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Biomedical subjects

Kosei Hirakawa

Publications and source records attributed to Kosei Hirakawa.

At least 19 recordsLinked to original sources
PubMed2007

Selective cyclooxygenase-2 inhibitor downregulates the paracrine epithelial-mesenchymal interactions of growth in scirrhous gastric carcinoma.

The importance of cancer-mesenchymal interactions in the aggressive behavior of scirrhous gastric cancer is supported by experimental and clinical evidences. We have previously reported that gastric fibroblasts secretion of keratinocyte growth factor (KGF) underline the remarkable proliferation of scirrhous gastric cancer cells. Cyclooxygenase-2 (COX-2) is not only expressed in cancer cells, but also in interstitial fibroblasts in gastric carcinoma. To clarify the mechanisms responsible for the antiproliferation effect of COX-2 inhibitors, effect of COX-2 inhibitor on the paracrine epithelial-mesenchymal interactions of growth was examined. Scirrhous gastric cancer cell line, OCUM-2M, gastric fibroblasts, NF-21, and COX-2 inhibitor, JTE-522, were used. Growth-interaction was examined by calculating the number of cancer cells or by measuring [(3)H] thymidine incorporation of cancer cells. Effect of JTE-522 on KGF expression from NF-21 cells and OCUM-2M cells was analyzed by ELISA and RT-PCR. The conditioned medium from gastric fibroblasts significantly stimulated the growth of scirrhous gastric cancer cells. JTE-522 at the concentrations of 10(-5) and 10(-6) M significantly decreased the growth-stimulating activity of gastric fibroblasts. JTE-522 reduced the expression of KGF mRNA and the production of KGF from gastric fibroblasts. Oral administration of JTE-522 significantly decreased the size of xenografted tumor coinoculated with OCUM-2M cells and NF-21 cells in nude mice. JTE-522 decreased COX-2 expression and Ki67 labeling index within the coinoculated tumor. These findings suggested that a selective COX-2 inhibitor, JTE-522, downregulates KGF production from gastric fibroblasts, resulting in the inhibition of paracrine epithelial-mesenchymal interactions of proliferation between scirrhous gastric cancer cells and gastric fibroblasts.

Animals↗
PubMed2006

A novel molecular targeting compound as K-samII/FGF-R2 phosphorylation inhibitor, Ki23057, for Scirrhous gastric cancer.

BACKGROUND & AIMS: Scirrhous gastric carcinoma carries the highest mortality of all gastric cancers. The poor prognosis is reported to be associated with K-samII amplification, which encodes fibroblast growth factor receptor type 2 (FGF-R2). Ki23057, a newly developed small molecule-acting K-samII/FGF-R2 autophosphorylation inhibitor, is a tyrosine kinase inhibitor that competes with adenosine triphosphate for the binding site. The aim of the current study is to clarify the possibility of molecular target therapy with Ki23057 for treating scirrhous gastric cancer. METHODS: Five human gastric cancer cell lines were used. OCUM-2MD3 and OCUM-8 were derived from scirrhous carcinomas. MKN-7, MKN-45, and MKN-74 cells were derived from nonscirrhous carcinomas. In vitro effects of Ki23057 on cell growth were determined by calculating the number of cancer cells. The influences of Ki23057 on the mitogen-activated protein kinase and phosphatidylinositol 3 kinase signaling pathways and the apoptosis pathway in the gastric cancer cells were also examined. For in vivo experiments, the Ki23057 was administered orally to mouse models of peritoneal dissemination. RESULTS: K-samII amplification was found in OCUM-2MD3 and OCUM-8 cells but not in MKN-7, MKN-45, or MKN-74 cells. Ki23057 significantly inhibited the proliferation of scirrhous cancer cells but not nonscirrhous gastric carcinoma cells. Ki23057 decreased phosphorylation of K-samII/FGF-R2, extracellular signal-regulated kinase, and Akt and increased apoptosis in scirrhous cancer lines. The oral Ki23057 administration significantly (P < .001) prolonged survival of mice with peritoneal dissemination following injection of OCUM-2MD3 scirrhous cancer cells. CONCLUSIONS: A novel K-samII/FGF-R2 phosphorylation inhibitor, Ki23057, appears therapeutically promising in scirrhous gastric carcinoma with K-samII amplification.

Adenocarcinoma, Scirrhous↗
PubMed2006

Antitumor effect of trastuzumab for pancreatic cancer with high HER-2 expression and enhancement of effect by combined therapy with gemcitabine.

PURPOSE: The purpose of the present study was to evaluate whether trastuzumab has antitumor effect against pancreatic cancer and whether this effect is concordant with levels of HER-2, which is reportedly overexpressed in pancreatic cancer. We also investigated whether the effect is potentiated in combined therapy with gemcitabine. EXPERIMENTAL DESIGN: Using immunohistochemistry and FACScan, we analyzed HER-2 expression in 16 pancreatic cancer cell lines. The in vitro antiproliferative effect of trastuzumab, alone and in combination with gemcitabine, was examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The in vitro antibody-dependent cell-mediated cytotoxicity of trastuzumab was investigated by (51)Cr release assay. The in vivo antitumor effect of trastuzumab, alone and in combination with gemcitabine, was evaluated in nude mouse xenograft growth. The survival benefit was evaluated in a Capan-1 orthotopic implanted nude mouse model. RESULTS: HER-2 expression of 2+ or more was observed in 10 and of 3+ in 2 of the 16 cell lines. No in vitro growth-inhibitory effect of trastuzumab was found in any cell line, but trastuzumab induced antibody-dependent cell-mediated cytotoxicity in proportion to HER-2 expression level. Trastuzumab inhibited tumor growth in Capan-1 (HER-2: 3+) xenografts and prolonged survival in the orthotopic model. These effects were increased by combined therapy with gemcitabine. In contrast, trastuzumab exhibited no antitumor effect against PANC-1 (HER-2: 1+) or SW1990 (HER-2: 2+) xenografts. CONCLUSIONS: The antitumor effect of trastuzumab in pancreatic cancer with high HER-2 expression was shown in vitro and in vivo. Clinical application of trastuzumab is expected in pancreatic cancer with 3+ HER-2 expression.

Animals↗
PubMed2006

Decreased expression of the adhesion molecule desmoglein-2 is associated with diffuse-type gastric carcinoma.

Desmoglein-2 (Dsg2) is one of the components of the cell-cell adherence junction. We previously reported that loss of heterozygosity at chromosome 18q12, on which the Dsg2 gene exists, is frequently found in diffuse-type gastric cancers. This study investigated the relationship between Dsg2 expression and diffuse-type gastric cancers. A total of 112 primary tumours resected from patients with gastric cancer were stained with a monoclonal antibody against Dsg2 and examined for correlations between the expression of Dsg2 and various clinicopathological factors, including loss of heterozygosity on chromosome 18q and prognosis. Dsg2 is immunolocalised at cell-cell boundaries in normal gastric mucosa. Loss of Dsg2 expression was observed in 33 of 112 gastric tumours. There was a statistically significant correlation between a decrease in Dsg2 staining and loss of tumour differentiation (P < 0.001), tumour macroscopic feature (P < 0.001) and peritoneal dissemination (P = 0.023), and Dsg2-negative staining was correlated significantly with loss of heterozygosity on chromosome 18q12 (P = 0.001). The prognosis of patients with Dsg2-negative tumours was significantly worse than that of those with Dsg2-positive tumours (log rank, P < 0.01), while multivariate analysis revealed that Dsg2 was not an independent prognostic factor. These findings suggest that decreased expression of Dsg2 is associated with diffuse-type gastric cancers and poor prognosis in gastric carcinoma.

Cadherins↗
PubMed2006

Laparoscopic adrenalectomy on a patient with primary aldosteronism during pregnancy.

A pregnant 26-year-old woman was referred for evaluation and management of progressive hypertension and hypokalemia at 14 weeks of gestation. Her plasma aldosterone level was markedly elevated and magnetic resonance imaging showed a right adrenal tumor. Primary aldosteronism due to an aldosterone producing-adenoma was diagnosed. Because of progressive severe hypertension, a laparoscopic adrenalectomy was performed at 17 weeks of gestation. The procedure was completed without complication, and plasma aldosterone and potassium levels rapidly improved post-operatively. However, her hypertension persisted and the growth retardation of the fetus was found. Regrettably, intrauterine fetal death was confirmed at 26 weeks of gestation. Histological examination of the placenta revealed that the placental artery had very thick walls which had apparently caused a critical failure in fetal blood flow. The optimal timing of laparoscopic surgery during pregnancy and perioperative management were subsequently discussed.

Adenoma↗
PubMed2006

Synergic antiproliferative effect of DNA methyltransferase inhibitor in combination with anticancer drugs in gastric carcinoma.

