RESUMEN

The role extracellular matrix (ECM) in multiple events of morphogenesis has been well described, little is known about its specific role in early eye development. One of the first morphogenic events in lens development is placodal thickening, which converts the presumptive lens ectoderm from cuboidal to pseudostratified epithelium. This process occurs in the anterior pre-placodal ectoderm when the optic vesicle approaches the cephalic ectoderm and is regulated by transcription factor Pax6 and secreted BMP4. Since cells and ECM have a dynamic relationship of interdependence and modulation, we hypothesized that the ECM evolves with cell shape changes during lens placode formation. This study investigates changes in optic ECM including both protein distribution deposition, extracellular gelatinase activity and gene expression patterns during early optic development using chicken and mouse models. In particular, the expression of Timp2, a metalloprotease inhibitor, corresponds with a decrease in gelatinase activity within the optic ECM. Furthermore, we demonstrate that optic ECM remodeling depends on BMP signaling in the placode. Together, our findings suggest that the lens placode plays an active role in remodeling the optic ECM during early eye development.

Asunto(s)

Matriz Extracelular , Regulación del Desarrollo de la Expresión Génica , Cristalino , Factor de Transcripción PAX6 , Animales , Matriz Extracelular/metabolismo , Ratones , Cristalino/metabolismo , Cristalino/crecimiento & desarrollo , Cristalino/citología , Factor de Transcripción PAX6/metabolismo , Factor de Transcripción PAX6/genética , Proteínas del Ojo/metabolismo , Proteínas del Ojo/genética , Proteína Morfogenética Ósea 4/metabolismo , Proteína Morfogenética Ósea 4/genética , Embrión de Pollo , Proteínas de Homeodominio/metabolismo , Proteínas de Homeodominio/genética , Inhibidor Tisular de Metaloproteinasa-2/metabolismo , Inhibidor Tisular de Metaloproteinasa-2/genética , Factores de Transcripción Paired Box/metabolismo , Factores de Transcripción Paired Box/genética , Proteínas Represoras/metabolismo , Proteínas Represoras/genética , Transducción de Señal , Pollos/genética , Ojo/metabolismo , Ojo/crecimiento & desarrollo , Ojo/embriología

RESUMEN

PURPOSE: To investigate the possibility of using the methylation level of PAX1/ZNF582 gene as molecular marker to differentiate the progression of cervical cancer. METHODS: From January 2016 to March 2018, 150 patients, who were admitted to Cervical Disease Diagnosis and Treatment Center of Xuzhu Maternity and Child Care Hospital, were enrolled in this study. Patients were classified into chronic cervicitis (for 19 cases), low-grade squamous intraepithelial lesion (LSIL) (18 cases), high-grade squamous intraepithelial lesion (HSIL) (37 cases) and squamous cell carcinoma (SCC) (31 cases). All patients underwent several tests including Thin-prep cytology test (TCT), HPV DNA detection and detection of methylation level of PAX1/ZNF582 genes. RESULTS: For diagnosis of HSIL, the area under curve (AUC) was 0.878 (95% CI 0.806 ~ 0.950); the threshold for PAX1 was 12.285, the sensitivity and specificity were 91.9% and 72.8%, respectively. The AUC of ZNF582 gene detection was 0.900 (95% CI 0.842 ~ 0.959), the threshold was 11.56, while the sensitivity and specificity were 97.3% and 76.7%, respectively. Among various tests we conducted, PAX gene detection methods showed the highest specificity (97.30%). PAX1/ZNF582 gene detection method demonstrated the highest accuracy. CONCLUSIONS: For patients with high-grade cervical lesion and cervical cancer, the methylation level of PAX1/ZNF582 gene could be applied as a noteworthy biomarker for diagnosis and for cervical cancer classification.

Asunto(s)

Carcinoma de Células Escamosas/genética , Factores de Transcripción de Tipo Kruppel/genética , Factores de Transcripción Paired Box/genética , Displasia del Cuello del Útero/genética , Neoplasias del Cuello Uterino/genética , Adulto , Anciano , Alphapapillomavirus/genética , Área Bajo la Curva , Carcinoma de Células Escamosas/patología , Carcinoma de Células Escamosas/virología , Enfermedad Crónica , Metilación de ADN , ADN Viral/análisis , Progresión de la Enfermedad , Femenino , Marcadores Genéticos , Humanos , Persona de Mediana Edad , Clasificación del Tumor , Sensibilidad y Especificidad , Neoplasias del Cuello Uterino/patología , Neoplasias del Cuello Uterino/virología , Cervicitis Uterina , Adulto Joven , Displasia del Cuello del Útero/patología , Displasia del Cuello del Útero/virología

RESUMEN

The association of anophthalmia, arrhinia, and hypogonadism constitutes the major clinical features for Bosma arrhinia microphthalmia syndrome. However, there is variability in the presentation of this disease; arrhinia is the most constant clinical feature, which is then combined with a spectrum of anophthalmia/microphthalmia and/or hypogonadism. This rare entity is not associated with any specific genes, but the genes that are related to arrhinia and anophthalmia have been studied in an attempt to explain this phenomenon. We analyzed the PAX6 gene in a Bosma arrhinia microphthalmia syndrome patient but found no variation or mutation that could constitute or establish a causal association in our patient.

