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1.
Cancer Med ; 12(11): 12861-12873, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37119050

RESUMEN

BACKGROUND: Immune checkpoint inhibitors (ICIs) have significantly improved survival in advanced melanoma but are associated with immune-related adverse events (irAEs). This single center, cross-sectional survey aimed to describe the long-term symptom burden and impact on health-related quality of life (HRQL) of advanced melanoma patients with sustained disease control following treatment with ICIs. METHODS: Advanced melanoma patients (stage IIB, III or IV, AJCCv8), treated with anti-PD1-based ICIs, who were off-treatment and had at least 6 months follow-up from their last infusion with an ongoing response in the metastatic setting or no evidence of disease recurrence in the adjuvant setting. A paper-based questionnaire, consisting of the EORTC QLQ-C30, EORTC QLQ-FA12, and the PRO-CTCAE was administered. RESULTS: Of 90 participants, 61 (68%) completed the questionnaire; 40 received single-agent anti-PD1, and 21 anti-PD1/anti-CTLA4. Thirty-three (54%) were treated in the adjuvant setting. At the time of enrolment, 31 (51%) participants had active treatment for a previous irAE. Overall, 18/61 (30%) participants reported long-term symptoms and trouble in physical and emotional functioning. Physical fatigue was common and interfered with daily activities (n = 12, 20%). In the PRO-CTCAE questionnaire, muscle ache (n = 12, 20%) and joint ache (n = 9, 15%) were commonly reported. Despite this, participants reported overall good health (6.00, range 2.00-7.00) and reasonable level of HRQL (6.00, range 3.00-7.00). DISCUSSION: Melanoma survivors experience long-term symptoms in physical and psychosocial HRQL domains after ICI treatment. These results underline the importance to address existing gaps in survivorship care, implement these findings in clinical practice and increase awareness for long-term symptoms in these patients.


Asunto(s)
Inhibidores de Puntos de Control Inmunológico , Melanoma , Humanos , Inhibidores de Puntos de Control Inmunológico/efectos adversos , Calidad de Vida , Estudios Transversales , Recurrencia Local de Neoplasia/tratamiento farmacológico , Melanoma/patología , Sobrevivientes
2.
J Eur Acad Dermatol Venereol ; 37(7): 1302-1310, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-36807595

RESUMEN

BACKGROUND: Primary cutaneous mucinoses (PCM) are rare diseases characterized by dermal or follicular mucin deposits. OBJECTIVES: A retrospective study characterizing PCM to compare dermal with follicular mucin to identify its potential origin on a single-cell level. MATERIAL AND METHODS: Patients diagnosed with PCM between 2010 and 2020 at our department were included in this study. Biopsy specimens were stained using conventional mucin stains (Alcian blue, PAS) and MUC1 immunohistochemical staining. Multiplex fluorescence staining (MFS) was used to investigate which cells were associated with MUC1 expression in select cases. RESULTS: Thirty-one patients with PCM were included, 14 with follicular mucinosis (FM), 8 with reticular erythematous mucinosis, 2 with scleredema, 6 with pretibial myxedema and one patient with lichen myxedematosus. In all 31 specimens, mucin stained positive for Alcian blue and negative for PAS. In FM, mucin deposition was exclusively found in hair follicles and sebaceous glands. None of the other entities showed mucin deposits in follicular epithelial structures. Using MFS, all cases showed CD4+ and CD8+ T cells, tissue histiocytes, fibroblasts and pan-cytokeratin+ cells. These cells expressed MUC1 at different intensities. MUC1 expression in tissue histiocytes, fibroblasts, CD4+ and CD8+ T cells, and follicular epithelial cells of FM was significantly higher than the same cell types in the dermal mucinoses (p < 0.001). CD8+ T cells were significantly more involved in expression of MUC1 than all other analysed cell types in FM. This finding was also significant in comparison with dermal mucinoses. CONCLUSION: Various cell types seem to contribute to mucin production in PCM. Using MFS, we showed that CD8+ T cells seem to be more involved in the production of mucin in FM than in dermal mucinoses, which could indicate that mucin in dermal and follicular epithelial mucinoses have different origins.


Asunto(s)
Mucinosis , Escleromixedema , Humanos , Mucinosis/diagnóstico , Mucinosis/metabolismo , Mucinosis/patología , Mucinas/metabolismo , Estudios Retrospectivos , Azul Alcián , Coloración y Etiquetado
3.
J Eur Acad Dermatol Venereol ; 33(4): 667-675, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30357969

RESUMEN

BACKGROUND: Primary melanoma ulceration is an unfavourable prognostic factor included in current staging systems. Yet, the immunological and molecular alterations responsible for this adverse outcome have not been fully elucidated. OBJECTIVES: We aimed to identify immunological differences between ulcerated and non-ulcerated primary melanomas concerning both innate and adaptive immunity and to correlate these with clinical outcome. METHODS: Formalin-fixed paraffin-embedded primary melanomas from 112 patients (pts) were analysed by immunohistochemistry. The expression of various markers identifying tumour-infiltrating lymphocytes, macrophages and dendritic cells was evaluated semi-quantitatively by three independent investigators. Tumour cell expression of programmed death-ligand 1 (PD-L1), transporter of antigen processing 1 and the MxA protein was also analysed. RESULTS: Recurrence occurred in 21/56 pts (37.5%) with ulcerated vs. 14/56 pts (25.0%) with non-ulcerated tumours (P = 0.15). Tumour ulceration was associated with more frequent development of brain metastasis (17.6 vs. 3.6% of pts, P = 0.015). Immunohistochemistry showed an association of ulceration with the presence of intratumoural CD68+ macrophages (P = 0.028) as well as with increased numbers of intratumoural CD11c+ dendritic cells (P = 0.014) and CD163+ macrophages (P = 0.001). PD-L1 positivity (expression in >1% of tumour cells) was more frequent in ulcerated than non-ulcerated tumours [40 (72.7%) vs. 25 (44.6%), P = 0.003]. A positive correlation between intratumoural CD11c+ (Spearman's correlation coefficient ρ: 0.42) and CD163+ (ρ: 0.31) cell count and frequency of tumour cell PD-L1 expression was detected. CONCLUSIONS: Our results confirm the adverse clinical outcome associated with primary melanoma ulceration, particularly concerning the risk of recurrence and subsequent development of brain metastases. The observed immunological differences suggest a conceivable role of increased intratumoural macrophage and dendritic cell counts associated with enhanced tumour cell PD-L1 expression potentially contributing to the immunosuppressive, growth-promoting microenvironment of ulcerated primary melanomas.


Asunto(s)
Antígeno B7-H1/metabolismo , Neoplasias Encefálicas/secundario , Melanoma/metabolismo , Recurrencia Local de Neoplasia/inmunología , Neoplasias Cutáneas/metabolismo , Úlcera Cutánea/inmunología , Microambiente Tumoral , Inmunidad Adaptativa , Adulto , Anciano , Anciano de 80 o más Años , Antígenos CD/metabolismo , Antígenos de Diferenciación Mielomonocítica/metabolismo , Antígeno CD11c/metabolismo , Células Dendríticas/metabolismo , Femenino , Humanos , Inmunidad Innata , Macrófagos/metabolismo , Masculino , Melanoma/complicaciones , Melanoma/secundario , Persona de Mediana Edad , Receptores de Superficie Celular/metabolismo , Neoplasias Cutáneas/complicaciones , Neoplasias Cutáneas/patología , Úlcera Cutánea/etiología , Úlcera Cutánea/patología , Adulto Joven
4.
J Eur Acad Dermatol Venereol ; 33(4): 686-692, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30468696

