Biomedical subjects

H Majima

Publications and source records attributed to H Majima.

At least 19 recordsLinked to original sources

PubMed2001

Overexpression of manganese superoxide dismutase suppresses tumor formation by modulation of activator protein-1 signaling in a multistage skin carcinogenesis model.

Manganese superoxide dismutase (MnSOD) is a nuclear encoded primary antioxidant enzyme localized in mitochondria. Because expression of MnSOD plays a major role in maintaining cellular redox status and reactive oxygen species are known to play a role in signal transduction and carcinogenesis, we investigated the role of MnSOD in the development of cancer using a two-stage [7,12-dimethylbenz(a)-anthracene plus 12-O-tetradecanoylphorbol-13-acetate (TPA)] skin carcinogenesis model. Female transgenic mice expressing the human MnSOD gene in the skin and their nontransgenic counterparts were used in this study. Pathological examination demonstrated significant reduction of papilloma formation in transgenic mice. Quantitative analysis of 4-hydroxy-2-nonenal-modified proteins showed greater accumulation of oxidative damage products in nontransgenic compared with transgenic mice, and this oxidative damage was demonstrated to be present in both mitochondria and nucleus. TPA increased activator protein-1 (AP-1) binding activity within 6 h in nontransgenic mice, but increased AP-1 binding activity was delayed in the transgenic mice. Electrophoretic mobility shift assay, transcription of the target genes, and Western analysis studies indicated that the increased AP-1 binding activity was attributable to induction of the Jun but not the Fos protein families. Overexpression of MnSOD selectively inhibited the TPA-induced activation of protein kinase Cepsilon and prevented subsequent activation of c-Jun NH(2)-terminal kinase in response to TPA. Overall, these results indicate that MnSOD regulates both cellular redox status and selectively modulates PKCepsilon signaling, thereby delaying AP-1 activation and inhibiting tumor promotion, resulting in reduction of tumors in MnSOD transgenic mice.

9,10-Dimethyl-1,2-benzanthracene↗

PubMed2001

Relative biological effectiveness of the 235 MeV proton beams at the National Cancer Center Hospital East.

A therapy-dedicated cyclotron was installed in the National Cancer Center Hospital East (NCCHE) at Kashiwa in 1997. Prior to the start of clinical use, we investigated the biological effectiveness of therapeutic proton beams for cell lethality. The proton beams accelerated up to 235 MeV were horizontally extracted from the cyclotron, and scattered by a bar-ridge filter to produce a Spread-Out-Bragg-Peak (SOBP) of 10-cm width. The biological systems used here were mouse intestinal crypt cells and three in vitro cell lines, including SCC61 human squamous cell carcinoma, NB1RGB human fibroblasts and V79 Chinese hamster cells. The dose responses after irradiation at either the entrance plateau or the middle portion of SOBP were compared with those after linac 6 MV X-ray irradiation. The fit of a linear quadratic model to survival curves showed that proton irradiation increased the alpha value of SCC61 and the beta value of V79 cells with a least change for alpha/beta ratio of NB1RGB cells. The isoeffect dose that reduces either cell survivals to 10% or mouse jejunum crypts to 10 per circumference was termed D10. The relative biological effectiveness (RBE) of protons obtained by comparing the D10 values between protons and X-rays ranged from 0.9 to 1.2. The depth distribution of cell lethality was measured by replating V79 cells after irradiation from a "cell stack chamber" that received a single dose of 7 Gy at the middle position of SOBP. The thus-obtained cell survivals at various depths coincided well with the estimated survivals, but tended to decrease at the distal end of SOBP. We conclude that an RBE of 1.1 would be appropriate for 235 MeV proton beams at the NCCHE.

Animals↗

PubMed2000

X-rays vs. carbon-ion tumor therapy: cytogenetic damage in lymphocytes.

PURPOSE: To measure chromosomal aberrations in peripheral blood lymphocytes from cancer patients treated with X-rays or carbon ions (C-ions). METHODS AND MATERIALS: Blood samples from patients diagnosed for esophageal or uterine cervical cancer were obtained before, during, and at the end of the radiation treatment. The novel technique of interphase chromosome painting was used to detect aberrations in prematurely condensed chromosomes 2 and 4. The fraction of aberrant lymphocytes was measured as a function of the dose to the tumor volume. For comparison, blood samples were also exposed in vitro to X-rays or to carbon ions accelerated at the HIMAC. RESULTS: C-ions were more efficient than X-rays in the induction of chromosomal aberrations in vitro. In patients with similar pathologies, tumor positions, and radiation field sizes, however, C-ions induced a lower fraction of aberrant lymphocytes than X-rays during the treatment. The initial slope of the dose-response curve for the induction of chromosomal aberrations during the treatment was correlated to the relative decrease in the number of white blood cells and lymphocytes during the treatment. CONCLUSION: C-ions induce a lower level of cytogenetic damage in lymphocytes than X-rays, reducing the risk of bone marrow morbidity.

