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1.
ESMO Open ; 6(4): 100172, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34242968

RESUMO

BACKGROUND: More than 80% of anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma (ALCL) patients harbor the (nucleophosmin) NPM1-ALK fusion gene t(2;5) chromosomal translocation. We evaluated the preclinical and clinical efficacy of ceritinib treatment of this aggressive lymphoma. MATERIALS AND METHODS: We studied the effects of ceritinib treatment in NPM1-ALK+ T-cell lymphoma cell lines in vitro and on tumor size and survival advantage in vivo utilizing tumor xenografts. We treated an NPM1-ALK+ ALCL patient with ceritinib. We reviewed all hematologic malignancies profiled by a large hybrid-capture next-generation sequencing (NGS)-based comprehensive genomic profiling assay for ALK alterations. RESULTS: In our in vitro experiments, ceritinib inhibited constitutive activation of the fusion kinase NPM1-ALK and downstream effector molecules STAT3, AKT, and ERK1/2, and induced apoptosis of these lymphoma cell lines. Cell cycle analysis following ceritinib treatment showed G0/G1 arrest with a concomitant decrease in the percentage of cells in S and G2/M phases. Further, treatment with ceritinib in the NPM1-ALK+ ALCL xenograft model resulted in tumor regression and improved survival. Of 19 272 patients with hematopoietic diseases sequenced, 58 patients (0.30%) harbored ALK fusions that include histiocytic disorders, multiple myeloma, B-cell neoplasms, Castleman's disease, and juvenile xanthogranuloma. A multiple relapsed NPM1-ALK+ ALCL patient treated with ceritinib achieved complete remission with ongoing clinical benefit to date, 5 years after initiation of therapy. CONCLUSIONS: This ceritinib translational study in NPM1-ALK+ ALCL provides a strong rationale for a prospective study of ceritinib in ALK+ T-cell lymphomas and other ALK+ hematologic malignancies.


Assuntos
Linfoma Anaplásico de Células Grandes , Quinase do Linfoma Anaplásico/genética , Humanos , Linfoma Anaplásico de Células Grandes/tratamento farmacológico , Linfoma Anaplásico de Células Grandes/genética , Nucleofosmina , Estudos Prospectivos , Pirimidinas , Receptores Proteína Tirosina Quinases/genética , Sulfonas
2.
Biochim Biophys Acta Mol Basis Dis ; 1866(5): 165648, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-31899295

RESUMO

The nuclear genome drives differences in immune cell populations and differentiation potentials, in part regulated by changes in metabolism. Despite this connection, the role of mitochondrial DNA (mtDNA) polymorphisms (SNP) in this process has not been examined. Using mitochondrial nuclear exchange (MNX) mice, we and others have shown that mtDNA strongly influences varying aspects of cell biology and disease. Based upon an established connection between mitochondria and immune cell polarization, we hypothesized that mtDNA SNP alter immune cell development, trafficking, and/or differentiation. Innate and adaptive immune cell populations were isolated and characterizated from the peritoneum and spleen. While most differences between mouse strains are regulated by nuclear DNA (nDNA), there are selective changes that are mediated by mtDNA differences (e.g., macrophage (CD11c) differentiation), These findings highlight how nuclear-mitochondrial crosstalk may alter pathology and physiology via regulation of specific components of the immune system.


Assuntos
Núcleo Celular/genética , Genoma Mitocondrial/imunologia , Linfócitos/imunologia , Macrófagos Peritoneais/imunologia , Locos de Características Quantitativas/imunologia , Imunidade Adaptativa/genética , Animais , Antígenos CD11/metabolismo , Diferenciação Celular/genética , Diferenciação Celular/imunologia , DNA Mitocondrial/genética , Feminino , Genoma Mitocondrial/genética , Imunidade Inata/genética , Linfócitos/metabolismo , Macrófagos Peritoneais/metabolismo , Masculino , Camundongos , Modelos Animais , Polimorfismo de Nucleotídeo Único
3.
Rev Sci Instrum ; 89(10): 10D123, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30399676

RESUMO

In the self-magnetic-pinch diode, the electron beam, produced through explosive field emission, focuses on the anode surface due to its own magnetic field. This process results in dense plasma formation on the anode surface, consisting primarily of hydrocarbons. Direct measurements of the beam's current profile are necessary in order to understand the pinch dynamics and to determine x-ray source sizes, which should be minimized in radiographic applications. In this paper, the analysis of the C IV doublet (580.1 and 581.2 nm) line shapes will be discussed. The technique yields estimates of the electron density and electron temperature profiles, and the method can be highly beneficial in providing the current density distribution in such diodes.

4.
Adv Cancer Res ; 132: 111-37, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27613131

RESUMO

Metastasis requires coordinated expression of multiple genetic cassettes, often via epigenetic regulation of gene transcription. BRMS1 blocks metastasis, but not orthotopic tumor growth in multiple tumor types, presumably via SIN3 chromatin remodeling complexes. Although there is an abundance of strong data supporting BRMS1 as a metastasis suppressor, the mechanistic data directly connecting molecular pathways with inhibition of particular steps in metastasis are not well defined. In this review, the data for BRMS1-mediated metastasis suppression in multiple tumor types are discussed along with the steps in metastasis that are inhibited.


Assuntos
Regulação Neoplásica da Expressão Gênica , Neoplasias/metabolismo , Neoplasias/patologia , Proteínas Repressoras/metabolismo , Humanos , Metástase Neoplásica
5.
Br J Cancer ; 110(8): 2054-62, 2014 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-24642624

RESUMO

BACKGROUND: Breast-cancer metastasis suppressor 1 (BRMS1) gene encodes for a predominantly nuclear protein that differentially regulates the expression of multiple genes, leading to suppression of metastasis without blocking orthotropic tumour growth. The aim of the present study was to evaluate for the first time the prognostic significance of BRMS1 promoter methylation in cell-free DNA (cfDNA) circulating in plasma of non-small cell lung cancer (NSCLC) patients. Towards this goal, we examined the methylation status of BRMS1 promoter in NSCLC tissues, matched adjacent non-cancerous tissues and corresponding cfDNA as well as in an independent cohort of patients with advanced NSCLC and healthy individuals. METHODS: Methylation of BRMS1 promoter was examined in 57 NSCLC tumours and adjacent non-cancerous tissues, in cfDNA isolated from 48 corresponding plasma samples, in cfDNA isolated from plasma of 74 patients with advanced NSCLC and 24 healthy individuals. RESULTS: The BRMS1 promoter was highly methylated both in operable NSCLC primary tissues (59.6%) and in corresponding cfDNA (47.9%) but not in cfDNA from healthy individuals (0%), while it was also highly methylated in cfDNA from advanced NSCLC patients (63.5%). In operable NSCLC, Kaplan-Meier estimates were significantly different in favour of patients with non-methylated BRMS1 promoter in cfDNA, concerning both disease-free interval (DFI) (P=0.048) and overall survival (OS) (P=0.007). In advanced NSCLC, OS was significantly different in favour of patients with non-methylated BRMS1 promoter in their cfDNA (P=0.003). Multivariate analysis confirmed that BRMS1 promoter methylation has a statistical significant influence both on operable NSCLC patients' DFI time and OS and on advanced NSCLC patients' PFS and OS. CONCLUSIONS: Methylation of BRMS1 promoter in cfDNA isolated from plasma of NSCLC patients provides important prognostic information and merits to be further evaluated as a circulating tumour biomarker.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Metilação de DNA/genética , Proteínas de Neoplasias/sangue , Adulto , Idoso , Biomarcadores Tumorais/sangue , Carcinoma Pulmonar de Células não Pequenas/sangue , Carcinoma Pulmonar de Células não Pequenas/patologia , Ilhas de CpG , DNA de Neoplasias/sangue , DNA de Neoplasias/genética , DNA de Neoplasias/isolamento & purificação , Intervalo Livre de Doença , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/isolamento & purificação , Estadiamento de Neoplasias , Células Neoplásicas Circulantes , Regiões Promotoras Genéticas , Proteínas Repressoras
6.
Oncogene ; 32(4): 462-70, 2013 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-22370640

