RESUMO
This report describes a dog that developed erythema multiforme in temporal association with administration of the sulphonamide-based anticonvulsant drug zonisamide. Similar adverse drug reactions have been associated with sulphonamide antimicrobial drugs. Caution should be exercised when prescribing this medication for dogs with known hypersensitivity to sulphonamides.
Assuntos
Anticonvulsivantes/efeitos adversos , Doenças do Cão/induzido quimicamente , Eritema Multiforme/veterinária , Isoxazóis/efeitos adversos , Animais , Doenças do Cão/patologia , Cães , Epilepsia/tratamento farmacológico , Epilepsia/veterinária , Eritema Multiforme/induzido quimicamente , Eritema Multiforme/patologia , Masculino , Pele/patologia , ZonisamidaRESUMO
BACKGROUND: Treatment with intravenous enzyme replacement therapy and hematopoietic stem cell transplantation for mucopolysaccharidosis (MPS) type I does not address joint disease, resulting in persistent orthopedic complications and impaired quality of life. A proof-of-concept study was conducted to determine the safety, tolerability, and efficacy of intra-articular recombinant human iduronidase (IA-rhIDUA) enzyme replacement therapy in the canine MPS I model. METHODS: Four MPS I dogs underwent monthly rhIDUA injections (0.58 mg/joint) into the right elbow and knee for 6 months. Contralateral elbows and knees concurrently received normal saline. No intravenous rhIDUA therapy was administered. Monthly blood counts, chemistries, anti-rhIDUA antibody titers, and synovial fluid cell counts were measured. Lysosomal storage of synoviocytes and chondrocytes, synovial macrophages and plasma cells were scored at baseline and 1 month following the final injection. RESULTS: All injections were well-tolerated without adverse reactions. One animal required prednisone for spinal cord compression. There were no clinically significant abnormalities in blood counts or chemistries. Circulating anti-rhIDUA antibody titers gradually increased in all dogs except the prednisone-treated dog; plasma cells, which were absent in all baseline synovial specimens, were predominantly found in synovium of rhIDUA-treated joints at study-end. Lysosomal storage in synoviocytes and chondrocytes following 6 months of IA-rhIDUA demonstrated significant reduction compared to tissues at baseline, and saline-treated tissues at study-end. Mean joint synovial GAG levels in IA-rhIDUA joints were 8.62 ± 5.86 µg/mg dry weight and 21.6 ± 10.4 µg/mg dry weight in control joints (60% reduction). Cartilage heparan sulfate was also reduced in the IA-rhIDUA joints (113 ± 39.5 ng/g wet weight) compared to saline-treated joints (142 ± 56.4 ng/g wet weight). Synovial macrophage infiltration, which was present in all joints at baseline, was abolished in rhIDUA-treated joints only. CONCLUSIONS: Intra-articular rhIDUA is well-tolerated and safe in the canine MPS I animal model. Qualitative and quantitative assessments indicate that IA-rhIDUA successfully reduces tissue and cellular GAG storage in synovium and articular cartilage, including cartilage deep to the articular surface, and eliminates inflammatory macrophages from synovial tissue. CLINICAL RELEVANCE: The MPS I canine IA-rhIDUA results suggest that clinical studies should be performed to determine if IA-rhIDUA is a viable approach to ameliorating refractory orthopedic disease in human MPS I.
Assuntos
Cartilagem Articular/patologia , Terapia de Reposição de Enzimas , Glicosaminoglicanos/metabolismo , Iduronidase/efeitos adversos , Iduronidase/uso terapêutico , Mucopolissacaridose I/tratamento farmacológico , Mucopolissacaridose I/metabolismo , Animais , Anticorpos/sangue , Cartilagem Articular/efeitos dos fármacos , Cartilagem Articular/ultraestrutura , Condrócitos/metabolismo , Condrócitos/ultraestrutura , Modelos Animais de Doenças , Cães , Humanos , Iduronidase/imunologia , Plasmócitos/metabolismo , Proteínas Recombinantes/uso terapêutico , Líquido Sinovial/metabolismo , Membrana Sinovial/patologia , Resultado do TratamentoRESUMO
Folate metabolism affects DNA synthesis, methylation, mutation rates, genomic stability, and gene expression, which are altered in colon cancer. Serine hydroxymethyltransferase 1 (SHMT1) regulates thymidylate (dTMP) biosynthesis and uracil accumulation in DNA, and as such affects genome stability. Previously, we showed that decreased SHMT1 expression in Shmt1 knockout mice (Shmt1(-/+)) or its impaired nuclear localization, as occurs in mice over-expressing an Shmt1 transgene (Shmt1(tg+)), results in elevated uracil incorporation into DNA, which could affect colon cancer risk. We used these 2 models to determine the effect of altered SHMT1 expression and localization, and its interaction with folate insufficiency, on azoxymethane (AOM)-induced colon cancer in mice. Shmt1(-/+) and Shmt1(tg+) mice were weaned to a control or folate-and-choline-deficient (FCD) diet and fed the diet for 28 or 32 wk, respectively. At 6 wk of age, mice were injected weekly for 6 wk with 10 mg/kg AOM (w/v in saline). Colon uracil concentrations in nuclear DNA were elevated 2-7 fold in Shmt1(-/+) and Shmt1(tg+) mice. However, colon tumor incidence and numbers were not dependent on SHMT1 expression in Shmt1(-/+) or Shmt1(-/-) mice. The FCD diet reduced tumor load independent of Shmt1 genotype. In contrast, Shmt1(tg+) mice exhibited a 30% reduction in tumor incidence, a 50% reduction in tumor number, and a 60% reduction in tumor load compared with wild-type mice independent of dietary folate intake. Our data indicate that uracil accumulation in DNA does not predict tumor number in AOM-mediated carcinogenesis. Furthermore, enrichment of SHMT1 in the cytoplasm, as observed in Shmt1(tg+) mice, protects against AOM-mediated carcinogenesis independent of its role in nuclear de novo dTMP biosynthesis.
