P1-01-03: The Cytotoxicity of Select Neutrophils in Cancer Patients and the Role of Chemokines in Inducing Neutrophil Cytotoxicity.

Abstract

Abstract Background: Using murine mammary tumor models, recent research conducted by our laboratory at the Sloan-Kettering Institute indicates that select neutrophils are mobilized by a primary breast tumor and uniquely have the capacity to inhibit metastatic seeding in the lung (Granot Z et al. unpublished). We sought to evaluate the cytotoxic role of select neutrophils in the peripheral blood of breast cancer patients as contrasted with those from women without breast cancer and women with DCIS. In addition, we sought to determine whether the addition of select chemokines to neutrophils from a DCIS patient could induce cytotoxicity. Methods: Neutrophils were purified from the blood of 21 newly diagnosed pre-operative breast cancer patients without evidence of metastatic disease, 9 healthy female volunteers with no history of any cancer, and 3 patients with newly diagnosed DCIS. Cytotoxicity was evaluated by incubating isolated neutrophils with luciferase labeled MDA-MB-231 cells. Luciferase activity, as a reflection of% cell kill, was measured using a Bio-Tek microplate luminescence reader. Neutrophils from a DCIS patient with low cytotoxicity were then co-cultured with various CC chemokines (CCl2, CCL3 and CCL5) or CXCL chemokines (CXCL1, CXCL12, and CXCL16) at 100ng/ml. Results: Significant cytotoxicity was notably observed when MDA-MB-231 cells were co-cultured with neutrophils purified from patients with invasive tumors. Pre-operative breast cancer patients (n=21) had a cell kill range of 0–30% (mean = 12.1%), whereas healthy subjects (n=9) had a cell kill range of 0.2-8% (mean = 2.6%), p<0.004. DCIS patients (N=3) had a cell kill range of 3–4% (mean = 2.7). The addition of select chemokines to neutrophils from a DCIS patient with low cytotoxicity (3.2%) resulted in significant increases in cytotoxicity. Table 1 indicates the relative cytotoxicity percentages from the addition of each chemokine. Conclusions: To date, this preliminary work is the first to demonstrate the cytotoxic role of select neutrophils in the peripheral blood of breast cancer patients as contrasted with those from women without breast cancer. We further demonstrate the novel induction of neutrophil cytotoxicity by select chemokines. Further studies are needed to evaluate the prognostic and therapeutic role of cytotoxic neutrophils as well as the role of chemokines in neutrophil cytotoxicity. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-01-03.