio were injected intramuscularly with Edwardsiella ictaluri at doses of 6 × 10, 6 × 10, or 6 × 10 colony-forming units per gram (CFU\\/g) or sterile phosphate-buffered saline (sham) or were not injected. Mortality occurred from 2 to 5 d postinjection (dpi) at rates of 0, 76.6, and 81.3% for the low,

L. Petrie-Hanson; C. L. Romano; R. B. Mackey; P. Khosravi; C. M. Hohn; C. R. Boyle

2007-01-01

299

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

SciTech Connect

Graphical abstract: Intervention of poorly differentiated RMS by rapamycin: In poorly differentiated RMS, rapamycin blocks mTOR and Hh signaling pathways concomitantly. This leads to dampening in cell cycle regulation and induction of apoptosis. This study provides a rationale for the therapeutic intervention of poorly differentiated RMS by treating patients with rapamycin alone or in combination with other chemotherapeutic agents. -- Highlights: •Rapamycin abrogates RMS tumor growth by modulating proliferation and apoptosis. •Co-targeting mTOR/Hh pathways underlie the molecular basis of effectiveness. •Reduction in mTOR/Hh pathways diminish EMT leading to reduced invasiveness. -- Abstract: 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.

Kaylani, Samer Z. [Division of Hematology and Oncology, Department of Pediatrics, University of Alabama at Birmingham, 1600 7th Avenue South, ACC 414, Birmingham, AL 35233 (United States)] [Division of Hematology and Oncology, Department of Pediatrics, University of Alabama at Birmingham, 1600 7th Avenue South, ACC 414, Birmingham, AL 35233 (United States); Xu, Jianmin; Srivastava, Ritesh K. [Department of Dermatology and Skin Diseases Research Center, University of Alabama at Birmingham, 1530 3rd Avenue South, VH 509, Birmingham, AL 35294-0019 (United States)] [Department of Dermatology and Skin Diseases Research Center, University of Alabama at Birmingham, 1530 3rd Avenue South, VH 509, Birmingham, AL 35294-0019 (United States); Kopelovich, Levy [Division of Cancer Prevention, National Cancer Institute, Bethesda (United States)] [Division of Cancer Prevention, National Cancer Institute, Bethesda (United States); Pressey, Joseph G. [Division of Hematology and Oncology, Department of Pediatrics, University of Alabama at Birmingham, 1600 7th Avenue South, ACC 414, Birmingham, AL 35233 (United States)] [Division of Hematology and Oncology, Department of Pediatrics, University of Alabama at Birmingham, 1600 7th Avenue South, ACC 414, Birmingham, AL 35233 (United States); Athar, Mohammad, E-mail: mathar@uab.edu [Department of Dermatology and Skin Diseases Research Center, University of Alabama at Birmingham, 1530 3rd Avenue South, VH 509, Birmingham, AL 35294-0019 (United States)] [Department of Dermatology and Skin Diseases Research Center, University of Alabama at Birmingham, 1530 3rd Avenue South, VH 509, Birmingham, AL 35294-0019 (United States)

2013-06-14

300

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

301

Assessing the Impact of HER2 Status on the Antitumor Activity of an HSP90 Inhibitor in Human Tumor Xenograft Mice Using Pharmacokinetic-Pharmacodynamic Modeling.  

PubMed

  The purpose of this study is to assess the impact of human epidermal growth factor receptor 2 (HER2) status on the antitumor activity of CH5164840, an orally available heat shock protein 90 (HSP90) inhibitor, using pharmacokinetic-pharmacodynamic modeling. Athymic mice, each implanted with one of eight human tumor xenografts, were treated with CH5164840 once daily at doses of 3.13 to 50 mg/kg. Plasma concentrations of CH5164840 were described by a one-compartment model with first-order absorption rate. Time profiles of tumor growth inhibition in the eight xenograft models were well captured by an indirect response model with a maximum tumor-killing rate constant (Emax model). Threshold plasma concentrations for tumor stasis, which are determined by multiple pharmacodynamic parameters, Emax, EC50 and tumor growth rate constant, were significantly lower in HER2-positive tumors (1.96-3.85 µM) than in HER2-negative tumors (4.48-23.4 µM). The results suggest that CH5164840 was more efficacious in HER2-positive tumors than in HER2-negative tumors in terms of the lower effective concentration of the drug in preclinical animal models. PMID:24126359

Saitoh, Ryoichi; Nagayasu, Miho; Shibahara, Norihito; Ono, Naomi; Suda, Atsushi; Kato, Motohiro; Ishigai, Masaki

2014-04-25

302

The Role of Alpha 6 Integrin in Prostate Cancer Migration and Bone Pain in a Novel Xenograft Model  

PubMed Central

Of the estimated 565,650 people in the U.S. who will die of cancer in 2008, almost all will have metastasis. Breast, prostate, kidney, thyroid and lung cancers metastasize to the bone. Tumor cells reside within the bone using integrin type cell adhesion receptors and elicit incapacitating bone pain and fractures. In particular, metastatic human prostate tumors express and cleave the integrin A6, a receptor for extracellular matrix components of the bone, i.e., laminin 332 and laminin 511. More than 50% of all prostate cancer patients develop severe bone pain during their remaining lifetime. One major goal is to prevent or delay cancer induced bone pain. We used a novel xenograft mouse model to directly determine if bone pain could be prevented by blocking the known cleavage of the A6 integrin adhesion receptor. Human tumor cells expressing either the wildtype or mutated A6 integrin were placed within the living bone matrix and 21 days later, integrin expression was confirmed by RT-PCR, radiographs were collected and behavioral measurements of spontaneous and evoked pain performed. All animals independent of integrin status had indistinguishable tumor burden and developed bone loss 21 days after surgery. A comparison of animals containing the wild type or mutated integrin revealed that tumor cells expressing the mutated integrin resulted in a dramatic decrease in bone loss, unicortical or bicortical fractures and a decrease in the ability of tumor cells to reach the epiphyseal plate of the bone. Further, tumor cells within the bone expressing the integrin mutation prevented cancer induced spontaneous flinching, tactile allodynia, and movement evoked pain. Preventing A6 integrin cleavage on the prostate tumor cell surface decreased the migration of tumor cells within the bone and the onset and degree of bone pain and fractures. These results suggest that strategies for blocking the cleavage of the adhesion receptors on the tumor cell surface can significantly prevent cancer induced bone pain and slow disease progression within the bone. Since integrin cleavage is mediated by Urokinase-type Plasminogen Activator (uPA), further work is warranted to test the efficacy of uPA inhibitors for prevention or delay of cancer induced bone pain.

King, Tamara E.; Pawar, Sangita C.; Majuta, Lisa; Sroka, Isis C.; Wynn, Danyel; Demetriou, Manolis C.; Nagle, Raymond B.; Porreca, Frank; Cress, Anne E.

2008-01-01

303

Inhalation Delivery and Anti-tumor Activity of Celecoxib in Human Orthotopic Non-Small Cell Lung Cancer Xenograft Model  

PubMed Central

Purpose To determine the in vivo anti-tumor effect of aerosolized Celecoxib (Cxb) in combination with i.v Docetaxel (Doc) and compare the anti-tumor effect with oral Cxb combined with i.v Doc in human orthotopic non-small cell lung cancer (NSCLC) xenograft model. Materials and Methods Female Nu/Nu mice were implanted with orthotopic tumors by injecting A549 cells into the lung parenchyma. Seven day after tumor implantation the mice were treated with aerosolized Cxb (30 min exposure/day, 5 mg/ml solution) + i.v Doc (10 mg/kg) and the effect was compared with oral Cxb (150 mg/kg/day) + i.v Doc (10 mg/kg), for 28 days. Small-animal nose only inhalation chamber (CH Technologies, Westwood, NJ) was utilized for aerosol exposure. Therapeutic activity of Cxb (aerosol/oral) + Doc was estimated by differences in lung weight, tumor area and animal body weight. Lung tumor samples isolated from mice were analyzed for (a) PGE2 levels by enzyme immunoassay (EIA) (b) expression of Fas and Factor VIII by immunohistochemistry (c) IL-8 expression using EIA kits and (d) mRNA expression for caspase-3 by Real-Time PCR. Results Mice treated with Cxb (aerosol/oral) + Doc showed significant reduction (P < 0.001) in lung weight and tumor area as compared to Cxb or Doc treatments. Cxb (aerosol/oral) + Doc showed increased apoptosis mediated via increased Fas and caspase-3 (P < 0.001) expression as compared to untreated control. Further, the combination treatment showed antiangiogenic effect as demonstrated by reduced expression of Factor VIII, IL-8 (P < 0.001) and PGE2 (P < 0.001) in lung tumors as compared to untreated control. Aerosolized Cxb at a significantly lower therapeutic dose (4.56 mg/kg/day) demonstrated comparable anti-tumor efficacy to orally administered Cxb (150 mg/kg/day). Conclusion Cxb was formulated and effectively delivered via aerosolization to treat orthotopic lung tumors in combination with i.v Doc. Cxb when administered by aerosol produced same therapeutic effect as oral Cxb, but at lower therapeutic dose and thus shows promise for the treatment of lung cancer.

