| 8221693 |
Santelli G, de Franciscis V, Portella G, Chiappetta G, D'Alessio A, Califano D, Rosati R, Mineo A, Monaco C, Manzo G, et al.: Production of transgenic mice expressing the Ki-ras oncogene under the control of a thyroglobulin promoter. Cancer Res. 1993 Nov 15;53(22):5523-7.
Transgenic mice have been generated bearing three fusion genes consisting of: (a) a 900-base pair rat thyroglobulin promoter followed by a gene coding for a chloramphenicol acetyl transferase activity; (b) the same promoter followed by the complementary DNA of the human activated Ki-ras oncogene; (c) a 2000-base pair rat thyroglobulin promoter followed by the complementary DNA of the human activated Ki-ras. We have shown that the 900-base pair rat thyroglobulin promoter is able to direct the expression of the reporter gene specifically in the thyroid gland of transgenic mice. The mice bearing the two Ki-ras constructs, which express the transgene in thyroid glands, show thyroid abnormalities, although at very low incidence. These lesions appear after a long latency and with a benign aspect, thus suggest that, in agreement with literature data on naturally occurring human thyroid tumors, the action of an activated ras gene is not sufficient to attain a complete malignant conversion of thyroid glands in vivo. However, ras expression in thyroid follicular cells represents a favorable ground for tumor development, as shown by the fact that goitrogen stimulation experiments increase the occurrence of tumors. |
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