PHF2 regulates genome topology and DNA replication in neural stem cells via cohesin.

Cohesin plays a crucial role in the organization of topologically-associated domains (TADs), which influence gene expression and DNA replication timing. Whether epigenetic regulators may affect TADs via cohesin to mediate DNA replication remains elusive. Here, we discover that the histone demethylase PHF2 associates with RAD21, a core subunit of cohesin, to regulate DNA replication in mouse neural stem cells (NSC). PHF2 loss impairs DNA replication due to the activation of dormant replication origins in NSC. Notably, the PHF2/RAD21 co-bound genomic regions are characterized by CTCF enrichment and epigenomic features that resemble efficient, active replication origins, and can act as boundaries to separate adjacent domains. Accordingly, PHF2 loss weakens TADs and chromatin loops at the co-bound loci due to reduced RAD21 occupancy. The observed topological and DNA replication defects in PHF2 KO NSC support a cohesin-dependent mechanism. Furthermore, we demonstrate that the PHF2/RAD21 complex exerts little effect on gene regulation, and that PHF2's histone-demethylase activity is dispensable for normal DNA replication and proliferation of NSC. We propose that PHF2 may serve as a topological accessory to cohesin for cohesin localization to TADs and chromatin loops, where cohesin represses dormant replication origins directly or indirectly, to sustain DNA replication in NSC.

Histone variant H3.3 promotes metastasis in alveolar rhabdomyosarcoma.

The relatively quiet mutational landscape of rhabdomyosarcoma (RMS) suggests that epigenetic deregulation could be central to oncogenesis and tumour aggressiveness. Histone variants have long been recognised as important epigenetic regulators of gene expression. However, the role of histone variants in RMS has not been studied hitherto. In this study, we show that histone variant H3.3 is overexpressed in alveolar RMS (ARMS), an aggressive subtype of RMS. Functionally, knockdown of H3F3A, which encodes for H3.3, significantly impairs the ability of ARMS cells to undertake migration and invasion and reduces Rho activation. In addition, a striking reduction in metastatic tumour burden and improved survival is apparent in vivo. Using RNA-sequencing and ChIP-sequencing analyses, we identified melanoma cell adhesion molecule (MCAM/CD146) as a direct downstream target of H3.3. Loss of H3.3 resulted in a reduction in the presence of active marks and an increase in the occupancy of H1 at the MCAM promoter. Cell migration and invasion were rescued in H3F3A-depleted cells through MCAM overexpression. Moreover, we identified G9a, a lysine methyltransferase encoded by EHMT2, as an upstream regulator of H3F3A. Therefore, this study identifies a novel H3.3 dependent axis involved in ARMS metastasis. These findings establish the potential of MCAM as a therapeutic target for high-risk ARMS patients. © 2022 The Pathological Society of Great Britain and Ireland.

Maneuvering through Life with Positivity: Estimating the Effects of Foster Youth's Appraisal on Coping Styles.

Youth in foster care tend to experience a disproportional number of adverse life experiences and demonstrate high rates of emotional and behavioral difficulties. According to the transactional model of stress and coping, how youth appraise their experiences influences the type of coping strategies they use in response to adversity, and these relations are key components to understanding later adjustment. However, few studies have examined potential effects of appraisal on coping for youth in foster care. Furthermore, it is not well understood if or how such interaction may vary across age. To address this gap, this study examined potential age moderation of contemporaneous primary, threat-based appraisal effects on coping in a large sample of 490 youth in foster care (48% female, ages 8 to 18) using a series of statistical models which were capable of detecting very general forms of effect moderation. Results indicated that primary appraisal positively predicted direct and prosocial coping, and negatively predicted asocial coping. The linear effects of appraisal on coping did not vary based on age of the youth. The findings suggest that primary appraisals of life events for youth in foster care does have a unique influence on certain coping styles, suggesting perhaps new directions for research on youth exposed to multiple adversities. To promote wider use of the non-parametric time-varying effect model in R, the analysis syntax is also included in the appendix.

Measuring the Multidimensional Construct of Pornography: A Long and Short Version of the Pornography Usage Measure.

With the increase in the availability and usage of pornography, the research on the effects of pornography has also increased. This research has uncovered several controversies in the field regarding how pornography usage influences attitudes, sexual behaviors, and relationships. However, many of the measures of pornography are problematic as there is often little reliability and validity information for them and it is not clear that participants in these research studies are referring to the same types of materials when they answer pornography usage questions. Consequently, many of the research findings are suspect and it is crucial to develop reliable and valid scales to measure general pornography usage. In this study, we present both a 20-item and a 7-item version of the Pornography Usage Measure (PUM) that is based on extensive previous research on what types of materials individuals consider pornographic and that indicates pornography is a multidimensional construct. We evaluated the reliability and validity of both versions by using an MTurk sample of 934 males and 705 females (N =1639 total) to conduct confirmatory factor analyses, item response analyses, and structural equation model analyses. These analyses demonstrated that there were adequate reliability and early evidence for content, construct, concurrent, and predictive validity for both versions of the PUM. This measure could improve the quality of future research on pornography by providing more consistency between different studies about what is being measured when individuals indicate their pornography usage patterns.

Sexual Passion in Committed Relationships: Measurement and Conceptual Issues.

The purpose of this study is to discuss the need for a new triadic model of sexual passion in relationships and to present the preliminary psychometric properties of a scale designed to measure these three approaches to passion (harmonious, obsessive, and inhibited) for use in clinical and scholarly work. Existing theory and measures of general passion are based on a dualistic model of passion that includes the harmonious and obsessive approaches to passion. We added the inhibited approach to passion from the sexuality research and develop measures for assessing sexual passion in relationships. We utilized an Amazon Mechanical Turk sample of 1,421 individuals in committed relationships to test this measure. Reliability analyses and confirmatory factory analyses evinced that these three approaches to sexual passion were unique constructs and distinct from sexual satisfaction. Sexual passion showed predictive validity above and beyond relationship length, sexual desire toward a partner, and a broader variable of sexual drive. Harmonious sexual passion robustly predicted higher sexual satisfaction and relationship satisfaction, and inhibited sexual passion moderately predicted lower sexual satisfaction and relationship satisfaction. Obsessive sexual passion had minimal associations with either outcome. These new constructs, especially harmonious and inhibited sexual passion, may help scholars and practitioners improve their understanding of sexual satisfaction and overall relationship satisfaction.

El propósito de este artículo es debatir la necesidad de un nuevo modelo triádico de pasión sexual en las relaciones y presentar las propiedades psicométricas preliminares de una escala diseñada para medir estos tres enfoques de la pasión (armonioso, obsesivo e inhibido) a fin de usarlos en trabajos clínicos y académicos. La teoría y las escalas actuales de la pasión en general se basan en un modelo dualista de la pasión que incluye los enfoques armonioso y obsesivo de la pasión. Nosotros agregamos el enfoque inhibido de la pasión a partir de la investigación sobre sexualidad y desarrollamos escalas para evaluar la pasión sexual en las relaciones. Utilizamos una muestra de Amazon Mechanical Turk de 1421 personas en relaciones de pareja estables para probar esta escala. Los análisis de fiabilidad y los análisis factoriales confirmatorios demostraron que estos tres enfoques de la pasión sexual eran constructos únicos y diferentes de la satisfacción sexual. La pasión sexual demostró validez predictiva más allá de la duración de la relación, el deseo sexual hacia una pareja y una variable más amplia de impulso sexual. La pasión sexual armoniosa predijo sólidamente mayor satisfaccion sexual y satisfacción con la relación, la pasión sexual inhibida predijo moderadamente menor satisfacción sexual y satisfacción con la relación. La pasión sexual obsesiva tuvo asociaciones mínimas con ambos criterios. Estos nuevos constructos, especialmente la pasión sexual armoniosa y la inhibida, pueden ayudar a los investigadores y a los profesionales a mejorar su comprensión de la la satisfacción sexual y de la satisfacción con la relación en general.

Evaluating the Dimensionality of Pornography.

Pornography may be a construct with a single trait or one with many traits. Research in the past was inconsistent in this regard with most researchers assuming that pornography was unidimensional (with one single trait of pornography). However, the considerable amounts of residual variation found in these studies beyond that explained by the single trait hints at what might be a multidimensional construct (with multiple traits such as sensitization and differentiation). Consequently, in this study, we intended to address the question of whether pornography consisted of a single trait or if it was multidimensional. Using MTurk, 2173 participants from the United States and the Commonwealth of Nations (in which pornography is not strictly illegal) were recruited and asked to rate how pornographic they thought a list of different depictions were. The data were analyzed utilizing the cross-validation procedure in which two subsamples were created from the main sample and one was used to establish the model building and the other to validate the model. Various models, including first-order and higher-order exploratory and confirmatory factor models, were tested. Results indicated that a bi-factor (multidimensional) model generated the best model fit, and that it was most appropriate to consider pornography multidimensional. The final model contained two dimensions ("Sensitization" and "Differentiation"). While sensitization revealed the participants' general tendency to rate all items to be more or less pornographic, differentiation revealed the participants' tendency to differentiate highly pornographic items from less pornographic items. Based on the findings of this study, we suggest that future research on the usage and effects of pornography be conducted while taking into consideration the multidimensional nature of pornography.

Mitochondrial calcium uptake regulates tumour progression in embryonal rhabdomyosarcoma.

Embryonal rhabdomyosarcoma (ERMS) is characterised by a failure of cells to complete skeletal muscle differentiation. Although ERMS cells are vulnerable to oxidative stress, the relevance of mitochondrial calcium homoeostasis in oncogenesis is unclear. Here, we show that ERMS cell lines as well as primary tumours exhibit elevated expression of the mitochondrial calcium uniporter (MCU). MCU knockdown resulted in impaired mitochondrial calcium uptake and a reduction in mitochondrial reactive oxygen species (mROS) levels. Phenotypically, MCU knockdown cells exhibited reduced cellular proliferation and motility, with an increased propensity to differentiate in vitro and in vivo. RNA-sequencing of MCU knockdown cells revealed a significant reduction in genes involved in TGFß signalling that play prominent roles in oncogenesis and inhibition of myogenic differentiation. Interestingly, modulation of mROS production impacted TGFß signalling. Our study elucidates mechanisms by which mitochondrial calcium dysregulation promotes tumour progression and suggests that targeting the MCU complex to restore mitochondrial calcium homoeostasis could be a therapeutic avenue in ERMS.

Mitochondrial Dysfunction at the Center of Cancer Therapy.

Significance: Mitochondria undergo constant morphological changes through fusion, fission, and mitophagy. As the key organelle in cells, mitochondria are responsible for numerous essential cellular functions such as metabolism, regulation of calcium (Ca2+), generation of reactive oxygen species, and initiation of apoptosis. Unsurprisingly, mitochondrial dysfunctions underlie many pathologies including cancer. Recent Advances: Currently, the gold standard for cancer treatment is chemotherapy, radiation, and surgery. However, the efficacy of these treatments varies across different cancer cells. It has been suggested that mitochondria may be at the center of these diverse responses. In the past decade, significant advances have been made in understanding distinct types of mitochondrial dysfunctions in cancer. Through investigations of underlying mechanisms, more effective treatment options are developed. Critical Issues: We summarize various mitochondria dysfunctions in cancer progression that have led to the development of therapeutic options. Current mitochondrial-targeted therapies and challenges are discussed. Future Directions: To address the "root" of cancer, utilization of mitochondrial-targeted therapy to target cancer stem cells may be valuable. Investigation of other areas such as mitochondrial trafficking may offer new insights into cancer therapy. Moreover, common antibiotics could be explored as mitocans, and synthetic lethality screens can be utilized to overcome the plasticity of cancer cells.

Genetics, epigenetics and redox homeostasis in rhabdomyosarcoma: Emerging targets and therapeutics.

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma accounting for 5-8% of malignant tumours in children and adolescents. Children with high risk disease have poor prognosis. Anti-RMS therapies include surgery, radiation and combination chemotherapy. While these strategies improved survival rates, they have plateaued since 1990s as drugs that target differentiation and self-renewal of tumours cells have not been identified. Moreover, prevailing treatments are aggressive with drug resistance and metastasis causing failure of several treatment regimes. Significant advances have been made recently in understanding the genetic and epigenetic landscape in RMS. These studies have identified novel diagnostic and prognostic markers and opened new avenues for treatment. An important target identified in high throughput drug screening studies is reactive oxygen species (ROS). Indeed, many drugs in clinical trials for RMS impact tumour progression through ROS. In light of such emerging evidence, we discuss recent findings highlighting key pathways, epigenetic alterations and their impacts on ROS that form the basis of developing novel molecularly targeted therapies in RMS. Such targeted therapies in combination with conventional therapy could reduce adverse side effects in young survivors and lead to a decline in long-term morbidity.