RESUMO
OBJECTIVES: The purpose of this study was to determine key features and define a strategy for differentiation between schwannomas and neurofibromas using sonography. METHODS: This retrospective study was approved by the Institutional Review Board at our hospital, and informed consent was waived. We reviewed sonograms of pathologically proven schwannomas and neurofibromas of the extremities and body wall. On grayscale images, tumors were evaluated on the basis of their size, maximum-to-minimum diameter ratio, shape, contour, margin, location, encapsulation, echogenicity, echo texture, cystic changes, presence of intratumoral calcifications, presence of a target sign, and presence of an entering or exiting nerve. If an entering or exiting nerve was identified, the nerve-tumor position and nerve-tumor transition were characterized. On color Doppler images, the presence and amount of vascularity were evaluated. Student t tests were used for analysis of continuous variables (size, maximum-to-minimum diameter ratio, and age); χ(2) and Fisher exact tests were used for analysis of categorical variables. RESULTS: A total of 146 pathologically proven tumors, including 115 schwannomas and 31 neurofibromas of the extremities and body wall, were included. The maximum diameter, maximum-to-minimum diameter ratio, contour, cystic portion, nerve-tumor position, nerve-tumor transition, and vascularity were significantly different in schwannomas versus neurofibromas (P < .05), and a lobulated contour, fusiform shape, and hypovascularity of neurofibromas could be helpful for differentiation when a prediction model is considered. The nerve-tumor position, nerve-tumor transition, and maximum-to-minimum diameter ratio were also significantly different between groups (P < .05) and thus could be useful for differentiation of neurogenic tumors. CONCLUSIONS: Sonographic findings are helpful in differentiating between schwannomas and neurofibromas.
Assuntos
Doenças Musculoesqueléticas/diagnóstico por imagem , Neurilemoma/diagnóstico por imagem , Neurofibroma/diagnóstico por imagem , Neoplasias do Sistema Nervoso Periférico/diagnóstico por imagem , Ultrassonografia/métodos , Diagnóstico Diferencial , Feminino , Humanos , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
The compound 20-HETE is involved in numerous physiological functions, including blood pressure and platelet aggregation. Glucuronidation of 20-HETE by UDP-glucuronosyltransferases (UGTs) is thought to be a primary pathway of 20-HETE elimination in humans. The present study identified major UGT enzymes responsible for 20-HETE glucuronidation and investigated their genetic influence on the glucuronidation reaction using human livers (n = 44). Twelve recombinant UGTs were screened to identify major contributors to 20-HETE glucuronidation. Based on these results, UGT2B7, UGT1A9, and UGT1A3 exhibited as major contributors to 20-HETE glucuronidation. The Km values of 20-HETE glucuronidation by UGT1A3, UGT1A9, and UGT2B7 were 78.4, 22.2, and 14.8 µM, respectively, while Vmax values were 1.33, 1.78, and 1.62 nmol/min/mg protein, respectively. Protein expression levels and genetic variants of UGT1A3, UGT1A9, and UGT2B7 were analyzed in human livers using Western blotting and genotyping, respectively. Glucuronidation of 20-HETE was significantly correlated with the protein levels of UGT2B7 (r(2) = 0.33, P < 0.001) and UGT1A9 (r(2) = 0.31, P < 0.001), but not UGT1A3 (r(2) = 0.02, P > 0.05). A correlation between genotype and 20-HETE glucuronidation revealed that UGT2B7 802C>T, UGT1A9 -118T9>T10, and UGT1A9 1399T>C significantly altered 20-HETE glucuronide formation (P < 0.05-0.001). Increased levels of 20-HETE comprise a risk factor for cardiovascular diseases, and the present data may increase our understanding of 20-HETE metabolism and cardiovascular complications.
Assuntos
Genótipo , Ácido Glucurônico/metabolismo , Glucuronosiltransferase/genética , Glucuronosiltransferase/metabolismo , Ácidos Hidroxieicosatetraenoicos/metabolismo , Adulto , Variação Genética , Humanos , Isoenzimas/genética , Isoenzimas/metabolismo , Cinética , Microssomos Hepáticos/metabolismoRESUMO
There has been a wide range of inter-individual variations in platelet responses to clopidogrel. The variations in response to clopidogrel can be driven by genetic polymorphisms involved in the pathway of absorption, distribution, metabolism, excretion, and the target receptor P2Y12. A set of genetic variants known for causing variations in clopidogrel responses was selected, which included CYP2C19*2, *3, *17, CYP2B6*4, *6, *9, CYP3A4*18, CYP3A5*3, MDR1 2677G>T/A, 3435C>T, and P2Y12 H2 (742T>C). The simultaneous detection of these 10 variants was developed by using a multiplex PCR and single-base extension (MSSE) methodology. The newly developed genotyping test was confirmed by direct DNA sequencing in the representative positive control samples and validated in an extended set of 100 healthy Korean subjects. Genotyping results from the developed MSSE exhibited a perfect concordance with the direct DNA sequencing data and all of variants tested in 100 healthy Korean subjects were in agreement with Hardy-Weinberg equilibrium (p>0.05). The present molecular diagnostic studies provide an accurate, convenient, and fast genotyping method for the detection of multiple variants. This would be helpful for researchers, as well as clinicians, to use genetic information toward more personalized medicine of clopidogrel and other antiplatelet drugs in the future.