Fulzele, Suniket V.; Chatterjee, Abhijit; Shaik, Madhu Sudhan; Jackson, Tanise; Singh, Mandip

2010-01-01

304

Effect of single and multiple administration of an O?6-benzylguanine\\/temozolomide combination: an evaluation in a human melanoma xenograft model  

Microsoft Academic Search

The purpose of the present study was to examine the effect of O\\u000a 6-benzylguanine (O\\u000a 6-BG) on the antitumour activity and toxicity of 8-carbamoyl-3-methylimidazo [5, 1-d?]?-1,2,3,5-tetrazine-4(3H)-one (temo-zolomide) in a human malignant melanoma xenograft model following single and multiple administration of the combination.\\u000a O\\u000a 6-BG irreversibly inactivates the DNA-repair protein O\\u000a 6-alkylguanine-DNA alkyltransferase (AGT), which confers resistance to temozolomide. Preadministration of

Stephen R. Wedge; Julia K. Porteous; E. S. Newlands

1997-01-01

305

Castration Induces Up-Regulation of Intratumoral Androgen Biosynthesis and Androgen Receptor Expression in an Orthotopic VCaP Human Prostate Cancer Xenograft Model.  

PubMed

Androgens are key factors involved in the development and progression of prostate cancer (PCa), and PCa growth can be suppressed by androgen deprivation therapy. In a considerable proportion of men receiving androgen deprivation therapy, however, PCa progresses to castration-resistant PCa (CRPC), making the development of efficient therapies challenging. We used an orthotopic VCaP human PCa xenograft model to study cellular and molecular changes in tumors after androgen deprivation therapy (castration). Tumor growth was monitored through weekly serum prostate-specific antigen measurements, and mice with recurrent tumors after castration were randomized to treatment groups. Serum prostate-specific antigen concentrations showed significant correlation with tumor volume. Castration-resistant tumors retained concentrations of intratumoral androgen (androstenedione, testosterone, and 5?-dihydrotestosterone) at levels similar to tumors growing in intact hosts. Accordingly, castration induced up-regulation of enzymes involved in androgen synthesis (CYP17A1, AKR1C3, and HSD17B6), as well as expression of full-length androgen receptor (AR) and AR splice variants (AR-V1 and AR-V7). Furthermore, AR target gene expression was maintained in castration-resistant xenografts. The AR antagonists enzalutamide (MDV3100) and ARN-509 suppressed PSA production of castration-resistant tumors, confirming the androgen dependency of these tumors. Taken together, the findings demonstrate that our VCaP xenograft model exhibits the key characteristics of clinical CRPC and thus provides a valuable tool for identifying druggable targets and for testing therapeutic strategies targeting AR signaling in CRPC. PMID:24949550

Knuuttila, Matias; Yatkin, Emrah; Kallio, Jenny; Savolainen, Saija; Laajala, Teemu D; Aittokallio, Tero; Oksala, Riikka; Häkkinen, Merja; Keski-Rahkonen, Pekka; Auriola, Seppo; Poutanen, Matti; Mäkelä, Sari

2014-08-01

306

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

307

A New Zebrafish Model of Oro-Intestinal Pathogen Colonization Reveals a Key Role for Adhesion in Protection by Probiotic Bacteria  

PubMed Central

The beneficial contribution of commensal bacteria to host health and homeostasis led to the concept that exogenous non-pathogenic bacteria called probiotics could be used to limit disease caused by pathogens. However, despite recent progress using gnotobiotic mammal and invertebrate models, mechanisms underlying protection afforded by commensal and probiotic bacteria against pathogens remain poorly understood. Here we developed a zebrafish model of controlled co-infection in which germ-free zebrafish raised on axenic living protozoa enabled the study of interactions between host and commensal and pathogenic bacteria. We screened enteric fish pathogens and identified Edwardsiella ictaluri as a virulent strain inducing a strong inflammatory response and rapid mortality in zebrafish larvae infected by the natural oro-intestinal route. Using mortality induced by infection as a phenotypic read-out, we pre-colonized zebrafish larvae with 37 potential probiotic bacterial strains and screened for survival upon E. ictaluri infection. We identified 3 robustly protective strains, including Vibrio parahaemolyticus and 2 Escherichia coli strains. We showed that the observed protective effect of E. coli was not correlated with a reduced host inflammatory response, nor with the release of biocidal molecules by protective bacteria, but rather with the presence of specific adhesion factors such as F pili that promote the emergence of probiotic bacteria in zebrafish larvae. Our study therefore provides new insights into the molecular events underlying the probiotic effect and constitutes a potentially high-throughput in vivo approach to the study of the molecular basis of pathogen exclusion in a relevant model of vertebrate oro-intestinal infection.

Begaud, Evelyne; Herbomel, Philippe; Levraud, Jean-Pierre; Ghigo, Jean-Marc

2012-01-01

308

In vivo efficacy of the recombinant anti-CD64 immunotoxin H22(scFv)-ETA' in a human acute myeloid leukemia xenograft tumor model.  

PubMed

Target-specific acute myeloid leukemia (AML) immunotherapy requires selective cell-surface antigens on AML blast cells. CD64 is a promising candidate antigen because it is abundantly expressed on monocytoid differentiated AML subtypes. In previous studies, a chemically linked full-length anti-CD64 immunotoxin based on ricin A showed promising results in several animal models, but further development has been hindered by its substantial, dose-limiting off-target effects. We recently constructed the recombinant immunotoxin H22(scFv)-ETA', comprising a truncated Pseudomonas exotoxin A (PE) and a humanized scFv antibody against CD64. This molecule was shown to kill CD64(+) AML-derived tumor cell lines and primary patient-derived AML cells specifically, both in vitro and ex vivo. Here we describe the in vivo efficiency of H22(scFv)-ETA' in the U937/SCID mouse xenograft model for human AML, by providing immunohistochemical evidence for the elimination of human CD64(+) tumor cells in mouse organs. H22(scFv)-ETA' showed potent antitumor activity against myeloid tumor cells and significantly prolonged the overall survival of AML xenograft animals. In conclusion, H22(scFv)-ETA' is efficacious against AML with monocytoid differentiation in vitro and in animal models in vivo, providing the basis for a novel therapeutic strategy for the treatment of AML patients. PMID:21077160

Tur, Mehmet Kemal; Huhn, Michael; Jost, Edgar; Thepen, Theo; Brümmendorf, Tim H; Barth, Stefan

2011-09-01

309

Vorinostat, an HDAC inhibitor attenuates epidermoid squamous cell carcinoma growth by dampening mTOR signaling pathway in a human xenograft murine model  

SciTech Connect

Histone deacetylase (HDAC) inhibitors are potent anticancer agents and show efficacy against various human neoplasms. Vorinostat is a potent HDAC inhibitor and has shown potential to inhibit growth of human xenograft tumors. However, its effect on the growth of skin neoplasm remains undefined. In this study, we show that vorinostat (2 ?M) reduced expression of HDAC1, 2, 3, and 7 in epidermoid carcinoma A431 cells. Consistently, it increased acetylation of histone H3 and p53. Vorinostat (100 mg/kg body weight, IP) treatment reduced human xenograft tumor growth in highly immunosuppressed nu/nu mice. Histologically, the vorinostat-treated tumor showed features of well-differentiation with large necrotic areas. Based on proliferating cell nuclear antigen (PCNA) staining and expression of cyclins D1, D2, E, and A, vorinostat seems to impair proliferation by down-regulating the expression of these proteins. However, it also induced apoptosis. The mechanism by which vorinostat blocks proliferation and makes tumor cells prone to apoptosis, involved inhibition of mTOR signaling which was accompanied by reduction in cell survival AKT and extracellular-signal regulated kinase (ERK) signaling pathways. Our data provide a novel mechanism-based therapeutic intervention for cutaneous squamous cell carcinoma (SCC). Vorinostat may be utilized to cure skin neoplasms in organ transplant recipient (OTR). These patients have high morbidity and surgical removal of these lesions which frequently develop in these patients, is difficult. -- Highlights: ? Vorinostat reduces SCC growth in a xenograft murine model. ? Vorinostat dampens proliferation and induces apoptosis in tumor cells. ? Diminution in mTOR, Akt and ERK signaling underlies inhibition in proliferation. ? Vorinostat by inhibiting HDACs inhibits epithelial–mesenchymal transition.

