FAM83B mediates EGFR- and RAS-driven oncogenic transformation
Rocky Cipriano, … , George R. Stark, Mark W. Jackson
Rocky Cipriano, … , George R. Stark, Mark W. Jackson
Published August 13, 2012
Citation Information: J Clin Invest. 2012;122(9):3197-3210. https://doi.org/10.1172/JCI60517.
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Research Article

FAM83B mediates EGFR- and RAS-driven oncogenic transformation

Abstract

Aberrant regulation of growth signaling is a hallmark of cancer development that often occurs through the constitutive activation of growth factor receptors or their downstream effectors. Using validation-based insertional mutagenesis (VBIM), we identified family with sequence similarity 83, member B (FAM83B), based on its ability to substitute for RAS in the transformation of immortalized human mammary epithelial cells (HMECs). We found that FAM83B coprecipitated with a downstream effector of RAS, CRAF. Binding of FAM83B with CRAF disrupted CRAF/14-3-3 interactions and increased CRAF membrane localization, resulting in elevated MAPK and mammalian target of rapamycin (mTOR) signaling. Ablation of FAM83B inhibited the proliferation and malignant phenotype of tumor-derived cells or RAS-transformed HMECs, implicating FAM83B as a key intermediary in EGFR/RAS/MAPK signaling. Analysis of human tumor specimens revealed that FAM83B expression was significantly elevated in cancer and was associated with specific cancer subtypes, increased tumor grade, and decreased overall survival. Cumulatively, these results suggest that FAM83B is an oncogene and potentially represents a new target for therapeutic intervention.

Authors

Rocky Cipriano, James Graham, Kristy L.S. Miskimen, Benjamin L. Bryson, Ronald C. Bruntz, Sarah A. Scott, H. Alex Brown, George R. Stark, Mark W. Jackson

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Figure 3

Inhibition of FAM83B suppresses breast cancer cell growth.

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Inhibition of FAM83B suppresses breast cancer cell growth. (A) Northern ...
(A) Northern analysis of FAM83B expression was performed using RNA from MCF7, HME1, and SD3-5 mutant cells. (B–D) MCF7 cells were infected with lentiviruses encoding a shRNA targeting GFP or 2 different shRNAs targeting FAM83B (B1 and B2). (B) Northern analysis. (C) Western analysis, performed using a rabbit polyclonal FAM83B antibody. (D) Cells were plated and grown for 3, 5, 7, or 10 days, and the cell number was determined. (E) Ablation of FAM83B by shRNA inhibited MCF7 AIG compared with control cells expressing a shRNA targeting GFP. (F) MCF7 cells expressing a shRNA targeting GFP or FAM83B were grown as 3D cultures in lrBM. Images were taken, and acini number was determined. Original magnification, ×10. (G) MCF7, MDA468, BT474, T47D, and MDA436 cells were infected with shRNA targeting GFP or FAM83B, and cell number was assessed. (H) Northern analysis of breast cancer cells for FAM83B. All experiments were performed in triplicate, and mean ± SD are shown. Lanes in B and H were run on the same gel but were noncontiguous (white lines).