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T Toko

Publications and source records attributed to T Toko.

25 records · Page 2Linked to original sources

Anticancer effect of 4-[3,5-bis(trimethylsilyl)benzamido] benzoic acid (TAC-101) against A549 non-small cell lung cancer cell line is related to its anti-invasive activity.

We examined the effects of TAC-101 on the invasion and metastasis of human non-small cell lung cancer (NSCLC) cell lines. TAC-101 showed an ability to inhibit in vitro invasiveness of NSCLC at a non-cytotoxic concentration range of 3-10 microM; such concentration levels were easily achievable following oral administration of therapeutically effective doses. The inhibition of cell invasion at 10 microM of TAC-101 accounted for 58-69% when compared with control cells. Oral administration of TAC-101 (4 mg/kg/day) to mice bearing lung implanted A549 lung cancer resulted in significant life-prolonging effect (T/C: 143%). More pronounced life-prolonging effect was observed in the experimental liver metastasis model of A549, where T/C of 215% was observed following administration at 4 mg/kg/day of TAC-101. However, TAC-101 did not show the direct anti-tumor effect against the established A549 tumor xenografts after subcutaneous implantation. These findings suggest that TAC-101 interferes with cell-to-cell interaction processes leading, for instance, to the inhibition of the invasion of NSCLC cells. Taking into account the pharmacological properties of TAC-101, it is expected that TAC-101 may be a suitable candidate drug for the treatment of lung cancer patients, especially those with a predictable metastasizing potential.

Animals↗

Antitumor activity of menogaril alone, and in combination against human mammary cancer models in mice and rats.

Menogaril is an antitumor agent different from other anthracyclines in being active after oral administration. To predict its clinical effectiveness by this route against human breast cancer, we compared its antitumor activity against breast cancer in experimental animals with that of injected Adriamycin. Menogaril had half the much antitumor activity of Adriamycin against human mammary cancer cell lines. Menogaril given orally also had a antitumor activity against mammary cancer caused by 7,12-dimethyl-benz[a]anthracene in rats comparable with that of Adriamycin. The high concentration of menogaril in tumor tissue seemed to contribute to its effectiveness. Of several combinations of cyclophosphamide, Adriamycin, menogaril, and 5-fluorouracil, the combination of cyclophosphamide, menogaril, and 5-fluorouracil was most effective against mouse leukemia L1210 and human breast cancer xenografts in mice. This combination might have antitumor activity against breast cancer superior to that of the therapy currently of first choice (cyclophosphamide, Adriamycin, and 5-fluorouracil) in the clinic.

9,10-Dimethyl-1,2-benzanthracene↗

Prediction of the optimum clinical dosing schedule for menogaril from results with tumor-bearing mice.

Menogaril is an antitumor agent active after oral administration, and unlike other anthracyclines, extravasation cannot occur. When the IC90 values of menogaril were plotted versus exposure time on a double-logarithmic scale, the regression lines had slopes between -0.64 and -0.80. These results showed that the mode of action of menogaril was type lb, dependent on the area under the curve (AUC) of concentration versus time, like Adriamycin. In calculations that simulated pharmacokinetic findings if administration were for three consecutive days (the single dose given was 79 mg/kg) or on days 1 and 8 (the single dose was 238 mg/kg), the peak tumor concentration of menogaril was 1870 and 2985 ng/g and the AUC was 68,363 and 89,352 ng/g hour, respectively. Of the dosing schedules tried, these two dosing schedules were the optimum, with satisfactory antitumor activity against mouse solid tumor Colon 26 and with a wide range of effective dose concentrations. Since menogaril was AUC-dependent, it was possible to predict antitumor activity and to choose optimum dosing schedules on the basis of cell-kill kinetic and pharmacokinetic information.

Animals↗

Activity of menogaril against various malignant lymphoma cell lines and a human lymphoma xenograft in mice.

Menogaril is an antitumor agent different from other anthracyclines in that it is active after oral administration; therefore, extravasation is not a side effect. In this basic study, we examined the antitumor activity of menogaril against malignant lymphoma. We compared its activity towards experimental malignant lymphoma with that of Adriamycin, epirubicin, pirarubicin, vincristine, and etoposide, treating mice with each drug at the dose schedule usually used for patients. Menogaril rapidly penetrated lymphoma cells and remained there at least 3 hours after the drug was washed out. Menogaril cleaved more double-stranded DNA in lymphoma cells than Adriamycin, epirubicin, pirarubicin, or etoposide. Menogaril had stronger antitumor activity against experimental malignant lymphoma in mice than Adriamycin, epirubicin, vincristine, and etoposide. Menogaril significantly lengthened the life span of mice bearing one of three lymphoma cell lines resistant to cisplatin, vincristine, or cyclophosphamide. Menogaril had stronger antitumor activity against the human malignant lymphoma xenograft LM-3 than Adriamycin. The strength of the cytotoxic activity of Menogaril might arise from its ready penetration into cells and its cleavage of double-stranded DNA. Therefore, Menogaril might become a useful drug for the treatment of patients with malignant lymphoma by oral administration; 7 days of administration was effective in the in vivo experiments.

Animals↗

Augmentation of the chemotherapeutic effectiveness of UFT, a combination of tegafur [1-(2-tetrahydrofuryl)-5-fluorouracil] with uracil, by oral l-leucovorin.

UFT, combination of tegafur [1-(2-tetrahydrofuryl)-5-fluorouracil] with uracil, is widely-used as an anti-neoplastic agent in Japan. We evaluated the anti-tumor efficacy of the combined modality of UFT with oral l-leucovorin. The augmentation of anti-tumor activity of UFT by co-administration of l-leucovorin was observed over a dose of 1.85 mg/kg (5.55 mg/m2) and was significant at a dose of 5.56 mg/kg (16.7 mg/m2). Using ten human tumor xenografts, l-leucovorin significantly enhanced the growth-suppressive ability of UFT against colon carcinoma (KM20C, Col-1) and mammary carcinoma (H-31, MX-1). Among various 5-fluorouracil (FUra) derivatives, such as UFT, 5'-deoxy-5-fluorouridine (5'-DFUR) and FUra, l-leucovorin gave the maximum augmentation to the anti-tumor activity of UFT, due to the prolonged half-life of FUra in plasma. Enhancement of the cytotoxic activity of FUra by l-leucovorin against KM20C colon carcinoma cell line was observed in a time-dependent manner at a concentration of 0.01 microM l-leucovorin. Based on these results, we conclude that the combination of UFT with oral l-leucovorin has significant antitumor activity and represents an interesting regimen to be evaluated in the clinical setting.

Administration, Oral↗