RESUMEN
Pancreatic ductal adenocarcinoma (PDAC) cells use glutamine (Gln) to support proliferation and redox balance. Early attempts to inhibit Gln metabolism using glutaminase inhibitors resulted in rapid metabolic reprogramming and therapeutic resistance. Here, we demonstrated that treating PDAC cells with a Gln antagonist, 6-diazo-5-oxo-L-norleucine (DON), led to a metabolic crisis in vitro. In addition, we observed a profound decrease in tumor growth in several in vivo models using sirpiglenastat (DRP-104), a pro-drug version of DON that was designed to circumvent DON-associated toxicity. We found that extracellular signal-regulated kinase (ERK) signaling is increased as a compensatory mechanism. Combinatorial treatment with DRP-104 and trametinib led to a significant increase in survival in a syngeneic model of PDAC. These proof-of-concept studies suggested that broadly targeting Gln metabolism could provide a therapeutic avenue for PDAC. The combination with an ERK signaling pathway inhibitor could further improve the therapeutic outcome.
Asunto(s)
Antineoplásicos , Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Humanos , Glutamina/metabolismo , Línea Celular Tumoral , Neoplasias Pancreáticas/tratamiento farmacológico , Neoplasias Pancreáticas/metabolismo , Antineoplásicos/farmacología , Carcinoma Ductal Pancreático/tratamiento farmacológico , Carcinoma Ductal Pancreático/metabolismo , Inhibidores Enzimáticos/farmacologíaRESUMEN
Pancreatic ductal adenocarcinoma (PDAC) cells maintain a high level of autophagy, allowing them to thrive in an austere microenvironment. However, the processes through which autophagy promotes PDAC growth and survival are still not fully understood. Here, we show that autophagy inhibition in PDAC alters mitochondrial function by losing succinate dehydrogenase complex iron sulfur subunit B expression by limiting the availability of the labile iron pool. PDAC uses autophagy to maintain iron homeostasis, while other tumor types assessed require macropinocytosis, with autophagy being dispensable. We observed that cancer-associated fibroblasts can provide bioavailable iron to PDAC cells, promoting resistance to autophagy ablation. To overcome this cross-talk, we used a low-iron diet and demonstrated that this augmented the response to autophagy inhibition therapy in PDAC-bearing mice. Our work highlights a critical link between autophagy, iron metabolism, and mitochondrial function that may have implications for PDAC progression.
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Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Animales , Ratones , Línea Celular Tumoral , Neoplasias Pancreáticas/patología , Carcinoma Ductal Pancreático/metabolismo , Autofagia , Homeostasis , Mitocondrias/metabolismo , Microambiente Tumoral , Neoplasias PancreáticasRESUMEN
α-ketoglutarate (KG), also referred to as 2-oxoglutarate, is a key intermediate of cellular metabolism with pleiotropic functions. Cell-permeable esterified analogs are widely used to study how KG fuels bioenergetic and amino acid metabolism and DNA, RNA, and protein hydroxylation reactions, as cellular membranes are thought to be impermeable to KG. Here we show that esterified KG analogs rapidly hydrolyze in aqueous media, yielding KG that, in contrast to prevailing assumptions, imports into many cell lines. Esterified KG analogs exhibit spurious KG-independent effects on cellular metabolism, including extracellular acidification, arising from rapid hydrolysis and de-protonation of α-ketoesters, and significant analog-specific inhibitory effects on glycolysis or mitochondrial respiration. We observe that imported KG decarboxylates to succinate in the cytosol and contributes minimally to mitochondrial metabolism in many cell lines cultured in normal conditions. These findings demonstrate that nuclear and cytosolic KG-dependent reactions may derive KG from functionally distinct subcellular pools and sources.
