Bicistronic vectors for animal models of breast and prostate cancer

Abstract

The improving of our understanding of cancer development still depends on cancer research at the molecular level. In his project, bigenic vectors for animal models of breast and prostate cancer are created. Bigenic constructs are useful because they create animals expressing two genes of interest at a time, with one injection step and no need for crossings. In order to produce these vectors, previous animal models have been analyzed, and the elements that worked successfully in previous models were gathered in a new arrangement for the creation of an improved model. In order to create a bigenic vector, the viral internal ribosomal entry site was utilized, as a means of obtaining two protein products from one transcript. One vector, the MMTV-Neu1842-IRES-Cre was successful in generating a line of transgenic mice. Female founders of this line already express the expected phenotype, tumors of the mammary tissue. Once this line is established, it can be crossed with the Rosa26 line, to determine the pattern of Cre expression. Other vectors were created for models of prostate cancer, using the probasin promoter and the MT oncogene. While transgenic mice were attempted, there were no phenotype differences between wild type and transgenic mice. All created vectors were tested for expression ofthe two genes carried in tissue culture experiments. All the experiments were successful, indicating a working oncogene (by means of a focus assay) and Cre activity (by excission assay). The new breast cancer animal model carrying the MMTV-Neu1842-IRESCre construct is promising and can be used in combination with existing models to answer some of the remaining questions regarding breast cancer signaling pathways.