Biomedical subjects

Hiroshi Inoue

Publications and source records attributed to Hiroshi Inoue.

At least 37 records · Page 2Linked to original sources

PubMed2006

PGP9.5 methylation in diffuse-type gastric cancer.

Diffuse-type gastric cancer (DGC) is the most deadly form of gastric cancer and is frequently accompanied by peritoneal dissemination and metastasis. The specific molecular events involved in DGC pathogenesis remain elusive. Accumulating evidence of epigenetic inactivation in tumor suppressor genes led us to conduct a comprehensive screen to identify novel methylated genes in human cancers using pharmacologic unmasking and subsequent microarray analysis. We compared differential RNA expression profiles of DGC and intestinal-type gastric cancer (IGC) cell lines treated with 5-aza-2'-deoxycytidine using microarrays containing 22,284 genes. We identified 16 methylated genes, including many novel genes, in DGC cell lines and studied PGP9.5 with particular interest. In primary gastric cancers, PGP9.5 was found to be more frequently methylated in DGCs (78%) than in IGCs (36%; DGC versus IGC, P < 0.05). Furthermore, real-time methylation-specific PCR analysis of PGP9.5 showed relatively higher methylation levels in DGC than in IGC. Our data thus implicate a molecular event common in the DGC phenotype compared with IGC.

Antimetabolites, Antineoplastic↗

PubMed2006

Angiopoietin 2 expression in invasive ductal carcinoma of the breast: its relationship to the VEGF expression and microvessel density.

Angiopoietin (Ang) is a ligand for the endothelium-specific tyrosine kinase receptor Tie-2, while a shift in the Ang-1:Ang-2 expression ratio in favor of Ang-2 was found to be associated with tumor angiogenesis. In the present study, we analyzed the immunohistochemical expression of Ang-2 in a series of 198 breast cancers, in which VEGF expression and microvessel density (MVD) were previously determined. Ang-2 expression was negative in 24 (12%), positive in 50 (25%) and strongly positive in 124 (63%) of 198 cases. A significant correlation was found between Ang-2 and VEGF expressions (p=0.0004) and between Ang-2 expression and MVD (p=0.0006), while a high MVD was found in 10 (77%) of 13 tumors with a strongly positive VEGF and positive Ang-2 expression and in 40 (71%) of 56 tumors with a strongly positive VEGF and strongly positive Ang-2 expression. Although there was no difference in the disease free survival (DFS) stratified according to Ang-2 expression alone, the 69 patients with a strongly positive VEGF and a strongly positive or positive Ang-2 expression had a significantly (p=0.0316) worse DFS than those with other combinations of VEGF and Ang-2 expressions. A multivariate analysis indicated lymph node metastasis and MVD to be independently significant prognostic factors for DFS, while the combination of VEGF and Ang-2 expressions was not a significant factor for DFS. In conclusion, the Ang-2 expression was found to be closely correlated with VEGF expression and MVD in breast cancer, while a high MVD was frequently found in tumors with a high expression of both VEGF and Ang-2. The survival analysis demonstrated a high MVD, which was induced by a high expression of both VEGF and Ang-2, to therefore have a strong prognostic significance in breast cancer.

Adult↗

PubMed2006

FHIT is up-regulated by inflammatory stimuli and inhibits prostaglandin E2-mediated cancer progression.

