Biomedical subjects

Tetsuya Hamaguchi

Publications and source records attributed to Tetsuya Hamaguchi.

At least 19 recordsLinked to original sources

PubMed2006

Novel SN-38-incorporating polymeric micelles, NK012, eradicate vascular endothelial growth factor-secreting bulky tumors.

7-Ethyl-10-hydroxy-camptothecin (SN-38), a biological active metabolite of irinotecan hydrochloride (CPT-11), has potent antitumor activity but has not been used clinically because it is a water-insoluble drug. For delivery by i.v. injection, we have successfully developed NK012, a SN-38-releasing nanodevice. The purpose of this study is to investigate the pharmacologic character of NK012 as an anticancer agent, especially in a vascular endothelial growth factor (VEGF)-secreting tumor model. The particle size of NK012 was approximately 20 nm with a narrow size distribution. NK012 exhibited a much higher cytotoxic effect against lung and colon cancer cell lines as compared with CPT-11. NK012 showed significantly potent antitumor activity against a human colorectal cancer HT-29 xenograft as compared with CPT-11. Enhanced and prolonged distribution of free SN-38 in the tumor was observed after the injection of NK012. NK012 also had significant antitumor activity against bulky SBC-3/Neo (1,533.1 +/- 1,204.7 mm(3)) and SBC-3/VEGF tumors (1,620.7 +/- 834.0 mm(3)) compared with CPT-11. Furthermore, NK012 eradicated bulky SBC-3/VEGF tumors in all mice but did not eradicate SBC-3/Neo tumors. In the drug distribution analysis, an increased accumulation of SN-38 in SBC-3/VEGF tumors was observed as compared with that in SBC-3/Neo tumors. NK012 markedly enhanced the antitumor activity of SN-38, especially in highly VEGF-secreting tumors, and could be a promising SN-38-based formulation.

Animals↗

PubMed2006

Establishment of an apoptosis-sensitive rat mammary carcinoma cell line with a mutation in the DNA-binding region of p53.

Seven mammary carcinoma cell lines were established from 7,12-dimethylbenz[a]anthracene-induced tumors developed in a human c-Ha-ras transgenic rat. Without apoptotic stimuli, a large amount of p53 protein was detected in the C11 cell line (C11), whereas all cell lines expressed variable levels of the assayed death receptor/ligand, bcl-2 family and p53 cascade-related genes. The p53 gene in C11 had a mutation at codon 246, in the DNA-binding region of p53. Transcriptional activity of the mutant protein appeared to be lower than that of the wild-type p53. Despite the presence of p53 mutation, C11 was more sensitive to apoptosis triggered by etoposide, paclitaxel and staurosporine than the cell lines expressing wild-type p53. These data suggest that the apoptosis induced by intracellular injury occurs via the transcriptionally impaired mutant p53 in C11.

Animals↗

PubMed2006

Phase I/II study of oxaliplatin with weekly bolus fluorouracil and high-dose leucovorin (ROX) as first-line therapy for patients with colorectal cancer.

BACKGROUND: Infusional fluorouracil (5-FU) and leucovorin (LV) with oxaliplatin is one of the current standard regimens for the treatment of patients with metastatic colorectal cancer. Weekly bolus 5-FU with high-dose LV (Roswell Park Memorial Institute Regimen: RPMI) is the most commonly used regimen in Japan. The objectives of this study were to determine the recommended dose (RD) of RPMI combined with oxaliplatin and to evaluate the toxicity and efficacy at the RD. METHODS: The subjects were 18 patients with metastatic colorectal cancer. Oxaliplatin (85 mg/m2) was given intravenously over 2 h on days 1 and 15 with l-LV (250 mg/m2) given intravenously over 2 h and 5-FU as an intravenous bolus on days 1, 8, and 15. This treatment was repeated every 4 weeks. The dose of 5-FU was escalated from 400 mg/m2 (level 1) to 500 mg/m2 (level 2). RESULTS: A total of 14 patients received level 1, and 4 received level 2. Three of the patients had dose-limiting toxicity (DLT) in cycle 1 of level 2 (grade 3 thrombocytopenia, grade 4 neutropenia and grade 2 neutropenia in one patient each), requiring that treatment was delayed for longer than 7 days. None of the 14 patients given level 1 had DLT or grade 3 or 4 gastrointestinal toxicity. Sensory neuropathy occurred in all patients. Objective response rates were 61% in the 18 patients studied and 64% at level 1. The median time to progression was 171 days, and the median overall survival time was 603 days in the 18 patients studied. CONCLUSIONS: Oxaliplatin (85 mg/m2) with weekly bolus 5-FU (400 mg/m2) and high-dose l-LV (250 mg/m2) is recommended for further phase III studies in patients with metastatic colorectal cancer.

Adult↗

PubMed2006

Genetic variation and haplotype structure of the ABC transporter gene ABCG2 in a Japanese population.

The ATP-binding cassette transporter, ABCG2, which is expressed at high levels in the intestine and liver, functions as an efflux transporter for many drugs, including clinically used anticancer agents such as topotecan and the active metabolite of irinotecan (SN-38). In this study, to elucidate the linkage disequilibrium (LD) profiles and haplotype structures of ABCG2, we have comprehensively searched for genetic variations in the putative promoter region, all the exons, and their flanking introns of ABCG2 from 177 Japanese cancer patients treated with irinotecan. Forty-three genetic variations, including 11 novel ones, were found: 5 in the 5'-flanking region, 13 in the coding exons, and 25 in the introns. In addition to 9 previously reported nonsynonymous single nucleotide polymorphisms (SNPs), 2 novel nonsynonymous SNPs, 38C>T (Ser13Leu) and 1060G>A (Gly354Arg), were found with minor allele frequencies of 0.3%. Based on the LD profiles between the SNPs and the estimated past recombination events, the region analyzed was divided into three blocks (Block -1, 1, and 2), each of which spans at least 0.2 kb, 46 kb, and 13 kb and contains 2, 24, and 17 variations, respectively. The two, eight, and five common haplotypes detected in 10 or more patients accounted for most (>90%) of the haplotypes inferred in Block -1, Block 1, and Block 2, respectively. The SNP and haplotype distributions in Japanese were different from those reported previously in Caucasians. This study provides fundamental information for the pharmacogenetic studies investigating the relationship between the genetic variations in ABCG2 and pharmacokinetic/pharmacodynamic parameters.

ATP Binding Cassette Transporter, Subfamily G, Mem↗

PubMed2006

Fourteen novel genetic variations and haplotype structures of the TYMS gene encoding human thymidylate synthase (TS).

Forty genetic variations including 14 novel ones were found in the human TYMS gene, which encodes thymidylate synthase, in 263 Japanese cancer patients who received 5-fluorouracil (FU)-based chemotherapy. Three novel variations were located within the 28-bp tandem repeat sequence in the 5'-untranslated region (UTR) and were designated 5Rc, 3Rc-ins and 4Rc. Allele frequencies were 0.021 for 5Rc, 0.006 for 3Rc-ins and 0.002 for 4Rc. Other novel variations included -133G>C and -125G>C in the 5'-UTR; IVS1-278G>A, IVS2-68C>T, IVS2-23T>C, IVS4+122_+123insATTG, IVS4-141G>A, IVS5-100A>T and IVS6-111G>A in the introns; and 1244(*302)A>G and 1264(*322)G>A in the 3'-UTR. The allele frequencies were 0.34 for IVS4+122_+123insATTG, 0.042 for -133G>C, 0.011 for IVS4-141G>A, 0.006 for -125G>C, 0.004 for IVS1-278G>A, IVS2-68C>T, 1244(*302)A>G and 1264(*322)G>A, and 0.002 for IVS2-23T>C, IVS5-100A>T and IVS6-111G>A. Using the detected polymorphisms, linkage disequilibrium (LD) analysis was performed, which divided the TYMS gene into three LD blocks. The 28-bp tandem repeat sequence in the 5'-UTR was assigned as Block 2 with a total of 7 alleles. In Blocks 1 and 3, 7 and 19 haplotypes were determined/inferred, respectively. Our findings provide fundamental and useful information for genotyping TYMS in the Japanese and probably other Asian populations.

3' Untranslated Regions↗

PubMed2005

Functional analysis of six human aryl hydrocarbon receptor variants in a Japanese population.

Aryl hydrocarbon receptor (AhR) is an important transcriptional regulator involved in the induction of CYP1A1, CYP1A2, CYP1B1, UGT1A1, and UGT1A6. In this study, functional properties of four novel naturally occurring human AhR variants (K401R, N487D, I514T, and K17T/R554K) were examined along with the single variants K17T and R554K. The luciferase reporter assay using the CYP1A1 promoter reporter in HeLa cells treated with beta-naphthoflavone or 3-methylcholanthrene, which are known as typical agonists for AhR, showed that reporter activities of the K401R and N487D variants were reduced to 40 to 58% of those of wild-type (WT) but not of the other variants. Similarly, the K401R and N487D variants also reduced the omeprazole-induced reporter activities to approximately 56 and 74% of those of the WT, respectively. The reduced activities of the two variants were probably caused by the reduced protein expression levels, since the protein levels of the K401R and N487D variants were approximately 52 and 47% of the WT, respectively, without any changes in their mRNA levels. The reduced protein levels were recovered by treatment with a proteasome inhibitor MG132 [N-benzoyloxycarbonyl (Z)-Leu-Leu-leucinal], suggesting that the reduced protein levels were caused by the accelerated proteasomal degradation by a proteasome. Together, the current data demonstrate that the K401R and N487D variants reduce their apparent transcriptional activities, both ligand-induced and omeprazole-induced activation, probably through reduced protein expression. Thus, these two variants may influence drug metabolism through reduced induction of CYP1A1 and other target enzymes.

Genes, Reporter↗

PubMed2005

High susceptibility of human c-Ha-ras proto-oncogene transgenic rats to carcinogenesis: a cancer-prone animal model.

Transgenic animals carrying human c-Ha-ras proto-oncogene, v-Ha-ras transgenic mice, pim-1 transgenic mice and several knockout mice deficient of tumor suppressor genes, such as p53, have been shown to exhibit increased carcinogen susceptibility. As a result, studies into practical application and medium-term screening of environmental carcinogens are under way. Given the advantages of rat models characterized by larger organ size, abundant information regarding preneoplasias and virus-free constitution, we have concentrated on the generation of transgenic rats bearing copies of the human c-Ha-ras proto-oncogene and shown the Hras128 strain to be extremely sensitive to the induction of mammary carcinomas, and to a lesser extent, lesions in the urinary bladder, esophagus and skin. In most, if not all, the mammary cancers mutations of the transgene but not the endogenous H-ras gene are present, appearing to occur early in the process of tumorigenesis, which involves proliferation of cells in TEB and intraductal hyperplasia before carcinomas arise. Preliminary findings suggest that this is independent of endogenous ovarian hormones, although inhibited by soy isoflavones and promoted by atrazine and nonylphenols. Although further studies of the mechanisms are clearly necessary, the model appears to have great potential for screening purposes, not only for modifiers active in the breast, but also other organs where tumors characterized by ras gene mutations develop.

Animals↗

PubMed2004

Retrospective analysis of clinical results and predictors of response in chemo-naive patients with advanced gastric cancer treated with S-1, an oral fluoropyrimidine derivative, as single-agent chemotherapy.

BACKGROUND: Despite the fact that there are only a few reports of phase II studies, S-1 is widely used in single-agent or combination therapies for patients with advanced gastric cancer in Japan. We retrospectively analyzed the effectiveness of S-1 as single-agent chemotherapy for patients with advanced gastric cancer. METHODS: A total of 119 patients with advanced or recurrent gastric cancer were treated with S-1 as first-line monochemotherapy from September 1999 to March 2003 at the National Cancer Center Hospital. S-1 was administered orally twice daily, at a standard dose of 80 mg/m2 per day for 28 days, followed by a 14-day rest. RESULTS: One hundred and eleven patients were analyzed retrospectively. The overall response rate was 26.1% (29/111; 95% confidence interval [CI], 17.8% to 34.1%). Median time to progression and median overall survival were 141 days (95% CI, 108 to 175 days) and 378 days (95% CI, 310 to 447 days), respectively. The response rate of ascites, according to the Japanese classification of gastric carcinoma, was 36.8% (14/38; 95% CI, 25.4% to 56.6%). Among all of the pretreatment variables examined, hemoglobin level and the presence of lymph node metastasis were related to the response. CONCLUSION: Single-agent chemotherapy of S-1 for chemo-naive patients with advanced gastric cancer was modestly effective and well-tolerated in the outpatient setting.

