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1.
J Exp Clin Cancer Res ; 38(1): 446, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31676012

RESUMO

BACKGROUND: NOTCH1 gene mutations in mantle cell lymphoma (MCL) have been described in about 5-10% of cases and are associated with significantly shorter survival rates. The present study aimed to investigate the biological impact of this mutation in MCL and its potential as a therapeutic target. METHODS: Activation of Notch1 signaling upon ligand-stimulation and inhibitory effects of the monoclonal anti-Notch1 antibody OMP-52M51 in NOTCH1-mutated and -unmutated MCL cells were assessed by Western Blot and gene expression profiling. Effects of OMP-52M51 treatment on tumor cell migration and tumor angiogenesis were evaluated with chemotaxis and HUVEC tube formation assays. The expression of Delta-like ligand 4 (DLL4) in MCL lymph nodes was analyzed by immunofluorescence staining and confocal microscopy. A MCL mouse model was used to assess the activity of OMP-52M51 in vivo. RESULTS: Notch1 expression can be effectively stimulated in NOTCH1-mutated Mino cells by DLL4, whereas in the NOTCH1-unmutated cell line JeKo-1, less effect was observed upon any ligand-stimulation. DLL4 was expressed by histiocytes in both, NOTCH1-mutated and -unmutated MCL lymph nodes. Treatment of NOTCH1-mutated MCL cells with the monoclonal anti-Notch1 antibody OMP-52M51 effectively prevented DLL4-dependent activation of Notch1 and suppressed the induction of numerous direct Notch target genes involved in lymphoid biology, lymphomagenesis and disease progression. Importantly, in lymph nodes from primary MCL cases with NOTCH1/2 mutations, we detected an upregulation of the same gene sets as observed in DLL4-stimulated Mino cells. Furthermore, DLL4 stimulation of NOTCH1-mutated Mino cells enhanced tumor cell migration and angiogenesis, which could be abolished by treatment with OMP-52M51. Importantly, the effects observed were specific for NOTCH1-mutated cells as they did not occur in the NOTCH1-wt cell line JeKo-1. Finally, we confirmed the potential activity of OMP-52M51 to inhibit DLL4-induced Notch1-Signaling in vivo in a xenograft mouse model of MCL. CONCLUSION: DLL4 effectively stimulates Notch1 signaling in NOTCH1-mutated MCL and is expressed by the microenvironment in MCL lymph nodes. Our results indicate that specific inhibition of the Notch1-ligand-receptor interaction might provide a therapeutic alternative for a subset of MCL patients.

2.
Haematologica ; 2019 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-31296574

RESUMO

CD38 is expressed in several types of non-Hodgkin lymphoma and constitutes a promising target for antibody-based therapy. Daratumumab (Darzalex) is a first-in-class anti-CD38 antibody approved for the treatment of relapsed/refractory multiple myeloma. It has also demonstrated clinical activity in Waldenstrom macroglobulinaemia and amyloidosis. Here, we have evaluated the activity and mechanism of action of daratumumab in preclinical in vitro and in vivo models of mantle cell lymphoma, follicular lymphoma and diffuse large B cell lymphoma, as monotherapy or in combination with standard chemo-immunotherapy. In vitro, daratumumab engages Fc-mediated cytotoxicity by antibody-dependent cell cytotoxicity and antibody-dependent cell phagocytosis in all lymphoma subtypes. In the presence of human serum, complement-dependent cell cytotoxicity was marginally engaged. We demonstrated by Selective Plane Illumination Microscopy that daratumumab fully penetrated a 3D lymphoma organoid and decreased organoid volume. In vivo, daratumumab completely prevents tumor outgrowth in models of mantle cell and follicular lymphoma, and shows comparable activity to rituximab in a disseminated in vivo model of blastic mantle cell lymphoma. Moreover, daratumumab improves overall survival in a mouse model of transformed CD20dim follicular lymphoma, where rituximab showed limited activity. Daratumumab potentiates the antitumor activity of CHOP and R-CHOP in mantle cell and follicular lymphoma xenografts. Furthermore, in a patient-derived diffuse large B cell lymphoma xenograft model, daratumumab anti-tumor activity was comparable to R-CHOP and the addition of daratumumab to either CHOP or R-CHOP led to full tumor regression. In summary, daratumumab constitutes a novel therapeutic opportunity in certain scenarios and these results warrant further clinical development.

