Genomic and phenotypic landscapes of X-linked hereditary hearing loss in the Chinese population.

BACKGROUND: Hearing loss (HL) is the most common sensory birth deficit worldwide, with causative variants in more than 150 genes. However, the etiological contribution and clinical manifestations of X-linked inheritance in HL remain unclear within the Chinese HL population. In this study, we focused on X-linked hereditary HL and aimed to assess its contribution to hereditary HL and identify the genotype-phenotype relationship. METHODS: We performed a molecular epidemiological investigation of X-linked hereditary HL based on next-generation sequencing and third-generation sequencing in 3646 unrelated patients with HL. We also discussed the clinical features associated with X-linked non-syndromic HL-related genes based on a review of the literature. RESULTS: We obtained a diagnostic rate of 52.72% (1922/3646) among our patients; the aggregate contribution of HL caused by genes on the X chromosome in this cohort was ~ 1.14% (22/1922), and POU3F4 variants caused ~ 59% (13/22) of these cases. We found that X-linked HL was congenital or began during childhood in all cases, with representative audiological profiles or typical cochlear malformations in certain genes. Genotypic and phenotypic analyses showed that causative variants in PRPS1 and AIFM1 were mainly of the missense type, suggesting that phenotypic variability was correlated with the different effects that the replaced residues exert on structure and function. Variations in SMPX causing truncation of the protein product were associated with DFNX4, which resulted in typical audiological profiles before and after the age of 10 years, whereas nontruncated proteins typically led to distal myopathy. No phenotypic differences were identified in patients carrying POU3F4 or COL4A6 variants. CONCLUSIONS: Our work constitutes a preliminary evaluation of the molecular contribution of X-linked genes in heritable HL (~ 1.14%). The 15 novel variants reported here expand the mutational spectrum of these genes. Analysis of the genotype-phenotype relationship is valuable for X-linked HL precise diagnostics and genetic counseling. Elucidation of the pathogenic mechanisms and audiological profiles of HL can also guide choices regarding treatment modalities.

Conserved transcriptional regulation by BRN1 and BRN2 in neocortical progenitors drives mammalian neural specification and neocortical expansion.

The neocortex varies in size and complexity among mammals due to the tremendous variability in the number and diversity of neuronal subtypes across species. The increased cellular diversity is paralleled by the expansion of the pool of neocortical progenitors and the emergence of indirect neurogenesis during brain evolution. The molecular pathways that control these biological processes and are disrupted in neurological disorders remain largely unknown. Here we show that the transcription factors BRN1 and BRN2 have an evolutionary conserved function in neocortical progenitors to control their proliferative capacity and the switch from direct to indirect neurogenesis. Functional studies in mice and ferrets show that BRN1/2 act in concert with NOTCH and primary microcephaly genes to regulate progenitor behavior. Analysis of transcriptomics data from genetically modified macaques provides evidence that these molecular pathways are conserved in non-human primates. Our findings thus demonstrate that BRN1/2 are central regulators of gene expression programs in neocortical progenitors critical to determine brain size during evolution.

The Oct4-related PouV gene, pou5f3, mediates isthmus development in zebrafish by directly and dynamically regulating pax2a.

Using a transgenic zebrafish line harboring a heat-inducible dominant-interference pou5f3 gene (en-pou5f3), we reported that this PouV gene is involved in isthmus development at the midbrain-hindbrain boundary (MHB), which patterns the midbrain and cerebellum. Importantly, the functions of pou5f3 reportedly differ before and after the end of gastrulation. In the present study, we examined in detail the effects of en-pou5f3 induction on isthmus development during embryogenesis. When en-pou5f3 was induced around the end of gastrulation (bud stage), the isthmus was abrogated or deformed by the end of somitogenesis (24 hours post-fertilization). At this stage, the expression of MHB markers -- such as pax2a, fgf8a, wnt1, and gbx2 -- was absent in embryos lacking the isthmus structure, whereas it was present, although severely distorted, in embryos with a deformed isthmus. We further found that, after en-pou5f3 induction at late gastrulation, pax2a, fgf8a, and wnt1 were immediately and irreversibly downregulated, whereas the expression of en2a and gbx2 was reduced only weakly and slowly. Induction of en-pou5f3 at early somite stages also immediately downregulated MHB genes, particularly pax2a, but their expression was restored later. Overall, the data suggested that pou5f3 directly upregulates at least pax2a and possibly fgf8a and wnt1, which function in parallel in establishing the MHB, and that the role of pou5f3 dynamically changes around the end of gastrulation. We next examined the transcriptional regulation of pax2a using both in vitro and in vivo reporter analyses; the results showed that two upstream 1.0-kb regions with sequences conserved among vertebrates specifically drove transcription at the MHB. These reporter analyses confirmed that development of the isthmic organizer is regulated by PouV through direct regulation of pax2/pax2a in vertebrate embryos.

