RESUMO
Background: The ARROW study demonstrated that once-weekly carfilzomib and dexamethasone (wKd) therapy significantly prolonged progression-free survival compared with twice-weekly carfilzomib and dexamethasone therapy in relapsed or refractory multiple myeloma patients. Aim: To describe the treatment patterns, effectiveness and safety of wKd therapy in real-world settings in Japan. Methods: We investigated data from the medical records of 126 Japanese patients with relapsed or refractory multiple myeloma. Results: The overall response rate was 66.3%. The median progression-free survival was 9.5 months. The incidence of treatment-emergent adverse events of any grade and grade ≥3 were 45.8 and 20.8%, respectively. Conclusion: There were no new or unexpected safety signals in this study. This study demonstrated the effectiveness and safety profiles of wKd therapy in Japan.
Carfilzomib became available for daily clinical practice as a drug for cancer of bone marrow (multiple myeloma) that comes back or does not respond to previous drug (relapsed or refractory). This drug was approved in the USA in 2012, and in Japan in 2016. In this study, we looked at how once-weekly carfilzomib works and how safe it is in real-life situations in Japan. We screened 126 patients with relapsed or refractory multiple myeloma in Japan. The median age of the patients was 70 years, with 25% being over 75 years. This study also included some patients who were not in the best overall health, had a history of many treatments or had heart complications. In 66.3% of patients, the cancer had disappeared or the extent of the cancer had reduced after treatment. Side effects and serious side effects occurred in 45.8 and 14.2% of patients, respectively. The most common side effects were low levels of blood platelets (9.2%), high blood pressure (5.8%), loose or watery stools (5.0%), fever (5.0%), and low levels of red blood cells (4.2%). Heart disorders occurred in five patients. But all patients recovered or improved with treatment such as blood pressure lowering drugs and diuretics. These results showed that once-weekly carfilzomib works well and is safe in real-world settings in Japan. This information can help us think about how to pick the right patients and handle heart disease risks when using carfilzomib treatment.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica , Dexametasona , Mieloma Múltiplo , Oligopeptídeos , Humanos , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/mortalidade , Oligopeptídeos/administração & dosagem , Oligopeptídeos/efeitos adversos , Oligopeptídeos/uso terapêutico , Masculino , Feminino , Idoso , Pessoa de Meia-Idade , Japão/epidemiologia , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Dexametasona/administração & dosagem , Dexametasona/efeitos adversos , Dexametasona/uso terapêutico , Idoso de 80 Anos ou mais , Esquema de Medicação , Adulto , Intervalo Livre de Progressão , Resultado do Tratamento , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/epidemiologiaRESUMO
T-cell large granular lymphocyte (T-LGL) leukemia is a chronic T-cell monoclonal disease that is occasionally associated with pure red cell aplasia (PRCA). A 71-year-old previously healthy man complained of physical fatigue and exhibited anemia (hemoglobin, 10.5 g/dl) with lymphocytosis (76%) showing LGL. The LGL cells expressed CD3, CD7, CD8, and T-cell receptor (TCR) -α/ß. TCR-ß/γ gene rearrangement was positive. He was thus diagnosed with CD8ï¼ T-LGL leukemia. Anemia progressed with low reticulocyte count (0.11%), and the patient became blood transfusion-dependent, but no distinct abnormality caused the anemia. Bone marrow aspiration revealed an increase in lymphocytes (33.6%) and a decrease in erythroblasts (M/E ratio, 6.1). He was thus diagnosed with T-LGL-associated PRCA. Oral cyclosporin A administration resulted in prompt improvement of anemia, suggesting its high sensitivity. Whole-exome sequencing of his peripheral blood DNA revealed somatic mutations in 33 genes, including the STAT3 gene, implying their roles in T-LGL leukemia.
Assuntos
Ciclosporina/uso terapêutico , Leucemia Linfocítica Granular Grande/complicações , Aplasia Pura de Série Vermelha/tratamento farmacológico , Fator de Transcrição STAT3/genética , Idoso , Humanos , Linfocitose , Masculino , MutaçãoRESUMO
Some aphid species are known to have mutualistic relationships with tending ants; that is, the aphids supply the ants with honeydew and are protected by the ants. Although spider mites and honeydew-producing aphids often live on the same host plant, it has not previously been determined whether the ants tending these aphids affect spider mite survival. Using replicated microcosms, each containing an artificial ant nest, we compared experimentally the survival of two-spotted spider mites on kidney bean plants with and without cowpea aphids. Our results showed significantly fewer spider mites on plants with aphids, indicating that spider mites were preyed upon by ants tending aphids. On the other hand, there was no detectable plant-mediated indirect effect of aphids on mite performance in the microcosms. Therefore, we conclude that aphids indirectly reduced the survival of spider mites living on the same host plant via their tending ants. Nonetheless, spider mites did not avoid settling on plant leaves infested with aphids.