3.
Mol Ther Methods Clin Dev ; 12: 134-144, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30623002

RESUMO

Genetically modifying autologous T cells to express an anti-CD19 chimeric antigen receptor (CAR) has shown impressive response rates for the treatment of CD19+ B cell malignancies in several clinical trials (CTs). Making this treatment available to our patients prompted us to develop a novel CART19 based on our own anti-CD19 antibody (A3B1), followed by CD8 hinge and transmembrane region, 4-1BB- and CD3z-signaling domains. We show that A3B1 CAR T cells are highly cytotoxic and specific against CD19+ cells in vitro, inducing secretion of pro-inflammatory cytokines and CAR T cell proliferation. In vivo, A3B1 CAR T cells are able to fully control disease progression in an NOD.Cg-Prkdc scid Il2rd tm1Wjl /SzJ (NSG) xenograph B-ALL mouse model. Based on the pre-clinical data, we conclude that our CART19 is clearly functional against CD19+ cells, to a level similar to other CAR19s currently being used in the clinic. Concurrently, we describe the implementation of our CAR T cell production system, using lentiviral vector and CliniMACS Prodigy, within a medium-sized academic institution. The results of the validation phase show our system is robust and reproducible, while maintaining a low cost that is affordable for academic institutions. Our model can serve as a paradigm for similar institutions, and it may help to make CAR T cell treatment available to all patients.

4.
Int J Cancer ; 144(11): 2762-2773, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30468254

RESUMO

The Bruton's tyrosine kinase (BTK) inhibitor ibrutinib has been shown to be highly effective in patients with chronic lymphocytic leukemia (CLL) and is approved for CLL treatment. Unfortunately, resistance and intolerance to ibrutinib has been observed in several studies, opening the door for more specific BTK inhibitors. CC-292 (spebrutinib) is a BTK inhibitor with increased specificity for BTK and less inhibition of other kinases. Our in vitro studies showed that CC-292 potently inhibited B-cell receptor signaling, activation, proliferation and chemotaxis of CLL cells. In in vivo studies using the adoptive transfer TCL1 mouse model of CLL, CC-292 reduced tumor load and normalized tumor-associated expansion of T cells and monocytes, while not affecting T cell function. Importantly, the combination of CC-292 and bendamustine impaired CLL cell proliferation in vivo and enhanced the control of CLL progression. Our results demonstrate that CC-292 is a specific BTK inhibitor with promising performance in combination with bendamustine in CLL. Further clinical trials are warranted to investigate the therapeutic efficacy of this combination regimen.


Assuntos
Acrilamidas/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Cloridrato de Bendamustina/farmacologia , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Pirimidinas/farmacologia , Acrilamidas/uso terapêutico , Adulto , Tirosina Quinase da Agamaglobulinemia/antagonistas & inibidores , Idoso , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Cloridrato de Bendamustina/uso terapêutico , Medula Óssea/patologia , Modelos Animais de Doenças , Ensaios de Seleção de Medicamentos Antitumorais , Sinergismo Farmacológico , Feminino , Humanos , Leucemia Linfocítica Crônica de Células B/sangue , Leucemia Linfocítica Crônica de Células B/genética , Leucemia Linfocítica Crônica de Células B/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Pessoa de Meia-Idade , Cultura Primária de Células , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Proto-Oncogênicas/genética , Pirimidinas/uso terapêutico , Células Tumorais Cultivadas
5.
Haematologica ; 104(4): 778-788, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-29954928

RESUMO

Constitutive activation of the chemokine receptor CXCR4 has been associated with tumor progression, invasion, and chemotherapy resistance in different cancer subtypes. Although the CXCR4 pathway has recently been suggested as an adverse prognostic marker in diffuse large B-cell lymphoma, its biological relevance in this disease remains underexplored. In a homogeneous set of 52 biopsies from patients, an antibody-based cytokine array showed that tissue levels of CXCL12 correlated with high microvessel density and bone marrow involvement at diagnosis, supporting a role for the CXCL12-CXCR4 axis in disease progression. We then identified the tetra-amine IQS-01.01RS as a potent inverse agonist of the receptor, preventing CXCL12-mediated chemotaxis and triggering apoptosis in a panel of 18 cell lines and primary cultures, with superior mobilizing properties in vivo than those of the standard agent. IQS-01.01RS activity was associated with downregulation of p-AKT, p-ERK1/2 and destabilization of MYC, allowing a synergistic interaction with the bromodomain and extra-terminal domain inhibitor, CPI203. In a xenotransplant model of diffuse large B-cell lymphoma, the combination of IQS-01.01RS and CPI203 decreased tumor burden through MYC and p-AKT downregulation, and enhanced the induction of apoptosis. Thus, our results point out an emerging role of CXCL12-CXCR4 in the pathogenesis of diffuse large B-cell lymphoma and support the simultaneous targeting of CXCR4 and bromodomain proteins as a promising, rationale-based strategy for the treatment of this disease.

