Abstract 379: Evaluating tissue expression of RANTES with subtype specific breast cancer biomarkers found elevated in plasma.

Proceedings: AACR 104th Annual Meeting 2013; Apr 6-10, 2013; Washington, DC Background: A previous analysis of 23 plasma proteins found that levels increased in cancer patients compared to benign-breast-disease controls when the cancer was analyzed based on tumor subtypes. Circulating levels of RANTES were significantly increased in cancer patients and were commonly associated with two or more of the following proteins; amphiregulin, EGF, HB-EGF, TGFa, PDGF, and VEGF in a tumor subtype specific pattern. However, it is unknown if expression of these proteins correlate in the tumor tissue of breast cancer subtypes thus contributing to the elevated expression seen in plasma. In this study, we evaluate the expression of 5 of plasma biomarkers in a 70-subject breast cancer tissue microarray (TMA) to determine if these proteins are increased differentially by tumor subtypes. Design: A BioChain TMA containing 70 duplicated cores covering the common types of breast cancer, 5 normal, and 5 benign cases are assayed using GBI Labs triple stain kits to evaluate subtype specific expression of amphiregulin and HB-EGF or PDGF and VEGF with RANTES. Imaging and quantitative assessment of the distribution and intensity of each stain was evaluated using a multispectral imaging (MSI) approach, automated morphologic analysis software and compared to a visual screen. Results: Results indicate that an algorithm can be develoed to accurately recognize tumor versus stromal tissue within each core. Furthermore, as compared to visual evaluation, the MSI approach has the added capability to separate the color of the three immunostains from the triple stain for precise quantification of each protein without crosstalk. The automated scoring algorithm compared well against visual assessment. Conclusion: The knowledge gained from correlating these subtype-specific patterns of tissue antigens with circulating levels in plasma may provide important information about the contribution of specific markers of breast cancers. Application of MSI to the triple staining in the TMA screen provided a superior quantitative method for evaluation of multiple chromogens linked proteins within a tumor core compared to visual observations/grading of the complex multicolor immunostaining in this study. Citation Format: James Mansfield, Chuanbo Xu, Rachel Gonzalez. Evaluating tissue expression of RANTES with subtype specific breast cancer biomarkers found elevated in plasma. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 379. doi:10.1158/1538-7445.AM2013-379