Biomedical subjects

Dan Hasson

Publications and source records attributed to Dan Hasson.

4 recordsLinked to original sources

PubMed2026

Ribonucleotide Reductase Inhibition Triggers Ferroptosis in Genetically Defined Subsets of Non-Small Cell Lung Cancer.

UNLABELLED: Non-small cell lung cancer (NSCLC) is responsible for the majority of cancer-related mortality worldwide. Lung adenocarcinoma is the most common NSCLC subtype. Despite advances in targeted therapies, treatment resistance remains a critical challenge. Ribonucleotide reductase (RNR), a crucial enzyme in deoxyribonucleotide triphosphate biosynthesis, is frequently upregulated in cancer, contributing to genomic instability and poor prognosis in multiple malignancies. However, the role of the RNR complex in driving tumorigenesis is not fully understood in oncogene-driven lung adenocarcinoma. Transcriptomic analysis of more than 27,000 real-world samples of patients with NSCLC revealed that RNR subunits (RRM1 and RRM2) are significantly upregulated in TP53-mutated NSCLC and are correlated with significantly poor prognosis in multiple oncogene-driven lung adenocarcinoma. Using pharmacologic and genetic approaches to inhibit RNR in lung adenocarcinoma models, we assessed functional consequences through molecular, biochemical, and imaging techniques. RNR inhibition induced appreciable replication stress and triggered DNA damage, leading to cell death in lung adenocarcinoma cells. Notably, we uncovered that RNR suppression preferentially induced ferroptosis, an iron-dependent cell death driven by lipid peroxidation. This represents a previously unrecognized mechanism of RNR-mediated cell death by which mutant lung adenocarcinoma cells can be selectively targeted. Our study establishes RNR inhibition as a potent strategy to selectively induce ferroptosis in oncogene-addicted lung adenocarcinoma, offering a new therapeutic avenue for genetically defined patient subgroups. Targeting nucleotide metabolism could serve as an effective approach to overcome treatment resistance and improve clinical outcomes for patients with high-risk lung adenocarcinoma. SIGNIFICANCE: Our findings highlight RNR as a promising therapeutic target in oncogene-driven lung adenocarcinoma. By demonstrating that RNR inhibition induces ferroptosis, our study opens up new possibilities for developing targeted therapies that selectively eliminate cancer cells in lung adenocarcinoma, paving the way for personalized treatment strategies and potentially overcoming resistance to current therapies.

Humans↗

PubMed2025

Lymphoid gene expression supports neuroprotective microglia function.

Microglia, the innate immune cells of the brain, play a defining role in the progression of Alzheimer's disease (AD)1. The microglial response to amyloid plaques in AD can range from neuroprotective to neurotoxic2. Here we show that the protective function of microglia is governed by the transcription factor PU.1, which becomes downregulated following microglial contact with plaques. Lowering PU.1 expression in microglia reduces the severity of amyloid disease pathology in mice and is linked to the expression of immunoregulatory lymphoid receptor proteins, particularly CD28, a surface receptor that is critical for T cell activation3,4. Microglia-specific deficiency in CD28, which is expressed by a small subset of plaque-associated PU.1low microglia, promotes a broad inflammatory microglial state that is associated with increased amyloid plaque load. Our findings indicate that PU.1low CD28-expressing microglia may operate as suppressive microglia that mitigate the progression of AD by reducing the severity of neuroinflammation. This role of CD28 and potentially other lymphoid co-stimulatory and co-inhibitory receptor proteins in governing microglial responses in AD points to possible immunotherapy approaches for treating the disease by promoting protective microglial functions.

Microglia↗

PubMed2025

In vitro protocol demonstrating five functional steps of trained immunity in mice: Implications on biomarker discovery and translational research.

We developed an in vitro methodology to study trained immunity using murine bone-marrow-derived macrophages stimulated with β-glucan and lipopolysaccharide (LPS). Longitudinal analysis of interleukin (IL)-6 and tumor necrosis factor (TNF) production demonstrates that trained macrophages secrete higher cytokine levels following primary stimulation with β-glucan compared to unstimulated macrophages (step 1). After a resting period, trained macrophages return to basal levels of cytokine production (step 2) but rapidly produce enhanced levels of IL-6 and TNF after secondary stimulation with LPS, compared to macrophages individually stimulated with either β-glucan (step 3) or LPS (step 4) alone. The combined cytokine production of macrophages after single stimulation with β-glucan (stimulus 1) and LPS (stimulus 2) is significantly lower than the cytokine levels produced by trained macrophages sequentially stimulated with both β-glucan and LPS (stimulus 1 + 2) (step 5). These results experimentally reproduce the distinctive functional stages that macrophages undergo during the training process.

Animals↗

PubMed2025

A single-cell spatial transcriptomic census of human skin anatomy.

The skin is the largest human organ and a site of significant disease burden, yet its cellular and molecular organization across the body are largely undefined. Here, we construct a spatially-resolved single-cell atlas of 1.2 million cells from normal adult human skin to localize 45 cell types across 15 anatomic sites. We define principles of organ-wide cell composition, including axes of cell diversity and specialization, and distinguish site-enriched cell types. Each body site is comprised of 10 multicellular neighborhoods that define cell-cell communication. Notably, we identify a perivascular neighborhood enriched for immune-stromal crosstalk with features resembling a homeostatic immune niche similar to skin-associated lymphoid tissue. Finally, mapping these neighborhoods onto skin disease reveals pathogenic neighborhood disruptions, including pan-disease immune alterations in the perivascular neighborhood. We present a framework charting the skin's multiscale spatial organization across a molecular to macroanatomic scale. This work advances our understanding of organ-wide skin cellular organization and communication, and its architectural disruption in disease.

Journal Article↗