RESUMEN

BACKGROUND: B-rapidly accelerated fibrosarcoma (BRAF) inhibitor encorafenib alone and in combination with MEK inhibitor binimetinib improves survival in BRAF-mutated melanoma patients. So far, the range of cutaneous adverse events has been characterized only for established BRAF inhibitors (vemurafenib, dabrafenib) and MEK inhibitors (trametinib, cobimetinib). OBJECTIVE: The aim of this study was to investigate cutaneous adverse events emerging in melanoma patients treated with encorafenib and binimetinib. METHODS: Patients treated with BRAF and MEK inhibitors in clinical trials at the University Hospital of Zurich were identified. Frequency and features of cutaneous adverse events as well as their management were assessed based on the prospectively collected clinical and histopathological data. The events emerging during encorafenib and/or binimetinib therapy were compared to other BRAF and MEK inhibitors at the institution and in the literature. RESULTS: The most frequent cutaneous adverse events observed in patients treated with encorafenib alone (n = 24) were palmoplantar hyperkeratosis (54%), palmoplantar erythrodysesthesia (58%) and alopecia (46%). Drug-induced papulopustular eruptions prevailed in patients with binimetinib monotherapy (n = 25). The most frequent cutaneous adverse events in patients treated with encorafenib/binimetinib (n = 49) were palmoplantar hyperkeratosis (10%). CONCLUSION: Compared to data published for established BRAFi, encorafenib monotherapy showed less hyperproliferative cutaneous adverse events. In contrast, palmoplantar hyperkeratosis and palmoplantar erythrodysesthesia seem to occur more often. The combination of encorafenib and binimetinib is well tolerated and induces few cutaneous adverse events.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Bencimidazoles/efectos adversos , Carbamatos/efectos adversos , Erupciones por Medicamentos/etiología , Melanoma/tratamiento farmacológico , Neoplasias Cutáneas/tratamiento farmacológico , Sulfonamidas/efectos adversos , Anciano , Alopecia/inducido químicamente , Bencimidazoles/administración & dosificación , Carbamatos/administración & dosificación , Femenino , Síndrome Mano-Pie/etiología , Humanos , Queratosis/inducido químicamente , Masculino , Melanoma/genética , Persona de Mediana Edad , Mutación , Proteínas Proto-Oncogénicas B-raf/genética , Neoplasias Cutáneas/genética , Sulfonamidas/administración & dosificación
5.
Oncogene ; 36(31): 4516-4524, 2017 08.
Artículo en Inglés | MEDLINE | ID: mdl-28368416

RESUMEN

Tumor initiation and metastasis formation in many cancers have been associated with emergence of a gene expression program normally active in embryonic or organ-specific stem cells. In particular, the stem cell transcription factor Sox2 is not only expressed in a variety of tumors, but is also required for their formation. Melanoma, the most aggressive skin tumor, derives from melanocytes that during development originate from neural crest stem cells. While neural crest stem cells do not express Sox2, expression of this transcription factor has been reported in melanoma. However, the role of Sox2 in melanoma is controversial. To study the requirement of Sox2 for melanoma formation, we therefore performed CRISPR-Cas9-mediated gene inactivation in human melanoma cells. In addition, we conditionally inactivated Sox2 in a genetically engineered mouse model, in which melanoma spontaneously develops in the context of an intact stroma and immune system. Surprisingly, in both models, loss of Sox2 did neither affect melanoma initiation, nor growth, nor metastasis formation. The lack of a tumorigenic role of Sox2 in melanoma might reflect a distinct stem cell program active in neural crest stem cells and during melanoma formation.


Asunto(s)
Melanoma/etiología , Factores de Transcripción SOXB1/fisiología , Animales , Humanos , Melanoma/mortalidad , Melanoma/secundario , Ratones
6.
Br J Dermatol ; 175(5): 966-978, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27168024

RESUMEN

BACKGROUND: There is a medical need for new drugs in patients with BRAF wild-type metastatic melanoma. Pazopanib is a multitarget tyrosine kinase inhibitor with antitumour and antiangiogenic activity. OBJECTIVES: The primary aim was to investigate the metabolic response to pazopanib monotherapy and pazopanib plus paclitaxel in patients with BRAF wild-type melanoma. Secondary end points were the early cytokine and chemokine profiles and histological findings. METHODS: Pazopanib (400 mg twice daily) was administered orally from days 1 to 10 and from days 14 to 70. An intravenous infusion with paclitaxel (150 mg m-2 body surface) was administered on days 14, 35 and 56. Metabolic response evaluation was performed before treatment, after treatment with pazopanib (day 10) and after treatment with pazopanib and paclitaxel (day 70). Skin biopsy of metastatic tissue for chemokine and cytokine expression analysis and histology and immunohistochemistry (CD68, CD163) evaluation, and blood samples were taken at the same time points. RESULTS: Two patients failed screening and 17 were dosed. Of 67 adverse events, nine (13%) were grade 3 or 4. Five of 14 evaluable patients had a partial metabolic response at day 10 under pazopanib monotherapy. The response rate at day 70 under combined pazopanib-paclitaxel treatment was 0%. Immunohistochemistry revealed an increase of M2-like macrophages in nonresponders compared with responders. We observed a significant upregulation of five cytokines (CXCL1, CXCL2, CXCL13, CCL22 and SPP1) in responding vs. nonresponding lesions. Overall, the median progression-free survival was 70 days (range 5-331), which did not differ significantly between responders (148 days) and nonresponders (70 days, P = 0·17). CONCLUSIONS: In this patient population pazopanib efficacy was limited. Response is associated with low M2-like macrophage density and increased expression of several chemokines.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Citocinas/metabolismo , Melanoma/tratamiento farmacológico , Neoplasias Cutáneas/tratamiento farmacológico , Administración Oral , Esquema de Medicación , Femenino , Humanos , Indazoles , Infusiones Intravenosas , Masculino , Melanoma/metabolismo , Paclitaxel/administración & dosificación , Pirimidinas/administración & dosificación , Neoplasias Cutáneas/metabolismo , Sulfonamidas/administración & dosificación , Resultado del Tratamiento , Regulación hacia Arriba
7.
Opt Express ; 24(5): 4532-4541, 2016 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-29092280

RESUMEN

We demonstrate that the lin-par-lin Ramsey coherent population trapping 87Rb clock using a dispersion detection technique has a promising performance. We theoretically and experimentally investigate the signal-to-noise ratio of the Ramsey spectrum signal by varying the relative angle of the polarizer and analyzer as well as the magnetic field. Based on the experimental results, the optimized relative angle and magnetic field are determined. This kind of atomic clock is attractive for the development of compact, high performance vapor clock based on CPT.

8.
Br J Dermatol ; 171(5): 1066-72, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24974741

RESUMEN

BACKGROUND: Basal cell carcinoma (BCC) is the most frequent skin cancer with increasing incidence and generally high cure rates. BCC can be quite aggressive and is difficult to treat. OBJECTIVES: To investigate BCCs with a focus on histological subtypes, treatment procedures and correlation to clinical progress to collect further information on complex BCC cases. METHODS: In this retrospective single-centre analysis the dermatopathology database, a network of cooperating dermatological surgeons, was queried for BCC cases between January 2007 and December 2011. Of 14,423 samples from a total of 9652 patients initially identified, 2938 patients were treated at the University Hospital Zurich and had corresponding local electronic patient records. RESULTS: Patients (n = 2938) (with 4769 diagnoses, 2006 re-excisions with 1180 microscopically controlled surgeries) were classified based on severity estimations into 2240 simple, 640 moderate, and 58 severe cases, including one BCC-treatment-associated death and 11 patients with subsequent participation in a clinical trial. In moderate and severe cases (n = 698), there were significantly higher rates of unique histological diagnoses (n = 2·5; P < 0·0001), higher association with basosquamous carcinoma [odds ratio (OR) 3·6; P < 0·0001] and sclerosing BCC (OR 2·48; P < 0·0001). Of the patients with basosquamous carcinoma 82·6% had a previous history of BCC. CONCLUSIONS: This is the first study that analyses the frequency of complicated BCCs in a tertiary referral centre. There were 6·6% moderate (640 of 9652) and 0·6% (58 of 9652) severe cases. We found significantly more varying histological diagnoses and significant association with aggressive subtypes in moderate and severe cases. These patients might especially benefit from new therapeutic options.


Asunto(s)
Carcinoma Basocelular/cirugía , Neoplasias Cutáneas/cirugía , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma Basocelular/patología , Femenino , Alemania , Hospitalización , Humanos , Masculino , Persona de Mediana Edad , Cirugía de Mohs/estadística & datos numéricos , Estudios Retrospectivos , Neoplasias Cutáneas/patología , Centros de Atención Terciaria
9.
J Cell Biol ; 155(3): 381-92, 2001 Oct 29.
Artículo en Inglés | MEDLINE | ID: mdl-11684706

RESUMEN

The epiblast of the chick embryo gives rise to the ectoderm, mesoderm, and endoderm during gastrulation. Previous studies revealed that MyoD-positive cells were present throughout the epiblast, suggesting that skeletal muscle precursors would become incorporated into all three germ layers. The focus of the present study was to examine a variety of organs from the chicken fetus for the presence of myogenic cells. RT-PCR and in situ hybridizations demonstrated that MyoD-positive cells were present in the brain, lung, intestine, kidney, spleen, heart, and liver. When these organs were dissociated and placed in culture, a subpopulation of cells differentiated into skeletal muscle. The G8 antibody was used to label those cells that expressed MyoD in vivo and to follow their fate in vitro. Most, if not all, of the muscle that formed in culture arose from cells that expressed MyoD and G8 in vivo. Practically all of the G8-positive cells from the intestine differentiated after purification by FACS. This population of ectopically located cells appears to be distinct from multipotential stem cells and myofibroblasts. They closely resemble quiescent, stably programmed skeletal myoblasts with the capacity to differentiate when placed in a permissive environment.


