The proximity interactome of PML isoforms I and II under fatty acid stress.

Promyelocytic leukemia (PML) protein forms the scaffold for PML nuclear bodies (PML NB) that reorganize into Lipid-Associated PML Structures (LAPS) under fatty acid stress. We determined how the fatty acid oleate alters the interactome of PMLI or PMLII by expressing fusions with the ascorbate peroxidase APEX2 in U2OS cells. The resultant interactome included ESCRT and COPII transport protein nodes.

SUMO promotes DNA repair protein collaboration to support alternative telomere lengthening in the absence of PML.

The alternative lengthening of telomeres (ALT) pathway maintains telomere length in a significant fraction of cancers that are associated with poor clinical outcomes. A better understanding of ALT mechanisms is therefore necessary for developing new treatment strategies for ALT cancers. SUMO modification of telomere proteins contributes to the formation of ALT telomere-associated PML bodies (APBs), in which telomeres are clustered and DNA repair proteins are enriched to promote homology-directed telomere DNA synthesis in ALT.

Nuclear lipid droplets in Caco2 cells originate from nascent precursors and in situ at the nuclear envelope.

Intestinal epithelial cells convert excess fatty acids into triglyceride (TAG) for storage in cytoplasmic lipid droplets and secretion in chylomicrons. Nuclear lipid droplets (nLDs) are present in intestinal cells but their origin and relationship to cytoplasmic TAG synthesis and secretion is unknown. nLDs and related lipid-associated promyelocytic leukemia structures (LAPS) were abundant in oleate-treated Caco2 but less frequent in other human colorectal cancer cell lines and mouse intestinal organoids.

SUMO Promotes DNA Repair Protein Collaboration to Support Alterative Telomere Lengthening in the Absence of PML.

Alternative lengthening of telomeres (ALT) pathway maintains telomeres in a significant fraction of cancers associated with poor clinical outcomes. A better understanding of ALT mechanisms can provide a basis for developing new treatment strategies for ALT cancers. SUMO modification of telomere proteins plays a critical role in the formation of ALT telomere-associated PML bodies (APBs), where telomeres are clustered and DNA repair proteins are enriched to promote homology-directed telomere DNA synthesis in ALT.

Lipid- and phospho-regulation of CTP:Phosphocholine Cytidylyltransferase α association with nuclear lipid droplets.

Fatty acids stored in triacylglycerol-rich lipid droplets are assembled with a surface monolayer composed primarily of phosphatidylcholine (PC). Fatty acids stimulate PC synthesis by translocating CTP:phosphocholine cytidylyltransferase (CCT) α to the inner nuclear membrane, nuclear lipid droplets (nLD) and lipid associated promyelocytic leukemia (PML) structures (LAPS). Huh7 cells were used to identify how CCTα translocation onto these nuclear structures are regulated by fatty acids and phosphorylation of its serine-rich P-domain.

From biosynthesis and beyond-Loss or overexpression of the cytokinin synthesis gene, iptA, alters cytokinesis and mitochondrial and amino acid metabolism in Dictyostelium discoideum.

Cytokinins (CKs) are a class of growth-promoting signaling molecules that affect multiple cellular and developmental processes. These phytohormones are well studied in plants, but their presence continues to be uncovered in organisms spanning all kingdoms, which poses new questions about their roles and functions outside of plant systems. Cytokinin production can be initiated by one of two different biosynthetic enzymes, adenylate isopentenyltransfases (IPTs) or tRNA isopentenyltransferases (tRNA-IPTs).

Suppressors of cGAS-STING are downregulated during fin-limb regeneration and aging in aquatic vertebrates.

During the early stages of limb and fin regeneration in aquatic vertebrates (i.e., fishes and amphibians), blastema undergo transcriptional rewiring of innate immune signaling pathways to promote immune cell recruitment.

LINE-1: an emerging initiator of cGAS-STING signalling and inflammation that is dysregulated in disease.

The cGAS-STING (cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING)) axis integrates DNA damage and cellular stress with type I interferon (IFN) signalling to facilitate transcriptional changes underlying inflammatory stress responses. The cGAS-STING pathway responds to cytosolic DNA in the form of double-stranded DNA, micronuclei, and long interspersed nuclear element 1 (L1) retroelements. L1 retroelements are a class of self-propagating non-long terminal repeat transposons that have remained highly active in mammalian genomes.