Assuntos
Afídeos/fisiologia , Plantas/parasitologia , Tetranychidae/crescimento & desenvolvimento , Animais , Formigas , SimbioseRESUMO
Fournier's gangrene (FG) is a fulminant infective necrotizing fasciitis, which includes the genital, perineal, and perianal regions. A 77-year-old man had previously been diagnosed as having diabetes mellitus (DM) and was treated with pioglitazone (15 mg) and miglitol (150 mg). He developed sudden perineal discomfort, fever with painful penile, and scrotal edema, subsequently leading to urinary retention. According to physical examination and CT scan results for the swollen penis and scrotum, he was diagnosed with FG. FG was eventually controlled by extensive treatment with broad spectrum antibiotics and repeated surgical debridement including penectomy and scrotectomy. He showed persistent anemia and decreased neutrophils exhibiting hypogranulation. Bone marrow aspiration revealed hypercellularity with 9% myeloblasts, micromegakaryocytes, abnormal leukocyte granulation, and erythrocytic dyspoiesis, leading to a diagnosis of myelodysplastic syndrome (MDS) RAEB-1, and he was evaluated as high risk according to IPSS-R. After 4 courses of azacitidine treatment, he achieved HI-E and had no further recurrence of FG for more than 18 months. Although DM and alcohol misuse are common systemic comorbidities in patients with FG, MDS should be considered in elderly FG cases, even when DM complications are present.
Assuntos
Antibacterianos/uso terapêutico , Gangrena de Fournier/tratamento farmacológico , Síndromes Mielodisplásicas/tratamento farmacológico , Tiazolidinedionas/uso terapêutico , Idoso , Gangrena de Fournier/diagnóstico , Gangrena de Fournier/patologia , Humanos , Masculino , Síndromes Mielodisplásicas/diagnóstico , Pioglitazona , Recidiva , Resultado do TratamentoRESUMO
Simultaneous onset of autoimmune hemolytic anemia (AIHA) and pure red cell aplasia (PRCA) is rare and any possible association between these two disorders remains obscure. A 46-year-old previously healthy woman was diagnosed as having AIHA based on severe anemia, positive direct and indirect Coomb's tests, decreased serum haptoglobin, elevated serum LDH, and indirect bilirubin-dominant hyperbilirubinemia. Oral steroid administration (1 mg/kg) and subsequent half-pulse steroid therapy ameliorated the AIHA, but the anemia was unexpectedly prolonged with the low peripheral blood reticulocyte count further decreasing to 0.11%. Bone marrow aspiration revealed a marked decrease in erythroblasts with an M/E ratio of 69.5. Anti-parvovirus B19 IgM antibody and serum B19 viral DNA (109 copy/ml) were detected but no other distinct abnormalities which might have caused acquired PRCA were detected. Therefore, she was considered likely to have idiopathic AIHA and acquired PRCA simultaneously. AIHA-mediated erythroblastosis probably raised the parvovirus B19 DNA level to an extraordinary degree and thereby led to severe aplastic crisis, subsequently causing prolonged anemia. Parvovirus B19 infection should be considered in AIHA patients showing unexpectedly low reticulocyte counts.
Assuntos
Anemia Hemolítica Autoimune/diagnóstico , Aplasia Pura de Série Vermelha/diagnóstico , Anemia Hemolítica Autoimune/complicações , Anemia Hemolítica Autoimune/patologia , Medula Óssea/patologia , Feminino , Febre/etiologia , Humanos , Pessoa de Meia-Idade , Parvovirus B19 Humano/genética , Aplasia Pura de Série Vermelha/complicações , Aplasia Pura de Série Vermelha/patologiaRESUMO
The properties of the coherence-or-power selectable operation of an external-cavity semiconductor diode laser through the control of intracavity polarization states have been characterized in detail. In our technique, a diffraction grating and a reflector functioned as a polarization-dependent output coupler, such that the portion of light fed back to the gain medium was readily controlled by rotating the intracavity polarization axis, which resulted in the selectable operation of either a high degree of coherence or a high power for the laser output. We could continuously sweep the correlation widths over a range of approximately one order of magnitude, as well as four-fold output powers by simply rotating the intracavity half-wave plate. We also demonstrated experiments on optical phase locking, using two independent coherence-or-power selectable lasers.