6.
J Immunol ; 200(8): 2581-2591, 2018 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-29531171

RESUMO

Mechanisms of immune regulation may control proliferation of aberrant plasma cells (PCs) in patients with monoclonal gammopathy of undetermined significance (MGUS) preventing progression to active multiple myeloma (MM). We hypothesized that CD85j (LILRB1), an inhibitory immune checkpoint for B cell function, may play a role in MM pathogenesis. In this study, we report that patients with active MM had significantly lower levels of CD85j and its ligand S100A9. Decreased CD85j expression could also be detected in the premalignant condition MGUS, suggesting that loss of CD85j may be an early event promoting tumor immune escape. To gain insight into the molecular mechanisms underlying CD85j functions, we next enforced expression of CD85j in human myeloma cell lines by lentiviral transduction. Interestingly, gene expression profiling of CD85j-overexpressing cells revealed a set of downregulated genes with crucial functions in MM pathogenesis. Furthermore, in vitro functional assays demonstrated that CD85j overexpression increased susceptibility to T cell- and NK-mediated killing. Consistently, ligation of CD85j decreased the number of PCs from individuals with MGUS but not from patients with MM. In conclusion, downregulation of inhibitory immune checkpoints on malignant PCs may provide a novel mechanism of immune escape associated with myeloma pathogenesis.


Assuntos
Antígenos CD/imunologia , Receptor B1 de Leucócitos Semelhante a Imunoglobulina/imunologia , Mieloma Múltiplo/imunologia , Plasmócitos/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Linfócitos B , Linhagem Celular Tumoral , Regulação para Baixo/imunologia , Feminino , Humanos , Células Matadoras Naturais/imunologia , Masculino , Pessoa de Meia-Idade , Linfócitos T/imunologia , Transcriptoma/imunologia
7.
Sci Rep ; 7(1): 13946, 2017 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-29066743

RESUMO

Mantle cell lymphoma (MCL) is a hematologic neoplasm characterised by the t(11;14)(q13;q32) translocation leading to aberrant cyclin D1 expression. The cell functions of cyclin D1 depend on its partners and/or subcellular distribution, resulting in different oncogenic properties. We observed the accumulation of cyclin D1 in the cytoplasm of a subset of MCL cell lines and primary cells. In primary cells, this cytoplasmic distribution was correlated with a more frequent blastoid phenotype. We performed immunoprecipitation assays and mass spectrometry on enriched cytosolic fractions from two cell lines. The cyclin D1 interactome was found to include several factors involved in adhesion, migration and invasion. We found that the accumulation of cyclin D1 in the cytoplasm was associated with higher levels of migration and invasiveness. We also showed that MCL cells with high cytoplasmic levels of cyclin D1 engrafted more rapidly into the bone marrow, spleen, and brain in immunodeficient mice. Both migration and invasion processes, both in vivo and in vitro, were counteracted by the exportin 1 inhibitor KPT-330, which retains cyclin D1 in the nucleus. Our data reveal a role of cytoplasmic cyclin D1 in the control of MCL cell migration and invasion, and as a true operator of MCL pathogenesis.


Assuntos
Movimento Celular , Ciclina D1/metabolismo , Citoplasma/metabolismo , Linfoma de Célula do Manto/metabolismo , Linfoma de Célula do Manto/patologia , Transporte Ativo do Núcleo Celular , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Núcleo Celular/metabolismo , Transformação Celular Neoplásica , Citosol/metabolismo , Feminino , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Invasividade Neoplásica , Metástase Neoplásica , Proteômica
9.
Haematologica ; 102(10): 1776-1784, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28751557

RESUMO

Most patients with multiple myeloma treated with current therapies, including immunomodulatory drugs, eventually develop relapsed/refractory disease. Clinical activity of lenalidomide relies on degradation of Ikaros and the consequent reduction in IRF4 expression, both required for myeloma cell survival and involved in the regulation of MYC transcription. Thus, we sought to determine the combinational effect of an MYC-interfering therapy with lenalidomide/dexamethasone. We analyzed the potential therapeutic effect of the combination of the BET bromodomain inhibitor CPI203 with the lenalidomide/dexamethasone regimen in myeloma cell lines. CPI203 exerted a dose-dependent cell growth inhibition in cell lines, indeed in lenalidomide/dexamethasone-resistant cells (median response at 0.5 µM: 65.4%), characterized by G1 cell cycle blockade and a concomitant inhibition of MYC and Ikaros signaling. These effects were potentiated by the addition of lenalidomide/dexamethasone. Results were validated in primary plasma cells from patients with multiple myeloma co-cultured with the mesenchymal stromal cell line stromaNKtert. Consistently, the drug combination evoked a 50% reduction in cell proliferation and correlated with basal Ikaros mRNA expression levels (P=0.04). Finally, in a SCID mouse xenotransplant model of myeloma, addition of CPI203 to lenalidomide/dexamethasone decreased tumor burden, evidenced by a lower glucose uptake and increase in the growth arrest marker GADD45B, with simultaneous downregulation of key transcription factors such as MYC, Ikaros and IRF4. Taken together, our data show that the combination of a BET bromodomain inhibitor with a lenalidomide-based regimen may represent a therapeutic approach to improve the response in relapsed/refractory patients with multiple myeloma, even in cases with suboptimal prior response to immunomodulatory drugs.


