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1.
Br J Cancer ; 112(8): 1340-8, 2015 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-25867259

RESUMO

BACKGROUND: Docetaxel improves symptoms and survival in metastatic castration-resistant prostate cancer (CRPC). However, ∼50% of patients are chemoresistant. This study examined whether changes in cytokine levels predict for docetaxel resistance in vitro and in a clinical cohort. METHODS: PC3 cells or their docetaxel-resistant subline (PC3Rx) were co-cultured with U937 monocytes, with and without docetaxel treatment, and cytokine levels were measured. The circulating levels of 28 cytokines were measured pre-/post cycle 1 of docetaxel from 55 men with CRPC, and compared with prostate-specific antigen (PSA) response. RESULTS: PC3Rx-U937 co-culture expressed more cytokines, chiefly markers of alternative macrophage differentiation, compared with PC3-U937 co-culture. Docetaxel treatment enhanced cytokine production by PC3Rx-U937 co-culture, while reducing cytokine levels in PC3-U937. In patients, changes in the levels of seven circulating cytokines (macrophage inhibitory cytokine 1 (MIC1), interleukin (IL)-1ra, IL-1ß, IL-4, IL-6, IL-12 and IFNγ) after cycle 1 of docetaxel were associated with progressive disease (all P<0.05). The combination of changes in MIC1, IL-4 and IL-6 most strongly predicted PSA response (P=0.002). CONCLUSIONS: In vitro studies suggest docetaxel resistance is mediated, at least in part, by cytokines induced by the interaction between the docetaxel-resistant tumour cells and macrophages. Early changes in circulating cytokine levels were associated with docetaxel resistance in CRPC patients. When considered together, these data suggest a significant role for the inflammatory response and macrophages in the development of docetaxel resistance in CRPC.


Assuntos
Citocinas/sangue , Resistencia a Medicamentos Antineoplásicos , Calicreínas/sangue , Macrófagos/metabolismo , Antígeno Prostático Específico/sangue , Neoplasias de Próstata Resistentes à Castração/metabolismo , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Técnicas de Cocultura , Docetaxel , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Taxoides/farmacologia
2.
Br J Cancer ; 110(10): 2462-71, 2014 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-24714754

RESUMO

BACKGROUND: Docetaxel is the first-line chemotherapy for castration-resistant prostate cancer (CRPC). However, response rates are ∼50% and determined quite late in the treatment schedule, thus non-responders are subjected to unnecessary toxicity. The potential of circulating microRNAs as early biomarkers of docetaxel response in CRPC patients was investigated in this study. METHODS: Global microRNA profiling was performed on docetaxel-resistant and sensitive cell lines to identify candidate circulating microRNA biomarkers. Custom Taqman Array MicroRNA cards were used to measure the levels of 46 candidate microRNAs in plasma/serum samples, collected before and after docetaxel treatment, from 97 CRPC patients. RESULTS: Fourteen microRNAs were associated with serum prostate-specific antigen (PSA) response or overall survival, according to Mann-Whitney U or log-rank tests. Non-responders to docetaxel and patients with shorter survival generally had high pre-docetaxel levels of miR-200 family members or decreased/unchanged post-docetaxel levels of miR-17 family members. Multivariate Cox regression with bootstrapping validation showed that pre-docetaxel miR-200b levels, post-docetaxel change in miR-20a levels, pre-docetaxel haemoglobin levels and visceral metastasis were independent predictors of overall survival when modelled together. CONCLUSIONS: Our study suggests that circulating microRNAs are potential early predictors of docetaxel chemotherapy outcome, and warrant further investigation in clinical trials.


Assuntos
Adenocarcinoma/tratamento farmacológico , Antagonistas de Androgênios/uso terapêutico , Antineoplásicos Hormonais/uso terapêutico , Antineoplásicos Fitogênicos/uso terapêutico , Biomarcadores Tumorais/sangue , Resistencia a Medicamentos Antineoplásicos/genética , MicroRNAs/sangue , Neoplasias da Próstata/tratamento farmacológico , RNA Neoplásico/sangue , Taxoides/uso terapêutico , Adenocarcinoma/genética , Adenocarcinoma/patologia , Adenocarcinoma/secundário , Adenocarcinoma/cirurgia , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos Fitogênicos/farmacologia , Linhagem Celular Tumoral/efeitos dos fármacos , Docetaxel , Perfilação da Expressão Gênica , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Curva ROC , Fatores de Risco , Taxoides/farmacologia , Resultado do Tratamento
3.
Oncogene ; 25(47): 6262-76, 2006 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-16702958

