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Two highly potent cytotoxic 26-membered macrolides, isocaribenolide-I (1) and a chlorohydrin 2, together with known amphidinolide N (3), have been isolated from a free-swimming dinoflagellate Amphidinium species (KCA09053 and KCA09056 strains) collected off Iriomote Island, Japan. The structures of 1 and 2 were determined to be a congener of 3 with an isobutyl terminus and the chlorohydrin form of 3, respectively, by detailed analyses of spectroscopic data. The relative stereochemistries of 1 and 2 were elucidated by the conformational analyses based on NMR data.
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Dinoflagellida/química , Macrolídeos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Células HeLa , Humanos , Macrolídeos/química , Macrolídeos/isolamento & purificação , Espectroscopia de Ressonância Magnética , Conformação Molecular , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
The article Differential effects of sevoflurane on the growth and apoptosis of human cancer cell lines, written by Takahiro Hirai, Yuko Konishi, Shoko Mizuno, Zhou Rui, Yao Sun and Kimitoshi Nishiwaki, was originally published electronically on the publisher's internet portal (currently SpringerLink) on 31 October 2019 with open access. With the author(s)' decision to step back from Open Choice, the copyright of the article changed on 5 December 2019 to © Japanese Society of Anesthesiologists 2019 and the article is forthwith distributed under the terms of copyright.
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PURPOSE: There have been contradictory findings regarding the effects of sevoflurane on the oncogenic properties of cancer cells. This study was conducted to gain insights into the fundamental rules governing the differential effects of sevoflurane exposure on various cancer cells derived from multiple origins. METHODS: A series of cancer cell lines were exposed to 1% (v/v) sevoflurane for 2-8 h and then assessed for their proliferation, Matrigel invasion, and apoptotic cell death, in comparison with their untreated counterparts. Cell proliferation and Matrigel invasion assays were performed using Coulter counter and Boyden chamber techniques, respectively. Apoptosis was evaluated by staining cells with Annexin V and 7-AAD followed by fluorescence flow cytometry. In addition, the expression of cleaved caspase-3 protein, another marker of apoptosis, was assessed using immunoblotting. RESULTS: Proliferation was significantly enhanced after sevoflurane exposure in six of eight cancer cell lines (NCI-H1299, MDA-MB-231, HCT116, DLD-1, HT29, and RKO). In contrast, sevoflurane attenuated proliferation in the last two cancer cell lines, A549 and MCF-7, as well as in the non-cancerous MCF10A cell line. Cell biological assays using four cancer cell lines demonstrated that accelerated but not attenuated cancer cell proliferation after sevoflurane exposure is associated with enhanced Matrigel invasion and suppressed apoptosis. CONCLUSION: Sevoflurane augmented or hampered cell proliferation and Matrigel invasion depending on the cancer cell line examined. Loss of sevoflurane-induced apoptosis occurring in cancer cell lines is likely to be correlated with their enhanced proliferation after sevoflurane exposure.
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Apoptose , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sevoflurano/farmacologia , Linhagem Celular , HumanosRESUMO
Polymers with a perylenediimide (PDI) side chain (PAc12PDI) consist of two kinds of crystalline structures with various types of orientations in a thin film. Understanding the population of the microcrystalline structure and its orientation along the thickness is strongly desired. Grazing-incidence wide-angle X-ray diffraction (GIWAXD) measurements with hard X-rays, which are generally chosen as λ = 0.1 nm, are a powerful tool to evaluate the molecular aggregation structure in thin films. A depth-resolved analysis for the outermost surface of the polymeric materials using conventional GIWAXD measurements, however, has limitations on depth resolution because the X-ray penetration depth dramatically increases above the critical angle. Meanwhile, tender X-rays (λ = 0.5 nm) have the potential advantage that the penetration depth gradually increases above the critical angle, leading to precise characterization for the population of crystallite distribution along the thickness. The population of the microcrystalline states in the PAc12PDI thin film was precisely characterized utilizing GIWAXD measurements using tender X-rays. The outermost surface of the PAc12PDI thin film is occupied by a monoclinic lattice with a = 2.38 nm, b = 0.74 nm, c = 5.98 nm, and ß = 108.13°, while maintaining the c-axis perpendicular to the substrate surface. Additionally, the presence of solid substrate controls the formation of the crystallite with unidirectional orientation.
