Table 3.

Effect of irinotecan 20 to 60 mg/kg on TS activity in AZ-521 human gastric cancer xenografts in mice.

Dose (mg/kg)	N	TS activity* (pmol/mg ± SD)	% of Control
Control	3	0.994 ± 0.188	100.0
20	3	0.526 ± 0.118	52.7
40	3	0.292 ± 0.088	29.3
60	3	0.214 ± 0.054	21.4
Control	5	0.622 ± 0.095	100.0
75	5	0.082 ± 0.019	13.2*

Mice received no irinotecan or irinotecan 20, 40, or 60 mg/kg on days 1 and 8; 24 hours after final treatment, tumors were dissected and TS activity was measured.

^*Data on 75 mg/kg treatment and control are from Table 2