Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 42
Filtrar
1.
Int J Mol Sci ; 24(15)2023 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-37569595

RESUMO

Venoms are a rich source of bioactive compounds, and among them is leberagin-C (Leb-C), a disintegrin-like protein derived from the venom of Macrovipera lebetina transmediterrannea snakes. Leb-C has shown promising inhibitory effects on platelet aggregation. Previous studies have demonstrated that this SECD protein specifically targets α5ß1, αvß3, and αvß6 integrins through a mimic mechanism of RGD disintegrins. In our current study, we focused on exploring the potential effects of Leb-C on metastatic breast cancer. Our findings revealed that Leb-C disrupted the adhesion, migration, and invasion capabilities of MDA-MB-231 breast cancer cells and its highly metastatic D3H2LN sub-population. Additionally, we observed significant suppression of adhesion, migration, and invasion of human umbilical vein endothelial cells (HUVECs). Furthermore, Leb-C demonstrated a strong inhibitory effect on fibroblast-growth-factor-2-induced proliferation of HUVEC. We conducted in vivo experiments using nude mice and found that treatment with 2 µM of Leb-C resulted in a remarkable 73% reduction in D3H2LN xenograft tumor size. Additionally, quantification of intratumor microvessels revealed a 50% reduction in tumor angiogenesis in xenograft after 21 days of twice-weekly treatment with 2 µM of Leb-C. Collectively, these findings suggest the potential utility of this disintegrin-like protein for inhibiting aggressive and resistant metastatic breast cancer.


Assuntos
Desintegrinas , Neoplasias de Mama Triplo Negativas , Animais , Camundongos , Humanos , Desintegrinas/farmacologia , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Camundongos Nus , Agregação Plaquetária , Células Endoteliais da Veia Umbilical Humana
2.
Int J Cancer ; 138(6): 1472-81, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26476272

RESUMO

The serrated neoplasia pathway accounts for 20-30% of colorectal cancers (CRC), which are characterized by extensive methylation (CpG island methylation phenotype, CIMP), frequent BRAF mutation and high microsatellite instability (MSI). We recently identified MUC5AC mucin gene hypomethylation as a specific marker of MSI CRC. The early identification of preneoplastic lesions among serrated polyps is currently challenging. Here, we performed a detailed pathological and molecular analysis of a large series of colorectal serrated polyps and evaluated the usefulness of mucin genes MUC2 and MUC5AC to differentiate serrated polyps and to identify lesions with malignant potential. A series of 330 colorectal polyps including 218 serrated polyps [42 goblet cell-rich hyperplastic polyps (GCHP), 68 microvesicular hyperplastic polyps (MVHP), 100 sessile serrated adenoma (SSA) and eight traditional serrated adenoma (TSA)] and 112 conventional adenomas was analyzed for BRAF/KRAS mutations, MSI, CIMP, MLH1 and MGMT methylation, and MUC2 and MUC5AC expression and methylation. We show that MUC5AC hypomethylation is an early event in the serrated neoplasia pathway, and specifically detects MVHP and SSA, arguing for a filiation between MVHP, SSA and CIMP-H/MSI CRC, whereas GCHP and TSA arise from a distinct pathway. Moreover, MUC5AC hypomethylation specifically identified serrated lesions with BRAF mutation, CIMP-H or MSI, suggesting that it may be useful to identify serrated neoplasia pathway-related precursor lesions. Our data suggest that MVHP should be recognized among HP and require particular attention.


Assuntos
Biomarcadores Tumorais , Pólipos do Colo/genética , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Metilação de DNA , Mucina-5AC/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Transformação Celular Neoplásica/genética , Pólipos do Colo/patologia , Neoplasias Colorretais/diagnóstico , Feminino , Expressão Gênica , Humanos , Masculino , Instabilidade de Microssatélites , Pessoa de Meia-Idade , Mutação , Prognóstico , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas ras/genética
3.
Int J Cancer ; 136(12): 2811-21, 2015 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-25403854