Administration, Oral↗

PubMed2004

Phase I/II study of irinotecan, 5-fluorouracil, and l-leucovorin combination therapy (modified Saltz regimen) in patients with metastatic colorectal cancer.

BACKGROUND: A combination of irinotecan 125 mg/m2, 5-fluorouracil (5-FU) 500 mg/m2, and leucovorin (LV) 20 mg/m2 (Saltz regimen; treatment on days 1, 8, 15, and 22 every 6 weeks) is widely used for the treatment of metastatic colorectal cancer. A modified schedule with chemotherapy on days 1 and 8 of a 21-day cycle was recommended in 2001 because of early treatment-related mortality. We conducted a phase I/II study of this modified Saltz regimen as first-line therapy in Japanese patients with metastatic colorectal cancer to assess the maximum tolerated dose (MTD) and the recommended dose of 5-FU when given with fixed doses of l-LV and irinotecan, and to evaluate the efficacy and the feasibility of this regimen. METHODS: Irinotecan, 5-FU, and l-LV were administered on days 1 and 8 of a 21-day cycle. Irinotecan 100 mg/m2 was given intravenously over the course of 90 min on day 1, followed by l-LV 10 mg/m2, and then 5-FU. The dose of 5-FU was escalated from 400 mg/m2 (level 1) to 500 mg/m2 (level 2). If neither level met the criteria for the MTD, the recommended dose was defined as level 2, and dose escalation was discontinued, because the maximum approved weekly dose of irinotecan alone in Japan is 100 mg/m2 and the dose of 5-FU in the original Saltz regimen was 500 mg/m2. RESULTS: One patient had grade 4 neutropenia with fever at level 1, and four patients had grade 3 neutropenia at level 2. There was no treatment-related death. Level 2 did not meet the criteria for the MTD. The relative dose intensities of the first five cycles were 91% for both 5-FU and irinotecan at level 1 and 86% for 5-FU and 93% for irinotecan at level 2. The response rates were 58% for all patients, and 69% for patients at level 2. CONCLUSION. Our results confirm that the modified Saltz regimen is safe and efficacious for Japanese patients. The recommended doses for phase II studies are irinotecan 100 mg/m2, 5-FU 500 mg/m2, and l-LV 10 mg/m2.

Adenocarcinoma↗

PubMed2004

Prognostic significance of thymidylate synthase in patients with metastatic colorectal cancer who receive protracted venous infusions of 5-fluorouracil.

BACKGROUND: This study was conducted to evaluate the prognostic significance of thymidylate synthase (TS) expression in the tumor tissue of patients with metastatic colorectal cancer (CRC) who received protracted venous infusions of 5-fluorouracil (5-FU). METHODS: We retrospectively analyzed the prognostic value of TS expression as compared with other clinical prognostic factors in 57 patients with metastatic CRC. RESULTS: On univariate analysis, survival was significantly related to TS expression (low vs high; P = 0.0015), alkaline phosphatase (ALP) level (<300 vs > or =300 IU/l; P = 0.0037), performance status (0 or 1 vs 2 or 3; P = 0.0073), and white blood cell count (<10,000/mm3 vs > or =10,000/mm3; P = 0.0001), with number of metastatic sites (1 vs > or =2; P = 0.06) approaching significance. On multivariate analysis, survival was significantly related to TS expression (hazard ratio [HR], 2.97) and ALP level (HR, 2.26). CONCLUSION: In patients with metastatic CRC who received protracted venous infusions of 5-FU, TS expression was related to survival independently of other established clinical prognostic factors.

Aged↗

PubMed2004

Terminal endbuds and acini as the respective major targets for chemical and sporadic carcinogenesis in the mammary glands of human c-Ha-ras protooncogene transgenic rats.

