Biological basis for cancer treatment.

The new knowledge of the regulation of cell growth and the genetic and biochemical changes that lead to malignancy have created many new opportunities for cancer drug discovery. These new targets include oncogenes, growth factors and their receptors, signal transduction pathways, and cell differentiation signals. Attempts to identify new therapies based on these targets can complement traditional drug discovery efforts that rely on high-volume screening of candidate natural products and synthetic chemicals against human tumor cell lines and against defined molecular reactions. Through modern computer-based data analysis, drug screening data can be used to establish mechanism of drug action of new agents; these analyses shed light on patterns of cross-resistance of new compounds and their interactions with defined molecular targets as well as allow selection of chemically and biologically unique agents as candidates for clinical development.