RESUMO
URBAN is a multicentric, ambispective study evaluating the effectiveness and safety of obinutuzumab-based immuno-chemotherapy and maintenance in patients with untreated advanced follicular lymphoma (FL). The study began before the COVID-19 emergency declaration in Italy. It is currently ongoing for follow-up, and the enrolment timeline encompassed different stages of the pandemic, various vaccination roll-out phases and prevalence of SARS-CoV-2 variants. Outcomes of interest of the present sub-analysis included SARS-CoV-2 infection rates and COVID-19-related hospitalizations/deaths. At data cut-off, 86 (28.8%) and 213 patients (71.2%) were treated before and during/after the COVID-19 outbreak respectively; 294 (98.3%) completed the induction, 31 (10.4%) completed maintenance and 170 (56.9%) were still on maintenance. Overall, 245 patients (81.9%) received at least one SARS-CoV-2 vaccine dose: 13.5%, 31.4% and 55.1% received one, two and three doses respectively. We observed a substantial decrease in COVID-19-related mortality rates in pre- versus post-vaccination phases, along with a reduction in COVID-19-related outcomes due to the shift from alpha/delta to omicron variant predominance. No differences emerged between patients given maintenance or not, although the schedule was modified in 65% of cases. To our knowledge, URBAN represents the largest dataset of COVID-19-related outcomes in FL patients extensively exposed to obinutuzumab. ClinicalTrials.gov identifier: NCT04034056.
RESUMO
BACKGROUND: A combination of bortezomib (1.3 mg/m(2)), melphalan (5 mg/m(2)), and dexamethasone (40 mg) (BMD), with all three drugs given as a contemporary intravenous administration, was retrospectively evaluated. PATIENTS AND METHODS: Fifty previously treated (median 2 previous lines) patients with myeloma (33 relapsed and 17 refractory) were assessed. The first 19 patients were treated with a twice-a-week (days 1, 4, 8, 11, 'base' schedule) administration while, in the remaining 31 patients, the three drugs were administered once a week (days 1, 8, 15, 22, 'weekly' schedule). RESULTS: Side-effects were predictable and manageable, with prominent haematological toxicity, and a better toxic profile in 'weekly' schedule (36% versus 66% in 'base' schedule). The overall response rate was 62%. After median follow-up of 24.5 months (range 2.7-50 months), the median progression-free survival (PFS) was 21.6 with no difference between the two schedules and the median overall survival (OS) was 33.8 months. Independently from the adopted schedule, we found that also in a cohort of relapsed/refractory patients achieving at least partial remission improved PFS (35.2 versus 9 months) and OS (unreached median versus 18 months). CONCLUSION: Taken together, our observations suggest that BMD is an effective regimen in advanced myeloma patients with acceptable toxicity.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Ácidos Borônicos/administração & dosagem , Dexametasona/administração & dosagem , Melfalan/administração & dosagem , Mieloma Múltiplo/tratamento farmacológico , Pirazinas/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Ácidos Borônicos/efeitos adversos , Bortezomib , Dexametasona/efeitos adversos , Intervalo Livre de Doença , Esquema de Medicação , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/induzido quimicamente , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/patologia , Feminino , Seguimentos , Humanos , Injeções Intravenosas , Masculino , Melfalan/efeitos adversos , Pessoa de Meia-Idade , Mieloma Múltiplo/patologia , Pirazinas/efeitos adversos , Recidiva , Estudos Retrospectivos , Resultado do TratamentoRESUMO
BRIT1 (BRCT-repeat inhibitor of hTERT expression), also known as microcephalin (MCPH1), is a crucial gene in the complex cellular machine that is devoted to DNA repair and acts as a regulator of both the intra-S and G2/M checkpoints. The most important role of BRIT1/MCPH1 in the regulation of cell cycle progression appears to be the G2/M checkpoint. The K562 and peripheral blood cells of chronic myeloid leukemia (CML) patients at diagnosis were found to downregulate BRIT1/MCPH1. However, we could not find any correlation between bcr/abl activity and the BRIT1/MCPH1 level. In order to study the genomic instability of CML cells, we evaluated the ability of these cells to arrest mitotic division after exposure to hydroxyurea, a known genotoxic agent. We showed that CML cells continue to proliferate without the activation of the G2/M cell cycle checkpoint arrest or of the apoptotic mechanism. This behavior may predispose the cells to accumulate genomic defects. In conclusion, we found that CML cells have a low BRIT1/MCPH1 level and show a defective G2/M arrest, confirming that these cells have a constitutive genomic instability.
