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1.
J Am Board Fam Med ; 37(2): 196-205, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38740486

RESUMEN

PURPOSE: Food insecurity (FI) is a hidden epidemic associated with worsening health outcomes affecting 33.8 million people in the US in 2021. Although studies demonstrate the importance of health care clinician assessment of a patient's food insecurity, little is known about whether Family Medicine clinicians (FMC) discuss FI with patients and what barriers influence their ability to communicate about FI. This study evaluated FM clinicians' food insecurity screening practices to evaluate screening disparities and identify barriers that influence the decision to communicate about FI. METHODS: Data were gathered and analyzed as part of the 2022 Council of Academic Family Medicine's Educational Research Alliance survey of Family Medicine general membership. RESULTS: The majority of respondents reported (66.9%) that their practice has a screening system for food insecurity, and most practices used a verbal screen with staff other than the clinician (41%) at specific visits (63.8%). Clinicians reported "rarely or never asking about FI" 40% of the time and only asking "always or frequently" 6.7% of the time. Inadequate time during appointments (44.5%) and other medical issues taking priority (29.4%) were identified as the most common barriers. The lack of resources available in the community was a significant barrier for clinicians who worked in rural areas. CONCLUSIONS: This survey provides insight into food insecurity screening disparities and identifies obstacles to FMC screening, such as time constraints, lack of resources, and knowledge of available resources. Understanding current communication practices could create opportunities for interventions to identify food insecurity and impact "Food as Medicine."


Asunto(s)
Medicina Familiar y Comunitaria , Inseguridad Alimentaria , Humanos , Medicina Familiar y Comunitaria/estadística & datos numéricos , Femenino , Masculino , Relaciones Médico-Paciente , Encuestas y Cuestionarios , Estados Unidos , Tamizaje Masivo/estadística & datos numéricos , Adulto , Persona de Mediana Edad , Comunicación , Barreras de Comunicación , Pautas de la Práctica en Medicina/estadística & datos numéricos
3.
PLoS Biol ; 12(12): e1002013, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25460353

RESUMEN

Most epithelial tubes arise as small buds and elongate by regulated morphogenetic processes including oriented cell division, cell rearrangements, and changes in cell shape. Through live analysis of Drosophila renal tubule morphogenesis we show that tissue elongation results from polarised cell intercalations around the tubule circumference, producing convergent-extension tissue movements. Using genetic techniques, we demonstrate that the vector of cell movement is regulated by localised epidermal growth factor (EGF) signalling from the distally placed tip cell lineage, which sets up a distal-to-proximal gradient of pathway activation to planar polarise cells, without the involvement for PCP gene activity. Time-lapse imaging at subcellular resolution shows that the acquisition of planar polarity leads to asymmetric pulsatile Myosin II accumulation in the basal, proximal cortex of tubule cells, resulting in repeated, transient shortening of their circumferential length. This repeated bias in the polarity of cell contraction allows cells to move relative to each other, leading to a reduction in cell number around the lumen and an increase in tubule length. Physiological analysis demonstrates that animals whose tubules fail to elongate exhibit abnormal excretory function, defective osmoregulation, and lethality.


Asunto(s)
Movimiento Celular , Polaridad Celular , Drosophila melanogaster/citología , Factor de Crecimiento Epidérmico/metabolismo , Túbulos de Malpighi/embriología , Morfogénesis , Miosina Tipo II/metabolismo , Transducción de Señal , Animales , Linaje de la Célula , Drosophila melanogaster/embriología , Drosophila melanogaster/genética , Embrión no Mamífero/citología , Embrión no Mamífero/metabolismo , Desarrollo Embrionario , Epitelio/embriología , Epitelio/metabolismo , Receptores ErbB/metabolismo , Genes de Insecto , Homeostasis , Túbulos de Malpighi/citología , Modelos Biológicos
4.
Am Fam Physician ; 90(12): 851-8, 2014 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-25591185

