Objectives:To characterize the current burden, outcomes, and costs of managing sepsis patients in U.S. hospitals.Design:A retrospective observational study was conducted using the Premier Healthcare Database, which represents ~20% of U.S. inpatient discharges among private and academic hospitals. Hospital costs were obtained from billing records per the cost accounting method used by each hospital. Descriptive statistics were performed on patient demographics, characteristics, and clinical and economic outcomes for the index hospitalization and 30-day readmissions.Setting:Sepsis patient hospitalizations, including inpatient, general ward, and ICU (intermediate and/or step-down).Patients:Adults over 18 years old with a hospital discharge diagnosis code of sepsis from January 1, 2010, to September 30, 2016.Interventions:None. This was a retrospective observational study of deidentified data.Measurements and Main Results:The final study cohort consisted of 2,566,689 sepsis cases, representing patients with a mean age of 65 years (50.8% female). Overall mortality was 12.5% but varied greatly by severity (5.6%, 14.9%, and 34.2%) for sepsis without organ dysfunction, severe sepsis, and septic shock, respectively. Costs followed a similar pattern increasing by severity level: $16,324, $24,638, and $38,298 and varied widely by sepsis present at admission ($18,023) and not present at admission ($51,022).Conclusions:The highest burden of incidence and total costs occurred in the lowest severity sepsis cohort population. Sepsis cases not diagnosed until after admission, and those with increasing severity had a higher economic burden and mortality on a case-by-case basis. Methods to improve early identification of sepsis may provide opportunities for reducing the severity and economic burden of sepsis in the United States.

Purpose: Incidence and mortality rates for renal cell carcinoma (RCC) have been rising for decades. Unfortunately, the molecular events that support RCC carcinogenesis remain poorly understood. In an effort to gain a better understanding of signaling events in clear cell RCC (cRCC), we investigated the antitumor activity of secreted frizzled-related protein 1 (sFRP1), a negative regulator of Wnt signaling. Experimental Design: Genomic profiling of cRCC tumors and patient-matched normal tissues was done and confirmed using quantitative PCR and immunohistochemistry. Methylation-specific PCR was done on patient samples to evaluate the mechanism responsible for sFRP1loss. sFRP1 expression was restored in cRCC cells and the effects on tumor phenotype were characterized. Results: Genomic profiling, quantitative PCR, and immunohistochemistry indicated that loss of sFRP1occurred in cRCC and papillary RCC patient tissues. Twelve Wnt-regulated genes were up-regulated in cRCC tissues, including c-myc and cyclin D1, potentiators of cell proliferation and survival. Methylation of the sFRP1 gene was one mechanism identified for attenuation of sFRP1 mRNA. Stable reexpression of sFRP1in cRCC cells resulted in decreased expression of Wnt target genes, decreased growth in cell culture, inhibition of anchorage-independent growth, and decreased tumor growth in athymic nude mice. Conclusions: To our knowledge, this is the first report to show that stable restoration of sFRP1 expression in cRCC cells attenuates the cRCC tumor phenotype. Our data support a role for sFRP1as a tumor suppressor in cRCC and that perhaps loss of sFRP1is an early, aberrant molecular event in renal cell carcinogenesis.

Cancer cells elude anti-tumour immunity through multiple mechanisms, including upregulated expression of ligands for inhibitory immune checkpoint receptors1,2. Phagocytosis by macrophages plays a critical role in cancer control3–6. Therapeutic blockade of signal regulatory protein (SIRP)-α, an inhibitory receptor on macrophages, or of its ligand CD47 expressed on tumour cells, improves tumour cell elimination in vitro and in vivo7–10, suggesting that blockade of the SIRPα–CD47 checkpoint could be useful in treating human cancer11–14. However, the prophagocytic receptor(s) responsible for tumour cell phagocytosis is(are) largely unknown. Here we find that macrophages are much more efficient at phagocytosis of haematopoietic tumour cells, compared with non-haematopoietic tumour cells, in response to SIRPα–CD47 blockade. Using a mouse lacking the signalling lymphocytic activation molecule (SLAM) family of homotypic haematopoietic cell-specific receptors, we determined that phagocytosis of haematopoietic tumour cells during SIRPα–CD47 blockade was strictly dependent on SLAM family receptors in vitro and in vivo. In both mouse and human cells, this function required a single SLAM family member, SLAMF7 (also known as CRACC, CS1, CD319), expressed on macrophages and tumour cell targets. In contrast to most SLAM receptor functions15–17, SLAMF7-mediated phagocytosis was independent of signalling lymphocyte activation molecule-associated protein (SAP) adaptors. Instead, it depended on the ability of SLAMF7 to interact with integrin Mac-1 (refs 18–20) and utilize signals involving immunoreceptor tyrosine-based activation motifs21,22. These findings elucidate the mechanism by which macrophages engulf and destroy haematopoietic tumour cells. They also reveal a novel SAP adaptor-independent function for a SLAM receptor. Lastly, they suggest that patients with tumours expressing SLAMF7 are more likely to respond to SIRPα–CD47 blockade therapy.

A common characteristic of aging is loss of skeletal muscle (sarcopenia), which can lead to falls and fractures. MicroRNAs (miRNAs) are novel posttranscriptional modulators of gene expression with potential roles as regulators of skeletal muscle mass and function. The purpose of this study was to profile miRNA expression patterns in aging human skeletal muscle with a miRNA array followed by in-depth functional and network analysis. Muscle biopsy samples from 36 men [young: 31 ± 2 (n = 19); older: 73 ± 3 (n = 17)] were 1) analyzed for expression of miRNAs with a miRNA array, 2) validated with TaqMan quantitative real-time PCR assays, and 3) identified (and later validated) for potential gene targets with the bioinformatics knowledge base software Ingenuity Pathways Analysis. Eighteen miRNAs were differentially expressed in older humans (P < 0.05 and >500 expression level). Let-7 family members Let-7b and Let-7e were significantly elevated and further validated in older subjects (P < 0.05). Functional and network analysis from Ingenuity determined that gene targets of the Let-7s were associated with molecular networks involved in cell cycle control such as cellular proliferation and differentiation. We confirmed with real-time PCR that mRNA expression of cell cycle regulators CDK6, CDC25A, and CDC34 were downregulated in older compared with young subjects (P < 0.05). In addition, PAX7 mRNA expression was lower in older subjects (P < 0.05). These data suggest that aging is characterized by a higher expression of Let-7 family members that may downregulate genes related to cellular proliferation. We propose that higher Let-7 expression may be an indicator of impaired cell cycle function possibly contributing to reduced muscle cell renewal and regeneration in older human muscle.

BackgroundClear cell renal cell carcinoma (ccRCC) is the most common kidney cancer. The purpose of this study is to define a biological pathway signature and a cellular differentiation program in ccRCC.MethodologyWe performed gene expression profiling of early-stage ccRCC and patient-matched normal renal tissue using Affymetrix HG-U133a and HG-U133b GeneChips combined with a comprehensive bioinformatic analyses, including pathway analysis. The results were validated by real time PCR and IHC on two independent sample sets. Cellular differentiation experiments were performed on ccRCC cell lines and their matched normal renal epithelial cells, in differentiation media, to determine their mesenchymal differentiation potential.Principal FindingsWe identified a unique pathway signature with three major biological alterations—loss of normal renal function, down-regulated metabolism, and immune activation–which revealed an adipogenic gene expression signature linked to the hallmark lipid-laden clear cell morphology of ccRCC. Culturing normal renal and ccRCC cells in differentiation media showed that only ccRCC cells were induced to undergo adipogenic and, surprisingly, osteogenic differentiation. A gene expression signature consistent with epithelial mesenchymal transition (EMT) was identified for ccRCC. We revealed significant down-regulation of four developmental transcription factors (GATA3, TFCP2L1, TFAP2B, DMRT2) that are important for normal renal development.ConclusionsccRCC is characterized by a lack of epithelial differentiation, mesenchymal/adipogenic transdifferentiation, and pluripotent mesenchymal stem cell-like differentiation capacity in vitro. We suggest that down-regulation of developmental transcription factors may mediate the aberrant differentiation in ccRCC. We propose a model in which normal renal epithelial cells undergo dedifferentiation, EMT, and adipogenic transdifferentiation, resulting in ccRCC. Because ccRCC cells grown in adipogenic media regain the characteristic ccRCC phenotype, we have indentified a new in vitro ccRCC cell model more resembling ccRCC tumor morphology.