beta-cyclodextrin-tetradecasulfate and Lung-Neoplasms

Tetrahydrocortisol, beta-cyclodextrin tetradecasulfate, and minocycline used alone or in combination are not very cytotoxic toward EMT-6 mouse mammary tumor cells growing in monolayer. Tetrahydrocortisol (100 microM, 24 h) and beta-cyclodextrin tetradecasulfate (100 microM, 24 h) protected EMT-6 cells from the cytotoxicity of CDDP, melphalan, 4-hydroperoxycyclophosphamide, BCNU, and X-rays under various conditions of oxygenation and pH. Minocycline (100 microM, 24 h) either had no effect upon or was additive with the antitumor alkylating agents or X-rays in cytotoxic activity toward the EMT-6 cells in culture. The combination of the three modulators either had no effect upon or was to a small degree protective against the cytotoxicity of the antitumor alkylating agents or X-rays. The Lewis lung carcinoma was chosen for primary tumor growth-delay studies and tumor lung-metastases studied. Tetrahydrocortisol and beta-cyclodextrin tetradecasulfate were given in a 1:1 molar ratio by continuous infusion over 14 days, and minocycline was given i.p. over 14 days, from day 4 to day 18 post tumor implantation. The combination of tetrahydrocortisol/beta-cyclodextrin tetradecasulfate diminished the tumor growth delay induced by CDDP and melphalan and produced modest increases in the tumor growth delay produced by cyclophosphamide and radiation. Minocycline co-treatment increased the tumor growth delay produced by CDDP, melphalan, radiation, bleomycin, and, especially cyclophosphamide, where 4 of 12 animals receiving minocycline (14 x 5 mg/kg, days 4-18) and cyclophosphamide (3 x 150 mg/kg, days 7, 9, 11) were long-term survivors. The 3 modulators given in combination produced further increases in tumor growth delay with all of the cytotoxic therapies, and 5 of 12 of the animals treated with the 3-modulator combination and cyclophosphamide were long-term survivors. Although neither tetrahydrocortisol/beta-cyclodextrin tetradecasulfate, minocycline, nor the three modulator combination impacted the number of lung metastases, there was a decrease in the number of large lung metastases. Treatment with the cytotoxic therapies alone reduced the number of lung metastases. Addition of the modulators to treatment with the cytotoxic therapies resulted in a further reduction in the number of lung metastases. These results indicate that agents that inhibit the breakdown of the extracellular matrix can be useful additions to the treatment of solid tumors.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; beta-Cyclodextrins; Cell Division; Cell Hypoxia; Cyclodextrins; Lung Neoplasms; Male; Mammary Neoplasms, Experimental; Mice; Mice, Inbred C57BL; Minocycline; Tetrahydrocortisol; Tumor Cells, Cultured

The formation of a blood supply (angiogenesis) is critical to the growth of solid tumors. The naturally occurring steroid tetrahydrocortisol, the synthetic cyclodextrin derivative beta-cyclodextrin tetradecasulfate, and the tetracycline derivative minocycline have antiangiogenic activity. Tetrahydrocortisol and beta-cyclodextrin tetradecasulfate in a 1:1 molar ratio by continuous infusion over 14 days and minocycline administered i.p. over 14 days from day 4 to day 18 postimplantation of the Lewis lung carcinoma significantly increased the growth delay of the primary tumor after treatment with cis-diamminedichloroplatinum(II), melphalan, cyclophosphamide, Adriamycin, bleomycin, and radiation therapy administered in standard regimens. Addition of the antiangiogenic agents to treatment with the cytotoxic therapies not only reduced the number of lung metastases formed from the primary tumor but also reduced the number of large metastases. Five of 12 animals treated with the antiangiogenic modulators and cyclophosphamide were long-term survivors (> 120 days). Thus, antiangiogenic therapies can potentiate the efficacy of standard anticancer therapies.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; beta-Cyclodextrins; Bleomycin; Cisplatin; Cyclodextrins; Doxorubicin; Drug Screening Assays, Antitumor; Drug Synergism; Lung Neoplasms; Mice; Mice, Inbred C57BL; Minocycline; Neoplasm Transplantation; Tetrahydrocortisol; Tumor Cells, Cultured