Mutsuo Sasaki

A hyaluronan synthase suppressor, 4‐methylumbelliferone, inhibits liver metastasis of melanoma cells

4‐Methylumbelliferone (MU) inhibits the cell surface hyaluronan (HA) formation, and that such inhibition results in suppression of adhesion and locomotion of cultured melanoma cells. Here, we examine the effect of MU on melanoma cell metastasis in vivo. MU‐treated melanoma cells showed both decreased cell surface HA formation and suppression of liver metastasis after injection into the mice. Oral administration of MU to mice decreased tissue HA content. These HA knock‐down mice displayed suppressed liver metastasis. Thus, both cell surface HA of melanoma cells and recipient liver HA can promote liver metastasis, indicating that MU has potential as an anti‐metastatic agent.

Late development of bile duct cancer after sphincteroplasty: A ten- to twenty-two-year follow-up study☆

BACKGROUND Transduodenal sphincteroplasty is designed to destroy the sphincteric muscle fibers, producing a terminal choledochoduodenostomy. In the absence of Oddis sphincter, intestinal contents with both activated pancreatic juice and bacterial flora are refluxed into the bile duct and remain there for a prolonged time. The long-term effect of producing the reflux has not been evaluated to date. METHODS One hundred nineteen consecutive patients undergoing transduodenal sphincteroplasty between February 1973 and July 1984 were included in this study. Postoperative clinical courses of 108 patients could be evaluated by means of a retrospective review of the hospital records. Median follow-up was 18 years. RESULTS Eight cases (7.4%) of primary bile duct cancer were found among the 108 cases at intervals of 1 to 20 years after sphincteroplasty. Two patients had concurrent hepatolithiasis. The patency of sphincteroplasty was confirmed in all cases, and the bile was infected in seven cases. Pathologic specimens obtained demonstrated cholangiocarcinomas and various degrees of atypical hyperplastic lesions under the background of chronic cholangitis. CONCLUSIONS Chronic cholangitis can be an important causative factor in late development of bile duct cancer after sphincteroplasty. Any patients treated with choledochoduodenostomy should be closely monitored for late cholangiocarcinoma.

Induction of differentiation and peroxisome proliferator-activated receptor γ expression in colon cancer cell lines by troglitazone

Purpose We investigated the relationship between the effects of troglitazone (TGZ) on cellular growth, differentiation and apoptosis induction, and the induction of peroxisome proliferator-activated receptor (PPAR) γ in three human colon cancer cell lines, HCT-15, DLD-1and LoVo.Methods Viable cell number was evaluated by the Alamar blue assay and apoptotic cell death by TUNEL methods. Expression of PPARγ mRNA and protein was examined by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot, respectively. The differentiation markers of colonic mucosa, villin and MUC2 mRNAs, were analyzed by real-time RT-PCR.Results HCT-15 and DLD-1 cells proliferated rapidly while LoVo cells grew slowly. TGZ dose-dependently inhibited the proliferation of all the cell lines, and also induced apoptotic cell death. High expression of PPARγ mRNA and protein was demonstrated in DLD-1 and LoVo cells before TGZ treatment. After the treatment, PPARγ mRNA and protein levels were increased in HCT-15 and LoVo cells. Villin and MUC2 mRNAs were increased by TGZ treatment in HCT-15 cells while villin mRNA was repressed in LoVo cells. Changes in expression of PPARγ, villin or MUC2 mRNAs were not observed in DLD-1 cells.Conclusions These results suggest that PPARγ levels are not correlated with the rates of cell proliferation. Differentiation induction by TGZ was only observed in the cell lines with enhanced PPARγ expression.

