Publications by authors named "Craig Ceol"

31 Publications

BMP signaling promotes neural crest identity and accelerates melanoma onset.

J Invest Dermatol 2021 Feb 18. Epub 2021 Feb 18.

Program in Molecular Medicine, University of Massachusetts Medical School, 368 Plantation St. Worcester, MA, 01605; Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, 368 Plantation St. Worcester, MA, 01605. Electronic address:

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jid.2021.01.021DOI Listing
February 2021

Melanoma models for the next generation of therapies.

Cancer Cell 2021 Feb 4. Epub 2021 Feb 4.

Center for Cancer Research, NCI, NIH, 37 Convent Drive, Bethesda, MD 20892, USA. Electronic address:

There is a lack of appropriate melanoma models that can be used to evaluate the efficacy of novel therapeutic modalities. Here, we discuss the current state of the art of melanoma models including genetically engineered mouse, patient-derived xenograft, zebrafish, and ex vivo and in vitro models. We also identify five major challenges that can be addressed using such models, including metastasis and tumor dormancy, drug resistance, the melanoma immune response, and the impact of aging and environmental exposures on melanoma progression and drug resistance. Additionally, we discuss the opportunity for building models for rare subtypes of melanomas, which represent an unmet critical need. Finally, we identify key recommendations for melanoma models that may improve accuracy of preclinical testing and predict efficacy in clinical trials, to help usher in the next generation of melanoma therapies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ccell.2021.01.011DOI Listing
February 2021

Making a melanoma: Molecular and cellular changes underlying melanoma initiation.

Pigment Cell Melanoma Res 2020 Dec 7. Epub 2020 Dec 7.

Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA.

Melanoma arises from the melanocyte lineage and is the most aggressive and lethal form of skin cancer. There are several genetic, genomic, and cellular changes associated with melanoma initiation. Here, we discuss these alterations and the melanoma cells of origin in which they are proposed to promote melanomagenesis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/pcmr.12950DOI Listing
December 2020

Loss of prdm1a accelerates melanoma onset and progression.

Mol Carcinog 2020 09 20;59(9):1052-1063. Epub 2020 Jun 20.

Department of Craniofacial Biology, University of Colorado Denver Anschutz Medical Campus, Aurora, Colorado.

Melanoma is an aggressive, deadly skin cancer derived from melanocytes, a neural crest cell derivative. Melanoma cells mirror the developmental program of neural crest cells in that they exhibit the same gene expression patterns and utilize similar cellular mechanisms, including increased cell proliferation, epithelial-mesenchymal transition, and migration. Here we studied the role of neural crest regulator PRDM1 in melanoma onset and progression. In development, Prdm1a functions to promote neural crest progenitor fate, and in melanoma, we found that PRDM1 has reduced copy number and is recurrently deleted in both zebrafish and humans. When examining expression of neural crest and melanocyte development genes, we show that sox10 progenitor expression is high in prdm1a mutants, while more differentiated melanocyte markers are reduced, suggesting that normally Prdm1a is required for differentiation. Data mining of human melanoma datasets indicates that high PRDM1 expression in human melanoma is correlated with better patient survival and decreased PRDM1 expression is common in metastatic tumors. When one copy of prdm1a is lost in the zebrafish melanoma model Tg(mitfa:BRAF );p53 ;prdm1a , melanoma onset occurs more quickly, and the tumors that form have a larger area with increased expression of sox10. These data demonstrate a novel role for PRDM1 as a tumor suppressor in melanoma.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/mc.23236DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7864383PMC
September 2020

From Tank to Treatment: Modeling Melanoma in Zebrafish.

Cells 2020 05 22;9(5). Epub 2020 May 22.

Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA.

Melanoma is the deadliest form of skin cancer and one of few cancers with a growing incidence. A thorough understanding of its pathogenesis is fundamental to developing new strategies to combat mortality and morbidity. Zebrafish-due in large part to their tractable genetics, conserved pathways, and optical properties-have emerged as an excellent system to model melanoma. Zebrafish have been used to study melanoma from a single tumor initiating cell, through metastasis, remission, and finally into relapse. In this review, we examine seminal zebrafish studies that have advanced our understanding of melanoma.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/cells9051289DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7290816PMC
May 2020

Regulation of zebrafish melanocyte development by ligand-dependent BMP signaling.

