Sachio Fushida | Kanazawa University (original) (raw)

Papers by Sachio Fushida

Gastric Cancer, 2020

Objectives Interleukin-17A (IL-17A) is pro-inflammatory cytokine and acts as profibrotic factor i... more Objectives Interleukin-17A (IL-17A) is pro-inflammatory cytokine and acts as profibrotic factor in the fibrosis of various organs. Fibrosis tumor-like peritoneal dissemination of gastric cancer interferes with drug delivery and immune cell infiltration because of its high internal pressure. In this study, we examined the relationship between IL-17A and tissue fibrosis in peritoneal dissemination and elucidated the mechanism of fibrosis induced by IL-17A using human peritoneal mesothelial cells (HPMCs) and a mouse xenograft model. Methods Seventy gastric cancer patients with peritoneal dissemination were evaluated. The correlation between IL-17A and fibrosis was examined by immunofluorescence and immunohistochemistry. A fibrosis tumor model was developed based on subcutaneous transplantation of co-cultured cells (HPMCs and human gastric cancer cell line MKN-45) into the dorsal side of nude mice. Mice were subsequently treated with or without IL-17A. We also examined the effect of IL-...

Cancer Management and Research, 2018

Background: In patients with gastric cancer, one of the greatest obstacles to effective chemother... more Background: In patients with gastric cancer, one of the greatest obstacles to effective chemotherapy is the development of chemoresistance. It has been previously reported that hypoxia-inducible factor-1 alpha (HIF-1α) is associated with acquisition of chemoresistance, and more recent studies have also noted an association of pyruvate kinase muscle 1 (PKM1) and chemoresistance. The purpose of this study was to identify the effect of HIF-1α and PKM1 expression on the development of acquired chemoresistance using a paclitaxel (PTX)-resistant gastric cancer cell line. Materials and methods: A cancer cell line resistant to PTX was established from MKN45 cells by stepwise exposure to drug (rMKN45-PTX). The expressions of HIF-1α, apoptosis, vascular endothelial growth factor (VEGF), multidrug transporters and glycolytic enzyme were examined by Western blotting, enzyme-linked immunosorbent assay and immunohistochemistry. We also assessed the tumor proliferation by subcutaneous tumor and peritoneal dissemination of mouse xenograft model. Results: The resistance index was 6.1 by determining as the ratio of the 50% growth inhibition (IC 50) of rMKN45-PTX/IC 50 of MKN45. Expression of nuclear factor kappa B and HIF-1α was increased in rMKN45-PTX cells compared with the parent cells. Expression of Bax and caspase-3 was significantly downregulated, whereas expression of Bcl-xL, P-glycoprotein, multidrug resistance-associated protein and VEGF was increased in rMKN45-PTX. The expression level of PKM1 was upregulated in rMKN45-PTX, leading to an increase in the PKM1/PKM2 ratio. Using xenograft models, we demonstrated that mouse subcutaneous tumors derived from rMKN45-PTX were significantly larger than those derived from MKN45 cells. Conclusion: Under the stress of chemotherapeutic agent exposure, high expression of HIF-1α affects various downstream genes. Although the underlying mechanism is unknown, our data suggest that PKM1 is also a molecular target for gastric cancer treatment.

BMC cancer, Jan 27, 2017

The theory of extravasated platelet aggregation in cancer lesions was recently introduced. We inv... more The theory of extravasated platelet aggregation in cancer lesions was recently introduced. We investigated the association of platelet aggregation in gastric cancer stroma with clinicopathological features, chemotherapeutic response, pathological response, and survival. The study comprised 78 patients with advanced gastric cancer who had undergone gastrectomy with or without combination of docetaxel, cisplatin and S-1 (DCS) as preoperative chemotherapy between 2005 and 2014. The patients were divided into two groups: patients who had received preoperative DCS therapy forming the p-DCS group and patients who had not received preoperative DCS therapy forming the control group. The 39 patients in the control group had received gastrectomy and postoperative chemotherapy of S-1 alone. Platelet aggregation in biopsy specimens before preoperative DCS therapy in the p-DCS group and at the time of diagnosis in the control group were evaluated using CD42b immunohistochemical staining. Twenty-...

Gastric cancer : official journal of the International Gastric Cancer Association and the Japanese Gastric Cancer Association, Jan 24, 2017

Scirrhous gastric cancer is an intractable disease with a high incidence of peritoneal disseminat... more Scirrhous gastric cancer is an intractable disease with a high incidence of peritoneal dissemination and obstructive symptoms (e.g., ileus, jaundice, and hydronephrosis) arising from accompanying marked fibrosis. Microenvironmental interactions between cancer cells and cancer-associated fibroblasts are the suggested cause of the disease. We elucidated the mechanisms of tumor growth and fibrosis using human peritoneal mesothelial cells (HPMCs) and investigated the effects of tranilast treatment on cells and a xenograft mouse model of fibrosis. HPMCs were isolated from surgically excised omentum and their interaction with MKN-45 gastric cancer cells was investigated using co-culture. Furthermore, a fibrosis tumor model was developed based on subcutaneous transplantation of co-cultured cells into the dorsal side of nude mice to form large fibrotic tumors. Mice were subsequently treated with or without tranilast. The morphology of HPMCs treated with transforming growth factor (TGF)-β1 c...

BMC cancer, Jan 5, 2017

The clinical prognosis of gastric cancer with peritoneal dissemination is poor because of its che... more The clinical prognosis of gastric cancer with peritoneal dissemination is poor because of its chemoresistance and rich fibrosis. While several gastric cancer cell lines have been used to establish models of peritoneal dissemination by intraperitoneal injection, most peritoneal tumors that form adopt a medullary pattern in microscopic appearance. This histological finding for the model differs from that in the clinical situation. This study was performed to demonstrate the contribution of human peritoneal mesothelial cells (HPMCs) to fibrotic tumor formation and to establish a new xenograft model with high potential for peritoneal dissemination with organ invasion and extensive fibrosis. We established four types of xenograft model: i) intraperitoneal injection of MKN45-P cells alone (control group), ii) injection of MKN45-P cells co-cultured with HPMCs (co-cultured group), iii) scratching the parietal peritoneum (parietal group), and iv) scratching the visceral peritoneum (visceral ...

