Wilms tumor 1 (WT1) regulates KRAS-driven oncogenesis and senescence in mouse and human models
Silvestre Vicent, … , William C. Hahn, E. Alejandro Sweet-Cordero
Silvestre Vicent, … , William C. Hahn, E. Alejandro Sweet-Cordero
Published October 25, 2010
Citation Information: J Clin Invest. 2010;120(11):3940-3952. https://doi.org/10.1172/JCI44165.
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Research Article

Wilms tumor 1 (WT1) regulates KRAS-driven oncogenesis and senescence in mouse and human models

Abstract

KRAS is one of the most frequently mutated human oncogenes. In some settings, oncogenic KRAS can trigger cellular senescence, whereas in others it produces hyperproliferation. Elucidating the mechanisms regulating these 2 drastically distinct outcomes would help identify novel therapeutic approaches in RAS-driven cancers. Using a combination of functional genomics and mouse genetics, we identified a role for the transcription factor Wilms tumor 1 (WT1) as a critical regulator of senescence and proliferation downstream of oncogenic KRAS signaling. Deletion or suppression of Wt1 led to senescence of mouse primary cells expressing physiological levels of oncogenic Kras but had no effect on wild-type cells, and Wt1 loss decreased tumor burden in a mouse model of Kras-driven lung cancer. In human lung cancer cell lines dependent on oncogenic KRAS, WT1 loss decreased proliferation and induced senescence. Furthermore, WT1 inactivation defined a gene expression signature that was prognostic of survival only in lung cancer patients exhibiting evidence of oncogenic KRAS activation. These findings reveal an unexpected role for WT1 as a key regulator of the genetic network of oncogenic KRAS and provide important insight into the mechanisms that regulate proliferation or senescence in response to oncogenic signals.

Authors

Silvestre Vicent, Ron Chen, Leanne C. Sayles, Chenwei Lin, Randal G. Walker, Anna K. Gillespie, Aravind Subramanian, Gregory Hinkle, Xiaoping Yang, Sakina Saif, David E. Root, Vicki Huff, William C. Hahn, E. Alejandro Sweet-Cordero

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Figure 1

A negative selection screen to identify Kras effectors.

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A negative selection screen to identify Kras effectors. (A) Design o...
(A) Design of shRNA screen. T1 and T2 show 3 and 6 weeks in vitro proliferation, respectively. T3 shows 3 weeks of subcutaneous growth. Colored bars represent the relative ratio of the MFI of a particular barcode corresponding to a shRNA at T1/T2/T3 over T0. Light blue bar depicts a theoretical barcode negatively selected over time. (B) Quantitation of each shRNA at T2 compared with T0. MFI measurements are average of 3 independent experiments done for each of the 2 cell lines at each time point. x axis shows log2 of average mean MFI for each shRNA. y axis shows log2 of fold change of MFI between the 2 time points. Red squares indicate shRNAs negatively selected as described in text, with at least 1 other negatively selected shRNA against the same gene. (C) Knockdown of intended target for each shRNA identified as negatively selected using rtPCR. Results show relative mRNA expression for each gene compared with a control shRNA. Results for knockdown of Kras are also shown. (D) Proliferation of LKR13 cells infected with shRNAs for target genes that showed on-target effect as demonstrated in C. Cells were place in 96-well plates and analyzed using the MTT assay at day 7 after selection. Results are the average of 3 independent measurements. Error bars indicate mean ± SD.