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1.
PLoS One ; 16(10): e0258090, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34597335

RESUMEN

IgA nephropathy (IgAN) is the most common form of glomerulonephritis worldwide. Pediatric patients in Japan are diagnosed with IgAN at an early stage of the disease through annual urinary examinations. Tumor necrosis factor-like weak inducer of apoptosis (TWEAK) and fibroblast growth factor-inducible 14 (Fn14) have various roles, including proinflammatory effects, and modulation of several kidney diseases; however, no reports have described their roles in pediatric IgAN. In this study, we performed pathological and immunohistochemical analyses of samples from 14 pediatric IgAN patients. Additionally, gene expression arrays of glomeruli by laser-captured microdissection were performed in hemi-nephrectomized high serum IgA (HIGA) mice, a model of IgA nephropathy, to determine the role of Fn14. Glomeruli with intense Fn14 deposition were observed in 80% of mild IgAN cases; however, most severe cases showed glomeruli with little or no Fn14 deposition. Fn14 deposition was not observed in obvious mesangial proliferation or the crescent region of glomeruli, but was detected strongly in the glomerular tuft, with an intact appearance. In HIGA mice, Fn14 deposition was observed mildly beginning at 11 weeks of age, and stronger Fn14 deposition was detected at 14 weeks of age. Expression array analysis indicated that Fn14 expression was higher in HIGA mice at 6 weeks of age, increased slightly at 11 weeks, and then decreased at 26 weeks when compared with controls at equivalent ages. These findings suggest that Fn14 signaling affects early lesions but not advanced lesions in patients with IgAN. Further study of the TWEAK/Fn14 pathway will contribute to our understanding of the progression of IgAN.


Asunto(s)
Factores de Crecimiento de Fibroblastos/inmunología , Glomerulonefritis por IGA/inmunología , Adolescente , Animales , Biomarcadores/sangre , Niño , Femenino , Humanos , Japón , Masculino , Ratones
2.
Glob Pediatr Health ; 8: 2333794X211044796, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34514060

RESUMEN

Background. Staphylococcus lugdunensis is one of the clinically important coagulase-negative staphylococci. The purpose of this study was to elucidate the microbiological features of S. lugdunensis in hospitalized children. Methods. From January 2012 to December 2019, all isolates were retrospectively screened for S. lugdunensis. Results. Twenty-five children were eligible for study. Nineteen and six children were classified into a critical care unit group (Group A) and a general medical ward group (Group B), respectively. The prevalence of methicillin-resistant S. lugdunensis was significantly higher in Group A than in Group B (68.4% vs 0%; P < .01). Eleven children (44%) had S. lugdunensis infections, while the remaining children were colonized. Six of the 11 infected children (55%) had healthcare-associated infections. Moreover, 3 isolates exhibited the methicillin resistance. Conclusions. The bacteriological characteristics of S. lugdunensis differ depending on patient background. Selection of antibiotic treatment should in part rely on patient background data.

3.
Case Rep Pediatr ; 2021: 6691569, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33898073

RESUMEN

The most common organisms isolated from pediatric catheter-related bloodstream infections (CRBSIs) are Gram-positive cocci, such as coagulase-negative staphylococci and Staphylococcus aureus. There are few formal reports of Brevibacterium casei infection and even fewer reports of CRBSI due to this Gram-positive rod. Here we report the first case of CRBSI due to B. casei in an 8-year-old girl with acute myeloid leukemia in Japan. The isolate exhibited decreased susceptibility to ß-lactam antibiotics. Antimicrobial therapy with meropenem and vancomycin, in addition to the removal of central venous catheter line, consequently led to a significant clinical improvement of the patient's symptoms. A literature review found available clinical courses in 16 cases (4 pediatric cases including our case) of B. casei infection. Our case and those in literature suggested that B. casei infection often occurs in patients with indwelling central venous catheters; the literature review further suggested that removal of central venous catheters is required in most cases. Special attention should be paid to the detection of opportunistic infections due to Brevibacterium spp. in immunocompromized children who are using a central venous catheter.

4.
Case Rep Oncol ; 13(1): 358-364, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32355490

RESUMEN

We report a case of a 4-year-old girl with an ovarian steroid cell tumor, not otherwise specified (SCT-NOS). She was admitted to the hospital with progressing virilization and Cushing's syndrome, which included abnormality of the perineum, hirsutism, hypertrichosis, flushing of face, hoarseness, and weight gain. Blood testing showed a significantly increased testosterone level and slightly increased cortisol level. Computed tomography scan revealed an 8.0 × 5.0 × 5.0 cm tumor of the right ovary. The patient underwent right salpingo-oophorectomy, and pathological examination showed malignant potential. Three courses of bleomycin, etoposide, and cisplatin were administered as postoperative chemotherapy. After tumor resection, her testosterone decreased to undetectable levels. However, during the course of the treatment, the patient suffered from adrenal insufficiency resulting in the need for hydrocortisone replacement therapy. Although SCT-NOS in childhood are typically benign, pathological findings should be carefully observed for potential malignancy. In cases of cortisol-producing SCT-NOS, serum levels should be monitored, and hydrocortisone replacement therapy should be considered before resection.

5.
Case Rep Pediatr ; 2020: 8304302, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32231839

RESUMEN

Brain abscesses, infections within the brain parenchyma, can arise as complications of various conditions including infections, trauma, and surgery. However, brain abscesses due to polymicrobial organisms have rarely been reported in children. We herein report a case of a 9-year-old girl with unresolved congenital cyanotic heart disease (CCHD) presenting with right hemiplegia who was diagnosed with brain abscess caused by Streptococcus intermedius, Parvimonas micra, and Fusobacterium nucleatum after oropharyngeal injury. She was treated with intravenous antimicrobial therapy, drainage under craniotomy, and antiedema therapy with glycerol and goreisan, which led to the improvement of right hemiplegia to baseline; she was discharged following eight weeks of intravenous antimicrobial therapy. The clinical diagnosis of the brain abscess was difficult due to the nonspecific presentation, highlighting the importance of cranial imaging without haste in patients at increased risk for brain abscesses such as those with CCHD, presenting with fever in the absence of localizing symptoms or fever, accompanied with abnormal neurological findings.

6.
Case Rep Transplant ; 2019: 7890673, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31263624

RESUMEN

The authors describe the high effectiveness of human mesenchymal stem cell (hMSC) therapy to treat steroid-refractory gastrointestinal acute graft-versus-host Disease (aGVHD) in a 15-year-old boy with acute lymphoblastic leukemia (ALL). He received allogeneic hematopoietic stem cell transplantation due to high-risk hypodiploid ALL. Around the time of engraftment, he developed severe diarrhea following high-grade fever and erythema. Although methylprednisolone pulse therapy was added to tacrolimus and mycophenolate mofetil, diarrhea progressed up to 5000~6000 ml/day and brought about hypocalcemia, hypoalbuminemia, and edema. Daily fresh frozen plasma (FFP), albumin, and calcium replacements were required to maintain blood circulation. After aGVHD was confirmed by colonoscopic biopsy, MSC therapy was administered. The patient received 8 biweekly intravenous infusions of 2×106 hMSCs/kg for 4 weeks, after which additional 4 weekly infusions were performed. A few weeks after initiation, diarrhea gradually resolved, and at the eighth dose of hMSC, lab data improved without replacements. MSC therapy successfully treated steroid-refractory gastrointestinal GVHD without complications. Despite life-threatening diarrhea, the regeneration potential of children and adolescents undergoing SMC therapy successfully supports restoration of gastrointestinal damage. Even with its high treatment costs, SMC therapy should be proactively considered in cases where young patients suffer from severe gastrointestinal GVHD.

