Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
1.
Liver Int ; 41(11): 2759-2767, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34173317

RESUMO

BACKGROUND & AIMS: Hepatocellular carcinoma (HCC) is a common complication of chronic liver disease with diverse underlying aetiologies. REACH/REACH-2 were global phase III studies investigating ramucirumab in advanced HCC (aHCC) following sorafenib treatment. We performed an exploratory analysis of outcomes by liver disease aetiology and baseline serum viral load. METHODS: Meta-analysis was conducted in patients with aHCC and alpha-fetoprotein (AFP) ≥400 ng/mL (N = 542) from REACH/REACH-2 trials. Individual patient-level data were pooled with results reported by aetiology subgroup (hepatitis B [HBV] or C [HCV] and Other). Pre-treatment serum HBV DNA and HCV RNA were quantified using Roche COBAS AmpliPrep/COBAS TaqMan. Overall survival (OS) and progression-free survival (PFS) were evaluated using the Kaplan-Meier method and Cox proportional hazard model (stratified by study). RESULTS: Baseline characteristics were generally balanced between arms in each subgroup (HBV: N = 225, HCV: N = 127, Other: N = 190). No significant difference in treatment effect by aetiology subgroup was detected (OS interaction P-value = .23). Median OS (ramucirumab vs placebo) in months was 7.7 versus 4.5 (HR 0.74, 95% CI 0.55-0.99) for HBV, 8.2 versus 5.5 (HR 0.82, 95% CI 0.55-1.23) for HCV and 8.5 versus 5.4 (HR 0.56, 95% CI 0.40-0.79) for Other. Ramucirumab showed similar overall safety profiles across subgroups. Worst outcomes were noted in patients with a detectable HBV load. Use of HBV antiviral therapy, irrespective of viral load, was beneficial for survival, liver function and liver-specific adverse events. CONCLUSIONS: Ramucirumab improved survival across aetiology subgroups with a tolerable safety profile, supporting its use in patients with aHCC and elevated AFP.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Anticorpos Monoclonais Humanizados/efeitos adversos , Carcinoma Hepatocelular/tratamento farmacológico , Ensaios Clínicos Fase III como Assunto , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Ramucirumab
2.
SAGE Open Med Case Rep ; 8: 2050313X20970753, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33224499

RESUMO

Gastric and gastroesophageal junction adenocarcinomas have poor prognoses. Ramucirumab is considered a second-line standard of care for patients with these cancers. Patients may develop chemotherapy-induced adverse events, and physicians may benefit from greater familiarity with treatment management in the setting of common adverse events. We report four cases of metastatic gastric or gastric and gastroesophageal junction adenocarcinoma treated with second-line ramucirumab plus paclitaxel. All patients developed chemotherapy-associated grade ⩾2 neutropenia and/or neuropathy, and one experienced recurrence of neurotoxicity, during second-line therapy. These adverse events were successfully managed by withholding or reducing the paclitaxel dose, without modifying the ramucirumab dosage schedule, and allowed administration of additional therapy cycles. In all patients, second-line therapy was associated with a best overall response of complete or partial response ranging from 2.2 to 12.4 months. These four cases demonstrate that paclitaxel-associated adverse events can be managed with dose modifications, thereby allowing continued therapy and potential survival benefits.

3.
J Biol Chem ; 281(32): 23274-84, 2006 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-16774923

RESUMO

Many neurodegenerative disorders, such as Parkinson disease, exhibit inclusion bodies containing ubiquitinated proteins. The mechanisms implicated in this aberrant protein deposition remain elusive. In these disorders signs of inflammation are also apparent in the affected central nervous system areas. We show that prostaglandin J2 (PGJ2), an endogenous product of inflammation, disrupts the cytoskeleton in neuronal cells. Furthermore, PGJ2 perturbed microtubule polymerization in vitro and decreased the number of free sulfhydryl groups on tubulin cysteines. A direct effect of PGJ2 on actin was not apparent, although actin filaments were altered in cells treated with PGJ2. This cyclopentenone prostaglandin triggered endoplasmic reticulum (ER) collapse and the redistribution of ER proteins, such as calnexin and catechol-O-methyltransferase, into a large centrosomal aggregate containing ubiquitinated proteins and alpha-synuclein. The PGJ2-dependent cytoskeletal rearrangement paralleled the development of the large centrosomal aggregate. Both of these events were replicated by treating cells with colchicine, which disrupts the microtubule/ER network, but not with brefeldin A, which impairs ER/Golgi transport. PGJ2 also perturbed 26 S proteasome assembly and activity, which preceded the accumulation of ubiquitinated proteins as detergent/salt-insoluble aggregates. Our data support a mechanism by which, upon PGJ2 treatment, cytoskeleton/ER collapse coincides with the relocation of ER proteins, other potentially neighboring proteins, and ubiquitinated proteins into centrosomal aggregates. Development of these large perinuclear aggregates is associated with disruption of the microtubule/ER network. This aberrant protein deposition, triggered by a product of inflammation, may be common to other compounds that disrupt microtubules and induce protein aggregation, such as MPP+ and rotenone, found to be associated with neurodegeneration.


