Mutant p53-induced immortalization of primary human mammary epithelial cells
| Autor: | Q, Gao, S H, Hauser, X L, Liu, D E, Wazer, H, Madoc-Jones, V, Band |
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| Rok vydání: | 1996 |
| Předmět: |
Cyclin-Dependent Kinase Inhibitor p21
G1 Phase Gene Expression Nuclear Proteins Breast Neoplasms Epithelial Cells Proto-Oncogene Proteins c-mdm2 Genes p53 Transfection Epithelium Cell Transformation Neoplastic Cyclins Proto-Oncogene Proteins Mutation Humans Female Breast RNA Messenger Tumor Suppressor Protein p53 Cells Cultured Gene Deletion |
| Zdroj: | Cancer research. 56(13) |
| ISSN: | 0008-5472 |
| Popis: | Mutations of the p53 gene are the most frequent genetic lesions in breast cancer, suggesting a critical role for p53 protein in normal mammary cell growth control. Indeed, the p53-targeting human papillomavirus oncogene E6 induces efficient immortalization of normal human mammary epithelial cells (MECs). To assess whether selective loss of p53 is sufficient for MEC immortalization, we introduced seven missense mutants and one single-amino acid deletion mutant (del239) of p53 into the 76N normal MEC strain. Although the missense mutants failed to immortalize MECs, the del239 mutant reproducibly immortalized these cells. The immortal cells were anchorage dependent and nontumorigenic, indicating a preneoplastic transformation. Gamma-irradiation of these cells failed to induce G1 cell cycle arrest and did not lead to an increase in WAF1 and mdm-2 mRNA levels, demonstrating a loss of the endogenous p53 function. These results demonstrate that selective ablation of p53 function by a dominant-negative mutant is sufficient for immortalization of MECs. Availability of an immortalizing as well as several nonimmortalizing p53 mutants should help identify functions critical for cell growth control by p53 in mammary epithelial cells. |
| Databáze: | OpenAIRE |
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