Assuntos
Carcinogênese/metabolismo , Colo/metabolismo , Neoplasias do Colo/metabolismo , DNA/metabolismo , Modelos Animais de Doenças , Ácido Fólico/metabolismo , Timidina Monofosfato/metabolismo , Animais , Azoximetano , Deficiência de Colina/fisiopatologia , Colo/enzimologia , Colo/patologia , Neoplasias do Colo/patologia , Neoplasias do Colo/prevenção & controle , Cruzamentos Genéticos , Proteínas da Matriz Extracelular/genética , Proteínas da Matriz Extracelular/metabolismo , Ácido Fólico/efeitos adversos , Deficiência de Ácido Fólico/fisiopatologia , Glicina Hidroximetiltransferase/biossíntese , Glicina Hidroximetiltransferase/genética , Glicina Hidroximetiltransferase/metabolismo , Masculino , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Proteínas de Neoplasias/biossíntese , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Proteína-Lisina 6-Oxidase/genética , Proteína-Lisina 6-Oxidase/metabolismo , Distribuição Aleatória , Carga Tumoral , Uracila/metabolismoRESUMO
BACKGROUND: Zyflamend, a mixture containing extracts of ten herbs, has shown promise in a variety of preclinical cancer models, including prostate cancer. The current experiments were designed to investigate the effects of Zyflamend on the expression of class I and II histone deacetylases, a family of enzymes known to be over expressed in a variety of cancers. METHODS: CWR22Rv1 cells, a castrate-resistant prostate cancer cell line, were treated with Zyflamend and the expression of class I and II histone deacetylases, along with their downstream target the tumor suppressor gene p21, was investigated. Involvement of p21 was confirmed with siRNA knockdown and over expression experiments. RESULTS: Zyflamend down-regulated the expression of all class I and II histone deacetylases where Chinese goldthread and baikal skullcap (two of its components) appear to be primarily responsible for these results. In addition, Zyflamend up regulated the histone acetyl transferase complex CBP/p300, potentially contributing to the increase in histone 3 acetylation. Expression of the tumor suppressor gene p21, a known downstream target of histone deacetylases and CBP/p300, was increased by Zyflamend treatment and the effect on p21 was, in part, mediated through Erk1/2. Knockdown of p21 with siRNA technology attenuated Zyflamend-induced growth inhibition. Over expression of p21 inhibited cell growth and concomitant treatment with Zyflamend enhanced this effect. CONCLUSIONS: Our results suggest that the extracts of this polyherbal combination increase histone 3 acetylation, inhibit the expression of class I and class II histone deacetylases, increase the activation of CBP/p300 and inhibit cell proliferation, in part, by up regulating p21 expression.
Assuntos
Coptis , Histona Desacetilases/metabolismo , Fitoterapia , Extratos Vegetais/farmacologia , Neoplasias da Próstata/metabolismo , Scutellaria , Proteínas Supressoras de Tumor/metabolismo , Acetilação , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Regulação para Baixo , Histonas/metabolismo , Humanos , Masculino , Extratos Vegetais/uso terapêutico , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/genética , RNA Interferente Pequeno/metabolismo , Ativação Transcricional , Proteínas Supressoras de Tumor/efeitos dos fármacos , Regulação para Cima , Fatores de Transcrição de p300-CBP/metabolismoRESUMO
Prostate cancer (PrC) is the second deadliest cancer of males in the United States Hormone deprivation therapy (HDT), a common therapy for advanced forms of the disease, results in tumor regression; unfortunately, tumors inevitably become castrate-resistant. Diet is not an appropriate primary therapy for refractory forms of the disease; however, diet may be effective as an adjuvant to HDT, potentially extending the latency period and delaying relapse and/or inhibiting refractory growth. Zyflamend® is a combination of extracts from multiple herbs, each with reported anticancer properties. Zyflamend can inhibit growth of various PrC cell lines, but no studies have investigated its potential use in vivo using a model of castrate-resistant PrC. In this study, oral doses of Zyflamend at human equivalent doses inhibited androgen-dependent and castrate-resistant tumor growth in a mouse model that mimics advanced stages of the disease, and reduced the expression of a number of biomarkers linked to PrC progression including pAKT, prostate specific antigen, histone deacetylases, and androgen receptor. In summary, this is the first article to report that Zyflamend, when provided at human equivalent doses, can potentiate the effects of hormone deprivation on tumor regression and growth inhibition of androgen-dependent and castrate-resistant PrC tumors in vivo.
Assuntos
Antineoplásicos Fitogênicos/uso terapêutico , Suplementos Nutricionais , Extratos Vegetais/uso terapêutico , Neoplasias da Próstata/dietoterapia , Animais , Castração , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Histona Desacetilases/genética , Histona Desacetilases/metabolismo , Humanos , Masculino , Camundongos , Camundongos Nus , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Neoplasias da Próstata/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Distribuição Aleatória , Receptores Androgênicos/genética , Receptores Androgênicos/metabolismo , Testosterona/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The causal metabolic pathways underlying associations between folate and risk for colorectal cancer (CRC) have yet to be established. Folate-mediated one-carbon metabolism is required for the de novo synthesis of purines, thymidylate and methionine. Methionine is converted to S-adenosylmethionine (AdoMet), the major one-carbon donor for cellular methylation reactions. Impairments in folate metabolism can modify DNA synthesis, genomic stability and gene expression, characteristics associated with tumorigenesis. The Mthfd1 gene product, C1-tetrahydrofolate synthase, is a trifunctional enzyme that generates one-carbon substituted tetrahydrofolate cofactors for one-carbon metabolism. In this study, we use Mthfd1(gt/+) mice, which demonstrate a 50% reduction in C1-tetrahydrofolate synthase, to determine its influence on tumor development in two mouse models of intestinal cancer, crosses between Mthfd1(gt/+) and Apc(min)(/+) mice and azoxymethane (AOM)-induced colon cancer in Mthfd1(gt/+) mice. Mthfd1 hemizygosity did not affect colon tumor incidence, number or load in Apc(min/+) mice. However, Mthfd1 deficiency increased tumor incidence 2.5-fold, tumor number 3.5-fold and tumor load 2-fold in AOM-treated mice. DNA uracil content in the colon was lower in Mthfd1(gt/+) mice, indicating that thymidylate biosynthesis capacity does not play a significant role in AOM-induced colon tumorigenesis. Mthfd1 deficiency-modified cellular methylation potential, as indicated by the AdoMet: S-adenosylhomocysteine ratio and gene expression profiles, suggesting that changes in the transcriptome and/or decreased de novo purine biosynthesis and associated mutability cause cellular transformation in the AOM CRC model. This study emphasizes the impact and complexity of gene-nutrient interactions with respect to the relationships among folate metabolism and colon cancer initiation and progression.
