RESUMO
BACKGROUND AND PURPOSE: Tapering immunosuppressants is desirable in patients with well-controlled myasthenia gravis (MG). However, the association between tapering of calcineurin inhibitor dosage and reduction-associated exacerbation is not known. The aim of this study was to clarify the frequency of reduction-associated exacerbation when tacrolimus is tapered in stable patients with anti-acetylcholine receptor antibody-positive MG, and to determine the factors that predict exacerbations. METHODS: We retrospectively analyzed 115 patients in whom tacrolimus dosage was tapered. The reduction-associated exacerbation was defined as the appearance or worsening of one or more MG symptoms <3 months after the reduction. RESULTS: Tacrolimus dosage was successfully tapered in 110 patients (96%) without any exacerbation. Five patients (4%) experienced an exacerbation, but symptoms were reversed in all patients when the tacrolimus dose was increased to the previous maintenance level. No patient developed an MG crisis. The age at onset was significantly earlier (30 vs. 56 years, P = 0.025) and the reduction in dosage was significantly larger (2.0 vs. 1.0 mg/day, P = 0.002) in patients with reduction-associated exacerbation than in those without exacerbation. The cut-off values determined in a receiver-operating characteristic curve analysis were 52 years (sensitivity, 57%; specificity, 100%) for the age at onset and 1.5 mg (sensitivity, 80%; specificity, 100%) for the dose reduction. CONCLUSION: Tapering of tacrolimus was possible in most patients with well-controlled anti-acetylcholine receptor antibody-positive MG. Early age at onset and a large reduction from maintenance dosage were associated with exacerbation. Reductions ≤1.5 mg/day from the maintenance dosage should be considered for patients with late-onset disease.
Assuntos
Imunossupressores/administração & dosagem , Imunossupressores/uso terapêutico , Miastenia Gravis/tratamento farmacológico , Miastenia Gravis/imunologia , Receptores Colinérgicos/imunologia , Tacrolimo/administração & dosagem , Tacrolimo/uso terapêutico , Adulto , Idade de Início , Anticorpos/análise , Redução da Medicação , Feminino , Humanos , Imunossupressores/efeitos adversos , Masculino , Pessoa de Meia-Idade , Curva ROC , Estudos Retrospectivos , Sensibilidade e Especificidade , Tacrolimo/efeitos adversosRESUMO
Disease recurrence is the major problem in the treatment of acute myeloid leukemia (AML). Relapse is driven by leukemia stem cells, a chemoresistant subpopulation capable of re-establishing disease. Patients with p53 mutant AML are at an extremely high risk of relapse. B-cell-specific Moloney murine leukemia virus integration site 1 (BMI-1) is required for the self-renewal and maintenance of AML stem cells. Here we studied the effects of a novel small molecule inhibitor of BMI-1, PTC596, in AML cells. Treatment with PTC596 reduced MCL-1 expression and triggered several molecular events consistent with induction of mitochondrial apoptosis: loss of mitochondrial membrane potential, BAX conformational change, caspase-3 cleavage and phosphatidylserine externalization. PTC596 induced apoptosis in a p53-independent manner. PTC596 induced apoptosis along with the reduction of MCL-1 and phosphorylated AKT in patient-derived CD34+CD38low/- stem/progenitor cells. Mouse xenograft models demonstrated in vivo anti-leukemia activity of PTC596, which inhibited leukemia cell growth in vivo while sparing normal hematopoietic cells. Our results indicate that PTC596 deserves further evaluation in clinical trials for refractory or relapsed AML patients, especially for those with unfavorable complex karyotype or therapy-related AML that are frequently associated with p53 mutations.
Assuntos
Leucemia Mieloide Aguda/genética , Proteína de Sequência 1 de Leucemia de Células Mieloides/genética , Complexo Repressor Polycomb 1/genética , Proteínas Proto-Oncogênicas/genética , Proteína Supressora de Tumor p53/genética , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células , Regulação para Baixo , Humanos , Camundongos , TransfecçãoRESUMO
Clinical significance of medullary abnormalities in the appendicular skeleton (AS) detected by low-dose whole-body multidetector computed tomography (MDCT) in patients with multiple myeloma (MM) was investigated. A total of 172 patients with monoclonal gammopathy of undetermined significance (MGUS) (n=17), smoldering MM (n=47) and symptomatic MM (n=108) underwent low-dose MDCT. CT values (CTv) of medullary density of AS⩾0 Hounsfield unit (HU) was considered as abnormal. Percentage of medullary abnormalities and the mean CTv of AS in patients with MGUS, smoldering MM and symptomatic MM were 18, 55 and 62% and -44.5 , -20.3 and 11.2 HU, respectively (P<0.001 and P<0.001). Disease progression of MM was independently associated with high CTv on multivariate analysis. In symptomatic MM, the presence of abnormal medullary lesions was associated with increased incidence of high-risk cytogenetic abnormalities (34.4% vs 7.7%; P=0.002) and extramedullary disease (10.4% vs 0%; P=0.032). It was also an independent poor prognostic predictor (hazard ratio 3.546, P=0.04). This study showed that CTv of AS by MDCT is correlated with disease progression of MM, and the presence of abnormal medullary lesions is a predictor for poor survival.