RESUMEN

Down syndrome is the most common chromosomal abnormality, occurring in one in 691 live births in the United States each year. Prenatally, the sequential contingent test for aneuploidy screening is highly sensitive for Down syndrome and has a low false-positive rate. The diagnosis should be confirmed with fluorescent in situ hybridization followed by chromosomal karyotyping at birth. Children with Down syndrome have varied degrees of intellectual disability and more health complications than other children. However, advancements in recent decades have led to improved life expectancy, satisfaction, and quality of life. Newborns with Down syndrome require echocardiography and cardiology evaluation. Children should have annual screenings for vision and hearing, and laboratory studies for subclinical thyroid disease and blood disorders. Clinicians should provide unbiased and comprehensive culturally sensitive information regarding available services for children with Down syndrome. There is good evidence that comprehensive early intervention programs (e.g., speech, visual, physical, and occupational therapy; child psychology) enhance development. It is important to enroll children with Down syndrome in state-specific resources as early as possible. Given the advances in medical care and early intervention programs, regular health supervision by family physicians can allow children with Down syndrome to lead healthy and productive lives.


Asunto(s)
Síndrome de Down , Intervención Educativa Precoz/métodos , Educación de las Personas con Discapacidad Intelectual/métodos , Pruebas Genéticas , Médicos de Familia , Calidad de Vida , Niño , Síndrome de Down/diagnóstico , Síndrome de Down/genética , Síndrome de Down/fisiopatología , Síndrome de Down/psicología , Síndrome de Down/terapia , Humanos , Recién Nacido , Tamizaje Neonatal/métodos , Rol del Médico , Diagnóstico Prenatal/métodos
5.
Int J Cancer ; 133(12): 2824-33, 2013 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-23754791

RESUMEN

Core 3-derived glycans, a major type of O-glycan expressed by normal epithelial cells of the gastrointestinal tract, are downregulated during malignancy because of loss of expression of functional ß3-N-acetylglucosaminyltransferase-6 (core 3 synthase). We investigated the expression of core 3 synthase in normal pancreas and pancreatic cancer and evaluated the biological effects of re-expressing core 3 synthase in pancreatic cancer cells that had lost expression. We determined that pancreatic tumors and tumor cell lines have lost expression of core 3 synthase. Therefore, we re-expressed core 3 synthase in human pancreatic cancer cells (Capan-2 and FG) to investigate the contribution of core 3 glycans to malignant progression. Pancreatic cancer cells expressing core 3 synthase showed reduced in vitro cell proliferation, migration and invasion compared to vector control cells. Expression of core 3 O-glycans induced altered expression of ß1 integrin, decreased activation of focal adhesion kinase, led to the downregulation of expression of several genes including REG1α and FGFR3 and altered lamellipodia formation. The addition of a GlcNAc residue by core 3 synthase leads to the extension of the tumor-associated Tn structure on MUC1. Orthotopic injection of FG cells expressing core 3 synthase into the pancreas of nude mice produced significantly smaller tumors and decreased metastasis to the surrounding tissues compared to vector control FG cells. These findings indicate that expression of core 3-derived O-glycans in pancreatic cancer cells suppresses tumor growth and metastasis through modulation of glycosylation of mucins and other cell surface and extracellular matrix proteins.


Asunto(s)
Proliferación Celular , N-Acetilglucosaminiltransferasas/fisiología , Neoplasias Pancreáticas/patología , Actinas/metabolismo , Línea Celular Tumoral , Proteína-Tirosina Quinasas de Adhesión Focal/metabolismo , Regulación Neoplásica de la Expresión Génica , Humanos , Integrina alfa2beta1/análisis , Mucina-1/metabolismo , N-Acetilglucosaminiltransferasas/genética , N-Acetilglucosaminiltransferasas/metabolismo , Metástasis de la Neoplasia
6.
Clin Cancer Res ; 19(8): 2025-35, 2013 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-23444213