Assuntos
Aminoidrolases/fisiologia , Neoplasias do Colo/genética , DNA de Neoplasias/metabolismo , Formiato-Tetra-Hidrofolato Ligase/fisiologia , Meteniltetra-Hidrofolato Cicloidrolase/fisiologia , Metilenotetra-Hidrofolato Desidrogenase (NADP)/fisiologia , Complexos Multienzimáticos/fisiologia , Enzimas Multifuncionais/fisiologia , S-Adenosil-Homocisteína/metabolismo , S-Adenosilmetionina/metabolismo , Aminoidrolases/genética , Animais , Apoptose , Azoximetano/toxicidade , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Western Blotting , Carcinógenos/toxicidade , Proliferação de Células , Neoplasias do Colo/induzido quimicamente , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Modelos Animais de Doenças , Feminino , Formiato-Tetra-Hidrofolato Ligase/genética , Perfilação da Expressão Gênica , Técnicas Imunoenzimáticas , Masculino , Meteniltetra-Hidrofolato Cicloidrolase/genética , Metilenotetra-Hidrofolato Desidrogenase (NADP)/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Complexos Multienzimáticos/genética , Enzimas Multifuncionais/genética , Análise de Sequência com Séries de Oligonucleotídeos , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Uracila/metabolismoRESUMO
Mucopolysaccharidosis-I (MPS-I) is an inherited deficiency of α-L-iduronidase (IdU) that causes lysosomal accumulation of glycosaminoglycans (GAG) in a variety of parenchymal cell types and connective tissues. The fundamental link between genetic mutation and tissue GAG accumulation is clear, but relatively little attention has been given to the morphology or pathogenesis of associated lesions, particularly those affecting the vascular system. The terminal parietal branches of the abdominal aorta were examined from a colony of dogs homozygous (MPS-I affected) or heterozygous (unaffected carrier) for an IdU mutation that eliminated all enzyme activity, and in affected animals treated with human recombinant IdU. High-resolution computed tomography showed that vascular wall thickenings occurred in affected animals near branch points, and associated with low endothelial shear stress. Histologically these asymmetric 'plaques' entailed extensive intimal thickening with disruption of the internal elastic lamina, occluding more than 50% of the vascular lumen in some cases. Immunohistochemistry was used to show that areas of sclerosis contained foamy (GAG laden) macrophages, fibroblasts and smooth muscle cells, with loss of overlying endothelial basement membrane and claudin-5 expression. Lesions contained scattered cells expressing nuclear factor-κß (p65), increased fibronectin and transforming growth factor ß-1 signaling (with nuclear Smad3 accumulation) in comparison to unaffected vessels. Intimal lesion development and morphology was improved by intravenous recombinant enzyme treatment, particularly with immune tolerance to this exogenous protein. The progressive sclerotic vasculopathy of MPS-I shares some morphological and molecular similarities to atherosclerosis, including formation in areas of low shear stress near branch points, and can be reduced or inhibited by intravenous administration of recombinant IdU.
Assuntos
Artérias/patologia , Mucopolissacaridose I/veterinária , Doenças Vasculares/veterinária , Animais , Cães , Feminino , Humanos , Iduronidase/administração & dosagem , Iduronidase/genética , Iduronidase/uso terapêutico , Imuno-Histoquímica , Masculino , Mucopolissacaridose I/genética , Mucopolissacaridose I/patologia , Mucopolissacaridose I/terapia , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/genética , Proteínas Recombinantes/uso terapêutico , Tomografia Computadorizada por Raios X , Doenças Vasculares/genética , Doenças Vasculares/patologia , Doenças Vasculares/terapiaRESUMO
Mucopolysaccharidoses (MPSs) are lysosomal storage diseases caused by a deficit in the enzymes needed for glycosaminoglycan (GAG) degradation. Enzyme replacement therapy with recombinant human alpha-L-iduronidase successfully reduces lysosomal storage in canines and humans with iduronidase-deficient MPS I, but therapy usually also induces antibodies specific for the recombinant enzyme that could reduce its efficacy. To understand the potential impact of alpha-L-iduronidase-specific antibodies, we studied whether inducing antigen-specific immune tolerance to iduronidase could improve the effectiveness of recombinant iduronidase treatment in canines. A total of 24 canines with MPS I were either tolerized to iduronidase or left nontolerant. All canines received i.v. recombinant iduronidase at the FDA-approved human dose or a higher dose for 9-44 weeks. Nontolerized canines developed iduronidase-specific antibodies that proportionally reduced in vitro iduronidase uptake. Immune-tolerized canines achieved increased tissue enzyme levels at either dose in most nonreticular tissues and a greater reduction in tissue GAG levels, lysosomal pathology, and urinary GAG excretion. Tolerized MPS I dogs treated with the higher dose received some further benefit in the reduction of GAGs in tissues, urine, and the heart valve. Therefore, immune tolerance to iduronidase improved the efficacy of enzyme replacement therapy with recombinant iduronidase in canine MPS I and could potentially improve outcomes in patients with MPS I and other lysosomal storage diseases.
