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Tetsuya Toge

Publications and source records attributed to Tetsuya Toge.

At least 55 records · Page 3Linked to original sources
PubMed2004

Bax is an important determinant for radiation sensitivity in esophageal carcinoma cells.

Apoptosis is a crucial phenomenon for radiation-induced cell death. Since Bax plays a critical role in inducing apoptosis via p53-dependent and -independent pathways, we analyzed a role of Bax in radiation sensitivity in esophageal carcinoma cells. Using eight human esophageal carcinoma cell lines, irradiation was performed with cobalt-60 (60Co) gamma-rays. Radiation sensitivity was determined by induction of apoptosis, which was assessed by morphological change in nuclear condensation of chromatin, DNA ladder formation and apoptosis-related genes after irradiation. The survival curve was evaluated by clonogenic assay using a parameter D0 after irradiation, compared to that of the control. After transfection of the bax gene into low radiation sensitivity, TE-1 cells were conducted by lipofection method using pSFFV-Neo vector carrying bax cDNA. Radiation sensitivity of esophageal carcinoma cells was associated with induction of apoptosis, in a time- and dose-dependent manner. Induction of apoptosis affects early responsiveness to irradiation rather than the parameter D0. Radiation-induced apoptosis was associated with an increase in expression of bax gene, regardless of p53 genetic status. The introduction of the bax gene into a low radiation sensitivity cell line, TE-1, enhanced radiation sensitivity in association with increased apoptotic cell death after irradiation. Radiation sensitivity of esophageal carcinoma cells can be evaluated by induction of apoptosis, as an early predictive marker for radiation response. The proapoptotic gene bax plays a critical role in the determination of tumor response in radiation therapy.

Apoptosis↗
PubMed2004

[A randomized phase II clinical trial of tailored CPT-11 + TS-1 vs TS-1 in patients with advanced or recurrent gastric carcinoma as the first-line chemotherapy (JFMC31-0301)].

The Japanese Foundation for Multidisciplinary Treatment of Cancer (JFMC) has designed and initiated a randomized Phase II clinical trial planned as a first-line of chemotherapy for advanced or recurrent gastric cancer. The trial focuses on two groups and selecting the better of two regimens. The first group was given tailored CPT-11, adjusting individual optimal dosage using toxicity-based grading as an index in combination with TS-1, and the second group was given standard TS-1 treatment. The aim of this tailored dosage regimen for each individual patient is to continue chemotherapy as long as possible, and eventually, to prolong survival. In this trial, subsidiary pharmacokinetics analysis for the tailored arm is also proposed. We would like to introduce the significance and theory of tailored dosage chemotherapy in this paper.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2004

[Combination chemotherapy of TS-1 and docetaxel on advanced and recurrent gastric cancer].

In the present article, we have summarized the clinical trials on docetaxel and the phase I study of docetaxel and combination therapy. Patients with a performance status (PS) of 0 to 2 received docetaxel at the starting dose of 40 mg/m2 by iv infusion over 1 hour on day 1 and TS-1 at the full dose of 80 mg/m2 daily for two weeks every three weeks. Nine patients were treated with increasing dose levels of docetaxel as follows: (docetaxel/TS-1, mg/m2): 40/80 (level 1), 50/80 (level 2) and 60/80 (level 3), and all the cases were found to be assessable for drug safety, while 7 were assessable for response. The MTD was reached at the 50/80 mg/m2 dose level in three patients out of six, who experienced a dose limiting toxicity (DLT). On the other hand, partial response was achieved in 5 (71.4%) of the 7 patients with evaluable lesions. The drug combination showed a good safety profile, and the responses observed in the study suggest that the drug combination shows a high degree of efficacy in patients with advanced and or recurrent gastric cancer.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2003

Randomized controlled trial comparing oral doxifluridine plus oral cyclophosphamide with doxifluridine alone in women with node-positive breast cancer after primary surgery.