Assuntos
Técnicas de Genotipagem , Inibidores da Agregação Plaquetária/farmacologia , Agregação Plaquetária/efeitos dos fármacos , Ticlopidina/análogos & derivados , Povo Asiático/genética , Clopidogrel , Citocromo P-450 CYP2C19/análise , Citocromo P-450 CYP2C19/genética , Genótipo , Técnicas de Genotipagem/economia , Humanos , Reação em Cadeia da Polimerase Multiplex , Infarto do Miocárdio/tratamento farmacológico , Inibidores da Agregação Plaquetária/uso terapêutico , Polimorfismo de Nucleotídeo Único , Medicina de Precisão , Receptores Purinérgicos P2Y12/análise , Receptores Purinérgicos P2Y12/genética , República da Coreia , Análise de Sequência de DNA , Ticlopidina/farmacologia , Ticlopidina/uso terapêuticoRESUMO
Human constitutive androstane receptor (hCAR, NR1I3) is a member of the orphan nuclear receptor family and regulates the transcription of many drug-metabolizing enzymes and drug transporters. Previous studies have shown that the hCAR gene produces a number of different kinds of mRNA splicing variants (SVs) in non-Asian ethnicities. In the present study, we identified 18 hCAR SVs (SV1-SV18), including four novel SVs in Korean human livers. Among the four novel SVs, SV2 showed enhanced transactivation activity when cotransfected with CYP2B6 reporter gene, whereas other SVs were nonfunctional. When profiles of major hCAR SVs were compared among 30 livers from Korean patients and 20 livers from Caucasian patients, the relative composition of each SV showed interethnic variation as well as interindividual variation. The most predominant form of hCAR SV was not wild type, but either SV4 or SV7. The summed relative amounts of SV4 and SV7 ranged from 34.5 to 57.6% in the 30 Korean livers and from 47.2 to 82.6% in the 20 Caucasian livers, suggesting large interindividual variation. The mean relative amount of nonfunctional SV9 was significantly higher in Koreans (29.8%) than in Caucasians (12.8%). The mean relative amount of novel SV2 was 9.7% in Korean livers and 3.5% in Caucasian livers. Expression profiling of hCAR proteins in human livers also supported large interindividual variation in the expressional ratio of wild-type and SVs. Our results describe for the first time the direct comparison of hCAR SV profiles between Koreans and Caucasians. The functional relevance of these interindividual and interethnic variations of hCAR mRNA expression needs to be further characterized.
Assuntos
Processamento Alternativo/genética , Povo Asiático/genética , Fígado/metabolismo , Receptores Citoplasmáticos e Nucleares/genética , População Branca/genética , Adulto , Idoso , Receptor Constitutivo de Androstano , Feminino , Perfilação da Expressão Gênica , Células Hep G2 , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Pristimerin is a naturally occurring triterpenoid that causes cytotoxicity in several cancer cell lines. However, the mechanism of action for the cytotoxic effect of pristimerin has not been unexplored. The purpose of this study was to investigate the effect of pristimerin on cytotoxicity using the epidermal growth factor receptor 2 (HER2)-positive SKBR3 human breast cancer cell line. Pristimerin inhibited proliferation in dose- and time-dependent manners in cells. We found it to be effective for suppressing HER2 protein and mRNA expression. Fatty acid synthase (FASN) expression and FASN activity were downregulated by pristimerin. Adding of exogenous palmitate, the end product of de novo fatty acid synthesis, reduced the proliferation activity of pristimerin. The changes in HER2 and FASN expression induced by pristimerin altered the levels of Akt and mitogen-activated protein kinase (MAPK) phosphorylation (Erk1/2, p38, and c-Jun N-terminal kinase (JNK)). Pristimerin lowered the levels of phosphorylated mammalian target of rapamycin (mTOR) and its downstream targets such as phosphoprotein 70 ribosomal protein S6 kinase and 4E binding protein1. Pristimerin inhibited migration and invasion of cells, and co-treatment with the mTOR inhibitor rapamycin additionally suppressed these activities. Pristimerin-induced apoptosis was evaluated using Western blotting for caspase-3, -8, -9, and poly (ADP-ribose) polymerase expression and flow cytometric analysis for propidium iodide labeling. These results suggest that pristimerin is a novel HER2-downregulated compound that is able to decrease fatty acid synthase and modulate the Akt, MAPK, and mTOR signaling pathways to influence metastasis and apoptosis. Pristimerin may be further evaluated as a chemotherapeutic agent for HER2-positive breast cancers.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Receptor ErbB-2/metabolismo , Triterpenos/farmacologia , Antineoplásicos Fitogênicos/isolamento & purificação , Apoptose/efeitos dos fármacos , Neoplasias da Mama/metabolismo , Caspases/metabolismo , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Ácido Graxo Sintase Tipo I/antagonistas & inibidores , Humanos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Triterpenos Pentacíclicos , Extratos Vegetais , Raízes de Plantas , Poli(ADP-Ribose) Polimerases/metabolismo , RNA Mensageiro/metabolismo , Receptor ErbB-2/genética , Salacia , Serina-Treonina Quinases TOR/antagonistas & inibidores , Triterpenos/isolamento & purificação , CicatrizaçãoRESUMO
