Figure 1: Effect of U-937 monocyte lineage cell co-cultures on prostate cancer cell invasion activity. (A) Relative invasion activity of labeledPC-3, DU145 or LNCaP cells with or without U-937 cells added to the lower chamber of the Transwell apparatus. The prostate cancer celllines co-cultured with U-937 cells lead to significantly increased prostate cancer cell invasion when compared to the cancer cells culturedalone. The results are expressed as relative invasion activity at 48 hours of at least 3 independent experiments ± SD. *P<0.05; **P<0.001. (B)Viable prostate cancer cell number was determined by MTT assay after 48 hours of co-culture. The viable cancer cell numbers did not differbetween cancer cells cultured alone and cancer cells co-cultured with U-937 cells. The data are representative of three independent experiments.