Detection of adenovirus and initiation of apoptosis in hepatocellular carcinoma cells after Ad-p53 treatment

Transcription of the p53 gene can regulate progression of apoptosis in a wi de variety of tissues. Three categories of human hepatocyte culture have be en used to show the initiation of apoptosis after treatment with p53-bearin g adenovirus, Chang liver cells are derived from normal liver tissue and ex press native p53, whereas hepatocellular carcinoma (HCC)-derived cell lines were Hep3B (p53-deleted) and PLC/PRF/5 (p53-mutant). Cultures were infecte d with Ad-p53 (15 particles per cell; 36 hours), and after treatment, morph ological changes in all cell categories were observed by electron microscop y. Infection was evident in the cytoplasm of all treated cell types: after entry across the plasma membrane viruses translocated and came to rest surr ounding and adjacent to nuclei, cytoplasm proximal to nuclear membranes bec ame dense with virus- and membrane-derived debris, but intact viruses did n ot enter nuclei. Apoptosis, recognized morphologically by characteristic ch romatin and cytoplasmic condensation, occurred more frequently in HCC-deriv ed cells, and the ultimate fate of apoptotic bodies was phagocytosis and de gradation by neighboring cells.