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GSE18387
Mus musculus
2 Downloadable Samples
Description
Naturally occurring CD25+CD4+ regulatory T cells (T reg cells) are currently intensively characterized because of their major importance in modulating host responses to tumors and infections, in preventing transplant rejection, and in inhibiting the development of autoimmunity and allergy. Originally, CD4+ T reg cells were identified exclusively by the constitutive expression of CD25, and many in vivo experiments have been performed using depleting antibodies directed against CD25. However, both the existence of CD25 T reg cells, especially within peripheral tissues, as well as the expression of CD25 on activated conventional T cells, which precludes discrimination between T reg cells and activated conventional T cells, limits the interpretation of data obtained by the use of anti-CD25 depleting antibodies. The most specific T reg cell marker currently known is the forkhead box transcription factor Foxp3, which has been shown to be expressed specifically in mouse CD4+ T reg cells and acts as a master switch in the regulation of their development and function. To address the question of the in vivo role of T reg cells in immunopathology, we have generated bacterial artificial chromosome (BAC)transgenic mice termed depletion of regulatory T cell (DEREG) mice, which express a diphtheria toxin receptor (DTR) enhanced GFP (eGFP) fusion protein under the control of the foxp3 locus, allowing both detection and inducible depletion of Foxp3+ T reg cells. The gene expression profile of both CD4+eGFP+FoxP3+ and CD4+eGFPnegFoxP3neg cells isolated from DEREG mice was here analyzed by micro array.
Publication Title
Immunostimulatory RNA blocks suppression by regulatory T cells.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 4 Downloadable Samples
Description
Plasmacytoid dendritic cells (pDC) efficiently produce large amounts of type I interferon in response to TLR7 and TLR9 ligands, whereas conventional DCs (cDC) predominantly secrete high levels of the cytokines IL-10 and IL-12. The molecular basis underlying this distinct phenotype is not well understood. Here, we identified the MAPK phosphatase Dusp9/MKP-4 by transcriptome analysis as selectively expressed in pDC, but not cDC. We confirmed the constitutive expression of Dusp9 at the protein level in pDC generated in vitro by culture with Flt3L and ex vivo in sorted splenic pDC. Dusp9 expression was low in B220- bone marrow precursors and was up-regulated during pDC differentiation, concomitant with established pDC markers. Higher expression of Dusp9 in pDC correlated with impaired phosphorylation of the MAPK ERK1/2 upon TLR9 stimulation. Notably, Dusp9 was not expressed at detectable levels in human pDC, although these displayed similarly impaired activation of ERK1/2 MAPK compared to cDC. Enforced retroviral expression of Dusp9 in mouse GM-CSF-induced cDC increased the expression of TLR7/9-induced IL-12p40 and IFNwhereas IL-10 levels were diminished. Taken together, our results suggest that the species-specific, selective expression of Dusp9 in murine pDC contributes to the differential cytokine/interferon output of pDC and cDC.
Publication Title
Selective Expression of the MAPK Phosphatase Dusp9/MKP-4 in Mouse Plasmacytoid Dendritic Cells and Regulation of IFN-β Production.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 6 Downloadable Samples
Description
Cancer metastasis is a fetal problem that claims life of over 90% of cancer patients. It is hypothesized that cancer stem cells (CSCs) mediate cancer metastasis and such cells are often resistant to chemotherapy. Studying BRCA1 associated cancers, we found that CSCs form fillopodia and protrusions enriching for active forms of ezrin/radixin/moesin proteins and they have a much higher potential to metastasize than non-CSCs. Microarray analysis indicated that many pathways related to cell adhesion, extracellular matrix and cytoskeleton were differentially regulated in CSCs. Although inhibition of cytoskeleton remodeling by cisplatin treatment retarded CSC motility and cancer metastasis, drug resistant cancers eventually emerge containing markedly increased number of CSCs. This event is at least partially attributed to the activation of PI3K/mTOR signaling, and can be significantly inhibited by the treatment of rapamycin. These results provide strong evidence that cytoskeletal rearrangement and PI3K/mTOR signaling play a distinct role in mediating CSC mobility and viability, and blocking of both pathways in CSCs synergistically inhibits primary and metastatic cancer growth in BRCA1 associated tumors.
Publication Title
Synergistic therapeutic effect of cisplatin and phosphatidylinositol 3-kinase (PI3K) inhibitors in cancer growth and metastasis of Brca1 mutant tumors.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 12 Downloadable Samples
Description
Hepatocellular carcinoma (HCC) is an important cause of morbidity and mortality worldwide. Although the risk factors of human HCC are well known, the molecular characterization of this disease is complex, and treatment options in general remain poor. The use of rodent models to study human cancer has been extensively pursued both through genetically engineered rodents and rodent models used in carcinogenicity and toxicology studies. In particular, the B6C3F1 mouse used in the National Toxicology Program (NTP) 2-year bioassay has been used to evaluate the carcinogenic effects of environmental and occupational chemicals, and other compounds. The high incidence of spontaneous HCC in the B6C3F1 mouse has challenged its use as a model for chemically induced HCC in terms of relevance to the human disease. Using global gene expression profiling, we identify the dysregulation of several mediators similarly altered in human HCC, including re-expression of fetal oncogenes, upregulation of protooncogenes, downregulation of tumor suppressor genes, and abnormal expression of cell cycle mediators, growth factors, apoptosis regulators, and angiogenesis and extracellular matrix remodeling factors. Although important differences in etiology and pathogenesis remain between human and mouse HCC, there are important similarities in global gene expression and the types of signaling networks dysregulated in mouse and human HCC. These data provide further relevance for the use of this model in hazard identification of compounds with potential human carcinogenicity risk, and may help in better understanding mechanisms of tumorigenesis due to chemical exposure in the NTP 2-year carcinogenicity bioassay.