Elife 2019 12 23;8. Epub 2019 Dec 23.

Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, United States.

Preventing terminal differentiation is important in the development and progression of many cancers including melanoma. Recent identification of the BMP ligand as a novel melanoma oncogene showed -activated BMP signaling suppresses differentiation of melanoma cells. Previous studies have identified roles for orthologs during early embryonic and neural crest development, but have not identified direct regulation of melanocyte development by GDF6. Here, we investigate the BMP ligand , a zebrafish ortholog of human , during the development of melanocytes from the neural crest. We establish that the loss of or inhibition of BMP signaling during neural crest development disrupts normal pigment cell development, leading to an increase in the number of melanocytes and a corresponding decrease in iridophores, another neural crest-derived pigment cell type in zebrafish. This shift occurs as pigment cells arise from the neural crest and depends on , an ortholog of , a key regulator of melanocyte development that is also targeted by oncogenic BMP signaling. Together, these results indicate that the oncogenic role ligand-dependent BMP signaling plays in suppressing differentiation in melanoma is a reiteration of its physiological roles during melanocyte development.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.7554/eLife.50047DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6968919PMC
December 2019

Ligand-activated BMP signaling inhibits cell differentiation and death to promote melanoma.

J Clin Invest 2018 01 4;128(1):294-308. Epub 2017 Dec 4.

Program in Molecular Medicine.

Oncogenomic studies indicate that copy number variation (CNV) alters genes involved in tumor progression; however, identification of specific driver genes affected by CNV has been difficult, as these rearrangements are often contained in large chromosomal intervals among several bystander genes. Here, we addressed this problem and identified a CNV-targeted oncogene by performing comparative oncogenomics of human and zebrafish melanomas. We determined that the gene encoding growth differentiation factor 6 (GDF6), which is the ligand for the BMP family, is recurrently amplified and transcriptionally upregulated in melanoma. GDF6-induced BMP signaling maintained a trunk neural crest gene signature in melanomas. Additionally, GDF6 repressed the melanocyte differentiation gene MITF and the proapoptotic factor SOX9, thereby preventing differentiation, inhibiting cell death, and promoting tumor growth. GDF6 was specifically expressed in melanomas but not melanocytes. Moreover, GDF6 expression levels in melanomas were inversely correlated with patient survival. Our study has identified a fundamental role for GDF6 and BMP signaling in governing an embryonic cell gene signature to promote melanoma progression, thus providing potential opportunities for targeted therapy to treat GDF6-positive cancers.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1172/JCI92513DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5749509PMC
January 2018

Identification and characterization of T reg-like cells in zebrafish.

J Exp Med 2017 Dec 24;214(12):3519-3530. Epub 2017 Oct 24.

Program in Molecular Medicine and Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA

Regulatory T (T reg) cells are a specialized sublineage of T lymphocytes that suppress autoreactive T cells. Functional studies of T reg cells in vitro have defined multiple suppression mechanisms, and studies of T reg-deficient humans and mice have made clear the important role that these cells play in preventing autoimmunity. However, many questions remain about how T reg cells act in vivo. Specifically, it is not clear which suppression mechanisms are most important, where T reg cells act, and how they get there. To begin to address these issues, we sought to identify T reg cells in zebrafish, a model system that provides unparalleled advantages in live-cell imaging and high-throughput genetic analyses. Using a orthologue as a marker, we identified CD4-enriched, mature T lymphocytes with properties of T reg cells. Zebrafish mutant for displayed excess T lymphocytes, splenomegaly, and a profound inflammatory phenotype that was suppressed by genetic ablation of lymphocytes. This study identifies T reg-like cells in zebrafish, providing both a model to study the normal functions of these cells in vivo and mutants to explore the consequences of their loss.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1084/jem.20162084DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5716030PMC
December 2017

Chromatin modification: A novel insight into BRAF-independent spontaneous melanoma.

