A TRANSPLANTED AND CULTURED CELL LINE ESTABLISHED FROM CANINE MALIGNANT HEMANGIOPERICYTOMA AND ITS IMMUNOHISTOCHEMICAL CHARACTERIZATION

Abstract

It is generally believed that hemangiopericytoma (HP) arises from Zimmermann's pericyte, although its origin and tumor categorization remain unestablished. In the present study, a transplanted and cultured cell line was established from canine hemangiopericytoma (CHP). The cell line showed a variety of morphologies including small N/C ratio of cells, multinucleated cells, spindle-shaped cells, bipolar and multipolar cells in addition to fibroblast-like cells. The doubling time of cells in culture was approximately 32 hours, when 1.9×10⁵ cells per ml were inoculated at the 51st subcultivation. lmmunohistochemical analysis showed that endothelial cells and pericytes were positive to actin, while the fibrosarcoma-like cells were positive to vimentin. Chromosome numbers in CHP cell line at the 35th passage in culture distributed in a wide range of 31 to 100 with a modal number of 79. Based on the findings obtained, tumor cells grown in in vitro cultivation and transplanted in nude rats showed almost the same histological feature as that of the original tumor, indicating that the tumor cells established in the present study may be useful as a model of CHP.