7.
Genes Chromosomes Cancer ; 58(8): 521-529, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-30739374

RESUMEN

Cell-free DNA (cfDNA), which are small DNA fragments in blood derived from dead cells including tumor cells, could serve as useful biomarkers and provide valuable genetic information about the tumors. cfDNA is now used for the genetic analysis of several types of cancers, as a surrogate for tumor biopsy, designated as "liquid biopsy." Rhabdomyosarcoma (RMS), the most frequent soft tissue tumor in childhood, can arise in any part of the body, and radiological imaging is the only available method for estimating the tumor burden, because no useful specific biological markers are present in the blood. Because tumor volume is one of the determinants of treatment response and outcome, early detection at diagnosis as well as relapse is essential for improving the treatment outcome. A 15-year-old male patient was diagnosed with alveolar RMS of prostate origin with bone marrow invasion. The PAX3-FOXO1 fusion was identified in the tumor cells in the bone marrow. After the diagnosis, cfDNA was serially collected to detect the PAX3-FOXO1 fusion sequence as a tumor marker. cfDNA could be an appropriate source for detecting the fusion gene; assays using cfDNA have proved to be useful for the early detection of tumor progression/recurrence. Additionally, the fusion gene dosage estimated by quantitative polymerase chain reaction reflected the tumor volume during the course of the treatment. We suggest that for fusion gene-positive RMSs, and other soft tissue tumors, the fusion sequence should be used for monitoring the tumor burden in the body to determine the diagnosis and treatment options for the patients.


Asunto(s)
Biomarcadores de Tumor , ADN Tumoral Circulante , Proteínas de Fusión Oncogénica/genética , Factores de Transcripción Paired Box/genética , Rabdomiosarcoma Alveolar/diagnóstico , Rabdomiosarcoma Alveolar/genética , Adolescente , Biopsia , Detección Precoz del Cáncer , Humanos , Masculino , Reacción en Cadena de la Polimerasa , Tomografía de Emisión de Positrones , Pronóstico , Recurrencia , Rabdomiosarcoma Alveolar/terapia , Análisis de Secuencia de ADN
8.
Pediatr Hematol Oncol ; 35(5-6): 355-361, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30457427

RESUMEN

Although outcomes for infant leukemia have improved recently, transient adrenal insufficiency is commonly observed during treatment, especially after glucocorticoid administration. We identified three infants with acute leukemia who suffered from prolonged adrenal insufficiency requiring long-term (from 15 to 66 months) hydrocortisone replacement. All infants showed life-threatening symptoms associated with adrenal crisis after viral infections or other stress. Severe and prolonged damage of hypothalamo-pituitary-adrenal (HPA) axis is likely to occur in early infants with leukemia, therefore routine tolerance testing to evaluate HPA axis and hydrocortisone replacement therapy are recommended for infants with leukemia to avoid life-threatening complications caused by adrenal crisis.


Asunto(s)
Insuficiencia Suprarrenal , Glucocorticoides/efectos adversos , Leucemia/tratamiento farmacológico , Enfermedad Aguda , Insuficiencia Suprarrenal/inducido químicamente , Insuficiencia Suprarrenal/metabolismo , Insuficiencia Suprarrenal/patología , Insuficiencia Suprarrenal/terapia , Preescolar , Femenino , Glucocorticoides/administración & dosificación , Humanos , Sistema Hipotálamo-Hipofisario/metabolismo , Sistema Hipotálamo-Hipofisario/patología , Recién Nacido , Leucemia/metabolismo , Leucemia/patología , Masculino , Sistema Hipófiso-Suprarrenal/metabolismo , Sistema Hipófiso-Suprarrenal/patología , Factores de Tiempo
9.
Pediatr Hematol Oncol ; 35(2): 125-130, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29648910

RESUMEN

Primary bone marrow lymphoma (PBML) is hard to diagnose in children, due to the difficult identification of malignant cells in bone marrow. The first case, a 5-year-old boy, showed knee swelling with an intermittent fever. The second case, a 12-year-old girl, showed fever of unknown origin without lymphadenopathy or hepatosplenomegaly. In both cases, the diagnosis was not confirmed despite the repeated bone marrow aspirations. Finally, bone marrow aspiration and biopsy at the positive site by positron emission tomography (PET)-CT contributed to definitive diagnosis of PBML. The PET-CT is useful for the accurate diagnosis of PBML in children with non-specific symptoms.