Pigment Cell Melanoma Res 2018 01 13;31(1):9-10. Epub 2017 Oct 13.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/pcmr.12648DOI Listing
January 2018

KIT Suppresses BRAF-Mutant Melanoma by Attenuating Oncogenic RAS/MAPK Signaling.

Cancer Res 2017 11 25;77(21):5820-5830. Epub 2017 Sep 25.

Program in Molecular Medicine, Department of Molecular, Cell, and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts.

The receptor tyrosine kinase KIT promotes survival and migration of melanocytes during development, and excessive KIT activity hyperactivates the RAS/MAPK pathway and can drive formation of melanomas, most notably of rare melanomas that occur on volar and mucosal surfaces of the skin. The much larger fraction of melanomas that occur on sun-exposed skin is driven primarily by BRAF- or NRAS-activating mutations, but these melanomas exhibit a surprising loss of KIT expression, which raises the question of whether loss of KIT in these tumors facilitates tumorigenesis. To address this question, we introduced a mutation into a strain of melanoma-prone zebrafish. Melanoma onset was accelerated in fish. Tumors from animals were more invasive and had higher RAS/MAPK pathway activation. KIT knockdown also increased RAS/MAPK pathway activation in a BRAF-mutant human melanoma cell line. We found that pathway stimulation upstream of BRAF could paradoxically reduce signaling downstream of BRAF, and wild-type BRAF was necessary for this effect, suggesting that its activation can dampen oncogenic BRAF signaling. , expression of wild-type BRAF delayed melanoma onset, but only in a -dependent manner. Together, these results suggest that KIT can activate signaling through wild-type RAF proteins, thus interfering with oncogenic BRAF-driven melanoma formation. .
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1158/0008-5472.CAN-17-0473DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5679278PMC
November 2017

Dissecting hematopoietic and renal cell heterogeneity in adult zebrafish at single-cell resolution using RNA sequencing.

J Exp Med 2017 Oct 6;214(10):2875-2887. Epub 2017 Sep 6.

Molecular Pathology Unit, Massachusetts General Hospital, Charlestown, MA

Recent advances in single-cell, transcriptomic profiling have provided unprecedented access to investigate cell heterogeneity during tissue and organ development. In this study, we used massively parallel, single-cell RNA sequencing to define cell heterogeneity within the zebrafish kidney marrow, constructing a comprehensive molecular atlas of definitive hematopoiesis and functionally distinct renal cells found in adult zebrafish. Because our method analyzed blood and kidney cells in an unbiased manner, our approach was useful in characterizing immune-cell deficiencies within DNA-protein kinase catalytic subunit (), interleukin-2 receptor γ a (), and double-homozygous-mutant fish, identifying blood cell losses in T, B, and natural killer cells within specific genetic mutants. Our analysis also uncovered novel cell types, including two classes of natural killer immune cells, classically defined and erythroid-primed hematopoietic stem and progenitor cells, mucin-secreting kidney cells, and kidney stem/progenitor cells. In total, our work provides the first, comprehensive, single-cell, transcriptomic analysis of kidney and marrow cells in the adult zebrafish.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1084/jem.20170976DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5626406PMC
October 2017

Melanoma-associated GRM3 variants dysregulate melanosome trafficking and cAMP signaling.

Pigment Cell Melanoma Res 2018 01 23;31(1):115-119. Epub 2017 Oct 23.

Program in Molecular Medicine and Department of Molecular Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA, USA.

