WT1: a weak spot in KRAS-induced transformation.
Activating mutations in the Ras alleles are found frequently in tumors, making the proteins they encode highly attractive candidate therapeutic targets. However, Ras proteins have proven difficult to target directly. Recent approaches have therefore focused on identifying indirect targets to inhibit Ras-induced oncogenesis. For example, RNAi-based negative selection screens to identify genes that when silenced in concert with activating Ras mutations are incompatible with cellular proliferation, a concept known as synthetic lethality. In this issue of the JCI, Vicent et al. report on the identification of Wilms tumor 1 (Wt1) as a Kras synthetic-lethal gene in a mouse model of lung adenocarcinoma. Silencing of Wt1 in cells expressing an endogenous allele of activated Kras triggers senescence in vitro and has an impact on tumor progression in vivo. These findings are of significant interest given previous studies suggesting that the ability of oncogenic Kras to induce senescence versus proliferation depends on its levels of expression.
Molecular and Cellular Oncogenesis Program, The Wistar Institute, Philadelphia, Pennsylvania 19104, USA.
Silvia
S
Licciulli
Joseph L
JL
Kissil
D000818:Animals; D049109:Cell Proliferation; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000378:metabolism*; D016922:Cellular Senescence / Q000502:physiology*; D006801:Humans; D051379:Mice; D009154:Mutation; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D025721:WT1 Proteins / Q000235:genetics* / Q000378:metabolism*; D018631:ras Proteins / Q000235:genetics / Q000378:metabolism*
C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; D034741:RNA, Small Interfering; D025721:WT1 Proteins; C495971:Hras protein, mouse; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins