RESUMO
The bone-derived hormone fibroblast growth factor-23 (FGF-23) activates complexes composed of FGF receptors (FGFRs), including FGFR1, and α-Klotho in the kidney distal tubule (DT), leading to increased sodium retention and hypertension. However, the role of FGFR1 in regulating renal processes linked to hypertension is unclear. Here, we investigated the effects of selective FGFR1 loss in the DT. Conditional knockout (cKO) of FGFR1 in the DT (FGFR1DT-cKO mice) resulted in left ventricular hypertrophy (LVH) and decreased kidney expression of α-Klotho in association with enhanced BP, decreased expression of angiotensin converting enzyme 2, and increased expression of the Na+-K+-2Cl- cotransporter. Notably, recombinant FGF-23 administration similarly decreased the kidney expression of α-Klotho and induced LVH in mice. Pharmacologic activation of FGFR1 with a monoclonal anti-FGFR1 antibody (R1MAb1) normalized BP and significantly attenuated LVH in the Hyp mouse model of excess FGF-23, but did not induce a response in FGFR1DT-cKO mice. The hearts of FGFR1DT-cKO mice showed increased expression of the transient receptor potential cation channel, subfamily C, member 6 (TRPC6), consistent with cardiac effects of soluble Klotho deficiency. Moreover, administration of recombinant soluble Klotho lowered BP in the Hyp mice. Thus, FGFR1 in the DT regulates systemic hemodynamic responses opposite to those predicted by the actions of FGF-23. These cardiovascular effects appear to be mediated by paracrine FGF control of kidney FGFR1 and subsequent regulation of soluble Klotho and TRPC6. FGFR1 in the kidney may provide a new molecular target for treating hypertension.
Assuntos
Pressão Sanguínea/efeitos dos fármacos , Pressão Sanguínea/genética , Hipertensão/genética , Hipertrofia Ventricular Esquerda/genética , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/genética , Enzima de Conversão de Angiotensina 2 , Animais , Anticorpos Monoclonais/farmacologia , Feminino , Fator de Crescimento de Fibroblastos 23 , Fatores de Crescimento de Fibroblastos/farmacologia , Glucuronidase/genética , Glucuronidase/metabolismo , Fatores Imunológicos/farmacologia , Túbulos Renais Distais , Proteínas Klotho , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Miocárdio/metabolismo , Peptidil Dipeptidase A/genética , Peptidil Dipeptidase A/metabolismo , RNA Mensageiro/metabolismo , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/imunologia , Proteínas Recombinantes/farmacologia , Simportadores de Cloreto de Sódio-Potássio/genética , Simportadores de Cloreto de Sódio-Potássio/metabolismo , Canais de Cátion TRPC/genética , Canais de Cátion TRPC/metabolismo , Canal de Cátion TRPC6RESUMO
Bruton's tyrosine kinase (BTK) is a member of the Tec family of cytoplasmic tyrosine kinases involved in B-cell and myeloid cell signaling. Small molecule inhibitors of BTK are being investigated for treatment of several hematologic cancers and autoimmune diseases. GDC-0853 ((S)-2-(3'-(hydroxymethyl)-1-methyl-5-((5-(2-methyl-4-(oxetan-3-yl)piperazin-1-yl)pyridin-2-yl)amino)-6-oxo-1,6-dihydro-[3,4'-bipyridin]-2'-yl)-7,7-dimethyl-3,4,7,8-tetrahydro-2H-cyclopenta[4,5]pyrrolo[1,2-a]pyrazin-1(6H)-one) is a selective and reversible oral small-molecule BTK inhibitor in development for the treatment of rheumatoid arthritis and systemic lupus erythematosus. In Sprague-Dawley (SD) rats, administration of GDC-0853 and other structurally diverse BTK inhibitors for 7 days or longer caused pancreatic lesions consisting of multifocal islet-centered hemorrhage, inflammation, fibrosis, and pigment-laden macrophages with adjacent lobular exocrine acinar cell atrophy, degeneration, and inflammation. Similar findings were not observed in mice or dogs at much higher exposures. Hemorrhage in the peri-islet vasculature emerged between four and seven daily doses of GDC-0853 and was histologically similar to spontaneously occurring changes in aging SD rats. This suggests that GDC-0853 could exacerbate a background finding in younger animals. Glucose homeostasis was dysregulated following a glucose challenge; however, this occurred only after 28 days of administration and was not directly associated with onset or severity of pancreatic lesions. There were no changes in other common serum biomarkers assessing endocrine and exocrine pancreatic function. Additionally, these lesions were not readily detectable via Doppler ultrasound, computed tomography, or magnetic resonance imaging. Our results indicate that pancreatic lesions in rats are likely a class effect of BTK inhibitors, which may exacerbate an islet-centered pathology that is unlikely to be relevant to humans.
