Background
Adenocarcinoma of the proximal stomach is the fastest rising malignancy in North America. It is commonly associated with peritoneal accumulation of malignant ascites (MA), a fluid ...containing cancer and inflammatory cells and soluble proteins. Peritoneal metastasis (PM) is the most common site of gastric cancer (GC) progression after curative-intent surgery and is the leading cause of death among GC patients.
Methods/results
Using a panel of gastric adenocarcinoma cell lines (human: MKN 45, SNU-5; murine: NCC-S1M), we demonstrate that prior incubation of GC cells with MA results in a significant (> 1.7-fold) increase in the number of cells capable of adhering to human peritoneal mesothelial cells (HPMC) (
p
< 0.05). We then corroborate these findings using an ex vivo PM model and show that MA also significantly enhances the ability of GC cells to adhere to strips of human peritoneum (
p
< 0.05). Using a multiplex ELISA, we identify MIF and VEGF as consistently elevated across MA samples from GC patients (
p
< 0.05). We demonstrate that agents that block the effects of MIF or VEGF abrogate the ability of MA to stimulate the adhesion of GC cells to adhere to human peritoneum and promote both ex vivo and in vivo metastases.
Conclusion
Agents targeting MIF or VEGF may be relevant to the treatment or prevention of PM in GC patients
.
Neutrophils promote tumor growth and metastasis at multiple stages of cancer progression. One mechanism through which this occurs is via release of neutrophil extracellular traps (NETs). We have ...previously shown that NETs trap tumor cells in both the liver and the lung, increasing their adhesion and metastasis following postoperative complications. Multiple studies have since shown that NETs play a role in tumor progression and metastasis. NETs are composed of nuclear DNA-derived web-like structures decorated with neutrophil-derived proteins. However, it is unknown which, if any, of these NET-affiliated proteins is responsible for inducing the metastatic phenotype. In this study, we identify the NET-associated carcinoembryonic Ag cell adhesion molecule 1 (CEACAM1) as an essential element for this interaction. Indeed, blocking CEACAM1 on NETs, or knocking it out in a murine model, leads to a significant decrease in colon carcinoma cell adhesion, migration and metastasis. Thus, this work identifies NET-associated CEACAM1 as a putative therapeutic target to prevent the metastatic progression of colon carcinoma.
Neutrophil Extracellular Traps (NETs) have been recently identified as part of the neutrophil's antimicrobial armamentarium. Apart from their role in fighting infections, recent research has ...demonstrated that they may be involved in many other disease processes, including cancer progression. Isolating purified NETs is a crucial element to allow the study of these functions. In this video, we demonstrate a simplified method of cell free NET isolation from human whole blood using readily available reagents. Isolated NETs can then be used for immunofluorescence staining, blotting or various functional assays. This enables an assessment of their biologic properties in the absence of the potential confounding effects of neutrophils themselves. A density gradient separation technique is employed to isolate neutrophils from healthy donor whole blood. Isolated neutrophils are then stimulated by phorbol 12-myristate 13-acetate (PMA) to induce NETosis. Activated neutrophils are then discarded, and a cell-free NET stock is obtained. We then demonstrate how isolated NETs can be used in an adhesion assay with A549 human lung cancer cells. The NET stock is used to coat the wells of a 96 well cell culture plate O/N, and after ensuring an adequate NET monolayer formation on the bottom of the wells, CFSE labeled A549 cells are added. Adherent cells are quantified using a Nikon TE300 fluorescent microscope. In some wells, 1000U DNAse1 is added 10 min before counting to degrade NETs.
