The translation elongation factor eEF1A promotes protein synthesis. Its methylation by METTL13 increases its activity, supporting tumor growth. However, in some cancers, a high abundance of eEF1A isoforms is associated with a good prognosis. Here, we found that eEF1A2 exhibited oncogenic or tumor-suppressor functions depending on its interaction with METTL13 or the phosphatase PTEN, respectively. METTL13 and PTEN competed for interaction with eEF1A2 in the same structural domain. PTEN-bound eEF1A2 promoted the ubiquitination and degradation of the mitosis-promoting Aurora kinase A in the S and G2 phases of the cell cycle. eEF1A2 bridged the interactions between the SKP1-CUL1-FBXW7 (SCF) ubiquitin ligase complex, the kinase GSK3β, and Aurora-A, thereby facilitating the phosphorylation of Aurora-A in a degron site that was recognized by FBXW7. Genetic ablation of Eef1a2 or Pten in mice resulted in a greater abundance of Aurora-A and increased cell cycling in mammary tumors, which was corroborated in breast cancer tissues from patients. Reactivating this pathway using fimepinostat, which relieves inhibitory signaling directed at PTEN and increases FBXW7 expression, combined with inhibiting Aurora-A with alisertib, suppressed breast cancer cell proliferation in culture and tumor growth in vivo. The findings demonstrate a therapeutically exploitable, tumor-suppressive role for eEF1A2 in breast cancer.

Amplification of human chromosome 20q has been reported as the most frequently recurring genetic abnormality associated with large scale changes in mRNA and protein levels in sporadic colorectal carcinomas. While some studies have found 20q amplification to be consistent between primary and metastatic samples from the same patient with a role in the development of metastasis and worse patient prognosis, others have reported association with improved overall survival for a subset of these patients with colorectal cancer (CRC). To fine map the Minimal Common Regions (MCRs) of amplification on chromosome 20q and identify the candidate genes playing roles in progression of the disease, microarray comparative genomic hybridization analyses of two in vitro cultured CRC liver metastasis cell line model systems was utilized. Microarray expression analysis led to the identification of a candidate gene signature comprising of four genes, BMP7, DNMT3B, UBE2C and YWHAB, residing in the MCRs that were over expressed in CRC cells. By validating our results in a training set of 23 adenocarcinomas (tumors) and five adenomas (polyps) using reverse transcription‑quantitative PCR, as well as analyses of two larger colorectal cancer test data sets derived from 195 The Cancer Genome Atlas and 182 MD Anderson Cancer Center patients with colorectal adenocarcinoma patients, this gene signature was ascertained to be associated with lymph node spread and/or distant metastasis (P<0.05). Previously reported functional studies of the gene signature indicated their involvement in inflammatory and immune response pathways driving CRC progression.