Induction of efficient apoptosis and cell-cycle arrest in tumor cells by adenovirus-mediated p53 A4 mutant.
p53 is an effective tumor suppressor and is inactivated in numerous cancer cells. In the present study, p53 mutant A4, which carries mutations in C-terminus of the protein and is resistant to murine double minute 2-mediated degradation, was exploited to introduce p53 function in tumor cells. The effect of p53 A4 mutant with recombinant adenovirus vector (Ad-p53 A4) was examined. Ad-p53 A4 infection at a low multiplicity of infection showed significant accumulation of p53 protein and strongly induced a killing effect on osteosarcoma cell line MG-63 that is less sensitive to transduction of wild-type p53. DNA fragmentation assay and caspase assay showed that the cell death induced by Ad-p53 A4 was more rapid and higher than that by Ad-p53 wild-type infection. It is also showed Ad-p53 A4 induces cell-cycle arrest in G1 phase. Moreover, a similar effect was observed in some human cancer cell lines (HeLa, HepG2, KATO III and Saos-2) in various status of endogenous p53 expression. These results suggest that Ad-p53 A4 has the ability to strongly suppress tumor cells and is a promising, novel tool for cancer gene therapy.
Division of Molecular Biology, Department of Molecular and Cellular Biology, School of Life Science, Tottori University Faculty of Medicine, Yonago, Japan.
Akihiro
A
Maeda
Seiichi
S
Nakamura
Masato
M
Isono
Mitsuhiko
M
Osaki
Hisao
H
Ito
Kenzo
K
Sato
D000256:Adenoviridae / Q000235:genetics*; D000595:Amino Acid Sequence; D017209:Apoptosis / Q000502:physiology*; D015152:Blotting, Northern; D015153:Blotting, Western; D002453:Cell Cycle / Q000502:physiology*; D045744:Cell Line, Tumor; D005434:Flow Cytometry; D018014:Gene Transfer Techniques; D016158:Genes, p53 / Q000235:genetics*; D005822:Genetic Vectors; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation