Autoantibodies against oncogenic ERG protein in prostate cancer: potential use in diagnosis and prognosis in a panel with C-MYC, AMACR and HERV-K Gag
Anshu Rastogi1, Amina Ali2, Shyh-Han Tan1, Sreedatta Banerjee1, Yongmei Chen1, Jennifer Cullen1, Charles P. Xavier1, Ahmed A. Mohamed1, Lakshmi Ravindranath1, Jigisha Srivastav1, Denise Young1, Isabell A. Sesterhenn3, Jacob Kagan4, Sudhir Srivastava4, David G. McLeod2, Inger L. Rosner2, Gyorgy Petrovics1, Albert Dobi1, Shiv Srivastava1, and Alagarsamy Srinivasan1
1 Center for Prostate Disease Research, Department of Surgery, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
2 Urology Service, Department of Surgery, Walter Reed National Military Medical Center, Bethesda, MD, USA
3 The Joint Pathology Center, Silver Spring, MD, USA
4 Cancer Biomarkers Research Group, Division of Cancer Prevention, National Cancer Institute, Bethesda, MD, USA
Correspondence:
Alagarsamy Srinivasan, email:
Keywords: prostate cancer, diagnosis, autoantibody, panel, ERG
Received: November 18, 2016 Accepted: January 07, 2017 Published: January 13, 2017
Abstract
Overdiagnosis and overtreatment of prostate cancer (CaP) is attributable to widespread reliance on PSA screening in the US. This has prompted us and others to search for improved biomarkers for CaP, to facilitate early detection and disease stratification. In this regard, autoantibodies (AAbs) against tumor antigens could serve as potential candidates for diagnosis and prognosis of CaP. Towards this, our goals were: i) To investigate whether AAbs against ERG oncoprotein (overexpressed in 25-50% of Caucasian American and African American CaP) are present in the sera of CaP patients; ii) To evaluate an AAb panel to enhance CaP detection. The results using an enzyme-linked immunosorbent assay (ELISA) showed that anti-ERG AAbs are present in a significantly higher proportion in the sera of CaP patients compared to healthy controls (p = 0.0001). Furthermore, a panel of AAbs against ERG, AMACR and human endogenous retrovirus-K Gag successfully differentiated CaP patient sera from healthy controls (AUC = 0.791). These results demonstrate for the first time that anti-ERG AAbs are present in the sera of CaP patients. In addition, the data also suggest that AAbs against ERG together with AMACR and HERV-K Gag may be a useful panel of biomarkers for diagnosis and prognosis of CaP.
