RESUMO
Extremely preterm infants are often treated with supraphysiological oxygen, which contributes to the development of bronchopulmonary dysplasia (BPD). These same infants exhibit compromised antioxidant capacities due in part to selenium (Se) deficiency. Se is essential for basal and inducible antioxidant responses. The present study utilized a perinatal Se deficiency (SeD) mouse model to identify the combined effects of newborn hyperoxia exposure and SeD on alveolarization and antioxidant responses, including the identification of affected developmental pathways. Se-sufficient (SeS) and SeD C3H/HeN breeding pairs were generated, and pups were exposed to room air or 85% O2 from birth to 14 d. Survival, antioxidant protein expression, and RNA seq analyses were performed. Greater than 40% mortality was observed in hyperoxia-exposed SeD pups. Surviving SeD pups had greater lung growth deficits than hyperoxia-exposed SeS pups. Gpx2 and 4 protein and Gpx activity were significantly decreased in SeD pups. Nrf2-regulated proteins, Nqo1 and Gclc were increased in SeD pups exposed to hyperoxia. RNA seq revealed significant decreases in the Wnt/ß-catenin and Notch pathways. Se is a biologically relevant modulator of perinatal lung development and antioxidant responses, especially in the context of hyperoxia exposure. The RNA seq analyses suggest pathways essential for normal lung development are dysregulated by Se deficiency.
RESUMO
Weight loss is an effective intervention for diminishing disease burden in obese older adults. Pharmacological interventions that reduce food intake and thereby promote weight loss may offer effective strategies to reduce age-related disease. We previously reported that 17α-estradiol (17α-E2) administration elicits beneficial effects on metabolism and inflammation in old male mice. These observations were associated with reduced calorie intake. Here, we demonstrate that 17α-E2 acts through pro-opiomelanocortin (Pomc) expression in the arcuate nucleus (ARC) to reduce food intake and body mass in mouse models of obesity. These results confirm that 17α-E2 modulates appetite through selective interactions within hypothalamic anorexigenic pathways. Interestingly, some peripheral markers of metabolic homeostasis were also improved in animals with near complete loss of ARC Pomc transcription. This suggests that 17α-E2 might have central and peripheral actions that can beneficially affect metabolism cooperatively or independently.
Assuntos
Estradiol/farmacologia , Comportamento Alimentar/efeitos dos fármacos , Hipotálamo/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Pró-Opiomelanocortina/farmacologia , Animais , Núcleo Arqueado do Hipotálamo/efeitos dos fármacos , Núcleo Arqueado do Hipotálamo/metabolismo , Comportamento Animal/efeitos dos fármacos , Ingestão de Alimentos/efeitos dos fármacos , Hipotálamo/metabolismo , Leptina/metabolismo , Camundongos Transgênicos , Neurônios/metabolismo , Obesidade/metabolismo , Pró-Opiomelanocortina/metabolismoRESUMO
BACKGROUND: Cancer-specific survival has changed remarkably little over the past half century, mainly because metastases that are occult at diagnosis and generally resistant to chemotherapy subsequently develop months, years or even decades following definitive therapy. Targeting the dormant micrometastases responsible for these delayed or occult metastases would represent a major new tool in cancer patient management. Our hypothesis is that these metastases develop from micrometastatic cells that are suppressed by normal extracellular matrix (ECM). METHODS: A new screening method was developed that compared the effect of drugs on the proliferation of cells grown on a normal ECM gel (small intestine submucosa, SISgel) to cells grown on plastic cell culture plates. The desired endpoint was that cells on SISgel were more sensitive than the same cells grown as monolayers. Known cancer chemotherapeutic agents show the opposite pattern. RESULTS: Screening 13,000 compounds identified two leads with low toxicity in mice and EC50 values in the range of 3-30 µM, depending on the cell line, and another two leads that were too toxic to mice to be useful. In a novel flank xenograft method of suppressed/dormant cells co-injected with SISgel into the flank, the lead compounds significantly eliminated the suppressed cells, whereas conventional chemotherapeutics were ineffective. Using a 4T1 triple negative breast cancer model, modified for physiological metastatic progression, as predicted, both lead compounds reduced the number of large micrometastases/macrometastases in the lung. One of the compounds also targeted cancer stem cells (CSC) isolated from the parental line. The CSC also retained their stemness on SISgel. Mechanistic studies showed a mild, late apoptotic response and depending on the compound, a mild arrest either at S or G2/M in the cell cycle. CONCLUSIONS: In summary we describe a novel, first in class set of compounds that target micrometastatic cells and prevent their reactivation to form recurrent tumors/macrometastases.