Assuntos
Acetamidas/farmacologia , Azepinas/farmacologia , Dexametasona/farmacologia , Fator de Transcrição Ikaros/metabolismo , Mieloma Múltiplo/metabolismo , Mieloma Múltiplo/patologia , Proteínas Proto-Oncogênicas c-myc/metabolismo , Transdução de Sinais/efeitos dos fármacos , Talidomida/análogos & derivados , Idoso , Idoso de 80 Anos ou mais , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Sinergismo Farmacológico , Feminino , Perfilação da Expressão Gênica , Humanos , Lenalidomida , Masculino , Camundongos , Pessoa de Meia-Idade , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/genética , Proteínas/antagonistas & inibidores , Talidomida/farmacologia , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
10.
Clin Cancer Res ; 23(6): 1493-1505, 2017 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-27637890

RESUMO

Purpose: To establish a proof-of-concept for the efficacy of the anti-CD38 antibody daratumumab in the poor prognosis CD38+ chronic lymphocytic leukemia (CLL) subtype.Experimental Design: The mechanism of action of daratumumab was assessed in CLL primary cells and cell lines using peripheral blood mononuclear cells to analyze antibody-dependent cell cytotoxicity (ADCC), murine and human macrophages to study antibody-dependent cell phagocytosis (ADCP), or human serum to analyze complement-dependent cytotoxicity (CDC). The effect of daratumumab on CLL cell migration and adhesion to extracellular matrix was characterized. Daratumumab activity was validated in two in vivo models.Results: Daratumumab demonstrated efficient lysis of patient-derived CLL cells and cell lines by ADCC in vitro and ADCP both in vitro and in vivo whereas exhibited negligible CDC in these cells. To demonstrate the therapeutic effect of daratumumab in CLL, we generated a disseminated CLL mouse model with the CD38+ MEC2 cell line and CLL patient-derived xenografts (CLL-PDX). Daratumumab significantly prolonged overall survival of MEC2 mice, completely eliminated cells from the infiltrated organs, and significantly reduced disease burden in the spleen of CLL-PDX. The effect of daratumumab on patient-derived CLL cell dissemination was demonstrated in vitro by its effect on CXCL12-induced migration and in vivo by interfering with CLL cell homing to spleen in NSG mice. Daratumumab also reduced adhesion of CLL cells to VCAM-1, accompanied by downregulation of the matrix metalloproteinase MMP9.Conclusions: These unique and substantial effects of daratumumab on CLL viability and dissemination support the investigation of its use in a clinical setting of CLL. Clin Cancer Res; 23(6); 1493-505. ©2016 AACR.


Assuntos
ADP-Ribosil Ciclase 1/genética , Anticorpos Monoclonais/administração & dosagem , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Microambiente Tumoral/efeitos dos fármacos , ADP-Ribosil Ciclase 1/imunologia , Animais , Linhagem Celular Tumoral , Citofagocitose/efeitos dos fármacos , Humanos , Leucemia Linfocítica Crônica de Células B/genética , Leucemia Linfocítica Crônica de Células B/imunologia , Leucemia Linfocítica Crônica de Células B/patologia , Metaloproteinase 9 da Matriz/genética , Camundongos , Ensaios Antitumorais Modelo de Xenoenxerto
11.
Oncotarget ; 6(26): 22734-49, 2015 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-26068951

RESUMO

Mutations or deregulated expression of the components of the spliceosome can influence the splicing pattern of several genes and contribute to the development of tumors. In this context, we report that the spliceosome modulator sudemycin induces selective cytotoxicity in primary chronic lymphocytic leukemia (CLL) cells when compared with healthy lymphocytes and tumor cells from other B-lymphoid malignancies, with a slight bias for CLL cases with mutations in spliceosome-RNA processing machinery. Consistently, sudemycin exhibits considerable antitumor activity in NOD/SCID/IL2Rγ-/- (NSG) mice engrafted with primary cells from CLL patients. The antileukemic effect of sudemycin involves the splicing modulation of several target genes important for tumor survival, both in SF3B1-mutated and -unmutated cases. Thus, the apoptosis induced by this compound is related to the alternative splicing switch of MCL1 toward its proapoptotic isoform. Sudemycin also functionally disturbs NF-κB pathway in parallel with the induction of a spliced RELA variant that loses its DNA binding domain. Importantly, we show an enhanced antitumor effect of sudemycin in combination with ibrutinib that might be related to the modulation of the alternative splicing of the inhibitor of Btk (IBTK). In conclusion, we provide first evidence that the spliceosome is a relevant therapeutic target in CLL, supporting the use of splicing modulators alone or in combination with ibrutinib as a promising approach for the treatment of CLL patients.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Cicloexilaminas/farmacologia , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Pirazóis/farmacologia , Pirimidinas/farmacologia , Compostos de Espiro/farmacologia , Adulto , Idoso , Animais , Cicloexilaminas/administração & dosagem , Sinergismo Farmacológico , Feminino , Humanos , Leucemia Linfocítica Crônica de Células B/sangue , Leucemia Linfocítica Crônica de Células B/genética , Leucemia Linfocítica Crônica de Células B/patologia , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Camundongos Transgênicos , Pessoa de Meia-Idade , Mutação , Pirazóis/administração & dosagem , Pirimidinas/administração & dosagem , Processamento de RNA , Compostos de Espiro/administração & dosagem , Spliceossomos/efeitos dos fármacos , Spliceossomos/genética , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
12.
Oncotarget ; 6(25): 21159-72, 2015 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-26110568

