Laparotomy for Abdominal Stab Wound With Combined Omental and Organ Evisceration: 10-Year Experience From a Major Trauma Centre in South Africa.

INTRODUCTION: Combined omental and organ evisceration following anterior abdominal stab wound (SW) is uncommon and there is a paucity of literature describing the management and spectrum of injuries encountered at laparotomy. METHODS: A retrospective study was undertaken on all patients who presented with anterior abdominal SW involving combined omental and organ evisceration who underwent laparotomy over a 10-year period from January 2008 to January 2018 at a major trauma centre in South Africa. RESULTS: A total of 61 patients were eligible for inclusion and all underwent laparotomy: 87% male, mean age: 29 years. Ninety-two percent (56/61) had a positive laparotomy whilst 8% (5/61) underwent a negative procedure. Of the 56 positive laparotomies, 91% (51/56) were considered therapeutic and 9% (5/56) were non-therapeutic. In addition to omental evisceration, 59% (36/61) had eviscerated small bowel, 28% (17/61) had eviscerated colon and 13% (8/61) had eviscerated stomach. A total of 92 organ injuries were identified. The most commonly injured organs were small bowel, large bowel and stomach. The overall complication rate was 11%. Twelve percent (7/61) required intensive care unit admission. The mean length of hospital stay was 9 days. The overall mortality rate for all 61 patients was 2%. CONCLUSIONS: The presence of combined omental and organ evisceration following abdominal SW mandates laparotomy. The small bowel, large bowel and stomach were the most commonly injured organs in this setting.

Fisher ratio feature selection by manual peak area calculations on comprehensive two-dimensional gas chromatography data using standard mixtures with variable composition, storage, and interferences.

Comprehensive two-dimensional gas chromatography (GC×GC) is becoming increasingly more common for non-targeted characterization of complex volatile mixtures. The information gained with higher peak capacity and sensitivity provides additional sample composition information when one-dimensional GC is not adequate. GC×GC generates complex multivariate data sets when using non-targeted analysis to discover analytes. Fisher ratio (FR) analysis is applied to discern class markers, limiting complex GC×GC profiles to the most discriminating compounds between classes. While many approaches for feature selection using FR analysis exist, FR can be calculated relatively easily directly on peak areas after any native software has performed peak detection. This study evaluated the success rates of manual FR calculation and comparison to a critical F-value for samples analyzed by GC×GC with defined concentration differences. Long-term storage of samples and other spiked interferences were also investigated to examine their impact on analyzing mixtures using this FR feature selection strategy. Success rates were generally high with mostly 90-100% success rates and some instances of percentages between 80 and 90%. There were rare cases of false positives present and a low occurrence of false negatives. When errors were made in the selection of a compound, it was typically due to chromatographic artifacts present in chromatograms and not from the FR approach itself. This work provides foundational experimental data on the use of manual FR calculations for feature selection from GC×GC data.

Adipocyte-derived lactate is a signalling metabolite that potentiates adipose macrophage inflammation via targeting PHD2.

Adipose tissue macrophage (ATM) inflammation is involved with meta-inflammation and pathology of metabolic complications. Here we report that in adipocytes, elevated lactate production, previously regarded as the waste product of glycolysis, serves as a danger signal to promote ATM polarization to an inflammatory state in the context of obesity. Adipocyte-selective deletion of lactate dehydrogenase A (Ldha), the enzyme converting pyruvate to lactate, protects mice from obesity-associated glucose intolerance and insulin resistance, accompanied by a lower percentage of inflammatory ATM and reduced production of pro-inflammatory cytokines such as interleukin 1ß (IL-1ß). Mechanistically, lactate, at its physiological concentration, fosters the activation of inflammatory macrophages by directly binding to the catalytic domain of prolyl hydroxylase domain-containing 2 (PHD2) in a competitive manner with α-ketoglutarate and stabilizes hypoxia inducible factor (HIF-1α). Lactate-induced IL-1ß was abolished in PHD2-deficient macrophages. Human adipose lactate level is positively linked with local inflammatory features and insulin resistance index independent of the body mass index (BMI). Our study shows a critical function of adipocyte-derived lactate in promoting the pro-inflammatory microenvironment in adipose and identifies PHD2 as a direct sensor of lactate, which functions to connect chronic inflammation and energy metabolism.