The FHIT gene is known to be susceptible to environmental carcinogens. Formation of prostaglandin E(2) (PGE(2)) is catalyzed by cyclooxygenase-2 (COX-2) and may influence malignant phenotype in colorectal cancer. We explored whether FHIT might play a role in progression of colorectal cancer through inflammation-associated PGE(2) activity. Immunohistochemical study of COX-2 and FHIT expression was done in 92 colorectal cancer tumors. We also used a FHIT-expressing cancer cell line (H460) induced by ponasterone A and two FHIT small interfering RNA-treated colorectal cancer cell lines (CCK81 and DLD1). After PGE(2) stimulation, we compared synthesis of PGE(2) (ELISA assay) and cell proliferation [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay]. Immunohistochemistry showed a significant association between COX-2 and FHIT expression in colorectal cancers (P < 0.01). In a subset of 41 COX-2-expressing tumors, 12 FHIT(-) tumors showed deeper cancer invasion than 29 FHIT(+) tumors (P < 0.01). Experimental study, however, showed there was no direct interaction between FHIT and COX-2. Considered with results from another experiment with epidermal growth factor receptor (EGFR), we hypothesize that FHIT and COX-2 might be regulated by a common molecule, such as EGFR. Additionally, there was an inverse and direct correlation between PGE(2) synthesis and FHIT in vitro, suggesting that FHIT's postulated antiaggressive effect on tumor goes through PGE(2) but not COX-2. Loss of FHIT expression in colorectal cancer suggests higher malignant potential. We conclude that FHIT suppressed cancer cell proliferation in this malignancy by directly inhibiting synthesis of PGE(2) but not affecting that of COX-2.

Acid Anhydride Hydrolases↗

PubMed2006

Significance of skp2 expression in primary breast cancer.

PURPOSE: We previously reported the p27 expression level to be an independent prognostic factor, and a high S-phase kinase-associated protein 2 (Skp2) expression level was significantly correlated with a poor prognosis in patients with gastric cancer. We herein examined the Skp2 expression in breast cancer and attempted to identify any associations between the Skp2 expression status and either the clinicopathologic variables or the patient's prognosis. EXPERIMENTAL DESIGN: We established four Skp2-transfected breast cancer cell lines and assessed the correlations between the Skp2 and p27 expressions using real-time reverse transcription-PCR and a Western blot analysis. We then analyzed the clinicopathologic significance of Skp2 mRNA expression in 169 Japanese patients with breast cancer. An immunohistochemical analysis was also done. RESULTS: The p27 protein expression markedly decreased after Skp2 transfection, whereas no alteration in the p27 mRNA expression was observed. The Skp2 protein expression level as determined by immunohistochemical staining thus showed a significant correlation with the Skp2 mRNA expression (P = 0.001) and a significant inverse correlation with the p27 protein expression (P = 0.042). The patients with a high Skp2 gene expression were significantly younger than those with a low expression (P = 0.002). The prognosis of patients with a high Skp2 expression was significantly (P = 0.022) poorer than for those with a low expression. Moreover, a high expression of Skp2 was an independent variable that correlated with a shorter disease-free survival (relative risk, 3.33; 95% confidence interval, 1.296-8.578; P = 0.013). CONCLUSIONS: The present results suggest that Skp2 may play an important role particularly in young breast cancer, and it is also considered to have strong independent prognostic potential and thus may prove to be a useful target for the treatment of breast cancer.

Blotting, Western↗

PubMed2006

Association of single-nucleotide polymorphisms in the suppressor of cytokine signaling 2 (SOCS2) gene with type 2 diabetes in the Japanese.

Several previous linkage scans in type 2 diabetes (T2D) families indicated a putative susceptibility locus on chromosome 12q15-q22, while the underlying gene for T2D has not yet been identified. We performed a region-wide association analysis on 12q15-q22, using a dense set of >500 single-nucleotide polymorphisms (SNPs), in 1492 unrelated Japanese individuals enrolled in this study. We identified an association between T2D and a haplotype block spanning 13.6 kb of genomic DNA that includes the entire SOCS2 gene. Evolutionary-based haplotype analysis of haplotype-tagging SNPs followed by a "sliding window" haplotypic analysis indicated SNPs that mapped to the 5' region of the SOCS2gene to be associated with T2D with high statistical significance. The SOCS2 gene was expressed ubiquitously in human and murine tissues, including pancreatic beta-cell lines. Adenovirus-mediated expression of the SOCS2 gene in MIN6 cells or isolated rat islets significantly suppressed glucose-stimulated insulin secretion. Our data indicate that SOCS2 may play a role in susceptibility to T2D in the Japanese.

Adenoviridae↗

PubMed2006

T-cell activation via CD26 and caveolin-1 in rheumatoid synovium.

