Table 1.

Cytotoxicity and collateral sensitivity of NAA in wild-type and MDR-Pgp cell lines

Compound	Cytotoxicity–IC50, μM*
	Hamster lung cells		Human lymphoblastic leukemic cells
	DC-3F	DC-3F/ADII	CCRF-CEM	CCRF-CEM/VBL100	CCRF-CEM/VM1
NAA	5.06	1.59	29.8	20.8	44.2
NADMA	26.1	14.6	22.7	32.9	35.8
DX	0.36	2.14	0.55	3.31	1.42
VBL†			0.00083	0.632	0.00045
VBL† + NAA (15 μM)			0.00021	0.00011	0.00004
VBL† + NADMA (15 μM)			0.00035	0.00017	0.00002
VBL† + VRPL (75 μM)			0.00015	0.00010	0.00016

^*The IC₅₀ values were determined from 5-6 concentrations of each compound and the dose-effect curves were analyzed with the median-effect plot using computer software (23, 24). 

^†VBL concentrations were varied.