Asunto(s)
Músculo Esquelético/citología , Proteína MioD/análisis , Células Madre/citología , Animales , Encéfalo/embriología , Diferenciación Celular , Embrión de Pollo , Citometría de Flujo , Expresión Génica , Corazón/embriología , Intestinos/embriología , Riñón/embriología , Hígado/embriología , Pulmón/embriología , Músculo Esquelético/química , Músculo Esquelético/embriología , Proteína MioD/genética , ARN Mensajero/análisis , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Bazo/embriología , Células Madre/química , Distribución Tisular
11.
Science ; 274(5292): 1523-7, 1996 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-8929412

RESUMEN

The proteins encoded by the myc proto-oncogene family are involved in cell proliferation, apoptosis, differentiation, and neoplasia. Myc acts through dimerization with Max to bind DNA and activate transcription. Homologs of the myc and max genes were cloned from the fruit fly Drosophila melanogaster and their protein products (dMyc and dMax) were shown to heterodimerize, recognize the same DNA sequence as their vertebrate homologs, and activate transcription. The dMyc protein is likely encoded by the Drosophila gene diminutive (dm), a mutation in which results in small body size and female sterility caused by degeneration of the ovaries. These findings indicate a potential role for Myc in germ cell development and set the stage for genetic analysis of Myc and Max.


Asunto(s)
Proteínas de Drosophila , Drosophila melanogaster/genética , Secuencias Hélice-Asa-Hélice , Factores de Transcripción/metabolismo , Secuencia de Aminoácidos , Animales , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico , Clonación Molecular , Elementos Transponibles de ADN , ADN Complementario , Proteínas de Unión al ADN/química , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Dimerización , Drosophila melanogaster/química , Drosophila melanogaster/crecimiento & desarrollo , Drosophila melanogaster/metabolismo , Femenino , Regulación del Desarrollo de la Expresión Génica , Genes de Insecto , Genes myc , Humanos , Datos de Secuencia Molecular , Sondas de Oligonucleótidos/metabolismo , Ovario/metabolismo , Proto-Oncogenes Mas , Proteínas Proto-Oncogénicas c-myc/química , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Proto-Oncogénicas c-myc/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Factores de Transcripción/química , Factores de Transcripción/genética , Transcripción Genética
12.
Mol Cell Biol ; 15(7): 3813-22, 1995 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-7791788

RESUMEN

With modified two-hybrid technology, we have isolated a member of a new family of basic helix-loop-helix (bHLH) transcription factors. Thing1 (Th1) was identified in a screen of a mouse embryo cDNA library as a partner for the Drosophila E protein daughterless. RNA in situ hybridization and reverse transcriptase-PCR demonstrate a stage- and tissue-specific distribution for the expression of Th1. Although tissue specific, the expression pattern of Th1 is fairly complex. During development, Th1 mRNA is widely expressed in extraembryonic tissues, portions of the heart, autonomic ganglia, the gut, and pharyngeal arches. At embryonic day 7.5 (E7.5), extraembryonic derivatives show robust Th1 expression. By E8.5, expression in the embryonic heart becomes detectable. During the next 2 days of development, the signal also includes gut and pharyngeal arches. Predominant expression at E13.5 is in neural crest derivatives, especially the autonomic nervous system and adrenal medulla. Expression of Th1 persists in the adult, in which it is localized to the smooth muscle cells of the gut. In vitro, Th1 protein recognizes a set of DNA sites that are more degenerate than has been determined for other bHLH factors, indicating a reduced binding specificity. Transient transfection of NIH 3T3 cells with GAL4-Th1 fusions reveals a repression activity mediated by the Th1 bHLH domain. In combination, these properties define Th1 as a new bHLH protein with a unique set of properties.