PURPOSE: We compared the therapeutic usefulness of doxifluridine (5'-DFUR) alone and a combination of 5'-DFUR plus cyclophosphamide (CPM), both of which are considered effective against advanced and recurrent breast cancer, to determine which treatment is more beneficial as postoperative adjuvant chemotherapy. PATIENTS AND METHODS: A total of 1,131 women with node-positive primary breast cancer were randomly assigned after primary surgery to receive 5'-DFUR alone or 5'-DFUR plus CPM. All patients initially received 5'-DFUR in an oral dose of 1,200 mg/d for 4 weeks, starting 4 weeks after surgery. Chemotherapy was then not given for 2 weeks. Patients in the 5'-DFUR group subsequently received five 4-week cycles of treatment consisting of oral 5'-DFUR (1,200 mg/d) for the first 2 weeks and no chemotherapy for the next 2 weeks. Those assigned to the 5'-DFUR plus CPM group also received oral CPM 100 mg/d for the first 2 weeks and no chemotherapy for the next 2 weeks. Women 50 years or older concurrently received 20 mg/d of tamoxifen for 2 years in both groups. RESULTS: Of the 1,088 eligible women, 546 were assigned to receive 5'-DFUR alone and 542 were assigned to receive 5'-DFUR plus CPM. Overall disease-free survival was significantly better in women who received 5'-DFUR plus CPM than in those who received 5'-DFUR alone (log-rank test, P =.021). Toxic effects occurred in 20.0% of patients (109 of 546) in the 5'-DFUR group and 32.3% of patients (175 of 542) in the 5'-DFUR plus CPM group (chi(2) test, P <.001). CONCLUSION: Combination therapy with 5'-DFUR plus CPM is more effective in preventing recurrence than 5'-DFUR alone.

Administration, Oral↗
PubMed2003

Future prospects of personalized chemotherapy in gastric cancer patients: results of a prospective randomized pilot study.

In the present study, in order to evaluate the feasibility of personalized chemotherapy, a prospective randomized pilot study was performed in 30 advanced or recurrent gastric cancer patients. As we have demonstrated previously, the expressions of mRNA from tumor biopsy samples for seven molecular markers, i.e., dihydropyrimidine dehydrogenase (DPD), glutathione S-transferase (GST)-pi, beta-tubulin (tub), O6-methylguanine-DNA methyltransferase (MGMT), multiple drug-resistant protein (MRP)-1, NADPH/quinone oxidoreductase (NQO)-1, and cytochrome p450 (P450), were examined by reverse transcription-polymerase chain reaction (RT-PCR) analysis and therapy was recommended in a flow chart that depended on the level of expression of these predictive molecular markers. We chose 12 therapeutic plans, including best supportive care (BSC). We treated 15 patients according to the gene expression profiles, and the remaining 15 patients (controls) were treated without recommended regimens, and the therapy was continued after the expression profiles were checked. Interestingly, 11 of 26 lesions (42.3%) responded after treatment given according to gene expression analysis; however, no clinical response was detected in the control group. The prediction of the response, including resistance, was successful in 75.9% by the gene expression profiles. Moreover, the survival of the patients with the recommended treatment was better than that of patients without a recommended protocol. These results indicate that personalized treatment may be beneficial for gastric cancer chemotherapy and further randomized trials should be carried out in the future.

Adult↗
PubMed2003

Inducing cancer cell death by targeting transcription factors.

We review the biological significance of transcription factors such as p53, Myc, E2F family and AP-1 (Jun/Fos) in anticancer drug-induced apoptosis. It is likely that the functional role of these transcription factors is complex in response to DNA damage depending on cancer cell type. Regulation of apoptosis following DNA damage is mediated by cell cycle arrest for DNA repair and subsequent signal transduction pathways leading to apoptosis, which is associated with mitochondrial dysfunction. Activation of transcription factors following anticancer drugs is located upstream of signal transduction pathways, thereby the downstream pathway is promoted, which is connected to activation or suppression of apoptosis-related proteins. Switching on apoptotic signals by anticancer drugs is amplified in mitochondria by releasing cytochrome from the ion channel to activate the caspase cascade, which is regulated by Bcl-2 families in the central gate for drug-induced apoptosis. Activation of transcription factors targeting downstream genes, some of which are apoptosis-related genes, can play a critical role in promoting apoptosis following treatment with anticancer drugs. The strategy of identification of downstream target proteins or transcription factors involved in apoptosis will be necessary for the development of an effective transcription factor-targeted chemotherapy for cancer.

Animals↗
PubMed2003

Chemosensitivity testing for gastrointestinal cancer: survival benefit potential and limitations.

Chemosensitivity testing is considered by some to be a useful method for predicting drug sensitivity of tumor tissues after surgery for gastrointestinal cancer. Although survival benefit is not fully established, several chemosensitivity testing methods have been used clinically, both in the selection of adjuvant therapy and in the treatment of metastatic disease. Chemosensitivity testing is used not only for determination of drug resistance, but also for determination of drug sensitivity conferring a potential survival benefit. Previous retrospective correlation studies showed survival of patients treated with a 'tested' drug to be superior to that of patients treated with a standard drug, but the clinical benefit of chemosensitivity testing in comparison to surgical therapy alone or standard chemotherapy has not been documented in a randomized controlled trial. The clinical usefulness of individualized versus standard therapy needs to be determined. Here we discuss the potential survival benefit and current limitations of chemosensitivity testing in patients with gastrointestinal cancer.

Antineoplastic Agents↗
PubMed2003

DNA hypermethylation and histone hypoacetylation of the HLTF gene are associated with reduced expression in gastric carcinoma.

The SWI/SNF proteins are ATP-dependent chromatin remodeling enzymes that have been implicated in the regulation of gene expression. Recent studies have shown that members of the SWI/SNF superfamily can function as tumor suppressor genes. DNA methylation and transcriptional inactivation of the HLTF gene, which is a homologue to the SWI/SNF genes, have been observed in colon cancer. In the present study, we studied the DNA methylation status of the HLTF gene by methylation-specific PCR in 50 gastric carcinoma tissues, and seven gastric carcinoma cell lines and compared the methylation status with the levels of HLTF mRNA expression. DNA methylation of the HLTF gene was found in 25 (50%) of 50 gastric carcinomas, and levels of HLTF mRNA were associated with methylation status of HLTF (P = 0.027; Mann-Whitney U test). No correlations were found between HLTF mRNA levels and DNA methylation and T grade, N grade, tumor stage, or histological type. In corresponding non-neoplastic mucosae, DNA methylation of the HLTF gene was found in 1 (7%) of 15 samples. The methylated allele was not detected in any of 10 normal gastric mucosae from 10 healthy volunteers. Among seven gastric carcinoma cell lines, the KATO-III cell line showed loss of HLTF mRNA expression associated with DNA methylation. This loss was rectified by treatment with both Aza-2'-deoxycytidine, a demethylating agent, and trichostatin A, a histone deacetylase inhibitor. Chromatin immunoprecipitation assay revealed that the acetylation levels of histones H3 and H4 in the 5' CpG island of the HLTF gene were inversely associated with DNA methylation status. These results suggest that transcriptional inactivation of HLTF by aberrant DNA methylation and histone deacetylation may be involved in stomach carcinogenesis through down-regulation of HLTF expression.

Acetylation↗
PubMed2003

Adoptive immunotherapy of cancer using activated autologous lymphocytes--current status and new strategies.

After the discovery of interleukin-2 (IL-2), lymphokine-activated killer (LAK) cells, tumor-infiltrating lymphocytes (TILs), and cytotoxic T lymphocytes (CTLs) sensitized with the mixed lymphocyte-tumor culture (MLTC) system have been conducted in adoptive immunotherapy (AIT) trials during past 15 years. Although the overall response rate of tumor shrinkage was marginal (9%), locoregional administration of TILs for malignant effusions was effective (77%) for a decrease or disappearance of the effusions even in terminally-ill patients, resulting in an improvement of QOL. Recent advances for molecular understanding of antigen presentation and recognition have promoted us to enhance the efficacy of AIT by using cultured dendritic cells (DCs) for generating antigen-specific CTLs in vitro. The peptide-pulsed DC-activated killer (PDAK) cells showed tumor recognition against antigen-expressing cells, and were efficiently propagated with the IL2 plus immobilized anti-CD3 antibody (IL-2/CD3) culture system. Clinical trials using PDAK cells against patients with lung metastases are now progressed, in which peptides suitable for generating CTLs were chosen in individual patients using the method designated as host-oriented peptide evaluation (HPOE) approach. Moreover, DCs were introduced with tumor-derived RNA, which was amplified with the T7 promoter system, and then were used for stimulating lymphocytes. The tumor RNA-introduced DC-activated killer (TRiDAK) cells showed tumor-specific interferon-gamma spots even in a patient in whom we failed to generate PDAK cells using DCs and peptides, suggesting that the clinical trial of AIT using TRiDAK cells is warranted for the treatment of patients with metastatic cancer. Thus, more understanding of antigen-presentation and -recognition mechanisms and immune regulation systems may promote clinical applications of AIT to establish a novel modality of cancer treatment.

