RESUMEN
Indoleamine 2,3 dioxygenase 1 (IDO1), a leader tryptophan-degrading enzyme, represents a recognized immune checkpoint molecule. In neoplasia, IDO1 is often highly expressed in dendritic cells infiltrating the tumor and/or in tumor cells themselves, particularly in human melanoma. In dendritic cells, IDO1 does not merely metabolize tryptophan into kynurenine but, after phosphorylation of critical tyrosine residues in the non-catalytic small domain, it triggers a signaling pathway prolonging its immunoregulatory effects by a feed-forward mechanism. We here investigated whether the non-enzymatic function of IDO1 could also play a role in tumor cells by using B16-F10 mouse melanoma cells transfected with either the wild-type Ido1 gene (Ido1WT ) or a mutated variant lacking the catalytic, but not signaling activity (Ido1H350A ). As compared to the Ido1WT -transfected counterpart (B16WT), B16-F10 cells expressing Ido1H350A (B16H350A) were characterized by an in vitro accelerated growth mediated by increased Ras and Erk activities. Faster growth and malignant progression of B16H350A cells, also detectable in vivo, were found to be accompanied by a reduction in tumor-infiltrating CD8+ T cells and an increase in Foxp3+ regulatory T cells. Our data, therefore, suggest that the IDO1 signaling function can also occur in tumor cells and that alternative therapeutic approach strategies should be undertaken to effectively tackle this important immune checkpoint molecule.
Asunto(s)
Melanoma Experimental , Triptófano , Ratones , Humanos , Animales , Linfocitos T CD8-positivos/metabolismo , Indolamina-Pirrol 2,3,-Dioxigenasa/genética , Indolamina-Pirrol 2,3,-Dioxigenasa/metabolismo , Proteínas de Punto de Control Inmunitario , Melanoma Experimental/genética , Transducción de SeñalRESUMEN
A great interest surrounds the development of nanoparticles (NPs) for biomedical applications such as drug delivery and cancer therapy. However, the interplay between nanoscale materials and biological systems and the associated hazards have not been completely clarified yet. In this study, bovine oviductal epithelial cells (BOECs) and embryos were used as in vitro models to investigate whether cell mitosis and early mammalian embryo development could be affected by the exposure to polystyrene (PS) nanoparticles. Analysis of the karyotype performed on BOECs exposed to PS-NPs did not show chromosomal anomalies compared to the control, although more tetraploid metaphase plates were observed in the former. In vitro fertilization experiments designed to understand whether exposure to PS-NPs could affect pre-implantation development showed that incubation with PS-NPs decreased 8-cell embryo and blastocyst rate in dose-dependent fashion. The quality of the blastocysts in terms of mean cell percent blastomeres with fragmented DNA was the same in exposed blastocysts compared to controls. These results show that the exposure to PS-NPs may impair development. In turn, this may affect the rate of mitosis in embryos and yield a lower developmental competence to reach the blastocyst stage. This suggests that release in the environment and the subsequent accumulation of PS-NPs into living organisms should be carefully monitored to prevent cytotoxic effects that may compromise their reproduction rates.
Asunto(s)
Bovinos/embriología , Embrión de Mamíferos/efectos de los fármacos , Desarrollo Embrionario/efectos de los fármacos , Mitosis/efectos de los fármacos , Nanopartículas/toxicidad , Poliestirenos/toxicidad , Animales , Técnicas de Cultivo de Embriones/veterinaria , Fertilización In Vitro , Nanopartículas/química , Poliestirenos/químicaRESUMEN
Indoleamine 2,3 dioxygenase 1 (IDO1) is a metabolic enzyme that catalyzes the conversion of the essential amino acid tryptophan (Trp) into a series of immunoactive catabolites, collectively known as kynurenines. Through the depletion of Trp and the generation of kynurenines, IDO1 represents a key regulator of the immune responses involved in physiologic homeostasis as well as in neoplastic and autoimmune pathologies. The IDO1 enzyme has been described as an important immune checkpoint to be targeted by catalytic inhibitors in the treatment of cancer. In contrast, a defective expression/activity of the enzyme has been demonstrated in autoimmune diseases. Beside its catalytic activity, the IDO1 protein is endowed with an additional function associated with the presence of two immunoreceptor tyrosine-based inhibitory motifs (ITIMs), which, once phosphorylated, bind SHP phosphatases and mediate a long-term immunoregulatory activity of IDO1. Herein, we report the screening of a focused library of molecules bearing a propanol core by a protocol combining microscale thermophoresis (MST) analysis and a cellular assay. As a result, the combined screening identified a 2-propanolol analogue, VIS351, as the first potent activator of the ITIM-mediated function of the IDO1 enzyme. VIS351 displayed a good dissociation constant (Kdâ¯=â¯1.90⯵M) for IDO1 and a moderate cellular inhibitor activity (IC50â¯=â¯11.463⯵M), although it did not show any catalytic inhibition of the recombinant IDO1 enzyme. Because we previously demonstrated that the enzymatic and non-enzymatic (i.e., ITIM-mediated) functions of IDO1 reside in different conformations of the protein, we hypothesized that in the cellular system VIS351 may shift the dynamic conformational balance towards the ITIM-favoring folding of IDO1, resulting in the activation of the signaling rather than catalytic activity of IDO1. We demonstrated that VIS351 activated the ITIM-mediated signaling of IDO1 also in mouse plasmacytoid dendritic cells, conferring those cells an immunosuppressive phenotype detectable in vivo. Thus the manuscript describes for the first time a small molecule as a positive modulator of IDO1 signaling function, paving the basis for an innovative approach to develop first-in-class drugs acting on the IDO1 target.