Assuntos
Pâncreas/efeitos dos fármacos , Piperazinas/toxicidade , Inibidores de Proteínas Quinases/toxicidade , Proteínas Tirosina Quinases/antagonistas & inibidores , Piridonas/toxicidade , Pirróis/toxicidade , Tirosina Quinase da Agamaglobulinemia , Animais , Cães , Relação Dose-Resposta a Droga , Feminino , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Glucose/metabolismo , Humanos , Masculino , Camundongos , Pâncreas/metabolismo , Proteínas Tirosina Quinases/metabolismo , Ratos , Especificidade da EspécieRESUMO
Dissipating excess calories as heat through therapeutic stimulation of brown adipose tissues (BAT) has been proposed as a potential treatment for obesity-linked disorders. Here, we describe the generation of a humanized effector-less bispecific antibody that activates fibroblast growth factor receptor (FGFR) 1/ßKlotho complex, a common receptor for FGF21 and FGF19. Using this molecule, we show that antibody-mediated activation of FGFR1/ßKlotho complex in mice induces sustained energy expenditure in BAT, browning of white adipose tissue, weight loss, and improvements in obesity-associated metabolic derangements including insulin resistance, hyperglycemia, dyslipidemia and hepatosteatosis. In mice and cynomolgus monkeys, FGFR1/ßKlotho activation increased serum high-molecular-weight adiponectin, which appears to contribute over time by enhancing the amplitude of the metabolic benefits. At the same time, insulin sensitization by FGFR1/ßKlotho activation occurs even before the onset of weight loss in a manner that is independent of adiponectin. Together, selective activation of FGFR1/ßKlotho complex with a long acting therapeutic antibody represents an attractive approach for the treatment of type 2 diabetes and other obesity-linked disorders through enhanced energy expenditure, insulin sensitization and induction of high-molecular-weight adiponectin.
Assuntos
Tecido Adiposo Marrom/metabolismo , Anticorpos Biespecíficos/farmacologia , Insulina/farmacologia , Proteínas de Membrana/agonistas , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/agonistas , Adiponectina/metabolismo , Tecido Adiposo Marrom/efeitos dos fármacos , Animais , Linhagem Celular , Metabolismo Energético/efeitos dos fármacos , Fatores de Crescimento de Fibroblastos/farmacologia , Células HEK293 , Humanos , Proteínas Klotho , Macaca fascicularis , Masculino , Proteínas de Membrana/metabolismo , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Obesos , Ligação Proteica/efeitos dos fármacos , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/metabolismo , Termogênese/efeitos dos fármacos , Redução de Peso/efeitos dos fármacosRESUMO
UNLABELLED: Primary liver cancer encompasses both hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA). The Notch signaling pathway, known to be important for the proper development of liver architecture, is also a potential driver of primary liver cancer. However, with four known Notch receptors and several Notch ligands, it is not clear which Notch pathway members play the predominant role in liver cancer. To address this question, we utilized antibodies to specifically target Notch1, Notch2, Notch3, or jagged1 (Jag1) in a mouse model of primary liver cancer driven by v-akt murine thymoma viral oncogene homolog and neuroblastoma RAS viral oncogene homolog (NRas). We show that inhibition of Notch2 reduces tumor burden by eliminating highly malignant HCC- and CCA-like tumors. Inhibition of the Notch ligand, Jag1, had a similar effect, consistent with Jag1 acting in cooperation with Notch2. This effect was specific to Notch2, because Notch3 inhibition did not decrease tumor burden. Unexpectedly, Notch1 inhibition altered the relative proportion of tumor types, reducing HCC-like tumors but dramatically increasing CC-like tumors. Finally, we show that Notch2 and Jag1 are expressed in, and Notch2 signaling is activated in, a subset of human HCC samples. CONCLUSIONS: These findings underscore the distinct roles of different Notch receptors in the liver and suggest that inhibition of Notch2 signaling represents a novel therapeutic option in the treatment of liver cancer.
Assuntos
Neoplasias Hepáticas/tratamento farmacológico , Receptores Notch/antagonistas & inibidores , Animais , Proteínas de Ligação ao Cálcio/análise , Proteínas de Ligação ao Cálcio/antagonistas & inibidores , Modelos Animais de Doenças , Proteína Forkhead Box M1 , Fatores de Transcrição Forkhead/análise , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/análise , Proteína Jagged-1 , Proteínas de Membrana/análise , Proteínas de Membrana/antagonistas & inibidores , Camundongos , Proteínas Proto-Oncogênicas c-akt/fisiologia , Proteínas Proto-Oncogênicas p21(ras)/fisiologia , Receptores Notch/análise , Receptores Notch/fisiologia , Proteínas Serrate-JaggedRESUMO
The connection between an altered gut microbiota and metabolic disorders such as obesity, diabetes, and cardiovascular disease is well established. Defects in preserving the integrity of the mucosal barriers can result in systemic endotoxaemia that contributes to chronic low-grade inflammation, which further promotes the development of metabolic syndrome. Interleukin (IL)-22 exerts essential roles in eliciting antimicrobial immunity and maintaining mucosal barrier integrity within the intestine. Here we investigate the connection between IL-22 and metabolic disorders. We find that the induction of IL-22 from innate lymphoid cells and CD4(+) T cells is impaired in obese mice under various immune challenges, especially in the colon during infection with Citrobacter rodentium. While innate lymphoid cell populations are largely intact in obese mice, the upregulation of IL-23, a cytokine upstream of IL-22, is compromised during the infection. Consequently, these mice are susceptible to C. rodentium infection, and both exogenous IL-22 and IL-23 are able to restore the mucosal host defence. Importantly, we further unveil unexpected functions of IL-22 in regulating metabolism. Mice deficient in IL-22 receptor and fed with high-fat diet are prone to developing metabolic disorders. Strikingly, administration of exogenous IL-22 in genetically obese leptin-receptor-deficient (db/db) mice and mice fed with high-fat diet reverses many of the metabolic symptoms, including hyperglycaemia and insulin resistance. IL-22 shows diverse metabolic benefits, as it improves insulin sensitivity, preserves gut mucosal barrier and endocrine functions, decreases endotoxaemia and chronic inflammation, and regulates lipid metabolism in liver and adipose tissues. In summary, we identify the IL-22 pathway as a novel target for therapeutic intervention in metabolic diseases.