RESUMO

The BRAF(V600E) mutation is found in approximately 6% of human cancers and mimics the phosphorylation of the kinase domain activation segment. In wild-type B-Raf (B-Raf(wt)), activation segment phosphorylation is thought to cooperate with negative charges within the N-region for full activation. In contrast to Raf-1, the N-region of B-Raf is constitutively negatively charged owing to the presence of residues D447/D448 and the phosphorylation of S446. Therefore, it has been suggested that this hallmark predisposes B-Raf for oncogenic activation. In this study, we demonstrate that neutralizing mutations of these residues (in particular S446 and S447), or uncoupling of B-Raf from Ras-guanine 5'-triphosphate (GTP), strongly reduce the biological activity of B-Raf in a PC12 cell differentiation assay. We also confirm that S365 is a 14-3-3 binding site, and determine that mutation of this residue rescues the impaired biological activity of B-Raf proteins with a neutralized N-region, suggesting that the N-region opposes a 14-3-3-mediated transition into an inactive conformation. However, in the case of B-Raf(V600E), although complete N-region neutralization resulted in a 2.5-fold reduction in kinase activity in vitro, this oncoprotein strongly induced PC12 differentiation or transformation and epithelial-mesenchymal transition of MCF-10A cells regardless of its N-region charge. Furthermore, the biological activity of B-Raf(V600E) was independent of its ability to bind Ras-GTP. Our analysis identifies important regulatory differences between B-Raf(wt) and B-Raf(V600E) and suggests that B-Raf(V600E) cannot be inhibited by strategies aimed at blocking S446 phosphorylation or Ras activation.


Assuntos
Substituição de Aminoácidos , Mutação de Sentido Incorreto , Mutação Puntual , Proteínas Proto-Oncogênicas B-raf/fisiologia , Proteínas 14-3-3/metabolismo , Animais , Sítios de Ligação , Diferenciação Celular , Linhagem Celular/citologia , Linhagem Celular/metabolismo , Transformação Celular Neoplásica , Galinhas , Ativação Enzimática , Células Epiteliais/citologia , Retroalimentação Fisiológica , Guanosina Trifosfato/metabolismo , Humanos , Sistema de Sinalização das MAP Quinases , Mesoderma/citologia , Camundongos , Modelos Biológicos , Células NIH 3T3 , Proteína Oncogênica p21(ras)/metabolismo , Células PC12 , Fosforilação , Mapeamento de Interação de Proteínas , Processamento de Proteína Pós-Traducional , Estrutura Terciária de Proteína , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Proteínas Proto-Oncogênicas B-raf/química , Proteínas Proto-Oncogênicas B-raf/genética , Ratos , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/fisiologia , Relação Estrutura-Atividade , Transfecção
4.
Mol Biol Cell ; 4(11): 1175-88, 1993 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8305738

RESUMO

Mutations in the Caenorhabditis elegans gene sem-5 affect cell signaling processes involved in guiding a class of cell migrations and inducing vulval cell fates. The sem-5 sequence encodes a protein comprised almost exclusively of SH2 and SH3 domains (SH, src homology region) that are found together in many signaling proteins and nonreceptor tyrosine kinases. A human protein, GRB2, was identified by its ability to associate with the activated human epidermal growth factor receptor (hEGFR). The GRB2 and Sem-5 proteins share an identical architecture of their SH2 and SH3 domains and 58% amino acid sequence identity. Here we demonstrate that GRB2 and a Drosophila sem-5-like gene Drk can specifically rescue sem-5 mutants. We also show that Sem-5, like GRB2, can bind to the activated hEGFR in vitro. We further correlate the abilities of several mutant variants of GRB2 and Sem-5 to bind to the hEGFR in vitro with their abilities to functionally replace sem-5 in vivo. These data indicate that GRB2 and Drk are functional homologues of Sem-5 and demonstrate the high degree of conservation of both structure and function between signaling systems throughout evolution.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Proteínas de Caenorhabditis elegans , Caenorhabditis elegans/genética , Proteínas de Drosophila , Receptores ErbB/genética , Proteínas de Helminto/genética , Hormônios de Inseto/genética , Proteínas/genética , Transdução de Sinais/genética , Animais , Animais Geneticamente Modificados , Sequência de Bases , Clonagem Molecular , Receptores ErbB/análise , Receptores ErbB/metabolismo , Feminino , Proteína Adaptadora GRB2 , Genes de Helmintos , Genes de Insetos/genética , Humanos , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Mutação Puntual/genética , Receptores do Fator de Crescimento Derivado de Plaquetas/metabolismo , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/isolamento & purificação , Transformação Genética , Vulva/crescimento & desenvolvimento
5.
Cancer Res ; 50(18): 5868-75, 1990 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-2393857