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Aminoácidos/metabolismo , Metabolismo Energético , Ésteres/metabolismo , Ácidos Cetoglutáricos/metabolismo , Mitocondrias/metabolismo , Ácido Succínico/metabolismo , Animales , Línea Celular Tumoral , Citosol/metabolismo , Ésteres/química , Glucólisis , Células HEK293 , Humanos , Hidrólisis , Interacciones Hidrofóbicas e Hidrofílicas , Ácidos Cetoglutáricos/química , Ratones , Consumo de Oxígeno , Células RAW 264.7RESUMEN
Immune evasion is a major obstacle for cancer treatment. Common mechanisms of evasion include impaired antigen presentation caused by mutations or loss of heterozygosity of the major histocompatibility complex class I (MHC-I), which has been implicated in resistance to immune checkpoint blockade (ICB) therapy1-3. However, in pancreatic ductal adenocarcinoma (PDAC), which is resistant to most therapies including ICB4, mutations that cause loss of MHC-I are rarely found5 despite the frequent downregulation of MHC-I expression6-8. Here we show that, in PDAC, MHC-I molecules are selectively targeted for lysosomal degradation by an autophagy-dependent mechanism that involves the autophagy cargo receptor NBR1. PDAC cells display reduced expression of MHC-I at the cell surface and instead demonstrate predominant localization within autophagosomes and lysosomes. Notably, inhibition of autophagy restores surface levels of MHC-I and leads to improved antigen presentation, enhanced anti-tumour T cell responses and reduced tumour growth in syngeneic host mice. Accordingly, the anti-tumour effects of autophagy inhibition are reversed by depleting CD8+ T cells or reducing surface expression of MHC-I. Inhibition of autophagy, either genetically or pharmacologically with chloroquine, synergizes with dual ICB therapy (anti-PD1 and anti-CTLA4 antibodies), and leads to an enhanced anti-tumour immune response. Our findings demonstrate a role for enhanced autophagy or lysosome function in immune evasion by selective targeting of MHC-I molecules for degradation, and provide a rationale for the combination of autophagy inhibition and dual ICB therapy as a therapeutic strategy against PDAC.
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Adenocarcinoma/inmunología , Autofagia/inmunología , Carcinoma Ductal Pancreático/inmunología , Antígenos de Histocompatibilidad Clase I/inmunología , Antígenos de Histocompatibilidad Clase I/metabolismo , Neoplasias Pancreáticas/inmunología , Escape del Tumor/inmunología , Adenocarcinoma/tratamiento farmacológico , Adenocarcinoma/genética , Adenocarcinoma/patología , Animales , Presentación de Antígeno/efectos de los fármacos , Presentación de Antígeno/inmunología , Autofagia/efectos de los fármacos , Autofagia/genética , Linfocitos T CD8-positivos/efectos de los fármacos , Linfocitos T CD8-positivos/inmunología , Carcinoma Ductal Pancreático/tratamiento farmacológico , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patología , Puntos de Control del Ciclo Celular/efectos de los fármacos , Puntos de Control del Ciclo Celular/inmunología , Línea Celular Tumoral , Cloroquina/farmacología , Femenino , Antígenos de Histocompatibilidad Clase I/genética , Humanos , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Lisosomas/efectos de los fármacos , Lisosomas/metabolismo , Masculino , Ratones , Neoplasias Pancreáticas/tratamiento farmacológico , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patología , Escape del Tumor/efectos de los fármacosRESUMEN
The roles of tumor-associated macrophages (TAMs) and circulating monocytes in human cancer are poorly understood. Here, we show that monocyte subpopulation distribution and transcriptomes are significantly altered by the presence of endometrial and breast cancer. Furthermore, TAMs from endometrial and breast cancers are transcriptionally distinct from monocytes and their respective tissue-resident macrophages. We identified a breast TAM signature that is highly enriched in aggressive breast cancer subtypes and associated with shorter disease-specific survival. We also identified an auto-regulatory loop between TAMs and cancer cells driven by tumor necrosis factor alpha involving SIGLEC1 and CCL8, which is self-reinforcing through the production of CSF1. Together these data provide direct evidence that monocyte and macrophage transcriptional landscapes are perturbed by cancer, reflecting patient outcomes.
Asunto(s)
Biomarcadores de Tumor/metabolismo , Neoplasias de la Mama/metabolismo , Reprogramación Celular , Macrófagos/metabolismo , Monocitos/metabolismo , Comunicación Paracrina , Transcripción Genética , Antineoplásicos/farmacología , Biomarcadores de Tumor/genética , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Quimiocina CCL8/genética , Quimiocina CCL8/metabolismo , Neoplasias Endometriales/genética , Neoplasias Endometriales/metabolismo , Neoplasias Endometriales/patología , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Células Madre Pluripotentes Inducidas/metabolismo , Factor Estimulante de Colonias de Macrófagos/genética , Macrófagos/patología , Terapia Molecular Dirigida , Monocitos/patología , Lectina 1 Similar a Ig de Unión al Ácido Siálico/genética , Lectina 1 Similar a Ig de Unión al Ácido Siálico/metabolismo , Transducción de Señal , Células THP-1 , Microambiente TumoralRESUMEN
Autophagy has been shown to be elevated in pancreatic ductal adenocarcinoma (PDAC), and its role in promoting established tumor growth has made it a promising therapeutic target. However, due to limitations of prior mouse models as well as the lack of potent and selective autophagy inhibitors, the ability to fully assess the mechanistic basis of how autophagy supports pancreatic cancer has been limited. To test the feasibility of treating PDAC using autophagy inhibition and further our understanding of the mechanisms of protumor effects of autophagy, we developed a mouse model that allowed the acute and reversible inhibition of autophagy. We observed that autophagy inhibition causes significant tumor regression in an autochthonous mouse model of PDAC. A detailed analysis of these effects indicated that the tumor regression was likely multifactorial, involving both tumor cell-intrinsic and host effects. Thus, our study supports that autophagy inhibition in PDAC may have future utility in the treatment of pancreatic cancer and illustrates the importance of assessing complex biological processes in relevant autochthonous models.Significance: This work demonstrates that autophagy is critical pancreatic tumor maintenance through tumor cell-intrinsic and -extrinsic mechanisms. These results have direct clinical relevance to ongoing clinical trials as well as drug-development initiatives. Cancer Discov; 8(3); 276-87. ©2018 AACR.See related commentary by Noguera-Ortega and Amaravadi, p. 266This article is highlighted in the In This Issue feature, p. 253.
