TY - JOUR
T1 - Antitumor activity of tiazofurin in human colon carcinoma HT-29
AU - Zhen, Weining
AU - Jayaram, Hiremagalur N.
AU - Weber, George
N1 - Funding Information:
Financial support for this project was provided by U.S. Public Health Service, National Cancer Institute Grant CA-51770 to HNJ and an Outstanding Investigator Grant CA-425 10 to GW.
PY - 1992
Y1 - 1992
N2 - Tiazofurin is effective in treating end-stage leukemic patients (Tricot et al., Cancer Res 49:3696-3701, 1989). In sensitive tumors, the active metabolite of tiazofurin, TAD, potently inhibits IMP dehydrogenase activity, resulting in reduced guanylate pools. To elucidate tiazofurin activity in human solid tumors, we examined its activity in human colon carcinoma HT-29. Tiazofurin exhibited an LC50 of 35 pM in cultured HT-29 cells. Incubation of HT-29 cells with 100 pM tiazofurin for 2 h resulted in TAD formation (9.3 nmollg cells) and in a 64% decrease in GTP pools. For biochemical and chemotherapy studies, athymic nude mice were transplanted s.c. with HT-29 cells. Twenty-four days later, mice were injected i.p. with tiazofurin (500 mg/kg); 6 h later, tumors were removed and analyzed. These tumors formed 17 nmollg of TAD with decreased GTP pools (56% To study oncolytic activity, transplanted mice were treated 24 h later with tiazofurin (500 mg/kg, once a day for 10 days). To examine the effectiveness of tiazofurin in established tumors, the drug was administered to mice 14 days after tumor implantation (500 mglkg, once a day for 5 days, course repeated 4 times with a 10-day rest). Both treatment schedules resulted in significant antitumor activity. This study illustrates the potential usefulness of tiazofurin in treating human colon carcinoma.
AB - Tiazofurin is effective in treating end-stage leukemic patients (Tricot et al., Cancer Res 49:3696-3701, 1989). In sensitive tumors, the active metabolite of tiazofurin, TAD, potently inhibits IMP dehydrogenase activity, resulting in reduced guanylate pools. To elucidate tiazofurin activity in human solid tumors, we examined its activity in human colon carcinoma HT-29. Tiazofurin exhibited an LC50 of 35 pM in cultured HT-29 cells. Incubation of HT-29 cells with 100 pM tiazofurin for 2 h resulted in TAD formation (9.3 nmollg cells) and in a 64% decrease in GTP pools. For biochemical and chemotherapy studies, athymic nude mice were transplanted s.c. with HT-29 cells. Twenty-four days later, mice were injected i.p. with tiazofurin (500 mg/kg); 6 h later, tumors were removed and analyzed. These tumors formed 17 nmollg of TAD with decreased GTP pools (56% To study oncolytic activity, transplanted mice were treated 24 h later with tiazofurin (500 mg/kg, once a day for 10 days). To examine the effectiveness of tiazofurin in established tumors, the drug was administered to mice 14 days after tumor implantation (500 mglkg, once a day for 5 days, course repeated 4 times with a 10-day rest). Both treatment schedules resulted in significant antitumor activity. This study illustrates the potential usefulness of tiazofurin in treating human colon carcinoma.
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U2 - 10.3109/07357909209024812
DO - 10.3109/07357909209024812
M3 - Article
C2 - 1358409
AN - SCOPUS:0026484741
SN - 0735-7907
VL - 10
SP - 505
EP - 511
JO - Cancer Investigation
JF - Cancer Investigation
IS - 6
ER -