Publication Title
Global gene profiling of spontaneous hepatocellular carcinoma in B6C3F1 mice: similarities in the molecular landscape with human liver cancer.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 1 Downloadable Sample
Description
Introduction: Lung cancer is the leading cause of cancer-related death in people. There are several chemically induced and genetically modified mouse models used to study lung cancer. We hypothesized that spontaneous murine (B6C3F1) lung tumors can serve as a model to study human non-small cell lung cancer (NSCLC). Methods: RNA was extracted from untreated 2-year-old B6C3F1 mouse spontaneous lung (SL) tumors and age-matched normal lung tissue from a chronic inhalation NTP study. Global gene expression analysis was performed using Affymetrix Mouse Genome 430 2.0 GeneChip arrays. After data normalization, for each probe set, pairwise comparisons between groups were made using a bootstrap t-test while controlling the mixed directional false discovery rate (mdFDR) to generate a differential gene expression list. IPA, KEGG, and EASE software tools were used to evaluate the overrepresented cancer genes and pathways. Results: MAPK and TGF-beta pathways were overrepresented within the dataset. Almost all of the validated genes by quantitative real time RT-PCR had comparable directional fold changes with the microarray data. The candidate oncogenes included Kras, Braf, Raf1, Id2, Hmga1, Cks1b, and Foxf1. The candidate tumor suppressor genes included Rb1, Cdkn2a, Hnf4a, Tcf21, Ptprd, Hpgd, Hopx, Ogn, Id4, Hoxa5, Smad6, Smad7, Zbtb16, Cyr61, Dusp4, and Ifi16. In addition, several genes important in lung development were also differentially expressed, such as Smad6, Hopx, Sox4, Sox9 and Mycn. Conclusion: In this study, we have demonstrated that several cancer genes and signaling pathways relevant for human NSCLC were similarly altered in spontaneous murine lung tumors.
Publication Title
Differential transcriptomic analysis of spontaneous lung tumors in B6C3F1 mice: comparison to human non-small cell lung cancer.
Sample Metadata Fields
Disease, Disease stage
View Samples- Mus musculus
- 24 Downloadable Samples
Description
Neuroblastoma, the most common extracranial pediatric solid tumor, is responsible for 15% of all childhood cancer deaths. Patients frequently present at diagnosis with metastatic disease, particularly to the bone marrow. Advances in therapy and understanding of the metastatic process have been limited due in part, to the lack of animal models harboring bone marrow disease. The widely employed transgenic model, the TH-MYCN mouse, exhibits limited metastasis to this site. Here we establish the first genetic immunocompetent mouse model for metastatic neuroblastoma with enhanced secondary tumors in the bone marrow. This model recapitulates two frequent alterations in metastatic neuroblasoma, over-expression of MYCN and loss of caspase-8 expression. In this model, the mouse caspase-8 gene was deleted in neural crest lineage cells by crossing a TH-Cre transgenic mouse with a caspase-8 conditional knockout mouse. This mouse was then crossed with the neuroblastoma prone TH-MYCN mouse. While over-expression of MYCN by itself rarely caused bone marrow metastasis (5% average incidence), combining MYCN overexpression and caspase-8 deletion significantly increased bone marrow metastasis (37% average incidence). Loss of caspase-8 expression did not alter the site, incidence, or latency of the primary tumors. However, secondary tumors were detected in the bone marrow of these mice as early as week 9-10. The mouse model described in this work is a valuable tool to enhance our understanding of metastatic neuroblastoma and treatment options and underscores the role of caspase-8 in neuroblastoma progression.
Publication Title
Th-MYCN mice with caspase-8 deficiency develop advanced neuroblastoma with bone marrow metastasis.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 16 Downloadable Samples
Description
Here we characterize and optimize both systems to increase their utility for preclinical studies. We show that TH-MYCN mice develop tumors in the paraspinal ganglia, but not in the adrenal, with cellular and gene expression patterns similar to human NB. In addition, we present a new ultrasound guided, non-invasive orthotopic xenograft method. This injection technique is rapid, provides accurate targeting of the injected cells and leads to efficient engraftment. We also demonstrate that tumors can be detected, monitored and quantified prior to visualization using ultrasound, MRI and bioluminescence. Finally we develop and test a standard of care chemotherapy regimen. This protocol, which is based on current treatments for neuroblastoma, provides a baseline for comparison of new therapeutic agents.
Publication Title
Preclinical models for neuroblastoma: establishing a baseline for treatment.
Sample Metadata Fields
Specimen part
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