Abstract
Glucocorticoids are effective inhibitors of epidermal proliferation and skin tumorigenesis. Glucocorticoids affect cellular functions via glucocorticoid receptor (GR), a well-known transcription factor. Recently, we generated skin-targeted transgenic mice overexpressing GR under control of the keratin5 promoter (K5-GR mice). To test the hypothesis that GR plays a role as a tumor suppressor in skin, we bred K5-GR transgenic mice with Tg.AC transgenic mice, which express v-Ha-ras oncogene in the skin, and compared the susceptibility of F1 offspring to TPA-induced skin carcinogenesis. GR overexpression in the epidermis dramatically inhibited skin tumor development. In K5-GR/ras+ double transgenic mice papillomas developed later and the average number of tumors per animal was 15% (in males) and 40% (in females) of the number seen in wild type (w.t./ras+) littermates. In addition, the papillomas in w.t./ras+ animals were eight to nine times larger. GR overexpression resulted in a decrease in keratinocyte proliferation combined with a modest increase in apoptosis and differentiation of keratinocytes in K5-GR/ras+ papillomas. Our data clearly indicate that interference of GR transgenic protein with nuclear factor kappa B (NF-κB) transcription factor had resulted in NF-κB blockage in K5-GR/ras+ tumors. We discuss the role of NF-κB blockage in tumor-suppressor effect of GR.
Original language | English (US) |
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Pages (from-to) | 3279-3287 |
Number of pages | 9 |
Journal | Oncogene |
Volume | 22 |
Issue number | 21 |
DOIs | |
State | Published - May 22 2003 |
Funding
We thank Dr R Cannon for his generous gift of reagents, technical support and valuable comments, Dr R Strange for his critical suggestions and P Wolfe for statistical analysis of data. We acknowledge Dr C Conti and Dr A Bravo for their help with histopathological diagnosis of tumors. This study was supported by NIH grant RO1-CA-79065-01 and partially by grant SAF2002-04368-C02-01 from the Spanish Ministry of Science and Technology.
Keywords
- Glucocorticoid receptor
- NF-κB
- Skin carcinogenesis
- Transgenic mice
ASJC Scopus subject areas
- Genetics
- Molecular Biology
- Cancer Research