RESUMEN

PURPOSE: The presence of TNF-α in approximately 50% of surgically resected tumors suggests that the canonical NF-κB and the mTOR pathways are activated. Inhibitor of IκB kinase ß (IKKß) acts as the signaling node that regulates transcription via the p-IκBα/NF-κB axis and regulates translation via the mTOR/p-S6K/p-eIF4EBP axis. A kinome screen identified a quinoxaline urea analog 13-197 as an IKKß inhibitor. We hypothesized that targeting the NF-κB and mTOR pathways with 13-197 will be effective in malignancies driven by these pathways. EXPERIMENTAL DESIGN: Retrospective clinical and preclinical studies in pancreas cancers have implicated NF-κB. We examined the effects of 13-197 on the downstream targets of the NF-κB and mTOR pathways in pancreatic cancer cells, pharmacokinetics, toxicity and tumor growth, and metastases in vivo. RESULTS: 13-197 inhibited the kinase activity of IKKß in vitro and TNF-α-mediated NF-κB transcription in cells with low-µmol/L potency. 13-197 inhibited the phosphorylation of IκBα, S6K, and eIF4EBP, induced G1 arrest, and downregulated the expression of antiapoptotic proteins in pancreatic cancer cells. Prolonged administration of 13-197 did not induce granulocytosis and protected mice from lipopolysaccharide (LPS)-induced death. Results also show that 13-197 is orally available with extensive distribution to peripheral tissues and inhibited tumor growth and metastasis in an orthotopic pancreatic cancer model without any detectable toxicity. CONCLUSION: These results suggest that 13-197 targets IKKß and thereby inhibits mTOR and NF-κB pathways. Oral availability along with in vivo efficacy without obvious toxicities makes this quinoxaline urea chemotype a viable cancer therapeutic.


Asunto(s)
Antineoplásicos/farmacología , Quinasa I-kappa B/antagonistas & inhibidores , FN-kappa B/metabolismo , Neoplasias Pancreáticas/tratamiento farmacológico , Transducción de Señal/efectos de los fármacos , Serina-Treonina Quinasas TOR/metabolismo , Animales , Antineoplásicos/química , Antineoplásicos/farmacocinética , Proteínas Reguladoras de la Apoptosis/metabolismo , Área Bajo la Curva , Western Blotting , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Puntos de Control de la Fase G1 del Ciclo Celular/efectos de los fármacos , Humanos , Quinasa I-kappa B/metabolismo , Inmunohistoquímica , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patología , Compuestos de Fenilurea/química , Compuestos de Fenilurea/farmacocinética , Compuestos de Fenilurea/farmacología , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacocinética , Inhibidores de Proteínas Quinasas/farmacología , Quinoxalinas/química , Quinoxalinas/farmacocinética , Quinoxalinas/farmacología , Carga Tumoral/efectos de los fármacos , Ensayos Antitumor por Modelo de Xenoinjerto
7.
Cancer Immunol Immunother ; 62(2): 225-36, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22864396

RESUMEN

Pancreatic ductal adenocarcinoma is a leading cause of cancer mortality with a dismal 2-5 % 5-year survival rate. Monotherapy with Gemcitabine has limited success, highlighting the need for additional therapies that enhance the efficacy of current treatments. We evaluated the combination of Gemcitabine and Rosiglitazone, an FDA-approved drug for the treatment of type II diabetes, in an immunocompetent transplantable mouse model of pancreatic cancer. Tumor progression, survival, and metastases were evaluated in immunocompetent mice with subcutaneous or orthotopic pancreatic tumors treated with Pioglitazone, Rosiglitazone, Gemcitabine, or combinations of these. We characterized the impact of high-dose Rosiglitazone and Gemcitabine therapy on immune suppressive mediators, including MDSC and T regulatory cells, and on modulation of peripheral and intra-tumoral T cell populations. Combinations of Rosiglitazone and Gemcitabine significantly reduced tumor progression and metastases, enhanced apoptosis, and significantly extended overall survival compared to Gemcitabine alone. Rosiglitazone altered tumor-associated immune suppressive mediators by limiting early MDSC accumulation and intra-tumoral T regulatory cells. Combination therapy with Rosiglitazone and Gemcitabine modulated T cell populations by enhancing circulating CD8(+) T cells and intra-tumoral CD4(+) and CD8(+) T cells while limiting T regulatory cells. The results suggest that Rosiglitazone, in combination with Gemcitabine, decreases immune suppressive mechanisms in immunocompetent animals and provides pre-clinical data in support of combining Rosiglitazone and Gemcitabine as a clinical therapy for pancreatic cancer.


