Growth of human urologic tumors on extracellular matrix

Surgical specimens of fifty urologic tumors, 19 renal, 19 bladder, nine prostate and three testicular, were disaggregated into a cell suspension by a two step mechanical and enzymatic method. Viability, cytology and flow cytometry (FCM) for DNA ploidy were subsequently determined. Growth of urological tumors on extracellular matrix (ECM) was carried out as follows: 2.5 to 5 X 10(5) cells were placed in plastic T25 flasks in RPMI 1640 + 10 per cent fetal bovine serum (FBS). 1.0 to 5 X 10(4) cells were plated in wells coated with ECM derived from bovine corneal endothelial cells with RPMI 1640 + 10 per cent FBS. Cultures were incubated for seven to 10 days at 37 degrees C. Only one (renal) out of 28 tumors grew on plastic. Forty out of 50 tumors (80 per cent) established primary cultures on ECM as determined by cell counting, protein determination, and/or [3H]thymidine incorporation. Previous experience with 106 urologic tumors grown on double layer agar demonstrated an overall success rate of 48 per cent. On ECM renal tumors showed 95 per cent growth success, prostate 89 per cent, bladder 63 per cent and testicular 67 per cent. Unlike viability by trypan blue exclusion, tumor DNA ploidy and percentage of malignant cells plated on ECM had no effect on growth success. The malignant nature of the cultured cells was confirmed by cytology. Twelve high grade and metastatic tumors caused degradation of the ECM. DNA ploidy was similar in four and different in six tumors before and after culture. Five tumors underwent in vitro drug testing on ECM with significant growth inhibition observed in three cases. The extracellular matrix seems to be a promising model for growing urologic tumors with excellent potential for drug testing in vitro.