Lorenzo E. Ferri

Neutrophil extracellular traps sequester circulating tumor cells and promote metastasis

The majority of patients with cancer undergo at least one surgical procedure as part of their treatment. Severe postsurgical infection is associated with adverse oncologic outcomes; however, the mechanisms underlying this phenomenon are unclear. Emerging evidence suggests that neutrophils, which function as the first line of defense during infections, facilitate cancer progression. Neutrophil extracellular traps (NETs) are extracellular neutrophil-derived DNA webs released in response to inflammatory cues that trap and kill invading pathogens. The role of NETs in cancer progression is entirely unknown. We report that circulating tumor cells become trapped within NETs in vitro under static and dynamic conditions. In a murine model of infection using cecal ligation and puncture, we demonstrated microvascular NET deposition and consequent trapping of circulating lung carcinoma cells within DNA webs. NET trapping was associated with increased formation of hepatic micrometastases at 48 hours and gross metastatic disease burden at 2 weeks following tumor cell injection. These effects were abrogated by NET inhibition with DNAse or a neutrophil elastase inhibitor. These findings implicate NETs in the process of cancer metastasis in the context of systemic infection and identify NETs as potential therapeutic targets.

IL-17 Promotes p38 MAPK-Dependent Endothelial Activation Enhancing Neutrophil Recruitment to Sites of Inflammation

Neutrophilic inflammation plays an important role in lung tissue destruction occurring in many chronic pulmonary diseases. Neutrophils can be recruited to sites of inflammation via the action of the cytokine IL-17. In this study, we report that IL-17RA and IL-17RC mRNA expression is significantly increased in asthmatic bronchoscopic biopsies and that these receptors are not only expressed on epithelial and inflammatory cells but also on endothelial cells. IL-17 potently stimulates lung microvascular endothelial cells to produce chemoattractants (CXCL8 and derivatives of the 5-lipoxygenase pathway) that selectively drive neutrophil but not lymphocyte chemotaxis. Moreover, IL-17 promotes endothelial activation by inducing the expression of endothelial adhesion markers (E-selectin, VCAM-1, and ICAM-1) in a p38 MAPK-dependent manner. This increased expression of adhesion molecules stimulates the trans-endothelial migration of neutrophils, as well as the transmigration of HT-29 colon carcinoma cells, suggesting a further role in promoting lung metastasis. Finally, IL-17 increased neutrophil adhesion to the endothelium in vivo as determined by intravital microscopy of mice cremaster muscle. Overall, our results demonstrate that IL-17 is a potent activator of the endothelium in vivo leading to neutrophil infiltration. Therefore, preventing neutrophil recruitment by blocking the action of IL-17 on endothelial cells may prove to be highly beneficial in diseases in which neutrophilic inflammation plays a key role.

Neutrophils promote liver metastasis via Mac-1 mediated interactions with circulating tumor cells.

Although circulating neutrophils are associated with distant metastasis and poor outcome in a number of epithelial malignancies, it remains unclear whether neutrophils play an active causal role in the metastatic cascade. Using in vivo models of metastasis, we found that neutrophils promote cancer cell adhesion within liver sinusoids and, thereby, influence metastasis. Neutrophil depletion before cancer cell inoculation resulted in a decreased number of gross metastases in an intrasplenic model of liver metastasis. This effect was reversed when inflamed neutrophils were co-inoculated with cancer cells. In addition, early adhesion within liver sinusoids was inhibited in the absence of neutrophils and partially restored with a short perfusion of isolated activated neutrophils. Intravital microscopy showed that cancer cells adhered directly on top of arrested neutrophils, indicating that neutrophils may act as a bridge to facilitate interactions between cancer cells and the liver parenchyma. The adhesion of lipopolysaccharide-activated neutrophils to cancer cells was mediated by neutrophil Mac-1/ICAM-1. Our findings, therefore, show a novel role for neutrophils in the early adhesive steps of liver metastasis.