Validation of positional candidates Rps6ka6 and Pou3f4 for a locus associated with skeletal muscle mass variability.

Genetic variability significantly contributes to individual differences in skeletal muscle mass; however, the specific genes involved in that process remain elusive. In this study, we examined the role of positional candidates, Rps6ka6 and Pou3f4, of a chromosome X locus, implicated in muscle mass variability in CFW laboratory mice. Histology of hindlimb muscles was studied in CFW male mice carrying the muscle "increasing" allele C (n = 15) or "decreasing" allele T (n = 15) at the peak marker of the locus, rs31308852, and in the Pou3f4y/- and their wild-type male littermates. To study the role of the Rps6ka6 gene, we deleted exon 7 (Rps6ka6-ΔE7) using clustered regularly interspaced palindromic repeats-Cas9 based method in H2Kb myogenic cells creating a severely truncated RSK4 protein. We then tested whether that mutation affected myoblast proliferation, migration, and/or differentiation. The extensor digitorum longus muscle was 7% larger (P < 0.0001) due to 10% more muscle fibers (P = 0.0176) in the carriers of the "increasing" compared with the "decreasing" CFW allele. The number of fibers was reduced by 15% (P = 0.0268) in the slow-twitch soleus but not in the fast-twitch extensor digitorum longus (P = 0.2947) of Pou3f4y/- mice. The proliferation and migration did not differ between the Rps6ka6-ΔE7 and wild-type H2Kb myoblasts. However, indices of differentiation (myosin expression, P < 0.0001; size of myosin-expressing cells, P < 0.0001; and fusion index, P = 0.0013) were significantly reduced in Rps6ka6-ΔE7 cells. This study suggests that the effect of the X chromosome locus on muscle fiber numbers in the fast-twitch extensor digitorum longus is mediated by the Rps6ka6 gene, whereas the Pou3f4 gene affects fiber number in slow-twitch soleus.

Research progress on incomplete partition type 3 inner ear malformation.

PURPOSE: This review aims to provides a comprehensive overview of the latest research progress on IP-III inner ear malformation, focusing on its geneticbasis, imaging features, cochlear implantation, and outcome. METHODS: Review the literature on clinical and genetic mechanisms associated with IP-III. RESULTS: Mutations in the POU3F4 gene emerge as the principal pathogenic contributors to IP-III anomalies, primarily manifesting through inner ear potential irregularities leading to deafness. While cochlear implantation stands as the primary intervention for restoring hearing, the unique nature of the inner ear anomaly escalates the complexity of surgical procedures and postoperative results. Hence, meticulous preoperative assessment to ascertain surgical feasibility and postoperative verification of electrode placement are imperative. Additionally, gene therapy holds promise as a prospective treatment modality. CONCLUSIONS: IP-III denotes X-linked recessive hereditary deafness, with cochlear implantation currently serving as the predominant therapeutic approach. Clinicians are tasked with preoperative assement and individualized postoperative rehabilitation.

FXR1 stabilizes SNORD63 to regulate blood-tumor barrier permeability through SNORD63 mediated 2'-O-methylation of POU6F1.