Hepatocellular carcinoma (HCC) is the most common type of liver cancer with high mortality worldwide. Traditional chemotherapy for HCC is not widely accepted by clinical practitioners because of its toxic side effects. Thus, there is a need to identify chemotherapeutic drugs against HCC. AMP-activated protein kinase (AMPK) is a biologic sensor for cellular energy status that acts a tumor suppressor and a potential cancer therapeutic target. The traditional Vietnamese medicinal plant Croton tonkinensis shows cytotoxicity in various cancer cells; however, its anticancer mechanism remains unclear. In this study, we determined whether the ent-kaurane diterpenoid ent-18-acetoxy-7ß-hydroxy kaur-15-oxo-16-ene (CrT1) isolated from this plant plays a role as a chemotherapeutic drug targeting AMPK. CrT1 blocked proliferation in dose- and time-dependent manners in human hepatocellular carcinoma SK-HEP1 cells. CrT1 induced sub-G(1) arrest and caspase-dependent apoptosis. CrT1 activated caspase-3, -7, -8, -9, and poly(ADP-ribose) polymerase, and its effect was inhibited by z-VAD-fmk suppressing caspase-3 cleavage. CrT1 induced increases in p53 and Bax levels but decreased Bcl(2) levels. In addition, CrT1 resulted in increased translocation of cytochrome c into the cytoplasm. We showed that CrT1-activated AMPK activation was followed by modulating the mammalian target of rapamycin/p70S6K pathway and was inactivated by treating cells with compound C. Treatment with CrT1 and aminoimidazole carboxamide ribonucleotide (AICAR) synergistically activated AMPK. CrT1-induced AMPK activation regulated cell viability and apoptosis. These results suggest that CrT1 is a novel AMPK activator and that AMPK activation in SK-HEP1 cells is responsible for CrT1-induced anticancer activity including apoptosis.
Assuntos
Antineoplásicos/farmacologia , Croton , Diterpenos do Tipo Caurano/farmacologia , Proteínas Quinases Ativadas por AMP/metabolismo , Apoptose/efeitos dos fármacos , Carcinoma Hepatocelular , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Humanos , Folhas de PlantaRESUMO
Fatty acid synthase (FASN) is a potential therapeutic target for treatment of cancer and obesity, and is highly elevated in 30% of HER2-overexpressing breast cancers. Considerable interest has developed in searching for novel FASN inhibitors as therapeutic agents in treatment of HER2-overexpressing breast cancers. Amentoflavone was found to be effective in suppressing FASN expression in HER2-positive SKBR3 cells. Pharmacological inhibition of FASN by amentoflavone specifically down-regulated HER2 protein and mRNA, and caused an up-regulation of PEA3, a transcriptional repressor of HER2. In addition, pharmacological blockade of FASN by amentoflavone preferentially decreased cell viability and induced cell death in SKBR3 cells. Palmitate reduced the cytotoxic effect of amentoflavone, as the percentage of viable cells was increased after the addition of exogenous palmitate. Amentoflavone-induced FASN inhibition inhibited the translocation of SREBP-1 in SKBR3 cells. Amentoflavone inhibited phosphorylation of AKT, mTOR, and JNK. The use of pharmacological inhibitors revealed that the modulation of AKT, mTOR, and JNK phosphorylation required synergistic amentoflavone-induced FASN inhibition and HER2 activation in SKBR3 cells. These results suggest that amentoflavone modulated FASN expression by regulation of HER2-pathways, and induced cell death to enhance chemopreventive or chemotherapeutic activity in HER2-positive breast cancers.
Assuntos
Antineoplásicos/farmacologia , Biflavonoides/farmacologia , Neoplasias da Mama/metabolismo , Ácido Graxo Sintases/antagonistas & inibidores , Receptor ErbB-2/metabolismo , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Fosforilação , Receptor ErbB-2/genéticaRESUMO
AMP-activated protein kinase (AMPK) is a sensor of cellular energy status found in all eukaryotes. Recent studies indicate that AMPK activation strongly suppresses cell proliferation in tumor cells, which requires high rates of protein synthesis and de novo fatty acid synthesis for their rapid growth. Pomolic acid (PA) has been previously described as being active in inhibiting the growth of cancer cells. In this study, we investigated PA activated AMPK, and this activity was related to proliferation and apoptosis in MCF7 breast cancer cells. PA inhibited cell proliferation and induced sub-G(1) arrest, elevating the mRNA levels of the apoptotic genes p53 and p21. PA activated caspase-3, -9, and poly(ADP-ribose) polymerase, and this effect was inhibited by z-VAD-fmk. AMPK activation was increased by treating cells with PA, inactivated by treating cells with a compound C, and co-treatment consisting of PA and aminoimidazole carboxamide ribonucleotide (AICAR) synergistically activated AMPK. These anti-cancer potentials of PA were accompanied by effects on de novo fatty acid synthesis as shown by the decreased expression of fatty acid synthase, and decreased acetyl-CoA carboxylase activation and incorporation of [(3)H]acetyl-CoA into fatty acids. In addition, PA inhibited key enzymes involved in protein synthesis such as mammalian target of rapamycin (mTOR), 70 kDa ribosomal protein S6 kinase (p70S6K), and eukaryotic translation initiation factor 4E-binding protein 1 (4EBP1). These results suggest that PA exerts anti-cancer properties through the modulation of AMPK pathways and its value as an anti-cancer agent in breast cancer therapy.
Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Antineoplásicos Fitogênicos/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Ácido Oleanólico/análogos & derivados , Fitoterapia , Extratos Vegetais/uso terapêutico , Acetil-CoA Carboxilase/metabolismo , Aminoimidazol Carboxamida/análogos & derivados , Aminoimidazol Carboxamida/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias da Mama/metabolismo , Caspase 3/metabolismo , Caspase 9/metabolismo , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Ativação Enzimática/efeitos dos fármacos , Ácido Graxo Sintases/metabolismo , Ácidos Graxos/biossíntese , Feminino , Fase G1/efeitos dos fármacos , Expressão Gênica/efeitos dos fármacos , Genes p53 , Humanos , Ácido Oleanólico/farmacologia , Ácido Oleanólico/uso terapêutico , Extratos Vegetais/farmacologia , Poli(ADP-Ribose) Polimerases/efeitos dos fármacos , Biossíntese de Proteínas/efeitos dos fármacos , RNA Mensageiro/metabolismo , Ribonucleotídeos/farmacologiaRESUMO
Colon cancer is the third most common malignancy around the world. Surgery, chemotherapy, and radiotherapy are generally used to treat colon cancer, but no effective therapy for advanced colon carcinoma is available. Therefore, there is a need to identify other therapeutic agents against this disease. Magnolol, a hydroxylated biphenyl compound present in Magnolia officinalis, exerts anticancer potential and low toxicity. Emerging evidence has suggested that activation of AMP-activated protein kinase (AMPK), a potential cancer therapeutic target is involved in apoptosis in colon cancer cells. However, the effects of magnolol on human colon cancer through activation of AMPK remain unexplored. In this study, we explored whether magnolol exerts an antiproliferative effect, and induces apoptosis in HCT-116 human colon cancer cells. Magnolol displayed several apoptotic features, including propidium iodide labeling, DNA fragmentation, and caspase-3 and poly(ADP-ribose) polymerase cleavages. We showed that magnolol induced the phosphorylation of AMPK in dose- and time-dependent manners. The selective AMPK inhibitor compound C abrogated the effect of magnolol on AMPK activation, suppression of proliferation, and caspase-3 cleavage. Magnolol downregulated expression of the antiapoptotic protein Bcl2, upregulated expression of pro-apoptotic protein p53 and Bax, and caused the release of mitochondrial cytochrome c. Magnolol-induced p53 and Bcl2 expression was abolished in the presence of compound C. Magnolol inhibited migration and invasion of HCT-116 cells through AMPK activation. These findings demonstrate that AMPK mediates the anticancer effects of magnolol through apoptosis in HCT-116 cells.
Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Antineoplásicos Fitogênicos/uso terapêutico , Apoptose/efeitos dos fármacos , Compostos de Bifenilo/uso terapêutico , Neoplasias do Colo/tratamento farmacológico , Lignanas/uso terapêutico , Magnolia/química , Fitoterapia , Antineoplásicos Fitogênicos/farmacologia , Compostos de Bifenilo/farmacologia , Caspase 3/metabolismo , Movimento Celular/efeitos dos fármacos , Neoplasias do Colo/metabolismo , Citocromos c/metabolismo , Fragmentação do DNA , Relação Dose-Resposta a Droga , Células HCT116 , Humanos , Lignanas/farmacologia , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Fosforilação , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Poli(ADP-Ribose) Polimerases/metabolismo , Propídio/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Transdução de Sinais , Proteína Supressora de Tumor p53/metabolismo , Proteína X Associada a bcl-2/metabolismoRESUMO
Purpose: Apurinic/apyrimidinic endonuclease 1 (APE1) is a key enzyme involved in the base excision repair pathway. It also has redox activity and maintains various transcription factors in an active reduced state. APE1 may be associated with chemoresistance. In the present study, we first investigated the expression level of APE1 protein and its correlation with oncologic outcomes of oxaliplatin-based chemotherapy in patients with stage III colon cancer. Further, we investigated the effects of human APE1 siRNA on the sensitivity of oxaliplatin in SNU-C2A colon cancer cells. Methods: Tissue specimens from tumor and normal colon of 33 patients with stage III colon cancer were obtained from 2006 to 2009. The patients received at least eight cycles of oxaliplatin-based chemotherapy. APE1 expression was analyzed by immunohistochemistry and Western blotting using a cultured SNU-C2A cell line. Cell viability and apoptosis were determined by Cell Counting Kit-8 and caspase-3 cleavage using Western blotting. Results: All the colon cancer tissues showed APE1 staining in the nucleus, whereas all the normal colon tissues were negative for APE1 staining in the cytoplasm. The group with a higher expression of APE1 demonstrated poorer prognosis than the group with low expression (P=0.026 for overall survival and P=0.021 for disease-free survival). Treatment with oxaliplatin resulted in a dose-dependent increase in APE1 expression in SNU-C2A cells. APE1 siRNA significantly enhanced oxaliplatin-induced growth inhibition, and also increased oxaliplatin-induced apoptosis in SNU-C2A cells. Conclusion: APE1 could be considered a prognostic factor in colon cancer patients treated with oxaliplatin-based chemotherapy.
