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Caring for hospitalized patients with COVID-19 raises ethical dilemmas in which clinicians must weigh the unknown value of an intervention against the unknown risk of viral transmission. Current guidelines for delivering high-value care in the time of the COVID-19 pandemic do not directly address ethical dilemmas that arise from the unique concerns of individual patients. We propose an "ethical pause" in which clinicians address ethical dilemmas by taking time to ask three questions that invoke the major bioethical principles of beneficence, nonmaleficence, and distributive justice: will this intervention help my patient? Could this intervention harm my patient? Could this intervention harm or help others? Using two exemplar cases, we demonstrate how the process of deliberately asking and answering structured ethical questions is a mindful problem-solving strategy that facilitates delivery of high-value care. [ABSTRACT FROM AUTHOR]

Histones are among the most conserved proteins known, but organismal differences do exist. In this study, we examined the contribution that divergent amino acids within histone H3 make to cell growth and chromatin structure in Saccharomyces cerevisiae. We show that, while amino acids that define histone H3.3 are dispensable for yeast growth, substitution of residues within the histone H3 a3 helix with human counterparts results in a severe growth defect. Mutations within this domain also result in altered nucleosome positioning, both in vivo and in vitro, which is accompanied by increased preference for nucleosome-favoring sequences. These results suggest that divergent amino acids within the histone H3 a3 helix play organismal roles in defining chromatin structure. [ABSTRACT FROM AUTHOR]

Mammalian SWI/SNF chromatin remodeling complexes move and evict nucleosomes at gene promoters and enhancers to modulate DNA access. Although SWI/SNF subunits are commonly mutated in disease, therapeutic options are limited by our inability to predict SWI/SNF gene targets and conflicting studies on functional significance. Here, we leverage a fast-acting inhibitor of SWI/SNF remodeling to elucidate direct targets and effects of SWI/SNF. Blocking SWI/SNF activity causes a rapid and global loss of chromatin accessibility and transcription. Whereas repression persists at most enhancers, we uncover a compensatory role for the EP400/TIP60 remodeler, which reestablishes accessibility at most promoters during prolonged loss of SWI/SNF. Indeed, we observe synthetic lethality between EP400 and SWI/SNF in cancer cell lines and human cancer patient data. Our data define a set of molecular genomic features that accurately predict gene sensitivity to SWI/SNF inhibition in diverse cancer cell lines, thereby improving the therapeutic potential of SWI/SNF inhibitors., Competing Interests: Declaration of interests K.A. is a consultant to Syros Pharmaceuticals and Odyssey Therapeutics, is on the SAB of CAMP4 Therapeutics, and received research funding from Novartis not related to this work., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Transcription factor (TF)-mediated regulation of genes is often disrupted during carcinogenesis. The DNA methylation state of TF-binding sites may dictate transcriptional activity of corresponding genes. Stilbenoid polyphenols, such as pterostilbene (PTS), have been shown to exert anticancer action by remodeling DNA methylation and gene expression. However, the mechanisms behind these effects still remain unclear. Here, the dynamics between oncogenic TF OCT1 binding and de novo DNA methyltransferase DNMT3B binding in PTS-treated MCF10CA1a invasive breast cancer cells has been explored. Using chromatin immunoprecipitation (ChIP) followed by next generation sequencing, we determined 47 gene regulatory regions with decreased OCT1 binding and enriched DNMT3B binding in response to PTS. Most of those genes were found to have oncogenic functions. We selected three candidates, PRKCA, TNNT2, and DANT2, for further mechanistic investigation taking into account PRKCA functional and regulatory connection with numerous cancer-driving processes and pathways, and some of the highest increase in DNMT3B occupancy within TNNT2 and DANT2 enhancers. PTS led to DNMT3B recruitment within PRKCA, TNNT2, and DANT2 at loci that also displayed reduced OCT1 binding. Substantial decrease in OCT1 with increased DNMT3B binding was accompanied by PRKCA promoter and TNNT2 and DANT2 enhancer hypermethylation, and gene silencing. Interestingly, DNA hypermethylation of the genes was not detected in response to PTS in DNMT3B-CRISPR knockout MCF10CA1a breast cancer cells. It indicates DNMT3B-dependent methylation of PRKCA, TNNT2, and DANT2 upon PTS. Our findings provide a better understanding of mechanistic players and their gene targets that possibly contribute to the anticancer action of stilbenoid polyphenols., Competing Interests: Declaration of competing interests The authors declare no conflict of interest., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Recent work from Zhu et al. (2021) reveals that extrachromosomal DNA circles harboring enhancers can serve as mobile regulatory elements that interact with chromosomal oncogenes, stimulating high-level gene activity and contributing to tumor heterogeneity and cancer progression., (Copyright © 2021 Elsevier Inc. All rights reserved.)