METTL8 links mt-tRNA m3C modification to the HIF1α/RTK/Akt axis to sustain GBM stemness and tumorigenicity.

Epitranscriptomic RNA modifications are crucial for the maintenance of glioma stem cells (GSCs), the most malignant cells in glioblastoma (GBM). 3-methylcytosine (m3C) is a new epitranscriptomic mark on RNAs and METTL8 represents an m3C writer that is dysregulated in cancer. Although METTL8 has an established function in mitochondrial tRNA (mt-tRNA) m3C modification, alternative splicing of METTL8 can also generate isoforms that localize to the nucleolus where they may regulate R-loop formation. The molecular basis for METTL8 dysregulation in GBM, and which METTL8 isoform(s) may influence GBM cell fate and malignancy remain elusive. Here, we investigated the role of METTL8 in regulating GBM stemness and tumorigenicity. In GSC, METTL8 is exclusively localized to the mitochondrial matrix where it installs m3C on mt-tRNAThr/Ser(UCN) for mitochondrial translation and respiration. High expression of METTL8 in GBM is attributed to histone variant H2AZ-mediated chromatin accessibility of HIF1α and portends inferior glioma patient outcome. METTL8 depletion impairs the ability of GSC to self-renew and differentiate, thus retarding tumor growth in an intracranial GBM xenograft model. Interestingly, METTL8 depletion decreases protein levels of HIF1α, which serves as a transcription factor for several receptor tyrosine kinase (RTK) genes, in GSC. Accordingly, METTL8 loss inactivates the RTK/Akt axis leading to heightened sensitivity to Akt inhibitor treatment. These mechanistic findings, along with the intimate link between METTL8 levels and the HIF1α/RTK/Akt axis in glioma patients, guided us to propose a HIF1α/Akt inhibitor combination which potently compromises GSC proliferation/self-renewal in vitro. Thus, METTL8 represents a new GBM dependency that is therapeutically targetable.

Effective strategies for Fecal Immunochemical Tests (FIT) programs to improve colorectal cancer screening uptake among populations with limited access to the healthcare system: a rapid review.

BACKGROUND: Colorectal cancer (CRC) is one of the leading causes of cancer death globally. CRC screening can reduce the incidence and mortality of CRC. However, socially disadvantaged groups may disproportionately benefit less from screening programs due to their limited access to healthcare. This poor access to healthcare services is further aggravated by intersecting, cumulative social factors associated with their sociocultural background and living conditions. This rapid review systematically reviewed and synthesized evidence on the effectiveness of Fecal Immunochemical Test (FIT) programs in increasing CRC screening in populations who do not have a regular healthcare provider or who have limited healthcare system access. METHODS: We used three databases: Ovid MEDLINE, Embase, and EBSCOhost CINAHL. We searched for systematic reviews, meta-analysis, and quantitative and mixed-methods studies focusing on effectiveness of FIT programs (request or receipt of FIT kit, completion rates of FIT screening, and participation rates in follow-up colonoscopy after FIT positive results). For evidence synthesis, deductive and inductive thematic analysis was conducted. The findings were also classified using the Cochrane Methods Equity PROGRESS-PLUS framework. The quality of the included studies was assessed. RESULTS: Findings from the 25 included primary studies were organized into three intervention design-focused themes. Delivery of culturally-tailored programs (e.g., use of language and interpretive services) were effective in increasing CRC screening. Regarding the method of delivery for FIT, specific strategies combined with mail-out programs (e.g., motivational screening letter) or in-person delivery (e.g., demonstration of FIT specimen collection procedure) enhanced the success of FIT programs. The follow-up reminder theme (e.g., spaced out and live reminders) were generally effective. Additionally, we found evidence of the social determinants of health affecting FIT uptake (e.g., place of residence, race/ethnicity/culture/language, gender and/or sex). CONCLUSIONS: Findings from this rapid review suggest multicomponent interventions combined with tailored strategies addressing the diverse, unique needs and priorities of the population with no regular healthcare provider or limited access to the healthcare system may be more effective in increasing FIT screening. Decision-makers and practitioners should consider equity and social factors when developing resources and coordinating efforts in the delivery and implementation of FIT screening strategies.

Inflammasome Activation Mediates Apoptotic and Pyroptotic Death in Astrocytes Under Ischemic Conditions.

