AKT signalling is required for ribosomal RNA synthesis and progression of E-mu-Myc B-cell lymphoma in vivo

Jennifer R Devlin, Katherine M Hannan, Pui Yee Ng, Megan Bywater, Jake Shortt, Carleen M Cullinane, Grant McArthur, Ricky W Johnstone, Ross Duncan Hannan, Richard Bruce Pearson

Research output: Contribution to journalArticleResearchpeer-review

17 Citations (Scopus)

Abstract

The dysregulation of PI3K/AKT/mTORC1 signalling and/or hyperactivation of MYC are observed in a high proportion of human cancers, and together they form a super signalling network mediating malignancy. A fundamental downstream action of this signalling network is up-regulation of ribosome biogenesis and subsequent alterations in the patterns of translation and increased protein synthesis, which are thought to be critical for AKT/MYC-driven oncogenesis. We have demonstrated that AKT and MYC cooperate to drive ribosomal DNA (rDNA) transcription and ribosome biogenesis, with AKT being essential for rDNA transcription and in vitro survival of lymphoma cells isolated from a MYC-driven model of B-cell lymphoma (Emu-Myc) [Chan JC et al., (2011) Science Signalling 4, ra56]. Here we show that the allosteric AKT inhibitor MK-2206 rapidly and potently antagonizes rDNA transcription in Emu-Myc B-cell lymphomas in vivo, and this is associated with a rapid reduction in indicators of disease burden, including spleen weight and the abundance of tumour cells in both the circulation and lymph nodes. Extended treatment of tumour-bearing mice with MK-2206 resulted in a significant delay in disease progression, associated with increased B-cell lymphoma apoptosis. Our findings suggest that malignant diseases characterized by unrestrained ribosome biogenesis may be vulnerable to therapeutic strategies that target the PI3K/AKT/mTORC1/MYC growth control network.
Original languageEnglish
Pages (from-to)5307 - 5316
Number of pages10
JournalThe FEBS Journal
Volume280
Issue number21
DOIs
Publication statusPublished - 2013

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