Molecular insights into altered cell cycle regulation and genitourinary malignancy.

The basis for malignancy is the deregulation of the cell cycle resulting in uncontrolled cellular proliferation. This review examines our current understanding of peptide growth factors, stimulatory and inhibitory signaling cascades, protooncogenes and tumor suppressor genes, cyclin dependent kinases and cyclins as they relate to the cell cycle. The epidermal growth factor and transforming growth factor β transduction pathways are presented to illustrate the complex interactions required for normal signaling and control of the cell cycle. The second part of the review explores the relevance of these pathways and their alterations in the genitourinary malignancies of the prostate, bladder, kidney and testis.