Assuntos
Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Micrometástase de Neoplasia/tratamento farmacológico , Animais , Antineoplásicos/uso terapêutico , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Feminino , Concentração Inibidora 50 , Dose Máxima Tolerável , Camundongos Endogâmicos BALB C , Camundongos Nus , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Therapy for treatment-resistant breast cancer provides limited options and the response rates are low. Therefore, the development of therapies with alternative chemotherapeutic strategies is necessary. AG311 (5-[(4-methylphenyl)thio]-9H-pyrimido[4,5-b]indole-2,4-diamine), a small molecule, is being investigated in preclinical and mechanistic studies for treatment of resistant breast cancer through necrosis, an alternative cell death mechanism. In vitro, AG311 induces rapid necrosis in numerous cancer cell lines as evidenced by loss of membrane integrity, ATP depletion, HMGB1 (high-mobility group protein B1) translocation, nuclear swelling, and stable membrane blebbing in breast cancer cells. Within minutes, exposure to AG311 also results in mitochondrial depolarization, superoxide production, and increased intracellular calcium levels. Additionally, upregulation of mitochondrial oxidative phosphorylation results in sensitization to AG311. This AG311-induced cell death can be partially prevented by treatment with the mitochondrial calcium uniporter inhibitor, Ru360 [(µ)[(HCO2)(NH3)4Ru]2OCl3], or an antioxidant, lipoic acid. Additionally, AG311 does not increase apoptotic markers such as cleavage of poly (ADP-ribose) polymerase (PARP) or caspase-3 and -7 activity. Importantly, in vivo studies in two orthotopic breast cancer mouse models (xenograft and allograft) demonstrate that AG311 retards tumor growth and reduces lung metastases better than clinically used agents and has no gross or histopathological toxicity. Together, these data suggest that AG311 is a first-in-class antitumor and antimetastatic agent inducing necrosis in breast cancer tumors, likely through the mitochondria.
Assuntos
Antineoplásicos/farmacologia , Indóis/farmacologia , Mitocôndrias/efeitos dos fármacos , Necrose/induzido quimicamente , Pirimidinas/farmacologia , Neoplasias de Mama Triplo Negativas/patologia , Animais , Antineoplásicos/toxicidade , Apoptose/efeitos dos fármacos , Cálcio/metabolismo , Linhagem Celular Tumoral , Permeabilidade da Membrana Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Feminino , Homeostase/efeitos dos fármacos , Humanos , Indóis/toxicidade , Masculino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Mitocôndrias/metabolismo , Metástase Neoplásica , Pirimidinas/toxicidade , Ratos , Superóxidos/metabolismo , Fatores de Tempo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Most cancer patients die with metastatic disease, thus, good models that recapitulate the natural process of metastasis including a dormancy period with micrometastatic cells would be beneficial in developing treatment strategies. Herein we report a model of natural metastasis that balances time to complete experiments with a reasonable dormancy period, which can be used to better study metastatic progression. The basis for the model is a 4T1 triple negative syngeneic breast cancer model without resection of the primary tumor. A cell titration from 500 to 15,000 GFP tagged 4T1 cells implanted into fat pad number four of immune proficient eight week female BALB/cJ mice optimized speed of the model while possessing metastatic processes including dormancy and beginning of reactivation. The frequency of primary tumors was less than 50% in animals implanted with 500-1500 cells. Although implantation with over 10,000 cells resulted in 100% primary tumor development, the tumors and macrometastases formed were highly aggressive, lacked dormancy, and offered no opportunity for treatment. Implantation of 7,500 cells resulted in >90% tumor take by 10 days; in 30-60 micrometastases in the lung (with many animals also having 2-30 brain micrometastases) two weeks post-implantation, with the first small macrometastases present at five weeks; many animals displaying macrometastases at five weeks and animals becoming moribund by six weeks post-implantation. Using the optimum of 7,500 cells the efficacy of a chemotherapeutic agent for breast cancer, doxorubicin, given at its maximal tolerated dose (MTD; 1 mg/kg weekly) was tested for an effect on metastasis. Doxorubicin treatment significantly reduced primary tumor growth and lung micrometastases but the number of macrometastases at experiment end was not significantly affected. This model should prove useful for development of drugs to target metastasis and to study the biology of metastasis.
