Highlights d The molecular profile of RMC distinguishes it from other renal malignancies d RMC harbors a high number of focal chromosomal alterations d RMC has a distinct immune profile characterized by upregulation of cGAS-STING d DNA replication stress is a hallmark of RMC that can be therapeutically targeted

No abstract

Intense research is being conducted using flow cytometers available in clinically oriented laboratories to assess extracellular vesicles (EVs) surface cargo in a variety of diseases. Using EVs of various sizes purified from the HT29 human colorectal adenocarcinoma cell line, we report on the difficulty to assess small and medium sized EVs by conventional flow cytometer that combines light side scatter off a 405 nm laser with the fluorescent signal from the EVs general labels Calcein-green and Calcein-violet, and surface markers. Small sized EVs (~70 nm) immunophenotyping failed, consistent with the scarcity of monoclonal antibody binding sites, and were therefore excluded from further investigation. Medium sized EVs (~250 nm) immunophenotyping was possible but their detection was plagued by an excess of coincident particles (swarm detection) and by a high abort rate; both factors affected the measured EVs concentration. By running samples containing equal amounts of Calcein-green and Calcein-violet stained medium sized EVs, we found that swarm detection produced false double positive events, a phenomenon that was significantly reduced, but not totally eliminated, by sample dilution. Moreover, running highly diluted samples required long periods of cytometer time. Present findings raise questions about the routine applicability of conventional flow cytometers for EV analysis.

Repositioning of clinically approved drugs that may reduce the severity, hospitalization events, and time of recovery from SARS-CoV2 infection is a global health priority. Clinical reports of drug effects and lung pathology are providing insight into the pathogenesis of Covid-19, and comparison of these findings with our knowledge of severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) can be used to develop rational hypotheses to prioritize clinical studies of available therapeutics. Recently, Cao and colleagues [1] investigated the addition of a lopinavir-ritonavir regimen to standard of care, which previously showed promising activity in an open-label clinical study of patients affected by SARS [2]. However, lopinavir-ritonavir therapy did not confer any clinical benefit for patients with Covid-19, even when patients received glucocorticoids as a supportive drug [1]. Several agents, including remdesivir and chloroquine/hydroxychloroquine alone or in combination with azithromycin, were tested as potential treatment for Covid-19 patients, however available data are still not sufficient to delineate a definitive therapeutic approach [3-5]. A relevant debate was ongoing concerning the use of non-steroidal anti-inflammatory drugs (NSAIDs) to treat patients with Covid-19 [6,7]. Following a survey by the French National Agency for Medicines and Health Products Safety (ANSM), US Food and Drug Administration (FDA) and European Medicines Agency (EMA) are investigating a potential correlation between NSAIDs and increased severity of Covid-19 symptomatology, supporting possible negative effects of these drugs to exacerbate Covid-19-related viral and bacterial pulmonary infections, leading to increased hospitalization rates and poor health outcomes. Although no clinical findings were previously reported to suggest any potential risk to use NSAIDs to treat patients with SARS or MERS, NSAID-induced down-regulation of prostaglandins and thromboxanes through cyclooxygenase (COXs) inhibition shifts metabolism of arachidonic acid toward the lipoxygenase (LOX) pathway, resulting in a net increase in leukotrienes production. Of note, leukotrienes are potent chemotactic and

Cellular de-differentiation is a key mechanism driving cancer progression. Acquisition of mesenchymal features has been associated with drug resistance, poor prognosis, and disease relapse in many tumor types. Therefore, successful targeting of tumors harboring these characteristics is a priority in oncology practice. The SWItch/Sucrose Non-Fermentable (SWI/SNF) chromatin remodeling complex has also emerged as a critical player in tumor progression, leading to the identification of several SWI/SNF complex genes as potential disease biomarkers and targets of anti-cancer therapies. AT-rich interaction domain-containing protein 1A (ARID1A) is a component of SWI/SNF, and mutations in ARID1A represent one of the most frequent molecular alterations in human cancers. ARID1A mutations occur in ~10% of pancreatic ductal adenocarcinomas (PDAC), but whether these mutations confer a therapeutic opportunity remains unclear. Here we demonstrate that loss of ARID1A promotes an epithelial-mesenchymal transition (EMT) phenotype and sensitizes PDAC cells to a clinical inhibitor of HSP90, NVP-AUY922, both in vitro and in vivo. While loss of ARID1A alone did not significantly affect proliferative potential or rate of apoptosis, ARID1A-deficient cells were sensitized to HSP90 inhibition, potentially by promoting the degradation of intermediate filaments driving EMT, resulting in cell death. Our results describe a mechanistic link between ARID1A defects and a quasi-mesenchymal phenotype, suggesting that deleterious mutations in ARID1A associated with protein loss exhibits potential as a biomarker for PDAC patients who may benefit by HSP90targeting drugs treatment. Statement of Significance This study identifies ARID1A loss as a promising biomarker for the identification of PDAC tumors that are potentially responsive to treatment with proteotoxic agents. Research.