Inflammation is a hallmark mechanism of ischemic stroke-induced brain injury. Recent studies have shown that an intracellular multimeric protein complex known as an inflammasome is a key factor for inducing an inflammatory response, and apoptotic and pyroptotic cell death in ischemic stroke. Inflammasome assembly leads to the activation of pro-inflammatory caspases, and the maturation and secretion of pro-inflammatory cytokines IL-1ß and IL-18. While the role of inflammasomes in ischemic stroke-induced neuronal death, and microglial activation and cell death have been established, little is known about the role of inflammasomes in astrocytes under ischemic conditions. In this study, we investigated the expression and activation of inflammasome components in protoplasmic and fibrous astrocytes under ischemic conditions. We found that both protoplasmic and fibrous astrocytes expressed a differential increase in inflammasome protein components, and that their activation promoted maturation of IL-1ß and IL-18, and secretion of IL-1ß, as well as initiating apoptotic and pyroptotic cell death. Pharmacological inhibition of caspase-1 decreased expression of cleaved caspase-1 and production of mature IL-1ß, and protected against inflammasome-mediated apoptotic and pyroptotic cell death. Overall, this study provides novel insights into the role of inflammasome signaling in astrocytes under ischemic conditions.

CAMK2D serves as a molecular scaffold for RNF8-MAD2 complex to induce mitotic checkpoint in glioma.

MAD2 is a spindle assembly checkpoint protein that participates in the formation of mitotic checkpoint complex, which blocks mitotic progression. RNF8, an established DNA damage response protein, has been implicated in mitotic checkpoint regulation but its exact role remains poorly understood. Here, RNF8 proximity proteomics uncovered a role of RNF8-MAD2 in generating the mitotic checkpoint signal. Specifically, RNF8 competes with a small pool of p31comet for binding to the closed conformer of MAD2 via its RING domain, while CAMK2D serves as a molecular scaffold to concentrate the RNF8-MAD2 complex via transient/weak interactions between its p-Thr287 and RNF8's FHA domain. Accordingly, RNF8 overexpression impairs glioma stem cell (GSC) mitotic progression in a FHA- and RING-dependent manner. Importantly, low RNF8 expression correlates with inferior glioma outcome and RNF8 overexpression impedes GSC tumorigenicity. Last, we identify PLK1 inhibitor that mimics RNF8 overexpression using a chemical biology approach, and demonstrate a PLK1/HSP90 inhibitor combination that synergistically reduces GSC proliferation and stemness. Thus, our study has unveiled a previously unrecognized CAMK2D-RNF8-MAD2 complex in regulating mitotic checkpoint with relevance to gliomas, which is therapeutically targetable.

E2F and STAT3 provide transcriptional synergy for histone variant H2AZ activation to sustain glioblastoma chromatin accessibility and tumorigenicity.

The histone variant H2AZ is overexpressed in diverse cancer types where it facilitates the accessibility of transcriptional regulators to the promoters of cell cycle genes. However, the molecular basis for its dysregulation in cancer remains unknown. Here, we report that glioblastomas (GBM) and glioma stem cells (GSCs) preferentially overexpress H2AZ for their proliferation, stemness and tumorigenicity. Chromatin accessibility analysis of H2AZ2 depleted GSC revealed that E2F1 occupies the enhancer region within H2AZ2 gene promoter, thereby activating H2AZ2 transcription. Exploration of other H2AZ2 transcriptional activators using a customized "anti-H2AZ2" query signature for connectivity map analysis identified STAT3. Co-targeting E2F and STAT3 synergistically reduced the levels of H2AZ, histone 3 lysine 27 acetylation (H3K27ac) and cell cycle gene transcription, indicating that E2F1 and STAT3 synergize to activate H2AZ gene transcription in GSCs. Remarkably, an E2F/STAT3 inhibitor combination durably suppresses GSC tumorigenicity in an orthotopic GBM xenograft model. In glioma patients, high STAT3 signaling is associated with high E2F1 and H2AZ2 expression. Thus, GBM has uniquely opted the use of E2F1- and STAT3-containing "enhanceosomes" that integrate multiple signaling pathways to achieve H2AZ gene activation, supporting a translational path for the E2F/STAT3 inhibitor combination to be applied in GBM treatment.

A chemical biology approach reveals a dependency of glioblastoma on biotin distribution.

Glioblastoma (GBM) is a uniformly lethal disease driven by glioma stem cells (GSCs). Here, we use a chemical biology approach to unveil previously unknown GBM dependencies. By studying sulconazole (SN) with anti-GSC properties, we find that SN disrupts biotin distribution to the carboxylases and histones. Transcriptomic and metabolomic analyses of SN-treated GSCs reveal metabolic alterations that are characteristic of biotin-deficient cells, including intracellular cholesterol depletion, impairment of oxidative phosphorylation, and energetic crisis. Furthermore, SN treatment reduces histone biotinylation, histone acetylation, and expression of superenhancer-associated GSC critical genes, which are also observed when biotin distribution is genetically disrupted by holocarboxylase synthetase (HLCS) depletion. HLCS silencing impaired GSC tumorigenicity in an orthotopic xenograft brain tumor model. In GBM, high HLCS expression robustly indicates a poor prognosis. Thus, the dependency of GBM on biotin distribution suggests that the rational cotargeting of biotin-dependent metabolism and epigenetic pathways may be explored for GSC eradication.

