In general RPMI 1640 medium, supplemented with 2 mM L-Glutamine and 1% Penicillin-Streptomycin and FCS (either 10% or 1% according to the assay) was used for monocyte/macrophage, NCI-H460, HCC1143 and DU145 cell culture. For MCF-7 cells we used Eagle´s MEM, supplemented with 10% FCS, 2 mM L-Glutamine, 1% Penicillin/Streptomycin and 1 mM Sodium Pyruvate and for PA-TU-8902 cells Dulbecco´s MEM High Glucose supplemented with 1 mM Sodium Pyruvate, 2 mM L-Glutamine, 1% Penicillin/Streptomycin and either 10% or 1% FCS was used (all reagents from Sigma, Buchs, Switzerland).
Cell lines were kept under standard culture conditions (37°C, 5% CO2 and 95% humidity), tumour cell conditioned media were obtained by 24 h incubation of 90% confluent tumour cells in 10 ml of fresh culture medium in 25 cm2 cell flasks. Cell free supernatants were carefully harvested, filtered through 0.5 μm filters and stored in aliquots at −80°C.