Aged↗

PubMed2000

Complex-type chromosomal exchanges in blood lymphocytes during radiation therapy correlate with acute toxicity.

The new method of chemical-induced premature chromosome condensation combined with fluorescence in situ hybridization was used to analyze chromosomal damage in peripheral blood mononuclear lymphocytes of patients undergoing radiation treatment for esophageal cancer with high-energy X-rays or accelerated carbon ions at the National Institute of Radiological Sciences (Chiba, Japan). Total number of aberrant cells correlated with radiation field size, but no correlation was found with acute toxicity. A high frequency of complex-type exchanges were also recorded. This aberration type presented a high individual variability, and correlated well with the acute morbidity. Cytogenetic analysis by interphase chromosome painting is proposed as a useful tool for monitoring normal tissue effects during radiotherapy.

Aged↗

PubMed2000

Induction by carbon-ion irradiation of the expression of vascular endothelial growth factor in lung carcinoma cells.

PURPOSE: To investigate the induction by carbon- ion irradiation of vascular endothelial growth factor (VEGF) mRNA and protein. MATERIALS AND METHODS: RERF-LC-AI lung squamous carcinoma cells were irradiated with carbon ions of either 13.3, 50 or 90keV/microm. Colony formation was used to determine cell survival. VEGF mRNA and protein of the irradiated cells were quantified by Northern blot analysis and ELISA assay, respectively. Genistein, Src tyrosine kinase inhibitor and H7, protein kinase C inhibitor, were used to inhibit VEGF mRNA expression. RESULTS: The relative biological effectiveness (RBE) of carbon ions (13.3, 50 and 90keV/microm) was 1.10, 1.97 and 2.30, respectively, in terms of D10 values. Single doses of 15 Gy with either X-rays or carbon ions significantly induced VEGF mRNA expression at 16-24h after irradiation with a maximum induction of 2.81-fold. A significant increase was also observed in VEGF protein levels, detected in culture supernatant 24h after irradiation with 50 and 90keV/microm carbon ions. Neither mRNA nor protein induction showed a dependence on LET. The induction of VEGF mRNA by carbon-ion irradiation was completely inhibited by pretreating cells with genistein and H7, indicating that Src tyrosine kinase and protein kinase C on cell surface membranes is involved in the induction. CONCLUSION: Irradiation of lung carcinoma cells with carbon ions induced VEGF mRNA expression and increased protein levels. The induction was dose-dependent. Radiation-induced DNA damage and/or its repair may not be a prerequisite for the induction of VEGF mRNA.

Carbon↗

PubMed1999

Mutations in the promoter reveal a cause for the reduced expression of the human manganese superoxide dismutase gene in cancer cells.

Manganese superoxide dismutase (MnSOD) has been shown to play an important role in preventing the development of cancer. MnSOD activity is reduced in many transformed cells and tumor tissues. We previously showed that the reduced level of MnSOD activity in cancer cells was not due to a defect in the primary structure of MnSOD protein, but rather was due to defects in gene expression. To elucidate the cause for the reduced expression of human MnSOD in cancer, we investigated the nucleotide sequence in the regulatory region of the MnSOD gene in a normal human cell line and various human tumor cell lines. A DNA fragment spanning 3.4 kb 5' flanking region of the MnSOD gene isolated from a normal human genomic DNA library was used to determine the DNA sequence of MnSOD promoter. PCR primers were used for amplification of the 3.4 kb 5' flanking region of the human MnSOD gene in cancer cells. Sequence analysis identified three heterozygous mutations in the proximal region of the promoter in five human tumor cell lines. These mutations, clustered around the GC-rich region of the human MnSOD promoter, change the binding pattern of AP-2 and lead to a reduction in transcription activity using a luciferase reporter assay system. These results suggest that the reduced level of MnSOD expression in some tumor cells is, at least in part, due to a defect in the DNA sequence of the promoter region.

Base Sequence↗

PubMed1999

Measurements of the equivalent whole-body dose during radiation therapy by cytogenetic methods.

