Research Paper Volume 12, Issue 6 pp 5091—5120

Time-dependent interactions of blood platelets and cancer cells, accompanied by extramedullary hematopoiesis, lead to increased platelet activation and reactivity in a mouse orthotopic model of breast cancer – implications for pulmonary and liver metastasis

Figure 10. In vitro response of whole blood platelets from mice with orthotopic model of breast cancer to increasing concentrations of thrombin. Results are presented as median (horizontal line) and interquartile range (box) (n = 8). The expressions of P-selectin (CD62P) (A), the active form of GPIIb/IIIa (B) and binding of endogenous vWF (C) and endogenous fibrinogen (Fg) (D) on platelets stimulated with low thrombin (0.025 U/ml) (A, C, E, G) or high thrombin (0.25 U/ml) (B, D, F, H) were measured using flow cytometry in non-fixed ‘washed blood’ withdrawn immediately (t0) or after 2 (t2), 3 (t3), 4 (t4) or 5 weeks (t5) from the injection of 4T1 cells. Results are expressed as the percent fraction of platelets positive for a given activation marker. More experimental details are given in the Materials and methods section. The statistical significance of differences, estimated with Kruskal-Wallis test followed by the post hoc Conover-Inman all-pairwise comparisons or one-way ANOVA followed by Tukey’s multiple comparisons test, was: P-selectin thr0.025U/ml, P1,α < 0.05, 4T1 t5 = 4T1 t4 > 4T1 t3 > 4T1 t2 > 4T1 t0; P-selectin thr0.25U/ml, P1,α < 0.001, 4T1 t5 > 4T1 t4 = 4T1 t3 > 4T1 t2 < 4T1 t0; active form of GPIIb/IIIa thr0.025U/ml, P1 < 0.05, 4T1 t5 < 4T1 t4 = 4T1 t3 > 4T1 t2 = 4T1 t0; vWF thr0.025U/ml, P1,α < 0.001, 4T1 t5 = 4T1 t4 = 4T1 t3 > 4T1 t2 = 4T1 t0; vWF thr0.25U/ml, P1,α < 0.01, 4T1 t5 = 4T1 t4 > 4T1 t3 < 4T1 t2 = 4T1 t0; Fgthr0.025U/ml,P1,α < 0.001, 4T1 t5 = 4T1 t4 = 4T1 t3 > 4T1 t2 = 4T1 t0; Fgthr0.25U/ml, P1,α < 0.05, 4T1 t5 < 4T1 t4 = 4T1 t3 > 4T1 t2 = 4T1 t0.