Assuntos
Citoesqueleto/metabolismo , Retículo Endoplasmático/metabolismo , Prostaglandina D2/análogos & derivados , Ubiquitina/química , Actinas/química , Linhagem Celular Tumoral , Centrossomo/metabolismo , Ciclopentanos/química , Humanos , Inflamação , Cinética , Microtúbulos/metabolismo , Doenças Neurodegenerativas/patologia , Prostaglandina D2/metabolismo , Prostaglandina D2/fisiologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Ligação Proteica , alfa-Sinucleína/metabolismo
4.
J Biol Chem ; 281(30): 21377-21386, 2006 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-16737963

RESUMO

Many neurodegenerative disorders are characterized by two pathological hallmarks: progressive loss of neurons and occurrence of inclusion bodies containing ubiquitinated proteins. Inflammation may be critical to neurodegeneration associated with ubiquitin-protein aggregates. We previously showed that prostaglandin J2 (PGJ2), one of the endogenous products of inflammation, induces neuronal death and the accumulation of ubiquitinated proteins into distinct aggregates. We now report that temporal microarray analysis of human neuroblastoma SK-N-SH revealed that PGJ2 triggered a "repair" response including increased expression of heat shock, protein folding, stress response, detoxification and cysteine metabolism genes. PGJ2 also decreased expression of cell growth/maintenance genes and increased expression of apoptotic genes. Over time pro-death responses prevailed over pro-survival responses, leading to cellular demise. Furthermore, PGJ2 increased the expression of proteasome and other ubiquitin-proteasome pathway genes. This increase failed to overcome PGJ2 inhibition of 26 S proteasome activity. Ubiquitinated proteins are degraded by the 26 S proteasome, shown here to be the most active proteasomal form in SK-N-SH cells. We demonstrate that PGJ2 impairs 26 S proteasome assembly, which is an ATP-dependent process. PGJ2 perturbs mitochondrial function, which could be critical to the observed 26 S proteasome disassembly, suggesting a cross-talk between mitochondrial and proteasomal impairment. In conclusion neurotoxic products of inflammation, such as PGJ2, may play a role in neurodegenerative disorders associated with the aggregation of ubiquitinated proteins by impairing 26 S proteasome activity and inducing a chain of events that culminates in neuronal cell death. Temporal characterization of these events is relevant to understanding the underlying mechanisms and to identifying potential early biomarkers.


Assuntos
Regulação Neoplásica da Expressão Gênica , Neuroblastoma/metabolismo , Prostaglandina D2/análogos & derivados , Complexo de Endopeptidases do Proteassoma/química , Biomarcadores/química , Linhagem Celular Tumoral , Sobrevivência Celular , Reparo do DNA , Humanos , Inflamação , Neurônios/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Prostaglandina D2/fisiologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa
5.
Neurobiol Dis ; 22(2): 294-301, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16406650

RESUMO

There is clear evidence that an inflammatory reaction is mounted within the CNS following trauma, stroke, infection and seizures, thus augmenting brain damage. Furthermore, chronic inflammation of the CNS is implicated in many neurodegenerative disorders. However, the effects of products of inflammation on neuronal cells are poorly understood. Herein, we characterize the effects of a neurotoxic product of inflammation, prostaglandin J2 (PGJ2), on catechol-O-methyltransferase (COMT) in human dopaminergic-like neuroblastoma SK-N-SH cells and rat (P2) cortical neurons. COMT metabolizes catechols and catecholamines, a pathway relevant to neurodegeneration. PGJ2 treatment reduced the expression and activity of COMT, induced its sequestration into perinuclear aggregates and potentiated dopamine toxicity. The large COMT aggregates were co-localized with the centrosome, suggesting an aggresome-like structure. Our results indicate that COMT impairment induced by PGJ2 treatment may increase the concentration of dopamine (or its metabolites) to neurotoxic levels. Thus, COMT impairment following pro-inflammatory events may be a potential risk factor in neurodegeneration.


Assuntos
Inibidores de Catecol O-Metiltransferase , Dopamina/toxicidade , Encefalite/metabolismo , Degeneração Neural/metabolismo , Neurônios/metabolismo , Prostaglandina D2/análogos & derivados , Animais , Dano Encefálico Crônico/metabolismo , Dano Encefálico Crônico/fisiopatologia , Catecol O-Metiltransferase/metabolismo , Catecolaminas/metabolismo , Linhagem Celular Tumoral , Córtex Cerebral/metabolismo , Córtex Cerebral/patologia , Córtex Cerebral/fisiopatologia , Dopamina/metabolismo , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/fisiologia , Encefalite/induzido quimicamente , Encefalite/fisiopatologia , Humanos , Corpos de Inclusão/efeitos dos fármacos , Corpos de Inclusão/metabolismo , Mediadores da Inflamação/metabolismo , Mediadores da Inflamação/farmacologia , Degeneração Neural/induzido quimicamente , Degeneração Neural/fisiopatologia , Neurônios/efeitos dos fármacos , Neurônios/patologia , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Prostaglandina D2/metabolismo , Prostaglandina D2/farmacologia , Ratos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA