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Abstract Genes encoding subunits of SWI/SNF (BAF) chromatin remodeling complexes are mutated in nearly 25% of cancers. To gain insight into the mechanisms by which SWI/SNF mutations drive cancer, we contributed ten rhabdoid tumor (RT) cell lines mutant for SWI/SNF subunit SMARCB1 to a genome-scale CRISPR–Cas9 depletion screen performed across 896 cell lines. We identify PHF6 as specifically essential for RT cell survival and demonstrate that dependency on Phf6 extends to Smarcb1-deficient cancers in vivo. As mutations in either SWI/SNF or PHF6 can cause the neurodevelopmental disorder Coffin-Siris syndrome, our findings of a dependency suggest a previously unrecognized functional link. We demonstrate that PHF6 co-localizes with SWI/SNF complexes at promoters, where it is essential for maintenance of an active chromatin state. We show that in the absence of SMARCB1, PHF6 loss disrupts the recruitment and stability of residual SWI/SNF complex members, collectively resulting in the loss of active chromatin at promoters and stalling of RNA Polymerase II progression. Our work establishes a mechanistic basis for the shared syndromic features of SWI/SNF and PHF6 mutations in CSS and the basis for selective dependency on PHF6 in SMARCB1-mutant cancers.

Proneural gliomas are brain tumors characterized by enrichment of oligodendrocyte progenitor cell (OPC) transcripts and genetic alterations. In this study we sought to identify transcriptional and epigenetic differences between OPCs with Trp53 deletion and PDGF-BB overexpression (BB-p53n) and those carrying only p53 deletion (p53n). In culture, the BB-p53n OPCs display growth characteristics more similar to glioma cells than p53n OPCs. When injected in mouse brains, BB-p53n OPC form tumors, while the p53n OPCs do not. Unbiased histone proteomics and transcriptomic analysis on these OPC populations identified higher levels of the histone H3K27me3 mark and lower levels of the histone H4K20me3. The transcriptome of the BB-p53n OPCs was characterized by higher levels of transcripts related to proliferation and cell adhesion compared to p53n OPCs. Pharmacological inhibition of the enzyme responsible for histone H3K27 trimethylation (EZH2i) in BB-p53n OPCs, reduced cell cycle transcripts and increased the expression of differentiation markers, but was not sufficient to restore their growth characteristics. This suggests that PDGF-BB overexpression in p53n OPCs favors the early stages of transformation, by promoting proliferation and halting differentiation in a H3K27me3-dependent pathway, and favoring growth characteristics in a H3K27me3 independent manner

Schizophrenia (SZ) is a severe psychiatric disorder; unfortunately, only ~1/3 of patients respond favorably to treatment. Here, the authors reveal hyperacetylation of histone H2A.Z in SZ neurons and postmortem SZ human brain tissues. They further show BRD4 is a reader of hyperacetylated H2A.Z and treatment with bromodomain inhibitor JQ1 largely rescues abnormal gene expression associated with SZ.

Evidence for sperm small noncoding RNA-mediated intergenerational transmission implies communication from responsive somatic cells to sperm. Here, authors show that epididymal cells alter extracellular vesicle cargo after stress exposure, to impact offspring neurodevelopment and stress reactivity.

K2P potassium channels are known to be modulated by volatile anesthetic (VA) drugs and play important roles in clinically relevant effects that accompany general anesthesia. Here, we utilize a photoaffinity analog of the VA isoflurane to identify a VA-binding site in the TREK1 K2P channel. The functional importance of the identified site was validated by mutagenesis and biochemical modification. Molecular dynamics simulations of TREK1 in the presence of VA found multiple neighboring residues on TREK1 TM2, TM3, and TM4 that contribute to anesthetic binding. The identified VA-binding region contains residues that play roles in the mechanisms by which heat, mechanical stretch, and pharmacological modulators alter TREK1 channel activity and overlaps with positions found to modulate TASK K2P channel VA sensitivity. Our findings define molecular contacts that mediate VA binding to TREK1 channels and suggest a mechanistic basis to explain how K2P channels are modulated by VAs.

Summary: Naked mole rat (NMR) is a valuable model for aging and cancer research due to its exceptional longevity and cancer resistance. We observed that the reprogramming efficiency of NMR fibroblasts in response to OSKM was drastically lower than that of mouse fibroblasts. Expression of SV40 LargeT antigen (LT) dramatically improved reprogramming of NMR fibroblasts. Inactivation of Rb alone, but not p53, was sufficient to improve reprogramming efficiency, suggesting that NMR chromatin may be refractory to reprogramming. Analysis of the global histone landscape revealed that NMR had higher levels of repressive H3K27 methylation marks and lower levels of activating H3K27 acetylation marks than mouse. ATAC-seq revealed that in NMR, promoters of reprogramming genes were more closed than mouse promoters, while expression of LT led to massive opening of the NMR promoters. These results suggest that NMR displays a more stable epigenome that resists de-differentiation, contributing to the cancer resistance and longevity of this species. : Tan et al. show that a more stable epigenome contributes to the resistance of NMR iPSCs to OSKM reprogramming. Reprogramming is facilitated by inactivation of Rb, which leads to opening of promoters of reprogramming genes. Keywords: naked mole rat, iPS cells, epigenome

A number of histone lysine modifications related to acetylation have been identified, but their functional significance is unclear. Here, the authors use in vitro and in vivo assays to characterize eight acyl histone post-translational modifications and link their abundance with metabolism.

