HAMSTER GREEN MELANOMA IN THE RABBIT EYE - IMMUNOSUPPRESSIVE TREATMENT TO IMPROVE THIS TUMOR-MODEL

Background: The hamster Greene melanoma (HGM) implanted in the anterio r chamber of the rabbit eye has been used to study experimental therap ies for human uveal melanoma. However, the occurrence of spontaneous n ecrosis limits the value of this model for long-term evaluation of exp erimental treatments. In the present study we tested the hypothesis th at an immune response is the cause of this necrosis and that preventio n of the immune response can prolong the experimentation time Methods: HGM was implanted in the anterior chamber of control, presensitized a nd immunosuppressed rabbits. The effects of sensitization and immunosu ppression were assessed by clinical and histological observation Resul ts: Sensitization led to a significant slowing down of tumor growth, b ut not to a difference in necrosis. Immunosuppressive treatment with c yclosporin A improved the success rate of implantation and decreased t he amount of necrosis in the tumor Conclusion: The immune response pla ys a role in the occurrence of necrosis. However, although immunosuppr essive treatment with cyclosporin A decreased the amount of necrosis, significant necrosis still occurred, suggesting that other factors lik e angiogenesis play a part as well and still limit the usefulness of t his model in the long-term evaluation of experimental therapies.