c-FOS Expression Analysis in Pterygia Cell Spot Arrays

Mechanisms of c-FOS activation in the onset and progression of pterygia remain under investigation. This study aimed to comparatively analyze c-FOS proto-oncogene expression levels in neoplastic pterygia and normal epithelia.

We used a liquid-based cytology assay on thirty (n=30) pterygia cell populations and normal epithelia (n=10) extracted by a smooth scraping of conjunctiva epithelia. Applying a cell spot-based technique, we constructed five (n=5) slides, each containing eight (n=8) cell spots. A modified immune-cytochemistry (ICC) assay for c-FOS protein was used. Additionally, digital image analysis was implemented to calculate c-FOS immunostaining intensity levels.

High staining intensity levels of c-FOS were detected in 12/30 (40%), whereas the rest 18/30 (60%) demonstrated moderate expression. c-FOS levels were statistically significantly higher in the pterygia compared to control tissues (p=0.001). c-FOS levels in the pterygia were not associated with the sex of patients (p=0.678), the presence of recurrent lesion (p=0.390) or the location of the lesion (p=0.158). The levels of c-FOS, however, were marginally significantly affected by the morphology of the pterygia (p=0.005). More precisely, the c-FOS levels were significantly higher in pterygia with a fleshy morphology.

c-FOS over-expression is observed frequently in pterygia. It seems to be critically involved in the molecular mechanism of the lesion by its over-expression affecting partially their morphological features. Cell spot liquid - based array analysis is an innovative, easy to implement technique for simultaneously evaluating a broad spectrum of molecules in multiple specimens on the same slide.