RESUMO

Colorectal cancers (CRC) with microsatellite instability (MSI) display unique clinicopathologic features including a mucinous pattern with frequent expression of the secreted mucins MUC2 and MUC5AC. The mechanisms responsible for this altered pattern of expression remain largely unknown. We quantified DNA methylation of mucin genes (MUC2, MUC5AC, MUC4) in colonic cancers and examined the association with clinicopathological characteristics and molecular (MSI, KRAS, BRAF, and TP53 mutations) features. A control cohort was used for validation. We detected frequent hypomethylation of MUC2 and MUC5AC in CRC. MUC2 and MUC5AC hypomethylation was associated with MUC2 and MUC5AC protein expression (p = 0.004 and p < 0.001, respectively), poor differentiation (p = 0.001 and p = 0.007, respectively) and MSI status (p < 0.01 and p < 0.001, respectively). Interestingly, MUC5AC hypomethylation was specific to MSI cancers. Moreover, it was significantly associated with BRAF mutation and CpG island methylator phenotype (p < 0.001 and p < 0.001, respectively). All these results were confirmed in the control cohort. In the multivariate analysis, MUC5AC hypomethylation was a highly predictive biomarker for MSI cancers. MUC5AC demethylation appears to be a hallmark of MSI in CRC. Determination of MUC5AC methylation status may be useful for understanding and predicting the natural history of CRC.


Assuntos
Neoplasias Colorretais/genética , Metilação de DNA , Instabilidade de Microssatélites , Mucina-5AC/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Azacitidina/análogos & derivados , Azacitidina/farmacologia , Linhagem Celular Tumoral , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Ilhas de CpG/genética , Decitabina , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células HCT116 , Células HT29 , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Mucina-5AC/metabolismo , Mutação , Prognóstico , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas p21(ras) , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Proteína Supressora de Tumor p53/genética , Proteínas ras/genética
4.
Mar Drugs ; 13(5): 2857-74, 2015 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-25962124

RESUMO

Astaxanthin, a powerful antioxidant, is a good candidate for the prevention of intracellular oxidative stress. The aim of the study was to compare the antioxidant activity of astaxanthin present in two natural extracts from Haematococcus pluvialis, a microalgae strain, with that of synthetic astaxanthin. Natural extracts were obtained either by solvent or supercritical extraction methods. UV, HPLC-DAD and (HPLC-(atmospheric pressure chemical ionization (APCI)+)/ion trap-MS) characterizations of both natural extracts showed similar compositions of carotenoids, but different percentages in free astaxanthin and its ester derivatives. The Trolox equivalent antioxidant capacity (TEAC) assay showed that natural extracts containing esters displayed stronger antioxidant activities than free astaxanthin. Their antioxidant capacities to inhibit intracellular oxidative stress were then evaluated on HUVEC cells. The intracellular antioxidant activity in natural extracts was approximately 90-times higher than synthetic astaxanthin (5 µM). No modification, neither in the morphology nor in the viability, of vascular human cells was observed by in vitro biocompatibility study up to 10 µM astaxanthin concentrations. Therefore, these results revealed the therapeutic potential of the natural extracts in vascular human cell protection against oxidative stress without toxicity, which could be exploited in prevention and/or treatment of cardiovascular diseases.


Assuntos
Células Endoteliais/efeitos dos fármacos , Microalgas/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Antioxidantes/farmacologia , Carotenoides/metabolismo , Células Cultivadas , Células Endoteliais da Veia Umbilical Humana , Humanos , Xantofilas/farmacologia
5.
Hum Mutat ; 33(1): 180-8, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21953887

RESUMO

Constitutional epimutations of DNA mismatch repair (MMR) genes have been recently reported as a possible cause of Lynch syndrome. However, little is known about their prevalence, the risk of transmission through the germline and the risk for carriers to develop cancers. In this study, we evaluated the contribution of constitutional epimutations of MMR genes in Lynch syndrome. A cohort of 134 unrelated Lynch syndrome-suspected patients without MMR germline mutation was screened for constitutional epimutations of MLH1 and MSH2 by quantitative bisulfite pyrosequencing. Patients were also screened for the presence of EPCAM deletions, a possible cause of MSH2 methylation. Tumors from patients with constitutional epimutations were extensively analyzed. We identified a constitutional MLH1 epimutation in two proband patients. For one of them, we report for the first time evidence of transmission to two children who also developed early colonic tumors, indicating that constitutional MLH1 epimutations are associated to a real risk of transgenerational inheritance of cancer susceptibility. Moreover, a somatic BRAF mutation was detected in one affected child, indicating that tumors from patients carrying constitutional MLH1 epimutation can mimic MSI-high sporadic tumors. These findings may have important implications for future diagnostic strategies and genetic counseling.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Neoplasias Colorretais Hereditárias sem Polipose/genética , Epigênese Genética , Predisposição Genética para Doença , Proteína 2 Homóloga a MutS/genética , Proteínas Nucleares/genética , Adulto , Idoso , Criança , Estudos de Coortes , Neoplasias Colorretais Hereditárias sem Polipose/diagnóstico , Reparo de Erro de Pareamento de DNA/genética , Feminino , Testes Genéticos , Mutação em Linhagem Germinativa , Hereditariedade , Heterozigoto , Humanos , Masculino , Metilação , Pessoa de Meia-Idade , Proteína 1 Homóloga a MutL , Linhagem , Proteínas Proto-Oncogênicas B-raf/genética , Análise de Sequência de DNA
6.
Mol Pharmacol ; 82(3): 521-8, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22723339