Antigen Presentation↗
PubMed2003

Effects of introduction of dThdPase cDNA on sensitivity to 5'-deoxy-5-fluorouridine and tumor angiogenesis.

Human thymidine phosphorylase (dThdPase) is an angiogenic factor identical to platelet-derived endothelial cell growth factor (PD-ECGF). Thymidine phosphorylase is also a converting enzyme of the prodrug 5'-deoxy-5-fluorouridine (5'-DFUR) to 5-fluorouracil (5-FU) in tumors. To assess the role of dThdPase in targeting chemotherapy, we examined the relationship between the expression of dThdPase and the sensitivity of 5'-DFUR in cancer cell lines, and also examined whether transfection of dThdPase cDNA enhanced the drug-sensitivity to 5'-DFUR with or without angiogenesis in breast cancer cells. Thirteen human cancer cell lines consisting of 4 breast cancer, 6 gastric cancer, and 3 colon cancer cell lines were used. Expression of dThdPase was assessed by reverse transcriptase-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). In vitro drug-sensitivity was assessed by MTT assay, and anti-tumor effect in vivo was assessed using nude mouse xenografts. Intratumoral microvessel density was evaluated by immunohistochemical staining to factor VIII related antigen. Transfection of dThdPase cDNA was performed using pcDNA3 expression vector encoding its cDNA by the lipofection method. An inverse relationship between the expression of dThdPase and the IC50 values of 5'-DFUR was observed (p=0.1278, rho=-0.440) in the 13 cancer cell lines. Transfection of dThdPase cDNA into MCF-7 breast cancer cells resulted in an approximately 2.6- and 10-fold increase of the expression of dThdPase mRNA and its enzyme activity, respectively, compared to the control vector alone. The sensitivity to 5'-DFUR in the transfected cells was increased approximately 20-fold compared to the parent cells and control vector alone, and the sensitivity to 5-FU was also somewhat increased. In contrast, the sensitivity to ADM, CDDP, and VP-16 was not different between the transfected and control cells. In nude mice xenografts of the transfected cells, treatment with 5'-DFUR had a significant anti-tumor effect compared to those of the untreated transfected cells and control vector alone treated with 5'-DFUR (p<0.01). Intratumoral microvessel density in the transfected cells was not significantly increased with or without treatment with 5'-DFUR compared to control vector alone. The high expression of dThdPase was correlated with an increase in the sensitivity to 5'-DFUR in gastrointestinal and breast cancer cell lines. The introduction of dThdPase cDNA in breast cancer cells enhanced the sensitivity to 5'-DFUR without an increase of tumor angiogenesis, and targeting chemotherapy of dThdPase may be a good tumor-specific and personalized therapy for improving the poor prognosis of cancer patients who show high expressions of dThdPase.

Breast Neoplasms↗
PubMed2003

Antisense Bcl-2 and HER-2 oligonucleotide treatment of breast cancer cells enhances their sensitivity to anticancer drugs.

