Androgen receptor expression, proliferation index and aneuploidy in tissue explant cultures derived prostate carcinoma cells co-cultivated on membranes.

Abstract

An improved explant cell culture technique to avoid selection of prostatic adenocarcinoma cells toward diploid cells is described. 21 prostatic carcinoma specimens which were obtained from 13 primary prostatic adenocarcinomas after radical prostatectomy were cultivated. Ploidy of the cells was monitored by fluorescence in situ DNA hybridization using the centromere-specific DNA probes pUC1.77, p alpha 7t1 and pY3.4. Phenotypic examination of androgen receptor (AR) expression was performed simultaneously with immunostaining by Ki-67 as proliferation marker to identify androgen-independent growing cell clones. Interestingly, a high aneuploidy rate of the cell cultures was found with maintenance of aneuploidy in 18 (86%) of the 21 paraffin-embedded cancer tissue specimens with proved aneuploidy. Significant aneuploid cell populations were retained up to a maximum of ten transfer steps. During serial transfer of tumor pieces the aneusomic fraction slightly decreased as well as the percentage of AR/Ki-67-positive cells. The presented in vitro model allows to study the proliferation of genetically abnormal cells with respect to hormone dependency in a paracrine situation.