Large-scale sequencing studies have revealed several genes that are recurrently mutated in melanomas. To annotate the melanoma genome, we have expressed tumor-associated variants of these genes in zebrafish and characterized their effects on melanocyte development and function. Here, we describe expression of tumor-associated variants of the recurrently mutated metabotropic glutamate receptor 3 (GRM3) gene. Unlike wild-type GRM3, tumor-associated GRM3 variants disrupted trafficking of melanosomes, causing their aggregation in the cell body. Melanosomes are trafficked in a cAMP-dependent manner, and drugs that directly or indirectly increased cAMP levels were able to suppress melanosome aggregation in mutant GRM3-expressing melanocytes. Our data show that oncogenic GRM3 variants dysregulate cAMP signaling, a heretofore unknown role for these oncogenes. cAMP signaling has been implicated in melanoma progression and drug resistance, and our data show that oncogenic properties of GRM3 could be mediated, at least in part, by alterations in cAMP signaling.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/pcmr.12610DOI Listing
January 2018

Melanoma Regression and Recurrence in Zebrafish.

Methods Mol Biol 2016 ;1451:143-53

Institute of Genetics and Molecular Medicine, MRC Human Genetics Unit & The University of Edinburgh Cancer Research UK Centre, University of Edinburgh, Crewe Road South, Edinburgh, EH4 2XU, UK.

Melanoma is the most lethal form of skin cancer with high mortality rates. Most melanoma cases have activating mutations in BRAF (V600E) and the selective inhibitors of BRAF(V600E) have been successfully used in patients. However, after initial tumor regression, the majority of patients develop drug resistance resulting in tumor regrowth. It is therefore important to understand the mechanisms underlying these processes. We have recently described the role of the master melanocyte transcription factor MITF in tumor growth, regression, and recurrence. Here, we describe protocols to study regression and recurrence in vivo, as well as for histology and immunohistochemistry, using a temperature-sensitive zebrafish model of human melanoma.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/978-1-4939-3771-4_10DOI Listing
January 2018

Uncharted Waters: Zebrafish Cancer Models Navigate a Course for Oncogene Discovery.

Adv Exp Med Biol 2016 ;916:3-19

Departments of Surgery and Medicine, Weill Cornell Medical College, 1300 York Avenue, New York, NY, 10065, USA.

Over a decade has elapsed since the first genetically-engineered zebrafish cancer model was described. During this time remarkable progress has been made. Sophisticated genetic tools have been built to generate oncogene expressing cancers and characterize multiple models of solid and blood tumors. These models have led to unique insights into mechanisms of tumor initiation and progression. New drug targets have been identified, particularly through the functional analysis of cancer genomes. Now in the second decade, zebrafish cancer models are poised for even faster growth as they are used in high-throughput genetic analyses to elucidate key mechanisms underlying critical cancer phenotypes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/978-3-319-30654-4_1DOI Listing
September 2016

Single-cell transcriptional analysis of normal, aberrant, and malignant hematopoiesis in zebrafish.

J Exp Med 2016 05 2;213(6):979-92. Epub 2016 May 2.

Molecular Pathology, Massachusetts General Hospital, Charlestown, MA 02129 Cancer Center, Massachusetts General Hospital, Charlestown, MA 02129 Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA 02114 Harvard Stem Cell Institute, Cambridge, MA 02139

Hematopoiesis culminates in the production of functionally heterogeneous blood cell types. In zebrafish, the lack of cell surface antibodies has compelled researchers to use fluorescent transgenic reporter lines to label specific blood cell fractions. However, these approaches are limited by the availability of transgenic lines and fluorescent protein combinations that can be distinguished. Here, we have transcriptionally profiled single hematopoietic cells from zebrafish to define erythroid, myeloid, B, and T cell lineages. We also used our approach to identify hematopoietic stem and progenitor cells and a novel NK-lysin 4(+) cell type, representing a putative cytotoxic T/NK cell. Our platform also quantified hematopoietic defects in rag2(E450fs) mutant fish and showed that these fish have reduced T cells with a subsequent expansion of NK-lysin 4(+) cells and myeloid cells. These data suggest compensatory regulation of the innate immune system in rag2(E450fs) mutant zebrafish. Finally, analysis of Myc-induced T cell acute lymphoblastic leukemia showed that cells are arrested at the CD4(+)/CD8(+) cortical thymocyte stage and that a subset of leukemia cells inappropriately reexpress stem cell genes, including bmi1 and cmyb In total, our experiments provide new tools and biological insights into single-cell heterogeneity found in zebrafish blood and leukemia.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1084/jem.20152013DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4886368PMC
May 2016

Poised Regeneration of Zebrafish Melanocytes Involves Direct Differentiation and Concurrent Replenishment of Tissue-Resident Progenitor Cells.