Oncology reports, 2016

Cancer stem cells (CSCs) have self-renewal and pluripotency capabilities and contribute to cancer... more Cancer stem cells (CSCs) have self-renewal and pluripotency capabilities and contribute to cancer progression and chemoresistance. It has been proposed that the treatment resistance and heterogeneity of CSCs are deeply involved in the prognosis of patients with esophageal squamous cell carcinoma (ESCC). The objective of this study was to identify the influence of the expression status of the CSC markers CD44 and CD133 on chemotherapeutic efficacy and prognosis in ESCC patients who underwent radical esophagectomy after neoadjuvant chemotherapy (NAC). Endoscopically biopsied specimens taken before NAC and surgically resected specimens after NAC were immunohistochemically assessed for CD44 and CD133 expression for 47 ESCC patients who underwent NAC followed by radical esophagectomy. The correlation between CD44 and CD133 expression status and clinicopathological findings and the prognosis of ESCC patients after NAC followed by esophagectomy were analyzed. The percentages of CD44-positi...

International Journal of Oncology, 2016

Esophageal carcinoma is one of the most aggressive malignancies, and is characterized by poor res... more Esophageal carcinoma is one of the most aggressive malignancies, and is characterized by poor response to current therapy and a dismal survival rate. In this study we investigated whether irradiation induces epithelial-mesenchymal transition (EMT) in esophageal squamous cell carcinoma (ESCC) TE9 cells and whether the classic histone deacetylase (HDAC) inhibitor valproic acid (VPA) suppresses these changes. First, we showed that 2 Gy irradiation induced spindle cell-like morphologic changes, decreased expression of membranous E-cadherin, upregulated vimentin expression, and altered the localization of β-catenin from its usual membrane-bound location to cytoplasm in TE9 cells. Irradiation induced upregulation of transcription factors including Slug, Snail, and Twist, which regulate EMT. Stimulation by irradiation resulted in increased TGF-β1 and HIF-1α expression and induced Smad2 and Smad3 phosphorylation. Furthermore, irradiation enhanced CD44 expression, indicating acquisition of cancer stem-like cell properties. In addition, irradiation enhanced invasion and migration ability with upregulation of matrix metalloproteinases. These findings indicate that single-dose irradiation can induce EMT in ESCC cells. Second, we found that treatment with 1 mM VPA induced reversal of EMT caused by irradiation in TE9 cells, resulting in attenuated cell invasion and migration abilities. These results suggest that VPA might have clinical value to suppress irradiation-induced EMT. The reversal of EMT by HDAC inhibitors may be a new therapeutic strategy to improve the effectiveness of radiotherapy in ESCC by inhibiting the enhancement of invasion and metastasis.

International Journal of Oncology, 2016

Esophageal cancer is one of the most aggressive tumor types because of its invasiveness and metas... more Esophageal cancer is one of the most aggressive tumor types because of its invasiveness and metastatic potential. Several reports have described an association between increased invasiveness after ionizing radiation (IR) treatment and epithelial-to-mesenchymal transition (EMT). The biguanide metformin is reported to prevent transforming growth factor-β (TGF-β)-induced EMT and proliferation of cancer. This study examined whether IR induces EMT and promotes the invasive potential of TE-9 esophageal squamous cell carcinoma cells and the effect of metformin on IR-induced EMT. After IR exposure, TE-9 cells showed a spindle-shaped morphology and lost cell-cell adhesion. Immunoblotting showed that IR induced expression of mesenchymal markers (vimentin and N-cadherin), transcription factors (Slug, Snail, and Twist), and matrix metalloproteinases. A scratch wound assay and Matrigel invasion assay showed that IR enhanced the invasive potential and migratory capacity of TE-9 cells. Expression of hypoxia-related factor-1α and TGF-β was increased after IR. IR also induced phosphorylation of Smad2 and Smad3. Metformin inhibited radiation-induced EMT-like morphological changes, and enhanced invasion and migration of TE-9 cells. Metformin inhibited IR-induced phosphorylation of Smad2 and Smad3. Although phosphory-lation of AMP-activated protein kinase was enhanced by IR and metformin, phosphorylation of mammalian target of rapamycin was enhanced by IR and suppressed by metformin. These results indicated that metformin suppressed IR-induced EMT via suppression of the TGF-β-Smad phosphorylation pathway, and a part of the non-Smad pathway. Metformin might be useful to prevent IR-induced invasion and metastasis of esophageal squamous cell carcinoma.

Modern rheumatology / the Japan Rheumatism Association, Jan 21, 2016

We describe a 67-year-old man with immunoglobulin G4-related disease (IgG4-RD) presenting with op... more We describe a 67-year-old man with immunoglobulin G4-related disease (IgG4-RD) presenting with optic neuropathy, dacryoadenitis, periaortitis, retroperitoneal fibrosis, and a gastric mass-like lesion. A mass-like lesion measuring 52 × 40 mm in the antrum of the stomach was found incidentally through whole-body screening for other organ involvement of IgG4-RD using contrast-enhanced computed tomography (CT). Histology of the stomach revealed that the lesion was also IgG4-related and was located in the submucosal layer extending to the subserosal region. This case suggests that the stomach can also be a site of involvement of IgG4-RD.

International Journal of Oncology, 2000

Oncology Reports, 2016

Platelets are crucial components of the tumor microenvironment that function to promote tumor pro... more Platelets are crucial components of the tumor microenvironment that function to promote tumor progression and metastasis. In the circulation, the interaction between tumor cells and platelets increases invasiveness, protects tumor cells from shear stress and immune surveillance, and facilitates tumor cell extravasation to distant sites. However, the role and presence of platelets in the primary tumor have not been fully determined. Here, we investigated the presence of platelets around breast cancer primary tumor cells and the associations between these cells. We further investigated the associations among platelets, tumor cells, chemoresistance, and epithelial-mesenchymal transition (EMT). We retrospectively analyzed data from 74 patients with human epidermal growth factor receptor 2 (HER2)-negative breast cancer who underwent biopsies before treatment and subsequent neo-adjuvant chemotherapy. In biopsy specimens, we evaluated the expression of platelet-specific markers and EMT markers using immunohistochemistry. The associations among the expression of platelet-specific markers in biopsy specimens, EMT, response to neo-adjuvant chemotherapy, and survival were analyzed. The presence of platelets was observed in 44 out of 74 (59%) primary breast cancer biopsy specimens. Platelet-positive tumor cells showed EMT-like morphological changes and EMT marker expression. Primary tumor cells associated with platelets were less responsive to neo-adjuvant chemotherapy (pCR rate: 10 vs. 50%, respectively; p=0.0001). Platelets were an independent predictor of the response to chemotherapy upon multivariable analysis (p<0.0001). In conclusion, there was a significant association between platelets surrounding primary tumor cells in the biopsy specimens and the chemotherapeutic response in breast cancer. Platelets surrounding primary tumor cells may represent novel predictors of chemotherapeutic responses.