Asunto(s)
Proteínas de Unión al ADN/genética , Proteínas de Drosophila , Secuencias Hélice-Asa-Hélice , Familia de Multigenes , Serina Endopeptidasas , Factores de Transcripción/genética , Secuencia de Aminoácidos , Animales , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Secuencia de Bases , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico , ADN Complementario/genética , Proteínas de Unión al ADN/clasificación , Proteínas de Unión al ADN/metabolismo , Embrión de Mamíferos/anatomía & histología , Embrión de Mamíferos/química , Biblioteca de Genes , Hibridación in Situ , Ratones , Datos de Secuencia Molecular , Proteínas Nucleares/metabolismo , Reacción en Cadena de la Polimerasa , Unión Proteica , Proteínas Recombinantes de Fusión , Factores de Tiempo , Distribución Tisular , Factores de Transcripción/clasificación , Factores de Transcripción/metabolismo , Transcripción Genética
13.
Proc Natl Acad Sci U S A ; 90(17): 8028-32, 1993 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-8396258

RESUMEN

DNA sequences encoding the hormone-binding domains of several steroid hormone receptors were fused in frame to the MyoD gene. When the gene for this chimeric protein was expressed in NIH 3T3 or 10T1/2 fibroblasts, these cells displayed hormone-dependent induction of myogenesis. Our experiments focused on cell lines expressing estrogen receptor-MyoD chimeras. Induction of these lines in the presence of estradiol and an inhibitor of protein synthesis, cycloheximide, resulted in the activation of the endogenous myogenin gene but did not activate the muscle-specific creatine kinase or cardiac alpha-actin gene. This result suggests that MyoD is not a "direct" activator of these downstream myogenic genes but must first activate myogenin as an intermediary. Once muscle is induced by estrogen receptor-MyoD the muscle phenotype is very stable and does not need the continued presence of estradiol for its maintenance.


Asunto(s)
Proteínas Musculares/metabolismo , Músculos/fisiología , Factores de Transcripción/metabolismo , Células 3T3 , Actinas/biosíntesis , Animales , Secuencia de Bases , Diferenciación Celular , Creatina Quinasa/biosíntesis , Cicloheximida/farmacología , Estradiol/farmacología , Regulación de la Expresión Génica , Vectores Genéticos , Humanos , Isoenzimas , Ratones , Datos de Secuencia Molecular , Proteínas Musculares/biosíntesis , Músculos/citología , Proteína MioD , Oligodesoxirribonucleótidos , Oligonucleótidos Antisentido , Reacción en Cadena de la Polimerasa , Receptores de Estrógenos/biosíntesis , Receptores de Estrógenos/metabolismo , Receptores de Glucocorticoides/biosíntesis , Receptores de Glucocorticoides/metabolismo , Receptores de Hormona Tiroidea/biosíntesis , Receptores de Hormona Tiroidea/metabolismo , Proteínas Recombinantes de Fusión/biosíntesis , Proteínas Recombinantes de Fusión/metabolismo , Transfección
14.
Genes Dev ; 5(8): 1321-32, 1991 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-1678362

RESUMEN

Retinoic acid (RA) treatment of Xenopus laevis embryos leads to anterior truncation of the body axis (Durston et al. 1989; Sive et al. 1990). These initial studies suggested that RA may play a role in the patterning of the primary body axis. At least one target of RA was shown previously to be dorsal ectoderm. In this report we extend this observation and also ask whether RA alters the determination and inducing capacity of mesodermal tissue. To facilitate this analysis we isolated the homeo-domain-containing genes Xhox.lab1 and Xhox.lab2. These genes were expressed in both ectoderm and mesoderm during the RA-sensitive period and were strongly induced by RA in both germ layers. In particular, anterior regions expressed low levels of Xhox.lab RNAs in untreated embryos but showed increased expression after RA application. We show further that although RA-treated embryos contained anterior-inducing mesoderm, the amount of this activity appeared to be lower than that of controls. Additionally, we document that RA suppressed lateral (muscle) and ventral (blood) mesoderm differentiation. The data indicate that RA alters mesodermal determination and causes axial perturbation both by depressing the ability of dorsal mesoderm to induce anterior structures and by altering the response of dorsal ectoderm to induction. These analyses suggest that Xhox.lab genes may be responsible, in part, for mediating the RA effect.