RESUMO

Murine double minute (MDM2) binding protein (MTBP) has been implicated in cancer progression. Here, we demonstrate one mechanism by which MTBP inhibits cancer metastasis. Overexpression of MTBP in human osteosarcoma cell lines lacking wild-type p53 did not alter primary tumor growth in mice, but significantly inhibited metastases. MTBP downregulation increased the migratory potential of MDM2(-/-)p53(-/-) mouse embryonic fibroblasts, suggesting that MTBP inhibited cell migration independently of the Mdm2-p53 pathway. Co-immunoprecipitation and mass spectrometric analysis identified alpha-actinin-4 (ACTN4) as an MTBP-interacting protein. Endogenous MTBP interacted with and partially colocalized with ACTN4. MTBP overexpression inhibited cell migration and filopodia formation mediated by ACTN4. Increased cell migration by MTBP downregulation was inhibited by concomitant downregulation of ACTN4. MTBP also inhibited ACTN4-mediated F-actin bundling. We furthermore demonstrated that nuclear localization of MTBP was dispensable for inhibiting ACTN4-mediated cell migration and filopodia formation. Thus, MTBP suppresses cell migration, at least partially, by inhibiting ACTN4 function. Our study not only provides a mechanism of metastasis suppression by MTBP, but also suggests MTBP as a potential biomarker for cancer progression.


Assuntos
Actinina/antagonistas & inibidores , Actinina/metabolismo , Proteínas de Transporte/metabolismo , Movimento Celular/fisiologia , Pseudópodes/metabolismo , Actinina/genética , Actinas/genética , Actinas/metabolismo , Animais , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Neoplasias Ósseas/genética , Neoplasias Ósseas/metabolismo , Neoplasias Ósseas/patologia , Proteínas de Transporte/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Núcleo Celular/genética , Núcleo Celular/metabolismo , Progressão da Doença , Regulação para Baixo , Humanos , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Metástase Neoplásica , Osteossarcoma/genética , Osteossarcoma/metabolismo , Osteossarcoma/patologia , Proteínas Proto-Oncogênicas c-mdm2/genética , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Pseudópodes/genética , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
7.
Phys Rev Lett ; 109(22): 225002, 2012 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-23368130

RESUMO

This work describes the scientific basis and associated simulation results for the magnetization of an unmagnetized plasma via beat-wave current drive. Two-dimensional electromagnetic particle-in-cell simulations have been performed for a variety of angles between the injected waves to demonstrate beat-wave generation in agreement with theoretical predictions of the beat-wave wave vector and saturation time, revealing new 2D effects. The simulations clearly demonstrate electron acceleration by the beat waves and resultant current drive and magnetic field generation. The basic process depends entirely on the angle between the parent waves and the ratio of the beat-wave phase velocity to the electron thermal velocity. The wave to magnetic energy conversion efficiency of the cases examined is as high as 0.2%. The technique could enable novel plasma experiments in which the use of magnetic coils is infeasible.

8.
Oncogene ; 30(8): 896-906, 2011 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-20935672

RESUMO

Breast cancer metastasis suppressor 1 (BRMS1) has been reported to suppress metastasis without significantly affecting tumorigenicity in breast cancer and ovarian cancer. To investigate the role of BRMS1 in human melanoma progression and prognosis, we established tissue microarray and BRMS1 expression was evaluated by immunohistochemistry in 41 dysplastic nevi, 90 primary melanomas and 47 melanoma metastases. We found that BRMS1 expression was significantly decreased in metastatic melanoma compared with primary melanoma or dysplastic nevi (P=0.021 and 0.001, respectively, χ(2) test). In addition, reduced BRMS1 staining was significantly correlated with American Joint Committee on Cancer stages (P=0.011, χ(2) test), but not associated with tumor thickness, tumor ulceration and other clinicopathological parameters. Furthermore, BRMS1 expression was significantly correlated with disease-specific 5-year survival of melanoma patients (P=0.007, log-rank test). Multivariate Cox regression analysis revealed that BRMS1 staining was an independent prognostic factor for melanoma patients (relative risk=0.51; confidence interval=0.29-0.91; P=0.022). Moreover, we demonstrated that BRMS1 overexpression inhibited endothelial cell growth and tube formation ability by suppressing NF-κB activity and IL-6 expression in vitro. We also showed that knockdown of BRMS1 increased IL-6 expression and promoted endothelial cell growth and tube formation. In addition, our data revealed that the BRMS1-mediated IL-6 expression is dependent on NF-κB. Strikingly, our in vivo studies using nude mice confirmed that BRMS1 inhibited blood vessel formation and the recruitment of CD31-positive cells in matrigel plugs. Taken together, BRMS1 expression was decreased in metastatic melanomas, which resulted in deficient suppression of angiogenesis and contributed to melanoma progression. BRMS1 may serve an important prognostic marker and therapeutic target for melanoma patients.


