FIGURE 6 from Humanized Patient-derived Xenograft Models of Disseminated Ovarian Cancer Recapitulate Key Aspects of the Tumor Immune Environment within the Peritoneal Cavity

HALO analysis of tumor vascularization. A, The levels of VEGF-A in PDX ascites fluid was measured by ELISA. B, To quantify tumor vascularization in huPDX versus non-huPDX tumors, vessels were labeled with anti-CD31 antibody and vessel area was determined by analyzing scanned slides. The tumor tissue was masked on the basis of H&E staining (green) and CD31 labeled vessels were detected (red). Vessel density was calculated using the tissue classifier analysis software on the HALO platform. C, The quantification of vascular density (% vascular area) across whole sections of huPDX and non-huPDX samples. Values are the average vascular densities among samples (n = 2–3). huPDX18 sections showed increased vascular density compared to non-huPDX18 (P t test). D and E, Comparison of vascularity in representative images from huPDX18 (D) and non-huPDX18 (E) labeled with anti-CD31 antibody. Scale bar, 200 μm.