[Signal pathways of cell proliferation and death as targets of potential chemotherapeutics]

The purpose of this paper is to review current information concerning signal transduction pathways of cell proliferation and cell death applicable in the research of antitumor compounds with a specific effect. Actually, cancer counts among the world gravest diseases. Research of the mechanisms of action of chemotherapeutics helps us to find compounds with high cytotoxic activity to tumor cells and low or no cytotoxicity to normal cells. Many present studies deal with the ability of drugs to hit the proliferation signal pathways or cell death pathways specifically. Various proliferation signal pathways have been identified, e.g. pathways of mitogen-activated proteinkinases. In original studies, cell death was considered to perform in necrotic and apoptotic forms, whereas in contrast to necrosis, apoptosis represented the programmed process. However, other forms of programmed cell death were discovered, the programmed necrosis and autophagic cell death. Similarly, beside the intrinsic, mitochondrial-mediated, and extrinsic, receptor-mediated pathways, new mechanisms of induction of apoptosis were discovered: the endoplasmic reticulum stress pathway in which calcium plays an important role, the lysosomal pathway and the ceramide-induced pathway. Current information concerning transduction of antiproliferative and death stimuli in cells allows to explain the mechanisms of action of known drugs and also brings novel therapeutical targets which can serve in treatment of such diseases as cancer.