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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.
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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.
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Proteínas Quinasas Activadas por AMP/metabolismo , Apoptosis/efectos de los fármacos , Compuestos de Bifenilo/farmacología , Movimiento Celular/efectos de los fármacos , Lignanos/farmacología , Neoplasias Ováricas/patología , Transducción de Señal/efectos de los fármacos , Serina-Treonina Quinasas TOR/metabolismo , Animales , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Activación Enzimática/efectos de los fármacos , Femenino , Humanos , Ratones , Modelos Biológicos , Células 3T3 NIH , Invasividad Neoplásica , Neoplasias Ováricas/enzimología , Ensayo de Tumor de Célula MadreRESUMEN
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.
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Autofagia/efectos de los fármacos , Neoplasias de la Mama/metabolismo , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Paclitaxel/farmacología , Triterpenos/farmacología , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Sinergismo Farmacológico , Femenino , Humanos , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Triterpenos PentacíclicosRESUMEN
Ovarian cancer is one of the most common causes of female mortalities from gynecological tumors. An entkaurane diterpenoid compound CRT1 (ent18acetoxy7ßhydroxy kaur15oxo16ene), mainly isolated from the Vietnamese herb Croton tonkinesis has been used in folk medicine in Vietnam for cancer treatment. However, the effect of this compound on human ovarian cancer cells has not yet been reported. The objective of the present study was to determine the effect of CRT1 on the cell viability, apoptosis and metastasis of SKOV3 human ovarian cancer cells using a Cell Counting Kit8 assay, flow cytometric analysis of Annexin Vfluorescein isothiocyanate/propidium iodide staining, western blot analysis, soft agar colony forming assay, wound healing assay and Matrigel invasion assay. The results revealed that CRT1 possessed significant antiproliferative effects on SKOV3 cells. CRT1 treatment at 25 and 50 µM induced apoptosis, enhanced the percentage of Annexin Vpositive cells, increased the expression of proapoptotic protein Bcell lymphoma 2 (Bcl2)associated X protein, cytochrome c release from the mitochondria to the cytosol, cleaved caspase3, caspase7, caspase9, and poly (adenosine diphosphateribose) polymerase. However, it decreased the expression of Bcl2 in a dosedependent manner. The percentage of necrotic cells increased following CRT1 treatment at <10 µM. CRT1 at 50 µM significantly induced the phosphorylation of extracellular signalregulated kinase (ERK). Growth inhibition and the apoptotic effects of CRT1 could be reversed by PD98059, an ERK inhibitor. Additionally, CRT1 inhibited cell migration and invasion via ERK1/2 activation in SKOV3 cells. These results indicated that CRT1, an entkaurane diterpenoid, may be a potential inhibitor of ovarian cancer by the activating ERK1/2/p90 ribosomal S6 kinase signaling pathway.
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Movimiento Celular/efectos de los fármacos , Diterpenos de Tipo Kaurano/farmacología , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Neoplasias Ováricas/patología , Proteínas Quinasas S6 Ribosómicas 90-kDa/metabolismo , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Femenino , Humanos , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Invasividad Neoplásica , Fosforilación/efectos de los fármacos , Inhibidores de Proteínas Quinasas/farmacología , Transducción de Señal/efectos de los fármacos , Factores de Tiempo , Ensayo de Tumor de Célula MadreRESUMEN
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.