Assuntos
Diabetes Mellitus/imunologia , Diabetes Mellitus/metabolismo , Imunidade nas Mucosas , Interleucinas/imunologia , Interleucinas/metabolismo , Doenças Metabólicas/metabolismo , Tecido Adiposo Branco/efeitos dos fármacos , Tecido Adiposo Branco/metabolismo , Animais , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Doença Crônica , Citrobacter rodentium/efeitos dos fármacos , Citrobacter rodentium/imunologia , Citrobacter rodentium/fisiologia , Colo/efeitos dos fármacos , Colo/imunologia , Colo/microbiologia , Diabetes Mellitus/patologia , Dieta Hiperlipídica , Feminino , Hiperglicemia/dietoterapia , Hiperglicemia/tratamento farmacológico , Hiperglicemia/metabolismo , Imunidade nas Mucosas/efeitos dos fármacos , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Inflamação/patologia , Insulina/metabolismo , Resistência à Insulina , Interleucina-23/imunologia , Interleucina-23/metabolismo , Interleucina-23/farmacologia , Interleucinas/farmacologia , Interleucinas/uso terapêutico , Metabolismo dos Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Doenças Metabólicas/dietoterapia , Doenças Metabólicas/tratamento farmacológico , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Obesidade/metabolismo , Receptores de Interleucina/deficiência , Receptores de Interleucina/metabolismo , Receptores para Leptina/deficiência , Receptores para Leptina/metabolismo , Interleucina 22RESUMO
Human cytomegalovirus (HCMV) is the most common cause of congenital virus infection. Congenital HCMV infection occurs in 0.2-1% of all births, and causes birth defects and developmental abnormalities, including sensorineural hearing loss and developmental delay. Several key studies have established the guinea pig as a tractable model for the study of congenital HCMV infection and have shown that polyclonal antibodies can be protective. In this study, we demonstrate that an anti-guinea pig CMV (GPCMV) glycoprotein H/glycoprotein L neutralizing monoclonal antibody protects against fetal infection and loss in the guinea pig. Furthermore, we have delineated the kinetics of GPCMV congenital infection, from maternal infection (salivary glands, seroconversion, placenta) to fetal infection (fetus and amniotic fluid). Our studies support the hypothesis that a neutralizing monoclonal antibody targeting an envelope GPCMV glycoprotein can protect the fetus from infection and may shed light on the therapeutic intervention of HCMV congenital infection in humans.
Assuntos
Anticorpos Monoclonais Murinos/farmacologia , Anticorpos Neutralizantes/farmacologia , Anticorpos Antivirais/farmacologia , Infecções por Citomegalovirus/congênito , Infecções por Citomegalovirus/tratamento farmacológico , Citomegalovirus/imunologia , Animais , Anticorpos Monoclonais Murinos/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Infecções por Citomegalovirus/imunologia , Infecções por Citomegalovirus/patologia , Modelos Animais de Doenças , Cobaias , Células HEK293 , HumanosRESUMO
BACKGROUND: Platelet-derived growth factor C (PDGF-C) has been reported to promote angiogenesis independently of vascular endothelial growth factor (VEGF), although its significance in postnatal angiogenesis in vivo remains poorly understood. VEGF has been employed as a major molecular tool to induce therapeutic angiogenesis. However, VEGF therapy is not very effective in models of cardiovascular diseases associated with diabetes, and the mechanisms of this phenomenon still remain to be elucidated. METHODS: We used a murine model of hind limb ischemia and of streptozotocin-induced diabetes. RESULTS: Expression of PDGF-C and its receptor PDGFR-α were markedly upregulated in ischemic limbs. Treatment with a neutralizing antibody against PDGF-C significantly impaired blood flow recovery and neovascularization after ischemia almost to the same extent as a VEGF-neutralizing antibody. Mice deficient in PDGF-C exhibited reduced blood flow recovery after ischemia compared with wild-type mice, confirming a strong proangiogenic activity of PDGF-C. Next, we injected an expression vector encoding PDGF-C into ischemic limbs. Blood flow recovery and neovascularization after ischemia were significantly improved in the groups treated with PDGF-C compared with controls. Attenuation of angiogenic responses to ischemia has been reported in patients with diabetes even after VEGF treatment, although a precise mechanism remains unknown. We hypothesized that PDGF-C might relate to the impaired angiogenesis of diabetes. We tested this hypothesis by inducing diabetes by intraperitoneal injection of streptozotocin. Expression levels of PDGF-C at baseline and after ischemia were significantly lower in limb tissues of diabetic mice than in those of control mice, whereas expression levels of other members of the PDGF family and VEGF were not changed or were even higher in diabetic mice. Introduction of VEGF complementary DNA expression plasmid vector into ischemic limbs did not improve blood flow recovery. However, these changes were effectively reversed by additional introduction of the PDGF-C complementary DNA plasmid vector. CONCLUSIONS: These results indicate that downregulation of PDGF-C expression in limb tissues of diabetic mice contributes to impaired angiogenesis and suggest that introduction of PDGF-C might be a novel strategy for therapeutic angiogenesis, especially in the diabetic state. CLINICAL RELEVANCE: Angiogenesis and arteriogenesis after ischemia are attenuated in most diabetic patients, although the precise mechanisms remain unclear. Platelet-derived growth factors (PDGFs) have a variety of functions on many cell types, and PDGF-C stimulates angiogenesis and revascularizes ischemic tissues. This study indicates the role for PDGF-C as a critical regulator of impaired angiogenesis of diabetes and suggests that PDGF-C might be a novel target for the treatment of ischemic cardiovascular diseases in diabetes.