Molecular and Clinical Oncology, 2015

The aim of the present study was to clarify the therapeutic effect of thoracoscopic esophagectomy... more The aim of the present study was to clarify the therapeutic effect of thoracoscopic esophagectomy with radical lymph node dissection based on the recurrence pattern, and identify the risk factors for relapse-free survival in patients with esophageal cancer. The recurrence patterns in 140 patients who underwent complete thoracoscopic radical esophagectomy between January 2003 and December 2012 were investigated. The risk factors for recurrence were examined by univariate and multivariate analysis. Mediastinal recurrence in association with initial lymphatic metastasis was precisely analyzed. Esophageal cancer recurred in 49 (35.0%) of the 140 patients. The median recurrence time was 259 (45-2,560) days after the initial treatment. The patterns of initial recurrence among the 140 patients included hematological recurrence in 24 patients (17.1%), lymphatic recurrence in 26 (18.6%), pleural dissemination in 5 (3.6%), peritoneal dissemination in 2 (1.4%), and local recurrence in 4 (2.9%). Lymphatic recurrence within the mediastinal regional lymphatic stations occurred in only 8 (5.7%) of the 140 patients. Univariate analysis for relapse-free survival showed that the statistically significant variables were a tumor location in the upper third of the esophagus, stage of pT3 or pT4, presence of nodal metastasis, pStage of III or IV, presence of a residual tumor, performance of preoperative chemotherapy and performance of postoperative therapy. Multivariate analysis showed that only nodal metastasis and a positive residual tumor were statistically significant independent risk factors for relapse-free survival. Lymphatic recurrence within the mediastinum, particularly the station around the bilateral recurrent laryngeal nerves, was infrequent and independent of the initial metastatic distribution. Thoracoscopic esophagectomy with radical lymph node dissection provides favorable locoregional control. Lymphatic recurrence within the mediastinal regional nodes is infrequent and independent of the initial lymph node metastasis. A pathological residual tumor and lymph node metastasis are significant risk factors for recurrence.

Experimental and therapeutic medicine, Nov 1, 2010

Here, we present a case of post-operative liver metastases from pancreatic head cancer in a patie... more Here, we present a case of post-operative liver metastases from pancreatic head cancer in a patient with leukocytopenia, who was safely treated by hepatic arterial infusion (HAI) chemotherapy consisting of gemcitabine and 5-FU. The patient was a 61-year-old woman who underwent pancreaticoduodenectomy for pancreatic head cancer, but was found to be an unsuitable candidate for adjuvant systemic chemotherapy due to the presence of leukocytopenia. Five months after surgery, a follow-up CT revealed two liver metastases. Intravenous systemic chemotherapy was also contraindicated due to the leukocytopenia. In the apparent absence of recurrence, excepting the liver metastases, we decided to administer HAI chemotherapy, which had already been administered following the curative surgery. HAI chemotherapy has been shown to be associated with a lower incidence of systemic side effects. Gemcitabine at a dose of 400 mg was administered via a bedside pump and infused over 30 min. After gemcitabine...

Clinical cancer research : an official journal of the American Association for Cancer Research, 2000

S100A4 is known to be involved in cancer cell motility by virtue of its ability to activate nonmu... more S100A4 is known to be involved in cancer cell motility by virtue of its ability to activate nonmuscle myosin. E-cadherin has an important role in the homophilic cell-cell adhesion and is called an invasion suppressor gene. In the current study, we investigate the histological type and metastatic potential of gastric cancer from the aspect of the interrelationship of E-cadherin and S100A4 expression. Expression of E-cadherin and S100A4 in gastric cancer cell lines, primary gastric cancers, and their normal counterparts were analyzed by reverse transcription-PCR, Western blot, and immunohistochemical methods. S100A4 protein and E-cadherin were expressed in five of eight gastric cancer cell lines, and inverse expression of the two proteins are found in four cell lines. In the clinical specimens, E-cadherin mRNA expression in differentiated adenocarcinomas (88%, 14 of 16) was significantly more frequent than that in poorly differentiated adenocarcinomas (50%, 22 of 44; P = 0.015). Weste...

Surgical Case Reports, 2015

Esophageal cancer invading the muscularis mucosa sometimes involves regional lymph node metastase... more Esophageal cancer invading the muscularis mucosa sometimes involves regional lymph node metastases. However, lymph node metastases are rare in the dorsal area of the thoracic aorta. We describe a patient with an intramucosal esophageal cancer invading the muscularis mucosa, accompanied by lymph node metastases in the dorsal area of the thoracic aorta. These lesions were successfully resected by hand-assisted laparoscopic surgery using a transhiatal approach. A 60-year-old man was diagnosed with superficial esophageal cancer during a routine health examination. Endoscopic examination and ultrasonography revealed a superficial cancer, of diameter 6.0 cm, invading the submucosal layer and intramural metastases caudal to the primary tumor. Enhanced computed tomography and F-deoxyglucose positron emission tomography demonstrated the two metastatic lymph nodes, one in the dorsal area of the thoracic aorta and the other near the left gastric artery. Thoracoscopic radical esophagectomy with three-field lymph node dissection was performed. The metastatic lymph node in the dorsal area of the thoracic aorta was successfully removed by hand-assisted laparoscopic surgery using a transhiatal approach. Histopathological examination showed primary cancer invading the muscularis mucosa and intramural metastases in the lamina propria mucosa and submucosal layer. The pathological diagnosis according to the Japanese classification of esophageal cancer was MtLt, 47 mm, 0-IIa + IIb, pT1a-MM, ie(+), INF-b, ly3, v0, pN4(4a), pIM1, M0, and pstage IVa. The patient underwent two courses of adjuvant chemotherapy, consisting of CDDP and 5-fluorouracil. At present, 1 year and 8 months after surgery, the patient remains alive without tumor recurrence. Although the lymph node in the dorsal area of the thoracic aorta is not recognized as regional nodes of thoracic esophageal cancer, solitary mediastinal metastases from a mucosal cancer may indicate the existence of direct lymphatic flow from the thoracic esophagus to the retroaortic region. Transhiatal approach by hand-assisted laparoscopic surgery is useful to dissect the metastatic lymph node in the dorsal area of the thoracic aorta.