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Proteínas Quinasas Activadas por AMP/metabolismo , Resistencia a Antineoplásicos/efectos de los fármacos , Fluorouracilo/farmacología , Triterpenos/farmacología , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Antineoplásicos/farmacología , Proteínas de Ciclo Celular , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Humanos , Fosfoproteínas/metabolismo , Fosforilación/efectos de los fármacos , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patología , Serina-Treonina Quinasas TOR/metabolismo , Triterpenos/química , Regulación hacia Arriba/efectos de los fármacosRESUMEN
Fatty acid synthase (FASN) is a key anabolic enzyme for de novo fatty acid synthesis, which is important in the development of colon carcinoma. The high expression of FASN is considered a promising molecular target for colon cancer therapy. Emodin, a naturally occurring anthraquinone, exhibits an anticancer effect in various types of human cancer, including colon cancer; however, the molecular mechanisms remain to be fully elucidated. Cell viability was evaluated using a Cell Counting Kit8 assay. The apoptosis rate of cells was quantified via flow cytometry following Annexin V/propidium iodide staining. FASN activity was measured by monitoring oxidation of nicotinamide adenine dinucleotide phosphate at a wavelength of 340 nm, and intracellular free fatty acid levels were detected using a Free Fatty Acid Quantification kit. Western blot analysis and reverse transcriptionpolymerase chain reaction were used to detect target gene and protein expression. The present study was performed to investigate whether the gene expression of FASN and its enzymatic activity are regulated by emodin in a human colon cancer cell line. Emodin markedly inhibited the proliferation of HCT116 cells and a higher protein level of FASN was expressed, compared with that in SW480, SNU-C2A or SNUC5 cells. Emodin significantly downregulated the protein expression of FASN in HCT116 cells, which was caused by protein degradation due to elevated protein ubiquitination. Emodin also inhibited intracellular FASN enzymatic activity and reduced the levels of intracellular free fatty acids. Emodin enhanced antiproliferation and apoptosis in a dose and timedependent manner. The combined treatment of emodin and cerulenin, a commercial FASN inhibitor, had an additive effect on these activities. Palmitate, the final product of the FASN reaction, rescued emodininduced viability and apoptosis. In addition, emodin altered FASNinvolved signaling pathways, including phosphatidylinositol 3-kinase/Akt and mitogenactivated protein kinases/extracellular signal-regulated kinases 1/2. These results suggested that emodin-regulated cell growth and apoptosis were mediated by inhibiting FASN and provide a molecular basis for colon cancer therapy.
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Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Neoplasias del Colon/tratamiento farmacológico , Emodina/farmacología , Ácido Graso Sintasas/antagonistas & inhibidores , Inhibidores de Proteínas Quinasas/farmacología , Ciclo Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Colon/efectos de los fármacos , Colon/metabolismo , Colon/patología , Neoplasias del Colon/metabolismo , Neoplasias del Colon/patología , Ácido Graso Sintasas/metabolismo , Células HCT116 , HumanosRESUMEN
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.
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Enfermedades Musculoesqueléticas/diagnóstico por imagen , Neurilemoma/diagnóstico por imagen , Neurofibroma/diagnóstico por imagen , Neoplasias del Sistema Nervioso Periférico/diagnóstico por imagen , Ultrasonografía/métodos , Diagnóstico Diferencial , Femenino , Humanos , Aumento de la Imagen/métodos , Interpretación de Imagen Asistida por Computador/métodos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
5Fluorouracil (5FU), one of the oldest anticancer therapeutic agents, is increasingly being administered in cancer chemotherapy. In the present study, the anticancer effects of 5FU combined with corosolic acid (CRA) were determined in SNU620 human gastric carcinoma cells and the underlying mechanisms were examined. A combination treatment of 5FU and CRA inhibited the viability of cells additively. Furthermore, apoptotic activity following combination treatment was found to be stronger than that of the single treatments, as observed using an Annexin V/propidium iodide assay. The protein level of Bcl2 was decreased significantly by the combination treatment, whereas the protein level of Bim was increased. The release of mitochondrial cytochrome c was increased as a result of the combination treatment, however, the combination treatment additively increased caspase3 and poly(ADPribose) polymerase cleavages. Additionally, the mammalian target of rapamycin (mTOR) signaling pathway, which is highly activated in gastric cancer, was regulated by 5FU and CRA, and additive mTOR/eukaryotic translation initiation factor 4Ebinding protein 1 (4EBP1) inhibition was observed with the combination treatment. Additional rapamycin treatment along with the combination treatment of 5FU and CRA showed a more marked inhibition of mTOR/4EBP1 in the cells, as well as increased apoptosis and antiproliferation. Thus, these data indicate that CRA enhances the anticancer activities of 5FU via mTOR inhibition in SNU620 human gastric carcinoma cells.