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Autofagia/fisiología , Carcinoma Ductal Pancreático/patología , Neoplasias Experimentales/genética , Neoplasias Pancreáticas/patología , Animales , Proteínas Relacionadas con la Autofagia/genética , Carcinoma Ductal Pancreático/tratamiento farmacológico , Carcinoma Ductal Pancreático/genética , Cisteína Endopeptidasas/genética , Doxiciclina/farmacología , Ratones Transgénicos , Neoplasias Experimentales/patología , Neoplasias Pancreáticas/tratamiento farmacológico , Neoplasias Pancreáticas/genéticaRESUMEN
BACKGROUND: Adults with congenital heart disease (CHD) face increased risk for morbidity and mortality with age, but few prognostic models exist. OBJECTIVE: This study aims to assess whether the Heart Failure Survival Score (HFSS), which risk stratifies patients for heart transplantation, predicts outcomes in adults with moderate or complex CHD. METHODS: This was a multicenter, retrospective study which identified 441 patients with moderate or complex CHD between 2005 and 2013, of whom 169 had all the HFSS parameters required to calculate the risk score. Because all study patients were deemed low risk by the HFSS, the score was dichotomized at the median (10.4). Outcomes included death, transplant or ventricular assist device (VAD), arrhythmia requiring treatment, nonelective cardiovascular (CV) hospitalizations, and the composite. Associations of mean HFSS and HFSS <10.4 with each outcome were assessed. RESULTS: The cohort had mean ± standard deviation age of 33.6 ± 12.6 years, peak VO2 21.8 ± 7.5 mL/kg/min, HFSS of 10.45 ± 0.88, and median years follow-up of 2.7 (1.1, 5.2). There were five deaths (2.8%), no transplants or VADs, 25 arrhythmias (14.8%), 22 CV hospitalizations (13%), and 39 composites (23.1%). Lower mean HFSS was observed for patients who died (9.6 ± 0.83 vs. 10.5 ± 0.87, P = .02), arrhythmia requiring treatment (10.0 ± 0.70 vs. 10.5 ± 0.89, P = .005), CV hospitalizations (9.9 ± 0.73 vs. 10.5 ± 0.88, P = .002), and the composite (10.0 ± 0.70 vs. 10.6 ± 0.89, P < .001). The positive and negative predictive values of HFSS <10.4 for the composite were 34% and 88% respectively, with sensitivity and specificity 74% and 56%. CONCLUSIONS: Although a low HFSS was significantly associated with outcomes, it did not adequately risk stratify adults with CHD, whose heterogeneous pathophysiology differs from that of the acquired heart failure population. Further studies are warranted to provide a more accurate prognosis.
Asunto(s)
Técnicas de Apoyo para la Decisión , Cardiopatías Congénitas/complicaciones , Insuficiencia Cardíaca/etiología , Adulto , Factores de Edad , Boston , Femenino , Cardiopatías Congénitas/diagnóstico , Cardiopatías Congénitas/mortalidad , Cardiopatías Congénitas/cirugía , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/mortalidad , Insuficiencia Cardíaca/cirugía , Trasplante de Corazón , Hospitalización , Humanos , Masculino , Persona de Mediana Edad , New York , Valor Predictivo de las Pruebas , Pronóstico , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Factores de Tiempo , Adulto JovenRESUMEN
Progression to an angiogenic state is a critical event in tumor development, yet few patient characteristics have been identified that can be mechanistically linked to this transition. Antiphospholipid autoantibodies (aPLs) are prevalent in many human cancers and can elicit proangiogenic expression in several cell types, but their role in tumor biology is unknown. Herein, we observed that the elevation of circulating aPLs among breast cancer patients is specifically associated with invasive-stage tumors. By using multiple in vivo models of breast cancer, we demonstrated that aPL-positive IgG from patients with autoimmune disease rapidly accelerates tumor angiogenesis and consequent tumor progression, particularly in slow-growing avascular tumors. The action of aPLs was local to the tumor site and elicited leukocytic infiltration and tumor invasion. Tumor cells treated with aPL-positive IgG expressed multiple proangiogenic genes, including vascular endothelial growth factor, tissue factor (TF), and colony-stimulating factor 1. Knockdown and neutralization studies demonstrated that the effects of aPLs on tumor angiogenesis and growth were dependent on tumor cell-derived TF. Tumor-derived TF was essential for the development of pericyte coverage of tumor microvessels and aPL-induced tumor cell expression of chemokine ligand 2, a mediator of pericyte recruitment. These findings identify antiphospholipid autoantibodies as a potential patient-specific host factor promoting the transition of indolent tumors to an angiogenic malignant state through a TF-mediated pathogenic mechanism.
