Impact of insulin-like growth factor-1 receptor (IGF-1R), epidermal growth factor receptor (EGFR), and HER2 expressions on outcomes of patients with gastric cancer

4539

Background: Insulin-like growth factor-1 receptor (IGF-1R), epidermal growth factor receptor (EGFR), and HER2 expressions have been reported to correlate with clinical outcomes in several solid tumors. However, the clinical significance of these biomarkers in gastric cancer (GC) remains unclear. Detailed exploratory evaluations are required to better understand their clinical implications. Methods: The study group comprised 87 patients who underwent gastrectomy at National Cancer Center Hospital and subsequently received chemotherapy for recurrent or residual tumor. Using immunohistochemical techniques, we analyzed the expressions of IGF-1R, EGFR, and HER2 in surgically removed tumor specimens to determine the prognostic significance of these biomarkers. Results: IGF-1R expression (defined as >10% membranous staining) was found in 67 tumors (77%), EGFR in 55 tumors (63%), and HER2 in 16 tumors (18%). IGF-1R expression correlated with EGFR expression (P=0.019) as well as with HER2 expression (P=0.001). A univariate analysis revealed that IGF-1R expression correlated with shorter survival (P=0.030). A multivariate analysis of potential prognostic factors showed that IGF-1R expression, worse performance status and pathological stage, and diffuse type tumor were independent predictors of poor outcomes ( Table ). Conclusions: IGF-1R expression in surgical GC specimens may be a predictor of poor outcomes in postoperative patients with GC. Our data suggest that anti-IGF-1R strategies may prove valuable in such patients.

[Table: see text]

No significant financial relationships to disclose.

Association of a novel polymorphism G-133C of thymidylate synthase (TYMS) gene with 5-FU-related severe diarrhea in Japanese patients with colorectal cancer

14108

Background: 5-FU remains a key drug for the treatment of several cancers, including cancers of the colorectum, stomach, and breast. Increasing evidence suggests that genetic polymorphism results in increased toxicity. This prospective study intended to elucidate the relations between 5-FU-related toxicity and polymorphisms of several genes. Methods: Blood for genotyping was obtained before treatment. Blood samples were drawn at 2-week intervals for 8 weeks to assess hematologic toxicity. Adverse events were assessed according to NCI CTC, v2.0. The genes encoding TYMS and thymidine phosphorylase (ECGF1) were analyzed with leukocyte DNA obtained from patients with colorectal cancer who received 5-FU (500 or 600 mg/m2) and leucovorin (LV) (250 mg/m2) weekly for 6 weeks every 8 weeks. Results: Seventy-eight patients with colorectal cancer were enrolled and genotyped. Toxicity was evaluated in all patients. No genetic polymorphisms detected were significantly associated with 5-FU-related hematological toxicity. Only G- 133C located in the 5’-UTR region of the TYMS gene was significantly associated with 5-FU-related grade 3 diarrhea. Conclusions: The TYMS G-133C SNP may be a critical determinant of severe diarrhea in patients treated with 5-FU/LV. [Table: see text]

No significant financial relationships to disclose.

Effect of alpha-helical CRH on quantitative electroencephalogram in patients with irritable bowel syndrome

Patients with irritable bowel syndrome (IBS) may have a higher tone of corticotropin-releasing hormone (CRH) in the brain. We tested our hypothesis that peripheral administration of CRH antagonist, alpha-helical CRH(9-41) (alphahCRH), improves decreased alpha power spectra and increased beta power spectra of electroencephalogram (EEG) in IBS patients. A barostat bag was inserted to the descending colon of 10 normal controls and 10 IBS patients. The EEG power spectra and topography were measured during baseline period and colonic distention period with the administration of saline followed by the administration of 10 microg kg(-1) of alphahCRH. IBS patients showed a significantly lower alpha power percentage and a higher beta power percentage than normal controls during baseline. Colonic distention induced a decrease in the alpha power percentage and an increase in the beta power percentage in both groups without difference between groups. After the administration of alphahCRH, changes in the EEG power spectra in response to colonic distention were blunted and the differences in the EEG power spectra between IBS patients and controls vanished. Peripheral administration of alphahCRH almost normalized EEG activities in IBS patients. Our data strongly suggest that CRH plays an important role in IBS.

Impairment in a negative regulatory system for TCR signaling in CD4+T cells from old mice

To examine the involvement of lipid rafts in an age-associated decline in T cell function, we analyzed the effect of aging on the constituents of lipid rafts in resting mouse CD4(+) T cells. We found a pronounced, age-dependent reduction in PAG/Cbp, which is involved in the regulation of Src family kinases (SFKs) by recruiting Csk (a negative regulator of SFKs) to lipid rafts. This reduction is specific for T cells and is attributed, at least in part, to the reduction in its mRNA level. The reduction of PAG accompanies marked impairment in recruiting Csk to lipid rafts and a concomitant decrease in the inactive forms of SFKs. These findings indicate that old mouse CD4(+) T cells have a defect in a negative SFK regulatory system.

Frequent methylation-associated silencing of a candidate tumor-suppressor, CRABP1, in esophageal squamous-cell carcinoma

Epigenetic alterations and the resulting inactivation of tumor suppressor genes often contribute to the development of various cancers. To identify novel candidates that may be silenced by aberrant methylation in esophageal squamous-cell carcinoma (ESCC), we analysed ESCC cell lines by a recently developed method known as bacterial artificial chromosome array-based methylated CpG island amplification (BAMCA), and selected candidates through BAMCA-assisted strategy. In the course of this program, we identified frequent CpG methylation-dependent silencing of the gene encoding cellular retinoic acid binding protein 1 (CRABP1) in our panel of ESCC cell lines. Expression of CRABP1 mRNA was restored in gene-silenced ESCC cells after treatment with 5-aza 2'-deoxycytidine. The DNA methylation status of the CRABP1 CpG island with clear promoter activity correlated inversely with expression of this gene. CpG methylation of CRABP1 was frequently observed in primary ESCC tissues as well. Restoration of CRABP1 expression in ESCC cells lacking the protein reduced cell growth by inducing arrest at G(0)-G(1), whereas knockdown of the gene in cells expressing CRABP1 promoted cell growth. Among 113 primary ESCC tumors, the absence of immunoreactive CRABP1 was significantly associated with de-differentiation of cancer cells and with distant lymph-node metastases in the patients. These results indicate that CRABP1 appears to have a tumor-suppressor function in esophageal epithelium, and its epigenetic silencing may play a pivotal role during esophageal carcinogenesis. Its expression status in biopsies or resected tumors might serve as an index for identifying ESCC patients for whom combined therapeutic modalities would be recommended.

