We demonstrated that introduction and expression of wild-type p53 gene in the human hepatocellular carcinoma cell line, Hep3B, resulted in up- regulation of both p21(WAF/CIP1) and bax gene expression and apoptosis. This cell line contains integrated hepatitis B virus sequences and lacks the expression of both p53 and retinoblastoma tumor suppressor genes because of deletions. Our results suggest that whereas an increased level of bax expression mediates apoptosis, an increased level of p21 (WAF1/CIP1) expression does not induce arrest of cell growth, presumably because of the deletion of the retinoblastoma gene. This study also confirms reported observations that p53 is a tumor suppressor gene, which induces apoptosis in malignant cells that lack normal p53 activity because of mutation, deletion, or inactivation of the gene by the presence of oncogenic viral proteins.
|Number of pages||10|
|Publication status||Published - Oct 1 1997|
ASJC Scopus subject areas
- Pathology and Forensic Medicine
- Molecular Biology
- Cell Biology