PML and PML-like exonucleases restrict retrotransposons in jawed vertebrates.

We have uncovered a role for the promyelocytic leukemia (PML) gene and novel PML-like DEDDh exonucleases in the maintenance of genome stability through the restriction of LINE-1 (L1) retrotransposition in jawed vertebrates. Although the mammalian PML protein forms nuclear bodies, we found that the spotted gar PML ortholog and related proteins in fish function as cytoplasmic DEDDh exonucleases. In contrast, PML proteins from amniote species localized both to the cytoplasm and formed nuclear bodies.

Differential contributions of phosphotransferases CEPT1 and CHPT1 to phosphatidylcholine homeostasis and lipid droplet biogenesis.

The cytidine diphosphate-choline (Kennedy) pathway culminates with the synthesis of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) by choline/ethanolamine phosphotransferase 1 (CEPT1) in the endoplasmic reticulum (ER), and PC synthesis by choline phosphotransferase 1 (CHPT1) in the Golgi apparatus. Whether the PC and PE synthesized by CEPT1 and CHPT1 in the ER and Golgi apparatus has different cellular functions has not been formally addressed. Here, we used CRISPR editing to generate CEPT1-and CHPT1-KO U2OS cells to assess the differential contribution of the enzymes to feedback regulation of nuclear CTP:phosphocholine cytidylyltransferase (CCT)α, the rate-limiting enzyme in PC synthesis, and lipid droplet (LD) biogenesis.

Genistein and Procyanidin B2 Reduce Carcinogen-Induced Reactive Oxygen Species and DNA Damage through the Activation of Nrf2/ARE Cell Signaling in Bronchial Epithelial Cells In Vitro.

Cancer is one of the leading causes of death worldwide. Chemotherapy and radiation therapy are currently providing the basis for cancer therapies, although both are associated with significant side effects. Thus, cancer prevention through dietary modifications has been receiving growing interest.

A Dietary Antioxidant Formulation Ameliorates DNA Damage Caused by γ-Irradiation in Normal Human Bronchial Epithelial Cells In Vitro.

Antioxidants can be used as radioprotectants to reduce DNA damage due to exposure to radiation that could result in malignancies, including lung cancer. Mortality rates are consistently higher in lung cancer, which is usually diagnosed at later stages of cancer development and progression. In this preliminary study, we examined the potential of an antioxidant formulation (AOX2) to reduce DNA damage using a cell model of human normal bronchial epithelial cells (BEAS-2B).

Tinker, Tailor, Tumour Suppressor: The Many Functions of PRP4K.

Pre-mRNA processing factor 4 kinase (PRP4K, also known as PRPF4B) is an essential kinase first identified in the fission yeast that is evolutionarily conserved from amoebae to animals. During spliceosomal assembly, PRP4K interacts with and phosphorylates PRPF6 and PRPF31 to facilitate the formation of the spliceosome B complex. However, over the past decade additional evidence has emerged that PRP4K has many diverse cellular roles beyond splicing that contribute to tumour suppression and chemotherapeutic responses in mammals.

Super-Resolution Radial Fluctuations (SRRF) Microscopy.

Super-resolution Radial Fluctuations (SRRF) imaging is a computational approach to fixed and live-cell super-resolution microscopy that is highly accessible to life science researchers since it uses common microscopes and open-source software plugins for ImageJ. This allows users to generate super-resolution images using the same equipment, fluorophores, fluorescent proteins and methods they routinely employ for their studies without specialized sample preparations or reagents. Here, we discuss a step-by-step workflow for acquiring and analyzing images using the NanoJ-SRRF software developed by the Ricardo Henriques group, with a focus on imaging chromatin.

Running 'LAPS' Around nLD: Nuclear Lipid Droplet Form and Function.

The nucleus harbours numerous protein subdomains and condensates that regulate chromatin organization, gene expression and genomic stress. A novel nuclear subdomain that is formed following exposure of cells to excess fatty acids is the nuclear lipid droplet (nLD), which is composed of a neutral lipid core surrounded by a phospholipid monolayer and associated regulatory and lipid biosynthetic enzymes. While structurally resembling cytoplasmic LDs, nLDs are formed by distinct but poorly understood mechanisms that involve the emergence of lipid droplets from the lumen of the nucleoplasmic reticulum and lipid synthesis.

Assessing kinetics and recruitment of DNA repair factors using high content screens.

Repair of genetic damage is coordinated in the context of chromatin, so cells dynamically modulate accessibility at DNA breaks for the recruitment of DNA damage response (DDR) factors. The identification of chromatin factors with roles in DDR has mostly relied on loss-of-function screens while lacking robust high-throughput systems to study DNA repair. In this study, we have developed two high-throughput systems that allow the study of DNA repair kinetics and the recruitment of factors to double-strand breaks in a 384-well plate format.

Vitamin-Containing Antioxidant Formulation Reduces Carcinogen-Induced DNA Damage through ATR/Chk1 Signaling in Bronchial Epithelial Cells In Vitro.

Lung cancer has the highest mortality rate worldwide and is often diagnosed at late stages, requiring genotoxic chemotherapy with significant side effects. Cancer prevention has become a major focus, including the use of dietary and supplemental antioxidants. Thus, we investigated the ability of an antioxidant formulation (AOX1) to reduce DNA damage in human bronchial epithelial cells (BEAS-2B) with and without the combination of apple peel flavonoid fraction (AF4), or its major constituent quercetin (Q), or Q-3--d-glucoside (Q3G) in vitro.

Haploinsufficient tumor suppressor PRP4K is negatively regulated during epithelial-to-mesenchymal transition.

The pre-mRNA processing factor 4 kinase (PRP4K, also known as PRPF4B) is an essential gene. However, reduced PRP4K expression is associated with aggressive breast and ovarian cancer phenotypes including taxane therapy resistance, increased cell migration and invasion in vitro, and cancer metastasis in mice. These results are consistent with PRP4K being a haploinsufficient tumor suppressor.

SARS-CoV-2 and wastewater: What does it mean for non-human primates?

In most of our lifetimes, we have not faced a global pandemic such as the novel coronavirus disease 2019. The world has changed as a result. However, it is not only humans who are affected by a pandemic of this scale.

Adding Some "Splice" to Stress Eating: Autophagy, ESCRT and Alternative Splicing Orchestrate the Cellular Stress Response.

Autophagy is a widely studied self-renewal pathway that is essential for degrading damaged cellular organelles or recycling biomolecules to maintain cellular homeostasis, particularly under cellular stress. This pathway initiates with formation of an autophagosome, which is a double-membrane structure that envelopes cytosolic components and fuses with a lysosome to facilitate degradation of the contents. The endosomal sorting complexes required for transport (ESCRT) proteins play an integral role in controlling autophagosome fusion events and disruption to this machinery leads to autophagosome accumulation.

Role of Dietary Antioxidants in p53-Mediated Cancer Chemoprevention and Tumor Suppression.

Cancer arises through a complex interplay between genetic, behavioral, metabolic, and environmental factors that combined trigger cellular changes that over time promote malignancy. In terms of cancer prevention, behavioral interventions such as diet can promote genetic programs that may facilitate tumor suppression; and one of the key tumor suppressors responsible for initiating such programs is p53. The p53 protein is activated by various cellular events such as DNA damage, hypoxia, heat shock, and overexpression of oncogenes.

LncRNA Promotes Proliferation and Migration, Is Associated with Cancer Stem Cells, and Alters the miRNA Landscape in Triple-Negative Breast Cancer.

Triple-negative breast cancers (TNBCs) are aggressive, lack targeted therapies and are enriched in cancer stem cells (CSCs). Novel therapies which target CSCs within these tumors would likely lead to improved outcomes for TNBC patients. Long non-coding RNAs (lncRNAs) are potential therapeutic targets for TNBC and CSCs.

Addressing the dark matter of gene therapy: technical and ethical barriers to clinical application.

Gene therapies for genetic diseases have been sought for decades, and the relatively recent development of the CRISPR/Cas9 gene-editing system has encouraged a new wave of interest in the field. There have nonetheless been significant setbacks to gene therapy, including unintended biological consequences, ethical scandals, and death. The major focus of research has been on technological problems such as delivery, potential immune responses, and both on and off-target effects in an effort to avoid negative clinical outcomes.

Cancer and the breakdown of multicellularity: What Dictyostelium discoideum, a social amoeba, can teach us.

Ancient pathways promoting unicellularity and multicellularity are associated with cancer, the former being pro-oncogenic and the latter acting to suppress oncogenesis. However, there are only a limited number of non-vertebrate models for studying these pathways. Here, we review Dictyostelium discoideum and describe how it can be used to understand these gene networks.