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1.
Cancer Res ; 79(11): 2892-2908, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31048499

RESUMO

Melanoma has an unusual capacity to spread in early-stage disease, prompting aggressive clinical intervention in very thin primary tumors. Despite these proactive efforts, patients with low-risk, low-stage disease can still develop metastasis, indicating the presence of permissive cues for distant spread. Here, we show that constitutive activation of the small GTPase ARF6 (ARF6Q67L) is sufficient to accelerate metastasis in mice with BRAFV600E/Cdkn2aNULL melanoma at a similar incidence and severity to Pten loss, a major driver of PI3K activation and melanoma metastasis. ARF6Q67L promoted spontaneous metastasis from significantly smaller primary tumors than PTENNULL, implying an enhanced ability of ARF6-GTP to drive distant spread. ARF6 activation increased lung colonization from circulating melanoma cells, suggesting that the prometastatic function of ARF6 extends to late steps in metastasis. Unexpectedly, ARF6Q67L tumors showed upregulation of Pik3r1 expression, which encodes the p85 regulatory subunit of PI3K. Tumor cells expressing ARF6Q67L displayed increased PI3K protein levels and activity, enhanced PI3K distribution to cellular protrusions, and increased AKT activation in invadopodia. ARF6 is necessary and sufficient for activation of both PI3K and AKT, and PI3K and AKT are necessary for ARF6-mediated invasion. We provide evidence for aberrant ARF6 activation in human melanoma samples, which is associated with reduced survival. Our work reveals a previously unknown ARF6-PI3K-AKT proinvasive pathway, it demonstrates a critical role for ARF6 in multiple steps of the metastatic cascade, and it illuminates how melanoma cells can acquire an early metastatic phenotype in patients. SIGNIFICANCE: These findings reveal a prometastatic role for ARF6 independent of tumor growth, which may help explain how melanoma spreads distantly from thin, early-stage primary tumors.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/79/11/2892/F1.large.jpg.

2.
Mol Cancer Res ; 17(9): 1787-1800, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31138602

RESUMO

Alterations in the PI3K/AKT pathway occur in up to 70% of melanomas and are associated with disease progression. The three AKT paralogs are highly conserved but data suggest they have distinct functions. Activating mutations of AKT1 and AKT3 occur in human melanoma but their role in melanoma formation and metastasis remains unclear. Using an established melanoma mouse model, we evaluated E17K, E40K, and Q79K mutations in AKT1, AKT2, and AKT3 and show that mice harboring tumors expressing AKT1E17K had the highest incidence of brain metastasis and lowest mean survival. Tumors expressing AKT1E17K displayed elevated levels of focal adhesion factors and enhanced phosphorylation of focal adhesion kinase (FAK). AKT1E17K expression in melanoma cells increased invasion and this was reduced by pharmacologic inhibition of either AKT or FAK. These data suggest that the different AKT paralogs have distinct roles in melanoma brain metastasis and that AKT and FAK may be promising therapeutic targets. IMPLICATIONS: This study suggests that AKT1E17K promotes melanoma brain metastasis through activation of FAK and provides a rationale for the therapeutic targeting of AKT and/or FAK to reduce melanoma metastasis.

3.
JCI Insight ; 4(6)2019 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-30721153

RESUMO

miR-155 has recently emerged as an important promoter of antitumor immunity through its functions in T lymphocytes. However, the impact of T cell-expressed miR-155 on immune cell dynamics in solid tumors remains unclear. In the present study, we used single-cell RNA sequencing to define the CD45+ immune cell populations at different time points within B16F10 murine melanoma tumors growing in either wild-type or miR-155 T cell conditional knockout (TCKO) mice. miR-155 was required for optimal T cell activation and reinforced the T cell response at the expense of infiltrating myeloid cells. Further, myeloid cells from tumors growing in TCKO mice were defined by an increase in wound healing genes and a decreased IFN-γ-response gene signature. Finally, we found that miR-155 expression predicted a favorable outcome in human melanoma patients and was associated with a strong immune signature. Moreover, gene expression analysis of The Cancer Genome Atlas (TCGA) data revealed that miR-155 expression also correlates with an immune-enriched subtype in 29 other human solid tumors. Together, our study provides an unprecedented analysis of the cell types and gene expression signatures of immune cells within experimental melanoma tumors and elucidates the role of miR-155 in coordinating antitumor immune responses in mammalian tumors.

