Abstract B40: Cytokines secreted by macrophages isolated from tumor microenvironment of inflammatory breast cancer patients possess chemotactic properties

Abstract

Abstract Introduction: Inflammatory breast cancer (IBC) is the most aggressive form of breast cancer and is characterized by rapid progression and dismal outcome. Although there is a growing literature describing the role of macrophages in non-IBC, the role of macrophages in IBC is unclear. The aims of the present study were to: 1) assess macrophages infiltration within the tumor tissues of non-IBC and IBC patients; 2) isolate and profile cytokines of macrophages drained from breast tumor axillary tributaries of non-IBC and IBC patients and 3) test whether major cytokines secreted by tumor draining macrophages induce motility of the IBC cell line SUM149. Methods: Tumor-infiltrating macrophages were measured by immunohistochemical (IHC) techniques using CD14 and CD68 monoclonal antibodies. Blood drained from axillary vein tributaries was collected from non-IBC and IBC patients during breast cancer surgery and total mononuclear cells isolated by density gradient centrifugation using Histopaque. The percentage of monocytes/macrophages (CD14+) in the total isolated leukocytes was calculated by flow cytometry using fluorochrome-labeled monoclonal antibodies (APC-CD14 and PerCP-CD3). CD14+ population was separated from total mononuclear cells using an immuno-magnetic bead separation technique. CD14+ cells were seeded overnight in appropriate culture media at 37°C in a humidified CO2 incubator and conditioned media were collected and cytokines profiled. To test whether cytokines secreted by CD14+ enhances motility and invasion of SUM149 cells, we used wound healing and invasion assays. Results: Our results revealed that there was an increase in the number of infiltrated macrophages (CD14+ cells) in IBC tumor tissues and axillary tributaries drained blood as compared to non-IBC. Cytokine profiling of IBC-CD14+ cells revealed a significant increase in tumor necrosis factor-alpha (TNF-α); monocyte chemoattractant protein-1 (MCP-1) also known as CC-chemokine ligand 2 (CCL-2); interleukin-10 (IL-10) and interleukin-8 (IL-8) as compared to non-IBC CD14+ cells. TNF-α, IL-8 and IL-10 cytokines significantly increased motility and invasion of SUM149 cells. Conclusion: IBC cancer tissues are characterized by high infiltration of monocytes/macrophages that secrete cytokines that may contribute to dissemination of IBC cells. Citation Format: Mona Mostafa Mohamed, Eslam A. El-Ghonaimy, Mohamed A. Nouh, Robert J. Schneider, Bonnie F. Sloane, Mohamed El-Shinawi. Cytokines secreted by macrophages isolated from tumor microenvironment of inflammatory breast cancer patients possess chemotactic properties. [abstract]. In: Proceedings of the Third AACR International Conference on Frontiers in Basic Cancer Research; Sep 18-22, 2013; National Harbor, MD. Philadelphia (PA): AACR; Cancer Res 2013;73(19 Suppl):Abstract nr B40.