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1.
SAGE Open Med Case Rep ; 7: 2050313X19842976, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31001426

RESUMO

In this study, we report a case of a 50-year-old Japanese man who had chronic whiplash-associated disorder, hyperlipidaemia, hyperuricacidaemia, and mild liver dysfunction due to excessive alcohol intake. Recently, he developed mild tremor in his left hand. Initiation of clonazepam (0.5 mg once daily before bedtime) helped to gradually ameliorate the tremor. However, 13 days after clonazepam initiation, his liver function and lipid profiles aggravated, and his postprandial glucose level increased to 400 mg/dL. Clonazepam was stopped promptly, and at 7 days after discontinuation, the abnormal triglyceride levels, liver dysfunction, and glycometabolism improved without any other medical intervention. This case may provide information on cautious use of clonazepam. When clonazepam is used for patients with existing hyperlipidaemia and liver dysfunction, it may cause abnormal lipid profile, aggravate liver dysfunction, and lead to remarkable glucose elevation.

2.
Case Rep Endocrinol ; 2019: 9415347, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30895163

RESUMO

A 66-year-old Japanese male presented with thirst, polyuria, and hemoglobin A1c and postprandial glucose levels (13.1% and 529 mg/dL, respectively) that indicated severe hyperglycemia. Based on his high immunoglobulin G4 level and the results of magnetic resonance imaging and magnetic resonance cholangiopancreatography, we diagnosed him with autoimmune pancreatitis. Insulin was initiated to control his diabetes. One month later, the patient commenced on prednisolone therapy for the treatment of autoimmune pancreatitis, after which his total insulin dosage increased to a maximum of 52 units/day. When the prednisolone dosage was later tapered, the patient's total dosage of insulin was reduced to 42 units/day. However, he had gained 3.6 kg from the start of prednisolone therapy, and 42 units/day was insufficient for maintaining glycemic control. Thus, empagliflozin, a sodium-dependent glucose transporter 2 (SGLT2) inhibitor, was added. Thereafter, we were able to reduce the patient's total dosage of insulin; it was eventually discontinued with good glycemic control and weight loss. Such results suggest that the combination of insulin with an SGLT2 inhibitor may be a viable option for the treatment of diabetic patients on prednisolone therapy.

3.
J Biol Chem ; 293(38): 14775-14785, 2018 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-30077972

RESUMO

Several serious diseases are associated with crystal-like amyloid fibrils or glass-like amorphous aggregates of denatured proteins. However, protein aggregation involving both types of aggregates has not yet been elucidated in much detail. Using a protein associated with dialysis-related amyloidosis, ß2-microglobulin (ß2m), we previously demonstrated that amyloid fibrils and amorphous aggregates form competitively depending on salt (NaCl) concentration. To examine the generality of the underlying competitive mechanisms, we herein investigated the effects of heat on acid-denatured ß2m at pH 2. Using thioflavin fluorescence, CD, and light scattering analysis along with atomic force microscopy imaging, we found that the temperature-dependent aggregation of ß2m markedly depends on NaCl concentration. Stepwise transitions from monomers to amyloids and then back to monomers were observed at low NaCl concentrations. Amorphous aggregates formed rapidly at ambient temperatures at high NaCl concentrations, but the transition from amorphous aggregates to amyloids occurred only as the temperature increased. Combining the data from the temperature- and NaCl-dependent transitions, we constructed a unified phase diagram of conformational states, indicating a parabolic solubility curve with a minimum NaCl concentration at ambient temperatures. Although amyloid fibrils formed above this solubility boundary, amorphous aggregates dominated in regions distant from this boundary. Kinetic competition between supersaturation-limited slow amyloid fibrillation and supersaturation-unlimited fast amorphous aggregation deformed the phase diagram, with amyloid regions disappearing with fast titration rates. We conclude that phase diagrams combining thermodynamics and kinetics data provide a comprehensive view of ß2m aggregation exhibiting severe hysteresis depending on the heat- or salt-titration rates.