Epigenetic alterations of DNA methylation play an important role in the regulation of gene expression associated with chemosensitivity of gastric carcinomas. With the aim of improving the chemotherapeutic efficacy of gastric carcinoma, the effect of DNA methyltransferase inhibitor, 5-aza-CdR, on the chemosensitivity of five anticancer drugs was investigated. Human gastric cancer cell lines, OCUM-2M and MKN-74, and five anticancer drugs, 5-FU, PTX, OXA, SN38, and GEM, were used. In both gastric cancer cell lines, a synergistic antiproliferative effect by a combination of 5-aza-CdR at 5 microM was found in SN38 and GEM. 5-Aza-CdR at 5 microM increased apoptosis induced by SN38 and GEM in both cell lines. 5-Aza-CdR increases the expression of DAPK-2 and DAPK-3, RASSF1, and THBS1 genes in both OCUM-2M and MKN-74 cells, but not that of hMLH1, p16, MGMT, E-cadherin, and p53 genes. These findings suggest that 5-aza-CdR is a promising chemotherapeutical agent for gastric carcinomas, in combination with the anticancer drugs SN38 and GEM, in apoptosis signaling. The upregulation of DAPK-2 and DAPK-3, RASSF1, and THBS1 genes by 5-aza-CdR might be associated with the synergistic effect.

Antineoplastic Agents↗
PubMed2006

A synergic inhibitory-effect of combination with selective cyclooxygenase-2 inhibitor and S-1 on the peritoneal metastasis for scirrhous gastric cancer cells.

An inhibitory-effect of a selective cyclooxygenase-2 (COX-2) inhibitor on peritoneal metastasis of scirrhous gastric carcinoma was investigated in vivo. Peritoneal metastasis had developed after intraperitoneal inoculation of scirrhous gastric cancer cells, OCUM-2MD3, in nude mice. COX-2 inhibitor and/or S-1 were administered orally in nude mice with peritoneal metastasis. Oral administration of COX-2 inhibitor and S-1 significantly prolonged survival rates of these nude mice, compared with either alone. These findings suggested that combining S-1 and COX-2 inhibitor administration obtain a synergistic inhibitory-effect on the peritoneal metastasis of scirrhous gastric carcinoma.

Adenocarcinoma, Scirrhous↗
PubMed2006

TIE2 gain-of-function mutation in a patient with pancreatic lymphangioma associated with blue rubber-bleb nevus syndrome: report of a case.

Abdominal lymphangioma is a rare tumor in adults. The most common location is the mesentery, but this tumor occasionally develops in the pancreas. We report a case of pancreatic lymphangioma associated with blue rubber-bleb nevus syndrome (BRBNS) in a Japanese woman. The pancreatic lymphangioma spread extensively throughout the retroperitoneum without causing any symptoms for more than 4 years after its histological diagnosis by laparoscopic biopsy. Multiple hemangiomas were also seen in the mucous membranes and on the skin. The hemangiomatosis was segregated in the dominant fashion in her family, and a germ-line gain-of-function mutation (Arg849Trp) in TIE2 gene was confirmed. To our knowledge, this is the first report of pancreatic lymphangioma occurring in association with BRBNS in a patient with genetic alteration. We describe the clinical features of this case and discuss a possible correlation between these two uncommon conditions.

Female↗
PubMed2006

Synchronous adenocarcinomas of the ileum and transverse colon detected by capsule endoscopy: report of a case.

A 77-year-old woman was admitted to our hospital with anemia and anorexia. Neither gastrointestinal endoscopy nor computed tomography showed by abnormal findings; however, a capsule endoscopy, performed to detect obscure gastrointestinal bleeding, revealed a tumor in the ileum. When we tried to take biopsies of the ileal tumor by push enteroscopy via the anus, we found another tumor in the transverse colon. On exploration, tumors were identified in the ileum and the transverse colon. Thus, we resected the ileum and transverse colon with regional lymph node dissection. Histologic sections from both the ileum and colon revealed moderately differentiated adenocarcinomas with no lymph node metastasis.

Adenocarcinoma↗
PubMed2006

Simultaneous bilateral laparoscopic adrenalectomy for adrenocorticotropic hormone-independent macronodular adrenal hyerplasia: report of a case.

Cushing's syndrome caused by adrenocorticotropic hormone (ACTH)-independent macronodular adrenal hyperplasia (AIMAH) is an extremely rare disease, which shows bilateral macronodular adrenal hypertrophy and autonomous cortisol production. We herein report a case of AIMAH treated successfully by minimally invasive simultaneous bilateral laparoscopic adrenalectomy. A 73-year-old woman with hypertension, diabetes mellitus, and osteoporosis was referred to our hospital because of an incidentally found huge bilateral adrenal mass. An abdominal computed tomography scan showed large bilateral adrenal glands with multiple nodules. A diagnosis of AIMAH was made and a simultaneous bilateral laparoscopic adrenalectomy was thus performed. The total operation time was 310 min and blood loss was 70 g. Both glands were hypertrophic (right 5 x 3 cm, 48.5 g and left 4 x 2 cm, 39.2 g) and consisted of multiple golden yellow macronodules. The postoperative course was uneventful. A simultaneous bilateral adrenalectomy for AIMAH performed by an experienced surgical team is therefore considered to be a safe and minimally invasive procedure.

