COMPARATIVE-STUDIES OF TAXOL AND TAXOTERE ON TUMOR-GROWTH AND LYMPHOCYTE FUNCTIONS

Taxotere, a semisynthetic derivative similar to taxol, has shown promi sing results in vitro and in preliminary in vivo studies. We have prev iously reported that taxol at 10 mu g/ml suppressed the cytotoxic func tion and activation of natural killer cells and major histocompatibili ty nonrestricted (MHC-NR) T cells against the ovarian cell line OV-277 4 and the erythroleukemia cell line K-562. In this paper, we investiga ted the effect of taxotere on lymphocyte function and found that a sup pression of MHC-NR cytotoxicity of naive lymphocytes is only seen at h igher doses of taxotere (50 mu g/ml). At the concentrations of 10 and 50 mu g/ml, taxotere did not have any effect on the cytotoxic function of IL-2-preactivated lymphocytes. On the contrary, both taxol and tax otere caused a significant suppression of lymphocyte growth and activa tion with IL-2 at 10 and 50 mu g/ml. Both drugs (at the concentration of 10 mu g/ml) were potent inhibitors of the growth of the tumor cell lines OV-2774 and K-562. In conclusion, despite the fact that taxotere shares with taxol a potent antitumor effect, it seems to be less supp ressive for lymphocyte cytotoxicity, an effect clearly desirable in ca ncer therapy. (C) 1994 Academic Press, Inc.