Serum Thrombospondin-2 Levels Are Closely Associated With the Severity of Metabolic Syndrome and Metabolic Associated Fatty Liver Disease.

CONTEXT: Metabolic associated fatty liver disease (MAFLD) is the hepatic manifestation of obesity-related metabolic syndrome (MetS). Noninvasive biomarkers for monitoring the progression and severity of these metabolic comorbidities are needed. OBJECTIVES: To investigate the associations of serum thrombospondin-2 (TSP2) with MetS and MAFLD severity, and the potential diagnostic value of serum TSP2 for identifying at-risk metabolic associated steatohepatitis (MASH). METHODS: Blood samples, clinical data, and liver biopsies were collected from consecutively recruited 252 individuals with morbid obesity receiving bariatric surgery. Histopathology samples of liver biopsies were examined in a blinded fashion by 3 independent pathologists. Serum TSP2 levels were measured by enzyme-linked immunosorbent assay. RESULTS: Serum TSP2 levels were significantly elevated in MetS (1.58 [1.07-2.20] ng/mL) compared with non-MetS (1.28 [0.84-1.73] ng/mL; P = .006) in obese patients and positively correlated with increasing number of the MetS components, fasting glucose, glycated hemoglobin, fasting insulin, C-peptide, and homeostatic model assessment of insulin resistance after adjustment of conventional confounders. Serum TSP2 levels differentiated MASH (1.74 [1.32-3.09] ng/mL) from the other non-MASH less severe groups: normal liver (1.41 [1.04-1.63] ng/mL), simple steatosis (1.45 [0.89-1.92] ng/mL), and borderline MASH (1.30 [0.99-2.17] ng/mL) (P < .05). Elevated serum TSP2 was positively associated with the severity of hepatic steatosis, inflammation, fibrosis, and abnormal liver function independent of age, sex and adiposity. Furthermore, high serum TSP2 identified at-risk MASH with area under the operating curve of 0.84 (95% CI 0.70-0.98). CONCLUSION: Serum TSP2 is closely associated with severity and progression of MetS and MAFLD, and is a promising noninvasive biomarker for differentiating MASH from benign steatosis and identifying at-risk MASH patients among individuals with obesity.

Investigating volatiles as the secondary metabolome of Piper methysticum from root powder and water extracts using comprehensive two-dimensional gas chromatography.

ETHNOPHARMACOLOGICAL RELEVANCE: Kava (Piper methysticum G. Forst) is a plant grown in the Pacific that is used in traditional medicines. The roots are macerated and powdered for consumption as a beverage in social settings as well as in ceremonies. Other types of preparations can also be used as traditional medicines. There has been an increase in demand for kava as there is continued traditional use and as it is becoming utilized more both socially and medicinally outside of Oceania. Currently, most research of this plant has focused on bioactive kavalactones and flavokawains, and there are few studies focusing on the other compounds that kava contains, such as volatile and semivolatile components. AIM OF THE STUDY: This study investigated the kava volatile organic compound (VOC) profile from nine different commercially available samples of dried, powdered kava root sourced across the Pacific region. MATERIALS AND METHODS: The headspace above the kava samples was analyzed, both from the root powder as originally purchased and by performing a scaled-down extraction into water mimicking traditional preparation of the beverage. The headspace of each sample was extracted using solid-phase microextraction arrow (SPME Arrow), followed by analysis using comprehensive two-dimensional gas chromatography - quadrupole mass spectrometry/flame ionization detection (GC×GC-qMS/FID). The superior peak capacity of GC×GC was invaluable in effectively separating the complex mixture of compounds found in all samples, which enabled improved monitoring of minor differences between batches. RESULTS: Dry root powder samples contained high levels of ß-caryophyllene while water extracted samples showed high levels of camphene. Many alcohols, aldehydes, ketones, terpenes, terpenoids, and aromatics were also characterized from both types of samples. All water extracted samples from the different brands followed similar trends in terms of compounds being detected or not. Additional major compounds found in water extracts included benzaldehyde, hexanal, methoxyphenyloxime, camphor, limonene, 1-hexanol, endoborneol, and copaene. While some samples could be differentiated based on brand, samples did not group by purported geographic origin. CONCLUSIONS: This study provides foundational data about a different subset of compounds within kava than previous research has studied, and also informs the community of the compounds that transfer into the consumed beverage during the traditional means of preparing kava.

Foley Catheter Balloon Tamponade for Actively Bleeding Wounds Following Penetrating Neck Injury is an Effective Technique for Controlling Non-Compressible Junctional External Haemorrhage.

BACKGROUND: The foley catheter balloon tamponade (FCBT) has been widely employed in the management of trauma. This study reviews our cumulative experience with the use of FCBT in the management of patients presenting with a penetrating neck injury (PNI). METHODS: A retrospective study was conducted at a major trauma centre in South Africa over a 9-year period from January 2012 to December 2020. All patients who presented with a PNI who had FCBT were included. RESULTS: A total of 1581 patients with a PNI were managed by our trauma centre, and 44 (3%) patients had an FCBT. Of the 44 cases of FCBT, stab wounds accounted for 93% (41/44) and the remaining 7% were for gunshot wounds. Seventy-five per cent of all FCBT (33/44) were inserted at a rural hospital prior to transfer to our trauma centre; the remaining 25% (11/44) were inserted in our resuscitation room. The success rate of FCBT was 80% (35/44), allowing further CT with angiography (CTA) to be performed. CTA findings were: 10/35 (29%) positive, 18/35 (51%) negative, and 7/35 (20%) equivocal. Fifteen patients required additional intervention (open surgery or endovascular intervention). The overall morbidity was 14% (6/44). Eighteen per cent required intensive care unit admission. The median length of stay was 1 day. The overall mortality rate was 11% (5/44). CONCLUSION: FCBT is a simple and effective technique as an adjunct in the management of major haemorrhage from a PNI. In highly selective patients, it may also be used as definitive management.

Trends in the Management of Abdominal Gunshot Wounds Over the Last Decade: A South African Experience.

BACKGROUND: This study aimed to review our decade-long experience with the management of abdominal gunshot wounds (GSWs), to document trends in our approach and to develop an evidence base for our contemporary management algorithms in a major trauma in South Africa. MATERIALS AND METHODS: This was a retrospective study that included all adult patients with abdominal GSWs between January 2013 and October 2020 managed at a major trauma centre in South Africa. RESULT: Five hundred and ninety-six cases were included (87% male, mean age: 32 years). The median Injury Severity Score (ISS) was 12. 52% (309/596) of cases had indications of immediate laparotomy and proceeded directly to the operating room without any CT imaging. Of this cohort, the laparotomy was positive in 292 and in the remainder (5%) was negative. Of the remaining 287 cases, 209 underwent a CT scan (35%). 78 were managed without any CT imaging. Of the 78 who did not undergo CT scan, all were managed without any operation and discharged home well. Of the 209 who underwent CT scan, 99 were observed and only one case in this group subsequently required a laparotomy. The remaining 110 cases underwent a laparotomy, which was negative in 7. There were correlations with increasing use of CT, as well as a decrease in those proceeding directly to laparotomy. The overall morbidity rate was 8% (47/596). 32% (190/596) require intensive care unit (ICU) admission. The overall mortality rate was 8% (67/596). CONCLUSIONS: The management of abdominal GSWs has continued to evolve. There is now a well-defined role for selective non-operative management in this group of patients and relies on accurate CT assessment. CT scan is now an important component in the management of abdominal GSW even in our resource-constrained environment.

The Management of Penetrating Neck Injury With Retained Knife: 15-Year Experience From a Major Trauma Center in South Africa.

BACKGROUND: This study reviews our cumulative experience with the management of patients presenting with a retained knife following a penetrating neck injury (PNI). METHODS: A retrospective cohort study was conducted at a major trauma center in South Africa over a 15-year period from July 2006 to December 2020. All patients who presented with a retained knife in the neck following a stab wound (SW) were included. RESULTS: Twenty-two cases were included: 20 males (91%), mean age: 29 years. 77% (17/22) were retained knives and 23% (5/22) were retained blades. Eighteen (82%) were in the anterior neck, and the remaining 4 cases were in the posterior neck. Plain radiography was performed in 95% (21/22) of cases, and computed tomography (CT) was performed in 91% (20/22). Ninety-five percent (21/22) had the knife or blade extracted in the operating room (OR). Formal neck exploration (FNE) was undertaken in 45% (10/22) of cases, and the remaining 55% (12/22) underwent simple extraction (SE) only. Formal neck exploration was more commonly performed for anterior neck retained knives than the posterior neck, although not statistically significant [56% (10/18) vs 0% (0/18), P = .096]. There were no significant differences in the need for intensive care admission, length of hospital stay, morbidities, or mortalities between anterior and posterior neck retained knives. DISCUSSION: Uncontrolled extraction of a retained knife in the neck outside of the operating room may be dangerous. Retained knives in the anterior neck commonly required formal neck exploration but not for posterior neck retained knives.

Extracellular Matrix in Synthetic Hydrogel-Based Prostate Cancer Organoids Regulate Therapeutic Response to EZH2 and DRD2 Inhibitors.

Following treatment with androgen receptor (AR) pathway inhibitors, ≈20% of prostate cancer patients progress by shedding their AR-dependence. These tumors undergo epigenetic reprogramming turning castration-resistant prostate cancer adenocarcinoma (CRPC-Adeno) into neuroendocrine prostate cancer (CRPC-NEPC). No targeted therapies are available for CRPC-NEPCs, and there are minimal organoid models to discover new therapeutic targets against these aggressive tumors. Here, using a combination of patient tumor proteomics, RNA sequencing, spatial-omics, and a synthetic hydrogel-based organoid, putative extracellular matrix (ECM) cues that regulate the phenotypic, transcriptomic, and epigenetic underpinnings of CRPC-NEPCs are defined. Short-term culture in tumor-expressed ECM differentially regulated DNA methylation and mobilized genes in CRPC-NEPCs. The ECM type distinctly regulates the response to small-molecule inhibitors of epigenetic targets and Dopamine Receptor D2 (DRD2), the latter being an understudied target in neuroendocrine tumors. In vivo patient-derived xenograft in immunocompromised mice showed strong anti-tumor response when treated with a DRD2 inhibitor. Finally, we demonstrate that therapeutic response in CRPC-NEPCs under drug-resistant ECM conditions can be overcome by first cellular reprogramming with epigenetic inhibitors, followed by DRD2 treatment. The synthetic organoids suggest the regulatory role of ECM in therapeutic response to targeted therapies in CRPC-NEPCs and enable the discovery of therapies to overcome resistance.

Recurrent pneumothorax following chest tube removal in thoracic stab wounds: a comparative study between end inspiratory versus end expiratory removal techniques at a major trauma centre in South Africa.

BACKGROUND: Tube thoracostomy (TT) insertion is a commonly performed procedure in trauma that is standardised, but the optimal removal technique based on the timing in relation to the respiratory cycle remains controversial. METHODS: A prospective study was undertaken at a major trauma centre in South Africa over a 4-year period from January 2010 to December 2013, and included all patients with pneumothorax secondary to thoracic stab wounds. TTs were removed by either end of inspiration technique (EIT) or end of expiration (EET) technique and the rate of recurrent pneumothorax (RPTX) following removal was compared. We hypothesized that there is no difference in the rate of RPTX between the end inspiratory (EI) and end expiratory (EE) removal technique. RESULTS: A total 347 patients were included. Of the 184 TTs removed by EIT, there were 17 (9%) RPTXs. Of the 163 with EET, there were 11 RPTXs (7%), (9% versus 7%, chi-squared, P = 0.395). Of the total 28 (9%) patients with RPTXs following removal of chest tubes, two (7%) required reinsertion of chest tube (0.5% (1/184) in EIT and 0.6% (1/163) in EET, P = 0.747). CONCLUSIONS: Timing of TT removal in relation to the respiratory cycle does not appear to influence the incidence of RPTX in patients with thoracic stab wounds. Technique of removal may well be a more important consideration and more attention must be focused on refining the optimal technique.

Retrospective cohort study of paediatric splenic injuries at a major adult trauma centre in South Africa identifies areas of success and improvement.

This study reviews our experience with paediatric splenic trauma in a major trauma centre in South Africa. We reviewed the management and outcomes of 66 paediatric patients and concluded that selective non-operative management of paediatric splenic trauma can be undertaken successfully in a middle-income country such as South Africa. The grade of splenic injury itself is rarely the sole determinant of operative or non-operative treatment and clinical outcome.

BACKGROUND: Over the last 50 years, the gold standard for paediatric trauma management has grown to be non-operative management. This study reviews a South African experience with paediatric splenic trauma in order to benchmark this against the international standard and to identify discrepancies in access to care and in surgical outcomes. METHODS: This was a retrospective study conducted at a major trauma centre in South Africa. All children less than 18 years of age who were admitted to our trauma centre following trauma between December 2012 and October 2020 were identified and all those who sustained splenic trauma were reviewed. RESULTS: Of the 66 patients reviewed, 48 (72%) were male, and the median age was 12 years (0-18 years). Thirty-three (51%) were of rural origin and 61 (93%) sustained blunt trauma. Only eight (12%) had an isolated splenic injury, while the remaining 58 (88%) had other associated injuries. Forty-five patients (68%) were managed non-operatively whilst the remainder were subjected to laparotomy. Five (7%) required a splenectomy and one required angio-embolisation. Twenty-six patients (39%) required intensive care unit (ICU) admission: 15 (37%) in the non-operative cohort required ICU admission and eight (40%) in the laparotomy group required ICU admission. Twenty-eight (42%) patients required ventilatory support. Median length of stay was 5.5 days. Four (6%) patients died. CONCLUSIONS: Although non-operative management of paediatric splenic trauma can be undertaken successfully by adult trauma surgeons in a middle-income country such as South Africa, there remains room for improvement. To achieve splenic salvage rates comparable to those in dedicated paediatric trauma centres in high-income countries will require systematic quality improvement programmes.

Vitamin D3 activates the autolysosomal degradation function against Helicobacter pylori through the PDIA3 receptor in gastric epithelial cells.

Helicobacter pylori (H. pylori) is a common human pathogenic bacterium. Once infected, it is difficult for the host to clear this organism using the innate immune system. Increased antibiotic resistance further makes it challenging for effective eradication. However, the mechanisms of immune evasion still remain obscure, and novel strategies should be developed to efficiently eliminate H. pylori infection in stomachs. Here we uncovered desirable anti-H. pylori effect of vitamin D3 both in vitro and in vivo, even against antibiotic-resistant strains. We showed that H. pylori can invade into the gastric epithelium where they became sequestered and survived in autophagosomes with impaired lysosomal acidification. Vitamin D3 treatment caused a restored lysosomal degradation function by activating the PDIA3 receptor, thereby promoting the nuclear translocation of PDIA3-STAT3 protein complex and the subsequent upregulation of MCOLN3 channels, resulting in an enhanced Ca2+ release from lysosomes and normalized lysosomal acidification. The recovered lysosomal degradation function drives H. pylori to be eliminated through the autolysosomal pathway. These findings provide a novel pathogenic mechanism on how H. pylori can survive in the gastric epithelium, and a unique pathway for vitamin D3 to reactivate the autolysosomal degradation function, which is critical for the antibacterial action of vitamin D3 both in cells and in animals, and perhaps further in humans. Abbreviations: 1,25D3: 1α, 25-dihydroxyvitamin D3; ATG5: autophagy related 5; Baf A1: bafilomycin A1; BECN1: beclin 1; CagA: cytotoxin-associated gene A; CFU: colony-forming unit; ChIP-PCR: chromatin immunoprecipitation-polymerase chain reaction; Con A: concanamycin A; CQ: chloroquine; CRISPR: clustered regularly interspaced short palindromic repeats; CTSD: cathepsin D; GPN: Gly-Phe-ß-naphthylamide; H. pylori: Helicobacter pylori; LAMP1: lysosomal associated membrane protein 1; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; MCOLN1: mucolipin 1; MCOLN3: mucolipin 3; MCU: mitochondrial calcium uniporter; MOI: multiplicity of infection; NAGLU: N-acetyl-alpha-glucosaminidase; PDIA3: protein disulfide isomerase family A member 3; PMA: phorbol 12-myristate 13-acetate; PRKC: protein kinase C; SQSTM1: sequestosome 1; STAT3: signal transducer and activator of transcription 3; SS1: Sydney Strain 1; TRP: transient receptor potential; VacA: vacuolating cytotoxin; VD3: vitamin D3; VDR: vitamin D receptor.

Fecal microbiota transplantation confers beneficial metabolic effects of diet and exercise on diet-induced obese mice.

Diet and exercise are conventional methods for controlling body weight and are linked to alterations in gut microbiota. However, the associations of diet, exercise, and gut microbiota in the control of obesity remain largely unknown. In the present study, using 16S rRNA amplicon sequencing and fecal microbiota transplantation (FMT), normal fat diet (NFD), exercise and their combination resulted in improved metabolic profiles in comparison to sedentary lifestyle with high fat diet (HFD). Moreover, diet exerted more influence than exercise in shaping the gut microbiota. HFD-fed mice receiving FMT from NFD-exercised donors not only showed remarkably reduced food efficacy, but also mitigated metabolic profiles (p < 0.05). The transmissible beneficial effects of FMT were associated with bacterial genera Helicobacter, Odoribacter and AF12 and overrepresentation of oxidative phosphorylation and glycolysis genes. Our findings demonstrate that the beneficial effects of diet and exercise are transmissible via FMT, suggesting a potential therapeutic treatment for obesity.

Patient derived organoids to model rare prostate cancer phenotypes.

A major hurdle in the study of rare tumors is a lack of existing preclinical models. Neuroendocrine prostate cancer is an uncommon and aggressive histologic variant of prostate cancer that may arise de novo or as a mechanism of treatment resistance in patients with pre-existing castration-resistant prostate cancer. There are few available models to study neuroendocrine prostate cancer. Here, we report the generation and characterization of tumor organoids derived from needle biopsies of metastatic lesions from four patients. We demonstrate genomic, transcriptomic, and epigenomic concordance between organoids and their corresponding patient tumors. We utilize these organoids to understand the biologic role of the epigenetic modifier EZH2 in driving molecular programs associated with neuroendocrine prostate cancer progression. High-throughput organoid drug screening nominated single agents and drug combinations suggesting repurposing opportunities. This proof of principle study represents a strategy for the study of rare cancer phenotypes.

Personalized In Vitro and In Vivo Cancer Models to Guide Precision Medicine.

Precision medicine is an approach that takes into account the influence of individuals' genes, environment, and lifestyle exposures to tailor interventions. Here, we describe the development of a robust precision cancer care platform that integrates whole-exome sequencing with a living biobank that enables high-throughput drug screens on patient-derived tumor organoids. To date, 56 tumor-derived organoid cultures and 19 patient-derived xenograft (PDX) models have been established from the 769 patients enrolled in an Institutional Review Board-approved clinical trial. Because genomics alone was insufficient to identify therapeutic options for the majority of patients with advanced disease, we used high-throughput drug screening to discover effective treatment strategies. Analysis of tumor-derived cells from four cases, two uterine malignancies and two colon cancers, identified effective drugs and drug combinations that were subsequently validated using 3-D cultures and PDX models. This platform thereby promotes the discovery of novel therapeutic approaches that can be assessed in clinical trials and provides personalized therapeutic options for individual patients where standard clinical options have been exhausted.Significance: Integration of genomic data with drug screening from personalized in vitro and in vivo cancer models guides precision cancer care and fuels next-generation research. Cancer Discov; 7(5); 462-77. ©2017 AACR.See related commentary by Picco and Garnett, p. 456This article is highlighted in the In This Issue feature, p. 443.

N-Myc Induces an EZH2-Mediated Transcriptional Program Driving Neuroendocrine Prostate Cancer.

The transition from castration-resistant prostate adenocarcinoma (CRPC) to neuroendocrine prostate cancer (NEPC) has emerged as an important mechanism of treatment resistance. NEPC is associated with overexpression and gene amplification of MYCN (encoding N-Myc). N-Myc is an established oncogene in several rare pediatric tumors, but its role in prostate cancer progression is not well established. Integrating a genetically engineered mouse model and human prostate cancer transcriptome data, we show that N-Myc overexpression leads to the development of poorly differentiated, invasive prostate cancer that is molecularly similar to human NEPC. This includes an abrogation of androgen receptor signaling and induction of Polycomb Repressive Complex 2 signaling. Altogether, our data establishes N-Myc as an oncogenic driver of NEPC.

A Computational Drug Repositioning Approach for Targeting Oncogenic Transcription Factors.

Mutations in transcription factor (TF) genes are frequently observed in tumors, often leading to aberrant transcriptional activity. Unfortunately, TFs are often considered undruggable due to the absence of targetable enzymatic activity. To address this problem, we developed CRAFTT, a computational drug-repositioning approach for targeting TF activity. CRAFTT combines ChIP-seq with drug-induced expression profiling to identify small molecules that can specifically perturb TF activity. Application to ENCODE ChIP-seq datasets revealed known drug-TF interactions, and a global drug-protein network analysis supported these predictions. Application of CRAFTT to ERG, a pro-invasive, frequently overexpressed oncogenic TF, predicted that dexamethasone would inhibit ERG activity. Dexamethasone significantly decreased cell invasion and migration in an ERG-dependent manner. Furthermore, analysis of electronic medical record data indicates a protective role for dexamethasone against prostate cancer. Altogether, our method provides a broadly applicable strategy for identifying drugs that specifically modulate TF activity.