Overexpression of the HER-2 correlates with drug-resistance and a poor prognosis in breast cancer, however the mechanism(s) of HER-2-mediated drug-resistance are unknown. We examined the effects of antisense Bcl-2 and HER-2 oligonucleotides (ODN) to assess the mechanism(s) through which down-regulation of Bcl-2 and HER-2 enhances drug-sensitivity. Using two human breast cancer cell lines, MDA-MB-231 and BT-474, the antitumor effects of a combination of antisense ODN and anticancer drugs, including mitomycin C (MMC), adriamycin (ADM), paclitaxel (TXL), and docetaxel (TXT) was evaluated. The expression of Bcl-2 protein was suppressed by treatment with antisense Bcl-2 ODN in a dose-dependent manner. An enhanced drug-sensitivity to MMC and TXL upon pretreatment with antisense Bcl-2 ODN was observed, with the IC50 values increasing 1.9- and 2.0-fold, respectively. Treatment of BT-474 cells with antisense HER-2 at 1.0 micro M suppressed HER-2 overexpression by 60.5%. Pretreatment with antisense HER-2 ODN increased the sensitivity of these cells to ADM and TXL 20.8- and 10.8-fold, respectively. In vivo experiments using a combination of antisense HER-2 and TXL showed the similar enhancement of antitumor effect of TXL as compared to that of antisense HER-2 or TXL alone (p=0.068). Enhancement of drug-sensitivity was associated with the induction of apoptosis. Of interest, treatment with antisense HER-2 ODN also suppressed the expression of Bcl-2 and pAkt. These results indicate that down-regulation of Bcl-2 and HER-2 increased drug-sensitivity by modulating drug-induced apoptotic pathways in breast cancer cells, and that antisense ODN therapy, targeting Bcl-2 and HER-2 may be a useful strategy to enhance drug-sensitivity.

Antibiotics, Antineoplastic↗
PubMed2003

Effect of Bcl-2 antisense oligonucleotide on drug-sensitivity in association with apoptosis in undifferentiated thyroid carcinoma.

Although attempts have been made to treat undifferentiated thyroid carcinoma using multidisciplinary therapeutic procedures including surgery, radiotherapy, and chemotherapy, the prognosis of undifferentiated thyroid carcinoma remains quite poor. New approaches to increase the sensitivity of patients to anticancer drugs and radiation will be needed to improve the survival rate for undifferentiated thyroid carcinoma. We examined the effect of Bcl-2 antisense oligonucleotide on drug-sensitivity in association with apoptosis in the 8305C undifferentiated thyroid carcinoma cell line. The drug sensitivity was evaluated by MTT assay for 48 h, while apoptosis was assessed according to the formation of internucleosomal DNA ladders. The Bcl-2 antisense was introduced into 8305C cells by using a 18-mer phosphorothioate oligonucleotide by lipopolyamine-mediated transfection twice for 12 h. The expression of apoptosis genes was assessed by Western blotting. The 8305C cells were sensitive to adriamycin (ADM), mitomycin (MMC), docetaxel (TXT), and paclitaxel (TXL), showing mean IC50 values of 0.72, 1.1, 1.3, and 4.1 microM, respectively. In contrast, the 8305C cells were resistant to cisplatin (CDDP) and 5-fluorouracil (5-FU), with mean IC50 values of 42.0 and 48.0 microM, respectively. Treatment with Bcl-2 antisense suppressed the protein level of Bcl-2 in 8305C cells in a dose-dependent manner up to 1.0 microM. Drug-sensitivity was increased by pretreatment with Bcl-2 antisense as assessed by the IC50 (x-fold): 0.48 (1.5-fold) in ADM; 0.42 (2.6-fold) in MMC, 0.56 (2.3-fold) in TXT, 1.5 (2.7-fold) in TXL, 8.6 (4.9-fold) in CDDP, and 25.0 (1.9-fold) in 5-FU, respectively. The increased drug-sensitivity was associated with the induction of apoptosis-related proteins, Fas, caspase 8, cytochrome c, caspase 3, and to subsequent apoptosis, as determined by the formation of internucleosomal DNA ladders and PARP in the treated cells. Susceptibility in apoptotic cell death following treatment with anticancer drugs was associated with induction of apoptosis-related genes in undifferentiated thyroid carcinoma cells, and induction of apoptosis was enhanced by pretreatment with Bcl-2 antisense oligonucleotide. These results imply a potential new strategy targeting an antiapoptotic protein, Bcl-2, by its antisense oligonucleotide for enhancement of chemotherapeutic efficacy in undifferentiated thyroid carcinomas.

