Changes in cell growth, cyclin/kinase, endogenous phosphoproteins and nm23 gene expression in human prostatic JCA-1 cells treated with modified citrus pectin.

Modified citrus pectin (MCP) added to the media of cultured androgen-independent human prostatic JCA-1 cells reduced cell growth and correspondingly [3H]thymidine incorporation into DNA, which was correlated with the down-regulation of cyclin B and p34cdc2 MCP also induced distinct increases in specific endogenous phosphoproteins, including a cAMP-stimulated 52,000 (52-kDa) protein. Since metastatis has been inversely correlated with nm23 gene expression in some cancer cells and was reportedly inhibited by MCP in a rat prostate model, we investigated steady state level changes in the nm23 protein in JCA-1 cells and found it to be unexpectedly suppressed as a result of exposure to MCP.