Assuntos
Neoplasias da Medula Óssea/diagnóstico por imagem , Medula Óssea/diagnóstico por imagem , Mieloma Múltiplo/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Medula Óssea/patologia , Neoplasias da Medula Óssea/mortalidade , Neoplasias da Medula Óssea/secundário , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada Multidetectores , Mieloma Múltiplo/mortalidade , Mieloma Múltiplo/patologia , Análise Multivariada , Prognóstico , Modelos de Riscos ProporcionaisRESUMO
BACKGROUND: Giant cell tumor of bone (GCTB) is a rare primary bone tumor, characterized by osteoclast-like giant cells that express receptor activator of nuclear factor-kappa B (RANK), and stromal cells that express RANK ligand (RANKL), a key mediator of osteoclast activation. A RANKL-specific inhibitor, denosumab, was predicted to reduce osteolysis and control disease progression in patients with GCTB. PATIENTS AND METHODS: Seventeen patients with GCTB were enrolled. Patients were treated with denosumab at 120 mg every 4 weeks, with a loading dose of 120 mg on days 8 and 15. To evaluate efficacy, objective tumor response was evaluated prospectively by an independent imaging facility on the basis of prespecified criteria. RESULTS: The proportion of patients with an objective tumor response was 88% based on best response using any tumor response criteria. The proportion of patients with an objective tumor response using individual response criteria was 35% based on the modified Response Evaluation Criteria in Solid Tumors (RECIST) criteria, 82% based on the modified European Organization for Research and Treatment of Cancer (EORTC) criteria, and 71% based on inverse Choi criteria. The median time of study treatment was 13.1 months. CONCLUSION: The findings demonstrate that denosumab has robust clinical efficacy in the treatment of GCTB.
Assuntos
Conservadores da Densidade Óssea/uso terapêutico , Neoplasias Ósseas/tratamento farmacológico , Denosumab/uso terapêutico , Tumor de Células Gigantes do Osso/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Adolescente , Adulto , Idoso , Neoplasias Ósseas/patologia , Feminino , Seguimentos , Tumor de Células Gigantes do Osso/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Estadiamento de Neoplasias , Prognóstico , Estudos Prospectivos , Adulto JovemRESUMO
Patients with chronic renal failure often have hypertension, but the cause of hypertension, other than an excess of body fluid, is not well known. We hypothesized that the bulbospinal neurons in the rostral ventrolateral medulla (RVLM) are stimulated by uremic toxins in patients with chronic renal failure. To investigate whether RVLM neurons are sensitive to uremic toxins, such as uric acid, indoxyl sulfate, or methylguanidine, we examined changes in the membrane potentials (MPs) of bulbospinal RVLM neurons of Wister rats using the whole-cell patch-clamp technique during superfusion with these toxins. A brainstem-spinal cord preparation that preserved the sympathetic nervous system was used for the experiments. During uric acid, indoxyl sulfate, or methylguanidine superfusion, almost all the RVLM neurons were depolarized. To examine the transporters for these toxins on RVLM neurons, histological examinations were performed. The uric acid-, indoxyl sulfate-, and methylguanidine-depolarized RVLM neurons showed the presence of urate transporter 1 (URAT 1), organic anion transporter (OAT)1 or OAT3, and organic cation transporter (OCT)3, respectively. Furthermore, the toxin-induced activities of the RVLM neurons were suppressed by the addition of an anti-oxidation drug (VAS2870, an NAD(P)H oxidase inhibitor), and a histological examination revealed the presence of NAD(P)H oxidase (nox)2 and nox4 in these RVLM neurons. The present results show that uric acid, indoxyl sulfate, and methylguanidine directly stimulate bulbospinal RVLM neurons via specific transporters on these neurons and by producing oxidative stress. These uremic toxins may cause hypertension by activating RVLM neurons.
Assuntos
Indicã/toxicidade , Bulbo/efeitos dos fármacos , Metilguanidina/toxicidade , Neurônios/efeitos dos fármacos , Neurotoxinas/toxicidade , Ácido Úrico/toxicidade , Animais , Proteínas de Transporte de Ânions/metabolismo , Benzoxazóis/farmacologia , Inibidores Enzimáticos/farmacologia , Bulbo/patologia , Bulbo/fisiopatologia , Glicoproteínas de Membrana/antagonistas & inibidores , Glicoproteínas de Membrana/metabolismo , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , NADPH Oxidase 2 , NADPH Oxidase 4 , NADPH Oxidases/antagonistas & inibidores , NADPH Oxidases/metabolismo , Neurônios/patologia , Neurônios/fisiologia , Fármacos Neuroprotetores/farmacologia , Proteína 1 Transportadora de Ânions Orgânicos/metabolismo , Transportadores de Ânions Orgânicos Sódio-Independentes/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Técnicas de Patch-Clamp , Ratos Wistar , Insuficiência Renal Crônica , Sistema Nervoso Simpático/efeitos dos fármacos , Sistema Nervoso Simpático/patologia , Sistema Nervoso Simpático/fisiopatologia , Triazóis/farmacologiaRESUMO
Group I metabotropic glutamate receptors (mGluR1 and mGluR5) are functionally linked to estrogen receptors and play a key role in the plasticity of central neurons. Estrogen status strongly influences sensory input from the temporomandibular joint (TMJ) to neurons at the spinomedullary (Vc/C1-2) region. This study tested the hypothesis that TMJ input to trigeminal subnucleus caudalis/upper cervical cord (Vc/C1-2) neurons involved group I mGluR activation and depended on estrogen status. TMJ-responsive neurons were recorded in superficial laminae at the Vc/C1-2 region in ovariectomized (OvX) female rats treated with low-dose estradiol (2 µg/day, LE) or high-dose estradiol (20 µg/day, HE) for 2 days. TMJ-responsive units were activated by adenosine triphosphate (ATP, 1mM) injected into the joint space. Receptor antagonists selective for mGluR1 (CPCCOEt) or mGluR5 (MPEP) were applied topically to the Vc/C1-2 surface at the site of recording 10 min prior to the intra-TMJ ATP stimulus. In HE rats, CPCCOEt (50 and 500 µM) markedly reduced ATP-evoked unit activity. By contrast, in LE rats, a small but significant increase in neural activity was seen after 50 µM CPCCOEt, while 500 µM caused a large reduction in activity that was similar in magnitude as that seen in HE rats. Local application of MPEP produced a significant inhibition of TMJ-evoked unit activity independent of estrogen status. Neither mGluR1 nor mGluR5 antagonism altered the spontaneous activity of TMJ units in HE or LE rats. High-dose MPEP caused a small reduction in the size of the convergent cutaneous receptive field in HE rats, while CPCCOEt had no effect. These data suggest that group I mGluRs play a key role in sensory integration of TMJ nociceptive input to the Vc/C1-2 region and are largely independent of estrogen status.
Assuntos
Neurônios/fisiologia , Nociceptividade/fisiologia , Receptores de Glutamato Metabotrópico/fisiologia , Articulação Temporomandibular/fisiologia , Núcleo Inferior Caudal do Nervo Trigêmeo/fisiologia , Trifosfato de Adenosina/farmacologia , Animais , Cromonas/farmacologia , Estradiol/administração & dosagem , Estradiol/fisiologia , Feminino , Neurônios/efeitos dos fármacos , Nociceptividade/efeitos dos fármacos , Piridinas/farmacologia , Ratos , Ratos Sprague-Dawley , Receptor de Glutamato Metabotrópico 5/antagonistas & inibidores , Receptores de Glutamato Metabotrópico/antagonistas & inibidores , Articulação Temporomandibular/efeitos dos fármacos , Articulação Temporomandibular/inervação , Núcleo Inferior Caudal do Nervo Trigêmeo/efeitos dos fármacosRESUMO
BACKGROUND: In the current era of total mesorectal excision, local relapse remains a main cause of recurrence. Although standard treatment for locally recurrent rectal cancer (LRRC) has not been established, R0 resection represents the only potentially curative treatment. However, extended surgery accompanying bony pelvic resection is technically demanding and is still challenging. METHODS: Studied were 35 patients with LRRC who underwent combined resection of bony pelvis between August 2006 and October 2013. Safety and prognostic factors for survival were analyzed. Median follow-up was 33 months. RESULTS: Sacrectomy was performed in 32 patients and 3 patients underwent combined resection of the pubis and ischium. The dominant operative procedure was total pelvic exenteration in 30 (86%) patients. R0 resection was achieved in 27 (77%) patients. No patients died. Pelvic sepsis was the most frequent complication (40%). Recurrence developed in 20 (57%), with the lung the most frequent site (10 patients). Three-year local relapse-free survival (LRFS) and disease-free survival (DFS) were 72.1% and 32.7%, respectively. On multivariate analysis, R1 resection was the only independent risk factor for local recurrence (p = 0.010), and concomitant liver metastasis and initial non sphincter-preserving surgery were independent predictors of worse DFS (p = 0.008 and p = 0.042, respectively). CONCLUSIONS: Aggressive surgical treatment combined with bony resection for carefully selected patients with LRRC was safe with a high rate of R0 resection and favorable LRFS. However, DFS was not satisfactory even after R0 resection and the main cause was lung metastasis. Preventing distant recurrence might be a key to improve survival.
