Centrosome Overduplication in Canine Hemangioma and Hemangiosarcoma

Centrosome overduplication (more than 2; >2C) is commonly associated with aneuploidy in many human cancers and is theorized to contribute to malignant transformation via increased chromosomal instability. >2C is not been described in endothelial cell (EC) tumors such as hemangioma (HA) and hemangiosarcoma (HSA). HAs are common, benign canine tumors that may undergo malignant transformation to HSA through unknown cellular mechanisms. To characterize the possible contribution of >2C to the development of HSA, archived formalin-fixed paraffin-embedded canine tissue (5-8 uM thick) with a previous diagnosis of HA (n=4) or HSA (n=6) from the subcutis, spleen or liver were labeled with EC (isolectin) and centrosome (gamma-tubulin) markers by immunofluorescence. Samples were imaged via confocal microscopy and quantified as % of neoplastic EC with >2C. HSAs had significantly greater >2C compared with HAs (20.1+/- 1.4% vs 4.4 +/- 2.3%; p 2C (control...