How selectively increase blood-tumor barrier (BTB) permeability is crucial to enhance the delivery of chemotherapeutic agents to brain tumor tissues. In this study, we established in vitro models of the blood-brain barrier (BBB) and BTB using endothelial cells (ECs) co-cultured with human astrocytes (AECs) and glioma cells (GECs), respectively. The findings revealed high expressions of the RNA-binding protein FXR1 and SNORD63 in GECs, where FXR1 was found to bind and stabilize SNORD63. Knockdown of FXR1 resulted in decreased expression of tight-junction-related proteins and increased BTB permeability by down-regulating SNORD63. SNORD63 played a role in mediating the 2'-O-methylation modification of POU6F1 mRNA, leading to the downregulation of POU6F1 protein expression. POU6F1 showed low expression in GECs and acted as a transcription factor to regulate BTB permeability by binding to the promoter regions of ZO-1, occludin, and claudin-5 mRNAs and negatively regulating their expressions. Finally, the targeted regulation of FXR1, SNORD63, and POU6F1 expressions, individually or in combination, effectively enhanced doxorubicin passage through the BTB and induced apoptosis in glioma cells. This study aims to elucidate the underlying mechanism of the FXR1/SNORD63/POU6F1 axis in regulating BTB permeability, offering a novel strategy to improve the efficacy of glioma chemotherapy.

The m6A modification mediated-lncRNA POU6F2-AS1 reprograms fatty acid metabolism and facilitates the growth of colorectal cancer via upregulation of FASN.

BACKGROUND: Long noncoding RNAs (lncRNAs) have emerged as key players in tumorigenesis and tumour progression. However, the biological functions and potential mechanisms of lncRNAs in colorectal cancer (CRC) are unclear. METHODS: The novel lncRNA POU6F2-AS1 was identified through bioinformatics analysis, and its expression in CRC patients was verified via qRT-PCR and FISH. In vitro and in vivo experiments, such as BODIPY staining, Oil Red O staining, triglyceride (TAG) assays, and liquid chromatography mass spectrometry (LC-MS) were subsequently performed with CRC specimens and cells to determine the clinical significance, and functional roles of POU6F2-AS1. Biotinylated RNA pull-down, RIP, Me-RIP, ChIP, and patient-derived organoid (PDO) culture assays were performed to confirm the underlying mechanism of POU6F2-AS1. RESULTS: The lncRNA POU6F2-AS1 is markedly upregulated in CRC and associated with adverse clinicopathological features and poor overall survival in CRC patients. Functionally, POU6F2-AS1 promotes the growth and lipogenesis of CRC cells both in vitro and in vivo. Mechanistically, METTL3-induced m6A modification is involved in the upregulation of POU6F2-AS1. Furthermore, upregulated POU6F2-AS1 could tether YBX1 to the FASN promoter to induce transcriptional activation, thus facilitating the growth and lipogenesis of CRC cells. CONCLUSIONS: Our data revealed that the upregulation of POU6F2-AS1 plays a critical role in CRC fatty acid metabolism and might provide a novel promising biomarker and therapeutic target for CRC.

RFX4 is an intrinsic factor for neuronal differentiation through induction of proneural genes POU3F2 and NEUROD1.

Proneural genes play a crucial role in neuronal differentiation. However, our understanding of the regulatory mechanisms governing proneural genes during neuronal differentiation remains limited. RFX4, identified as a candidate regulator of proneural genes, has been reported to be associated with the development of neuropsychiatric disorders. To uncover the regulatory relationship, we utilized a combination of multi-omics data, including ATAC-seq, ChIP-seq, Hi-C, and RNA-seq, to identify RFX4 as an upstream regulator of proneural genes. We further validated the role of RFX4 using an in vitro model of neuronal differentiation with RFX4 knock-in and a CRISPR-Cas9 knock-out system. As a result, we found that RFX4 directly interacts with the promoters of POU3F2 and NEUROD1. Transcriptomic analysis revealed a set of genes associated with neuronal development, which are highly implicated in the development of neuropsychiatric disorders, including schizophrenia. Notably, ectopic expression of RFX4 can drive human embryonic stem cells toward a neuronal fate. Our results strongly indicate that RFX4 serves as a direct upstream regulator of proneural genes, a role that is essential for normal neuronal development. Impairments in RFX4 function could potentially be related to the development of various neuropsychiatric disorders. However, understanding the precise mechanisms by which the RFX4 gene influences the onset of neuropsychiatric disorders requires further investigation through human genetic studies.

Homeodomain proteins hierarchically specify neuronal diversity and synaptic connectivity.

