A ’translation factor’ protein over-expressed in breast cancer cells might be an oncoprotein

The tissue-specific elongation factor eEF1A2 might be an oncoprotein involved in breast cancer. Research published in the open access journal BMC Cancer shows that eEF1A2, which is usually present only in muscle cells and neurons, is abnormally expressed in two thirds of breast tumours. This means it could be used as a new diagnostic marker and, once its role as been identified, as a therapeutic target for the treatment of breast tumours.

Catherine Abbott, Victoria Tomlinson and colleagues, from the University of Edinburgh in the UK, studied the expression of eEF1A2 in breast tumour cells both at the RNA and at the protein level. The results from both analyses show that eEF1A2 is moderately to highly expressed in two-thirds of malignant tumour cells, whereas the protein is only barely expressed in normal breast cells; the expression of eEF1A2 is up to 30-fold higher in tumour cells than in normal cells. Over-expression is considerably more significant in tumour cells bearing the estrogen receptor (ER) than in ER-negative tumour cells: 18% of ER-negative tumours showed slight expression of eEF1A2, whereas 63% of ER-positive tumours showed significant expression of the protein.

Recent studies had shown that eEF1A2 is over-expressed in ovarian cancer cells, but the protein had not been shown to be expressed in breast cancer cells. More research is needed to identify its exact role in the development of breast tumours. “The oncogenicity of eEF1A2 may be related to its role in protein synthesis or to its potential non-canonical functions in cytoskeletal remodelling or apoptosis”, write the authors.