Growth Factors Affecting Normal and Malignant Prostatic Cells

Abstract

The growth of any tissue, whether normal or malignant, depends upon the quantitative relationship between the rate of cell proliferation and cell death. In normal adult tissues, these rates are balanced such that a steady state (i.e., self-renewing) relationship is maintained in which the size of the normal tissue does not increase continuously with time. Studies in a variety of different tissues have demonstrated that this steady state balance is regulated by a series of both systemic and local growth factors. A fundamental characteristic of cancer is that unlike their normal counterparts, their rate of cell proliferation exceeds their rate of cell death, thus resulting in continuous net growth of the cancer. This does not mean, however, that cancer cells are unresponsive and therefore autonomous to such growth factors. On the contrary, many types of cancer cells respond to normal growth factors and often in a manner very similar to that of the normal cell of origin.