Figure 4: CCL2 levels from prostate cancer cells cultured alone or co-cultured with U-937 cells. (A) The PC-3 High Invasion prostate cancercells cultured alone expressed very low supernatant levels of CCL2 compared with U-937 cells and PC-3 High Invasion/U-937 co-culturesupernatants. Also, significantly increased CCL2 levels were detected in the supernatants of U-937 cells co-cultured with DU145 and LNCaPprostate cancer cells. Data are expressed as the mean ± SD of 4 independent experiments. **P<0.001. (B) Increased CCL2 levels (>30 pg/100 μgextract) were detected in the adherent cell extracts from co-cultures of PC-3 High Invasive, DU145 and LNCaP with U-937 cells whencompared with the cancer cells alone. The non-adherent cell extracts from PC-3 High Invasive/U-937 and LNCaP/U-937 co-cultures showedsimilar CCL2 levels as the U-937 cell extracts. Non-adherent cell extracts from DU145/LNCaP co-cultures were increased above U-937 cellextracts. The data are representative of 4 independent experiments.