@article{oai:repo.qst.go.jp:00044526, author = {Ukai, Hideki and Ishii-Ohba, Hiroko and Ukai-tadenuma, Maki and Ogiu, Toshiaki and Tsuji, Hideo and 鵜飼 英樹 and 石井 洋子 and 荻生 俊昭 and 辻 秀雄}, journal = {Molecular Carcinogenesis}, month = {}, note = {Although many reports suggest that aberrant regulation of cytokine signaling pathways via the interleukin-2 receptor (IL-2R) induces tumorigenic transformation, constitutively active IL-2R in tumors has not been reported. We searched for genomic alteration of the IL-2/15R beta-subunit gene (IL-2/15R beta) in cytokine-independent cell lines established from radiation-induced mouse thymic lymphomas. In the TL34 cell line and its primary tumor, one of the IL-2/15R beta alleles was rearranged by the insertion of an intracisternal A particle (IAP) retrotransposon. The IAP-IL2/15R beta chimeric gene expressed chimeric mRNA in which IAP-coding Gag-Pol mRNA was fused to IL-2/15R beta mRNA and coded for Gag-Pol-IL-2/15R beta chimeric protein. Forced expression of the Gag-Pol-IL-2/15R beta chimeric cDNA in a mouse cytotoxic T-cell line (CTLL-2) converted IL-2-dependent cell growth to IL-2-independent growth, suggesting that the chimeric protein activates some of the IL-2 signaling pathways necessary for cell proliferation. Downregulation of the expression of the Gag-Pol-IL-2/15R beta chimeric protein in TL34 by antisense RNA inhibited cell growth, and concomitantly reduced the level of c-myc protein. These results suggest that the Gag-Pol-IL-2/15R beta is a constitutively active form that transmits proliferative signals by expressing downstream target genes, including c-myc. Thus, we demonstrated that the chimeric receptor gene produced by the insertion of an IAP functions as an oncogene by providing IL-2-independent autonomous growth potential.}, pages = {110--119}, title = {Formation of an Active Form of the Interleukin-2/15 Receptor beta-Chain by Insertion of the Intracisternal A Particle in a Radiation-Induced Mouse Thymic Lymphoma and Its Role in Tumorigenesis}, volume = {37}, year = {2003} }