neutrophil-extracellular-traps-generated-low-density-neutrophils

Neutrophil Extracellular Traps Generated by Low Density Neutrophils Obtained from Peritoneal Lavage Fluid Mediate Tumor Cell Growth and Attachment

Activated neutrophils release neutrophil extracellular traps (NETs), which can capture and destroy microbes. Recent studies suggest that NETs are involved ...

Jichi Medical University

The human peritoneal cavity contains a small number of free cells of mesenchymal cell lineage. Intraperitoneal mesenchymal cells (PMC) play supportive roles in metastasis formation on the peritoneum. In this study, we found that PMC, when co-cultuerd with human gastric cancer cells, MKN45, enhanced the proliferation of MKN45 when cultured at low, but not high, cellular density. Also, PMC suppressed apoptotic cell death of MKN45 only under low density culture conditions. Time-lapse videoanalysis clearly demonstrated that PMC randomly migrated more vigorously than did MKN45, and strongly enhanced the migration behavior of co-cultured MKN45. In fact, the majority of MKN45 migrated together in direct physical contact with PMC, and the sum of migration lengths from original position of co-cultured MKN45 for 48 hours was approximately 10 times longer than that of MKN45 cultured alone. Our data suggest that enhanced migration can increase the chance of direct contact or positional proximity among sparcely distributed MKN45, which may bring survival advantages to tumor cells. This may be one of the important mechanisms of peritoneal metastasis, since only a small number of tumor cells are considered to be disseminated in the early step of metastasis formation on the peritoneum. 

Intraperitoneal Mesenchymal Cells Promote the Development of Peritoneal Metastasis Partly by Supporting Long Migration of Disseminated Tumor Cells.

Objectives The aim of this study was to evaluate the safety and efficacy of intravenous and intraperitoneal paclitaxel (PTX) combined with S-1 for treatment of gemcitabine-refractory pancreatic cancer with malignant ascites. Methods After the feasibility of this regimen was first confirmed in an interim analysis in 10 patients, a total of 35 patients were enrolled between April 2011 and December 2014. PTX was administered intravenously (50 mg/m(2)) and intraperitoneally (20 mg/m(2)) on days 1 and 8, and 80 mg/m(2) S-1 was administered on days 1-14 every 3 weeks. The primary endpoint was overall survival (OS). The secondary endpoints were progression-free survival (PFS), the objective tumor response, efficacy against malignant ascites, and safety. Result In all 35 patients, the median OS and PFS were 4.8 (95 % confidence interval [CI], 2.1-5.3) months and 2.8 (95 % CI, 0.9-4.1) months, respectively. The 26 patients who were evaluable for efficacy achieved a response rate of 8 % and a disease control rate of 69 %. Malignant ascites had disappeared or decreased in 18 (69 %) patients, including complete resolution in 4 (15 %), and a negative change in cytological status was achieved in 8 (31 %) patients. The major grade 3/4 adverse events included neutropenia (34 %), anemia (31 %), nausea (9 %), and catheter-related infections (6 %). Conclusion Combination chemotherapy consisting of intravenous and intraperitoneal PTX with S-1 showed acceptable toxicity and favorable efficacy in pancreatic cancer patients with malignant ascites. (

Intravenous and intraperitoneal paclitaxel with S-1 for treatment of refractory pancreatic cancer with malignant ascites.

Peritoneal metastasis of gastric cancer remains a refractory disease, and the standard treatment strategy is still unclear. Intraperitoneally administered paclitaxel(PTX)remains in the intraperitoneal(IP)cavity for a long time and directly infiltrates peritoneal metastatic nodules, thereby producing antitumor effects. We designed an IP chemotherapy regimen of S-1 combined with weekly intravenous(IV)and IP PTXadministration. In our phase I study, the recommended dose of IP PTXwas determined to be 20mg/m2. In our phase II study for patients with P1(macroscopic peritoneal metastasis-positive)or CY1 (cytology-positive)gastric cancer, the 1-year overall survival(OS)rate was 78%and the median survival time(MST)was 23.6 months. In another phase II study of patients with P1 gastric cancer, the 1-year OS rate was 77%and the MST was 17.1 months. A phase III PHOENIX-GC trial comparing IP chemotherapy to S-1 plus cisplatin has recently been completed. Phase II studies of the IP administration of docetaxel have also shown favorable results. Recently, the results of several clinical studies investigating the effects of S-1 combined with weekly IV and IP PTXadministration for peritoneal metastasis of pancreatic cancer have been published.