Assuntos
Iduronidase/uso terapêutico , Tolerância Imunológica , Doenças por Armazenamento dos Lisossomos/tratamento farmacológico , Mucopolissacaridose I/tratamento farmacológico , Animais , Azatioprina/farmacologia , Ciclosporina/farmacologia , Modelos Animais de Doenças , Cães , Relação Dose-Resposta a Droga , Glicosaminoglicanos/metabolismo , Glicosaminoglicanos/urina , Humanos , Iduronidase/genética , Iduronidase/metabolismo , Iduronidase/farmacologia , Imunossupressores/farmacologia , Rim/efeitos dos fármacos , Rim/metabolismo , Doenças por Armazenamento dos Lisossomos/patologia , Lisossomos/efeitos dos fármacos , Lisossomos/metabolismo , Lisossomos/patologia , Valva Mitral/efeitos dos fármacos , Valva Mitral/metabolismo , Mucopolissacaridose I/patologia , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/farmacologia , Proteínas Recombinantes/uso terapêutico , Membrana Sinovial/efeitos dos fármacos , Membrana Sinovial/metabolismo , Fatores de TempoRESUMO
Prostate cancer is the most commonly diagnosed solid malignancy, and tumor cells eventually transform to castrate resistance through multiple pathways including activation of the androgen receptor via insulin-like growth factor receptor (IGF-1R) signaling involving phospho-AKT (pAKT). In this study, a mixture of herbal extracts, Zyflamend®, was used as a treatment in a model of castrate-resistant prostate cancer using CWR22Rv1 cells. Zyflamend reduced androgen receptor and IGF-1R expression along with a reduction of IGF-1-mediated proliferation of CWR22Rv1 cells. IGF-1 induced downstream AKT phosphorylation; however, the induction of pAKT was not associated with androgen receptor expression. Further, constitutively active form of AKT had no effect on nuclear expression of androgen receptor, indicating that upregulation of pAKT did not promote androgen receptor expression or nuclear translocation in castrate-resistant CWR22Rv1 cells. Conversely, Zyflamend reduced androgen receptor expression following IGF-1 stimulation and in cells overexpressing pAKT. These results demonstrated that Zyflamend inhibited IGF-1-stimulated cell growth, IGF-1R expression, and androgen receptor expression and its nuclear localization, but these effects were not dependent upon phosphatidylinositol 3-kinase/pAKT signaling. In conclusion, Zyflamend decreased cell proliferation and inhibited IGF-1R and androgen receptor expression in a phosphatidylinositol 3-kinase/pAKT independent manner.
Assuntos
Proliferação de Células , Extratos Vegetais/farmacologia , Receptor IGF Tipo 1/metabolismo , Receptores Androgênicos/metabolismo , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Fator de Crescimento Insulin-Like I/metabolismo , Masculino , Fosfatidilinositol 3-Quinase/genética , Fosfatidilinositol 3-Quinase/metabolismo , Fosforilação , Neoplasias da Próstata/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptor Cross-Talk , Receptor IGF Tipo 1/antagonistas & inibidores , Receptor IGF Tipo 1/genética , Receptores Androgênicos/genética , Transdução de Sinais/efeitos dos fármacos , Regulação para CimaRESUMO
Enzyme replacement therapy (ERT) with intravenous recombinant human alpha-l-iduronidase (IV rhIDU) is a treatment for patients with mucopolysaccharidosis I (MPS I). Spinal cord compression develops in MPS I patients due in part to dural and leptomeningeal thickening from accumulated glycosaminoglycans (GAG). We tested long-term and every 3-month intrathecal (IT) and weekly IV rhIDU in MPS I dogs age 12-15months (Adult) and MPS I pups age 2-23days (Early) to determine whether spinal cord compression could be reversed, stabilized, or prevented. Five treatment groups of MPS I dogs were evaluated (n=4 per group): IT+IV Adult, IV Adult, IT + IV Early, 0.58mg/kg IV Early and 1.57mg/kg IV Early. IT + IV rhIDU (Adult and Early) led to very high iduronidase levels in cervical, thoracic, and lumber spinal meninges (3600-29,000% of normal), while IV rhIDU alone (Adult and Early) led to levels that were 8.2-176% of normal. GAG storage was significantly reduced from untreated levels in spinal meninges of IT + IV Early (p<.001), IT+IV Adult (p=.001), 0.58mg/kg IV Early (p=.002) and 1.57mg/kg IV Early (p<.001) treatment groups. Treatment of dogs shortly after birth with IT+IV rhIDU (IT + IV Early) led to normal to near-normal GAG levels in the meninges and histologic absence of storage vacuoles. Lysosomal storage was reduced in spinal anterior horn cells in 1.57mg/kg IV Early and IT + IV Early animals. All dogs in IT + IV Adult and IV Adult groups had compression of their spinal cord at 12-15months of age determined by magnetic resonance imaging and was due to protrusion of spinal disks into the canal. Cord compression developed in 3 of 4 dogs in the 0.58mg/kg IV Early group; 2 of 3 dogs in the IT + IV Early group; and 0 of 4 dogs in the 1.57mg/kg IV Early group by 12-18months of age. IT + IV rhIDU was more effective than IV rhIDU alone for treatment of meningeal storage, and it prevented meningeal GAG accumulation when begun early. High-dose IV rhIDU from birth (1.57mg/kg weekly) appeared to prevent cord compression due to protrusion of spinal disks.
