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S Tsukagoshi

Publications and source records attributed to S Tsukagoshi.

At least 127 records · Page 7Linked to original sources
PubMed1987

Synthesis and antitumor activity of tropolone derivatives. 6. Structure-activity relationships of antitumor-active tropolone and 8-hydroxyquinoline derivatives.

The bis derivative 6 of 8-hydroxyquinoline, which, like tropolones, readily forms a chelate, was synthesized and found to have high potency (dose = 12.5 mg/kg, T/C % = 164) against leukemia P388 in mice approximately equivalent to that of the bistropolone 1b. 8-Hydroxyquinoline analogues with broad structural variation were synthesized and their structure-activity relationships followed the same pattern as in the tropolone series. In addition, the bistropolones 1a-e were tested for their ability to bind to tubulin and found to have no such property. The results of this study suggested that bistropolone and bis(8-hydroxyquinoline) derivatives must form a chelate with the metal necessary for the enzyme, such as ribonucleotide reductase, which catalyzes the DNA biosynthetic pathways.

Animals↗
PubMed1987

A novel antitumor cyclic hexapeptide (RA-700) obtained from Rubiae radix.

The antitumor activity of a newly obtained cyclic hexapeptide, RA-700, from Rubiae Radix was studied using several murine experimental tumor systems. In P388 leukemia (inoculated intraperitoneally (i.p.), administered i.p.: i.p.-i.p.) the maximal increase in life span (ILSmax) resulting from an administration of RA-700 (4 mg/kg/d for 9 d) was 134% and the therapeutic ratio was 400. These values indicate that RA-700 has higher anti-tumor activity and broader active dose range than that of mitomycin C (MMC, 1 mg/kg/d for 9 d) which was used as a positive control. In the study of the treatment schedules on P388, RA-700 had the highest activity by consecutive injections. In MOPC-104E mouse plasmacytoma system (i.p.-i.p.), ILSmax of RA-700 (2.5 mg/kg/d for 9 d) was 84%. In a solid tumor, colon adenocarcinoma 38 (subcutaneously (s.c.)-intravenously (i.v.], RA-700 (4 mg/kg/d for 11 d) showed complete cures (8/8) compared to MMC (0.5 mg/kg/d for 11 d) which showed one cure out of 8 animals. In the study of a model of the inhibition of lymph node metastasis using P388 leukemia, the administration of RA-700 at more than 2.5 mg/kg/d i.v. for 7 d resulted in the survival of all animals (5/5) for over 60 d. In the amputation system of the same metastasis model at a dose of 4 mg/kg/d i.v. for 7 d, 3 animals out of 5 survived over 60 d.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

[A new anticancer drug, 5'-deoxy-5-fluorouridine (5'-DFUR)].

Recently 5'-DFUR (5'-deoxy-5-fluorouridine) was developed as a new anticancer drug in Japan. The compound was active against various murine tumors by oral administration and the toxicity was almost comparable to the other prodrugs of 5-fluorouracil (5-FU). 5'-DFUR is converted to 5-FU in vivo by pyrimidine nucleoside phosphorylase which was found to exist relatively much in tumor tissues compared to normal ones except intestinal tract. In the phase I study, the dose-limiting toxicities were gastro-intestinal (GI) ones such as nausea, vomiting, anorexia etc., and the MTD was 2,100 mg/body/day (oral administration). In the multi-institutional phase II studies, clinical activity of 5'-DFUR was found in head and neck, thyroidal, esophageal, gastric, colo-rectal, gall-bladder and breast cancers at daily doses of 800-1,200 mg/body. The main side effects were consisted of GI-toxicities in which diarrhea appeared most frequently (26.3%). This diarrhea, however, disappeared rapidly by decreasing the dosage or termination of treatment. In the comparative clinical studies of 5'-DFUR with tegafur against advanced breast cancer cases, 5'-DFUR was found superior to tegafur in the clinical responses. From these results, 5'-DFUR was judged as an useful new anticancer drug.

Adult↗
PubMed1987

[Ifomide].

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Animals↗
PubMed1987

[FO-152].

5'-O-(L-valyl)-5-fluorouridine hydrochloride (FO-152) is a derivative of 5-fluorouridine. In preclinical studies, FO-152 has demonstrated more favorable antitumor effect with greater therapeutic index compared with the parent compound, 5-fluorouridine. A phase I study was performed in 38 cases with advanced cancer. Myelosuppression was dose limiting, with leukopenia more pronounced than thrombocytopenia. Other side effects included mild hot feeling of the body during infusion and slight G.I. toxicities. Clinical responses were seen in patients with adenocarcinoma of the stomach, lung, etc. FO-152 has major advantages over 5-fluorouridine in terms of reduced toxicity. The recommended phase II dose for patients with solid tumors is 250 mg/m2 X 1, or 35 mg/m2 X 5 consecutive days with a 4-week rest, provided there is reversal of drug related myelosuppression.

Absorption↗
PubMed1987

Mechanisms of action of a novel macromolecular antitumor antibiotic, SN-07, on mouse leukemia L1210 cells in culture.