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It is well-known that a mixture of isotactic and syndiotactic polymethyl methacrylate (PMMA) forms a stereocomplex consisting of a multihelical structure in which an isotactic chain is surrounded by a syndiotactic chain. Here, we report the basic structure of the stereocomplex formed when the syndiotactic PMMA chains are tethered to a silicon substrate and form a high-density polymer brush. The influence of geometric confinement was investigated by preparing the high-density polymer brushes on a flat and spherical substrate. In both cases, mixing the untethered isotactic PMMA with the grafted syndiotactic PMMA led to the formation of a stereocomplex with a multihelical structure. Static contact angle measurements showed a hindered surface mobility at the outermost surface of the polymer brush, indicating that the stereocomplex forms a crystalline structure. A syndiotactic polymer brush with substituted fluoroalkyl groups was prepared to increase the contrast for grazing incidence wide-angle X-ray diffraction (GIWAXD) measurements. The GIWAXD results verified that the stereocomplex forms a crystalline structure oriented perpendicular to the substrate with a relatively low degree of orientation.
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The adeno-associated virus (AAV)-based targeting vector has been one of the tools commonly used for genome modification in human cell lines. It allows for relatively efficient gene targeting associated with 1-4-log higher ratios of homologous-to-random integration of targeting vectors (H/R ratios) than plasmid-based targeting vectors, without actively introducing DNA double-strand breaks. In this study, we sought to improve the efficiency of AAV-mediated gene targeting by introducing a 2A-based promoter-trap system into targeting constructs. We generated three distinct AAV-based targeting vectors carrying 2A for promoter trapping, each targeting a GFP-based reporter module incorporated into the genome, PIGA exon 6 or PIGA intron 5. The absolute gene targeting efficiencies and H/R ratios attained using these vectors were assessed in multiple human cell lines and compared with those attained using targeting vectors carrying internal ribosome entry site (IRES) for promoter trapping. We found that the use of 2A for promoter trapping increased absolute gene targeting efficiencies by 3.4-28-fold and H/R ratios by 2-5-fold compared to values obtained with IRES. In CRISPR-Cas9-assisted gene targeting using plasmid-based targeting vectors, the use of 2A did not enhance the H/R ratios but did upregulate the absolute gene targeting efficiencies compared to the use of IRES.
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Dependovirus/genética , Marcação de Genes/métodos , Vetores Genéticos/metabolismo , Peptídeos/metabolismo , Ribossomos/metabolismo , Sequência de Bases , Sistemas CRISPR-Cas , Linhagem Celular Tumoral , Dependovirus/metabolismo , Éxons , Genes Reporter , Vetores Genéticos/química , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Células HCT116 , Células HEK293 , Humanos , Sítios Internos de Entrada Ribossomal , Íntrons , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Dados de Sequência Molecular , Peptídeos/genética , Regiões Promotoras Genéticas , Ribossomos/química , Integração ViralRESUMO
Two new macrolides, iriomoteolides-10a (1) and -12a (2), have been isolated from a marine dinoflagellate Amphidinium sp. (KCA09053 strain), and their structures were elucidated on the basis of a detailed two dimensional (2D)-NMR analysis. Compound 1 is a novel 21-membered Amphidinium macrolide, which contains one tetrahydrofuran ring, two ketone carbonyls, two hydroxyl groups, and six one-carbon branches. Compound 2 is a new 12-membered macrolide related to amphidinolide Q. Compound 1 exhibited cytotoxic activity against human cervix adenocarcinoma HeLa and murine hepatocellular carcinoma MH134 cells.