Kurundkar, Deepali; Srivastava, Ritesh K.; Chaudhary, Sandeep C. [Department of Dermatology and Skin Diseases Research Center, University of Alabama at Birmingham, 1530 3rd Avenue South, VH 509, Birmingham, AL 35294-0019 (United States)] [Department of Dermatology and Skin Diseases Research Center, University of Alabama at Birmingham, 1530 3rd Avenue South, VH 509, Birmingham, AL 35294-0019 (United States); Ballestas, Mary E. [Department of Pediatrics Infectious Disease, Children's of Alabama, School of Medicine, University of Alabama at Birmingham, AL (United States)] [Department of Pediatrics Infectious Disease, Children's of Alabama, School of Medicine, University of Alabama at Birmingham, AL (United States); Kopelovich, Levy [Division of Cancer Prevention, National Cancer Institute, 6130 Executive Blvd., Suite 2114, Bethesda, MD 20892 (United States)] [Division of Cancer Prevention, National Cancer Institute, 6130 Executive Blvd., Suite 2114, Bethesda, MD 20892 (United States); Elmets, Craig A. [Department of Dermatology and Skin Diseases Research Center, University of Alabama at Birmingham, 1530 3rd Avenue South, VH 509, Birmingham, AL 35294-0019 (United States)] [Department of Dermatology and Skin Diseases Research Center, University of Alabama at Birmingham, 1530 3rd Avenue South, VH 509, Birmingham, AL 35294-0019 (United States); Athar, Mohammad, E-mail: mathar@uab.edu [Department of Dermatology and Skin Diseases Research Center, University of Alabama at Birmingham, 1530 3rd Avenue South, VH 509, Birmingham, AL 35294-0019 (United States)] [Department of Dermatology and Skin Diseases Research Center, University of Alabama at Birmingham, 1530 3rd Avenue South, VH 509, Birmingham, AL 35294-0019 (United States)

2013-01-15

310

Broad spectrum and potent antitumor activities of YM155, a novel small-molecule survivin suppressant, in a wide variety of human cancer cell lines and xenograft models.  

PubMed

Antitumor activities of YM155, a novel small-molecule survivin suppressant, were investigated in a wide variety of human cancer cell lines and xenograft models. YM155 inhibited the growth of 119 human cancer cell lines, with the greatest activity in lines derived from non-Hodgkin's lymphoma, hormone-refractory prostate cancer, ovarian cancer, sarcoma, non-small-cell lung cancer, breast cancer, leukemia and melanoma. The mean log growth inhibition of 50% (GI(50) ) value was 15 nM. The mean GI(50) values of YM155 were 11 nM for p53 mut/null cell lines and 16 nM for p53 WT cell lines, suggesting that YM155 inhibits the growth of human tumor cell lines regardless of their p53 status. In non-small-cell lung cancer (Calu 6, NCI-H358), melanoma (A375), breast cancer (MDA-MB-231) and bladder cancer (UM-UC-3) xenograft models, 3- or 7-day continuous infusions of YM155 (1-10 mg/kg) demonstrated significant antitumor activity without showing significant bodyweight loss. Tumor regressions induced by YM155 were associated with reduced intratumoral survivin expression levels, increased apoptosis and decreased mitotic indices. The broad and potent antitumor activity presented in the present study is indicative of the therapeutic potential of YM155 in the clinical setting. PMID:21205082

Nakahara, Takahito; Kita, Aya; Yamanaka, Kentaro; Mori, Masamichi; Amino, Nobuaki; Takeuchi, Masahiro; Tominaga, Fumiko; Kinoyama, Isao; Matsuhisa, Akira; Kudou, Masafumi; Sasamata, Masao

2011-03-01

311

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

312

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

313

CD19 target-engineered T-cells accumulate at tumor lesions in human B-cell lymphoma xenograft mouse models.  

PubMed

Adoptive T-cell therapy with CD19-specific chimeric antigen receptors (CARs) is promising for treatment of advanced B-cell malignancies. Tumor targeting of CAR-modified T-cells is likely to contribute therapeutic potency; therefore we examined the relationship between the ability of CD19-specific CAR (CD19-CAR)-transduced T-cells to accumulate at CD19(+) tumor lesions, and their ability to provide anti-tumor effects in xenograft mouse models. Normal human peripheral blood lymphocytes, activated with immobilized RetroNectin and anti-CD3 antibodies, were transduced with retroviral vectors that encode CD19-CAR. Expanded CD19-CAR T-cells with a high transgene expression level of about 75% produced IL-2 and IFN-? in response to CD19, and lysed both Raji and Daudi CD19(+) human B-cell lymphoma cell lines. Furthermore, these cells efficiently accumulated at Raji tumor lesions where they suppressed tumor progression and prolonged survival in tumor-bearing Rag2(-/-)?c(-/-) immunodeficient mice compared to control cohorts. These results show that the ability of CD19-CAR T-cells to home in on tumor lesions is pivotal for their anti-tumor effects in our xenograft models, and therefore may enhance the efficacy of adoptive T-cell therapy for refractory B-cell lymphoma. PMID:23872144

Tsukahara, Tomonori; Ohmine, Ken; Yamamoto, Chihiro; Uchibori, Ryosuke; Ido, Hiroyuki; Teruya, Takeshi; Urabe, Masashi; Mizukami, Hiroaki; Kume, Akihiro; Nakamura, Masataka; Mineno, Junichi; Takesako, Kazutoh; Riviere, Isabelle; Sadelain, Michel; Brentjens, Renier; Ozawa, Keiya

2013-08-16

314

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

315

Development of clinically relevant orthotopic xenograft mouse model of metastatic lung cancer and glioblastoma through surgical tumor tissues injection with trocar  

PubMed Central

Objective Orthotopic models are important in cancer research. Here we developed orthotopic xenograft mouse model of metastatic lung cancer and glioblastoma with a specially designed system. Methods Tiny fragments of surgical tumors were implanted into the mice brain with a trocar system. Immunohistochemistry was performed to detect brain tumor stem cells among glioblastoma tissues, including both the original and resulting ones with monoclonal antibody against CD133. Results Besides the constant high take rates in both models; brain transplants perfectly resembled their original tumors in biological behaviors. The brain tumor stem cells, positively stained with CD133 were found, though not frequently, in both original and resulting glioblastoma tissues. Conclusions Orthotopic model established with a trocar system is effective and injection of tumor tissues containing stem cells promise the forming of new tumor mass when grafted.

2010-01-01

316

XH1--a new cervical carcinoma cell line and xenograft model of tumour invasion, 'metastasis' and regression.  

PubMed Central

A new cell line, XH1, has been derived from an invasive focally keratinising adenosquamous carcinoma of the cervix in a 32 year old patient. It has been maintained in long term monolayer culture for 26 months, and passaged over 100 times (much greater than 300 population doublings). It is aneuploid with a mean chromosome number of 78. Examination using two minisatellite hypervariable DNA probes has shown it to be different from other cell lines maintained in this laboratory and from HeLa. Two sublines, XH1a and XH1b, show marked differences in monolayer culture, growth in soft agar, and xenograft formation. XH1 and XH1a cells readily form subcutaneous xenografts, and lung colonies can be established by their intravenous injection. Subcutaneous injection of XH1b cells results in rapid cell growth for a few days after which the tumour undergoes degeneration and then regresses completely. The XH1 karyotype has many rearranged chromosomes. Parental XH1 cells and both sublines show integration of HPV16 into the genome. Images Figure 1 Figure 2 Figure 4 Figure 5 Figure 6 Figure 9 Figure 7 Figure 8 Figure 10 Figure 13 Figure 14 Figure 11 Figure 12 Figure 15 Figure 16 Figure 17 Figure 18

Han, X.; Lyle, R.; Eustace, D. L.; Jewers, R. J.; Parrington, J. M.; Das, A.; Chana, T.; Dagg, B.; Money, S.; Bates, T. D.

1991-01-01

317

The role of recombinant epidermal growth factor and serotonin in the stimulation of tumor growth in a SCCHN xenograft model  

PubMed Central

One challenge of squamous cell carcinoma of the head and neck (SCCHN) chemotherapy is a small percentage of tumor cells that arrest in the G0 phase of the cell cycle and are thus not affected by chemotherapy. This could be one reason for tumor recurrence at a later date. The recruitment of these G0-arresting cells into the active cell cycle and thus, proliferation, may increase the efficacy of chemotherapeutic agents. The aim of this study was to investigate whether stimulation with recombinant epidermal growth factor (EGF) or serotonin leads to an increased tumor cell proliferation in xenografts. Detroit 562 cells were injected into NMRI-Foxn1nu mice. Treatment was performed with 15 ?g murine or human EGF, or 200 ?g serotonin. The control mice were treated with Lactated Ringer’s solution (5 mice/group). Tumor size was measured on days 4, 8 and 12 after tumor cell injection. The EGF stimulated mice showed a significantly higher tumor growth compared to the serotonin-stimulated mice and the untreated controls. In the present study, we show that it is possible to stimulate tumor cells in xenografts by EGF and thus, enhance cell proliferation, resulting in a higher tumor growth compared to the untreated control group. In our future investigations, we plan to include a higher number of mice, an adjustment of the EGF dosage and cell subanalysis, considering the heterogeneity of SCCHN tumors.