Induction of prostaglandin E synthase by gastroesophageal reflux contents in normal esophageal epithelial cells and esophageal cancer cells

The synthesis of prostaglandin E2 (PGE2) requires cyclooxygenase (COX) and prostaglandin E synthase (PGES). There are two forms of PGES: cytosolic PGES (cPGES) and microsomal PGES (mPGES)-1. In this study, we investigated the effects of gastroesophageal reflux (GER) contents on PGES and COX-2 in esophageal cells. We incubated a human normal esophageal cell line, two esophageal squamous cell carcinoma (SCC) cell lines, and two esophageal adenocarcinoma (ADC) cell lines with GER contents. The production of PGE2 by these cells was assayed with an enzyme immunoassay kit. The protein expression of COX-2, cPGES, and mPGES-1 was confirmed by immunoblot analysis. The following results were obtained: GER contents induced the expression of COX-2 in all five cell lines. In normal esophageal cells, cPGES, but not mPGES-1, was detected in the cytosolic fraction. GER contents induced the expression of cPGES in the microsomal fraction. In SCC cells, cPGES was expressed in the cytosolic fraction, and mPGES-1 was expressed in the microsomal fraction. GER contents induced the expression of mPGES-1 in the microsomal fraction. In ADC cells, cPGES was expressed in both the cytosolic and microsomal fractions. GER contents induced the expression of both cPGES and mPGES-1 in the microsomal fraction. In conclusion, our results suggest that GER contents induce PGE2 production in esophageal cells. However, there are different isoforms of PGES in normal cells, SCC cells, and ADC cells.

Interleukin-8 production via protease-activated receptor 2 in human esophageal epithelial cells

Interaction between proteases and protease-activated receptor (PAR) 2 has been proposed to mediate inflammatory and immune response in the gastrointestinal tract. Recently, increase in interleukin (IL)-8 in the esophageal mucosa has been associated with the pathogenesis of esophagitis induced by reflux of gastric acids, bile acids or trypsin. The aims of the present study were to determine PAR2 expression in normal human esophageal epithelial cells (HEEC) and to evaluate the mediation of IL-8 production by trypsin-PAR2 interaction in HEEC. Reverse transcription polymerase chain reaction (RT-PCR) and Western blot analysis revealed that PAR2 mRNA and protein were constitutively expressed in HEEC without upregulation by the stimulation with tumor necrosis factor alpha or trypsin. IL-8 was produced in a dose-dependent fashion when cells were stimulated with a PAR2 agonist such as trypsin or SLIGKV-amide. Blocking antibody to PAR2, camostat mesilate (a trypsin inhibitor), p-38 mitogen-activated protein kinase (MAPK) inhibitors or ERK1/2 inhibitors reduced IL-8 production from trypsin-stimulated HEEC. Mutation of the NFkappaB-, AP-1- and NF-IL-6-binding site on the IL-8 gene promoter abrogated the induction of luciferase activities stimulated with trypsin by 100, 80 and 50%, respectively. These results indicate that PAR2 activation in HEEC by trypsin induces NFkappaB- and AP-1-dependent IL-8 production in association with activation of p38 MAPK and ERK1/2, suggesting that esophageal inflammation may be induced by PAR2 activation via reflux of trypsin.

Proteins and protein-rich biomass as environmentally friendly adsorbents selective for precious metal ions

Proteins exhibit specific interactions with various metal ions, which play important roles in a living cell. Here, we found that various proteins selectively adsorbed precious metal ions at a wide range of pH values. Studies on protein sequences and on synthesized peptides revealed that a histidine-containing sequence had specific interactions with precious metal ions (Au3+ and Pd2+). We then investigated a few types of protein-rich biomass as adsorbents for precious metal ions. In the presence of various transition metal ions, Au3+ and Pd2+ were also selectively adsorbed onto the biomass tested. The bound precious metal ions were recovered by aqua regia after charring the metal-bound biomass. Finally, we demonstrated the successful recovery of Au3+ and Pd2+ from a metal refining solution and a metal plating waste using the biomass. We propose an environmentally friendly recycling system for precious metal ions using protein-rich biomass.

Inhibitory effect of cinnamaldehyde, derived from Cinnamomi cortex, on the growth of influenza A/PR/8 virus in vitro and in vivo

We have investigated the inhibitory effect of trans-cinnamaldehyde (CA), one of the principal constituents of essential oil derived from Cinnamomi cortex, on the growth of influenza A/PR/8 virus in vitro and in vivo. When 1-h drug treatment was initiated at various times post-infection (p.i.) in Madin-Darby canine kidney cells using a fixed dose of CA (40 microM), the maximum inhibitory effect (29.7% virus yield of control) was obtained when drug treatment was started at 3h p.i. Under the same treatment schedule, CA inhibited the virus growth in a dose-dependent manner (20-200 microM), and, at 200 microM, the virus yield was reduced to an undetectable level. RT-PCR and SDS-PAGE analyses showed that CA inhibited viral protein synthesis at the post-transcriptional level. In mice infected with the lung-adapted PR-8 virus, inhalation (50mg/cage/day) and nasal inoculation (250 microg/mouse/day) of CA significantly increased survival rates on the 8 days to 100% and 70%, respectively, in contrast to a survival rate of 20% in the untreated control group. Importantly, inhalation of CA caused virus yield reduction by 1 log in bronchoalveolar lavage fluid on day 6 after infection, compared with that of the untreated control group. These findings might provide further support to the empirical indication of Cinnamomi cortex-containing Kampo medicines for acute respiratory infectious diseases.