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Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Fluorouracilo/farmacología , Serina-Treonina Quinasas TOR/antagonistas & inhibidores , Triterpenos/farmacología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Ensayos de Selección de Medicamentos Antitumorales , Sinergismo Farmacológico , Humanos , Transducción de Señal , Neoplasias Gástricas , Serina-Treonina Quinasas TOR/metabolismoRESUMEN
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.
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Genotipo , Ácido Glucurónico/metabolismo , Glucuronosiltransferasa/genética , Glucuronosiltransferasa/metabolismo , Ácidos Hidroxieicosatetraenoicos/metabolismo , Adulto , Variación Genética , Humanos , Isoenzimas/genética , Isoenzimas/metabolismo , Cinética , Microsomas Hepáticos/metabolismoRESUMEN
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.
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Técnicas de Genotipaje , Inhibidores de Agregación Plaquetaria/farmacología , Agregación Plaquetaria/efectos de los fármacos , Ticlopidina/análogos & derivados , Pueblo Asiatico/genética , Clopidogrel , Citocromo P-450 CYP2C19/análisis , Citocromo P-450 CYP2C19/genética , Genotipo , Técnicas de Genotipaje/economía , Humanos , Reacción en Cadena de la Polimerasa Multiplex , Infarto del Miocardio/tratamiento farmacológico , Inhibidores de Agregación Plaquetaria/uso terapéutico , Polimorfismo de Nucleótido Simple , Medicina de Precisión , Receptores Purinérgicos P2Y12/análisis , Receptores Purinérgicos P2Y12/genética , República de Corea , Análisis de Secuencia de ADN , Ticlopidina/farmacología , Ticlopidina/uso terapéuticoRESUMEN
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.
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Antineoplásicos Fitogénicos/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Receptor ErbB-2/metabolismo , Triterpenos/farmacología , Antineoplásicos Fitogénicos/aislamiento & purificación , Apoptosis/efectos de los fármacos , Neoplasias de la Mama/metabolismo , Caspasas/metabolismo , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Acido Graso Sintasa Tipo I/antagonistas & inhibidores , Humanos , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Triterpenos Pentacíclicos , Extractos Vegetales , Raíces de Plantas , Poli(ADP-Ribosa) Polimerasas/metabolismo , ARN Mensajero/metabolismo , Receptor ErbB-2/genética , Salacia , Serina-Treonina Quinasas TOR/antagonistas & inhibidores , Triterpenos/aislamiento & purificación , Cicatrización de HeridasRESUMEN
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.
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Empalme Alternativo/genética , Pueblo Asiatico/genética , Hígado/metabolismo , Receptores Citoplasmáticos y Nucleares/genética , Población Blanca/genética , Adulto , Anciano , Receptor de Androstano Constitutivo , Femenino , Perfilación de la Expresión Génica , Células Hep G2 , Humanos , Masculino , Persona de Mediana EdadRESUMEN
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.
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Antineoplásicos/farmacología , Croton , Diterpenos de Tipo Kaurano/farmacología , Proteínas Quinasas Activadas por AMP/metabolismo , Apoptosis/efectos de los fármacos , Carcinoma Hepatocelular , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Humanos , Hojas de la PlantaRESUMEN
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.
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Antineoplásicos/farmacología , Biflavonoides/farmacología , Neoplasias de la Mama/metabolismo , Ácido Graso Sintasas/antagonistas & inhibidores , Receptor ErbB-2/metabolismo , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Supervivencia Celular , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Fosforilación , Receptor ErbB-2/genéticaRESUMEN
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.
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Proteínas Quinasas Activadas por AMP/metabolismo , Antineoplásicos Fitogénicos/uso terapéutico , Apoptosis/efectos de los fármacos , Compuestos de Bifenilo/uso terapéutico , Neoplasias del Colon/tratamiento farmacológico , Lignanos/uso terapéutico , Magnolia/química , Fitoterapia , Antineoplásicos Fitogénicos/farmacología , Compuestos de Bifenilo/farmacología , Caspasa 3/metabolismo , Movimiento Celular/efectos de los fármacos , Neoplasias del Colon/metabolismo , Citocromos c/metabolismo , Fragmentación del ADN , Relación Dosis-Respuesta a Droga , Células HCT116 , Humanos , Lignanos/farmacología , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Fosforilación , Extractos Vegetales/farmacología , Extractos Vegetales/uso terapéutico , Poli(ADP-Ribosa) Polimerasas/metabolismo , Propidio/metabolismo , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Transducción de Señal , Proteína p53 Supresora de Tumor/metabolismo , Proteína X Asociada a bcl-2/metabolismoRESUMEN
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.