Asunto(s)

Atresia de las Coanas/genética , Proteínas del Ojo/genética , Proteínas de Homeodominio/genética , Microftalmía/genética , Nariz/anomalías , Factores de Transcripción Paired Box/genética , Proteínas Represoras/genética , Humanos , Lactante , Masculino , México , Mutación , Factor de Transcripción PAX6

RESUMEN

Aniridia is an autosomal dominant disorder characterized by the complete or partial loss of the iris and is almost associated with mutations in the paired box gene 6 (PAX6). We examined three generations of a Chinese family with congenital aniridia and observed genetic defects. Exons of PAX6 from 12 family members were amplified by polymerase chain reaction, sequenced, and compared with reference sequences in NCBI reference sequence database (http://www.ncbi.nlm.nih.gov/nuccore/NG_008679.1?from=5001&to=38170&report=genbank). A rare mutation c.2T>A (M1K) in exon 4 of PAX6 was identified in all affected family members but not in unaffected family members. Our results suggest that the c.2T>A (M1K) mutation may be responsible for the pathogenesis of congenital aniridia in this family. To our knowledge, this is the first report of the M1K mutation in PAX6 in a Chinese family with this disease and the second report worldwide.

Asunto(s)

Aniridia/diagnóstico , Aniridia/genética , Proteínas del Ojo/genética , Proteínas de Homeodominio/genética , Mutación , Factores de Transcripción Paired Box/genética , Proteínas Represoras/genética , Adolescente , Adulto , Secuencia de Aminoácidos , Pueblo Asiatico/genética , China , Topografía de la Córnea , Análisis Mutacional de ADN , Exones , Proteínas del Ojo/química , Familia , Femenino , Proteínas de Homeodominio/química , Humanos , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Factor de Transcripción PAX6 , Factores de Transcripción Paired Box/química , Linaje , Proteínas Represoras/química , Alineación de Secuencia , Adulto Joven

RESUMEN

This study aimed to investigate whether the differential expression of muscle development-related genes is one of the reasons why muscle development differs between Pekin, Jianchang, and Heiwu ducks, which are all domesticated duck breeds (Anas platyrhynchos domestica) breeds. At 2 weeks of age, the RNA expression of paired box 7 (Pax7), paired box 3 (Pax3), myogenic differentiation antigen (MYOD), and myogenin (MYOG) genes were measured by quantitative polymerase chain reaction, and Pax3 and Pax7 protein levels were detected by western blot assay. Myofiber morphology was investigated using paraffin-embedded muscle sections. At 8 weeks of age, 30 ducks of each breed were slaughtered for meat quality determination. The results revealed that Pax3 and Pax7 expression levels at both the RNA and protein levels were high in the Pekin duck. In addition, MYOG expression levels in the Jianchang duck were significantly higher than in the other two duck breeds (P < 0.05). There were no significant differences in MYOD expression levels between the breeds (P > 0.05). Myofiber diameter and cross-sectional area were the largest in the Pekin duck and the smallest in the Heiwu duck. There were significant differences in slaughter data between these breeds, and muscle content was greatest in the Pekin duck. The results indicate that the muscle content of three different duck breeds is associated with the expression of satellite-cell marker genes.

Asunto(s)

Patos/genética , Músculo Esquelético/anatomía & histología , Músculo Esquelético/metabolismo , Factores de Transcripción Paired Box/genética , Mataderos , Animales , Western Blotting , Cruzamiento , Extremidades , Regulación de la Expresión Génica , Proteína MioD/genética , Proteína MioD/metabolismo , Miogenina/genética , Miogenina/metabolismo , Tamaño de los Órganos/genética , Factores de Transcripción Paired Box/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo

RESUMEN

The pancreatic and duodenal homeobox factor 1 (Pdx1) protein is the most pivotal transcription factor in the development of islet ß cells. This study investigated the role of Pdx1 and its mechanism in differentiating induced pluripotent stem cells (iPSCs) into islet ß cells. iPSCs derived from human skin fibroblasts were cultured in vitro and directionally induced to differentiate for 20 days. The expression of insulin-related genes was then detected by RT-PCR, and the expression of several differentiation-related transcription factors was assessed both before and after the differentiation process. Lastly, the specific promoter regions where Pdx1 binds were detected by ChIP. The insulin-related genes, MafA, insulin, Glut2, Nkx6.1, GCK, and Tcf1, showed increased expression during differentiation, and nearly peaked on the 20th day. Similarly, the expression of transcription factors, Pdx1, Ngn3, and Pax6 showed enhanced expression during differentiation as compared with that of the control group. ChIP experiments confirmed that Pdx1 activates the expression of the downstream transcription factors, Ngn3 and Pax6, by combined with the promoter regions of insulin (Insulin-P), Ngn3 (Ngn3-P), and Pax6 (Pax6-P). In conclusion, Pdx1 activates downstream transcription factors Ngn3 and Pax6, and may be one of the mechanisms that promote differentiation of iPSCs into islet ß cells.

Asunto(s)

Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/biosíntesis , Proteínas del Ojo/biosíntesis , Proteínas de Homeodominio/biosíntesis , Células Madre Pluripotentes Inducidas/metabolismo , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Proteínas del Tejido Nervioso/biosíntesis , Factores de Transcripción Paired Box/biosíntesis , Proteínas Represoras/biosíntesis , Transactivadores/biosíntesis , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Diferenciación Celular/efectos de los fármacos , Diferenciación Celular/genética , Inmunoprecipitación de Cromatina , Células Madre Embrionarias/citología , Células Madre Embrionarias/metabolismo , Proteínas del Ojo/genética , Genes Homeobox , Proteínas de Homeodominio/genética , Humanos , Células Madre Pluripotentes Inducidas/citología , Insulina/genética , Células Secretoras de Insulina/citología , Proteínas del Tejido Nervioso/genética , Factor de Transcripción PAX6 , Factores de Transcripción Paired Box/genética , Proteínas Represoras/genética , Transactivadores/genética , Activación Transcripcional

RESUMEN

OBJECTIVES: To correlate thyroid cancer genotype with histology and outcomes. BACKGROUND: The prognostic significance of molecular signature in thyroid cancer (TC) is undefined but can potentially change surgical management. METHODS: We reviewed a consecutive series of 1510 patients who had initial thyroidectomy for TC with routine testing for BRAF, RAS, RET/PTC, and PAX8/PPARG alterations. Histologic metastatic or recurrent TC was tracked for 6 or more months after oncologic thyroidectomy. RESULTS: Papillary thyroid cancer (PTC) was diagnosed in 97% of patients and poorly differentiated/anaplastic TC in 1.1%. Genetic alterations were detected in 1039 (70%); the most common mutations were BRAFV600E (644/1039, 62%), and RAS isoforms (323/1039, 31%). BRAFV600E-positive PTC was often conventional or tall cell variant (58%), with frequent extrathyroidal extension (51%) and lymph node metastasis (46%). Conversely, RAS-positive PTC was commonly follicular variant (87%), with infrequent extrathyroidal extension (4.6%) and lymph node metastasis (5.6%). BRAFV600E and RET/PTC-positive PTCs were histologically similar. Analogously, RAS and PAX8/PPARG-positive PTCs were histologically similar. Compared with RAS or PAX8/PPARG-positive TCs, BRAFV600E or RET/PTC-positive TCs were more often associated with stage III/IV disease (40% vs 15%, P < 0.001) and recurrence (10% vs 0.7%, P < 0.001; mean follow-up 33 ± 21 mo). Distant metastasis was highest in patients with RET/PTC-positive TC (10.8%, P = 0.02). CONCLUSIONS: In this large study of prospective mutation testing in unselected patients with TC, molecular signature was associated with distinctive phenotypes including cancers, with higher risks of both distant metastasis and early recurrence. Preoperative genotype provides valuable prognostic data to appropriately inform surgery.

Asunto(s)

Carcinoma/genética , Carcinoma/mortalidad , Regulación Neoplásica de la Expresión Génica , Proteínas Proto-Oncogénicas/genética , Neoplasias de la Tiroides/genética , Neoplasias de la Tiroides/mortalidad , Adulto , Anciano , Carcinoma/patología , Carcinoma/cirugía , Carcinoma Papilar , Bases de Datos Factuales , Supervivencia sin Enfermedad , Femenino , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Mutación , Invasividad Neoplásica , Estadificación de Neoplasias , Factor de Transcripción PAX8 , Factores de Transcripción Paired Box/genética , Fenotipo , Valor Predictivo de las Pruebas , Pronóstico , Proteínas Proto-Oncogénicas B-raf/genética , Proteínas Proto-Oncogénicas c-ret/genética , Estudios Retrospectivos , Análisis de Supervivencia , Cáncer Papilar Tiroideo , Neoplasias de la Tiroides/patología , Neoplasias de la Tiroides/cirugía , Tiroidectomía/métodos , Tiroidectomía/mortalidad , Resultado del Tratamiento