4-methylumbelliferone, a hyaluronan synthase suppressor, enhances the anticancer activity of gemcitabine in human pancreatic cancer cells

Hyaluronan (HA) is a ubiquitous, major component of the pericellular matrix and is necessary for various physiological processes. It plays a very important role in biological barriers. We previously reported that 4-methylumbelliferone (MU) inhibits HA synthesis and pericellular HA matrix formation in cultured human skin fibroblasts, Streptococcus equi FM100, and B16F10 melanoma cells. We hypothesized that MU-mediated inhibition of HA synthesis and pericellular HA matrix formation would increase the efficacy of anticancer drugs. We have already demonstrated in vitro, using a sandwich binding protein assay and a particle exclusion assay, that MU inhibits HA synthesis and formation of the pericellular HA matrix, respectively, in human KP1-NL pancreatic cancer cells. AlamarBlue assay revealed that the anticancer effect of gemcitabine in KP1-NL cells was increased by pretreatment with MU. In vivo simultaneous administration of MU and gemcitabine to tumor-bearing mice with severe combined immunodeficiency disease (SCID) decreased the size of the primary and metastatic tumors more than did gemcitabine alone. These data strongly suggest that a combination of MU and gemcitabine is effective against human pancreatic cancer cells. MU may have potential as a chemosensitizer and may provide us with a new anticancer strategy.

The effect of aging on the relationship between the cytochrome P450 2C19 genotype and omeprazole pharmacokinetics.

Background and objectiveThe metabolic activity of cytochrome P450 (CYP) 2C19 is genetically determined, and the pharmacokinetics of omeprazole, a substrate for CYP2C19, are dependent on the CYP2C19 genotype. However, a discrepancy between the CYP2C19 genotype and omeprazole pharmacokinetics was reported in patients with liver disease or advanced cancer. The objective of the present study was to evaluate the effect of aging on the relationship between the CYP2C19 genotype and its phenotype.MethodsTwenty-eight elderly and 23 young Japanese volunteers were enrolled after being genotyped. Each subject received a single intravenous dose of omeprazole (10mg and 20mg for the elderly and the young groups, respectively) and blood samples were obtained up to 6 hours after dose administration to determine the plasma concentrations of omeprazole and its metabolites, 5-hydroxyomeprazole and omeprazole sulfone. Pharmacokinetic parameters were obtained by noncompartmental analysis. Linear regression models were used to examine the joint effects of covariates such as genotype, age, etc., on the pharmacokinetic parameters, and the pharmacokinetic parameters showing statistical significance were compared by ANOVA.ResultsThere were significant differences between genotypes in the area under the plasma concentration-time curve of the young group and the elderly group. The number of mutation alleles and age were significant covariates for systemic clearance (CL), but age was the only significant covariate for volume of distribution at steady state (Vss). There were significant age- and genotype-related differences and a significant age × genotype interaction in CL (20.6 ± 11.0/12.7 ± 4.0/3.2 ± 1.0 and 5.4 ± 4.0/3.7 ± 1.4/2.1 ± 0.7 L/h for homozygous extensive metabolisers [EMs]/heterozygous EMs/poor metabolisers [PMs] of the young and the elderly groups, respectively). In Vss, a significant difference was found between the young and the elderly groups (219 ± 115 and 107 ± 44.5 mL/kg, respectively), but not between three genotypes (178 ± 142, 173 ± 79 and 110 ± 51 mL/kg for homozygous EMs, heterozygous EMs and PMs, respectively).ConclusionThe elderly EMs showed wide variance in the in vivo CYP2C19 activity and were phenotypically closer to the elderly PMs than the young EMs were to the young PMs. Some of the elderly homozygous EMs, as well as heterozygous EMs, have a metabolic activity similar to PMs, and the CYP2C19 genotype may therefore not be as useful as phenotyping in the elderly.

Influence of cold ischemia time and graft transport distance on postoperative outcome in human liver transplantation.

Abstract.Purpose: The association between hepatic allograft cold ischemia time (CIT) and graft transport distance (GTD) in human liver transplantation was examined by investigating whether extended graft transportation prolongs the CIT and adversely affects graft survival.Methods: We retrospectively analyzed 186 consecutive orthotopic liver transplants (OLTs) done between May 1997 and July 1998. The number of miles from the donor hospital to the University of Pittsburgh Medical Center in a straight line was measured in each case, and defined as the GTD. The OLTs were divided into two groups according to whether the GTD was ≤200 miles or >200 miles. The latter group was then subdivided into groups of GTD 200–400 miles, GTD 400–600 miles, and GTD >600 miles. The CIT and graft outcome within 90 days after OLT were assessed.Results: Extended GTD prolonged the CIT (P < 0.001). The rate of hepatic allograft loss in the long GTD group was significantly higher than that in the short GTD group (P= 0.018). When the OLTs were subdivided according to GTD, the CIT increased and graft survival decreased as the GTD extended. Hepatic allograft transportation for a long distance prolonged the CIT and decreased the graft survival rate.Conclusion: Since prolonged CIT is a major risk factor, avoiding long-distance graft transportation is recommended when the donor risk factors are high.

