Abstract A51: Investigation of the DEK oncogene as a blood biomarker for breast cancer

Breast cancer (BC) is one of the leading causes of death for women in the United States. This is due, in part, because women wait too long to get a diagnosis or the disease returns, sometimes years later, due to ineffective treatment. Therefore, it is critically important to identify biomarkers that can better inform clinicians while providing a screening test more amenable to patients than mammograms. We are investigating the feasibility of using DEK protein levels in patient plasma as a biomarker for disease stage and prognosis. DEK is a chromatin-organizing protein that functions in DNA replication and repair, transcription, and mRNA splicing. The DEK oncoprotein is highly upregulated in many types of cancer including breast, head and neck, and melanoma. Using human cell culture and murine models, our previous studies have shown that DEK is functionally important for the promotion of cellular growth, invasion/metastasis, drug resistance, and breast cancer stem cell maintenance. Work by the Markovitz laboratory indicated that DEK is secreted by macrophages as a pro-inflammatory signaling molecule and can be internalized by neighboring cancer cells to promote typical DEK functions. This led to our hypothesis that DEK may be present in the plasma of cancer patients. In fact, the detection of DEK protein in urine is currently being explored as a diagnostic biomarker for bladder cancer. To test this hypothesis, we collected peripheral blood from patients with newly diagnosed, untreated BC (irrespective of the clinical stage) and age- and ethnicity-matched normal healthy controls. Plasma was separated from the samples and subjected to DEK specific ELISA (Cusabio, Wuhan, China). Preliminary results demonstrate that DEK is indeed present in the plasma of BC patients and we are currently comparing these levels to normal healthy controls. Further analyses are ongoing to determine whether DEK levels correlate with pertinent clinical and pathological variables including age, tumor stage, and ER/PR/HER-2 status. In addition, we are examining if DEK levels can predict response to various treatment modalities and risk of relapse. These data will be important to verify DEK plasma measurements as a clinically useful test and may give insight to future personalized and targeted treatment strategies for BC. Citation Format: Arun Sendilnathan, Mahmoud Charif, Elizabeth Shaughnessy, Jaime D. Lewis, Neetu Radhakrishnan, Elyse Lower, Catherine Lanigan, Harriet Kumar, Trisha M. Wise-Draper, Lisa Privette Vinnedge. Investigation of the DEK oncogene as a blood biomarker for breast cancer. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research; Oct 17-20, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(2_Suppl):Abstract nr A51.