Assuntos
Pontos de Checagem da Fase G2 do Ciclo Celular , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Proteínas de Neoplasias/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Actinas/antagonistas & inibidores , Adulto , Idoso , Proteínas de Ciclo Celular , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Citocalasina B/toxicidade , Citocinese/efeitos dos fármacos , Proteínas do Citoesqueleto , Feminino , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica , Instabilidade Genômica , Humanos , Hidroxiureia/antagonistas & inibidores , Hidroxiureia/toxicidade , Células K562 , Leucemia Mielogênica Crônica BCR-ABL Positiva/sangue , Leucócitos/efeitos dos fármacos , Leucócitos/metabolismo , Masculino , Pessoa de Meia-Idade , Mutagênicos/toxicidade , Proteínas de Neoplasias/genética , Proteínas do Tecido Nervoso/genética , RNA Mensageiro/metabolismoRESUMO
In chronic lymphocytic leukemia (CLL), stabilizing mutations of NOTCH1, affecting up to 10-15% of cases, have been associated to poor prognosis, disease progression and refractoriness to chemotherapy. NOTCH1 mutations are significantly overrepresented in trisomy 12 CLL, a disease subset frequently expressing CD49d, the α4 chain of the very-late-activation-4 integrin, a well-known key regulator of microenviromental interactions, and negative prognosticator in CLL. In the present study, by analysing a wide cohort of 1180 CLL, we observed a very strong association between the presence of NOTCH1 mutations and the expression of CD49d (P<0.0001), occurring also outside the trisomy 12 CLL subset. Using both the MEC-1 CLL-like cells stably transfected with the NOTCH1 intracellular domain and primary CLL cells bearing a mutated or wild-type NOTCH1 gene configuration, we provide evidence that triggering of the NOTCH1 pathway resulted in a positive CD49d expression regulation, which was driven by a NOTCH1-dependent activation of nuclear factot-κB (NF-κB). Consistently, pharmacological inhibition of the NOTCH1 and/or of the NF-κB pathways resulted in impaired NF-κB nuclear translocation with consequent down-modulation of CD49d expression. Altogether, our data link for the first time NOTCH1 mutations to CD49d expression regulation through the involvement of the NF-κB pathway in CLL.
Assuntos
Regulação Leucêmica da Expressão Gênica , Integrina alfa4/genética , Leucemia Linfocítica Crônica de Células B/genética , Mutação , Receptor Notch1/genética , Humanos , Integrina alfa4/metabolismo , Leucemia Linfocítica Crônica de Células B/metabolismo , Leucemia Linfocítica Crônica de Células B/patologia , NF-kappa B/metabolismo , Receptor Notch1/metabolismo , Transdução de SinaisRESUMO
BACKGROUND: Although the stomach is the most frequent site of intestinal lymphomas, few data are available on both clinical endoscopic presentation of gastric lymphoma and possible differences between low-grade and high-grade lymphomas. METHODS: Clinical, histological and endoscopic records of consecutive patients with primary low-grade or high-grade lymphoma diagnosed were retrieved. Symptoms were categorized as 'alarm' or 'not alarm'. The endoscopic findings were classified as 'normal' or 'abnormal'. RESULTS: Overall, 144 patients with primary gastric lymphoma were detected, including 74 low-grade and 70 high-grade lymphoma. Alarm symptoms, particularly persistent vomiting and weight loss, were more frequently present in patients with high-grade lymphoma than in those with low-grade lymphoma (54% vs. 28%; P = 0.002). Low-grade lymphomas presented as 'normal' appearing mucosa (20% vs. 0%; P = 0.0004) or petechial haemorrhage in the fundus (9% vs. 0%; P = 0.02) more frequently than high-grade lymphomas, being also more often confined to the antrum (47% vs. 27%, P = 0.03) and associated with Helicobacter pylori infection (88% vs. 52%, P < 0.0001). On the contrary, high-grade lymphomas presented more commonly as ulcerative type (70% vs. 52%; P = 0.03), being also more frequently diagnosed in stage >I when compared with low-grade lymphomas (70% vs. 21%, P < 0.0001). CONCLUSIONS: The overall prevalence of alarm symptoms is quite low and may be absent in more than 70% of patients with low-grade lymphoma.
