Centrosome defects are a common feature of many cancers. Surprisingly, flies can proceed through the majority of development without centrosomes or with amplified centrosomes in most of their cells. It is unclear whether this is because centrosome defects do not cause many problems in Drosophila cells, or because they can adapt to cope with any problems that arise. Indeed, centrosome loss and centrosome amplification predispose fly brain cells to form tumours. Here we assess how centrosome loss or centrosome amplification perturbs cell physiology by profiling the global transcriptome of Drosophila larval brains and imaginal discs that either lack centrosomes or have too many centrosomes.
Centrosome loss or amplification does not dramatically perturb global gene expression in Drosophila.
Specimen part
View SamplesTranscript profiling analysis of csn3-1, csn4-1 and csn5 (csn5a-2 csn5b) light grown and dark grown mutant seedlings compared to light grown and dark grown wild type using Arabidopsis ATH1 GeneChip array
The Arabidopsis COP9 signalosome is essential for G2 phase progression and genomic stability.
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View SamplesHuman engeneered skin carrying GFP positive melanoma cells was transplanted in immunocompromised rats.
low neurotrophin receptor CD271 regulates phenotype switching in melanoma.
Specimen part, Time
View SamplesWe have shown that activin promoted skin tumorigenesis in mice induced by the human papilloma virus 8 oncogenes. Activin attracted blood monocytes to the skin as revealed by depletion of CCR2-positive monocytes. To determine if activin also altered the gene expression profile of these cells, we performed RNA-Sequencing of macrophages FACS-sorted from the pre-cancerous ear skin. We have found that activin induces a pro-migratiory, pro-angiogenic and pro-tumorigenic genes in skin macrophages in vivo. This largely contributes to the pro-tumorigenic function of activin, since macrophage depletion delayed spontaneous tumorigenesis in HPV8-transgenic mice by reducing keratinocyte proliferation and angiogenesis. Overall design: F4/80+CD11b+CD45+ cells were FACS-sorted from the pre-cancerous ear skin of wt/wt, HPV8/wt, wt/Act and HPV8/Act mice and their expression profile was analysed by RNA-Sequencing. Experiment was performed in triplicates, for each replicate ear skin of 3-6 mice of corresponding genotype was pooled.
Activin promotes skin carcinogenesis by attraction and reprogramming of macrophages.
Specimen part, Cell line, Subject
View SamplesSOX9 is generally not expressed in melanomas with a high proliferative capacity but is expressed in melanomas with a high invasive capacity. Here we overexpress full length SOX9 in M010817, a melanoma cell culture with high proliferative capacity but low invasive capacity.
Methylation-dependent SOX9 expression mediates invasion in human melanoma cells and is a negative prognostic factor in advanced melanoma.
Specimen part, Cell line
View SamplesCharacterized by striking metastatic propensity and chemoresistance, melanoma is among the most lethal cutaneous malignancies. The transcription factor ATF2 was shown to elicit oncogenic activities in melanoma, and its inhibition attenuates melanoma development. Here, a mouse model engineered to express a transcriptionally inactive form of Atf2 (Atf2?8,9) was found to be sufficient to induce nevi formation and, when crossed with BrafV600E animals, to promote melanoma development. The cross of Atf2?8,9 with BrafV600E;Pten-/- mice augmented pigmentation, tumorigenicity, and metastasis. Similar to mouse Atf2?8,9, the human ATF2 splice variant 5 enhanced growth and migration capacity of cultured melanoma and immortalized melanocytes. Induced Melan-A, CXCL9, S100A8, CCR7 expression, seen in Atf2?8,9-driven tumors associate with their enhanced pigmentation, immune infiltration and propensity to metastasize. Notably, elevated ATF2SV5 expression in melanoma specimens coincided with poor prognosis. The gain-of-function activity elicited by the truncated ATF2 form offers unexpected insight into mechanisms underlying melanoma development and progression. Overall design: Compared silencing of ATF2SV5 in H3A cells vs. silencing of ATF2WT via Ampliseq whole transcriptome analysis on the Ion Proton
A Transcriptionally Inactive ATF2 Variant Drives Melanomagenesis.