Assuntos
Carcinoma/cirurgia , Ísquio/cirurgia , Recidiva Local de Neoplasia/cirurgia , Exenteração Pélvica/métodos , Osso Púbico/cirurgia , Neoplasias Retais/cirurgia , Adulto , Idoso , Carcinoma/patologia , Estudos de Coortes , Intervalo Livre de Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Prognóstico , Neoplasias Retais/patologiaRESUMO
Two types of fracture, early and late, have been reported following limb lengthening in patients with achondroplasia (ACH) and hypochondroplasia (HCH). We reviewed 25 patients with these conditions who underwent 72 segmental limb lengthening procedures involving the femur and/or tibia, between 2003 and 2011. Gender, age at surgery, lengthened segment, body mass index, the shape of the callus, the amount and percentage of lengthening and the healing index were evaluated to determine predictive factors for the occurrence of early (within three weeks after removal of the fixation pins) and late fracture (> three weeks after removal of the pins). The MannWhitney U test and Pearson's chi-squared test for univariate analysis and stepwise regression model for multivariate analysis were used to identify the predictive factor for each fracture. Only one patient (two tibiae) was excluded from the analysis due to excessively slow formation of the regenerate, which required supplementary measures. A total of 24 patients with 70 limbs were included in the study. There were 11 early fractures in eight patients. The shape of the callus (lateral or central callus) was the only statistical variable related to the occurrence of early fracture in univariate and multivariate analyses. Late fracture was observed in six limbs and the mean time between removal of the fixation pins and fracture was 18.3 weeks (3.3 to 38.4). Lengthening of the tibia, larger healing index, and lateral or central callus were related to the occurrence of a late fracture in univariate analysis. A multivariate analysis demonstrated that the shape of the callus was the strongest predictor for late fracture (odds ratio: 19.3, 95% confidence interval: 2.91 to 128). Lateral or central callus had a significantly larger risk of fracture than fusiform, cylindrical, or concave callus. Radiological monitoring of the shape of the callus during distraction is important to prevent early and late fracture of lengthened limbs in patients with ACH or HCH. In patients with thin callus formation, some measures to stimulate bone formation should be considered as early as possible.
Assuntos
Acondroplasia/cirurgia , Alongamento Ósseo , Osso e Ossos/anormalidades , Nanismo/cirurgia , Fraturas do Fêmur/etiologia , Deformidades Congênitas dos Membros/cirurgia , Lordose/cirurgia , Complicações Pós-Operatórias/etiologia , Fraturas da Tíbia/etiologia , Adolescente , Osso e Ossos/cirurgia , Criança , Feminino , Fêmur/lesões , Fêmur/cirurgia , Seguimentos , Humanos , Modelos Logísticos , Masculino , Análise Multivariada , Estudos Retrospectivos , Fatores de Risco , Tíbia/lesões , Tíbia/cirurgia , Fatores de Tempo , Resultado do Tratamento , Adulto JovemRESUMO
Reversal of renal dysfunction significantly affects the prognosis of multiple myeloma (MM) with renal impairment (RI). There is no reliable test for predicting reversibility of RI in MM patients. We postulated that MM with high albuminuria may reflect glomerular disease that is difficult to reverse. Here, we examined the impact of urinary albumin excretion. We retrospectively analyzed 279 patients admitted to our hospital from April 2000 to December 2013. Clinical variables and laboratory data that may affect myeloma treatment response were extracted. The results were examined for relationship to renal response by univariate and multivariate analysis. RI (estimated glomerular filtration rate â¦50 ml/min per 1.73 m(2)) was observed in 116 patients (46%) and renal responses of renal complete response, renal partial response, renal minor response and no response were obtained in 46 (40%), 15 (13%), 13 (11%) and 42 (36%) patients, respectively. Although renal recovery was significantly associated with Durie-Salmon 1 or 2 (P=0.02), myeloma response better than very good partial response (P=0.03), involved free light-chain (iFLC) reduction from baseline 80% at day 12 (P=0.005), â§95% at day 21 (P<0.001) and urinary albumin â¦25% on admission (P<0.001) on univariate analysis, only reduction of iFLC 95% at day 21 (P=0.015) and urinary albumin â¦25% (P=0.007) remained significant for any renal response. Our observation indicates that increased urinary albumin excretion >25% and reduction of iFLC â¦95% on day 21 were associated with favorable renal recovery in MM patients with RI, and were considered as negative predictors for renal response.