Assuntos
Biomarcadores Tumorais/análise , Melanoma/metabolismo , Proteínas de Neoplasias/biossíntese , Neovascularização Patológica/metabolismo , Neoplasias Cutâneas/metabolismo , Animais , Western Blotting , Ensaio de Desvio de Mobilidade Eletroforética , Ensaio de Imunoadsorção Enzimática , Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Interleucina-6/metabolismo , Estimativa de Kaplan-Meier , Melanoma/irrigação sanguínea , Melanoma/genética , Melanoma/patologia , Camundongos , Camundongos Nus , NF-kappa B/metabolismo , Proteínas de Neoplasias/genética , Estadiamento de Neoplasias , Neovascularização Patológica/genética , Neovascularização Patológica/patologia , Prognóstico , Modelos de Riscos Proporcionais , Proteínas Repressoras , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Neoplasias Cutâneas/irrigação sanguínea , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/patologia , Análise Serial de Tecidos
9.
Phys Rev Lett ; 105(1): 015002, 2010 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-20867454

RESUMO

We describe ab initio, self-consistent, 3D, fully electromagnetic numerical simulations of current drive and field-reversed-configuration plasma formation by odd-parity rotating magnetic fields (RMF{o}). Magnetic-separatrix formation and field reversal are attained from an initial mirror configuration. A population of punctuated-betatron-orbit electrons, generated by the RMF{o}, carries the majority of the field-normal azimuthal electrical current responsible for field reversal. Appreciable current and plasma pressure exist outside the magnetic separatrix whose shape is modulated by the RMF{o} phase. The predicted plasma density and electron energy distribution compare favorably with RMF{o} experiments.

10.
Phys Rev Lett ; 103(25): 255002, 2009 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-20366259

RESUMO

We present the first fully kinetic, collisional, and electromagnetic simulations of the complete time evolution of a deuterium gas puff z pinch. Recent experiments with 15-MA current pinches have suggested that the dominant neutron-production mechanism is thermonuclear. We observe distinct differences between the kinetic and magnetohydrodynamic simulations in the pinch evolution with the kinetic simulations producing both thermonuclear and beam-target neutrons. The kinetic approach demonstrated in this Letter represents a viable alternative for performing future plasma physics calculations.

11.
Br J Dermatol ; 157(4): 780-2, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17711523

RESUMO

BACKGROUND: As distinct from intravascular dissemination, extravascular migratory metastasis (EVMM) has been described as a potential additional mechanism of melanoma spread in which tumour cells migrate along the external surfaces of vessels. Recent experimental studies strongly suggest a correlation of angiotropism of melanoma cells with EVMM. Angiotropic melanoma cells are linked to the endothelium by an amorphous matrix confirmed to contain laminin. OBJECTIVES: To investigate whether laminin plays a role in this extravascular mechanism of tumour spread. METHODS: We tested the effect of the C16 laminin peptide on melanoma spread in a shell-less chick chorioallantoic membrane model. RESULTS: After 3 days, green fluorescent protein-expressing melanoma cells were observed spreading along or in the immediate proximity of vessels. The C16 laminin peptide significantly lengthened the distance of extravascular, angiotropic migration of melanoma cells. Histopathology confirmed the angiotropism of melanoma cells without intravasation, compatible with that observed with human angiotropic melanoma. CONCLUSIONS: The results of this study suggest that the C16 laminin gamma1 chain peptide has angiotropic, extravascular migration-promoting activity on human melanoma cells, and might be a molecular target for preventing melanoma metastasis.


Assuntos
Laminina/farmacologia , Melanoma Experimental/patologia , Animais , Movimento Celular/efeitos dos fármacos , Embrião de Galinha , Membrana Corioalantoide/patologia , Humanos , Melanoma Experimental/secundário , Microcirculação/patologia , Modelos Biológicos , Invasividade Neoplásica , Fragmentos de Peptídeos/farmacologia
12.
J Res Natl Inst Stand Technol ; 111(1): 41-55, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-27274916

