SUMMARY PARAGRAPH MicroRNAs (miRNAs) are short non-coding RNAs expressed in different tissue and cell types that suppress the expression of target genes. As such, miRNAs are critical cogs in numerous biological processes1,2, and dysregulated miRNA expression is correlated with many human diseases. Certain miRNAs, called oncomiRs, play a causal role in the onset and maintenance of cancer when overexpressed. Tumors that depend on these miRNAs are said to display oncomiR addiction3–5. Some of the most effective anticancer therapies target oncogenes like EGFR and HER2; similarly, inhibition of oncomiRs using antisense oligomers (i.e. antimiRs) is an evolving therapeutic strategy6,7. However, the in vivo efficacy of current antimiR technologies is hindered by physiological and cellular barriers to delivery into targeted cells8. Here we introduce a novel antimiR delivery platform that targets the acidic tumor microenvironment, evades systemic clearance by the liver, and facilitates cell entry via a non-endocytic pathway. We found that the attachment of peptide nucleic acid (PNA) antimiRs to a peptide with a low pH-induced transmembrane structure (pHLIP) produced a novel construct that could target the tumor microenvironment, transport antimiRs across plasma membranes under acidic conditions such as those found in solid tumors (pH ~6), and effectively inhibit the miR-155 oncomiR in a mouse model of lymphoma. This study introduces a new paradigm in the use of antimiRs as anti-cancer drugs, which can have broad impacts on the field of targeted drug delivery.

Growing evidence suggests that tumor-associated macrophages (TAMs) promote cancer progression and therapeutic resistance by enhancing angiogenesis, matrix-remodeling and immunosuppression. In this study prostate cancer (PCa) under androgen blockade therapy (ABT) was investigated, demonstrating that TAMs contribute to PCa disease recurrence through paracrine signaling processes. ABT induced the tumor cells to express macrophage colony-stimulating factor 1 (M-CSF-1 or CSF-1) and other cytokines that recruit and modulate macrophages, causing a significant increase in TAM infiltration. Inhibitors of CSF-1 signaling through its receptor, CSF-1R, were tested in combination with ABT, demonstrating that blockade of TAM influx in this setting disrupts tumor promotion and sustains a more durable therapeutic response compared to ABT alone.

Objective To describe HARVEST, a novel point-of-care patient summarization and visualization tool, and to conduct a formative evaluation study to assess its effectiveness and gather feedback for iterative improvements.Materials and methods HARVEST is a problem-based, interactive, temporal visualization of longitudinal patient records. Using scalable, distributed natural language processing and problem salience computation, the system extracts content from the patient notes and aggregates and presents information from multiple care settings. Clinical usability was assessed with physician participants using a timed, task-based chart review and questionnaire, with performance differences recorded between conditions (standard data review system and HARVEST).Results HARVEST displays patient information longitudinally using a timeline, a problem cloud as extracted from notes, and focused access to clinical documentation. Despite lack of familiarity with HARVEST, when using a task-based evaluation, performance and time-to-task completion was maintained in patient review scenarios using HARVEST alone or the standard clinical information system at our institution. Subjects reported very high satisfaction with HARVEST and interest in using the system in their daily practice.Discussion HARVEST is available for wide deployment at our institution. Evaluation provided informative feedback and directions for future improvements.Conclusions HARVEST was designed to address the unmet need for clinicians at the point of care, facilitating review of essential patient information. The deployment of HARVEST in our institution allows us to study patient record summarization as an informatics intervention in a real-world setting. It also provides an opportunity to learn how clinicians use the summarizer, enabling informed interface and content iteration and optimization to improve patient care.

Glucocorticoid (GC) administration induces atrophy of skin, bone, and other organs, partly by reducing tissue content of glycosaminoglycans, particularly hyaluronic acid (HA). We took advantage of the recent cloning of the three human hyaluronan synthase (HAS) enzymes (HAS1, HAS2 and HAS3), to explore the molecular mechanisms of this side effect. Northern and slot blots performed on RNA extracted from cultured dermal fibroblasts and the MG-63 osteoblast-like osteosarcoma cell line indicated that HAS2 is the predominant HAS mRNA in these cells. Incubation of both cell types for 24 h in the presence of 10(-6) M dexamethasone (DEX) resulted in a striking 97--98% suppression of HAS2 mRNA levels. Time-course studies in fibroblasts demonstrated suppression of HAS2 mRNA to 28% of control by 1 h, and to 1.2% of control by 2 h, after addition of DEX. Dose-response studies in fibroblasts indicated that the majority of the suppressive effect required concentrations characteristic of cell-surface GC receptors, a point confirmed by persistent DEX-induced suppression in the presence of RU486, an antagonist of classic cytosolic steroid hormone receptors. Nuclear run-off experiments showed a 70% suppression of HAS2 gene transcription in nuclei from DEX-treated fibroblasts, which is unlikely to fully explain the rapid 50--80-fold reduction in message levels. Experiments with actinomycin D (AMD) demonstrated that the message half-life was 25 min in cells without DEX, whereas the combination of AMD with DEX dramatically increased the half-life of HAS2 mRNA, suggesting that DEX acts by inducing a short-lived destabilizer of the HAS2 message. Direct assessment of HAS2 mRNA stability by wash-out of incorporated uridine label established a half-life of 31 min in cells without DEX, which substantially shortened in the presence of DEX. In conclusion, GCs induce a rapid and sustained, near-total suppression of HAS2 message levels, mediated through substantial decreases in both gene transcription and message stability. These effects may contribute to the loss of HA in GC-treated organs.

Notch controls skeletogenesis, but its role in the remodeling of adult bone remains conflicting. In mature mice, the skeleton can become osteopenic or osteosclerotic depending on the time point at which Notch is activated or inactivated. Using adult EGFP reporter mice, we find that Notch expression is localized to osteocytes embedded within bone matrix. Conditional activation of Notch signaling in osteocytes triggers profound bone formation, mainly due to increased mineralization, which rescues both age-associated and ovariectomy-induced bone loss and promotes bone healing following osteotomy. In parallel, mice rendered haploinsufficient in γ-secretase presenilin-1 (Psen1), which inhibits downstream Notch activation, display almost-absent terminal osteoblast differentiation. Consistent with this finding, pharmacologic or genetic disruption of Notch or its ligand Jagged1 inhibits mineralization. We suggest that stimulation of Notch signaling in osteocytes initiates a profound, therapeutically relevant, anabolic response.