Assuntos
Terapia de Reposição de Enzimas/veterinária , Iduronidase/uso terapêutico , Mucopolissacaridose I/tratamento farmacológico , Mucopolissacaridose I/veterinária , Compressão da Medula Espinal/tratamento farmacológico , Compressão da Medula Espinal/veterinária , Animais , Cães , Humanos , Injeções Espinhais , Imageamento por Ressonância Magnética/veterinária , Medula Espinal/patologia , Compressão da Medula Espinal/patologiaRESUMO
BACKGROUND & AIMS: Green tea catechins are known to have anticarcinogenic effects. Epigallocatechin-3-gallate (EGCG) accounts for almost 50% of the total catechin content in green tea extract and has very potent antioxidant effects. EGCG also inhibits angiogenesis, possibly through the inhibition of proangiogenic factors including vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF), which in turn, inhibits tumor growth and metastasis. However, the exact molecular mechanism by which EGCG suppresses bFGF expression is not known. Our objective was to elucidate the molecular mechanisms by which EGCG inhibits bFGF expression in colorectal cancer. METHODS: We examined posttranslational regulation of bFGF by EGCG in human colorectal cancer cells. We also examined bFGF in intestinal tumor formation of APC(Min/+) mice with and without catechin treatment. RESULTS: The bFGF protein was quickly degraded in the presence of EGCG, but a proteasome inhibitor suppressed this degradation. EGCG was also found to increase ubiquitination of bFGF and trypsin-like activity of the 20S proteasome, thereby resulting in the degradation of bFGF protein. Furthermore, EGCG suppressed tumor formation in APC(Min/+) mice, compared with vehicle-treated mice, in association with reduced bFGF expression. CONCLUSIONS: The ubiquitin-proteasome degradation pathway contributes significantly to down-regulation of bFGF expression by EGCG. Catechin compounds have fewer adverse effects than chemotherapeutic agents and hence can be used as proof-of-concept in cancer therapeutics to suppress growth and metastasis by targeting proteins such as bFGF.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Camellia sinensis , Catequina/análogos & derivados , Neoplasias Colorretais/tratamento farmacológico , Fator 2 de Crescimento de Fibroblastos/metabolismo , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Acetilcisteína/análogos & derivados , Acetilcisteína/farmacologia , Polipose Adenomatosa do Colo/genética , Polipose Adenomatosa do Colo/metabolismo , Polipose Adenomatosa do Colo/prevenção & controle , Animais , Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/uso terapêutico , Camellia sinensis/química , Catequina/isolamento & purificação , Catequina/farmacologia , Catequina/uso terapêutico , Transformação Celular Neoplásica/efeitos dos fármacos , Transformação Celular Neoplásica/metabolismo , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/prevenção & controle , Cicloeximida/farmacologia , Inibidores de Cisteína Proteinase/farmacologia , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Regulação para Baixo , Fator 2 de Crescimento de Fibroblastos/genética , Genes APC , Células HCT116 , Células HT29 , Humanos , Camundongos , Complexo de Endopeptidases do Proteassoma/metabolismo , Inibidores de Proteassoma , Inibidores da Síntese de Proteínas/farmacologia , Fatores de Tempo , TransfecçãoRESUMO
Hormone ablation therapy typically causes regression of prostate cancer and represents an important means of treating this disease, particularly after metastasis. However, hormone therapy inevitably loses its effectiveness as tumors become androgen-independent, and this conversion often leads to death because of subsequent poor responses to other forms of treatment. Because environmental factors, such as diet, have been strongly linked to prostate cancer, we examined the affects of dietary polyunsaturated fatty acids (PUFAs; at 1.5 wt%) on growth of androgen-dependent (CWR22) and androgen-independent (CWR22R) human prostatic cancer xenografts, the acute response of CWR22 tumors to ablation therapy, and their progression to androgen independence. Significant diet-induced changes in tumor n-3 or n-6 PUFA content had no affect on CWR22 or CWR22R tumors growing with or without androgen support, respectively. However, dietary changes that increased tumor eicosapentaenoic acid and linoleic acid content enhanced responses to ablation therapy, measured by cancer cell apoptosis and mitosis. In addition, relapse to androgen-independent growth (measured by renewed increases in tumor volume and serum prostate-specific antigen after ablation) positively correlated with tumor arachidonic acid content. There was no correlation between expression of 15-lipoxygenase isozymes or their products and tumor growth or responses to ablation. In conclusion, dietary n-3 PUFA may enhance the response of prostate cancer to ablation therapy and retard progression to androgen-independent growth by altering tumor PUFA content.
Assuntos
Gorduras Insaturadas na Dieta/uso terapêutico , Ácidos Graxos Insaturados/uso terapêutico , Neoplasias Hormônio-Dependentes/dietoterapia , Neoplasias da Próstata/dietoterapia , Antagonistas de Androgênios/uso terapêutico , Animais , Apoptose/fisiologia , Ácido Araquidônico/uso terapêutico , Western Blotting , Resistencia a Medicamentos Antineoplásicos/fisiologia , Eicosanoides/biossíntese , Ácido Eicosapentaenoico/uso terapêutico , Humanos , Ácido Linoleico/uso terapêutico , Masculino , Camundongos , Ácido Oleico/uso terapêutico , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Espectrometria de Massas por Ionização por Electrospray , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
A large body of studies has suggested that peroxisome proliferator-activated receptor gamma (PPARgamma) ligands, such as thiazolidinedione, are potent candidates for chemopreventive agents. MCC-555 is a PPARgamma/alpha dual agonist and has been shown previously to induce apoptosis in vitro; however, the molecular mechanisms by which MCC-555 affects antitumorigenesis in vivo are poorly understood. In this study, we explored the antitumorigenic effects of MCC-555 both in cell culture and in Apc-deficient mice, an animal model for human familial adenomatous polyposis. MCC-555 increased MUC2 expression in colorectal and lung cancer cells, and treatment with the PPARgamma antagonist GW9662 revealed that MUC2 induction by MCC-555 was mediated in a PPARgamma-dependent manner. Moreover, MCC-555 increased transcriptional activity of human and mouse MUC2 promoters. Subsequently, treatment with MCC-555 (30 mg/kg/d) for 4 weeks reduced the number of small intestinal polyps to 54.8% of that in control mice. In agreement with in vitro studies, enhanced Muc2 expression was observed in the small intestinal tumors of Min mice treated with MCC-555, suggesting that MUC2 expression may be associated at least in part with the antitumorigenic action of MCC-555. In addition, highly phosphorylated extracellular signal-regulated kinase (ERK) was found in the intestinal tumors of MCC-555-treated Min mice, and inhibition of the ERK pathway by a specific inhibitor markedly suppressed MCC-555-induced Muc2 expression in vitro. Overall, these results indicate that MCC-555 has a potent tumor suppressor activity in intestinal tumorigenesis, likely involving MUC2 up-regulation by ERK and PPARgamma pathways.