Assuntos
Albuminúria , Cadeias Leves de Imunoglobulina/sangue , Nefropatias , Mieloma Múltiplo , Adulto , Idoso , Idoso de 80 Anos ou mais , Albuminúria/sangue , Albuminúria/mortalidade , Albuminúria/urina , Intervalo Livre de Doença , Feminino , Seguimentos , Taxa de Filtração Glomerular , Humanos , Nefropatias/sangue , Nefropatias/mortalidade , Nefropatias/urina , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/sangue , Mieloma Múltiplo/mortalidade , Mieloma Múltiplo/urina , Estudos Retrospectivos , Taxa de SobrevidaRESUMO
Sensory input from the temporomandibular joint (TMJ) to neurons in superficial laminae at the spinomedullary (Vc/C1-2) region is strongly influenced by estrogen status. This study determined if GABAergic mechanisms play a role in estrogen modulation of TMJ nociceptive processing in ovariectomized female rats treated with high- (HE) or low-dose (LE) estradiol (E2) for 2days. Superficial laminae neurons were activated by ATP (1mM) injections into the joint space. The selective GABAA receptor antagonist, bicuculline methiodide (BMI, 5 or 50µM, 30µl), applied at the site of recording greatly enhanced the magnitude and duration of ATP-evoked responses in LE rats, but not in units from HE rats. The convergent cutaneous receptive field (RF) area of TMJ neurons was enlarged after BMI in LE but not HE rats, while resting discharge rates were increased after BMI independent of estrogen status. By contrast, the selective GABAA receptor agonist, muscimol (50µM, 30µl), significantly reduced the magnitude and duration of ATP-evoked activity, resting discharge rate, and cutaneous RF area of TMJ neurons in LE and HE rats, whereas lower doses (5µM) affected only units from LE rats. Protein levels of GABAA receptor ß3 isoform at the Vc/C1-2 region were similar for HE and LE rats. These results suggest that GABAergic mechanisms contribute significantly to background discharge rates and TMJ-evoked input to superficial laminae neurons at the Vc/C1-2 region. Estrogen status may gate the magnitude of GABAergic influence on TMJ neurons at the earliest stages of nociceptive processing at the spinomedullary region.
Assuntos
Estrogênios/metabolismo , Neurônios/fisiologia , Receptores de GABA-A/metabolismo , Articulação Temporomandibular/citologia , Núcleo Inferior Caudal do Nervo Trigêmeo/citologia , Potenciais de Ação/efeitos dos fármacos , Trifosfato de Adenosina/farmacologia , Animais , Relação Dose-Resposta a Droga , Feminino , GABAérgicos/farmacologia , Neurônios/efeitos dos fármacos , Ovariectomia , Ratos , Ratos Sprague-Dawley , Tempo de Reação/efeitos dos fármacosAssuntos
Capnocytophaga , Doença Enxerto-Hospedeiro/microbiologia , Infecções por Bactérias Gram-Negativas/diagnóstico , Leucemia Mieloide Aguda/complicações , Sepse/etiologia , Baço/fisiopatologia , Animais , Antibacterianos/administração & dosagem , Transplante de Medula Óssea/efeitos adversos , Progressão da Doença , Doenças do Cão/transmissão , Cães/microbiologia , Feminino , Doença Enxerto-Hospedeiro/complicações , Infecções por Bactérias Gram-Negativas/complicações , Humanos , Leucemia Mieloide Aguda/terapia , Meropeném , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Saliva/microbiologia , Tienamicinas/administração & dosagem , Trombocitose/complicações , Resultado do Tratamento , Vancomicina/administração & dosagemRESUMO
BACKGROUND: The surgical management of soft tissue sarcoma (STS) in elderly patients has only been addressed in a few studies. The objective of the current study was to assess surgical outcomes in patients with STS aged 70 years and older and the association of older age with the survival after complete resection. METHODS: A retrospective analysis was conducted in 158 elderly patients with localized STS who visited 11 institutions participating in Japanese Musculoskeletal Oncology Group between 1995 and 2006 and were treated by surgical resection. Univariate and multivariate analyses were performed to identify prognostic factors. RESULTS: Median follow-up period was 38 months. Histologically high-grade tumors were detected in 71% of the patients. Wide resection with adequate margins was performed in 66% of the cases. Systemic chemotherapy was performed in only 5 patients. Univariate analysis identified histological grade and gender as statistically significant prognostic factors for sarcoma-specific survival. Multivariate analysis did not identify significant prognostic factors for sarcoma-specific survival, although high grade sarcoma emerged as a potentially significant prognostic factor (P = 0.050). Local recurrence was detected in 19% of the patients. Multivariate analysis of local recurrence-free survival showed that tumor site and surgical margins were statistically significant prognostic factors. CONCLUSIONS: Older age was not identified as a prognostic factor for sarcoma-specific survival, which is not consistent with the findings of previous studies showing that older age was associated with decreased sarcoma-specific survival. Complete resection should be indicated and can lead to optimal treatment outcome for properly selected elderly patients.