GEISSLER, CHRISTIN; HAMBEK, MARKUS; ECKARDT, ANNE; ARNOLDNER, CHRISTOPH; DIENSTHUBER, MARC; STOVER, TIMO; WAGENBLAST, JENS

2012-01-01

318

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

319

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

320

Toxicity to embryo and adult zebrafish of copper complexes with two malonic acids as models for dissolved organic matter  

SciTech Connect

The toxicity to embryo and adult zebrafish (Danio rerio) of Cu complexes with two substituted malonic acids, benzyl- and n-hexadecyl-, chosen as models for low-molecular-weight natural dissolved organic matter, were investigated. Toxicity test solutions at pH 6.5 {+-} 0.1 with the required Cu ion-specific electrode. In the absence of malonic acids, concentrations of Cu{sup 2+} up to 1.13 {mu}mol/L increased the embryo hatching time from approx. 2 d in control solutions (no Cu or malonic acid) and solutions containing malonic acids without Cu to approx. 8 d. The Cu-benzylmalonic acid complex in the presence of inorganic Cu species did not delay hatching beyond that attributable to Cu{sup 2+}. In contrast, 0.60 {mu}mol/L Cu-n-hexadecylmalonic complexes delayed hatching by 5.5 d in excess of that attributable to 1.13 {mu}mol/L Cu{sup 2+}, assuming that the hatching delays caused by the different Cu species were additive, possibly because of Cu entry into the embryo as the lipophilic Cu-n-hexadecylmalonic complex. None of the Cu-malonic acid complexes was acutely toxic to adult zebrafish at concentrations up to 1.4 {mu}mol/L, possibly because Cu was removed from the Cu-malonic acid complexes by stronger chelating groups at the gill surface. Substituted malonic acids with similar proton and Cu association constants can be readily prepared with a variety of simple substituents, radiolabeled if required. Their results show that these acids could be useful ligands for investigating intracellular transport and metabolism of metal-organic complexes.

Palmer, F.B.; Evans, C.W. [Univ. of Auckland (New Zealand); Butler, C.A. [Woodward Clyde NZ Ltd., Auckland (New Zealand); Timperley, M.H. [National Inst. of Water and Atmospheric Research, Auckland (New Zealand)

1998-08-01

321

RNA-Sequencing Analysis of TCDD-Induced Responses in Zebrafish Liver Reveals High Relatedness to In Vivo Mammalian Models and Conserved Biological Pathways  

PubMed Central

TCDD is one of the most persistent environmental toxicants in biological systems and its effect through aryl hydrocarbon receptor (AhR) has been well characterized. However, the information on TCDD-induced toxicity in other molecular pathways is rather limited. To fully understand molecular toxicity of TCDD in an in vivo animal model, adult zebrafish were exposed to TCDD at 10 nM for 96 h and the livers were sampled for RNA-sequencing based transcriptomic profiling. A total of 1,058 differently expressed genes were identified based on fold-change>2 and TPM (transcripts per million) >10. Among the top 20 up-regulated genes, 10 novel responsive genes were identified and verified by RT-qPCR analysis on independent samples. Transcriptomic analysis indicated several deregulated pathways associated with cell cycle, endocrine disruptors, signal transduction and immune systems. Comparative analyses of TCDD-induced transcriptomic changes between fish and mammalian models revealed that proteomic pathway is consistently up-regulated while calcium signaling pathway and several immune-related pathways are generally down-regulated. Finally, our study also suggested that zebrafish model showed greater similarity to in vivo mammalian models than in vitro models. Our study indicated that the zebrafish is a valuable in vivo model in toxicogenomic analyses for understanding molecular toxicity of environmental toxicants relevant to human health. The expression profiles associated with TCDD could be useful for monitoring environmental dioxin and dioxin-like contamination.

Li, Zhi-Hua; Xu, Hongyan; Zheng, Weiling; Lam, Siew Hong; Gong, Zhiyuan

2013-01-01

322

RNA-sequencing analysis of TCDD-induced responses in zebrafish liver reveals high relatedness to in vivo mammalian models and conserved biological pathways.  

PubMed

TCDD is one of the most persistent environmental toxicants in biological systems and its effect through aryl hydrocarbon receptor (AhR) has been well characterized. However, the information on TCDD-induced toxicity in other molecular pathways is rather limited. To fully understand molecular toxicity of TCDD in an in vivo animal model, adult zebrafish were exposed to TCDD at 10 nM for 96 h and the livers were sampled for RNA-sequencing based transcriptomic profiling. A total of 1,058 differently expressed genes were identified based on fold-change>2 and TPM (transcripts per million) >10. Among the top 20 up-regulated genes, 10 novel responsive genes were identified and verified by RT-qPCR analysis on independent samples. Transcriptomic analysis indicated several deregulated pathways associated with cell cycle, endocrine disruptors, signal transduction and immune systems. Comparative analyses of TCDD-induced transcriptomic changes between fish and mammalian models revealed that proteomic pathway is consistently up-regulated while calcium signaling pathway and several immune-related pathways are generally down-regulated. Finally, our study also suggested that zebrafish model showed greater similarity to in vivo mammalian models than in vitro models. Our study indicated that the zebrafish is a valuable in vivo model in toxicogenomic analyses for understanding molecular toxicity of environmental toxicants relevant to human health. The expression profiles associated with TCDD could be useful for monitoring environmental dioxin and dioxin-like contamination. PMID:24204792

Li, Zhi-Hua; Xu, Hongyan; Zheng, Weiling; Lam, Siew Hong; Gong, Zhiyuan

2013-01-01

323

Assessing appetitive choice discrimination learning in zebrafish.  

PubMed

Within the last decade, the zebrafish (Danio rerio) has emerged as an important vertebrate model in developmental biology and medicine for problems typically associated with humans. However, where behavioral assays are needed, the utility of the zebrafish model has been limited by the narrow range of procedures so far developed to investigate zebrafish learning. The purpose of this study was to further develop and test procedures to study appetitive choice discrimination learning in zebrafish. Zebrafish were conditioned to swim into one of three chambers for food reinforcement. The correct (S+) chamber on a trial was signaled by the presence of a light stimulus in the chamber; the two negative (S-) chambers were dark. Each of the 15 fish tested learned the discrimination to a criterion of 80% correct in both of two consecutive sessions. Tests for stimulus control showed that discriminative behavior was indeed under the control of the S+ discriminandum. These results were discussed in relation to the recent report of zebrafish discrimination learning in a two-alternative task, and the importance of examining individual zebrafish learning curves. PMID:18248184

Bilotta, Joseph; Risner, Michael L; Davis, Erin C; Haggbloom, Steven J

2005-01-01

324

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

325

?-Mangostin: A Dietary Antioxidant Derived from the Pericarp of Garcinia mangostana L. Inhibits Pancreatic Tumor Growth in Xenograft Mouse Model.  

