Decreased Egr-1 expression in human, mouse and rat mammary cells and tissues correlates with tumor formation
✍ Scribed by Ruo-Pan Huang; Yan Fan; Ian De Belle; Christina Niemeyer; Marco M. Gottardis; Dan Mercola; Eileen D. Adamson
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- French
- Weight
- 306 KB
- Volume
- 72
- Category
- Article
- ISSN
- 0020-7136
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✦ Synopsis
We have examined several types of tumor cell lines and shown that they invariably expressed little or no Egr-1, in contrast to their normal counterparts. We have previously shown that the expression of exogenous Egr-1 in human breast and other tumor cells markedly reduces transformed growth and tumorigenicity. We therefore hypothesized that the loss of Egr-1 expression plays a role in transformation. All human and mouse breast cancer cell lines and tumors examined had reduced Egr-1 expression compared with their normal counterparts. Reduced Egr-1 expression was also observed in 7,12-dimethylbenz(a)anthracene (DMBA)-induced rat mammary tumors, and this level increased to normal levels in tumors that regressed after tamoxifen treatment. We concluded, therefore, that loss of Egr-1 expression may play a role in the deregulation of normal growth in the tumorigenic process and that Egr-1 acts as a tumor suppressor gene. Int.