RESUMO

The phase transformation between the orthorhombic and tetragonal structures of six high-T c superconductors, Ba2RCu3O7- δ , where R = Nd, Sm, Gd, Y, Ho, and Er, and δ = 0 to 1, has been investigated using techniques of x-ray diffraction, differential thermal analysis/thermogravimetric analysis (DTA/TGA) and electron diffraction. The transformation from the oxygen-rich orthorhombic phase to the oxygen-deficient tetragonal phase involves two orthorhombic phases. A superlattice cell caused by oxygen ordering, with a' = 2a, was observed for materials with smaller ionic radius (Y, Ho, and Er). For the larger lanthanide samples (Nd, Sm, and Gd), the a' = 2a type superlattice cell was not observed. The structural phase transition temperatures, oxygen stoichiometry and characteristics of the T c plateaus appear to correlate with the ionic radius, which varies based on the number of f electrons. Lanthanide elements with a smaller ionic radius stabilize the orthorhombic phase to higher temperatures and lower oxygen content. Also, the superconducting temperature is less sensitive to the oxygen content for materials with smaller ionic radius. The trend of dependence of the phase transformation temperature on ionic radius across the lanthanide series can be explained using a quasi-chemical approximation (QCA) whereby the strain effect plays an important role on the order-disorder transition due to the effect of oxygen content on the CuO chain sites.

13.
Phys Rev Lett ; 95(23): 234801, 2005 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-16384309

RESUMO

Longitudinal compression of a velocity-tailored, intense neutralized beam at 300 keV, 25 mA has been demonstrated. The compression takes place in a 1-2 m drift section filled with plasma to provide space-charge neutralization. An induction cell produces a head-to-tail velocity ramp that longitudinally compresses the neutralized beam, enhancing the beam peak current by a factor of 50 and producing a pulse duration of about 3 ns. This measurement has been confirmed independently with two different diagnostic systems.

14.
Phys Rev Lett ; 94(5): 055001, 2005 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-15783653

RESUMO

We report on unique particle-in-cell simulations to understand the relativistic electron beam thermalization and subsequent heating of highly compressed plasmas. The simulations yield heated core parameters in good agreement with the GEKKO-PW experimental measurements, given reasonable assumptions of laser-to-electron coupling efficiency and the distribution function of laser-produced electrons. The classical range of the hot electrons exceeds the mass density-core diameter product rhoL by a factor of several. Anomalous stopping appears to be present and is created by the growth and saturation of an electromagnetic filamentation mode that generates a strong back-EMF impeding hot electrons on the injection side of the density maxima.

17.
Clin Exp Metastasis ; 19(5): 369-76, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12198764

RESUMO

Surgical resection of lung tissue is employed clinically as a therapy for pulmonary metastases; however, local cancer recurrence is a frequent post-surgical complication. In a variety of small mammals, left pneumonectomy (PNX) initiates rapid compensatory hyperplasia of the remnant lung lobes restoring normal tissue mass, structure and function. Post-PNX compensatory lung growth is known to promote lung tumor formation in carcinogen-treated mice. The present study tests the hypothesis that PNX enhances experimental metastasis to lung. C57B1/6 mice subjected to PNX were given an intravenous injection of B16F10 melanoma cells at various stages of compensatory lung growth. Animals injected with B16F10 cells during the linear phase of the response had 77% to 260% more pulmonary metastases than mice subjected to thoracotomy (P < 0.01). Moreover, measurements of tumor area (mm2) revealed that PNX mice harbored a substantially larger lung tumor burden than control animals. Normalization of the tumor cell inoculum to lung mass yielded similar results. PNX had no effect on growth of sub-cutaneous B16F10 melanoma tumors, suggesting that experimental melanoma metastasis was enhanced by local alterations in the lung microenvironment. These results suggest (1) that PNX is a relevant model in which to investigate mechanisms of local cancer recurrence and, (2) melanoma cell metastatic potential is influenced, at least in part, by local factors modified during post-PNX compensatory lung growth.


Assuntos
Neoplasias Pulmonares/secundário , Melanoma Experimental/secundário , Pneumonectomia/efeitos adversos , Animais , Hiperplasia , Injeções Intravenosas , Pulmão/patologia , Neoplasias Pulmonares/etiologia , Melanoma Experimental/etiologia , Camundongos , Camundongos Endogâmicos C57BL , Transplante de Neoplasias , Pneumonectomia/métodos , Neoplasias Cutâneas/secundário , Toracotomia/efeitos adversos
18.
Cancer Res ; 61(24): 8866-72, 2001 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-11751410

RESUMO

Tumor metastasis is one of the most important clinical aspects of neoplastic disease because patient mortality is frequently attributable to disseminated rather than primary tumors. However, it still is not possible to definitively distinguish those individuals at high risk for disseminated disease, who would benefit from aggressive adjuvant therapy, from the low-risk patients who might be spared the side effects of additional anticancer therapy. To identify factors that predispose toward metastatic disease, we have used a genetic approach. Using a highly metastatic model of mammary cancer, we identified previously inbred mouse strains (DBA/2J, NZB/B1NJ, and I/LnJ) that harbor genetic factors that significantly suppress metastatic efficiency. In this study, we report the results of four experiments to localize the genetic map locations of the metastasis efficiency modifier genes. One statistically significant locus was identified on proximal Chr 19 designated Mtes1. Secondary candidate intervals were detected on Chrs 6, 9, 13, and 17. Interestingly, Mtes1 colocalizes with the murine orthologue of the human breast cancer metastasis suppressor gene Brms1, suggesting that allelic variants of Brms1 might be responsible for the metastasis suppression observed.


