RESUMO
HYPOTHESIS: Solid lipid nanoparticles (SLNs), co-encapsulating superparamagnetic iron oxide nanoparticles and sorafenib, have been exploited for magnetic-guided drug delivery to the liver. Two different magnetic configurations, both comprising two small magnets, were under-skin implanted to investigate the effect of the magnetic field topology on the magnetic SLNP accumulation in liver tissues. A preliminary simulation analysis was performed to predict the magnetic field topography for each tested configuration. EXPERIMENTS: SLNs were prepared using a hot homogenization approach and characterized using complementary techniques. Their in vitro biological behavior was assessed in HepG-2 liver cancer cells; wild-type mice were used for the in vivo study. The magnet configuration that resulted in a higher magnetic targeting efficiency was investigated by evaluating the iron content in homogenated murine liver tissues. FINDINGS: SLNs, characterized by an average size smaller than 200 nm, retained their superparamagnetic behavior and relevant molecular resonance imaging properties as negative contrast agents. The evaluation of iron accumulation in the liver tissues was consistent with the magnetic induction profile of each magnet configuration, concurring with the results predicted by simulation analysis and obtained by measurements in living mice.
Assuntos
Nanopartículas de Magnetita , Animais , Lipossomos , Fígado , Campos Magnéticos , Camundongos , Nanopartículas , SorafenibeRESUMO
Grapes contain many flavonoid and non-flavonoid compounds with anticancer effects. In this work we fully characterized the polyphenolic profile of two grape skin extracts (GSEs), Autumn Royal and Egnatia, and assessed their effects on Polyunsaturated Fatty Acid (PUFA) membrane levels of Caco2 and SW480 human colon cancer cell lines. Gene expression of 15-lipoxygenase-1 (15-LOX-1), and peroxisome proliferator-activated receptor gamma (PPAR-γ), as well as cell morphology, were evaluated. The polyphenolic composition was analyzed by Ultra-High-Performance Liquid Chromatography/Quadrupole-Time of Flight mass spectrometry (UHPLC/QTOF) analysis. PUFA levels were evaluated by gas chromatography, and gene expression levels of 15-LOX-1 and PPAR-γ were analyzed by real-time Polymerase Chain Reaction (PCR). Morphological cell changes caused by GSEs were identified by field emission scanning electron microscope (FE-SEM) and photomicrograph examination. We detected a different profile of flavonoid and non-flavonoid compounds in Autumn Royal and Egnatia GSEs. Cultured cells showed an increase of total PUFA levels mainly after treatment with Autumn Royal grape, and were richer in flavonoids when compared with the Egnatia variety. Both GSEs were able to affect 15-LOX-1 and PPAR-γ gene expression and cell morphology. Our results highlighted a new antitumor mechanism of GSEs that involves membrane PUFAs and their downstream pathways.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Membrana Celular/química , Neoplasias do Colo/metabolismo , Ácidos Graxos Insaturados/análise , Flavonoides/farmacologia , Vitis/química , Antineoplásicos Fitogênicos/química , Araquidonato 15-Lipoxigenase/genética , Células CACO-2 , Linhagem Celular Tumoral , Membrana Celular/efeitos dos fármacos , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/genética , Flavonoides/química , Cromatografia Gasosa-Espectrometria de Massas , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Lipidômica , PPAR gama/genética , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Vitis/classificaçãoRESUMO
The polyphenolic compounds present in grape extracts have chemopreventive and anticancer properties. Here, we studied the ability of two grape skin extracts (GSEs), Autumn Royal and Egnatia, to influence the cell motility and membrane fluidity regulated by the enzyme Stearoyl-CoA desaturase-1 (SCD1) which increases with the cancer aggressiveness. Caco2 and SW480 human colon cancer cell lines were treated with increasing concentrations of GSEs to evaluate cell proliferation and motility. SCD1 levels were evaluated in both treated cell lines, by membrane lipidomic analysis conducted by gas chromatography. The expression levels of SCD1 and other factors involved in the reorganization of the cytoskeleton and focal adhesions were assessed by Real-time PCR, Western Blotting, and Immunofluorescence staining. High-performance liquid chromatography (HPLC) analyses were performed to determine the phenolic composition in the GSEs, finding them more expressed in Autumn Royal than in Egnatia. Both treatments reduced the levels of SCD1, phospho-Rac1/Cdc42/Rac1/Cdc42 ratio, Cofilin, Vimentin, and phospho-Paxillin especially in Caco2 compared to SW480, showing a different behavior of the two cell lines to these natural compounds. Our findings show that GSEs block the cell migration and membrane fluidity through a new mechanism of action involving structural cellular components.
Assuntos
Inibidores Enzimáticos/farmacologia , Fluidez de Membrana/efeitos dos fármacos , Extratos Vegetais/farmacologia , Estearoil-CoA Dessaturase/antagonistas & inibidores , Vitis/química , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Neoplasias do Colo , Inibidores Enzimáticos/química , Humanos , Extratos Vegetais/química , Polifenóis/química , Polifenóis/farmacologiaRESUMO
BACKGROUND/AIM: The expression of cannabinoid receptor-1 (CB1-R) seems to be modulated by bioactive natural components such as the flavonoid quercetin. The aim of this study was to determine in an animal model of induced-colon cancer, whether quercetin inhibits colon carcinogenesis through changes in the expression of CB1-R. MATERIALS AND METHODS: C57BL/6J male mice were randomly assigned to standard diet or experimental diet supplemented with 0.5% quercetin. Azoxymethane (AOM) (10 mg/kg body weight) or saline solution (PBS) was intraperitoneally injected, once weekly for 6 weeks. RESULTS: The diet supplemented with quercetin induced CB1-R gene expression and protein, inhibiting the protein levels of STAT3 and p-STAT3 (both mediators of cell proliferation). Dietary quercetin also caused a significant increase in Bax/Bcl2 ratio protein expression. CONCLUSION: The anti-proliferative and pro-apoptotic effects of quercetin in AOM-treated mice are mediated by induction of the protein and gene expression levels of CB1-R.
Assuntos
Azoximetano/farmacologia , Quercetina/farmacologia , Receptor CB1 de Canabinoide/metabolismo , Regulação para Cima/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Carcinogênese/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/metabolismo , Dieta , Suplementos Nutricionais , Flavonoides/farmacologia , Expressão Gênica/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteína X Associada a bcl-2/metabolismoRESUMO
The statins, inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCoAR) and orlistat, an inhibitor of fatty acid synthase (FAS), inhibit tumor cell growth by restricting cholesterol and fatty acid synthesis, respectively. We previously demonstrated that an omega (ω)-3 polyunsaturated fatty acid (PUFA)- or olive oil-enriched diet reduced the polyp number and volume in ApcMin/+ mice. This phenomenon was associated with a significant inhibition of FAS and HMGCoAR, as well as an increase in the estrogen receptor (ER)ß/α ratio. Herein, we evaluated the effect of lovastatin and orlistat on polyp development and ER expression in ApcMin/+ mice, in order to confirm previous data obtained with ω3-PUFAs and olive oil. As expected, the use of lovastatin and orlistat significantly reduced HMGCoAR and FAS enzymatic activities and gene expression in colonic tissues, but did not affect the number of intestinal polyps, while there was a statistically significant reduction in polyp volume only in the mouse group treated with lovastatin. In the mice receiving orlistat, we observed a significant increase in cell proliferation in the polyp tissue, as well as enhanced expression of ERα. Moreover, the overexpression of ERα was associated with a statistically significant increase in PES1, Shh and Gli1 protein levels, considered ERα-related molecular targets.
Assuntos
Pólipos Intestinais/tratamento farmacológico , Lactonas/farmacologia , Lovastatina/farmacologia , Animais , Proteínas de Ciclo Celular , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Modelos Animais de Doenças , Receptor alfa de Estrogênio/genética , Receptor beta de Estrogênio/genética , Ácido Graxo Sintases/genética , Ácidos Graxos Ômega-3/administração & dosagem , Expressão Gênica/efeitos dos fármacos , Proteínas Hedgehog/genética , Pólipos Intestinais/genética , Camundongos , Azeite de Oliva/administração & dosagem , Orlistate , Proteínas/genética , Proteínas de Ligação a RNA , Proteína GLI1 em Dedos de Zinco/genéticaRESUMO
AIM: To assess the safety and effect of the supplementation of a patented blend of dietary phytoestrogens and insoluble fibers on estrogen receptor (ER)-ß and biological parameters in sporadic colonic adenomas. METHODS: A randomized, double-blind placebo-controlled trial was performed. Patients scheduled to undergo surveillance colonoscopy for previous sporadic colonic adenomas were identified, and 60 eligible patients were randomized to placebo or active dietary intervention (ADI) twice a day, for 60 d before surveillance colonoscopy. ADI was a mixture of 175 mg milk thistle extract, 20 mg secoisolariciresinol and 750 mg oat fiber extract. ER-ß and ER-α expression, apoptosis and proliferation (Ki-67 LI) were assessed in colon samples. RESULTS: No adverse event related to ADI was recorded. ADI administration showed a significant increases in ER-ß protein (0.822 ± 0.08 vs 0.768 ± 0.10, P = 0.04) and a general trend to an increase in ER-ß LI (39.222 ± 2.69 vs 37.708 ± 5.31, P = 0.06), ER-ß/ER-α LI ratio (6.564 ± 10.04 vs 2.437 ± 1.53, P = 0.06), terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (35.592 ± 14.97 vs 31.541 ± 11.54, P = 0.07) and Ki-67 (53.923 ± 20.91 vs 44.833 ± 10.38, P = 0.07) approximating statistical significance. A significant increase of ER-ß protein (0.805 ± 0.13 vs 0.773 ± 0.13, P = 0.04), mRNA (2.278 ± 1.19 vs 1.105 ± 1.07, P < 0.02) and LI (47.533 ± 15.47 vs 34.875 ± 16.67, P < 0.05) and a decrease of ER-α protein (0.423 ± 0.06 vs 0.532 ± 0.11, P < 0.02) as well as a trend to increase of ER-ß/ER-α protein in ADI vs placebo group were observed in patients without polyps (1.734 ± 0.20 vs 1.571 ± 0.42, P = 0.07). CONCLUSION: The role of ER-ß on the control of apoptosis, and its amenability to dietary intervention, are supported in our study.
Assuntos
Adenoma/metabolismo , Neoplasias do Colo/metabolismo , Pólipos do Colo/metabolismo , Suplementos Nutricionais , Receptor beta de Estrogênio/metabolismo , Fitoestrógenos/química , Adenoma/diagnóstico , Idoso , Apoptose , Biomarcadores/metabolismo , Biópsia , Proliferação de Células , Neoplasias do Colo/diagnóstico , Pólipos do Colo/diagnóstico , Colonoscopia , Dieta , Método Duplo-Cego , Receptor alfa de Estrogênio/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Marcação In Situ das Extremidades Cortadas , Masculino , Microscopia de Fluorescência , Pessoa de Meia-IdadeRESUMO
Most sporadic colorectal cancers (CRCs) develop through the adenoma-carcinoma sequence pathway and are initiated by adenomatous polyposis coli (APC) gene mutations. Estrogen receptor beta (ERbeta) is recognized to progressively reduce its expression in adenomatous and carcinomatous tissues in humans. Moreover, ERbeta deficiency enhances small intestinal tumorigenesis in rodents. In the Apc(Min/+) mouse model, we evaluated intestinal polyp development and ERbeta expression plus other biological parameters influencing tumor growth (epithelial cell proliferation, apoptosis and migration) following the addition of a combination of the ERbeta-selective agonist silymarin (SIL) and/or lignin (LIG) to a high-fat/low-fiber diet. Forty-five Apc(Min/+) mice were divided in four groups: animals fed on the tumorigenic high-fat/low-fiber diet, the tumorigenic diet supplemented with SIL (0.02%) or purified LIG (6.24%) or SIL (0.005%) + LIG (6.24%). In these animals, we assessed polyp number and volume and their degree of dysplasia together with ERbeta messenger RNA (mRNA) and protein levels and epithelial cell proliferation, migration and apoptosis. The latter group of parameters was evaluated in normal and adenomatous mucosa and the results compared with those found in wild-type (WT) mice fed on the control diet. The addition of SIL or LIG to the diet and even more the specific combination of the two significantly counteracted intestinal tumorigenesis and increased ERbeta mRNA and protein levels. Cell proliferation and apoptosis were rebalanced and cell migration accelerated, restoring values similar to those observed in WT animals. Our results further support a protective effect of ERbeta in CRC suggesting the use of the combination of SIL-LIG as a potential approach against CRC development.