Asunto(s)
2-Propanol/química , 2-Propanol/metabolismo , Indolamina-Pirrol 2,3,-Dioxigenasa/química , Indolamina-Pirrol 2,3,-Dioxigenasa/metabolismo , Animales , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/fisiología , Relación Dosis-Respuesta a Droga , Femenino , Ratones , Ratones Endogámicos C57BL , Simulación del Acoplamiento Molecular/métodos , Estructura Secundaria de ProteínaRESUMEN
Osteocartilagineous differentiation within malignant melanoma is a rare occurrence with several implications for diagnosis. Most of the reported cases have occurred in acral lentiginous malignant melanomas. In this paper, the authors describe the clinical, morphological, immunohistochemical features and surgical treatment of a case of primary oral mucosal melanoma with osteocartilaginous differentiation and they review the existing literature. The clinical history of a 67-year-old man affected of oral malignant melanoma was described from the first presentation to the second recurrence. FISH analysis on primary lesion and on relapses showed positive results both in epithelioid and in osteocondroblastic areas. Because of the scarcity of literature in osteogenic melanoma, histological identification may be problematic and prognostic factors and therapeutic protocols are nor well established. Immunohistochemical and molecular techniques can help to diagnosis this rare lesion.
Asunto(s)
Melanoma/patología , Neoplasias Cutáneas/patología , Anciano , Diferenciación Celular , Humanos , Masculino , Melanoma/diagnóstico , Mucosa Bucal/patología , Neoplasias Cutáneas/diagnósticoRESUMEN
Thymidylate synthase (TYMS) is a key enzyme in nucleotide synthesis and therefore, an important target of many chemotherapeutic agents. Expression of TYMS mRNA is thought to be modulated by a 28-bp tandem repeat polymorphism within its 5'-untranslated region, raising the question of this variant's utility in predicting the efficacy and toxicity of cancer treatment regimens. The aim of the present research was to describe the distribution of this TYMS polymorphism in the Argentinean population. A total of 199 randomly selected DNA samples from healthy volunteers were analyzed using polymerase chain reaction and polyacrylamide gel electrophoresis. The 2R and 3R alleles were present in 47.74 and 52.26% of samples, respectively, with frequencies of 21.6 (43), 52.3 (104), and 26.1% (52) recorded for the 2R/2R, 2R/3R, and 3R/3R genotypes, respectively. No significant difference regarding gender was observed. Our prevalence data are similar to those reported for other Caucasian populations. This opens a discussion concerning the reference population valid for comparisons and the clinical importance of this genotyping test as an additional tool in personalized medicine.