Assuntos
Neoplasias da Mama/patologia , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/secundário , Metástase Neoplásica/patologia , Micrometástase de Neoplasia/patologia , Animais , Neoplasias da Mama/tratamento farmacológico , Linhagem Celular Tumoral , Progressão da Doença , Doxorrubicina/farmacologia , Feminino , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Mamárias Experimentais/tratamento farmacológico , Neoplasias Mamárias Experimentais/patologia , Camundongos , Camundongos Endogâmicos BALB C , Metástase Neoplásica/tratamento farmacológico , Micrometástase de Neoplasia/tratamento farmacológicoRESUMO
The design, synthesis and biological evaluations of fourteen 4-substituted 2,6-dimethylfuro[2,3-d]pyrimidines are reported. Four compounds (11-13, 15) inhibit vascular endothelial growth factor receptor-2 (VEGFR-2), platelet-derived growth factor receptor ß (PDGFR-ß), and target tubulin leading to cytotoxicity. Compound 11 has nanomolar potency, comparable to sunitinib and semaxinib, against tumor cell lines overexpressing VEGFR-2 and PDGFR-ß. Further, 11 binds at the colchicine site on tubulin, depolymerizes cellular microtubules and inhibits purified tubulin assembly and overcomes both ßIII-tubulin and P-glycoprotein-mediated drug resistance, and initiates mitotic arrest leading to apoptosis. In vivo, its HCl salt, 21, reduced tumor size and vascularity in xenograft and allograft murine models and was superior to docetaxel and sunitinib, without overt toxicity. Thus 21 affords potential combination chemotherapy in a single agent.
Assuntos
Compostos de Anilina/farmacologia , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Descoberta de Drogas , Microtúbulos/efeitos dos fármacos , Neoplasias Experimentais/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Pirimidinas/farmacologia , Receptores Proteína Tirosina Quinases/antagonistas & inibidores , Água/química , Compostos de Anilina/síntese química , Compostos de Anilina/química , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Células HeLa , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neoplasias Experimentais/patologia , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Pirimidinas/síntese química , Pirimidinas/química , Receptores Proteína Tirosina Quinases/metabolismo , Solubilidade , Relação Estrutura-AtividadeRESUMO
Antiangiogenic agents (AA) are cytostatic, and their utility in cancer chemotherapy lies in their combination with cytotoxic chemotherapeutic agents. Clinical combinations of vascular endothelial growth factor receptor-2 (VEGFR2) inhibitors with antitubulin agents have been particularly successful. We have discovered a novel, potentially important analogue, that combines potent VEGFR2 inhibitory activity (comparable to that of sunitinib) with potent antitubulin activity (comparable to that of combretastatin A-4 (CA)) in a single molecule, with GI50 values of 10(-7) M across the entire NCI 60 tumor cell panel. It potently inhibited tubulin assembly and circumvented the most clinically relevant tumor resistance mechanisms (P-glycoprotein and ß-III tubulin expression) to antimicrotubule agents. The compound is freely water-soluble as its HCl salt and afforded excellent antitumor activity in vivo, superior to docetaxel, sunitinib, or Temozolomide, without any toxicity.
RESUMO
Probestin is a potent aminopeptidase N (APN) inhibitor originally isolated from the bacterial culture broth. Here, we report probestin synthesis by solid phase peptide synthesis (SPPS) method and evaluated its activity to inhibit angiogenesis using a chicken embryo chorioallantoic membrane (CAM) assay and a CAM tumor xenograft model. Results from these studies demonstrate that probestin inhibits the angiogenic activity and tumor growth.
Assuntos
Inibidores da Angiogênese/síntese química , Inibidores da Angiogênese/farmacologia , Oligopeptídeos/síntese química , Oligopeptídeos/farmacologia , Inibidores da Angiogênese/química , Animais , Neoplasias da Mama/irrigação sanguínea , Neoplasias da Mama/tratamento farmacológico , Antígenos CD13/antagonistas & inibidores , Linhagem Celular Tumoral , Embrião de Galinha , Membrana Corioalantoide/irrigação sanguínea , Feminino , Humanos , Camundongos Endogâmicos BALB C , Neovascularização Fisiológica/efeitos dos fármacos , Oligopeptídeos/química , Técnicas de Síntese em Fase Sólida/métodos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Six novel N(4)-phenylsubstituted-6-(2-pyridin-2-ylethyl)-7H-pyrrolo[2,3-d]pyrimidine-2,4-diamines and their N(2)-trimethylacetyl substituted analogs were synthesized as receptor tyrosine kinase (RTK) inhibitors. A microwave-mediated Sonogashira reaction was used as a key step for the synthesis of these compounds. Biological evaluation, in whole cell assays, showed that some analogs had remarkable inhibitory activity against a variety of RTKs and in particular cytotoxic activity against A431 tumor cells in culture. The inhibitory data against RTKs in this study demonstrated that variation of the 4-anilino substituents of these analogs dictates both potency and specificity of inhibitory activity against various RTKs. The study also supported the hypothesis that interaction of substituents on the 2-amino group with hydrophobic site-II provides an increase in potency. Compound 8 of this series was selected for evaluation in vivo in a B16-F10 syngeneic mouse tumor model and exhibited significant reduction in tumor growth rate, in tumor vascular density and in metastases to the lung compared to the control.
