Use of avian retroviral vectors to introduce transcriptional regulators into mammalian cells for analyses of tumor maintenance

摘要: Abstract A key issue in cancer biology is whether genetic lesions involved tumor initiation or progression are required for maintenance. This question can be addressed with mouse models that conditionally express oncogenic transgenes, i.e., under the control of tetracycline (tet)-dependent transcriptional regulators. We have developed a system studying maintenance by using avian retroviral [i.e., replication-competent leukosis virus long terminal repeat splice acceptor (RCAS)] vectors to deliver reverse tet transactivator (rtTA) gene somatic mammalian cells. rtTA regulate any transgene which protein coding sequence preceded tet-operator (tet-o); RCAS viruses infect only cells engineered ectopically receptor, TVA. One vector, RCAS-rtTA-IRES-GFP, also encodes GFP identify infected Infection from β-actin TVA transgenic mice this vector permits efficient regulation tet-responsive transgenes. Sarcomas arise when p53-deficient murine embryonic fibroblasts carrying and tet-o-K-ras4bG12D transgenes RCAS-rtTA-IRES-GFP introduced into nude treated analog, doxycycline (dox); dox withdrawn, K-ras4bG12D levels fall, undergo apoptosis, tumors regress. Regression prevented means complementation assay superinfected before withdrawal other viruses, such as those an active allele K-ras. Many tet-regulated been generated; thus, method cell-specific temporally controlled expression may broad applications study oncogenesis maintenance, well cell functions development.