Dev Cell 2015 Jun 11;33(6):631-43. Epub 2015 Jun 11.

Program in Molecular Medicine and Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA 01605, USA. Electronic address:

Efficient regeneration following injury is critical for maintaining tissue function and enabling organismal survival. Cells reconstituting damaged tissue are often generated from resident stem or progenitor cells or from cells that have dedifferentiated and become proliferative. While lineage-tracing studies have defined cellular sources of regeneration in many tissues, the process by which these cells execute the regenerative process is largely obscure. Here, we have identified tissue-resident progenitor cells that mediate regeneration of zebrafish stripe melanocytes and defined how these cells reconstitute pigmentation. Nearly all regeneration melanocytes arise through direct differentiation of progenitor cells. Wnt signaling is activated prior to differentiation, and inhibition of Wnt signaling impairs regeneration. Additional progenitors divide symmetrically to sustain the pool of progenitor cells. Combining direct differentiation with symmetric progenitor divisions may serve as a means to rapidly repair injured tissue while preserving the capacity to regenerate.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.devcel.2015.04.025DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4480189PMC
June 2015

Zebrafish as a platform to study tumor progression.

Methods Mol Biol 2014 ;1176:143-55

Program in Molecular Medicine, Department of Cancer Biology, Program in Cell and Developmental Dynamics, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA, 01605, USA.

The zebrafish has emerged as a powerful model system to study human diseases, including a variety of neoplasms. Principal components that have contributed to the rise in use of this vertebrate model system are its high fecundity, ease of genetic manipulation, and low cost of maintenance. Vital imaging of the zebrafish is possible from the transparent embryonic stage through adulthood, the latter enabled by a number of mutant lines that ablate pigmentation. As a result, high-resolution analyses of tumor progression can be accomplished in vivo. Straightforward transgenesis of zebrafish has been employed to develop numerous tumor models that recapitulate many aspects of human neoplastic disease, both in terms of pathologic and molecular conservation. The small size of zebrafish embryos has enabled screens for novel chemotherapeutic agents. Its facile genetics have been exploited in studies that extend beyond modeling cancer to investigations that define new cancer genes and mechanisms of cancer progression. Together, these attributes have established the zebrafish as a robust and versatile model system for investigating cancer. In this chapter we describe methods that are used to study a gene's impact on melanoma progression. We detail methods for making transgenic animals and screening for tumor onset as well as methods to investigate tumor invasion and propagation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/978-1-4939-0992-6_12DOI Listing
March 2015

Screening for melanoma modifiers using a zebrafish autochthonous tumor model.

J Vis Exp 2012 Nov 13(69):e50086. Epub 2012 Nov 13.

Program in Molecular Medicine and Department of Cancer Biology, University of Massachusetts Medical School, USA.

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

Download full-text PDF

Source
http://dx.doi.org/10.3791/50086DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3520576PMC
November 2012

Loss of 5-hydroxymethylcytosine is an epigenetic hallmark of melanoma.

Cell 2012 Sep;150(6):1135-46

Division of Endocrinology, Diabetes and Hypertension, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.

DNA methylation at the 5 position of cytosine (5-mC) is a key epigenetic mark that is critical for various biological and pathological processes. 5-mC can be converted to 5-hydroxymethylcytosine (5-hmC) by the ten-eleven translocation (TET) family of DNA hydroxylases. Here, we report that "loss of 5-hmC" is an epigenetic hallmark of melanoma, with diagnostic and prognostic implications. Genome-wide mapping of 5-hmC reveals loss of the 5-hmC landscape in the melanoma epigenome. We show that downregulation of isocitrate dehydrogenase 2 (IDH2) and TET family enzymes is likely one of the mechanisms underlying 5-hmC loss in melanoma. Rebuilding the 5-hmC landscape in melanoma cells by reintroducing active TET2 or IDH2 suppresses melanoma growth and increases tumor-free survival in animal models. Thus, our study reveals a critical function of 5-hmC in melanoma development and directly links the IDH and TET activity-dependent epigenetic pathway to 5-hmC-mediated suppression of melanoma progression, suggesting a new strategy for epigenetic cancer therapy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.cell.2012.07.033DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3770275PMC
September 2012

The histone methyltransferase SETDB1 is recurrently amplified in melanoma and accelerates its onset.

Nature 2011 Mar;471(7339):513-7

Stem Cell Program and Hematology/Oncology, Children's Hospital Boston, Howard Hughes Medical Institute, Harvard Medical School, Boston, Massachusetts 02115, USA.

The most common mutation in human melanoma, BRAF(V600E), activates the serine/threonine kinase BRAF and causes excessive activity in the mitogen-activated protein kinase pathway. BRAF(V600E) mutations are also present in benign melanocytic naevi, highlighting the importance of additional genetic alterations in the genesis of malignant tumours. Such changes include recurrent copy number variations that result in the amplification of oncogenes. For certain amplifications, the large number of genes in the interval has precluded an understanding of the cooperating oncogenic events. Here we have used a zebrafish melanoma model to test genes in a recurrently amplified region of chromosome 1 for the ability to cooperate with BRAF(V600E) and accelerate melanoma. SETDB1, an enzyme that methylates histone H3 on lysine 9 (H3K9), was found to accelerate melanoma formation significantly in zebrafish. Chromatin immunoprecipitation coupled with massively parallel DNA sequencing and gene expression analyses uncovered genes, including HOX genes, that are transcriptionally dysregulated in response to increased levels of SETDB1. Our studies establish SETDB1 as an oncogene in melanoma and underscore the role of chromatin factors in regulating tumorigenesis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/nature09806DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3348545PMC
March 2011

Hematopoietic stem cell development is dependent on blood flow.

Cell 2009 May;137(4):736-48

Stem Cell Program and Hematology/Oncology, Children's Hospital, Howard Hughes Medical Institute, Harvard Stem Cell Institute, Harvard Medical School, Boston, MA 02115, USA.

During vertebrate embryogenesis, hematopoietic stem cells (HSCs) arise in the aorta-gonads-mesonephros (AGM) region. We report here that blood flow is a conserved regulator of HSC formation. In zebrafish, chemical blood flow modulators regulated HSC development, and silent heart (sih) embryos, lacking a heartbeat and blood circulation, exhibited severely reduced HSCs. Flow-modifying compounds primarily affected HSC induction after the onset of heartbeat; however, nitric oxide (NO) donors regulated HSC number even when treatment occurred before the initiation of circulation, and rescued HSCs in sih mutants. Morpholino knockdown of nos1 (nnos/enos) blocked HSC development, and its requirement was shown to be cell autonomous. In the mouse, Nos3 (eNos) was expressed in HSCs in the AGM. Intrauterine Nos inhibition or embryonic Nos3 deficiency resulted in a reduction of hematopoietic clusters and transplantable murine HSCs. This work links blood flow to AGM hematopoiesis and identifies NO as a conserved downstream regulator of HSC development.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.cell.2009.04.023DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2722870PMC
May 2009

Melanoma biology and the promise of zebrafish.

Zebrafish 2008 Dec;5(4):247-55

Stem Cell Program and Division of Hematology/Oncology, Children's Hospital Boston, 300 Longwood Avenue, Boston, MA 02115, USA.

Advantageous organismal and technical attributes of the zebrafish are being increasingly applied to study cancer biology. Along with other tumor models, zebrafish that develop melanomas have been generated. In both genetics and phenotype, zebrafish melanomas are strikingly similar to their human counterparts. For this reason, studies in the zebrafish are poised to make significant contributions to melanoma biology. In this review, we summarize important features of human melanoma and discuss how the zebrafish can be used to address many questions that remain unanswered about this devastating disease.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1089/zeb.2008.0544DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2784934PMC
December 2008

Construction and application of a zebrafish array comparative genomic hybridization platform.

