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Abstract: Basement membranes possess a complex three-dimensional topography in the nanoscale and submicron range which have been shown to profoundly modulate a large menu of fundamental cell behaviors. Using the topographic features found in native vascular endothelial basement membranes as a guide, polyurethane substrates were fabricated containing anisotropically ordered ridge and groove structures and isotropically ordered pores from 200nm to 2000nm in size. We investigated the impact of biomimetic length-scale topographic cues on orientation/elongation, proliferation and migration on four human vascular endothelial cell-types from large and small diameter vessels. We found that all cell-types exhibited orientation and alignment with the most pronounced response on anisotropically ordered ridges ≥800nm. HUVEC cells were the only cell-type examined to demonstrate a decrease in proliferation in response to the smallest topographic features regardless of surface order. On anisotropically ordered surfaces all cell-types migrated preferentially parallel to the long axis of the ridges, with the greatest increase in cell migration being observed on the 1200nm pitch. In contrast, cells did not exhibit any preference in direction or increase in migration speed on isotropically ordered surfaces. Overall, our data demonstrate that surface topographic features impact vascular endothelial cell behavior and that the impact of features varies with the cell behavior being considered, topographic feature scale, surface order, and the anatomic origin of the cell being investigated. [Copyright &y& Elsevier]

Canine hemangiosarcoma (HSA) is a devastating disease. Investigation of novel therapies has been limited by the limited availability of canine HSA-derived cell lines. We report the development of a canine HSA-derived cell line, DEN-HSA, which recapitulates features of angiogenic endothelium. DEN-HSA cells were derived from a spontaneous HSA arising in the kidney of a dog, DEN-HSA displayed surface molecules distinctive of endothelial histogenesis, including factor VIII-related antigen, ICAM-1 and αvβ3 integrin. In vitro, DEN-HSA formed microvascular tube-like structures on Matrigel®, and proliferated in response to a variety of angiogenic growth factors. The cells expressed mRNA and protein specific for bFGF and its receptors, and VEGF and its receptors, among others. DEN-HSA conditioned medium evoked a marked angiogenic response in a murine corneal pocket assay, indicating potent proangiogenic activity of substances secreted by this cell line. This research confirms the DEN-HSA cell line as endothelial in origin, suggests the presence of angiogenic growth factor autocrine loops, and offers the potential to utilize DEN-HSA cells for the study of novel therapies that modulate endothelial proliferation. [ABSTRACT FROM AUTHOR]

We established a canine hemangiosarcoma cell line derived from malignant endothelial cells comprising a spontaneous tumor in a dog to provide a renewable source of endothelial cells for studies of angiogenesis in malignancy. Pieces of the hemangiosarcoma biopsy were engrafted subcutaneously in a bg/nu/XID mouse allowing the tumor cells to expand in vivo. A cell line, SB-HSA, was derived from the xenograft. SB-HSA cells expressed vascular endothelial growth factor (VEGF) receptors 1 and 2, CD31, CD146, and αvβ3 integrin, and produced several growth factors and cytokines, including VEGF, basic fibroblast growth factor, and interleukin (IL)-8 that are stimulatory to endothelial cell growth. These results indicated that the cells recapitulated features of mitotically activated endothelia. In vivo, SB-HSA cells stimulated robust angiogenic responses in mice and formed tumor masses composed of aberrant vascular channels in immunocompromised mice providing novel opportunities for investigating the effectiveness of antiangiogenic agents. Using this model, we determined that IL-12, a cytokine with both immunostimulatory and antiangiogenic effects, suppressed angiogenesis induced by, and tumor growth of, SB-HSA cells. The endothelial cell model we have described offers unique opportunities to pursue further investigations with IL-12, as well as other antiangiogenic approaches in cancer therapy. [ABSTRACT FROM AUTHOR]