While emerging data suggest nucleotide oligomerization domain receptor 1 (NOD1), a cytoplasmic pattern recognition receptor, may play an important and complementary role in the immune response to ...bacterial infection, its role in cancer metastasis is entirely unknown. Hence, we sought to determine the effects of NOD1 on metastasis. NOD1 expression in paired human primary colon cancer, human and murine colon cancer cells were determined using immunohistochemistry and immunoblotting (WB). Clinical significance of NOD1 was assessed using TCGA survival data. A series of in vitro and in vivo functional assays, including adhesion, migration, and metastasis, was conducted to assess the effect of NOD1. C12-iE-DAP, a highly selective NOD1 ligand derived from gram-negative bacteria, was used to activate NOD1. ML130, a specific NOD1 inhibitor, was used to block C12-iE-DAP stimulation. Stable knockdown (KD) of NOD1 in human colon cancer cells (HT29) was constructed with shRNA lentiviral transduction and the functional assays were thus repeated. Lastly, the predominant signaling pathway of NOD1-activation was identified using WB and functional assays in the presence of specific kinase inhibitors. Our data demonstrate that NOD1 is highly expressed in human colorectal cancer (CRC) and human and murine CRC cell lines. Clinically, we demonstrate that this increased NOD1 expression negatively impacts survival in patients with CRC. Subsequently, we identify NOD1 activation by C12-iE-DAP augments CRC cell adhesion, migration and metastasis. These effects are predominantly mediated via the p38 mitogen activated protein kinase (MAPK) pathway. This is the first study implicating NOD1 in cancer metastasis, and thus identifying this receptor as a putative therapeutic target.
BackgroundWe describe a novel process using positive deviance (PD) with the Canadian Association of Thoracic Surgeons members, to identify perioperative best practice to minimise anastomotic leak ...(AL) and length of stay (LOS) following oesophagectomy. To our knowledge, this is the first National combination of level 1 evidence with expert opinion (ie, PD seminar) aimed at reducing AL and LOS in oesophageal surgery. Our primary hypothesis is that a multicentre National PD seminar is feasible, and could lead to the generation of best practices recommendations aimed at reducing AL and LOS in patients with oesophageal cancer.MethodsAdverse events, LOS and AL incidence/severity following oesophagectomy were prospectively collected from seven Canadian thoracic institutions using Thoracic Morbidity and Mortality classification system (2017–2020). Anonymised display of centre’s data were presented, with identification of centres demonstrating PD. Surgeons from PD sites discussed principles of care, culminating in the consensus recommendations, anonymously rated by all (5-point Likert scale).ResultsData from 795 esophagectomies were included, with 25 surgeons participating. Two centres were identified as having the lowest AL rates 44/395 (11.1%) (vs five centres 71/400 (17.8%) (p<0.01)) and shortest LOS 8 days 45 (IQR: 6–14) (vs 10 days (IQR: 8–18) (p<0.001)). Recommendations included preoperative (prehabilitation, smoking cessation, chemotherapy for patients with dysphagia, minimise stents/feeding tubes), intraoperative (narrow gastric conduit, intrathoracic anastomosis, avoid routine jejunostomy, use small diameter closed-suction drains), postoperative day (POD) (early (POD 2–3) enteral feeding initiation, avoid routine barium swallow studies, early removal of tubes/drains (POD 2–3)). All ranked above 80% (4/5) in agreement to implement recommendations into their practice.ConclusionWe report the feasibility of a National multicentre PD seminar with the generation of best practice recommendations aimed at reducing AL and LOS following oesophagectomy. Further research is required to demonstrate whether National PD seminars can be an effective quality improvement tool.
Neutrophils are being increasingly recognized as an important element in tumor progression. They have been shown to exert important effects at nearly every stage of tumor progression with a number of ...studies demonstrating that their presence is critical to tumor development. Novel aspects of neutrophil biology have recently been elucidated and its contribution to tumorigenesis is only beginning to be appreciated. Neutrophil extracellular traps (NETs) are neutrophil-derived structures composed of DNA decorated with antimicrobial peptides. They have been shown to trap and kill microorganisms, playing a critical role in host defense. However, their contribution to tumor development and metastasis has recently been demonstrated in a number of studies highlighting NETs as a potentially important therapeutic target. Here, studies implicating NETs as facilitators of tumor progression and metastasis are reviewed. In addition, potential mechanisms by which NETs may exert these effects are explored. Finally, the ability to target NETs therapeutically in human neoplastic disease is highlighted.
