Mechanisms of synthetic serine protease inhibitor (FUT-175)-mediated cell death

Recent advances in targeted therapy for pancreatic adenocarcinoma

Pancreatic adenocarcinoma (PDAC) is a fatal disease with a 5-year survival rate of 8% and a median survival of 6 mo. In PDAC, several mutations in the genes are involved, with Kirsten rat sarcoma oncogene (90%), cyclin-dependent kinase inhibitor 2A (90%), and tumor suppressor 53 (75%–90%) being the most common. Mothers against decapentaplegic homolog 4 represents 50%. In addition, the self-preserving cancer stem cells, dense tumor microenvironment (fibrous accounting for 90% of the tumor volume), and suppressive and relatively depleted immune niche of PDAC are also constitutive and relevant elements of PDAC. Molecular targeted therapy is widely utilized and effective in several solid tumors. In PDAC, targeted therapy has been extensively evaluated; however, survival improvement of this aggressive disease using a targeted strategy has been minimal. There is currently only one United States Food and Drug Administration-approved targeted therapy for PDAC – erlotinib, but the absolute benefit of erlotinib in combination with gemcitabine is also minimal (2 wk). In this review, we summarize current targeted therapies and clinical trials targeting dysregulated signaling pathways and components of the PDAC oncogenic process, analyze possible reasons for the lack of positive results in clinical trials, and suggest ways to improve them. We also discuss emerging trends in targeted therapies for PDAC: combining targeted inhibitors of multiple pathways. The PubMed database and National Center for Biotechnology Information clinical trial website (www.clinicaltrials.gov) were queried to identify completed and published (PubMed) and ongoing (clinicaltrials.gov) clinical trials (from 2003-2022) using the keywords pancreatic cancer and targeted therapy. The PubMed database was also queried to search for information about the pathogenesis and molecular pathways of pancreatic cancer using the keywords pancreatic cancer and molecular pathways.

The effectiveness of adjuvant chemotherapy for Stage I pancreatic cancer based on the UICC 8th edition

BACKGROUND

Adjuvant chemotherapy is recommended for patients with pancreatic cancer after curative resection. However, there is limited evidence regarding the efficacy and prognostic factors for adjuvant chemotherapy in patients with stage I pancreatic cancer. This study aimed to identify patients in whom chemotherapy was effective and to detect prognostic factors for stage I pancreatic cancer based on guidelines of the 8^th edition of the Union for International Cancer Control (UICC).

METHODS

Between 2009 and 2017, 108 patients diagnosed with stage I pancreatic cancer were enrolled in this study. They were distributed into invasion (n = 68) and non-invasion (n = 40) groups. The relationship between clinicopathological variables, including various prognostic factors, disease-free survival (DFS), and overall survival (OS), were investigated by univariate and multivariate analyses.

RESULTS

Five-year survival in all patients with stage I pancreatic cancer was 38.9%. Adjuvant chemotherapy failed to improve DFS or OS in patients with stage I cancer (DFS, p = 0.26; OS, p = 0.30). In subgroup analysis, adjuvant chemotherapy significantly improved DFS (multivariate-adjusted hazard ratio (HR), 0.40; 95% confidence interval [CI], 0.21-0.78; p = 0.007) and OS (multivariate-adjusted HR, 0.32; 95% CI, 0.15-0.68; p = 0.003) in the invasion group than in non-invasion group. In contrast, in the non-invasion group, adjuvant chemotherapy failed to improve DFS and OS in univariate analysis (DFS, p = 0.992; OS, p = 0.808).

CONCLUSION

For stage I pancreatic cancer, based on guidelines of the UICC 8^th edition, adjuvant chemotherapy may benefit patients with extrapancreatic invasion.

Phase II trial of nafamostat mesilate/gemcitabin/S-1 for unresectable pancreatic cancer

PURPOSE

To assess the efficacy of combination chemotherapy with nafamostat mesilate, gemcitabine and S-1 for unresectable pancreatic cancer patients.

MATERIALS AND METHODS

The study was conducted as a single-arm, single center, institutional review board-approved phase II trial. Patients received nafamosntat mesilate (4.8 mg/kg continuous transregional arterial infusion) with gemcitabine (1000 mg/m2 transvenous) on days 1 and15, and with oral S-1 [(80 mg/day (BSA<1.25 m2), 100 mg/day (1.25 ≤ BSA<1.5 m2), or 120 mg/day (BSA ≥1.5 m2)] on days 1-14 or, days 1-7 and 15-21. This regimen was repeated at 28-day intervals.

RESULTS

Forty-seven evaluable patients (Male/Female: 31/16, Age (median): 66 (range 35-78) yrs, Stage III/IV 10/37.) were candidates in this study. Two patients in stage III (20%) could undergo conversion surgery. Twenty-four patients (51%) underwent subsequent treatment (1st line/ 2nd line / 4th line, 13/ 10/ 1, FOLFIRINOX: 12, GEM/nab-PTX: 18, TAS-118: 3, chemoradiation with S-1: 2, GEM/Erlotinib: 1, nal-IRI: 1, surgery: 2). Median PFS and OS were 9.7 (95% CI, 8.9-14.7 mo) and 14.2 months (99% CI, 13.3-23.9 mo), respectively. Median PFS in stage IV patients was 9.2 months (95% CI, 8.4-12.0 mo). Median OS in patients without subsequent treatment was 10.8 months (95% CI, 9.1-13.8 mo). Median OS in patients with subsequent treatment was 19.3 months (95% CI, 18.9-31.9 mo). Grade 4 treatment-related hematological toxicities were encountered in 7 patients. Two patients developed grade 3 allergic reaction after 6 cycles or later. No febrile neutropenia has been observed.

