Biology subjects

Ng, M.

Publications and source records attributed to Ng, M..

At least 19 recordsLinked to original sources

bioRxiv2026

Allele-specific chromatin modifications of HPV-associated extrachromosomal DNAs in cervical cancer

Cervical cancer, a human papillomavirus (HPV) driven malignancy, is the fourth deadliest cancer in females. Approximately 25% of primary cervical cancers contain circular structures called extrachromosomal DNAs (ecDNAs), which can be entirely composed of human DNA (human-only ecDNAs) or a combination of HPV and human DNA sequences (HPV-human hybrid ecDNAs). Human-only ecDNAs harbour cancer-driving oncogenes, but epigenetic differences between human-only and HPV-human hybrid ecDNAs are unexplored. Here we report that 30% of cervical cancers contained at least one ecDNA. HPV-human hybrid ecDNAs contained more active enhancers and promoters than human-only ecDNAs and invariably contained the HPV oncogenes E6 and E7. These ecDNAs also contained an allelic hypomethylation region associated with putative human promoters, as well as enrichments for motifs associated with recombination hotspots. By leveraging long-read WGS phasing data to separate ChIP-seq data into alleles, we revealed allele-specific peaks in enhancers and promoters on ecDNAs, of which HPV-human hybrid ecDNAs contained a higher density. Overall, we found HPV-human hybrid and human-only ecDNAs differed in their regulation, often at an allele-specific level. Our study more firmly establishes the importance of epigenome disruption in cervical cancer and how structural variation, particularly surrounding HPV integration sites, may shape the surrounding regulatory architecture.

genomics↗

bioRxiv2026

Reprogramming insulin receptor activation with a de novo agonist to overcome severe insulin resistance

Computational protein engineering provides a powerful approach to address longstanding clinical challenges. Severe insulin resistance syndromes caused by mutations in the insulin receptor (IR) are life-threatening disorders for which effective long-term therapies remain lacking. Here, we define the in vivo activity and therapeutic potential of RF-409, a de novo-designed IR agonist that activates the receptor through a mechanism distinct from insulin. RF-409 exhibits markedly prolonged circulation compared to insulin and produces sustained improvements in glucose homeostasis without detectable adverse effects on body composition or liver function. In a patient-derived IR D707A mouse model of severe insulin resistance, RF-409--but not insulin--activates the mutant receptor, restoring glucose regulation and ameliorating hyperglycemia, hyperinsulinemia, lipoatrophy, and pancreatic atrophy. Mechanistically, RF-409 engages the IR through a noncanonical binding geometry while stabilizing an active conformation resembling that induced by insulin. Phosphoproteomic profiling shows that RF-409 elicits broadly insulin-like signaling with distinct temporal features in receptor-proximal regulation. Together, these findings establish a framework for reactivating dysfunctional receptors and suggest broader applications beyond rare receptoropathies, including diabetes and liver disease.

pharmacology and toxicology↗

bioRxiv2026

A Genetic Tool for Specific Tracking of Mature Neutrophils

Tracking mature neutrophils remains challenging due to the lack of reliable cell surface markers. Although CD101 is a promising candidate for mature neutrophils, its stability under pathological conditions is unclear. Using a CD101-tdTomato reporter mouse model, we confirmed that the reporting system does not alter CD101 expression, and tdTomato fluorescence is predominantly expressed in mature neutrophils across peripheral tissues. Further analysis revealed that CD101+ and tdTomato+ neutrophils display identical characteristics of mature neutrophil, including poly-segmented nuclei, cell size, and key functions under homeostasis. By comparing tdTomato fluorescence with CD101 protein levels, we demonstrate that reduced CD101 expression under pathological states was not attributed to shedding or degradation. Our finding enhances CD101 as a robust and reliable marker of neutrophil maturity, providing a foundation for future applications in spatial transcriptomics and lineage tracing studies to dissect neutrophil heterogeneity and function. Highlights of the studyO_LIIn CD101-tdTomato homozygous mice, tdTomato is predominantly expressed in neutrophils and labels nearly 100% of mature neutrophils, aligning with the phenotype of CD101+ mature neutrophils; C_LIO_LIThe CD101-tdTomato reporting system does not interrupt CD101 expression or neutrophil functions; C_LIO_LICD101 remains a stable and reliable cell surface marker for labeling mature neutrophils, even under pathological conditions. C_LI