Apoptosis↗
PubMed2003

[Generation of TRiDAK (tumor RNA-introduced dendritic cell-activated killer) cells].

Tumor-reactive effector lymphocytes were generated using tumor-derived amplified RNA and cultured dendritic cells (DC). Tumor RNAs were extracted from gastric cancer cell line MKN45 or cancer cells of malignant effusions, and were processed with T7 amplification. DCs were induced from an adherent cell population of peripheral blood mononuclear cells (PBMCs) with GM-CSF and IL-4. Tumor-RNA was introduced into DCs using electroporation. Effector cells were generated by stimulating a non-adherent fraction of PBMCs with tumor RNA-introduced DCs. It was observed that milligram RNA could efficiently be amplified from microgram RNA. The effector cells, designated as tumor-RNA-introduced DC-activated killer (TRiDAK) cells, showed IFN-gamma spots in a tumor-specific manner when examined using ELISPOT analysis, and demonstrated cytotoxic activities against tumor cells from which RNA was extracted. TRiDAK cells produced more tumor-specific IFN-gamma spots when stimulated repeatedly. These results suggest that TRiDAK cells are practical and may be effective lymphocytes for adoptive cancer immunotherapy.

Cell Line, Tumor↗
PubMed2003

[Tumor RNA introduction into dendritic cells and Epstein-Barr virus transformed B cells].

In induction of autologous tumor-reactive antigen (TRA) specific cytotoxic T lymphocytes (CTLs) using antigenic peptides and cultured dendritic cells (DCs), identification of the adequate tumor antigens and HLA typing of individuals are required. These restrictions have promoted the use of tumor cells themselves, including tumor cell lysates and tumor cell-DC fusion cells. However, it is very difficult to obtain enough tumor cells for treatment in the clinical setting. We have studied the use of RNA derived from tiny tumor cells. RNA was reverse-transcribed into cDNA, after which T7-amplification and in vitro transcription were carried out. The amplified RNA was successfully electroporated into DCs, and polyclonal polyspecific CTLs could be generated. EBV transformed B cells were also good candidates to be electroporated with the RNA. This suggests that tumor RNA amplification followed by introduction into DCs or EBV transformed B cells is a feasible and practical method to prepare potent APCs.

Antigens, Neoplasm↗
PubMed2003

[A new tracer for sentinel node detection in esophageal and lung cancer--fluorescent microspheres].

Tracers commonly used for sentinel node detection are blue dye and radioisotope (RI)-labeled colloids. In esophageal cancer or lung cancer, it is impossible to detect the sentinel node among anthracotic mediastinal nodes with blue dye. RI-labeled colloids must be treated in a special facility under complicated regulations. To overcome these problems, we used fluorescent microspheres as a tracer in animals and detected fluorescence-positive nodes using the ultraviolet light irradiation method. Systemic and local injection of fluorescent microspheres revealed no side effects in rats. Submucosal and subadventitial injection of fluorescent microspheres to the esophagus of pigs stained the lymphatic pathway and sentinel nodes under ultraviolet light irradiation. This sentinel node detection system is considered to be useful for sentinel node detection especially for mediastinal nodes that show anthracotic pigmentation. It should be noted that this non-RI method is acceptable at any general medical facility.

Animals↗
PubMed2003

[Weekly docetaxel therapy is useful for gastric carcinoma as a second-line chemotherapy].

In the present study, we demonstrate the results of weekly administered docetaxel treatments as a second-line chemotherapy after TS-1 treatment in 4 gastric cancer patients. Twenty-five mg/m2 of docetaxel was administered once a week for 3 weeks followed by a 1-week rest period as one cycle. The treatment was continued for 2 to 16 weeks. In case 1, a 60% reduction of the primary tumor was observed for 20 weeks. In cases 2 and 3, the decrease of tumor marker was observed. In one case, progression of the tumor was observed and the treatment was not performed. As for adverse effects, no hematological toxicity was observed; however, in one case, grade 2 hair loss, pleural effusion and grade 2 nail changes were observed. These results indicate that the weekly docetaxel therapy is useful for gastric carcinoma patients, as it reduces the hematologic toxicities and improves the quality of life of the patients in the outpatient setting.

Aged↗