Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 26
Filtrar
4.
Br J Surg ; 107(10): 1334-1343, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32452559

RESUMO

BACKGROUND: In gallbladder cancer, stage T2 is subdivided by tumour location into lesions on the peritoneal side (T2a) or hepatic side (T2b). For tumours on the peritoneal side (T2a), it has been suggested that liver resection may be omitted without compromising the prognosis. However, data to validate this argument are lacking. This study aimed to investigate the prognostic value of tumour location in T2 gallbladder cancer, and to clarify the adequate extent of surgical resection. METHODS: Clinical data from patients who underwent surgery for gallbladder cancer were collected from 14 hospitals in Korea, Japan, Chile and the USA. Survival and risk factor analyses were conducted. RESULTS: Data from 937 patients were available for evaluation. The overall 5-year disease-free survival rate was 70·6 per cent, 74·5 per cent for those with T2a and 65·5 per cent among those with T2b tumours (P = 0·028). Regarding liver resection, extended cholecystectomy was associated with a better 5-year disease-free survival rate than simple cholecystectomy (73·0 versus 61·5 per cent; P = 0·012). The 5-year disease-free survival rate was marginally better for extended than simple cholecystectomy in both T2a (76·5 versus 66·1 per cent; P = 0·094) and T2b (68·2 versus 56·2 per cent; P = 0·084) disease. Five-year disease-free survival rates were similar for extended cholecystectomies including liver wedge resection versus segment IVb/V segmentectomy (74·1 versus 71·5 per cent; P = 0·720). In multivariable analysis, independent risk factors for recurrence were presence of symptoms (hazard ratio (HR) 1·52; P = 0·002), R1 resection (HR 1·96; P = 0·004) and N1/N2 status (N1: HR 3·40, P < 0·001; N2: HR 9·56, P < 0·001). Among recurrences, 70·8 per cent were metastatic. CONCLUSION: Tumour location was not an independent prognostic factor in T2 gallbladder cancer. Extended cholecystectomy was marginally superior to simple cholecystectomy. A radical operation should include liver resection and adequate node dissection.


ANTECEDENTES: En el cáncer de vesícula biliar, la ubicación del tumor subdivide el estadio T2 en tumores con invasión del lado peritoneal y del lado del hígado (T2a y T2b). Para los tumores que invaden el lado peritoneal (T2a) se sugiere que se puede obviar la resección hepática sin que ello comprometa el pronóstico. Sin embargo, este argumento no ha sido validado. El estudio tuvo como objetivo investigar el valor pronóstico de la localización del tumor en el cáncer de vesícula biliar T2 y establecer la extensión adecuada de la resección quirúrgica. MÉTODOS: Se recogieron los datos clínicos de pacientes que se sometieron a cirugía por cáncer de vesícula biliar en 14 hospitales de Corea, Japón, Chile y Estados Unidos. Se realizaron análisis de la supervivencia y de los factores de riesgo. RESULTADOS: Se dispuso de datos de 937 pacientes para ser evaluados. La tasa de supervivencia global libre de enfermedad a los 5 años fue del 70,6%, y las de T2a y T2b del 74,5% y 65,5% (P = 0,028). Con respecto a la resección hepática, la colecistectomía extendida presentó una tasa mejor de supervivencia libre de enfermedad a los 5 años que la colecistectomía simple (73,0% versus 61,5%, P = 0,012). La tasa de supervivencia libre de enfermedad a los 5 años fue marginalmente mejor para la colecistectomía extendida que para la colecistectomía simple tanto en T2a (76,5% versus 66,1%, P = 0,094) como en T2b (68,2% versus 56,2%, P = 0,084). Las tasas de supervivencia libre de enfermedad a los 5 años no fueron diferentes entre la resección hepática en cuña y la segmentectomía S4b+S5 (74,1% versus 71,5%, P = 0,720). En el análisis multivariable, los factores de riesgo independientes para la recidiva fueron la presencia de síntomas (cociente de riesgos instantáneos, hazard ratio, HR 1,52, P = 0,002), la resección R1 (HR 1,96, P = 0,004) y el estadio N1/N2 (N1 HR 3,40, P < 0,001; N2 HR 9,56, P < 0,001). El 70,8% de las recidivas eran metastásicas. CONCLUSIÓN: La localización del tumor no fue un factor pronóstico independiente en el cáncer de vesícula biliar T2. La colecistectomía extendida fue marginalmente superior que la colecistectomía simple. La cirugía radical debe incluir una resección hepática y una linfadenectomía adecuada.