Asunto(s)
Embrión no Mamífero/fisiología , Genes Homeobox/efectos de los fármacos , Mesodermo/fisiología , Familia de Multigenes , Tretinoina/farmacología , Secuencia de Aminoácidos , Animales , Northern Blotting , Ectodermo/efectos de los fármacos , Ectodermo/fisiología , Embrión no Mamífero/efectos de los fármacos , Embrión no Mamífero/efectos de la radiación , Expresión Génica/efectos de los fármacos , Expresión Génica/efectos de la radiación , Mesodermo/efectos de los fármacos , Mesodermo/efectos de la radiación , Datos de Secuencia Molecular , Plásmidos , Homología de Secuencia de Ácido Nucleico , Rayos Ultravioleta , Xenopus laevis
15.
Cell ; 60(5): 733-46, 1990 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-2155707

RESUMEN

A 60 amino acid domain of the myogenic determination gene MyoD is necessary and sufficient for sequence-specific DNA binding in vitro and myogenic conversion of transfected C3H10T1/2 cells. We show that a highly basic region, immediately upstream of the helix-loop-helix (HLH) oligomerization motif, is required for MyoD DNA binding in vitro. Replacing helix1, helix2, or the loop of MyoD with the analogous sequence of the Drosophila T4 achaete-scute protein (required for peripheral neurogenesis) has no substantial effect on DNA binding in vitro or muscle-specific gene activation in transfected C3H10T1/2 cells. However, replacing the basic region of MyoD with the analogous sequence of other HLH proteins (the immunoglobulin enhancer binding E12 protein or T4 achaete scute protein) allows DNA binding in vitro, yet abolishes muscle-specific gene activation. These findings suggest that a recognition code that determines muscle-specific gene activation lies within the MyoD basic region and that the capacity for specific DNA binding is insufficient to activate the muscle program.


Asunto(s)
ADN/genética , Regulación de la Expresión Génica , Genes , Proteínas Musculares/genética , Músculos/citología , Transfección , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Diferenciación Celular , Células Cultivadas , Deleción Cromosómica , ADN/metabolismo , Elementos de Facilitación Genéticos , Ratones , Modelos Moleculares , Datos de Secuencia Molecular , Proteína MioD , Sondas de Oligonucleótidos , Conformación Proteica , Activación Transcripcional
16.
Princess Takamatsu Symp ; 20: 267-78, 1989.
Artículo en Inglés | MEDLINE | ID: mdl-2562185

RESUMEN

The myogenic determination gene MyoD contains a 60 amino acid domain that is necessary for both sequence-specific DNA binding and myogenic conversion of transfected C3H10T1/2 mouse embryo fibroblasts. We have generated deletion, insertion, and substitution mutants to probe the structure and function of this region, both in vitro and in vivo. Our results are consistent with a previous proposal that a helix-loop-helix (HLH) motif mediates protein dimerization. A highly basic region located immediately upstream of the HLH motif is required for DNA binding, which occurs if and only if the HLH motif is capable of dimerization. All mutants of MyoD that do not bind DNA in vitro fail to activate myogenesis or expression of a co-transfected muscle-specific reporter gene in transfected C3H10T1/2 cells. Replacing either helix 1, helix 2, or the loop sequence of MyoD with the analogous sequence of the Drosophila T4 achaete-scute protein (which is required for neurogenesis) has no substantial effect on DNA binding or biological activity. However, replacing the basic region of MyoD with the analogous sequence of the kappa immunoglobulin enhancer binding protein E12, or the T4 achaete-scute protein, produces proteins still capable of specific DNA binding in vitro, yet without significant biological activity. These findings suggest that within the 13 amino acid sequence of the MyoD basic region lies a recognition code that determines muscle-specific gene expression, although specific DNA binding per se is not sufficient to activate the muscle program.


Asunto(s)
Proteínas de Unión al ADN/fisiología , Proteínas Musculares/fisiología , Músculos/embriología , Nervios Periféricos/embriología , Secuencia de Aminoácidos , Animales , Diferenciación Celular , Proteínas de Unión al ADN/genética , Drosophila melanogaster/metabolismo , Elementos de Facilitación Genéticos , Fibroblastos/citología , Genes , Ratones , Ratones Endogámicos C3H , Datos de Secuencia Molecular , Familia de Multigenes , Proteínas Musculares/genética , Mutagénesis Sitio-Dirigida , Proteína MioD , Especificidad de Órganos , Unión Proteica , Conformación Proteica , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/fisiología
17.
Science ; 242(4877): 405-11, 1988 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-3175662