Assuntos
Proteínas de Fusão bcr-abl/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Cromossomos em Anel , Cariótipo Anormal , Adulto , Feminino , Humanos , Hibridização in Situ Fluorescente , Cromossomo FiladélfiaRESUMO
Although heat stress induces a variety of illnesses, there have been few studies designed to uncover the molecular mechanisms underlining the illnesses. We here demonstrate that heat activates ER stress, which inhibits heat shock responses (HSR) via translational block. In heat-stressed rats, ER stress responses, as represented by eIF2α phosphorylation and XBP1 splicing, occurred mainly in the cortex, where the HSR was substantially inhibited. Heat exposure also activated ER stress signals in primary cortical neurons. Since HSF1 knockdown enhanced heat-induced ER stress and subsequent cell death, HSR inhibition in turn augments ER stress, implying a vicious spiral of both stresses. Taken together, heat-induced ER stress impairs the HSR and enhances cell damage, thereby manifesting its unique effect on heat stress.
Assuntos
Córtex Cerebral/metabolismo , Córtex Cerebral/patologia , Estresse do Retículo Endoplasmático/genética , Resposta ao Choque Térmico/genética , Transdução de Sinais/genética , Animais , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Humanos , Neurônios/metabolismo , Neurônios/patologia , Ratos , Ratos WistarRESUMO
4-AP, a voltage-gated potassium channel blocker, was identified to exert critical pro-apoptotic properties in various types of cancer cells. The present study aims to explore the effect of 4-AP on the apoptosis of human AML cells and the underlying mechanism. We found 4-AP inhibited the proliferation and induces apoptosis in both AML cell lines and primary cultured human AML cells. The apoptosis of AML cells after 4-AP treatment was further confirmed by the disruption of mitochondrial membrane potential (MMP) and activation of caspase 3 and 9. 4-AP inhibited Kv currents in NB(4), HL-60 and THP-1 cells. Furthermore, 4-AP induced significant increment in [Ca(2+)](i), which were inhibited by KN-62, a specific blocker of P(2)X(7) receptors. KN-62 also abrogated 4-AP induced apoptosis. Knockdown of P(2)X(7) receptor by small interfering RNA blocked the effect of 4-AP. Conclusively, this study indicated that 4-AP promotes apoptosis in human AML cells via increasing [Ca(2+)](i) through P(2)X(7) receptor.
Assuntos
4-Aminopiridina/farmacologia , Apoptose/efeitos dos fármacos , Cálcio/metabolismo , Leucemia Mieloide Aguda/patologia , Bloqueadores dos Canais de Potássio/farmacologia , Receptores Purinérgicos P2X7/metabolismo , 1-(5-Isoquinolinasulfonil)-2-Metilpiperazina/análogos & derivados , 1-(5-Isoquinolinasulfonil)-2-Metilpiperazina/farmacologia , Canais de Cálcio/metabolismo , Caspase 3/metabolismo , Caspase 9/metabolismo , Humanos , Leucemia Mieloide Aguda/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Canais de Potássio de Abertura Dependente da Tensão da Membrana/antagonistas & inibidores , Canais de Potássio de Abertura Dependente da Tensão da Membrana/metabolismo , Canais de Potássio de Abertura Dependente da Tensão da Membrana/fisiologia , Antagonistas do Receptor Purinérgico P2X/farmacologia , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Receptores Purinérgicos P2X7/química , Receptores Purinérgicos P2X7/genética , Células Tumorais CultivadasRESUMO
The purpose of this study was to investigate the hypothesis that electrical stimulation regulates the levels of gene expression related to apoptosis in denervated muscle and prevents muscle atrophy after denervation.Nineteen rats were used in this study. To denervate soleus muscle, sciatic nerve was resected under aseptic condition. Electrical stimulation with 4 mA rectangular pulses of 0.5 ms duration at 2 Hz lasting for 1 hour was delivered to lower limb including the soleus muscle using two surface electrodes. After the stimulation periods of 4 weeks, the levels of gene expression related to apoptosis were evaluated. Electrical stimulation increased valosin-containing protein (VCP) expression and decreased cleaved caspase-12 expression in denervated muscles. These results indicated that electrical stimulation to denervated muscle suppresses ER-specific apoptosis by enhancing VCP expression. We proposed that electrical stimulation would be a potential treatment for preventing atrophy of denervated skeletal muscles.