Assuntos
Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Angiopatias Diabéticas/metabolismo , Isquemia/metabolismo , Linfocinas/metabolismo , Músculo Esquelético/irrigação sanguínea , Neovascularização Fisiológica , Fator de Crescimento Derivado de Plaquetas/metabolismo , Animais , Anticorpos Neutralizantes/administração & dosagem , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/fisiopatologia , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/fisiopatologia , Angiopatias Diabéticas/genética , Angiopatias Diabéticas/fisiopatologia , Angiopatias Diabéticas/terapia , Técnicas de Transferência de Genes , Membro Posterior , Isquemia/genética , Isquemia/fisiopatologia , Isquemia/terapia , Linfocinas/antagonistas & inibidores , Linfocinas/deficiência , Linfocinas/genética , Linfocinas/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neuropilina-1/metabolismo , Neuropilina-2/metabolismo , Fator de Crescimento Derivado de Plaquetas/antagonistas & inibidores , Fator de Crescimento Derivado de Plaquetas/deficiência , Fator de Crescimento Derivado de Plaquetas/genética , Fator de Crescimento Derivado de Plaquetas/imunologia , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/metabolismo , Recuperação de Função Fisiológica , Fluxo Sanguíneo Regional , Transdução de Sinais , Fatores de Tempo , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/imunologia , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
Quantifying oxygenation in viable tumor remains a major obstacle toward a better understanding of the tumor micro-environment and improving treatment strategies. Current techniques are often complicated by tumor heterogeneity. Herein, a novel in vivo approach that combines (19)F magnetic resonance imaging ((19)F-MRI) R 1 mapping with diffusion-based multispectral (MS) analysis is introduced. This approach restricts the partial pressure of oxygen (pO2) measurements to viable tumor, the tissue of therapeutic interest. The technique exhibited sufficient sensitivity to detect a breathing gas challenge in a xenograft tumor model, and the hypoxic region measured by MS (19)F-MRI was strongly correlated with histologic estimates of hypoxia. This approach was then applied to address the effects of antivascular agents on tumor oxygenation, which is a research question that is still under debate. The technique was used to monitor longitudinal pO2 changes in response to an antibody to vascular endothelial growth factor (B20.4.1.1) and a selective dual phosphoinositide 3-kinase/mammalian target of rapamycin inhibitor (GDC-0980). GDC-0980 reduced viable tumor pO2 during a 3-day treatment period, and a significant reduction was also produced by B20.4.1.1. Overall, this method provides an unprecedented view of viable tumor pO2 and contributes to a greater understanding of the effects of antivascular therapies on the tumor's microenvironment.
Assuntos
Neoplasias Colorretais/metabolismo , Oxigênio/metabolismo , Animais , Hipóxia Celular/fisiologia , Linhagem Celular Tumoral , Feminino , Xenoenxertos , Humanos , Imageamento por Ressonância Magnética/métodos , Camundongos , Camundongos Nus , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Serina-Treonina Quinases TOR/antagonistas & inibidores , Serina-Treonina Quinases TOR/metabolismo , Microambiente Tumoral/fisiologia , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
The phosphatidylinositol 3-kinase (PI3K) pathway is a central mediator of vascular endothelial growth factor (VEGF)-driven angiogenesis. The discovery of small molecule inhibitors that selectively target PI3K or PI3K and mammalian target of rapamycin (mTOR) provides an opportunity to pharmacologically determine the contribution of these key signaling nodes in VEGF-A-driven tumor angiogenesis in vivo. This study used an array of micro-vascular imaging techniques to monitor the antivascular effects of selective class I PI3K, mTOR, or dual PI3K/mTOR inhibitors in colorectal and prostate cancer xenograft models. Micro-computed tomography (micro-CT) angiography, dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), vessel size index (VSI) MRI, and DCE ultrasound (DCE-U/S) were employed to quantitatively evaluate the vascular (structural and physiological) response to these inhibitors. GDC-0980, a dual PI3K/mTOR inhibitor, was found to reduce micro-CT angiography vascular density, while VSI MRI demonstrated a significant reduction in vessel density and an increase in mean vessel size, consistent with a loss of small functional vessels and a substantial antivascular response. DCE-MRI showed that GDC-0980 produces a strong functional response by decreasing the vascular permeability/perfusion-related parameter, K (trans). Interestingly, comparable antivascular effects were observed for both GDC-980 and GNE-490 (a selective class I PI3K inhibitor). In addition, mTOR-selective inhibitors did not affect vascular density, suggesting that PI3K inhibition is sufficient to generate structural changes, characteristic of a robust antivascular response. This study supports the use of noninvasive microvascular imaging techniques (DCE-MRI, VSI MRI, DCE-U/S) as pharmacodynamic assays to quantitatively measure the activity of PI3K and dual PI3K/mTOR inhibitors in vivo.