Adrenal Glands↗
PubMed2006

Close association between activated platelets and neutrophils in the active phase of ulcerative colitis in humans.

BACKGROUND: Neutrophils are considered to play a causative role in inflammatory mucosal injury in ulcerative colitis (UC), and an association between platelets and neutrophils may contribute to the progression of the inflammatory processes. To test this hypothesis, we performed immunohistochemical and flow cytometric analyses on tissue and blood samples from patients with UC. MATERIALS AND METHODS: Colonic mucosal tissues of patients with active (n = 27) or inactive (n = 16) UC and normal controls (n = 11) were subjected to immunohistochemical staining for markers of activated platelets (glycoprotein IIb/IIIa and P-selectin) and neutrophils (neutrophil elastase, myeloperoxidase, and CD66b). The amounts of stained cells were evaluated by computer-aided morphometry. Peripheral blood samples from patients (n = 8) and healthy volunteers (n = 8) were subjected to comparative flow cytometric analysis of activated platelets. RESULTS: P-selectin-positive activated platelets were frequently aggregated in the inflamed mucosa, especially in ulcerative lesions, and were close to regions of dense neutrophil infiltration. An increase in the number of activated platelets in the colonic lesions was associated with an increase in infiltrating neutrophils and was related to the severity of the disease. The flow cytometric analysis indicated that circulating platelets of patients with UC were highly activated. CONCLUSIONS: The present study demonstrated that a close association between activated platelets and neutrophils is a prominent pathological change in both the affected colonic mucosa and peripheral blood of patients with active-phase UC. This suggests that platelet-neutrophil association may play an important role in the progression of inflammatory processes in UC.

Adult↗
PubMed2006

Frequent p16 CpG island hypermethylation in primary remnant gastric cancer suggesting an independent carcinogenic pathway.

Cancer found in the post-operative remnant stomach includes both newly developed cancer after surgery for benign-disease (PRC) and metachronous multiple cancer (MRC). Differences in the carcinogenic pathway between PRC and MRC have been suspected from clinical studies. However, no study has demonstrated the difference in molecular alteration between these diseases. P16 is inactivated predominantly by epigenetic change, rather than genetic alteration. We analyzed the methylation status and protein expression of the p16 gene in cancers of the remnant stomach. Eleven lesions of PRC, 24 lesions of MRC and corresponding non-cancerous tissue, as well as 13 primary gastric cancer (PC) lesions were examined. DNA was extracted by the micro-dissection method from paraffin-embedded surgical specimens. The methylation status of the promoter CpG island of the p16 gene was examined by using a methylation-specific polymerase chain reaction technique. To detect protein expression, immunohistochemical staining was employed. p16 promoter hypermethylation was observed more often in remnant gastric cancer than in PC. A significantly more frequent hypermethylation in the p16 gene was found in PRC (64%) than in MRC (21%) or PC (23%). Moreover, a significant correlation was found between p16 promoter hypermethylation and diminishment of protein expression in cancers of the remnant stomach. Silencing of the p16 gene by methylation of its promoter CpG island was suggested as a unique molecular mechanism in the carcinogenesis of PRC compared with MRC or PC.

Aged↗
PubMed2006

Histone deacetylase inhibitor, trichostatin A, increases the chemosensitivity of anticancer drugs in gastric cancer cell lines.

Epigenetic alterations of the histone acetylation play an important role in the regulation of gene expression associated with cell cycles and apoptosis that may affect the chemosensitivity of gastric carcinomas. Recently, a histone deacetylase inhibitor, trichostatin A (TSA), was proven to be a chemo-sensitizer on human erythroleukemia cells. With the aim of improving the chemotherapeutic efficacy of gastric carcinoma, the effect of TSA on the chemosensitivity of several anticancer drugs in gastric carcinoma cells was investigated. Human gastric cancer cell lines, OCUM-8 and MKN-74, and 5 anticancer drugs, 5-fluorouracil (5-FU), paclitaxel (PTX), oxaliplatin (OXA), irinotecan (SN38) and gemcitabine (GEM) were used. In both gastric cancer cell lines, a synergistic anti-proliferative effect by the combination of TSA (30 ng/ml) with 5-FU, PTX or SN38 showed a synergistic anti-proliferative effect in OCUM-8 and MKN-74 cells. TSA increases the expression of p21, p53, DAPK-1 and the DAPK-2 gene in both OCUM-8 and MKN-74 cells. In conclusion, TSA is a promising chemotherapeutical agent in combination with anticancer drugs of 5-FU, PTX and SN38 in gastric cancer cell lines. The up-regulation of p53, p21, DAPK-1 and DAPK-2 might be associated with the synergistic effect of TSA.