CD26 is a T-cell costimulatory molecule with dipeptidyl peptidase IV (DPPIV) activity in its extracellular region. We previously reported that recombinant soluble CD26 enhances peripheral blood T-cell proliferation induced by the recall antigen tetanus toxoid (TT). Recently, we demonstrated that CD26 binds caveolin-1 on antigen-presenting cell (APC), and that residues 201-211 of CD26 along with the serine catalytic site at residue 630, which constitute a pocket structure of CD26/DPPIV, contribute to binding to caveolin-1 scaffolding domain. In addition, following CD26-caveolin-1 interaction on TT-loaded monocytes, caveolin-1 is phosphorylated, with linkage to NF-kappaB activation, followed by upregulation of CD86. Finally, reduced caveolin-1 expression on APC inhibits CD26-mediated CD86 upregulation and abrogates CD26 effect on TT-induced T-cell proliferation, and immunohistochemical studies revealed an infiltration of CD26+ T cells in the sub-lining region of rheumatoid synovium and high expression of caveolin-1 in the increased vasculature and synoviocytes of the rheumatoid synovium. Taken together, these results strongly suggest that CD26-cavolin-1 interaction plays a role in the upregulation of CD86 on TT-loaded APC and subsequent engagement with CD28 on T cells, leading to antigen-specific T-cell activation such as the T-cell-mediated antigen-specific response in rheumatoid arthritis.

Abatacept↗

PubMed2006

Klinefelter's syndrome associated with systemic lupus erythematosus and autoimmune hepatitis.

Klinefelter's syndrome (KFS) tends to be associated with immunological disorders. We describe a 37-year-old man who presented signs of testicular atrophy and decreased body hair. He showed pancytopenia and elevated levels of liver enzymes. Chromosome analysis revealed 47XXY karyotype; therefore, he was diagnosed with KFS, with systemic lupus erythematosus and autoimmune hepatitis. Treatment with a high dose of methylprednisolone and methyltestosterone improved thrombocytopenia and symptoms, suggesting that methyltestosterone may have a clinical benefit in the treatment of KFS with a low level of testosterone accompanying immunological disorders.

Adult↗

PubMed2006

Compromised video-assisted thoracoscopic segmental resection for high-risk patients with stage I lung cancer near the lung hilum.

We performed a video-assisted thoracoscopic segmental resection without doing a mini-thoracotomy in two patients (one octogenarian and one with poor lung function) with early stage (T1-2N0) lung cancer located at the lung hilum who required preservation of their cardiopulmonary function. After 2 years of follow-up, both patients are alive without recurrence. We describe the cases and the method used for the video-assisted thoracoscopic segmental resection using an endoscopic stapler.

Aged↗

PubMed2006

Role of hepatic STAT3 in brain-insulin action on hepatic glucose production.

STAT3 regulates glucose homeostasis by suppressing the expression of gluconeogenic genes in the liver. The mechanism by which hepatic STAT3 is regulated by nutritional or hormonal status has remained unknown, however. Here, we show that an increase in the plasma insulin concentration, achieved either by glucose administration or by intravenous insulin infusion, stimulates tyrosine phosphorylation of STAT3 in the liver. This effect of insulin was mediated by the hormone's effects in the brain, and the increase in hepatic IL-6 induced by the brain-insulin action is essential for the activation of STAT3. The inhibition of hepatic glucose production and of expression of gluconeogenic genes induced by intracerebral ventricular insulin infusion was impaired in mice with liver-specific STAT3 deficiency or in mice with IL-6 deficiency. These results thus indicate that IL-6-STAT3 signaling in the liver contributes to insulin action in the brain, leading to the suppression of hepatic glucose production.

Animals↗

PubMed2006

Cancer stem cells in human gastrointestinal cancers.

The concept of cancer stem cell has developed in leukemia. Recently, it has expanded to include solid tumors such as brain or breast tumors. However, the descriptions are not recognized in human gastrointestinal cancers. We used flow cytometry and the DNA-binding dye (Hoechst 33342) to isolate side population (SP) cells from various human gastrointestinal system cancer cell lines. The SP cell fraction is considered to contain abundant stem cells. Fifteen of 16 cancer cell lines from the gastrointestinal system contained 0.3-2.2% SP cells. We studied the characteristics of the SP cells in hepatic or colon cancer cell lines. The results demonstrated that cancers of the gastrointestinal system do contain SP cells that show some characters of so-called stem cells. In this paper, we report our study results with a review of the literature.

