Generation of Tumors in Transgenic Mice Expressing the SV40 T Antigen Under the Control of Ovarian-Specific Promoter 1
Department of Cellular and Molecular Medicine, University of Ottawa and Ottawa Regional Cancer Centre, Ottawa, Ontario, Canada; and Ovarian Cancer Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania
Centre for Cancer Therapeutics, Ottawa Regional Cancer Centre, 3rd Floor, 503 Smyth Road, Ottawa, ON, Canada, K1H 1C4 Objective: The ovarian-specific promoter, OSP-1, which was cloned from the transcript of a rat retrovirus-like element specifically expressed in ovarian tissue, was tested for its ability to drive ovary-specific transcription in transgenic mice. Methods: Transgenic mice were generated with the lacZ reporter gene (OSP-lacZ) or the early region of SV40 virus (OSP-TAg) placed under the control of the OSP-1 promoter. OSP-lacZ and OSP-TAg transgenic animals were examined, respectively, for the expression of lacZ (OSP-lacZ) or the development of tumors (OSP-TAg). Results: The expression of lacZ in the resulting OSP-lacZ mice was restricted to the ovary as determined by X-gal staining of multiple organs. Immunohistochemical detection of ß-galactosidase showed lacZ expression mainly in the granulosa cells and ovarian surface epithelial cells. OSP-TAg mice developed tumors in a variety of tissues, including unilateral granulosa cell tumors in two of three female founder mice. In the contralateral ovary of one mouse with a granulosa cell tumor, there wee alterations in the ovarian surface epithelial cells suggestive of preneoplasia. Conclusions: Although the OSP-1 promoter was able to restrict reporter gene expression to the ovary in transgenic mice, the expression of TAg in the OSP-TAg mice resulted in ovarian tumors as well as tumors in numerous other organs. This indicated that although transcription from the OSP-1 promoter occurs predominantly in the ovary, this promoter is sufficiently leaky in cells in other tissues to permit their tumorigenic conversion by SV40 TAg.
Key Words: Ovarian cancer ovary OSP-1 promoter granulosa tumor transgenic
Journal of the Society for Gynecologic Investigation, Vol. 10, No. 4,
244-250 (2003) |
|
|||