The mechanisms of action of a novel macromolecular antitumor antibiotic (SN-07) were examined using cultured mouse lymphoid leukemia L1210 cells. A shoulder exponential-type cytotoxicity was observed when the cells were treated with 3.13 to 100 ng/ml SN-07 for 1 hr and surviving colonies were counted after a 14-day incubation. It was found that 500 ng/ml SN-07 inhibited both RNA and DNA syntheses significantly at 40 and 80 min, respectively, while 8,000 ng/ml did not affect protein synthesis at 80 min. Treatment with a low concentration (80 ng/ml) of SN-07 for 1 hr inhibited both RNA and DNA syntheses after a 24-hr post-incubation. The alkaline elution technique revealed that 8,000 ng/ml SN-07 induced DNA interstrand cross-links time-dependently for 1 to 4 hr, and a 1-hr treatment with 80 to 8,000 ng/ml SN-07 induced DNA breaks after a 24-hr post-incubation. According to flow cytometric analysis, most L1210 cells progressed to the G2 phase in the cell cycle at a cytostatic concentration (25 ng/ml) of SN-07, and typical inhibition of the cell cycle progression was observed at a cytocidal concentration (200 ng/ml).

Animals↗
PubMed1987

[Introduction of a new anticancer drug, novantrone].

Novantrone (mitoxantrone) is a novel anticancer drug, having an anthraquinone structure. This compound was selected from many candidate compounds for purpose to find out a drug having lesser cardiac toxicity than doxorubicin and excellent antitumor activities. In the Japanese clinical trials, Novantrone was proved to be active against breast cancer, malignant lymphoma and acute leukemia. Major side effects observed in the clinical trials were: GI-tract toxicities, and mild alopecia, mild disturbance in the circulatory organs, fever and dermatological toxicities.

Animals↗
PubMed1987

[A new antitumor drug with immunomodulating activity, ubenimex (bestatin)].

Ubenimex (Bestatin) was discovered by Umezawa et al. in 1976 from the culture broth of Streptomyces olivoreticuli. Bestatin is a compound of low-molecular weight peptide and inhibits leucine aminopeptidase and aminopeptidase B which localized in cell membrane. Bestatin exhibited antitumor effect against murine syngeneic tumors including mouse colon 26 and C1498 leukemia, and also it was active against MNNG-induced rat tumor by oral administration. Combination treatment of mouse colon 26 with bestatin and mitomycin C, 5-FU or CDDP was effective for the life prolongation of the treated mice compared to mono-therapy alone. Bestatin was found to exhibit the antitumor effect through T lymphocyte stimulation, macrophage activation and bone marrow stem cell stimulation were also observed by bestatin treatment experimentally. Values of T cell subsets in cancer patients recovered to the normal levels by Bestatin treatment. Release of Interleukin-1 and -2 was enhanced by Bestatin treatment in vitro. In the phase I study, clinical optimal daily dose was estimated as 10-100 mg to give 2-3 times weekly or daily continuously. In the comparative clinical trials, Bestatin was found to be effective for the prolongation of survival time of the patients with acute non-lymphocytic leukemia after induction of complete remission in combination with maintenance chemotherapy. Minimal side effects were noted.

Adjuvants, Immunologic↗
PubMed1987

[Introduction of natural interferon-alpha "Sumiferon"].

Natural interferon-alpha preparation "Sumiferon" was recently developed in Japan. This is a human lymphoblastoid interferon (HLBI) preparation. Like other interferon preparations, this preparation showed both direct and indirect antitumor effect and the toxicities were moderate. The phase I-II studies were carried out in 38 major institutions in Japan. In the phase I study in 5 patients with advanced breast cancer, the maximum tolerated dose (MTD) was found to be 12 X 10(6) units/day given for 1 month. In the phase II study, HLBI was given in at 3 approximately 6 X 10(6) units/day. Out of 391 cases, 280 were evaluable. Complete and partial responses (CR and PR) were observed in 40 (14.3%) out of 280 evaluable cases, including 11 (19.6%) out of 56 renal cell cancer, 14 (19.2%) out of 73 multiple myeloma, and 9 (17.3) out of 52 malignant lymphoma among others. Major side effects observed were: fever (69.8%), gastrointestinal disturbances (31.4%), leukopenia (30.7%), thrombocytopenia (27.8%), hepatotoxicities (23.6%) and general fatigue (22.1%). Sumiferon seemed to be one of useful antitumor drugs effective against renal cancer.

Animals↗
PubMed1987

[Cyclophosphamide].

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Cyclophosphamide↗
PubMed1986

Selective reduction of intracellular guanosine 5'-triphosphate pool by 4-carbamoylimidazolium 5-olate in murine tumor cells.

