Abstract B69: Macrophages along with pathogens in the microenvironment enhance the aggressive behavior of triple-negative breast cancer (TNBC) in an in vitro model

Background: Macrophages in breast cancer microenvironment have been associated with earlier relapse and decreased overall survival especially in patients with TNBC (Campbell et al. 2011). Infectious agents have been linked to approximately 20% of all cancers but the role of pathogens in TNBC has not been fully explored. We sought to investigate in an in vitro model the effect of macrophages along with pathogens in the tumor microenvironment on enhancing the aggressive behavior of TNBC. Methods: Expression patterns of Toll-like receptors were examined in 4 breast cancer cell lines and THP-1 cell line. THP-1 cell line was differentiated into macrophages using phorbol 12-myristate 13-acetate (PMA). Calcein®-labeled MDA-MB-231 TNBC cell line was seeded in trans-wells in the presence and absence of macrophages grown in multi-well cell culture plates. Pattern of invasion of the MDA-MB-231 breast cancer cell line in the presence of virus infected serum free condition media (CM) was assessed using a modified Boyden Chamber concept in the absence and presence of macrophages. Lipopolysaccharide (LPS) and Polyinosine-polycitidylic acid (poly I:C) were used as toll-like receptor ligands simulating pathogen infection. Results: Data showed an increased invasion of MDA-MB-231 in the presence of macrophages and macrophage condition media (percent invasion 17.7% media only, 37.8 % with macrophages, and 36.1% with condition media from macrophages, p Citation Format: Elias I. Obeid, Bifeng Zhang, Olufunmilayo I. Olopade. Macrophages along with pathogens in the microenvironment enhance the aggressive behavior of triple-negative breast cancer (TNBC) in an in vitro model. [abstract]. In: Proceedings of the Fifth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2012 Oct 27-30; San Diego, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2012;21(10 Suppl):Abstract nr B69.