Asunto(s)
Antineoplásicos/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica , Carcinoma Ductal Pancreático/tratamiento farmacológico , Desoxicitidina/análogos & derivados , Terapia de Inmunosupresión , Neoplasias Pancreáticas/tratamiento farmacológico , Linfocitos T/efectos de los fármacos , Tiazolidinedionas/uso terapéutico , Animales , Apoptosis/efectos de los fármacos , Apoptosis/inmunología , Carcinoma Ductal Pancreático/inmunología , Carcinoma Ductal Pancreático/patología , Línea Celular Tumoral , Desoxicitidina/uso terapéutico , Humanos , Ratones , Ratones Endogámicos C57BL , Neoplasias Pancreáticas/inmunología , Neoplasias Pancreáticas/patología , Pioglitazona , Rosiglitazona , Linfocitos T/inmunología , Ensayos Antitumor por Modelo de Xenoinjerto , Gemcitabina
8.
Genesis ; 50(12): 914-20, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22926963

RESUMEN

The Drosophila testis has proven to be a valuable model organ for investigation of germline stem cell (GSC) maintenance and differentiation as well as elucidation of the genetic programs that regulate differentiation of daughter spermatogonia. Development of germ cell specific GAL4 driver transgenes has facilitated investigation of gene function in GSCs and spermatogonia but specific GAL4 tools are not available for analysis of postmitotic spermatogonial differentiation into spermatocytes. We have screened publically available pGT1 strains, a GAL4-encoding gene trap collection, to identify lines that can drive gene expression in late spermatogonia and early spermatocytes. While we were unable to identify any germline-specific drivers, we did identify an insertion in the chiffon locus, which drove expression specifically in early spermatocytes within the germline along with the somatic cyst cells of the testis.


Asunto(s)
Proteínas de Drosophila/genética , Drosophila/genética , Elementos de Facilitación Genéticos , Marcación de Gen , Espermatocitos/crecimiento & desarrollo , Factores de Transcripción/genética , Transcripción Genética , Transgenes , Animales , Proteínas de Drosophila/metabolismo , Proteínas del Huevo/genética , Masculino , Espermatocitos/metabolismo
9.
Database (Oxford) ; 2012: bas024, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22554788

RESUMEN

Much of the data within Model Organism Databases (MODs) comes from manual curation of the primary research literature. Given limited funding and an increasing density of published material, a significant challenge facing all MODs is how to efficiently and effectively prioritize the most relevant research papers for detailed curation. Here, we report recent improvements to the triaging process used by FlyBase. We describe an automated method to directly e-mail corresponding authors of new papers, requesting that they list the genes studied and indicate ('flag') the types of data described in the paper using an online tool. Based on the author-assigned flags, papers are then prioritized for detailed curation and channelled to appropriate curator teams for full data extraction. The overall response rate has been 44% and the flagging of data types by authors is sufficiently accurate for effective prioritization of papers. In summary, we have established a sustainable community curation program, with the result that FlyBase curators now spend less time triaging and can devote more effort to the specialized task of detailed data extraction. Database URL: http://flybase.org/


Asunto(s)
Sistemas de Administración de Bases de Datos , Bases de Datos Factuales , Correo Electrónico , Anotación de Secuencia Molecular/métodos , Minería de Datos , Humanos , Publicaciones Periódicas como Asunto
10.
Gene Expr Patterns ; 11(1-2): 72-8, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-20888931

RESUMEN

The lysyl hydroxylase (LH) family of enzymes has important roles in the biosynthesis of collagen. In this paper we present the first description of Drosophila LH3 (dPlod), the only lysyl hydroxylase encoded in the fly genome. We have characterised in detail the developmental expression patterns of dPlod RNA and protein during embryogenesis. Consistent with its predicted function as a collagen-modifying enzyme, we find that dPlod is highly expressed in type-IV collagen-producing cells, particularly the haemocytes and fat body. Examination of dPlod subcellular localisation reveals that it is an endoplasmic reticulum resident protein, that partially overlaps with intracellular type-IV collagen. Furthermore, we show that dPlod is required for type-IV collagen secretion from haemocytes and fat body, and thus establish that LH3 enzyme function is conserved across widely separated animal phyla. Our findings, and the new tools we describe, establish the fly as an attractive model in which to study this important collagen biosynthesis enzyme.


