R-94138, a
matrix metalloproteinase inhibitor, was examined for the ability to prevent peritoneal dissemination of a human
gastric cancer xenograft, TMK-1. When the supernatant of a co-culture of TMK-1 cells and human normal fibroblast cells was subjected to
gelatin zymography, it was clear that the
protein expression of MMP-2 had been inhibited by
R-94138. When TMK-1 was injected intraperitoneally (i.p.) into nude mice at 5 x 10(5) cells/body, the resulting peritoneal dissemination mimicked clinical carcinomatous
peritonitis. When the maximum tolerated dose of
mitomycin C (MMC) or
cisplatin (DDP) was given 12 h after the
tumor inoculation, peritoneal dissemination was completely inhibited, while the effect of
R-94138 was limited when it was given i.p. at a dose of 20 mg/kg in a schedule of q.d. x 5 starting 12 h after
tumor injection. MMC and DDP also suppressed peritoneal dissemination when they were administered 1 week after the
tumor inoculation at a single dose of 2 and 3 mg/kg i.p., respectively.
R-94138 inhibited peritoneal dissemination when it was administered i.p. at a dose of 30 mg/kg in a schedule of q.d. x 5 starting from 1 week after
tumor injection. The combination of MMC and
R-94138 increased the preventive effect on peritoneal dissemination.
R-94138 seems to be a promising candidate to prevent peritoneal dissemination of
gastric cancer.