Abortive apoptosis as an initiator of chromosomal translocations

Apoptosis is a well-recognized regulator of a cell populations size and str ucture. Irreversible stages of apoptosis lead to activation of different en zymatic cascades, changes in cell morphology and DNA fragmentation. However , little is known about nuclear events which accompany the initial stages o f apoptosis. These events are connected with introduction of limited amount s of double strand breaks into genomic DNA, some of which may be subsequent ly rejoined. We hypothesize here that the initial stages of apoptotic DNA f ragmentation may be reversible and connected with the initiation of recombi national events and certain chromosomal translocations. The factors influen cing apoptosis reversibility and cell survival after delivery of apoptotic stimuli may provide new insights into mechanisms of lymphocyte development and tumorigenesis.