Autoimmune Response to IGF2 mRNA-Binding Protein 2 (IMP2/p62) in Breast Cancer

The purpose of this study was to understand the autoimmune response and immunogenicity of a tumour-associated antigen IMP2/p62 in breast cancer. Autoantibody responses to IMP2/p62 were evaluated by enzyme-linked immunosorbent assay (ELISA), Western blotting and indirect immunofluorescence assay in sera from patients with breast cancer, benign breast tumour and normal human individuals. Immunohistochemistry (IHC) study with breast cancer tissues was also performed to analyse protein expression of IMP2/p62. The results have demonstrated that IMP2/p62 can induce a relatively higher frequency of autoantibody response in breast cancer (14.3%, 7/49) compared to patients with benign breast tumour (5.6%, 2/36) and normal individuals (2.2%, 1/44). The frequency of IMP2/p62 expression in breast cancer tissues was significantly higher than that in normal tissues (P<0.01). The data suggest that autoantibody against IMP2/p62 may be a useful serum biomarker for early-stage breast cancer screening and diagnosis.