CONCLUSION

NAM/GEM/S-1 therapy is safe and could be promising option for unresectable pancreatic cancer, especially for stage IV cancer.

Nafamostat mesylate overcomes endocrine resistance of breast cancer through epigenetic regulation of CDK4 and CDK6 expression

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Nafamostat mesylate (NM) causes apoptosis and suppresses metastasis of endocrine-resistant ER-positive breast cancer (ERPBC).

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Epigenetic downregulation of CDK4/CDK6 by NM in endocrine-resistant ERPBC via disruption of binding of H3K27Ac on promoter region.

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Combination of nafamostat mesylate and CDK4/6 inhibitor synergistically overcomes endocrine resistance of breast cancer.

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Nafamostat mesylate would be a well-efficient drug for endocrine-resistant ERPBC.

Breast cancer is common worldwide, and the estrogen receptor-positive subtype accounts for approximately 70% of breast cancer in women. Tamoxifen and fulvestrant are drugs currently used for endocrinal therapy. Breast cancer exhibiting endocrine resistance can undergo metastasis and lead to the death of breast cancer patients. Drug repurposing is an active area of research in clinical medicine. We found that nafamostat mesylate, clinically used for patients with pancreatitis and disseminated intravascular coagulation, acts as an anti-cancer drug for endocrine-resistant estrogen receptor-positive breast cancer (ERPBC). Epigenetic repression of CDK4 and CDK6 by nafamostat mesylate induced apoptosis and suppressed the metastasis of ERPBC through the deacetylation of Histone 3 Lysine 27. A combination of nafamostat mesylate and CDK4/6 inhibitor synergistically overcame endocrine resistance in ERPBC. Nafamostat mesylate might be an essential adjuvant or alternative drug for the treatment of endocrine-resistant ERPBC due to the low cost-efficiency of the CDK4/6 inhibitor.

Nafamostat mesilate, a nuclear factor kappa B inhibitor, enhances the antitumor action of radiotherapy on gallbladder cancer cells

Nuclear factor kappa B (NF-κB) is a transcriptional factor that can be activated by radiotherapy and chemotherapy. The synthetic protease inhibitor nafamostat mesilate (NM) inhibits NF-κB activity and exerts antitumor actions in various types of cancer. In the present study, we hypothesized that NM might enhance the antitumor action of radiotherapy on gallbladder cancer (GBC) cells by inhibiting radiation-induced NF-κB activity. Thus, we investigated the correlation between radiotherapy and NF-κB activity in GBC cells. We assessed the in vitro effects of radiotherapy with or without NM on NF-κB activity, apoptosis of GBC cells (NOZ and OCUG-1), induction of apoptotic cascade, cell cycle progression, and viability of GBC cells using four treatment groups: 1) radiation (5 Gy) alone; 2) NM (80 μg/mL and 40 μg/mL, respectively) alone; 3) combination (radiation and NM); and 4) vehicle (control). The same experiments were performed in vivo using a xenograft GBC mouse model. In vitro, NM inhibited radiation-induced NF-κB activity. Combination treatment significantly attenuated cell viability and increased cell apoptosis and G2/M phase cell cycle arrest compared with those in the other groups for NOZ and OCUG-1 cells. Moreover, combination treatment upregulated the expression of apoptotic proteins compared with that after the other treatments. In vivo, NM improved the antitumor action of radiation and increased the population of Ki-67-positive cells. Overall, NM enhanced the antitumor action of radiotherapy on GBC cells by suppressing radiation-induced NF-κB activity. Thus, the combination of radiotherapy and NM may be useful for the treatment of locally advanced unresectable GBC.

Phase II Study of Adjuvant Chemotherapy With Gemcitabine and Nafamostat Mesilate for Pancreatic Cancer

OBJECTIVES

The aim of this study was to clarify the effectiveness of combination chemotherapy targeting gemcitabine (GEM)-induced nuclear factor kappa B as adjuvant therapy for pancreatic cancer.

METHODS

Patients who were planned after curative surgery (residual tumor classification R0 or R1) for pancreatic cancer to receive six cycles of adjuvant chemotherapy of regional arterial infusion of nafamostat mesilate with GEM between June 2011 and April 2017 were enrolled in this single-center, institutional review board-approved phase II trial (UMIN000006163). The Kaplan-Meier method was used to estimate disease-free survival and overall survival.

RESULTS

In 32 patients [male/female: 18/14; age: median, 65.5 years (range, 48-77 years); pathological stage (Union for International Cancer Control 8th): IA/IB/IIA/IIB/III, 2/2/9/18/1, respectively] who met the eligibility criteria, the median overall survival and disease-free survival were 36.4 months (95% confidence interval, 31.7-48.3) and 16.4 months (95% confidence interval, 14.3-22.0), respectively. Grade 4 treatment-related hematological toxicities were seen in 5 patients (15.6%) (all neutropenia). One patient developed grade 3 nonhematological toxicities (rash).