Asunto(s)
Neoplasias de la Médula Ósea/diagnóstico por imagen , Linfoma/diagnóstico por imagen , Tomografía de Emisión de Positrones , Tomografía Computarizada por Rayos X , Niño , Preescolar , Femenino , Humanos , Masculino
10.
Am J Med Genet A ; 176(2): 351-358, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29265763

RESUMEN

22q11.2 deletion syndrome is one of the most common human microdeletion syndromes. The clinical phenotype of 22q11.2 deletion syndrome is variable, ranging from mild to life-threatening symptoms, depending mainly on the extent of the deleted region. Brain malformations described in association with 22q11.2 deletion syndrome include polymicrogyria, cerebellar hypoplasia, megacisterna magna, and agenesis of the corpus callosum (ACC), although these are rare. We report here for the first time a patient who manifested combined D-2- and L-2-hydroxyglutaric aciduria as a result of a hemizygous mutation in SLC25A1 in combination with 22q11.2 deletion. The girl was diagnosed to have ACC shortly after birth and a deletion of 22q11.2 was identified by genetic analysis. Although the patient showed cardiac anomalies, which is one of the typical symptoms of 22q11.2 deletion syndrome, her rather severe phenotype and atypical face prompted us to search for additional pathogenic mutations. Three genes present in the deleted 22q11.2 region, SLC25A1, TUBA8, and SNAP29, which have been reported to be associated with brain malformation, were analyzed for the presence of pathogenic mutations. A frameshift mutation, c.18_24dup (p.Ala9Profs*82), was identified in the first exon of the remaining SLC25A1 allele, resulting in the complete loss of normal SLC25A1 function in the patient's cells. Our results support the notion that the existence of another genetic abnormality involving the retained allele on 22q11.2 should be considered when atypical or rare phenotypes are observed.


Asunto(s)
Encefalopatías Metabólicas Innatas/diagnóstico , Encefalopatías Metabólicas Innatas/genética , Síndrome de DiGeorge/diagnóstico , Síndrome de DiGeorge/genética , Genes Recesivos , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Agenesia del Cuerpo Calloso/diagnóstico por imagen , Agenesia del Cuerpo Calloso/genética , Alelos , Proteínas de Transporte de Anión/química , Proteínas de Transporte de Anión/genética , Secuencia de Bases , Femenino , Estudios de Asociación Genética/métodos , Humanos , Hibridación Fluorescente in Situ , Masculino , Proteínas Mitocondriales/química , Proteínas Mitocondriales/genética , Mutación , Transportadores de Anión Orgánico , Análisis de Secuencia de ADN
11.
Pediatr Hematol Oncol ; 35(5-6): 341-349, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30633606

RESUMEN

Chronic granulomatous disease (CGD) is a hereditary immunodeficiency syndrome caused by a defect in the NADPH oxidase complex, which is essential for bactericidal function of phagocytes. Approximately 70% of patients with CGD have a mutation in the CYBB gene on the X chromosome, resulting in defective expression of gp91phox, one of the membrane-bound subunits of NADPH oxidase. Although most patients with X-linked CGD are males, owing to transmission of this disease as an X-linked recessive trait, there are female patients with X-linked CGD. Here, we report the case of a teenage girl with X-linked CGD associated with a heterozygous mutation in exon 5 of the CYBB gene (c.389G > C; R130P), which causes skipping of exon 5, resulting in a premature stop codon in exon 6 of CYBB. Accurate pro-mRNA splicing for mature mRNA formation is regulated by several splicing mechanisms that are essential for appropriate recognition of exonic sequences. The c.389G > C mutation disrupts exonic-splicing regulator sequences, thereby resulting in the aberrant skipping of exon 5 in the CYBB transcript of the patient. The patient showed an extremely skewed (≥96%) X inactivation pattern of the HUMARA locus; this inactivation is thought to be responsible for the development of CGD not only in neutrophils but also in monocytic, T-cell, and B-cell lineages and in CD34-positive immature hematopoietic cells. Our case and other reports indicate that the onset of X-linked CGD in female patients tends to occur later in life, and that the symptoms tend to be milder as compared to male patients.


Asunto(s)
Cromosomas Humanos X/genética , Exones , Enfermedad Granulomatosa Crónica , NADPH Oxidasa 2 , Mutación Puntual , ARN Mensajero , Inactivación del Cromosoma X , Niño , Femenino , Sitios Genéticos , Enfermedad Granulomatosa Crónica/enzimología , Enfermedad Granulomatosa Crónica/genética , Enfermedad Granulomatosa Crónica/patología , Humanos , NADPH Oxidasa 2/genética , NADPH Oxidasa 2/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Receptores Androgénicos/genética , Receptores Androgénicos/metabolismo
12.
Gan To Kagaku Ryoho ; 43(11): 1341-1345, 2016 Nov.
Artículo en Japonés | MEDLINE | ID: mdl-27899775

RESUMEN

Leukemia is derived from hematopoietic stem/progenitor cells that have acquired genetic abnormalities, leading to malignant transformation. The basis of therapyfor leukemia is a combination of anti-cancer drugs based on risk stratification. The overall 5-year survival rate in leukemia patients of all ages is still 40%, although it has improved in pediatric patients. Leuke- mia itself is a heterogeneous disease that includes various entities/subtypes with different pathogenic gene aberrations. Selection of the treatment strategylargelydepends on risk stratification, and this in turn is mainlybased on specific recurrent chromosome aberrations. However, in acute myeloid leukemia(AML), a significant proportion of patients present with a normal karyotype according to conventional cytogenetic analysis and are classified into an intermediate-risk group, which actuallyconsists of various subtypes with different prognoses. In addition, leukemic cells usuallyharbor one or more driver mutations among their various genetic aberrations, and these driver mutations could affect prognosis. The discoveryof additional mutations in genes such as NPM1, CEBPA and FLT3, which are frequent in AML patients with a normal karyotype, have improved the precision of risk stratification in AML. In this regard, array-based gene expression analysis and whole exome/ transcriptome sequencing could be useful tools for identifying the whole spectrum of genetic aberrations, or for compiling a complete list of mutated genes within leukemic cells. Genetic profiling information obtained using these newlydeveloped methods could provide more accurate information for molecular subtyping and risk stratification in leukemia.


Asunto(s)
Leucemia/genética , Aberraciones Cromosómicas , Cromosomas Humanos , Regulación Leucémica de la Expresión Génica , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Leucemia/diagnóstico , Nucleofosmina , Pronóstico
13.
Pediatr Int ; 58(12): 1261-1265, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27562900

RESUMEN

BACKGROUND: Recently, a student died of idiopathic ventricular fibrillation in a school where an automated external defibrillator (AED) had been installed. The tragedy could not be prevented because the only AED in the school was installed in the teachers' office, far from the school ground where the accident took place. This prompted establishment of a multiple AED system in schools. The aim of this study was to analyze the efficacy of the multiple AED system to prevent sudden death in school-aged children. METHODS: Assumed accident sites consisted of the school ground, gymnasium, Judo and Kendo hall, swimming pool, and classrooms on the first and the fourth floor. Multiple AED were installed in the teachers' office, gymnasium, some classrooms, and also provided as a portable AED in a rucksack. The time from the accident site to the teachers' office for single AED, and from the accident site to the nearest AED for multiple AED, was calculated. RESULTS: The AED retrieval time was significantly shorter in 55 elementary schools and in 29 junior high schools when multiple AED were installed compared with single AED. Except for the classroom on the fourth floor, the number of people who took >120 s to bring the AED to the accident site was lower when multiple AED were installed compared with the single AED. CONCLUSION: Multiple AED provided in appropriate sites can reduce the time to reach the casualty and hence prevent sudden death in school-aged children.


Asunto(s)
Muerte Súbita/prevención & control , Desfibriladores , Instituciones Académicas , Fibrilación Ventricular/terapia , Adolescente , Niño , Femenino , Humanos , Masculino , Estudiantes
14.
Rinsho Ketsueki ; 56(10): 1871-81, 2015 Oct.
Artículo en Japonés | MEDLINE | ID: mdl-26458424

RESUMEN

Leukemic stem cells (LSCs) were originally identified in acute myeloid leukemia (AML) cases by using xenograft models, as a distinct cell population that can initiate leukemia in immunodeficient mice. Since then, many efforts have been made to clarify the identities of LSCs and other cancer stem cells in various cancer types, to both understand their biology and determine the most suitable targets for anti-cancer therapies. LSCs were identified as existing in the immature CD34+CD38- leukemic population in most AML cases, and these cells were found to share some features with normal hematopoietic stem cells. On the other hand, recent studies have shown that in childhood acute lymphoblastic leukemia (ALL), LSCs exist among B-lineage-committed progenitors expressing CD19. In contrast to AML, in which LSCs generate leukemic cells in a hierarchical order with LSCs at the top, leukemia propagation in childhood ALL is better explained by a stochastic model. In B-precursor ALL, LSCs form via acquisition of additional genetic change(s) in CD19+ B-lineage progenitor cells with self-renewing capacity. These LSCs possess a growth advantage and the capacity to produce progeny with the same ability as the LSCs. Identification of genetic and cellular targets in leukemic transformation is necessary to develop improved anti-cancer therapies.


Asunto(s)
Leucemia , Células Madre Neoplásicas , Edad de Inicio , Animales , Transformación Celular Neoplásica , Niño , Humanos , Leucemia/genética , Leucemia/metabolismo , Células Madre Neoplásicas/metabolismo , Investigación con Células Madre
15.
Br J Haematol ; 171(5): 818-29, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26403224

RESUMEN

Acute lymphoblastic leukaemia (ALL) in infants is an intractable cancer in childhood. Although recent intensive chemotherapy progress has considerably improved ALL treatment outcome, disease cure is often accompanied by undesirable long-term side effects, and efficient, less toxic molecular targeting therapies have been anticipated. In infant ALL cells with KMT2A (MLL) fusion, the microRNA let-7b (MIRLET7B) is significantly downregulated by DNA hypermethylation of its promoter region. We show here that the expression of HMGA2, one of the oncogenes repressed by MIRLET7B, is reversely upregulated in infant ALL leukaemic cells, particularly in KMT2A-AFF1 (MLL-AF4) positive ALL. In addition to the suppression of MIRLET7B, KMT2A fusion proteins positively regulate the expression of HMGA2. HMGA2 is one of the negative regulators of CDKN2A gene, which encodes the cyclin-dependent kinase inhibitor p16(INK4A) . The HMGA2 inhibitor netropsin, when combined with demethylating agent 5-azacytidine, upregulated and sustained the expression of CDKN2A, which resulted in growth suppression of KMT2A-AFF1-expressing cell lines. This effect was more apparent compared to treatment with 5-azacytidine alone. These results indicate that the MIRLET7B-HMGA2-CDKN2A axis plays an important role in cell proliferation of leukaemic cells and could be a possible molecular target for the therapy of infant ALL with KMT2A-AFF1.


Asunto(s)
Proteína HMGA2/antagonistas & inhibidores , MicroARNs/farmacología , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Azacitidina/farmacología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Inhibidor p16 de la Quinasa Dependiente de Ciclina/metabolismo , Inhibidor p16 de la Quinasa Dependiente de Ciclina/fisiología , Metilación de ADN/efectos de los fármacos , Proteínas de Unión al ADN/metabolismo , Sinergismo Farmacológico , Técnicas de Silenciamiento del Gen , Genes p16 , N-Metiltransferasa de Histona-Lisina/metabolismo , N-Metiltransferasa de Histona-Lisina/fisiología , Humanos , Lactante , MicroARNs/fisiología , Terapia Molecular Dirigida/métodos , Proteína de la Leucemia Mieloide-Linfoide/metabolismo , Proteína de la Leucemia Mieloide-Linfoide/fisiología , Netropsina/farmacología , Proteínas Nucleares/metabolismo , Regiones Promotoras Genéticas/efectos de los fármacos , Factores de Elongación Transcripcional , Regulación hacia Arriba
16.
Hum Genome Var ; 2: 15004, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-27081520

RESUMEN

Cardiac anomaly is one of the hallmarks of DiGeorge syndrome (DGS), observed in approximately 80% of patients. It often shows a characteristic morphology, termed as conotruncal heart defects. In many cases showing only the conotruncal heart defect, deletion of 22q11.2 region cannot be detected by fluorescence in situ hybridization (FISH), which is used to detect deletion in DGS. We investigated the presence of genomic aberrations in six patients with congenital conotruncal heart defects, who show no deletion at 22q11.2 in an initial screening by FISH. In these patients, no abnormalities were identified in the coding region of the TBX1 gene, one of the key genes responsible for the phenotype of DGS. However, when copy number alteration was analyzed by high-resolution array analysis, a small deletion or duplication in the proximal end of DiGeorge critical region was detected in two patients. The affected region contains the DGCR6 and PRODH genes. DGCR6 has been reported to affect the expression of the TBX1 gene. Our results suggest that altered dosage of gene(s) other than TBX1, possibly DGCR6, may also be responsible for the development of conotruncal heart defects observed in patients with DGS and, in particular, in those with stand-alone conotruncal heart defects.

17.
Blood ; 125(6): 967-80, 2015 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-25538041

RESUMEN

Translocation of the mixed-lineage leukemia (MLL) gene with AF4, AF9, or ENL results in acute leukemia with both lymphoid and myeloid involvement. We characterized leukemia-initiating cells (LICs) in primary infant MLL-rearranged leukemia using a xenotransplantation model. In MLL-AF4 patients, CD34(+)CD38(+)CD19(+) and CD34(-)CD19(+) cells initiated leukemia, and in MLL-AF9 patients, CD34(-)CD19(+) cells were LICs. In MLL-ENL patients, either CD34(+) or CD34(-) cells were LICs, depending on the pattern of CD34 expression. In contrast, in patients with these MLL translocations, CD34(+)CD38(-)CD19(-)CD33(-) cells were enriched for normal hematopoietic stem cells (HSCs) with in vivo long-term multilineage hematopoietic repopulation capacity. Although LICs developed leukemic cells with clonal immunoglobulin heavy-chain (IGH) rearrangement in vivo, CD34(+)CD38(-)CD19(-)CD33(-) cells repopulated recipient bone marrow and spleen with B cells, showing broad polyclonal IGH rearrangement and recipient thymus with CD4(+) single positive (SP), CD8(+) SP, and CD4(+)CD8(+) double-positive (DP) T cells. Global gene expression profiling revealed that CD9, CD32, and CD24 were over-represented in MLL-AF4, MLL-AF9, and MLL-ENL LICs compared with normal HSCs. In patient samples, these molecules were expressed in CD34(+)CD38(+) and CD34(-) LICs but not in CD34(+)CD38(-)CD19(-)CD33(-) HSCs. Identification of LICs and LIC-specific molecules in primary human MLL-rearranged acute lymphoblastic leukemia may lead to improved therapeutic strategies for MLL-rearranged leukemia.


Asunto(s)
Antígenos CD34/genética , Regulación Leucémica de la Expresión Génica , Proteína de la Leucemia Mieloide-Linfoide/genética , Proteínas de Fusión Oncogénica/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Animales , Antígeno CD24/genética , Niño , Preescolar , Femenino , Reordenamiento Génico , Células Madre Hematopoyéticas/metabolismo , Células Madre Hematopoyéticas/patología , Humanos , Inmunofenotipificación , Lactante , Masculino , Ratones , Ratones Endogámicos NOD , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , Receptores de IgG/genética , Tetraspanina 29/genética
18.
Eur J Haematol ; 94(2): 177-81, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24766281

RESUMEN

Juvenile myelomonocytic leukemia (JMML) is a clonal disease arising from abnormal hematopoietic stem cells, although the involvement of lymphoid lineage differs among reported cases. Here, we present a case of JMML with a KRAS G13D mutation. The mutation was detected in various hematopoietic lineages, including T and B lymphocytes and also in lineage(-) CD34(+) CD38(-) hematopoietic stem cells, showing a different percentage of affected cells in each lineage. Single cell-based analysis of hematopoietic cells revealed the loss of wild-type KRAS in a significant proportion of G13D-harboring cells. The percentage of loss of heterozygosity (LOH)/non-LOH cells showed lineage-dependent skewing in hematopoietic cells. The loss of the wild-type KRAS allele may be a common secondary genetic change in KRAS-related JMML and may affect the differentiation behavior of early JMML progenitors.


Asunto(s)
Linaje de la Célula/genética , Leucemia Mielomonocítica Juvenil/diagnóstico , Leucemia Mielomonocítica Juvenil/genética , Pérdida de Heterocigocidad , Proteínas Proto-Oncogénicas/genética , Proteínas ras/genética , Alelos , Médula Ósea/patología , Células de la Médula Ósea/metabolismo , Células de la Médula Ósea/patología , Humanos , Inmunofenotipificación , Lactante , Leucemia Mielomonocítica Juvenil/metabolismo , Leucocitos Mononucleares/metabolismo , Leucocitos Mononucleares/patología , Masculino , Mutación , Polimorfismo de Nucleótido Simple , Proteínas Proto-Oncogénicas p21(ras)
19.
Genes Chromosomes Cancer ; 53(1): 78-89, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24142740

RESUMEN

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a subtype of acute myeloid leukemia, affecting mainly the elderly. It is thought to be derived from plasmacytoid dendritic cell precursors, which frequently present as cutaneous lesions. We have made a detailed analysis of an infant with BPDCN, who manifested with hemophagocytic lymphohistiocytosis. The peripheral blood leukocytes revealed the t(2;17;8)(p23;q23;p23) translocation and a CLTC-ALK fusion gene, which have never been reported in BPDCN or in any myeloid malignancies thus far. Neonatal blood spots on the patient's Guthrie card were analyzed for the presence of the CLTC-ALK fusion gene, identifying the in utero origin of the leukemic cell. Although the leukemic cells were positive for CD4, CD56, CD123, and CD303, indicating a plasmacytoid dendritic cell phenotype, detailed analysis of the lineage distribution of CLTC-ALK revealed that part of monocytes, neutrophils, and T cells possessed the fusion gene and were involved in the leukemic clone. These results indicated that leukemic cells with CLTC-ALK originated in a multipotent hematopoietic progenitor in utero. This is the first report of the CLTC-ALK fusion gene being associated with a myeloid malignancy, which may give us an important clue to the origin of this rare neoplasm.


Asunto(s)
Células Dendríticas/patología , Leucemia Mieloide Aguda/genética , Proteínas de Fusión Oncogénica/genética , Cromosomas Humanos Par 2/genética , Femenino , Fusión Génica , Humanos , Lactante , Leucemia Mieloide Aguda/congénito , Leucemia Mieloide Aguda/patología
20.
J Mol Med (Berl) ; 89(1): 43-50, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21120445

RESUMEN

HDR syndrome is an autosomal dominant disorder characterized by hypoparathyroidism, sensorineural deafness, and renal anomaly caused by mutation of the GATA3 gene located at chromosome 10p15. We report the case of a neonate with HDR syndrome and a novel GATA3 mutation. We performed genetic and functional analysis of GATA3 in this patient and identified a novel heterozygous 1516G> C missense mutation in exon 5, resulting in a cysteine-to-serine substitution at codon 321 (Cys321Ser). Mutated and wild-type GATA3 proteins were expressed at a similar level in vitro, indicating that the mutated GATA3 protein was stable. Luciferase assay revealed that the Cys321Ser-mutated GATA3 lacked transactivation activity due to loss of DNA-binding activity as confirmed by gel shift assay. Moreover, mutated GATA3 exerted a dominant-negative effect over the transactivation activity of wild-type GATA3. These findings indicate that not only haploinsufficiency of GATA3 but also the dominant-negative effect of Cys321Ser-mutated GATA3 might have been responsible for the HDR syndrome phenotype of our patient.


Asunto(s)
Factor de Transcripción GATA3/genética , Genes Dominantes , Proteínas Mutantes , Animales , Secuencia de Bases , Células COS , Técnicas de Cultivo de Célula , Chlorocebus aethiops , Proteínas de Unión al ADN/metabolismo , Factor de Transcripción GATA3/metabolismo , Perfilación de la Expresión Génica , Regulación de la Expresión Génica , Células HEK293 , Pérdida Auditiva Sensorineural/genética , Humanos , Hipoparatiroidismo/genética , Recién Nacido , Masculino , Datos de Secuencia Molecular , Proteínas Mutantes/genética , Mutación Missense/genética , Nefrosis/genética , Activación Transcripcional
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