PubMed

Abstract Aims: Pancreatic cancer (PC) is the most aggressive malignant disease, ranking as the fourth most leading cause of cancer-related death among men and women in the United States. In this study, we provide evidence of chemotherapeutic effects of ?-mangostin, a dietary antioxidant isolated from the pericarp of Garcinia mangostana L. against human PC. Results: The chemotherapeutic effect of ?-mangostin was determined using four human PC cells (PL-45, PANC1, BxPC3, and ASPC1). ?-Mangostin resulted in a significant inhibition of PC cells viability without having any effects on normal human pancreatic duct epithelial cells. ?-Mangostin showed a dose-dependent increase of apoptosis in PC cells. Also, ?-mangostin inhibited the expression levels of pNF-?B/p65Ser552, pStat3Ser727, and pStat3Tyr705. ?-Mangostin inhibited DNA binding activity of nuclear factor kappa B (NF-?B) and signal transducer and activator 3 (Stat3). ?-Mangostin inhibited the expression levels of matrix metallopeptidase 9 (MMP9), cyclin D1, and gp130; however, increased expression of tissue inhibitor of metalloproteinase 1 (TIMP1) was observed in PC cells. In addition, i.p. administration of ?-mangostin (6?mg/kg body weight, 5 days a week) resulted in a significant inhibition of both primary (PL-45) and secondary (ASPC1) human PC cell-derived orthotopic and ectopic xenograft tumors in athymic nude mice. No sign of toxicity was observed in any of the mice administered with ?-mangostin. ?-Mangostin treatment inhibited the biomarkers of cell proliferation (Ki-67 and proliferating cell nuclear antigen [PCNA]) in the xenograft tumor tissues. Innovation: We present, for the first time, that dietary antioxidant ?-mangostin inhibits the growth of PC cells in vitro and in vivo. Conclusion: These results suggest the potential therapeutic efficacy of ?-mangostin against human PC. Antioxid. Redox Signal. 21, 682-699. PMID:24295217

Hafeez, Bilal Bin; Mustafa, Ala; Fischer, Joseph W; Singh, Ashok; Zhong, Weixiong; Shekhani, Mohammed Ozair; Meske, Louise; Havighurst, Thomas; Kim, KyungMann; Verma, Ajit Kumar

2014-08-10

326

Enhanced antitumour activity of 6-hydroxymethylacylfulvene in combination with topotecan or paclitaxel in the MV522 lung carcinoma xenograft model.  

PubMed

6-Hydroxymethylacylfulvene (HMAF; MGI 114; Irofulven) is a semisynthetic analogue of the toxin illudin S, which is a product of the Omphalotus mushroom. MGI 114 induces cytotoxicity against a broad range of solid tumours in vivo, including the drug-refractory MV522 human lung cancer xenograft. In this study, the potential application of MGI 114 in the treatment of lung cancer was explored by evaluating the activity of MGI 114 in combination with either topotecan (TPT) or paclitaxel. Groups of eight nude mice bearing MV522 xenografts were treated with MGI 114, TPT or paclitaxel as single agents and with MGI 114 in combination with TPT or paclitaxel. MGI 114 was administered at doses of 2.5 and 5.0 mg/kg intraperitoneally (i.p.) daily on days 1-5, while TPT and paclitaxel were administered at doses of 0.5 or 1.0 mg/kg and 20 mg/kg, respectively, i.p. on days 1-5. In the single-agent studies, MGI 114, TPT and paclitaxel all resulted in decreased final tumour weights compared with vehicle-treated controls. As single agents, TPT, at the 0.5 mg/kg dose level, and paclitaxel, at the 20 mg/kg dose level, produced partial shrinkages (PSs). All combinations of MGI 114, and either TPT or paclitaxel, produced decrements in final tumour weights compared with monotherapy with the same doses of MGI 114, TPT and paclitaxel. Although all animals treated with the combination of MGI 114 and paclitaxel experienced PSs or complete shrinkages (CSs) (or died), analysis of the time to tumour doubling revealed that the combination of MGI 114 and TPT at 2.5 and 0.5 mg/kg, respectively, was synergistic. These results suggest that cytotoxic activity is enhanced when MGI 114 is combined with either TPT or paclitaxel, and clinical trials to further evaluate these combination regimens are warranted. PMID:11094320

Hammond, L A; Hilsenbeck, S G; Eckhardt, S G; Marty, J; Mangold, G; MacDonald, J R; Rowinsky, E K; Von Hoff, D D; Weitman, S

2000-12-01

327

Automated measurement of zebrafish larval movement.  

PubMed

The zebrafish is a powerful vertebrate model that is readily amenable to genetic, pharmacological and environmental manipulations to elucidate the molecular and cellular basis of movement and behaviour. We report software enabling automated analysis of zebrafish movement from video recordings captured with cameras ranging from a basic camcorder to more specialized equipment. The software, which is provided as open-source MATLAB functions, can be freely modified and distributed, and is compatible with multiwell plates under a wide range of experimental conditions. Automated measurement of zebrafish movement using this technique will be useful for multiple applications in neuroscience, pharmacology and neuropsychiatry. PMID:21646414

Cario, Clinton L; Farrell, Thomas C; Milanese, Chiara; Burton, Edward A

2011-08-01

328

Automated measurement of zebrafish larval movement  

PubMed Central

Abstract The zebrafish is a powerful vertebrate model that is readily amenable to genetic, pharmacological and environmental manipulations to elucidate the molecular and cellular basis of movement and behaviour. We report software enabling automated analysis of zebrafish movement from video recordings captured with cameras ranging from a basic camcorder to more specialized equipment. The software, which is provided as open-source MATLAB functions, can be freely modified and distributed, and is compatible with multiwell plates under a wide range of experimental conditions. Automated measurement of zebrafish movement using this technique will be useful for multiple applications in neuroscience, pharmacology and neuropsychiatry.

Cario, Clinton L; Farrell, Thomas C; Milanese, Chiara; Burton, Edward A

2011-01-01

329

Characterization of zebrafish larval inflammatory macrophages.  

PubMed

Zebrafish have emerged as a powerful model system to study leukocyte recruitment and inflammation. Here we characterize the morphology and function of inflammatory macrophages in zebrafish larvae. These macrophages can be distinguished from neutrophils by immunolabeling of L-Plastin without MPO co-expression and by an elongated morphology. Live imaging of transgenic zMPO:GFP larvae demonstrate that GFP(lo) macrophages migrate to wounds by extension of thin pseudopods and carry out phagocytosis of tissue debris, and FACS analysis of leukocyte markers indicates expression of CSF1R in these macrophages. These findings identify distinct functional and morphological characteristics of inflammatory macrophages in zebrafish larvae. PMID:19619578

Mathias, Jonathan R; Dodd, M Ernest; Walters, Kevin B; Yoo, Sa Kan; Ranheim, Erik A; Huttenlocher, Anna

2009-11-01

330

Correlations of 3T DCE-MRI Quantitative Parameters with Microvessel Density in a Human-Colorectal-Cancer Xenograft Mouse Model  

PubMed Central

Objective To investigate the correlation between quantitative dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) parameters and microvascular density (MVD) in a human-colon-cancer xenograft mouse model using 3 Tesla MRI. Materials and Methods A human-colon-cancer xenograft model was produced by subcutaneously inoculating 1 × 106 DLD-1 human-colon-cancer cells into the right hind limbs of 10 mice. The tumors were allowed to grow for two weeks and then assessed using MRI. DCE-MRI was performed by tail vein injection of 0.3 mmol/kg of gadolinium. A region of interest (ROI) was drawn at the midpoints along the z-axes of the tumors, and a Tofts model analysis was performed. The quantitative parameters (Ktrans, Kep and Ve) from the whole transverse ROI and the hotspot ROI of the tumor were calculated. Immunohistochemical microvessel staining was performed and analyzed according to Weidner's criteria at the corresponding MRI sections. Additional Hematoxylin and Eosin staining was performed to evaluate tumor necrosis. The Mann-Whitney test and Spearman's rho correlation analysis were performed to prove the existence of a correlation between the quantitative parameters, necrosis, and MVD. Results Whole transverse ROI of the tumor showed no significant relationship between the MVD values and quantitative DCE-MRI parameters. In the hotspot ROI, there was a difference in MVD between low and high group of Ktrans and Kep that had marginally statistical significance (ps = 0.06 and 0.07, respectively). Also, Ktrans and Kep were found to have an inverse relationship with MVD (r = -0.61, p = 0.06 in Ktrans; r = -0.60, p = 0.07 in Kep). Conclusion Quantitative analysis of T1-weighted DCE-MRI using hotspot ROI may provide a better histologic match than whole transverse section ROI. Within the hotspots, Ktrans and Kep tend to have a reverse correlation with MVD in this colon cancer mouse model.

Ahn, Sung Jun; An, Chan Sik; Koom, Woong Sub; Suh, Jin-Suck

2011-01-01

331

Effect of yeast-derived beta-glucan in conjunction with bevacizumab for the treatment of human lung adenocarcinoma in subcutaneous and orthotopic xenograft models.  