RESUMO
Inactivation of epidermal growth factor receptor (EGFR) is a prime method used in colon cancer therapy. Here it is shown that chrysophanic acid, a natural anthraquinone, has anticancer activity in EGFR-overexpressing SNU-C5 human colon cancer cells. Chrysophanic acid preferentially blocked proliferation in SNU-C5 cells but not in other cell lines (HT7, HT29, KM12C, SW480, HCT116 and SNU-C4) with low levels of EGFR expression. Chrysophanic acid treatment in SNU-C5 cells inhibited EGF-induced phosphorylation of EGFR and suppressed activation of downstream signaling molecules, such as AKT, extracellular signal-regulated kinase (ERK) and the mammalian target of rapamycin (mTOR)/ribosomal protein S6 kinase (p70S6K). Chrysophanic acid (80 and 120 µm) significantly blocked cell proliferation when combined with the mTOR inhibitor, rapamycin. These findings offer the first evidence of anticancer activity for chrysophanic acid via EGFR/mTOR mediated signaling transduction pathway.
Assuntos
Antraquinonas/farmacologia , Neoplasias do Colo/tratamento farmacológico , Receptores ErbB/antagonistas & inibidores , Serina-Treonina Quinases TOR/antagonistas & inibidores , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Neoplasias do Colo/enzimologia , Neoplasias do Colo/patologia , Fator de Crescimento Epidérmico/antagonistas & inibidores , Fator de Crescimento Epidérmico/farmacologia , Receptores ErbB/metabolismo , Fallopia japonica/química , Inibidores do Crescimento/fisiologia , Humanos , Proteína Oncogênica v-akt/antagonistas & inibidores , Proteína Oncogênica v-akt/metabolismo , Fosforilação/efeitos dos fármacos , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Rheum/química , Proteínas Quinases S6 Ribossômicas 70-kDa/antagonistas & inibidores , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismoRESUMO
PURPOSE: To evaluate the feasibility of using computed tomographic (CT) colonography for preoperative examination of the proximal colon after metallic stent placement in patients with acute colon obstruction caused by colorectal cancer. MATERIALS AND METHODS: Institutional review board approval was obtained, and patient informed consent was waived. Fifty patients (mean age +/- standard deviation, 58.5 years +/- 11.7), who demonstrated no postprocedural complication after successful placement of self-expandable metallic stents to treat acute colon obstruction caused by cancer, underwent CT colonography 1-43 days (median, 5 days) after stent placement. CT colonography was performed after cathartic preparation by using magnesium citrate (n = 20) or sodium phosphate (n = 3), combined with oral bisacodyl, or by using polyethylene glycol (n = 27). Fecal/fluid tagging was achieved by using 100 mL of meglumine diatrizoate. The colon was distended by means of pressure-monitored CO(2) insufflation. The sensitivity and specificity of CT colonography in evaluating the colon proximal to the stent and CT colonography-related complications were assessed. The 95% confidence intervals (CIs) were calculated for proportional data. RESULTS: Per-lesion and per-patient sensitivities of CT colonography for lesions 6 mm or larger in diameter in the colon proximal to the stent were 85.7% (12 of 14 lesions; 95% CI: 58.8%, 97.2%) and 90% (nine of 10 patients; 95% CI: 57.4%, 99.9%), respectively. CT colonography depicted all synchronous cancers (two lesions) and advanced adenomas (five lesions). Per-patient specificity for lesions 6 mm and larger in the proximal colon was 85.7% (18 of 21 patients; 95% CI: 64.5%, 95.9%). CT colonography did not generate any false diagnosis of synchronous cancer. False-positive findings at CT colonography did not result in a change in surgical plan for any patients. No CT colonography-associated stent dislodgment/migration or colonic perforation occurred in any patient (95% CI: 0%, 6.2%). CONCLUSION: CT colonography is a safe and useful method for preoperative examination of the proximal colon after metallic stent placement in patients with acute colon obstruction caused by cancer. (c) RSNA, 2010.