Cancer research, 1991

Using a polyclonal antibody that is monospecific for the erbB-2 oncogene product, an immunohistoc... more Using a polyclonal antibody that is monospecific for the erbB-2 oncogene product, an immunohistochemical study of the expression of erbB-2 protein was performed in formalin-fixed paraffin-embedded tissue sections from 260 primary gastric cancers. erbB-2 protein expression in which the reaction was localized to the cell membranes was observed in 31 (11.9%) cancers. All nontumor cells and normal gastric epithelium were negative for membrane staining. There was not a significant association between erbB-2 staining and histological type or venous invasion. erbB-2 protein expression was associated with serosal invasion, lymph node metastasis, and lymphatic invasion. In addition, erbB-2 protein expression correlated with a high number of lymph node metastases. Furthermore, the risk of recurrence in lymph node was over 3 times higher in patients with erbB-2 protein-positive tumors than in those with erbB-2 protein-negative ones. When erbB-2 protein expression and the clinical parameters we...

Gastric Cancer, 2014

Background The G-Project committee was erected by the Japan Society for Gastroenterological Carci... more Background The G-Project committee was erected by the Japan Society for Gastroenterological Carcinogenesis with an aim of establishing a new classification scheme based on molecular biological characteristics that would supplement the conventional TNM classification to better predict outcome. Methods In a literature search involving 822 articles on gastric cancer, eight molecules including p53, vascular endothelial growth factor (VEGF)-A, VEGF-C, matrix metalloproteinase-7 (MMP-7), human epidermal growth factor receptor 2, Regenerating islet-derived family, member 4, olfactomedin-4 and Claudin-18 were selected as candidates to be included in the new molecular classification scheme named G-factor. A total of 210 cases of gastric cancer who underwent curative R0 resection were registered from four independent facilities. Immunohistochemical staining for the aforementioned molecules was performed for the surgically resected specimens of the 210 cases to investigate the correlation between clinicopathological factors and expression of each molecule. Results No significant correlation was observed between the immunostaining expression of any of the eight factors and postoperative recurrence. However, the expressions of

Liver International, 1999

AimslBackground: Nerve growth factor (NGF) has recently been shown to influence the survival and ... more AimslBackground: Nerve growth factor (NGF) has recently been shown to influence the survival and function of non-neuronal inflammatory cells, possibly through its activity as a colony-stimulating factor. It may also play an important role in acute inflammation and tissue repair. However, no prior report has focused on NGF in chronic inflammatory diseases of the gastrointestinal and biliary tracts. The aim of this study was to examine the expression of NGF in hepatolithiasis. Methods: Twenty-six liver specimens resected from 22 patients with intrahepatic calcium bilirubinate stones and from 4 patients with intrahepatic cholesterol stones were examined immunohistochemically. Results: The 22 patients with calcium bilirubinate stones demonstrated NGF immunoreactivity associated with surrounding inflammatory cel Is that was localized to the epithelia of proliferative peribiliary glands in tlhe ductal wall. However, neither the surface lining of the bile duct nor hepatocytes expressed detectable NGF immunoreactivity. In the cholesterol stones cases in contrast, peribiliary glandular elements and inflammatory cell infiltration were less extensive than those observed in cases of calcium bilirubinate stones, and NGF immunoreactivity was not noted. Conclusions: These observations suggest that proliferative peribiliary glands express NGF protein in chronic proliferative cholangitis. This is characteristic of intrahepatic cal

Journal of Surgical Oncology, 1998

The most reliable method for the diagnosis of peritoneal dissemination of gastric cancer at the p... more The most reliable method for the diagnosis of peritoneal dissemination of gastric cancer at the present time is cytological examination of ascitic fluid, which is unavailable to patients without ascites or may be inadequate for those with ascites containing few cancer cells. It has been reported recently that human gastric cancer immunoreacted with a monoclonal antibody against pancreatic trypsinogen. We therefore examined the expression of trypsinogen as a new marker for the early diagnosis of peritoneal dissemination of gastric cancer. Pancreatic trypsinogen protein was immunohistochemically stained with a three-step indirect immunoperoxidase method and cationic trypsinogen (trypsinogen-1) mRNA expression was examined by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis in gastric cancer. Twenty-nine of 30 primary tumors (97%) and all 12 tumors (100%) of the peritoneal seedings immunohistochemically reacted with trypsinogen. Preliminary study for early diagnosis of peritoneal dissemination was carried out for eight more recent patients who showed positive immunoreactivity to trypsinogen protein and expressed trypsinogen- mRNA in the primary tumor. The expression of trypsinogen-1 mRNA was detected by using peritoneal lavage fluid preoperatively collected in these patients. All three patients in whom peritoneal dissemination was diagnosed at the time of their operation(s) expressed trypsinogen-1 mRNA. One patient, who did not show peritoneal dissemination at the operation but was positive for trypsinogen-1 mRNA detection, later died of the recurrence of peritoneal dissemination. These results indicated that trypsinogen protein and trypsinogen-1 mRNA frequently expressed in peritoneal dissemination as well as primary tumors in gastric cancer and detection of trypsinogen-1 mRNA expression was a useful method for early diagnosis in peritoneal dissemination of gastric cancer.

International Journal of Cancer, 2001

Various studies have described increased expression of cationic trypsinogen in malignant tumor ce... more Various studies have described increased expression of cationic trypsinogen in malignant tumor cells. To explore the role of secreted cationic trypsinogen in invasion by cancer cells, we introduced cationic trypsinogen cDNA into Panc-1, a pancreatic adenocarcinoma-derived cell line that lacks expression of endogeneous trypsinogen. Four independent clones (designated Panc-1-Try-7, -9, -11 and -24) stably expressing cationic trypsinogen mRNA were isolated and processed for further study. In a zymographic analysis, gelatinolytic activity for cationic trypsinogen was detectable in serum-free conditioned media obtained from all 4 transfectants but not in media from mock-transfected or parental Panc-1 cells. A Matrigel invasion assay revealed that all trypsinogen-expressing transfectants acquired significantly greater invasive ability than that shown by mock-transfected and parental Panc-1 cells. In addition, enhanced invasiveness of the transfectants was suppressed by FUT-175, a serine protease inhibitor, to the level seen in parental cells. These results provide direct evidence that cationic trypsinogen can increase the invasive ability of carcinoma cells.

