The inhibitory effects of a novel
matrix metalloproteinase inhibitor,
ONO-4817, on the development of mammary
tumors and the progression of uterine
adenomyosis were examined in SHN mice. First, multiparous mice which developed mammary
tumors spontaneously were used. The first palpable
tumor was removed, and the mice were thereafter fed chow containing
ONO-4817. Any second mammary
tumor developing in the other mammary fat pad was also removed, and the mice were continuously fed the chow containing
ONO-4817. The mice were killed when a third
tumor was detected in the other fat pad. The periods between the occurrence of the first and second
tumors, and the second and third ones were significantly increased in the mice treated with
ONO-4817 compared to the mice not given
ONO-4817 treatment. Second, to test
ONO-4817 suppression of the progression of the invasion of uterine adenomyotic tissue, mice with experimentally-induced
adenomyosis were treated with
ONO-4817 for 4 weeks. The degree of pathological progression of
adenomyosis was less in the uteri exposed to
ONO-4817 than in the uteri not exposed to the inhibitor.