RESUMO

Statins and bisphosphonates are two distinct classes of isoprenoid pathway inhibitors targeting downstream enzyme to HMG-CoA reductase (upstream enzyme) and farnesyl-pyrophosphate synthase, respectively. Here, we studied fluvastatin (Fluva) and zoledronate (Zol), representative molecules of each class, respectively. In vivo metastatic potentials of both molecules were assessed. For the first time, we observed a significant reduction in progression of established metastases with Fluva treatment. Treatment with both Zol at 100 µg/kg and Fluva at 15 mg/kg inhibited 80% of the metastasis bioluminescence signal and increased survival of mice. The Zol and Fluva transcriptomic profiles of treated MDA-MB-231 cells revealed analogous patterns of affected genes, but each of them reached with different kinetics. The observable changes in gene expression started after 24 h for Fluva IC(50 72 h) and only after 48 h for Zol IC(50 72 h). To obtain early changes in gene expression of Zol-treated cells, a 3 times higher dose of Zol IC(50 72 h) had to be applied. Combining Fluva and Zol in vivo showed no synergy, but a benefit of several days in survival of mice. This study demonstrated that Zol or Fluva is of potential clinical use for the treatment of established metastasis.


Assuntos
Adenocarcinoma/tratamento farmacológico , Neoplasias da Mama/tratamento farmacológico , Difosfonatos/farmacologia , Ácidos Graxos Monoinsaturados/farmacologia , Imidazóis/farmacologia , Indóis/farmacologia , Neoplasias Mamárias Experimentais/tratamento farmacológico , Transcriptoma/efeitos dos fármacos , Adenocarcinoma/genética , Adenocarcinoma/patologia , Animais , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Modelos Animais de Doenças , Progressão da Doença , Feminino , Fluvastatina , Expressão Gênica/efeitos dos fármacos , Perfilação da Expressão Gênica/métodos , Humanos , Neoplasias Mamárias Experimentais/genética , Neoplasias Mamárias Experimentais/patologia , Camundongos , Camundongos Nus , Metástase Neoplásica , Ácido Zoledrônico
7.
Hemoglobin ; 34(4): 389-93, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20642337

RESUMO

A 37-year-old man presented a slight debility. The hemogram showed a phenotype of beta-thalassemia minor: Hb (13.1 g/dL), mean corpuscular volume (MCV) (62 fL) with low mean corpuscular hemoglobin (MCH) (20.8 pg), associated with a high level of Hb A(2) of 5.3%. The serum ferritin level was 1,072 ng/mL. The sequencing of the mutated fragment revealed a duplication of four bases of codons 7/8 involving a shift in the open reading frame starting from codon 9 with a TGA stop codon at codon 23: codons 7/8/9 (+AGAA); GAG.AAG.TCT(Gly-Lys-Ser)>GAG.AAAGAAG. The human hemoglobin (Hb) instability tests were negative. The patient did not present the high iron Fe (HFE) mutation (C282Y, H63D). The same mutation was found in five other unrelated families (representing a total of 23 patients). All of their ancestors came from the north of France. This mutation has not been described before and could have its origins in the native populations of Northern France.


Assuntos
Códon/genética , Mutação , Globinas beta/genética , Talassemia beta/genética , Adulto , Sequência de Aminoácidos , Sequência de Bases , Análise Mutacional de DNA , Saúde da Família , Feminino , França , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido Nucleico , Irmãos , Talassemia beta/patologia
8.
Nutr Rev ; 78(1): 65-76, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31407778

RESUMO

Although chemotherapy succeeds in reducing tumor burden, the efficacy is limited due to acquired drug resistance and often irreparable side effects. Studies show that antioxidants may influence the response to chemotherapy and its side effects, although their use remains controversial. The evidence shows that some chemo-drugs induce oxidative stress and lead to normal tissue apoptosis and the entry of cancer cells to a dormant G0 state. Through the suppression of oxidative stress, antioxidants could protect normal cells and bring the tumor out of dormancy so as to expose it to chemotherapies. This review is focused on the redox biology of cancer/normal cells and association of reactive oxygen species with drug resistance, cancer dormancy, and side effects. To this end, evidence from cellular, animal, and clinical studies is provided to better understand the conundrum of dietary antioxidants in cancer chemotherapy.