Asunto(s)
Drosophila melanogaster/enzimología , Procolágeno-Lisina 2-Oxoglutarato 5-Dioxigenasa/genética , Secuencia de Aminoácidos , Animales , Colágeno/biosíntesis , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Datos de Secuencia Molecular , Procolágeno-Lisina 2-Oxoglutarato 5-Dioxigenasa/química , Procolágeno-Lisina 2-Oxoglutarato 5-Dioxigenasa/metabolismo , Alineación de Secuencia
11.
Dev Cell ; 19(2): 296-306, 2010 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-20708591

RESUMEN

Details of the mechanisms that determine the shape and positioning of organs in the body cavity remain largely obscure. We show that stereotypic positioning of outgrowing Drosophila renal tubules depends on signaling in a subset of tubule cells and results from enhanced sensitivity to guidance signals by targeted matrix deposition. VEGF/PDGF ligands from the tubules attract hemocytes, which secrete components of the basement membrane to ensheath them. Collagen IV sensitizes tubule cells to localized BMP guidance cues. Signaling results in pathway activation in a subset of tubule cells that lead outgrowth through the body cavity. Failure of hemocyte migration, loss of collagen IV, or abrogation of BMP signaling results in tubule misrouting and defective organ shape and positioning. Such regulated interplay between cell-cell and cell-matrix interactions is likely to have wide relevance in organogenesis and congenital disease.


Asunto(s)
Proteínas Morfogenéticas Óseas/metabolismo , Colágeno Tipo IV/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/embriología , Hemocitos/metabolismo , Animales , Proteínas Morfogenéticas Óseas/genética , Colágeno Tipo IV/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/anatomía & histología , Drosophila melanogaster/citología , Drosophila melanogaster/metabolismo , Embrión no Mamífero/anatomía & histología , Embrión no Mamífero/metabolismo , Hemocitos/citología , Túbulos Renales/embriología , Morfogénesis , Transducción de Señal
12.
J Leukoc Biol ; 85(6): 996-1004, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19261929

RESUMEN

Myeloid-derived suppressor cells (MDSC) are potent inhibitors of anti-tumor immunity that facilitate tumor progression by blocking the activation of CD4(+) and CD8(+) T cells and by promoting a type 2 immune response through their production of IL-10 and down-regulation of macrophage production of IL-12. MDSC accumulate in many cancer patients and are a significant impediment to active cancer immunotherapies. Chronic inflammation has been shown recently to enhance the accumulation of MDSC and to increase their suppression of T cells. These findings led us to hypothesize that inflammation contributes to tumor progression through the induction of MDSC, which create a favorable environment for tumor growth. As chronic inflammation also drives type 2 immune responses, which favor tumor growth, we asked if inflammation mediates this effect through MDSC. We find that IL-1beta-induced inflammation increased IL-10 production by MDSC and induces MDSC, which are more effective at down-regulating macrophage production of IL-12 as compared with MDSC isolated from less-inflammatory tumor microenvironments, thereby skewing tumor immunity toward a type 2 response. Inflammation heightens MDSC phenotype by signaling through the TLR4 pathway and involves up-regulation of CD14. Although this pathway is well-recognized in other myeloid cells, it has not been implicated previously in MDSC function. These studies demonstrate that MDSC are an intermediary through which inflammation promotes type 2 immune responses, and they identify the TLR4 pathway in MDSC as a potential target for down-regulating immune suppression and promoting anti-tumor immunity.