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Dinoflagellida/química , Macrolídeos/farmacologia , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Células HeLa , Humanos , Macrolídeos/química , Macrolídeos/isolamento & purificação , Camundongos , Conformação Molecular , Relação Estrutura-AtividadeRESUMO
A novel linear polyketide, amphirionin-2 (1), with two unique hexahydrofuro[3,2-b]furan moieties has been isolated from the cultivated algal cells of a benthic dinoflagellate Amphidinium sp. (strain KCA09051). The structure was elucidated on the basis of detailed analyses of 2D NMR data, and the absolute configuration of C-5 was determined by using modified Mosher's method. Amphirionin-2 (1) exhibited potent cytotoxic activity against human colon carcinoma Caco-2 cells and human lung adenocarcinoma A549 cells.
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Dinoflagellida/química , Furanos/química , Policetídeos/química , Actinas/antagonistas & inibidores , Actinas/metabolismo , Células CACO-2 , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Dinoflagellida/metabolismo , Furanos/isolamento & purificação , Furanos/toxicidade , Humanos , Espectroscopia de Ressonância Magnética , Conformação Molecular , Policetídeos/isolamento & purificação , Policetídeos/toxicidade , EstereoisomerismoRESUMO
BACKGROUND: Telomeres are repetitive nucleotide sequences that stabilize the ends of chromosomes. Critically short telomeres are thought to contribute to cancer development by increasing chromosomal instability. We hypothesized that shorter leukocyte telomere length, a surrogate for inherited prostate cell telomere length, would be associated with increased risk of prostate cancer in hereditary prostate cancer (HPC) families. METHODS: One hundred twelve affected and 63 unaffected men from 28 families were drawn from the Johns Hopkins HPC family database. Relative mean telomere length was measured in isolated peripheral leukocyte DNA by quantitative PCR. Conditional logistic regression was used to estimate the association between quartile of age-adjusted telomere length and prostate cancer. RESULTS: Men in the shortest quartile of telomere length did not have increased odds of prostate cancer compared to men in the other three quartiles (OR = 0.84, 95% CI: 0.32-2.20, P = 0.73). However, when the analysis was restricted to affected men with blood drawn before or within a year of diagnosis (N = 39) and all unaffected men, shorter telomere length was moderately associated with increased odds of prostate cancer (OR = 3.55, 95% CI: 0.82-15.43, P = 0.09). CONCLUSIONS: Though we found no association overall, shorter leukocyte telomere length may be associated with increased odds of prostate cancer when measured in pre-diagnostic samples. Further prospective research is warranted exploring the utility of telomere length as a prostate cancer biomarker.
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Predisposição Genética para Doença , Neoplasias da Próstata/genética , Encurtamento do Telômero , Adulto , Idoso , Idoso de 80 Anos ou mais , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Fumar/genética , TelômeroRESUMO
Peridinin and fucoxanthin, which are natural carotenoids isolated from a symbiotic dinoflagellate, Symbiodinium sp., and a brown alga, Petalonia fascia, respectively, were compared for inhibitory effects on delayed-type hypersensitivity in mice. The number of eosinophils at the site of inflammation and in peripheral blood was compared for the administration of peridinin and fucoxanthin applied by painting and intraperitoneally. Peridinin, but not the structurally-related fucoxanthin, significantly suppressed the number of eosinophils in both the ear lobe and peripheral blood. Furthermore, peridinin applied topically, but not administered intraperitoneally, suppressed the level of eotaxin in the ears of sensitized mice. Fucoxanthin weakly suppressed the concentration of eotaxin in ears only by intraperitoneal administration. Although both carotenoids inhibited the migration of eosinophils toward eotaxin, the inhibitory effect of peridinin was higher than that of fucoxanthin. Peridinin may be a potential agent for suppressing allergic inflammatory responses, such as atopic dermatitis, in which eosinophils play a major role in the increase of inflammation.
