Fig. 6
Response of triple-negative breast cancer (TNBC) patient-derived xenografts (PDXs) to the anti-programmed cell death protein 1 (anti-PD-1) therapy. a In vivo treatment with anti-PD-1 antibody (10 mg/kg intravenous [i.v.] once weekly) of either TNBC MC1 PDX-engrafted nonhumanized (left graph, n = 5) or humanized (right graph, n = 5) nonobese diabetic/severe combined immunodeficiency IL2Rγnull (hNSG) mice. Tumor volume was measured twice weekly. b Kaplan-Meier analysis of median survival of mice treated with vehicle (n = 6) vs. anti-PD-1 antibody (n = 6). c hNSG mice engrafted with an additional TNBC BCM-4913 PDX tumor line were treated with either vehicle control or anti-PD-1 antibody (10 mg/kg i.v. once weekly). Tumor volumes were measured twice weekly. d In vivo treatment with anti-PD-1 antibody (10 mg/kg i.v. once weekly) of TNBC BCM-4664 (n = 5) and HM-3818 (n = 5) PDXs engrafted in hNSG mice. Tumor volume was measured twice weekly. e Analysis of tumor-infiltrating lymphocyte (TIL) cytotoxic activity. TILs isolated by Ficoll gradient from vehicle- or anti-PD-1 antibody-treated MC1 PDX tumors engrafted in hNSG mice were cocultured with disaggregated MC1 tumor cells obtained from the corresponding PDX grown in nonhumanized NSG mice. Cytotoxic activity was measured using the CytoTox 96® Non-Radioactive Cytotoxicity Assay as per the manufacturer’s instructions. f Levels of granzyme B tumor were measured by incubating tumor protein lysates with antibody-immobilized magnetic beads and evaluated using a Luminex LX200 Multiplexing Assay System. **P < 0.01, ***P < 0.001. NS Nonsignificant