ANGIOGENIC FACTORS ASSOCIATED WITH UVEAL MELANOMA

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Uveal melanoma is the most prevalent primary ocular tumor found in adults. The annual incidence of uveal melanoma is equivalent to the number of new cases of retinitis pigmentosa. The genetic alterations underlying the disease are unknown, and there are few prognostic indicators that can be observed clinically, contributing to enucleation as a principal method of treatment. Unfortunately, events leading to systemic metastases may have occured by the time the ocular symptoms are recognized, and death due to hepatic disease and other complications usually ensues. Clearly, improved methods are needed for the early detection and treatment of the disease. The current application focuses on the contributions of angiogenic growth factors and inhibitors to the progression of the disease. We hypothesize that the malignant and metastatic properties of such tumors depend on the simultaneous expression of multiple angiogenic factors, specifically Cyr61, Tissue Factor, and VEGF. Further, the balance between the expression of these growth factors and inhibitors determines the quiescent period prior to detectable metastases. Specific Aims include: 1. Verify the expression of Cyr61, Tissue Factor and VEGF in primary ocular melanoma using both archival specimens and fresh biopsies of tumor tissue. Methods of detection will include immunohistochemistry, Northern blot hybridization, RT-PCR, and in situ hybridization. Expression will be correlated with vascular density. 2. Assess the importance of Cyr61, Tissue Factor and VEGF during growth of the primary tumor and its metastases using an animal model. Transfected cell lines of uveal melanoma with varying levels of expression of these three genes will be transplanted into the anterior chambers of nude mice, and the growth of the primary ocular tumors, the extent of hepatic lesions, and the vascular density at both sites will be measured. 3. Determine the cellular localization of Cyr61, Tissue Factor and VEGF using a combination of immunocytochemical methods and cellular fractionation. 4. Identify additional angiogenic growth factors (angiopoietin-1) and inhibitors (angiostatin and endostatin) associated with uveal melanoma by RT_PCR, immunoblotting and Northern blot hybridization.