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Carotenoides/farmacologia , Eosinofilia/tratamento farmacológico , Eosinófilos/efeitos dos fármacos , Xantofilas/farmacologia , Administração Tópica , Animais , Carotenoides/administração & dosagem , Carotenoides/isolamento & purificação , Dinoflagellida/química , Eosinófilos/metabolismo , Feminino , Inflamação/tratamento farmacológico , Inflamação/patologia , Injeções Intraperitoneais , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H , Camundongos Transgênicos , Phaeophyceae/química , Xantofilas/administração & dosagem , Xantofilas/isolamento & purificaçãoRESUMO
Biallelic inactivation of cancer susceptibility gene BRCA1 leads to breast and ovarian carcinogenesis. Paradoxically, BRCA1 deficiency in mice results in early embryonic lethality, and similarly, lack of BRCA1 in human cells is thought to result in cellular lethality in view of BRCA1's essential function. To survive homozygous BRCA1 inactivation during tumorigenesis, precancerous cells must accumulate additional genetic alterations, such as p53 mutations, but this requirement for an extra genetic "hit" contradicts the two-hit theory for the accelerated carcinogenesis associated with familial cancer syndromes. Here, we show that heterozygous BRCA1 inactivation results in genomic instability in nontumorigenic human breast epithelial cells in vitro and in vivo. Using somatic cell gene targeting, we demonstrated that a heterozygous BRCA1 185delAG mutation confers impaired homology-mediated DNA repair and hypersensitivity to genotoxic stress. Heterozygous mutant BRCA1 cell clones also showed a higher degree of gene copy number loss and loss of heterozygosity in SNP array analyses. In BRCA1 heterozygous clones and nontumorigenic breast epithelial tissues from BRCA mutation carriers, FISH revealed elevated genomic instability when compared with their respective controls. Thus, BRCA1 haploinsufficiency may accelerate hereditary breast carcinogenesis by facilitating additional genetic alterations.
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Mama/citologia , Células Epiteliais/fisiologia , Genes BRCA1 , Instabilidade Genômica/genética , Haploinsuficiência/genética , Feminino , Inativação Gênica , Instabilidade Genômica/fisiologia , Heterozigoto , Humanos , Hibridização in Situ Fluorescente , Polimorfismo de Nucleotídeo Único , Deleção de Sequência/genéticaRESUMO
Arsenic trioxide (ATO) is one of the most potent drugs in cancer chemotherapy, and is highly effective in treating both newly diagnosed and relapse patients with acute promyelocytic leukemia (APL). Despite a number of reports regarding the molecular mechanisms by which ATO promotes anti-tumor or pro-apoptotic activity in hematological and other solid malignancies, the effects of ATO on immune responses remain poorly understood. To further understand and clarify the effects of ATO on immune responses, we sought to examine whether ATO affects the production of nitric oxide (NO) in a lipopolysaccharide (LPS)-stimulated mouse macrophage cell line, RAW 264.7. Arsenic trioxide was found to prevent NO production in a dose-dependent manner. Arsenic trioxide significantly inhibited the increase in inducible nitric oxide synthase (iNOS) at both the mRNA and protein levels. Furthermore, our analyses revealed that the inhibitory effect of ATO on iNOS expression was ascribed to the prevention of IRF3 phosphorylation, interferon (IFN)-ß expression, and STAT1 phosphorylation, but not the prevention of the MyD88-dependent pathway. Taken together, our results indicate that ATO prevents NO production by inhibiting the TIR-domain-containing adaptor protein inducing IFN-ß (TRIF)-dependent pathway, thus highlighting an anti-inflammatory property of ATO in innate immunity.