Assuntos
Proteína da Polipose Adenomatosa do Colo/deficiência , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Pólipos Intestinais/enzimologia , Pólipos Intestinais/patologia , Receptores Ativados por Proliferador de Peroxissomo/metabolismo , Tiazolidinedionas/farmacologia , Animais , Linhagem Celular Tumoral , Neoplasias Colorretais/enzimologia , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Ligantes , Neoplasias Pulmonares/genética , Camundongos , Camundongos Endogâmicos C57BL , Mucina-2 , Mucinas/genética , Mucinas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Tiazolidinedionas/química , Transcrição Gênica/efeitos dos fármacosRESUMO
The TALLYHO/JngJ (TH) strain is a newly established, polygenic mouse model for type 2 diabetes (T2D) and obesity, and we have previously reported some key physiological features of this model after the overt onset of diabetes. In the present work, we conducted a comprehensive phenotypic characterization of TH in order to completely characterize this new and relevant model for human T2D and obesity. We monitored the development of obesity and diabetes starting at 4 weeks of age by measuring body weight, glucose tolerance, and plasma levels of insulin, glucose, and triglyceride. Additionally, histological alterations in the pancreas and glucose uptake and glucose transporter 4 (GLUT4) content in soleus muscle were also examined. Compared with age- and sex-matched C57BL/6J (B6) mice, both male and female TH mice were significantly heavier, hyperleptinemic, and hyperinsulinemic at 4 weeks of age, without glucose intolerance or hyperglycemia. TH mice maintained higher body weights throughout the study period of 16 weeks. The hyperinsulinemia in TH mice worsened with age, but to a lesser degree in females than in males. Both the male and the female TH mice had enlarged pancreatic islets. Male TH mice showed impaired glucose tolerance at 8 weeks that became more prominent at 16 weeks. Plasma glucose levels continuously increased with age in male TH mice resulting in frank diabetes, while female TH mice remained normoglycemic throughout the study. Impaired glucose tolerance and hyperglycemia in male TH mice were accompanied by impaired 2-deoxyglucose uptake in the soleus muscle at basal and insulin-stimulated states, but without any reduction in GLUT4 content. Interestingly, male TH mice exhibited a drastic elevation in plasma triglyceride levels in the pre-diabetic stage that was maintained throughout the study. These findings suggest that obesity and insulin resistance are an inherent part of the TH phenotype and glucose intolerance is evident preceding progression to overt diabetes in male TH mice.
Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Camundongos Endogâmicos/metabolismo , Animais , Glicemia/análise , Western Blotting/métodos , Peso Corporal , Cruzamento , Colesterol/sangue , Desoxiglucose/metabolismo , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/patologia , Feminino , Teste de Tolerância a Glucose/veterinária , Transportador de Glucose Tipo 4/metabolismo , Insulina/sangue , Masculino , Camundongos , Músculo Esquelético/metabolismo , Pâncreas/patologia , Fenótipo , Fatores de Tempo , Triglicerídeos/sangueRESUMO
Nonsteroidal anti-inflammatory drugs (NSAIDs) are antitumorigenic in humans as well as in animal models of intestinal neoplasia, such as the adenomatous polyposis coli (Min/+) (Apc(Min/+)) mouse. NSAIDs inhibit cyclooxygenase (COX) isozymes, which are responsible for the committed step in prostaglandin biosynthesis, and this has been considered the primary mechanism by which NSAIDs exert their antitumorigenic effects. However, mounting evidence suggests the existence of COX-independent mechanisms. In the present study, we attempted to clarify this issue by treating Apc(Min/+) mice bearing established tumors with NSAIDs (piroxicam and sulindac, 0.5 and 0.6 mg/mouse/day, respectively) for 6 days and concomitantly bypassing COX inhibition by treatment with the E prostaglandin (EP) receptor agonists 16,16-dimethyl-prostaglandin E(2) (PGE(2)) and 17-phenyl-trinor-PGE(2) (10 microg each, three times daily) administered via gavage and/or i.p. routes. Treatment with piroxicam and sulindac resulted in 95% and 52% fewer tumors, respectively, and a higher ratio of apoptosis:mitosis in tumors from sulindac-treated mice as compared with controls. These effects were attenuated by concomitant EP receptor agonist treatment, suggesting PGE(2) is important in the maintenance of tumor integrity. Immunological sequestration of PGE(2) with an anti-PGE(2) monoclonal antibody likewise resulted in 33% fewer tumors in Apc(Min/+) mice relative to untreated controls, additionally substantiating a role for PGE(2) in tumorigenesis. The EP receptor subtype EP1 mediates the effects of PGE(2) by increasing intracellular calcium levels ([Ca(2+)](i)), whereas antagonism of EP1 has been shown to attenuate tumorigenesis in Apc(Min/+) mice. We demonstrate that [Ca(2+)](i) is significantly elevated in tumors of Apc(Min/+) mice relative to the adjacent normal-appearing mucosa. Furthermore, treatment with piroxicam results in significantly lower [Ca(2+)](i) in tumors, and this effect is attenuated by concomitant treatment with the EP1/EP3 receptor agonist 17-phenyl-trinor-PGE(2). Overall, our results suggest that NSAIDs exert their antitumorigenic effects, in part, via interference with PGE(2) biosynthesis, and these effects may be mediated through changes in intracellular calcium levels.
