ABSTRACT
Rhabdomyosarcoma (RMS) is a common soft tissue sarcoma in children that resembles developing skeletal muscle. Unlike normal muscle cells, RMS cells fail to differentiate despite expression of the myogenic determination protein MYOD. The TWIST2 transcription factor is frequently overexpressed in fusion-negative RMS (FN-RMS). TWIST2 blocks differentiation by inhibiting MYOD activity in myoblasts, but its role in FN-RMS pathogenesis is incompletely understood. Here, we show that knockdown of TWIST2 enables FN-RMS cells to exit the cell cycle and undergo terminal myogenesis. TWIST2 knockdown also substantially reduces tumor growth in a mouse xenograft model of FN-RMS. Mechanistically, TWIST2 controls H3K27 acetylation at distal enhancers by interacting with the chromatin remodelers SMARCA4 and CHD3 to activate growth-related target genes and repress myogenesis-related target genes. These findings provide insights into the role of TWIST2 in maintaining an undifferentiated and tumorigenic state of FN-RMS and highlight the potential of suppressing TWIST2-regulated pathways to treat FN-RMS.
Subject(s)
Rhabdomyosarcoma , Sarcoma , Humans , Animals , Mice , Chromatin Assembly and Disassembly/genetics , Gene Expression Regulation, Neoplastic , Rhabdomyosarcoma/genetics , Rhabdomyosarcoma/metabolism , Rhabdomyosarcoma/pathology , Sarcoma/genetics , Cell Differentiation/genetics , Cell Line, Tumor , DNA Helicases/metabolism , Nuclear Proteins/genetics , Nuclear Proteins/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism , Repressor Proteins/metabolism , Twist-Related Protein 1/genetics , Twist-Related Protein 1/metabolismABSTRACT
In this study, we synthesized 22 compounds in a series with various substitution on imidazo[2,1-b][1,3,4]thiadiazole. The potential cytotoxic activity of these compounds investigated in leukemia cell lines by Differential Nuclear Staining (DNS). Our results identified two compounds, 2-(4-methoxybenzyl)-6-(2-oxo-2H-chromen-3-yl)imidazo[2,1-b][1,3,4]thiadiazol-5-yl thiocyanate and 6-(4-chlorophenyl)-2-(4-methoxybenzyl)imidazo[2,1-b][1,3,4]thiadiazole-5-carbaldehyde, exhibited the most cytotoxic effect against murine leukemia cells (L1210), human T-lymphocyte cells (CEM) and human cervix carcinoma cells (HeLa) with IC50 values ranging between 0.79 and 1.6â µM. The results indicate that 2-(4-methoxybenzyl)-6-(2-oxo-2H-chromen-3-yl)imidazo[2,1-b][1,3,4]thiadiazol-5-yl thiocyanate is inducing phosphatidylserine externalization and caspase-3 activation which are both a hallmark of apoptosis. Docking studies showed that 2-(4-methoxybenzyl)-6-(2-oxo-2H-chromen-3-yl)imidazo[2,1-b][1,3,4]thiadiazol-5-yl thiocyanate binds within the active sites of transforming growth factor beta (TGF-ß) type I receptor kinase domain by strong hydrogen binding and hydrophobic interactions.
Subject(s)
Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Leukemia/drug therapy , Thiadiazoles/chemistry , Thiadiazoles/pharmacology , Animals , Apoptosis/drug effects , Benzyl Compounds/chemistry , Benzyl Compounds/pharmacology , Cell Line, Tumor , Drug Screening Assays, Antitumor , HeLa Cells , Humans , Imidazoles/chemistry , Imidazoles/pharmacology , Leukemia/metabolism , Mice , Molecular Docking Simulation , Receptor, Transforming Growth Factor-beta Type I/metabolismABSTRACT
Resumen Objetivo: Determinar la prevalencia y espectro de las enfermedades que predisponen la muerte súbita cardiaca en niños mexicanos e identificar los principales signos y síntomas tempranos que pueden permitir al personal de salud sospechar acerca de estas enfermedades y referir a los pacientes a un hospital de tercer nivel de manera temprana. Métodos: La incidencia, prevalencia y prevalencia de periodo, así como los primeros síntomas, los datos clínicos y el seguimiento, se describen en todos los niños con enfermedades que predisponen a la muerte súbita cardiaca en el Hospital Infantil de México. Resultados: Cincuenta y nueve pacientes de 8 ± 5 años, 40 con miocardiopatías y 19 con enfermedades arritmogénicas hereditarias. La prevalencia del periodo fue de 9.5/1,000 pacientes/año. Los primeros síntomas más comunes fueron disnea, palpitaciones y síncope. En 9 casos se encontró un patrón de herencia mendeliana. Tres pacientes fallecieron de muerte súbita cardiaca durante el periodo de estudio. Conclusión: Las enfermedades que predisponen a la muerte súbita cardiaca en los niños no son muy conocidas por la comunidad médica y general. Todo niño con disnea, palpitaciones y/o síncope debe referirse para la búsqueda intensiva de estas enfermedades. Una evaluación cardiológica completa en todos los miembros de la familia está indicada.
Abstract Objective: To determine the prevalence and spectrum of diseases that predispose to sudden cardiac death in Mexican children, and to identify the main early signs and symptoms that can enable the health personnel to suspect these diseases and to refer the patients to a tertiary hospital in a timely manner. Methods: Incidence, prevalence, and period prevalence, as well as early symptoms, clinical data, and follow-up were recorded on all children found with diseases that predispose to sudden cardiac death in The Children's Hospital of Mexico. Results: The study included 59 patients, with a mean age of 8 ± 5 years old, with 40 cardiomyopathies, and 19 with inherited arrhythmogenic diseases. The period prevalence was 9.5/1,000 patients/year. The most common early symptoms were dyspnoea, palpitations, and syncope. A Mendelian inheritance pattern was found in 9 cases. Three patients died of sudden cardiac death during the period of the study. Conclusion: Diseases that predispose to sudden cardiac death in children are not very well known by the general medical community. Every child with dyspnoea, palpitations and/or syncope, should be referred for the intensive search of these diseases. A complete cardiological evaluation in all members of the family is indicated.
Subject(s)
Humans , Male , Female , Infant, Newborn , Infant , Child, Preschool , Child , Adolescent , Arrhythmias, Cardiac/epidemiology , Death, Sudden, Cardiac/epidemiology , Dyspnea/epidemiology , Cardiomyopathies/epidemiology , Arrhythmias, Cardiac/complications , Syncope/epidemiology , Incidence , Prevalence , Follow-Up Studies , Longitudinal Studies , Death, Sudden, Cardiac/etiology , Hospitals, Pediatric , Mexico/epidemiology , Cardiomyopathies/complicationsABSTRACT
OBJECTIVE: To determine the prevalence and spectrum of diseases that predispose to sudden cardiac death in Mexican children, and to identify the main early signs and symptoms that can enable the health personnel to suspect these diseases and to refer the patients to a tertiary hospital in a timely manner. METHODS: Incidence, prevalence, and period prevalence, as well as early symptoms, clinical data, and follow-up were recorded on all children found with diseases that predispose to sudden cardiac death in The Children's Hospital of Mexico. RESULTS: The study included 59 patients, with a mean age of 8 ± 5 years old, with 40 cardiomyopathies, and 19 with inherited arrhythmogenic diseases. The period prevalence was 9.5/1,000 patients/year. The most common early symptoms were dyspnoea, palpitations, and syncope. A Mendelian inheritance pattern was found in 9 cases. Three patients died of sudden cardiac death during the period of the study. CONCLUSION: Diseases that predispose to sudden cardiac death in children are not very well known by the general medical community. Every child with dyspnoea, palpitations and/or syncope, should be referred for the intensive search of these diseases. A complete cardiological evaluation in all members of the family is indicated.