4.
J Mol Neurosci ; 68(1): 11-18, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30778836

RESUMO

Scoliosis is a common manifestation of neurofibromatosis type 1, causing significant morbidity. The etiology of dystrophic scoliosis in neurofibromatosis type 1 is not fully understood and therapies are lacking. Somatic mutations in NF1 have been shown in tibial pseudarthrosis providing rationale for similar processes in neurofibromatosis type 1-associated dystrophic scoliosis. Spinal samples from surgical procedures with matched peripheral blood of two individuals with neurofibromatosis type 1 and dystrophic scoliosis were obtained and DNA extracted. Next generation sequencing of various spinal sections as well as the germline/blood sample were performed using a RASopathy gene panel (includes the NF1 gene). Variants were compared between the spinal tissue samples and the germline data. In addition, the next generation sequencing allele frequency data were used to detect somatic loss of heterozygosity. All samples had a detected potentially inactivating NF1 germline mutation. Both individuals demonstrated an allelic imbalance inclusive of NF1 in the next generation sequencing data. In addition, for the same two individuals, there was an increase in the % variant reads for the germline mutation in some of the surgical spinal samples corresponding to the allelic imbalance. Contra analysis did not show any deletion in Chromosome 17 next generation sequencing data. Microarray analysis verified somatic copy neutral loss of heterozygosity for these two individuals for the majority of the chromosome 17 q-arm, inclusive of the NF1 gene. These results suggest that the cause of dystrophic scoliosis is multifactorial and that a somatic NF1 mutation contributes to the etiology.


Assuntos
Neurofibromatose 1/genética , Neurofibromina 1/genética , Escoliose/genética , Criança , Feminino , Frequência do Gene , Humanos , Perda de Heterozigosidade , Masculino , Mutação , Neurofibromatose 1/complicações , Neurofibromatose 1/patologia , Escoliose/etiologia , Escoliose/patologia , Coluna Vertebral/metabolismo , Coluna Vertebral/patologia
5.
J Clin Invest ; 128(1): 207-218, 2018 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-29202462

RESUMO

Synovial sarcoma (SS) is an aggressive soft-tissue sarcoma that is often discovered during adolescence and young adulthood. Despite the name, synovial sarcoma does not typically arise from a synoviocyte but instead arises in close proximity to bones. Previous work demonstrated that mice expressing the characteristic SS18-SSX fusion oncogene in myogenic factor 5-expressing (Myf5-expressing) cells develop fully penetrant sarcomagenesis, suggesting skeletal muscle progenitor cell origin. However, Myf5 is not restricted to committed myoblasts in embryos but is also expressed in multipotent mesenchymal progenitors. Here, we demonstrated that human SS and mouse tumors arising from SS18-SSX expression in the embryonic, but not postnatal, Myf5 lineage share an anatomic location that is frequently adjacent to bone. Additionally, we showed that SS can originate from periosteal cells expressing SS18-SSX alone and from preosteoblasts expressing the fusion oncogene accompanied by the added stabilization of ß-catenin, which is a common secondary change in SS. Expression and secretion of the osteoclastogenesis inhibitory factor osteoprotegerin enabled early growth of SS18-SSX2-transformed cells, indicating a paracrine link between the bone and synovial sarcomagenesis. These findings explain the skeletal contact frequently observed in human SS and may provide alternate means of enabling SS18-SSX-driven oncogenesis in cells as differentiated as preosteoblasts.

6.
Small GTPases ; : 1-12, 2016 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-28001501

RESUMO

The activation of the small GTPase ARF6 has been implicated in promoting several pathological processes related to vascular instability and tumor formation, growth, and metastasis. ARF6 also plays a vital role during embryonic development. Recent studies have suggested that ARF6 carries out these disparate functions primarily by controlling protein trafficking within the cell. ARF6 helps direct proteins to intracellular or extracellular locations where they function in normal cellular responses during development and in pathological processes later in life. This transport of proteins is accomplished through a variety of mechanisms, including endocytosis and recycling, microvesicle release, and as yet uncharacterized processes. This Commentary will explore the functions of ARF6, while focusing on the role of this small GTPase in development and postnatal physiology, regulating barrier function and diseases associated with its loss, and tumor formation, growth, and metastasis.