ERG induces taxane resistance in castration-resistant prostate cancer.

Taxanes are the only chemotherapies used to treat patients with metastatic castration-resistant prostate cancer (CRPC). Despite the initial efficacy of taxanes in treating CRPC, all patients ultimately fail due to the development of drug resistance. In this study, we show that ERG overexpression in in vitro and in vivo models of CRPC is associated with decreased sensitivity to taxanes. ERG affects several parameters of microtubule dynamics and inhibits effective drug-target engagement of docetaxel or cabazitaxel with tubulin. Finally, analysis of a cohort of 34 men with metastatic CRPC treated with docetaxel chemotherapy reveals that ERG-overexpressing prostate cancers have twice the chance of docetaxel resistance than ERG-negative cancers. Our data suggest that ERG plays a role beyond regulating gene expression and functions outside the nucleus to cooperate with tubulin towards taxane insensitivity. Determining ERG rearrangement status may aid in patient selection for docetaxel or cabazitaxel therapy and/or influence co-targeting approaches.

Role of ghrelin in the pathophysiology of gastrointestinal disease.

Ghrelin is a 28-amino-acid peptide that plays multiple roles in humans and other mammals. The functions of ghrelin include food intake regulation, gastrointestinal (GI) motility, and acid secretion by the GI tract. Many GI disorders involving infection, inflammation, and malignancy are also correlated with altered ghrelin production and secretion. Although suppressed ghrelin responses have already been observed in various GI disorders, such as chronic gastritis, Helicobacter pylori infection, irritable bowel syndrome, functional dyspepsia, and cachexia, elevated ghrelin responses have also been reported in celiac disease and inflammatory bowel disease. Moreover, we recently reported that decreased fasting and postprandial ghrelin levels were observed in female patients with functional dyspepsia compared with healthy subjects. These alterations of ghrelin responses were significantly correlated with meal-related symptoms (bloating and early satiation) in female functional dyspepsia patients. We therefore support the notion that abnormal ghrelin responses may play important roles in various GI disorders. Furthermore, human clinical trials and animal studies involving the administration of ghrelin or its receptor agonists have shown promising improvements in gastroparesis, anorexia, and cancer. This review summarizes the impact of ghrelin, its family of peptides, and its receptors on GI diseases and proposes ghrelin modulation as a potential therapy.

Characterization of a cellular denitrase activity that reverses nitration of cyclooxygenase.

Protein 3-nitrotyrosine (3-NT) formation is frequently regarded as a simple biomarker of disease, an irreversible posttranslational modification that can disrupt protein structure and function. Nevertheless, evidence that protein 3-NT modifications may be site selective and reversible, thus allowing for physiological regulation of protein activity, has begun to emerge. We have previously reported that cyclooxygenase (COX)-1 undergoes heme-dependent nitration of Tyr(385), an internal and catalytically essential residue. In the present study, we demonstrate that nitrated COX-1 undergoes a rapid reversal of nitration by substrate-selective and biologically regulated denitrase activity. Using nitrated COX-1 as a substrate, denitrase activity was validated and quantified by analytic HPLC with electrochemical detection and determined to be constitutively active in murine and human endothelial cells, macrophages, and a variety of tissue samples. Smooth muscle cells, however, contained little denitrase activity. Further characterizing this denitrase activity, we found that it was inhibited by free 3-NT and may be enhanced by endogenous nitric oxide and exogenously administered carbon monoxide. Finally, we describe a purification protocol that results in significant enrichment of a discrete denitrase-containing fraction, which maintains activity throughout the purification process. These findings reveal that nitrated COX-1 is a substrate for a denitrase in cells and tissues, implying that the reciprocal processes of nitration and denitration may modulate bioactive lipid synthesis in the setting of inflammation. In addition, our data reveal that denitration is a controlled process that may have broad importance for regulating cell signaling events in nitric oxide-generating systems during oxidative/nitrosative stress.