Assuntos
Inibidores da Angiogênese/química , Antineoplásicos/química , Desenho de Fármacos , Inibidores de Proteínas Quinases/química , Pirimidinas/química , Pirróis/química , Receptores Proteína Tirosina Quinases/antagonistas & inibidores , Inibidores da Angiogênese/uso terapêutico , Inibidores da Angiogênese/toxicidade , Animais , Antineoplásicos/uso terapêutico , Antineoplásicos/toxicidade , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Modelos Animais de Doenças , Humanos , Melanoma Experimental/tratamento farmacológico , Camundongos , Camundongos Nus , Micro-Ondas , Inibidores de Proteínas Quinases/uso terapêutico , Inibidores de Proteínas Quinases/toxicidade , Pirimidinas/uso terapêutico , Pirimidinas/toxicidade , Pirróis/uso terapêutico , Pirróis/toxicidade , Receptores Proteína Tirosina Quinases/metabolismo , Relação Estrutura-AtividadeRESUMO
Obesity in the elderly individuals is increasing at alarming rates and there is evidence suggesting that elderly individuals are more vulnerable to the deleterious cardiovascular effects of obesity than younger individuals. However, the specific mechanisms through which aging and obesity interact to promote the development of cardiovascular disease remain unclear. The present study was designed to test the hypothesis that aging exacerbates obesity-induced inflammation in perivascular adipose tissue, which contributes to increased vascular oxidative stress and inflammation in a paracrine manner. To test this hypothesis, we assessed changes in the secretome, reactive oxygen species production, and macrophage infiltration in periaortic adipose tissue of young (7 month old) and aged (24 month old) high-fat diet-fed obese C57BL/6 mice. High-fat diet-induced vascular reactive oxygen species generation significantly increased in aged mice, which was associated with exacerbation of endothelial dysfunction and vascular inflammation. In young animals, high-fat diet-induced obesity promoted oxidative stress in the perivascular adipose tissue, which was associated with a marked proinflammatory shift in the profile of secreted cytokines and chemokines. Aging exacerbated obesity-induced oxidative stress and inflammation and significantly increased macrophage infiltration in periaortic adipose tissue. Using cultured arteries isolated from young control mice, we found that inflammatory factors secreted from the perivascular fat tissue of obese aged mice promote significant prooxidative and proinflammatory phenotypic alterations in the vascular wall, mimicking the aging phenotype. Overall, our findings support an important role for localized perivascular adipose tissue inflammation in exacerbation of vascular oxidative stress and inflammation in aging, an effect that likely enhances the risk for development of cardiovascular diseases from obesity in the elderly individuals.
Assuntos
Tecido Adiposo/metabolismo , Envelhecimento , Dieta Hiperlipídica/efeitos adversos , Inflamação/metabolismo , Obesidade/metabolismo , Estresse Oxidativo , Doenças Vasculares/metabolismo , Animais , Modelos Animais de Doenças , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Obesidade/complicações , Obesidade/patologia , Oxirredução , Doenças Vasculares/complicações , Doenças Vasculares/patologiaRESUMO
We designed, synthesized and evaluated 13 novel tricyclic indeno[2,1-d]pyrimidines as RTK inhibitors. These analogues were synthesized via a Dieckmann condensation of 1,2-phenylenediacetonitrile followed by cyclocondensation with guanidine carbonate to afford the 2-amino-3,9-dihydro-indeno[2,1-d]pyrimidin-4-one. Sulfonation of the 4-position followed by displacement with appropriately substituted anilines afforded the target compounds. These compounds were potent inhibitors of platelet-derived growth factor receptor ß (PDGFRß) and inhibited angiogenesis in the chicken embryo chorioallantonic membrane (CAM) assay compared to standards. In addition, compound 7 had a two digit nanomolar GI(50) against nine tumor cell lines, a submicromolar GI(50) against 29 of other tumor cell lines in the preclinical NCI 60 tumor cell line panel. Compound 7 also demonstrated significant in vivo inhibition of tumor growth and angiogenesis in a B16-F10 syngeneic mouse melanoma model.