Assuntos
Antineoplásicos/farmacologia , Antioxidantes/farmacologia , Dieta , Neoplasias/metabolismo , Animais , Antineoplásicos/uso terapêutico , Resistencia a Medicamentos Antineoplásicos , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/imunologia , Neoplasias/prevenção & controle , Prevenção Primária , Espécies Reativas de Oxigênio/metabolismo
9.
Endocr Connect ; 9(10): 1042-1050, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33112832

RESUMO

OBJECTIVE: We previously described a family in which predisposition to pheochromocytoma (PCC) segregates with a germline heterozygous KIF1B nucleotide variant (c.4442G>A, p.Ser1481Asn) in three generations. During the clinical follow-up, one proband's brother, negative for the KIF1B nucleotide variant, developed a bilateral PCC at 31 years. This prompted us to reconsider the genetic analysis. DESIGN AND METHODS: Germline DNA was analyzed by next-generation sequencing (NGS) using a multi-gene panel plus MLPA or by whole exome sequencing (WES). Tumor-derived DNA was analyzed by SnapShot, Sanger sequencing or NGS to identify loss-of-heterozygosity (LOH) or additional somatic mutations. RESULTS: A germline heterozygous variant of unknown significance in MAX (c.145T>C, p.Ser49Pro) was identified in the proband's brother. Loss of the wild-type MAX allele occurred in his PCCs thus demonstrating that this variant was responsible for the bilateral PCC in this patient. The proband and her affected grandfather also carried the MAX variant but no second hit could be found at the somatic level. No other pathogenic mutations were detected in 36 genes predisposing to familial PCC/PGL or familial cancers by WES of the proband germline. Germline variants detected in other genes, TFAP2E and TMEM214, may contribute to the multiple tumors of the proband. CONCLUSION: In this family, the heritability of PCC is linked to the MAX germline variant and not to the KIF1B germline variant which, however, may have contributed to the occurrence of neuroblastoma (NB) in the proband.

10.
Biochim Biophys Acta ; 1780(4): 723-32, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18325345

RESUMO

We previously demonstrated that a non sulfated analogue of heparin, phenylacetate carboxymethyl benzylamide dextran (NaPaC) inhibited angiogenesis. Here, we observed that NaPaC inhibited the VEGF165 binding to both VEGFR2 and NRP-1 and abolished VEGFR2 activity. Further, we explored the effects of NaPaC on VEGF165 interactions with its receptors, VEGFR2 and NRP-1, co-receptor of VEGFR2. Surface plasmon resonance and affinity gel electrophoresis showed that NaPaC interacted directly with VEGF165, VEGFR2 and NRP-1 but not with heparin-independent factor such as VEGF121. NaPaC completely inhibited the heparin binding to VEGF165, NRP-1 and VEGFR2. We found that NaPaC bound to all three molecules, VEGF165, VEGFR2 and NRP-1, but was more effective in inhibiting heparin binding to VEGF165. These results suggested that heparin binding sites of VEGFR2 and NRP-1 were different from those of VEGF165.


Assuntos
Dextranos/metabolismo , Heparina/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Animais , Sítios de Ligação , Ligação Competitiva/efeitos dos fármacos , Western Blotting , Células Cultivadas , Dextranos/farmacologia , Relação Dose-Resposta a Droga , Heparina/farmacologia , Neuropilina-1/genética , Neuropilina-1/metabolismo , Ligação Proteica/efeitos dos fármacos , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteínas Recombinantes/metabolismo , Suínos , Fator A de Crescimento do Endotélio Vascular/genética , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/genética
11.
Anticancer Res ; 29(4): 1335-43, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19414384