Antineoplastic Agents↗
PubMed2006

[S-1+Low-Dose CDDP].

A review of the published literature was undertaken to ascertain the trends in treatment schedules of combination of an oral fluorouracil derivative S-1 with low-dose CDDP (25 mg/m2 or less) for un-resectable and recurrent gastric cancer. The case reports demonstrated as follows: S-1 was given as standard doses of 80-120 mg/body. With regard to CDDP administration, 4 mg/m2 or less was given for 4-consecutive weeks following 2-weeks rest and 6-10 mg/m2 was given for 3-consecutive weeks following 2-weeks rest in the case of 5-day/week CDDP administration. There have been reports of 6-8 mg/m2 CDDP given once or twice a week and weekly CDDP of 10-25 mg/m2 without grade 3 or more adverse events. A phase I study demonstrated the recommend dose of CDDP in the case of 5-day/week was 4 mg/m2 in the regimen of 4-consecutive weeks and 2-weeks rest with a standard dose of S-1. Three phase I studies on weekly low-dose CDDP with S-1 showed the recommend doses were 20-25 mg/m2. S-1+low-dose and a high-dose (30-90 mg/m2) CDDP have come into wide use in Japan. There have been no differences between the case reports and the clinical studies in quantity and quality for both regimens. The unified regimen of S-1+low-dose CDDP as an outpatient based chemotherapy should be developed.

Ambulatory Care↗
PubMed2006

[A case of advanced gastric cancer with malignant ascites responding to weekly paclitaxel therapy].

A 54-year-old woman with scirrhous gastric cancer in the upper third area was admitted to our hospital. She was diagnosed with advanced gastric cancer that was inoperable due to peritoneal metastasis, so weekly paclitaxel (PTX) therapy was carried out. After 2 courses, malignant ascites completely disappeared and bilateral hydronephrosis improved. After 4 courses, no ascites or hydronephrosis were seen. Only neutropenia (grade 2) and alopecia (grade 1) were observed as adverse events during the therapy, but no major adverse events were noted. We also investigated the concentration of paclitaxel in ascites. Two hours after intravenous injection of PTX, the concentration of PTX in ascites rose over the reported cytotoxic dose of PTX, and this available concentration was maintained after 48 hours. Weekly paclitaxel therapy is suggested to be one of the safe and useful treatments for advanced gastric cancer with malignant ascites.

Adenocarcinoma, Scirrhous↗
PubMed2005

Clinicopathologic and biological significance of kallikrein 6 overexpression in human gastric cancer.

PURPOSE: Human kallikrein genes (KLK) have been reported to be involved in human malignancies and several KLKs are promising biomarkers of prostate, ovarian, testicular, and breast cancers. Herein, we investigated the clinicopathologic and biological significance of KLK6 gene expression in human gastric cancer. PATIENTS AND METHODS: Using real-time reverse transcription-PCR, we analyzed the KLK6 expression status with respect to various clinicopathologic variables in 66 patients with gastric cancer. In addition, we established a KLK6 stably suppressed gastric cancer cell line (MKN28) using small interfering RNA-mediated gene silencing, and investigated its effects on the cell proliferation rate, cell cycle, and invasiveness. RESULTS: The KLK6 gene expression in cancerous tissue (0.37 +/- 0.53) was significantly (P < 0.000001) higher than that in noncancerous tissue (0.026 +/- 0.060). Elevated KLK6 expression was significantly associated with lymphatic invasion (P = 0.03). Furthermore, patients with a high KLK6 expression had a significantly poorer survival rate than those with a low KLK6 expression (P = 0.03). Therefore, we showed that KLK6 gene silencing with KLK6 small interfering RNA effectively suppressed the cell proliferation rate (P = 0.002), cell population in the S phase (P < 0.01), and invasiveness (P < 0.01) in comparison to mock-transfected cells. CONCLUSIONS: The KLK6 gene is markedly overexpressed in gastric cancer tissue and its expression status may be a powerful prognostic indicator for patients with gastric cancer. Our findings also suggest that KLK6 may possibly be a novel target for gastric cancer therapy by gene-silencing procedures.

Biomarkers, Tumor↗