CONCLUSIONS

Adjuvant chemotherapy with regional arterial infusion of nafamostat mesilate and GEM is safe and has potential as an option in adjuvant setting after curative surgery for pancreatic cancer.

The Molecular Aspect of Antitumor Effects of Protease Inhibitor Nafamostat Mesylate and Its Role in Potential Clinical Applications

Nafamostat mesylate (NM), a synthetic serine protease inhibitor first placed on the market by Japan Tobacco in 1986, has been approved to treat inflammatory-related diseases, such as pancreatitis. Recently, an increasing number of studies have highlighted the promising effects of NM in inhibiting cancer progression. Alone or in combination treatments, studies have shown that NM attenuates various malignant tumors, including pancreatic, colorectal, gastric, gallbladder, and hepatocellular cancers. In this review, based on several activating pathways, including the canonical Nuclear factor-κB (NF-κB) signaling pathway, tumor necrosis factor receptor-1 (TNFR1) signaling pathway, and tumorigenesis-related tryptase secreted by mast cells, we summarize the anticancer properties of NM in existing studies both in vitro and in vivo. In addition, the efficacy and side effects of NM in cancer patients are summarized in detail. To further clarify NM's antitumor activities, clinical trials devoted to validating the clinical applications and underlying mechanisms are needed in the future.

Nafamostat Mesilate Enhances the Radiosensitivity and Reduces the Radiation-Induced Invasive Ability of Colorectal Cancer Cells

Neoadjuvant chemoradiotherapy followed by radical surgery is the standard treatment for patients with locally advanced low rectal cancer. However, several studies have reported that ionizing radiation (IR) activates nuclear factor kappa B (NF-κB) that causes radioresistance and induces matrix metalloproteinase (MMP)-2/-9, which promote tumor migration and invasion. Nafamostat mesilate (FUT175), a synthetic serine protease inhibitor, enhances the chemosensitivity to cytotoxic agents in digestive system cancer cells by inhibiting NF-κB activation. Therefore, we evaluated the combined effect of IR and FUT175 on cell proliferation, migration and invasion of colorectal cancer (CRC) cells. IR-induced upregulation of intranuclear NF-κB, FUT175 counteracted this effect. Moreover, the combination treatment suppressed cell viability and induced apoptosis. Similar effects were also observed in xenograft tumors. In addition, FUT175 prevented the migration and invasion of cancer cells caused by IR by downregulating the enzymatic activity of MMP-2/-9. In conclusion, FUT175 enhances the anti-tumor effect of radiotherapy through downregulation of NF-κB and reduces IR-induced tumor invasiveness by directly inhibiting MMP-2/-9 in CRC cells. Therefore, the use of FUT175 during radiotherapy might improve the efficacy of radiotherapy in patients with CRC.

Pomalidomide enhanced gemcitabine and nab-paclitaxel on pancreatic cancer both in vitro and in vivo

Background

Chemotherapy with gemcitabine and nab-paclitaxel (gemcitabine/nab-paclitaxel) is recommended for unresectable pancreatic cancer. However, the therapeutic efficacy is attenuated by the antitumor agent-induced activation of nuclear factor-κB (NF-κB). Thalidomide inhibits NF-κB activation, therefore, we hypothesized that pomalidomide, a third-generation IMiD, would also inhibit NF-κB activation and enhance the antitumor effects of gemcitabine/nab-paclitaxel.

Methods

In vitro, we assessed NF-κB activity and apoptosis in response to pomalidomide alone, gemcitabine/nab-paclitaxel, or combination of pomalidomide and gemcitabine/nab-paclitaxel in human pancreatic cancer cell lines (PANC-1 and MIA PaCa-2). In vivo, we established orthotopic model and the animals were treated with oral pomalidomide and injection of gemcitabine/nab-paclitaxel.

Results

In pomalidomide and gemcitabine/nab-paclitaxel group, gemcitabine/nab-paclitaxel-induced NF-κB activation was inhibited and apoptosis was enhanced in comparison with those in the other groups both in vitro and in vivo. Especially, this study revealed for the first time that pomalidomide enhances p53 on pancreatic cancer cells. The tumor growth in the pomalidomide and gemcitabine/nab-paclitaxel group was significantly slower than that in the gemcitabine/nab-paclitaxel group. Moreover, pomalidomide induced G0/G1 cell cycle arrest and suppressed angiogenesis.

Conclusions

Pomalidomide enhanced the antitumor effect of gemcitabine/nab-paclitaxel by inhibition of NF-κB activation. This combination regimen would be a novel strategy for treating pancreatic cancer.

Continuous Renal Replacement Therapy and Anticoagulation: What Are the Options?

Continuous renal replacement therapy is currently used as a standard treatment for acute kidney injury in the intensive care unit, particularly for patients with unstable hemodynamic status. Because this therapy is continuous, for days or weeks, and the extracorporeal blood circuit is large, the circuit is prone to clotting. Several methods of keeping the extracorporeal circuit patent are available, including heparin infusion, flushes with physiological saline, use of thrombin inhibitors, and citrate. This article reviews methods for continuous renal replacement therapy, anticoagulation, efficacy, and implications for bedside critical care.

Nafamostat mesilate negatively regulates the metastasis of triple-negative breast cancer cells

Triple-negative breast cancer (TNBC) lacking of oestrogen receptor, progesterone receptor, and epidermal growth factor receptor type 2 is a highly malignant disease which results in a poor prognosis and rare treatment options. Despite the use of conventional chemotherapy for TNBC tumours, resistance and short duration responses limit the treatment efficacy. Therefore, a need exists to develop a new chemotherapy for TNBC. The aim of this study was to examine the anti-cancer effects of nafamostat mesilate (NM), a previously known serine protease inhibitor and highly safe drug on breast cancer cells. Here, we showed that NM significantly inhibits proliferation, migration, and invasion in MDA-MB231 cells, induces G2/M phase cell-cycle arrest, and inhibits the expression of cyclin-dependent kinase 1 (CDK1). Exposure of MDA-MB231 cells to NM also resulted in decreased transcription factor activities accompanied by the regulated phosphorylation of signalling molecules and a decrease in metalloproteinases, the principal modulators of the extracellular environment during cancer progression. Especially, inhibition of TGFβ-stimulated Smad2 phosphorylation and subsequent metastasis-related gene expression, and downregulation of ERK activity may be pivotal mechanisms underlying inhibitory effects of NM on NM inhibits lung metastasis of breast cancer cells and growth of colonized tumours in mice. Taken together, our data revealed that NM inhibits cell growth and metastasis of TNBC cells and indicated that NM is a multi-targeted drug that could be an adjunct therapy for TNBC treatment.

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.

Radical Resection of a Primarily Unresectable Pancreatic Cancer After Neoadjuvant Chemotherapy Using Gemcitabine, TS-1, and Nafamostat Mesilate; Report of a Case

A 58-year-old male visited his primary physician for epigastric and back pain. Abdominal-enhanced computed tomography (CT) revealed a hypovascular pancreatic tumor measuring 17 × 11 mm in the uncinate process of the pancreas extending into the superior mesenteric plexus for greater than 180°. With a diagnosis of unresectable pancreatic cancer, the patient received gemcitabine and TS-1 with arterial infusion of nafamostat mesilate. After 3 courses of chemotherapy, enhanced CT revealed a decrease in size of the pancreatic tumor with no lymph node and distant metastasis and improved invasion of the superior mesenteric plexus down to 120°. The patient underwent R0 pancreaticoduodenectomy. The patient made a satisfactory recovery without complications and was discharged on postoperative day 10. We herein report the first curative resected case of a primarily unresectable pancreatic cancer after neoadjuvant chemotherapy using gemcitabine, TS-1, and nafamostat mesilate.

New treatment strategy with nuclear factor-κB inhibitor for pancreatic cancer

BACKGROUND

Because of difficulties with early diagnosis, most patients with pancreatic cancer receive chemotherapy. The National Comprehensive Cancer Network guidelines (version 2.2015) suggest therapy with gemcitabine (GEM) plus nab-paclitaxel (nPTX) as a category 1 recommendation for metastatic pancreatic ductal adenocarcinoma. According to the results of many studies, the activation of chemotherapeutic agents-induced nuclear factor-κB (NF-κB) causes chemoresistance. Hence, we hypothesized that the addition of nafamostat mesilate (NM), a potent NF-κB inhibitor, to GEM/nPTX therapy could enhance the antitumor effect in the treatment of pancreatic ductal adenocarcinoma.

MATERIALS AND METHODS

In vitro, we assessed NF-κB activity and apoptosis under treatment with NM alone (80 μg/mL), with GEM/nPTX, or with a combination of NM and GEM/nPTX in human pancreatic cancer cell lines (PANC-1, MIA PaCa-2, and AsPC-1). In vivo, orthotopic pancreatic cancer mice (BALBc nu/nu) were divided into four groups: control (n = 13), NM (n = 13), GEM/nPTX (n = 13), and triple combination (n = 13). NM (30 mg/kg) was delivered intraperitoneally three times a week, and GEM/nPTX was injected intravenously once a week to orthotopic pancreatic cancer model mice. In the triple combination group, mice received NM followed by GEM/nPTX on the first day to avoid GEM/nPTX-induced NF-κB activation.

RESULTS

In vitro and in vivo, NM inhibited GEM/nPTX-induced NF-κB activation, and a synergistic effect of apoptosis was observed in the triple combination group. Furthermore, tumor growth was significantly suppressed in the triple combination group compared with the other groups.

CONCLUSIONS

NM enhances the antitumor effect of GEM/nPTX chemotherapy for orthotopic pancreatic cancer by inhibition of NF-κB activation.

Inhibition of the NF-κB pathway by nafamostat mesilate suppresses colorectal cancer growth and metastasis

Nafamostat mesilate is an anti-inflammatory drug that is usually used to treat pancreatitis. Recent studies show that it can suppress pancreatic cancer via inhibition of the nuclear factor κB (NF-κB) pathway. However, whether it has anti-tumor activity in some other cancer, including colorectal cancer (CRC), has not been investigated and remained unclear. Here, our study showed that nafamostat mesilate abrogated the constitutive NF-κB activation in CRC cells, which is mediated through inhibition of phosphorylation of IκBα and nuclear translocation of p65. Also, we found that nafamostat mesilate inhibited phosphorylation of Erk in CRC cells. Consistently, our study demonstrated that nafamostat mesilate inhibited the CRC cell proliferation, invasion and migration and induced mitochondria-dependent apoptosis. Furthermore, nafamostat mesilate could reverse oxaliplatin induced NF-κB and Erk activation in CRC cells, and enhance the sensitivity of CRC cells to oxaliplatin. Nafamostat mesilate combined with oxaliplatin repressed subcutaneous tumor growth and hepatic metastasis in vivo. Overall, our data suggest that nafamostat mesilate, a relatively non-toxic drug that targets NF-κB and Erk, may, in combination with oxaliplatin, represent a novel therapeutic strategy for CRC treatment.