7.
Cancer Cell ; 29(6): 889-904, 2016 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-27265506

RESUMO

Activating mutations in Gαq proteins, which form the α subunit of certain heterotrimeric G proteins, drive uveal melanoma oncogenesis by triggering multiple downstream signaling pathways, including PLC/PKC, Rho/Rac, and YAP. Here we show that the small GTPase ARF6 acts as a proximal node of oncogenic Gαq signaling to induce all of these downstream pathways as well as ß-catenin signaling. ARF6 activates these diverse pathways through a common mechanism: the trafficking of GNAQ and ß-catenin from the plasma membrane to cytoplasmic vesicles and the nucleus, respectively. Blocking ARF6 with a small-molecule inhibitor reduces uveal melanoma cell proliferation and tumorigenesis in a mouse model, confirming the functional relevance of this pathway and suggesting a therapeutic strategy for Gα-mediated diseases.


Assuntos
Fatores de Ribosilação do ADP/metabolismo , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/genética , Melanoma/tratamento farmacológico , Bibliotecas de Moléculas Pequenas/administração & dosagem , Neoplasias Uveais/tratamento farmacológico , beta Catenina/metabolismo , Fatores de Ribosilação do ADP/antagonistas & inibidores , Fatores de Ribosilação do ADP/genética , Animais , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Núcleo Celular/metabolismo , Proliferação de Células/efeitos dos fármacos , Citoplasma/metabolismo , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo , Humanos , Melanoma/genética , Melanoma/metabolismo , Camundongos , Transplante de Neoplasias , Transporte Proteico/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/farmacologia , Neoplasias Uveais/genética , Neoplasias Uveais/metabolismo
8.
Cell Rep ; 13(5): 898-905, 2015 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-26565903

RESUMO

Metastases are the major cause of melanoma-related mortality. Previous studies implicating aberrant AKT signaling in human melanoma metastases led us to evaluate the effect of activated AKT1 expression in non-metastatic BRAF(V600E)/Cdkn2a(Null) mouse melanomas in vivo. Expression of activated AKT1 resulted in highly metastatic melanomas with lung and brain metastases in 67% and 17% of our mice, respectively. Silencing of PTEN in BRAF(V600E)/Cdkn2a(Null) melanomas cooperated with activated AKT1, resulting in decreased tumor latency and the development of lung and brain metastases in nearly 80% of tumor-bearing mice. These data demonstrate that AKT1 activation is sufficient to elicit lung and brain metastases in this context and reveal that activation of AKT1 is distinct from PTEN silencing in metastatic melanoma progression. These findings advance our knowledge of the mechanisms driving melanoma metastasis and may provide valuable insights for clinical management of this disease.


Assuntos
Neoplasias Encefálicas/metabolismo , Neoplasias Pulmonares/metabolismo , Melanoma/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Neoplasias Encefálicas/secundário , Linhagem Celular Tumoral , Embrião de Galinha , Inibidor p16 de Quinase Dependente de Ciclina/genética , Humanos , Neoplasias Pulmonares/secundário , Melanoma/genética , Melanoma/patologia , Camundongos , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/metabolismo , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas c-akt/genética , Serina-Treonina Quinases TOR/metabolismo
9.
Oncotarget ; 6(26): 22758-66, 2015 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-26259251

RESUMO

ß-catenin is a master regulator in the cellular biology of development and neoplasia. Its dysregulation is implicated as a driver of colorectal carcinogenesis and the epithelial-mesenchymal transition in other cancers. Nuclear ß-catenin staining is a poor prognostic sign in synovial sarcoma, the most common soft-tissue sarcoma in adolescents and young adults. We show through genetic experiments in a mouse model that expression of a stabilized form of ß-catenin greatly enhances synovial sarcomagenesis. Stabilization of ß-catenin enables a stem-cell phenotype in synovial sarcoma cells, specifically blocking epithelial differentiation and driving invasion. ß-catenin achieves its reprogramming in part by upregulating transcription of TCF/LEF target genes. Even though synovial sarcoma is primarily a mesenchymal neoplasm, its progression towards a more aggressive and invasive phenotype parallels the epithelial-mesenchymal transition observed in epithelial cancers, where ß-catenin's transcriptional contribution includes blocking epithelial differentiation.


Assuntos
Proteínas de Fusão Oncogênica/genética , Sarcoma Sinovial/metabolismo , Sarcoma Sinovial/patologia , beta Catenina/metabolismo , Animais , Modelos Animais de Doenças , Transição Epitelial-Mesenquimal , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Sarcoma Sinovial/genética , Ativação Transcricional , Transfecção , Via de Sinalização Wnt
10.
Int J Surg Pathol ; 23(6): 500-4, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26116579

RESUMO

We report a case of a Ewing sarcoma/primitive neuroectodermal tumor in an 85-year-old woman who presented with an enlarging circumscribed left flank mass. Magnetic resonance imaging revealed a 3 × 5 × 10 cm heterogeneous mass arising from the 10th rib. Computed tomography demonstrated a small nodule in the right middle lobe and bilateral pleural effusions. The patient underwent computed tomography-guided biopsy followed by open biopsy. The tumor cells were characterized by loosely cohesive sheets of tumor cells with uniform nuclei, and scant, granular, eosinophilic cytoplasm with indistinct cell membranes. Frequent mitoses, apoptosis, and necrosis were present. The cells were positive for CD99 with a strong concentric staining pattern. Epithelial, hematopoietic, and neural markers were all negative. Fluorescence in situ hybridization was performed and demonstrated EWSR1 (22q12) gene rearrangement. Sanger sequencing of the reverse transcriptase polymerase chain reaction product from the patient's tumor demonstrated the EWSR1-FLI1 type 1 fusion. Following diagnosis the patient elected to proceed with localized radiation and declined chemotherapy. She developed progressive lung disease and subsequently died of her disease a year after her initial diagnosis. Ewing sarcoma is predominantly a pediatric disease and uncommon in patients older than 40 years of age. To the best of our knowledge, this is the oldest documented case of Ewing sarcoma, diagnosed using modern molecular techniques.


Assuntos
Biomarcadores Tumorais/genética , Proteínas de Ligação a Calmodulina/genética , Neoplasias Pulmonares/diagnóstico , Neoplasias Complexas Mistas/diagnóstico , Tumores Neuroectodérmicos Primitivos/diagnóstico , Proteínas de Ligação a RNA/genética , Sarcoma de Ewing/diagnóstico , Idoso de 80 Anos ou mais , Evolução Fatal , Feminino , Humanos , Neoplasias Pulmonares/genética , Neoplasias Complexas Mistas/genética , Tumores Neuroectodérmicos Primitivos/genética , Proteína EWS de Ligação a RNA , Sarcoma de Ewing/genética
11.
Genes Cancer ; 6(1-2): 9-18, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25821557

RESUMO

In-frame BRAF fusions have been observed in over 80% of sporadic pilocytic astrocytomas. In each fusion, the N-terminal autoinhibitory domain of BRAF is lost, which results in constitutive activation via the retained C-terminal kinase domain (BRAF-KD). We set out to determine if the BRAF-KD is sufficient to induce gliomas alone or in combination with Ink4a/Arf loss. Syngeneic cell lines demonstrated the transforming ability of the BRAF-KD following Ink4a/Arf loss. In vivo, somatic cell gene transfer of the BRAF-KD did not cause tumors to develop; however, gliomas were detected in 21% of the mice following Ink4a/Arf loss. Interestingly, these mice demonstrated no obvious symptoms. Histologically the tumors were highly cellular and atypical, similar to BRAF(V600E) tumors reported previously, but with less invasive borders. They also lacked the necrosis and vascular proliferation seen in BRAFV600E-driven tumors. The BRAF-KD-expressing astrocytes showed elevated MAPK signaling, albeit at reduced levels compared to the BRAF(V600E) mutant. Pharmacologic inhibition of MEK and PI3K inhibited cell growth and induced apoptosis in astrocytes expressing BRAF-KD. Our findings demonstrate that the BRAF-KD can cooperate with Ink4a/Arf loss to drive the development of gliomas and suggest that glioma development is determined by the level of MAPK signaling.