[Intraperitoneal Chemotherapy for Peritoneal Metastasis of Gastric Cancer].

Despite recent progress in systemic chemotherapy, the prognosis of gastric cancer patients with peritoneal metastasis (P1) or positive peritoneal cytology findings (CY1) is still poor. We developed a regimen combining intraperitoneal (IP) paclitaxel (PTX) with S-1 and PTX, which can produce notable efficacy with regard to peritoneal lesions. Surgery after response to combination chemotherapy is a promising option for P1 or CY1 gastric cancer. A retrospective study was performed to evaluate the safety and efficacy.

Surgery after intraperitoneal and systemic chemotherapy for gastric cancer with peritoneal metastasis or positive peritoneal cytology findings.

The purpose of this study was to investigate medication adherence to oral chemotherapy medications and determinants of medication non-adherence to them among gastroenterological cancer patients.

Adherence to oral chemotherapy medications among gastroenterological cancer patients visiting an outpatient clinic.

The outcome of gastric cancer patients with peritoneal metastasis remains poor. We treated these patients with intraperitoneal and intravenous paclitaxel plus oral S-1 (tegafur/gimeracil/oteracil), followed by gastrectomy in responders. We evaluated the clinical significance of peritoneal lavage carcinoembryonic antigen (CEA) messenger RNA (mRNA) levels as a biomarker for indication of conversion gastrectomy.

Peritoneal Lavage CEA mRNA Levels Predict Conversion Gastrectomy Outcomes after Induction Chemotherapy with Intraperitoneal Paclitaxel in Gastric Cancer Patients with Peritoneal Metastasis.

Intraperitoneal administration of chemotherapeutics is expected for the treatment of peritoneally disseminated gastric cancer because of poor migration of the drugs from the systemic circulation to the peritoneal cavity. In this study, for intraperitoneal delivery of cisplatin (CDDP), we developed a hyaluronan (HA)-based hybrid system in which CDDP-loaded HA nanogels were either physically encapsulated in or chemically conjugated to injectable HA hydrogels. Physical encapsulation enabled sustained release of HA nanogels from the HA hydrogel matrix for over a week. This was a longer release period than that of encapsulated free CDDP, which released 80% of the drug in 2 days. The longer release was attributed to delayed diffusion of HA nanogels from the hydrogel matrix network. The release profile could be tuned by modifying the chemical conjugation of HA nanogels to the HA hydrogel matrix, as well as the type of chelating ligands used to load CDDP to the nanogel. Furthermore, intraperitoneally administered hybrid had significant antitumor activity in a mouse model of peritoneally disseminated gastric cancer, especially for nodules smaller than 1.0 mm.

Intraperitoneal Delivery of Cisplatin via a Hyaluronan-Based Nanogel/in Situ Cross-Linkable Hydrogel Hybrid System for Peritoneal Dissemination of Gastric Cancer.

Many types of immune cells appear in peritoneal cavity after abdominal surgery. In patients who underwent laparotomy due to gastric cancer, peritoneal lavages were obtained before and after surgical procedure. Cells were recovered from intermediate layer after Ficoll-Hypaque centrifugation and analyzed for phenotypes and functions, especially focused on low density neutrophils (LDN). The number of CD66b (+) LDN with mature phenotype was markedly elevated in postoperative as compared with preoperative lavages. Short term culture of the purified LDN produced many threadlike structures positive for SYTOX, nucleic acid staining, as well as histone and myeloperoxidase, suggesting the NETs formation. Human gastric cancer cells, MKN45, OCUM-1 and NUGC-4, were selectively attached on the NETs, which was totally abolished by the pretreatment of DNAse I. Intraperitoneal (IP) co-transfer of the LDN with MKN45 in nude mice strongly augments the metastasis formation on peritoneum, which was strongly suppressed by the following IP administration of DNAse I. Many NETs-like structures were detected on the surface of human omental tissue resected by gastrectomy. NETs on peritoneal surface can assist the clustering and growth of free tumor cells disseminated in abdomen. Disruption of the NETs by DNAse might be useful to prevent the peritoneal recurrence after abdominal surgery.