Detection of cholesterol-rich microdomains in the inner leaflet of the plasma membrane

The C-terminal domain (D4) of perfringolysin O binds selectively to cholesterol in cholesterol-rich microdomains. To address the issue of whether cholesterol-rich microdomains exist in the inner leaflet of the plasma membrane, we expressed D4 as a fusion protein with EGFP in MEF cells. More than half of the EGFP-D4 expressed in stable cell clones was bound to membranes in raft fractions. Depletion of membrane cholesterol with beta-cyclodextrin reduced the amount of EGFP-D4 localized in raft fractions, confirming EGFP-D4 binding to cholesterol-rich microdomains. Subfractionation of the raft fractions showed most of the EGFP-D4 bound to the plasma membrane rather than to intracellular membranes. Taken together, these results strongly suggest the existence of cholesterol-rich microdomains in the inner leaflet of the plasma membrane.

Ikaros is a mutational target for lymphomagenesis in Mlh1-deficient mice

Deficiencies in DNA mismatch repair (MMR) result in replication errors within key tumor suppressor genes or oncogenes, and cause hereditary nonpolyposis colorectal cancer (HNPCC). Hematological malignancy with microsatellite instability is also associated with defective MMR, but little is known about the target genes for MMR. Here we identified Ikaros, a master transcription factor of lymphoid lineage commitment and differentiation, as a mutational target in spontaneous and radiation-induced T-cell lymphomas in Mlh1-deficient mice. Three quarters of lymphomas lacked Ikaros protein expression, which resulted from a frameshift mutation that created a stop codon. Mononucleotide repeat sequences at 1029-1034(C)6 and 1567-1572(G)6 in Ikaros were mutational hot spots with a one-base deletion occurring with a frequency of 45 and 50%, respectively. Point mutations and splicing alterations were also observed. In total, 85% of the lymphomas showed aberrations in Ikaros. The characteristic of Mlh1-deficient lymphomas is harboring of multiple mutations simultaneously in the same tumor, displaying a combination of two frameshift mutations at different repeats, frameshift and point mutations, and/or deletion mutations. This is the first report of Ikaros mutations coupled with Mlh1 deficiency in lymphomagenesis.

Increased lipid rafts and accelerated lipopolysaccharide-induced tumor necrosis factor-alpha secretion in Abca1-deficient macrophages

Lipid rafts on the cell surface are believed to be very important as platforms for various cellular functions. The aim of this study was to know whether defective lipid efflux may influence lipid rafts on the cell surface and their related cellular functions. We investigated macrophages with defective lipid efflux from ATP binding cassette transporter A1-deficient (Abca1-KO) mice. Lipid rafts were evaluated by the following two novel probes: a biotinylated and protease (subtilisin Carlsberg)-nicked derivative of theta-toxin and a fluorescein ester of polyethylene glycol-derived cholesterol. Lipid rafts in Abca1-KO macrophages were increased, as demonstrated by both probes. Moreover, activities of nuclear factor kappaB, mRNA and intracellular distribution, and secretion of tumor necrosis factor-alpha (TNF-alpha) were examined after stimulation by lipopolysaccharides (LPSs). LPS-induced responses of the activation of nuclear factor kappaB and TNF-alpha were more prompt and accelerated in the Abca1-KO macrophages compared with wild-type macrophages. Modification of lipid rafts by cyclodextrin and nystatin corrected the abnormal response, suggesting an association between the increased lipid rafts and abnormal TNF-alpha secretion. We report here that Abca1-KO macrophages with defective lipid efflux exhibited increased lipid rafts on the cell surface and accelerated TNF-alpha secretion.

Genetic variations and haplotype structures of the ABCB1 gene in a Japanese population: an expanded haplotype block covering the distal promoter region, and associated ethnic differences

As functional ABCB1 haplotypes were recently reported in the promoter region of the gene, we resequenced the ABCB1 distal promoter region, along with other regions (the enhancer and proximal promoter regions, and all 28 exons), in a total of 533 Japanese subjects. Linkage disequilibrium (LD) analysis based on 92 genetic variations revealed 4 LD blocks with the same make up as previously described (Blocks -1, 1, 2 and 3), except that Block 1 was expanded to include the distal promoter region, and that a new linkage between polymorphisms -1,789G>A in the distal promoter region and IVS5 + 123A>G in intron 5 was identified. We re-assigned Block 1 haplotypes, and added novel haplotypes to the other 3 blocks. The reported promoter haplotypes were further classified into several types according to tagging variations within Block 1 coding or intronic regions. Our current data reconfirm the haplotype profiles of the other three blocks, add more detailed information on functionally-important haplotypes in Block 1 and 2 in the Japanese population, and identified differences in haplotype profiles between ethnic groups. Our updated analysis of ABCB1 haplotype blocks will assist pharmacogenetic and disease-association studies carried out using Asian subjects.

Significance of nerve growth factor overexpression and its autocrine loop in oesophageal squamous cell carcinoma

Nerve growth factor (NGF) is overexpressed not only in nervous system, but also in several types of cancers. However, the role of NGF in oesophageal squamous cell carcinoma (OESCC) remains unclear. Here, we show the first evidence of NGF-TrkA autocrine loop and clinical significance of NGF overexpression in OESCC. Immunohistochemical study of 109 OESCC specimens revealed that NGF overexpression, found in 63 out of 109 patients (57.8%), was associated with lymph node metastasis, distant metastasis, higher TNM stage, poorer tumour differentiation, and poorer survival. NGF overexpression was also associated with strong expression of TrkA and negative expression of low-affinity neurotrophin receptor (p75NTR). Semiquantitative reverse transcription–polymerase chain reaction (RT–PCR) of 19 surgical specimens showed upregulation of NGF mRNA in 17 out of 19 (89%) patients. All five OESCC cell lines tested in vitro secreted detectable NGF in enzyme-linked immunosorbent assay, and expressed TrkA and p75NTR on RT–PCR and Western blot. The motility of HSA/c, one of the OESCC cell lines overexpressing NGF, was significantly decreased by either neutralising anti-NGF antibody, an inhibitor of TrkA, or NGF-small interfering RNA in transwell migration assay. Our findings suggest that NGF is of potential interest not only as a prognostic factor, but also as a novel therapeutic target in OESCC.

Phase I study of NK105, a paclitaxel-incorporating micellar nanoparticle, in patients with advanced cancer

2018

Background: NK105 is a new polymeric micelle carrier system for paclitaxel (PTX). A preclinical study revealed that the plasma AUC and tumor AUC of NK105 were 90-fold higher and 25-fold higher, respectively, than those of free-PTX, i.e., the conventional PTX formulation. NK105 had higher in vivo antitumor activity and lower neurotoxicity than free-PTX. This phase I study was designed to examine the MTD, DLTs, recommended dose (RD) for phase II, and the pharmacokinetics of NK105. Methods: NK105 was administered as a 1-hour intravenous infusion every 3 weeks, without antiallergic premedication. The starting dose was 10 mg PTX equivalent/m2, and the dose was escalated according to the accelerated titration method. Results: To date, 17 patients (pts) have received the following doses: 10 mg/m2 (n=1); 20 mg/m2 (n=1); 40 mg/m2 (n=1); 80 mg/m2 (n=1); 110 mg/m2 (n=3); 150 mg/m2 (n=5); and 180 mg/m2 (n=5). The tumor types treated included pancreatic (n=9), bile duct (n=5), gastric (n=2), and colonic (n=1) cancers. Neutropenia was the most common hematological toxicity. Grade 3 fever developed in 1 pt given 180 mg/m2. No other grade 3 or 4 non-hematological toxicity, including neuropathy, was observed. DLTs occurred in pts given 180 mg/m2 (grade 4 neutropenia lasting for more than 5 days). This dose was designated as the MTD. Allergic reactions developed in only one pt at 180 mg/m2, who was sensitive to other drugs such as antibiotics anti-inflammatory. A partial response was observed in one pt with pancreatic cancer and pts with colonic and gastric cancer had stable disease. The Cmax and AUC of NK105 were dose dependent. The plasma AUC of NK105 at 180 mg/m2 was approximately 30-fold higher than that of the conventional formulation of PTX. Conclusions: Accrual is ongoing at the 150 mg/m2 dose level to determine the RD. DLT was Grade 4 neutropenia. NK105 produces prolonged high levels of PTX in plasma. A 1-hour infusion of NK105 every 3 weeks was feasible, well tolerated, and effective in patients with pancreatic cancer. Even after the long term usage, only grade 1 or 2 neuropathy was observed. NK105 will be evaluated in Phase II studies of patients with advanced pancreatic and gastric cancers.

No significant financial relationships to disclose.

Phase II study of S-1 plus irinotecan (SIR) in patients with advanced colorectal cancer

13508

Background: Infusional fluorouracil and leucovorin (5-FU/LV) plus irinotecan is one of the standard regimens for the treatment of metastatic colorectal cancer (MCRC). S-1, a combination of tegafur, 5-chloro-2,4-dihydroxypyridine, and oxonic acid, is an oral DPD inhibitory fluoropyrimidine shown to be very effective as first-line treatment for MCRC. The response rate with S-1 was 35–40% in patients with chemo-naïve MCRC. This study evaluated the efficacy and toxicity of S-1 plus irinotecan (SIR). Methods: Eligible patients had untreated MCRC as confirmed histologically, PS 0–1, adequate organ function, and provided written informed consent. First-line SIR was given in 3-week treatment cycles: intravenous irinotecan 150 mg/m2 (day 1) and oral S-1 40 mg/m2 twice daily for 14 days followed by 7 days of rest. Results: Forty-one patients were enrolled; 40 fulfilled all eligibility criteria, and 1 had double cancers. There were 28 men; median age 60 years (range, 23–74); ECOG PS 0/1, 35/6. The overall response rate was 63% (95%CI, 48–78%). Five patients had a CR, 20 a PR, 11 SD, and 2 PD. Median TTP was 8.0 months (range, 1.4–13.8 months); MST was not reached. The most frequent grade 3/4 toxicities included: neutropenia (17%), diarrhea (15%), and anorexia (12%). One patient had Grade 4 constipation. The relative dose intensity of irinotecan was 84%, and that of S-1 was 79%. Dose reduction of irinotecan was required in 41 of 327 administered cycles, and that of S-1 was required in 15 of 327. Conclusions: SIR is a highly active and convenient first-line therapy for MCRC, with an acceptable toxicity profile. S-1 has the potential to replace infusional 5-FU/LV plus irinotecan for MCRC.

No significant financial relationships to disclose.

Impact of dihydrofolate reductase (DHFR) and thymidylate synthase (TS) on outcomes of postoperative patients with gastric cancer

4053

Background: The clinical significance of biomarkers in resected gastric cancer (GC) remains unclear. Detailed exploratory evaluations are required to better understand the clinical implications of biomarkers. Methods: The study group comprised 87 patients who received chemotherapy for recurrent or residual GC after resection of their primary tumors at National Cancer Center Hospital. The patients received 1 to 5 regimens of chemotherapy (median: 2). Total RNA was isolated from laser-captured tumor cells of the resected cancer specimens, and the gene expressions of TS, DPD, DHFR, ERCC1, MRP1, and 22 other biomarkers related to anticancer drug sensitivity were quantitatively evaluated by a real-time RT-PCR assay. Results: The gene expressions of TS, DHFR, MTHFD, RRM1, and ERCC1 were significantly related to survival ( Table ). Multivariate analysis revealed that high DHFR (p < 0.001, RR = 1.70 [95% CI, 1.28–2.29]) and high TS (p = 0.004, RR = 1.53 [1.15–2.06]) gene expressions were independently related to poor survival. As compared with intestinal type tumors, diffuse type tumors had higher DPD (p < 0.001) and lower Her2 (p < 0.001) gene expressions. As for first line chemotherapy, an analysis of 29 patients treated with S-1, an oral DPD inhibitory fluoropyrimidine, showed that patients with diffuse type tumors tended to respond better (p = 0.13) than those with intestinal type tumors. An analysis of 29 patients treated with cisplatin plus irinotecan as first line therapy showed that low ERCC1 gene expression was slightly but not significantly related to a better response (p = 0.087). Analyses of patients treated with other first line regimens revealed no significant correlation of any biomarker with response. Conclusions: Increased gene expressions of DHFR and TS in surgical specimens are significantly predictors of poor outcomes in postoperative patients with GC.

[Table: see text]

[Table: see text]

Phase II study of combination therapy with S-1 and irinotecan in patients with advanced colorectal cancer

BACKGROUND

A combination of irinotecan with continuous intravenous infusions of 5-fluorouracil (5-FU) and leucovorin (LV) is often used to treat advanced colorectal cancer. However, recent concerns about safety and convenience have prompted the development of new oral fluoropyrimidine derivatives and improved regimens. This phase II study evaluated the efficacy and safety of the oral fluoropyrimidine S-1 plus irinotecan in patients with previously untreated advanced or recurrent colorectal cancer.