RESUMEN

Expression of a complementary DNA (cDNA) encoding the mouse MyoD1 protein in a variety of fibroblast and adipoblast cell lines converts them to myogenic cells. Polyclonal antisera to fusion proteins containing the MyoD1 sequence show that MyoD1 is a phosphoprotein present in the nuclei of proliferating myoblasts and differentiated myotubes but not expressed in 10T1/2 fibroblasts or other nonmuscle cell types. Functional domains of the MyoD1 protein were analyzed by site-directed deletional mutagenesis of the MyoD1 cDNA. Deletion of a highly basic region (residues 102 to 135) interferes with both nuclear localization and induction of myogenesis. Deletion of a short region (residues 143 to 162) that is similar to a conserved region in the c-Myc family of proteins eliminates the ability of the MyoD1 protein to initiate myogenesis but does not alter nuclear localization. Deletions of regions spanning the remainder of MyoD1 did not affect nuclear localization and did not inhibit myogenesis. Furthermore, expression of only 68 amino acids of MyoD1, containing the basic and the Myc similarity domains, is sufficient to activate myogenesis in stably transfected 10T1/2 cells. Genetic analysis maps the MyoD1 gene to mouse chromosome 7 and human chromosome 11.


Asunto(s)
Genes , Proteína MioD , Proteínas Nucleares/genética , Oncogenes , Fosfoproteínas/genética , Animales , Diferenciación Celular , División Celular , Células Cultivadas , Mapeo Cromosómico , ADN/genética , Fibroblastos/citología , Humanos , Ratones , Músculos/citología , Proteínas Nucleares/fisiología , Fosfoproteínas/fisiología
18.
Cell ; 46(1): 115-22, 1986 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-3459589

RESUMEN

Supercoiled DNAs, especially those containing enhancers, yield markedly higher levels of expression than linearized DNA when transfected into CV-1 cells or L cells. Different templates, linear or supercoiled, enhancer-containing or not, saturate for expression at 2 micrograms DNA per dish, suggesting that one role for enhancers and supercoiling is to increase the efficiency with which the same limiting component is used. Plasmids containing only enhancers or only promoters do not compete for expression with an enhancer-driven gene. However, plasmids that contain both enhancers and promoters do complete, suggesting that a second role for enhancers is to increase the binding of a limiting transcription factor. Linear and supercoiled enhancer-promoter plasmids compete equivalently. This suggests that supercoiling affects the ability of transcription factors to activate a given promoter, once bound.


Asunto(s)
ADN/genética , Regulación de la Expresión Génica , Transfección , Acetiltransferasas/genética , Animales , Línea Celular , Cloranfenicol O-Acetiltransferasa , Chlorocebus aethiops , ADN Superhelicoidal/genética , Elementos de Facilitación Genéticos , Células L , Conformación de Ácido Nucleico , Plásmidos , Regiones Promotoras Genéticas , Moldes Genéticos , Transcripción Genética
20.
Proc Natl Acad Sci U S A ; 79(20): 6265-9, 1982 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-6959116

RESUMEN

In order to identify potential red cell-specific regulatory proteins and to define additional red cell-specific markers, we have isolated a series of hybridomas that produce monoclonal antibodies that react with nuclear preparations from avian red blood cells. Several antibodies have been well characterized for their tissue- and species-specific reactions by using solid-phase and protein-transfer radioimmunoassays as well as immunofluorescence. These antibodies should allow isolation and characterization of individual nuclear proteins that are tissue and species specific and may prove useful for the study of gene expression in the erythropoietic system. The majority of the well-characterized antibodies appear to have tissue-specific properties. However, three antibodies react with all tested chicken tissues; one of these reacts with multiple peptides in a pattern that varies qualitatively and quantitatively between the tissues. This may reflect a common protein domain or modification that is used in several different tissues for similar functions but is nevertheless present in an overall protein framework that is tissue specific. Because the major fraction of the hybridomas initially produced is tissue specific, we presume that the immune system selects for tissue-specific determinants. This property of the immune system may prove to be a useful general feature of this type of analysis.


Asunto(s)
Núcleo Celular/inmunología , Eritrocitos/inmunología , Regulación de la Expresión Génica , Animales , Anticuerpos Monoclonales , Especificidad de Anticuerpos , Pollos , Eritrocitos/ultraestructura , Ratones , Peso Molecular , Proteínas/inmunología , Especificidad de la Especie , Distribución Tisular
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