RESUMO

Acadesine is a nucleoside analogue with known activity against B-cell malignancies. Herein, we showed that in mantle cell lymphoma (MCL) cells acadesine induced caspase-dependent apoptosis through turning on the mitochondrial apoptotic machinery. At the molecular level, the compound triggered the activation of the AMPK pathway, consequently modulating known downstream targets, such as mTOR and the cell motility-related vasodilator-stimulated phosphoprotein (VASP). VASP phosphorylation by acadesine was concomitant with a blockade of CXCL12-induced migration. The inhibition of the mTOR cascade by acadesine, committed MCL cells to enter in apoptosis by a translational downregulation of the antiapoptotic Mcl-1 protein. In contrast, Bcl-2 protein levels were unaffected by acadesine and MCL samples expressing high levels of Bcl-2 tended to have a reduced response to the drug. Targeting Bcl-2 with the selective BH3-mimetic agent ABT-199 sensitized Bcl-2high MCL cells to acadesine. This effect was validated in vivo, where the combination of both agents displayed a more marked inhibition of tumor outgrowth than each drug alone. These findings support the notions that antiapoptotic proteins of the Bcl-2 family regulate MCL cell sensitivity to acadesine and that the combination of this agent with Bcl-2 inhibitors might be an interesting therapeutic option to treat MCL patients.


Assuntos
Aminoimidazol Carboxamida/análogos & derivados , Compostos Bicíclicos Heterocíclicos com Pontes/administração & dosagem , Moléculas de Adesão Celular/metabolismo , Linfoma de Célula do Manto/metabolismo , Proteínas dos Microfilamentos/metabolismo , Fosfoproteínas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Ribonucleosídeos/administração & dosagem , Sulfonamidas/administração & dosagem , Actinas/química , Aminoimidazol Carboxamida/administração & dosagem , Animais , Apoptose , Linhagem Celular Tumoral/efeitos dos fármacos , Movimento Celular , Quimiocina CXCL12/metabolismo , Quimiotaxia , Regulação para Baixo , Resistencia a Medicamentos Antineoplásicos , Sinergismo Farmacológico , Feminino , Citometria de Fluxo , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Camundongos SCID , Proteína de Sequência 1 de Leucemia de Células Mieloides/metabolismo , Transplante de Neoplasias
13.
Clin Cancer Res ; 20(13): 3458-71, 2014 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-24799524

RESUMO

PURPOSE: To uncover the signaling pathways underlying follicular lymphoma-follicular dendritic cells (FL-FDC) cross-talk and its validation as new targets for therapy. EXPERIMENTAL DESIGN: FL primary cells and cell lines were cocultured in the presence or absence of FDC. After 24 and 48 hours, RNA was isolated from FL cells and subjected to gene expression profiling (GEP) and data meta-analysis using DAVID and GSEA softwares. Blockade of PI3K pathway by the pan-PI3K inhibitor BKM120 (buparlisib; Novartis Pharmaceutical Corporation) and the effect of PI3K inhibition on FL-FDC cross-talk were analyzed by means of ELISA, RT-PCR, human umbilical vein endothelial cell tube formation, adhesion and migration assays, Western blot, and in vivo studies in mouse FL xenografts. RESULTS: GEP of FL-FDC cocultures yields a marked modulation of FL transcriptome by FDC. Pathway assignment by DAVID and GSEA software uncovered an overrepresentation of genes related to angiogenesis, cell adhesion, migration, and serum-response factors. We demonstrate that the addition of the pan-PI3K inhibitor BKM120 to the cocultures was able to downregulate the expression and secretion of proangiogenic factors derived from FL-FDC cocultures, reducing in vitro and in vivo angiogenesis. Moreover, BKM120 efficiently counteracts FDC-mediated cell adhesion and impedes signaling and migration induced by the chemokine CXCL12. BKM120 inhibits both constitutive PI3K/AKT pathway and FDC- or CXCL12-induced PI3K/AKT pathway, hampers FDC survival signaling, and reduces cell proliferation of FL cells in vitro and in mouse xenografts. CONCLUSIONS: These data support the use of BKM120 in FL therapy to counteract microenvironment-related survival signaling in FL cells.