RESUMO

When deprived of steroid in the long term, both estrogen-dependent (ZR-75-1) and estrogen-responsive (T-47-D) human breast cancer cells lose estrogen regulation of cell growth in a reproducible time course using both stock lines and recloned cells. The estrogen-stimulated growth rate was unaffected by such treatment, but there was an increase in the basal growth rate without steroid. For ZR-75-1 cells, the effects are clonal but occur at high frequency (1 in 1000 cells) and synchronously between clones, suggesting a phenotypic mechanism. These changes in cell growth occur without any coordinated loss of estrogen sensitivity of molecular markers (pS2 mRNA, progesterone receptor protein) showing that functional estrogen receptors remain present throughout. The constitutive expression of progesterone receptor in one clone of steroid-deprived ZR-75-1 cells does suggest, however, that alterations in expression of individual estrogen-sensitive genes can occur. Loss of estrogen-stimulated growth was not accompanied by loss of growth inhibition by antiestrogen, and the latter effect remained reversible by estradiol. In an attempt to understand the molecular mechanisms underlying the loss of steroid sensitivity in the two cell lines, growth factor gene expression was investigated. Progression to steroid autonomy in T-47-D cells was accompanied by an upregulation of transforming growth factor (TGF) alpha, TGF beta 1, and TGF beta 2 mRNA. However, TGF beta 1 mRNA was downregulated in two ZR-75-1 steroid-deprived clones. These findings are discussed in relation to possible autocrine mechanisms in the loss of steroid sensitivity of breast cancer cells.


Assuntos
Neoplasias da Mama/patologia , Estrogênios/farmacologia , Proteínas , Feminino , Expressão Gênica , Humanos , Fator de Crescimento Insulin-Like II/genética , Proteínas de Neoplasias/genética , RNA Mensageiro/análise , Receptores de Estrogênio/análise , Tamoxifeno/farmacologia , Fatores de Crescimento Transformadores/genética , Fator Trefoil-1 , Células Tumorais Cultivadas , Proteínas Supressoras de Tumor
6.
Cancer Res ; 59(20): 5376-85, 1999 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-10537323

RESUMO

The structural characteristics of EMS1 (human cortactin) suggest that it may link signaling events to reorganization of the actin cytoskeleton. Interestingly, the EMS1 gene is commonly amplified and overexpressed in several human cancers, which may alter their invasive or metastatic properties. An 80 to 85-kDa mobility shift of EMS1 correlates with an alteration in subcellular distribution and is likely to represent an important regulatory event. In HEK 293 cells, epidermal growth factor treatment or cell detachment induced this shift, and this was blocked by the mitogen-activated protein/extracellular signal-regulated kinase kinase (MEK) inhibitor PD98059. Furthermore, expression of a constitutively active form of MEK induced the shift, indicating that MEK activation was both sufficient and necessary for this modification. The epidermal growth factor-induced shift correlated with increased phosphorylation on serine and threonine residues of the same tryptic phosphopeptides detected under basal conditions. Deletion of the helical-proline-rich region of the protein blocked the mobility shift and EMS1 phosphorylation. In vitro kinase assays demonstrated that the extracellular signal-regulated kinases represent candidate kinases for this region, although other MEK-regulated enzymes must also participate. These data identify MEK as an important intermediate involved in EMS1 phosphorylation and highlight the helical-proline-rich region as a key regulatory domain.


Assuntos
MAP Quinase Quinase Quinase 1 , Proteínas dos Microfilamentos/metabolismo , Proteínas de Neoplasias/metabolismo , Proteínas Serina-Treonina Quinases , Adesão Celular , Células Cultivadas , Cortactina , Fator de Crescimento Epidérmico/farmacologia , Flavonoides/farmacologia , Humanos , MAP Quinase Quinase Quinases/fisiologia , Proteínas dos Microfilamentos/química , Fosforilação , Serina/metabolismo , Relação Estrutura-Atividade , Treonina/metabolismo , Domínios de Homologia de src
7.
Cancer Res ; 58(9): 1773-8, 1998 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-9581810

RESUMO

The molecular genetic events involved in the etiology of human granulosa cell (GC) tumors, which represent approximately 7% of all malignant ovarian neoplasms, are unknown. Amplification and/or overexpression of the ERBB genes are a feature of many cancer types, and overexpression of erbB2 correlates with poor prognosis in epithelial ovarian cancer. In the present study, we used immunohistochemistry to determine the level and frequency of expression of different erbB receptors in GC tumors. Ten of 12 tumors expressed erbB4 at moderate to high levels in >50% of cancer cells, whereas erbB2 (6 of 12) and erbB3 (2 of 12) were expressed less frequently. Western blot experiments showed that the only available GC tumor cell line, COV434, also expressed erbB receptors. Heregulin (HRG)-beta2, a ligand for erbB3 and erbB4 receptors, stimulated tyrosine phosphorylation of the erbB receptors, which was accompanied by activation of Erk1 and Erk2, two mitogen-activated protein kinases with a functional role in mitogenesis. Importantly, HRG increased cell proliferation in COV434 cells, and treatment with HRG/PE40, a ligand toxin shown previously to be cytotoxic against human breast cancer cells overexpressing erbB receptors, led to a dramatic and irreversible decrease in cell number. These results indicate that erbB receptor signaling pathways may be critical in the control of GC tumor cell proliferation and that HRG/PE40 is a potential therapeutic agent for the treatment of GC tumors.


Assuntos
Proteínas de Transporte/toxicidade , Receptores ErbB/metabolismo , Glicoproteínas/toxicidade , Tumor de Células da Granulosa/metabolismo , Neuregulina-1 , Neoplasias Ovarianas/metabolismo , Northern Blotting , Western Blotting , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Divisão Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Eletroforese em Gel de Poliacrilamida , Feminino , Tumor de Células da Granulosa/tratamento farmacológico , Tumor de Células da Granulosa/patologia , Humanos , Técnicas Imunoenzimáticas , Imuno-Histoquímica , Ligantes , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/patologia , Fosforilação , Receptor ErbB-4 , Transdução de Sinais/efeitos dos fármacos , Células Tumorais Cultivadas/efeitos dos fármacos , Células Tumorais Cultivadas/metabolismo
8.
Oncogene ; 9(9): 2723-7, 1994 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8058337

RESUMO

A receptor blotting technique was used to detect SH2 domain containing epidermal growth factor receptor (EGFR) substrates that exhibited differential expression either between normal breast epithelial cells and breast cancer cells or between different human breast cancer cell lines. This identified a 25 kD protein, subsequently identified as Grb2, which was markedly overexpressed in three breast cancer cell lines (MCF-7, MDA-MB-361 and -453) relative to both normal breast epithelial cells and the majority of breast cancer cell lines. Northern blot analysis revealed that 7/19 breast cancer cell lines exhibited more than twofold overexpression of Grb2 mRNA, with overexpression correlating with high expression of erbB receptors. In MCF-7, MDA-MB-361 and -453 cells the overexpression of Grb2 mRNA and protein was accompanied by a small amplification of the Grb2 gene locus. Overexpression of Grb2 correlated with increased complex formation between Grb2 and the hSos-1 Ras GDP-GTP exchange protein. This upregulation of the Ras signalling pathway might modulate the growth factor sensitivity of human breast cancer cells and therefore play a role in tumour progression.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Neoplasias da Mama/metabolismo , Receptores ErbB/genética , Regulação Neoplásica da Expressão Gênica , Proteínas/genética , DNA/biossíntese , Feminino , Proteína Adaptadora GRB2 , Genes ras , Humanos , Células Tumorais Cultivadas
9.
Oncogene ; 9(12): 3601-8, 1994 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-7970720

RESUMO

The c-erbB-2 proto-oncogene encodes a receptor tyrosine kinase (RTK) closely related to the epidermal growth factor receptor (EGFR). Overexpression of erbB-2 occurs in approximately 20% of human breast tumours, where increased expression correlates with poor patient prognosis. The EGFR is coupled to the Ras signalling pathway by interaction with the adaptor protein Grb2, and Sos, a Ras GDP-GTP exchange factor. In this study, activation of the erbB-2 receptor and its association with Grb2 and Sos was investigated in breast cancer cell lines which overexpress erbB-2. The receptor was found to be tyrosine phosphorylated in all cell lines in which it is overexpressed. Western blotting of Grb2 and Sos immuneprecipitates from such cells revealed co-precipitation of erbB-2, demonstrating association of the Grb2/Sos complex with erbB-2 in vivo. Furthermore, a fusion protein containing only the SH2 domain of Grb2 bound to erbB-2 immobilized on nitrocellulose, indicating that association with Grb2 is direct and mediated by the SH2 domain of Grb2. The degree of association between the erbB-2 receptor and Grb2 in vivo was related to erbB-2 overexpression, and MAP kinase, which functions downstream from Ras, displayed markedly increased activity in cell lines overexpressing erbB-2. These results demonstrate that erbB-2 is coupled to Ras signalling via the Grb2/Sos complex, and that overexpression of this receptor in breast cancer cells leads to amplification of the Ras signalling pathway.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Neoplasias da Mama/metabolismo , Regulação Neoplásica da Expressão Gênica , Genes erbB-2 , Transdução de Sinais , Neoplasias da Mama/enzimologia , Neoplasias da Mama/genética , Proteína Adaptadora GRB2 , Fatores de Troca do Nucleotídeo Guanina , Humanos , Proteína Quinase 1 Ativada por Mitógeno , Fenótipo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Tirosina Quinases/metabolismo , Proteínas/metabolismo , Proto-Oncogene Mas , Células Tumorais Cultivadas , Fatores ras de Troca de Nucleotídeo Guanina
10.
Oncogene ; 15(13): 1617-23, 1997 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-9380415