Assuntos
16,16-Dimetilprostaglandina E2/farmacologia , Polipose Adenomatosa do Colo/tratamento farmacológico , Anti-Inflamatórios não Esteroides/antagonistas & inibidores , Dinoprostona/análogos & derivados , Dinoprostona/farmacologia , Polipose Adenomatosa do Colo/metabolismo , Polipose Adenomatosa do Colo/patologia , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Anticorpos Monoclonais/farmacologia , Apoptose/efeitos dos fármacos , Cálcio/metabolismo , Inibidores de Ciclo-Oxigenase/farmacologia , Dinoprostona/imunologia , Modelos Animais de Doenças , Interações Medicamentosas , Intestino Delgado/efeitos dos fármacos , Intestino Delgado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mitose/efeitos dos fármacos , Piroxicam/antagonistas & inibidores , Piroxicam/farmacologia , Receptores de Prostaglandina E/agonistas , Receptores de Prostaglandina E Subtipo EP1 , Receptores de Prostaglandina E Subtipo EP2 , Sulindaco/antagonistas & inibidores , Sulindaco/farmacologiaRESUMO
Cyclooxygenase (COX) inhibitors have antitumorigenic activity and increase the expression of the early growth response gene Egr-1, a tumor suppressor gene and transcription factor. In this study, we have investigated the gene regulatory and anti-invasive activity of two traditional nonsteroidal anti-inflammatory drugs (NSAID), sulindac sulfide and indomethacin. These compounds inhibited tumor cell invasion and induced Egr-1 expression in lung adenocarcinoma A549 cells. Overexpression of Egr-1 reduced cellular invasion in the Matrigel system, whereas suppression of Egr-1 by small interference RNA (siRNA) attenuated the inhibition of Matrigel invasion by these compounds, indicating that Egr-1 is responsible for the decrease in invasion reported following treatment with NSAIDs. Egr-1-overexpressing cells were analyzed for genes involved in invasion and metastasis. Thrombospondin-1 (TSP-1) an antiangiogenic and anti-invasion protein was up-regulated by Egr-1 overexpression, which was confirmed following treatment with sulindac sulfide. Furthermore, the induction of TSP-1 by sulindac sulfide was blocked by Egr-1 siRNA. When TSP-1 was sequestered by the addition of anti-TSP-1 antibody, the inhibition of invasion by sulindac sulfide was attenuated, indicating that TSP-1 is involved in the inhibition of invasion by NSAIDs. We used the Min mouse model to determine if sulindac sulfide would increase Egr-1 and TSP-1 in vivo, because this model is widely used to study the effects of NSAIDs on tumor formation. Treatment of Min mice with concentrations of sulindac sulfide that inhibit tumor formation increased the expression of Egr-1 and TSP-1 in colonic tissues and in the polyps of these mice. This is the first report suggesting that COX inhibitors suppress tumor cell invasion via TSP-1, which occurs downstream of Egr-1.
Assuntos
Adenocarcinoma/tratamento farmacológico , Neoplasias Colorretais/tratamento farmacológico , Inibidores de Ciclo-Oxigenase/farmacologia , Proteína 1 de Resposta de Crescimento Precoce/genética , Genes Supressores de Tumor/efeitos dos fármacos , Neoplasias Pulmonares/tratamento farmacológico , Trombospondina 1/biossíntese , Adenocarcinoma/genética , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Linhagem Celular Tumoral , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Proteína 1 de Resposta de Crescimento Precoce/biossíntese , Genes Supressores de Tumor/fisiologia , Humanos , Indometacina/farmacologia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Camundongos , Invasividade Neoplásica , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , Sulindaco/análogos & derivados , Sulindaco/farmacologia , Trombospondina 1/metabolismoRESUMO
Arachidonic acid is an important polyunsaturated fatty acid involved in cell signaling. It is derived primarily from dietary linoleic acid, and the rate-limiting step in its biosynthesis is the initial desaturation of linoleic acid via Delta-6 desaturase. Evidence suggests that downstream metabolic products of arachidonic acid, e.g. prostaglandins, are involved in colorectal cancer, but involvement of the biosynthetic pathway of arachidonic acid has not been previously investigated. In the present study, we report the effects of a novel selective Delta-6 desaturase inhibitor, SC-26196, on tumorigenesis in two in vivo models of intestinal cancer. SC-26196 treatment resulted in 36-37% fewer tumors in Apc(Min/+) mice and 35% decrease in primary tumor size in nude mice bearing HT-29 human colon cancer cell xenografts (P<0.05). As expected, SC-26196 treatment resulted in significantly higher linoleic acid levels in tissue phospholipids and lower levels of arachidonic acid. The effects on both tissue fatty acid composition and tumorigenesis in Apc(Min/+) mice were abrogated by concomitant treatment with dietary arachidonic acid, indicating that the observed effects were due to interference with the biosynthetic pathway of arachidonic acid.
