Ryota Iwase

Combination chemotherapy of serine protease inhibitor nafamostat mesilate with oxaliplatin targeting NF-κB activation for pancreatic cancer

In this study, we assessed if nafamostat mesilate may enhance anti-tumor effects of oxaliplatin on Panc-1 cells and pancreatic cancer mouse model. In combination treatment with nafamostat mesilate and oxaliplatin, NF-κB activation was inhibited by suppressing IκBα phosphorylation, and caspase-8-mediated apoptosis was more prominent than that treated with oxaliplatin alone, both in vitro and in vivo. Nafamostat mesilate reduced proliferation rate of Panc-1 cells as compared with oxaliplatin alone in vitro and enhanced oxaliplatin-induced tumor growth inhibition in vivo. Combination chemotherapy using nafamostat mesilate and oxaliplatin induces synergistic cytotoxicity in pancreatic cancer and could be a novel strategy for treatment.

Inhibition of Nuclear Factor Kappa-B Enhances the Antitumor Effect of Combination Treatment with Tumor Necrosis Factor-Alpha Gene Therapy and Gemcitabine for Pancreatic Cancer in Mice

BACKGROUND Combination therapy with tumor necrosis factor-alpha (TNF-α) gene delivery and gemcitabine is a new therapeutic approach for pancreatic cancer. However, the efficacy of both TNF-α and gemcitabine is suppressed due to activation of nuclear factor-kappa B (NF-κB). We hypothesized that nafamostat mesilate (FUT175), an NF-κB inhibitor, enhances the antitumor effect of combination treatment with an adenoviral vector-expressing TNF-α (AxCAhTNF-α) and gemcitabine for pancreatic cancer in mice. STUDY DESIGN In vitro, we assessed that FUT175 inhibited both TNF-α- and gemcitabine-induced NF-κB activation and enhanced apoptosis in human pancreatic cancer cell lines (MIAPaCa-2 and AsPC-1). In vivo, we established a xenograft pancreatic cancer model in mice by subcutaneous injection of MIAPaCa-2 and AsPC-1. The animals were treated with AxCAhTNF-α intratumorally and gemcitabine intraperitoneally once a week (combination group) or AxCAhTNF-α intratumorally and gemcitabine intraperitoneally once a week as well as FUT175 intraperitoneally 3 times a week (triple combination group). RESULTS In vitro, FUT175 inhibited both TNF-α- and gemcitabine-induced NF-κB activation and enhanced induction of apoptosis. In the triple combination group, tumor growth in vivo was significantly slower and there were more apoptotic cells than in the combination group (p < 0.05). CONCLUSIONS Inhibition of NF-κB by FUT175 enhances the antitumor effect of combined TNF-α gene therapy and gemcitabine for pancreatic cancer.

Dual inhibition of nuclear factor kappa-B and Mdm2 enhance the antitumor effect of radiation therapy for pancreatic cancer

INTRODUCTION Radiation therapy, alone or in combination with chemotherapy, is effective for patients with locally advanced and recurrent pancreatic cancer. Ionizing radiation induces cell cycle arrest and cell apoptosis through enhancement several signals such as p53, p21(Waf1/Cip1), and caspase. However, the therapeutic efficacy is attenuated by radiation-induced activation of NF-κB. Nafamostat mesilate, a synthetic serine protease inhibitor, inhibits NF-κB activation in pancreatic cancer. Therefore, we hypothesized that nafamostat mesilate inhibited radiation-induced activation of NF-κB and improves therapeutic outcome. RESULTS In combination group, NF-κB activation was significantly inhibited in comparison with that of radiation group. Nafamostat mesilate obviously down-regulated the expression levels of Mdm2 compared with control cells or irradiated cells. Consequently, p53 expression was stabilized inversely in correlation with Mdm2 protein expression level. The expression levels of p53, p21(Waf1/Cip1), cleaved caspase-3 and -8 were the highest in the combination group. Nafamostat mesilate enhanced ionizing radiation-induced cell apoptosis and G2/M cell cycle arrest. In combination group, cell proliferation and tumor growth were significantly slower than those in other groups. CONCLUSION Combination therapy of radiation with nafamostat mesilate exerts enhanced anti-tumor effect against human pancreatic cancer.

The Decline of Amylase Level of Pancreatic Juice After Pancreaticoduodenectomy Predicts Postoperative Pancreatic Fistula.

Objectives Postoperative pancreatic fistula (POPF) is a life-threatening complication after pancreaticoduodenectomy (PD). The aim of this study is to evaluate the significance of pancreatic amylase level of pancreatic juice for PF after PD. Methods The subjects were 46 patients who underwent PD between January 2012 and August 2015 at Jikei University Hospital. We retrospectively investigated the relation between patient characteristics including pancreatic amylase level of pancreatic juice through the pancreatic drainage tube and the incidence of POPF (grade B or grade C according to the International Study Group on the Pancreatic Fistula) using univariate and multivariate analyses. The decline of pancreatic amylase level of pancreatic juice was evaluated by 1 − postoperative day 3/postoperative day 1 ratio. Results In univariate analysis, nonductal adenocarcinoma (P = 0.0252), soft pancreatic remnant (P = 0.0155), and decline of pancreatic amylase level of pancreatic juice ≥ 80% (P = 0.0010) were significant predictors of POPF. In multivariate analysis, decline of pancreatic amylase level of pancreatic juice of 80% or greater (P = 0.0192) was the only significant independent parameter. Conclusions Decline of pancreatic amylase level of pancreatic juice can predict POPF after PD.

