| First Author | Sayan AE | Year | 2001 |
| Journal | Oncogene | Volume | 20 |
| Issue | 37 | Pages | 5111-7 |
| PubMed ID | 11526499 | Mgi Jnum | J:71360 |
| Mgi Id | MGI:2149873 | Doi | 10.1038/sj.onc.1204669 |
| Citation | Sayan AE, et al. (2001) Acquired expression of transcriptionally active p73 in hepatocellular carcinoma cells. Oncogene 20(37):5111-7 |
| abstractText | p53 and p73 proteins activate similar target genes and induce apoptosis and cell cycle arrest. However, p53, but not p73 is considered a tumour-suppressor gene. Unlike p53, p73 deficiency in mice does not lead to a cancer-prone phenotype, and p73 gene is not mutated in human cancers, including hepatocellular carcinoma. Here we report that normal liver cells express only DeltaN-p73 transcript forms giving rise to the synthesis of N-terminally truncated, transcriptionally inactive and dominant negative p73 proteins. In contrast, most hepatocellular carcinoma cells express TA-p73 transcript forms encoding full-length and transcriptionally active p73 proteins, in addition to DeltaN-p73. We also show that together with the acquired expression of TA-p73, the 'retinoblastoma pathway' is inactivated, and E2F1-target genes including cyclin E and p14(ARF) are activated in hepatocellular carcinoma. However, there was no full correlation between 'retinoblastoma pathway' inactivation and TA-p73 expression. Most TA-p73-expressing hepatocellular carcinoma cells have also lost p53 function either by lack of expression or missense mutations. The p73 gene, encoding only DeltaN-p73 protein, may function as a tumour promoter rather than a tumour suppressor in liver tissue. This may be one reason why p73 is not a mutation target in hepatocellular carcinoma. |
