Novel Molecular Targets for Ductal Carcinoma In Situ (DCIS)

This project is an immunohistochemical study of archived patient breast tissue, specifically pre-invasive lesion specimens. The purpose is the discovery of novel molecular markers of pre-invasive breast lesions. These novel markers, once validated in this study, can serve as targets for individualized prevention therapy, neoadjuvant therapy for ductal carcinoma in situ (DCIS), or predictors of lesion aggressiveness. We have discovered two novel classes of DCIS molecular pathways required for the survival of DCIS neoplastic cells that will serve as the basis for the candidate molecules to be evaluated in this proposed study. The first class of DCIS molecular markers is autophagy, a cell survival mechanism that we discovered to be highly augmented in the hypoxic and nutrient deprived intraductal neoplastic cells of human DCIS (1-4). The second class of biomarker is calcium efflux that is mediated in breast cells by the calcium export pump Plasma Membrane Calcium ATPase (PMCA2) (5, 6). During normal lactation, breast epithelium pumps large concentrations of calcium into milk. In neoplastic lesions, calcium is exported by PMCA2 as a cell survival mechanism, since cells under metabolic stress accumulate calcium to a toxic level. Calcium export in DCIS may also contribute to intraductal calcifications, a hallmark of high grade DCIS and the most common marker of DCIS on mammography (7).

Sentara cares for hundreds of patients per year who are diagnosed with breast pre-invasive lesions, including atypical ductal hyperplasia (ADH), ductal carcinoma in situ (DCIS), and lobular carcinoma in situ (LCIS). Sentara treats 25% of the women with breast cancer in Virginia. Coupled with information from the Sentara Cancer Registry, Dr. Hoefer or a research team member will identify eligible patients with ADH, DCIS, and/or LCIS at the time of the core biopsy diagnosis, surgical therapy, and/or upon lesion recurrence. After receiving written informed consent from the eligible patients, Sentara Pathology will retrieve the corresponding tissue blocks. The recut tissue sections will be processed at George Mason University, Center for Applied Proteomics and Molecular Medicine for markers relevant to calcium signaling, Vitamin D response, proliferation, autophagy and inflammation. Combined with the translational research expertise/technology in the Center for Applied Proteomics and Molecular Medicine at George Mason University, Sentara's diverse patient cohort provides an opportunity to address the most fundamental unanswered questions surrounding the etiology, progression, and therapy of pre-invasive breast lesions.