RESUMO

Chromosome 11q13 is amplified in about 13% of primary breast cancers. CCND1, encoding the cell cycle regulatory gene cyclin D1, and EMS1, encoding a filamentous actin binding protein, are favoured candidate onocogenes, whereas INT-2 is an unexpressed gene at this locus. In this study we tested the possibility that different regions of this large amplicon could be independently amplified and subsequently defined the phenotype of EMS1 amplified tumours in a series of 961 primary breast carcinomas. Using DNA slot blots, EMS1 was amplified in 15.2% of samples: 5.4% were coamplified for CCND1; 7.9% coamplified for INT-2 and 6.7% showed EMS1 amplification alone. The degree of amplification of CCND1 and INT-2 was highly correlated (P =0.0001). In contrast, no such relationship existed between EMS1 and CCND1 or INT-2 amplification, demonstrating independent amplification of EMS1 in 44% of amplified tumours. EMS1 amplification (> or = twofold increase in copy number) was positively correlated with patient age > or = 50 years (P = 0.025), ER positivity (P = 0.022), PgR positivity (P = 0.018), and was negatively correlated with HER-2/neu (c-erbB2) amplification (P = 0.01). In common with CCND1/INT-2, EMS1 amplification was associated with increased risk of relapse in patients with lymph node-negative disease (P = 0.028). In contrast, EMS1 and CCND1/INT-2 amplification appeared to confer different phenotypes in ER positive and negative tumours. A > or = threefold increase in EMS1 copy number was associated with an apparent increased risk of relapse and death in patients with ER negative tumours, but was without effect in ER positive tumours. In contrast, CCND1/INT-2 amplification had no effect in the patients with ER negative tumours but was associated with early relapse in ER positive patients. Thus EMS1 amplification may identify subgroups of breast cancer patients with increased probability of relapse and death distinct from those identified by CCND1/INT-2 amplification. Further studies are required to more clearly determine the functional consequences of EMS1 overexpression and a biological basis for the relationship between EMS1 amplification and phenotype in breast cancer.


Assuntos
Neoplasias da Mama/genética , Cromossomos Humanos Par 11 , Amplificação de Genes , Proteínas dos Microfilamentos , Proteínas de Neoplasias/genética , Cortactina , Ciclina D1/metabolismo , Fator 3 de Crescimento de Fibroblastos , Fatores de Crescimento de Fibroblastos/metabolismo , Marcadores Genéticos , Humanos , Fenótipo , Proteínas Proto-Oncogênicas/metabolismo
11.
Oncogene ; 16(21): 2803-13, 1998 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-9652748

RESUMO

Members of the erbB family of receptor tyrosine kinases are commonly overexpressed in human breast cancer. However, the relative contribution of particular signalling pathways activated downstream of these receptors to the mitogenic response of transformed breast epithelial cells remains poorly characterized. Administration of heregulin-beta2 (HRG), a ligand for erbB3 and erbB4, to growth arrested T-47D human breast cancer cells leads to activation of both the PI3-kinase and MAP kinase signalling pathways and potent stimulation of cell cycle progression. Specific inhibitors were used to assess the role of these pathways in HRG-induced mitogenesis and to identify underlying mechanisms in terms of regulation of gene expression. Treatment with the MEK inhibitor PD98059 led to a complete block of HRG-induced entry into S-phase, whilst administration of the PI3-kinase inhibitor wortmannin resulted in only modest inhibition. In addition, administration of PD98059 8 h after HRG was equipotent with simultaneous administration in inhibiting entry into S-phase. However, delaying addition for 14-16 h after HRG, when the cells were entering S-phase, was without effect. HRG stimulation led to sequential induction of c-myc, cyclin D1, cyclin E and cyclin A gene expression and hyperphosphorylation of the retinoblastoma protein pRB. p21 (WAF1/CIP1/SDI1) gene expression was rapidly induced by HRG, but significant changes in p27 (KIP1) protein levels were not detected. Preincubation with PD98059 blocked the HRG-dependent induction of cyclin D1 mRNA, p21 and c-Myc protein and pRB phosphorylation. These findings demonstrate that MEK activation is critical to HRG-induced S-phase entry in these cells whilst PI3-kinase plays a minor role. Moreover, these data are compatible with HRG-induced activation of MEK being critical for a mid-G1 transition point and implicate c-myc and cyclin D1 as key targets of the MAP kinase pathway involved in this response.