Assuntos
Aminopiridinas/farmacologia , Células Dendríticas Foliculares/imunologia , Células Dendríticas Foliculares/metabolismo , Linfoma Folicular/imunologia , Linfoma Folicular/metabolismo , Morfolinas/farmacologia , Animais , Adesão Celular/imunologia , Comunicação Celular/efeitos dos fármacos , Comunicação Celular/imunologia , Linhagem Celular Tumoral , Movimento Celular/imunologia , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/imunologia , Quimiocina CXCL12/metabolismo , Análise por Conglomerados , Modelos Animais de Doenças , Matriz Extracelular/metabolismo , Perfilação da Expressão Gênica , Humanos , Linfoma Folicular/genética , Linfoma Folicular/patologia , Camundongos , Neovascularização Patológica/genética , Neovascularização Patológica/imunologia , Receptores CXCR4/metabolismo , Transdução de Sinais/efeitos dos fármacos , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
14.
PLoS One ; 8(11): e79364, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24223931

RESUMO

Regulation of eukaryotic cell cycle progression requires sequential activation and inactivation of cyclin-dependent kinases (CDKs). Activation of the cyclin B-cdc2 kinase complex is a pivotal step in mitotic initiation and the tyrosine kinase Wee1 is a key regulator of cell cycle sequence during G2/M transition and inhibits mitotic entry by phosphorylating the inhibitory tyrosine 15 on the cdc2 M-phase-inducing kinase. Wee1 degradation is essential for the exit from the G2 phase. In trypanosomatids, little is known about the genes that regulate cyclin B-cdc2 complexes at the G2/M transition of their cell cycle. Although canonical tyrosine kinases are absent in the genome of trypanosomatids, phosphorylation on protein tyrosine residues has been reported in Trypanosoma brucei. Here, we characterized a Wee1-like protein kinase gene from T. brucei. Expression of TbWee1 in a Schizosaccharomyces pombe strain null for Wee1 inhibited cell division and caused cell elongation. This demonstrates the lengthening of G2, which provided cells with extra time to grow before dividing. The Wee1-like protein kinase was expressed in the procyclic and bloodstream proliferative slender forms of T. brucei and the role of Wee1 in cell cycle progression was analyzed by generating RNA interference cell lines. In the procyclic form of T. brucei, the knock-down of TbWee1 expression by RNAi led to inhibition of parasite growth. Abnormal phenotypes showing an increase in the percentage of cells with 1N0K, 0N1K and 2N1K were observed in these RNAi cell lines. Using parasites with a synchronized cell cycle, we demonstrated that TbWee1 is linked to the G2/M phase. We also showed that TbWee1 is an essential gene necessary for proper cell cycle progression and parasite growth in T. brucei. Our results provide evidence for the existence of a functional Wee1 in T. brucei with a potential role in cell division at G2/M.


Assuntos
Proteínas Tirosina Quinases/genética , Trypanosoma brucei brucei/citologia , Trypanosoma brucei brucei/genética , Sequência de Aminoácidos , Divisão Celular , Bases de Dados Genéticas , Regulação para Baixo , Fase G2 , Genoma de Protozoário/genética , Dados de Sequência Molecular , Fenótipo , Fosforilação , Proteínas Tirosina Quinases/química , Proteínas Tirosina Quinases/metabolismo , Schizosaccharomyces/genética , Homologia de Sequência do Ácido Nucleico , Análise de Sobrevida , Trypanosoma brucei brucei/enzimologia , Trypanosoma brucei brucei/crescimento & desenvolvimento
15.
J Invertebr Pathol ; 106(2): 255-62, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21047512

RESUMO

Dione juno and Agraulis vanillae are very common butterflies in natural gardens in South America, and also bred worldwide. In addition, larvae of these butterflies are considered as pests in crops of Passiflora spp. For these reasons, it is important to identify and describe pathogens of these species, both for preservation purposes and for use in pest control. Baculoviridae is a family of insect viruses that predominantly infect species of Lepidoptera and are used as bioinsecticides. Larvae of D. juno and A. vanillae exhibiting symptoms of baculovirus infection were examined for the presence of baculoviruses by PCR and transmission electron microscopy. Degenerate primers were designed and used to amplify partial sequences from the baculovirus p74, cathepsin, and chitinase genes, along with previously designed primers for amplification of lef-8, lef-9, and polh. Sequence data from these six loci, along with ultrastructural observations on occlusion bodies isolated from the larvae, confirmed that the larvae were infected with nucleopolyhedroviruses from genus Alphabaculovirus. The NPVs from the two different larval hosts appear to be variants of the same, previously undescribed baculovirus species. Phylogenetic analysis of the sequence data placed these NPVs in Alphabaculovirus group I/clade 1b.