immunology↗

bioRxiv2026

Upregulation of Genetic Markers of Poor Prognosis following Chemotherapy in Acute Myeloid Leukemia Cells

Chemoresistance, a leading cause of treatment failure in cancer, is commonly explained by Darwinian selection of treatment-resistant cell clones. However, recurring resistant tumors invariably display complex phenotypes that contribute to increased malignancy, unlikely to have been selected for by chemotherapy. The growing awareness of (non - genetic) phenotypic plasticity led to the hypothesis that chemotherapy, while reducing tumor burden, also inflicts cell stress that induces stem-like states in cells that survive treatment. Here we examined the transcriptomes of HL-60 leukemic cancer cells that survived exposure to three commonly used drugs at submaximal doses for two to four days, and compared differentially expressed genes to those associated with prognosis in public transcriptome databases of acute myeloid leukemia cohorts. While among the genes differentially upregulated in surviving cells, some reflect the therapeutic effect of chemotherapy as they were associated with favorable outcomes in cohort data, many genes upregulated were associated with poor survival, notably genes involved in stemness, epithelial-mesenchymal transition (EMT), inflammation, drug resistance, and apoptosis evasion. These findings support the idea that treatment effectiveness is the net result of an intrinsic tradeoff: Cytocidal treatment, intended to quantitatively reduce cancer cells, also qualitatively increases the malignancy of non-killed cells, which could contribute to residual disease and relapse. This result has implications for drug screening of new therapeutics, as well as in vitro profiling of patient-derived tumor cell susceptibility to existing drugs, which only assess suppression of cancer cell growth and survival. Statement of SignificanceCells surviving chemotherapy upregulate many genes that may affect prognosis. Therefore, drug screening must embrace a more holistic assessment of the biological quality of cell response beyond the rate of cell killing.

cancer biology↗

bioRxiv2026

Environmental hypoxia controls the evolution of cavefish heart asymmetry

The environmental factors responsible for the evolution of novel traits and their underlying mechanisms are poorly understood. Here we use the teleost Astyanax mexicanus consisting of ancestral surface fish and derived cavefish morphotypes to address the evolution of heart asymmetry. As in other vertebrates, surface fish develop right(D)-looping heart tubes, whereas high levels of left(L)-looping heart tubes have uniquely evolved in cavefish. Cavefish cardiac L-looping is mediated by the upregulation of Sonic Hedgehog (Shh) signalling during gastrulation, which disrupts left-right organizer (LRO) function and modifies the downstream left-oriented Nodal signalling cascade. As a proxy for the original cave colonizers, we exposed contemporary surface fish to key cave-associated environmental factors, namely complete darkness, reduced electrical conductivity, low temperature, hypoxia, or combinations of these conditions. Only hypoxia induced the cavefish L-looping phenotype. Hypoxia increased expression of genes in an integrated Hypoxia Inducing Factor 1(HIF1)-Shh axis, disrupted LRO function, and modified the L-R determination program in surface fish similarly to naturally evolved changes in cavefish. In contrast to surface fish, which show high plasticity in response to hypoxia, cavefish were unable to survive acute hypoxia, suggesting evolutionary refinement and canalization of the ancestral hypoxia response. These studies establish hypoxia as the driver of heart asymmetry and reveal a mechanistic connection between the hypoxic cave environment and the evolution of a novel trait.

