Paper Title
Eno-1 May be an Immune Biomarker of ER+/PR+/HER2- Breast Cancer Phenotype

Abstract
Efficient and affordable prognosis or diagnosis of the heterogeneous breast neoplasms can be achieved by the introduction of common biomarkers in all the subtypes of breast cancer (BC). In this regard, immune biomarkers have been in the spotlight of a variety researches over the years. Recently, it has been shown that ENO-1 can induce the humoral immune response in ER+/PR-/HER2- and ER-/PR-/HER2+ BC patients;however, its antigenicity has not yet been studied in the ER+/PR+/HER2- phenotype. Hence, to check any probable similarities in the humoral immune response against ENO-1 in these 3 subtypes of breast malignancies, herein, sera of the newly diagnosed ER+/PR+/HER2- BC patients were used in a 2D immunoblotting approach. The immunoreactivity of ENO-1 was assessed by a dedicated image analysis platform which further approved by MALDI mass spectrometry. Results of the present study can be an initial step to introduce ENO-1 as a potential clinical biomarker candidate. 2D immunoblotting is a suitable indicator of the immunogenicity assay; hence, the antigenic characteristics reapproves by the pI and molecular weight of the protein spots and covers the bias induced by non-specific interaction in commonly-used high-throughput approaches like ELISA. Nevertheless, we strongly suggest that the results of this study must be further confirmed by more high-throughput approaches in larger populations. Keywords - ENO-1; immunoantigen; proteome analysis; 2D immunoblotting; antigenicity; breast cancer.