Assuntos
Adenosina Trifosfatases/metabolismo , Apoptose , Caspase 12/metabolismo , Proteínas de Ciclo Celular/metabolismo , Estimulação Elétrica , Denervação Muscular/reabilitação , Músculo Esquelético/fisiopatologia , Adenosina Trifosfatases/genética , Animais , Western Blotting , Caspase 12/genética , Proteínas de Ciclo Celular/genética , Modelos Animais de Doenças , Estimulação Elétrica/métodos , Feminino , Imuno-Histoquímica , Extremidade Inferior/inervação , Extremidade Inferior/fisiopatologia , Denervação Muscular/métodos , Músculo Esquelético/inervação , Músculo Esquelético/metabolismo , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Nervo Isquiático/lesões , Fatores de Tempo , Resultado do Tratamento , Proteína com ValosinaRESUMO
To understand the role of cholinoceptive, medial pontine reticular formation (mPRF) neurons in the control of upper airway, pharyngolaryngeal reflexes, we measured activities of intrinsic laryngeal muscles (posterior cricoarytenoid, PCA; thyroarytenoid, TA), diaphragm (DIA), genioglossus (GG) and a neck muscle (trapezius) in unanesthetized, decerebrated, spontaneously breathing cats with and without mPRF carbachol injections. The ethimoidal nerve was electrically stimulated to evoke sneezing, and the superior laryngeal nerve to evoke the laryngeal reflex, swallowing, and coughing. Carbachol reduced the amplitudes of the spontaneous electromyographic activities in the neck, TA, PCA, GG, and DIA to 7%, 30%, 54%, 45% and 71% of control, respectively, reduced the respiratory rate to 53% without changes in expiratory CO(2) concentration; the magnitude of the laryngeal reflex in the TA muscle to 56%; increased its latency by 13%; and reduced the probability of stimulus-induced sneezing, swallowing, and coughing to less than 40%. These changes lasted more than 1h. These data demonstrate that important upper airway reflexes are suppressed by increasing cholinergic neurotransmission in the mPRF. Because acetylcholine release in the mPRF changes in accordance with sleep-wake cycles, the present findings are relevant to the control of upper airway reflexes during various vigilance states.
Assuntos
Carbacol/farmacologia , Agonistas Colinérgicos/farmacologia , Músculos Laríngeos/efeitos dos fármacos , Faringe/efeitos dos fármacos , Ponte/efeitos dos fármacos , Reflexo/efeitos dos fármacos , Formação Reticular/efeitos dos fármacos , Animais , Gatos , Tosse/fisiopatologia , Estado de Descerebração , Deglutição/efeitos dos fármacos , Estimulação Elétrica , Eletromiografia , Feminino , Músculos Laríngeos/fisiologia , Nervos Laríngeos/fisiologia , Laringe/efeitos dos fármacos , Laringe/fisiologia , Masculino , Músculos do Pescoço/efeitos dos fármacos , Músculos do Pescoço/fisiologia , Faringe/inervação , Faringe/fisiologia , Ponte/fisiologia , Formação Reticular/fisiologia , Espirro/efeitos dos fármacosRESUMO
BACKGROUND: Environmental changes, air pollution and ozone depletion are increasing oxidative stress, and global warming threatens health by heat stress. We now face a high risk of simultaneous exposure to heat and oxidative stress. However, there have been few studies investigating their combined adverse effects on cell viability. PRINCIPAL FINDINGS: Pretreatment of hydrogen peroxide (H(2)O(2)) specifically and highly sensitized cells to heat stress, and enhanced loss of mitochondrial membrane potential. H(2)O(2) exposure impaired the HSP40/HSP70 induction as heat shock response (HSR) and the unfolded protein recovery, and enhanced eIF2alpha phosphorylation and/or XBP1 splicing, land marks of ER stress. These H(2)O(2)-mediated effects mimicked enhanced heat sensitivity in HSF1 knockdown or knockout cells. Importantly, thermal preconditioning blocked H(2)O(2)-mediated inhibitory effects on refolding activity and rescued HSF1 +/+ MEFs, but neither blocked the effects nor rescued HSF1 -/- MEFs. These data strongly suggest that inhibition of HSR and refolding activity is crucial for H(2)O(2)-mediated enhanced heat sensitivity. CONCLUSIONS: H(2)O(2) blocks HSR and refolding activity under heat stress, thereby leading to insufficient quality control and enhancing ER stress. These uncontrolled stress responses may enhance cell death. Our data thus highlight oxidative stress as a crucial factor affecting heat tolerance.