RESUMO

The effects of sodium phenylacetate (NaPa), an antitumoral molecule, on cell death and matrix metalloproteinase (MMP) activities and synthesis were investigated in two metastatic breast tumour cell lines, MDA-MB-231 and MDA-MB-435, cultured on three-dimensional type I collagen gels (3-D cultures). In both cell lines, NaPa inhibited cell proliferation and induced apoptotic cell death as measured by TUNEL assay, with an IC(30) of 20 mM and 10 mM for MDA-MB-231 and MDA-MB-435 cells, respectively. In MDA-MB-231 cells, NaPa also induced (i) an autophagic process evidenced by the appearance of autophagic vacuoles and an increased phosphatase acid activity, (ii) the formation of pseudopodia and (iii) an increase in MMP-1 and MMP-9 secretion without affecting MT1-MMP. In NaPa-treated MDA-MB-435 cells, no autophagic vacuoles were formed but F-actin depolymerisation was observed. MMP-1, MMP-9 and MT1-MMP levels were strongly enhanced in these cells but MMPs were not secreted and accumulated intracellularly. When breast cancer cells were treated with NaPa in the presence of an MMP inhibitor (GM6001), apoptotic cell death decreased and the induction of autophagic vacuoles in MDA-MB-231 cells was inhibited. Taken together, these data suggest that MMPs are involved in the autophagic cell death and/or apoptosis of breast tumour cells.


Assuntos
Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Neoplasias da Mama/patologia , Metaloproteinase 14 da Matriz/metabolismo , Metaloproteinase 1 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Fenilacetatos/farmacologia , Antimetabólitos Antineoplásicos/farmacologia , Western Blotting , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/enzimologia , Técnicas de Cultura de Células , Feminino , Humanos , Células Tumorais Cultivadas
12.
Anticancer Res ; 29(6): 2347-55, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19528501

RESUMO

Mutual interactions between human breast cancer cells and endothelial cells were studied in a model mimicking tumor cell intravasation. MDA-MB-231 tumor cells and human umbilical vein endothelial cells (HUVEC) were cocultured on opposite sides of a Transwell filter allowing tumor cell contacts with the basement membrane of the HUVEC forming endothelium and tumor cell transendothelial migration. Confocal microscopy analysis showed that transmigrating MDA-MB-231 cells lay under the HUVEC, thereby inducing HUVEC detachment and tumor cell-HUVEC contact-dependent apoptosis. GM6001 a matrix metalloproteinase (MMP) inhibitor inhibited almost completely, the MDA-MB-231 cell transendothelial migration and the anoikis process. In this intravasation model, a tumor cell invasive mechanism was demonstrated (i) induction of extensive endothelial anoikis induced by degradation of the extracellular matrix (ECM) components, (ii) activation of pro-matrix metalloproteinase (MMP)-2 into MMP-2 by the MT1-MMP-TIMP (tissue inhibitor metalloproteinase) 2-pro-MMP-2 membrane complex and (iii) attraction and migration of metastatic cell through apoptotic endothelium. These interactions could partly explain the necrosis-angiogenesis relationship in tumor angiogenesis.


Assuntos
Anoikis , Neoplasias da Mama/patologia , Movimento Celular , Endotélio Vascular/patologia , Matriz Extracelular/metabolismo , Western Blotting , Células Cultivadas , Técnicas de Cocultura , Feminino , Humanos , Técnicas Imunoenzimáticas , Metaloproteinase 14 da Matriz/metabolismo , Metaloproteinases da Matriz/metabolismo , Veias Umbilicais/citologia
13.
J Clin Endocrinol Metab ; 104(8): 3362-3366, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31046099

RESUMO

CONTEXT: Heterozygous germline pathogenic variants found in succinate dehydrogenase (SDH) complex genes predispose to hereditary paraganglioma (PGL) syndromes. No mosaicism has yet been reported in this setting. DESIGN AND PARTICIPANT: We describe the clinical history of a case of SDH complex, subunit B (SDHB) mosaicism. A 24-year-old woman who developed a cardiogenic shock during dental surgery was diagnosed with a functional para-aortic PGL, which produced predominantly norepinephrine and its metabolites. The tumor was removed and showed a loss of SDHB expression by immunohistochemistry. Four years after initial laparotomy, the patient had a rapid cardiac decompensation during her second pregnancy, despite negative imaging 10 months before. Two recurrent functional PGLs were found and surgically removed. Initial genetic analysis performed by Sanger sequencing did not reveal any germline pathogenic variant in SDHB, VHL, SDHD, SDHC, SDHAF2, RET, MAX, and TMEM127. Next-generation sequencing performed on tumor- and blood-extracted DNAs highlighted the presence of a mosaic rare variant in SDHB (c.557G>A, p.Cys186Tyr) with an allelic ratio of 15% in the blood DNA. CONCLUSIONS: We report the full clinical description of a proband with SDHB mosaicism associated with a functional, recurrent PGL. This case strengthens the necessity to complete the genetic analysis with methodologies able to identify germline mosaicism, especially in the case of early disease onset.


