An elongation factor-like protein (EF-Tu) elicits a humoral response in infiltrating ductal breast carcinomas: An immunoproteomics investigation

OBJECTIVES:In the current study, we have used an immunoproteomics approach to identify proteins that commonly elicit a humoral response in patients with infiltrating ductal carcinomas of the breast. DESIGN AND METHODS:Sera obtained at the time of diagnosis from 40 patients with invasive breast cancer and 42 healthy controls were screened for the presence of IgG antibodies to MCF-7 cell line proteins using a serological proteomics-based approach. RESULTS:An immunoreactive protein detected in sera from 21 of 40 patients was isolated and subsequently identified as elongation factor-Tu. CONCLUSIONS:The immunoproteomic approach implemented here offers a powerful tool for determining novel tumor antigens that induce a humoral immune response in cancer patients. From our findings, the immunoreactive EF-Tu protein and/or the related circulating antibodies may display clinical usefulness as potential diagnostic markers and provide a means for a better understanding of the molecular mechanisms underlying breast cancer development.