MODULATION OF PROLIFERATION AND CELLULAR-CHANGES OF HUMAN PROSTATIC-CANCER CELLS BY ACTIVATED LYMPHOCYTES

The effect of immune cells on the growth and development of human pros tatic cancer cells was investigated. Cell proliferation of androgen-in dependent human prostatic cancer cells JCA-1 was reduced 30-40% with t he supplementation of a growth modulating activity present in lymphocy te conditioned medium. The slower growing cells had a longer doubling time revealing a blocking for G(1) cells entering into S phase. The cl onogenicity of the cells was also reduced. Displayed in parallel was a ltered phenotypes including the development of dendrite-like processes with less intercellular contact. Immunocytochemical staining showed s ignificantly increased: expression of actin, vimentin and cytokeratin 8, suggesting a differentiated cell type. Activated lymphocytes were s hown to require RNA synthesis for providing the modulating activity wh ich was estimated to be 18,500-27,500 Da. The role of immune cells in growth regulation of prostatic cells is discussed.