Diethylstilbestrol-induced immortalization of human endometrial cells: alterations in p53 and estrogen receptor
1996 Study Abstract
Carcinogenesis is a process requiring multiple steps. Immortalization is one step in this process and may be rate limiting.
To further our understanding of estrogen-induced carcinogenesis, we evaluated diethylstilbestrol (DES)-induced immortalization of human endometrial stromal cells.
This was achieved by assessing at the restrictive temperature the colony-forming efficiency of cells that were conditionally immortalized with a temperature-sensitive simian virus 40 large T antigen.
- Treatment with DES for 1 wk did not increase the immortalization frequency;
- however, cultures that were treated for 20 wk had a twofold increase in immortalization frequency,
- and continued treatment for a total of 44 wk produced a threefold increase in immortalization frequency that was dose dependent.
DES-treated restrictive temperature variants (RTVs) but not spontaneous RTVs lost the temperature-sensitive phenotype. DES-RTVs also had a shorter doubling time than spontaneous RTVs did. p53 expression was increased in DES-RTVs, and its localization within the cell was altered. Conversely, expression of the estrogen receptor was decreased in DES-immortalized cells.
These changes in gene expression often occur in estrogen-related malignancies, and our results are consistent with a causal role for estrogens in these p53 and the estrogen receptor alterations. Immortalization of human cells may be analogous to initiation of rodent cells, and our results suggest that estrogen-induced alterations in p53 or other genes that regulate life span could contribute to estrogen-induced initiation.
Sources and more information
- Diethylstilbestrol-induced immortalization of human endometrial cells: alterations in p53 and estrogen receptor, Molecular carcinogenesis, NCBI PubMed PMID: 8599578, 1996 Feb.
- Crystal structure of four p53 DNA binding domains featured image credit wikipedia.