PATIENTS AND METHODS

Forty eligible patients with histologically confirmed colorectal adenocarcinoma received this treatment. S-1 was administered orally on days 1 to 14 of a 21-day cycle. Patients were assigned on the basis of body surface area (BSA) to receive one of the following oral doses twice daily: 40 mg (BSA < 1.25 m(2)), 50 mg (BSA > or = 1.25 to < 1.50 m(2)), or 60 mg (BSA > or = 1.50 m(2)). Irinotecan (150 mg/m(2)) was administered by intravenous infusion on day 1.

RESULTS

A total of 327 courses of treatment were administered to 40 patients. Five patients had complete responses, and 20 had partial responses. The overall response rate was 62.5% (95% confidential interval, 47.5%-77.5%). Median progression-free survival was 8.0 months (95% confidential interval, 5.2-11.4 months). The rates of grade 3 or 4 toxicity were as follows: neutropenia, 15%; anemia, 7.5%; anorexia, 12.5%; and diarrhea, 7.5%.

CONCLUSIONS

Combined treatment with S-1 and irinotecan is an effective, well tolerated, and convenient regimen in patients with advanced colorectal cancer. Our findings suggest that combined treatment with S-1 and irinotecan is a promising regimen, offering benefits in terms of safety and survival as compared with conventional regimens in patients with advanced colorectal cancer.

Resin adhesion to caries-affected dentine after different removal methods

BACKGROUND

Caries-affected dentine is the common bonding substrate when treating a patient. At present, there are many methods used for caries removal. The aim of this study was to evaluate the microtensile bond strength of two adhesives (Clearfil Protect Bond and OptiBond Solo Plus Total-Etch) to caries-affected dentine after three different caries removal methods.

METHODS

Extracted carious human third molars were used and caries-affected dentine surfaces were obtained from one of the three removal methods: (i) round steel bur in a slow-speed handpiece; (ii) Er:YAG laser; or (iii) 600-grit silicon carbide abrasive paper. Each of the adhesives was used to bond resin composite to the caries-affected dentine according to the manufacturers' instructions. Hourglass-shaped specimens were prepared and stressed in tension at 1mm/min. Data were analysed using two-way analysis of variance and least significant difference test.

RESULTS

Clearfil Protect Bond showed significantly lower bond strength than OptiBond Solo Plus Total-Etch after caries removal with round steel bur, but the opposite was found for specimens treated with silicon carbide abrasive paper. For laser-treated dentine, no significant differences between the adhesives were revealed.

CONCLUSIONS

Besides the differences in adhesives, different caries removal methods seem to influence resin adhesion to caries-affected dentine.

Expression of the gene for a membrane-bound fatty acid receptor in the pancreas and islet cell tumours in humans: evidence for GPR40 expression in pancreatic beta cells and implications for insulin secretion

AIMS/HYPOTHESIS

G protein-coupled receptor 40 (GPR40) is abundantly expressed in pancreatic beta cells in rodents, where it facilitates glucose-induced insulin secretion in response to mid- to long-chain fatty acids in vitro. However, GPR40 gene expression in humans has not been fully investigated, and little is known about the physiological and pathophysiological roles of GPR40 in humans. The aim of this study, therefore, was to examine GPR40 expression and its clinical implications in humans.

METHODS

GPR40 mRNA expression in the human pancreas, pancreatic islets and islet cell tumours was analysed using TaqMan PCR.

RESULTS

GPR40 mRNA was detected in all human pancreases collected intraoperatively. It was enriched approximately 20-fold in isolated islets freshly prepared from the pancreases of the same individuals. The estimated mRNA copy number for the GPR40 gene in pancreatic islets was comparable to those for genes encoding sulfonylurea receptor 1, glucagon-like peptide 1 receptor and somatostatin receptors, all of which are known to be expressed abundantly in the human pancreatic islet. A large amount of GPR40 mRNA was detected in insulinoma tissues, whereas mRNA expression was undetectable in glucagonoma or gastrinoma. The GPR40 mRNA level in the pancreas correlated with the insulinogenic index, which reflects beta cell function (r=0.82, p=0.044), but not with glucose levels during the OGTT, the insulin area under the OGTT curve or the index for the homeostasis model assessment of insulin resistance (HOMA-IR).

CONCLUSIONS/INTERPRETATION

The present study provides evidence for GPR40 gene expression in pancreatic beta cells and implicates GPR40 in insulin secretion in humans.

Detachment-associated changes in lipid rafts of senescent human fibroblasts

We characterized the effects of in vitro cellular aging on constituents of lipid rafts in human diploid fibroblasts, TIG-1. Cholesterol recovery from lipid rafts of senescent cells was decreased by the detaching treatment, while the decrease was far less obvious in young cells. A probe that binds selectively to cholesterol in lipid rafts revealed that the amount of lipid rafts on the cell surface decreased in senescent cells upon cell detachment. Accompanying this change was the release of the raft-associated molecules caveolin and Fyn from lipid rafts upon cell detachment, suggesting a detachment-associated disorganization of lipid rafts in senescent cells. In addition, our observations showing differential sensitivities of lipid rafts from young and senescent cells to detaching treatment indicate a caution in how to detach cells. Particular attention needs to be paid to interpreting the results when lipid rafts are prepared from mechanically detached cells under detergent-free conditions.

Alpha 2 integrin +807 polymorphism in drug-induced gingival overgrowth

Alpha2 integrin on fibroblasts is reported to play an important role in the induction of drug-induced gingival overgrowth, which is characterized by excessive accumulation of type I collagen in gingival connective tissue. Silent polymorphism 807 T/C within the alpha2 integrin gene is associated with high/low alpha2 integrin expression. The aim of this study was to test the hypothesis that expression of alpha2 integrin 807 T/C polymorphism correlates with drug-induced gingival overgrowth. A case-control study comparing 136 subjects taking calcium channel blockers (72 with vs. 64 without drug-induced gingival overgrowth) demonstrated that the frequency of the +807 C allele was significantly higher in the case group than in the controls (odds ratio, 3.61; 95% confidence interval, 2.14 - 6.10; P < 0.05). The present findings suggest that the alpha2 +807 C allele is one of the genetic risk factors for drug-induced gingival overgrowth.