Assuntos
Linfoma/patologia , Neoplasias Gástricas/patologia , Endoscopia Gastrointestinal/métodos , Feminino , Mucosa Gástrica/patologia , Infecções por Helicobacter/complicações , Infecções por Helicobacter/patologia , Helicobacter pylori/isolamento & purificação , Humanos , Linfoma/complicações , Linfoma/microbiologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Estudos Retrospectivos , Estômago/patologia , Neoplasias Gástricas/complicações , Neoplasias Gástricas/microbiologiaRESUMO
Protein restriction impairs the salivary flow rate and composition in human and rats. The aim of the present work was to establish the effect of low protein (casein 5%) and protein free (casein 0%) isocaloric diets on sympathetic activity and salivary evoked secretion in the submandibular gland (SMG) of the rat. After 21 days, rats fed casein 0% presented: (a) a significant shift to the left of the dose-response curves (DRC) to the autonomic agonists-norepinephrine (NE), methoxamine, isoproterenol (ISO) and methacholine; (b) increased food consumption (p<0.001); (c) decreased body (p<0.001) and SMG (p<0.001) weights maintaining SMG/body (w/w) relation; (d) enhanced submandibular alpha1-adrenoceptor number without changes in the apparent dissociation constant (Kd); (e) increased submandibular NE content (p<0.05) and phosphoinositoside hydrolysis (p<0.001); (f) decreased submandibular tyrosine hydroxylase activity (TH) (p<0.01). Casein 5% feeding increased food consumption (p<0.01) and reduced body weight (p<0.05). This protein restriction increased metacholine-evoked salivation, but it altered neither submandibular sympathetic activity nor sympathetic-induced salivary secretion as compared to the Control group (C) fed a similar diet containing 25.5% protein. Present results suggest that in the adult rat, a protein free diet during 21 days lowers SMG sympathetic and cholinergic activity leading to supersensitivity as revealed by up-regulation of alpha1-adrenergic receptor number and increased autonomic-evoked salivation.
Assuntos
Caseínas/administração & dosagem , Dieta com Restrição de Proteínas , Desnutrição Proteico-Calórica/metabolismo , Salivação/efeitos dos fármacos , Glândula Submandibular/metabolismo , Sistema Nervoso Simpático/fisiologia , Agonistas alfa-Adrenérgicos/farmacologia , Agonistas Adrenérgicos beta/farmacologia , Animais , Biomarcadores/análise , Caseínas/metabolismo , Agonistas Colinérgicos/farmacologia , Isoproterenol/farmacologia , Masculino , Cloreto de Metacolina/farmacologia , Metoxamina/farmacologia , Modelos Animais , Fosfatidilinositóis/metabolismo , Distribuição Aleatória , Ratos , Ratos Wistar , Glândula Submandibular/efeitos dos fármacos , Sistema Nervoso Simpático/efeitos dos fármacos , Tirosina 3-Mono-Oxigenase/análise , Tirosina 3-Mono-Oxigenase/metabolismoRESUMO
An array of polypeptide growth factors contribute to the development of breast cancer, the most common tumor-related cause of death in women of Western countries. Therefore, breast cancer therapy should be aimed at inhibition of growth factor-dependent breast cancerous cell proliferation. However, the relative contribution of each individual factor in the development and maintenance of the transformed phenotype is largely unknown. Here we report for the first time that the proliferative effects of nerve growth factor, (NGF) a typical neurotrophin, are similar to those of epidermal growth factor (EGF) and insulin-like growth factor II, and are enhanced by 17beta-estradiol in the human breast cancer cell line MCF-7. The effect of NGF appeared to be mediated by its trkA receptors (trkA(NGFR)), as suggested by the potent inhibition of both MCF-7 cell proliferation and trkA(NGFR) phosphorylation occurring upon treatment of cultures with the selective trkA(NGFR) inhibitor K252a. Surprisingly, the antiestrogen drug tamoxifen (TAM) inhibited NGF-induced MCF-7 cell proliferation and trkA(NGFR) phosphorylation in a concentration-related fashion. The effect of TAM seemed to be estrogen receptor-independent, because the pure estrogen receptor antagonist ICI 182.780 was unable to block NGF-induced trkA(NGFR) phosphorylation. Our data underline the new emerging role of trkA(NGFR) in breast tumor growth, and suggest a related novel therapeutic use of TAM in breast cancer.