Assuntos
Borboletas/virologia , /isolamento & purificação , Animais , DNA Viral/genética , Corpos de Inclusão/virologia , Larva/virologia , Controle Biológico de Vetores , América do Sul
16.
Plant Biotechnol J ; 9(2): 136-50, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20497372

RESUMO

It is expected that the next generation of biotech crops displaying enhanced quality traits with benefits to both farmers and consumers will have a better acceptance than first generation biotech crops and will improve public perception of genetic engineering. This will only be true if they are proven to be as safe as traditionally bred crops. In contrast with the first generation of biotech crops where only a single trait is modified, the next generation of biotech crops will add a new level of complexity inherent to the mechanisms underlying their output traits. In this study, a comprehensive evaluation of the comparative safety approach on a quality-improved biotech crop with metabolic modifications is presented. Three genetically engineered potato lines with silenced polyphenol oxidase (Ppo) transcripts and reduced tuber browning were characterized at both physiological and molecular levels and showed to be equivalent to wild-type (WT) plants when yield-associated traits and photosynthesis were evaluated. Analysis of the primary metabolism revealed several unintended metabolic modifications in the engineered tubers, providing evidence for potential compositional inequivalence between transgenic lines and WT controls. The silencing construct sequence was in silico analysed for potential allergenic cross-reactivity, and no similarities to known allergenic proteins were identified. Moreover, in vivo intake safety evaluation showed no adverse effects in physiological parameters. Taken together, these results provide the first evidence supporting that the safety of next generation biotech crops can be properly assessed following the current evaluation criterion, even if the transgenic and WT crops are not substantially equivalent.


Assuntos
Inocuidade dos Alimentos , Engenharia Genética , Solanum tuberosum/genética , Alérgenos/análise , Animais , Catecol Oxidase/genética , Biologia Computacional , Feminino , Inativação Gênica , Camundongos , Camundongos Endogâmicos BALB C , Fotossíntese
17.
PLoS One ; 5(11): e14030, 2010 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-21103333

RESUMO

Sensory analysis studies are critical in the development of quality enhanced crops, and may be an important component in the public acceptance of genetically modified foods. It has recently been established that odor preferences are shared between humans and mice, suggesting that odor exploration behavior in mice may be used to predict the effect of odors in humans. We have previously found that mice fed diets supplemented with engineered nonbrowning potatoes (-PPO) consumed more potato than mice fed diets supplemented with wild-type potatoes (WT). This prompted us to explore a possible role of potato odor in mice preference for nonbrowning potatoes. Taking advantage of two well established neuroscience paradigms, the "open field test" and the "nose-poking preference test", we performed experiments where mice exploration behavior was monitored in preference assays on the basis of olfaction alone. No obvious preference was observed towards -PPO or WT lines when fresh potato samples were tested. However, when oxidized samples were tested, mice consistently investigated -PPO potatoes more times and for longer periods than WT potatoes. Congruently, humans discriminated WT from -PPO samples with a considerably better performance when oxidized samples were tested than when fresh samples were tested in blind olfactory experiments. Notably, even though participants ranked all samples with an intermediate level of pleasantness, there was a general consensus that the -PPO samples had a more intense odor and also evoked the sense-impression of a familiar vegetable more often than the WT samples. Taken together, these findings suggest that our previous observations might be influenced, at least in part, by differential odors that are accentuated among the lines once oxidative deterioration takes place. Additionally, our results suggest that nonbrowning potatoes, in addition to their extended shelf life, maintain their odor quality for longer periods of time than WT potatoes. To our knowledge this is the first report on the use of an animal model applied to the sensory analysis of a transgenic crop.


Assuntos
Odorantes/análise , Tubérculos/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Solanum tuberosum/metabolismo , Análise de Variância , Animais , Catecol Oxidase/genética , Catecol Oxidase/metabolismo , Cor , Comportamento Exploratório/fisiologia , Feminino , Análise de Alimentos , Preferências Alimentares/fisiologia , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Percepção Olfatória/fisiologia , Oxirredução , Tubérculos/química , Tubérculos/genética , Plantas Geneticamente Modificadas/genética , Olfato/fisiologia , Solanum tuberosum/genética
18.
BMC Biotechnol ; 10: 68, 2010 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-20843354