Assuntos
Mutação em Linhagem Germinativa , Paraganglioma/genética , Succinato Desidrogenase/genética , Feminino , Humanos , Fenótipo , Adulto Jovem
14.
J Mol Diagn ; 21(3): 462-470, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30731206

RESUMO

Von Hippel-Lindau disease (VHL) is a monogenic disorder characterized by the development of tumors affecting the central nervous system, kidney, pancreas, or adrenal glands, and due to germline mutations in the VHL tumor suppressor gene. About 5% of patients with a typical VHL phenotype have no mutation detected by conventional techniques, so a postzygotic VHL mosaicism can be suspected. The aim of this study was therefore to implement a next-generation sequencing (NGS) strategy for VHL mosaic mutation detection, including an optimization of the original Personal Genome Machine design by enrichment with oligonucleotides corresponding to amplicons with insufficient depth of coverage. Two complementary strategies were developed for the confirmation of mosaic mutations identified by NGS, SNaPshot for variants present at an allelic ratio greater than 5%, and droplet digital PCR for allelic ratio above 1%. VHL mutant plasmids were generated to assess VHL mosaic mutation detection in different exons and to set up an internal quality control that could be included in each run or regularly to validate the assay. This strategy was applied to 47 patients with a suggestive or clinical VHL disease, and mosaic mutations were identified in 8.5% of patients. In conclusion, NGS technologies combined with SNaPshot or droplet digital PCR allow the detection and confirmation of mosaic mutations in a clinical laboratory setting.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala/métodos , Mosaicismo , Mutação/genética , Proteína Supressora de Tumor Von Hippel-Lindau/genética , Adolescente , Adulto , Humanos , Limite de Detecção , Masculino , Pessoa de Meia-Idade , Plasmídeos/genética , Reprodutibilidade dos Testes
15.
J Clin Endocrinol Metab ; 93(5): 1609-15, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18211978

RESUMO

CONTEXT: Inactivating mutations of SDHD, which is mapped to 11q23 and encodes the cybS subunit of succinate dehydrogenase, predispose to hereditary paraganglioma (PGL) and/or pheochromocytoma. So far no disease was shown to occur in case of maternal transmission of a SDHD mutation, suggesting the existence of genomic imprinting. A hypothetic model, involving the loss of the maternal copy of a tumor suppressor gene mapped to 11p15 in the tumoral tissue, has been proposed to explain this mode of inheritance. OBJECTIVE: Our objective was to investigate the possibility of maternal transmission of SDHD-linked PGL. DESIGN: A three-generation family carrying the SDHD W43X mutation was studied at the clinical, pathological, and genetical levels. RESULTS: The germline's mutation was probably inherited from the grandfather. In the second generation, three carriers (two females and one male), who had the same at risk 11q13-q23 haplotype, developed multiple cervical PGLs. In the third generation, one boy received the mutation from his mother and developed a glomus tympanicum PGL at 11 yr. He shared only the 11q23 haplotype with the other affected members of the family. Methylation analysis of the differentially methylated region upstream of the maternally expressed H19 gene, mapped to 11p15, showed that the seventh CTCF binding site is hypermethylated in the germline of the affected boy suggesting a gain of imprinting. CONCLUSION: Our data show that maternal transmission of a SDHD-linked PGL, even if a rare event, can occur. Therefore, we propose that children who inherited a pathogenic mutation from their mother should be considered as at risk of PGL.


Assuntos
Mutação em Linhagem Germinativa , Neoplasias de Cabeça e Pescoço/genética , Paraganglioma/genética , Succinato Desidrogenase/genética , Adulto , Idoso , Metilação de DNA , Feminino , Ligação Genética , Humanos , Masculino , Pessoa de Meia-Idade
16.
Clin Exp Metastasis ; 25(1): 53-64, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-17952617