Assuntos
Neoplasias da Mama/patologia , Estradiol/análogos & derivados , Moduladores de Receptor Estrogênico/farmacologia , Fator de Crescimento Neural/antagonistas & inibidores , Tamoxifeno/farmacologia , Animais , Antineoplásicos/farmacologia , Western Blotting , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Divisão Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Estradiol/farmacologia , Fulvestranto , Humanos , Fator de Crescimento Neural/farmacologia , Células PC12 , Fosforilação/efeitos dos fármacos , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Ratos , Receptor trkA/biossíntese , Receptor trkA/genética , Receptor trkA/metabolismo , Células Tumorais CultivadasRESUMO
In chronic lymphocytic leukemia (CLL), NOTCH1 mutations have been associated with clinical resistance to the anti-CD20 rituximab, although the mechanisms behind this peculiar behavior remain to be clarified. In a wide CLL series (n=692), we demonstrated that CLL cells from NOTCH1-mutated cases (87/692) were characterized by lower CD20 expression and lower relative lysis induced by anti-CD20 exposure in vitro. Consistently, CD20 expression by CLL cells was upregulated in vitro by γ-secretase inhibitors or NOTCH1-specific small interfering RNA and the stable transfection of a mutated (c.7541-7542delCT) NOTCH1 intracellular domain (NICD-mut) into CLL-like cells resulted in a strong downregulation of both CD20 protein and transcript. By using these NICD-mut transfectants, we investigated protein interactions of RBPJ, a transcription factor acting either as activator or repressor of NOTCH1 pathway when respectively bound to NICD or histone deacetylases (HDACs). Compared with controls, NICD-mut transfectants had RBPJ preferentially complexed to NICD and showed higher levels of HDACs interacting with the promoter of the CD20 gene. Finally, treatment with the HDAC inhibitor valproic acid upregulated CD20 in both NICD-mut transfectants and primary CLL cells. In conclusion, NOTCH1 mutations are associated with low CD20 levels in CLL and are responsible for a dysregulation of HDAC-mediated epigenetic repression of CD20 expression.
Assuntos
Antígenos CD20/análise , Epigênese Genética , Regulação Neoplásica da Expressão Gênica , Leucemia Linfocítica Crônica de Células B/genética , Mutação , Receptor Notch1/genética , Histona Desacetilase 1/análise , Histona Desacetilase 2/análise , Inibidores de Histona Desacetilases/farmacologia , Humanos , Proteína de Ligação a Sequências Sinal de Recombinação J de Imunoglobina/metabolismo , Leucemia Linfocítica Crônica de Células B/imunologiaRESUMO
Neurofibromatosis type 2 [NF2; MIM # 101000] is an autosomal dominant disorder characterised by the occurrence of vestibular schwannomas (VSs), schwannomas of other cranial, spinal and cutaneous nerves, cranial and spinal meningiomas and/or other central nervous system (CNS) tumours (e.g., ependymomas, astrocytomas). Additional features include early onset cataracts, optic nerve sheath meningiomas, retinal hamartomas, dermal schwannomas (i.e., NF2-plaques), and (few) café-au-lait spots. Clinically, NF2 children fall into two main groups: (1) congenital NF2 - with bilateral VSs detected as early as the first days to months of life, which can be stable/asymptomatic for one-two decades and suddenly progress; and (2) severe pre-pubertal (Wishart type) NF2- with multiple (and rapidly progressive) CNS tumours other-than-VS, which usually present first, years before VSs [vs. the classical adult (Gardner type) NF2, with bilateral VSs presenting in young adulthood, sometimes as the only disease feature]. Some individuals can develop unilateral VS associated with ipsilateral meningiomas or multiple schwannomas localised to one part of the peripheral nervous system [i.e., mosaic NF2] or multiple non-VS, non-intradermal cranial, spinal and peripheral schwannomas (histologically proven) [schwannomatosis]. NF2 is caused by mutations in the NF2 gene at chromosome 22q12.1, which encodes for a protein called merlin or schwannomin, most similar to the exrin-readixin-moesin (ERM) proteins; mosaicNF2 is due to mosaic phenomena for the NF2 gene, whilst schwannomatosis is caused by coupled germ-line and mosaic mutations either in the SMARCB1 gene [SWNTS1; MIM # 162091] or the LZTR1 gene [SWNTS2; MIM # 615670] both falling within the 22q region and the NF2 gene. Data driven from in vitro and animal studies on the merlin pathway [e.g., post-translational and upstream/downstream regulation] allowed biologically targeted treatment strategies [e.g., Lapatinib, Erlotinib, Bevacizumab] aimed to multiple tumour shrinkage and/or regression and tumour arrest of progression with functional improvement.