Targeting mast cells tryptase in tumor microenvironment: a potential antiangiogenetic strategy

Angiogenesis is a complex process finely regulated by the balance between angiogenesis stimulators and inhibitors. As a result of proangiogenic factors overexpression, it plays a crucial role in cancer development. Although initially mast cells (MCs) role has been defined in hypersensitivity reactions and in immunity, it has been discovered that MCs have a crucial interplay on the regulatory function between inflammatory and tumor cells through the release of classical proangiogenic factors (e.g., vascular endothelial growth factor) and nonclassical proangiogenic mediators granule-associated (mainly tryptase). In fact, in several animal and human malignancies, MCs density is highly correlated with tumor angiogenesis. In particular, tryptase, an agonist of the proteinase-activated receptor-2 (PAR-2), represents one of the most powerful angiogenic mediators released by human MCs after c-Kit receptor activation. This protease, acting on PAR-2 by its proteolytic activity, has angiogenic activity stimulating both human vascular endothelial and tumor cell proliferation in paracrine manner, helping tumor cell invasion and metastasis. Based on literature data it is shown that tryptase may represent a promising target in cancer treatment due to its proangiogenic activity. Here we focused on molecular mechanisms of three tryptase inhibitors (gabexate mesylate, nafamostat mesylate, and tranilast) in order to consider their prospective role in cancer therapy.

Inhibition of nuclear factor-κB enhances the antitumor effect of tumor necrosis factor-α gene therapy for hepatocellular carcinoma in mice

BACKGROUND

Hepatocellular carcinoma (HCC) is often resistant to chemotherapy. Gene therapy using an adenoviral vector-expressing tumor necrosis factor (TNF)-α is a new therapeutic approach for chemoresistant malignancies. The efficacy of TNF-α, however, is limited, because it leads to the activation of nuclear factor (NF)-κB. We hypothesized that the NF-κB inhibitor nafamostat mesilate would enhance the antitumor effect of adenovirus vector-mediated TNF-α gene therapy for HCC.

METHODS

In vitro, we assessed the inhibitory effect of nafamostat mesilate on TNF-α-induced NF-κB activation and enhanced apoptosis in human HCC cell lines (Huh-7 and Hep3B). In vivo, we established a xenograft HCC model in mice by subcutaneous injection of Huh-7 and Hep3B cells. The animals received intraperitoneal (IP) injections of nafamostat mesilate 3 times a week (nafamostat mesilate group), intratumoral (IT) injections of the human TNF-α-expressing adenoviral vector (AxCAhTNF-α) once a week (TNF-α group), IT injections of AxCAhTNF-α once a week, or IP injections of nafamostat mesilate 3 times a week (combination group).

RESULTS

In the combination group, TNF-α-induced NF-κB activation was inhibited and TNF-α-induced apoptosis was enhanced in comparison with the other groups both in vitro and in vivo. In the combination group, tumor growth was significantly slower and the apoptotic cell numbers were significantly greater than those of the TNF-α group.

CONCLUSION

Inhibition of NF-κB by nafamostat mesilate enhances the antitumor effect of adenoviral vector-mediated TNF-α gene therapy for HCC in mice.

Autocrine extra-pancreatic trypsin 3 secretion promotes cell proliferation and survival in esophageal adenocarcinoma

Trypsin or Tumor associated trypsin (TAT) activation of Protease-activated receptor 2 (PAR-2) promotes tumor cell proliferation in gastrointestinal cancers. The role of the trypsin/PAR-2 network in esophageal adenocarcinoma (EA) development has not yet been investigated. The aim of this study is to investigate the role of trypsin/PAR-2 activation in EA tumorogenesis and therapy. We found that esophageal adenocarcinoma cells (EACs) and Barrett’s Metaplasia (BART) expressed high levels of type 3 extra-pancreatic trypsinogen (PRSS3), a novel type of TAT. Activity of secreted trypsin was detected in cultured media from EA OE19 and OE33 cultures but not from BART culture. Surface PAR-2 expression in BART and EACs was confirmed by both flow cytometry and immunofluorescence. Trypsin induced cell proliferation (∼ 2 fold; P<0.01) in all tested cell lines at a concentration of 10 nM. Inhibition of PAR-2 activity in EACs via the PAR-2 antagonist ENMD (500 µM), anti-PAR2 antibody SAM-11 (2 µg/ml), or siRNA PAR-2 knockdown, reduced cell proliferation and increased apoptosis by up to 4 fold (P<0.01). Trypsin stimulation led to phosphorylation of ERK1/2, suggesting involvement of MAPK pathway in PAR-2 signal transduction. Inhibition of PAR-2 activation or siRNA PAR-2 knockdown in EACs prior to treatment with 5 FU reduced cell viability of EACs by an additional 30% (P<0.01) compared to chemotherapy alone. Our data suggest that extra-pancreatic trypsinogen 3 is produced by EACs and activates PAR-2 in an autocrine manner. PAR-2 activation increases cancer cell proliferation, and promotes cancer cell survival. Targeting the trypsin activated PAR-2 pathway in conjunction with current chemotherapeutic agents may be a viable therapeutic strategy in EA.

Phase II study of gemcitabine in combination with regional arterial infusion of nafamostat mesilate for advanced pancreatic cancer

PURPOSE

To evaluate the efficacy of regional arterial infusion of the synthetic serine protease inhibitor nafamostat mesilate combined with gemcitabine for the treatment of patients with unresectable locally advanced or metastatic pancreatic cancer.

MATERIALS AND METHODS

A single-arm, single center, institutional review board-approved phase II trial was conducted. Thirty-five of 38 consecutive patients were included in the study. Patients received nafamostat mesilate (4.8 mg/kg continuous regional arterial infusion) with gemcitabine (1000 mg/m intravenously) on days 1, 8, and 15. This treatment was repeated at 28-day intervals. The primary endpoints were to evaluate overall survival and 1-year survival rate. The secondary endpoints were to assess therapeutic response and clinical benefit response. Overall survival times were estimated by the Kaplan-Meier survival analysis.

RESULTS

The median survival time was 10.0 months, and the 1-year survival rate was 40.0%. The response rate and disease control rate were 17.1% and 88.6%, respectively. A fraction of 25% of the patients who required opioids for cancer-related pain could reduce their opioid intake, and 37.1% of the patients showed healthy weight gain. Among the patients with metastatic pancreatic cancer, the median survival time was 9.0 months, and the 1-year survival rate was 32.0%. The proposed regimen offers an economic advantage compared with recent therapy regimens that have shown significant improvements in median survival over standard chemotherapy with gemcitabine.

CONCLUSIONS

An alternative regimen for unresectable pancreatic cancer, especially for metastatic pancreatic cancer, is proposed based on acceptable survival time, clinical benefit, and cost advantage.

Immediate early response gene X-1, a potential prognostic biomarker in cancers

INTRODUCTION

The immediate early response gene X-1 (IEX-1) plays a pivotal role in the regulation of cell apoptosis, proliferation, differentiation and metabolism. Deregulation of IEX-1 expression has been confirmed in multiple cancers in humans, in association with either poor or better prognosis depending on the type and progression stages of the cancer.

AREAS COVERED

This review summarizes clinical studies of altered IEX-1 expression in ovarian, pancreatic, blood, breast and colorectal cancers, lymphoma and myeloma. The authors also outline the current understandings of the complex functions of IEX-1 gained from studies with animal models and tumor cell lines so as to help us comprehend the significance of the clinical findings.

EXPERT OPINION

IEX-1 holds great promise to be a valuable biomarker, either alone or in combination with other genes, for monitoring progression of some cancers. IEX-1 expression is highly sensitive to environmental cues and distinct between normal and cancer cells. However, use of IEX-1 as a biomarker remains a significant challenge because too little is understood about the mechanism underlying the diverse activities of IEX-1 and a standardized clinical assay for IEX-1 detection and validation of clinical results across different studies are still critically lacking.

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-κB enhances the antitumor effect of paclitaxel against gastric cancer with peritoneal dissemination in mice

BACKGROUND

Intraperitoneal (i.p.) administration of paclitaxel is useful for treating malignant tumors with peritoneal dissemination, but the therapeutic efficacy is limited. Chemoresistance due to paclitaxel-induced nuclear factor-kappa B (NF-κB) activation is an important cause of suboptimal therapeutic efficacy.

AIMS

The purpose of this study was to prove that addition of nafamostat mesilate (FUT-175), a synthetic serine protease inhibitor and an NF-κB inhibitor, to i.p. paclitaxel enhances antitumor effects of paclitaxel against gastric cancer with peritoneal dissemination.

METHODS

In vitro, we assessed NF-κB activity and apoptosis in response to treatment with FUT-175 alone, paclitaxel alone, or a combination of FUT-175 and paclitaxel in a human gastric cancer cell line (MKN-45). In vivo, we established peritoneal dissemination in nude mice by i.p. injection of MKN-45 cells. The animals received i.p. injections of FUT-175 alone three times a week (FUT-175 group), of paclitaxel alone once a week (paclitaxel group), or a combination of FUT-175 and paclitaxel (combination group) three times and once a week, respectively.

RESULTS

In the combination group, paclitaxel-induced NF-κB activation was inhibited and apoptosis was enhanced in comparison with those in the other groups both in vitro and in vivo. In the combination group, number and weight of peritoneal nodules were significantly lower than those in the paclitaxel group (p = 0.0009 and p = 0.0417, respectively). In the survival analysis, the combination group had a significantly better survival than the paclitaxel group (p = 0.0048).

CONCLUSION

FUT-175 enhances the antitumor effect of i.p. paclitaxel against gastric cancer with peritoneal dissemination by inhibiting NF-κB activation in mice.

Nuclear factor κB activity correlates with the progression and prognosis of pancreatic cancer in a mouse model

INTRODUCTION

Constitutive NF-κB activation is considered to play a key role in the aggressive behavior of pancreatic cancer. Although NF-κB in tumors may contribute to aggressive characteristic features via transcription of angiogenesis and invasion-related factors, there is no definitive evidence showing a correlation between quantitated NF-κB activity and prognosis. In this study, we quantitated NF-κB activity of various human pancreatic cancer cell lines and evaluated whether NF-κB activity was related to tumor progression and prognosis for pancreatic cancer in mice.