Assuntos
Classe I de Fosfatidilinositol 3-Quinases/antagonistas & inibidores , Inibidores Enzimáticos , Neoplasias/diagnóstico , Neovascularização Patológica/diagnóstico , Angiografia/métodos , Animais , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Classe I de Fosfatidilinositol 3-Quinases/metabolismo , Modelos Animais de Doenças , Inibidores Enzimáticos/farmacologia , Xenoenxertos , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Imageamento por Ressonância Magnética/métodos , Camundongos , Imagem Multimodal , Neoplasias/metabolismo , Neoplasias/patologia , Neovascularização Patológica/tratamento farmacológico , Neovascularização Patológica/metabolismo , Pirimidinas/farmacologia , Serina-Treonina Quinases TOR/antagonistas & inibidores , Carga Tumoral/efeitos dos fármacos , Ultrassonografia/métodos , Microtomografia por Raio-X/métodosRESUMO
Imaging of tumor microvasculature has become an important tool for studying angiogenesis and monitoring antiangiogenic therapies. Ultrasmall paramagnetic iron oxide contrast agents for indirect imaging of vasculature offer a method for quantitative measurements of vascular biomarkers such as vessel size index, blood volume, and vessel density (Q). Here, this technique is validated with direct comparisons to ex vivo micro-computed tomography angiography and histologic vessel measurements, showing significant correlations between in vivo vascular MRI measurements and ex vivo structural vessel measurements. The sensitivity of the MRI vascular parameters is also demonstrated, in combination with a multispectral analysis technique for segmenting tumor tissue to restrict the analysis to viable tumor tissue and exclude regions of necrosis. It is shown that this viable tumor segmentation increases sensitivity for detection of significant effects on blood volume and Q by two antiangiogenic therapeutics [anti-vascular endothelial growth factor (anti-VEGF) and anti-neuropilin-1] on an HM7 colorectal tumor model. Anti-vascular endothelial growth factor reduced blood volume by 36±3% (p<0.0001) and Q by 52±3% (p<0.0001) at 48 h post-treatment; the effects of anti-neuropilin-1 were roughly half as strong with a reduction in blood volume of 18±6% (p<0.05) and a reduction in Q of 33±5% (p<0.05) at 48 h post-treatment.
Assuntos
Neoplasias Colorretais/diagnóstico por imagem , Neovascularização Patológica/diagnóstico por imagem , Angiografia , Animais , Antineoplásicos/uso terapêutico , Neoplasias Colorretais/tratamento farmacológico , Imageamento por Ressonância Magnética/métodos , Camundongos , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios X , Carga Tumoral/efeitos dos fármacosRESUMO
Priming of the organ-specific premetastatic sites is thought to be an important yet incompletely understood step during metastasis. In this study, we show that the metastatic tumors we examined overexpress granulocyte-colony stimulating factor (G-CSF), which expands and mobilizes Ly6G+Ly6C+ granulocytes and facilitates their subsequent homing at distant organs even before the arrival of tumor cells. Moreover, G-CSF-mobilized Ly6G+Ly6C+ cells produce the Bv8 protein, which has been implicated in angiogenesis and mobilization of myeloid cells. Anti-G-CSF or anti-Bv8 antibodies significantly reduced lung metastasis. Transplantation of Bv8 null fetal liver cells into lethally irradiated hosts also reduced metastasis. We identified an unexpected role for Bv8: the ability to stimulate tumor cell migration through activation of one of the Bv8 receptors, prokineticin receptor (PKR)-1. Finally, we show that administration of recombinant G-CSF is sufficient to increase the numbers of Ly6G+Ly6C+ cells in organ-specific metastatic sites and results in enhanced metastatic ability of several tumors.