Assuntos
Terapia Biológica , Neurofibromatose 2/terapia , Criança , Humanos , Neurofibromatose 2/complicações , Neurofibromatose 2/diagnóstico , Neurofibromatose 2/genéticaRESUMO
CD49d, the alpha-chain of the integrin heterodimer α4ß1, was identified among the strongest predictors of overall survival (OS) in chronic lymphocytic leukemia (CLL), along with IGHV mutational status and deletion of the 17p chromosome involving TP53. In addition to TP53, the clinical relevance of NOTCH1, SF3B1 and BIRC3 gene mutations has been recently emphasized. By analyzing a cohort of 778 unselected CLL patients, we assessed the clinical relevance of CD49d as an OS predictor in subgroups defined by mutation/deletion of the TP53, NOTCH1, SF3B1 and BIRC3 genes. In this context, CD49d emerged as an independent predictor of OS in multivariate Cox analysis (Hazard ratio =1.88, P<0.0001). Consistently, high CD49d expression identified CLL subsets with inferior OS in the context of each category of a previously reported hierarchical risk stratification model. Moreover, by evaluating the relative importance of biological prognosticators by random survival forests, CD49d was selected among the top-ranked OS predictor (variable importance =0.0410), along with IGHV mutational status and TP53 abnormalities. These results confirmed CD49d as an independent negative OS prognosticator in CLL also in comprehensive models comprising the novel recurrent mutations. In this context, TP53 disruption and NOTCH1 mutations retained prognostic relevance, in keeping with their roles in CLL cell immuno-chemoresistance.
Assuntos
Integrina alfa4/fisiologia , Leucemia Linfocítica Crônica de Células B/mortalidade , Mutação , Adulto , Idoso , Idoso de 80 Anos ou mais , Proteína 3 com Repetições IAP de Baculovírus , Humanos , Proteínas Inibidoras de Apoptose/genética , Leucemia Linfocítica Crônica de Células B/diagnóstico , Pessoa de Meia-Idade , Fosfoproteínas/genética , Prognóstico , Fatores de Processamento de RNA/genética , Receptores de Antígenos de Linfócitos B/genética , Taxa de Sobrevida , Proteína Supressora de Tumor p53/genética , Ubiquitina-Proteína Ligases/genéticaRESUMO
Ligand binding to cytokine receptors rapidly triggers tyrosine phosphorylation of Janus family tyrosine kinases (Jaks) and signal transducers and activators of transcription (Stats). Jak2 activation is mediated by PRL receptor homodimers as well as by receptors for the interleukin (IL)-3, IL-5, and granulocyte macrophage-colony stimulating factor, which share the common beta c-subunit. Otherwise, Jak1 and Jak3 are involved in IL-2 signaling through heterodimerization of the IL-2 receptor-beta (IL-2R beta) and gamma c-chains. Stat5, a member of the Stat family, confers the PRL response on milk protein genes. Here we show that chimeric PRL receptors that contain the transmembrane and cytoplasmic domains of the IL-2R beta or beta c-chains transduce in response to PRL tyrosine phosphorylation and activation of Jak1 and Jak2, respectively. Tyrosine phosphorylation of Stat5, activation of its DNA-binding activity assessed in bandshift experiments using a lactogenic hormone responsive region (LHRR) probe, and transcriptional induction of a beta-casein promoter luciferase construct in stably transfected CHO cells are observed with both chimeras upon PRL stimulation. Our results demonstrate that distinct cytoplasmic domains of these cytokine receptors elicit convergent signaling pathways and provide evidence that beta c and IL-2R beta function as a complete signal transducer. Our data strengthen previous observations that Stat5 activation is not dependent on the activation of a specific Jak kinase and also suggest that neither Jak3 nor gamma c have a specific role in this process.
Assuntos
Hormônio do Crescimento/farmacologia , Proteínas do Leite , Prolactina/farmacologia , Proteínas Proto-Oncogênicas , Receptores de Interleucina-2/fisiologia , Receptores da Prolactina/fisiologia , Transdução de Sinais , Sequência de Aminoácidos , Animais , Células CHO , Cricetinae , Reagentes de Ligações Cruzadas , Proteínas de Ligação a DNA/metabolismo , Dexametasona/farmacologia , Humanos , Janus Quinase 1 , Janus Quinase 2 , Janus Quinase 3 , Luciferases/biossíntese , Substâncias Macromoleculares , Dados de Sequência Molecular , Proteínas Tirosina Quinases/metabolismo , Coelhos , Ratos , Receptores de Interleucina-2/biossíntese , Receptores da Prolactina/biossíntese , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Recombinantes/farmacologia , Fator de Transcrição STAT5 , Ovinos , Transdução de Sinais/efeitos dos fármacos , Transativadores/metabolismo , Transcrição Gênica , TransfecçãoRESUMO
We have investigated the effect of nerve growth factor (NGF) in the androgen-dependent, prostate adenocarcinoma LNCaP cell line. Exposure of LNCaP cells to NGF resulted in a significant increase of cell proliferation. The effect was concentration dependent and equally present in serum- or charcoal-stripped serum-supplemented and serum-deprived conditions. The mitogenic action of NGF was accompanied by an enhanced expression of prostate-specific antigen (PSA) and resulted additive to the proliferative effect of dihydrotestosterone. The proliferative effect of NGF appeared to be mediated by the high-affinity NGF receptor, p140trka. Only p140trka, but not the low-affinity NGF receptor, p75LNGFR, was expressed in LNCaP cells; both the proliferative response and the phosphorylation of p140trka upon NGF treatment were prevented by the tyrosine kinase inhibitor K252a. LNCaP cells transiently transfected with the cDNA encoding for p75LNGFR appeared more sensitive to NGF, as demonstrated by the increased number of p75LNGFR-transfected LNCaP cells exposed for 72 h to NGF compared with wild LNCaP cultures. However, p75LNGFR-transfected LNCaP cells rapidly underwent apoptotic death when deprived of NGF. Our study demonstrates the physiological relevance of NGF in the regulation of prostate cell proliferation and the relative contribution of the high- and low-affinity NGF receptors in this control.