Assuntos
Neoplasias da Vesícula Biliar/mortalidade , Neoplasias da Vesícula Biliar/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Chile , Colecistectomia , Intervalo Livre de Doença , Feminino , Neoplasias da Vesícula Biliar/patologia , Hepatectomia , Humanos , Japão , Excisão de Linfonodo , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Recidiva Local de Neoplasia , Prognóstico , República da Coreia , Fatores de Risco , Estados Unidos
5.
Endocr Relat Cancer ; 25(10): 821-836, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29848667

RESUMO

Cell plasticity of 'stem-like' cancer-initiating cells (CICs) is a hallmark of cancer, allowing metastasis and cancer progression. Here, we studied whether simvastatin, a lipophilic statin, could impair the metastatic potential of CICs in high-grade serous ovarian cancer (HGS-ovC), the most lethal among the gynecologic malignancies. qPCR, immunoblotting and immunohistochemistry were used to assess simvastatin effects on proteins involved in stemness and epithelial-mesenchymal cell plasticity (EMT). Its effects on tumor growth and metastasis were evaluated using different models (e.g., spheroid formation and migration assays, matrigel invasion assays, 3D-mesomimetic models and cancer xenografts). We explored also the clinical benefit of statins by comparing survival outcomes among statin users vs non-users. Herein, we demonstrated that simvastatin modifies the stemness and EMT marker expression patterns (both in mRNA and protein levels) and severely impairs the spheroid assembly of CICs. Consequently, CICs become less metastatic in 3D-mesomimetic models and show fewer ascites/tumor burden in HGS-ovC xenografts. The principal mechanism behind statin-mediated effects involves the inactivation of the Hippo/YAP/RhoA pathway in a mevalonate synthesis-dependent manner. From a clinical perspective, statin users seem to experience better survival and quality of life when compared with non-users. Considering the high cost and the low response rates obtained with many of the current therapies, the use of orally or intraperitoneally administered simvastatin offers a cost/effective and safe alternative to treat and potentially prevent recurrent HGS-ovCs.


Assuntos
Plasticidade Celular/efeitos dos fármacos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Metástase Neoplásica/patologia , Células-Tronco Neoplásicas/efeitos dos fármacos , Neoplasias Ovarianas/patologia , Sinvastatina/farmacologia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Feminino , Humanos , Células-Tronco Neoplásicas/patologia
6.
Oncogene ; 35(48): 6189-6202, 2016 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-27157613

RESUMO

ErbB-2 amplification/overexpression accounts for an aggressive breast cancer (BC) subtype (ErbB-2-positive). Enhanced ErbB-2 expression was also found in gastric cancer (GC) and has been correlated with poor clinical outcome. The ErbB-2-targeted therapies trastuzumab (TZ), a monoclonal antibody, and lapatinib, a tyrosine kinase inhibitor, have proved highly beneficial. However, resistance to such therapies remains a major clinical challenge. We here revealed a novel mechanism underlying the antiproliferative effects of both agents in ErbB-2-positive BC and GC. TZ and lapatinib ability to block extracellular signal-regulated kinases 1/2 and phosphatidylinositol-3 kinase (PI3K)/AKT in sensitive cells inhibits c-Myc activation, which results in upregulation of miR-16. Forced expression of miR-16 inhibited in vitro proliferation in BC and GC cells, both sensitive and resistant to TZ and lapatinib, as well as in a preclinical BC model resistant to these agents. This reveals miR-16 role as tumor suppressor in ErbB-2-positive BC and GC. Using genome-wide expression studies and miRNA target prediction algorithms, we identified cyclin J and far upstream element-binding protein 1 (FUBP1) as novel miR-16 targets, which mediate miR-16 antiproliferative effects. Supporting the clinical relevance of our results, we found that high levels of miR-16 and low or null FUBP1 expression correlate with TZ response in ErbB-2-positive primary BCs. These findings highlight a potential role of miR-16 and FUBP1 as biomarkers of sensitivity to TZ therapy. Furthermore, we revealed miR-16 as an innovative therapeutic agent for TZ- and lapatinib-resistant ErbB-2-positive BC and GC.


Assuntos
Neoplasias da Mama/genética , Ciclinas/genética , DNA Helicases/genética , Proteínas de Ligação a DNA/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , MicroRNAs/genética , Quinazolinas/farmacologia , Neoplasias Gástricas/genética , Trastuzumab/farmacologia , Regiões 3' não Traduzidas , Animais , Antineoplásicos/farmacologia , Sítios de Ligação , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Modelos Animais de Doenças , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Genes Supressores de Tumor , Humanos , Lapatinib , Masculino , Camundongos , Modelos Biológicos , Regiões Promotoras Genéticas , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-myc/metabolismo , Interferência de RNA , Proteínas de Ligação a RNA , Receptor ErbB-2/antagonistas & inibidores , Receptor ErbB-2/metabolismo , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/metabolismo
7.
Oncogene ; 35(17): 2208-22, 2016 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-26212010

RESUMO

Membrane overexpression of the receptor tyrosine kinase ErbB-2 (MErbB-2) accounts for a clinically aggressive breast cancer (BC) subtype (ErbB-2-positive) with increased incidence of metastases. We and others demonstrated that nuclear ErbB-2 (NErbB-2) also plays a key role in BC and is a poor prognostic factor in ErbB-2-positive tumors. The signal transducer and activator of transcription 3 (Stat3), another player in BC, has been recognized as a downstream mediator of MErbB-2 action in BC metastasis. Here, we revealed an unanticipated novel direction of the ErbB-2 and Stat3 interaction underlying BC metastasis. We found that Stat3 binds to its response elements (GAS) at the ErbB-2 promoter to upregulate ErbB-2 transcription in metastatic, ErbB-2-positive BC. We validated these results in several BC subtypes displaying metastatic and non-metastatic ability, highlighting Stat3 general role as upstream regulator of ErbB-2 expression in BC. Moreover, we showed that Stat3 co-opts NErbB-2 function by recruiting ErbB-2 as its coactivator at the GAS sites in the promoter of microRNA-21 (miR-21), a metastasis-promoting microRNA (miRNA). Using an ErbB-2 nuclear localization domain mutant and a constitutively activated ErbB-2 variant, we found that NErbB-2 role as a Stat3 coactivator and also its direct role as transcription factor upregulate miR-21 in BC. This reveals a novel function of NErbB-2 as a regulator of miRNAs expression. Increased levels of miR-21, in turn, downregulate the expression of the metastasis-suppressor protein programmed cell death 4 (PDCD4), a validated miR-21 target. Using an in vivo model of metastatic ErbB-2-postive BC, in which we silenced Stat3 and reconstituted ErbB-2 or miR-21 expression, we showed that both are downstream mediators of Stat3-driven metastasis. Supporting the clinical relevance of our results, we found an inverse correlation between ErbB-2/Stat3 nuclear co-expression and PDCD4 expression in ErbB-2-positive primary invasive BCs. Our findings identify Stat3 and NErbB-2 as novel therapeutic targets to inhibit ErbB-2-positive BC metastasis.


Assuntos
Proteínas Reguladoras de Apoptose/biossíntese , Neoplasias da Mama/genética , MicroRNAs/biossíntese , Proteínas de Ligação a RNA/biossíntese , Receptor ErbB-2/biossíntese , Fator de Transcrição STAT3/genética , Adolescente , Adulto , Idoso , Proteínas Reguladoras de Apoptose/genética , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , MicroRNAs/genética , Pessoa de Meia-Idade , Metástase Neoplásica , Proteínas de Ligação a RNA/genética , Receptor ErbB-2/genética , Transdução de Sinais , Ativação Transcricional/genética , Transfecção
8.
Oncogene ; 34(26): 3413-28, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25174405

RESUMO

Membrane overexpression of ErbB-2/HER2 receptor tyrosine kinase (membrane ErbB-2 (MErbB-2)) has a critical role in breast cancer (BC). We and others have also shown the role of nuclear ErbB-2 (NErbB-2) in BC, whose presence we identified as a poor prognostic factor in MErbB-2-positive tumors. Current anti-ErbB-2 therapies, as with the antibody trastuzumab (Ttzm), target only MErbB-2. Here, we found that blockade of NErbB-2 action abrogates growth of BC cells, sensitive and resistant to Ttzm, in a scenario in which ErbB-2, ErbB-3 and Akt are phosphorylated, and ErbB-2/ErbB-3 dimers are formed. Also, inhibition of NErbB-2 presence suppresses growth of a preclinical BC model resistant to Ttzm. We showed that at the cyclin D1 promoter, ErbB-2 assembles a transcriptional complex with Stat3 (signal transducer and activator of transcription 3) and ErbB-3, another member of the ErbB family, which reveals the first nuclear function of ErbB-2/ErbB-3 dimer. We identified NErbB-2 as the major proliferation driver in Ttzm-resistant BC, and demonstrated that Ttzm inability to disrupt the Stat3/ErbB-2/ErbB-3 complex underlies its failure to inhibit growth. Furthermore, our results in the clinic revealed that nuclear interaction between ErbB-2 and Stat3 correlates with poor overall survival in primary breast tumors. Our findings challenge the paradigm of anti-ErbB-2 drug design and highlight NErbB-2 as a novel target to overcome Ttzm resistance.


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Proliferação de Células/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Terapia de Alvo Molecular , Proteínas Mutantes/farmacologia , Receptor ErbB-2/antagonistas & inibidores , Transporte Ativo do Núcleo Celular/efeitos dos fármacos , Animais , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Proliferação de Células/genética , Resistencia a Medicamentos Antineoplásicos/genética , Sinergismo Farmacológico , Feminino , Genes Dominantes/fisiologia , Humanos , Camundongos Endogâmicos BALB C , Camundongos Nus , Terapia de Alvo Molecular/métodos , Proteínas Mutantes/uso terapêutico , Isoformas de Proteínas/farmacologia , Isoformas de Proteínas/uso terapêutico , Transporte Proteico/efeitos dos fármacos , Receptor ErbB-2/genética , Receptor ErbB-2/metabolismo , Receptor ErbB-2/fisiologia , Trastuzumab , Células Tumorais Cultivadas
9.
Int. j. morphol ; 32(4): 1243-1247, Dec. 2014. ilus
Artigo em Espanhol | LILACS | ID: lil-734665

RESUMO

La leucemia linfoblástica aguda (LLA) es la neoplasia maligna hematooncólogica más frecuente en pacientes pediátricos contando hasta 75% de las leucemias y 32-35% del total de cánceres infantiles. Aunque la LLA es considerada una enfermedad con base genética, es cada vez más evidente que alteraciones epigenéticas desempeñan un rol central en su patogénia y progresión. La hipermetilación de regiones promotoras de genes es asociada con la pérdida de función génica. El gen supresor de tumores p53 (GST), es uno de los principales genes en el ciclo celular y apoptosis. El objetivo de este trabajo fue determinar el estado de metilación en la región del promotor-exón 1 del GST p53 y la asociación con la supervivencia en menores de 15 años con LLA. Se analizaron 40 pacientes provenientes de la Región de la Araucanía-Chile. La hipermetilación del p53 se determinó combinando enzimas de restricción sensibles a metilación (HpaII y EcoR II) y reacción en cadena de la polimerasa. Los resultados indicaron que 15/40 casos (37,5%) presentaron hipermetilación. Se encontró una diferencia estadística en la supervivencia según estado de metilación de p53 en el grupo de niñas (p=0,02). Considerando el total de pacientes, una tendencia a mejor supervivencia cuando los recuentos de leucocitos fueron <30.000/mm3 (p=0,08). Se encontró frecuentemente hipermetilado el gen p53 en la región del promotor-exon1. Esto indicaría que la hipermetilación del GST p53 puede ser un evento importante en la patogénesis de la LLA.