LPS-Induced TLR4 Signaling in Human Colorectal Cancer Cells Increases β1 Integrin-Mediated Cell Adhesion and Liver Metastasis

Infectious complications resulting from resection of colorectal cancer (CRC) elevates the risk of cancer recurrence and metastasis, but the reason for this risk relationship is unknown. Defining the mechanisms responsible may offer opportunities to improve outcomes in a majority of patients whose tumors are resected as part of their therapy. The complex formed between Toll receptor TLR4 and myeloid differentiation factor MD2 defines a major cell surface receptor for lipopolysaccharide (LPS), a gram-negative bacterial antigen that has been implicated in infectious complications after CRC resection. As the TLR4/MD2 complex is expressed on CRC cells, we hypothesized that LPS may promote liver metastasis in CRC by stimulating TLR4 signaling. In support of this hypothesis, we report here that LPS enhances liver metastasis of human CRC cells that express TLR4/MD2 after intrasplenic graft of immunocompromised nude mice. Compared with TLR4 nonexpressing, nonmetastatic CRC cells, we observed increased in vitro adherence to different extracellular matrices and human umbilical vein endothelial cells (HUVEC). Furthermore, we observed an increased likelihood of in vivo capture within hepatic sinusoids after LPS treatment. No differences were apparent in phosphorylation of p38 and MAPK isoforms, but in metastatic CRC cells expressing surface TLR4 treatment with LPS increased Ser473 phosphorylation of AKT kinase. We showed that enhanced adherence elicited by LPS in these cells could be blocked at three different levels, using Eritoran (TLR4 small molecule antagonist), PI-103 (PI3K inhibitor), or anti-β1 integrin blocking antibodies. Taken together, the results indicate that stimulation of the TLR4/MD2 complex by LPS activates PI3K/AKT signaling and promotes downstream β1 integrin function, thereby increasing the adhesiveness and metastatic capacity of CRC cells. Our findings suggest that inhibiting LPS-induced TLR4 signaling could improve therapeutic outcomes by preventing cancer metastasis during the perioperative period of CRC resection.

Systemic inflammation increases cancer cell adhesion to hepatic sinusoids by neutrophil mediated mechanisms

Interactions between endothelial selectins and selectin ligands expressed on tumor cells have been implicated in the binding of circulating metastatic cancer cells to the vascular endothelium during extravasation. Moreover, there is mounting evidence that inflammatory environments can accelerate the progression of metastasis by neutrophil mediated mechanisms. In this study, a physiologically relevant in vivo model of early metastasis coupled with intravital microscopy was used to visualize the trafficking of tumor cells within the liver vasculature in real time. Using GFP‐labeled Lewis lung carcinoma subline H‐59 cells, we show here that disrupting the interactions between endothelial selectins and tumor cell selectin ligands diminished tumor cell recruitment to the liver. Furthermore, systemic inflammation induced by intravenous injection of lipopolysaccharide significantly enhanced the metastatic potential of these lung carcinoma cells by increasing their propensity to adhere to the liver sinusoidal endothelium. Confocal microscopy revealed frequent colocalization of cancer cells with neutrophils and neutrophil depletion in vivo significantly attenuated the lipopolysaccharide‐induced increase in H‐59 cell adhesion. Although direct selectin–selectin ligand interactions contributed significantly to tumor cell adhesion to sinusoidal endothelial cells, we show here that in addition, interactions between adherent neutrophils within the inflamed sinusoids and circulating tumor cells may further increase tumor cell arrest in the liver.

Hypertonic saline resuscitation attenuates neutrophil lung sequestration and transmigration by diminishing leukocyte-endothelial interactions in a two-hit model of hemorrhagic shock and infection.