A rat strain carrying the human c-Ha-ras protooncogene, established by our laboratory, is highly susceptible to mammary chemical carcinogens. The transgenic rats exhibit increased number of terminal endbuds (TEBs) at the tips of developing ducts in the mammary gland compared to non-transgenic littermates. Confocal microscopy revealed the level of active mitogen-activated protein kinase to be elevated in these TEBs, and a close correlation between their numbers and tumorigenic response initiated by 7,12-dimethylbenz[a]anthracene was confirmed. Single injections of N-methyl-N-nitrosourea into the transgenic rats caused mutations in codon 12 of human c-Ha-ras transgene in TEBs before tumor development, supporting the conclusion that these structures are the major targets of chemical carcinogens. In contrast, with spontaneous development of lesions, alveolar hyperplasia with elevated expression levels of rat and human c-Ha-ras protooncogenes is the first morphological alteration which becomes apparent. Some but not all hyperplastic alveolar nodules were found to harbor mutations in the transgene. The results indicate that elevated expression of c-Ha-ras protooncogene is sufficient in itself to cause a highly proliferative phenotype of mammary alveoli. Our data suggest that TEBs and acini are the major targets for chemical and sporadic carcinogenesis, respectively, in the mammary glands of human c-Ha-ras protooncogene transgenic rats.

9,10-Dimethyl-1,2-benzanthracene↗

PubMed2004

Rapid induction of skin and mammary tumors in human c-Ha-ras proto-oncogene transgenic rats by treatment with 7,12-dimethylbenz[a]anthracene followed by 12-O-tetradecanoylphorbol 13-acetate.

We have established a transgenic rat line carrying 3 copies of the human c-Ha-ras proto-oncogene with its own promoter region (Jcl/SD-TgN(HrasGen)128Ncc) (Hras128 rat), expression being detectable in almost all organs. We have already demonstrated that the rat is highly sensitive to mammary, esophagus and bladder carcinogenesis. In the present study, male and female transgenic and wild-type littermates were topically treated with 2.5 mg of 7,12-dimethylbenz[a]anthracene (DMBA) dissolved in 1.0 ml of acetone on the back skin at 50 days after birth. Starting 1 week thereafter, they were again topically treated with 100 nmol of 12-O-tetradecanoylphorbol 13-acetate (TPA) dissolved in 0.5 ml of acetone 3 times weekly for the following 31 weeks. In males treated with DMBA and/or TPA, skin tumors, including both squamous cell papillomas (SCP) and carcinomas (SCC), were preferentially induced at the DMBA-TPA painting sites: DMBA-TPA, 15/15 (100%); DMBA, 6/8 (75%); TPA, 1/6 (16.7%). They were also, unexpectedly, induced on remote scrotal skin: DMBA-TPA, 13/15 (86.7%); DMBA, 5/8 (62.5%); TPA, 0/6 (0%). Lesions were thus more frequent in the DMBA-TPA group than with DMBA or TPA alone. In females, adenomas and adenocarcinomas of the mammary glands were preferentially induced: DMBA-TPA, 12/14 (85.7%); DMBA, 6/8 (75%); TPA, 3/6 (50%), with only a few small skin papillomas at painting sites. Incidences and numbers of the mammary and skin tumors were much greater in Hras128 rats than in their wild-type counterparts. PCR-RFLP analysis of the transgene indicated that the percentage of the cell populations harboring a mutation in codons 12 and/or 61 ranged from 2% to 60% in individual tumors; skin tumors showed more mutations in codon 61 in the DMBA-treated groups. In contrast, no mutations were detected in the endogenous rat c-Ha-ras gene. These results indicate that the Hras128 rat is highly susceptible to DMBA-TPA skin and mammary carcinogenesis, thus providing a unique painting model for skin as well as mammary gland carcinogenesis, that would be suitable for investigating the role of transgene mutations.

Animals↗

PubMed2004

Antitumor effect of MCC-465, pegylated liposomal doxorubicin tagged with newly developed monoclonal antibody GAH, in colorectal cancer xenografts.

