The Ets-1 Transcription Factor is Involved in Pterygial Angiogenesis

Pterygial pathology is characterized by abnormal corneal epithelial proliferation, stromal modulation, matrix degradation and a strong tendency for otherwise absent corneal vascularization. As the proto-oncogene Ets-1 is known to play a key role in angiogenesis and matrix degradation in other tissues, its involvement in corneal vascularization was investigated. Fifteen pterygia representing two groups were studied. Group 1 consisted of five clinically active pterygia, and group 2 consisted of 10 samples of clinically non-active pterygia. (35)S-labelled ets-1 antisense and sense riboprobes were used for in-situ hybridization of Ets-1 transcription factor in all pterygia. The cytoplasm of blood vessel endothelial cells showed strong expression of ets-1 mRNA in all group 1 pterygia. In contrast, no expression of ets-1 was found in group 2 pterygia. Proto-oncogene ets-1 expression has been shown for the first time in the metaplastic pterygium, an eye tissue of unknown pathogenesis.