Upregulation of α-synuclein by lipopolysaccharide and interleukin-1 in human macrophages

α‐Synuclein was originally identified as the presynaptic nerve terminal protein. Recently, we reported that α‐synuclein is also expressed in cultured human astrocytes and that its levels are increased by stimulation with interleukin‐1β, suggesting that it may be involved in inflammatory processes. We therefore investigated the effect of inflammatory stimuli on α‐synuclein expression in human macrophages. α‐Synuclein mRNA and protein were detected in cultured human macrophages and levels of α‐synuclein protein were increased by stimulation with lipopolysaccharide and interleukin‐1β in a time‐ and concentration‐dependent manner. Immunofluorescent staining showed that α‐synuclein protein was expressed within the cytoplasm and nucleus. Furthermore, α‐synuclein immunoreactivity was present in alveolar macrophages from human lung tissues. These findings suggest that the function of α‐synuclein is not exclusive to the nervous system and that α‐synuclein may play a role in inflammatory processes and immune responses.

Survival and recurrence after low anterior resection and abdominoperineal resection for rectal cancer: the results of a long-term study with a review of the literature.

Morbidity, survival, and recurrence in 203 patients treated with curative low anterior resection (LAR) were compared with those in 100 patients treated with curative abdominoperineal resection (APR). The overall 5-year survival figures for the total number of, LAR and APR patients were 75.6±5.7%, 79.8±6.4% and 67.7±9.6%, respectively. The prognosis for cancers situated low enough in the rectum to involve the anal canal was poor even when managed by APR, as evidenced by a low survival at 5 years of 59.0±9.6% and a high pelvic recurrence rate of 34%. For all except these tumors, LAR proved at least equal to, or better than APR as a curative surgical method for middle and low rectal cancers, on the basis of 5-year survival being 79.8±6.4% vs 78.7±5.2%, operative mortality being 1.5% vs 1.0%, morbidity being 39.4% vs 59.0%, and the incidence of pelvic recurrence being 8.9% vs 13.5%. When deciding upon the most appropriate surgical procedure for rectal cancer, especially for middle or low rectal lesions, the patient should not simply be condemned to a permanent colostomy. Thus, we first attempt LAR for every lesion except those which are very advanced or those with anal canal involvement, if technically feasible and suitable for the individual patient.

Influence of methylated p15 INK4b and p16 INK4a genes on clinicopathological features in colorectal cancer

Background and Aim:  Genetic silencing by promoter methylation has attracted attention in the carcinogenesis of colorectal cancer. Methylation of the p16INK4a gene has been found in primary colorectal cancer. Although the p15INK4b gene displays high homology to the p16INK4a gene in the amino acid sequence, methylation of p15INK4b has not been fully studied. We investigated p15INK4b methylation status in patients with colorectal cancer to verify the association between the methylation of p15INK4b and clinicopathological features compared with p16INK4a.

Altered Bile Composition in the Gallbladder and Common Bile Duct of Patients with Anomalous Pancreaticobiliary Ductal Junction

The high incidence of biliary tract carcinoma in patients with anomalous pancreaticobiliary ductal junction (APBDJ) has been well documented. Elevation of the secondary and free bile acid (FBA) concentrations is considered a risk factor for biliary carcinogenesis in these patients. Bile from the gallbladder and common bile duct in 12 patients with APBDJ was analyzed and compared with gallbladder bile from 19 patients with gastric cancer and a normal hepatobiliary tract. The concentrations of secondary bile acids were significantly lower in the APBDJ group than in the control group, and FBA concentrations were not detected in the gallbladder in either group. The lysolecithin (LL) in the phospholipid, which is produced from lecithin by activated phospholipase A2 in refluxing pancreatic juice, was significantly elevated in the APBDJ group. Elevation of the LL concentration in the bile is one of the factors for the development of biliary tract carcinoma in patients with APBDJ.