Assuntos
Adenocarcinoma/patologia , Fator de Crescimento Neural/fisiologia , Neoplasias da Próstata/patologia , Receptores de Fator de Crescimento Neural/fisiologia , Adenocarcinoma/genética , Adenocarcinoma/metabolismo , Western Blotting , Divisão Celular/efeitos dos fármacos , Di-Hidrotestosterona/farmacologia , Relação Dose-Resposta a Droga , Citometria de Fluxo , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Masculino , Mitógenos/metabolismo , Fator de Crescimento Neural/farmacologia , Antígeno Prostático Específico/biossíntese , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Fatores de Tempo , Transfecção , Células Tumorais CultivadasRESUMO
Cytokine receptor signaling involves the Jak/Stat pathways. Heterotrimeric IL-2R (alpha, beta, gamma[c] chains) activates Jak1 and Jak3, whereas homodimeric PRLR activates Jak2. The requirements directing such specificity of Jak activation are unknown. We show that chimeric receptors containing the intracellular domain of IL-2Rbeta chain fused to the extracellular domain of either EPOR or Kit, a non-cytokine receptor, activate Jak2. This observation provides evidence that IL-2Rbeta intrinsically possesses the ability to activate Jak2, but that this property is only displayed in homodimerized complexes. Our data suggest a role for the stoichiometry of cytokine receptors in selective activation of Janus kinases.
Assuntos
Proteínas do Leite , Proteínas Tirosina Quinases/metabolismo , Proteínas Proto-Oncogênicas , Receptores de Interleucina-2/química , Receptores de Interleucina-2/fisiologia , Transdução de Sinais , Animais , Células CHO , Caseínas/biossíntese , Caseínas/genética , Cricetinae , Proteínas de Ligação a DNA/metabolismo , Dimerização , Ativação Enzimática , Eritropoetina/farmacologia , Humanos , Janus Quinase 2 , Camundongos , Fosforilação , Prolactina/farmacologia , Regiões Promotoras Genéticas , Receptores da Eritropoetina/biossíntese , Receptores da Eritropoetina/química , Receptores da Eritropoetina/fisiologia , Receptores de Interleucina-2/biossíntese , Receptores da Prolactina/biossíntese , Receptores da Prolactina/fisiologia , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Recombinantes/farmacologia , Fator de Transcrição STAT5 , Transativadores/metabolismo , TransfecçãoRESUMO
1. Endothelium is a target for an array of factors involved in inflammation. Endothelial cells express receptors for CRH, a neuropeptide produced during inflammation. We report both the concentration-dependent inhibitory effect of CRH upon cytokine-stimulated nitrite release by H5V murine endothelioma cells, and its stimulatory one in HUVEC cells. 2. Western blot analysis showed that CRH inhibits cytokine-stimulated iNOS protein in H5V cells, and, instead, potentiated it in HUVEC cells. 3. H5V cells expressed both CRH receptors (CRH-R1 and R2) mRNAs, whereas HUVEC cells expressed the CRH-R2 mRNA solely. 4. CRH increased medium nitrites and iNOS protein expression in H5V cells pretreated with the selective CRH-R1 antagonist CP 154,526. However, the selective CRH-R2 antagonist anti-Svg-30 failed to produce similar effects. In fact, anti-Svg-30 inhibited CRH-induced increase of nitrite release and iNOS expression in HUVEC cells. 5. Our results confirm the activating role of CRH on endothelial cells, although it suggests its possible inhibitory role in the late phase of the inflammatory response. NO-mediated effects of CRH on endothelial cells could be exploited in therapeutic strategies related to inflammatory and/or degenerative diseases.