RESUMO

The integrin alpha(v)beta(3) is involved in multiple aspects of malignant cancer, including tumor angiogenesis and metastasis, which makes the receptor a key target for the development of anti-cancer therapies. We report here on the production, the characterization and the in vivo anti-angiogenic and anti-metastatic properties of a novel alpha(v)beta(3)-binding disintegrin, DisBa-01, isolated from a cDNA library made with RNAs from the venom gland of Bothrops alternatus. The 11,637 Da-recombinant monomeric form of DisBa-01 displayed an RGD motif and interacted with purified alpha(v)beta(3) integrin in surface plasmon resonance studies, in a dose-dependent and cation sensitive manner. A three-dimensional molecular model of DisBa-01 in complex with alpha(v)beta(3) predicted a large surface of contacts with the beta(3) subunit. DisBa-01 inhibited the adhesion of alpha(v)beta(3)-expressing human microvascular endothelial cell line-1 (HMEC-1) and murine melanoma cell line B16F10 to vitronectin (IC(50) = 555 nM and 225 nM, respectively), and transiently inhibited their proliferation without direct cell toxicity, but did not affect the binding nor the proliferation of a human breast cancer-derived cell line (MDA-MB-231) not expressing alpha(v)beta(3). In vivo, DisBa-01 dose-dependently decreased bFGF-induced angiogenesis in a matrigel plug assay in athymic nude mice (IC(50) = 83 nM). When injected intravenously to C57BL/6 mice together with B16F10 melanoma cells, DisBa-01 time- and dose-dependently inhibited lung metastasis monitored by bioluminescent imaging. We conclude that DisBa-01 is a potent new inhibitor of alpha(v)beta(3)-dependent adherence mechanisms involved in neo-vascularization and tumor metastasis processes.


Assuntos
Venenos de Crotalídeos/farmacologia , Desintegrinas/farmacologia , Integrina alfaVbeta3/antagonistas & inibidores , Melanoma Experimental/tratamento farmacológico , Metástase Neoplásica/tratamento farmacológico , Neovascularização Patológica/tratamento farmacológico , Motivos de Aminoácidos , Sequência de Aminoácidos , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Sequência de Bases , Bothrops , Adesão Celular/efeitos dos fármacos , Clonagem Molecular , Venenos de Crotalídeos/química , Desintegrinas/química , Desintegrinas/genética , Fatores de Crescimento de Fibroblastos/metabolismo , Humanos , Integrina alfaVbeta3/efeitos dos fármacos , Camundongos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Conformação Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacologia
17.
Front Biosci ; 13: 6604-16, 2008 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-18508682

RESUMO

A monomeric RGD-disintegrin was recently identified from a cDNA library from the venom gland of Bothrops alternatus. The corresponding 12 kDa-recombinant protein, DisBa-01, specifically interacted with alpha(v)beta3 integrin and displayed potent anti-metastatic and anti-angiogenic properties. Here, the interaction of DisBa-01 with platelet alphaIIb beta3 integrin and its effects on hemostasis and thrombosis were investigated. DisBa-01 bound to Chinese Hamster Ovary (CHO) cells expressing beta3 or alphaIIb beta3 and promoted their adhesion and the adhesion of resting platelets onto glass coverslips. The disintegrin inhibited the binding of FITC-fibrinogen and FITC-PAC-1 to ADP-stimulated platelets and inhibited ADP-, TRAP- and collagen-induced aggregation of murine, rabbit or human platelets. In a flow chamber assay, DisBa-01 inhibited and reverted platelet adhesion to immobilized fibrinogen. DisBa-01 inhibited the phosphorylation of FAK following platelet activation. The intravenous injection of DisBa-01 in C57Bl6/j mice, prolonged tail bleeding time as well as thrombotic occlusion time in mesenteric venules and arterioles following vessel injury with FeCl3. In conclusion, DisBa-01 antagonizes the platelet alphaIIb beta3 integrin and potently inhibits thrombosis.


Assuntos
Venenos de Crotalídeos/toxicidade , Hemostasia/efeitos dos fármacos , Hemostáticos/farmacologia , Animais , Bothrops , Células CHO/efeitos dos fármacos , Cricetinae , Cricetulus , Quinase 1 de Adesão Focal/efeitos dos fármacos , Quinase 1 de Adesão Focal/metabolismo , Humanos , Fosforilação , Adesividade Plaquetária/efeitos dos fármacos , Agregação Plaquetária/efeitos dos fármacos , Proteínas Recombinantes/toxicidade , Transfecção
18.
Anticancer Res ; 28(2A): 1029-37, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18507051