Redox regulation of cell state and fate.

The failure in effective cancer treatment is thought to be attributed to a subpopulation of tumor cells with stem cell-like properties. These cancer stem cells (CSCs) are intimately linked to tumor initiation, heterogeneity, maintenance, recurrence and metastasis. Increasing evidence supports the view that a tight redox regulation is crucial for CSC proliferation, tumorigenicity, therapy resistance and metastasis in many cancer types. Since the distinct metabolic and epigenetic states of CSCs may influence ROS levels, and hence their malignancy, ROS modulating agents hold promise in their utility as anti-CSC agents that may improve the durability of current cancer treatments. This review will focus on (i) how ROS levels are regulated for CSCs to elicit their hallmark features; (ii) the link between ROS and metabolic plasticity of CSCs; and (iii) how ROS may interface with epigenetics that would enable CSCs to thrive in a stressful tumor microenvironment and survive therapeutic insults.

Degree of Unsaturation and Backbone Orientation of Amphiphilic Macromolecules Influence Local Lipid Properties in Large Unilamellar Vesicles.

Liposomes have become increasingly common in the delivery of bioactive agents due to their ability to encapsulate hydrophobic and hydrophilic drugs with excellent biocompatibility. While commercial liposome formulations improve bioavailability of otherwise quickly eliminated or insoluble drugs, tailoring formulation properties for specific uses has become a focus of liposome research. Here, we report the design, synthesis, and characterization of two series of amphiphilic macromolecules (AMs), consisting of acylated polyol backbones conjugated to poly(ethylene glycol) (PEG) that can serve as the sole additives to stabilize and control hydrophilic molecule release rates from distearoylphosphatidylcholine (DSPC)-based liposomes. As compared to DSPC alone, all AMs enable liposome formation and stabilize their colloidal properties at low incorporation ratios, and the AM's degree of unsaturation and hydrophobe conformation have profound impacts on stability duration. The AM's chemical structures, particularly hydrophobe unsaturation, also impact the rate of hydrophilic drug release. Course-grained molecular dynamics simulations were utilized to better understand the influence of AM structure on lipid properties and potential liposomal stabilization. Results indicate that both hydrophobic domain structure and PEG density can be utilized to fine-tune liposome properties for the desired application. Collectively, AMs demonstrate the potential to simultaneously stabilize and control the release profile of hydrophilic cargo.

El agotamiento emocional está asociado con factores estresantes relacionados con el trabajo: Estudio multicéntrico y transversal en hospitales públicos de Malasia / Emotional exhaustion is associated with work related stressors: a cross-sectional multicenter study in Malaysian public hospitals

Introducción. El agotamiento emocional es un componente importante del síndrome de burnout (desgaste profesional). El burnout es común entre los médicos. Afecta su salud física y mental, su rendimiento y la calidad de la atención que brindan. Este estudio tuvo como propósito investigar el nivel y los factores asociados con el agotamiento emocional en los médicos pediatras, en Malasia. Población y métodos. Eneste estudiomulticéntrico y transversal se utilizó un cuestionario autoadministrado, que incluía preguntas acerca de las características sociodemográficas y laborales, el agotamiento emocional, la escala de estrés percibido y las fuentes laborales de estrés. Con el software SPSS, se llevaron a cabo análisis descriptivos, univariantes y multivariantes. Resultados. Un total de 197 médicos de los departamentos de pediatría de ocho hospitales respondieron el cuestionario. El 25,4% y el 24,4% de los médicos informaron, respectivamente, agotamiento emocional alto y moderado. En el análisis bivariante, 29 de las 38 opciones correspondientes a fuentes de estrés mostraron una asociación importante con el agotamiento emocional (p < 0,05). En el análisis multivariante, los predictores importantes de agotamiento emocional fueron: puntajes más altos en la escala del estrés percibido, abordaje de problemas psicosociales de los pacientes, falta de cortesía en las interacciones con colegas/subordinados, falta de reconocimiento de parte de los superiores, falta de incentivos y promociones, trabajo bajo presión del tiempo y necesidad de cumplir con los plazos, y establecimiento de metas inaccesibles o autoimposición de ese tipo de metas (p < 0,05). La fuente de estrés mencionada con mayor frecuencia fue el trato con padres difíciles (80,2%). Conclusiones. El agotamiento emocional está asociado con fuentes de estrés en el entorno laboral pero no con factores sociodemográficos.

Introduction. Emotional exhaustion is an important component of burnout. Burnout is common among doctors. It affects the physical and mental health of doctors, their performance and the quality of care they provide. This study aimed to investigate the level and factors associated with emotional exhaustion among doctors in pediatric practice in Malaysia. Population and methods. A self-administered questionnaire was used in this multicenter cross-sectional study. It included questions on the socio-demographics, work characteristics, Emotional Exhaustion, Perceived Stress Scale and sources of job stress. Descriptive, univariate and multivariate analysis were conducted using the SPSS software. Results. A total of 197 doctors working in the Pediatric department in eight hospitals returned complete questionnaire. High and moderate emotional exhaustion was reported by 25.4% and 24.4% doctors, respectively. In bivariate analysis, 29 out of the 38 items of sources of stress showed significant association with emotional exhaustion (p <0.05).The significant predictors of emotional exhaustion in the multivariate analysis were: scoring higher on the Perceived Stress Score, dealing with patient's psychosocial problems, disrespectful interactions with colleagues/subordinates, lack of appreciation from supervisors, lack of incentives and promotions, time pressures and deadlines to meet, and setting unrealistic goals of having them imposed on oneself (p <0.05). The most common source of stress was dealing with difficult parents (80.2%). Conclusions. Emotional exhaustion is associated with sources of stress in the workplace but not with socio-demographic factors.

Emotional exhaustion is associated with work related stressors: a cross-sectional multicenter study in Malaysian public hospitals. / El agotamiento emocional está asociado con factores estresantes relacionados con el trabajo: Estudio multicéntrico y transversal en hospitales públicos de Malasia.

INTRODUCTION: Emotional exhaustion is an important component of burnout. Burnout is common among doctors. It affects the physical and mental health of doctors, their performance and the quality of care they provide. This study aimed to investigate the level and factors associated with emotional exhaustion among doctors in pediatric practice in Malaysia. POPULATION AND METHODS: A self-administered questionnaire was used in this multicenter cross-sectional study. It included questions on the socio-demographics, work characteristics, Emotional Exhaustion, Perceived Stress Scale and sources of job stress. Descriptive, univariate and multivariate analysis were conducted using the SPSS software. RESULTS: A total of 197 doctors working in the Pediatric department in eight hospitals returned complete questionnaire. High and moderate emotional exhaustion was reported by 25.4% and 24.4% doctors, respectively. In bivariate analysis, 29 out of the 38 items of sources of stress showed significant association with emotional exhaustion (p <0.05).The significant predictors of emotional exhaustion in the multivariate analysis were: scoring higher on the Perceived Stress Score, dealing with patient's psychosocial problems, disrespectful interactions with colleagues/ subordinates, lack of appreciation from supervisors, lack of incentives and promotions, time pressures and deadlines to meet, and setting unrealistic goals of having them imposed on oneself (p <0.05). The most common source of stress was dealing with difficult parents (80.2%). CONCLUSIONS: Emotional exhaustion is associated with sources of stress in the workplace but not with socio-demographic factors.

INTRODUCCIÓN: El agotamiento emocional es un componente importante del síndrome de burnout (desgaste profesional). El burnout es común entre los médicos. Afecta su salud física y mental, su rendimiento y la calidad de la atención que brindan. Este estudio tuvo como propósito investigar el nivel y los factores asociados con el agotamiento emocional en los médicos pediatras, en Malasia. POBLACIÓN Y MÉTODOS: Eneste estudiomulticéntrico y transversal se utilizó un cuestionario autoadministrado, que incluía preguntas acerca de las características sociodemográficas y laborales, el agotamiento emocional, la escala de estrés percibido y las fuentes laborales de estrés. Con el software SPSS, se llevaron a cabo análisis descriptivos, univariantes y multivariantes. RESULTADOS: Un total de 197 médicos de los departamentos de pediatría de ocho hospitales respondieron el cuestionario. El 25,4% y el 24,4% de los médicos informaron, respectivamente, agotamiento emocional alto y moderado. En el análisis bivariante, 29 de las 38 opciones correspondientes a fuentes de estrés mostraron una asociación importante con el agotamiento emocional (p < 0,05). En el análisis multivariante, los predictores importantes de agotamiento emocional fueron: puntajes más altos en la escala del estrés percibido, abordaje de problemas psicosociales de los pacientes, falta de cortesía en las interacciones con colegas/subordinados, falta de reconocimiento de parte de los superiores, falta de incentivos y promociones, trabajo bajo presión del tiempo y necesidad de cumplir con los plazos, y establecimiento de metas inaccesibles o autoimposición de ese tipo de metas (p < 0,05). La fuente de estrés mencionada con mayor frecuencia fue el trato con padres difíciles (80,2%). CONCLUSIONES: El agotamiento emocional está asociado con fuentes de estrés en el entorno laboral pero no con factores sociodemográficos.