BACKGROUND Hypertonic saline (HTS) attenuates polymorphonuclear neutrophil (PMN)-mediated tissue injury after hemorrhagic shock. We hypothesized that HTS resuscitation reduces early in vivo endothelial cell (EC)-PMN interactions and late lung PMN sequestration in a two-hit model of hemorrhagic shock followed by mimicked infection. METHODS Thirty-two mice were hemorrhaged (40 mm Hg) for 60 minutes and then given intratracheal lipopolysaccharide (10 microg) 1 hour after resuscitation with shed blood and either HTS (4 mL/kg 7.5% NaCl) or Ringers lactate (RL) (twice shed blood volume). Eleven controls were not manipulated. Cremaster intravital microscopy quantified 5-hour EC-PMN adherence, myeloperoxidase assay assessed lung PMN content (2 1/2 and 24 hours), and lung histology determined 24-hour PMN transmigration. RESULTS Compared with RL, HTS animals displayed 55% less 5-hour EC-PMN adherence (p = 0.01), 61% lower 24-hour lung myeloperoxidase ( p= 0.007), and 57% lower mean 24-hour lung histologic score ( p= 0.027). CONCLUSION Compared with RL, HTS resuscitation attenuates early EC-PMN adhesion and late lung PMN accumulation in hemorrhagic shock followed by inflammation. HTS resuscitation may attenuate PMN-mediated organ damage.

Should laparoscopic paraesophageal hernia repair be abandoned in favor of the open approach

BackgroundThe most appropriate approach to the repair of large paraesophageal hernias remains controversial. Despite early results of excellent outcomes after laparoscopic repair, recent reports of high recurrence require that this approach be reevaluated.MethodsFor this study, 60 primary paraesophageal hernias consecutively repaired at one institution from 1990 to 2002 were reviewed. These 25 open transabdominal and 35 laparoscopic repairs were compared for operative, short-, and long-term outcomes on the basis of quality-of -life questionnaires and radiographs.ResultsNo difference in patient characteristics was detected. Laparoscopic repair resulted in lower blood loss, fewer intraoperative complications, and a shorter length of hospital stay. No difference in general or disease-specific quality-of-life was documented. Radiographic follow-up was available for 78% open and 91% laparoscopic repairs, showing anatomic recurrence rates of 44% and 23%, respectively (p = 0.11).ConclusionsLaparoscopic repair should remain in the forefront for the management of paraesophageal hernias. However, there is considerable room for improvement in reducing the incidence of recurrence.

The Influence of Technical Complications on Postoperative Outcome and Survival After Esophagectomy

The dismal survival associated with esophagectomy for cancer has led to the search for potentially correctable factors responsible for this poor prognosis. Although it is intuitive that technical complications could increase postoperative mortality, the effect on long-term survival is controversial. From 1990 to 2002, 434 patients underwent resection for squamous cell carcinoma of the intrathoracic esophagus. Prospectively collected data were reviewed for the presence of technical complications. Patient, tumor, and operative variables, postoperative outcome, and survival were compared between patients with technical complications and those without. Prognostic factors were assessed by multivariate analysis. Technical complications occurred in 98 (22.6%) patients. Patients with technical complications had a higher prevalence of cardiac disease, more proximal tumors, and more cervical anastomoses. Technical complications were associated with an increased rate of pulmonary complications (37.8% vs. 10.7%; P < .001) and increased hospital mortality (9.2% vs. 3.3%; P = .025), but no difference in 30-day mortality (2% vs. 1.2%; P = .6). Poor-prognostic factors for survival included male sex, stage III/IV disease, cirrhosis, proximal tumors, and R1/R2 resection, but not technical complications. Although immediate postoperative outcome and hospital mortality rates were increased, no effect on long-term survival was seen in patients with complications related to errors in surgical technique.BackgroundThe dismal survival associated with esophagectomy for cancer has led to the search for potentially correctable factors responsible for this poor prognosis. Although it is intuitive that technical complications could increase postoperative mortality, the effect on long-term survival is controversial.MethodsFrom 1990 to 2002, 434 patients underwent resection for squamous cell carcinoma of the intrathoracic esophagus. Prospectively collected data were reviewed for the presence of technical complications. Patient, tumor, and operative variables, postoperative outcome, and survival were compared between patients with technical complications and those without. Prognostic factors were assessed by multivariate analysis.ResultsTechnical complications occurred in 98 (22.6%) patients. Patients with technical complications had a higher prevalence of cardiac disease, more proximal tumors, and more cervical anastomoses. Technical complications were associated with an increased rate of pulmonary complications (37.8% vs. 10.7%; P < .001) and increased hospital mortality (9.2% vs. 3.3%; P = .025), but no difference in 30-day mortality (2% vs. 1.2%; P = .6). Poor-prognostic factors for survival included male sex, stage III/IV disease, cirrhosis, proximal tumors, and R1/R2 resection, but not technical complications.ConclusionsAlthough immediate postoperative outcome and hospital mortality rates were increased, no effect on long-term survival was seen in patients with complications related to errors in surgical technique.

