Expression of glucose transporter protein-1 (Glut-1) in ocular surface squamous neoplasia.

PURPOSE

To examine the expression of glucose transporter protein-1 (GLUT-1) in ocular surface squamous neoplasia and to study its relationship with degree of neoplasia and cell proliferation index (Ki-67 labeling index).

METHODS

Twelve cases diagnosed as ocular surface squamous neoplasia (4 invasive and 8 intraepithelial tumors) at Inonu University Faculty of Medicine, Department of Pathology, were included in this study. There were 3 squamous cell carcinomas, 1 basosquamous cell carcinoma, and 8 conjunctival intraepithelial neoplasms. Immunohistochemically, GLUT-1 and Ki-67 antibody staining were performed.

RESULTS

GLUT-1 membranous immunoreactivity was seen in all tumors except in 1 case. GLUT-1 immunostaining was observed in all layers of the neoplastic epithelium of squamous cell carcinoma. Intense staining for GLUT-1 was determined in the upper two thirds of the severe dysplastic squamous epithelium. Although immunoreactivity for Ki-67 nuclear antigen was present throughout the epithelium, it was higher in the lower two thirds. Ki-67 labeling index ranged between 6% and 80%, and the mean value was 35% for invasive tumors and 20% for intraepithelial tumors.

CONCLUSIONS

Marked GLUT-1 and Ki-67 immunoreactive cells throughout the neoplastic epithelium of ocular surface squamous neoplasia were observed. In most cases, it was observed that GLUT-1 expression was severe in cases having >10% Ki-67 labeling index. These findings indicate that glucose uptake was increased in dysplastic cells, especially by GLUT-1. To our knowledge, this is the first study on the subject in the literature, and further studies with more cases are needed with GLUT-1 and other GLUT members.