PubMed

Human lung cancer is the leading cause of cancer death worldwide. Bevacizumab, a monoclonal antibody against vascular endothelial growth factor (VEGF), in combination with chemotherapy showed significant therapeutic efficacy in human lung cancer patients. However, increased adverse effects limit its clinical utilization. Previous studies demonstrated that polysaccharide beta-glucan significantly augments antitumor monoclonal antibody-mediated efficacy via stimulation of the innate effector neutrophil complement receptor 3. Here, we explored combined beta-glucan with bevacizumab therapy for human lung cancer using murine xenograft models. To that end, human lung adenocarcinomas were screened for membrane-bound VEGF expression. Both subcutaneous and orthotopic lung cancer xenograft models were used to evaluate the combination therapy. We found that PC14PE6 adenocarcinoma cells express membrane-bound VEGF both in vitro and in vivo. Bevacizumab bound to surface VEGF on PC14PE6 cells and activated complement. In the subcutaneous PC14PE6 tumor model, beta-glucan plus bevacizumab showed augmented efficacy in terms of tumor progression and long-term survival compared with bevacizumab-treated alone. These effects were accompanied with massive complement deposition and neutrophil infiltration within tumors. However, this effect was not observed in surface-bound VEGF-negative human lung tumors. Therapeutic efficacy of beta-glucan with bevacizumab was further demonstrated in an orthotopic lung cancer model. Thus, our data suggest that beta-glucan enhances bevacizumab-mediated efficacy and may provide therapeutic benefits for lung cancers with membrane-bound VEGF expression. PMID:19561538

Zhong, Wangjian; Hansen, Richard; Li, Bing; Cai, Yihua; Salvador, Carolina; Moore, Grace D; Yan, Jun

2009-09-01

332

A novel orally available inhibitor of focal adhesion signaling increases survival in a xenograft model of diffuse large B-cell lymphoma with central nervous system involvement.  

PubMed

Central nervous system dissemination is a relatively uncommon but almost always fatal complication in diffuse large B-cell lymphoma patients. Optimal therapy for central nervous involvement in this malignancy has not been established. In this paper, we aimed to evaluate the therapeutic effect of E7123, a celecoxib derivative that inhibits focal adhesion signaling, in a novel xenograft model of diffuse large B-cell lymphoma with central nervous system involvement. Cells obtained after disaggregation of HT subcutaneous tumors (HT-SC cells) were intravenously injected in NOD/SCID mice. These mice received oral vehicle or 75 mg/kg of E7123 daily until they were euthanized for weight loss or signs of sickness. The antitumor effect of E7123 was validated in an independent experiment using a bioluminescent mouse model. Intravenously injected HT-SC cells showed higher take rate and higher central nervous system tropism (associated with increased expression of ?1-integrin and p130Cas proteins) than HT cells. The oral administration of E7123 significantly increased survival time in 2 independent experiments using mice injected with unmodified or bioluminescent HT-SC cells. We have developed a new xenograft model of diffuse large B-cell lymphoma with central nervous system involvement that can be used in the pre-clinical evaluation of new drugs for this malignancy. E7123 is a new, well-tolerated and orally available therapeutic agent that merits further investigation since it may improve current management of diffuse large B-cell lymphoma patients with central nervous system involvement. PMID:23716554

Bosch, Rosa; Moreno, María José; Dieguez-Gonzalez, Rebeca; Céspedes, María Virtudes; Gallardo, Alberto; Trias, Manuel; Grañena, Albert; Sierra, Jorge; Casanova, Isolda; Mangues, Ramon

2013-08-01

333

Prostate cancer xenografts engineered from 3D precision-porous poly(2-hydroxyethyl methacrylate) hydrogels as models for tumorigenesis and dormancy escape.  

PubMed

Synthetic biomaterial scaffolds show promise for in vitro and in vivo 3D cancer models. Tumors engineered in biomaterial scaffolds have shown evidence of being more physiologically relevant than some traditional preclinical model systems, and synthetic biomaterials provide the added benefit of defined and consistent microenvironmental control. Here, we examine sphere-templated poly(2-hydroxyethyl methacrylate) (pHEMA) scaffolds as the basis for engineering xenografts from multiple human prostate cancer cell lines. pHEMA scaffolds seeded and pre-cultured with tumorigenic M12 cells prior to implantation generated tumors in athymic nude mice, demonstrating the ability of the scaffolds to be used as a synthetic vehicle for xenograft generation. pHEMA scaffolds seeded with LNCaP C4-2 cells, which require Matrigel or stromal cell support for tumor formation, were poorly tumorigenic up to 12 weeks after implantation even when Matrigel was infused into the scaffold, demonstrating a lack of necessary pro-tumorigenic signaling within the scaffolds. Finally, M12mac25 cells, which are ordinarily rendered non-tumorigenic through the expression of the tumor suppressor insulin-like growth factor binding protein 7 (IGFBP7), displayed a tumorigenic response when implanted within porous pHEMA scaffolds. These M12mac25 tumors showed significant macrophage infiltration within the scaffolds driven by the foreign body response to the materials. These findings show the potential for this biomaterials-based model system to be used in the study of prostate cancer tumorigenesis and dormancy escape. PMID:24942815

Long, Thomas J; Sprenger, Cynthia C; Plymate, Stephen R; Ratner, Buddy D

2014-09-01

334

In Silico cancer cell versus stroma cellularity index computed from species-specific human and mouse transcriptome of xenograft models: towards accurate stroma targeting therapy assessment  

PubMed Central

Background The current state of the art for measuring stromal response to targeted therapy requires burdensome and rate limiting quantitative histology. Transcriptome measures are increasingly affordable and provide an opportunity for developing a stromal versus cancer ratio in xenograft models. In these models, human cancer cells are transplanted into mouse host tissues (stroma) and together coevolve into a tumour microenvironment. However, profiling the mouse or human component separately remains problematic. Indeed, laser capture microdissection is labour intensive. Moreover, gene expression using commercial microarrays introduces significant and underreported cross-species hybridization errors that are commonly overlooked by biologists. Method We developed a customized dual-species array, H&M array, and performed cross-species and species-specific hybridization measurements. We validated a new methodology for establishing the stroma vs cancer ratio using transcriptomic data. Results In the biological validation of the H&M array, cross-species hybridization of human and mouse probes was significantly reduced (4.5 and 9.4 fold reduction, respectively; p < 2x10-16 for both, Mann-Whitney test). We confirmed the capability of the H&M array to determine the stromal to cancer cells ratio based on the estimation of cellularity index of mouse/human mRNA content in vitro. This new metrics enable to investigate more efficiently the stroma-cancer cell interactions (e.g. cellularity) bypassing labour intensive requirement and biases of laser capture microdissection. Conclusion These results provide the initial evidence of improved and cost-efficient analytics for the investigation of cancer cell microenvironment, using species-specificity arrays specifically designed for xenografts models.

2014-01-01

335

A vertebrate model for the study of lipid binding/transfer protein function: conservation of OSBP-related proteins between zebrafish and human.  

PubMed

Oxysterol-binding protein (OSBP) and OSBP-related (ORP) or OSBP-like (OSBPL) proteins constitute a family of lipid-binding/transfer proteins (LTPs) present in eukaryotes from yeast to man. The mechanisms of ORP function have remained incompletely understood. However, several ORPs are present at membrane contact sites and act as either lipid transporters or sensors that control lipid metabolism, cell signaling, and vesicle transport. Zebrafish, Danio rerio, has gained increasing popularity as a model organism in developmental biology, human disease, toxicology, and drug discovery. However, LTPs in the fish are thus far unexplored. In this article we report a series of bioinformatic analyses showing that the OSBPL gene family is highly conserved between the fish and human. The OSBPL subfamily structure is markedly similar between the two organisms, and all 12 human genes have orthologs, designated osbpl and located on 11 chromosomes in D. rerio. Interestingly, osbpl2 and osbpl3 are present as two closely related homologs (a and b), due to gene duplication events in the teleost lineage. Moreover, the domain structures of the distinct ORP proteins are almost identical between zebrafish and man, and molecular modeling in the present study suggests that ORD liganding by phosphatidylinositol-4-phosphate (PI4P) is a feature conserved between yeast Osh3p, human ORP3, and zebrafish Osbpl3. The present analysis identifies D. rerio as an attractive model to study the functions of ORPs in vertebrate development and metabolism. PMID:24326072

Zhou, You; Wohlfahrt, Gerd; Paavola, Jere; Olkkonen, Vesa M

2014-04-11

336

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

337

Histocompatibility and Hematopoietic Transplantation in the Zebrafish  

PubMed Central

The zebrafish has proven to be an excellent model for human disease, particularly hematopoietic diseases, since these fish make similar types of blood cells as humans and other mammals. The genetic program that regulates the development and differentiation of hematopoietic cells is highly conserved. Hematopoietic stem cells (HSCs) are the source of all the blood cells needed by an organism during its lifetime. Identifying an HSC requires a functional assay, namely, a transplantation assay consisting of multilineage engraftment of a recipient and subsequent serial transplant recipients. In the past decade, several types of hematopoietic transplant assays have been developed in the zebrafish. An understanding of the major histocompatibility complex (MHC) genes in the zebrafish has lagged behind transplantation experiments, limiting the ability to perform unbiased competitive transplantation assays. This paper summarizes the different hematopoietic transplantation experiments performed in the zebrafish, both with and without immunologic matching, and discusses future directions for this powerful experimental model of human blood diseases.

de Jong, Jill L. O.; Zon, Leonard I.