MCC-465 is an immunoliposome-encapsulated doxorubicin. The liposome is tagged with polyethylene glycol and the F(ab')2 of a monoclonal antibody named GAH, a human antibody obtained by the hybridoma technique. The epitope recognized by GAH is not well characterized, but human gastric, colorectal, and mammary cancer cells were GAH-positive, while the normal counterparts were GAH-negative. Pegylated liposome doxorubicin (PLD) and MCC-465 did not show significant antitumor activity against GAH-negative Caco-2 xenografts. On the other hand, MCC-465 exhibited significantly superior antitumor effects against GAH-positive WiDr-Tc and SW837 xenografts, compared with PLD. Immunohistochemistry with GAH revealed that 94% (100 of 106) of surgical specimens of colorectal cancer were GAH-positive. These results warrant a phase I clinical trial of MCC-465 for patients with metastatic colorectal cancer.

Animals↗

PubMed2003

Randomized study of dexamethasone treatment for delayed emesis, anorexia and fatigue induced by irinotecan.

The prevention of post-chemotherapy symptoms such as delayed emesis, anorexia, and fatigue induced by irinotecan has not been studied. We compared the effects of dexamethasone (Dex) with those of a placebo on these symptoms in a randomized study. Seventy patients scheduled to receive irinotecan chemotherapy were enrolled in the study and randomly divided into a treatment or a placebo group. In the treatment group, 8 mg of Dex were administered on days 2-4 after the start of chemotherapy. All patients in both groups received Dex and granisetron for prophylaxis against acute emesis on day 1. We evaluated 68 patients (35 receiving Dex, 33 receiving the placebo). Although delayed emesis was completely prevented in most of patients in both groups (Dex, 82.9%; placebo, 78.8%), anorexia and fatigue were more completely prevented in those in the Dex group (Dex, 62.9% and 77.1%, placebo, 39.4% and 57.6%, respectively). The effect of Dex on improving simultaneous prophylaxis against all three symptoms was almost significant (Dex, 60.0%; placebo, 36.4%; P=0.058). The safety profiles of the two groups were not discernibly different. These results suggest that treatment with Dex may be beneficial to reduce post-chemotherapy symptoms induced by irinotecan, specifically anorexia and fatigue, with acceptable toxicities.

Adult↗

PubMed2003

Phase I study of irinotecan and S-1 combination therapy in patients with metastatic gastric cancer.

BACKGROUND: Irinotecan plus intravenous 5-fluorouracil with leucovorin is effective against gastrointestinal cancer. S-1 is an oral fluoropyrimidine derivative combining tegafur with the modulators 5-chloro-2,4-dihydroxypyrimidine (a potent dihydropyrimidine dehydrogenase inhibitor), and potassium oxonate (an orotate phosphoribosyl transferase inhibitor), in a molar ratio of 1 : 0.4 : 1. S-1 has a high response rate, of about 40%, in advanced gastric cancer. A phase I study was conducted to assess the maximum tolerated dose and the recommended dose of the combination of irinotecan and S-1. METHODS: Irinotecan was given intravenously over the course of 90 min on day 1 and S-1 was given orally from days 1 to 14 of a 21-day cycle. The dose of S-1 was 80 mg/m2 per day, given in two divided doses. The dose of irinotecan was escalated in a stepwise fashion from 100 mg/m2 (level 1; n = 3), to 125 mg/m2 (level 2; n = 3), and 150 mg/m2 (level 3; n = 6). RESULTS: Dose-limiting toxicity did not occur during cycle 1, and the recommended dose for phase II studies was determined to be level 3, which was associated with grade 3 diarrhea in one patient, and with refusal to continue treatment because of prolonged fatigue in two patients. Grade 3 neutropenia developed in one of three patients at level 1 and level 2, and in two of six during cycle 1 of level 3. The recommended dose was determined to be 150 mg/m2 of irinotecan on day 1 and 80 mg/m2 per day of S-1 on days 1 to 14 of a 21-day cycle. Five of seven patients with measurable lesions had a partial response. CONCLUSIONS: A combination of irinotecan and S-1 can be recommended for further phase II studies in patients with gastric cancer.

Administration, Oral↗

PubMed2002

Neuronal leucine-rich repeat protein-3 amplifies MAPK activation by epidermal growth factor through a carboxyl-terminal region containing endocytosis motifs.