Asunto(s)
Anticuerpos Antifosfolípidos/química , Neoplasias/metabolismo , Neovascularización Patológica , Tromboplastina/metabolismo , Animales , Neoplasias de la Mama/patología , Línea Celular Tumoral , Proliferación Celular , Supervivencia Celular , Progresión de la Enfermedad , Endotoxinas/química , Femenino , Regulación de la Expresión Génica , Humanos , Inmunoglobulina G/química , Ratones , Ratones Endogámicos C57BL , Ratones Desnudos , Microscopía Fluorescente , Trasplante de NeoplasiasRESUMEN
Accumulated evidences have demonstrated that signal transducer and activator of transcription 3 (STAT3) is a critical link between inflammation and cancer. Multiple studies have indicated that persistent activation of STAT3 in epithelial/tumor cells in inflammation-associated colorectal cancer (CRC) is associated with sphingosine-1-phosphate (S1P) receptor signaling. In inflammatory response whereby interleukin (IL)-6 production is abundant, STAT3-mediated pathways were found to promote the activation of sphingosine kinases (SphK1 and SphK2) leading to the production of S1P. Reciprocally, S1P encourages the activation of STAT3 through a positive autocrine-loop signaling. The crosstalk between IL-6, STAT3 and sphingolipid regulated pathways may play an essential role in tumorigenesis and tumor progression in inflamed intestines. Therapeutics targeting both STAT3 and sphingolipid are therefore likely to contribute novel and more effective therapeutic strategies against inflammation-associated CRC.
Asunto(s)
Neoplasias Colorrectales/etiología , Mediadores de Inflamación/metabolismo , Inflamación/complicaciones , Lisofosfolípidos/metabolismo , Factor de Transcripción STAT3/metabolismo , Esfingosina/análogos & derivados , Animales , Antiinflamatorios/uso terapéutico , Antineoplásicos/uso terapéutico , Comunicación Autocrina , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/inmunología , Neoplasias Colorrectales/metabolismo , Humanos , Inflamación/tratamiento farmacológico , Inflamación/inmunología , Inflamación/metabolismo , Interleucina-6/metabolismo , Terapia Molecular Dirigida , Transducción de Señal , Esfingosina/metabolismoRESUMEN
B7-H1 (PD-L1) on immune cells plays an important role in T cell coinhibition by binding its receptor PD-1. Here, we show that both human and mouse intestinal epithelium express B7-H1 and that B7-H1-deficient mice are highly susceptible to dextran sodium sulfate (DSS)- or trinitrobenzenesulfonic acid (TNBS)-induced gut injury. B7-H1 deficiency during intestinal inflammation leads to high mortality and morbidity, which are associated with severe pathological manifestations in the colon, including loss of epithelial integrity and overgrowth of commensal bacteria. Results from bone marrow chimeric and knockout mice show that B7-H1 expressed on intestinal parenchyma, but not on hematopoietic cells, controls intestinal inflammation in an adaptive immunity-independent fashion. Finally, we demonstrate that B7-H1 dampened intestinal inflammation by inhibiting tumor necrosis factor α (TNF-α) production and by stimulating interleukin 22 secretion from CD11c(+)CD11b(+) lamina propria cells. Thus, our data uncover a mechanism through which intestinal tissue-expressed B7-H1 functions as an essential ligand for innate immune cells to prevent gut inflammation.