2012-01-01

338

Thymoquinone overcomes chemoresistance and enhances the anticancer effects of bortezomib through abrogation of NF-?B regulated gene products in multiple myeloma xenograft mouse model  

PubMed Central

Multiple myeloma (MM) is a B cell malignancy characterized by clonal proliferation of plasma cells in the bone marrow. With the advent of novel targeted agents, the median survival rate has increased to 5?7 years. However, majority of patients with myeloma suffer relapse or develop chemoresistance to existing therapeutic agents. Thus, there is a need to develop novel alternative therapies for the treatment of MM. Thus in the present study, we investigated whether thymoquinone (TQ), a bioactive constituent of black seed oil, could suppress the proliferation and induce chemosensitization in human myeloma cells and xenograft mouse model. Our results show that TQ inhibited the proliferation of MM cells irrespective of their sensitivity to doxorubicin, melphalan or bortezomib. Interestingly, TQ treatment also resulted in a significant inhibition in the proliferation of CD138+ cells isolated from MM patient samples in a concentration dependent manner. TQ also potentiated the apoptotic effects of bortezomib in various MM cell lines through the activation of caspase-3, resulting in the cleavage of PARP. TQ treatment also inhibited chemotaxis and invasion induced by CXCL12 in MM cells. Furthermore, in a xenograft mouse model, TQ potentiated the antitumor effects of bortezomib (p < 0.05, vehicle versus bortezomib + TQ; p < 0.05, bortezomib versus bortezomib + TQ), and this correlated with modulation of various markers for survival and angiogenesis, such as Ki-67, vascular endothelial growth factor (VEGF), Bcl-2 and p65 expression. Overall, our results demonstrate that TQ can enhance the anticancer activity of bortezomib in vitro and in vivo and may have a substantial potential in the treatment of MM.

Siveen, Kodappully Sivaraman; Mustafa, Nurulhuda; Li, Feng; Kannaiyan, Radhamani; Ahn, Kwang Seok; Kumar, Alan Prem; Chng, Wee-Joo; Sethi1, Gautam

2014-01-01

339

Poly(ethylene glycol)-block-poly(?-caprolactone) Micelles for Combination Drug Delivery: Evaluation of Paclitaxel, Cyclopamine and Gossypol in Intraperitoneal Xenograft Models of Ovarian Cancer  

PubMed Central

Ovarian cancer is the most lethal gynecological malignancy, characterized by a high rate of chemoresistance. Current treatment strategies for ovarian cancer focus on novel drug combinations of cytotoxic agents and molecular targeted agents or novel drug delivery strategies that often involve intraperitoneal (IP) injection. Poly(ethylene glycol)-block-poly(?-caprolactone) (PEG-b-PCL) micelles were loaded with paclitaxel (cytotoxic agent), cyclopamine (hedgehog inhibitor), and gossypol (Bcl-2 inhibitor). After physicochemical studies focusing on combination drug solubilization, 3-drug PEG-b-PCL micelles were evaluated in vitro in 2-D and 3-D cell culture and in vivo in xenograft models of ovarian cancer, tracking bioluminescence signals from ES-2 and SKOV3 human ovarian cancer cell lines after IP injection. 3-drug PEG-b-PCL micelles were not significantly more potent in 2-D cell culture in comparison to paclitaxel; however, they disaggregated ES-2 tumor spheroids, whereas single drugs or 2-drug combinations only slowed growth of ES-2 tumor spheroids or had no noticeable effects. In ES-2 and SKOV3 xenograft models, 3-drug PEG-b-PCL micelles had significantly less tumor burden than paclitaxel based on bioluminescence imaging, 3?-deoxy-3?-18F-fluorothymidine (18F-FLT) PET imaging, and overall survival. 18F-FLT-PET images clearly showed that 3-drug PEG-b-PCL micelles dramatically reduce tumor volumes over paclitaxel and vehicle controls. In summary, PEG-b-PCL micelles enable the IP combination drug delivery of paclitaxel, cyclopamine and gossypol, resulting in tumor growth inhibition and prolonged survival over paclitaxel alone. These results validate a novel treatment strategy for ovarian cancer based on drug combinations of cytotoxic agents and molecular targeted agents, delivered concurrently by a nanoscale drug delivery system, e.g. PEG-b-PCL micelles.

Cho, Hyunah; Lai, Tsz Chung; Kwon, Glen S.

2012-01-01

340

YM155, a novel survivin suppressant, enhances taxane-induced apoptosis and tumor regression in a human Calu 6 lung cancer xenograft model.  

PubMed

Survivin, an apoptotic inhibitor, is overexpressed in the majority of human tumor types and represents a novel target for anticancer therapy. Taxanes induce a mitotic cell-cycle block through the inhibition of microtubule depolymerization, with subsequent elevated expression/stabilization of survivin. We investigated the administration of survivin suppressant YM155 monobromide (YM155), in combination with docetaxel, in a human non-small-cell lung cancer (NSCLC) xenograft model. Animals received a 7-day continuous infusion of YM155, 2 mg/kg, and/or three bolus doses of docetaxel, 20 mg/kg, according to three dosing schedules: YM155 administered concomitantly with docetaxel, before docetaxel, and after docetaxel. YM155 administered either concomitantly with or before docetaxel showed significant antitumor activity (tumor regression ? 99%), with complete regression of the established human NSCLC-derived tumors in mice (eight of eight and seven of eight animals, respectively). Significantly fewer complete responses (three of eight animals) were achieved when YM155 was administered after docetaxel. No statistically significant decreases in body weight were observed in the combination versus docetaxel groups. YM155 administered concomitantly with docetaxel resulted in significant decreases in mitotic and proliferative indices, and in a significant increase in the apoptosis index. Elevated survivin expression was seen in tumors from mice treated with docetaxel alone; a significant reduction in survivin expression was seen in tumors from mice treated with YM155 alone or in combination with docetaxel, but not in the control group. These results indicate that in a human NSCLC xenograft model YM155 in combination with docetaxel diminished the accumulation of survivin by docetaxel and induced more intense apoptosis and enhanced antitumor activity, compared with single-agent YM155 or docetaxel. PMID:21389848

Nakahara, Takahito; Yamanaka, Kentaro; Hatakeyama, Shinji; Kita, Aya; Takeuchi, Masahiro; Kinoyama, Isao; Matsuhisa, Akira; Nakano, Kenji; Shishido, Takao; Koutoku, Hiroshi; Sasamata, Masao

2011-06-01

341

Cisplatin and 4-hexylresorcinol synergise to decrease metastasis and increase survival rate in an oral mucosal melanoma xenograft model: a preliminary study.  

PubMed

The present study was undertaken to examine the effects of cisplatin plus 4-hexylresorcinol (4-HR) combination therapy on oral mucosal melanoma (OMM) using cultured primary OMM cells in a tumour xenograft model. Cultured primary OMM cells were used for the MTT assay and DNA microarray. OMM cells were implanted into the submandibular glands of nude mice. The mice were then treated with cisplatin only or cisplatin plus 4-HR. Tumour size changes, survival rate and tumour metastasis were compared between the two groups by observation, micro-positron emission tomography (PET) and histological examination. In the MTT assay, the cisplatin plus 4-HR group showed significantly higher inhibition of OMM cell growth compared to the other groups (p<0.05). DNA microarray results showed significant inhibition of matrix metalloproteinase (MMP)-2 gene expression upon 4-HR application. The necropsy and micro-PET results showed that the mice from the cisplatin-only group had more distant metastases than the mice from the cisplatin plus 4-HR combination group (p=0.002). MMP-2 expression was lower in the primary tumours in the cisplatin plus 4-HR combination group than in the cisplatin-only group (p<0.001). Overall survival was longer in mice from the cisplatin plus 4-HR combination group than in the cisplatin-only group (p=0.049). In conclusion, the combined effect of cisplatin and 4-HR resulted in fewer metastases and longer survival than cisplatin-only treatment in the OMM xenograft model. PMID:23412976

Lee, Sang-Woon; Kim, Seong-Gon; Park, Young-Wook; Kweon, Haeyong; Kim, Jwa-Young; Rotaru, Horatiu

2013-06-01

342

Effect of single and multiple administration of an O6-benzylguanine/temozolomide combination: an evaluation in a human melanoma xenograft model.  