Assuntos
Antígenos Ly/imunologia , Fator Estimulador de Colônias de Granulócitos/farmacologia , Granulócitos/efeitos dos fármacos , Granulócitos/imunologia , Neoplasias Pulmonares/patologia , Metástase Neoplásica , Animais , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Movimento Celular , Feminino , Perfilação da Expressão Gênica , Fator Estimulador de Colônias de Granulócitos/genética , Granulócitos/citologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Nus , Camundongos SCID , Análise em Microsséries , Transplante de Neoplasias , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacologiaRESUMO
Imaging of tumor microvasculature has become an important tool for studying angiogenesis and monitoring antiangiogenic therapies. Ultrasmall paramagnetic iron oxide contrast agents for indirect imaging of vasculature offer a method for quantitative measurements of vascular biomarkers such as vessel size index, blood volume, and vessel density. Here, this technique is validated with direct comparisons to ex vivo micro-CT angiography and histologic vessel measurements, showing significant correlations between in vivo vascular MRI measurements and ex vivo structural vessel measurements. The sensitivity of the MRI vascular parameters is also demonstrated, in combination with a multispectral analysis technique for segmenting tumor tissue to restrict the analysis to viable tumor tissue and exclude regions of necrosis. It is shown that this viable tumor segmentation increases sensitivity for detection of significant effects on blood volume and vessel density by two antiangiogenic therapeutics (anti-VEGF and anti-neuropilin-1) on an HM7 colorectal tumor model. Anti-VEGF reduced blood volume by 36 +/- 3% (P < 0.0001) and vessel density by 52 +/- 3% (P < 0.0001) at 48 h posttreatment; the effects of anti-neuropilin-1 were roughly half as strong with a reduction in blood volume of 18 +/- 6% (P < 0.05) and a reduction in vessel density of 33 +/- 5% (P < 0.05) at 48 h posttreatment.
Assuntos
Angiografia , Neoplasias Colorretais/diagnóstico por imagem , Imageamento por Ressonância Magnética , Neovascularização Patológica/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Animais , Antineoplásicos/uso terapêutico , Neoplasias Colorretais/tratamento farmacológico , Imageamento por Ressonância Magnética/métodos , Camundongos , Sensibilidade e Especificidade , Carga Tumoral/efeitos dos fármacosRESUMO
It has been recently reported that treatment with an anti-placenta growth factor (PlGF) antibody inhibits metastasis and primary tumor growth. Here we show that, although anti-PlGF treatment inhibited wound healing, extravasation of B16F10 cells, and growth of a tumor engineered to overexpress the PlGF receptor (VEGFR-1), neutralization of PlGF using four novel blocking antibodies had no significant effect on tumor angiogenesis in 15 models. Also, genetic ablation of the tyrosine kinase domain of VEGFR-1 in the host did not result in growth inhibition of the anti-VEGF-A sensitive or resistant tumors tested. Furthermore, combination of anti-PlGF with anti-VEGF-A antibodies did not result in greater antitumor efficacy than anti-VEGF-A monotherapy. In conclusion, our data argue against an important role of PlGF during primary tumor growth in most models and suggest that clinical evaluation of anti-PlGF antibodies may be challenging.
Assuntos
Neoplasias/irrigação sanguínea , Neovascularização Patológica , Proteínas da Gravidez/metabolismo , Animais , Anticorpos Monoclonais/farmacologia , Linhagem Celular Tumoral , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Fator de Crescimento Placentário , Proteínas da Gravidez/antagonistas & inibidores , Fatores de Crescimento do Endotélio VascularRESUMO
PURPOSE: Little is known concerning the onset, duration, and magnitude of direct therapeutic effects of anti-vascular endothelial growth factor (VEGF) therapies. Such knowledge would help guide the rational development of targeted therapeutics from bench to bedside and optimize use of imaging technologies that quantify tumor function in early-phase clinical trials. EXPERIMENTAL DESIGN: Preclinical studies were done using ex vivo microcomputed tomography and in vivo ultrasound imaging to characterize tumor vasculature in a human HM-7 colorectal xenograft model treated with the anti-VEGF antibody G6-31. Clinical evaluation was by quantitative magnetic resonance imaging in 10 patients with metastatic colorectal cancer treated with bevacizumab. RESULTS: Microcomputed tomography experiments showed reduction in perfused vessels within 24 to 48 h of G6-31 drug administration (P Assuntos
Inibidores da Angiogênese/uso terapêutico
, Anticorpos Monoclonais/uso terapêutico
, Neoplasias Colorretais/irrigação sanguínea
, Neoplasias Colorretais/tratamento farmacológico
, Diagnóstico por Imagem
, Fator A de Crescimento do Endotélio Vascular/imunologia
, Adolescente
, Animais
, Anticorpos Monoclonais/farmacologia
, Anticorpos Monoclonais Humanizados
, Bevacizumab
, Linhagem Celular Tumoral
, Sistemas de Liberação de Medicamentos
, Feminino
, Humanos
, Camundongos
, Camundongos Nus
, Neovascularização Patológica/tratamento farmacológico
, Ensaios Antitumorais Modelo de Xenoenxerto
RESUMO
Whole-body MRI combined with a semiautomated hierarchical multispectral image analysis technique was evaluated as a method for detecting viable tumor tissue in a murine model of metastatic breast cancer (4T1 cell line). Whole-body apparent diffusion coefficient, T(2), and proton density maps were acquired in this study. The viable tumor tissue segmentation included three-stage k-means clustering of the parametric maps, morphologic operations, application of a size threshold, and reader discrimination of the segmented objects. The segmentation results were validated by histologic evaluation, and the detection accuracy of the technique was evaluated at three size thresholds (15, 100, and 500 voxels). The accuracy was 88.9% for a 500-voxel size threshold, and the area under receiver operating characteristic curve was 0.84. The regions of segmented viable tumor tissue within the primary tumors were found mostly on the periphery of the tumors in agreement with the histologic findings. The presented technique was found capable of detecting metastases and segmenting the viable tumor from necrotic regions within tumors found in this model. It offers a noninvasive, whole-body, viable tumor tissue detection method for preclinical and potentially clinical applications such as tumor screening and evaluating therapeutic efficacy.