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Proteínas Quinasas Activadas por AMP/metabolismo , Antineoplásicos Fitogénicos/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Ácido Oleanólico/análogos & derivados , Fitoterapia , Extractos Vegetales/uso terapéutico , Acetil-CoA Carboxilasa/metabolismo , Aminoimidazol Carboxamida/análogos & derivados , Aminoimidazol Carboxamida/farmacología , Antineoplásicos Fitogénicos/farmacología , Apoptosis/efectos de los fármacos , Neoplasias de la Mama/metabolismo , Caspasa 3/metabolismo , Caspasa 9/metabolismo , Puntos de Control del Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/genética , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/metabolismo , Activación Enzimática/efectos de los fármacos , Ácido Graso Sintasas/metabolismo , Ácidos Grasos/biosíntesis , Femenino , Fase G1/efectos de los fármacos , Expresión Génica/efectos de los fármacos , Genes p53 , Humanos , Ácido Oleanólico/farmacología , Ácido Oleanólico/uso terapéutico , Extractos Vegetales/farmacología , Poli(ADP-Ribosa) Polimerasas/efectos de los fármacos , Biosíntesis de Proteínas/efectos de los fármacos , ARN Mensajero/metabolismo , Ribonucleótidos/farmacologíaRESUMEN
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.
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Antraquinonas/farmacología , Neoplasias del Colon/tratamiento farmacológico , Receptores ErbB/antagonistas & inhibidores , Serina-Treonina Quinasas TOR/antagonistas & inhibidores , Antineoplásicos/farmacología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Neoplasias del Colon/enzimología , Neoplasias del Colon/patología , Factor de Crecimiento Epidérmico/antagonistas & inhibidores , Factor de Crecimiento Epidérmico/farmacología , Receptores ErbB/metabolismo , Fallopia japonica/química , Inhibidores de Crecimiento/fisiología , Humanos , Proteína Oncogénica v-akt/antagonistas & inhibidores , Proteína Oncogénica v-akt/metabolismo , Fosforilación/efectos de los fármacos , Extractos Vegetales/farmacología , Plantas Medicinales/química , Rheum/química , Proteínas Quinasas S6 Ribosómicas 70-kDa/antagonistas & inhibidores , Proteínas Quinasas S6 Ribosómicas 70-kDa/metabolismo , Transducción de Señal/efectos de los fármacos , Serina-Treonina Quinasas TOR/metabolismoRESUMEN
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.
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Anticoagulantes/farmacología , Hidrocarburo de Aril Hidroxilasas/genética , Genotipo , Implantación de Prótesis de Válvulas Cardíacas , Polimorfismo de Nucleótido Simple/genética , Warfarina/farmacología , Pueblo Asiatico/genética , Citocromo P-450 CYP2C9 , Análisis Mutacional de ADN , Exones , Frecuencia de los Genes , Cardiopatías/genética , Cardiopatías/cirugía , Humanos , Intrones , Corea (Geográfico) , Regiones Promotoras Genéticas/genética , Análisis de Secuencia de ADNRESUMEN
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.
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Proteínas Quinasas Activadas por AMP/metabolismo , Antineoplásicos Fitogénicos/farmacología , Apoptosis/efectos de los fármacos , Caprifoliaceae/química , Neoplasias Gástricas/tratamiento farmacológico , Triterpenos/farmacología , Caspasa 3/metabolismo , Línea Celular Tumoral , Humanos , Hojas de la Planta/química , Poli(ADP-Ribosa) Polimerasas/metabolismo , Serina-Treonina Quinasas TOR/metabolismoRESUMEN
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.