Augmented growth inhibition of B16-BL6 melanoma by combined treatment with a selective matrix metalloproteinase inhibitor, MMI-166, and cytotoxic agents.
BACKGROUND
MMI-166 is a selective matrix metalloproteinase (MMP) inhibitor. The purpose of this study was to evaluate the antitumor efficacy of the combined treatment of MMI-166 with paclitaxel or carboplatin.


METHODS
Mice bearing B16-BL6 melanoma were treated p.o. with MMI-166 from 1 day after tumor inoculation. The mice were administered i.v. with either paclitaxel or carboplatin at the maximum tolerated dose (MTD).


RESULTS
MMI-166 monotherapy inhibited in vivo growth of the B16-BL6 tumor to an extent similar to that of paclitaxel or carboplatin monotherapy. When MMI-166 was combined with paclitaxel or carboplatin, the antitumor efficacy was significantly (p < 0.01) augmented in comparison with either MMI-166 or each cytotoxic agent alone. The hematotoxicity study demonstrated that daily treatment with MMI-166 did not affect the blood cell number in the mice and more importantly the combination of MMI-166 with paclitaxel did not augment the hematotoxicity caused by paclitaxel. An in vitro cytotoxicity study showed that MMI-166 itself has neither direct cytotoxicity against B16-BL6 tumor cells nor does it augment the cytotoxicity of paclitaxel or carboplatin.


CONCLUSIONS
These results indicate that augmented antitumor activity of the combination treatment was not simply due to the augmentation of direct cytotoxic activity, but was rather an additive effect of the antitumor activities of different mechanisms. They suggest the effectiveness of a combination therapy of MMI-166 with paclitaxel or carboplatin in clinical therapy.
Hojo
Kanji
K
Shionogi Research Laboratories, Shionogi & Co. Ltd, 12-4 Sagisu, 5-Chome, Fukushima-ku, Osaka, Japan.
Maki
Hideo
H
Sawada
Takuko Yamada
TY
Maekawa
Ryuji
R
Yoshioka
Takayuki
T
D000818:Animals; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology*; D016190:Carboplatin / Q000008:administration & dosage / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D004357:Drug Synergism; D004791:Enzyme Inhibitors / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D061965:Matrix Metalloproteinase Inhibitors; D008546:Melanoma, Experimental / Q000188:drug therapy* / Q000201:enzymology / Q000473:pathology; D051379:Mice; D017239:Paclitaxel / Q000008:administration & dosage / Q000494:pharmacology; D013449:Sulfonamides / Q000008:administration & dosage / Q000494:pharmacology*
D004791:Enzyme Inhibitors; D061965:Matrix Metalloproteinase Inhibitors; C419963:N-alpha-(4-(2-phenyl-2H- tetrazole-5-yl) phenyl sulfonyl)-D-tryptophan; D013449:Sulfonamides; D016190:Carboplatin; D017239:Paclitaxel