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Proteínas Adaptadoras de Transporte Vesicular/antagonistas & inibidores , Arsenicais/farmacologia , Lipopolissacarídeos/farmacologia , Óxido Nítrico/biossíntese , Óxidos/farmacologia , Proteínas Adaptadoras de Transporte Vesicular/genética , Proteínas Adaptadoras de Transporte Vesicular/metabolismo , Animais , Anti-Inflamatórios/farmacologia , Antineoplásicos/farmacologia , Trióxido de Arsênio , Fator Regulador 3 de Interferon/antagonistas & inibidores , Fator Regulador 3 de Interferon/genética , Fator Regulador 3 de Interferon/metabolismo , Interferon beta/antagonistas & inibidores , Interferon beta/genética , Interferon beta/metabolismo , Receptores de Lipopolissacarídeos/genética , Receptores de Lipopolissacarídeos/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Quinases de Proteína Quinase Ativadas por Mitógeno/genética , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/metabolismo , NF-kappa B/genética , NF-kappa B/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/antagonistas & inibidores , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/metabolismo , Fosforilação/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fator de Transcrição STAT1/antagonistas & inibidores , Fator de Transcrição STAT1/genética , Fator de Transcrição STAT1/metabolismo , Transdução de Sinais/efeitos dos fármacos , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/imunologia , Receptor 4 Toll-Like/metabolismo , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Although chronic arsenic exposure is a well-known risk factor for cardiovascular diseases, including atherosclerosis, the molecular mechanism underlying arsenic-induced atherosclerosis remains obscure. Therefore, this study aimed to elucidate this molecular mechanism. We examined changes in the mRNA level of the lectin-like oxidized LDL (oxLDL) receptor (LOX-1) in a mouse aortic endothelial cell line, END-D, after sodium arsenite (SA) treatment. SA treatment significantly upregulated LOX-1 mRNA expression; this finding was also verified at the protein expression level. Flow cytometry and fluorescence microscopy analyses showed that the cellular uptake of fluorescence (Dil)-labeled oxLDL was significantly augmented with SA treatment. In addition, an anti-LOX-1 antibody completely abrogated the augmented uptake of Dil-oxLDL. We observed that SA increased the levels of the phosphorylated forms of nuclear factor of kappa light polypeptide gene enhancer in B cells (NF-κB)/p65. SA-induced upregulation of LOX-1 protein expression was clearly prevented by treatment with an antioxidant, N-acetylcysteine (NAC), or an NF-κB inhibitor, caffeic acid phenethylester (CAPE). Furthermore, SA-augmented uptake of Dil-oxLDL was also prevented by treatment with NAC or CAPE. Taken together, our results indicate that arsenic upregulates LOX-1 expression through the reactive oxygen species-mediated NF-κB signaling pathway, followed by augmented cellular oxLDL uptake, thus highlighting a critical role of the aberrant LOX-1 signaling pathway in the pathogenesis of arsenic-induced atherosclerosis.
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Aorta/citologia , Arsenitos/toxicidade , Células Endoteliais/efeitos dos fármacos , Lipoproteínas LDL/farmacocinética , Receptores Depuradores Classe E/metabolismo , Compostos de Sódio/toxicidade , Acetilcisteína/farmacologia , Animais , Aorta/efeitos dos fármacos , Aterosclerose/induzido quimicamente , Aterosclerose/patologia , Ácidos Cafeicos/farmacologia , Linhagem Celular , Células Endoteliais/metabolismo , Camundongos , NF-kappa B/antagonistas & inibidores , NF-kappa B/genética , NF-kappa B/metabolismo , Álcool Feniletílico/análogos & derivados , Álcool Feniletílico/farmacologia , Fosforilação , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Receptores Depuradores Classe E/genética , Transdução de Sinais , Regulação para CimaRESUMO
Propofol is a pharmaceutical agent commonly used as an intravenous anesthetic in surgical treatments and a sedative in intensive care. However, it is largely unknown how exposure to propofol affects the proliferation, invasion, and apoptosis of neoplastic cells in esophageal cancer. In this study, we sought to elucidate the impact of propofol exposure on the growth properties of human esophageal cancer cell lines in vitro. We treated two human esophageal cancer cell lines, KYSE30 and KYSE960, with up to 10 µg/mL of propofol for 12-36 h. The treated cells were then analyzed by cell proliferation assay, Matrigel invasion assay, quantification of caspase-3/7 and -9 activities, and cell staining with Annexin V and 7-aminoactinomycin D to detect early apoptosis and cell death, respectively, via flow cytometry. We found that 3-5 µg/mL propofol reduced the growth and Matrigel invasion of both cell lines in a dose-dependent manner. Executioner caspase-3/7, but not caspase-9 involved in intrinsic apoptosis pathway, was activated by cell exposure to 3-5 µg/mL propofol. In addition, 3-5 µg/mL propofol augmented early apoptosis in both cell lines and increased cell death in the KYSE30 cell line. In summary, exposure to propofol, at concentrations up to 5 µg/mL, led to the reduction of cell growth and Matrigel invasion, as well as the augmentation of apoptosis in esophageal cancer cell lines. These data will help define a methodology to safely utilize propofol, a common general anesthetic and sedative, with esophageal cancer patients.
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Neoplasias Esofágicas , Propofol , Humanos , Propofol/farmacologia , Caspase 3/farmacologia , Linhagem Celular Tumoral , Apoptose , Hipnóticos e Sedativos , Proliferação de Células , Neoplasias Esofágicas/tratamento farmacológicoRESUMO
INTRODUCTION: Although a high frequency of androgen receptor (AR) expression in human breast cancers has been described, exploiting this knowledge for therapy has been challenging. This is in part because androgens can either inhibit or stimulate cell proliferation in pre-clinical models of breast cancer. In addition, many breast cancers co-express other steroid hormone receptors that can affect AR signaling, further obfuscating the effects of androgens on breast cancer cells. METHODS: To create better-defined models of AR signaling in human breast epithelial cells, we took estrogen receptor (ER)-α-negative and progesterone receptor (PR)-negative human breast epithelial cell lines, both cancerous and non-cancerous, and engineered them to express AR, thus allowing the unambiguous study of AR signaling. We cloned a full-length cDNA of human AR, and expressed this transgene in MCF-10A non-tumorigenic human breast epithelial cells and MDA-MB-231 human breast-cancer cells. We characterized the responses to AR ligand binding using various assays, and used isogenic MCF-10A p21 knock-out cell lines expressing AR to demonstrate the requirement for p21 in mediating the proliferative responses to AR signaling in human breast epithelial cells. RESULTS: We found that hyperactivation of the mitogen-activated protein kinase (MAPK) pathway from both AR and epidermal growth factor receptor (EGFR) signaling resulted in a growth-inhibitory response, whereas MAPK signaling from either AR or EGFR activation resulted in cellular proliferation. Additionally, p21 gene knock-out studies confirmed that AR signaling/activation of the MAPK pathway is dependent on p21. CONCLUSIONS: These studies present a new model for the analysis of AR signaling in human breast epithelial cells lacking ERα/PR expression, providing an experimental system without the potential confounding effects of ERα/PR crosstalk. Using this system, we provide a mechanistic explanation for previous observations ascribing a dual role for AR signaling in human breast cancer cells. As previous reports have shown that approximately 40% of breast cancers can lack p21 expression, our data also identify potential new caveats for exploiting AR as a target for breast cancer therapy.
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Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Sistema de Sinalização das MAP Quinases , Receptores Androgênicos/fisiologia , Antagonistas de Androgênios/farmacologia , Androgênios/farmacologia , Anilidas/farmacologia , Neoplasias da Mama , Linhagem Celular Tumoral , Proliferação de Células , Ciclina D1/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/genética , Ativação Enzimática , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Células Epiteliais/fisiologia , Receptor alfa de Estrogênio/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Feminino , Expressão Gênica , Humanos , Metribolona/farmacologia , Nitrilas/farmacologia , Receptores Androgênicos/biossíntese , Receptores Androgênicos/genética , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Compostos de Tosil/farmacologia , Regulação para CimaRESUMO
ß-actin (ACTB) is one of the genes expressed most abundantly and ubiquitously in human non-muscular tissues. Here, we investigated the long-term activity of a 550-bp-long human ACTB promoter region in human cells in comparison with other commonly used constitutive promoters. We first constructed plasmid vectors expressing enhanced green fluorescent protein (GFP) driven by one of the 5 promoters, human ACTB, human elongation factor-1α (EF1α), cytomegalovirus early enhancer/chicken ß-actin (CAG), cytomegalovirus (CMV), and herpes simplex virus thymidine kinase, and transfected them into multiple human somatic cell lines. Stable transfectants were maintained for 45 days, and GFP signals from the cells were quantified by fluorescence flow cytometry. GFP signals driven by the human ACTB and the CMV promoters were also compared over time for up to 60 days following transfection. We observed robust, prolonged transcriptional activity with the human ACTB promoter that is comparable to the human EF1α and the CAG promoters and significantly more stable than the CMV promoter.
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Actinas/genética , Vetores Genéticos , Plasmídeos/genética , Regiões Promotoras Genéticas , Expressão Gênica , Proteínas de Fluorescência Verde , Células HCT116 , Humanos , Transcrição GênicaRESUMO
The phosphatidylinositol 3-kinase subunit PIK3CA is frequently mutated in human cancers. Here we used gene targeting to "knock in" PIK3CA mutations into human breast epithelial cells to identify new therapeutic targets associated with oncogenic PIK3CA. Mutant PIK3CA knockin cells were capable of epidermal growth factor and mTOR-independent cell proliferation that was associated with AKT, ERK, and GSK3beta phosphorylation. Paradoxically, the GSK3beta inhibitors lithium chloride and SB216763 selectively decreased the proliferation of human breast and colorectal cancer cell lines with oncogenic PIK3CA mutations and led to a decrease in the GSK3beta target gene CYCLIN D1. Oral treatment with lithium preferentially inhibited the growth of nude mouse xenografts of HCT-116 colon cancer cells with mutant PIK3CA compared with isogenic HCT-116 knockout cells containing only wild-type PIK3CA. Our findings suggest GSK3beta is an important effector of mutant PIK3CA, and that lithium, an FDA-approved therapy for bipolar disorders, has selective antineoplastic properties against cancers that harbor these mutations.
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Mutação , Oncogenes , Fosfatidilinositol 3-Quinases/genética , Animais , Neoplasias da Mama/enzimologia , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Classe I de Fosfatidilinositol 3-Quinases , Neoplasias Colorretais/enzimologia , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Técnicas de Introdução de Genes , Quinase 3 da Glicogênio Sintase/metabolismo , Glicogênio Sintase Quinase 3 beta , Humanos , Glândulas Mamárias Humanas/metabolismo , Camundongos , Camundongos Nus , Fosforilação , Proteínas Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Serina-Treonina Quinases TOR , Transplante HeterólogoRESUMO
Telomeres are nucleoprotein structures that protect chromosome ends from degradation and recombination. Cancers often have critically shortened telomeres, contributing to genomic instability. Many of these tumors activate telomerase to stabilize telomeric ends and achieve a capacity for unlimited replication. Telomere shortening has been reported in in situ and invasive carcinomas, including breast, and has been associated with disease recurrence after surgical resection. However, previous studies have not evaluated breast cancer subtypes. The objective of this study was to evaluate telomere lengths in different subtypes of breast cancer. Breast carcinomas (n=103) identified between 2001 and 2010 from patients seen at the Johns Hopkins Hospital were categorized into luminal A (n=18), luminal B (n=28), HER-2-positive (n=20) and triple-negative carcinomas (n=37) based on tumor characteristics. Telomere lengths were assessed directly at the single cell level by fluorescence in situ hybridization, and patient groups were compared using Fisher's exact tests. ER-negative status (P=0.022), PR-negative status (P=0.008), HER-2-positive status (P=0.023) and p53-positive status (P=0.022) were associated with shorter telomere length. A larger proportion of luminal A cancers had normal or long telomere lengths as compared with luminal B cases (P=0.002), HER-2-positive cases (P=0.011) or triple-negative cases (P=0.0003). Luminal B, HER-2-positive and triple-negative cases did not differ significantly. Telomere length was shorter in more aggressive subtypes, such as luminal B, HER-2-positive and triple-negative tumors, suggesting that tumor telomere length may have utility as a prognostic and/or risk marker for breast cancer.
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Neoplasias da Mama/genética , Carcinoma/genética , Telômero/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Carcinoma/metabolismo , Carcinoma/patologia , Feminino , Humanos , Imuno-Histoquímica , Hibridização in Situ Fluorescente , Prognóstico , Receptor ErbB-2/genética , Receptores de Estrogênio/genética , Receptores de Estrogênio/metabolismo , Receptores de Progesterona/genética , Receptores de Progesterona/metabolismo , Telômero/metabolismo , Telômero/patologia , Análise Serial de Tecidos , Proteína Supressora de Tumor p53/genéticaRESUMO
Tamoxifen is widely used for the treatment of hormonally responsive breast cancers. However, some resistant breast cancers develop a growth proliferative response to this drug, as evidenced by tumor regression upon its withdrawal. To elucidate the molecular mediators of this paradox, tissue samples from a patient with tamoxifen-stimulated breast cancer were analyzed. These studies revealed that loss of the cyclin-dependent kinase inhibitor p21 was associated with a tamoxifen growth-inducing phenotype. Immortalized human breast epithelial cells with somatic deletion of the p21 gene were then generated and displayed a growth proliferative response to tamoxifen, whereas p21 wild-type cells demonstrated growth inhibition upon tamoxifen exposure. Mutational and biochemical analyses revealed that loss of p21's cyclin-dependent kinase inhibitory property results in hyperphosphorylation of estrogen receptor-alpha, with subsequent increased gene expression of estrogen receptor-regulated genes. These data reveal a previously uncharacterized molecular mechanism of tamoxifen resistance and have potential clinical implications for the management of tamoxifen-resistant breast cancers.
Assuntos
Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Receptor alfa de Estrogênio/metabolismo , Tamoxifeno/farmacologia , Linhagem Celular Tumoral , Proliferação de Células , Metilação de DNA , Análise Mutacional de DNA , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Humanos , Pessoa de Meia-Idade , Moduladores Seletivos de Receptor Estrogênico/farmacologia , Resultado do TratamentoRESUMO
BACKGROUND: The objective of the study was to evaluate the efficacy and safety of upadacitinib over 84 weeks in Japanese patients with active rheumatoid arthritis (RA) and an inadequate response to conventional synthetic disease-modifying anti-rheumatic drugs. METHODS: All patients completing a 12-week, randomized, double-blind treatment period entered a blinded extension and continued upadacitinib 7.5, 15, or 30 mg once daily (QD), or were switched from placebo to upadacitinib 7.5, 15, or 30 mg QD. Efficacy and safety were assessed over 84 weeks. RESULTS: Of 197 randomized patients, 187 (94.9%) completed the 12-week period and entered the blinded extension; 152 (77.2%) patients were ongoing at week 84. At week 84, the proportions of patients achieving a 20% improvement in American College of Rheumatology criteria (ACR20) were 85.7%, 77.6%, and 58.0% with continued upadacitinib 7.5, 15, and 30 mg, respectively (nonresponder imputation), and were similar in patients who had switched from placebo. Favorable response rates were also observed for more stringent measures of response (ACR50/70) and remission (defined by the Disease Activity Score of 28 joints with C-reactive protein, Clinical Disease Activity Index, or Simplified Disease Activity Index). The 15 mg and 30 mg doses of upadacitinib were associated with more rapid and numerically higher initial responses for some measures of disease activity and remission compared with the 7.5 mg dose. Rates of adverse events, infection, opportunistic infection, serious infection, and herpes zoster were lower with upadacitinib 7.5 and 15 mg versus 30 mg. CONCLUSIONS: Upadacitinib demonstrated sustained efficacy and was well tolerated over 84 weeks in Japanese patients with RA, with upadacitinib 15 mg offering the most favorable benefit-risk profile. TRIAL REGISTRATION: ClinicalTrials.gov NCT02720523 . Registered on March 22, 2016.