Expression of Pluripotency Markers, SOX2 and OCT4, in Pterygium Development

Pterygium is a common ocular surface disease characterized by the abnormal epithelial proliferation, matrix remodeling, vascularization and the migration of the lesion. Although the etiology of pterygium is elusive, recent studies have focused on the role of limbal stem cells (LSCs) damage and effects of UVB. This study aimed to determine the expression levels of pluripotent markers of SOX2 and OCT4 in primary pterygium and normal conjunctiva. Using real time polymerase chain reaction (PCR), the SOX2 and OCT4 expressions were compared in primary pterygium and normal conjunctiva. This study assessed the correlation between SOX2 mRNA expression and OCT4 mRNA expression, as well as the association between the clinicopathological indices and both gene expression levels. The relative mRNA expression levels of OCT4 genes in primary pterygium were significantly reduced compared to the normal conjunctiva tissues. The association between OCT4 gene expression and the clinicopathological indices reported significant laterality (P = .004) and marginal growth activity indices (P = .063). The univariate correlation between the SOX2 and OCT4 expressions was statistically significant (P = .001). The present study emphasized the downregulation of pluripotent marker OCT4 genes in the pterygium. It is speculated that these results may predict a new avenue for exploring the role of stem cell deficiency in the development of pterygium.