Assuntos
Sarcoma/mortalidade , Sarcoma/cirurgia , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Quimioterapia Adjuvante , Feminino , Seguimentos , Humanos , Japão/epidemiologia , Imageamento por Ressonância Magnética , Masculino , Gradação de Tumores , Recidiva Local de Neoplasia/diagnóstico , Recidiva Local de Neoplasia/epidemiologia , Prognóstico , Modelos de Riscos Proporcionais , Radioterapia Adjuvante , Estudos Retrospectivos , Fatores de Risco , Sarcoma/diagnóstico , Sarcoma/epidemiologia , Sarcoma/patologia , Análise de Sobrevida , Tomografia Computadorizada por Raios X , Resultado do TratamentoRESUMO
BACKGROUND: Hyaluronan (HA) plays crucial roles in the tumourigenicity of many types of malignant tumours. 4-Methylumbelliferone (MU) is an inhibitor of HA synthesis. Several studies have shown its inhibitory effects on malignant tumours; however, none have focused on its effects on osteosarcoma. METHODS: We investigated the effects of MU on HA accumulation and tumourigenicity of highly metastatic murine osteosarcoma cells (LM8) that have HA-rich cell-associated matrix, and human osteosarcoma cell lines (MG-63 and HOS). RESULTS: In vitro, MU inhibited HA retention, thereby reducing the formation of functional cell-associated matrices, and also inhibited cell proliferation, migration, and invasion. Akt phosphorylation was suppressed by MU (1.0 mM). In vivo, although MU showed only a mild inhibitory effect on the growth of the primary tumour, it markedly inhibited (75% reduction) the development of lung metastasis. Hyaluronan retention in the periphery of the primary tumour was markedly suppressed by MU. CONCLUSION: These findings suggested that MU suppressed HA retention and cell-associated matrix formation in osteosarcoma cells, resulting in a reduction of tumourigenicity, including lung metastasis. 4-Methylumbelliferone is a promising therapeutic agent targeting both primary tumours and distant metastasis of osteosarcoma, possibly via suppression of HA retention.
Assuntos
Ácido Hialurônico/metabolismo , Himecromona/análogos & derivados , Neoplasias Pulmonares/secundário , Osteossarcoma/patologia , Apoptose/efeitos dos fármacos , Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos , Ácido Hialurônico/antagonistas & inibidores , Himecromona/farmacologia , Imuno-Histoquímica , Marcação In Situ das Extremidades Cortadas , Técnicas In Vitro , Neoplasias Pulmonares/metabolismo , Osteossarcoma/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Reação em Cadeia da Polimerase em Tempo RealRESUMO
We undertook a study of the anti-tumour effects of hyperthermia, delivered via magnetite cationic liposomes (MCLs), on local tumours and lung metastases in a mouse model of osteosarcoma. MCLs were injected into subcutaneous osteosarcomas (LM8) and subjected to an alternating magnetic field which induced a heating effect in MCLs. A control group of mice with tumours received MCLs but were not exposed to an AMF. A further group of mice with tumours were exposed to an AMF but had not been treated with MCLs. The distribution of MCLs and local and lung metastases was evaluated histologically. The weight and volume of local tumours and the number of lung metastases were determined. Expression of heat shock protein 70 was evaluated immunohistologically. Hyperthermia using MCLs effectively heated the targeted tumour to 45 degrees C. The mean weight of the local tumour was significantly suppressed in the hyperthermia group (p = 0.013). The mice subjected to hyperthermia had significantly fewer lung metastases than the control mice (p = 0.005). Heat shock protein 70 was expressed in tumours treated with hyperthermia, but was not found in those tumours not exposed to hyperthermia. The results demonstrate a significant effect of hyperthermia on local tumours and reduces their potential to metastasise to the lung.