Gastric Cancer, 2020

Objectives Interleukin-17A (IL-17A) is pro-inflammatory cytokine and acts as profibrotic factor i... more Objectives Interleukin-17A (IL-17A) is pro-inflammatory cytokine and acts as profibrotic factor in the fibrosis of various organs. Fibrosis tumor-like peritoneal dissemination of gastric cancer interferes with drug delivery and immune cell infiltration because of its high internal pressure. In this study, we examined the relationship between IL-17A and tissue fibrosis in peritoneal dissemination and elucidated the mechanism of fibrosis induced by IL-17A using human peritoneal mesothelial cells (HPMCs) and a mouse xenograft model. Methods Seventy gastric cancer patients with peritoneal dissemination were evaluated. The correlation between IL-17A and fibrosis was examined by immunofluorescence and immunohistochemistry. A fibrosis tumor model was developed based on subcutaneous transplantation of co-cultured cells (HPMCs and human gastric cancer cell line MKN-45) into the dorsal side of nude mice. Mice were subsequently treated with or without IL-17A. We also examined the effect of IL-...

Cancer Management and Research, 2018

Background: In patients with gastric cancer, one of the greatest obstacles to effective chemother... more Background: In patients with gastric cancer, one of the greatest obstacles to effective chemotherapy is the development of chemoresistance. It has been previously reported that hypoxia-inducible factor-1 alpha (HIF-1α) is associated with acquisition of chemoresistance, and more recent studies have also noted an association of pyruvate kinase muscle 1 (PKM1) and chemoresistance. The purpose of this study was to identify the effect of HIF-1α and PKM1 expression on the development of acquired chemoresistance using a paclitaxel (PTX)-resistant gastric cancer cell line. Materials and methods: A cancer cell line resistant to PTX was established from MKN45 cells by stepwise exposure to drug (rMKN45-PTX). The expressions of HIF-1α, apoptosis, vascular endothelial growth factor (VEGF), multidrug transporters and glycolytic enzyme were examined by Western blotting, enzyme-linked immunosorbent assay and immunohistochemistry. We also assessed the tumor proliferation by subcutaneous tumor and peritoneal dissemination of mouse xenograft model. Results: The resistance index was 6.1 by determining as the ratio of the 50% growth inhibition (IC 50) of rMKN45-PTX/IC 50 of MKN45. Expression of nuclear factor kappa B and HIF-1α was increased in rMKN45-PTX cells compared with the parent cells. Expression of Bax and caspase-3 was significantly downregulated, whereas expression of Bcl-xL, P-glycoprotein, multidrug resistance-associated protein and VEGF was increased in rMKN45-PTX. The expression level of PKM1 was upregulated in rMKN45-PTX, leading to an increase in the PKM1/PKM2 ratio. Using xenograft models, we demonstrated that mouse subcutaneous tumors derived from rMKN45-PTX were significantly larger than those derived from MKN45 cells. Conclusion: Under the stress of chemotherapeutic agent exposure, high expression of HIF-1α affects various downstream genes. Although the underlying mechanism is unknown, our data suggest that PKM1 is also a molecular target for gastric cancer treatment.

BMC cancer, Jan 27, 2017

The theory of extravasated platelet aggregation in cancer lesions was recently introduced. We inv... more The theory of extravasated platelet aggregation in cancer lesions was recently introduced. We investigated the association of platelet aggregation in gastric cancer stroma with clinicopathological features, chemotherapeutic response, pathological response, and survival. The study comprised 78 patients with advanced gastric cancer who had undergone gastrectomy with or without combination of docetaxel, cisplatin and S-1 (DCS) as preoperative chemotherapy between 2005 and 2014. The patients were divided into two groups: patients who had received preoperative DCS therapy forming the p-DCS group and patients who had not received preoperative DCS therapy forming the control group. The 39 patients in the control group had received gastrectomy and postoperative chemotherapy of S-1 alone. Platelet aggregation in biopsy specimens before preoperative DCS therapy in the p-DCS group and at the time of diagnosis in the control group were evaluated using CD42b immunohistochemical staining. Twenty-...

Gastric cancer : official journal of the International Gastric Cancer Association and the Japanese Gastric Cancer Association, Jan 24, 2017

Scirrhous gastric cancer is an intractable disease with a high incidence of peritoneal disseminat... more Scirrhous gastric cancer is an intractable disease with a high incidence of peritoneal dissemination and obstructive symptoms (e.g., ileus, jaundice, and hydronephrosis) arising from accompanying marked fibrosis. Microenvironmental interactions between cancer cells and cancer-associated fibroblasts are the suggested cause of the disease. We elucidated the mechanisms of tumor growth and fibrosis using human peritoneal mesothelial cells (HPMCs) and investigated the effects of tranilast treatment on cells and a xenograft mouse model of fibrosis. HPMCs were isolated from surgically excised omentum and their interaction with MKN-45 gastric cancer cells was investigated using co-culture. Furthermore, a fibrosis tumor model was developed based on subcutaneous transplantation of co-cultured cells into the dorsal side of nude mice to form large fibrotic tumors. Mice were subsequently treated with or without tranilast. The morphology of HPMCs treated with transforming growth factor (TGF)-β1 c...

BMC cancer, Jan 5, 2017

The clinical prognosis of gastric cancer with peritoneal dissemination is poor because of its che... more The clinical prognosis of gastric cancer with peritoneal dissemination is poor because of its chemoresistance and rich fibrosis. While several gastric cancer cell lines have been used to establish models of peritoneal dissemination by intraperitoneal injection, most peritoneal tumors that form adopt a medullary pattern in microscopic appearance. This histological finding for the model differs from that in the clinical situation. This study was performed to demonstrate the contribution of human peritoneal mesothelial cells (HPMCs) to fibrotic tumor formation and to establish a new xenograft model with high potential for peritoneal dissemination with organ invasion and extensive fibrosis. We established four types of xenograft model: i) intraperitoneal injection of MKN45-P cells alone (control group), ii) injection of MKN45-P cells co-cultured with HPMCs (co-cultured group), iii) scratching the parietal peritoneum (parietal group), and iv) scratching the visceral peritoneum (visceral ...