MATERIALS AND METHODS

We quantitated NF-κB activity in six pancreatic cancer cell lines (AsPC-1, BxPC-3, Capan-2, MIAPaCa-2, Panc-1 and PL45) and evaluated downstream target genes of NF-κB such as VEGF, IL-8 and MMP-9 in vitro. Next, we evaluated tumor progression and prognosis using subcutaneous tumor model in vivo between cell lines with the highest and lowest NF-κB activity.

RESULTS

BxPC-3 had the highest and AsPC-1 had the lowest NF-κB activity in the 6 cell lines. Expression of VEGF, IL-8 and MMP-9 in BxPC-3 was significantly higher than those in AsPC-1 cells in vitro (p < 0.001) and tumor growth in BxPC-3 was faster than that in AsPC-1 group (p < 0.001) resulting in worse survival in vivo (p = 0.0339).

CONCLUSION

These results suggested that NF-κB activity is related to expression of its downstream target genes, tumor progression and prognosis in experimental pancreatic cancer model.

Nafamostat mesylate, a serine protease inhibitor, demonstrates novel antimicrobial properties and effectiveness in Chlamydia-induced arthritis

Introduction

Effective treatment of reactive arthritis would ideally achieve both control of inflammation and eradication of persisting arthritogenic pathogens. We use a model of experimental Chlamydia trachomatis-induced arthritis (CtIA) to evaluate the effectiveness of nafamostat mesilate (NM), a serine protease inhibitor with complement-modifying effects and anticoagulant properties. To date clinical use of NM has largely been in Asia and has been primarily confined to inflammatory states such as pancreatitis.

Methods

In vitro studies examined inhibition of Chlamydia proliferation using fibroblast cell lines as targets and phase contrast microscopy. In vivo studies used an established protocol, experimental CtIA, induced in Lewis rats by injection of synoviocyte-packaged C. trachomatis. NM was dissolved in water and administered by daily intraperitoneal injection at a dose of 10 mg/kg beginning the day prior to the administration of Chlamydia. Readouts in vivo included (i) joint swelling, (ii) histopathology scoring of severity of arthritis, (iii) host clearance of the pathogen (by ELISA, the IDEIA PCE Chlamydia).

Results

NM exerted a dose-dependent inhibition of chlamydial proliferation in vitro. Without NM, the mean number of inclusion bodies (IB) per well was 17,886 (± 1415). At 5 μg/mL NM, there were 8,490 (± 756) IB, at 25 μg/mL NM there were 35 IB and at 50 μg/mL NM no IB was observed. Chlamydial antigens in each well along the concentration gradient were assayed by ELISA, demonstrating that at 25 μg/mL NM inhibition of Chlamydia was almost complete. In the experimental arthritis model, joint swelling was significantly reduced with NM treatment: average joint width for the NM-treated animals was 8.55 mm (s.d. ± 0.6578, n = 10) versus 11.18 mm (s.d. ± 0.5672, n = 10) in controls (P < 0.001). Histopathology scoring indicated that NM resulted in a marked attenuation of the inflammatory infiltration and joint damage: mean pathology score in NM-treated animals was 10.9 (± 2.45, n = 11) versus 15.9 (± 1.45, n = 10) in controls (P < 0.0001). With respect to persistence of Chlamydia within the synovial tissues, NM treatment was accompanied by a reduction in the microbial load in the joint: mean optical density (O.D.) for ELISA with NM treatment was 0.05 (± 0.02, n = 4) versus 0.18 (± 0.05, n = 4) in controls (P < 0.001).

Conclusions

NM is a protease inhibitor not previously recognized to possess antimicrobial properties. The present study demonstrates for the first time that NM exerts significant impact on C. trachomatis-induced arthritis and suggests that such approaches may prove clinically useful in chronic reactive arthritis.

Nafamostat mesilate can prevent adhesion, invasion and peritoneal dissemination of pancreatic cancer thorough nuclear factor kappa-B inhibition

BACKGROUND

Constitutive activation of nuclear factor kappa-B (NF-κB) contributes to the aggressive behavior of pancreatic cancer. Over-expression of downstream target genes of NF-κB such as intercellular adhesion molecule-1 (ICAM-1), interleukin-8 (IL-8), vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9) leads to the promotion of cell adhesion, angiogenesis, invasion and metastasis. We previously reported that nafamostat mesilate, a synthetic serine protease inhibitor, blocks NF-κB activation in pancreatic cancer. We hypothesized that nafamostat mesilate may inhibit cell adhesion, angiogenesis, invasion and metastases in peritoneal dissemination of pancreatic cancer.

METHODS

In vitro, we assessed inhibition of NF-κB, phosphorylated IκBα, ICAM-1, VEGF and MMP-9 activity by nafamostat mesilate using human pancreatic cancer cell lines (AsPC-1, BxPC-3 and PANC-1). Changes in adhesion and invasion abilities of cancer cells were then evaluated by nafamostat mesilate treatment. In vivo, the efficacy of nafamostat mesilate treatment was assessed using peritoneal dissemination of pancreatic cancer in mice.