ATP-Binding Cassette Transporters↗

PubMed2006

Nonlinear mixed effects model analysis of the pharmacokinetics of routinely administered bepridil in Japanese patients with arrhythmias.

This study was performed to evaluate variability in the pharmacokinetics of bepridil in 38 Japanese patients with arrhythmias, and to investigate the effects of aprindine as well as CYP2D6 and CYP3A5 polymorphisms on the oral clearance of bepridil. We determined the polymorphic alleles of CYP2D6 and CYP3A5 in each subject. The plasma concentration of bepridil at steady-state following repetitive oral administration was measured with an HPLC-based method, and the oral clearance was estimated using the nonlinear mixed effects model (NONMEM) program. Mean oral clearance was significantly greater in the patients with the CYP2D6*10 allele than in those without it. On the other hand, no significant effect of the CYP3A5 polymorphism was observed on the pharmacokinetics of bepridil. In addition, aprindine seemed to reduce the oral clearance of bepridil in the patients with the CYP2D6*10 allele.

Adult↗

PubMed2006

Multiple regression analysis of pharmacogenetic variability of carvedilol disposition in 54 healthy Japanese volunteers.

The aim of this study was to evaluate the pharmacogenetic variability in the disposition of carvedilol in the Japanese population. Five or 10 mg of carvedilol was orally administered to 54 healthy Japanese subjects (22-44 years old), and blood samples were taken at 2 and 6 h after dosing. We determined the polymorphic alleles of CYP2D6, CYP2C9, CYP2C19, CYP3A5, UGT2B7, and MDR1 in each subject. The whole blood concentration of R- and S-carvedilol was measured by an HPLC method. The pharmacokinetic parameters in individual subjects were estimated by the Bayesian method using the nonlinear mixed effects model (NONMEM) program. We then examined the effect of the genetic polymorphisms on the variability in the pharmacokinetics of carvedilol using a multiple regression analysis. The oral clearance (CL/F) and also apparent volume of distribution (V/F) of both enantiomers were significantly lower in the subjects with the CYP2D6*10 allele than those with the CYP2D6*1/*1, *1/*2, or *2/*2 genotype, confirming our previous finding that the bioavailability (F) and systemic clearance (CL) of R- and S-carvedilol in the liver is significantly altered in Japanese with the CYP2D6*10 allele. On the other hand, CYP2C9*3, CYP2C19*2, CYP2C19*3, CYP3A5*3, UGT2B7*2, and MDR1 C3435T did not significantly affect the pharmacokinetics of carvedilol in Japanese subjects.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2006

Pharmacological cardioversion of persistent atrial fibrillation with and without a history of drug-resistant paroxysmal atrial fibrillation.

BACKGROUND: Suppression by antiarrhythmic drugs of the maintenance mechanisms could convert persistent atrial fibrillation (AF) to sinus rhythm (SR). Whether a history of drug-resistant paroxysmal AF (PAF) would affect the outcome of pharmacological conversion of persistent AF by bepridil or in combination with aprindine was evaluated in the present study. METHODS AND RESULTS: The study group comprised 51 consecutive patients (24 men, 61+/-8 years) undergoing pharmacological conversion of persistent AF lasting >1 month. Drug-resistant PAF was defined as AF and at least 2 ineffective antiarrhythmic drugs for suppression of AF recurrence. Fast Fourier transform analysis of fibrillation waves was used to measure fibrillation cycle length (FCL) from the peak frequency. Fifteen patients had a history of drug-resistant PAF (Group I), and the remaining 36 did not (Group II) before diagnosis of persistent AF. Ten patients (67%) in Group I and 26 patients (72%) in Group II were restored to SR by bepridil alone or in combination with aprindine after 29+/-15 days of drug administration. Before conversion to SR, bepridil increased the FCL more in Group II than in Group I. During a 12-month follow-up period, 4 of 10 patients in Group I and 2 of 26 patients in Group II (p<0.01) had recurrence of persistent AF with bepridil alone or in combination with aprindine. CONCLUSIONS: A history of drug-resistant PAF does not affect the efficacy of pharmacological conversion by bepridil or in combination with aprindine. However, recurrence of AF was significantly higher in patients with such a history.