Syndrome of Inappropriate Secretion of Antidiuretic Hormone due to Selective Serotonin Reuptake Inhibitors After Pancreaticoduodenectomy for Carcinoma of the Ampulla of Vater: Case Report

A 68-year-old man underwent pancreaticoduodenectomy with lymph nodes dissection for carcinoma of the ampulla of Vater. The patient had anxiety neurosis and had been treated with a selective serotonin reuptake inhibitor (SSRI). Postoperatively, SSRI was resumed on postoperative day 2. His serum sodium concentration gradually decreased, and the patient was given a sodium supplement. However, 11 days after the operation, laboratory findings included serum sodium concentration of 117 mEq/L, serum vasopressin of 2.0 pg/mL, plasma osmolality of 238 mOsm/kg, urine osmolality of 645 mOsm/kg, urine sodium concentration of 66 mEq/L, serum creatinine concentration of 0.54 mg/dL, and serum cortisol concentration of 29.1 μg/dL. With a diagnosis of syndrome of inappropriate secretion of antidiuretic hormone (SIADH), the antianxiety neurosis medication was changed from the SSRI to another type of drug. After switching the medication, the patient made a satisfactory recovery with normalization of serum sodium by postoperative day 20.

Pomalidomide promotes chemosensitization of pancreatic cancer by inhibition of NF-κB

Introduction Nuclear factor κB (NF-κB) plays an important role in cancer progression and causes therapeutic resistance to chemotherapy. Pomalidomide, a third-generation immunomodulating drug derived from thalidomide, has been approved for uncontrolled multiple myeloma. We hypothesized that pomalidomide may inhibit the anticancer agent-induced NF-κB activity and enhance chemosensitization of combination chemotherapy with gemcitabine and S1 (Gem/S1) in pancreatic cancer. Methods In vitro, we assessed NF-κB activity, induction of caspase cascade, cell apoptosis and cell proliferation using human pancreatic cancer cell lines (MIA PaCa-2 and PANC-1). In vivo, we established an orthotopic xenograft mouse model for human pancreatic cancer by injection of PANC-1 cells. At 5 weeks after injection, the animals were randomly divided into four groups and treated with Gem (100 mg/kg) /S1 (10 mg/kg), with oral administration of pomalidomide (0.5 mg/kg), with combination of gemcitabine, S1, and pomalidomide or vehicle only. Results Although chemotherapeutic agents induced NF-κB activation in pancreatic cancer cells, pomalidomide inhibited anticancer agent-induced NF-κB activation (p < 0.01). Of the four groups tested for the apoptosis-related caspase signals and apoptosis under both in vitro and in vivo conditions, Gem/S1/Pomalidomide group demonstrated the strongest activation of the caspase signals and proapoptotic effect. In Gem/S1/Pomalidomide group, cell proliferation and tumor growth were slower than those in other groups both in vitro and in vivo (p < 0.01). There were no obvious adverse effects except for thrombocytosis by using pomalidomide. Conclusions Pomalidomide promotes chemosensitization of pancreatic cancer by inhibiting chemotherapeutic agents-induced NF-κB activation.

Glycogen synthase kinase‐3β activity plays a key role in the antitumor effect of nafamostat mesilate in pancreatic cancer cells

Pancreatic cancer is often resistant to chemotherapy. We previously showed the efficacy of combination treatment using gemcitabine and nafamostat mesilate (FUT‐175) for patients with unresectable pancreatic cancer. However, the mechanisms that affect the sensitivity of FUT‐175 are not fully understood. The purpose of the present study was to clarify the mechanism of the sensitivity to FUT‐175, with a focus on the activity of glycogen synthase kinase‐3β (GSK‐3β). In vitro, we assessed sensitivity to FUT‐175 in human pancreatic cancer cell lines (PANC‐1 and MIAPaCa‐2) and difference of signaling in these cells by cell proliferation assay, Western blot analysis and microarray. Next, we assessed cell viability, apoptotic signal and nuclear factor‐kappa B (NF‐κB) activity in response to treatment with FUT‐175 alone and in combination with GSK‐3 inhibitor or protein phosphatase 2A (PP2A) by cell proliferation assay, Western blot analysis and enzyme‐linked immunosorbent assay. Phosphorylated GSK‐3β level was significantly higher in MIAPaCa‐2 (high sensitivity cell) than in PANC‐1 (low sensitivity cell). Cell viability and NF‐κB activity were significantly decreased by addition of GSK‐3 inhibitor to FUT‐175, and levels of cleaved caspase‐8 were increased by inhibition of GSK‐3. PP2A inhibitor increased the levels of phosphorylated GSK‐3β and sensitized both cell lines to FUT‐175 as measured by cell viability and apoptotic signal. The results indicate that GSK‐3β activity plays a key role in the antitumor effect of FUT‐175 in pancreatic cancer cells, and regulation of GSK‐3β by PP2A inhibition could be a novel therapeutic approach for pancreatic cancer.