12.
J Med Genet ; 52(4): 256-61, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25612910

RESUMO

BACKGROUND: Tibial pseudarthrosis is associated with neurofibromatosis type 1 (NF1) and there is wide clinical variability of the tibial dysplasia in NF1, suggesting the possibility of genetic modifiers. Double inactivation of NF1 is postulated to be necessary for the development of tibial pseudarthrosis, but tissue or cell of origin of the 'second hit' mutation remains unclear. METHODS: Exome sequencing of different sections of surgically resected NF1 tibial pseudarthrosis tissue was performed and compared to germline (peripheral blood). RESULTS: A germline NF1 splice site mutation (c.61-2A>T, p.L21 M68del) was identified from DNA extracted from peripheral blood. Exome sequencing of DNA extracted from tissue removed during surgery of the tibial pseudarthrosis showed a somatic mutation of NF1 (c.3574G>T, p.E1192*) in the normal germline allele. Further analysis of different regions of the tibial pseudarthrosis sample showed enrichment of the somatic mutation in the soft tissue within the pseudarthrosis site and absence of the somatic mutation in cortical bone. In addition, a germline variant in PTPN11 (c.1658C>T, p.T553M), a gene involved in the RAS signal transduction pathway was identified, although the clinical significance is unknown. CONCLUSIONS: Given that the NF1 somatic mutation was primarily detected in the proliferative soft tissue at the pseudarthrosis site, it is likely that the second hit occurred in mesenchymal progenitors from the periosteum. These results are consistent with a defect of differentiation, which may explain why the mutation is found in proliferative cells and not within cortical bone tissue, as the latter by definition contains mostly mature differentiated osteoblasts and osteocytes.


Assuntos
Genes da Neurofibromatose 1 , Mutação , Neurofibromatose 1/genética , Pseudoartrose/genética , Tíbia/patologia , Pré-Escolar , Análise Mutacional de DNA , Feminino , Humanos , Radiografia , Tíbia/diagnóstico por imagem
13.
Circulation ; 131(3): 289-99, 2015 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-25486933

RESUMO

BACKGROUND: Cerebral cavernous malformation (CCM) is a hemorrhagic stroke disease affecting up to 0.5% of North Americans that has no approved nonsurgical treatment. A subset of patients have a hereditary form of the disease due primarily to loss-of-function mutations in KRIT1, CCM2, or PDCD10. We sought to identify known drugs that could be repurposed to treat CCM. METHODS AND RESULTS: We developed an unbiased screening platform based on both cellular and animal models of loss of function of CCM2. Our discovery strategy consisted of 4 steps: an automated immunofluorescence and machine-learning-based primary screen of structural phenotypes in human endothelial cells deficient in CCM2, a secondary screen of functional changes in endothelial stability in these same cells, a rapid in vivo tertiary screen of dermal microvascular leak in mice lacking endothelial Ccm2, and finally a quaternary screen of CCM lesion burden in these same mice. We screened 2100 known drugs and bioactive compounds and identified 2 candidates, cholecalciferol (vitamin D3) and tempol (a scavenger of superoxide), for further study. Each drug decreased lesion burden in a mouse model of CCM vascular disease by ≈50%. CONCLUSIONS: By identifying known drugs as potential therapeutics for CCM, we have decreased the time, cost, and risk of bringing treatments to patients. Each drug also prompts additional exploration of biomarkers of CCM disease. We further suggest that the structure-function screening platform presented here may be adapted and scaled to facilitate drug discovery for diverse loss-of-function genetic vascular disease.


Assuntos
Neoplasias do Sistema Nervoso Central/tratamento farmacológico , Modelos Animais de Doenças , Reposicionamento de Medicamentos/métodos , Hemangioma Cavernoso do Sistema Nervoso Central/tratamento farmacológico , Animais , Células Cultivadas , Neoplasias do Sistema Nervoso Central/patologia , Colecalciferol/farmacologia , Colecalciferol/uso terapêutico , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/patologia , Depuradores de Radicais Livres/farmacologia , Depuradores de Radicais Livres/uso terapêutico , Hemangioma Cavernoso do Sistema Nervoso Central/patologia , Humanos , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Resultado do Tratamento
15.
Cancer Cell ; 26(6): 851-862, 2014 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-25453902

RESUMO

Alveolar soft part sarcoma (ASPS), a deadly soft tissue malignancy with a predilection for adolescents and young adults, associates consistently with t(X;17) translocations that generate the fusion gene ASPSCR1-TFE3. We proved the oncogenic capacity of this fusion gene by driving sarcomagenesis in mice from conditional ASPSCR1-TFE3 expression. The completely penetrant tumors were indistinguishable from human ASPS by histology and gene expression. They formed preferentially in the anatomic environment highest in lactate, the cranial vault, expressed high levels of lactate importers, harbored abundant mitochondria, metabolized lactate as a metabolic substrate, and responded to the administration of exogenous lactate with tumor cell proliferation and angiogenesis. These data demonstrate lactate's role as a driver of alveolar soft part sarcomagenesis.


Assuntos
Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Encéfalo/patologia , Proteínas de Transporte/metabolismo , Ácido Láctico/metabolismo , Proteínas de Fusão Oncogênica/metabolismo , Sarcoma Alveolar de Partes Moles/patologia , Adolescente , Adulto , Animais , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Encéfalo/metabolismo , Proteínas de Transporte/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Neoplasias Experimentais , Proteínas de Fusão Oncogênica/genética , Sarcoma Alveolar de Partes Moles/metabolismo , Microambiente Tumoral
16.
Mol Biol Cell ; 25(18): 2695-709, 2014 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-25057021

RESUMO

Ewing sarcoma is the second-most-common bone cancer in children. Driven by an oncogenic chromosomal translocation that results in the expression of an aberrant transcription factor, EWS/FLI, the disease is typically aggressive and micrometastatic upon presentation. Silencing of EWS/FLI in patient-derived tumor cells results in the altered expression of hundreds to thousands of genes and is accompanied by dramatic morphological changes in cytoarchitecture and adhesion. Genes encoding focal adhesion, extracellular matrix, and actin regulatory proteins are dominant targets of EWS/FLI-mediated transcriptional repression. Reexpression of genes encoding just two of these proteins, zyxin and α5 integrin, is sufficient to restore cell adhesion and actin cytoskeletal integrity comparable to what is observed when the EWS/FLI oncogene expression is compromised. Using an orthotopic xenograft model, we show that EWS/FLI-induced repression of α5 integrin and zyxin expression promotes tumor progression by supporting anchorage-independent cell growth. This selective advantage is paired with a tradeoff in which metastatic lung colonization is compromised.


Assuntos
Neoplasias Ósseas/metabolismo , Adesão Celular , Citoesqueleto/metabolismo , Neoplasias Pulmonares/metabolismo , Proteínas de Fusão Oncogênica/metabolismo , Proteína Proto-Oncogênica c-fli-1/metabolismo , Proteína EWS de Ligação a RNA/metabolismo , Sarcoma de Ewing/metabolismo , Animais , Neoplasias Ósseas/patologia , Linhagem Celular Tumoral , Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Integrina alfaV/metabolismo , Pulmão/patologia , Neoplasias Pulmonares/secundário , Masculino , Camundongos Endogâmicos NOD , Camundongos SCID , Transplante de Neoplasias , Sarcoma de Ewing/patologia , Zixina/metabolismo
17.
J Mol Diagn ; 16(4): 405-17, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24813172

RESUMO

The identification of recurrent gene rearrangements in the clinical laboratory is the cornerstone for risk stratification and treatment decisions in many malignant tumors. Studies have reported that targeted next-generation sequencing assays have the potential to identify such rearrangements; however, their utility in the clinical laboratory is unknown. We examine the sensitivity and specificity of ALK and KMT2A (MLL) rearrangement detection by next-generation sequencing in the clinical laboratory. We analyzed a series of seven ALK rearranged cancers, six KMT2A rearranged leukemias, and 77 ALK/KMT2A rearrangement-negative cancers, previously tested by fluorescence in situ hybridization (FISH). Rearrangement detection was tested using publicly available software tools, including Breakdancer, ClusterFAST, CREST, and Hydra. Using Breakdancer and ClusterFAST, we detected ALK rearrangements in seven of seven FISH-positive cases and KMT2A rearrangements in six of six FISH-positive cases. Among the 77 ALK/KMT2A FISH-negative cases, no false-positive identifications were made by Breakdancer or ClusterFAST. Further, we identified one ALK rearranged case with a noncanonical intron 16 breakpoint, which is likely to affect its response to targeted inhibitors. We report that clinically relevant chromosomal rearrangements can be detected from targeted gene panel-based next-generation sequencing with sensitivity and specificity equivalent to that of FISH while providing finer-scale information and increased efficiency for molecular oncology testing.


Assuntos
Adenocarcinoma/genética , Carcinoma de Células Grandes/genética , Rearranjo Gênico , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Leucemia/genética , Neoplasias Pulmonares/genética , Proteína de Leucina Linfoide-Mieloide/genética , Receptores Proteína Tirosina Quinases/genética , Adenocarcinoma de Pulmão , Quinase do Linfoma Anaplásico , Histona-Lisina N-Metiltransferase , Humanos , Hibridização in Situ Fluorescente , Sensibilidade e Especificidade
19.
Sci Signal ; 6(265): ra14, 2013 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-23462101

RESUMO

ß-Catenin has a dual function in cells: fortifying cadherin-based adhesion at the plasma membrane and activating transcription in the nucleus. We found that in melanoma cells, WNT5A stimulated the disruption of N-cadherin and ß-catenin complexes by activating the guanosine triphosphatase adenosine diphosphate ribosylation factor 6 (ARF6). Binding of WNT5A to the Frizzled 4-LRP6 (low-density lipoprotein receptor-related protein 6) receptor complex activated ARF6, which liberated ß-catenin from N-cadherin, thus increasing the pool of free ß-catenin, enhancing ß-catenin-mediated transcription, and stimulating invasion. In contrast to WNT5A, the guidance cue SLIT2 and its receptor ROBO1 inhibited ARF6 activation and, accordingly, stabilized the interaction of N-cadherin with ß-catenin and reduced transcription and invasion. Thus, ARF6 integrated competing signals in melanoma cells, thereby enabling plasticity in the response to external cues. Moreover, small-molecule inhibition of ARF6 stabilized adherens junctions, blocked ß-catenin signaling and invasiveness of melanoma cells in culture, and reduced spontaneous pulmonary metastasis in mice, suggesting that targeting ARF6 may provide a means of inhibiting WNT/ß-catenin signaling in cancer.


Assuntos
Fatores de Ribosilação do ADP/fisiologia , Melanoma/patologia , Invasividade Neoplásica , Metástase Neoplásica , Proteínas Proto-Oncogênicas/fisiologia , Ativação Transcricional/fisiologia , Proteínas Wnt/fisiologia , beta Catenina/fisiologia , Inativação Gênica , Humanos , Transdução de Sinais , Proteína Wnt-5a , beta Catenina/metabolismo
20.
Appl Immunohistochem Mol Morphol ; 21(2): 132-8, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22820664

RESUMO

Atypical intradermal smooth muscle neoplasms (AISMN, formerly known as cutaneous leiomyosarcomas) are uncommon neoplasms, which seem to be remarkable for their excellent prognosis in contrast to their deeper counterparts. The rarity of AISMN has posed a challenge for characterizing the morphologic spectrum, immunohistochemical staining pattern, and behavior. In this study we evaluated the histologic and immunohistochemical features of 20 cases of AISMN. Clinical follow-up was available on 19 out of 20 patients and ranged from 1 to 124 months with an average of 35 months and a median of 20 months with a male predominance (male to female ratio was 2.3:1). Our data show a wide variation in differentiation and atypical features. Among these, the presence of mitotic figures is diagnostically valuable in rendering the final diagnosis. A broad panel of immunohistochemical stains revealed that smooth muscle actin and muscle specific actin, when used in combination, identified smooth muscle differentiation in 100% of the cases. With some caveats, CD34, S100, and CK 5/6 were helpful in ruling out other important cutaneous spindle cell neoplasms. Significantly, loss of phosphatase and tensin homolog (PTEN) staining was seen in the majority of our cases (80%), supporting a role for PTEN loss in the etiology of these lesions. Logistic regression analysis revealed that positive margin status was helpful for predicting recurrence (100% sensitivity and 94% specificity). We conclude that AISMN can have significant morphologic variation and overlap with other spindle cell neoplasms of the skin and that a limited panel of key immunohistochemical stains should be used to distinguish this lesion. The different surgical measures such as wide excision versus Mohs procedure showed a similar clinical outcome. Although the significance of frequent PTEN loss supports a molecular mechanism of tumor genesis, the diagnostic utility of the stain remains to be determined.


Assuntos
Biomarcadores Tumorais/genética , Leiomiossarcoma/diagnóstico , Neoplasias Musculares/diagnóstico , PTEN Fosfo-Hidrolase/deficiência , Neoplasias Cutâneas/diagnóstico , Tumor de Músculo Liso/diagnóstico , Actinas/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Imuno-Histoquímica , Leiomiossarcoma/genética , Leiomiossarcoma/patologia , Masculino , Pessoa de Meia-Idade , Neoplasias Musculares/genética , Neoplasias Musculares/patologia , PTEN Fosfo-Hidrolase/genética , Prognóstico , Recidiva , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/patologia , Tumor de Músculo Liso/genética , Tumor de Músculo Liso/patologia , Microambiente Tumoral/genética
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