Specimen part, Subject
View SamplesThe MYB oncogene is widely expressed in acute leukemias and is important for the continued proliferation of leukemia cells, raising the possibility that MYB may be a therapeutic target. However realization of this potential requires (i) a significant therapeutic window for MYB inhibition, given its essential role in normal hematopoiesis; and (ii) an approach for developing an effective therapeutic. We previously showed that the interaction of Myb with the coactivator CBP/p300 is essential for its transforming activity. Here we use hematopoietic cells from the Booreana mouse strain, which carries a mutation in Myb that prevents interaction with CBP/p300, to examine the requirement for this interaction in myeloid transformation and leukemogenesis. Using this strain and a strain (plt6) carrying a complementary mutation in p300, we show that the Myb-p300 interaction is essential for in vitro transformation by the myeloid leukemia oncogenes AML1-ETO, AML1-ETO9a, MLL-ENL, and MLL-AF9. We further show that unlike cells from wild-type (WT) mice, Booreana cells fail to induce leukemia upon transplantation into irradiated recipients following transduction with an AML1-ETO9a retrovirus. These data highlight disruption of the Myb-p300 interaction as a potential therapeutic strategy for AML and suggest that such a strategy would have a useable therapeutic index since Booreana mice, unlike Myb null mice, are viable. Finally we have begun to explore the molecular basis of the these observations by gene expression profiling; this highlighted several genes previously implicated in myeloid leukemogenesis as being differentially expressed between WT and Booreana cells transduced with AML1-ETO9a.
Interaction of c-Myb with p300 is required for the induction of acute myeloid leukemia (AML) by human AML oncogenes.
Specimen part
View SamplesIncreased activity of the epigenetic modifier EZH2 has been associated with different cancers. However, evidence for a functional role of EZH2 in tumourigenesis in vivo remains poor, in particular in metastasising solid cancers. Here we reveal central roles of EZH2 in promoting growth and metastasis of cutaneous melanoma. In a melanoma mouse model, conditional Ezh2 ablation as much as treatment with the preclinical Ezh2 inhibitor GSK503 stabilises the disease through inhibition of growth and virtually abolishes metastases formation without affecting normal melanocyte biology. Comparably, in human melanoma cells, EZH2 inactivation impairs proliferation and invasiveness, accompanied by re-expression of tumour suppressors connected to increased patient survival. These EZH2 target genes suppress melanoma growth and prevent EMT / metastasis in vivo revealing the dual function of EZH2 in promoting tumour progression. Thus, EZH2-mediated epigenetic repression is highly relevant especially during advanced melanomagenesis, which makes EZH2 a promising target for novel melanoma therapies.
The epigenetic modifier EZH2 controls melanoma growth and metastasis through silencing of distinct tumour suppressors.
Specimen part, Cell line
View SamplesEwing sarcoma family of tumors (ESFT) are aggressive bone and soft tissue tumors of unknown cellular origin. Most ESFT express EWS-FLI1, a chimeric protein which functions as a growth-promoting oncogene in ESFT but is toxic to most normal cells. A major difficulty in understanding EWS-FLI1 function has been the lack of an adequate model in which to study EWS-FLI1-induced transformation. Although the cell of origin of ESFT remains elusive, both mesenchymal (MSC) and neural crest (NCSC) have been implicated. We recently developed the tools to generate NCSC from human embryonic stem cells (hNCSC). In the current study we used this model to test the hypothesis that neural crest-derived stem cells are the cells of origin of ESFT and to evaluate the consequences of EWS-FLI1 expression on human neural crest biology.
Modeling initiation of Ewing sarcoma in human neural crest cells.
Specimen part
View SamplesTo elucidate the gene expression footprint of antigenically challenged T-cells which had been treated with anti-LFA-1, CTLA4Ig, anti-CD40-ligand antibodies, we performed microarray gene expression analysis comparing the expression profile of costimulatory blockade treated and untreated responder T-cells.
Short-term immunosuppression promotes engraftment of embryonic and induced pluripotent stem cells.
Specimen part
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