evolutionary biology↗

bioRxiv2024

Tuning Insulin Receptor Signaling Using De Novo Designed Agonists

Binding of insulin to the insulin receptor (IR) induces conformational changes in the extracellular portion of the receptor that lead to activation of the intracellular kinase domain and the AKT and MAPK pathways, and downstream modulation of glucose metabolism and cell proliferation. We reasoned that designed agonists that induce different conformational changes in the receptor might induce different downstream responses, which could be useful both therapeutically and to shed light on how extracellular conformation is coupled to intracellular signaling. We used de novo protein design to first generate binders to individual IR extracellular domains, and then to fuse these together in different orientations and with different conformational flexibility. We describe a series of synthetic agonists that signal through the IR that differ from insulin and from each other in the induction of receptor autophosphorylation, MAPK activation, intracellular trafficking, and cell proliferation. We identify designs that are more potent than insulin causing much longer lasting reductions in glucose levels, and that retain signaling activity on disease-causing receptor mutants that do not respond to insulin. These results inform our understanding of how changes in receptor conformation and dynamics are transmitted to downstream signaling, and our synthetic agonists have considerable therapeutic potential for diabetes and severe insulin resistance syndromes. HighlightsO_LIComputational design yielded super agonists, partial agonists, and antagonists of IR. C_LIO_LIDe novo agonists induce a distinct IR active conformation. C_LIO_LIDesigned agonists tune IR signaling by modulating conformational dynamics of activated IR. C_LIO_LIDesigned agonists are more potent than insulin, reducing glucose levels longer and activating disease-causing IR mutants. C_LI

bioengineering↗

bioRxiv2024

nSMase2-mediated exosome secretion shapes the tumor microenvironment to immunologically support pancreatic cancer

The pleiotropic roles of nSMase2-generated ceramide include regulation of intracellular ceramide signaling and exosome biogenesis. We investigated the effects of eliminating nSMase2 on early and advanced PDA, including its influence on the microenvironment. Employing the KPC mouse model of pancreatic cancer, we demonstrate that pancreatic epithelial nSMase2 ablation reduces neoplasia and promotes a PDA subtype switch from aggressive basal-like to classical. nSMase2 elimination prolongs survival of KPC mice, hinders vasculature development, and fosters a robust immune response. nSMase2 loss leads to recruitment of cytotoxic T cells, N1-like neutrophils, and abundant infiltration of anti-tumorigenic macrophages in the pancreatic preneoplastic microenvironment. Mechanistically, we demonstrate that nSMase2-expressing PDA cell small extracellular vesicles (sEVs) reduce survival of KPC mice; PDA cell sEVs generated independently of nSMase2 prolong survival of KPC mice and reprogram macrophages to a proinflammatory phenotype. Collectively, our study highlights previously unappreciated opposing roles for exosomes, based on biogenesis pathway, during PDA progression. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=189 SRC="FIGDIR/small/614610v1_ufig1.gif" ALT="Figure 1"> View larger version (43K): org.highwire.dtl.DTLVardef@b6e6d1org.highwire.dtl.DTLVardef@1ebb41eorg.highwire.dtl.DTLVardef@17e4275org.highwire.dtl.DTLVardef@3d31f1_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

bioRxiv2024

M2 Macrophage Exosomes Reverse Cardiac Functional Decline in Mice with Diet-Induced Myocardial Infarction by Suppressing Type 1 Interferon Signaling in Myeloid Cells

Effective treatment strategies to alleviate heart failure that develops as a consequence of myocardial infarction (MI) remain an unmet need in cardiovascular medicine. In this study, we uncovered that exosomes produced by human THP-1 macrophages cultured with the cytokine IL-4 (THP1-IL4-exo), reverse cardiac functional decline in mice that develop MI as a consequence of diet-induced occlusive coronary atherosclerosis. Therapeutic benefits of THP1-IL4-exo stem from their ability to reprogram circulating Ly-6Chi monocytes into an M2-like phenotype and suppress Type 1 Interferon signaling in myeloid cells within the bone marrow, the circulation, and cardiac tissue. Collectively, these benefits suppress myelopoiesis, myeloid cell recruitment to cardiac tissue, and preserve populations of resident cardiac macrophages that together mitigate cardiac inflammation, adverse ventricular remodeling, and heart failure. Our findings introduce THP1-IL4-exo, one form of M2-macrophage exosomes, as novel therapeutics to preserve cardiac function subsequent to MI.

immunology↗

bioRxiv2023

Natural reversal of cavefish heart asymmetry is controlled by Sonic Hedgehog effects on the left-right organizer

The direction of left-right (L-R) visceral asymmetry is conserved in vertebrates. Deviations of the asymmetric pattern are rare, and the underlying mechanisms are not understood. Here we use the teleost Astyanax mexicanus, a single species consisting of surface fish with normal left-oriented heart asymmetry and cavefish with high levels of reversed right-oriented heart asymmetry, to explore natural changes in L-R determination. We show that Sonic Hedgehog (Shh) signaling is increased at the posterior midline, Kupffers Vesicle (KV), the teleost L-R Organizer (LRO), is enlarged and contains longer cilia, and the number of dorsal forerunner cells, the KV precursors, is increased in cavefish. Furthermore, Shh overexpression in surface fish induces KV modifications and changes in heart asymmetry resembling the cavefish phenotype. Asymmetric expression of the Nodal antagonist dand5 is equalized or reversed in the cavefish KV, and Shh overexpression in surface fish mimics changes in cavefish L-R dand5 asymmetry and shifts Nodal laterality in the lateral plate mesoderm. Our results show that naturally occurring modifications in cavefish heart asymmetry are controlled by the effects of enhanced Shh signaling on LRO function. SummaryNatural reversal of cavefish heart asymmetry is controlled by enhanced Sonic Hedgehog signaling at the posterior midline, which modifies left-right organizer function and subsequent Nodal laterality.

developmental biology↗

bioRxiv2023

Genomic structures and regulation patterns at HPV integration sites in cervical cancer

Human papillomavirus (HPV) integration has been implicated in transforming HPV infection into cancer, but its genomic consequences have been difficult to study using short-read technologies. To resolve the dysregulation associated with HPV integration, we performed long-read sequencing on 63 cervical cancer genomes. We identified six categories of integration events based on HPV-human genomic structures. Of all HPV integrants, defined as two HPV-human breakpoints bridged by an HPV sequence, 24% contained variable copies of HPV between the breakpoints, a phenomenon we termed heterologous integration. Analysis of DNA methylation within and in proximity to the HPV genome at individual integration events revealed relationships between methylation status of the integrant and its orientation and structure. Dysregulation of the human epigenome and neighboring gene expression in cis with the HPV-integrated allele was observed over megabase-ranges of the genome. By elucidating the structural, epigenetic, and allele-specific impacts of HPV integration, we provide insight into the role of integrated HPV in cervical cancer.

genomics↗

bioRxiv2023

Characterization of a novel mouse model for Fuchs Endothelial Corneal Dystrophy

PurposeFuchs Endothelial Corneal Dystrophy (FECD) is a progressive blinding disorder prevalent in 4% of Americans over 40. Corneal transplantation is the standard treatment. Animal models with partial FECD features exist, but a model encompassing all the major disease characteristics is desirable to improve the understanding of the pathogenesis and to identify signaling pathways involved in the disease onset and progression. Such an animal model can be helpful to develop intervention strategies. Here, we developed a mouse model that recapitulates all the features of FECD. MethodLoss of function mutations in Slc4a11 and a knock-in mutation in Col8a2 (Q455K) are implicated in FECD. Mice with Slc4a11 and Col8a2 mutations in C57BL/6J background were crossed to generate double mutant mice at F2 generation. At five weeks of age, a subset of the animals were fed tamoxifen-enriched chow or standard chow for two weeks, followed by standard chow. Corneal thickness, endothelial cell density, and guttae were measured at 5 (baseline) and 16 weeks of age. Corneas collected from mice at 16 weeks were stained for tight and adherens junctions, and reactive oxygen species. A lactate assay was performed to evaluate the endothelial pump function. ResultsThe double mutant tamoxifen-fed mice showed increased corneal thickness, decreased endothelial cell density, presence of guttae, and elevated stromal lactate levels. The endothelial cells showed altered morphology with disrupted adherens junctions and elevated ROS. ConclusionOverall, this mouse model recapitulates all the important phenotypic features associated with FECD.

cell biology↗

bioRxiv2023

Quantification of circulating tumor DNA using deep learning

Quantification of circulating tumor DNA (ctDNA) levels in blood enables non-invasive surveillance of cancer progression. Fragle is an ultra-fast deep learning-based method for ctDNA quantification directly from cell-free DNA fragment length profiles. We developed Fragle using low-pass whole genome sequence (lpWGS) data from multiple cancer types and healthy control cohorts, demonstrating high accuracy, and improved lower limit of detection in independent cohorts as compared to existing tumor-naive methods. Uniquely, Fragle is also compatible with targeted sequencing data, exhibiting high accuracy across both research and commercial targeted gene panels. We used this method to study longitudinal plasma samples from colorectal cancer patients, identifying strong concordance of ctDNA dynamics and treatment response. Furthermore, prediction of minimal residual disease in resected lung cancer patients demonstrated significant risk stratification beyond a tumor-naive gene panel. Overall, Fragle is a versatile, fast, and accurate method for ctDNA quantification with potential for broad clinical utility.

bioinformatics↗

bioRxiv2023

The Septin Cytoskeleton is Required for Plasma Membrane Repair

Mammalian cells are frequently exposed to mechanical and biochemical stressors resulting in plasma membrane injuries. Repair mechanisms reseal the plasma membrane to restore homeostasis and prevent cell death. In the present work, a silencing RNA screen was performed to uncover plasma membrane repair mechanisms of cells exposed to a pore-forming toxin (listeriolysin O). This screen identified molecules previously known to repair the injured plasma membrane such as annexin A2 (ANXA2) as well as novel plasma membrane repair candidate proteins. Of the novel candidates, we focused on septin 7 (SEPT7) because the septins are an important family of conserved eukaryotic cytoskeletal proteins. Using diverse experimental approaches, we established for the first time that SEPT7 plays a general role in plasma membrane repair of cells perforated by pore-forming toxins and mechanical wounding. Remarkably, upon cell injury, the septin cytoskeleton is extensively redistributed in a Ca2+-dependent fashion, a hallmark of plasma membrane repair machineries. The septins reorganize into subplasmalemmal domains arranged as knob and loop (or ring) structures containing F-actin, myosin II, and annexin A2 (ANXA2) and protrude from the cell surface. Importantly, the formation of these domains correlates with the plasma membrane repair efficiency. Super-resolution microscopy shows that septins and actin are arranged in intertwined filaments associated with ANXA2. Silencing SEPT7 expression prevented the formation of the F-actin/myosin II/ANXA2 domains, however, silencing expression of ANXA2 had no observable effect on their formation. These results highlight the key structural role of the septins in remodeling the plasma membrane and in the recruitment of the repair molecule ANXA2. Collectively, our data support a novel model in which the septin cytoskeleton acts as a scaffold to promote the formation of plasma membrane repair domains containing contractile F-actin and annexin A2.

cell biology↗

bioRxiv2023

Exomap1 mouse: a transgenic model for in vivo studies of exosome biology

Exosomes are small extracellular vesicles (sEVs) of [~]30-150 nm in diameter that have the same topology as the cell, are enriched in selected exosome cargo proteins, and play important roles in health and disease. To address large unanswered questions regarding exosome biology in vivo, we created the exomap1 transgenic mouse model. In response to Cre recombinase, exomap1 mice express HsCD81mNG, a fusion protein between human CD81, the most highly enriched exosome protein yet described, and the bright green fluorescent protein mNeonGreen. As expected, cell type-specific expression of Cre induced the cell type-specific expression of HsCD81mNG in diverse cell types, correctly localized HsCD81mNG to the plasma membrane, and selectively loaded HsCD81mNG into secreted vesicles that have the size ([~]80 nm), topology (outside out), and content (presence of mouse exosome markers) of exosomes. Furthermore, mouse cells expressing HsCD81mNG released HsCD81mNG-marked exosomes into blood and other biofluids. Using high-resolution, single-exosome analysis by quantitative single molecule localization microscopy, we show here that that hepatocytes contribute [~]15% of the blood exosome population whereas neurons contribute <1% of blood exosomes. These estimates of cell type-specific contributions to blood EV population are consistent with the porosity of liver sinusoidal endothelial cells to particles of [~]50-300 nm in diameter, as well as with the impermeability of blood-brain and blood-neuron barriers to particles >5 nm in size. Taken together, these results establish the exomap1 mouse as a useful tool for in vivo studies of exosome biology, and for mapping cell type-specific contributions to biofluid exosome populations. In addition, our data confirm that CD81 is a highly-specific marker for exosomes and is not enriched in the larger microvesicle class of EVs.

cell biology↗

bioRxiv2021

Variants in ALDH1A2 reveal an anti-inflammatory role for retinoic acid and a new class of disease-modifying drugs in osteoarthritis

Over 40% of individuals will develop osteoarthritis (OA) during their lifetime, yet there are currently no licensed disease modifying treatments for this disabling condition. Common polymorphic variants in ALDH1A2, that encodes the key enzyme in the synthesis of all-trans retinoic acid (atRA), have been associated with severe hand OA. In this study, we sought to elucidate the biological significance of this association. We first confirmed that ALDH1A2 risk variants were associated with hand OA in UK Biobank. Articular cartilage was acquired from 33 consenting individuals with hand OA at the time of routine hand OA surgery. They were stratified by genotype and RNA sequencing performed. A reciprocal relationship between ALDH1A2 mRNA and inflammatory genes was observed. Articular cartilage injury up-regulates similar inflammatory genes by a process that we have previously termed mechanoflammation, and which we believe is a primary driver of OA. Cartilage injury was also associated with a concomitant drop in atRA-dependent genes, indicative of cellular atRA levels, and both responses to injury were reversed using talarozole, a retinoic acid metabolism blocking agent (RAMBA). Suppression of mechanoflammation by talarozole was mediated by a peroxisome proliferator activated receptor (PPAR)-{gamma} dependent mechanism. Talarozole, delivered by minipump, was able to suppress mechano-inflammatory genes in articular cartilage in vivo 6h after mouse knee joint destabilization, and reduced cartilage degradation and osteophyte formation after 4 weeks. These data show that boosting atRA suppresses mechanoflammation in the articular cartilage in vitro and in vivo, and identifies RAMBAs as potential disease modifying drugs in OA. One Sentence SummaryAnalysis of hand OA cartilage stratified by ALDH1A2 polymorphic variants reveals a targetable, anti-inflammatory role for retinoic acid in OA.

molecular biology↗

bioRxiv2021

Allelic variation in Class I HLA determines pre-existing memory responses to SARS-CoV-2 that shape the CD8+ T cell repertoire upon viral exposure

Effective presentation of antigens by HLA class I molecules to CD8+ T cells is required for viral elimination and generation of long-term immunological memory. In this study, we applied a single-cell, multi-omic technology to generate the first unified ex vivo characterization of the CD8+ T cell response to SARS-CoV-2 across 4 major HLA class I alleles. We found that HLA genotype conditions key features of epitope specificity, TCR /{beta} sequence diversity, and the utilization of pre-existing SARS-CoV-2 reactive memory T cell pools. Single-cell transcriptomics revealed functionally diverse T cell phenotypes of SARS-CoV-2-reactive T cells, associated with both disease stage and epitope specificity. Our results show that HLA variations influence pre-existing immunity to SARS-CoV-2 and shape the immune repertoire upon subsequent viral exposure. One-Sentence SummaryWe perform a unified, multi-omic characterization of the CD8+ T cell response to SARS-CoV-2, revealing pre-existing immunity conditioned by HLA genotype.

immunology↗

bioRxiv2021

The megakaryocytic transcription factor ARID3A suppresses leukemia pathogenesis

Given the plasticity of hematopoietic stem/progenitor cells, multiple routes of differentiation must be blocked during acute myeloid leukemia pathogenesis - the molecular basis of which is incompletely understood. Here we report that post-transcriptional repression of transcription factor ARID3A by miR-125b is a key event in megakaryoblastic leukemia (AMKL) pathogenesis. AMKL is frequently associated with trisomy 21 and GATA1 mutations (GATA1s), and children with Down syndrome are at a high risk of developing this disease. We show that chromosome 21-encoded miR-125b synergizes with Gata1s to drive leukemogenesis in this context. Leveraging forward and reverse genetics, we uncover Arid3a as the main miR-125b target underlying this synergy. We demonstrate that during normal hematopoiesis this transcription factor promotes megakaryocytic differentiation in concert with GATA1 and mediates TGF{beta}-induced apoptosis and cell cycle arrest in complex with SMAD2/3. While Gata1s mutations perturb erythroid differentiation and induce hyperproliferation of megakaryocytic progenitors, intact ARID3A expression assures their megakaryocytic differentiation and growth restriction. Upon knockdown, these tumor suppressive functions are revoked, causing a dual megakaryocytic/erythroid differentiation blockade and subsequently AMKL. Inversely, restoring ARID3A expression relieves the megakaryocytic differentiation arrest in AMKL patient-derived xenografts. This work illustrates how mutations in lineage-determining transcription factors and perturbation of post-transcriptional gene regulation interplay to block multiple routes of hematopoietic differentiation and cause leukemia. Surmounting this differentiation blockade in megakaryoblastic leukemia by restoring the tumor suppressor ARID3A represents a promising strategy for treating this lethal pediatric disease. Key pointsO_LIRepression of megakaryocytic transcription factor ARID3A by miR-125b synergizes with GATA1s to induce leukemia C_LIO_LIRestoring ARID3A expression relieves megakaryocytic differentiation arrest in megakaryoblastic leukemia C_LI Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=198 SRC="FIGDIR/small/440795v1_ufig1.gif" ALT="Figure 1"> View larger version (49K): org.highwire.dtl.DTLVardef@146c2a7org.highwire.dtl.DTLVardef@9599fdorg.highwire.dtl.DTLVardef@1b0d22borg.highwire.dtl.DTLVardef@1b61447_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

bioRxiv2020

Dehydrated Caenorhabditis elegans stocks are resistant to multiple freeze-thaw cycles

Ultracold preservation is widely used for storage of genetic stocks of Caenorhabditis elegans. Current cryopreservation protocols are vulnerable to refrigeration failures, which can result in the loss of stock viability due to damage during re-freezing. Here we present a method for preserving worms in a dehydrated and frozen form that retains viability after multiple freeze/thaw cycles. After dehydration in the presence of trehalose or glycerol, C. elegans stocks can be frozen and thawed multiple times while maintaining viability. While both dauer and non-dauer larvae survive desiccation and freezing, the dauer defective mutant daf-16 does not survive desiccation. Our technique is useful for storing stocks in a manner robust to freezer failures, and potentially for shipping strains between laboratories.

genetics↗