RESUMEN

Congenital aniridia is a rare genetic disorder characterized by varying degrees of iris hypoplasia that are associated with additional ocular abnormalities. More than 90% of the causal mutations identified are found in the PAX6 gene, a transcription factor of critical importance in the process of neurogenesis and ocular development. Here, we investigate clinical, molecular, and craniofacial features of a large Brazilian family with congenital aniridia. Among the 56 eyes evaluated, phenotype variation encompassed bilateral total aniridia to mild iris defects with extensive variation between eyes of the same individual. PAX6 molecular screening indicated a heterozygous splice mutation (c.141 + 1G>A). Thus, we hypothesize that this splicing event may cause variation in the expression of the wild-type transcript, which may lead to the observed variation in phenotype. Affected individuals were more brachycephalic, even though their face height and cephalic circumference were not significantly different when compared to those of non-affected relatives. From this, we infer that the head shape of affected subjects may also be a result of the PAX6 splice-site mutation. Our data summarize the clinical variability associated with the ocular phenotype in a large family with aniridia, and help shed light on the role of PAX6 in neurocranial development.

Asunto(s)

Aniridia/genética , Aniridia/patología , Anomalías Craneofaciales/patología , Anomalías del Ojo/patología , Proteínas del Ojo/genética , Proteínas de Homeodominio/genética , Factores de Transcripción Paired Box/genética , Fenotipo , Proteínas Represoras/genética , Adolescente , Adulto , Anciano , Análisis de Varianza , Secuencia de Bases , Brasil , Niño , Femenino , Humanos , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Mutación/genética , Factor de Transcripción PAX6 , Linaje , Análisis de Secuencia de ADN

RESUMEN

Genetic variations within the paired box gene 6 (PAX6) gene are associated with congenital aniridia. To detect the genetic defects in a Chinese twin family with congenital aniridia and nystagmus, exons of PAX6 were amplified by polymerase chain reaction (PCR), sequenced and compared with a reference database. Six members from the family of three generations were included in the study. The twins' father presented with congenital aniridia, nystagmus and cataract at birth, while the twins presented with congenital aniridia and nystagmus. A novel mutation c.888 insA in exon 10 of PAX6 was identified in all affected individuals. This study suggests that the novel mutation c.888 insA is likely responsible for the pathogenesis of the congenital aniridia and nystagmus in this pedigree. To the best of our knowledge, this is the first report of this mutation in PAX6 gene in pedigree with aniridia. Furthermore, no PAX6 gene defect was reported in twins with congenital aniridia.

Asunto(s)

Aniridia/genética , Proteínas del Ojo/genética , Proteínas de Homeodominio/genética , Mutación , Nistagmo Congénito/genética , Factores de Transcripción Paired Box/genética , Proteínas Represoras/genética , Adulto , Aniridia/complicaciones , Aniridia/diagnóstico , Catarata/complicaciones , Niño , Exones , Femenino , Humanos , Masculino , Nistagmo Congénito/complicaciones , Factor de Transcripción PAX6 , Linaje , Gemelos

RESUMEN

Tumor suppressor genes (TSGs) are commonly inactivated by somatic mutation and/or promoter methylation; yet, recent high-throughput genomic studies have not identified key TSGs inactivated by both mechanisms. We pursued an integrated molecular analysis based on methylation binding domain sequencing (MBD-seq), 450K Methylation arrays, whole exome sequencing, and whole genome gene expression arrays in primary head and neck squamous cell carcinoma (HNSCC) tumors and matched uvulopalatopharyngoplasty tissue samples (UPPPs). We uncovered 186 downregulated genes harboring cancer specific promoter methylation including PAX1 and PAX5 and we identified 10 key tumor suppressor genes (GABRB3, HOXC12, PARP15, SLCO4C1, CDKN2A, PAX1, PIK3AP1, HOXC6, PLCB1, and ZIC4) inactivated by both promoter methylation and/or somatic mutation. Among the novel tumor suppressor genes discovered with dual mechanisms of inactivation, we found a high frequency of genomic and epigenomic alterations in the PAX gene family of transcription factors, which selectively impact canonical NOTCH and TP53 pathways to determine cell fate, cell survival, and genome maintenance. Our results highlight the importance of assessing TSGs at the genomic and epigenomic level to identify key pathways in HNSCC, deregulated by simultaneous promoter methylation and somatic mutations.