Assuntos
Hormônio Liberador da Corticotropina/farmacologia , Endotélio Vascular/efeitos dos fármacos , Óxido Nítrico Sintase/efeitos dos fármacos , Receptores de Hormônio Liberador da Corticotropina/genética , Animais , Western Blotting , Linhagem Celular , Linhagem Celular Transformada , Endotélio Vascular/citologia , Endotélio Vascular/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Interleucina-1/farmacologia , Óxido Nítrico Sintase/metabolismo , Óxido Nítrico Sintase Tipo III , Nitritos/metabolismo , Fragmentos de Peptídeos/farmacologia , Isoformas de Proteínas/genética , Pirimidinas/farmacologia , Pirróis/farmacologia , RNA Mensageiro/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de Hormônio Liberador da Corticotropina/antagonistas & inibidores , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
Chick embryos aged 7-18 days of development were injected with N-[ (3)H] acetylmannosamine into one eye. The labeling of gangliosides was significantly higher in the contralateral- than in the ipsilateral-optic tectum in embryos aged 14 days or older. Comparison of the radioactivities of thin-layer chromatograms of gangliosides from the contralateral- and ipsilateral-optic tecta showed that in the 14-day-old embryo about 56 and 29% of the transported radioactivity chromatographed as GD1a and GT1, respectively. Most of the remaining radioactivity chromatographed in the zone of less complex gangliosides (GM2-GD3, 3%; GM3, 6%). In the 18-day-old embryo about 72% of the transported radioactivity chromatographed as GD1a; the radioactivity in the zone of GT1 was reduced to about 2% and that in the less complex gangliosides remained low (about 14% in the zone of GM2-GD3 and 7% in the zone of GM3).
RESUMO
We tested the ability of dopamine, apomorphine, phenylethylamine and pergolide to inhibit the proliferation of fetal calf serum-stimulated human breast cancer (MCF)-7 cells. While the first three compounds were able to block the proliferation of MCF-7 cells, pergolide failed to do so (up to 100 microM). The inhibitory effect of dopamine, apomorphine and phenylethylamine was also evident in serum-starved insulin-stimulated MCF-7 cells. Apomorphine also inhibited the proliferation of the human oestrogen receptor-negative breast cancer (MDA-MB231) and prostate carcinoma (LNCaP) cell lines. In a second set of experiments, we measured the ability of dopamine, apomorphine, phenylethylamine and pergolide to inhibit the phosphorylation (or increase the dephosphorylation) of the insulin receptor substrate (IRS)-1, a major intracellular substrate of the insulin-like growth factor (IGF)-1 receptor. Dopamine, apomorphine and phenylethylamine all reduced to zero the level of phosphorylated IRS-1 with potencies ranging between 0.01 and 1 microM. Finally, we found that fibroblasts from IRS-1 null (-/-) mice were less sensitive to the anti-proliferative effect of apomorphine compared to fibroblasts from wild type-mice, suggesting that the inhibition of IRS-1 phosphorylation by apomorphine is an important aspect of the activity of this compound.
Assuntos
Apomorfina/farmacologia , Dopamina/farmacologia , Fenetilaminas/farmacologia , Fosfoproteínas/metabolismo , Divisão Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Proteínas Substratos do Receptor de Insulina , Pergolida/farmacologia , Fosforilação , Células Tumorais CultivadasRESUMO
We have studied the effect of intravenous injection of interleukin-1 (dose range: from 0.25 to 4.5 microg/kg of body weight) on plasma ACTH and cortisol levels in the marmoset, a primate paradygm of peripheral glucocorticoid resistance. Blood sampling were collected and body temperature recorded 0, 15, 30, 60, 120, 180, 240 and 300 min after injection. Interleukin-1 stimulated secretion of ACTH in a dose-dependent fashion. Maximal secretion occurred 120 min after injection, and lasted up to 240 min. Plasma ACTH levels returned to baseline 300 min after interleukin-1 injection. Plasma cortisol levels were related to ACTH levels. Body temperature elevation, which occurred 10-15 min after injection was dose-dependent, and lasted 3 h. Results suggest that the pyrogenic effect of interleukin is associated, in the marmoset, with integrated activation of the hypothalamic-pituitary-adrenal axis. In light of the proneness of marmosets to hyperimmune disorders, our data are consistent with the hypothesized central biological role of IL-1, as well as the pathophysiological relevance of the neuro-endocrine-immune cross-talk during the acute phase response.