Low density neutrophils (LDN) in postoperative abdominal cavity assist the peritoneal recurrence through the production of neutrophil extracellular traps (NETs).

Purpose Intraperitoneal paclitaxel plus systemic chemotherapy demonstrated promising clinical effects in patients with gastric cancer with peritoneal metastasis. We aimed to verify its superiority over standard systemic chemotherapy in overall survival. Patients and Methods This randomized phase III trial enrolled patients with gastric cancer with peritoneal metastasis who had received no or short-term (< 2 months) chemotherapy. Patients were randomly assigned at a two-to-one ratio to receive intraperitoneal and intravenous paclitaxel plus S-1 (IP; intraperitoneal paclitaxel 20 mg/m and intravenous paclitaxel 50 mg/m on days 1 and 8 plus S-1 80 mg/m per day on days 1 to 14 for a 3-week cycle) or S-1 plus cisplatin (SP; S-1 80 mg/m per day on days 1 to 21 plus cisplatin 60 mg/m on day 8 for a 5-week cycle), stratified by center, previous chemotherapy, and extent of peritoneal metastasis. The primary end point was overall survival. Secondary end points were response rate, 3-year overall survival rate, and safety. Results We enrolled 183 patients and performed efficacy analyses in 164 eligible patients. Baseline characteristics were balanced between the arms, except that patients in the IP arm had significantly more ascites. The median survival times for the IP and SP arms were 17.7 and 15.2 months, respectively (hazard ratio, 0.72; 95% CI, 0.49 to 1.04; stratified log-rank P = .080). In the sensitivity analysis adjusted for baseline ascites, the hazard ratio was 0.59 (95% CI, 0.39 to 0.87; P = .008). The 3-year overall survival rate was 21.9% (95% CI, 14.9% to 29.9%) in the IP arm and 6.0% (95% CI, 1.6% to 14.9%) in the SP arm. Both regimens were well tolerated. Conclusion This trial failed to show statistical superiority of intraperitoneal paclitaxel plus systemic chemotherapy. However, the exploratory analyses suggested possible clinical benefits of intraperitoneal paclitaxel for gastric cancer.

Phase III Trial Comparing Intraperitoneal and Intravenous Paclitaxel Plus S-1 Versus Cisplatin Plus S-1 in Patients With Gastric Cancer With Peritoneal Metastasis: PHOENIX-GC Trial.

Despite recent advances in chemotherapy, outcomes of patients with peritoneal metastases (PM) from gastric cancer are still very poor and standard treatment has not been established. Although oral S-1 appears to be effective for patients with PM, the effects of systemic chemotherapy are limited. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) yield fewer benefits in patients with PM from gastric cancer than in patients with PM from other malignancies. In comparison, repeated intraperitoneal chemotherapy (RIPEC) with taxanes using an implantable peritoneal access port has a pharmacokinetic advantage for the control of peritoneal lesions and in combination with systemic chemotherapy can result in surprisingly long-term survival in patients with PM from gastric cancer. Herein, we review the results of recent clinical studies specifically targeting PM from gastric cancer and discuss future prospects for an intraperitoneal approach to the ideal treatment of patients with gastric cancer with peritoneal involvement.

Hironori Yamaguchi

Department of Gastrointestinal Surgery

Jichi Medical University

Neutrophil Extracellular Traps Generated by Low Density Neutrophils Obtained from Peritoneal Lavage Fluid Mediate Tumor Cell Growth and Attachment

Hironori Yamaguchi

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Department of Gastrointestinal Surgery

Jichi Medical University

Neutrophil Extracellular Traps Generated by Low Density Neutrophils Obtained from Peritoneal Lavage Fluid Mediate Tumor Cell Growth and Attachment

Department of Gastrointestinal Surgery