Assuntos
Óxido Ferroso-Férrico/administração & dosagem , Hipertermia Induzida/métodos , Osteossarcoma/terapia , Sarcoma Experimental/terapia , Animais , Proteínas de Choque Térmico HSP70/metabolismo , Lipossomos , Neoplasias Pulmonares/prevenção & controle , Neoplasias Pulmonares/secundário , Masculino , Nanopartículas Metálicas/administração & dosagem , Camundongos , Camundongos Endogâmicos C3H , Necrose , Osteossarcoma/patologia , Osteossarcoma/secundário , Sarcoma Experimental/patologia , Sarcoma Experimental/secundário , Temperatura CutâneaRESUMO
Programmed cell death is a crucial process in the normal development and physiology of metazoans, and it can be divided into several categories that include type I death (apoptosis) and type II death (autophagic cell death). The Bcl-2 family proteins are well-characterized regulators of apoptosis, among which multidomain pro-apoptotic members (such as Bax and Bak) function as a mitochondrial gateway at which various apoptotic signals converge. Although embryonic fibroblasts from Bax/Bak double-knockout (DKO) mice are resistant to apoptosis, we have previously reported that these cells still die by autophagy in response to various death stimuli. In this study, we found that jun N-terminal kinase (JNK) was activated in etoposide- and staurosporine-treated, but not serum-starved, Bax/Bak DKO cells, and that autophagic cell death was suppressed by the addition of a JNK inhibitor and by a dominant-negative mutant of JNK. Studies with sek1(-/-)mkk7(-/-) cells revealed that disruption of JNK prevented the induction of autophagic cell death. Co-activation of JNK and autophagy induced autophagic cell death. Activation of JNK occurred downstream of the induction of autophagy, and was dependent on the autophagic process. These results indicate that JNK activation is crucial for the autophagic death of Bax/Bak DKO cells.
Assuntos
Autofagia/fisiologia , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Animais , Autofagia/efeitos dos fármacos , Sequência de Bases , Ativação Enzimática , Etoposídeo/farmacologia , Regulação da Expressão Gênica , Técnicas de Silenciamento de Genes , Células HeLa , Humanos , Camundongos , Fosforilação , Estaurosporina/farmacologia , Proteína Killer-Antagonista Homóloga a bcl-2/deficiência , Proteína Killer-Antagonista Homóloga a bcl-2/genética , Proteína X Associada a bcl-2/deficiência , Proteína X Associada a bcl-2/genética , Proteína bcl-X/metabolismoRESUMO
Mitochondrial membrane permeabilization is central to apoptotic signaling and is directly regulated by the Bcl-2 family of proteins, consisting of anti-apoptotic members and pro-apoptotic members, although the precise mechanisms involved remain elusive. When cells are deficient in both pro-apoptotic multidomain members of this family (Bax and Bak), mitochondrial membrane permeabilization does not occur in response to various apoptotic stimuli. We have previously reported that the voltage-dependent anion channel (VDAC or porin) plays a role in apoptotic mitochondrial membrane permeabilization by interacting with Bcl-2 family members. Here, we have provided additional evidence that VDAC2 is required for pro-apoptotic activity of Bax in the absence of Bak. In the absence of Bak, VDAC2-deficient cells showed strong resistance to various apoptotic stimuli, whereas re-introduction of the Vdac2 gene restored their apoptotic response. Consistently, silencing of VDAC2 in Bak-deficient cells, but not Bax-deficient cells, also conferred resistance to various apoptotic stimuli. In the absence of VDAC2 and Bak, the activation of Bax (assessed by mitochondrial membrane integration, conformational changes and oligomerization) was markedly impaired. Taken together, these findings indicate that VDAC2 is required for pro-apoptotic activity of Bax in the absence of Bak.