Genes Chromosomes Cancer 2009 Feb;48(2):155-70

Department of Pathology, Brigham and Women's Hospital, Boston, MA 02115, USA.

The zebrafish is emerging as a prominent model system for studying the genetics of human development and disease. Genetic alterations that underlie each mutant model can exist in the form of single base changes, balanced chromosomal rearrangements, or genetic imbalances. To detect genetic imbalances in an unbiased genome-wide fashion, array comparative genomic hybridization (CGH) can be used. We have developed a 5-Mb resolution array CGH platform specifically for the zebrafish. This platform contains 286 bacterial artificial chromosome (BAC) clones, enriched for orthologous sequences of human oncogenes and tumor suppressor genes. Each BAC clone has been end-sequenced and cytogenetically assigned to a specific location within the zebrafish genome, allowing for ease of integration of array CGH data with the current version of the genome assembly. This platform has been applied to three zebrafish cancer models. Significant genomic imbalances were detected in each model, identifying different regions that may potentially play a role in tumorigenesis. Hence, this platform should be a useful resource for genetic dissection of additional zebrafish developmental and disease models as well as a benchmark for future array CGH platform development.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/gcc.20623DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2605212PMC
February 2009

APC mutant zebrafish uncover a changing temporal requirement for wnt signaling in liver development.

Dev Biol 2008 Aug 20;320(1):161-74. Epub 2008 May 20.

Stem Cell Program and Hematology/Oncology, Children's Hospital and Dana-Farber Cancer Institute, HHMI, Harvard Medical School, Boston, MA 02115, USA.

Developmental signaling pathways hold the keys to unlocking the promise of adult tissue regeneration, and to inhibiting carcinogenesis. Patients with mutations in the Adenomatous Polyposis Coli (APC) gene are at increased risk of developing hepatoblastoma, an embryonal form of liver cancer, suggesting that Wnt affects hepatic progenitor cells. To elucidate the role of APC loss and enhanced Wnt activity in liver development, we examined APC mutant and wnt inducible transgenic zebrafish. APC(+/-) embryos developed enlarged livers through biased induction of hepatic gene programs and increased proliferation. Conversely, APC(-/-) embryos formed no livers. Blastula transplantations determined that the effects of APC loss were cell autonomous. Induction of wnt modulators confirmed biphasic consequences of wnt activation: endodermal pattern formation and gene expression required suppression of wnt signaling in early somitogenesis; later, increased wnt activity altered endodermal fate by enhancing liver growth at the expense of pancreas formation; these effects persisted into the larval stage. In adult APC(+/-) zebrafish, increased wnt activity significantly accelerated liver regeneration after partial hepatectomy. Similarly, liver regeneration was significantly enhanced in APC(Min/+) mice, indicating the conserved effect of Wnt pathway activation in liver regeneration across vertebrate species. These studies reveal an important and time-dependent role for wnt signaling during liver development and regeneration.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ydbio.2008.05.526DOI Listing
August 2008

Transparent adult zebrafish as a tool for in vivo transplantation analysis.

Cell Stem Cell 2008 Feb;2(2):183-9

Department of Medical Oncology, Dana Farber Cancer Institute, Boston, MA 02115, USA.

The zebrafish is a useful model for understanding normal and cancer stem cells, but analysis has been limited to embryogenesis due to the opacity of the adult fish. To address this, we have created a transparent adult zebrafish in which we transplanted either hematopoietic stem/progenitor cells or tumor cells. In a hematopoiesis radiation recovery assay, transplantation of GFP-labeled marrow cells allowed for striking in vivo visual assessment of engraftment from 2 hr-5 weeks posttransplant. Using FACS analysis, both transparent and wild-type fish had equal engraftment, but this could only be visualized in the transparent recipient. In a tumor engraftment model, transplantation of RAS-melanoma cells allowed for visualization of tumor engraftment, proliferation, and distant metastases in as little as 5 days, which is not seen in wild-type recipients until 3 to 4 weeks. This transparent adult zebrafish serves as the ideal combination of both sensitivity and resolution for in vivo stem cell analyses.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.stem.2007.11.002DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2292119PMC
February 2008

APC and colon cancer: two hits for one.

