Proliferation of human neuroblastoma cells (U87-L) is attenuated by conditioned media with high Aβ levels. U87-L cells (500 cells/well) and 7W/CHO, SKAPP/SH-SY5Y, SW293/HEK293 cells (1000 cells/well) were seeded in separate 96 well plates. The U87-L cells were measured by BLI assay at 24, 48 and 72 hr after incubation of 36 hr-CM. No inhibitory effect was found by the 36 hr-CM from 7W cells (A) and SKAPP cells (B). (C) CM were harvested after SW293 and HEK293 cells were grown for 36 hr, 60 hr and 84 hr, The inhibitory effect of 60 hr and 84 hr SW293 CM on U87-L cells was stronger than the ability of 36 hr-CM. All values represent means ± SEM (n = 6), and the difference is statistically significant, * P < 0.05 compared with 36 hr-CM.