Assuntos
Proteínas de Choque Térmico HSP40/química , Proteínas de Choque Térmico HSP70/química , Resposta ao Choque Térmico , Estresse Oxidativo , Animais , Linhagem Celular Tumoral , Sobrevivência Celular , Proteínas de Ligação a DNA/metabolismo , Fator de Iniciação 2 em Eucariotos/metabolismo , Fibroblastos/metabolismo , Proteínas de Choque Térmico HSP40/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Humanos , Peróxido de Hidrogênio/química , Potencial da Membrana Mitocondrial , Camundongos , Fosforilação , Desnaturação Proteica , Fatores de Transcrição de Fator Regulador X , Fatores de Transcrição/metabolismo , Proteína 1 de Ligação a X-BoxRESUMO
OBJECTIVES: To investigate the anticancer effect and potential mechanism of combination treatment with arsenic trioxide (ATO) and parthenolide (PTL) in human pancreatic cancer cells. METHODS: The effects of PTL/ATO on 2 pancreatic carcinoma cell lines, PANC-1 and BxPC-3, were determined by trypan blue exclusion, annexin V/propidium iodide, 4',6-diamidino-2-phenylindole HCl, terminal deoxynucleotidyltransferase-mediated nick-end labeling, flow cytometry, Western blot, and clonogenic assay. In vivo study was performed in PANC-1 tumor xenografts in nude mice. RESULTS: The combination of PTL and ATO inhibited the growth of pancreatic tumor cell lines much greater than each agent alone. The PTL/ATO treatment induced apoptosis and reactive oxygen species generation. Both of them were inhibited by L-N-acetylcysteine and diphenylene iodonium chloride. During ATO/PTL-mediated apoptosis, the collapse of mitochondrial transmembrane potential occurred with cytochrome c release, which was reversed by L-N-acetylcysteine. The combination treatment significantly reduced tumor growth rates of PANC-1 xenografts compared with those treated with either PTL or ATO alone. CONCLUSIONS: Combination therapy with ATO and PTL has an augmented anticancer effect on pancreatic cancer in vitro and in vivo, which provides a novel promising approach in the treatment of pancreatic cancer. The mechanism of growth-suppressive effect of combination therapy was correlated with its ability to induce reactive oxygen species generation and apoptosis via the mitochondrial pathway.
Assuntos
Arsenicais/farmacologia , Óxidos/farmacologia , Neoplasias Pancreáticas/tratamento farmacológico , Sesquiterpenos/farmacologia , Acetilcisteína/farmacologia , Animais , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Apoptose/efeitos dos fármacos , Trióxido de Arsênio , Arsenicais/administração & dosagem , Western Blotting , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Citometria de Fluxo , Inibidores do Crescimento/administração & dosagem , Inibidores do Crescimento/farmacologia , Humanos , Marcação In Situ das Extremidades Cortadas , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Camundongos Nus , Óxidos/administração & dosagem , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Espécies Reativas de Oxigênio/metabolismo , Sesquiterpenos/administração & dosagem , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
A 44-year-old man was admitted to hospital because of respiratory distress and progressive edema in the lower extremities. He was diagnosed as having congestive heart failure, but his condition improved following intensive care. Echocardiogram revealed a thickened interventricular septum, insufficient diastolic function, and granular sparkling pattern in the ventricular wall. Pathological examination of a myocardial biopsy specimen showed the deposition of AL amyloid, resulting in a diagnosis of AL amyloidosis. He was then referred to our hospital for treatment. After a course of high-dose dexamethasone therapy, peripheral blood stem cells induced by the administration of granulocyte colony stimulating factor were harvested. He then received high-dose melphalan (HDM) with autologous peripheral blood stem cell transplantation (auto-PBSCT) support, leading to complete remission. He has been well for more than three years after the transplantation and enjoys the same daily life as before the onset of symptoms. HDM/auto-PBSCT for AL amyloidosis confers a higher response rate and longer survival than conventional chemotherapies; however, treatment-related toxicity is also high. Refinements of treatment strategies are urgently needed. This case provides insights into appropriate strategies for HDM/auto-PBSCT for AL amyloidosis with regard to patient selection, the best induction therapy, and the risk-adjusted melphalan conditioning dose; all of which should be confirmed by randomized controlled trials.