Asunto(s)
Regiones no Traducidas 5' , Variación Genética , Genética de Población , Timidilato Sintasa/genética , Argentina , HumanosRESUMEN
The barley grass stripe rust (BGYR) pathogen Puccinia striiformis f. sp. pseudohordei was first detected in Australia in 1997. While studies have established that it is virulent on wild barley grass, and can infect several barley cultivars, the basis of genetic resistance to this pathogen in barley is largely unknown. Understanding the genetic basis of host resistance and ensuring the selection of germplasm with multiple resistance genes are important to mitigate the potential impact of BGYR in barley production. Genetic analysis of seedling resistance to BGYR in two barley doubled haploid populations, Amaji Nijo/WI2585 (AN/WI) and Galleon/Haruna Nijo (GL/HN), indicated that resistance is governed by several genes. Marker regression analysis of the seedling resistance data from the AN/WI population detected a major QTL, BGYR_WI1 (resistance contributed by WI2585 with the closest marker explaining 52 % of the total phenotypic effect) on chromosome 1HS, flanked by the loci Xabg59 and Xabc310b at map positions 0.0 and 6.9 cM, respectively. Similarly, a major QTL, BGYR_HN1, (resistance contributed by Haruna Nijo with the closest marker explaining 70 % of the total phenotypic effect) was detected in the GL/HN population and was mapped to 1HS, flanked by the loci Xbcd135 and XHOR1 at map positions 12.8 and 24.5 cM, respectively. In addition, several minor loci that provided resistance against BGYR were detected in both populations. While defined QTL intervals were large, the analysis nonetheless provides new information on sources of major QTL controlling resistance to BGYR.
Asunto(s)
Resistencia a la Enfermedad/genética , Hordeum/genética , Enfermedades de las Plantas/genética , Sitios de Carácter Cuantitativo , Basidiomycota/patogenicidad , Mapeo Cromosómico , Marcadores Genéticos , Genotipo , Hordeum/microbiología , Fenotipo , Enfermedades de las Plantas/microbiología , Plantones/genética , Plantones/microbiologíaRESUMEN
Genes that enable crops to limit Na(+) accumulation in shoot tissues represent potential sources of salinity tolerance for breeding. In barley, the HvNax4 locus lowered shoot Na(+) content by between 12% and 59% (g(-1) DW), or not at all, depending on the growth conditions in hydroponics and a range of soil types, indicating a strong influence of environment on expression. HvNax4 was fine-mapped on the long arm of barley chromosome 1H. Corresponding intervals of â¼200 kb, containing a total of 34 predicted genes, were defined in the sequenced rice and Brachypodium genomes. HvCBL4, a close barley homologue of the SOS3 salinity tolerance gene of Arabidopsis, co-segregated with HvNax4. No difference in HvCBL4 mRNA expression was detected between the mapping parents. However, genomic and cDNA sequences of the HvCBL4 alleles were obtained, revealing a single Ala111Thr amino acid substitution difference in the encoded proteins. The known crystal structure of SOS3 was used as a template to obtain molecular models of the barley proteins, resulting in structures very similar to that of SOS3. The position in SOS3 corresponding to the barley substitution does not participate directly in Ca(2+) binding, post-translational modifications or interaction with the SOS2 signalling partner. However, Thr111 but not Ala111 forms a predicted hydrogen bond with a neighbouring α-helix, which has potential implications for the overall structure and function of the barley protein. HvCBL4 therefore represents a candidate for HvNax4 that warrants further investigation.
Asunto(s)
Hordeum/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Sitios de Carácter Cuantitativo , Sodio/metabolismo , Secuencia de Aminoácidos , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Transporte Biológico , Mapeo Cromosómico , Hordeum/química , Hordeum/genética , Conformación Molecular , Datos de Secuencia Molecular , Proteínas de Plantas/química , Alineación de SecuenciaRESUMEN
Rye is a diploid crop species with many outstanding qualities, and is important as a source of new traits for wheat and triticale improvement. Rye is highly tolerant of aluminum (Al) toxicity, and possesses a complex structure at the Alt4 Al tolerance locus not found at the corresponding locus in wheat. Here we describe a BAC library of rye cv. Blanco, representing a valuable resource for rye molecular genetic studies, and assess the library's suitability for investigating Al tolerance genes. The library provides 6 x genome coverage of the 8.1 Gb rye genome, has an average insert size of 131 kb, and contains only ~2% of empty or organelle-derived clones. Genetic analysis attributed the Al tolerance of Blanco to the Alt4 locus on the short arm of chromosome 7R, and revealed the presence of multiple allelic variants (haplotypes) of the Alt4 locus in the BAC library. BAC clones containing ALMT1 gene clusters from several Alt4 haplotypes were identified, and will provide useful starting points for exploring the basis for the structural variability and functional specialization of ALMT1 genes at this locus.
