Abstract
Purpose: :
To establish a model of retinoblastoma in rabbits with in vivo evaluation and histopathologic confirmation of tumor growth.
Methods: :
Twelve white New Zealand rabbits were immunosuppressed with Cyclosporin A at doses of 10-15 mg/kg starting at day 1. At day 3, the animals received a 30 µl subretinal injection of cultured WERI retinoblastoma cells (1 x 106 cells). The rabbits were sacrificed each week until postoperative week 8. Digital fundus images were captured prior to euthanasia, and the eyes were enucleated and submitted for histopathologic examination.
Results: :
Subretinal retinoblastoma cells grew in all the rabbits and established a tumor under the retina and/or in the vitreous. New vessel growth in the tumor was observed in vivo starting at postoperative week 5. Cuffs of viable tumor cells surrounded the blood vessels with regions of necrosis beginning 70-80 µm from the nutrient vascular channels. Occasional tumor seeds in the vitreous histologically exhibited central necrosis.
Conclusions: :
Subretinal injection of cultured retinoblastoma cells established a tumor in rabbits. Tumor size continued to increase up to 8 weeks, and the tumors became vascularized starting at week 5. The rabbit model demonstrated a similar fundus appearance and pathologic features to human retinoblastoma. This rabbit model of retinoblastoma will be used as a model to evaluate the effectiveness of various routes of drug delivery.
Keywords: retinoblastoma • oncology • pathology: experimental