Mode of Growth Determines Differential Expression of Prostasomes in Cultures of Prostate Cancer Cell Lines and Opens for Studies of Prostasome Gene Expression

Abstract

The exocrine secretion of the acinar gland cells in the human prostate consists of, among other components, a serous secretion and prostasomes. The prostasomes are functionally associated with both reproduction and prostate cancer development and are capable to raise autoantibodies at various pathologies. Therefore, we are trying to characterize prostasome antigens by analysing prostasome-producing cell lines of prostate cancers with the cDNA microarray technique. To obtain one state with synthesis of prostasomes and another state without synthesis, we checked whether the prostasome differentiation was influenced by the mode of growing the cells, that is, whether the cells had been growing on a solid support or on a flexible one.

We studied the expression of prostasomes in the cell lines PC3, DU145 and LNCaP. We grew the cells with the following methods: Monocellular layers on microbeads, multicellular spheroids, single cells in suspension cultures, and xenotransplants in nude rats. The presence of prostasomes was examined by ELISA, immunocytochemistry or electron microscopy.

The results showed that growing the cells on microbeads (solid support) produced a differentiation of prostasomes, while growing the cells in multicellular spheroids (flexible support) did not. Thus it should be possible to apply cDNAmicroarray analyses for characterizing the genes which are active at the cellular expression of prostasomes and then deduce the prostasome antigens.