Assuntos
Neoplasias da Mama/patologia , Proteínas Quinases Dependentes de Cálcio-Calmodulina/antagonistas & inibidores , Proteínas de Transporte/farmacologia , Glicoproteínas/farmacologia , Neuregulina-1 , Androstadienos/farmacologia , Neoplasias da Mama/enzimologia , Ciclo Celular/efeitos dos fármacos , Ciclina D1/genética , Quinases Ciclina-Dependentes/antagonistas & inibidores , Ciclinas/genética , Ativação Enzimática , Inibidores Enzimáticos/farmacologia , Feminino , Flavonoides/farmacologia , Expressão Gênica , Humanos , Quinases de Proteína Quinase Ativadas por Mitógeno , Mitógenos/farmacologia , Inibidores de Fosfoinositídeo-3 Quinase , Fosforilação , Inibidores de Proteínas Quinases , Proteínas Quinases/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , RNA Mensageiro , Proteína do Retinoblastoma/metabolismo , Células Tumorais Cultivadas , Regulação para Cima , Wortmanina
12.
Oncogene ; 17(8): 1053-9, 1998 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-9747885

RESUMO

The EMS1 and CCND1 genes at chromosome 11q13 are amplified in about 15% of primary breast cancers but appear to confer different phenotypes in ER positive and ER negative tumours. Since there are no published data on EMS1 expression in large series of breast cancers we examined the relationship of EMS1 expression with EMS1 gene copy number and expression of mRNAs for cyclin D1 and ER. In a subset of 129 patients, where matched tumour RNA and DNA was available, EMS1 mRNA overexpression was associated predominantly with gene amplification (P = 0.0061), whereas cyclin D1 mRNA overexpression was not (P = 0.3142). In a more extensive series of 351 breast cancers, there was no correlation between cyclin D1 and EMS1 expression in the EMS1 and cyclin D1 overexpressors (P = 0.3503). Although an association between EMS1 mRNA expression and ER positivity was evident (P = 0.0232), when the samples were divided into quartiles of EMS1 or cyclin D1 mRNA expression, the increase in the proportion of ER positive tumours in the ascending EMS1 mRNA quartiles was not statistically significant (P = 0.0951). In marked contrast there was a significant stepwise increase in ER positivity in ascending quartiles of cyclin D1 mRNA (P = 0.030). A potential explanation for this difference was provided by the observation that in ER positive breast cancer cells oestradiol treatment resulted in increased cyclin D1 gene expression but was without effect on EMS1. The relationship between EMS1 expression and clinical outcome was examined in a subset of 234 patients with median follow-up of 74 months. High EMS1 expression was associated with age > 50 years (P = 0.0001), postmenopausal status (P = 0.0008), lymph node negativity (P = 0.019) and an apparent trend for worse prognosis in the ER negative subgroup. These data demonstrate that overexpression of EMS1 mRNA is largely due to EMS1 gene amplification, is independent of cyclin D1 and ER expression and, in contrast to cyclin D1, is not regulated by oestrogen. Independent overexpression of these genes may confer different phenotypes and disease outcomes in breast cancer as has been inferred from recent studies of EMS1 and CCND1 gene amplification.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Ciclina D1/biossíntese , Regulação Neoplásica da Expressão Gênica , Proteínas dos Microfilamentos , Proteínas de Neoplasias/genética , Receptores de Estrogênio/biossíntese , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/mortalidade , Cromossomos Humanos Par 11/genética , Cortactina , Ciclina D1/genética , Humanos , Pessoa de Meia-Idade , RNA Mensageiro/biossíntese
13.
Cell Signal ; 10(9): 613-8, 1998 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9794242

RESUMO

The Grb7 family is a rapidly emerging group of Src homology (SH)2 domain-containing signalling proteins that currently contains three members, Grb7, 10 and 14. These proteins possess a conserved multidomain structure, including a central region exhibiting significant homology to the Caenorhabditis elegans protein Mig10. Differences in tissue expression and SH2 binding selectivity suggest that these adaptor proteins function in a tissue-specific manner to link specific receptor tyrosine kinases (RTKs) and other tyrosine phosphorylated proteins to as yet uncharacterised downstream effectors. Interestingly, Grb7 proteins exhibit differential expression amongst a variety of human cancers and cancer cell lines. Consequently, these proteins not only are likely to perform a fundamental signalling role, but may also modulate RTK signalling in cancer cells.


Assuntos
Proteínas de Caenorhabditis elegans , Proteínas/metabolismo , Transdução de Sinais/fisiologia , Sequência de Aminoácidos , Animais , Proteína Adaptadora GRB7 , Expressão Gênica , Proteínas de Helminto/metabolismo , Humanos , Dados de Sequência Molecular , Neoplasias/metabolismo , Fosforilação , Proteínas/química , Proteínas/genética , Receptores Proteína Tirosina Quinases/metabolismo , Domínios de Homologia de src
14.
Mol Cell Endocrinol ; 59(3): 205-12, 1988 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-2903103

