Prostate epithelial cell lines form spheroids with evidence of glandular differentiation in three-dimensional Matrigel cultures

Normal (PNT2-C2) and metastatic (PC-3) prostate cell lines were grown in Ma trigel to observe the effects on morphology and phenotype in comparison to monolayer culture. In monolayer cultures, PNT2-C2 showed typical round/cubo idal epithelial morphology, with tight cell associations, whereas in Matrig el they formed smooth spheroids, tightly packed with cells. In both monolay er and Matrigel, PNT2-C2 had a differentiated luminal epithelial phenotype with high expression of cytokeratin 8, prostate specific antigen (PSA), pro state specific membrane antigen (PSMA), E-cadherin and desmoglein. In contr ast, PC-3 cells possessed an epithelial/mesenchyme morphology in monolayer with loose cell to cell contact and pseudopodial extensions. Immunohistoche mical phenotyping indicated the cells were undifferentiated, expressing hig h levels of vimentin, beta1 integrin, CD44 and low expression of cytokerati n 8. In Matrigel they formed smooth and irregular spheroids, which had a lu men surrounded by a single cell layer. Matrigel also influenced the express ion of PSA, PSMA and CD44. These results indicate that Matrigel culture can induce morphological differentiation of prostate cancer cells which initia lly had a basal phenotype. (C) 2001 Cancer Research Campaign http://www.bic ancer.com.