Ehrlich carcinoma and P388 leukemia cells were rendered resistant to 4-carbamoylimidazolium 5-olate (SM-108), and assessments were made of biochemical and pharmacological determinants for the sensitivity to SM-108 using both sensitive and resistant sublines. We observed that the treatment of cells with SM-108 in vitro caused a remarkable decrease in the intracellular guanosine 5'-triphosphate pool level in sensitive but not in resistant sublines. There was no difference in the ability to take up SM-108 between sensitive and resistant sublines, but the cellular conversion of SM-108 to its nucleotide, which is the putative active anabolite of SM-108, proceeded only in sensitive sublines. Enzymological studies revealed that the activity of adenine phosphoribosyltransferase (EC 2.4.2.7), which is believed to conjugate SM-108 with 5-phospho-alpha-D-ribose 1-diphosphate, was very low in the resistant sublines. These results strongly support our previous hypothesis that SM-108 is activated by adenine phosphoribosyltransferase to SM-108-nucleotide which then inhibits hypoxanthine-5'-monophosphate dehydrogenase (EC 1.2.1.14), a key enzyme for the de novo synthesis of guanosine 5'-monophosphate.

Adenine Phosphoribosyltransferase↗
PubMed1986

Rhizoxin, a macrocyclic lactone antibiotic, as a new antitumor agent against human and murine tumor cells and their vincristine-resistant sublines.

Rhizoxin, isolated from a plant pathogenic fungus which causes rice seedling blight, inhibits the mitosis of the tumor cells in a manner similar to that of Vinca alkaloids as revealed by morphological study and flow cytometry analysis. This new 16-membered macrocyclic lactone showed similar chemotherapeutic effects to those of vincristine against L1210 and P388 leukemia-bearing mice. The drug is also effective against B16 melanoma inoculated i.p. or s.c. Rhizoxin, in contrast to the ansamacrolide, maytansine, was effective against human and murine tumor cells resistant to vincristine and Adriamycin in vitro and in vivo. A maximum 60% increase in life span was obtained in mice inoculated with P388 leukemia resistant to vincristine. Rhizoxin showed greater cytotoxicity in cultured tumor cells than did vincristine. Rhizoxin seems to bear consideration for further development as a new chemotherapeutic agent.

Animals↗
PubMed1986

Biochemical mode of cytotoxic action of neplanocin A in L1210 leukemic cells.

Neplanocin A, a novel antitumor antibiotic, was investigated to determine the biochemical mode(s) of its cytotoxic action. The molecule is an adenosine analogue with a unique cyclopentane structure in its ribose moiety. Both sublines of L1210 and P388 leukemia resistant to neplanocin A were cross-resistant in vitro to bredinin and 9-beta-D-arabinofuranosyladenine, which have been reported to be activated by adenosine kinase. The adenosine kinase activity was markedly reduced in the resistant sublines as compared with that of the respective sensitive lines. Furthermore, neplanocin A competitively inhibited the phosphorylation reaction of adenosine in a cell-free system. The results indicate that neplanocin A is activated by adenosine kinase. Regarding the target site for neplanocin A, the antibiotic suppressed RNA synthesis to a significantly greater extent than DNA synthesis. This RNA-preferential effect is unique among common antimetabolic antitumor agents.

Adenosine↗
PubMed1985

Potentiation of antitumor agents by calcium channel blockers with special reference to cross-resistance patterns.

The calcium channel blockers verapamil, diltiazem, nicardipine, and niludipine potentiated the antitumor activities of mitotic poison antitumor agents, such as vincristine, vinblastine, vindesine, VP16-213, and taxol in P388 leukemia cells resistant to vincristine. The potentiating effect was generally dependent on the extent of cross-resistance seen in the cell line for these drugs. Calcium channel blockers also potentiate the antitumor activities of several DNA-interacting drugs, such as adriamycin, THP-adriamycin, daunomycin, aclacinomycin A, mitomycin C, actinomycin D, mitoxantrone, and nogalamycin derivatives in P388 leukemia resistant to adriamycin. Greater potentiation was observed for those antitumor agents to which the ADM-resistant cell line had become markedly cross-resistant, with the exception of the nogalamycin derivatives. Only a two-fold enhancement was observed for mitomycin C and aclacinomycin, as the cell line was only weakly cross-resistant to these agents. These results suggest the potential for therapeutic gain through the use of calcium channel blockers in combination with classic chemotherapeutic agents.

Animals↗
PubMed1985

Inhibition of spontaneous and experimental tumor metastasis by the calcium antagonist verapamil.

Verapamil, a calcium antagonist, inhibited both experimental (IV inoculation of tumor cells) and spontaneous metastasis (SC inoculation) of the highly metastatic B16 melanoma and colon adenocarcinoma 26 cell lines. Verapamil treatment resulted in a maximum 80% inhibition of metastases, the degree of inhibition varying among the different metastatic systems. Verapamil inhibited platelet aggregation induced by these tumor cell lines, the patterns of inhibition being different for B16 melanoma and colon adenocarcinoma. The inhibition of platelet aggregation induced by tumor cells is proposed as a mechanism by which the calcium antagonist exerts its antimetastatic effect. These results, together with our previous findings that calcium antagonists can increase the cytotoxicity of drugs in tumor cells with induced or inherent drug resistance by inhibiting outward transport of the drug, indicate that calcium antagonists have potential as a new class of adjuvant agents in the field of cancer chemotherapy.

Animals↗