Oncology reports, 2016

Cancer stem cells (CSCs) have self-renewal and pluripotency capabilities and contribute to cancer... more Cancer stem cells (CSCs) have self-renewal and pluripotency capabilities and contribute to cancer progression and chemoresistance. It has been proposed that the treatment resistance and heterogeneity of CSCs are deeply involved in the prognosis of patients with esophageal squamous cell carcinoma (ESCC). The objective of this study was to identify the influence of the expression status of the CSC markers CD44 and CD133 on chemotherapeutic efficacy and prognosis in ESCC patients who underwent radical esophagectomy after neoadjuvant chemotherapy (NAC). Endoscopically biopsied specimens taken before NAC and surgically resected specimens after NAC were immunohistochemically assessed for CD44 and CD133 expression for 47 ESCC patients who underwent NAC followed by radical esophagectomy. The correlation between CD44 and CD133 expression status and clinicopathological findings and the prognosis of ESCC patients after NAC followed by esophagectomy were analyzed. The percentages of CD44-positi...

International Journal of Oncology, 2016

Esophageal carcinoma is one of the most aggressive malignancies, and is characterized by poor res... more Esophageal carcinoma is one of the most aggressive malignancies, and is characterized by poor response to current therapy and a dismal survival rate. In this study we investigated whether irradiation induces epithelial-mesenchymal transition (EMT) in esophageal squamous cell carcinoma (ESCC) TE9 cells and whether the classic histone deacetylase (HDAC) inhibitor valproic acid (VPA) suppresses these changes. First, we showed that 2 Gy irradiation induced spindle cell-like morphologic changes, decreased expression of membranous E-cadherin, upregulated vimentin expression, and altered the localization of β-catenin from its usual membrane-bound location to cytoplasm in TE9 cells. Irradiation induced upregulation of transcription factors including Slug, Snail, and Twist, which regulate EMT. Stimulation by irradiation resulted in increased TGF-β1 and HIF-1α expression and induced Smad2 and Smad3 phosphorylation. Furthermore, irradiation enhanced CD44 expression, indicating acquisition of cancer stem-like cell properties. In addition, irradiation enhanced invasion and migration ability with upregulation of matrix metalloproteinases. These findings indicate that single-dose irradiation can induce EMT in ESCC cells. Second, we found that treatment with 1 mM VPA induced reversal of EMT caused by irradiation in TE9 cells, resulting in attenuated cell invasion and migration abilities. These results suggest that VPA might have clinical value to suppress irradiation-induced EMT. The reversal of EMT by HDAC inhibitors may be a new therapeutic strategy to improve the effectiveness of radiotherapy in ESCC by inhibiting the enhancement of invasion and metastasis.

International Journal of Oncology, 2016

Esophageal cancer is one of the most aggressive tumor types because of its invasiveness and metas... more Esophageal cancer is one of the most aggressive tumor types because of its invasiveness and metastatic potential. Several reports have described an association between increased invasiveness after ionizing radiation (IR) treatment and epithelial-to-mesenchymal transition (EMT). The biguanide metformin is reported to prevent transforming growth factor-β (TGF-β)-induced EMT and proliferation of cancer. This study examined whether IR induces EMT and promotes the invasive potential of TE-9 esophageal squamous cell carcinoma cells and the effect of metformin on IR-induced EMT. After IR exposure, TE-9 cells showed a spindle-shaped morphology and lost cell-cell adhesion. Immunoblotting showed that IR induced expression of mesenchymal markers (vimentin and N-cadherin), transcription factors (Slug, Snail, and Twist), and matrix metalloproteinases. A scratch wound assay and Matrigel invasion assay showed that IR enhanced the invasive potential and migratory capacity of TE-9 cells. Expression of hypoxia-related factor-1α and TGF-β was increased after IR. IR also induced phosphorylation of Smad2 and Smad3. Metformin inhibited radiation-induced EMT-like morphological changes, and enhanced invasion and migration of TE-9 cells. Metformin inhibited IR-induced phosphorylation of Smad2 and Smad3. Although phosphory-lation of AMP-activated protein kinase was enhanced by IR and metformin, phosphorylation of mammalian target of rapamycin was enhanced by IR and suppressed by metformin. These results indicated that metformin suppressed IR-induced EMT via suppression of the TGF-β-Smad phosphorylation pathway, and a part of the non-Smad pathway. Metformin might be useful to prevent IR-induced invasion and metastasis of esophageal squamous cell carcinoma.

Modern rheumatology / the Japan Rheumatism Association, Jan 21, 2016

We describe a 67-year-old man with immunoglobulin G4-related disease (IgG4-RD) presenting with op... more We describe a 67-year-old man with immunoglobulin G4-related disease (IgG4-RD) presenting with optic neuropathy, dacryoadenitis, periaortitis, retroperitoneal fibrosis, and a gastric mass-like lesion. A mass-like lesion measuring 52 × 40 mm in the antrum of the stomach was found incidentally through whole-body screening for other organ involvement of IgG4-RD using contrast-enhanced computed tomography (CT). Histology of the stomach revealed that the lesion was also IgG4-related and was located in the submucosal layer extending to the subserosal region. This case suggests that the stomach can also be a site of involvement of IgG4-RD.

International Journal of Oncology, 2000

Oncology Reports, 2016

Platelets are crucial components of the tumor microenvironment that function to promote tumor pro... more Platelets are crucial components of the tumor microenvironment that function to promote tumor progression and metastasis. In the circulation, the interaction between tumor cells and platelets increases invasiveness, protects tumor cells from shear stress and immune surveillance, and facilitates tumor cell extravasation to distant sites. However, the role and presence of platelets in the primary tumor have not been fully determined. Here, we investigated the presence of platelets around breast cancer primary tumor cells and the associations between these cells. We further investigated the associations among platelets, tumor cells, chemoresistance, and epithelial-mesenchymal transition (EMT). We retrospectively analyzed data from 74 patients with human epidermal growth factor receptor 2 (HER2)-negative breast cancer who underwent biopsies before treatment and subsequent neo-adjuvant chemotherapy. In biopsy specimens, we evaluated the expression of platelet-specific markers and EMT markers using immunohistochemistry. The associations among the expression of platelet-specific markers in biopsy specimens, EMT, response to neo-adjuvant chemotherapy, and survival were analyzed. The presence of platelets was observed in 44 out of 74 (59%) primary breast cancer biopsy specimens. Platelet-positive tumor cells showed EMT-like morphological changes and EMT marker expression. Primary tumor cells associated with platelets were less responsive to neo-adjuvant chemotherapy (pCR rate: 10 vs. 50%, respectively; p=0.0001). Platelets were an independent predictor of the response to chemotherapy upon multivariable analysis (p<0.0001). In conclusion, there was a significant association between platelets surrounding primary tumor cells in the biopsy specimens and the chemotherapeutic response in breast cancer. Platelets surrounding primary tumor cells may represent novel predictors of chemotherapeutic responses.

