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Abstract The transcription factor regulatory factor X 7 (RFX7) has been identified as a tumor suppressor that is recurrently mutated in lymphoid cancers and appears to be dysregulated in many other cancers. RFX7 is activated by the well-known tumor suppressor p53 and regulates several other known tumor suppressor genes. However, what other factors regulate RFX7 and its target genes remains unclear. Here, reporter gene assays were used to identify that RFX7 regulates the tumor suppressor gene PDCD4 through direct interaction with its X-box promoter motif. We utilized mass spectrometry to identify factors that bind to DNA together with RFX7. In addition to RFX7, we also identified RFX5, RFXAP, RFXANK, and ANKRA2 that bind to the X-box motif in the PDCD4 promoter. We demonstrate that ANKRA2 is a bona fide direct p53 target gene. We used transcriptome analyses in two cell systems to identify genes regulated by ANKRA2, its sibling RFXANK, and RFX7. These results revealed that ANKRA2 functions as a critical cofactor of RFX7, whereas RFXANK regulates largely distinct gene sets.

ABSTRACTIntroduction: There are conflicting results concerning the outcome of patients after an allogeneic hematopoietic stem cell transplantation (allo-HSCT) who required treatment in the intensive care unit (ICU). The aim of this study was to evaluate the outcome and prognostic parameters in terms of patient survival after allo-HSCT and admission to the ICU within the first 30 days after transplantation.Methods: Patients after allo-HSCT, who were ≥18 years and admitted to the ICU after the initiation of conditioning therapy and within the first 30 days after allo-HSCT at the University Hospital of Bonn between January 2017 and April 2021, were analysed retrospectively. Baseline data, laboratory parameters, established scoring systems, vital parameters, and outcome were collected.Results: 44 patients (median age of 63 years) were analysed. The 90-day survival rate was 50% (N = 22) and the 1-year survival rate was 27% (N = 12). The 90-day and 1-year survival rates of patients who required MV were 38% (N = 13) and 18% (N = 6). There was a significant correlation between increased mortality and an APACHE-Score ≥20 (p = 0.03), a SAPS-II-Score ≥60 (p = 0.04) and a SOFA-Score ≥9 (p = 0.03). Invasive mechanical ventilation (p = 0.05) and vasopressor support (p = 0.03) showed a negative correlation with the outcome.Conclusion: This study found several parameters (APACHE-II-Score, SAPS-II-Score, SOFA-Score, MV and vasopressor support) associated with increased mortality after allo-HSCT and admission to the ICU. The outcome of allo-HSCT patients admitted to the ICU is not as poor as previously reported. Even older patients under long-term ventilation may benefit from intensive care therapy.

Abstract Background Hospitals with their high antimicrobial selection pressure represent the presumably most important reservoir of multidrug-resistant human pathogens. Antibiotics administered in the course of treatment are excreted and discharged into the wastewater system. Not only in patients, but also in the sewers, antimicrobial substances exert selection pressure on existing bacteria and promote the emergence and dissemination of multidrug-resistant clones. In previous studies, two main clusters were identified in all sections of the hospital wastewater network that was investigated, one K. pneumoniae ST147 cluster encoding NDM- and OXA-48 carbapenemases and one VIM-encoding P. aeruginosa ST823 cluster. In the current study, we investigated if NDM- and OXA-48-encoding K. pneumoniae and VIM-encoding P. aeruginosa isolates recovered between 2014 and 2021 from oncological patients belonged to those same clusters. Methods The 32 isolates were re-cultured, whole-genome sequenced, phenotypically tested for their antimicrobial susceptibility, and analyzed for clonality and resistance genes in silico. Results Among these strains, 25 belonged to the two clusters that had been predominant in the wastewater, while two others belonged to a sequence-type less prominently detected in the drains of the patient rooms. Conclusion Patients constantly exposed to antibiotics can, in interaction with their persistently antibiotic-exposed sanitary facilities, form a niche that might be supportive for the emergence, the development, the dissemination, and the maintenance of certain nosocomial pathogen populations in the hospital, due to antibiotic-induced selection pressure. Technical and infection control solutions might help preventing transmission of microorganisms from the wastewater system to the patient and vice versa, particularly concerning the shower and toilet drainage. However, a major driving force might also be antibiotic induced selection pressure and parallel antimicrobial stewardship efforts could be essential.

Abstract Recurrently mutated in lymphoid neoplasms, the transcription factor RFX7 is emerging as a tumor suppressor. Previous reports suggested that RFX7 may also have a role in neurological and metabolic disorders. We recently reported that RFX7 responds to p53 signaling and cellular stress. Furthermore, we found RFX7 target genes to be dysregulated in numerous cancer types also beyond the hematological system. However, our understanding of RFX7’s target gene network and its role in health and disease remains limited. Here, we generated RFX7 knock-out cells and employed a multi-omics approach integrating transcriptome, cistrome, and proteome data to obtain a more comprehensive picture of RFX7 targets. We identify novel target genes linked to RFX7’s tumor suppressor function and underscoring its potential role in neurological disorders. Importantly, our data reveal RFX7 as a mechanistic link that enables the activation of these genes in response to p53 signaling.

Oxidative modification of cysteine residues has been shown to regulate the activity of several protein-tyrosine kinases. We explored the possibility that Fms-like tyrosine kinase 3 (FLT3), a hematopoietic receptor-tyrosine kinase, is subject to this type of regulation. An underlying rationale was that the FLT3 gene is frequently mutated in Acute Myeloid Leukemia patients, and resulting oncogenic variants of FLT3 with ‘internal tandem duplications (FLT3ITD)’ drive production of reactive oxygen in leukemic cells.FLT3 was moderately activated by treatment of intact cells with hydrogen peroxide. Conversely, FLT3ITD signaling was attenuated by cell treatments with agents inhibiting formation of reactive oxygen species. FLT3 and FLT3ITD incorporated DCP-Bio1, a reagent specifically reacting with sulfenic acid residues. Mutation of FLT3ITD cysteines 695 and 790 reduced DCP-Bio1 incorporation, suggesting that these sites are subject to oxidative modification. Functional characterization of individual FLT3ITD cysteine-to-serine mutants of all 8 cytoplasmic cysteines revealed phenotypes in kinase activity, signal transduction and cell transformation. Replacement of cysteines 681, 694, 695, 807, 925, and 945 attenuated signaling and blocked FLT3ITD-mediated cell transformation, whereas mutation of cysteine 790 enhanced activity of both FLT3ITD and wild-type FLT3. These effects were not related to altered FLT3ITD dimerization, but likely caused by changed intramolecular interactions.The findings identify the functional relevance of all cytoplasmic FLT3ITD cysteines, and indicate the potential for redox regulation of this clinically important oncoprotein. Keywords: Fms-like tyrosine kinase, FLT3, Cysteine residues, Oxidation, Signal transduction, Leukemic cell transformation