mutation suppresses colorectal cancer by promoting eEF2 phosphorylation via eEF2K.

Abstract

Increased protein synthesis supports the rapid cell proliferation associated with cancer. Themutant mouse reduces the expression of the ribosomal protein RPL24 and has been used to suppress translation and limit tumorigenesis in multiple mouse models of cancer. Here, we show thatalso suppresses tumorigenesis and proliferation in a model of colorectal cancer (CRC) with two common patient mutations,and. In contrast to previous reports,mutation has no effect on ribosomal subunit abundance but suppresses translation elongation through phosphorylation of eEF2, reducing protein synthesis by 40% in tumour cells. Ablating eEF2 phosphorylation inmutant mice by inactivating its kinase, eEF2K, completely restores the rates of elongation and protein synthesis. Furthermore, eEF2K activity is required for themutant to suppress tumorigenesis. This work demonstrates that elevation of eEF2 phosphorylation is an effective means to suppress colorectal tumorigenesis with two driver mutations. This positions translation elongation as a therapeutic target in CRC, as well as in other cancers where themutation has a tumour suppressive effect in mouse models.