Ethyl esterification of docosahexaenoic acid in an organic solvent-free system with immobilized Candida antarctica lipase

Ethyl docosahexaenoate (EtDHA) is regarded as a potentially useful pharmaceutical substance on account of its beneficial physiological activities. We attempted the ethyl esterification of docosahexaenoic acid (DHA) in an organic solvent-free system using Candida antarctica lipase, which acts strongly on DHA and ethanol. Esterification of 88% was attained by shaking a mixture of DHA/ethanol (1:1, mol/mol) and 2 wt% immobilized C. antarctica lipase at 30 degrees C for 24 h. However, even in the presence of an excess amount of ethanol, the extent of esterification could not be raised above 90%. To attain a higher level of esterification, a two-step reaction was found to be effective. The first step was performed in a mixture of DHA/ethanol (1:1, mol/mol), and the reaction mixture was then dehydrated. In the second step, the resulting mixture was shaken at 30 degrees C for 24 h with 5 molar equivalents of ethanol against the remaining DHA using 2 wt% immobilized lipase. By means of this two-step procedure, 96% esterification was attained. Repetition of the first and second reactions showed that the immobilized lipase was reusable for at least 50 cycles. In addition, DHA remaining in the second-step reaction mixture was removed by a conventional alkali refining process, giving purified EtDHA with a high yield.

Enzymatic purification of polyunsaturated fatty acids

Polyunsaturated fatty acids (PUFAs) have various physiological functions. Of these, ethyl eicosapentaenoate is industrially purified and used as a medicine. Other PUFAs, such as docosahexaenoic acid (DHA), gamma-linolenic acid (GLA), and arachidonic acid (AA), are also expected to be used as pharmaceutical agents; however, their industrial purification processes have not been established. Because PUFAs are highly unstable against heat and oxidation, we attempted to purify them by taking advantage of their enzymatic reactions. When free fatty acids (FFAs) originating from PUFA-containing oil were selectively esterified with lauryl alcohol (LauOH) using a lipase acting on a desired PUFA very weakly, the PUFA was efficiently enriched in the FFA fraction. In addition, when selective alcoholysis of ethyl esters originating from PUFA-containing oil with LauOH was carried out, the PUFA ethyl ester (EtPUFA) was enriched to a desired purity in the unreacted ethyl ester fraction. These reaction mixtures contain LauOH, PUFA (EtPUFA), and lauryl esters, and their molecular weights are different from one another. Hence, PUFA or EtPUFA can be easily separated by conventional distillation. Selective esterification increased the purity of DHA, GLA, and n-6 PUFAs rich in AA to 91, 98, and 96 wt%, respectively. Selective alcoholysis was also effective for increasing the purity of ethyl docosahexaenoate to 90 wt%.

Separation of a cholesterol-enriched microdomain involved in T-cell signal transduction

We isolated a cholesterol-enriched membrane subpopulation from the so-called lipid raft fractions of Jurkat T-cells by taking advantage of its selective binding to a cholesterol-binding probe, BCtheta. The BCtheta-bound membrane subpopulation has a much higher cholesterol/phospholipid (C/P) molar ratio (approximately 1.0) than the BCtheta-unbound population in raft fractions (approximately 0.3). It contains not only the raft markers GM1 and flotillin, but also some T-cell receptor (TCR) signalling molecules, including Lck, Fyn and LAT. In addition, Csk and PAG, inhibitory molecules of the TCR signalling cascade, are also contained in the BCtheta-bound membranes. On the other hand, CD3epsilon, CD3zeta and Zap70 are localized in the BCtheta-unbound membranes, segregated from other TCR signalling molecules under nonstimulated conditions. However, upon stimulation of TCR, portions of CD3epsilon, CD3zeta and Zap70 are recruited to the BCtheta-bound membranes. The Triton X-100 concentration used for lipid raft preparation affects neither the C/P ratio nor protein composition of the BCtheta-bound membranes. These results show that our method is useful for isolating a particular cholesterol-rich membrane domain of T-cells, which could be a core domain controlling the TCR signalling cascade.

A randomized double blind placebo-controlled clinical trial of Hochuekkito, a traditional herbal medicine, in the treatment of elderly patients with weakness N of one and responder restricted design

OBJECTIVE

To evaluate the effects of Hochuekkito, a traditional Japanese and Chinese medicine, in the treatment of elderly patients with general weakness. To devise a suitable study design for assessing the clinical effectiveness of traditional herbal medicines.

METHODS

Fifteen elderly patients (mean +/- SD: age 78.4 +/- 7.8; m/f 3/12) participated in this study. A multicenter, prospective, randomized, double-blind, placebo-controlled study with N of one and responder restricted design was performed. After the run-in period, the patients were divided into responders and non-responders. Only responders were entered in the study, and were randomized into three groups: an active-placebo group, a placebo-active group and an active-active group. The study consisted of two 6-week terms with a 2-week washout period in between. We assessed the Short Form 36 Health Survey (SF-36) and Profile of Mood States (POMS) as an endpoint of quality of life (QOL). In addition, we assessed the biodefense status by measuring the natural killer cytolytic activity (NK activity), IL-2 producing activity of peripheral lymphocytes, lymphocyte proliferating activity and lymphocyte cell-surface antigens.

RESULTS

The physical component summary of the SF-36 analysis significantly improved in the Hochuekkito-treated group. Four components (A-H: anger-hostility, F: fatigue, T-A: tension-anxiety, C: confusion) out of six improved in the Hochuekkito-treated group in the POMS analysis. Lymphocyte proliferating activity improved in the Hochuekkito-treated group but not significantly. Concerning the surface antigens of peripheral lymphocytes, the population of CD3 positive cells and CD3CD4 double positive cells increased in the Hochuekkito-treated group.

CONCLUSION

We revealed that Hochuekkito improved the QOL and immunological status of elderly patients with weakness by randomized controlled trial. Our study design might be useful for assessing the efficacy of traditional herbal medicine in the future.