Assuntos
Apoptose , Canal de Ânion 2 Dependente de Voltagem/fisiologia , Proteína X Associada a bcl-2/fisiologia , Animais , Células Cultivadas , Camundongos , Tunicamicina/farmacologia , Proteína Killer-Antagonista Homóloga a bcl-2/fisiologiaRESUMO
Mucin 4 (MUC4) is a high molecular weight transmembrane mucin that is overexpressed in many carcinomas and is a risk factor associated with a poor prognosis. In this study, we show that the DNA methylation pattern is intimately correlated with MUC4 expression in breast, lung, pancreas and colon cancer cell lines. We mapped the DNA methylation status of 94 CpG sites from -3622 to +29 using MassARRAY analysis that utilises base-specific cleavage of nucleic acids. MUC4-negative cancer cell lines and those with low MUC4 expression (eg, A427) were highly methylated near the transcriptional start site, whereas MUC4-positive cell lines (eg, NCI-H292) had low methylation levels. Moreover, 5-aza-2'-deoxycytidine and trichostatin A treatment of MUC4-negative cells or those with low MUC4 expression caused elevation of MUC4 mRNA. Our results suggest that DNA methylation in the 5' flanking region play an important role in MUC4 gene expression in carcinomas of various organs. An understanding of epigenetic changes in MUC4 may contribute to the diagnosis of carcinogenic risk and prediction of outcome in patients with cancer.
Assuntos
Ilhas de CpG , Metilação de DNA , Mucina-4/genética , Neoplasias/genética , Regiões Promotoras Genéticas/genética , Acetilação , Azacitidina/análogos & derivados , Azacitidina/farmacologia , Linhagem Celular Tumoral , Metilases de Modificação do DNA/antagonistas & inibidores , DNA de Neoplasias/genética , Decitabina , Inibidores Enzimáticos/farmacologia , Epigênese Genética , Inibidores de Histona Desacetilases , Histona Desacetilases/metabolismo , Histonas/metabolismo , Humanos , Ácidos Hidroxâmicos/farmacologia , Neoplasias/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Cyclooxygenase-2 (COX-2) inhibitors have been shown to exert inhibitory effects on many types of malignant tumors and several groups have suggested that COX-2 inhibitors enhance the cytotoxic effects of other anti-cancer agents. We previously reported that meloxicam has an anti-tumorigenic effect on COX-2-expressing osteosarcoma cells. In the current study, we evaluated the synergy between meloxicam and cisplatin (CDDP), doxorubicin (DXR) and 4-hydroperoxy ifosfamide (4OOH-IFM), using the human osteosarcoma cell line, MG-63. Cytotoxicity was determined using 3-(4,5'-dimethylthiazol-2-yl)-2,5'-diphenyltetrazolium bromide (MTT) assays, and isobolographic analysis was used to evaluate any synergy. Apoptotic activity was determined by terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL), and by evaluating Bax and Bcl-2 expression levels using real-time RT-PCR and western blotting analysis. Cell cycling was evaluated by flow cytometry. The cytotoxic effects of CDDP and DXR were enhanced synergistically in the presence of meloxicam and were partially due to an increase in apoptosis. By contrast, meloxicam enhanced neither the cytotoxic nor the apoptotic activity of 4OOH-IFM. Combining meloxicam with DXR significantly up-regulated Bax expression, whereas it down-regulated Bcl-2 expression in combination with CDDP. Furthermore, the number of cells in the G2/M phase was significantly increased in DXR-treated samples by the addition of meloxicam, but not in CDDP-treated or 4OOH-IFM-treated samples. These results suggest a potential clinical application of meloxicam in combination with cytotoxic drugs in patients with COX-2-positive osteosarcoma.
Assuntos
Antineoplásicos/farmacologia , Osteossarcoma/tratamento farmacológico , Tiazinas/farmacologia , Tiazóis/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Inibidores de Ciclo-Oxigenase 2/farmacologia , Sinergismo Farmacológico , Humanos , Meloxicam , Osteossarcoma/patologia , Proteínas Proto-Oncogênicas c-bcl-2/efeitos dos fármacos , Proteína X Associada a bcl-2/efeitos dos fármacosRESUMO
We evaluated the effectiveness of magnetic resonance image (MRI) guidance using an optical tracking system (MRI-guided therapy: MRT) in performing endoscopic sinus surgery (ESS). The profiles of the fourteen patients in the present study were as follows: eleven with mucocele in the paranasal sinus, one with recurrent chronic sinusitis, one with maxillary cancer, and one with Graves' ophthalmopathy. Preparation of the MRT system required an additional 54 min in cases involving general anesthesia, and an additional 17 min in cases involving local anesthesia, in comparison with corresponding control groups undergoing ESS in a traditional operating room. We developed nonmetal probes that were visualized in a real-time mode and assistive devices for the optical tracking system that were equipped to avoid obstruction caused by surgical instruments as well as by the hands of surgeons. Using these unique devices, anatomic landmarks were visualized using the present MRT system. The prognosis of patients was favorable, and in particular, no patients with sinus mucocele showed a recurrence of their lesions. We concluded that the MRT system used here for performing ESS was beneficial, especially in terms of the intranasal marsupialization of sinus mucoceles and for the verification of orbital contents.