Assuntos
Algoritmos , Inteligência Artificial , Neoplasias da Mama/diagnóstico , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Reconhecimento Automatizado de Padrão/métodos , Imagem Corporal Total/métodos , Animais , Neoplasias da Mama/secundário , Linhagem Celular Tumoral , Aumento da Imagem/métodos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
Krüppel-like factor 6 (Klf6) belongs to a family of zinc finger transcription factors known to play a role in development and tumor suppression. Although Klf6 is highly mutated in prostate cancer, its function in prostate development is unknown. We have generated a prostate-specific Klf6-deficient mouse model and report here a novel role for Klf6 in the regulation of prostate branching morphogenesis. Importantly, our study reveals a novel relationship between Klf6 and the Shh pathway. Klf6-deficiency leads to elevated levels of hedgehog pathway components (Shh, Ptc, and Gli) and loss of their localized expression, which in turn causes impaired lateral branching.
Assuntos
Inativação Gênica , Proteínas Hedgehog/metabolismo , Fatores de Transcrição Kruppel-Like/genética , Morfogênese , Próstata/crescimento & desenvolvimento , Próstata/metabolismo , Proteínas Proto-Oncogênicas/genética , Transdução de Sinais , Animais , Proteína Morfogenética Óssea 4/metabolismo , Deleção de Genes , Regulação da Expressão Gênica no Desenvolvimento , Fator 6 Semelhante a Kruppel , Fatores de Transcrição Kruppel-Like/deficiência , Fatores de Transcrição Kruppel-Like/metabolismo , Masculino , Camundongos , Músculo Liso/crescimento & desenvolvimento , Especificidade de Órgãos , Próstata/anormalidades , Próstata/patologia , Proteínas Proto-Oncogênicas/deficiência , Proteínas Proto-Oncogênicas/metabolismo , Regulação para Cima/genética , beta-Galactosidase/metabolismoRESUMO
UNLABELLED: Imaging of the glial activation that occurs in response to central nervous system trauma and inflammation could become a powerful technique for the assessment of several neuropathologies. The selective uptake and metabolism of 2-(18)F-fluoroacetate ((18)F-FAC) in glia may represent an attractive strategy for imaging glial metabolism. METHODS: We have evaluated the use of (18)F-FAC as a specific PET tracer of glial cell metabolism in rodent models of glioblastoma, stroke, and ischemia-hypoxia. RESULTS: Enhanced uptake of (18)F-FAC was observed (6.98 +/- 0.43 percentage injected dose per gram [%ID/g]; tumor-to-normal ratio, 1.40) in orthotopic U87 xenografts, compared with healthy brain tissue. The lesion extent determined by (18)F-FAC PET correlated with that determined by MRI (R(2) = 0.934, P = 0.007). After transient middle cerebral artery occlusion in the rat brain, elevated uptake of (18)F-FAC (1.00 +/- 0.03 %ID/g; lesion-to-normal ratio, 1.90) depicted the ischemic territory and correlated with infarct volumes as determined by 2,3,5-triphenyltetrazolium chloride staining (R(2) = 0.692, P = 0.010) and with the presence of activated astrocytes detected by anti-glial fibrillary acidic protein. Ischemia-hypoxia, induced by permanent ligation of the common carotid artery with transient hypoxia, resulted in persistent elevation of (18)F-FAC uptake within 30 min of the induction of hypoxia. CONCLUSION: Our data support the further evaluation of (18)F-FAC PET for the assessment of glial cell metabolism associated with neuroinflammation.
Assuntos
Radioisótopos de Flúor , Fluoracetatos , Neuroglia/metabolismo , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos , Animais , Isquemia Encefálica/metabolismo , Fluordesoxiglucose F18 , Glioblastoma/metabolismo , Hipóxia-Isquemia Encefálica/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Ratos , Ratos WistarRESUMO
Despite the availability of new targeted therapies, ductal pancreatic adenocarcinoma continues to carry a poor prognosis. Carcinoembryonic antigen-related cell adhesion molecule (CEACAM)6 has been reported as a potential biomarker and therapy target for this malignancy. We have evaluated CEACAM6 as a potential therapy target, using an antibody-drug conjugate (ADC). Expression of CEACAM6 in pancreatic adenocarcinomas was determined using immunohistochemistry on tissue microarrays. The expression pattern in granulocytes and granulocytic precursors was measured by flow cytometry. Murine xenograft and non-human primate models served to evaluate efficacy and safety, respectively. Robust expression of CEACAM6 was found in > 90% of invasive pancreatic adenocarcinomas as well as in intraepithelial neoplastic lesions. In the granulocytic lineage, CEACAM6 was expressed at all stages of granulocytic maturation except for the early lineage-committed precursor cell. The anti-CEACAM6 ADC showed efficacy against established CEACAM6-expressing tumours. In non-human primates, antigen-dependent toxicity of the ADC consisted of dose-dependent and reversible depletion of granulocytes and their precursors. This was associated with preferential and rapid localization of the antibody in bone marrow, as determined by sequential in vivo PET imaging of the radiolabelled anti-CEACAM6. Localization of the radiolabelled tracer could be attenuated by predosing with unlabelled antibody confirming specific accumulation in this compartment. Based on the expression pattern in normal and malignant pancreatic tissues, efficacy against established tumours and limited and reversible bone marrow toxicity, we propose that CEACAM6 should be considered for an ADC-based therapy approach against pancreatic adenocarcinomas and possibly other CEACAM6-positive neoplasms.
Assuntos
Adenocarcinoma/terapia , Moléculas de Adesão Celular/antagonistas & inibidores , Imunoconjugados/uso terapêutico , Neoplasias Pancreáticas/terapia , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Animais , Anticorpos Monoclonais/uso terapêutico , Anticorpos Monoclonais/toxicidade , Antígenos CD/imunologia , Antígenos CD/metabolismo , Moléculas de Adesão Celular/imunologia , Moléculas de Adesão Celular/metabolismo , Avaliação Pré-Clínica de Medicamentos/métodos , Estudos de Viabilidade , Feminino , Proteínas Ligadas por GPI , Células-Tronco Hematopoéticas/metabolismo , Humanos , Imunoconjugados/farmacocinética , Imunoconjugados/toxicidade , Macaca fascicularis , Masculino , Camundongos , Camundongos Nus , Proteínas de Neoplasias/metabolismo , Ativação de Neutrófilo , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologiaRESUMO
PURPOSE: Apomab is a fully human monoclonal antibody that induces programmed cell death through the proapoptotic receptor DR5 in various cancer cells but not in normal cells. Several lung cancer cell lines express DR5 and exhibit apoptosis in response to apomab in vitro. EXPERIMENTAL DESIGN: We investigated the efficacy of apomab and its interaction with chemotherapy in xenograft models based on human NCI-H460 non-small-cell lung carcinoma cells. In an established model of s.c. tumor xenografts, apomab or Taxol plus carboplatin chemotherapy delayed tumor progression, whereas combined treatment caused tumor regression and a substantially longer growth delay. To test apomab activity in a setting that may more closely mimic lung cancer pathology in patients, we developed a lung orthotopic model. RESULTS: In this model, microcomputed tomography imaging showed that apomab, chemotherapy, or combination treatment significantly inhibited tumor growth compared with vehicle, whereas the combination caused greater inhibition in tumor growth relative to chemotherapy or apomab. Similarly, histologic analysis revealed that apomab, chemotherapy, or the combination significantly reduced tumor size compared with vehicle, whereas the combination induced significantly greater reduction in tumor size than did chemotherapy or apomab. Furthermore, combined treatment improved 105-day survival relative to vehicle (P = 0.0023) as well as to apomab (P = 0.0445) or chemotherapy (P = 0.0415). CONCLUSION: These results show a positive interaction of apomab with chemotherapy, evidenced by significant inhibition of tumor growth as well as improved survival, thus supporting further investigation of this therapeutic approach in lung cancer patients.
Assuntos
Anticorpos Monoclonais/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/agonistas , Animais , Apoptose/efeitos dos fármacos , Carboplatina/administração & dosagem , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Feminino , Humanos , Immunoblotting , Marcação In Situ das Extremidades Cortadas , Camundongos , Camundongos Nus , Paclitaxel/administração & dosagem , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/efeitos dos fármacos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The hepatocyte growth factor (HGF) and its receptor, c-Met, have been implicated in driving proliferation, invasion, and poor prognosis in pancreatic cancer. Here, we investigated the expression of HGF and c-Met in primary pancreatic cancers and described in vitro and in vivo models in which MetMAb, a monovalent antibody against c-Met, was evaluated. First, expression of HGF and MET mRNA was analyzed in 59 primary pancreatic cancers and 51 normal samples, showing that both factors are highly expressed in pancreatic cancer. We next examined HGF responsiveness in pancreatic cancer lines to select lines that proliferate in response to HGF. Based on these studies, two lines were selected for further in vivo model development: BxPC-3 (c-Met(+), HGF(-)) and KP4 (c-Met(+), HGF(+)) cells. As BxPC-3 cells are responsive to exogenous HGF, s.c. tumor xenografts were grown in a paracrine manner with purified human HGF provided by osmotic pumps, wherein MetMAb treatment significantly inhibited tumor growth. KP4 cells are autocrine for HGF and c-Met, and MetMAb strongly inhibited s.c. tumor growth. To better model pancreatic cancer and to enable long-term survival studies, an orthotopic model of KP4 was established. MetMAb significantly inhibited orthotopic KP4 tumor growth in 4-week studies monitored by ultrasound and also improved survival in 90-day studies. MetMAb significantly reduced c-Met phosphorylation in orthotopic KP4 tumors with a concomitant decrease in Ki-67 staining. These data suggest that the HGF/c-Met axis plays an important role in the progression of pancreatic cancer and that targeting c-Met therein may have therapeutic value.