Asunto(s)
Adaptación Fisiológica/genética , Aluminio/farmacología , Cromosomas Artificiales Bacterianos/genética , Genes de Plantas , Biblioteca Genómica , Mapeo Físico de Cromosoma/métodos , Secale/genética , Adaptación Fisiológica/efectos de los fármacos , Southern Blotting , Cromosomas de las Plantas/genética , Mapeo Contig , Sondas de ADN/metabolismo , ADN de Plantas/genética , Marcadores Genéticos , Haplotipos , Familia de Multigenes , Secale/efectos de los fármacosAsunto(s)
Western Blotting/métodos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Animales , Anticuerpos , Especificidad de Anticuerpos , Humanos , Mutación , Proteínas Nucleares/inmunología , Nucleofosmina , ConejosRESUMEN
Aluminum toxicity is a major problem in agriculture worldwide. Among the cultivated Triticeae, rye (Secale cereale L.) is one of the most Al tolerant and represents an important potential source of Al tolerance for improvement of wheat. The Alt4 Al-tolerance locus of rye contains a cluster of genes homologous to the single-copy Al-activated malate transporter (TaALMT1) Al-tolerance gene of wheat. Tolerant (M39A-1-6) and intolerant (M77A-1) rye haplotypes contain five and two genes, respectively, of which two (ScALMT1-M39.1 and ScALMT1-M39.2) and one (ScALMT1-M77.1) are highly expressed in the root tip, typically the main site of plant Al tolerance/susceptibility. All three transcripts are upregulated by exposure to Al. High-resolution genetic mapping identified two resistant lines resulting from recombination within the gene cluster. These recombinants exclude all genes flanking the gene cluster as candidates for controlling Alt4 tolerance, including a homolog of the barley HvMATE Al-tolerance gene. In the recombinants, one hybrid gene containing a chimeric open reading frame and the ScALMT1-M39.1 gene each appeared to be sufficient to provide full tolerance. mRNA splice variation was observed for two of the rye ALMT1 genes and in one case, was correlated with a approximately 400-bp insertion in an intron.
Asunto(s)
Aluminio/toxicidad , Tolerancia a Medicamentos/genética , Familia de Multigenes/genética , Transportadores de Anión Orgánico/genética , Secale/genética , Secuencia de Bases , Southern Blotting , Cruzamiento/métodos , Mapeo Cromosómico , Haplotipos/genética , Modelos Genéticos , Datos de Secuencia Molecular , Transportadores de Anión Orgánico/metabolismo , Análisis de Secuencia de ADNRESUMEN
The neural cell adhesion molecule (NCAM) is involved in the intercellular junctions of neurons and glial cells. We investigated its relevance as a biomarker in gliomas which main characteristic is their high invasiveness. We studied by Western blot the pattern of serum NCAM bands in patients with gliomas (n = 34), with brain metastasis of different primary cancers (n = 27) and with benign brain tumors (n = 22)] compared with healthy controls (n = 69). For densitometric analysis NCAM bands > or = 130 kDa (HMW) and <130 kDa (LMW) were clustered. We observed that glioma patients presented higher NCAM HMW and lower NCAM LMW levels than control subjects (P < 0.01). A similar pattern was found in patients with brain metastasis or brain benign tumors, suggesting that the pattern of serum NCAM bands would be useful to detect brain tumor pathology. On the other hand, serum NCAM expression was not associated with the main clinicopathological features of gliomas, including overall survival. Interestingly, we found that 9/12 patients with glioma showed a significant decrease in NCAM HMW/LMW ratio between 1-3 months after successful tumor removal. Thus, serum NCAM could be a useful marker for monitoring treatment.NCAM expression was also analyzed at tissular level in 59 glioma sections from paraffined tumors. We observed that NCAM immunostaining was inversely correlated with the histological grade of malignancy, remaining this association in a multivariate analysis. Besides, loss of NCAM staining was significantly associated with bad prognosis in an univariate analysis.