Assuntos
Anticarcinógenos/farmacologia , Inibidores Enzimáticos/farmacologia , Ácidos Graxos Dessaturases/antagonistas & inibidores , Neoplasias Intestinais/prevenção & controle , Piperazinas/farmacologia , Animais , Linoleoil-CoA Desaturase , Masculino , Camundongos , Camundongos Endogâmicos C57BLRESUMO
The nonsteroidal anti-inflammatory drug tolfenamic acid has been shown to suppress cancer cell growth and tumorigenesis in different cancer models. However, the underlying mechanism by which tolfenamic acid exerts its antitumorigenic effect remains unclear. Previous data from our group and others indicate that tolfenamic acid alters expression of apoptosis- and cell-cycle arrest-related genes in colorectal cancer cells. Here, we show that tolfenamic acid markedly reduced the number of polyps and tumor load in APC(min)(/+) mice, accompanied with cyclin D1 downregulation in vitro and in vivo. Mechanistically, tolfenamic acid promotes endoplasmic reticulum (ER) stress, resulting in activation of the unfolded protein response (UPR) signaling pathway, of which PERK-mediated phosphorylation of eukaryotic translation initiation factor 2α (eIF2α) induces the repression of cyclin D1 translation. Moreover, the PERK-eIF2α-ATF4 branch of the UPR pathway plays a role in tolfenamic acid-induced apoptosis in colorectal cancer cells, as silencing ATF4 attenuates tolfenamic acid-induced apoptosis. Taken together, these results suggest ER stress is involved in tolfenamic acid-induced inhibition of colorectal cancer cell growth, which could contribute to antitumorigenesis in a mouse model.
Assuntos
Proteína da Polipose Adenomatosa do Colo/fisiologia , Anti-Inflamatórios não Esteroides/farmacologia , Transformação Celular Neoplásica/efeitos dos fármacos , Pólipos do Colo/tratamento farmacológico , Neoplasias Colorretais/tratamento farmacológico , Estresse do Retículo Endoplasmático/efeitos dos fármacos , ortoaminobenzoatos/farmacologia , Fator 4 Ativador da Transcrição/genética , Fator 4 Ativador da Transcrição/metabolismo , Animais , Western Blotting , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Pólipos do Colo/metabolismo , Pólipos do Colo/patologia , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Ciclina D1/genética , Ciclina D1/metabolismo , Humanos , Imunoprecipitação , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fosforilação/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais , Células Tumorais Cultivadas , Resposta a Proteínas não Dobradas/efeitos dos fármacos , eIF-2 Quinase/genética , eIF-2 Quinase/metabolismoRESUMO
The current world-wide epidemic of obesity has stimulated interest in developing simple screening methods to identify individuals with undiagnosed diabetes mellitus type 2 (DM2) or metabolic syndrome (MS). Prior work utilizing body composition obtained by sophisticated technology has shown that the ratio of abdominal fat to total fat is a good predictor for DM2 or MS. The goals of this study were to determine how well simple anthropometric variables predict the fat mass distribution as determined by dual energy x-ray absorptometry (DXA), and whether these are useful to screen for DM2 or MS within a population. To accomplish this, the body composition of 341 females spanning a wide range of body mass indices and with a 23% prevalence of DM2 and MS was determined using DXA. Stepwise linear regression models incorporating age, weight, height, waistline, and hipline predicted DXA body composition (i.e., fat mass, trunk fat, fat free mass, and total mass) with good accuracy. Using body composition as independent variables, nominal logistic regression was then performed to estimate the probability of DM2. The results show good discrimination with the receiver operating characteristic (ROC) having an area under the curve (AUC) of 0.78. The anthropometrically-derived body composition equations derived from the full DXA study group were then applied to a group of 1153 female patients selected from a general endocrinology practice. Similar to the smaller study group, the ROC from logistical regression using body composition had an AUC of 0.81 for the detection of DM2. These results are superior to screening based on questionnaires and compare favorably with published data derived from invasive testing, e.g., hemoglobin A1c. This anthropometric approach offers promise for the development of simple, inexpensive, non-invasive screening to identify individuals with metabolic dysfunction within large populations.
Assuntos
Absorciometria de Fóton/métodos , Antropometria/métodos , Composição Corporal/fisiologia , Diabetes Mellitus/diagnóstico , Adulto , Idoso , Feminino , Humanos , Masculino , Síndrome Metabólica/diagnóstico , Pessoa de Meia-Idade , Adulto JovemRESUMO
PURPOSE: Mucopolysaccharidosis I (MPS I) is an inherited metabolic disorder resulting from deficiency of α-L-iduronidase and lysosomal accumulation of glycosaminoglycans (GAG) in multiple tissues. Accumulation of GAG in corneal stromal cells causes corneal opacity and reduced vision. The purpose of this study was to determine the extent of ocular GAG accumulation and investigate the effectiveness of intravenous enzyme replacement therapy (ERT) on corneal GAG accumulation in dogs. METHODS: Ocular tissues were obtained from 58 dogs with mucopolysaccharidosis I and four unaffected controls. Affected dogs received either low-dose ERT, high-dose ERT, or no treatment; some low-dose dogs also received intrathecal treatments. Histologic severity of corneal stromal GAG accumulation was scored. RESULTS: Accumulation of GAG was found in corneal stromal cells and scleral fibroblasts but not in corneal epithelium, endothelium, ciliary epithelium, choroid, retina, retinal pigment epithelium, or optic nerve. Corneal GAG accumulation increased in severity with increasing age. Although low-dose ERT did not significantly reduce corneal stromal GAG accumulation in comparison with untreated animals, high-dose ERT did result in significantly less GAG accumulation compared with the untreated dogs (adjusted P = 0.0143) or the low-dose ERT group (adjusted P = 0.0031). Intrathecal treatments did not significantly affect GAG accumulation. Dogs that began ERT shortly after birth also had significantly less (P < 0.0001) GAG accumulation in the corneal stroma than dogs with a later onset of treatment. CONCLUSIONS: These data suggest that high-dose, intravenous ERT is effective at preventing and/or clearing corneal stromal GAG accumulation, particularly if initiated early after birth.