Background Ongoing gastrointestinal bleeding (GIB) following endoscopic therapy and deciding between mesenteric angiography and surgery often challenge surgeons. We sought to identify predictors of ...positive angiographic study (active contrast medium extravasation) and characterize outcomes of embolization for acute GIB. Methods We retrospectively analyzed angiographies for GIB at 2 teaching hospitals from January 2005 to December 2008. The χ2 , Wilcoxon rank sum and t tests determined significance. A Cox proportional hazards model was used for multivariate analyses. Results Eighteen of 83 (22%) patients had active extravasation on initial angiography and 25 (30%) were embolized. Patients with active extravasation had more packed red blood cell (PRBC; 5.3 v. 2.8 units, p < 0.001) and fresh frozen plasma (4.8 v. 1.7 units, p = 0.005) transfusions 24 hours preangiography and were more likely to be hemodynamically unstable at the time of the procedure (67% v. 28%, p = 0.001) than patients without active extravasation. Each unit of PRBC transfused increased the risk of a positive study by 30% (hazard ratio HR 1.3, 95% confidence interval CI 1.2–1.6 per unit). Embolization did not decrease recurrent bleeding (53% v. 52%) or length of stay in hospital (28.1 v. 27.5 d, p = 0.95), but was associated with a trend toward fewer emergency surgical interventions (13% v. 26%, p = 0.31) and greater 30-day mortality (33% v. 7%, p = 0.006) than nonembolization. Blind embolization was performed in 10 of 83 (12%) patients and was found to be an independent predictor of death in patients without active extravasation (HR 9.2, 95% CI 1.5–55.9). Conclusion The number of PRBC units transfused correlates with greater likelihood of a positive study. There was a significant increase in mortality in patients who underwent angioembolization. Large prospective studies are needed to further characterize the indications for angiography and blind embolization.
Despite advances in cancer treatment, metastasis remains today the main cause of cancer death. Local control through complete surgical resection of the primary tumor continues to be a key principle ...in cancer treatment. However, surgical interventions themselves lead to adverse oncologic outcomes and are associated with significantly increased rates of metastasis. Neutrophils through release of neutrophil extracellular traps (NETs) in response to infections were shown to be able to capture circulating cancer cells, and in doing so, support the development of metastatic disease. To be able to intervene on this process, understanding the exact molecular nature of these mechanisms is crucial. We therefore hypothesize and demonstrate that beta1-integrin is an important factor mediating the interactions between circulating tumor cells and NETs. We show that beta1-integrin expression on both cancer cells and NETs is important for the adhesion of circulating tumor cells to NETs both in vitro and in vivo. Using a murine model of intra-abdominal sepsis to mimic the postoperative inflammatory environment, we show that beta1-integrin expression is upregulated in the context of inflammation in vivo. Ultimately, we show that this increased early cancer cell adhesion to NETs in vivo and this effect is abrogated when mice are administered DNAse 1. Our data therefore sheds light on the first molecular mechanism by which NETs can trap circulating tumor cells (CTCs), broadening our understanding of this process. What's new? Surgical removal of tumors can increase inflammation. When neutrophils respond to inflammatory signals, they sometimes form web-like projections called "neutrophil extracellular traps" (NETs). These NETs are able to enhance metastasis, because they bind circulating tumor cells (CTCs) and cause them to adhere to distant organs. In our study, the authors found that beta1-integrins play an essential role in the interaction between NETs and tumor cells. Then, they found that hepatic adhesion of CTCs in mice could be significantly reduced by blocking beta1-integrins. These results suggest that targeting beta1-integrins may help to reduce metastases.
PDF