Asunto(s)
Biomarcadores de Tumor/metabolismo , Neoplasias Encefálicas/metabolismo , Regulación Neoplásica de la Expresión Génica/fisiología , Glioma/metabolismo , Moléculas de Adhesión de Célula Nerviosa/metabolismo , Adulto , Anciano , Biomarcadores de Tumor/sangre , Encéfalo/metabolismo , Neoplasias Encefálicas/mortalidad , Neoplasias Encefálicas/secundario , Estudios de Casos y Controles , Femenino , Perfilación de la Expresión Génica , Glioma/mortalidad , Glioma/patología , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Masculino , Melanoma/metabolismo , Melanoma/secundario , Persona de Mediana Edad , Moléculas de Adhesión de Célula Nerviosa/sangre , Isoformas de Proteínas , Neoplasias Cutáneas/metabolismo , Neoplasias Cutáneas/patología , Estadísticas no Paramétricas , Análisis de Supervivencia , Neoplasias del Cuello Uterino/metabolismo , Neoplasias del Cuello Uterino/patologíaRESUMEN
Hasta el presente, la TC es el examen por imágenes más aceptado y utilizado en oncología. El objetivo del presente trabajo fue evaluar la capacidad diagnóstica del PET fusionado con TC versus la TC previa sola para la detección de metástasis en pacientes (ptes.) oncológicos. Se efectuó un análisis retrospectivo de los exámenes PET-TC y de TC previa de 85 ptes., 49 hombres y 36 mujeres (edad media 56 años, raqngo 3-96 años) con diversos antecedentes oncológicos. Las variables registradas en los estudios fueron presencia, número y localización de metástasis basándose en criterios morfológicos y metabólicos. La diferencia en la performance entre métodos se estableció utilizando un test de McNemar y un Wilcoxon signed-rank test...
Asunto(s)
Humanos , Masculino , Preescolar , Adolescente , Adulto , Persona de Mediana Edad , Femenino , Niño , Fluorodesoxiglucosa F18 , Metástasis de la Neoplasia , Neoplasias , Neoplasias de la Mama , Neoplasias del Colon , Neoplasias Renales , Neoplasias Pulmonares , Linfoma , Melanoma , Metástasis de la Neoplasia , Neoplasias , Radiofármacos , Estudios Retrospectivos , Neoplasias Testiculares , Tomografía Computarizada de Emisión , Tomografía Computarizada por Rayos XRESUMEN
Hasta el presente, la TC es el examen por imágenes más aceptado y utilizado en oncología. El objetivo del presente trabajo fue evaluar la capacidad diagnóstica del PET fusionado con TC versus la TC previa sola para la detección de metástasis en pacientes (ptes.) oncológicos. Se efectuó un análisis retrospectivo de los exámenes PET-TC y de TC previa de 85 ptes., 49 hombres y 36 mujeres (edad media 56 años, raqngo 3-96 años) con diversos antecedentes oncológicos. Las variables registradas en los estudios fueron presencia, número y localización de metástasis basándose en criterios morfológicos y metabólicos. La diferencia en la performance entre métodos se estableció utilizando un test de McNemar y un Wilcoxon signed-rank test...(AU)
Asunto(s)
Humanos , Masculino , Preescolar , Adolescente , Adulto , Persona de Mediana Edad , Estudio Comparativo , Femenino , Niño , Anciano , Metástasis de la Neoplasia/diagnóstico por imagen , Neoplasias/diagnóstico por imagen , Fluorodesoxiglucosa F18/diagnóstico , Estudios Retrospectivos , Metástasis de la Neoplasia/diagnóstico , Neoplasias/diagnóstico , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/diagnóstico por imagen , Neoplasias del Colon/diagnóstico , Neoplasias del Colon/diagnóstico por imagen , Neoplasias Testiculares/diagnóstico , Neoplasias Testiculares/diagnóstico por imagen , Neoplasias Renales/diagnóstico , Neoplasias Renales/diagnóstico por imagen , Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/diagnóstico por imagen , Melanoma/diagnóstico , Melanoma/diagnóstico por imagen , Linfoma/diagnóstico , Linfoma/diagnóstico por imagen , Radiofármacos , Tomografía Computarizada por Rayos X , Tomografía Computarizada de EmisiónRESUMEN
Se presentan 3 pacientes (ptes.) con diagnósticos de tumores neuroendocrinos con metástasis hepáticas que se manifestaron durante la evolución como síndrome de Cushing ectópico. La producción de ACTH por tumores endocrinos es poco frecuente y está cumúnmente asociada a tumores supradiafragmáticos; se discuten las posibles causas de esta rara presentación
Asunto(s)
Humanos , Masculino , Femenino , Persona de Mediana Edad , Tumor Carcinoide , Tumores Neuroendocrinos , Síndrome de Cushing/etiología , Tumor Carcinoide , Tumores Neuroendocrinos , Síndrome de Cushing/complicaciones , Síndrome de Cushing/diagnósticoRESUMEN
Se presentan 3 pacientes (ptes.) con diagnósticos de tumores neuroendocrinos con metástasis hepáticas que se manifestaron durante la evolución como síndrome de Cushing ectópico. La producción de ACTH por tumores endocrinos es poco frecuente y está cumúnmente asociada a tumores supradiafragmáticos; se discuten las posibles causas de esta rara presentación (AU)