Immunetics (United States)

Activation of transcription factors is a key driver event in cancer. We and others have recently reported that the Krüppel-like transcription factor KLF5 is activated in multiple epithelial cancer types including squamous cancer and gastrointestinal adenocarcinoma, yet the functional consequences and the underlying mechanisms of this activation remain largely unknown. Here we demonstrate that activation of KLF5 results in strongly selective KLF5 dependency for these cancer types. KLF5 bound lineage-specific regulatory elements and activated gene expression programs essential to cancer cells. HiChIP analysis revealed that multiple distal KLF5 binding events cluster and synergize to activate individual target genes. Immunoprecipitation-mass spectrometry assays showed that KLF5 interacts with other transcription factors such as TP63 and YAP1, as well as the CBP/EP300 acetyltransferase complex. Furthermore, KLF5 guided the CBP/EP300 complex to increase acetylation of H3K27, which in turn enhanced recruitment of the bromodomain protein BRD4 to chromatin. The 3D chromatin architecture aggregated KLF5-dependent BRD4 binding to activate polymerase II elongation at KLF5 target genes, which conferred a transcriptional vulnerability to proteolysis-targeting chimera-induced degradation of BRD4. Our study demonstrates that KLF5 plays an essential role in multiple epithelial cancers by activating cancer-related genes through 3D chromatin loops, providing an evidence-based rationale for targeting the KLF5 pathway. SIGNIFICANCE: An integrative 3D genomics methodology delineates mechanisms underlying the function of KLF5 in multiple epithelial cancers and suggests potential strategies to target cancers with aberrantly activated KLF5.

Introduction: The purpose of this project was to conduct a secondary validation of 6 novel predictors of sepsis in the burn patient (heart rate (HR) >130 bpm, mean arterial pressure (MAP) <60 mmHg, base deficit (BD) <-6 mEq/L, temp <36°C, use of vasoactive medications, and glucose >150 mg/dl). Three identified time periods were compared: sepsis (“sick”) with positive blood culture, sepsis (“sick”) with negative blood culture, and control (“non-sick”). This model was significant in predicting positive sick and all sick with area under the receiver operating curve (AUROC) of 0.775 (p < 0.001) and 0.714 (p < .001), respectively, up to 48 hours prior. Methods: Analysis was performed using 11 clinical variables from an existing within-patient comparison database of 59 burn patients from a single center. Secondary analysis compared 4 groups: non-sick vs positive sick; non-sick vs negative sick; negative sick vs positive sick; and non-sick versus all sick. Modified-random forest and CART (Classification and Regression Tree) decision tree approaches were applied to the dataset. Limitations of data excluded 2 “novel predictors” from this analysis: glucose and BD. Results: Positive sick vs not sick was the only paring with AUROC > 0.7, significant only 24 hours prior. Classifiers that achieved target AUROC include: max temp > 39.4 OR max blood transfusion (BT) ≥2 OR MAP < 58 = AUROC 0.737; MAP < 55 OR min BT ≥2 = AUROC 0.728; and any 2 of max 24 hour urine < 299, MAP < 57, Temp < 36.2°C = AUROC 0.720. High HR and low MAP were important to discriminate any sick vs non-sick patient. Conclusions: Positive sick versus not sick is the dichotomy best predicted accurately overall. Elevated HR and low MAP have been further validated as strong predictors of burn sepsis. Ongoing prospective validation of clinical predictors continues at our burn center as decision support technology solutions are in development to incorporate best predictors into useful tools for bedside providers.

Scuba divers typically rinse equipment in communal tanks. Studies show these tanks are contaminated with bacteria, but the types of bacteria have not been studied. We sought to identify bacteria in rinse tanks at a dive facility at San Pedro, Belize, to determine the origin of the bacteria and determine whether the bacteria represented potential threats to human health. The identity of bacteria was investigated using reverse line blot (RLB) assays based on 28 different rDNA probes designed to detect known pathogens of sepsis, as well as by sequencing 23S rDNA from isolates and performing VITEK identification of several isolates. Based on the identities of bacteria in divers' rinse tanks, many likely originate from the ocean, and others likely originate from the divers themselves. None of the bacteria identified would be considered overt human pathogens. However, some of the bacteria found in the tanks are known to be associated with unsanitary conditions and can cause opportunistic infections, which may pose health problems to some individuals. Rinsing scuba equipment in communal tanks has the potential to transmit disease among some divers. Equipment, especially regulators and masks, should be rinsed/cleaned individually and not be placed in communal tanks.