Estimates of equivalent whole-body dose following partial body exposure can be performed using different biophysical models. Calculations should be compared with biodosimetry data, but measurements are complicated by mitotic selection induced in target cells after localized irradiation. In this paper we measured chromosomal aberrations in peripheral blood lymphocytes during radiotherapy, and estimated the equivalent whole-body dose absorbed, by using the novel technique of interphase chromosome painting. Premature chromosome condensation was induced in stimulated lymphocytes by incubation in calyculin A, and slides were hybridized in situ with whole-chromosome DNA probes specific for human chromosomes 2 and 4. Reciprocal exchanges were used to estimate the equivalent whole-body dose, based on individual pre-treatment in vitro calibration curves. Equivalent whole-body dose increased as a function of the number of fractions, and reached a plateau at high fraction numbers. Chromosomal aberration yields were dependent on field size, tumour position and concurrent chemotherapy. Results suggest that interphase chromosome painting is a simple technique able to give a reliable estimate of the equivalent whole-body dose absorbed during therapeutic partial-body irradiation.

Aged↗

PubMed1999

An intronic NF-kappaB element is essential for induction of the human manganese superoxide dismutase gene by tumor necrosis factor-alpha and interleukin-1beta.

Tumor necrosis factor-alpha (TNF) and interleukin-1beta (IL-1) are cytokines that induce expression of various genes through activation of the redox-sensitive transcription factor nuclear factor-kappaB (NF-kappaB). We have previously cloned the entire human MnSOD (SOD2) gene and found several NF-kappaB-binding sites in the 5' and 3' flanking and intronic regions. To test whether these putative NF-kappaB-binding sites are able to respond to TNF and IL-1, we performed induction analysis using various deletion constructs ligated to a luciferase reporter gene. We found that the 5' and 3' flanking regions containing several NF-kappaB-binding sites do not mediate MnSOD induction by TNF or IL-1. When a 342-bp intron 2 fragment containing NF-kappaB, C/EBP, and NF-1 binding sites was linked to the basal promoter of the SOD2 gene, transcriptional activities were significantly increased in response to TNF and IL-1 in an orientation- and position-independent manner. To accurately identify the element that is most critical for the enhancer activity, deletions and specific mutations of each individual site were studied. The results indicated that the NF-kappaB binding site is essential but not sufficient for TNF- or IL-1-mediated induction. Furthermore, NF-kappaB elements in the 5' and 3' flanking regions could be made to function in TNF or IL-1 induction when they were transposed to the intronic fragment. Taken together, these results suggest that an NF-kappaB element and its location in the SOD2 gene is critical for TNF/IL-1-mediated induction. However, a complex interaction between NF-kappaB and other transcription elements is needed for a high-level induction.

Base Sequence↗

PubMed1999

Association between G2-phase block and repair of radiation-induced chromosome fragments in human lymphocytes.

We have studied the induction of chromosomal aberrations in human lymphocytes exposed in G0 to X rays or carbon ions. Aberrations were analyzed in G0, G1, G2 or M phase. Analysis during the interphase was performed by chemically induced premature chromosome condensation, which allows scoring of aberrations in G1, G2 and M phase; fusion-induced premature chromosome condensation was used to analyze the damage in G0 cells after incubation for repair; M-phase cells were obtained by conventional Colcemid block. Aberrations were scored by Giemsa staining or fluorescence in situ hybridization (chromosomes 2 and 4). Similar yields of fragments were observed in G1 and G2 phase, but lower yields were scored in metaphase. The frequency of chromosomal exchanges was similar in G0 (after repair), G2 and M phase for cells exposed to X rays, while a lower frequency of exchanges was observed in M phase when lymphocytes were irradiated with high-LET carbon ions. The results suggest that radiation-induced G2-phase block is associated with unrejoined chromosome fragments induced by radiation exposure during G0.

Adult↗

PubMed1998

Evidence for mRNA expression of vascular endothelial growth factor by X-ray irradiation in a lung squamous carcinoma cell line.

Vascular endothelial growth factor (VEGF) is a multipotent cytokine which plays an important role in various angiogenic conditions as well as in some tumor behaviors. Here we examined the induction of VEGF mRNA by X-ray irradiation in a lung squamous cell carcinoma cell line (RERF-LC-AI). Irradiating the cells with 15 Gy X-rays significantly increased the mRNA expression up to 2.5-fold of control at a post-irradiation time of 16-24 h. The induction of VEGF mRNA by X-ray irradiation was completely blocked by treating cells with either genistein (Src tyrosine kinase inhibitor) or H7 (protein kinase C inhibitor). This suggests that the mechanism of induction might be concerned with the pathway which triggers Src tyrosine kinase of the cell surface and the protein kinase C pathway.

Antineoplastic Agents↗

PubMed1997

[TUT-7 phase I clinical study. TUT-7 Study Group].