Assuntos
Amiloide/biossíntese , Cloreto de Sódio/química , Temperatura , Microglobulina beta-2/metabolismo , Amiloide/química , Animais , Células Cultivadas , Dicroísmo Circular , Feminino , Fluorescência , Cinética , Masculino , Camundongos Endogâmicos C57BL , Microscopia de Força Atômica , Transição de Fase , Ligação Proteica , Solubilidade , Termodinâmica
4.
Biophys Rev ; 10(2): 493-502, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29256120

RESUMO

Amyloid fibrils are misfolded forms of proteins and are involved in various diseases. They have been studied extensively with the aim to obtain a comprehensive understanding of protein folding and misfolding and to use this knowledge to develop therapeutic strategies against the associated diseases. Salt conditions are important factors determining the formation and stability of amyloid fibrils. In the 1990s, salt effects were studied extensively to understand the conformational stability of acid-denatured proteins, and the results of these studies revealed the role of electrostatic repulsion in forming the compact intermediate states. In this review, we compare the effects of salts on the compact intermediate states with those on the formation of amyloid fibrils under acidic conditions. The results argue that both protein folding and misfolding are driven by the same forces, although the resultant conformations are distinct because they are monomeric and multimeric reactions, respectively.

5.
J Biol Chem ; 292(52): 21219-21230, 2017 12 29.
Artigo em Inglês | MEDLINE | ID: mdl-29101231

RESUMO

Heparin, a biopolymer possessing high negative charge density, is known to accelerate amyloid fibrillation by various proteins. Using hen egg white lysozyme, we studied the effects of heparin on protein aggregation at low pH, raised temperature, and applied ultrasonic irradiation, conditions under which amyloid fibrillation was promoted. Heparin exhibited complex bimodal concentration-dependent effects, either accelerating or inhibiting fibrillation at pH 2.0 and 60 °C. At concentrations lower than 20 µg/ml, heparin accelerated fibrillation through transient formation of hetero-oligomeric aggregates. Between 0.1 and 10 mg/ml, heparin rapidly induced amorphous heteroaggregation with little to no accompanying fibril formation. Above 10 mg/ml, heparin again induced fibrillation after a long lag time preceded by oligomeric aggregate formation. Compared with studies performed using monovalent and divalent anions, the results suggest two distinct mechanisms of heparin-induced fibrillation. At low heparin concentrations, initial hen egg white lysozyme cluster formation and subsequent fibrillation is promoted by counter ion binding and screening of repulsive charges. At high heparin concentrations, fibrillation is caused by a combination of salting out and macromolecular crowding effects probably independent of protein net charge. Both fibrillation mechanisms compete against amorphous aggregation, producing a complex heparin concentration-dependent phase diagram. Moreover, the results suggest an active role for amorphous oligomeric aggregates in triggering fibrillation, whereby breakdown of supersaturation takes place through heterogeneous nucleation of amyloid on amorphous aggregates.


Assuntos
Heparina/farmacologia , Muramidase/química , Agregados Proteicos/fisiologia , Amiloide/química , Amiloide/fisiologia , Proteínas Amiloidogênicas , Amiloidose , Animais , Clara de Ovo , Concentração de Íons de Hidrogênio , Muramidase/fisiologia
6.
Anal Biochem ; 510: 56-71, 2016 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-27430932

RESUMO

We examine the phenomenon of variability in the kinetics of amyloid formation and detail methods for its simulation, identification and analysis. Simulated data, reflecting intrinsic variability, were produced using rate constants, randomly sampled from a pre-defined distribution, as parameters in an irreversible nucleation-growth kinetic model. Simulated kinetic traces were reduced in complexity through description in terms of three characteristic parameters. Practical methods for assessing convergence of the reduced parameter distributions were introduced and a bootstrap procedure was applied to determine convergence for different levels of intrinsic variation. Statistical methods for assessing the significance of shifts in parameter distributions, relating to either change in parameter mean or distribution shape, were tested. Robust methods for analyzing and interpreting kinetic data possessing significant intrinsic variance will allow greater scrutiny of the effects of anti-amyloid compounds in drug trials.


Assuntos
Amiloide/química , Simulação por Computador , Modelos Químicos , Agregados Proteicos , Animais , Humanos
7.
Biochemistry ; 55(28): 3937-48, 2016 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-27345358

RESUMO

Ultrasonication is considered one of the most effective agitations for inducing the spontaneous formation of amyloid fibrils. When we induced the ultrasonication-dependent fibrillation of ß2-microglobulin and insulin monitored by amyloid-specific thioflavin T (ThT) fluorescence, both proteins showed a significant decrease in ThT fluorescence after the burst-phase increase. The decrease in ThT fluorescence was accelerated when the ultrasonic power was stronger, suggesting that this decrease was caused by the partial denaturation of preformed fibrils. The possible intermediates of denaturation retained amyloid-like morphologies, secondary structures, and seeding potentials. Similar denaturation intermediates were also observed when fibrils were denatured by guanidine hydrochloride or sodium dodecyl sulfate. The presence of these denaturation intermediates is consistent with the main-chain-dominated architecture of amyloid fibrils. Moreover, in the three types of denaturation experiments conducted, insulin fibrils were more stable than ß2-microglobulin fibrils, suggesting that the relative stability of various fibrils is independent of the method of denaturation.


Assuntos
Amiloide/química , Agregados Proteicos , Desnaturação Proteica , Tiazóis/química , Animais , Benzotiazóis , Sobrevivência Celular/efeitos dos fármacos , Guanidina/farmacologia , Humanos , Insulina/química , Células PC12 , Agregados Proteicos/efeitos dos fármacos , Desnaturação Proteica/efeitos dos fármacos , Estrutura Secundária de Proteína , Ratos , Ondas Ultrassônicas , Microglobulina beta-2/química , Microglobulina beta-2/toxicidade
8.
Oncol Lett ; 11(4): 2408-2410, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27073488

RESUMO

A 71-year-old Japanese woman presented to the Department of Neurosurgery of Keio University School of Medicine (Tokyo, Japan) with a leiomyosarcoma originating in the infratemporal fossa and an 85-mm metastasis to the right lung. Since the pulmonary lesion was associated with risk of airway obstruction, radiation therapy (50 Gy/20 fractions) was administered to the patient, which resulted in remarkable tumor shrinkage. Subsequently, the patient was administered 800 mg/day pazopanib for 10 weeks, which resulted in further reduction in tumor size. However, the patient succumbed to a massive hemorrhage of sudden onset. Three possible explanations for the fatal hemorrhage are: i) adverse reaction to pazopanib; ii) side effects of radiation; and iii) remarkable tumor shrinkage. As a result, it may be proposed that the synergic effects of the aforementioned hypotheses may have been responsible for the bleeding observed in the present case. Therefore, clinicians should be alert to the possibility of this adverse event. In the present study, the first case of mortality due to massive hemorrhage following remarkable tumor shrinkage induced by radiation therapy and subsequent pazopanib treatment is reported.

9.
Oncol Lett ; 11(1): 231-233, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26870193

RESUMO

Tumoral cavity formation is a characteristic phenomenon reported in anti-angiogenic therapy in lung lesions. A 57-year-old male with multiple pulmonary metastases from colorectal cancer treated with an oral tyrosine kinase inhibitor, regorafenib, exhibited a characteristic cavity formation after the first two cycles. The decrease in the size of tumors was calculated as 38%, and there were associated decreases in the serum concentrations of the tumor markers carcinoembryonic antigen and CA19-9. After eight cycles of treatment, the cavity gradually disappeared through filling-in. This unique morphological response is not only reported in lung cancer but also in liver metastasis in colorectal cancer. However, the association between morphological changes including cavity formation and clinical benefit remains controversial. Pulmonary hemorrhage and pneumothorax are well-known consequences of cavitation, as reported with the other anti-angiogenic inhibitors. Early tumor cavitation in lung metastasis may demonstrate the predictive potential of regorafenib in colorectal cancer, although it is necessary to be mindful of toxicity.

10.
J Biochem ; 159(2): 247-60, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26319711

RESUMO

Cu, Zn-superoxide dismutase (SOD1), an enzyme implicated in the progression of familial amyotrophic lateral sclerosis (fALS), forms amyloid fibrils under certain experimental conditions. As part of our efforts to understand ALS pathogenesis, in this study we found that reduction of the intramolecular disulfide bond destabilized the tertiary structure of metal free wild-type SOD1 and greatly enhanced fibril formation in vitro. We also identified fibril core peptides that are resistant to protease digestion by using mass spectroscopy and Edman degradation analyses. Three regions dispersed throughout the sequence were detected as fibril core sequences of SOD1. Interestingly, by using three synthetic peptides that correspond to these identified regions, we determined that each region was capable of fibril formation, either alone or in a mixture containing multiple peptides. It was also revealed that by reducing the disulfide bond and causing a decrease in the structural stability, the amyloid fibril formation of a familial mutant SOD1 G93A was accelerated even under physiological conditions. These results demonstrate that by destabilizing the structure of SOD1 by removing metal ions and breaking the intramolecular disulfide bridge, multiple fibril-forming core regions are exposed, which then interact with each another and form amyloid fibrils under physiological conditions.


Assuntos
Amiloide/química , Esclerose Lateral Amiotrófica/enzimologia , Peptídeos/química , Superóxido Dismutase/química , Sequência de Aminoácidos , Esclerose Lateral Amiotrófica/genética , Humanos , Microscopia Eletrônica de Transmissão , Dados de Sequência Molecular , Mutação , Oxirredução , Estrutura Terciária de Proteína , Superóxido Dismutase/genética , Superóxido Dismutase-1
11.
J Biol Chem ; 290(29): 18134-18145, 2015 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-26063798

RESUMO

Although amyloid fibrils and amorphous aggregates are two types of aggregates formed by denatured proteins, their relationship currently remains unclear. We used ß2-microglobulin (ß2m), a protein responsible for dialysis-related amyloidosis, to clarify the mechanism by which proteins form either amyloid fibrils or amorphous aggregates. When ultrasonication was used to accelerate the spontaneous fibrillation of ß2m at pH 2.0, the effects observed depended on ultrasonic power; although stronger ultrasonic power effectively accelerated fibrillation, excessively strong ultrasonic power decreased the amount of fibrils formed, as monitored by thioflavin T fluorescence. An analysis of the products formed indicated that excessively strong ultrasonic power generated fibrillar aggregates that retained ß-structures but without high efficiency as seeds. On the other hand, when the spontaneous fibrillation of ß2m was induced at higher concentrations of NaCl at pH 2.0 with stirring, amorphous aggregates became more dominant than amyloid fibrils. These apparent complexities in fibrillation were explained comprehensively by a competitive mechanism in which supersaturation-limited reactions competed with supersaturation-unlimited reactions. We link the kinetics of protein aggregation and a conformational phase diagram, in which supersaturation played important roles.


Assuntos
Amiloide/química , Agregados Proteicos , Microglobulina beta-2/química , Amiloide/ultraestrutura , Cristalização , Humanos , Cinética , Transição de Fase , Estrutura Secundária de Proteína , Sais/química , Sonicação , Microglobulina beta-2/ultraestrutura
12.
J Biol Chem ; 290(2): 815-26, 2015 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-25406316

RESUMO

The deposition of amyloid ß (Aß) peptides is a pathological hallmark of Alzheimer disease. Aß peptides were previously considered to interact specifically with ganglioside-containing membranes. Several studies have suggested that Aß peptides also bind to phosphatidylcholine membranes, which lead to deformation of membranes and fibrillation of Aß. Moreover, the role of membrane curvature, one type of deformation produced by binding of proteins to a membrane, in the binding and fibrillation of Aß remains unclear. To clearly understand the relationship between the binding, consequent membrane deformation, and fibrillation of Aß, we examined the amyloid fibrillation of Aß-(1-40) in the presence of liposomes of various sizes. Membrane curvature increased with a decrease in the size of the liposomes. We used liposomes made of 1,2-dioleoyl-sn-glycero-3-phosphocholine to eliminate electrostatic effects. The results obtained showed that liposomes of smaller sizes (≤50 nm) significantly accelerated the nucleation step, thereby shortening the lag time of fibrillation. On the other hand, liposomes of larger sizes decreased the amount of fibrils but did not notably affect the lag time. The morphologies of fibrils, which were monitored by total internal reflection fluorescence microscopy, atomic force microscopy, and transmission electron microscopy, revealed that the length of Aß-(1-40) fibrils became shorter and the amount of amorphous aggregates became larger as liposomes increased in size. These results suggest that the curvature of membranes coupled with an increase in water-accessible hydrophobic regions is important for binding and concentrating Aß monomers, leading to amyloid nucleation. Furthermore, amyloid fibrillation on membranes may compete with non-productive binding to produce amorphous aggregates.


Assuntos
Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/química , Bicamadas Lipídicas/química , Fragmentos de Peptídeos/química , Agregados Proteicos/genética , Doença de Alzheimer/patologia , Amiloide/química , Amiloide/metabolismo , Peptídeos beta-Amiloides/metabolismo , Humanos , Interações Hidrofóbicas e Hidrofílicas , Bicamadas Lipídicas/metabolismo , Lipossomos/química , Lipossomos/metabolismo , Microscopia de Força Atômica , Fragmentos de Peptídeos/metabolismo , Ligação Proteica , Estrutura Secundária de Proteína
13.
Biochim Biophys Acta ; 1854(3): 209-17, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25528988

RESUMO

Ultrasonication can be used to break the supersaturation of α-synuclein, a protein associated with Parkinson's disease, at pH7.4 above the critical concentration of fibrillation, thereby inducing the formation of amyloid fibrils. We speculated that ultrasonication could also be used to depolymerize preformed fibrils below the critical concentration. However, extensive ultrasonic irradiation transformed preformed fibrils into amorphous aggregates even above the critical concentration. Exposing preformed fibrils to the hydrophobic air-water interface of cavitation bubbles may have destabilized the fibrils and stabilized amorphous aggregates. Upon extensive ultrasonic irradiation, the accompanying decomposition of chemical structures was suggested when monitored by analytical ultracentrifugation. Amorphous aggregates produced by extensive ultrasonication showed higher cytotoxicity, suggesting that, although ultrasonication might be a useful approach for inactivating amyloid fibrils, potential cytotoxicity of amorphous aggregates should be considered.


Assuntos
Amiloide/síntese química , Amiloide/efeitos da radiação , Sonicação/métodos , alfa-Sinucleína/química , alfa-Sinucleína/efeitos da radiação , Amiloide/administração & dosagem , Animais , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Relação Dose-Resposta à Radiação , Ondas de Choque de Alta Energia , Células PC12 , Agregados Proteicos , Proteólise , Doses de Radiação , Ratos , alfa-Sinucleína/administração & dosagem
14.
Hepatol Res ; 43(6): 658-69, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23107150

RESUMO

AIM: Liver macrophages play integral roles in both the progression and resolution of hepatic inflammation and fibrosis, comprising opposing functions that largely coincide with the activation state of nearby hepatic stellate cells (HSC). While cross-talk between HSC and macrophages may be essential at various stages of inflammation and fibrogenesis, many facets of this interaction have yet to be thoroughly explored. Here, we examine the potential roles of HSC-derived signaling molecules as mediators of liver macrophage differentiation. METHODS: Human peripheral blood mononuclear cells (PBMC) were differentiated to macrophages in the presence or absence of cultured HSC-derived conditioned media. The phenotype of resulting macrophages was characterized by examination of cell surface marker expression, antigen-presenting capabilities and cytokine secretion. RESULTS: Conditioned media from activated human HSC promoted the differentiation of a unique set of macrophages that differed in morphology and function from both classical (M1) and alternative (M2) macrophages, expressing increased levels of CD14 and CD16, as well as a distinct interleukin (IL)-6(high) /IL-10(low) /transforming growth factor (TGF)-ß(high) expression profile. These macrophages expressed high levels of CD206, CD209, CD80 and human leukocyte antigen DR, though no significant increases in antigen presentation were apparent. HSC-derived macrophages exhibited specific activation of p38 mitogen-activated protein kinase, and inhibition of this activation by p38 inhibitors during differentiation effectively reversed increases in IL-6 and TGF-ß. CONCLUSION: The present results suggest that HSC-derived signaling molecules promote differentiation of liver macrophages with both pro-inflammatory and profibrotic functions. Furthermore, these effects appear to be mediated, at least partially, in a p38-dependent manner.

15.
Cancer Sci ; 104(2): 157-64, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23121112

RESUMO

Cancer-associated fibroblasts contribute to cancer progression that is caused by epithelial-mesenchymal transition (EMT). Recently, mesenchymal stem cells (MSCs) were found to be the major candidate involved in the development of tumor-promoting cancer stroma. Here we report that α-smooth muscle actin-positive myofibroblast-like cells originating from MSCs contribute to inducing EMT in side population cells of pancreatic cancer. More importantly, MSC-derived myofibroblasts function to maintain tumor-initiating stem cell-like characteristics, including augmenting expression levels of various stemness-associated genes, enhancing sphere- forming activity, promoting tumor formation in a mouse xenograft model, and showing resistance to anticancer drugs. Furthermore, both γ-secretase inhibitor and siRNA directed against Jagged-1 attenuated MSC-associated E-cadherin suppression and sphere formation in pancreatic cancer side population cells. Thus, our results suggest that MSC-derived myofibroblasts play important roles in regulating EMT and tumor-initiating stem cell-like properties of pancreatic cancer cells through an intermediating Notch signal.


Assuntos
Transição Epitelial-Mesenquimal/fisiologia , Células-Tronco Mesenquimais/patologia , Neoplasias Pancreáticas/patologia , Actinas/genética , Actinas/metabolismo , Secretases da Proteína Precursora do Amiloide/genética , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Proteínas de Ligação ao Cálcio/genética , Proteínas de Ligação ao Cálcio/metabolismo , Linhagem Celular Tumoral , Progressão da Doença , Transição Epitelial-Mesenquimal/genética , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Proteína Jagged-1 , Masculino , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Células-Tronco Mesenquimais/metabolismo , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Miofibroblastos/metabolismo , Miofibroblastos/patologia , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , RNA Interferente Pequeno/genética , Receptores Notch/genética , Receptores Notch/metabolismo , Proteínas Serrate-Jagged , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo
16.
Gastric Cancer ; 16(1): 100-10, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22527182

RESUMO

BACKGROUND: Myeloid cell leukemia-1 (Mcl-1) is an anti-apoptotic protein that regulates apoptosis sensitivity in a variety of cell types. Here we evaluate the roles of Mcl-1 in chemotherapy-associated apoptosis in gastric cancer cells. In addition, our study examined whether Mcl-1 contributed to apoptosis resistance in so-called cancer stem cell (CSC)-like populations in gastric cancer. METHODS: Seven gastric cancer cell lines were used. The expression of Mcl-1 was assessed by either real-time polymerase chain reaction or Western blot analysis. Apoptosis was quantitated by morphological observation and caspase activity measurement. Adenovirus-mediated RNA interference (RNAi) technology was used to knockdown the expression of Mcl-1. The release of cytochrome c was evaluated by subcellular fractionation and immunoblot analysis. To identify and isolate the CSC-like populations, we used the CSC-associated cell surface marker CD44 and flow cytometry. RESULTS: Six out of the 7 gastric cancer cell lines overexpressed Mcl-1 protein. These Mcl-1-expressing cell lines were relatively resistant to chemotherapeutic agents such as 5-fluorouracil (5-FU) and cisplatin (CDDP). Depletion of Mcl-1 protein by RNAi technology effectively sensitized the cells to anticancer drug-induced mitochondrial cytochrome c release, caspase activation, and apoptosis. In addition, vast amounts of Mcl-1 mRNA were expressed in CD44-positive CSC-like cells. Mcl-1 suppression enhanced the apoptosis in CD44-positive cells to a level equivalent to that in CD44-negative cells, suggesting that Mcl-1 mediates chemotherapy resistance in CSC-like populations. CONCLUSION: These results suggest that Mcl-1 mediates the resistance to apoptosis in gastric cancer cells by blocking the mitochondrial pathway of cell death. Mcl-1 depletion appears to be an attractive strategy to overcome chemotherapy resistance in gastric cancer cells.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Neoplasias Gástricas/tratamento farmacológico , Western Blotting , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Regulação Neoplásica da Expressão Gênica , Humanos , Mitocôndrias/metabolismo , Proteína de Sequência 1 de Leucemia de Células Mieloides , Células-Tronco Neoplásicas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Interferência de RNA , Reação em Cadeia da Polimerase em Tempo Real , Neoplasias Gástricas/patologia
17.
Oncol Lett ; 5(1): 117-122, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23255905

RESUMO

Small cell esophageal carcinoma is a type of small cell neuroendocrine carcinoma (SCNEC). SCNEC follows an aggressive clinical course and has a poor prognosis despite multidisciplinary therapies. A standard therapeutic strategy, including surgery, radiation and first-/second-line chemotherapy, has not yet been established for SCNEC. We present a case of SCNEC of the esophagus. A 66-year-old male with SCNEC as extensive disease was treated with 60 mg/m(2) cisplatin on day 1 plus 60 mg/m(2) irinotecan on days 1, 8 and 15 every 4 weeks (IP) with successful complete remission. After the sixth course of IP, increasing pro-gastrin-releasing peptide (ProGRP) and nonspecific enolase (NSE) levels and intense fluorodeoxyglucose (FDG) avidity in a lymph node around the celiac artery (SUV(max), 8.3) indicated a refractory relapse of the disease. The patient was treated with three courses of amrubicin (AMR, 35 mg/m(2)) administered intravenously for 3 consecutive days every 3 weeks as a second-line chemotherapy. The ProGRP and NSE levels returned to the normal range 1 month after the initiation of second-line chemotherapy. However, the ProGRP and NSE levels were elevated after the third course of AMR, and PET-CT revealed progressive disease with liver metastasis and extended lymph node metastasis. As the patient remained asymptomatic, paclitaxel (100 mg/m(2)) was started as third-line chemotherapy. Patients with SCNEC of the esophagus with extensive disease should be treated with aggressive chemotherapy rather than surgery or radiation monotherapy. In the present case, tumor markers such as ProGRP and NSE were predictive of relapse and PET-CT was used to detect relapse. Further research is required to identify and exploit promising agents for resistant SCNEC.

18.
Anticancer Res ; 32(9): 3847-53, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22993328

RESUMO

BACKGROUND: The aim of this study was to evaluate whether apoptosis-resistant cancer cells have cancer stem cell (CSC)-like properties. MATERIALS AND METHODS: Panc-1 pancreatic cancer cells were incubated in the presence of 5-fluorouracil (5-FU) for 24 h, and further incubated without 5-FU for 28 days. To assess the capacity of self-renewal, surviving cells were planted for sphere-forming assay. Epithelial-to-mesenchymal transition (EMT) was induced with TGF-ß, then mRNA expression was evaluated by real-time PCR for E-cadherin, SNAIL, and vimentin. The E-Cadherin protein levels were also examined by immunoblot analysis. The Local invasion ability was analyzed by Matrigel invasion assay. RESULTS: The frequency of cells that were capable of initiating spheres was higher in 5-FU-pre treated cells, which also overexpressed stem cell marker genes, OCT4 and NANOG. Matrigel invasion activity of apoptosis-resistant Panc-1 cells was greater than that of control Panc-1 cells. CONCLUSION: Apoptosis-resistant cancer cells have CSC-like properties, i.e., able to initiate sphere formation, express stem cell genes, and respond to EMT stimulation.


Assuntos
Antimetabólitos Antineoplásicos/farmacologia , Fluoruracila/farmacologia , Células-Tronco Neoplásicas/patologia , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Processos de Crescimento Celular/efeitos dos fármacos , Processos de Crescimento Celular/fisiologia , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Transição Epitelial-Mesenquimal/genética , Proteínas de Homeodomínio/biossíntese , Proteínas de Homeodomínio/genética , Humanos , Proteína Homeobox Nanog , Fator 3 de Transcrição de Octâmero/biossíntese , Fator 3 de Transcrição de Octâmero/genética , Neoplasias Pancreáticas/genética , Fator de Crescimento Transformador beta/farmacologia
19.
Anticancer Res ; 32(9): 4097-103, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22993367

RESUMO

BACKGROUND: Although previous studies indicate that gastrointestinal (GI) cancer may originate from cells recruited from bone marrow (BM) in mice, whether similar phenomena occur in humans is controversial. In the current study, we evaluated two female patients who developed colonic adenocarcinoma more than 10 years after gender-mismatched BM transplantation, and followingly underwent successful endoscopic mucosal resection. MATERIALS AND METHODS: Fluorescent in situ hybridization (FISH) analysis was used to determine whether the tumours contained donor-derived BM cells. RESULTS: Approximately 1.2% of the tumour cells contained Y-chromosome-positive signals, and a comparable percentage of normal colonic epithelial cells close to the tumour also contained Y-chromosome-positive signals. CONCLUSION: These results do not support the concept that GI cancer can originate from BM-derived cells.


Assuntos
Adenocarcinoma/patologia , Células da Medula Óssea/patologia , Transplante de Medula Óssea/patologia , Neoplasias do Colo/patologia , Células-Tronco Neoplásicas/patologia , Adenocarcinoma/etiologia , Adenocarcinoma/genética , Adulto , Células da Medula Óssea/ultraestrutura , Transplante de Medula Óssea/efeitos adversos , Cromossomos Humanos X , Cromossomos Humanos Y , Neoplasias do Colo/etiologia , Neoplasias do Colo/genética , Feminino , Humanos , Hibridização in Situ Fluorescente , Pessoa de Meia-Idade , Células-Tronco Neoplásicas/ultraestrutura , Fatores Sexuais
20.
Gan To Kagaku Ryoho ; 38(7): 1167-70, 2011 Jul.
Artigo em Japonês | MEDLINE | ID: mdl-21772104

RESUMO

A 64-year-old male presented with discomfort in the chest. His endoscopic examination and CT scan showed esophageal cancer with multiple liver metastases. A total of ten courses of systemic chemotherapy by 5-fluorouracil (5-FU) (800 mg for five days) and cisplatin (CDDP) (80 mg/day on the first day of the week for four weeks) were performed, and liver and lymph node metastases disappeared. The primary lesion was the only site detected positive by PET scan. After a concurrent chemoradiation therapy, salvage endoscopic mucosal resection (EMR) was performed on the remainder of the primary site and the patient gained a complete response (CR). We report this case because, although the mean survival time of advanced esophageal cancer is less than one year, this patient responded to chemotherapy and gained complete response by salvage EMR. This patient has had no recurrence for four years since his initial diagnosis.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Cisplatino/uso terapêutico , Neoplasias Esofágicas/tratamento farmacológico , Fluoruracila/uso terapêutico , Neoplasias Hepáticas/tratamento farmacológico , Cisplatino/administração & dosagem , Terapia Combinada , Endoscopia , Neoplasias Esofágicas/patologia , Neoplasias Esofágicas/cirurgia , Fluoruracila/administração & dosagem , Humanos , Neoplasias Hepáticas/secundário , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X
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