Asunto(s)
Colitis/metabolismo , Mucosa Intestinal/metabolismo , Receptor de Muerte Celular Programada 1/metabolismo , Animales , Células de la Médula Ósea/metabolismo , Colitis/inducido químicamente , Colitis/inmunología , Humanos , Inmunidad Innata , Inflamación/metabolismo , Interleucinas/metabolismo , Mucosa Intestinal/inmunología , Ratones , Ratones Endogámicos C57BL , Receptor de Muerte Celular Programada 1/genética , Dodecil Sulfato de Sodio/toxicidad , Ácido Trinitrobencenosulfónico/toxicidad , Factor de Necrosis Tumoral alfa/metabolismo , Interleucina-22RESUMEN
Chronic inflammation is an important risk factor for the development of colorectal cancer; however, the mechanism of tumorigenesis especially tumor progression to malignancy in the inflamed colon is still unclear. Our study shows that epithelial signal transducer and activator of transcription 3 (STAT3), persistently activated in inflamed colon, is not required for inflammation-induced epithelial overproliferation and the development of early-stage tumors; however, it is essential for tumor progression to advanced malignancy. We found that one of the mechanisms that epithelial STAT3 regulates in tumor progression might be to modify leukocytic infiltration in the large intestine. Activation of epithelial STAT3 promotes the infiltration of the CD8+ lymphocyte population but inhibits the recruitment of regulatory T (Treg) lymphocytes. The loss of Stat3 in epithelial cells promoted the expression of cytokines/chemokines including CCL19, CCL28, and RANTES, which are known to be able to recruit Treg lymphocytes. Linked to these changes was the pathway mediated by sphingosine 1-phosphate receptor 1 and sphingosine 1-phosphate kinases, which is activated in colonic epithelial cells in inflamed colon with functional STAT3 but not in epithelial cells deleted of STAT3. Our data suggest that epithelial STAT3 plays a critical role in inflammation-induced tumor progression through regulation of leukocytic recruitment especially the infiltration of Treg cells in the large intestine.
Asunto(s)
Transformación Celular Neoplásica/metabolismo , Colitis Ulcerosa/metabolismo , Neoplasias Colorrectales/metabolismo , Factor de Transcripción STAT3/metabolismo , Linfocitos T Reguladores/inmunología , Adenocarcinoma/metabolismo , Anciano , Animales , Linfocitos T CD8-positivos/inmunología , Movimiento Celular/inmunología , Proliferación Celular , Quimiocina CCL19/biosíntesis , Quimiocina CCL5/biosíntesis , Quimiocinas CC/biosíntesis , Colon/inmunología , Colon/patología , Células Epiteliales/metabolismo , Humanos , Inflamación/inmunología , Mucosa Intestinal/metabolismo , Leucocitos/metabolismo , Activación de Linfocitos/inmunología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Persona de Mediana Edad , Receptores de Lisoesfingolípidos/metabolismo , Factor de Transcripción STAT3/genéticaRESUMEN
UNLABELLED: Annexin A5 (AnxA5) has a high affinity for phosphatidylserine. The protein is widely used to detect apoptotic cells because phosphatidylserine, a phospholipid that is normally present in the inner leaflets of cytoplasmic membranes, becomes translocated to the outer leaflets during programmed cell death. Here we report the novel observation that AnxA5 binds to Gram-negative bacteria via the lipid A domain of lipopolysaccharide (LPS). Binding of AnxA5 to bacteria was measured quantitatively, confirmed by fluorescence microscopy, and found to be inhibited by antibodies against lipid A. AnxA5 also bound to purified dot-blotted LPS and lipid A. Through ellipsometry, we found that the binding of AnxA5 to purified LPS was calcium dependent and rapid and showed a high affinity-characteristics similar to those of AnxA5 binding to phosphatidylserine. Initial functional studies indicated that AnxA5 can affect LPS activities. AnxA5 inhibited LPS-mediated gelation in the Limulus amebocyte lysate assay. Incubation of LPS with the protein reduced the quantity of tumor necrosis factor alpha (TNF-α) released by cultured monocytes compared to that released upon incubation with LPS alone. Initial in vivo experiments indicated that injection of mice with LPS preincubated with AnxA5 produced serum TNF-α levels lower than those seen after injection of LPS alone. These data demonstrate that AnxA5 binds to LPS and open paths to investigation of the potential biological and therapeutic implications of this interaction. IMPORTANCE: AnxA5 is highly expressed in cells that have a barrier function-including, among others, vascular endothelium, placental trophoblasts, and epithelial cells lining bile ducts, renal tubules, mammary ducts, and nasal epithelium. The protein has been well characterized for its binding to phospholipid bilayers that contain phosphatidylserine. This report of a previously unrecognized activity of AnxA5 opens the door to investigation of the possibility that this binding may have biological and therapeutic ramifications. In view of the tissue expression of the protein, the present results suggest the possibility that AnxA5 plays a role in modulating the host defense against lipopolysaccharide at these anatomic sites, where cells may interface with microorganisms. These results also raise the intriguing possibility that AnxA5 or analogous proteins or peptides could provide novel approaches to addressing the difficult clinical problem of Gram-negative sepsis.
