Effects of Dietary Effectors on Signal Transduction Pathways Related to Cancer Prevention
A major focus of much of our work has been the elucidation of molecular and cellular mechanisms and the identication of gene and protein targets in cancer development and prevention. A signicant outcome of these investigations has been a clarication of signal transduction pathways induced by tumor promoters in cancer development. Signal transduction is the process by which information from a stimulus outside the cell is transmitted through the cell membrane (e.g., through a protein receptor) into the cell and along an intracellular chain of signaling proteins (e.g., protein kinases) to transcription factors, causing a cellular response (Figure 13.1). A transcription factor is comprised of one or more proteins that bind to a specic DNA sequence and act to initiate transcription that results in production of a specic protein product. DNA binding is commonly induced by protein kinases. Transcription factors acting downstream of these signaling cascades are heavily involved in numerous cellular functions that include survival, development, proliferation, apoptosis, cell cycle regulation, inammation, and differentiation (Figure 13.1).