Assuntos
Amiloidose/terapia , Insuficiência Cardíaca/complicações , Transplante de Células-Tronco de Sangue Periférico , Adulto , Amiloidose/complicações , Humanos , Masculino , Indução de Remissão , Transplante AutólogoRESUMO
BACKGROUND: Noxious stimulation of the nasal mucosa may induce protective reflexes in the upper airway in rats. Previously, we have reported that nasal air-jet stimulation increases the activities of the laryngeal muscles in decerebrate cats; however, the neuronal mechanism of this phenomenon still is not clarified. METHODS: After the application of nasal air-jet stimulation for 2 hours, we investigated the distribution of Fos-positive cells (FPCs) throughout the medulla compared with sham-operated rats using Fos immunoreactivity. RESULTS: FPCs in the spinal trigeminal nucleus, the parvocellular reticular nucleus, and the nucleus of the solitary tract were more frequent than the sham-operated rats. CONCLUSION: These results suggest that the afferents induced by air-jet stimulation were conveyed to these FPCs and that some of these cells might participate in the augmentation of laryngeal muscle activities during nasal air-jet stimulation.
Assuntos
Expressão Gênica , Genes fos/fisiologia , Cavidade Nasal/inervação , Núcleo Solitário/metabolismo , Ar , Animais , Feminino , Masculino , Estimulação Física/métodos , Ratos , Ratos Sprague-Dawley , Núcleo Solitário/ultraestruturaRESUMO
PURPOSE: 2-Methoxyestradiol (2ME), an estrogen metabolite, induces apoptosis in various cell types. We investigated whether 2ME pretreatment can radiosensitize colon adenocarcinoma cells. EXPERIMENTAL DESIGN: Radiosensitizing effects of 2ME were evaluated by cell death, clonogenic assay, nuclear fragmentation, and tumor progression of xenografts. Ionizing radiation-induced DNA damage was evaluated by histone H2AX phosphorylation and its foci. The c-Jun NH2-terminal kinase (JNK) activation was evaluated by anti-phosphorylated JNK antibody and inhibited by the JNK-specific inhibitor SP600125 or dominant-negative SEK1 expression. RESULTS: Clonogenic assays revealed that 2ME, but not estradiol, radiosensitized three colon carcinoma cells, DLD-1, HCT-8, and HCT-15, and strongly suppressed tumor progression of DLD-1 xenografts. Gene transfer-mediated Bcl-xL overexpression largely abolished both augmented apoptosis and reduced survival fractions. Pretreatment with 2ME enhanced H2AX phosphorylation, its foci, and phosphorylation of ATM kinase and delayed re-entry of cell cycle progression after ionizing radiation. Augmentation of both radiosensitivity and H2AX phosphorylation was substantially reduced by SP600125 or overexpression of a dominant-negative mutant SEK1. CONCLUSION: 2ME radiosensitized colon carcinoma cells through enhanced DNA damage via JNK activation, thereby representing a novel radiosensitizing therapy against colon cancer.
Assuntos
Adenocarcinoma/terapia , Neoplasias do Colo/terapia , Estradiol/análogos & derivados , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Radiossensibilizantes/farmacocinética , 2-Metoxiestradiol , Animais , Apoptose/fisiologia , Western Blotting , Ciclo Celular/efeitos da radiação , Linhagem Celular Tumoral , Terapia Combinada , Dano ao DNA/efeitos da radiação , Estradiol/metabolismo , Estradiol/farmacocinética , Histonas/metabolismo , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/efeitos dos fármacos , Camundongos , Camundongos Nus , Microscopia Confocal , Fosforilação , Radiação Ionizante , Transfecção , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The sesquiterpene lactone, parthenolide (PTL), possesses strong anticancer activity against various cancer cells. We report that PTL strongly induced apoptosis in 4 multiple myeloma (MM) cell lines and primary MM cells (CD38(+) high), but barely induced death in normal lymphocytes (CD38(-/+)low). PTL-mediated apoptosis correlated well with ROS generation and was almost completely inhibited by L-N-acetylcysteine (L-NAC), indicating the crucial role of oxidative stress in the mechanism. Among 4 MM cell lines, there is considerable difference in susceptibility to PTL. KMM-1 and MM1S cells sensitive to PTL possess less catalase activity than the less sensitive KMS-5 and NCI-H929 cells as well as normal lymphocytes. A catalase inhibitor 3-amino-1,2,4-triazole enhanced their PTL-mediated ROS generation and cell death. The siRNA-mediated knockdown of catalase in KMS-5 cells decreased its activity and sensitized them to PTL. Our findings indicate that PTL induced apoptosis in MM cells depends on increased ROS and intracellular catalase activity is a crucial determinant of their sensitivity to PTL.
Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Apoptose/efeitos dos fármacos , Catalase/metabolismo , Mieloma Múltiplo/patologia , Espécies Reativas de Oxigênio/metabolismo , Sesquiterpenos/farmacologia , Acetilcisteína/farmacologia , Idoso de 80 Anos ou mais , Antioxidantes/metabolismo , Catalase/antagonistas & inibidores , Sobrevivência Celular/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Humanos , Oniocompostos/farmacologia , Estresse Oxidativo/efeitos dos fármacosRESUMO
Histone deacetylase (HDAC) inhibitors augment ionizing radiation (IR)-induced apoptosis in several cancer cells by undefined mechanism(s). We recently found that the HDAC inhibitors induce a BH3-only protein Bmf in human squamous carcinoma SAS cells. We extended this study and found that 2.5 nM FK228 pretreatment could not induce apoptosis but augmented IR-induced death. The FK228 pretreatment increased Bmf expression level, and siRNA-mediated knockdown of Bmf transcripts strongly inhibited its augmentation of IR-induced cell death, disruption of mitochondrial membrane potential and DNA fragmentation. Another HDAC inhibitor CBHA pretreatment similarly augmented IR-induced apoptosis, and this effect was also inhibited by Bmf knockdown. Bmf overexpression augmented IR-induced death, and the augmented effects of FK228 were similarly observed in another squamous carcinoma HSC2 cells. Overexpression of histone acetyltransferase p300 mimicked the effects of the HDAC inhibitors, i.e., it enhanced IR-induced death, which was mostly abolished by Bmf knockdown. Taken together, histone hyperacetylation may enhance IR-induced death via activation of Bmf transcription, thereby implying Bmf as a key molecule for HDAC inhibitors (FK228 and CBHA)-mediated enhancing effect on IR-induced cell death.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/fisiologia , Apoptose/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Inibidores de Histona Desacetilases , Radiossensibilizantes/farmacologia , Apoptose/efeitos da radiação , Proteínas de Ciclo Celular/metabolismo , Cinamatos/farmacologia , Cisplatino/farmacologia , Depsipeptídeos/farmacologia , Histona Acetiltransferases/metabolismo , Humanos , Raios Infravermelhos , RNA Interferente Pequeno/metabolismo , Fatores de Transcrição/metabolismo , Células Tumorais Cultivadas , Raios X , Fatores de Transcrição de p300-CBPRESUMO
PURPOSE: Histone deacetylase (HDAC) inhibitors are believed to be promising radiosensitizers. To explore their effects on ionizing radiation (IR), we examined whether the HDAC inhibitors m-carboxycinnamic acid bis-hydroxamide (CBHA) and depsipeptide FK228 affect H2AX phosphorylation (gamma-H2AX), a landmark of DNA double-strand breaks after IR exposure. METHODS AND MATERIALS: We evaluated the effects of the HDAC inhibitors on clonogenic assay in human lung carcinoma A549 cells and progression of A549 xenograft tumors. IR-induced DNA damage was evaluated by histone gamma-H2AX. Histone hyperacetylation was induced by overexpression of histone acetyltransferase p300 and evaluated by Western blots. RESULTS: M-carboxycinnamic acid bishydroxyamide pretreatment radiosensitized A549 cells and strongly inhibited A549 xenograft tumor progression. CBHA and FK228, but not 5-fluorouracil, enhanced IR-induced gamma-H2AX in A549 and other cancer cell lines. Overexpression of p300 similarly augmented IR-induced gamma-H2AX. CONCLUSION: The results of this study suggest that HDAC inhibitors enhance IR-induced gamma-H2AX, most likely through histone hyperacetylation, and radiosensitize various cancers.