Asunto(s)
Inflamación/inmunología , Células Mieloides/inmunología , Receptor Cross-Talk , Transducción de Señal , Receptor Toll-Like 4/metabolismo , Animales , Línea Celular Tumoral , Regulación hacia Abajo/efectos de los fármacos , Interleucina-10/biosíntesis , Interleucina-12/biosíntesis , Interleucina-1beta , Receptores de Lipopolisacáridos/metabolismo , Lipopolisacáridos/farmacología , Activación de Macrófagos/efectos de los fármacos , Macrófagos/citología , Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Ratones , Ratones Endogámicos BALB C , Células Mieloides/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Regulación hacia Arriba/efectos de los fármacos
13.
Cancer Res ; 67(20): 10019-26, 2007 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-17942936

RESUMEN

Chronic inflammation is frequently associated with malignant growth and is thought to promote and enhance tumor progression, although the mechanisms which regulate this relationship remain elusive. We reported previously that interleukin (IL)-1beta promoted tumor progression by enhancing the accumulation of myeloid-derived suppressor cells (MDSC), and hypothesized that inflammation leads to cancer through the production of MDSC which inhibit tumor immunity. If inflammation-induced MDSC promote tumor progression by blocking antitumor immunity, then a reduction in inflammation should reduce MDSC levels and delay tumor progression, whereas an increase in inflammation should increase MDSC levels and hasten tumor progression. We have tested this hypothesis using the 4T1 mammary carcinoma and IL-1 receptor (IL-1R)-deficient mice which have a reduced potential for inflammation, and IL-1R antagonist-deficient mice, which have an increased potential for inflammation. Consistent with our hypothesis, IL-1R-deficient mice have a delayed accumulation of MDSC and reduced primary and metastatic tumor progression. Accumulation of MDSC and tumor progression are partially restored by IL-6, indicating that IL-6 is a downstream mediator of the IL-1beta-induced expansion of MDSC. In contrast, excessive inflammation in IL-1R antagonist-deficient mice promotes the accumulation of MDSC and produces MDSC with enhanced suppressive activity. These results show that immune suppression by MDSC and tumor growth are regulated by the inflammatory milieu and support the hypothesis that the induction of suppressor cells which down-regulate tumor immunity is one of the mechanisms linking inflammation and cancer.


Asunto(s)
Linfocitos T CD8-positivos/inmunología , Neoplasias Mamarias Experimentales/inmunología , Neoplasias Mamarias Experimentales/patología , Animales , Progresión de la Enfermedad , Humanos , Inflamación/inmunología , Inflamación/patología , Proteína Antagonista del Receptor de Interleucina 1/deficiencia , Proteína Antagonista del Receptor de Interleucina 1/inmunología , Interleucina-1/inmunología , Interleucina-6/biosíntesis , Interleucina-6/genética , Interleucina-6/inmunología , Neoplasias Pulmonares/inmunología , Neoplasias Pulmonares/secundario , Activación de Linfocitos , Ratones , Ratones Endogámicos BALB C , Ratones Transgénicos , Receptores de Interleucina-1/deficiencia , Receptores de Interleucina-1/genética , Receptores de Interleucina-1/inmunología , Linfocitos T/inmunología , Transfección
14.
J Immunol ; 179(2): 977-83, 2007 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-17617589

RESUMEN

Although the immune system has the potential to protect against malignancies, many individuals with cancer are immunosuppressed. Myeloid-derived suppressor cells (MDSC) are elevated in many patients and animals with tumors, and contribute to immune suppression by blocking CD4(+) and CD8(+) T cell activation. Using the spontaneously metastatic 4T1 mouse mammary carcinoma, we now demonstrate that cross-talk between MDSC and macrophages further subverts tumor immunity by increasing MDSC production of IL-10, and by decreasing macrophage production of IL-12. Cross-talk between MDSC and macrophages requires cell-cell contact, and the IL-12 decrease is dependent on MDSC production of IL-10. Treatment with the chemotherapeutic drug gemcitabine, which reduces MDSC, promotes rejection of established metastatic disease in IL-4Ralpha(-/-) mice that produce M1 macrophages by allowing T cell activation, by maintaining macrophage production of IL-12, and by preventing increased production of IL-10. Therefore, MDSC impair tumor immunity by suppressing T cell activation and by interacting with macrophages to increase IL-10 and decrease IL-12 production, thereby promoting a tumor-promoting type 2 response, a process that can be partially reversed by gemcitabine.