RESUMO

A cDNA library has been constructed from the poly(A)+ mRNA of oestrogen-stimulated ZR-75-1 human breast cancer cells. Screening by differential hybridization has identified eight clones which are stimulated between 4- and 16-fold by oestrogen. Two clones (pLIV-1) that are stimulated 4-fold, hybridize to three different mRNA species. A further five recombinants encode for a mRNA 600 bp long which is induced greater than 16-fold and have been shown to cross-hybridize to the oestrogen-responsive clone, pS2, isolated from the MCF-7 breast cancer cell line. Oestradiol was shown to be without detectable effect upon the expression of mRNA for dihydrofolate reductase, which is reported to be oestrogen regulated in MCF-7 cells. Actin gene expression is also unresponsive to oestradiol in ZR-75-1 cells. These results suggest that pLIV-1 represents a previously unidentified mRNA that may be involved in the oestrogen-regulated growth of ZR-75-1 human breast cancer cells.


Assuntos
Neoplasias da Mama/genética , Estradiol/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , RNA Mensageiro/genética , Sondas de DNA , Humanos , Hibridização de Ácido Nucleico , Plasmídeos , Poli A/genética , Células Tumorais Cultivadas
15.
J Steroid Biochem Mol Biol ; 37(6): 753-63, 1990 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-2285587

RESUMO

An in vitro model system is described for studying the problem of loss of steroid sensitivity in breast cancer cells. Growth of cloned oestrogen-sensitive human breast cancer cells in the long-term absence of steroid gives rise to a population of oestrogen-insensitive cells. In ZR-75-1 cells, the effect is clonal but occurs at high frequency suggesting a mechanism affecting a wide proportion of the cell population synchronously. This does not involve any reduction in oestrogen receptor number. Furthermore, there is no coordinated loss of oestrogen-sensitive molecular markers, showing that oestrogen receptors remain not only present but functional. These growth changes are not accompanied by any loss of growth inhibition by antioestrogen. Although steroid deprivation does not result in loss of oestrogen-sensitive markers, this does not hold true for other steroids. There was a reduction in progestin, androgen and glucocorticoid regulation on transfected LTRs. Loss of steroid-sensitive growth was accompanied by changes in response to exogenous growth factors and altered endogenous growth factor mRNA production. Steroid-deprived T-47-D cells acquire sensitivity to stimulation by TGF beta and have raised TGF beta 1 and TGF beta 2 mRNA levels. ZR-75-1 cells are growth inhibited by TGF beta and have reduced TGF beta 1 mRNA levels. In MCF-7 cells, increased IGFII mRNA, following transfection, can result in an increased basal cell growth rate in the absence of steroid. These findings are discussed in relation to possible autocrine mechanisms in the loss of steroid sensitivity of breast cancer cells.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Estrogênios/farmacologia , Neoplasias da Mama/genética , Transformação Celular Neoplásica/efeitos dos fármacos , Marcadores Genéticos , Substâncias de Crescimento/farmacologia , Humanos , RNA Mensageiro/metabolismo , Receptores de Estrogênio/genética , Células Tumorais Cultivadas
16.
J Steroid Biochem Mol Biol ; 54(1-2): 21-9, 1995 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7632611

RESUMO

Progression to steroid autonomy is a major clinical problem in the treatment of steroid-sensitive tumours. Molecular mechanisms remain unknown but recent hypotheses imply a role for growth factors in this progression. Since S115 + A androgen-responsive mouse mammary tumour cells provide a model system to study this phenomenon in vitro, we have used this model to investigate growth factor gene expression and sensitivity during progression from a steroid sensitive to insensitive state. S115 + A androgen-responsive cells showed a positive proliferative response, morphological response and increased saturation density to various forms of fibroblast growth factor (FGF) and transforming growth factor beta (TGF beta) in both monolayer and suspension culture. A marked synergy was noted, however, between FGF and TGF beta in promoting growth in suspension culture. S115 + A cells possessed mRNA for both acidic FGF (aFGF) and TGF beta 1, both of which were increased by testosterone. Progression to androgen insensitivity was associated with a reversal of growth factor response such that all growth factor responses became generally inhibitory on growth of the unresponsive cells but with a particularly striking synergistic action between FGF and TGF beta 1 on inhibition of both monolayer and suspension growth. Levels of aFGF and TGF beta 1 mRNAs remained low in steroid-insensitive S115-A cells, indicating that loss of response was not associated with any constitutive upregulation of endogenous production of one of these growth factors. The scientific and clinical implications are discussed.


