Versatile and enhanced tumour modelling in mice via somatic cell transduction.
Bottom Line: The vectors deliver a tamoxifen-inducible and self-inactivating Cre recombinase, conditional bioluminescent and fluorescent proteins and an shRNA component.We also show that a variant vector expressing shRNA alters tumour growth dynamics and the histological grade associated with the inherited genotype.They should also be useful for inducing imageable tumours in organs other than the lung, provided that the inherited conditional genotype is sufficiently penetrant.
Affiliation: Department of Molecular Imaging, CRUK Cambridge Institute, University of Cambridge, UK.Show MeSH
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Mentions: To induce conditional and bioluminescent tumours in floxed mice, we built a lentivirus (LVâ€“indLS1) that contained CreERT2 (tamoxifen-inducible Cre recombinase), as well as firefly luciferase and mStrawberry expression cassettes. To couple expression of the transgenic reporters with tumour initiation and to limit the total size of the vector, we employed a single CAG promoter 21, flanked by inverted mutant loxP sites 22, to drive transgene expression. As depicted in Figure 1, only CreERT2 is expressed from the CAG promoter upon cell transduction. Following the functional activation of Cre recombinase by administration of tamoxifen, the promoter inverts and locks in the opposite orientation, resulting in expression of the reporter transgenes and Cre inactivation. Should other conditional tumour-related alleles also be present in the cell, they too should be activated or deleted by Cre recombinase. Consequently, tumours initiated in this way will be amenable to in vivo visualization by BLI.
Affiliation: Department of Molecular Imaging, CRUK Cambridge Institute, University of Cambridge, UK.