Table 1. Cell growth inhibition effect of HSP90 inhibitors as measured by sulforhodamine B assay in GB cell lines.

IC₅₀ values of NVP-AUY922, its less potent analogs VER-50589 and VER-49009, the natural product radicicol, the ansamycin benzoquinones 17-AAG and 17-DMAG, and the synthetic purine scaffold HSP90 inhibitor BIIB021, in 2 adult (U87MG, SF268) and 2 pediatric (SF188, KNS42) GB lines.

	Adult cell lines		Pediatric cell lines
IC50 (nM)	U87MG	SF268	SF188	KNS42
NVP-AUY922	7.8 ± 1.2	6.1 ± 1.5	7.6 ± 2.2	4.8 ± 2.1
VER-50589	57.1 ±20.8	28.0 ± 10.8	54.4 ±14.1	57.6 ± 31.2
VER-49009	587.8 ± 99.3	414.2 ± 20.3	328.3 ± 11.9	681.0 ± 150.4
Radicicol	44.9 ± 4.9	32.4 ± 12.0	35.2 ± 5.7	41.3 ± 21.1
17-AAG	13.9 ± 2.0	12.4 ± 0.6	11.2 ± 0.6	29.7 ± 2.3
17-DMAG	3.7 ± 1.3	3.2 ± 1.4	3.3 ± 0.4	3.1 ± 0.2
BIIB021	75.1 ± 47.0	80.5 ± 39.0	142.1 ± 89.7	109.6 ± 29.9

Values are mean ± SD from at least 3 independent experiments