A phase I study with TUT-7, a new anthracycline antitumor antibiotic, was conducted in 35 malignant tumor patients at 11 institutions nationwide. The study was initiated with a single dose at 100 mg/body which was equivalent to 2n, then the dose as escalated up to 700 mg/body in accordance with the modified Fibonacci's scheme. The dose limiting factor (DLF) was considered to be leukopenia, and maximum tolerated dose (MTD) was 700 mg/ body. The consecutive days dosing study subsequently conducted started with 25 mg/body/day, and the dose level was escalated up to 150 mg /body/day. TUT-7 was orally administered for seven (7) to fourteen (14) consecutive days in principle. It was considered that DLF was leukopenia and MTD was 100 mg/body/day for consecutive days dosing. The study indicated that serum drug concentrations reached their plateaus on the 5th day after initiation of TUT-7 treatment and the accumulation of this compound was low. With these findings, a regimen with a dose of 100 mg/body/day orally administered for 14 consecutive days was recommended for early phase II studies.

Administration, Oral↗

PubMed1997

[TUT-7 early phase II clinical study for various solid tumors and hematologic malignancies].

An early Phase II study with TUT-7 (menogaril), a new anthracycline antitumor antibiotic, was conducted in patients with various malignant tumors at 81 departments of 65 institutions nationwide. One course of TUT-7 treatment consisted of seven (7) or fourteen (14) consecutive days of administration at 75 or 100 mg/body/day with two-week drug withdrawal; at least two courses of treatment were given in principle. Among the 165 patients registered, 145 patients were eligible and 128 patients were evaluable for antitumor efficacy. In 11 patients with malignant lymphoma, one (1) had CR and five (5) had PR (54.5%); in three (3) patients with prostate cancer, one (1) had PR (33.3%); and in 12 patients with uterine cervical cancer, two (2) had PR (16.7%). Adverse drug reactions frequently observed were digestive organ disorders (anorexia and nausea/vomiting) and malaise. The abnormality in laboratory tests observed frequently was myelosuppression (leukopenia and neutropenia).

Adult↗

PubMed1997

[Cardiotoxicity due to prolonged administration of THP (2"R-4'-O-tetrahydropyranyl-adriamycin)].

The effect of the anthracycline analogue, pirarubicin, on cardiac function was examined. One hundred and four patients with gynecologic malignancies were treated with 40-50 mg/body THP ADM every 3 to 4 weeks by iv bolus injection. Three out of 104 cases that had developed cardiac failure received more than 1,500 mg. One case receiving 1,340 mg developed cardiac failure and expired 3 years after completion of treatment for malignancy. From the above experience, it is concluded that the MTD of pirarubicin seems to be 1,500 mg/body or 1,100 mg/m2.

Adult↗

PubMed1996

[LY188011 phase I study. Research Group of Gemcitabine (LY188011)].

LY188011 (Gemcitabine hydrochloride) is a new derivative of deoxycytidine. Phase I study was carried out by a cooperative study group. LY188011 was administered weekly for 3 consecutive weeks starting with an initial dose of 60 mg/m2 (1n) and then increasing the dosage to 1,000 mg/m2 (16.7n). Dose limiting factor was found to be myelosuppression (decreases of WBC, neutrophils and platelet), and MTD was considered to be 1,000 mg/m2. The nadir of WBC and platelet were observed after about 1-3 weeks. It took 1-2 weeks for their recovery. Other adverse reactions included fever, fatigue, anorexia, nausea/vomiting, anemia and transient elevations of GOT and GPT. However, those adverse reactions were mild. T1/2 rho of plasma concentration was about 19 min and the C5min was dependent on the dose. Anti-cancer effects were observed in one gastric cancer and two colon cancer patients. It is recommended that the dosing schedule for an early phase II study is 800 mg/m2 weekly for 3 weeks with 1 week of rest as one cycle, in multiple cycles.

Adult↗

PubMed1995

Phase I study of NKT-01.

