Fibroblasts isolated from human pterygia exhibit transformed cell characteristics

Pterygium is a degenerative corneal limbal process and UV irradiation has been suggested as being a major environmental predisposing factor. The invasive nature of the fibroblasts associated with pterygia raises the question as to whether these cells are transformed. To test this hypothesis, we established fibroblast strains from autologous and heterologous pterygial and conjunctival specimens, respectively, from subjects between 40 to 50 yr of age, and compared their growth characteristics in culture. All pterygial fibroblast strains exhibited a reduced dependence on serum and exogenous growth factors for growth and reached a saturation population density that was threefold higher than conjunctival fibroblasts cultured under the same conditions. In addition, all pterygial fibroblast strains were able to form colonies in soft agar in 5% fetal bovine serum at a 6.0 to 7.5% efficiency. Under the same experimental conditions, none of the conjunctival fibroblast strains were able to grow. The results presented support the conclusion that pterygial fibroblasts have acquired many of the properties of the transformed phenotype.