RESULTS

In vitro, nafamostat mesilate inhibited activities of NF-κB, phosphorylated IκBα, ICAM-1, VEGF and MMP-9. Moreover, nafamostat mesilate not only inhibited cell adhesion and invasion but also increased the sensitivity of anoikis. In vivo, tumor growth using AsPC-1 cells of the treatment group was significantly slower, and survival rate was significantly better, than those in control group (p < 0.05).

CONCLUSION

Nafamostat mesilate reduced peritoneal metastasis and prolonged survival of pancreatic cancer-bearing mice.

Combination paclitaxel and inhibitor of nuclear factor κB activation improves therapeutic outcome for model mice with peritoneal dissemination of pancreatic cancer

OBJECTIVES

Paclitaxel (PTX) is a useful treatment for peritoneal dissemination of malignant tumors. However, chemoresistance due to PTX-induced nuclear factor κB (NF-κB) activation is an important cause of suboptimal therapeutic effect. We previously reported nafamostat mesilate (FUT175) inhibits NF-κB activation and promotes apoptosis in pancreatic cancer. We hypothesized that addition of FUT175 to PTX may enhance the antitumor effect in peritoneal dissemination of pancreatic cancer.

METHODS

In vitro, we assessed NF-κB activity and apoptosis by the combination of FUT175 and PTX using human pancreatic cancer cell line (AsPc-1). In vivo, we established peritoneal dissemination in nude mice by intraperitoneal injection of AsPc-1 cells. The animals were treated with intraperitoneal injection thrice a week of FUT175, once a week of PTX, or a combination of thrice a week of FUT175 and once a week of PTX (combination group).

RESULTS

In the combination groups, PTX-induced NF-κB activation was inhibited, and apoptosis was enhanced in comparison with other groups both in vitro and in vivo. In the combination group, tumor growth, serum tumor marker, and survival rate were significantly better than those in other groups (P < 0.05).

CONCLUSIONS

Combination chemotherapy using PTX with FUT175 exerts an antitumor effect for peritoneal dissemination of pancreatic cancer.

Resistance of cutaneous anaplastic large-cell lymphoma cells to apoptosis by death ligands is enhanced by CD30-mediated overexpression of c-FLIP

Death ligands, including TNF-alpha, CD95L/FasL, and TRAIL, mediate safeguard mechanisms against tumor growth and critically contribute to lymphocyte homeostasis. We investigated death receptor-mediated apoptosis and CD30/CD95 crosstalk in four CD30-positive cell lines of cutaneous anaplastic large-cell lymphoma (cALCL). Whereas CD95 stimulation strongly induced apoptosis in cALCL cells, the pro-apoptotic pathways of TNF-alpha and TRAIL were completely blocked at an early step. Expression of TNF receptor 1 was lost in three of four cell lines, providing an explanation for TNF-alpha unresponsiveness. TRAIL resistance may be explained by the consistent overexpression of cellular flice inhibitory protein (c-FLIP) (four of four cell lines) and frequent loss of the pro-apoptotic Bcl-2 protein Bid (three of four cell lines). Changes at the receptor-expression level were largely ruled out. CD30/CD95 crosstalk experiments showed that CD30 ligation leads to NF-kappaB-mediated c-FLIP upregulation in cALCL cells, which in turn conferred enhanced resistance to CD95-mediated apoptosis. Knockdown of c-FLIP by a lentiviral approach enhanced basic apoptosis rates in cALCL cells and diminished the CD30-mediated suppression of apoptosis, thus proving the significance of c-FLIP in this context. These in vitro findings may be indicative of the clinical situation of cALCL. Further clarifying the defects in apoptosis pathways in cutaneous lymphomas may lead to improved therapies for these disorders.

A phase I study of full-dose gemcitabine and regional arterial infusion of nafamostat mesilate for advanced pancreatic cancer

BACKGROUND

The primary end points of this study were to determine the dose-limiting toxic effects (DLTs), maximum tolerated dose, and a recommended phase II dose of a synthetic serine protease inhibitor, nafamostat mesilate, in combination with full-dose gemcitabine in patients with unresectable locally advanced or metastatic pancreatic cancer. The secondary end point was to assess therapeutic response.

PATIENTS AND METHODS

Patients with previously untreated pancreatic cancer received gemcitabine (1 000 mg/m(2) i.v. for 30 min) on days 1, 8, and 15, with nafamostat mesilate (continuous regional arterial infusion for 24 h through a port-catheter system) on days 1, 8, and 15; this regimen was repeated at 28-day intervals. The initial dose of nafamostat mesilate was 2.4 mg/kg and was escalated in increments of 1.2 mg/kg until a dose of 4.8 mg/kg was achieved. A standard '3+3' phase I dose-escalation design was used. Therapeutic response and clinical benefit response were assessed.

RESULTS

Twelve patients were enrolled in this study. None of the patients experienced DLTs, and nafamostat mesilate was well tolerated at doses up to 4.8 mg/kg in combination with full-dose gemcitabine. This combination chemotherapy yielded a reduction of a high serum level of the tumor marker CA19-9. Pain was reduced in three of seven patients without oral morphine sulfate. Overall survival was 7.1 months for all patients.

CONCLUSION

This phase I study was carried out safely. This combination chemotherapy showed beneficial improvement in health-related quality of life. The recommended phase II dose of nafamostat mesilate in combination with full-dose gemcitabine is 4.8 mg/kg.