Perioperative docetaxel, cisplatin, and 5-fluorouracil (DCF) for locally advanced esophageal and gastric adenocarcinoma: a multicenter phase II trial

BACKGROUND Although perioperative chemotherapy for esophagogastric adenocarcinoma (ADC) improves survival, the overall poor prognosis suggests that further refinement of treatment is required. Docetaxel, cisplatin, and 5-fluorouracil (5-FU) (DCF) is effective for metastatic ADC of the upper gastrointestinal (GI) tract; we thus sought to investigate the efficacy of this regimen in patients with resectable disease. PATIENTS AND METHODS Patients with resectable ADC of the upper GI tract received DCF [docetaxel (Taxotere) 75 mg/m(2) I.V. day 1, cisplatin 75 mg/m(2) I.V. day 1, 5-FU 750 mg/m(2) continuous infusion for 120 h, every 3 weeks] for three cycles before and after resection. Primary end point was complete resection; secondary end points were response, toxicity, surgical morbidity, and overall survival. RESULTS Forty-three patients with ADC of the esophagus (11), gastroesophageal junction (25), or stomach (7) started treatment and 86% completed all preoperative cycles with grade 3-4 toxicity arising in 47%. Metabolic response to chemotherapy (reduction in maximal standard uptake value >35%) was achieved in 25/33 (76%) patients. Surgery was carried out in 41/43 and complete resection was achieved in all 41 patients with pathologic complete response in 4/41. Postoperative chemotherapy was started in 29 patients and completed in 24. Three-year overall survival was 60%. CONCLUSION Perioperative DCF is a tolerable and highly effective regimen for the treatment of esophagogastric ADC.

Claudin-2 Promotes Breast Cancer Liver Metastasis by Facilitating Tumor Cell Interactions with Hepatocytes

ABSTRACT We previously identified claudin-2 as a functional mediator of breast cancer liver metastasis. We now confirm that claudin-2 levels are elevated in liver metastases, but not in skin metastases, compared to levels in their matched primary tumors in patients with breast cancer. Moreover, claudin-2 is specifically expressed in liver-metastatic breast cancer cells compared to populations derived from bone or lung metastases. The increased liver tropism exhibited by claudin-2-expressing breast cancer cells requires claudin-2-mediated interactions between breast cancer cells and primary hepatocytes. Furthermore, the reduction of the claudin-2 expression level, either in cancer cells or in primary hepatocytes, diminishes these heterotypic cell-cell interactions. Finally, we demonstrate that the first claudin-2 extracellular loop is essential for mediating tumor cell-hepatocyte interactions and the ability of breast cancer cells to form liver metastases in vivo. Thus, during breast cancer liver metastasis, claudin-2 shifts from acting within tight-junctional complexes to functioning as an adhesion molecule between breast cancer cells and hepatocytes.