Nat Med 2007 Nov;13(11):1286-7

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/nm1107-1286DOI Listing
November 2007

Some C. elegans class B synthetic multivulva proteins encode a conserved LIN-35 Rb-containing complex distinct from a NuRD-like complex.

Proc Natl Acad Sci U S A 2006 Nov 30;103(45):16782-7. Epub 2006 Oct 30.

Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.

The Caenorhabditis elegans synthetic multivulva (synMuv) genes act redundantly to antagonize the specification of vulval cell fates, which are promoted by an RTK/Ras pathway. At least 26 synMuv genes have been genetically identified, several of which encode proteins with homologs that act in chromatin remodeling or transcriptional repression. Here we report the molecular characterization of two synMuv genes, lin-37 and lin-54. We show that lin-37 and lin-54 encode proteins in a complex with at least seven synMuv proteins, including LIN-35, the only C. elegans homolog of the mammalian tumor suppressor Rb. Biochemical analyses of mutants suggest that LIN-9, LIN-53, and LIN-54 are required for the stable formation of this complex. This complex is distinct from a second complex of synMuv proteins with a composition similar to that of the mammalian Nucleosome Remodeling and Deacetylase complex. The class B synMuv complex we identified is evolutionarily conserved and likely functions in transcriptional repression and developmental regulation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1073/pnas.0608461103DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1636532PMC
November 2006

Identification and classification of genes that act antagonistically to let-60 Ras signaling in Caenorhabditis elegans vulval development.

Genetics 2006 Jun 19;173(2):709-26. Epub 2006 Apr 19.

Department of Biology, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.

The synthetic multivulva (synMuv) genes negatively regulate Ras-mediated vulval induction in the nematode Caenorhabditis elegans. The synMuv genes define three classes, A, B, and C, such that double mutants carrying mutations in genes of any two classes are multivulva. The class B synMuv genes include lin-35, a homolog of the retinoblastoma (Rb) tumor suppressor gene, as well as homologs of genes that function with Rb in transcriptional regulation. We screened for additional synMuv mutations using a strategy different from that of previous synMuv genetic screens. Some of the mutations we recovered affect new synMuv genes. We present criteria for assigning synMuv mutations into different genetic classes. We also describe the molecular characterization of the class B synMuv gene lin-65.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1534/genetics.106.056465DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1526536PMC
June 2006

A new class of C. elegans synMuv genes implicates a Tip60/NuA4-like HAT complex as a negative regulator of Ras signaling.

Dev Cell 2004 Apr;6(4):563-76

Howard Hughes Medical Institute, Department of Biology, 68-425, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.

The class A and class B synMuv genes are functionally redundant negative regulators of a Ras signaling pathway that induces C. elegans vulval development. A number of class B synMuv genes encode components of an Rb and histone deacetylase complex that likely acts to repress transcription of genes required for vulval induction. We discovered a new class of synMuv genes that acts redundantly with both the A and B classes of genes in vulval cell-fate determination. These new class C synMuv genes encode TRRAP, MYST family histone acetyltransferase, and Enhancer of Polycomb homologs, which form a putative C. elegans Tip60/NuA4-like histone acetyltransferase complex. A fourth gene with partial class C synMuv properties encodes a homolog of the mammalian SWI/SNF family ATPase p400. Our findings indicate that the coordinated action of two chromatin-modifying complexes, one with histone deacetylase and the other with histone acetyltransferase activity, is important in regulating Ras signaling and specifying cell fates during C. elegans development.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/s1534-5807(04)00065-6DOI Listing
April 2004