RESUMO

BACKGROUND: Sodium phenylacetate (NaPa) inhibits breast cancer cell proliferation decreasing prenylation of small G proteins including Ras. MATERIALS AND METHODS: Aponecrosis induced by NaPa in MCF-7 and MCF-7ras breast cancer cells was evaluated by measuring Annexin V/PI labelling by flow cytometry. Specific inhibitors of p42/44 (PD 98059), p38 (SB 600125) and JNK (SP 202190) in association with NaPa were also tested. Mitogen-activated kinase (MAPK) activation was measured by immunoprecipitation. RESULTS: NaPa induced cell death more efficiently (80%) in the MCF-7ras cells compared to the MCF-7 cells (60%). NaPa activated ERK 1/2 and its combination with PD 98059 decreased cell death in the MCF-7ras cells in contrast to the MCF-7 cells. Combination of NaPa with specific inhibitors of both JNK and p38 kinases also partly decreased MCF-7ras cell death. CONCLUSION: NaPa induced cell death differently when ras was overexpressed in breast cancer cells, partly involving p42/44, JNK and p38 pathways.


Assuntos
Genes ras , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Fenilacetatos/farmacologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Flavonoides/farmacologia , Camundongos , Proteínas Proto-Oncogênicas p21(ras)/metabolismo
19.
Respir Med Case Rep ; 24: 58-62, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29977761

RESUMO

Alpha-1 antitrypsin deficiency is an autosomal, codominant disorder caused by mutations of the SERPINA1 gene. This genetic disorder is mainly associated with development of pulmonary emphysema and/or chronic liver disease and cirrhosis. Here we report a very rare alpha-1 antitrypsin Null Q0cairo homozygous mutation characterized by a complete absence of alpha-1 antitrypsin in the plasma, in a non-consanguineous Moroccan family. This mutation has been previously described in heterozygosis in only three cases worldwide: an Italian/Egyptian family and two Italian families (Zorzetto et al., 2005). The main clinical features in two members of this Moroccan family were the severity and precocity of bronchiectasis, quickly spreading and seriously limiting respiratory function and physical activity by the second decade of age. Moreover, the index case presented with many episodes of pulmonary infections concomitant with severe neutropenia. The third member of the family presented with ankylosing spondyloarthritis and developed panniculitis later but had no respiratory symptoms. The presence of this alpha-1-antitrypsin Q0cairo homozygous mutation could explain the severity of clinical manifestations. Moreover, our observations highlight a great variability of clinical expression for the same mutation: early severe bronchiectasis, panniculitis, rheumatologic manifestations. This study further underlines the importance of genotyping by whole SERPINA1 gene sequencing in addition to serum alpha-1 antitrypsin determination, to enable detection of alpha-1 antitrypsin deficiency due to rare genotypes.

20.
Anticancer Res ; 27(2): 953-8, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17465226

RESUMO

BACKGROUND: Multiform glioblastomas represent the most aggressive brain tumors. Here, the cooperative effects of sodium phenylacetate (NaPa) and/or tamoxifen (TAM) on CNS1 and 9L glioblastoma cell lines in vitro and in an experimental animal tumor model were investigated. MATERIALS AND METHODS: The drug effects on cell cycle and apoptosis were investigated by flow cytometry. CNS1 cells were implanted subcutaneously in nude mice to form tumors which were then treated with NaPa, TAM or NaPa/TAM. RESULTS: A significant inhibitory effect of NaPa on the two glioma cell lines (LD50 of 10 mM) was observed. 10(-5) M of TAM inhibited approximately 35% of 9L cell growth, and 90% of CNS1 cell growth. When a combination of both drugs included 10(-9) M of TAM, inhibition of about 50% of 9L cell growth and 75% of CNS1 cell growth occurred. The NaPa/TAM combined treatment increased the number of G0/G1 arrested cells and apoptotic cells as compared to treatments with NaPa or TAM alone. Inhibition of CNS1 tumor growth were observed after a two week treatment with NaPa (32 mg/kg/day) or TAM (6 mg/kg/day). CONCLUSION: These results showed a synergistic effect between these two drugs on tumor cell proliferation, caused by cell cycle arrest in the G0/G1 phase and by induction of apoptosis.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Neoplasias Encefálicas/tratamento farmacológico , Glioblastoma/tratamento farmacológico , Animais , Apoptose/efeitos dos fármacos , Neoplasias Encefálicas/patologia , Processos de Crescimento Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sinergismo Farmacológico , Feminino , Glioblastoma/patologia , Gliossarcoma/tratamento farmacológico , Gliossarcoma/patologia , Camundongos , Camundongos Nus , Fenilacetatos/administração & dosagem , Ratos , Tamoxifeno/administração & dosagem
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa