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1.
J Korean Soc Radiol ; 84(6): 1367-1372, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38107679

RESUMO

Primary angiitis of the central nervous system (PACNS) is a rare vasculitis in the central nervous system. Herein, we report a case of diagnosis and treatment of necrotic pattern PACNS, which was difficult to differentiate from a brain abscess. A 19-year-old male presented with blurred vision and a headache. Brain MRI revealed irregular rim-enhancing necrotic masses with central diffusion-high signal intensity in the corpus callosum and peripheral diffusion-high signal intensity in the left parietotemporal periventricular area. Susceptibility-weighted imaging revealed multiple punctate hemorrhages in the lesions. The patient was diagnosed with unusual abscess or tumefactive PACNS. Therefore, we initially treated the patient with antibiotics to rule out brain abscess. However, the brain lesions did not improve on follow-up MRI after the antibiotic treatment. Surgical biopsy was performed, and the histopathological diagnosis was PACNS with a necrotic pattern. The necrotic lesions became smaller on follow-up MRI after high-dose corticosteroid treatment.

2.
J Korean Soc Radiol ; 84(5): 1140-1145, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37869121

RESUMO

Cerebral amyloid angiopathy-related inflammation (CAA-RI) is an encephalopathy caused by inflammation of ß-amyloid peptide deposition in cerebrovascular vessels. It is a rare disease that mainly occurs in the elderly and is characterized by rapidly progressive dementia, headache, seizures, and focal neurologic deficits. CAA-RI can demonstrate characteristic brain MRI findings and can be reversed by steroids or other immunosuppressive therapies. Here, we report a case of CAA-RI, which was initially misdiagnosed as a subacute infarction but was diagnosed while reviewing follow-up brain MRI images, and spontaneous remission was achieved.

3.
J Korean Soc Radiol ; 84(5): 1080-1090, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37869130

RESUMO

Purpose: This study aimed to compare the volume and normative percentiles of brain volumetry in the Korean population using quantitative brain volumetric MRI analysis tools NeuroQuant® (NQ) and DeepBrain® (DB), and to evaluate whether the differences in the normative percentiles of brain volumetry between the two tools is related to cranial shape. Materials and Methods: In this retrospective study, we analyzed the brain volume reports obtained from NQ and DB in 163 participants without gross structural brain abnormalities. We measured three-dimensional diameters to evaluate the cranial shape on T1-weighted images. Statistical analyses were performed using intra-class correlation coefficients and linear correlations. Results: The mean normative percentiles of the thalamus (90.8 vs. 63.3 percentile), putamen (90.0 vs. 60.0 percentile), and parietal lobe (80.1 vs. 74.1 percentile) were larger in the NQ group than in the DB group, whereas that of the occipital lobe (18.4 vs. 68.5 percentile) was smaller in the NQ group than in the DB group. We found a significant correlation between the mean normative percentiles obtained from the NQ and cranial shape: the mean normative percentile of the occipital lobe increased with the anteroposterior diameter and decreased with the craniocaudal diameter. Conclusion: The mean normative percentiles obtained from NQ and DB differed significantly for many brain regions, and these differences may be related to cranial shape.

4.
BMC Med Imaging ; 22(1): 219, 2022 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-36536325

RESUMO

BACKGROUND: Knowing the lowest acceptable radiation dose of multiphase hepatic CT may allow us to reduce the radiation dose for detecting HCC. PURPOSE: To prospectively assess the image quality and diagnostic performance of low-dose and ultra-low-dose multiphase hepatic computed tomography using a dual-source CT scanner. METHODS: Three reconstructed different dose scan images (standard-dose, low-dose, and ultra-low-dose) of hepatic multiphase CT were obtained from 67 patients with a dual-source CT scanner. The image quality and the diagnostic performance of the three radiation dose CT scans of the hepatic focal lesion (≥ 0.5 cm) were analyzed by two independent readers using the Liver Imaging Reporting and Data System. RESULTS: Qualitative image quality and signal-to-noise ratio were significantly different among the radiation doses (p < 0.001). In total, 154 lesions comprising 32 hepatocellular carcinomas (HCC) and 122 non-HCC were included. The sensitivities of SDCT, LDCT, and ULDCT were 90.6%(29/32), 81.3%(26/32), and 56.2%(18/32), respectively. The accuracies of SDCT, LDCT, and ULDCT were 98.1%(151/154), 96.1%(148/154), and 89.6%(138/154), respectively. On per-lesion analysis, SDCT and LDCT did not show significantly different sensitivity and accuracy in diagnosing HCC (p = 0.250 and 0.250). CONCLUSIONS: The diagnostic performance of dynamic hepatic LDCT with 33% reduced radiation dose in comparison to SDCT would be acceptable even though its image quality was qualitatively and quantitatively inferior. However, few HCCs could be overlooked. Therefore, with caution, radiation dose reduction by one-third could be implemented for follow-up CT scans for patients suspected of having HCC with caution and further studies are needed in the future.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/diagnóstico por imagem , Doses de Radiação , Neoplasias Hepáticas/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Interpretação de Imagem Radiográfica Assistida por Computador/métodos
5.
Acta Radiol ; 63(11): 1453-1462, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34839679

RESUMO

BACKGROUND: Knowing the advantages and disadvantages of each magnetic resonance (MR) technique, would allow us to choose a sequence better suited in patients with a high risk of breath-holding failure. PURPOSE: To compare the image quality of free-breathing contrast-enhanced multiphase MR imaging (MRI) using incoherent Cartesian k-space sampling combined with a motion-resolved compressed sensing reconstruction (XD-VIBE) and Golden-Angle Radial Sparse Parallel MRI (GRASP). MATERIAL AND METHODS: A total of 67 patients were included. Overall image quality, motion artifacts, and liver edge sharpness on arterial and portal-venous phase were evaluated by two radiologists. We evaluated the signal intensity ratio between liver in the late arterial phase to aorta at peak enhancement and the detection rate of hypervascular lesions. RESULTS: Overall image quality, artifact, and liver edge sharpness scores of XD-VIBE and GRASP were not significantly different (P = 0.070-0.397). Four (reviewer 1, 12.1%) and seven patients (reviewer 2, 21.2%) received non-diagnostic quality in the XD-VIBE group whereas one patient (reviewer 2, 2.9%) received non-diagnostic quality in the GRASP group. The ratio between the aorta and liver signal for GRASP was significantly higher than that of XD-VIBE (0.32 ± 0.10 vs. 0.47 ± 0.13; P < 0.001). The hypervascular lesion detection rate of XD-VIBE (86.7%) was higher than that of GRASP (57.1%) in the arterial phase without a statistically significant difference (P = 0.081). CONCLUSION: Overall image quality of XD-VIBE and GRASP were not significantly different. More XD-VIBE examinations were rated non-diagnostic. On the other hand, the relative liver parenchymal enhancement to the aorta in the late arterial phase of GRASP was higher than that of XD-VIBE, which potentially leads to lower detectability of hypervascular lesions on arterial phase images.


Assuntos
Meios de Contraste , Imageamento por Ressonância Magnética , Artefatos , Suspensão da Respiração , Humanos , Aumento da Imagem/métodos , Imageamento Tridimensional/métodos , Fígado/diagnóstico por imagem , Fígado/patologia , Imageamento por Ressonância Magnética/métodos , Respiração
6.
Ann Lab Med ; 41(5): 489-492, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-33824238

RESUMO

Botulism is a neuroparalytic disease caused by a neurotoxin produced by Clostridium botulinum. This study aimed to genetically characterize C. botulinum strain isolated from the first case of infant botulism in Korea reported on June 17, 2019. We isolated C. botulinum strain CB-27 from a stool sample of the patient and analyzed the toxin types and toxin gene cluster compositions of the strain using a mouse bioassay, real-time PCR, and genome sequencing. Toxin gene cluster analysis showed that strain CB-27 possesses a C. botulinum neurotoxin type A harboring an unexpressed B gene. Although the nucleotide and amino acid sequences of toxin genes as well as the toxin gene cluster arrangements in strain CB-27 were identical to those of the known strain CDC_69094, the total nucleotide sequences of the toxin gene clusters of CB-27 differed from those of CDC_69094 by 0.47%, indicating genetic diversity of toxin gene clusters of CB-27 among other previously reported C. botulinum strains. To our knowledge, this is the first description of a C. botulinum strain with two separate toxin gene clusters in Korea.


Assuntos
Toxinas Botulínicas , Botulismo , Clostridium botulinum , Toxinas Botulínicas/genética , Botulismo/diagnóstico , Clostridium botulinum/genética , Humanos , Lactente , Filogenia , República da Coreia
7.
Heart Lung Circ ; 30(6): 817-836, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33541820

RESUMO

AIMS: To identify the biomedical, socioeconomic and demographic predictors of heart failure (HF) related readmissions in adult patients with HF. METHODS: This systematic review was conducted in March 2020 using the databases EMBASE, CINAHL and Medline to identify publications between 2015-2020. The resulting articles were systematically reviewed according to the PRISMA guidelines. RESULTS: Eighteen (18) studies were included in this review. Unemployment (HR=1.09; 95%CI=1.05-1.14; p=0.03) was the only socioeconomic factor predictive of HF-readmissions. Socio-Economic Indexes for Areas (SEIFA) scores did not predict HF readmissions in adults with HF (p>0.05). All patients included in the studies had pre-existing HF. Based on the included studies, Indigenous status was identified as a risk factor for HF readmissions in 1 study (p<0.05), and age or sex did not affect HF readmission patterns (p>0.05). New York Heart Association (NYHA) class, brain natriuretic peptide (BNP) levels, and heart rate were also predictive of HF readmission (p<0.05). Left ventricular ejection fraction and blood pressure, however, were non-significant risk factors of HF readmissions (p>0.05). CONCLUSIONS: This review identified unemployment, Indigenous status, NYHA class, heart rate, and BNP levels to predict HF related readmissions in adult patients with HF. Adding demographic and socioeconomic variables to readmission risk models has the potential to more accurately target patients at risk of readmissions.


Assuntos
Insuficiência Cardíaca , Readmissão do Paciente , Adulto , Demografia , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/epidemiologia , Insuficiência Cardíaca/terapia , Humanos , Fatores Socioeconômicos , Volume Sistólico , Função Ventricular Esquerda
8.
Anticancer Res ; 38(1): 271-277, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29277783

RESUMO

The ultraviolent irradiation resistance-associated gene (UVRAG), a component of the Beclin 1/autophagy-related 6 complex, regulates the autophagy initiation step and functions in the DNA-damage response. UVRAG is frequently mutated in various cancer types, and mutations of UVRAG increase sensitivity to chemotherapy by impairing DNA-damage repair. In this study, we addressed the epigenetic regulation of UVRAG in colorectal cancer cells. UVRAG expression was increased in cells treated with histone deacetylase (HDAC) inhibitors, such as valproic acid and suberoylanilide hydroxamic acid. Down-regulation of HDAC1 enhanced UVRAG expression in colorectal cancer cells. In addition, both chemical and genetic inhibition of HDAC1 reduced the activation of caspase-3 and cytotoxicity in 5-fluorouracil (5FU)-treated cancer cells. In contrast, UVRAG overexpression inhibited caspase activation and cell death in 5FU-treated cells. Taken together, our findings suggest that up-regulation of UVRAG by HDAC1 inhibition potentiates DNA-damage-mediated cell death in colorectal cancer cells.


Assuntos
Antimetabólitos Antineoplásicos/farmacologia , Neoplasias Colorretais/metabolismo , Fluoruracila/farmacologia , Histona Desacetilase 1/antagonistas & inibidores , Proteínas Supressoras de Tumor/metabolismo , Morte Celular/efeitos dos fármacos , Neoplasias Colorretais/tratamento farmacológico , Dano ao DNA , Epigênese Genética , Células HCT116 , Histona Desacetilase 1/metabolismo , Inibidores de Histona Desacetilases/farmacologia , Humanos , Regulação para Cima
9.
Cell Oncol (Dordr) ; 40(3): 235-246, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28401485

RESUMO

PURPOSE: Approximately 20% of all salivary gland cancer patients who are treated with current treatment modalities will ultimately develop metastases. Its most common form, mucoepidermoid carcinoma (MEC) is a highly aggressive tumor with an overall 5-year survival rate of ~30%. Until now, several chemotherapeutic drugs have been tested for the treatment of salivary gland tumors, but the results have been disappointing and the drugs often cause unwanted side effects. Therefore, several recent studies have focused on the potential of alternative and/or complementary therapeutic options, including the use of silymarin. METHODS: The effects of silymarin and its active component silibinin on salivary gland cancer-derived MC3 and HN22 cells and their underlying molecular mechanisms were examined using trypan blue exclusion, 4'-6-diamidino-2-phenylindole (DAPI) staining, Live/Dead, Annexin V/PI staining, mitochondrial membrane potential (ΔΨm) measurement, quantitative RT-PCR, soft agar colony formation and Western blotting analyses. RESULTS: We found that silymarin and silibinin dramatically increased the expression of the pro-apoptotic protein Bim in a concentration- and time-dependent manner and, concomitantly, induced apoptosis in MC3 and HN22 cells. We also found that ERK1/2 signaling inhibition successfully sensitized these cells to the apoptotic effects of silymarin and silibinin, which indicates that the ERK1/2 signaling pathway may act as an upstream regulator that modulates the silymarin/silibinin-induced Bim signaling pathway. CONCLUSIONS: Taken together, we conclude that ERK1/2 signaling pathway inhibition by silymarin and silibinin increases the expression of the pro-apoptotic Bcl-2 family member Bim which, subsequently, induces mitochondria-mediated apoptosis in salivary gland cancer-derived cells.


Assuntos
Proteína 11 Semelhante a Bcl-2/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Neoplasias das Glândulas Salivares/patologia , Silimarina/farmacologia , Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Silibina
10.
Cancer Lett ; 385: 21-27, 2017 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-27836735

RESUMO

Autophagy plays complex roles in tumor initiation and development, and the expression of autophagy-related genes (ATGs) is differentially regulated in various cancer cells, depending on their environment. In this study, we analyzed the expressional relationship between polypyrimidine tract-binding protein 1 (PTBP1) and ATG10 in metastatic colorectal cancer. PTBP1 is associated with tumor metastasis in primary colorectal tumors and colorectal cancer liver metastasis (CLM) tissues. In addition, PTPB1 directly interacts with mRNA of ATG10, and regulates ATG10 expression level in colorectal cancer cells. Ectopic expression of PTBP1 decreased ATG10 expression, whereas down-regulation of PTBP1 increased ATG10 level. In contrast to PTBP1, expression of ATG10 was decreased in CLM tissues. Knock down of ATG10 promoted cell migration and invasion of colorectal cancer cells. Moreover, depletion of ATG10 modulated epithelial-mesenchymal transition-associated proteins in colorectal cancer cells: N-cadherin, TCF-8/ZEB1, and CD44 were up-regulated, whereas E-cadherin was down-regulated. Taken together, our findings suggest that expression of ATG10 negatively regulated by PTBP1 is associated with metastasis of colorectal cancer cells.


Assuntos
Proteínas Relacionadas à Autofagia/metabolismo , Movimento Celular , Neoplasias Colorretais/metabolismo , Ribonucleoproteínas Nucleares Heterogêneas/metabolismo , Proteína de Ligação a Regiões Ricas em Polipirimidinas/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Antígenos CD/metabolismo , Proteínas Relacionadas à Autofagia/genética , Caderinas/metabolismo , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Regulação para Baixo , Transição Epitelial-Mesenquimal , Regulação Neoplásica da Expressão Gênica , Células HCT116 , Ribonucleoproteínas Nucleares Heterogêneas/genética , Humanos , Receptores de Hialuronatos/metabolismo , Invasividade Neoplásica , Metástase Neoplásica , Proteína de Ligação a Regiões Ricas em Polipirimidinas/genética , Interferência de RNA , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transdução de Sinais , Transfecção , Proteínas de Transporte Vesicular/genética , Homeobox 1 de Ligação a E-box em Dedo de Zinco/metabolismo
11.
Sci Rep ; 4: 7162, 2014 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-25418289

RESUMO

Cervical cancer is the third most common cancer and the third leading cause of death among women. However, the standard treatment for cervical cancer includes cisplatin, which can cause side effects such as hematological damage or renal toxicity. New innovations in cervical cancer treatment focus on developing more effective and better-tolerated therapies such as Sp1-targeting drugs. Previous studies suggested that mithramycin A (Mith) inhibits the growth of various cancers by decreasing Sp1 protein. However, how Sp1 protein is decreased by Mith is not clear. Few studies have investigated the regulation of Sp1 protein by proteasome-dependent degradation as a possible control mechanism for the regulation of Sp1 in cancer cells. Here, we show that Mith decreased Sp1 protein by inducing proteasome-dependent degradation, thereby suppressing cervical cancer growth through a DR5/caspase-8/Bid signaling pathway. We found that prolonged Mith treatment was well tolerated after systemic administration to mice carrying cervical cancer cells. Reduction of body weight was minimal, indicating that Mith was a good therapeutic candidate for treatment of cancers in which Sp1 is involved in promoting and developing disease.


Assuntos
Proliferação de Células/efeitos dos fármacos , Plicamicina/análogos & derivados , Transdução de Sinais/efeitos dos fármacos , Fator de Transcrição Sp1/metabolismo , Neoplasias do Colo do Útero/tratamento farmacológico , Animais , Antibióticos Antineoplásicos/farmacologia , Antibióticos Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/metabolismo , Caspase 8/metabolismo , Linhagem Celular Tumoral , Feminino , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Camundongos Nus , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Peptídeo Hidrolases/metabolismo , Plicamicina/farmacologia , Plicamicina/uso terapêutico , Interferência de RNA , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Fator de Transcrição Sp1/antagonistas & inibidores , Fator de Transcrição Sp1/genética , Transplante Heterólogo , Neoplasias do Colo do Útero/patologia
12.
PLoS One ; 9(11): e112130, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25390895

RESUMO

To date, several regulatory proteins involved in mitochondrial dynamics have been identified. However, the precise mechanism coordinating these complex processes remains unclear. Mitochondrial chaperones regulate mitochondrial function and structure. Chaperonin 10 (Cpn10) interacts with heat shock protein 60 (HSP60) and functions as a co-chaperone. In this study, we found that down-regulation of Cpn10 highly promoted mitochondrial fragmentation in SK-N-MC and SH-SY5Y neuroblastoma cells. Both genetic and chemical inhibition of Drp1 suppressed the mitochondrial fragmentation induced by Cpn10 reduction. Reactive oxygen species (ROS) generation in 3-NP-treated cells was markedly enhanced by Cpn10 knock down. Depletion of Cpn10 synergistically increased cell death in response to 3-NP treatment. Furthermore, inhibition of Drp1 recovered Cpn10-mediated mitochondrial dysfunction in 3-NP-treated cells. Moreover, an ROS scavenger suppressed cell death mediated by Cpn10 knockdown in 3-NP-treated cells. Taken together, these results showed that down-regulation of Cpn10 increased mitochondrial fragmentation and potentiated 3-NP-mediated mitochondrial dysfunction in neuroblastoma cells.


Assuntos
Chaperonina 10/metabolismo , Mitocôndrias/patologia , Dinâmica Mitocondrial , Neuroblastoma/fisiopatologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Chaperonina 10/antagonistas & inibidores , Chaperonina 10/genética , Regulação para Baixo/efeitos dos fármacos , Dinaminas , GTP Fosfo-Hidrolases/antagonistas & inibidores , GTP Fosfo-Hidrolases/genética , GTP Fosfo-Hidrolases/metabolismo , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Proteínas Associadas aos Microtúbulos/antagonistas & inibidores , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/genética , Mitocôndrias/metabolismo , Proteínas Mitocondriais/antagonistas & inibidores , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Neuroblastoma/metabolismo , Nitrocompostos/farmacologia , Propionatos/farmacologia , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Espécies Reativas de Oxigênio/metabolismo
13.
Pigment Cell Melanoma Res ; 27(6): 1051-62, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25065405

RESUMO

Mitochondrial dynamics control mitochondrial functions as well as their morphology. However, the role of mitochondrial dynamics in melanogenesis is largely unknown. Here, we show that mitochondrial dynamics regulate melanogenesis by modulating the ROS-ERK signaling pathway. Genetic and chemical inhibition of Drp1, a mitochondrial fission protein, increased melanin production and mitochondrial elongation in melanocytes and melanoma cells. In contrast, down-regulation of OPA1, a mitochondria fusion regulator, suppressed melanogensis but induced massive mitochondrial fragmentation in hyperpigmented cells. Consistently, treatment with CCCP, a mitochondrial fission chemical inducer, also efficiently repressed melanogenesis. Furthermore, we found that ROS production and ERK phosphorylation were increased in cells with fragmented mitochondria. And inhibition of ROS or ERK suppressed the antimelanogenic effect of mitochondrial fission in α-MSH-treated cells. In addition, the activation of ROS-ERK pathway by mitochondrial fission induced phosphorylation of serine73 on MITF accelerating its proteasomal degradation. In conclusion, mitochondrial dynamics may regulate melanogenesis by modulating ROS-ERK signaling pathway.


Assuntos
MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Melaninas/biossíntese , Fator de Transcrição Associado à Microftalmia/metabolismo , Dinâmica Mitocondrial , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteólise , Espécies Reativas de Oxigênio/metabolismo , Animais , Carbonil Cianeto m-Clorofenil Hidrazona/farmacologia , Linhagem Celular Tumoral , Regulação para Baixo/efeitos dos fármacos , Dinaminas/metabolismo , Células Epidérmicas , Humanos , Melanócitos/efeitos dos fármacos , Melanócitos/enzimologia , Melanoma Experimental/metabolismo , Melanoma Experimental/patologia , Camundongos Endogâmicos C57BL , Dinâmica Mitocondrial/efeitos dos fármacos , Quinases de Proteína Quinase Ativadas por Mitógeno/antagonistas & inibidores , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Proteólise/efeitos dos fármacos , Quinazolinonas/farmacologia , alfa-MSH/farmacologia
14.
Exp Dermatol ; 23(3): 204-6, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24499351

RESUMO

Autophagy degrades cellular components and organelles through a cooperative process involving autophagosomes and lysosomes. Although autophagy is known to mainly regulate the turnover of cellular components, the role of autophagy in melanogenesis has not been well addressed. Here, we show that inhibition of autophagy suppresses the antimelanogenesis activity of resveratrol (RSV), a well-known antimelanogenic agent. RSV strongly increased autophagy in melanocytes. However, the depletion of ATG5 significantly suppressed RSV-mediated antimelanogenesis as well as RSV-induced autophagy in melanocytes. Moreover, suppression of ATG5 retrieved the RSV-mediated downregulation of tyrosinase and TRP1 in α-MSH-treated cells. Most importantly, electron microscopy analysis revealed that autophagosomes engulfed melanin or melanosomes after combined treatment of α-MSH and RSV. Taken together, these results suggest that RSV-mediated autophagy regulates melanogenesis.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Autofagia/efeitos dos fármacos , Melaninas/biossíntese , Melanócitos/efeitos dos fármacos , Estilbenos/farmacologia , alfa-MSH/farmacologia , Proteína 5 Relacionada à Autofagia , Linhagem Celular Tumoral , Regulação para Baixo/efeitos dos fármacos , Humanos , Melanócitos/metabolismo , Melanócitos/ultraestrutura , Melanossomas/ultraestrutura , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Monofenol Mono-Oxigenase/metabolismo , Resveratrol , Tripsina/metabolismo
15.
Oral Oncol ; 50(3): 189-95, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24309154

RESUMO

OBJECTIVES: Dibenzylideneacetone (DBA), a curcumin analogue that has anti-cancer activity in a variety of tumor cells. In this study, we investigated the apoptotic effects of DBA and its molecular mechanism in human mucoepidermoid carcinoma (MEC) cell lines and tumor xenografts. MATERIAL AND METHODS: The apoptotic effects and related molecular mechanisms of DBA on MEC cell lines were evaluated using cell viability assay, DAPI staining, Western blot analysis, reverse transcriptase-polymerase chain reaction (RT-PCR) and Dual-luciferase Reporter Assay. The anti-tumor activity using in vivo were determined by Nude mouse xenograft assay and histopathological examination. RESULTS: DBA decreased cell viability and induced apoptosis in MEC cells. These events were accompanied by inhibition of specificity protein 1 (Sp1). DBA did not induce major changes in Sp1 mRNA and promoter activity. Furthermore, inhibition of protein synthesis by cycloheximide demonstrated that DBA decreased Sp1 protein stability, but DBA did not attenuate phosphorylation of eIF4E. DBA also increased Bim and truncated Bid (t-Bid) via Sp1. Finally, DBA exhibited significant anti-tumor activity in athymic nude mice xenografts bearing MC-3 cells by regulating Sp1, Bim and t-Bid without any systemic toxicity. CONCLUSION: These results elucidate a crucial apoptotic mechanism of DBA and suggest that DBA may be a potent anticancer drug candidate for MEC.


Assuntos
Carcinoma Mucoepidermoide/metabolismo , Pentanonas/farmacologia , Fator de Transcrição Sp1/metabolismo , Animais , Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose/metabolismo , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/metabolismo , Proteína 11 Semelhante a Bcl-2 , Biomarcadores Tumorais/metabolismo , Linhagem Celular Tumoral , Cicloeximida/farmacologia , Fator de Iniciação 4E em Eucariotos/metabolismo , Feminino , Humanos , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Nus , Neoplasias Experimentais , Inibidores da Síntese de Proteínas/farmacologia , Proteínas Proto-Oncogênicas/metabolismo , Fator de Transcrição Sp1/antagonistas & inibidores , Ensaios Antitumorais Modelo de Xenoenxerto
16.
Cell Biochem Funct ; 32(3): 229-35, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24037733

RESUMO

In the present study, we examined the effects of methanol extracts of Picrasma quassioides (MEPQ) on apoptosis in human cervical cancer cells. The results showed that MEPQ decreased the viability and induced caspase-dependent apoptosis in HEp-2 cells. MEPQ decreased specificity protein 1 (Sp1) in HEp-2 cells, whereas Sp1 mRNA was not changed. We found that MEPQ reduced Sp1 protein through proteasome-dependent protein degradation, but not the inhibition of protein synthesis. Also, MEPQ increased the expressions of Bad and truncated Bid (t-Bid) but did not alter other Bcl-2 family members. The knock-down of Sp1 by both Sp1 interfering RNA and Mithramycin A, Sp1 specific inhibitor clearly increased Bad and t-Bid expression to decrease cell viability and induce apoptosis. In addition, MEPQ inhibited cell viability and induced apoptotic cell death through the modulation of Sp1 in KB cells. These results suggest that MEPQ may be a potential anticancer agent for human cervical cancer.


Assuntos
Apoptose/efeitos dos fármacos , Picrasma , Extratos Vegetais/farmacologia , Fator de Transcrição Sp1/metabolismo , Neoplasias do Colo do Útero/metabolismo , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/metabolismo , Linhagem Celular Tumoral/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Feminino , Humanos , Metanol , Plicamicina/análogos & derivados , Plicamicina/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , RNA Interferente Pequeno/genética , Solventes , Fator de Transcrição Sp1/genética , Neoplasias do Colo do Útero/patologia , Proteína de Morte Celular Associada a bcl/metabolismo
17.
Exp Ther Med ; 7(1): 228-232, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24348795

RESUMO

Fucoidan is a sulfated polysaccharide present in brown algae that has been identified to exhibit multiple biological effects. In this study, the apoptotic effects of fucoidan in MC3 human mucoepidermoid carcinoma (MEC) cells were investigated. The apoptotic effects of fucoidan on MC3 MEC cells were evaluated by cell proliferation assay, 4',6-diamidino-2-phenylindole staining and western blot analysis. The results showed that fucoidan decreased cell proliferation and induced caspase-dependent apoptosis in MC3 MEC cells. Fucoidan downregulated the phosphorylation of extracellular signal-regulated kinase (ERK) 1/2, whereas phospho-p38 mitogen-activated protein kinase or phospho-c-Jun NH2-terminal kinase (JNK) levels were not altered. In addition, fucoidan significantly decreased the expression levels of myeloid cell leukemia-1 (Mcl-1). These results suggest that fucoidan is able to modulate the ERK1/2 pathway and thereby regulate Mcl-1 protein expression and induce apoptosis in MC3 MEC cells. Therefore, fucoidan may be a promising agent for the treatment of human MEC.

18.
Biochem Biophys Res Commun ; 442(3-4): 165-70, 2013 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-24269817

RESUMO

Autophagy is a cellular degradation process for cellular aggregates and unneeded cellular compartments including damaged mitochondria, ER, and peroxisomes. Melanosome is cellular organelle that is the cellular site of generation, storage and transports of melanin in melanocytes. Despite potential importance of autophagy, the role of autophagy in melanogenesis and melanosome autophagy are largely unknown. In here, we identified 3'-hydroxydaidzein (3'-ODI) as an autophagy inducer from a phytochemical library screening. Treatment with 3'-ODI significantly reduced α-MSH-mediated melanogenesis but efficiently increased autophagy both in melanoma cells and melanocytes. Furthermore, inhibition of autophagy significantly reduced the anti-melanogenic effects of 3'-ODI in α-MSH-stimulated melanoma cells. Taken together, these results suggest that autophagy mediates anti-melanogenic activity of 3'-ODI.


Assuntos
Autofagia/efeitos dos fármacos , Isoflavonas/farmacologia , Melaninas/antagonistas & inibidores , Melanócitos/efeitos dos fármacos , Melanossomas/efeitos dos fármacos , Animais , Autofagia/genética , Proteína 5 Relacionada à Autofagia , Linhagem Celular Tumoral , Melaninas/biossíntese , Melanócitos/metabolismo , Melanossomas/metabolismo , Camundongos , Proteínas Associadas aos Microtúbulos/antagonistas & inibidores , Proteínas Associadas aos Microtúbulos/genética , Interferência de RNA , alfa-MSH/farmacologia
19.
FEBS Lett ; 587(24): 3955-60, 2013 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-24188823

RESUMO

Autophagy is a cooperative process between autophagosomes and lysosomes that degrades cellular organelles. Although autophagy regulates the turnover of cellular components, its role in melanogenesis is not clearly established. Previously, we reported that ARP101 induces autophagy in various cancer cells. Here, we show that ARP101 inhibits melanogenesis by regulation of autophagy. ARP101 inhibited α-MSH-stimulated melanin synthesis and suppressed the expression of tyrosinase and TRP1 in immortalized mouse melanocytes. ARP101 also induced autophagy in melanocytes. Knockdown of ATG5 reduced both anti-melanogenic activity and autophagy mediated by ARP101 in α-MSH treated melanocytes. Electron microscopy analysis further revealed that autophagosomes engulf melanin or melanosome in α-MSH and ARP101-treated cells. Collectively, our results suggest that ARP101 inhibits α-MSH-stimulated melanogenesis through the activation of autophagy in melanocytes.


Assuntos
Autofagia/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Melanócitos/efeitos dos fármacos , Sulfonamidas/farmacologia , alfa-MSH/farmacologia , Animais , Autofagia/genética , Proteína 5 Relacionada à Autofagia , Diferenciação Celular/genética , Células Cultivadas , Regulação para Baixo/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Melanócitos/metabolismo , Melanócitos/fisiologia , Camundongos , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Monofenol Mono-Oxigenase/genética , Monofenol Mono-Oxigenase/metabolismo , Oxirredutases/genética , Oxirredutases/metabolismo
20.
J Clin Biochem Nutr ; 53(2): 89-93, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24062605

RESUMO

Mithramycin A (Mith) is an aureolic acid-type polyketide produced by various soil bacteria of the genus Streptomyces. Mith inhibits myeloid cell leukemia-1 (Mcl-1) to induce apoptosis in prostate cancer, but the molecular mechanism underlying this process has not been fully elucidated. The aim of this study was therefore to investigate the detailed molecular mechanism related to Mith-induced apoptosis in prostate cancer cells. Mith decreased the phosphorylation of mammalian target of rapamycin (mTOR) in both cell lines overexpressing phospho-mTOR compared to RWPE-1 human normal prostate epithelial cells. Mith significantly induced truncated Bid (tBid) and siRNA-mediated knock-down of Mcl-1 increased tBid protein levels. Moreover, Mith also inhibited the phosphorylation of mTOR on serine 2448 and Mcl-1, and increased tBid protein in prostate tumors in athymic nude mice bearing DU145 cells as xenografts. Thus, Mith acts as an effective tumor growth inhibitor in prostate cancer cells through the mTOR/Mcl-1/tBid signaling pathway.

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