Effects of a recombinant adenovirus expressing WAF1/Cip1 on cell growth, cell cycle, and apoptosis.
To evaluate the effects of a p53-inducible gene WAF1/Cip1 on cell proliferation and apoptosis, a recombinant adenovirus vector (E1 minus) expressing WAF1/Cip1 cDNA (AdWAF1) was constructed and compared with a previously studied recombinant adenovirus vector expressing wild-type p53 (AdWTp53). Infection of normal and tumor cells of lung and mammary epithelial origin with AdWAF1 resulted in high levels of WAF1/Cip1 gene expression, which was comparable to that induced by AdWTp53. AdWAF1 and AdWTp53 inhibited growth of all cells studied; tumor cells devoid of endogenous p53 (H-358) or cells expressing endogenous mutant p53 (MDA-MB-231) were more sensitive to the inhibitory effect than tumor (MCF-7) or normal mammary epithelial cells expressing endogenous wild-type p53. Cell cycle analysis of AdWTp53-infected cells indicated a decline in the cell number in S phase and a significant increase in cell number in G2-M phase. AdWAF1 infection also led to a decline in the percentage of cells in S phase and a significant accumulation of cells in G1. AdWAF1 failed to induce apoptosis in any of the cells tested. In contrast, AdWTp53 induced apoptosis in H-358 and in MDA-MB-231 cells. These data suggest that AdWTp53-mediated WAF1/Cip1 induction and cytotoxicity are likely to be associated with WAF1/Cip1-mediated cell cycle arrest. However, because overexpression of WAF1/Cip1 protein failed to induce apoptosis, AdWTp53 effects on apoptosis apparently require cellular factors in addition to WAF1/Cip1 induction.
Katayose
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Medical Breast Cancer Section, National Cancer Institute, NIH, Bethesda, Maryland 20892, USA.
Wersto
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Cowan
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Seth
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D000256:Adenoviridae / Q000235:genetics*; D017209:Apoptosis / Q000502:physiology*; D001483:Base Sequence; D001940:Breast / Q000166:cytology; D002453:Cell Cycle / Q000502:physiology*; D002455:Cell Division; D002460:Cell Line; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D004847:Epithelial Cells; D005822:Genetic Vectors; D006801:Humans; D008168:Lung / Q000166:cytology; D008969:Molecular Sequence Data; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis / Q000502:physiology
C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D016159:Tumor Suppressor Protein p53