RESUMEN
BACKGROUND: Biallelic deletions at 15q15.3, including STRC and CATSPER2, cause autosomal recessive deafness-infertility syndrome (DIS), while biallelic deletions of STRC alone cause nonsyndromic hearing loss. These deletions are among the leading genetic causes of mild-moderate hearing loss, but their detection using chromosomal microarray (CMA) is impeded by a tandem duplication containing highly homologous pseudogenes. We sought to assess copy number variant (CNV) detection in this region by a commonly-employed CMA platform. METHODS: Twenty-two specimens with known 15q15.3 CNVs, determined by droplet digital PCR (ddPCR), were analyzed by CMA. To investigate the impact of pseudogene homology on CMA performance, a probe-level analysis of homology was performed, and log2 ratios of unique and pseudogene-homologous probes compared. RESULTS: Assessment of 15q15.3 CNVs by CMA compared to ddPCR revealed 40.9% concordance, with frequent mis-assignment of zygosity by the CMA automated calling software. Probe-level analysis of pseudogene homology suggested that probes with high homology contributed to this discordance, with significant differences in log2 ratios between unique and pseudogene-homologous CMA probes. Two clusters containing several unique probes could reliably detect CNVs involving STRC and CATSPER2, despite the noise of surrounding probes, discriminating between homozygous vs heterozygous losses and complex rearrangements. CNV detection by these probe clusters showed 100% concordance with ddPCR. CONCLUSIONS: Manual analysis of clusters containing unique CMA probes without significant pseudogene homology improves CNV detection and zygosity assignment in the highly homologous DIS region. Incorporation of this method into CMA analysis and reporting processes can improve DIS diagnosis and carrier detection.
Asunto(s)
Sordera , Pérdida Auditiva Sensorineural , Infertilidad Masculina , Humanos , Masculino , Variaciones en el Número de Copia de ADN , Pérdida Auditiva Sensorineural/diagnóstico , Pérdida Auditiva Sensorineural/genética , Sordera/genética , Infertilidad Masculina/genética , Análisis por Micromatrices/métodos , Péptidos y Proteínas de Señalización Intercelular/genéticaRESUMEN
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
RESUMEN
PURPOSE: The ability of a single technology, next-generation sequencing, to provide both sequence and copy number variant (CNV) results has driven the merger of clinical cytogenetics and molecular genetics. Consequently, the distinction between the definition of a sequence variant and a CNV is blurry. As the 2015 American College of Medical Genetics and Genomics/Association for Molecular Pathology (ACMG/AMP) standards and guidelines for interpretation of sequence variants address CNV classification only sparingly, this study focused on adapting ACMG/AMP criteria for single-gene CNV interpretation. METHODS: CNV-specific modifications of the 2015 ACMG/AMP criteria were developed and their utility was independently tested by three diagnostic laboratories. Each laboratory team interpreted the same 12 single-gene CNVs using three systems: (1) without ACMG/AMP guidance, (2) with ACMG/AMP criteria, and (3) with new modifications. A replication study of 12 different CNVs validated the modified criteria. RESULTS: The adapted criteria system presented here showed improved concordance and usability for single-gene CNVs compared with using the ACMG/AMP interpretation guidelines focused on sequence variants. CONCLUSION: These single-gene CNV criteria modifications could be used as a supplement to the ACMG/AMP guidelines for sequence variants, allowing for a streamlined workflow and a step toward a uniform classification system for both sequence and copy number alterations.
Asunto(s)
Variaciones en el Número de Copia de ADN/genética , Secuenciación de Nucleótidos de Alto Rendimiento/normas , Análisis de Secuencia de ADN/clasificación , Biología Computacional/métodos , Dosificación de Gen/genética , Pruebas Genéticas/métodos , Variación Genética/genética , Genoma Humano/genética , Genómica/métodos , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Humanos , Laboratorios , Mutación/genética , Análisis de Secuencia de ADN/métodosRESUMEN
Aberrant MYC oncogene activation is one of the most prevalent characteristics of cancer. By overlapping datasets of Drosophila genes that are insulin-responsive and also regulate nucleolus size, we enriched for Myc target genes required for cellular biosynthesis. Among these, we identified the aminoacyl tRNA synthetases (aaRSs) as essential mediators of Myc growth control in Drosophila and found that their pharmacologic inhibition is sufficient to kill MYC-overexpressing human cells, indicating that aaRS inhibitors might be used to selectively target MYC-driven cancers. We suggest a general principle in which oncogenic increases in cellular biosynthesis sensitize cells to disruption of protein homeostasis.
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Aminoacil-ARNt Sintetasas/metabolismo , Proteínas de Unión al ADN/metabolismo , Proteínas de Drosophila/metabolismo , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Neoplasias/tratamiento farmacológico , Factores de Transcripción/metabolismo , Aminoacil-ARNt Sintetasas/antagonistas & inhibidores , Animales , Animales Modificados Genéticamente , Línea Celular , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/genética , Proteínas de Unión al ADN/genética , Proteínas de Drosophila/genética , Células Epiteliales , Femenino , Humanos , Insulina/metabolismo , Masculino , Neoplasias/genética , Neoplasias/patología , Interferencia de ARN , Transducción de Señal/efectos de los fármacos , Transducción de Señal/genética , Factores de Transcripción/genéticaRESUMEN
Mitochondrial defects underlie a multitude of human diseases. Genetic manipulation of mitochondrial regulatory pathways represents a potential therapeutic approach. We have carried out a high-throughput overexpression screen for genes that affect mitochondrial abundance or activity using flow-cytometry-based enrichment of a cell population expressing a high-complexity, concentration-normalized pool of human ORFs. The screen identified 94 candidate mitochondrial regulators including the nuclear protein GLTSCR2, also known as PICT1. GLTSCR2 enhances mitochondrial function and is required for the maintenance of oxygen consumption, consistent with a pivotal role in the control of cellular respiration. RNAi inactivation of the Caenorhabditis elegans ortholog of GLTSCR2 reduces respiration in worms, indicating functional conservation across species. GLTSCR2 controls cellular proliferation and metabolism via the transcription factor Myc, and is induced by mitochondrial stress, suggesting it may constitute a significant component of the mitochondrial signaling pathway.
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Mitocondrias/fisiología , Proteínas Proto-Oncogénicas c-myc/metabolismo , Transducción de Señal/fisiología , Estrés Fisiológico , Proteínas Supresoras de Tumor/metabolismo , Adenosina Trifosfato/metabolismo , Animales , Western Blotting , Caenorhabditis elegans , Células Cultivadas , Cartilla de ADN/genética , Bases de Datos Genéticas , Citometría de Flujo , Humanos , Inmunoprecipitación , Análisis por Micromatrices , Mitocondrias/metabolismo , Sistemas de Lectura Abierta/genética , Consumo de Oxígeno/fisiología , Interferencia de ARN , Estrés Fisiológico/fisiologíaRESUMEN
Intracellular pathogens directly alter host cells in order to replicate and survive. While infection-induced changes in host transcription can be readily assessed, posttranscriptional alterations are more difficult to catalog. We applied the global protein stability (GPS) platform, which assesses protein stability based on relative changes in an adjoining fluorescent tag, to identify changes in the host proteome following infection with the obligate intracellular bacteria Chlamydia trachomatis. Our results indicate that C. trachomatis profoundly remodels the host proteome independently of changes in transcription. Additionally, C. trachomatis replication depends on a subset of altered proteins, such as Pin1 and Men1, that regulate the host transcription factor AP-1 controlling host inflammation, stress, and cell survival. Furthermore, AP-1-dependent transcription is activated during infection and required for efficient Chlamydia growth. In summary, this experimental approach revealed that C. trachomatis broadly alters host proteins and can be applied to examine host-pathogen interactions and develop host-based therapeutics.
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Infecciones por Chlamydia/microbiología , Chlamydia trachomatis/fisiología , Procesamiento Proteico-Postraduccional , Proteoma/metabolismo , Factor de Transcripción AP-1/metabolismo , Animales , Supervivencia Celular , Infecciones por Chlamydia/genética , Infecciones por Chlamydia/metabolismo , Replicación del ADN , Femenino , Colorantes Fluorescentes , Células HeLa , Interacciones Huésped-Patógeno , Humanos , Ratones , Ratones Endogámicos C57BL , Microscopía Fluorescente , Peptidilprolil Isomerasa de Interacción con NIMA , Isomerasa de Peptidilprolil/genética , Isomerasa de Peptidilprolil/metabolismo , Proteoma/genética , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas/metabolismo , Transducción de Señal , Factor de Transcripción AP-1/genética , Transcripción GenéticaRESUMEN
Aneuploidy has been recognized as a hallmark of cancer for more than 100 years, yet no general theory to explain the recurring patterns of aneuploidy in cancer has emerged. Here, we develop Tumor Suppressor and Oncogene (TUSON) Explorer, a computational method that analyzes the patterns of mutational signatures in tumors and predicts the likelihood that any individual gene functions as a tumor suppressor (TSG) or oncogene (OG). By analyzing >8,200 tumor-normal pairs, we provide statistical evidence suggesting that many more genes possess cancer driver properties than anticipated, forming a continuum of oncogenic potential. Integrating our driver predictions with information on somatic copy number alterations, we find that the distribution and potency of TSGs (STOP genes), OGs, and essential genes (GO genes) on chromosomes can predict the complex patterns of aneuploidy and copy number variation characteristic of cancer genomes. We propose that the cancer genome is shaped through a process of cumulative haploinsufficiency and triplosensitivity.