Molecular and Clinical Oncology, 2015

The aim of the present study was to clarify the therapeutic effect of thoracoscopic esophagectomy... more The aim of the present study was to clarify the therapeutic effect of thoracoscopic esophagectomy with radical lymph node dissection based on the recurrence pattern, and identify the risk factors for relapse-free survival in patients with esophageal cancer. The recurrence patterns in 140 patients who underwent complete thoracoscopic radical esophagectomy between January 2003 and December 2012 were investigated. The risk factors for recurrence were examined by univariate and multivariate analysis. Mediastinal recurrence in association with initial lymphatic metastasis was precisely analyzed. Esophageal cancer recurred in 49 (35.0%) of the 140 patients. The median recurrence time was 259 (45-2,560) days after the initial treatment. The patterns of initial recurrence among the 140 patients included hematological recurrence in 24 patients (17.1%), lymphatic recurrence in 26 (18.6%), pleural dissemination in 5 (3.6%), peritoneal dissemination in 2 (1.4%), and local recurrence in 4 (2.9%). Lymphatic recurrence within the mediastinal regional lymphatic stations occurred in only 8 (5.7%) of the 140 patients. Univariate analysis for relapse-free survival showed that the statistically significant variables were a tumor location in the upper third of the esophagus, stage of pT3 or pT4, presence of nodal metastasis, pStage of III or IV, presence of a residual tumor, performance of preoperative chemotherapy and performance of postoperative therapy. Multivariate analysis showed that only nodal metastasis and a positive residual tumor were statistically significant independent risk factors for relapse-free survival. Lymphatic recurrence within the mediastinum, particularly the station around the bilateral recurrent laryngeal nerves, was infrequent and independent of the initial metastatic distribution. Thoracoscopic esophagectomy with radical lymph node dissection provides favorable locoregional control. Lymphatic recurrence within the mediastinal regional nodes is infrequent and independent of the initial lymph node metastasis. A pathological residual tumor and lymph node metastasis are significant risk factors for recurrence.

Experimental and therapeutic medicine, Nov 1, 2010

Here, we present a case of post-operative liver metastases from pancreatic head cancer in a patie... more Here, we present a case of post-operative liver metastases from pancreatic head cancer in a patient with leukocytopenia, who was safely treated by hepatic arterial infusion (HAI) chemotherapy consisting of gemcitabine and 5-FU. The patient was a 61-year-old woman who underwent pancreaticoduodenectomy for pancreatic head cancer, but was found to be an unsuitable candidate for adjuvant systemic chemotherapy due to the presence of leukocytopenia. Five months after surgery, a follow-up CT revealed two liver metastases. Intravenous systemic chemotherapy was also contraindicated due to the leukocytopenia. In the apparent absence of recurrence, excepting the liver metastases, we decided to administer HAI chemotherapy, which had already been administered following the curative surgery. HAI chemotherapy has been shown to be associated with a lower incidence of systemic side effects. Gemcitabine at a dose of 400 mg was administered via a bedside pump and infused over 30 min. After gemcitabine...

Clinical cancer research : an official journal of the American Association for Cancer Research, 2000

S100A4 is known to be involved in cancer cell motility by virtue of its ability to activate nonmu... more S100A4 is known to be involved in cancer cell motility by virtue of its ability to activate nonmuscle myosin. E-cadherin has an important role in the homophilic cell-cell adhesion and is called an invasion suppressor gene. In the current study, we investigate the histological type and metastatic potential of gastric cancer from the aspect of the interrelationship of E-cadherin and S100A4 expression. Expression of E-cadherin and S100A4 in gastric cancer cell lines, primary gastric cancers, and their normal counterparts were analyzed by reverse transcription-PCR, Western blot, and immunohistochemical methods. S100A4 protein and E-cadherin were expressed in five of eight gastric cancer cell lines, and inverse expression of the two proteins are found in four cell lines. In the clinical specimens, E-cadherin mRNA expression in differentiated adenocarcinomas (88%, 14 of 16) was significantly more frequent than that in poorly differentiated adenocarcinomas (50%, 22 of 44; P = 0.015). Weste...

Surgical Case Reports, 2015

Esophageal cancer invading the muscularis mucosa sometimes involves regional lymph node metastase... more Esophageal cancer invading the muscularis mucosa sometimes involves regional lymph node metastases. However, lymph node metastases are rare in the dorsal area of the thoracic aorta. We describe a patient with an intramucosal esophageal cancer invading the muscularis mucosa, accompanied by lymph node metastases in the dorsal area of the thoracic aorta. These lesions were successfully resected by hand-assisted laparoscopic surgery using a transhiatal approach. A 60-year-old man was diagnosed with superficial esophageal cancer during a routine health examination. Endoscopic examination and ultrasonography revealed a superficial cancer, of diameter 6.0 cm, invading the submucosal layer and intramural metastases caudal to the primary tumor. Enhanced computed tomography and F-deoxyglucose positron emission tomography demonstrated the two metastatic lymph nodes, one in the dorsal area of the thoracic aorta and the other near the left gastric artery. Thoracoscopic radical esophagectomy with three-field lymph node dissection was performed. The metastatic lymph node in the dorsal area of the thoracic aorta was successfully removed by hand-assisted laparoscopic surgery using a transhiatal approach. Histopathological examination showed primary cancer invading the muscularis mucosa and intramural metastases in the lamina propria mucosa and submucosal layer. The pathological diagnosis according to the Japanese classification of esophageal cancer was MtLt, 47 mm, 0-IIa + IIb, pT1a-MM, ie(+), INF-b, ly3, v0, pN4(4a), pIM1, M0, and pstage IVa. The patient underwent two courses of adjuvant chemotherapy, consisting of CDDP and 5-fluorouracil. At present, 1 year and 8 months after surgery, the patient remains alive without tumor recurrence. Although the lymph node in the dorsal area of the thoracic aorta is not recognized as regional nodes of thoracic esophageal cancer, solitary mediastinal metastases from a mucosal cancer may indicate the existence of direct lymphatic flow from the thoracic esophagus to the retroaortic region. Transhiatal approach by hand-assisted laparoscopic surgery is useful to dissect the metastatic lymph node in the dorsal area of the thoracic aorta.

Cancer research, 1991

Using a polyclonal antibody that is monospecific for the erbB-2 oncogene product, an immunohistoc... more Using a polyclonal antibody that is monospecific for the erbB-2 oncogene product, an immunohistochemical study of the expression of erbB-2 protein was performed in formalin-fixed paraffin-embedded tissue sections from 260 primary gastric cancers. erbB-2 protein expression in which the reaction was localized to the cell membranes was observed in 31 (11.9%) cancers. All nontumor cells and normal gastric epithelium were negative for membrane staining. There was not a significant association between erbB-2 staining and histological type or venous invasion. erbB-2 protein expression was associated with serosal invasion, lymph node metastasis, and lymphatic invasion. In addition, erbB-2 protein expression correlated with a high number of lymph node metastases. Furthermore, the risk of recurrence in lymph node was over 3 times higher in patients with erbB-2 protein-positive tumors than in those with erbB-2 protein-negative ones. When erbB-2 protein expression and the clinical parameters we...

Gastric Cancer, 2014

Background The G-Project committee was erected by the Japan Society for Gastroenterological Carci... more Background The G-Project committee was erected by the Japan Society for Gastroenterological Carcinogenesis with an aim of establishing a new classification scheme based on molecular biological characteristics that would supplement the conventional TNM classification to better predict outcome. Methods In a literature search involving 822 articles on gastric cancer, eight molecules including p53, vascular endothelial growth factor (VEGF)-A, VEGF-C, matrix metalloproteinase-7 (MMP-7), human epidermal growth factor receptor 2, Regenerating islet-derived family, member 4, olfactomedin-4 and Claudin-18 were selected as candidates to be included in the new molecular classification scheme named G-factor. A total of 210 cases of gastric cancer who underwent curative R0 resection were registered from four independent facilities. Immunohistochemical staining for the aforementioned molecules was performed for the surgically resected specimens of the 210 cases to investigate the correlation between clinicopathological factors and expression of each molecule. Results No significant correlation was observed between the immunostaining expression of any of the eight factors and postoperative recurrence. However, the expressions of

Liver International, 1999

AimslBackground: Nerve growth factor (NGF) has recently been shown to influence the survival and ... more AimslBackground: Nerve growth factor (NGF) has recently been shown to influence the survival and function of non-neuronal inflammatory cells, possibly through its activity as a colony-stimulating factor. It may also play an important role in acute inflammation and tissue repair. However, no prior report has focused on NGF in chronic inflammatory diseases of the gastrointestinal and biliary tracts. The aim of this study was to examine the expression of NGF in hepatolithiasis. Methods: Twenty-six liver specimens resected from 22 patients with intrahepatic calcium bilirubinate stones and from 4 patients with intrahepatic cholesterol stones were examined immunohistochemically. Results: The 22 patients with calcium bilirubinate stones demonstrated NGF immunoreactivity associated with surrounding inflammatory cel Is that was localized to the epithelia of proliferative peribiliary glands in tlhe ductal wall. However, neither the surface lining of the bile duct nor hepatocytes expressed detectable NGF immunoreactivity. In the cholesterol stones cases in contrast, peribiliary glandular elements and inflammatory cell infiltration were less extensive than those observed in cases of calcium bilirubinate stones, and NGF immunoreactivity was not noted. Conclusions: These observations suggest that proliferative peribiliary glands express NGF protein in chronic proliferative cholangitis. This is characteristic of intrahepatic cal

Journal of Surgical Oncology, 1998

The most reliable method for the diagnosis of peritoneal dissemination of gastric cancer at the p... more The most reliable method for the diagnosis of peritoneal dissemination of gastric cancer at the present time is cytological examination of ascitic fluid, which is unavailable to patients without ascites or may be inadequate for those with ascites containing few cancer cells. It has been reported recently that human gastric cancer immunoreacted with a monoclonal antibody against pancreatic trypsinogen. We therefore examined the expression of trypsinogen as a new marker for the early diagnosis of peritoneal dissemination of gastric cancer. Pancreatic trypsinogen protein was immunohistochemically stained with a three-step indirect immunoperoxidase method and cationic trypsinogen (trypsinogen-1) mRNA expression was examined by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis in gastric cancer. Twenty-nine of 30 primary tumors (97%) and all 12 tumors (100%) of the peritoneal seedings immunohistochemically reacted with trypsinogen. Preliminary study for early diagnosis of peritoneal dissemination was carried out for eight more recent patients who showed positive immunoreactivity to trypsinogen protein and expressed trypsinogen- mRNA in the primary tumor. The expression of trypsinogen-1 mRNA was detected by using peritoneal lavage fluid preoperatively collected in these patients. All three patients in whom peritoneal dissemination was diagnosed at the time of their operation(s) expressed trypsinogen-1 mRNA. One patient, who did not show peritoneal dissemination at the operation but was positive for trypsinogen-1 mRNA detection, later died of the recurrence of peritoneal dissemination. These results indicated that trypsinogen protein and trypsinogen-1 mRNA frequently expressed in peritoneal dissemination as well as primary tumors in gastric cancer and detection of trypsinogen-1 mRNA expression was a useful method for early diagnosis in peritoneal dissemination of gastric cancer.

International Journal of Cancer, 2001

Various studies have described increased expression of cationic trypsinogen in malignant tumor ce... more Various studies have described increased expression of cationic trypsinogen in malignant tumor cells. To explore the role of secreted cationic trypsinogen in invasion by cancer cells, we introduced cationic trypsinogen cDNA into Panc-1, a pancreatic adenocarcinoma-derived cell line that lacks expression of endogeneous trypsinogen. Four independent clones (designated Panc-1-Try-7, -9, -11 and -24) stably expressing cationic trypsinogen mRNA were isolated and processed for further study. In a zymographic analysis, gelatinolytic activity for cationic trypsinogen was detectable in serum-free conditioned media obtained from all 4 transfectants but not in media from mock-transfected or parental Panc-1 cells. A Matrigel invasion assay revealed that all trypsinogen-expressing transfectants acquired significantly greater invasive ability than that shown by mock-transfected and parental Panc-1 cells. In addition, enhanced invasiveness of the transfectants was suppressed by FUT-175, a serine protease inhibitor, to the level seen in parental cells. These results provide direct evidence that cationic trypsinogen can increase the invasive ability of carcinoma cells.