PubMed

The purpose of the present study was to examine the effect of O6-benzylguanine (O6-BG) on the antitumour activity and toxicity of 8-carbamoyl-3-methylimidazo [5, 1-d]-1,2,3,5-tetrazine-4(3H)-one (temozolomide) in a human malignant melanoma xenograft model following single and multiple administration of the combination. O6-BG irreversibly inactivates the DNA-repair protein O6-alkylguanine-DNA alkyltransferase (AGT), which confers resistance to temozolomide. Preadministration of O6-BG (35 mg/kg, i.p.) 1 h prior to temozolomide (i.p.) was examined using single and daily x5 dosing regimens in athymic mice bearing subcutaneous A375P xenografts. The AGT activity of A375P tumors was 95 +/- 8 fmol/mg protein (mean +/- SE, n = 4). O6-BG alone completely suppressed xenograft AGT activity within 1 h of administration but had no effect upon tumor growth. O6-BG did not significantly increase the tumor growth delay induced by a single 200-mg/ kg dose of temozolomide (P > 0.05, two-tailed Mann-Whitney test) but did increase the associated mean body weight loss (P < 0.025). In contrast, when the same dose of temozolomide was divided into five equal fractions (40 mg/kg) and given with O6-BG on 5 consecutive days, a comparable increase in toxicity was accompanied by a very significant increase in tumor growth delay (P < 0.0025), equivalent to that produced by a 3-fold greater dose of temozolomide alone. O6-BG with temozolomide also produced a greater antitumour effect than an equitoxic dose of temozolomide alone on this schedule (P < 0.005). These data indicate that the enhancement of temozolomide antitumour activity by O6-BG preadministration is dependent upon the schedule of drug administration, with multiple dosing of O6-BG + temozolomide producing the greatest effect. The results also suggest that prolonged administration of the combination can lead to an increase in the therapeutic index of temozolomide. PMID:9219512

Wedge, S R; Porteous, J K; Newlands, E S

1997-01-01

343

Antibody Directed against Human YKL-40 Increases Tumor Volume in a Human Melanoma Xenograft Model in Scid Mice  

PubMed Central

Induced overexpression of the secretory protein YKL-40 promotes tumor growth in xenograft experiments. We investigated if targeting YKL-40 with a monoclonal antibody could inhibit tumor growth. YKL-40 expressing human melanoma cells (LOX) were injected subcutenously in Balb/c scid mice. Animals were treated with intraperitoneal injections of anti-YKL-40, isoptype control or PBS. Non-YKL-40 expressing human pancreatic carcinoma cell line PaCa 5061 served as additional control. MR imaging was used for evaluation of tumor growth. Two days after the first injections of anti-YKL-40, tumor volume had increased significantly compared with controls, whereas no effects were observed for control tumors from PaCa 5061 cells lacking YKL-40 expression. After 18 days, mean tumor size of the mice receiving repeated anti-YKL-40 injections was 1.82 g, >4 times higher than mean tumor size of the controls (0.42 g). The effect of anti-YKL-40 on the increase of tumor volume started within hours after injection and was dose dependent. Intratumoral hemorrhage was observed in the treated animals. The strong effect on tumor size indicates important roles for YKL-40 in melanoma growth and argues for a careful evaluation of antibody therapy directed against YKL-40.

Salamon, Johannes; Hoffmann, Tatjana; Elies, Eva; Peldschus, Kersten; Johansen, Julia S.; Luers, Georg; Schumacher, Udo; Wicklein, Daniel

2014-01-01

344

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

345

Filamentous, mixed micelles of triblock copolymers enhance tumor localization of indocyanine green in a murine xenograft model  

PubMed Central

Polymeric micelles formed by the self-assembly of amphiphilic block copolymers can be used to encapsulate hydrophobic drugs for tumor-delivery applications. Filamentous carriers with high aspect ratios offer potential advantages over spherical carriers, including prolonged circulation times. In this work, mixed micelles comprised of poly (ethylene oxide)-poly-[(R)-3-hydroxybutyrate]-poly (ethylene oxide) (PEO-PHB-PEO) and Pluronic F-127 (PF-127) were used to encapsulate a near-infrared fluorophore. The micelle formulations were assessed for tumor accumulation after tail vein injection to xenograft tumor-bearing mice by non-invasive optical imaging. The mixed micelle formulation that facilitated the highest tumor accumulation was shown by cryo-electron microscopy to be filamentous in structure compared to spherical structures of pure PF-127 micelles. In addition, increased dye loading efficiency and dye stability was attained in this mixed micelle formulation compared to pure PEO-PHB-PEO micelles. Therefore, the optimized PEO-PHB-PEO/PF-127 mixed micelle formulation offers advantages for cancer delivery over micelles formed from the individual copolymer components.

Kim, Tae Hee; Mount, Christopher W; Dulken, Benjamin W; Ramos, Jenelyn; Fu, Caroline J; Khant, Htet A; Chiu, Wah; Gombotz, Wayne R; Pun, Suzie H

2012-01-01

346

Mycobacteria Counteract a TLR-Mediated Nitrosative Defense Mechanism in a Zebrafish Infection Model  

PubMed Central

Pulmonary tuberculosis (TB), caused by the intracellular bacterial pathogen Mycobacterium tuberculosis (Mtb), is a major world health problem. The production of reactive nitrogen species (RNS) is a potent cytostatic and cytotoxic defense mechanism against intracellular pathogens. Nevertheless, the protective role of RNS during Mtb infection remains controversial. Here we use an anti-nitrotyrosine antibody as a readout to study nitration output by the zebrafish host during early mycobacterial pathogenesis. We found that recognition of Mycobacterium marinum, a close relative of Mtb, was sufficient to induce a nitrosative defense mechanism in a manner dependent on MyD88, the central adaptor protein in Toll like receptor (TLR) mediated pathogen recognition. However, this host response was attenuated by mycobacteria via a virulence mechanism independent of the well-characterized RD1 virulence locus. Our results indicate a mechanism of pathogenic mycobacteria to circumvent host defense in vivo. Shifting the balance of host-pathogen interactions in favor of the host by targeting this virulence mechanism may help to alleviate the problem of infection with Mtb strains that are resistant to multiple drug treatments.

van Hensbergen, Vincent; Schutz, Esther; Redd, Michael J.; Murayama, Emi; Spaink, Herman P.; Meijer, Annemarie H.

2014-01-01

347

Cardiovascular toxicity evaluation of silica nanoparticles in endothelial cells and zebrafish model.  

PubMed

Environmental exposure to nanomaterials is inevitable as nanomaterials become part of our daily life, and as a result, nanotoxicity research is gaining attention. However, most investigators focus on the evaluation of overall toxicity instead of a certain organism system. In this regard, the evaluation of cardiovascular effects of silica nanoparticles was preformed in vitro and in vivo. It's worth noting that silica nanoparticles induced cytotoxicity as well as oxidative stress and apoptosis. ROS and apoptosis were considered as major factor to endothelial cells dysfunction, involved in several molecular mechanisms of cardiovascular diseases. In vivo study, mortality, malformation, heart rate and whole-embryo cellular death were measured in zebrafish embryos. Results showed that silica nanoparticles induced pericardia toxicity and caused bradycardia. We also examined the expression of cardiovascular-related proteins in embryos by western blot analysis. Silica nanoparticles inhibited the expression of p-VEGFR2 and p-ERK1/2 as well as the downregulation of MEF2C and NKX2.5, revealed that silica nanoparticles could inhibit the angiogenesis and disturb the heart formation and development. In summary, our results suggest that exposure to silica nanoparticles is a possible risk factor to cardiovascular system. PMID:23663927

Duan, Junchao; Yu, Yongbo; Li, Yang; Yu, Yang; Sun, Zhiwei

2013-07-01

348

Purpurin inhibits adipocyte-derived leucine aminopeptidase and angiogenesis in a zebrafish model.  

PubMed

Adipocyte-derived leucine aminopeptidase (A-LAP) is a novel member of the M1 family of zinc metallopeptidases, which has been reported to play a crucial role in angiogenesis. In the present study, we conducted a target-based screening of natural products and synthetic chemical libraries using the purified enzyme to search novel inhibitors of A-LAP. Amongst several hits isolated, a natural product purpurin was identified as one of the most potent inhibitors of A-LAP from the screening. In vitro enzymatic analyses demonstrated that purpurin inhibited A-LAP activity in a non-competitive manner with a Ki value of 20M. In addition, purpurin showed a strong selectivity toward A-LAP versus another member of M1 family of zinc metallopeptidase, aminopeptidase N (APN). In angiogenesis assays, purpurin inhibited the vascular endothelial growth factor (VEGF)-induced invasion and tube formation of human umbilical vein endothelial cells (HUVEC). Moreover, purpurin inhibited in vivo angiogenesis in zebrafish embryo without toxicity. These data demonstrate that purpurin is a novel specific inhibitor of A-LAP and could be developed as a new anti-angiogenic agent. PMID:24928393

Park, Hyomi; Shim, Joong Sup; Kim, Beom Seok; Jung, Hye Jin; Huh, Tae-Lin; Kwon, Ho Jeong