Although non-small cell lung cancer (NSCLC) patients benefit from standard taxane-platin chemotherapy, many relapse, developing drug resistance. We established preclinical taxane-platin-chemoresistance models and identified a 35-gene resistance signature, which was associated with poor recurrence-free survival in neoadjuvant-treated NSCLC patients and included upregulation of the JumonjiC lysine demethylase KDM3B. In fact, multi-drug-resistant cells progressively increased the expression of many JumonjiC demethylases, had altered histone methylation, and, importantly, showed hypersensitivity to JumonjiC inhibitors in vitro and in vivo. Increasing taxane-platin resistance in progressive cell line series was accompanied by progressive sensitization to JIB-04 and GSK-J4. These JumonjiC inhibitors partly reversed deregulated transcriptional programs, prevented the emergence of drug-tolerant colonies from chemo-naive cells, and synergized with standard chemotherapy in vitro and in vivo. Our findings reveal JumonjiC inhibitors as promising therapies for targeting taxane-platin-chemoresistant NSCLCs.

Summary: Global changes in chromatin organization and the cessation of transcription during mitosis are thought to challenge the resumption of appropriate transcription patterns after mitosis. The acetyl-lysine binding protein BRD4 has been previously suggested to function as a transcriptional “bookmark” on mitotic chromatin. Here, genome-wide location analysis of BRD4 in erythroid cells, combined with data normalization and peak characterization approaches, reveals that BRD4 widely occupies mitotic chromatin. However, removal of BRD4 from mitotic chromatin does not impair post-mitotic activation of transcription. Additionally, histone mass spectrometry reveals global preservation of most posttranslational modifications (PTMs) during mitosis. In particular, H3K14ac, H3K27ac, H3K122ac, and H4K16ac widely mark mitotic chromatin, especially at lineage-specific genes, and predict BRD4 mitotic binding genome wide. Therefore, BRD4 is likely not a mitotic bookmark but only a “passenger.” Instead, mitotic histone acetylation patterns may constitute the actual bookmarks that restore lineage-specific transcription patterns after mitosis. : Chromatin reader protein BRD4 is thought to bookmark mitotic chromatin to propagate transcriptional states across mitosis. Behera et al. profiled and perturbed mitotic BRD4 chromatin occupancy to show that BRD4 is dispensable for this process. Instead, BRD4 mitotic chromatin association is likely a mere reflection of mitotically stable histone marks. Keywords: erythroid cells, mitotic bookmarking, mitosis, cell identity, BRD4, histone marks

Disconnection can be a pathophysiological mechanism in language disorders. We report three cases where disconnection is postulated as a causative factor for the aphasic syndromes. These are alexia without agraphia, conduction aphasia and aphasia. The pathophysiology is discussed and the :neural network" theory of brain function highlighted.

One hundred and sixty subjects in the general population were studied for the possible role of ABO blood groups in the infection and asymptomatic carriage rate of Pityrosporum ovale. Out of 160, 149 were positive for P. ovale in culture. Of them, 57 had dandruff and 6 had seborrhoic dermatitis. The remaining 86 were harbouring P. ovale asymptomatically. The rate of infection was almost in identical proportion with the rate of asymptomatic carrier state of P.ovale. Our study also revelated that blood group O subjects may be the most susceptible, followed by AB group. The incidence of dandruff was relatively high in males when compared to females.

Diabetes Mellitus (DM) is a persistent metabolic disorder characterised by elevated glucose concentration in blood. Approximately, 422 million individuals globally suffer from diabetes, with the majority residing among middle-class and lower-class countries as per the reports of World Health Organisation (WHO) 2023. Strict blood sugar control in conjunction with high-dose insulin therapy might potentially prevent or delay the progression of microvascular issues, lower overall mortality, and lessen the chance of macrovascular problems. These conclusions were supported by the Diabetes Control and Complications Trial and the large longitudinal investigation known as the epidemiology of diabetes and its complications. Numerous drugs and receptors involved in glucose metabolism are currently being used to treat diabetes, including a-Glucosidase inhibitors, dopamine D-2 agonists, biguanides, glinides, amylin analogues, Peroxisome Proliferator-activated Receptors (PPARs), Glucagon-like Peptide-1 (GLP-1), and biguanides. Due to the associated side effects and the financial difficulties in obtaining traditional antidiabetic regimens, the current review has placed a higher priority on investigating novel molecular targets for the development of antidiabetic medications intended to manage the progression of the illness. This emphasises how important it is to find new molecular targets associated with the illness's onset instead of only treating its symptoms or outward signs. [ABSTRACT FROM AUTHOR]