Background: Apoptotic nuclear morphology can occur independently of DFF40/CAD-mediated DNA fragmentation. Results: DFF40/CAD induces 3Ј-OH single-strand DNA nicks/breaks and nuclear collapse during caspase-dependent apoptosis. Conclusion: Caspase-dependent apoptotic nuclear collapse is prompted by DFF40/CAD-mediated single-strand DNA damage. Significance: The knowledge of how apoptotic nuclear collapse occurs should be relevant to understand the final steps of cell demise and its influence on the cellular environment.

Background: Apoptotic oligonucleosomal DNA degradation is mediated by DFF40/CAD endonuclease. Results: Poor DFF40/CAD expression in the cytosol coupled to the caspase-dependent cytosolic processing of ICAD L/S impair oligonucleosomal DNA degradation in SK-N-AS cells. Conclusion: Oligonucleosomal DNA fragmentation during apoptosis is directly correlated with adequate DFF40/CAD cytosolic levels. Significance: Learning how DFF40/CAD works is crucial for understanding the relevance of apoptosis ending in cancer development.