Carcinogenesis and apoptosis: paradigms and paradoxes

Apoptosis is a physiological process of cell elimination, which is important for both maintenance of cellular homeostasis, and cell proliferation and differentiation. Disturbances in the cell death process might lead to uncontrolled cell growth and to tumor formation. In addition, proper function of the apoptotic machinery is critical for tumor susceptibility to treatment. Many pro-apoptotic and anti-apoptotic genes have been cloned and their significance for the proper function of the apoptotic pathways carefully investigated. However, the precise role of these genes and their products in cancer development is less clear. Here, we will discuss some of the current paradigms and paradoxes concerning the involvement of apoptotic genes in carcinogenesis.