Asunto(s)
Anexina A5/metabolismo , Bacterias/metabolismo , Endotoxinas/antagonistas & inhibidores , Endotoxinas/metabolismo , Lipopolisacáridos/antagonistas & inhibidores , Lipopolisacáridos/metabolismo , Animales , Calcio/metabolismo , Línea Celular , Endotoxinas/toxicidad , Femenino , Cinética , Prueba de Limulus , Lipopolisacáridos/toxicidad , Masculino , Ratones , Ratones Endogámicos C57BL , Microscopía Fluorescente , Monocitos/efectos de los fármacos , Monocitos/inmunología , Factor de Necrosis Tumoral alfa/sangre , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Nutritional and genetic risk factors for intestinal tumors are additive on mouse tumor phenotype, establishing that diet and genetic factors impact risk by distinct combinatorial mechanisms. In a mouse model of dietary-induced sporadic small and large intestinal cancer in WT mice in which tumor etiology, lag, incidence, and frequency reflect >90% of intestinal cancer in Western societies, dietary-induced risk altered gene expression profiles predominantly in villus cells of the histologically normal mucosa, in contrast to targeting of crypt cells by inheritance of an Apc(1638N) allele or homozygous inactivation of p21(Waf1/cip1), and profiles induced by each risk factor were distinct at the gene or functional group level. The dietary-induced changes in villus cells encompassed ectopic expression of Paneth cell markers (a lineage normally confined to the bottom of small intestinal crypts), elevated expression of the Wnt receptor Fzd5 and of EphB2 (genes necessary for Paneth cell differentiation and localization to the crypt bottom), and increased Wnt signaling in villus cells. Ectopic elevation of these markers was also present in the colon crypts, which are also sites of sporadic tumors in the nutritional model. Elevating dietary vitamin D(3) and calcium, which prevents tumor development, abrogated these changes in the villus and colon cells. Thus, common intestinal cancer driven by diet involves mechanisms of tumor development distinct from those mechanisms that cause tumors induced by the rare inheritance of a mutant adenomatous polyposis coli (Apc) allele. This is fundamental for understanding how common sporadic tumors arise and in evaluating relative risk in the population.
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Biomarcadores/metabolismo , Colon , Neoplasias del Colon/etiología , Dieta/efectos adversos , Mucosa Intestinal , Neoplasias Intestinales/etiología , Células de Paneth/metabolismo , Animales , Transformación Celular Neoplásica , Colon/citología , Colon/fisiología , Neoplasias del Colon/genética , Neoplasias del Colon/metabolismo , Neoplasias del Colon/patología , Modelos Animales de Enfermedad , Expresión Génica , Humanos , Mucosa Intestinal/citología , Mucosa Intestinal/fisiología , Neoplasias Intestinales/genética , Neoplasias Intestinales/metabolismo , Neoplasias Intestinales/patología , Ratones , Ratones Endogámicos C57BL , Células de Paneth/citología , Distribución Aleatoria , Factores de RiesgoAsunto(s)
Colon/metabolismo , Colon/patología , Inflamación/metabolismo , Inflamación/patología , Lesiones Precancerosas/metabolismo , Lesiones Precancerosas/patología , Factor de Transcripción STAT3/metabolismo , Animales , Progresión de la Enfermedad , Hematopoyesis , Humanos , Ratones , Modelos Biológicos , Serina-Treonina Quinasas TOR/metabolismoRESUMEN
Antiretroviral drugs are ineffective at treating viral infection in the brain because they cannot freely diffuse across the blood-brain barrier (BBB). Therefore, HIV-1 viral replication persists in the central nervous system (CNS) and continues to augment the neuropathogenesis process. Nanotechnology can play a pivotal role in HIV-1 therapeutics as it can increase drug solubility, enhance systemic bioavailability, and at the same time offer multifunctionality. Moreover, following conjugation with transferrin (Tf), these drug-loaded nanoformulations can permeate across biological barriers such as the blood brain barrier (BBB) via a receptor mediated transport mechanism. In the current study, we have stably incorporated the antiviral drug, Saquinavir, within Tf-conjugated quantum rods (QRs), which are novel nanoparticles with unique optical properties. We have evaluated the transversing ability of the QR-Tf-Saquinavir nanoformulation across an in vitro model of BBB. In addition, we have analyzed the subsequent antiviral efficacy of this targeted nanoformulation in HIV-1 infected peripheral blood mononuclear cells (PBMCs), which are cultured on the basolateral end of the in vitro BBB model. Our results show a significant uptake of QR-Tf-Saquinavir by brain microvascular endothelial cells (BMVECs), which constitute the BBB. In addition, we observed a significant enhancement in the transversing capability of QR-Tf-Saquinavir across the BBB, along with a marked decrease in HIV-1 viral replication in the PBMCs. These observations indicate that drug-loaded nanoparticles can deliver therapeutics across the BBB. These results highlight the potential of this nanoformulation in the treatment of Neuro-AIDS and other neurological disorders.