Asunto(s)
Macrófagos/inmunología , Células Mieloides/inmunología , Neoplasias Experimentales/inmunología , Receptor Cross-Talk/inmunología , Linfocitos T Reguladores/inmunología , Escape del Tumor/inmunología , Animales , Técnicas de Cocultivo , Citometría de Flujo , Interleucina-10/biosíntesis , Interleucina-12/biosíntesis , Activación de Linfocitos/inmunología , Ratones , Ratones Endogámicos BALB C , Ratones Transgénicos
15.
J Immunol ; 176(1): 284-90, 2006 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-16365420

RESUMEN

Epidemiological and experimental observations support the hypothesis that chronic inflammation contributes to cancer development and progression; however, the mechanisms underlying the relationship between inflammation and cancer are poorly understood. To study these mechanisms, we have transfected the mouse 4T1 mammary carcinoma with the proinflammatory cytokine IL-1beta to produce a chronic inflammatory microenvironment at the tumor site. Mice with 4T1/IL-1beta tumors have a decreased survival time and elevated levels of immature splenic Gr1+CD11b+ myeloid-derived cells. These myeloid suppressor cells (MSC) are present in many patients with cancer and inhibit the activation of CD4+ and CD8+ T lymphocytes. 4T1/IL-1beta-induced MSC do not express the IL-1R, suggesting that the cytokine does not directly activate MSC. Neither T or B cells nor NKT cells are involved in the IL-1beta-induced increase of MSC because RAG2-/- mice and nude mice with 4T1/IL-1beta tumors also have elevated MSC levels. MSC levels remain elevated in mice inoculated with 4T1/IL-1beta even after the primary tumor is surgically removed, indicating that the IL-1beta effect is long lived. Collectively, these findings suggest that inflammation promotes malignancy via proinflammatory cytokines, such as IL-1beta, which enhance immune suppression through the induction of MSC, thereby counteracting immune surveillance and allowing the outgrowth and proliferation of malignant cells.


Asunto(s)
Inflamación/inmunología , Interleucina-1/metabolismo , Neoplasias Mamarias Experimentales/inmunología , Células Mieloides/inmunología , Animales , Línea Celular Tumoral , Ensayo de Inmunoadsorción Enzimática , Femenino , Citometría de Flujo , Inflamación/fisiopatología , Interleucina-1/inmunología , Células Asesinas Naturales/inmunología , Linfocitos/inmunología , Ratones , Ratones Transgénicos , Transfección
16.
Genesis ; 39(2): 84-93, 2004 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15170693

RESUMEN

The mechanisms that control differentiation of stem cells to specialised cell types probably include factors intrinsic to stem cells as well as extrinsic factors produced by the microenvironment of the stem cell niche. The Drosophila male germline is renewed from a population of stem cells located in the apical tip of the adult testis. The morphological relationship between germline stem cells and their surrounding somatic cells is well understood but the factors that regulate stem cell proliferation and differentiation are still being uncovered. This study examined the effect of stimulating Dpp signalling directly in male germ cells. Ectopic Dpp or Activin signalling resulted in overproliferation of both stem cell-like and spermatogonial-like cells in the apical region of the testis. A third cell population that expressed stem cell markers was seen to proliferate in the distal testis when Dpp signalling was either stimulated or repressed in germline stem cells.


Asunto(s)
Diferenciación Celular/fisiología , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/fisiología , Células Germinativas/citología , Transducción de Señal/fisiología , Activinas/fisiología , Animales , Proliferación Celular , Proteínas de Drosophila/fisiología , Masculino , Espermatogonias/citología , Espermatogonias/fisiología , Células Madre/fisiología , Testículo/citología , Factor de Crecimiento Transformador beta/metabolismo
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