How our brain generates diverse neuron types that assemble into precise neural circuits remains unclear. Using Drosophila lamina neuron types (L1-L5), we show that the primary homeodomain transcription factor (HDTF) brain-specific homeobox (Bsh) is initiated in progenitors and maintained in L4/L5 neurons to adulthood. Bsh activates secondary HDTFs Ap (L4) and Pdm3 (L5) and specifies L4/L5 neuronal fates while repressing the HDTF Zfh1 to prevent ectopic L1/L3 fates (control: L1-L5; Bsh-knockdown: L1-L3), thereby generating lamina neuronal diversity for normal visual sensitivity. Subsequently, in L4 neurons, Bsh and Ap function in a feed-forward loop to activate the synapse recognition molecule DIP-ß, thereby bridging neuronal fate decision to synaptic connectivity. Expression of a Bsh:Dam, specifically in L4, reveals Bsh binding to the DIP-ß locus and additional candidate L4 functional identity genes. We propose that HDTFs function hierarchically to coordinate neuronal molecular identity, circuit formation, and function. Hierarchical HDTFs may represent a conserved mechanism for linking neuronal diversity to circuit assembly and function.

Notch signaling and Bsh homeodomain activity are integrated to diversify Drosophila lamina neuron types.

Notch signaling is an evolutionarily conserved pathway for specifying binary neuronal fates, yet how it specifies different fates in different contexts remains elusive. In our accompanying paper, using the Drosophila lamina neuron types (L1-L5) as a model, we show that the primary homeodomain transcription factor (HDTF) Bsh activates secondary HDTFs Ap (L4) and Pdm3 (L5) and specifies L4/L5 neuronal fates. Here we test the hypothesis that Notch signaling enables Bsh to differentially specify L4 and L5 fates. We show asymmetric Notch signaling between newborn L4 and L5 neurons, but they are not siblings; rather, Notch signaling in L4 is due to Delta expression in adjacent L1 neurons. While Notch signaling and Bsh expression are mutually independent, Notch is necessary and sufficient for Bsh to specify L4 fate over L5. The NotchON L4, compared to NotchOFF L5, has a distinct open chromatin landscape which allows Bsh to bind distinct genomic loci, leading to L4-specific identity gene transcription. We propose a novel model in which Notch signaling is integrated with the primary HDTF activity to diversify neuron types by directly or indirectly generating a distinct open chromatin landscape that constrains the pool of genes that a primary HDTF can activate.

POU6F1 promotes ferroptosis by increasing lncRNA-CASC2 transcription to regulate SOCS2/SLC7A11 signaling in gastric cancer.

OBJECTIVE: This study investigated the effect and mechanism of POU6F1 and lncRNA-CASC2 on ferroptosis of gastric cancer (GC) cells. METHODS: GC cells treated with erastin and RSL3 were detected for ferroptosis, reactive oxygen species (ROS) level, and cell viability. The expression levels of POU6F1, lncRNA-CASC2, SOCS2, and ferroptosis-related molecules (GPX4 and SLC7A11) were also measured. The regulations among POU6F1, lncRNA-CASC2, FMR1, SOCS2, and SLC7A11 were determined. Subcutaneous tumor models were established, in which the expressions of Ki-67, SOCS2, and GPX4 were detected by immunohistochemistry. RESULTS: GC patients with decreased expressions of POU6F1 and lncRNA-CASC2 had lower survival rate. Overexpression of POU6F1 or lncRNA-CASC2 decreased cell proliferation and GSH levels in GC cells, in addition to increasing total iron, Fe2+, MDA, and ROS levels. POU6F1 directly binds to the lncRNA-CASC2 promoter to promote its transcription. LncRNA-CASC2 can target FMR1 and increase SOCS2 mRNA stability to promote SLC7A11 ubiquitination degradation and activate ferroptosis signaling. Knockdown of SOCS2 inhibited the ferroptosis sensitivity of GC cells and reversed the effects of POU6F1 and lncRNA-CASC2 overexpression on ferroptosis in GC cells. CONCLUSION: Transcription factor POU6F1 binds directly to the lncRNA-CASC2 promoter to promote its expression, while upregulated lncRNA-CASC2 increases SOCS2 stability and expression by targeting FMR1, thereby inhibiting SLC7A11 signaling to promote ferroptosis in GC cells and inhibit GC progression.

Transcriptional Coactivator BOB1 (OBF1, OCA-B) Modulates the Specificity of DNA Recognition by the POU-Domain Factors OCT1 and OCT2 in a Monomeric Configuration.