RESUMO

BACKGROUND: Anticarsia gemmatalis is a pest in South America's soybean crops, which could be controlled by the Multinucleopolyhedrovirus of A. gemmatalis (AgMNPV). Currently, its commercial production is based on infected larvae. However, the possibility of using modified baculoviruses in Integrated Pest Management programs has stimulated an interest to develop alternative multiplication processes. This study evaluated the AgMNPV production in UFL-Ag-286 cells previously deprived Fetal Bovine Serum. RESULTS: Culture media containing 1% FBS during the previous 48 hours achieved a synchronized condition where 90% of cells were found in G0/G1 stage, showing the presence of non-filamentous actin. All characteristics were estimated from cellular viability tests, cell actin detection trials and flow cytometer cell cycle analysis. AgMNPV production was tested by transcript studies and budded viruses (BVs) and occlusion bodies (OBs) yield quantitation. Results showed that the productivity in FBS deprived cells was 9.8 times more in BVs and 3.8 times more in OBs with respect to non-treated cells. CONCLUSIONS: UFL-Ag-286 cells previously deprived in FBS shown to be a better host for AgMNPV propagation, increasing the useful for both in vitro bioinsecticide production and applications such as recombinant protein expression or gene delivery.


Assuntos
Meios de Cultura/química , Cultura de Vírus/métodos , Animais , Bovinos , Linhagem Celular , Meios de Cultura Livres de Soro , Mariposas/virologia , Soro/química
19.
J Urol ; 182(2): 749-55, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19539312

RESUMO

PURPOSE: We developed and characterized an orthotopic invasive bladder tumor model. MATERIAL AND METHODS: The MB49-I invasive bladder tumor cell line was obtained after 13 consecutive in vivo passages of primary tumor obtained by subcutaneous inoculation of MB49 bladder tumor cells in C57Bl/6J male mice. RESULTS: MB49-I tumor local invasiveness, tumor weight and spontaneous metastatic capacity were higher than in MB49 tumors. In MB49-I bladder tumors increased vimentin was observed, suggesting epithelial mesenchymal transition. In vitro the MB49-I cell line showed higher invasive properties associated with an increase in cathepsin B, metalloproteinase 9 and urokinase-type plasminogen activator proteolytic activities. Orthotopic bladder tumors induced by electrocautery of the bladder wall and subsequent instillation of MB49 and MB49-I bladder cancer cells generated superficial and invasive bladder tumors, respectively. CONCLUSIONS: The new murine bladder model described resembles human bladder disease, making it a useful tool for studying the molecular mechanisms of tumor progression and metastasis, and assaying antimetastatic and anti-invasive agents.


Assuntos
Catepsina B/fisiologia , Modelos Animais de Doenças , Neoplasias da Bexiga Urinária/patologia , Animais , Linhagem Celular Tumoral , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Invasividade Neoplásica
20.
Breast Cancer Res Treat ; 116(2): 247-55, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18622696

RESUMO

Currently, to our knowledge, there are no continuous cell lines derived from estrogen dependent, tamoxifen sensitive spontaneous mouse mammary carcinomas. We describe here the establishment and characterization of a cell line derived from the M05 mouse mammary tumor, LM05-Mix, composed of both an epithelial and a fibroblastic component. From it the respective epithelial LM05-E and fibroblastic LM05-F cell lines were generated by limiting dilution. Immunofluorescence studies confirmed that the epithelial cells were positive for E-cadherin, cytokeratins and vimentin whereas the fibroblastic cells were negative for the epithelial markers and positive for alpha-smooth muscle actin and vimentin. Both cell types expressed estrogen and progesterone receptors, although only the epithelial LM05-E cells were stimulated by estradiol and inhibited by tamoxifen. In the bicellular LM05-Mix cell line estradiol proved to stimulate cell proliferation whereas the response to tamoxifen was dependent on confluency and the degree of epithelial-fibroblastic interactions. The presence of membrane estrogen receptors in both cell types was suggested by the achievement of non-genomic responses to short treatments with estradiol, leading to the phosphorylation of ERK1/2. Finally, cytogenetic studies suggest that these two cell types represent independent cell populations within the tumor and would not be the result of an epithelial-mesenchymal transition. This model presents itself as a valuable alternative for the study of estrogen responsiveness and tamoxifen resistance in the context of epithelial-stromal interactions.


Assuntos
Linhagem Celular Tumoral/citologia , Células Epiteliais/citologia , Fibroblastos/citologia , Neoplasias Mamárias Experimentais/metabolismo , Camundongos , Animais , Apoptose/fisiologia , Western Blotting , Linhagem Celular Tumoral/metabolismo , Resistencia a Medicamentos Antineoplásicos/fisiologia , Células Epiteliais/metabolismo , Estradiol/farmacologia , Estrogênios/farmacologia , Feminino , Fibroblastos/metabolismo , Imunofluorescência , Hibridização in Situ Fluorescente , Marcação In Situ das Extremidades Cortadas , Técnicas In Vitro , Neoplasias Mamárias Experimentais/genética , Receptores Estrogênicos/metabolismo , Receptores de Progesterona/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Moduladores Seletivos de Receptor Estrogênico/farmacologia , Tamoxifeno/farmacologia , Translocação Genética
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