Assuntos
Androgênios/farmacologia , Fatores de Crescimento de Fibroblastos/biossíntese , Neoplasias Mamárias Experimentais/metabolismo , Fator de Crescimento Transformador beta/biossíntese , Animais , Divisão Celular/efeitos dos fármacos , Linhagem Celular Transformada , Fatores de Crescimento de Fibroblastos/farmacologia , Camundongos , RNA Mensageiro/análise , Fator de Crescimento Transformador beta/farmacologia
17.
Schizophr Res ; 29(3): 263-7, 1998 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-9516667

RESUMO

Immunological mechanisms have been implicated in schizophrenia, but laboratory results have been variable. We evaluated soluble interleukin 2 receptor (sIL2R alpha) levels in sera of Irish patients with schizophrenia. Twenty-seven patients, 12 females and 15 males, with schizophrenia or schizophreniform psychosis, were sampled, along with 32 controls. Diagnosis was made using the Structured Clinical Interview for DSM IIIR. All but one of the patient group were in the first fortnight of an acute hospital admission. Soluble IL2R alpha levels were measured by ELISA. Soluble IL2R alpha levels were significantly higher (two-tailed p = 0.0019) in patients (median = 1010.4 pg/ml, range = 748.7-5673.3 pg/ml) than in controls (median = 792.3 pg/ml, range = 399.6-1479.5 pg/ml). The elevated sIL2R alpha levels in an Irish population with schizophrenia are consistent with other reports and support the implication of immunological mechanisms in this disorder.


Assuntos
Receptores de Interleucina-2/sangue , Esquizofrenia/imunologia , Adolescente , Adulto , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Irlanda , Masculino , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica , Valores de Referência , Fatores de Risco , Esquizofrenia/diagnóstico
18.
Gen Hosp Psychiatry ; 8(2): 119-22, 1986 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-3957017

RESUMO

A brief summary of the pattern of mental illness in Ireland is given and the work of a psychiatric consultation-liaison service in a general hospital in the southern part of the country is discussed in this context. The referral rates to the service mirror the referral rates in the United Kingdom more than those in the United States. The high rates of alcoholism and functional psychosis found in referred patients probably reflect the increased prevalence of these conditions in the general community. In Ireland, as elsewhere, the rate of referral of general hospital inpatients to a psychiatric consultation-liaison service is below the rate of psychiatric illness found in hospital inpatients.


Assuntos
Hospitais Gerais , Psiquiatria , Encaminhamento e Consulta , Adulto , Feminino , Humanos , Irlanda , Masculino , Transtornos Mentais/epidemiologia , Pessoa de Meia-Idade
19.
Suicide Life Threat Behav ; 17(1): 33-49, 1987.
Artigo em Inglês | MEDLINE | ID: mdl-3590270

RESUMO

Self-poisoning patients (n = 40) were compared with psychiatric patients (n = 40) and nonpatient controls (n = 20) on measures of interpersonal problem-solving skills and locus of control in an effort to determine the importance of these cognitive and personality variables in self-poisoning behavior. The psychiatric and self-poisoning groups showed deficits on measures assessing interpersonal problem solving when compared with nonpatient controls. The self-poisoning group performed below the level of the psychiatric patients on all except one test, on which they performed at the level of the psychiatric group. Locus of control did not differentiate self-poisoning patients from nonpatient controls, and it was concluded that this variable is not an important factor in self-poisoning behavior.


Assuntos
Relações Interpessoais , Intoxicação/psicologia , Resolução de Problemas , Adolescente , Adulto , Transtorno Depressivo/psicologia , Feminino , Humanos , Controle Interno-Externo , Masculino , Pessoa de Meia-Idade , Transtornos da Personalidade/psicologia , Testes Psicológicos , Meio Social , Tentativa de Suicídio/psicologia
20.
Suicide Life Threat Behav ; 24(4): 382-94, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-7740595

RESUMO

The present study evaluated the effectiveness of interpersonal problem-solving skills training (IPSST) for the treatment of self-poisoning patients. Thirty-nine self-poisoning patients were assigned randomly either to IPSST or to a control treatment condition (a brief problem-oriented approach). Both conditions were equally effective in reducing the number of presenting problems and in reducing hopelessness levels. However, the IPSST condition was significantly more effective than the control condition as determined by other outcome measures (measures of interpersonal cognitive problem solving, self-rated personal problem-solving ability, perceived ability to cope with ongoing problems, and self-perception). Follow-up studies showed maintenance of IPSST treatment gains at 6 months and a greater reduction of repetition of self-poisoning in the IPSST group at 1 year posttreatment.


Assuntos
Overdose de Drogas/psicologia , Relações Interpessoais , Resolução de Problemas , Tentativa de Suicídio/psicologia , Adolescente , Adulto , Alcoolismo/psicologia , Alcoolismo/terapia , Transtorno da Personalidade Dependente/psicologia , Transtorno da Personalidade Dependente/terapia , Transtorno Depressivo/psicologia , Transtorno Depressivo/terapia , Overdose de Drogas/prevenção & controle , Feminino , Humanos , Masculino , Motivação , Equipe de Assistência ao Paciente , Inventário de Personalidade , Fatores de Risco , Tentativa de Suicídio/prevenção & controle
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