Characterization of the Src-regulated kinome identifies SGK1 as a key mediator of Src-induced transformation

• DOI: 10.1038/s41467-018-08154-1
• Publication Date: 2019-01-11T15:38:41Z
• Authors: Xiuquan Ma; Luxi Zhang; Jiangning Song; Elizabeth Nguyen; Rachel S. Lee; Samuel J. Rodgers; Fuyi Li; Cheng Huang; Ralf B. Schittenhelm; Howard Chan; Chanly Chheang; Jianmin Wu; Kristin K. Brown; Christina A. Mitc...; Kaylene J. Simpson; Roger J. Daly
• Keywords: Proteomics; 0301 basic medicine; 570; oncogenes; Science; Nude; 610; Mice, Nude; Triple Negative Breast Neoplasms; Antineoplastic Agents; Protein Serine-Threonine Kinases; Cell Transformation; Small Interfering; Article; Mass Spectrometry; Cell Line; Immediate-Early Proteins; Mice; 03 medical and health sciences; proteomics; Cell Line, Tumor; Protein Interaction Mapping; Animals; Humans; Benzodioxoles; RNA, Small Interfering; Inbred BALB C; Neoplastic; Mice, Inbred BALB C; Tumor; Q; Oncogenes; Xenograft Model Antitumor Assays; Gene Expression Regulation, Neoplastic; kinases; src-Family Kinases; Cell Transformation, Neoplastic; HEK293 Cells; Gene Expression Regulation; Gene Knockdown Techniques; Quinazolines; RNA; Female; Cell signalling; Signal Transduction

AbstractDespite significant progress, our understanding of how specific oncogenes transform cells is still limited and likely underestimates the complexity of downstream signalling events. To address this gap, we use mass spectrometry-based chemical proteomics to characterize the global impact of an oncogene on the expressed kinome, and then functionally annotate the regulated kinases. As an example, we identify 63 protein kinases exhibiting altered expression and/or phosphorylation in Src-transformed mammary epithelial cells. An integrated siRNA screen identifies nine kinases, including SGK1, as being essential for Src-induced transformation. Accordingly, we find that Src positively regulates SGK1 expression in triple negative breast cancer cells, which exhibit a prominent signalling network governed by Src family kinases. Furthermore, combined inhibition of Src and SGK1 reduces colony formation and xenograft growth more effectively than either treatment alone. Therefore, this approach not only provides mechanistic insights into oncogenic transformation but also aids the design of improved therapeutic strategies.