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Fármacos Anti-VIH/farmacocinética , Barrera Hematoencefálica , Portadores de Fármacos/farmacocinética , Nanotubos/química , Saquinavir/farmacocinética , Transferrina/farmacocinética , Fármacos Anti-VIH/química , Técnicas de Cultivo de Célula/métodos , Células Cultivadas , Portadores de Fármacos/química , Células Endoteliales/metabolismo , VIH-1/efectos de los fármacos , Humanos , Leucocitos Mononucleares/virología , Saquinavir/química , Transferrina/química , Carga ViralRESUMEN
Inflammatory bowel disease (IBD) is a high-risk condition for human colorectal cancer. However, our mechanistic understanding of the link between inflammation and tumorigenesis in the colon is limited. Here we established a novel mouse model of colitis-associated cancer by genetically inactivating signal transducer and activator of transcription 3 (Stat3) in macrophages, with partial deletion in other myeloid and lymphoid cells. Inflammation developed in the colon of mutant mice spontaneously, and tumor lesions, including invasive carcinoma, arose in the inflamed region of the intestine with a frequency similar to that observed in human IBD patients. The development of both inflammation and tumors in the mutant mice required the presence of microflora. Indeed, inflammation was associated with disruption of colonic homeostasis, fulminant epithelial/tumor cell proliferation, and activation of the mammalian target of rapamycin (mTOR)-Stat3 pathway in epithelial and tumor cells. The activation of this pathway was essential for both the excess proliferation of epithelial/tumor cells and the disruption of colonic homeostasis in the mutant mice. Notably, a similar abnormal up-regulation of mTOR-Stat3 signaling was consistently observed in the colonic epithelial cells of human IBD patients with active disease. These studies demonstrate a novel mouse model of IBD-colorectal cancer progression in which disrupted immune regulation, mTOR-Stat3 signaling, and epithelial hyperproliferation are integrated and simultaneously linked to the development of malignancy.
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Proliferación Celular , Transformación Celular Neoplásica/genética , Modelos Animales de Enfermedad , Inflamación/genética , Enfermedades Inflamatorias del Intestino/patología , Mucosa Intestinal/patología , Péptidos y Proteínas de Señalización Intracelular/fisiología , Ratones , Proteínas Serina-Treonina Quinasas/fisiología , Animales , Carcinoma/etiología , Carcinoma/genética , Carcinoma/patología , Transformación Celular Neoplásica/inmunología , Transformación Celular Neoplásica/patología , Colitis/complicaciones , Colitis/genética , Colitis/patología , Colon/metabolismo , Colon/patología , Neoplasias Colorrectales/etiología , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , Progresión de la Enfermedad , Humanos , Inflamación/complicaciones , Inflamación/patología , Enfermedades Inflamatorias del Intestino/complicaciones , Enfermedades Inflamatorias del Intestino/genética , Mucosa Intestinal/metabolismo , Péptidos y Proteínas de Señalización Intracelular/genética , Ratones Endogámicos C57BL , Ratones Transgénicos , Proteínas Serina-Treonina Quinasas/genética , Factor de Transcripción STAT3/genética , Factor de Transcripción STAT3/fisiología , Transducción de Señal/genética , Transducción de Señal/fisiología , Serina-Treonina Quinasas TORRESUMEN
A Western-style diet (WD), defined by high-fat, low-calcium, and vitamin D content, is associated with increased risk of human colorectal cancer. Understanding molecular mechanisms altered by the WD is crucial to develop preventive and therapeutic strategies. Effects of a WD on the colonic transcriptome of C57Bl/6J mice, a model for sporadic colon cancer, were studied at endpoints before tumors occur. To assess whether a WD induces inflammatory changes, expression profiles of a broad spectrum of inflammatory proteins were performed and numbers of lamina propria macrophages were determined with semiquantitative morphometry. Transcriptome changes were translated into molecular interaction network maps and pathways. Pathways related to oxidative stress response; lipid, glutathione, and xenobiotic metabolism; and the immune response were perturbed by the WD. Several nuclear factor-erythroid 2-related factor 2- and aryl hydrocarbon receptor-dependent genes, including those coding for enzymes involved in phase 1 and 2 drug metabolism and oxidative stress responses, were induced. Oxidative stress was demonstrated by measurements of endogenous colonic redox-sensitive compound concentrations. Perturbations in immune response-related pathways, expression of inflammatory proteins, and increased numbers of lamina propria macrophages showed that the WD significantly alters the local colonic immune response. Collectively, these data suggest that consumption of a WD interferes with networks of related biological response pathways involving colonic lipid metabolism, oxidative stress, and the immune response. These new findings impact our understanding of links between consumption of WD and colon carcinogenesis, providing additional information for developing preventive means for decreasing colorectal cancer risk.
