A NEW SERIAL TRANSFER EXPLANT CELL-CULTURE SYSTEM FOR HUMAN PROSTATIC-CANCER TISSUES PREVENTING SELECTION TOWARD DIPLOID-CELLS

An improved explant cell culture technique to avoid selection of prost atic adenocarcinoma cells toward diploid cells is described. This meth od is based on 1) histologically characterized tissue explants, 2) the use of polyethylenteraphthalate (PET) membranes as growth surface, wh ich are part of special inserts in six-well-plates to allow 3) coculti vation with heterologous fibroblasts, and 4) coating of the membranes with elements of the extracellular matrix. The main characteristic of this particular approach is the serial transfer of the tissue explant from one membrane to the other, Up to ten serial transfer steps could be performed to produce cell monolayers growing out of the same tissue specimen. Using this approach, 21 prostatic carcinoma specimens that were obtained from 13 primary prostatic adenocarcinomas after radical prostatectomy were cultivated. Ploidy of the cells was monitored by fl uorescence in situ DNA hybridization using the centromere specific DNA probes pUC1.77, p alpha 7t1, and pY3.4. Interestingly, a high aneuplo idy rate of the cell cultures was found with maintainance of aneuploid y in 18 (86%) of the 21 paraffin-embedded cancer tissue specimens with proved aneuploidy. Although a slight decrease of the proportion of an euploid cells during serial transfer bt as observed, significant aneup loid cell populations were retained up to a maxim um of ten transfer s teps. These findings indicate that selection toward diploid cells can be prevented by improved cell culture techniques that mimic the in viv o situation. (C) Elsevier Science Inc., 1998.