Asunto(s)

Carcinoma de Células Escamosas/genética , Metilación de ADN , Silenciador del Gen , Genes Supresores de Tumor , Neoplasias de Cabeza y Cuello/genética , Regiones Promotoras Genéticas , Carcinoma de Células Escamosas/metabolismo , Línea Celular Tumoral , Estudios de Cohortes , Islas de CpG , Femenino , Neoplasias de Cabeza y Cuello/metabolismo , Humanos , Masculino , Mutación , Factor de Transcripción PAX5/genética , Factor de Transcripción PAX5/metabolismo , Factores de Transcripción Paired Box/genética , Factores de Transcripción Paired Box/metabolismo , Receptor Notch1/genética , Receptor Notch1/metabolismo , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismo

RESUMEN

Mutations in the PAX6 gene that cause aniridia have been identified in various ethnicities but not in the Malaysian population. Therefore, the objective of this study was to investigate the PAX6 mutation in a Malaysian family with congenital aniridia. In this study, a complete ophthalmic examination was performed on a Dusun ethnic family with aniridia. Genomic DNA was extracted from the peripheral blood of the subjects and screened for the PAX6 gene mutation using polymerase chain reaction amplification high-resolution melting curve analysis (PCR-HRM) followed by confirmation via direct DNA sequencing. A heterozygous G deletion (c.857delG) in exon 7 causing a frame shift in PAX6 was identified in all affected family members. Genotype-phenotype correlation analysis revealed congenital cataract and all affected family members showed a similar spectrum of aniridia with no phenotypic variability but with differences in severity that were age-dependent. In summary, by using a PCR-HRM approach, this study is the first to report a PAX6 mutation in a Malaysian family. This mutation is the cause of the aniridia spectra observed in this family and of congenital cataract.

Asunto(s)

Aniridia/genética , Proteínas del Ojo/genética , Secuenciación de Nucleótidos de Alto Rendimiento , Proteínas de Homeodominio/genética , Factores de Transcripción Paired Box/genética , Polimorfismo Conformacional Retorcido-Simple/genética , Proteínas Represoras/genética , Aniridia/patología , Pueblo Asiatico/genética , Femenino , Estudios de Asociación Genética , Humanos , Malasia , Masculino , Mutación , Desnaturalización de Ácido Nucleico , Factor de Transcripción PAX6 , Linaje

RESUMEN

Paired box (PAX) genes are transcription factors that play important roles in embryonic development. Although the PAX gene family occurs in animals only, it is widely distributed. Among the vertebrates, its 9 genes appear to be the product of complete duplication of an original set of 4 genes, followed by an additional partial duplication. Although some studies of PAX genes have been conducted, no comprehensive survey of these genes across the entire taxonomic unit has yet been attempted. In this study, we conducted a detailed comparison of PAX sequences from 188 chordates, which revealed restricted variation. The absence of PAX4 and PAX8 among some species of reptiles and birds was notable; however, all 9 genes were present in all 74 mammalian genomes investigated. A search for signatures of selection indicated that all genes are subject to purifying selection, with a possible constraint relaxation in PAX4, PAX7, and PAX8. This result indicates asymmetric evolution of PAX family genes, which can be associated with the emergence of adaptive novelties in the chordate evolutionary trajectory.

Asunto(s)

Cordados/genética , Biología Computacional , Evolución Molecular , Factores de Transcripción Paired Box/genética , Animales , Secuencia Conservada , Bases de Datos Genéticas , Humanos , Filogenia , Selección Genética , Sintenía

RESUMEN

BACKGROUND- Intima-media thickness (IMT) of the common and internal carotid arteries is an established surrogate for atherosclerosis and predicts risk of stroke and myocardial infarction. Often IMT is measured as the average of these 2 arteries; yet, they are believed to result from separate biological mechanisms. The aim of this study was to conduct a family-based genome-wide association study (GWAS) for IMT to identify polymorphisms influencing IMT and to determine if distinct carotid artery segments are influenced by different genetic components. METHODS AND RESULTS- IMT for the common and internal carotid arteries was determined through B-mode ultrasound in 772 Mexican Americans from the San Antonio Family Heart Study. A GWAS using 931219 single-nucleotide polymorphisms was undertaken with 6 internal and common carotid artery IMT phenotypes using an additive measured genotype model. The most robust association detected was for 2 single-nucleotide polymorphisms (rs16983261, rs6113474; P=1.60e(-7)) in complete linkage disequilibrium on chromosome 20p11 for the internal carotid artery near wall, next to the gene PAX1. We also replicated previously reported GWAS regions on chromosomes 19q13 and 7q22. We found no overlapping associations between internal and common carotid artery phenotypes at P<5.0e(-6). The genetic correlation between the 2 carotid IMT arterial segments was 0.51. CONCLUSIONS- This study represents the first large-scale GWAS of carotid IMT in a non-European population and identified several novel loci. We do not detect any shared GWAS signals between common and internal carotid arterial segments, but the moderate genetic correlation implies both common and unique genetic components.

Asunto(s)

Arteria Carótida Común/diagnóstico por imagen , Grosor Intima-Media Carotídeo , Americanos Mexicanos/genética , Adulto , Arteria Carótida Interna/diagnóstico por imagen , Cromosomas Humanos Par 19 , Cromosomas Humanos Par 20 , Cromosomas Humanos Par 7 , Femenino , Estudio de Asociación del Genoma Completo , Genotipo , Humanos , Desequilibrio de Ligamiento , Masculino , Persona de Mediana Edad , Factores de Transcripción Paired Box/genética , Fenotipo , Polimorfismo de Nucleótido Simple

RESUMEN

BACKGROUND: The axial skeleton develops from the sclerotome, a mesenchymal cell population derived from somites. Sclerotomal cells migrate from somites to the perinotochordal and perineural space where they differentiate into chondrocytes to form cartilage and bone. In anurans, little is known about the way how the sclerotome changes as development proceeds and how these events are regulated at the molecular level. Pax1, Pax9, and Uncx4.1 genes play a central role in the morphogenesis of the axial skeleton in vertebrates, regulating cell proliferation and chondrogenic specification of the sclerotome. RESULTS: In this work, we cloned and examined through whole-mount in situ hybridization and reverse transcriptase-polymerase chain reaction the expression patterns of pax1, pax9, and uncx transcription factors in the anuran Xenopus laevis. CONCLUSIONS: We found that these genes are similarly expressed in the sclerotome and in the pharyngeal pouch. A detailed analysis of the location of these transcripts showed that they are expressed in different subdomains of the sclerotomal compartment and differ from that observed in other vertebrates.

Asunto(s)

Desarrollo Embrionario/genética , Factor de Transcripción PAX9/genética , Factores de Transcripción Paired Box/genética , Xenopus laevis , Secuencia de Aminoácidos , Animales , Desarrollo Óseo/genética , Condrocitos/metabolismo , Condrocitos/fisiología , Clonación Molecular , Embrión no Mamífero , Regulación del Desarrollo de la Expresión Génica , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Hibridación in Situ , Datos de Secuencia Molecular , Factor de Transcripción PAX9/metabolismo , Factores de Transcripción Paired Box/metabolismo , Filogenia , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Homología de Secuencia de Aminoácido , Somitos/metabolismo , Proteínas de Xenopus/genética , Proteínas de Xenopus/metabolismo , Xenopus laevis/embriología , Xenopus laevis/genética , Xenopus laevis/metabolismo

RESUMEN

The purpose of our study was to investigate the prevalence of the PAX3/7-FKHR fusion genes and quantify the IGF2 gene expression in rhabdomyosarcoma (RMS) samples. Soft tissue sarcomas account 5% of childhood cancers and 50% of them are RMS. Morphological evaluation of pediatric RMS has defined two histological subtypes, embryonal (ERMS) and alveolar (ARMS). Chromosomal analyses have demonstrated two translocations associated with ARMS, resulting in the PAX3/7-FKHR rearrangements. Reverse transcriptase-polymerase chain reaction (RT-PCR) is extremely useful in the diagnosis of ARMS positive for these rearrangements. Additionally, several studies have shown a significant involvement of IGF pathway in the pathogenesis of RMS. The presence of PAX3/7-FKHR gene fusions was studied in 25 RMS samples from patients attending the IOP-GRAACC/UNIFESP and three RMS cell lines by RT-PCR. IGF2 gene expression was quantified by qPCR and related with clinic pathological parameters. Of the 25 samples, nine (36%) were ARMS and 16 (64%) were ERMS. PAX3/7-FKHR gene fusions expression was detected in 56% of ARMS tumor samples. IGF2 overexpression was observed in 80% of samples and could indicate an important role of this pathway in RMS biology.

