PAX8/PAX8-AS1 DNA methylation levels are associated with objective sleep duration in persons with unexplained hypersomnolence using a deep phenotyping approach

Study Objectives Patients with unexplained hypersomnolence have significant impairment related to daytime sleepiness and excessive sleep duration, the biological bases of which are poorly understood. This investigation sought to examine relationships between objectively measured hypersomnolence phenotypes and epigenetic modification of candidate hypersomnolence genes to advance this line of inquiry. Methods Twenty-eight unmedicated clinical patients with unexplained hypersomnolence were evaluated using overnight ad libitum polysomnography, multiple sleep latency testing, infrared pupillometry, and the psychomotor vigilance task. DNA methylation levels on CpG sites annotated to 11 a priori hypersomnolence candidate genes were assessed for statistical association with hypersomnolence measures using independent regression models with adjusted local index of significance (aLIS) P-value threshold of 0.05. Results Nine CpG sites exhibited significant associations between DNA methylation levels and total sleep time measured using ad libitum polysomnography (aLIS p-value < .05). All nine differentially methylated CpG sites were annotated to the paired box 8 (PAX8) gene and its related antisense gene (PAX8-AS1). Among these nine differentially methylated positions was a cluster of five CpG sites located in the body of the PAX8 gene and promoter of PAX8-AS1. Conclusions This study demonstrates that PAX8/PAX8-AS1 DNA methylation levels are associated with total sleep time in persons with unexplained hypersomnolence. Given prior investigations that have implicated single nucleotide polymorphisms in PAX8/PAX8-AS1 with habitual sleep duration, further research that clarifies the role of DNA methylation levels on these genes in the phenotypic expression of total sleep time is warranted.

Genetic Variability of the Paired Box Transcription Factor; PAX8 Gene: Guidance Towards Treatment Strategies in a Cohort of Congenital Hypothyroidism

The contribution of PAX8 genetic variants to congenital hypothyroidism (CH) is not well understood. We aimed to study the genetic variability of exons 3 and 5 of PAX8 gene among a cohort of children with congenital hypothyroidism in correspondence to their clinical aspect. Blood samples were collected from 117 children (63 girls and 54 boys) with CH and enrolled as cases (Group I). All cases underwent biochemical confirmation with low FT4 and high TSH levels and thyroid gland imaging, along with equal number of matched apparently healthy individuals who served as controls (Group II). Genomic materials for exons 3 and 5 of PAX8 gene were extracted, amplified by PCR, detected by electrophoresis, purified, and sequenced by the Sanger technique through the application of ABI 3730x1 DNA Sequencer. Out of 117 cases, eight different effective PAX8 mutations were detected in exon 3 (G23D, V35I, I34T, Q40P, p.R31C, p.R31H, p.R31A, and p.I47T) in 14 patients with their sonographic findings ranged from normal, hypoplastic to thyroid agenesis. Besides the reported mutations, one novel mutation; R31A was detected in 1 euotopic case. Exon 5 analysis revealed no detected mutations elsewhere. In contrast, all healthy control children showed no mutation and normal sonographic findings. Mutations in exon 3 of PAX8 gene, implies its important role in thyroid development and function, as a first estimate of PA8 mutation rate in Egyptian patients with CH having normal and dysgenetic gland. Using ultrasound is mandatory for diagnosis and guiding the treatment of children with CH.

PAX8 regulon in human ovarian cancer links lineage dependency with epigenetic vulnerability to HDAC inhibitors

PAX8 is a prototype lineage-survival oncogene in epithelial ovarian cancer. However, neither its underlying pro-tumorigenic mechanisms nor potential therapeutic implications have been adequately elucidated. Here, we identified an ovarian lineage-specific PAX8 regulon using modified cancer outlier profile analysis, in which PAX8-FGF18 axis was responsible for promoting cell migration in an autocrine fashion. An image-based drug screen pinpointed that PAX8 expression was potently inhibited by small-molecules against histone deacetylases (HDACs). Mechanistically, HDAC blockade altered histone H3K27 acetylation occupancies and perturbed the super-enhancer topology associated with PAX8 gene locus, resulting in epigenetic downregulation of PAX8 transcripts and related targets. HDAC antagonists efficaciously suppressed ovarian tumor growth and spreading as single agents, and exerted synergistic effects in combination with standard chemotherapy. These findings provide mechanistic and therapeutic insights for PAX8-addicted ovarian cancer. More generally, our analytic and experimental approach represents an expandible paradigm for identifying and targeting lineage-survival oncogenes in diverse human malignancies.

Novel Mutations in the NKX2.1 gene and the PAX8 gene in a Boy with Brain-Lung-Thyroid Syndrome

Objective To elucidate the molecular mechanism which causes thyroid dysgenesis (TD) in a boy with brain-lung-thyroid syndrome. Design, patients, measurements We describe a patient with TD, respiratory disease and cerebral palsy who is heterozygous for mutations in two different genes, the PAX8 (p.E234K) and the NKX2.1 (p.A329GfsX108). In vitro studies were performed to functionally characterize these mutations. Congenital hypothyroidism (CH) was identified by neonatal screening associated with a hypoplastic thyroid gland. Postpartum he developed a brain-lung-thyroid syndrome with severe respiratory failure, symptomatic epilepsy and a considerable psychomotor retardation. The DNA-binding capability and the transcriptional activity of the two mutated transcription factors were investigated in vitro. Results The NKX2.1 mutation did not show any transcriptional activity and had almost no DNA-binding. The PAX8 mutation was normally located to the nucleus and showed a normal transactivation and a normal binding to the known downstream targets. Conclusions The molecular defect explaining the phenotype of brain-lung-thyroid syndrome was identified. To what extent the PAX8 mutation contributes to the phenotype needs to be further investigated. We recommend to screen patients with CH and TD for mutations in all known TD candidate genes.

Analysis of the PAX8 gene in 32 children with thyroid dysgenesis and functional characterization of a promoter variant

The molecular basis underlying the development of thyroid dysgenesis remains largely unknown. The objective of this study was to analyze theThe 5′-untranslated region and the entire coding region of theThirty children did not have any sequence alterations. Two individuals had a previously identified monoallelic cytosine to thymine transition at position -983 in the promoter (-983C>T; mutant P. A of the ATG of the initiator codon is designated as +1), and a novel guanine to cytosine transversion in the non-coding exon 1 (-465G>C; mutant E). Functional analysis revealed that the basal transcriptional activity of the mutants is decreased compared to the wild type. Gel mobility shift assays indicated that mutant P does not interact with a transacting factor whose nature remains to be elucidated. The DNA binding property of mutant E were similar compared to the wild type.These results suggest that mutations in

Genetic analysis of the paired box transcription factor (PAX8) gene in a cohort of Polish patients with primary congenital hypothyroidism and dysgenetic thyroid glands

The morphological and biochemical phenotype ofSome 48 children (37 girls and 11 boys) with CH associated with thyroid ectopy (n=22), agenesis (n=10), hypoplasia (n=6), or thyroid dysgenesis of unknown cause (n=10) were enrolled. The study participants were born in south-eastern Poland in the years 1993–2012 and were selected for neonatal mass screening for CH. DNA was extracted from peripheral blood samples using Master Pure DNA Purification Kit (Epicentre Biotechnologies, Madison, WI, USA). The 12 exons of theNovel heterozygous transition in exon 3 (c.68G>A) was detected in a 3-year-old girl with a thyroid hypoplasia. This substitution was not identified in the patient’s parents (de novo event). Additionally, a novel genetic variant in 3′UTR region of exon 12 (c.*416C>T) occurred in a 3-year-old boy with ectopic thyroid tissue and concomitant congenital urogenital malformation. This heterozygous variant was also detected in other healthy family members. Thirteen well-described single nucleotide polymorphisms were revealed in theThe study reports on the occurrence of two novel heterozygous substitutions in the