Neuronal leucine-rich repeat protein-3 (NLRR-3) belongs to the LRR superfamily. Expression of rat NLRR-3 gene isolated from c-Ha-ras transgenic rat tumor is regulated mainly through the Ras-MAPK signaling pathway. NLRR-3 was found to enhance phosphorylation of MAPK when COS-7 cells were transfected with NLRR-3 and stimulated with a low concentration (0.01 ng/ml) of epidermal growth factor (EGF), but the amplification of MAPK phosphorylation by NLRR-3 was no longer observed when the carboxyl-terminal 30 amino acid stretch containing clathrin-mediated endocytosis motifs was deleted. A green fluorescent protein-tagged NLRR-3 localized at the plasma membrane was efficiently internalized in COS-7 cells, but internalization of a carboxyl-terminal-deleted version (NLRRDeltaC) was less efficient. The presence of clathrin-adaptor protein complexes containing NLRR-3 in brain lysate was confirmed by immunoprecipitation and glutathione S-transferase pull-down experiments, and affinity column chromatography revealed that the carboxyl-terminal region of NLRR-3 interacts with beta-adaptin. We propose that NLRR-3 potentiates Ras-MAPK signaling by facilitating internalization of EGF in clathrin-coated vesicles.

3T3 Cells↗

PubMed2002

Effect of a 3-hour interval between methotrexate and 5-fluorouracil in the treatment of metastatic colorectal cancer.

OBJECTIVE: This phase II study was designed to evaluate the efficacy and toxicity of 3-h interval sequential methotrexate (MTX) and 5-fluorouracil (5-FU) with leucovorin (LV) rescue in the treatment of patients with metastatic colorectal cancer. METHODS: Forty-two patients with histologically confirmed metastatic colorectal cancer and at least one two-dimensionally measurable lesion, aged 30-74 years old, with performance status < or =2 and no or one prior chemotherapy were selected. Patients received sequential MTX 100 mg/m2 by bolus injection and 5-FU 600 mg/m2 at 3 h followed by LV rescue initiated after 24 h (15 mg per body every 6 h for six doses). The treatment was repeated every week or every 2 weeks until disease progression. All patients were treated as out-patients unless complications arose. RESULTS: All 42 patients entered in this study were assessable both for response and toxicity. Fifteen patients achieved objective responses (one complete and 14 partial), for an overall response rate of 36% (95% CI: 11-51%). Response rates in pretreated patients and patients with naive chemotherapy were 27 and 42%, respectively. Sixteen patients had stable disease and 11 progressed with therapy. The median survival for all patients was 378 days. The hematological toxicity was mild with no grade 3/4 leukopenia. The major non-hematological toxicity was diarrhea (one grade 4, four grade 3). CONCLUSIONS: This 3-h interval sequential MTX and 5-FU with LV rescue is an active regimen in patients with metastatic colorectal cancer. The treatment showed mild toxicity and was administered on an out-patient basis. The present findings suggest that this regimen warrants further investigation in patients with metastatic colorectal cancer.

Adult↗

PubMed2002

Prognostic factors for patients with metastatic colorectal cancer receiving protracted venous infusion of 5-FU.

The objective of this study was to investigate the possible prognostic factors in patients with metastatic colorectal cancer (CRC) treated with protracted venous infusion (PVI) of 5-fluorouracil (5-FU). PVI of 5-FU is considered to be one of the standard therapies for patients with CRC because of its high efficacy and low toxicity, but possible prognostic factors in patients with CRC treated with PVI of 5-FU have not been reported until now. One hundred two consecutive patients with metastatic CRC, treated with PVI of 250 mg/m(2) /d of 5-FU at the National Cancer Center Hospital between January 1991 and December 1998, were investigated retrospectively. The data were evaluated for possible correlations with clinicopathologic indices or prognosis. In this study, grade III nausea, stomatitis, diarrhea, and hand-foot syndrome occurred in only 3%, 5%, 5%, and 6% of cases, respectively. No grade III or more hematologic toxicities were observed. The overall response (complete response + partial response) rate for all 102 cases was 26%, with a 95% CI of 18% to 35%. Overall median survival time for the 102 cases was 303 days. In multivariate analysis, the favorable prognostic factors were normal albumin level (<or=3.7 g/dl), histologic grades I, II, and low carcinoembryonic antigen level (<100 ng/ml).

Aged↗