A phase I study of NKT-01 (deoxyspergualin), which is a derivative of an antitumor antibiotic, spergualin, was performed by a cooperative study group. NKT-01 was given intravenously by 3-h infusion. The effect of single administration was studied prior to evaluation of daily administration for 5 consecutive days. In all, 5 and 33 patients with various malignancies, including leukemia, were entered into the trials of single and daily administration, respectively. In the single-administration study, all patients were evaluable and no clear adverse effect was observed at doses ranging from 20 to 320 mg/m2. In the daily-administration study, 28 evaluable patients (16 men and 12 women; median age, 55.5 years) were treated with a daily dose of 20-500 mg/m2. Toxicities such as myelosuppression, mild nausea/vomiting, anorexia, alopecia, tongue and perioral numbness, and hypotension were observed dose-dependently during or after the treatment. Grade 2 leukopenia, thrombocytopenia, and anemia were experienced at a dose of 500 mg/m2. These usually recovered to normal values by approximately 3 weeks after treatment. A pharmacokinetic analysis of single administration revealed rapid plasma clearance, with mean half-lives for the alpha and beta phases being 28 min and 6.9 h, respectively. Approximately 12% of the infused dose was excreted into the urine in unmetabolized form. The pharmacokinetic parameters obtained after 5-day administration were similar to those recorded after single administration. Concerning treatment response, a transient but significant reduction in the number of leukemic cells was observed in one patient with adult T-cell leukemia. In this study, perioral numbness, hypotension, and hematological toxicity were concluded to be dose-limiting, with the maximal acceptable dose being 500 mg/m2. The recommended dose for a phase II study of NKT-01 against solid tumors was judged to be 400 mg/m2 given daily by 3-h infusion for 5 days, every 3 weeks. In hematological malignancies, however, higher myelosuppressive schedules of administration should be investigated.

Adult↗

PubMed1995

Further application and evaluation of critical cell number and modifying factors in radiocurability of multicellular spheroids.

Relationship of cure and surviving clonogenic cell number after various doses of X-irradiation was examined in multicellular spheroids of LCT1 human lung adenocarcinoma cells, LCT2 human lung small cell carcinoma cells and FSA1233 mouse fibrosarcoma cells. Some of these spheroids were cured at such doses that considerable number of clonogenic cells still survived after irradiation. Radiocurability was analyzed by comparing total clonogenic cell number in spheroids, cellular radiosensitivity and critical cell number Nc, i.e., the minimum number of clonogenic cells required to produce regrowth. (Nc-1) cells were killed by post-radiation processes and the larger the critical cell number, the more radiocurable. The LCT2 spheroids had the largest critical cell number and were most radiocurable. To investigate underlying mechanisms, modifying effect of heavily irradiated (HIR) tumor cells on the clonogenicity, i.e., plating efficiency of unirradiated tumor cells was investigated. Plating efficiencies with HIR cells showed significant decrease in LCT2 cells, no change in LCT1 cells and increase in FSA1233 cells. The results indicated that in case of LCT2 spheroids some of viable cells surrounded by dying or dead cells might have been killed with unknown toxic effect additional to direct irradiation effect. Thus, critical cell number analysis may be useful to quantify and to compare modifying effect of cellular/environmental factors in curing process of spheroids or tumors.

Adenocarcinoma↗

PubMed1994

p53 proteins accumulated by heat stress associate with heat shock proteins HSP72/HSC73 in human glioblastoma cell lines.

We investigated the accumulation of p53 proteins after heat stress and their association with HSP72/HSC73 using four human glioblastoma cell lines. Human glioblastoma cell lines U-87MG and A-172 exhibited no mutation in the region between the 2nd and 11th exons of the p53 gene, whereas A-7 and T98G had mutations in exon 5 and exon 7 of the p53 gene, respectively. In U-87MG and A-172, the levels of wild-type p53 protein were slightly increased by heat stress. Levels of mutant p53 protein were apparently increased by heat stress in A-7, but not in T98G. Furthermore, wild-type p53 proteins in both U-87MG and A-172 co-immunoprecipitated with anti-HSP72/HSC73 antibody and HSP72 and HSC73 in them co-immunoprecipitated with anti-p53 antibody as did the mutant p53 proteins. These findings suggest that p53 proteins accumulated by heat stress are associated with HSP72 and HSC73.

Blotting, Western↗

PubMed1994

[Early phase II study of MST-16 (sobuzoxane) for breast cancer].

An early phase II study of MST-16 for breast cancer was conducted with the participation of 9 hospitals. MST-16 was administered at three doses; 1) 1,600 mg/body for 5 consecutive days repeating every 4 weeks, 2) 1,200 mg/body for 10-14 consecutive days every 5 weeks, and 3) 1,200 mg/body daily for at least 4 weeks. A total of 28 patients were entered, and 27 cases were eligible. Twenty-five cases were evaluated for efficacy and 27 cases for safety. One patient achieved complete response, 2 patients attained partial response, and the response rate thus obtained was 12.0%. Major side effects observed were myelosuppression represented by leukopenia (69.2%) followed by gastrointestinal disorders. These symptoms, however, were reversible by the cessation of administration.

Adult↗