Acute lymphoblastic leukemia (ALL) is the most common hematology oncology malignancy in pediatric patients counting up to 75% of leukemias and 32­35% of all childhood cancers. Although ALL is considered a disease with a genetic basis, it is increasingly clear that epigenetic alterations play a central role in the pathogenesis and work was to determine the methylation status in promoter-exon1 of the TSG-p53 and association with survival in children under 15 years with ALL. In our study 40 patients from the Araucanía Region, Chile were analyzed. Hypermethylation of p53 was determined by combining restriction enzymes sensitive to methylation (HpaII and EcoR II) and polymerase chain reaction. Results indicated that 15/40 cases (37.5%) showed hypermethylation. Statistical difference was found in survival according to p53 methylation status in the girls group (p=0.02). Considering all patients, there was a trend to improved survival when leukocyte counts were <30.000/ul (p=0.08). We found the p53 gene frequently hypermethylated in the promoter-exon1 region. This would indicate that TSG p53 hypermethylation may be an important event in the pathogenesis of ALL.


Assuntos
Humanos , Masculino , Feminino , Lactente , Pré-Escolar , Criança , Adolescente , Genes p53 , Metilação de DNA , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Medula Óssea , Enzimas de Restrição do DNA , Análise de Sobrevida , Regiões Promotoras Genéticas , Epigênese Genética , Distribuição por Idade e Sexo , Reação em Cadeia da Polimerase Multiplex , Contagem de Leucócitos
10.
Rev. méd. Chile ; 132(9): 1069-1077, sept. 2004. tab
Artigo em Espanhol | LILACS | ID: lil-443219

RESUMO

BACKGROUND: Genomic DNA methylation, mutations and allelic deletions explain the inactivation of genes involved in cell proliferation and cell cycle control mechanisms. AIM: To analyze the methylation pattern of important genes related to different carcinogenic mechanisms in patients with breast cancer and the relationship with its biological behavior. MATERIAL AND METHODS: Seventy fresh-frozen breast cancer samples were selected. The methylation specific PCR (MSP) test was used to analyze promoter methylation status for genes CDKN2A (p16), hMLH1, APC, CDH1 (Cadherin E) and FHIT. RESULTS: We found methylation in at least one of the genes studied in 88% of cases and in 3 or more genes in 40.5% of cases. The frequencies of promoter hypermethylation of CDKN2A, hMLH1, APC, CDH1 and FHT were 41.4%, 11.4%, 52.9%, 70% and 42.9%, respectively. We found a relationship between CDKN2A methylatlon and better survival (p=0.002). CDH1 methylation and poor histological differentiation (p=0.007), hMLH1 methylation and non-Mapuche ethnicity (p=-0.03), APC methylation and larger tumor size (p<0.05), FHIT methylatton and lack of estrogen rectptor IHC expression (p<0.05). CONCLUSIONS: The high frequency of promoter methylation in patients with breast cancer confirms its role in breast carcinogenesis. The finding of alterations in the methylation pattern of genes studied and its association with prognostic factors is a helpful tool in the search of new criteria for clinical and therapeutic decision making.


Assuntos
Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Regiões Promotoras Genéticas , Carcinoma Ductal de Mama/genética , Genes Supressores de Tumor , Metilação de DNA , Neoplasias da Mama/genética , Amplificação de Genes/genética , Caderinas/genética , Carcinoma Ductal de Mama/patologia , Estudos de Casos e Controles , Genes APC , Hidrolases Anidrido Ácido/genética , Neoplasias da Mama/patologia , Proteínas Nucleares/genética , Proteínas de Neoplasias/genética , Proteínas de Transporte , Reação em Cadeia da Polimerase/métodos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA