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BackgroundLiquid biopsies have become an integral part of cancer management as minimally invasive options to detect molecular and genetic changes. However, current options show poor sensitivity in peritoneal carcinomatosis (PC). Novel exosome-based liquid biopsies may provide critical information on these challenging tumors. In this initial feasibility analysis, we identified an exosome gene signature of 445 genes (ExoSig445) from colon cancer patients, including those with PC, that is distinct from healthy controls.MethodsPlasma exosomes from 42 patients with metastatic and non-metastatic colon cancer and 10 healthy controls were isolated and verified. RNAseq analysis of exosomal RNA was performed and differentially expressed genes (DEGs) were identified by the DESeq2 algorithm. The ability of RNA transcripts to discriminate control and cancer cases was assessed by principal component analysis (PCA) and Bayesian compound covariate predictor classification. An exosomal gene signature was compared with tumor expression profiles of The Cancer Genome Atlas.ResultsUnsupervised PCA using exosomal genes with greatest expression variance showed stark separation between controls and patient samples. Using separate training and test sets, gene classifiers were constructed capable of discriminating control and patient samples with 100% accuracy. Using a stringent statistical threshold, 445 DEGs fully delineated control from cancer samples. Furthermore, 58 of these exosomal DEGs were found to be overexpressed in colon tumors.ConclusionsPlasma exosomal RNAs can robustly discriminate colon cancer patients, including patients with PC, from healthy controls. ExoSig445 can potentially be developed as a highly sensitive liquid biopsy test in colon cancer.

IntroductionTumor agnostic circulating tumor DNA (ctDNA) is routinely used to guide treatment decisions in gastrointestinal (GI) cancers, especially metastatic cancers. The amount of ctDNA detected in plasma is affected by stage, tumor burden, and tumor vascularization. We hypothesized that peritoneal carcinomatosis (PC) is associated with lower ctDNA levels than other metastatic sites in GI cancers due to the plasma-peritoneal barrier.MethodsWe conducted a retrospective analysis of patients with stage II-IV GI cancers treated at our institution between 2015 and 2020 with available panel-based ctDNA results (Guardant 360TM). ctDNA analysis was performed on early and pretreatment samples. We compared the reported maximum variant allele frequency (mVAF) of somatic mutations across metastatic sites.ResultsOf the 279 patients with GI cancers (colorectal, upper GI, pancreaticobiliary), 212 had stage IV disease (PC: n = 61; visceral metastases: n = 138; other metastases: n = 13). Mean mVAF increased with increasing stages of disease (stage II: 3.6 ± 7; stage III: 6.4 ± 10; stage IV: 28.0 ± 51; p

Background: The abdominal seat belt sign (SBS) is associated with an increased risk of hollow viscus injury (HVI). Older age is associated with worse outcomes in trauma patients. Thus, older trauma patients ≥65 years of age (OTPs) may be at an increased risk of HVI with abdominal SBS. Therefore, we hypothesized an increased incidence of HVI and mortality for OTPs vs younger trauma patients (YTPs) with abdominal SBS. Study design: This post hoc analysis of a multi-institutional, prospective, observational study (8/2020-10/2021) included patients >18 years old with an abdominal SBS who underwent abdominal computed tomography (CT) imaging. Older trauma patients were compared to YTPs (18-64 years old) with bivariate analyses. Results: Of the 754 patients included in this study from nine level-1 trauma centers, there were 110 (14.6%) OTPs and 644 (85.4%) YTPs. Older trauma patients were older (mean 75.3 vs 35.8 years old, P < .01) and had a higher mean Injury Severity Score (10.8 vs 9.0, P = .02). However, YTPs had an increased abdominal abbreviated-injury scale score (2.01 vs 1.63, P = .02). On CT imaging, OTPs less commonly had intraabdominal free fluid (21.7% vs 11.9%, P = .02) despite a similar rate of abdominal soft tissue contusion (P > .05). Older trauma patients also had a statistically similar rate of HVI vs YTPs (5.5% vs 9.8%, P = .15). Despite this, OTPs had increased mortality (5.5% vs 1.1%, P < .01) and length of stay (LOS) (5.9 vs 4.9 days P < .01). Conclusion: Despite a similar rate of HVI, OTPs with an abdominal SBS had an increased rate of mortality and LOS. This suggests the need for heightened vigilance when caring for OTPs with abdominal SBS. [ABSTRACT FROM AUTHOR]

Macrophages play a key role in the development of atherosclerosis. Murine noroviruses (MNV) are highly prevalent in research mouse colonies and infect macrophages and dendritic cells. Our laboratory found that MNV4 infection in mice lacking the LDL receptor alters the development of atherosclerosis, potentially confounding research outcomes. Therefore, we investigated whether MNV4 likewise altered atherosclerosis in ApoE(-/-) mice. In the presence of oxidized LDL, MNV4 infection of ApoE(-/-) bone marrow-derived macrophages increased the gene expression of the inflammatory markers inducible nitric oxide synthase, monocyte chemoattractant protein 1, and IL6. In addition, proteins involved in cholesterol transport were altered in MNV4-infected ApoE -/- bone marrow-derived macrophages and consisted of increased CD36 and decreased ATP-binding cassette transporter A1. MNV4 infection of ApoE(-/-) mice at 12 wk of age (during the development of atherosclerosis) had a variable effect on atherosclerotic lesion size. In one study, MNV4 significantly increased atherosclerotic plaque area whereas in a second study, no effect was observed. Compared with controls, MNV4-infected mice had higher circulating Ly6C-positive monocytes, and viral RNA was detected in the aortas of some mice, suggesting potential mechanisms by which MNV4 alters disease progression. Plaque size did not differ when ApoE -/- mice were infected at 4 wk of age (early during disease development) or in ApoE -/- mice maintained on a high-fat, high-cholesterol diet. Therefore, these data show that MNV4 has the potential to exert a variable and unpredictable effect on atherosclerosis in ApoE(-/-) mice. We therefore propose that performing experiments in MNV-free mouse colonies is warranted.