Table 1

Summary of exisulind and CP461 in colon tumor cells

Cell Line	cG-PDE^1-a	cG-PDE IC₅₀^1-b		CGMP 1, 24, 72 h		PKG Activity		Cell Growth IC₅₀^1-c		Apoptosis EC₅₀^1-c
Cell Line	cG-PDE^1-a	Exi	CP461	Exi	CP461	Exi	CP461	Exi	CP461	Exi	CP461
		μM						μM
SW480	PDE5,2	114,335	3,14	↑	↑	↑	↑	165	1.1	557	2.4
T84	PDE5	^1-150	^1-150	↑	↑	↑	↑	165	1	465	1.2
HT29	PDE5	113	3.5	↑	N.D.	↑	↑	235	0.7	495	1.6
HCT116	PDE5,2	198,183	8,13	N.D.	N.D.	↑	↑	170	2	492	2.4

IC₅₀ and EC₅₀ (mean values) were calculated using sigmodial dose-response, variable slope, nonlinear regression in Prism (GraphPad, San Diego, CA) and deviations are within 5 to 10%.

Exi, exisulind; N.D., not determined.
↑, represents increase compared with no drug control;
↵1-150 same isoform.
↵1-a Major cGMP PDE isoforms expressed.
↵1-b Inhibition of DEAE column fractionated PDE5 and two activities at 0.25 μM cGMP substrate was determined as described in Thompson et al. (2000a) and Soh et al. (2000).
↵1-c Cell growth inhibition (6-day assay) and DNA fragmentation (2-day assay) were determined as described under Experimental Procedures and in Thompson et al. (2000).