Structure and function of lipid rafts in human activated T cells

Lipid rafts, specialized membrane microdomains enriched in sphingolipids and cholesterol, have been shown to function as signaling platforms in T cells. Surface raft expression is known to be increased in human T cells upon activation, and this increased raft expression may account for efficient signaling capability and decreased dependency for co-stimulation in effector and/or activated T cells. However, raft-mediated signaling ability in activated T cells remains to be clarified. In this study, we analyzed the structure and function of lipid rafts in human activated T cells. We demonstrated that raft protein constituents are dramatically changed after activation along with an increase in lipid contents. T cells stimulated with anti-CD3 plus anti-CD28 antibodies showed an increase not only in surface monosialoganglioside GM1 expression but also in total amounts of raft-associated lipids such as sphingomyelin, cholesterol and glycosphingolipids. Raft proteins increased after activation include Csk, Csk-binding protein and Fyn, the molecules known to be involved in negative regulation of T cell activation. Consistent with the increase in expression of these proteins, TCR-mediated Ca(2+) response, a response dependent on raft integrity, was clearly inhibited in activated T cells. Thus, the structure and function of lipid rafts in human activated T cells seem to be quite distinct from those in naive T cells. Further, human activated T cells are relatively resistant to signaling, at least transiently, by TCR re-stimulation even though their raft expression is increased.

Severe hypertension after stellate ganglion block

Haemodynamic effects may occur after stellate ganglion block (SGB) arising from autonomic imbalance and local anaesthetic infiltration to barosensitive areas. We report seven patients who developed severe hypertension (systolic arterial pressure >200 mm Hg) after SGB in our pain clinic service. We postulate that diffusion of the local anaesthetic along the carotid sheath may produce vagal blockade causing unopposed sympathetic activity as a result of attenuation of the baroreceptor reflex. We recommend close monitoring of arterial pressure measurement in patients who received SGB.

Vasodilative effect of perillaldehyde on isolated rat aorta

The vasodilative effect of perillaldehyde, one of the major oil components in Perilla frutescens BRITTON, was studied using isolated rat aorta. Perillaldehyde at final concentrations of 0.01 to 1 mM showed dose-dependent relaxation of the aorta contracted by treatment with prostaglandin F2alpha or norepinephrine. Neither the presence of NG-nitro-L-arginine methyl ester nor removal of the aortic endothelium affected the vasodilatation, suggesting that perillaldehyde exerts a direct effect on vascular smooth muscle cells. The vasodilative effect of perillaldehyde was not inhibited by pretreatment with a beta-adrenergic receptor blocker (propranolol), an inhibitor of phosphodiesterase (theophylline), a delayed rectifier K+ channel blocker (tetraethylammonium chloride), or an ATP-sensitive K+ channel blocker (glibenclamide). However, perillaldehyde showed contrasting effects on vasodilatation of the aorta contracted by an influx of extracellular Ca2+ - perillaldehyde caused little vasodilatation on the aorta contracted by the Ca2+ ionophore A23187, while it inhibited the vasoconstriction induced by treatment with high-concentration K+, which dominantly opened the voltage-dependent Ca2+ channel. These results suggest that the vasodilative effect of perillaldehyde is derived from blocking the Ca2+ channels.

The effect of Juzen-taiho-to/TJ-48 on the expression of killer-cell immunoglobulin-like receptors (CD158a/b) on peripheral lymphocytes in vitro experiment

Juzen-taiho-to (TJ-48), a mixture of extracts from 10 medicinal herbs, has been used traditionally to treat patients with anemia, anorexia or fatigue. It is well known that the treatment of TJ-48 result in the decrease of patient's complaints, as well as the increase of NK cytolytic activity (NK activity) although its augmentation is not clear in the other kampo formula from the clinical viewpoint. To investigate its biological activities, such as the augmentation of NK activity, we analyzed the effects of TJ-48 on the expression of killer-cell immunoglobulin-like receptors (KIRs) in vitro experiment. The peripheral lymphocytes were incubated in medium alone, or medium containing TJ-48 or interleukin-2 (IL-2) plus TJ-48 at several concentrations for 48 h. After each incubation, cells were collected and their KIRs were detected by flow cytometry using monoclonal antibodies CD158a and CD158b. TJ-48 increased the populations of CD16+CD158a+ and CD16+CD158b+ cells in a dose-dependent manner. In contrast, CD16-CD158a/b+ cells did not increase. Additionally, the extract of TJ-48 enhanced the increase of KIRs expression induced by IL-2. These actions contribute to the augmentation of NK cytolytic activity by TJ-48, and might explain, in part, its antitumor effects which has been observed in vivo.

Distinct localization of lipid rafts and externalized phosphatidylserine at the surface of apoptotic cells

Externalization of phosphatidylserine (PS) takes place in apoptotic cells as well as in viable cells under certain circumstances. Recent studies showed that externalized PS is localized at the lipid raft in viable activated immune cells. We found that lipid rafts and PS existed in a mutually exclusive manner in apoptotic cells. The number of PS-exposing apoptotic cells decreased when lipid rafts were disrupted. BCtheta;, which binds selectively to cholesterol in a cholesterol-rich region, did not effectively recognize lipid rafts of apoptotic cells. Lipid rafts rich in GM1 were successfully prepared from apoptotic cells, but the lipid raft protein LAT was not enriched in the preparation. Furthermore, the amount of PS and phosphatidylethanolamine but not of cholesterol in lipid rafts appeared to change after induction of apoptosis. These results suggest that lipid rafts are structurally modified during apoptosis and, despite being localized differently from PS, are involved in the externalization of PS.

Autoantibodies directed against the protease inhibitor calpastatin in psoriasis

Psoriasis is believed to be a T cell-mediated autoimmune disease, but also exhibits autoantibody production. Calpastatin is an endogenous inhibitor of calpain, a ubiquitous protease that regulates inflammatory processes. Anti-calpastatin autoantibody was first identified as an autoantibody specific to rheumatoid arthritis, but has been also detected in other autoimmune diseases. In this study, we examined the presence and levels of anti-calpastatin antibody in 77 psoriasis patients by enzyme-linked immunosorbent assay. Compared with normal controls, psoriasis patients exhibited significantly elevated IgG anti-calpastatin antibody levels that were similar to those found in rheumatoid arthritis patients. Remarkably, IgG anti-calpastatin autoantibody in sera from psoriasis patients inhibited calpastatin activity. Calpain II expression was up-regulated in psoriasis skin lesions compared with normal skin while calpastatin expression was normal. The results of this study reveal the presence of anti-calpastatin autoantibody in psoriasis.