Anti-Arrhythmia Agents↗

PubMed2006

Randomized study of angiotensin II type 1 receptor blocker vs dihydropiridine calcium antagonist for the treatment of paroxysmal atrial fibrillation in patients with hypertension.

BACKGROUND: Mega trials of rhythm vs rate control could not demonstrate the usefulness of available antiarrhythmic drugs, so a more effective and safer therapy for atrial fibrillation (AF) is now required. One candidate is the so-called "upstream therapy", which refers to the blockade of upstream modifying elements (renin - angiotensin system, cathecholamines, oxidative stress etc) that contribute to the arrhythmogenic substrate. METHODS AND RESULTS: The Japanese Rhythm Management Trial II for Atrial Fibrillation (J-RHYTHM II study) is a randomized comparative evaluation of an angiotensin II type 1 blocker (candesartan) and a dihydropiridine calcium blocker (amlodipine), both combined with antithrombotic therapy, as an antiarrhythmic therapy for the treatment of paroxysmal AF (PAF) associated with hypertension. To test the usefulness of this therapy, this study will reveal the recurrence rate of asymptomatic as well as symptomatic PAF during 1-year of treatment with candesartan or amlodipine, using daily transtelephonic monitoring. CONCLUSIONS: The J-RHYTHM II study will follow 400 patients with PAF and hypertension who were treated at approximately 50 sites throughout Japan, and will provide clinically important information.

Amlodipine↗

PubMed2006

Influence of beta-adrenoceptor blockade on the myocardial accumulation of fatty acid tracer and its intracellular metabolism in the heart after ischemia-reperfusion injury.

BACKGROUND: Increases in sympathetic nerve activity during ischemia may increase intracellular fatty acid (FA) accumulation via enhanced FA uptake and inhibition of beta-oxidation. Therefore, the beneficial effects of beta-adrenoceptor blockade on myocardial ischemic injury might result from the suppression of FA accumulation. METHODS AND RESULTS: Carvedilol (1 mg/kg) or propranolol (1 mg/kg) was injected 10 min before 15-min occlusion of coronary artery in rats. Myocardial FA accumulation and intracellular metabolites of FA tracer were determined 3 days after reperfusion using (125)I-and (131)I-9-metylpentadecanoic acid (9MPA). Carvedilol significantly decreased 9MPA accumulation in both the ischemic region (IR) and non-IR, as compared with vehicle, and increased its clearance. However, the non-metabolized 9MPA fraction was not different between carvedilol- and vehicle-treated rats. Consequently, the amount of non-metabolized 9MPA in the myocardium was lower in rats treated with carvedilol than in those given vehicle. These effects of carvedilol were not different from those of propranolol. CONCLUSION: Beta-adrenoceptor blockade did not affect a visual assessment of the autoradiographic image of 9MPA in hearts subjected to ischemia-reperfusion, but it accelerated the clearance of 9MPA in both the IR and non-IR. The administration of beta-blockade before ischemia could accelerate the recovery from ischemia-reperfusion injury by inhibiting myocardial FA accumulation before beta-oxidation.

Adrenergic beta-Antagonists↗

PubMed2006

Early administration of fluvastatin, but not at the onset of ischemia or reperfusion, attenuates myocardial ischemia-reperfusion injury through the nitric oxide pathway rather than its antioxidant property.

