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Biology subjects

Michalik, L.

Publications and source records attributed to Michalik, L..

2 recordsLinked to original sources

Estrogen Receptors/E2F1/CDKN3 Axis Protects from UV-induced Skin Cancers in Females

Men have a significantly higher risk of developing cutaneous squamous cell carcinoma (SCC) compared to women, but models and comprehensive analysis of signaling pathways highlighting this sexual dimorphism are missing. In this study, we display a UV-induced SCC model in hairless mice recapitulating this sex difference, with enhanced SCC development in males. While UV-induced DNA damage is similar between sexes, we uncovered sex-specific responses in epidermal cell proliferation and differentiation. Using global transcriptional profile analyses, we identified E2F transcription factors as key sex-specific markers involved in the proliferative response to UV. Notably, E2F1/2, along with their target gene CDKN3, were selectively downregulated in female mice and human epidermis following UV exposure. Mechanistically, UV-induced and sex-specific modulation of E2F1 and CDKN3 expression is mediated by Estrogen Receptors. Lastly, low levels of CDKN3 in head and neck SCC are observed exclusively in female patients correlating with better prognosis. These findings shed new light on fundamental mechanisms protecting women from cancer after carcinogen exposure and could lead to better sex-targeted preventive and therapeutic strategies in SCC and other malignancies. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=199 SRC="FIGDIR/small/637819v1_ufig1.gif" ALT="Figure 1"> View larger version (43K): org.highwire.dtl.DTLVardef@7edcc5org.highwire.dtl.DTLVardef@d0215corg.highwire.dtl.DTLVardef@3e248forg.highwire.dtl.DTLVardef@1d25cb9_HPS_FORMAT_FIGEXP M_FIG C_FIG Sex differences in UV-Induced cutaneous Squamous Cell Carcinoma: key insights into female cancer protection

cancer biology↗

Insights into standards of care: dexamethasone and antibodies against COVID-19 in hamster models

RationaleIn face of the ongoing SARS-CoV-2 pandemic, effective and well-understood treatment options are still scarce. While vaccines have proven instrumental in fighting SARS-CoV-2, their efficacy is challenged by vaccine hesitancy, novel variants and short-lasting immunity. Therefore, understanding and optimization of therapeutic options remains essential. ObjectivesWe aimed at generating a deeper understanding on how currently used drugs, specifically dexamethasone and anti-SARS-CoV-2 antibodies, affect SARS-CoV-2 infection and host responses. Possible synergistic effects of both substances are investigated to evaluate combinatorial treatments. MethodsBy using two COVID-19 hamster models, pulmonary immune responses were analyzed to characterize effects of treatment with either dexamethasone, anti-SARS-CoV-2 spike monoclonal antibody or a combination of both. scRNA sequencing was employed to reveal transcriptional response to treatment on a single cell level. Measurements and main resultsDexamethasone treatment resulted in similar or increased viral loads compared to controls. Anti-SARS-CoV-2 antibody treatment alone or combined with dexamethasone successfully reduced pulmonary viral burden. Dexamethasone exhibited strong anti-inflammatory effects and prevented fulminant disease in a severe COVID-19-like disease model. Combination therapy showed additive benefits with both anti-viral and anti-inflammatory potency. Bulk and single-cell transcriptomic analyses confirmed dampened inflammatory cell recruitment into lungs upon dexamethasone treatment and identified a candidate subpopulation of neutrophils specifically responsive to dexamethasone. ConclusionsOur analyses i) confirm the anti-inflammatory properties and indicate possible modes of action for dexamethasone, ii) validate anti-viral effects of anti-SARS-CoV-2 antibody treatment, and iii) reveal synergistic effects of a combination therapy and can thus inform more effective COVID-19 therapies.

molecular biology↗