Assuntos
Neoplasias do Colo/diagnóstico por imagem , Colonografia Tomográfica Computadorizada/métodos , Obstrução Intestinal/diagnóstico por imagem , Stents , Doença Aguda , Idoso , Neoplasias do Colo/patologia , Neoplasias do Colo/cirurgia , Meios de Contraste , Feminino , Humanos , Obstrução Intestinal/patologia , Obstrução Intestinal/cirurgia , Iohexol/análogos & derivados , Masculino , Metais , Pessoa de Meia-Idade , Interpretação de Imagem Radiográfica Assistida por Computador , Padrões de Referência , Estudos Retrospectivos , Sensibilidade e EspecificidadeRESUMO
WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT * CYP2C9 single nucleotide polymorphisms (SNPs) are important in safe and effective oral anticoagulation with warfarin use. * Although CYP2C9*2 and *3 are important genetic factors for the warfarin dose, one of the CYP2C9 SNPs, IVS-65G>C, has been suggested to be associated with warfarin sensitivity. However, as of yet, there has been no explanation about the possible mechanism and linkage analysis. WHAT THIS PAPER ADDS * New information on CYP2C9 SNPs and their occurrences in common haplotype structures in healthy unrelated Koreans and in individuals who require low warfarin dose after mechanical heart valve replacements (MHVRs) were studied. * Additional evidence showed that an Asian dominant haplotype consisting of -1565C>T, -1188T>C, IVS3+197G>A, IVS3-334C>T, IVS3-65G>C, IVS4-115A>G and IVS5-73A>G could be associated with a low warfarin maintenance dose in mechanical heart valve replacement (MHVR) patients. AIMS The objectives of this study were to determine the distribution of CYP2C9 variants in Koreans and investigate their association with warfarin dose requirements in patients who received MHVRs. METHODS All nine exons, intron-exon junction, and promoter region of CYP2C9 were amplified and directly sequenced in 50 healthy normal Koreans. Additional direct DNA sequencing of the CYP2C9 gene was conducted in 36 of the 267 MHVR patients who required low maintenance warfarin doses without carrying CYP2C9*3 and VKORC1 1173T mutations. The effects of CYP2C9 genetics on warfarin maintenance dose were assessed in 267 MHVR patients. RESULTS Thirty-nine single nucleotide polymorphisms (SNPs) including seven previously unidentified SNPs were identified in 50 Koreans by direct DNA sequencing. One of the CYP2C9 haplotypes exhibited an association with warfarin low dose requirement. The adjusted odds ratio for the haplotype between the low dose group and the normal subjects was 2.5 (95% confidence interval 1.05, 6.16). This haplotype consisting of -1565C>T, -1188T>C, IVS3+197G>A, IVS3-334C>T, IVS3-65G>C, IVS4-115A>G, and IVS5-73A>G was found in 15% of 36 MHVR patients who required low warfarin doses, while 4% of 50 normal healthy subjects exhibited this haplotype. One of the SNPs comprising this haplotype, -1565C>T, apparently changed a protein binding pattern as observed in electrophoretic mobility shift assay. CONCLUSION The haplotype including -1565C>T, -1188T>C, IVS3+197G>A, IVS3-334C>T, IVS3-65G>C, IVS4-115A>G, and IVS5-73A>G seems to be associated with low warfarin dose requirement and this haplotype could be considered in the development of a warfarin dose prediction model for Asian populations.
Assuntos
Anticoagulantes/farmacologia , Hidrocarboneto de Aril Hidroxilases/genética , Genótipo , Implante de Prótese de Valva Cardíaca , Polimorfismo de Nucleotídeo Único/genética , Varfarina/farmacologia , Povo Asiático/genética , Citocromo P-450 CYP2C9 , Análise Mutacional de DNA , Éxons , Frequência do Gene , Cardiopatias/genética , Cardiopatias/cirurgia , Humanos , Íntrons , Coreia (Geográfico) , Regiões Promotoras Genéticas/genética , Análise de Sequência de DNARESUMO
Overexpression/amplification of human epidermal growth factor receptor (HER)2/neu (erbB-2) oncogene plays a causal role in carcinogenesis and correlates with a poor clinical prognosis. However, little is known about HER2 in gastric cancer. In this study, we explored the pharmacological activities of natural triterpenoid corosolic acid (CRA) in HER2 signaling and its role in gastric cancer development and progression. In this study, CRA dramatically inhibited HER2 expression in a dose- and time-dependent manner, effectively inhibited cell proliferation, and induced G(0)/G(1) arrest through the induction of p27(kip1) and cyclin D(1) down-regulation. CRA exposure enhanced apoptotic cell death, as confirmed by caspase-3 and poly (ADP-ribose) polymerase cleavage activities. CRA inhibited signaling pathways downstream of HER2, including phospho-proteins such as Akt and Erk. In addition, CRA combined with adriamycin and 5-fluorouracil enhanced this growth inhibition, but not with docetaxel and paclitaxel. These findings demonstrate that CRA suppresses HER2 expression, which in turn promotes cell cycle arrest and apoptotic cell death of gastric cancer cells, providing a rationale for future clinical trials of CRA in the treatment of HER2-positive gastric cancers.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Extratos Vegetais/farmacologia , Receptor ErbB-2/metabolismo , Neoplasias Gástricas/tratamento farmacológico , Triterpenos/farmacologia , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Antineoplásicos Fitogênicos/uso terapêutico , Caspase 3/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Regulação para Baixo , Expressão Gênica/efeitos dos fármacos , Genes erbB-2 , Humanos , Fitoterapia , Extratos Vegetais/uso terapêutico , Poli(ADP-Ribose) Polimerases/metabolismo , Receptor ErbB-2/genética , Transdução de Sinais/efeitos dos fármacos , Triterpenos/uso terapêuticoRESUMO
Corosolic acid is one of the triterpenoids present in the leaves of Weigela subsessilis. The antidiabetic activity of corosolic acid has been reported previously, but to date, the anticancer effects on gastric cancer have been poorly studied. In this study, corosolic acid showed growth inhibition on SNU-601 human gastric cancer cells, with an IC50 value of 16.9 ± 2.9 µM. Corosolic acid also triggered the activation of caspase-3 and poly (ADP-ribose) polymerase, while it was recovered by Z-VAD-FMK. Moreover, the cell growth/apoptosis activities of corosolic acid were regulated by the AMP-activated protein kinase-mammalian target of rapamycin (AMPK-mTOR) signals. These results showed that corosolic acid-mediated AMPK activation leads to inhibition of mTOR, thus providing a possible mechanism of action of corosolic acid in the inhibition of cancer cell growth and the induction of apoptosis.
Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Caprifoliaceae/química , Neoplasias Gástricas/tratamento farmacológico , Triterpenos/farmacologia , Caspase 3/metabolismo , Linhagem Celular Tumoral , Humanos , Folhas de Planta/química , Poli(ADP-Ribose) Polimerases/metabolismo , Serina-Treonina Quinases TOR/metabolismoRESUMO
UNLABELLED: Hepatocyte nuclear factor-4 alpha (HNF4A) is an essential transcriptional regulator for many genes that are expressed preferentially in the liver. Among the important functions of the liver is drug metabolism in response to xenobiotic exposure. Recent studies have suggested that HNF4A regulates the expression of cytochrome P450 (CYP), including CYP2D6 and CYP3A4, which show large individual variations in their activities. To understand the genetic factors that influence individual CYP activities, a genetic variant of HNF4A and the effects of genetic variants of HNF4A on CYP activity were investigated. Here, we report the identification of a novel coding variant of HNF4A that influences CYP2D6 activity in humans. After direct sequencing, a polymorphism search revealed the HNF4A G60D variant in Koreans. This variant was unable to bind to the recognition site in the CYP2D6 promoter and therefore lacked the regulatory function for this gene. Human liver specimens with the heterozygous HNF4A G60D genotype showed a tendency toward lower levels of CYP2D6 activity than the wild-type genotype in the same genetic background of CYP2D6. Furthermore, human subjects with the HNF4A G60D genotype tended to have lower CYP2D6 activity than those with the wild-type HNF4A. The HNF4A G60D variant was detected at low frequency in Asian populations, including Koreans, Chinese, and Vietnamese, and was not found in Africans or Caucasians. CONCLUSION: This is the first report to show that the genetic polymorphism of liver-enriched nuclear receptor HNF4A influences downstream CYP2D6 function in human subjects.
Assuntos
Citocromo P-450 CYP2D6/metabolismo , Fator 4 Nuclear de Hepatócito/genética , Polimorfismo Genético/fisiologia , Adulto , Idoso , Povo Asiático/genética , Sítios de Ligação , Linhagem Celular , DNA/metabolismo , Feminino , Genótipo , Heterozigoto , Humanos , Desequilíbrio de Ligação , Fígado/metabolismo , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Transcrição Gênica , TransfecçãoRESUMO
DNA damage by ionizing radiation (IR) can induce activations of both NF-kappaB and p53 through the upstream kinase ataxia telangiectasia mutated (ATM). NF-kappaB activation could also be signaled through two distinct or overlapped pathways; IkappaB kinases (IKKs)-IkappaBalpha and Akt-glycogen synthase kinase-3 (GSK-3). In the present study, however, we show that activation of Akt1 and the subsequent phosphorylation and inactivation of GSK-3beta by IR could also occur in ATM-deficient AT5BIVA cells as well as in normal MRC5CV1 fibroblasts. Similarly, lithium chloride (LiCl) was found to increase the phosphorylation of GSK-3beta independently of ATM. Transfection with either wild-type or kinase dead mutant GSK-3beta to the cells further indicated that phosphorylations of Akt1 and GSK-3beta were closely associated with the transcriptional transactivation of NF-kappaB in response to ionizing radiation. On the other hand, LiCl, having no effect on caspase-3 activation, significantly increased p53 phosphorylation and apoptotic death of the normal MRC5CV1 cells while IR, activating both caspase-3 and p53, profoundly affected AT5BIVA cell death. Hence, our data suggest that although ATM-mediated IKK-IkappaBalpha pathway might be a typical pathway for IR-induced NF-kappaB activation, GSK-3beta phosphorylation could also partially contribute to the transcriptional transactivation of NF-kappaB in an ATM-independent manner and that GSK-3beta phosphorylation could induce ATM-mediated cell apoptosis through the activation of p53.
Assuntos
Proteínas de Ciclo Celular/metabolismo , Proteínas de Ligação a DNA/metabolismo , Fibroblastos/efeitos da radiação , Quinase 3 da Glicogênio Sintase/metabolismo , NF-kappa B/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais/efeitos da radiação , Ativação Transcricional/efeitos da radiação , Proteínas Supressoras de Tumor/metabolismo , Apoptose/efeitos da radiação , Proteínas Mutadas de Ataxia Telangiectasia , Camptotecina/farmacologia , Caspase 3/metabolismo , Linhagem Celular , Proteínas de Ligação a DNA/deficiência , Ativação Enzimática , Fibroblastos/efeitos dos fármacos , Fibroblastos/enzimologia , Fibroblastos/metabolismo , Quinase 3 da Glicogênio Sintase/genética , Glicogênio Sintase Quinase 3 beta , Humanos , Cloreto de Lítio/farmacologia , Mutação , NF-kappa B/genética , Fosforilação , Proteínas Serina-Treonina Quinases/deficiência , Proteínas Proto-Oncogênicas c-akt/metabolismo , Radiação Ionizante , Transdução de Sinais/efeitos dos fármacos , Ativação Transcricional/efeitos dos fármacos , Transfecção , Proteína Supressora de Tumor p53/metabolismo , Proteínas Supressoras de Tumor/deficiênciaRESUMO
Honokiol, a natural biphenolic compound, exerts anticancer effects through a variety of mechanisms on multiple types of cancer with relatively low toxicity. Adenosine 5'phosphateactivated protein kinase (AMPK), an essential regulator of cellular homeostasis, may control cancer progression. The present study aimed to investigate whether the anticancer activities of honokiol in ovarian cancer cells were mediated through the activation of AMPK. Honokiol decreased cell viability of 2 ovarian cancer cell lines, with an halfmaximal inhibitory concentration value of 48.71±11.31 µM for SKOV3 cells and 46.42±5.37 µM for Caov3 cells. Honokiol induced apoptosis via activation of caspase3, caspase7 and caspase9, and cleavage of poly(adenosine 5'diphosphateribose) polymerase. Apoptosis induced by honokiol was weakened by compound C, an AMPK inhibitor, suggesting that honokiolinduced apoptosis was dependent on the AMPK/mechanistic target of rapamycin signaling pathway. Additionally, honokiol inhibited the migration and invasion of ovarian cancer cells. The combined treatment of honokiol with compound C reversed the activities of honokiol in wound healing and Matrigel invasion assays. These results indicated that honokiol may have therapeutic potential in ovarian cancer by targeting AMPK activation.
Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Apoptose/efeitos dos fármacos , Compostos de Bifenilo/farmacologia , Movimento Celular/efeitos dos fármacos , Lignanas/farmacologia , Neoplasias Ovarianas/patologia , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Feminino , Humanos , Camundongos , Modelos Biológicos , Células NIH 3T3 , Invasividade Neoplásica , Neoplasias Ovarianas/enzimologia , Ensaio Tumoral de Célula-TroncoRESUMO
Pristimerin, a quinonemethide triterpenoid, has demonstrated anticancer activity against a number of types of cancer, including breast cancer. However, its mechanism of action remains unclear. The present study investigated the autophagyinduced anticancer efficacy of pristimerin on MDAMB231 human breast cancer cells. Pristimerin inhibited the growth of these cells in a concentrationdependent manner. Treatment with pristimerin dosedependently induced an increase of light chain 3B (LC3II), whereas autophagy inhibitor 3methyladenine (3MA) inhibited pristimerininduced LC3II accumulation and cytotoxic effects. Autophagy was also activated by paclitaxel as observed by an elevated LC3II level. Although 24 µM paclitaxel induced autophagy without cytotoxicity, combined with pristimerin it additively induced cell growth inhibition and autophagy induction. Autophagy induction was measured with an autophagy detection kit and LC3II levels were monitored by western blot analysis. Treatment with 3MA inhibited LC3II accumulation and cell death induced by a combination of paclitaxel and pristimerin. Pristimerin and paclitaxel inhibited extracellular signalregulated kinase (ERK)1/2/p90RSK signaling, consistent with autophagy indicators, namely p62 degradation and beclin 1 expression. In addition, ERK activator ceramide C6 treatment suppressed the LC3II levels induced by a combination of paclitaxel and pristimerin. These results suggested that exposure to pristimerin induced autophagic cell death, whereas a combination treatment of pristimerin and paclitaxel resulted in an additive effect on ERKdependent autophagic cell death.
Assuntos
Autofagia/efeitos dos fármacos , Neoplasias da Mama/metabolismo , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Paclitaxel/farmacologia , Triterpenos/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sinergismo Farmacológico , Feminino , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Triterpenos PentacíclicosRESUMO
5Fluorouracil (5FU) is one of the most commonly used chemotherapeutic agents for gastric cancer. Resistance to 5FUbased chemotherapy remains the major obstacle in the treatment of gastric cancer. A growing body of evidence has suggested that adenosine monophosphateactivated protein kinase (AMPK) is pivotal for chemoresistance. However, the mechanism by which AMPK regulates the chemosensitivity of gastric cancer remains unclear. In the present study, how corosolic acid enhanced the chemosensitivity of gastric cancer cells to 5FU via AMPK activation was investigated. A 5FUresistant gastric cancer cell line (SNU620/5FUR) was established, which had a marked increase in thymidine synthase (TS) expression but reduced AMPK phosphorylation when compared with the parental cell line, SNU620. AMPK regulation by 5aminoimidazole4carboxamide ribonucleotide or compound c was revealed to be markedly associated with TS expression and 5FUresistant cell viability. In addition, corosolic acid activated AMPK, and decreased TS expression and the phosphorylation of mammalian target of rapamycin/4Ebinding protein 1 in a dosedependent manner. Corosolic acid treatment significantly reduced cell viability while compound c reversed corosolic acidinduced cell growth inhibition. The 5FUresistance sensitization effect of corosolic acid was determined by the synergistic reduction of TS expression and inhibition of cell viability in the presence of 5FU. The corosolic acidinduced AMPK activation was markedly increased by additional 5FU treatment, while compound c reversed AMPK phosphorylation. In addition, compound c treatment reversed corosolic acidinduced apoptotic markers such as capase3 and PARP cleavage, and cytochrome c translocation to cytosol, in the presence of 5FU. Corosolic acid treatment in the presence of 5FU induced an increase in the apoptotic cell population based on flow cytometry analysis. This increase was abolished by compound c. In conclusion, these results implied that corosolic acid may have therapeutic potential to sensitize the resistance of gastric cancer to 5FU by activating AMPK.