Effect of halothane on intercellular adhesion molecule-1 (ICAM-1) in melanoma cells

There have only been a few reports relating to the effect of inhalational anesthetics on the tumor cell morphology in cancer patients undergoing surgery. We hypothesized that some anesthetic agents might influence the spread of unresectable cancer cells and might additionally worsen the condition of the patient due to depressed host immune surveillance. We therefore evaluated the influence of halothane on tumor cell adhesion, which is closely linked to tumor cell metastasis. Human melanoma cells from SK-MEL-37 cell-line were exposed to 4% halothane for 3, 6, 12 or 24 hours, respectively. Furthermore, after 24 hours halothane exposure, they were incubated in a 5% CO2 atmosphere for 12 or 24 hours. The cells were then analyzed using a fluorescence flowcytometer and intercellular adhesion molecule-1 (ICAM-1) expression in SK-MEL-37 cells was quantified as the intensity of fluorescence of ICAM-1 expressed in 10,000 cells. ICAM-1 expression in cells exposed to halothane for 3, 6, 12 or 24 hours was lower than that of non-exposed cells and returned to control level after further incubation in 5% CO2 atmosphere for either 12 or 24 hours. We conclude that halothane might affect the progression of tumor cell metastasis in vitro.

Interleukin-6 (IL-6) − 373 A9T11 allele is associated with reduced susceptibility to chronic periodontitis in Japanese subjects and decreased serum IL-6 level

We investigated whether interleukin-6 (IL-6) gene polymorphisms could be associated with chronic periodontitis (CP) and serum IL-6 level. One hundred and twelve CP and 77 non-CP Japanese subjects were analyzed for IL-6 -597 (G/A), -572 (C/G), -373 (A(n)T(m)), -190 (C/T), and -174 (G/C) polymorphisms. We could only detect -572 and -373 polymorphisms and found that the frequency and carriage rate of the -373 A9T11 allele were significantly higher in non-CP subjects. Enzyme-linked immunosorbent assay confirmed that the -572 and -373 G[A9T11] haplotypes were associated with lower serum IL-6 level. These findings suggest that IL-6 -373 A9T11 allele could be associated with reduced susceptibility to CP among Japanese subjects and decreased serum IL-6 level.

Control of cell polarity in response to intra- and extracellular signals in budding yeast

Budding yeast serves as a powerful genetic model organism for studying the molecular mechanisms of cell polarity in single cells. Like other polarized eukaryotic cells, yeast cells possess polarity programs that regulate where they grow and divide. Establishment of a site of cell polarity may be conceptualized in several stages. First, cells mark a specific location at the cell surface for polarized cell growth and cell division. To define these sites, cells use intrinsic cues present in the cell or landmarks determined by extracellular signals such as morphogens. Second, these landmark proteins then recruit or activate polarity establishment proteins including small GTPases and their regulators. Positive and negative feedback mechanisms are required to transform these site-selection processes into a stable axis of polarity. Finally, these locally activated GTPase modules recruit and activate proteins that organize the actin cytoskeleton and cell growth. In this short review, we describe molecular pathways required to establish oriented cell polarity, and emphasize recent advances in defining positive and negative feedback mechanisms that together may translate an initially weak symmetry-breaking signal into a robust axis of polarity.

Phase I clinical trial and pharmacokinetic evaluation of NK911, a micelle-encapsulated doxorubicin

NK911 is a novel supramolecular nanocarrier designed for the enhanced delivery of doxorubicin (DXR) and is one of the successful polymer micelle systems to exhibit an efficient accumulation in solid tumours in mice. The purpose of this study was to define the maximum-tolerated dose (MTD) and dose-limiting toxicities (DLTs) of NK911 and to evaluate its pharmacokinetic profile in man. NK911 was given intravenously to patients with solid tumours every 3 weeks using an infusion pump at a rate of 10 mg DXR equivalent min⁻¹. The starting dose was 6 mg DXR equivalent m⁻², and the dose was escalated according to the accelerated titration method. A total of 23 patients participated in this study. Neutropenia was the predominant haematological toxicity, and grade 3 or 4 neutropenia was observed at doses of 50 and 67 mg m⁻². Common nonhaematological toxicities were mild alopecia, stomatitis, and anorexia. In the dose identification part of the study, DLTs were observed at a dose of 67 mg m⁻² (grade 4 neutropenia lasting more than 5 days). Thus, this dosage level was determined to be the MTD. Infusion-related reactions were not observed in any cases. The C_5 min and area under the concentration curve parameters of NK911 exhibited dose-dependent characteristics. Among the 23 patients, a partial response was obtained in one patient with metastatic pancreatic cancer. NK911 was well tolerated and produced only moderate nausea and vomiting at myelosuppressive dosages. The recommended phase II dose was determined to be 50 mg m⁻² every 3 weeks.

Axon-dominant localization of cell-surface cholesterol in cultured hippocampal neurons and its disappearance in Niemann-Pick type C model cells

There is growing evidence showing the important role of cholesterol in maintaining neuronal function. In particular, much attention has been paid to the role of the cholesterol-rich microdomains called lipid rafts. However, the cholesterol distribution on neurons is not clear. Here, we investigated localization of cholesterol in cultured rat hippocampal neurons, using filipin and a novel cholesterol-binding reagent BCtheta. In our culture system, BCtheta detects only cell-surface cholesterol, whereas filipin stains both intracellular and cell-surface cholesterol. BCtheta staining appeared visible in a maturation-dependent manner and showed axon-dominant distribution of cell-surface cholesterol in fully matured neurons. A part of this cholesterol on axons was resistant to detergents at 4 degrees C, and thus might be involved in lipid rafts. Interestingly, Niemann-Pick type C model neurons induced by class 2 amphiphiles lost the cell-surface but not the intracellular cholesterol staining. Niemann-Pick type C disease is caused by the disruption of intracellular cholesterol transport and is known to induce neurodegeneration in brains accompanied by formation of neurofibrillary tangles. Our observations suggest the important role of cell-surface cholesterol in maintaining a functional axonal membrane and indicate that the observed defect in axonal surface cholesterol might lead to neurodegeneration.