Assuntos
Hormônio Adrenocorticotrópico/metabolismo , Callithrix/metabolismo , Hidrocortisona/metabolismo , Interleucina-1/farmacologia , Hormônio Adrenocorticotrópico/sangue , Animais , Temperatura Corporal/fisiologia , Relação Dose-Resposta a Droga , Humanos , Hidrocortisona/sangue , Injeções Intravenosas , Interleucina-1/administração & dosagem , Masculino , Proteínas Recombinantes/farmacologiaRESUMO
Epidemiological studies have shown a reduced incidence of cancer in Parkinson's disease. Since nearly all parkinsonian patients with clinical impairment are treated with L-beta-3,4-dihydroxyphenylalanine (L-DOPA) and dopamine (DA)ergic agonists, a possibility exists that these therapeutic agents can influence the risk of cancer. We studied the antiproliferative effect of these therapeutic agents (and substances structurally correlated) on Chinese hamster ovary (CHO)-K1 cell growth. Among the compounds tested, apomorphine proved to be the most potent inhibitor of CHO-K1 cell growth, with an EC(50) of 3.35 +/- 0.12 micro M. The apomorphine analogues, apocodeine and hydroxyethylnorapomorphine, were less active as inhibitors of CHO-K1 cell growth. The activity of DA, 6-hydroxydopamine (6-OHDA), phenylethylamine (PEA), L-DOPA and bromocriptine as antiproliferative was one order of magnitude lower than that of apomorphine while pergolide was ineffective. To test whether or not the oxidative potential of these compounds was important for their antiproliferative effect, several antioxidants were assayed. Among them glutathione (GSH) and dithiothreitol (DTT) were effective in reversing the anti-proliferative effect of apomorphine, DA, 6-OHDA and PEA, conversely they did not work with bromocriptine. GSH and DTT are sulphydryl-reducing agents; while their effect could explain the efficacy against apomorphine, DA and 6-OHDA, it is difficult to understand why they should have any effect on PEA as this substance does not react with sulphydryl groups. The oxidative potential as a mechanism of action was also questioned by the results obtained with dihydrorhodamine 123, a probe that changes its fluorescent emission wave when oxidized. None of the compounds, with the exception of 6-OHDA, had any effect on the fluorescent emission wave of the probe at the maximal concentrations used to inhibit CHO-K1 cell growth. At concentrations five times higher, apomorphine and DA generated reactive oxygen species but PEA and bromocriptine did not. These data demonstrate that the antiproliferative effect of these compounds is not due to their oxidative potential, but another mechanism must be postulated.
RESUMO
The effects of continuous light on ultrastructural organization and sympathetic secretory responses of the rat parotid gland are reported. After 50 days of continuous light exposure, the fine structure of the parotid gland exhibited features of enhanced secretory activity as judged by the striking development of rough endoplasmic reticulum and Golgi complexes, the depletion of secretory granules and the increased turnover of secretory cells. The secretory responses of parotid gland to isoproterenol revealed that continuous light induced a 30% increase in amylase release. This secretory hyperactivity appears to be related to a postsynaptic supersensitivity of sympathetic fibers of the autonomic nervous system.
Assuntos
Luz , Glândula Parótida/ultraestrutura , Amilases/metabolismo , Animais , Grânulos Citoplasmáticos/ultraestrutura , Retículo Endoplasmático/ultraestrutura , Complexo de Golgi/ultraestrutura , Isoproterenol/farmacologia , Masculino , Microscopia Eletrônica , Glândula Parótida/metabolismo , Ratos , Ratos Endogâmicos , Fatores de TempoRESUMO
We studied the effect of thymopentin, a synthetic thymic peptide, on spontaneous behavior and stress models in BALB/c mice in which a WEHI 164 clone 13 murine fibrosarcoma had been implanted, as well as in the intact Sprague-Dawley rat. In untreated animals with tumors, spontaneous behavior was significantly inhibited. Resistance to swimming in cold water was also decreased in untreated animals. Thymopentin (10, 100, 1,000, and 5,000 micrograms/kg body weight, IP, 20 min before the test) enhanced spontaneous behavior in tumor-implanted mice. In addition, thymopentin partially restored floating capability of tumor bearers in either freely moving or animals on which an additional weight had been applied. In the latter test, plasma corticotropin and corticosterone levels were relatedly modified according to treatment. Rats treated with thymopentin showed a decreased sensitivity to painful stimuli. The effect of thymopentin was comparable to acetylsalicylate. Finally, thymic factors appeared capable of restoring the diminished behavioral activity of animals bearing tumors, as well as of increasing resistance to stressful stimuli and pain.