Effect of thalidomide on growth and metastasis of canine osteosarcoma cells after xenotransplantation in athymic mice.
OBJECTIVE
To determine whether thalidomide inhibits the growth of primary and pulmonary metastatic canine osteosarcoma in mice after xenotransplantation.


METHODS
Athymic nude mice.


METHODS
Canine osteosarcoma cells were injected SC in 50 mice. Mice were randomly placed into the following groups: control group (n = 13; DMSO [drug vehicle] alone [0.1 mL/d, IP]); low-dose group (12; thalidomide [100 mg/kg, IP]), mid-dose group (13; thalidomide [200 mg/kg, IP]); and high-dose group (12; thalidomide [400 mg/kg, IP]). Starting on day 8, treatments were administered daily and tumor measurements were performed for 20 days. On day 28, mice were euthanatized and primary tumors were weighed. Lungs were examined histologically to determine the number of mice with metastasis and tumor emboli. Mean area of the pulmonary micrometastatic foci was determined for mice from each group.


RESULTS
Primary tumor size and weight were not significantly different among groups. The number of mice in the mid-dose (200 mg/kg) and high-dose (400 mg/kg) groups with micrometastasis was significantly less than the number of control group mice; however, the number of mice with tumor emboli was not affected by thalidomide treatment. Size of micrometastasis lesions was not affected by thalidomide treatment.


CONCLUSIONS
Mean area of micrometastases was not affected by treatment; however, growth of micrometastases had not yet reached an angiogenesis-dependent size. Although thalidomide did not affect growth of primary tumors in mice after xenotransplantation of canine osteosarcoma cells, our findings indicate that thalidomide may interfere with the ability of embolic tumor cells to complete the metastatic process within the lungs.
Farese
James P
JP
Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32610, USA.
Fox
Leslie E
LE
Detrisac
Carol J
CJ
Van Gilder
James M
JM
Roberts
Sara L
SL
Baldwin
Jamie M
JM
D020533:Angiogenesis Inhibitors / Q000627:therapeutic use*; D000818:Animals; D004121:Dimethyl Sulfoxide; D004283:Dog Diseases / Q000188:drug therapy*; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D005260:Female; D008175:Lung Neoplasms / Q000473:pathology / Q000556:secondary / Q000662:veterinary*; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D012516:Osteosarcoma / Q000188:drug therapy / Q000662:veterinary*; D013792:Thalidomide / Q000627:therapeutic use*; D013997:Time Factors; D014407:Tumor Cells, Cultured
D020533:Angiogenesis Inhibitors; D013792:Thalidomide; D004121:Dimethyl Sulfoxide