Assuntos
Inibidores da Angiogênese/química , Antineoplásicos/química , Indenos/química , Pirimidinas/química , Inibidores da Angiogênese/uso terapêutico , Inibidores da Angiogênese/toxicidade , Animais , Antineoplásicos/uso terapêutico , Antineoplásicos/toxicidade , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Embrião de Galinha , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Indenos/uso terapêutico , Indenos/toxicidade , Melanoma Experimental/tratamento farmacológico , Camundongos , Pirimidinas/uso terapêutico , Pirimidinas/toxicidade , Receptor beta de Fator de Crescimento Derivado de Plaquetas/antagonistas & inibidores , Receptor beta de Fator de Crescimento Derivado de Plaquetas/metabolismoRESUMO
Recent studies demonstrate that age-related dysfunction of NF-E2-related factor-2 (Nrf2)-driven pathways impairs cellular redox homeostasis, exacerbating age-related cellular oxidative stress and increasing sensitivity of aged vessels to oxidative stress-induced cellular damage. Circulating levels of insulin-like growth factor (IGF)-1 decline during aging, which significantly increases the risk for cardiovascular diseases in humans. To test the hypothesis that adult-onset IGF-1 deficiency impairs Nrf2-driven pathways in the vasculature, we utilized a novel mouse model with a liver-specific adeno-associated viral knockdown of the Igf1 gene using Cre-lox technology (Igf1(f/f) + MUP-iCre-AAV8), which exhibits a significant decrease in circulating IGF-1 levels (~50%). In the aortas of IGF-1-deficient mice, there was a trend for decreased expression of Nrf2 and the Nrf2 target genes GCLC, NQO1 and HMOX1. In cultured aorta segments of IGF-1-deficient mice treated with oxidative stressors (high glucose, oxidized low-density lipoprotein, and H(2)O(2)), induction of Nrf2-driven genes was significantly attenuated as compared with control vessels, which was associated with an exacerbation of endothelial dysfunction, increased oxidative stress, and apoptosis, mimicking the aging phenotype. In conclusion, endocrine IGF-1 deficiency is associated with dysregulation of Nrf2-dependent antioxidant responses in the vasculature, which likely promotes an adverse vascular phenotype under pathophysiological conditions associated with oxidative stress (eg, diabetes mellitus, hypertension) and results in accelerated vascular impairments in aging.
Assuntos
Envelhecimento/metabolismo , Modelos Animais de Doenças , Fator de Crescimento Insulin-Like I/biossíntese , Fígado/metabolismo , Fator 2 Relacionado a NF-E2/biossíntese , Animais , Aorta/metabolismo , Apoptose , Feminino , Técnicas de Silenciamento de Genes , Glutamato-Cisteína Ligase/biossíntese , Heme Oxigenase-1/biossíntese , Peróxido de Hidrogênio/metabolismo , Hiperglicemia/metabolismo , Fator de Crescimento Insulin-Like I/análise , Fator de Crescimento Insulin-Like I/genética , Lipoproteínas LDL/metabolismo , Masculino , Proteínas de Membrana/biossíntese , Camundongos , Camundongos Endogâmicos C57BL , NAD(P)H Desidrogenase (Quinona)/biossíntese , Estresse Oxidativo , Técnicas de Cultura de TecidosRESUMO
Previous studies suggest that the age-related decline in circulating growth hormone (GH) and insulin-like growth factor-1 (IGF-1) levels significantly contribute to vascular dysfunction in aging by impairing cellular oxidative stress resistance pathways. Obesity in elderly individuals is increasing at alarming rates, and there is evidence suggesting that elderly individuals are more vulnerable to the deleterious cardiovascular effects of obesity than younger individuals. However, the specific mechanisms through which aging, GH/IGF-1 deficiency, and obesity interact to promote the development of cardiovascular disease remain unclear. To test the hypothesis that low circulating GH/IGF-1 levels exacerbate the pro-oxidant and proinflammatory vascular effects of obesity, GH/IGF-1-deficient Lewis dwarf rats and heterozygous control rats were fed either a standard diet or a high-fat diet (HFD) for 7 months. Feeding an HFD resulted in similar relative weight gains and increases in body fat content in Lewis dwarf rats and control rats. HFD-fed Lewis dwarf rats exhibited a relative increase in blood glucose levels, lower insulin, and impaired glucose tolerance as compared with HFD-fed control rats. Analysis of serum cytokine expression signatures indicated that chronic GH/IGF-1 deficiency exacerbates HFD-induced inflammation. GH/IGF-1 deficiency also exacerbated HFD-induced endothelial dysfunction, oxidative stress, and expression of inflammatory markers (tumor necrosis factor-α, ICAM-1) in aortas of Lewis dwarf rats. Overall, our results are consistent with the available clinical and experimental evidence suggesting that GH/IGF-1 deficiency renders the cardiovascular system more vulnerable to the deleterious effects of obesity.