Assuntos
Genes Supressores de Tumor , Neoplasias Pulmonares/secundário , Neoplasias Mamárias Experimentais/genética , Neoplasias Mamárias Experimentais/patologia , Proteínas de Neoplasias , Proteínas/genética , Animais , Feminino , Predisposição Genética para Doença , Endogamia , Neoplasias Pulmonares/genética , Masculino , Camundongos , Camundongos Endogâmicos DBA , Camundongos Transgênicos , Metástase Neoplásica , Proteínas Repressoras
19.
Cancer Res ; 61(5): 1765-7, 2001 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-11280719

RESUMO

Breast cancer progresses toward increasingly malignant behavior in tumorigenic and metastatic stages. In the series of events in the metastatic stage, tumor cells leave the primary tumor in breast and travel to distant sites where they establish secondary tumors, or metastases. In this report, we demonstrate that cell-cell communication via gap junctions is restored in the metastatic human breast carcinoma cell line MDA-MB-435 when it is transfected with breast metastasis suppressor 1 (BRMS1) cDNA. Furthermore, the expression profile of connexins (Cxs), the protein subunits of gap junctions, changes. Specifically, the expression of BRMS1 in MDA-MB-435 cells increases Cx43 expression and reduces Cx32 expression, resulting in a gap junction phenotype more similar to normal breast tissue. Taken together, these results suggest that gap junctional communication and the Cx expression profile may contribute to the metastatic potential of these breast cancer cells.


Assuntos
Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/patologia , Comunicação Celular/fisiologia , Junções Comunicantes/fisiologia , Proteínas de Neoplasias , Comunicação Celular/genética , Conexinas/biossíntese , Conexinas/genética , DNA Complementar/genética , Feminino , Corantes Fluorescentes , Junções Comunicantes/genética , Humanos , Metilaminas , Metástase Neoplásica , Proteínas/genética , Proteínas/fisiologia , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Proteínas Repressoras , Transfecção , Células Tumorais Cultivadas
20.
Biochem Biophys Res Commun ; 281(1): 159-65, 2001 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-11178974

RESUMO

Metastatic tumors grow under conditions that restrict proliferation of non-metastatic, more differentiated cells. To investigate this prediction, we developed a simple adhesion-restrictive assay which allows proliferation of human metastatic C8161 melanoma, but prevents growth of neo 6.3/C8161 cells in which metastasis is suppressed by introduction of neo-tagged chromosome 6. We show that tyrosinase, a key enzyme in melanocytic cell differentiation, and expression of chromosome 6-encoded cell cycle modulators like p21WAF1 and cyclin D3 is selectively increased in C8161 tumors in which metastasisis is suppressed by chromosome 6. In the latter cells, growth arrest evidenced only under adhesion-restrictive conditions correlated with down-regulation of cyclin D3 and anti-apoptotic bcl-2. No comparable growth arrest or down-regulation was detected under comparable conditions in metastatic cells, which showed activation of invasion-associated MMP-9 92 kDa gelatinase B. Our data suggests that the metastasis-suppressing effects of chromosome 6 involving increased differentiation-associated tyrosinase and growth arrest on adhesion-restrictive substrates; are partly mediated by modulation of growth regulators, like p21WAF1 and cyclin D3.


Assuntos
Cromossomos Humanos Par 6 , Ciclinas/metabolismo , Regulação para Baixo , Melanoma/genética , Monofenol Mono-Oxigenase/metabolismo , Metástase Neoplásica/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Supressão Genética , Regulação para Cima , Animais , Apoptose , Adesão Celular , Diferenciação Celular , Divisão Celular , Ciclina D3 , Inibidor de Quinase Dependente de Ciclina p21 , Gelatinases/metabolismo , Humanos , Immunoblotting , Metaloproteinase 9 da Matriz/metabolismo , Camundongos , Camundongos SCID , Transplante de Neoplasias , Células Tumorais Cultivadas
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