title: SUMOylated IRF-1 shows oncogenic potential by mimicking IRF-2.
abstract: Interferon regulatory factor-1 (IRF-1) is an interferon-induced transcriptional activator that suppresses tumors by impeding cell proliferation. Recently, we demonstrated that the level of SUMOylated IRF-1 is elevated in tumor cells, and that SUMOylation of IRF-1 attenuates its tumor-suppressive function. Here we report that SUMOylated IRF-1 mimics IRF-2, an antagonistic repressor, and shows oncogenic potential. To demonstrate the role of SUMOylated IRF-1 in tumorigenesis, we used SUMO-IRF-1 recombinant protein. Stable expression of SUMO-IRF-1 in NIH3T3 cells resulted in focus formation and anchorage-independent growth in soft agar. Inoculation of SUMO-IRF-1-transfected cells into athymic nude mice resulted in tumor formation and infiltration of adipose tissues. Finally, we demonstrated that SUMO-IRF-1 transforms NIH3T3 cells in a dose-dependent manner suggesting that SUMOylated IRF-1 may act as an oncogenic protein in tumor cells.
authors: Yonsei University, Division of Biological Science and Technology, Wonju 220-100, Republic of Korea.
authors: Sun-Mi
authors: SM
authors: Park
authors: Myounghee
authors: M
authors: Chae
authors: Bo-Kyoung
authors: BK
authors: Kim
authors: Taegun
authors: T
authors: Seo
authors: Ik-Soon
authors: IS
authors: Jang
authors: Jong-Soon
authors: JS
authors: Choi
authors: Il-Chul
authors: IC
authors: Kim
authors: Je-Ho
authors: JH
authors: Lee
authors: Junsoo
authors: J
authors: Park
mesh_terms: D000818:Animals; D002460:Cell Line; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D050856:Interferon Regulatory Factor-1 / Q000235:genetics / Q000378:metabolism*; D050836:Interferon Regulatory Factor-2 / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D041681:NIH 3T3 Cells; D011499:Protein Processing, Post-Translational; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D025841:Small Ubiquitin-Related Modifier Proteins / Q000378:metabolism*; D014162:Transfection
chemical_list: D050856:Interferon Regulatory Factor-1; D050836:Interferon Regulatory Factor-2; D011994:Recombinant Proteins; D025841:Small Ubiquitin-Related Modifier Proteins