BACKGROUND: Three-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (statins) are known to attenuate myocardial ischemia-reperfusion (IR) injury. Fluvastatin (FV) has a potent free radical scavenging action, but it is unclear whether the timing of FV administration could affect its cardioprotective effect or if the antioxidant property of FV might attenuate IR injury. METHODS AND RESULTS: IR was induced in rats by left coronary artery occlusion for 30 min followed by 24-h reperfusion. The rats were divided into 4 groups: oral FV group (10 mg/kg per day for 2 weeks before ischemia); iv, FV group (10 mg/kg) before ischemia; iv, FV group (10 mg/kg) before reperfusion; and control group. Oxidative stress was evaluated by myocardial 8-hydroxydeoxyguanosine (8-OHdG) content. The area at risk did not different among the 4 groups. Pretreatment with FV for 2 weeks significantly reduced the infarct size by 28% as compared with the control group, but FV administered just before ischemia or reperfusion did not. Myocardial 8-OHdG content was not affected by FV. The infarct-sparing effect of FV was completely abolished by N(omega)-nitro-l-arginine methyl ester or wortmannin. CONCLUSIONS: The present results indicate that pretreatment with FV, but not just before ischemia or reperfusion, attenuates IR injury primarily through the nitric oxide pathway, not through its antioxidant property.

8-Hydroxy-2'-Deoxyguanosine↗

PubMed2006

Accumulation of risk factors increases risk of thromboembolic events in patients with nonvalvular atrial fibrillation.

BACKGROUND: Accumulation of risk factors could increase thromboembolic event rates in patients with nonvalvular atrial fibrillation (NVAF). To validate this hypothesis, a post hoc analysis was performed to determine the relationship of risk levels and thromboembolic events in patients with NVAF from our previous prospective study. METHODS AND RESULTS: Risk levels were quantified using the CHADS2 index in 509 patients with NVAF (66.3+/-10.3 years old). One point each was given for patients with advanced age (>or=75 years), hypertension, congestive heart failure, and diabetes mellitus, and 2 points, to those with prior ischemic stroke or transient ischemic attack. Patients with a CHADS2 score of 0 were classified as low risk, 1 to 2 a moderate risk and 3 or more were high risk. Because hypertrophic cardiomyopathy had emerged as an independent risk factor for thromboembolism, the original CHADS2 score was modified by adding 1 point to patients with hypertrophic cardiomyopathy. Warfarin was given to 263 patients (mean international normalized ratio (INR) at enrollment, 1.86), antiplatelets (aspirin or ticlopidine) to 163 patients and no antithrombotic therapy to 83. During a mean follow-up period of 2 years, 31 thromboembolic events occurred. As the risk level (modified CHADS2 score) increased, the event rate increased for both the patient groups receiving warfarin (p=0.035) and those not receiving warfarin (p=0.048). When a thromboembolic event occurred in patients who had been treated with warfarin, the mean INR level was 1.41. Twelve (75%) of 16 patients complicated with thromboembolism during warfarin treatment had INR levels below the optimal levels (1.6-2.6) for Japanese patients. CONCLUSION: Accumulation of risk factors could increase risk of thromboembolic events in patients with NVAF. Adherence to the guidelines for anticoagulation therapy is recommended.

Aged↗

PubMed2006

Pharmacological conversion of persistent atrial fibrillation into sinus rhythm with oral pilsicainide: pilsicainide suppression trial for persistent atrial fibrillation II.

BACKGROUND: The present study was conducted to determine the antiarrhythmic efficacy and safety of oral pilsicainide, a class Ic antiarrhythmic drug, in patients with persistent atrial fibrillation (AF). METHODS AND RESULTS: One hundred and eight patients (mean age, 58.9 years) with AF lasting >or=48 h and or=3 weeks prior to the study enrolment or after verification of the absence of left atrial thrombi by transesophageal echocardiography. After 2 weeks of treatment, an electrocardiogram was recorded to determine whether sinus rhythm was restored. Sinus rhythm was restored in 22.4% of patients treated with pilsicainide and in 2% treated with placebo (p=0.002). Cardioversion was less likely to occur with oral pilsicainide when the AF duration exceeded 2 months or if the left atrial diameter exceeded 45 mm. There was no significant difference in the adverse cardiovascular event rate between the pilsicainide- and placebo-treated groups. One patient in the pilsicainide group developed an atrial flutter without any hemodynamic deterioration. CONCLUSION: A 2-week oral administration of pilsicainide is well tolerated and moderately effective in converting persistent AF into sinus rhythm.

Administration, Oral↗