BOB1, a mammalian lymphocyte-specific transcriptional coactivator of the transcription factors OCT1 and OCT2 (OCT1/2), plays important roles in normal immune responses, autoimmunity, and hematologic malignancies. The issue of a DNA sequence preference change imposed by BOB1 was raised more than two decades ago but remains unresolved. In this paper, using the EMSA-SELEX-Seq approach, we have reassessed the intrinsic ability of BOB1 to modulate the specificity of DNA recognition by OCT1 and OCT2. Our results have reaffirmed previous conclusions regarding BOB1 selectivity towards the dimer configuration of OCT1/2. However, they suggest that the monomeric configuration of these factors, assembled on the classical octamer ATGCAAAT and related motifs, are the primary targets of BOB1. Our data further specify the DNA sequence preference imposed by BOB1 and predict the probability of ternary complex formation. These results provide an additional insight into the action of BOB1-an essential immune regulator and a promising molecular target for the treatment of autoimmune diseases and hematologic malignancies.

Genome sequencing detects a balanced pericentric inversion with breakpoints that impact the DMD and upstream region of POU3F4 genes.

We describe a family with two maternal half-brothers both of whom presented with muscular dystrophy, autism spectrum disorder, developmental delay, and sensorineural hearing loss. The elder brother had onset of features at ~3 months of age, followed by clinical confirmation of muscular dystrophy at 3 years. Skeletal biopsy staining at 4.7 years showed an absence of dystrophin protein which prompted extensive molecular testing over 4 years that included gene panels, targeted single-gene assays, arrays, and karyotyping, all of which failed to identify a clinically significant variant in the DMD gene. At 10 years of age, clinical whole-genome sequencing (cWGS) was performed, which revealed a novel hemizygous ~50.7 Mb balanced pericentric inversion on chromosome X that disrupts the DMD gene in both siblings, consistent with the muscular dystrophy phenotype. This inversion also impacts the upstream regulatory region of POU3F4, structural rearrangements which are known to cause hearing loss. The unaffected mother is a heterozygous carrier for the pericentric inversion. This finding illustrates the ability of cWGS to detect a wide breadth of disease-causing genomic variations including large genomic rearrangements.

POU6F2 mutation in humans with pubertal failure alters GnRH transcript expression.

Idiopathic hypogonadotropic hypogonadism (IHH) is characterized by the absence of pubertal development and subsequent impaired fertility often due to gonadotropin-releasing hormone (GnRH) deficits. Exome sequencing of two independent cohorts of IHH patients identified 12 rare missense variants in POU6F2 in 15 patients. POU6F2 encodes two distinct isoforms. In the adult mouse, expression of both isoform1 and isoform2 was detected in the brain, pituitary, and gonads. However, only isoform1 was detected in mouse primary GnRH cells and three immortalized GnRH cell lines, two mouse and one human. To date, the function of isoform2 has been verified as a transcription factor, while the function of isoform1 has been unknown. In the present report, bioinformatics and cell assays on a human-derived GnRH cell line reveal a novel function for isoform1, demonstrating it can act as a transcriptional regulator, decreasing GNRH1 expression. In addition, the impact of the two most prevalent POU6F2 variants, identified in five IHH patients, that were located at/or close to the DNA-binding domain was examined. Notably, one of these mutations prevented the repression of GnRH transcripts by isoform1. Normally, GnRH transcription increases as GnRH cells mature as they near migrate into the brain. Augmentation earlier during development can disrupt normal GnRH cell migration, consistent with some POU6F2 variants contributing to the IHH pathogenesis.

Therapeutic response to pazopanib: case report and literature review on molecular abnormalities of aggressive prolactinomas.

Introduction: Aggressive prolactinomas (APRLs) pose a significant clinical challenge due to their high rate of regrowth and potentially life-threatening complications. In this study, we present a case of a patient with an APRL who had a trial of multiple therapeutic modalities with the aim to provide a review of molecular abnormalities and management of APRLs by corroborating our experience with previous literature. Methods: A total of 268 articles were reviewed and 46 were included. Case reports and series, and studies that investigated the molecular and/or genetic analysis of APRLs were included. Special care was taken to include studies describing prolactinomas that would fall under the APRL subtype according to the European Society of Endocrinology guidelines; however, the author did not label the tumor as "aggressive" or "atypical". Addiontionally, we present a case report of a 56-year-old man presented with an invasive APRL that was resistant to multiple treatment modalities. Results: Literature review revealed multiple molecular abnormalities of APRLs including mutations in and/or deregulation of ADAMTS6, MMP-9, PITX1, VEGF, POU6F2, CDKN2A, and Rb genes. Mismatch repair genes, downregulation of microRNAs, and hypermethylation of specific genes including RASSF1A, p27, and MGMT were found to be directly associated with the aggressiveness of prolactinomas. APRL receptor analysis showed that low levels of estrogen receptor (ER) and an increase in somatostatin receptors (SSTR5) and epidermal growth factor receptors (EGFR) were associated with increased invasiveness and higher proliferation activity. Our patient had positive immunohistochemistry staining for PD-L1, MSH2, and MSH6, while microarray analysis revealed mutations in the CDKN2A and POU6F2 genes. Despite undergoing two surgical resections, radiotherapy, and taking dopamine agonists, the tumor continued to progress. The patient was administered pazopanib, which resulted in a positive response and the patient remained progression-free for six months. However, subsequent observations revealed tumor progression. The patient was started on PD-L1 inhibitor pembrolizumab, yet the tumor continued to progress. Conclusion: APRLs are complex tumors that require a multidisciplinary management approach. Knowledge of the molecular underpinnings of these tumors is critical for understanding their pathogenesis and identifying potential targets for precision medical therapy.

POU3F3-related disorder: Defining the phenotype and expanding the molecular spectrum.

POU3F3 variants cause developmental delay, behavioral problems, hypotonia and dysmorphic features. We investigated the phenotypic and genetic landscape, and genotype-phenotype correlations in individuals with POU3F3-related disorders. We recruited unpublished individuals with POU3F3 variants through international collaborations and obtained updated clinical data on previously published individuals. Trio exome sequencing or single exome sequencing followed by segregation analysis were performed in the novel cohort. Functional effects of missense variants were investigated with 3D protein modeling. We included 28 individuals (5 previously published) from 26 families carrying POU3F3 variants; 23 de novo and one inherited from an affected parent. Median age at study inclusion was 7.4 years. All had developmental delay mainly affecting speech, behavioral difficulties, psychiatric comorbidities and dysmorphisms. Additional features included gastrointestinal comorbidities, hearing loss, ophthalmological anomalies, epilepsy, sleep disturbances and joint hypermobility. Autism, hearing and eye comorbidities, dysmorphisms were more common in individuals with truncating variants, whereas epilepsy was only associated with missense variants. In silico structural modeling predicted that all (likely) pathogenic variants destabilize the DNA-binding region of POU3F3. Our study refined the phenotypic and genetic landscape of POU3F3-related disorders, it reports the functional properties of the identified pathogenic variants, and delineates some genotype-phenotype correlations.

Long noncoding RNA POU6F2-AS2 contributes to the aggressiveness of nonsmall-cell lung cancer via microRNA-125b-5p-mediated E2F3 upregulation.

The role of the majority of long noncoding RNAs (lncRNAs) in the progression of nonsmall-cell lung cancer (NSCLC) remains elusive, despite their potential value, thus warranting in-depth studies. For example, detailed functions of the lncRNA POU6F2 antisense RNA 2 (POU6F2-AS2) in NSCLC are unknown. Herein, we investigated the expression status of POU6F2-AS2 in NSCLC. Furthermore, we systematically delineated the biological roles of POU6F2-AS2 in NSCLC alongside its downstream molecular events. We measured the expression levels of POU6F2-AS2 using quantitative real-time polymerase chain reaction and performed a series of functional experiments to address its regulatory effects in NSCLC cells. Using bioinformatic platforms, RNA immunoprecipitation, luciferase reporter assays, and rescue experiments, we investigated the potential mechanisms of POU6F2-AS2 in NSCLC. Subsequently, we confirmed the remarkable overexpression of POU6F2-AS2 in NSCLC using The Cancer Genome Atlas database and our own cohort. Functionally, inhibiting POU6F2-AS2 decreased NSCLC cell proliferation, colony formation, and motility, whereas POU6F2-AS2 overexpression exhibited contrasting effects. Mechanistically, POU6F2-AS2 acts as an endogenous decoy for microRNA-125b-5p (miR-125b-5p) in NSCLC that causes the overexpression of the E2F transcription factor 3 (E2F3). Moreover, suppressing miR-125b-5p or increasing E2F3 expression levels sufficiently recovered the anticarcinostatic activities in NSCLC induced by POU6F2-AS2 silencing. Thus, POU6F2-AS2 aggravates the oncogenicity of NSCLC by targeting the miR-125b-5p/E2F3 axis. Our findings suggest that POU6F2-AS2 is a novel therapeutic target for NSCLC.

Hereditary etiology of non-syndromic sensorineural hearing loss in the Republic of North Ossetia-Alania.

More than 50% of congenital hearing loss is hereditary, in which the majority form is non-syndromic. In this study we estimate the most prevalent pathogenic genetic changes in an Ossetian cohort of patients. This is useful for local public health officials to promote genetic counseling of affected families with regard to high allele frequencies of prevalent pathogenic variants and assortative mating in the community of people with hearing loss. In this study, genetic heterogeneity of hereditary non-syndromic sensorineural hearing loss (NSNHL) in a cohort of 109 patients and an assessment of the frequency of two GJB2 gene pathogenic variants in a cohort of 349 healthy individuals from the populations of the Republic of North Ossetia-Alania (RNO-Alania) were assessed. The molecular genetic cause of NSNHL in the GJB2 gene in RNO-Alania was confirmed in ~30% of the cases, including ~27% in Ossetians. In Russian patients, the most frequent variant is GJB2:c.35delG (~83%). The GJB2:c.358_360delGAG variant was found to be the most frequent among Ossetians (~54%). Two genetic variants in GJB2, c.35delG and c.358_360delGAG, accounted for 91% of GJB2 pathogenic alleles in the Ossetian patients. A search for large genome rearrangements revealed etiological cause in two Ossetian patients, a deletion at the POU3F4 gene locus associated with X-linked hearing loss (type DFNX2). In another Ossetian patient, a biallelic pathogenic variant in the MYO15A gene caused hearing loss type DFNB3 was identified, and in one Russian family a heterozygous MYH14 gene variant associated with dominant NSNHL was found. Thus, the informative value of the diagnosis was ~37% among all patients with NSNHL from RNO-Alania and ~32% among the Ossetians. These estimates correspond to the literature data on the fraction of recessive genetic forms of hearing loss within the affected population. The importance of this study consists not only in the estimation of the most prevalent pathogenic genetic changes in the Ossetian cohort of patients which could be useful for the public health but also in the genetic counselling of the affected families with regard to the high allele frequencies of revealed pathogenic variants as well as to the assortative mating in community of people with hearing loss.

LncRNA POU6F2-AS2 contributes to malignant phenotypes and paclitaxel resistance by promoting SKP2 expression in stomach adenocarcinoma.

This study aimed to investigate the role and mechanism of POU6F2-AS2 in the development of gastric cancer. POU6F2-AS2 expression was considerably higher in clinical stomach adenocarcinoma (STAD) tissues and gastric cancer cell lines (MKN-28 and MGC-803) than in neighbouring normal tissues and gastric mucosa epithelial cells (GES-1). POU6F2-AS2 overexpression resulted in a low overall survival probability, progression-free survival probability and post progression survival probability, as well as increased cell viability, migration and invasion of gastric cancer cells, thereby inhibiting apoptosis. Based on RNA pull-down, cycloheximide and MG132 incubation experiments, POU6F2-AS2 promoted SKP2 by stabilizing NONO expression. In addition, in vivo silencing of POU6F2-AS2 in gastric cancer cells can inhibit tumour progression and produce a synergistic antitumour effect when combined with paclitaxel. POU6F2-AS2 is overexpressed in STAD, which is attributed to a bad prognosis. In vitro and in vivo experiments have confirmed that the POU6F2-AS2/NONO/SKP2 axis promotes STAD progression, and that the silencing of POU6F2-AS2 plays a synergistic antitumour effect when combined with paclitaxel. Therefore, POU6F2-AS2 may be potentially developed as a target to inhibit STAD and reduce chemoresistance.