Asunto(s)

Factores de Transcripción Forkhead/genética , Regulación Neoplásica de la Expresión Génica , Factor II del Crecimiento Similar a la Insulina/genética , Proteínas de Fusión Oncogénica , Factor de Transcripción PAX7/genética , Factores de Transcripción Paired Box/genética , Rabdomiosarcoma/genética , Adenocarcinoma Bronquioloalveolar/genética , Adenocarcinoma Bronquioloalveolar/metabolismo , Adolescente , Línea Celular Tumoral , Niño , Femenino , Proteína Forkhead Box O1 , Factores de Transcripción Forkhead/metabolismo , Humanos , Factor II del Crecimiento Similar a la Insulina/metabolismo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Masculino , Factor de Transcripción PAX3 , Factor de Transcripción PAX7/metabolismo , Factores de Transcripción Paired Box/metabolismo , Estudios Retrospectivos , Rabdomiosarcoma/metabolismo , Rabdomiosarcoma Embrionario/genética , Rabdomiosarcoma Embrionario/metabolismo

RESUMEN

OBJECTIVES: To precisely classify the various forms of TD, and then to screen for mutations in transcription factor genes active in thyroid development. SUBJECTS AND METHODS: Patients underwent ultrasound, thyroid scan, and serum thyroglobulin measurement to accurately diagnose the form of TD. DNA was extracted from peripheral leukocytes. The PAX8, and NKX2.5 genes were evaluated in all patients, and TSH receptor (TSHR) gene in those with hypoplasia. RESULTS: In 27 nonconsanguineous patients with TD, 13 were diagnosed with ectopia, 11 with hypoplasia, and 3 with athyreosis. No mutations were detected in any of the genes studied. CONCLUSION: Sporadic cases of TD are likely to be caused by epigenetic factors, rather than mutations in thyroid transcription factors or genes involved in thyroid development.

Asunto(s)

Hipotiroidismo Congénito/genética , Proteínas de Homeodominio/genética , Mutación , Factores de Transcripción Paired Box/genética , Disgenesias Tiroideas/genética , Tirotropina/genética , Factores de Transcripción/genética , Adolescente , Niño , Preescolar , Femenino , Proteína Homeótica Nkx-2.5 , Humanos , Masculino , Factor de Transcripción PAX8 , Disgenesias Tiroideas/diagnóstico , Adulto Joven

RESUMEN

OBJECTIVES: To precisely classify the various forms of TD, and then to screen for mutations in transcription factor genes active in thyroid development. SUBJECTS AND METHODS: Patients underwent ultrasound, thyroid scan, and serum thyroglobulin measurement to accurately diagnose the form of TD. DNA was extracted from peripheral leukocytes. The PAX8, and NKX2.5 genes were evaluated in all patients, and TSH receptor (TSHR) gene in those with hypoplasia. RESULTS: In 27 nonconsanguineous patients with TD, 13 were diagnosed with ectopia, 11 with hypoplasia, and 3 with athyreosis. No mutations were detected in any of the genes studied. CONCLUSION: Sporadic cases of TD are likely to be caused by epigenetic factors, rather than mutations in thyroid transcription factors or genes involved in thyroid development.

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OBJETIVOS: Classificar corretamente as várias formas de DT e depois rastrear por mutações em genes que participam no desenvolvimento da tireoide. SUJEITOS E MÉTODOS: Os pacientes realizaram ultrassonografia, cintilografia e tireoglobulina sérica para o diagnóstico preciso de DT. DNA foi extraído de leucócitos periféricos. Os genes PAX8 e NKX2.5 foram estudados em todos os pacientes e o gene do receptor do TSH (TSHR) foi estudado na hipoplasia. RESULTADOS: Avaliaram-se 27 pacientes sem consanguinidade com DT, dos quais 13 foram diagnosticados com ectopia, 11 com hipoplasia e 3 com atireose. Nenhuma mutação foi detectada nos genes estudados. CONCLUSÃO: Casos esporádicos de DT são provavelmente causados mais por fatores epigenéticos do que por mutações em fatores de transcrição ou genes envolvidos no desenvolvimento tireoidiano.

Asunto(s)

Adolescente , Niño , Preescolar , Femenino , Humanos , Adulto Joven , Hipotiroidismo Congénito/genética , Proteínas de Homeodominio/genética , Mutación , Factores de Transcripción Paired Box/genética , Disgenesias Tiroideas/genética , Tirotropina/genética , Factores de Transcripción/genética , Disgenesias Tiroideas/diagnóstico

Asunto(s)

Hipotiroidismo Congénito/epidemiología , Hipotiroidismo Congénito/genética , Factores de Transcripción Paired Box/genética , Secuencia de Bases , Preescolar , Exones , Femenino , Regulación de la Expresión Génica , Genotipo , Humanos , Incidencia , Recién Nacido , México/epidemiología , Mutación , Factor de Transcripción PAX8 , Isoformas de Proteínas

RESUMEN

PURPOSE: Retinal ganglion cells (RGCs) expressing the photopigment melanopsin (Opn4) display intrinsic photosensitivity. In this study, the presence of nonvisual phototransduction cascade components in the developing chicken retina and primary RGCs cultures was investigated, focusing on the two Opn4 genes: the Xenopus (Opn4x) and the mammalian (Opn4m) orthologs. METHODS: Retinas were dissected at different embryonic (E) and postnatal (P) days, and primary RGC cultures were obtained at E8 and kept for 1 hour to 5 days. Samples were processed for RT-PCR and immunochemistry. RESULTS: Embryonic retinas expressed the master eye gene Pax6, the prospective RGC specification gene Brn3, and components of the nonvisual phototransduction cascade, such as Opn4m and the G protein q (Gq) mRNAs at very early stages (E4-E5). By contrast, expression of photoreceptor cell markers (CRX, red-opsin, rhodopsin, and α-transducin) was observed from E7 to E12. Opn4m protein was visualized in the whole retina as early as E4 and remained elevated from E6 to the postnatal days, whereas Opn4x was weakly detected at E8 and highly expressed after E11. RGC cultures expressed Gq mRNA, as well as both Opn4 mRNAs and proteins. Opn4m was restricted exclusively to the GC layer at all ages, whereas Opn4x was limited to the forming GC layer and optic nerve at E8, but by E15, its expression was mostly in Prox1(+) horizontal cells. CONCLUSIONS: The early expression onset of nonvisual phototransduction molecules could confer premature photosensitivity to RGCs, while the appearance of Opn4x expression in horizontal cells suggests the identification of a novel type of photosensitive cell in birds.

Asunto(s)

Regulación del Desarrollo de la Expresión Génica/fisiología , Retina/embriología , Células Ganglionares de la Retina/metabolismo , Opsinas de Bastones/genética , Animales , Western Blotting , Células Cultivadas , Embrión de Pollo , Proteínas del Ojo/genética , Proteínas del Ojo/metabolismo , Técnica del Anticuerpo Fluorescente Indirecta , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Microscopía Confocal , Sondas de Oligonucleótidos/química , Factor de Transcripción PAX6 , Factores de Transcripción Paired Box/genética , Factores de Transcripción Paired Box/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , ARN Mensajero/metabolismo , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Rodopsina/genética , Rodopsina/metabolismo , Opsinas de Bastones/metabolismo , Factor de Transcripción 3/genética , Factor de Transcripción 3/metabolismo , Transducina/genética , Transducina/metabolismo , Visión Ocular

RESUMEN

OBJECTIVE: Pax3 and Pax7 are closely related genes that are involved in commitment of cells to a myogenic lineage during skeletal muscle development and regeneration. Several Pax3 and Pax7 transcripts are expressed from the genes, generating different isoforms with potentially distinct DNA binding and transactivation properties. The aim of this study was to investigate the implication of Pax3 and Pax7 C-terminal isoforms during myogenic differentiation and tumorigenesis, since fusions involving these genes are commonly associated with alveolar rhabdomyosarcoma (ARMS). METHODS: Uncommitted (mouse mesenchymal stem cells, MSCs) and committed (C2C12) myogenic precursor cells were stably transfected with PAX3/FKHR and PAXC7/ FKHR fusion genes. We analysed gene and protein expression comparing the newly generated cells with the parental cells, to determine the functional importance of Pax3 and Pax7 C-terminal isoforms. RESULTS: We found that the transcript Pax3c was expressed at low levels in undifferentiated C2C12 and MSCs cells, but its expression levels increased considerably at later stages of differentiation. However, expression levels of Pax3d transcript increased only slightly after differentiation. Pax7 transcripts, present before differentiation in committed C2C12 cells, but absent in uncommitted MSCs, increased noticeably in MSCs after differentiation. We also found that the presence of PAX/FKHR fusions prevented both C2C12 and MSC cells from terminal myogenic differentiation and increased the expression of discrete endogenous Pax3/7 transcripts, in particular Pax3d and Pax7B. CONCLUSIONS: Our results suggest that both Pax3 and Pax7 transcripts are required for commitment of cells to the myogenic lineage, with each transcript having a distinct role. More specifically, the Pax3c isoform may be required for terminal myogenic differentiation whereas the Pax3d isoform may be involved in undifferentiated cell maintenance and/or proliferation.

Asunto(s)

Diferenciación Celular/fisiología , Células Musculares/citología , Factor de Transcripción PAX7/genética , Factor de Transcripción PAX7/metabolismo , Factores de Transcripción Paired Box/genética , Factores de Transcripción Paired Box/metabolismo , Rabdomiosarcoma Alveolar/genética , Animales , Línea Celular , Linaje de la Célula/fisiología , Humanos , Inmunohistoquímica , Células Madre Mesenquimatosas/citología , Ratones , Células Musculares/metabolismo , Factor de Transcripción PAX3 , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteínas Recombinantes de Fusión , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Rabdomiosarcoma Alveolar/metabolismo , Transfección