Asunto(s)
Neoplasias del Colon/etiología , Dieta/efectos adversos , Homeostasis/efectos de los fármacos , Inmunidad/efectos de los fármacos , Estrés Oxidativo/fisiología , Animales , Neoplasias Colorrectales/epidemiología , Neoplasias Colorrectales/etiología , Modelos Animales de Enfermedad , Perfilación de la Expresión Génica , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Análisis de Secuencia por Matrices de Oligonucleótidos , ARN/genética , ARN/aislamiento & purificación , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transcripción Genética/efectos de los fármacos , Aumento de PesoRESUMEN
Curcumin exhibits anti-inflammatory and antitumor activity and is being tested in clinical trials as a chemopreventive agent for colon cancer. Curcumin's chemopreventive activity was tested in a transgenic mouse model of lung cancer that expresses the human Ki-ras(G12C) allele in a doxycycline (DOX) inducible and lung-specific manner. The effects of curcumin were compared with the lung tumor promoter, butylated hydroxytoluene (BHT), and the lung cancer chemopreventive agent, sulindac. Treatment of DOX-induced mice with dietary curcumin increased tumor multiplicity (36.3 +/- 0.9 versus 24.3 +/- 0.2) and progression to later stage lesions, results which were similar to animals that were co-treated with DOX/BHT. Microscopic examination showed that the percentage of lung lesions that were adenomas and adenocarcinomas increased to 66% in DOX/BHT, 66% in DOX/curcumin and 49% in DOX/BHT/curcumin-treated groups relative to DOX only treated mice (19%). Immunohistochemical analysis also showed increased evidence of inflammation in DOX/BHT, DOX/curcumin and DOX/BHT/curcumin mice relative to DOX only treated mice. In contrast, co-treatment of DOX/BHT mice with 200 p.p.m. [DOSAGE ERROR CORRECTED] of sulindac inhibited the progression of lung lesions and reduced the inflammation. Lung tissue from DOX/curcumin-treated mice demonstrated a significant increase (33%; P = 0.01) in oxidative damage, as assessed by the levels of carbonyl protein formation, relative to DOX-treated control mice after 1 week on the curcumin diet. These results suggest that curcumin may exhibit organ-specific effects to enhance reactive oxygen species formation in the damaged lung epithelium of smokers and ex-smokers. Ongoing clinical trials thus may need to exclude smokers and ex-smokers in chemopreventive trials of curcumin.
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Anticarcinógenos/farmacología , Transformación Celular Neoplásica/efectos de los fármacos , Curcumina/farmacología , Neoplasias Pulmonares/tratamiento farmacológico , Animales , Anticarcinógenos/efectos adversos , Hidroxitolueno Butilado/toxicidad , Curcumina/efectos adversos , Doxiciclina/farmacología , Genes ras , Neoplasias Pulmonares/inducido químicamente , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Ratones , Ratones Transgénicos , Especificidad de Órganos , Especies Reactivas de Oxígeno/metabolismo , Sulindac/farmacologíaRESUMEN
The development of a supportive vasculature is essential for tumor progression. In a mouse model of breast cancer, we found that tumor-associated macrophages that are recruited to the tumor just before malignant conversion are essential for the angiogenic switch. These findings establish a causal linkage to explain well-documented clinical correlations between macrophages, microvessel density, and poor prognosis in breast tumors.
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Transformación Celular Neoplásica/patología , Macrófagos/patología , Neoplasias Mamarias Experimentales/irrigación sanguínea , Animales , Transformación Celular Neoplásica/inmunología , Modelos Animales de Enfermedad , Macrófagos/inmunología , Neoplasias Mamarias Experimentales/inmunología , Neoplasias Mamarias Experimentales/patología , Ratones , Ratones Transgénicos , Neovascularización Patológica/inmunología , Neovascularización Patológica/patologíaRESUMEN
Although the presence of macrophages in tumors has been correlated with poor prognosis, until now there was no direct observation of how macrophages are involved in hematogenous metastasis. In this study, we use multiphoton microscopy to show, for the first time, that tumor cell intravasation occurs in association with perivascular macrophages in mammary tumors. Furthermore, we show that perivascular macrophages of the mammary tumor are associated with tumor cell intravasation in the absence of local angiogenesis. These results show that the interaction between macrophages and tumor cells lying in close proximity defines a microenvironment that is directly involved in the intravasation of cancer cells in mammary tumors.