Mutation of K-Ras Gene in Squamous Cell Carcinoma of the Conjunctiva

Abstract

Abstract: : Purpose: To determine the frequency of mutation in the K-ras oncogene in samples of squamous cell carcinoma of the conjunctiva Methods: Twenty-four paraffin embedded samples of histologically identified squamous cell carcinomas of the conjunctiva were obtained from the University of Cincinnati and the Wilmer eye pathology labs. Tumor cells were microdissected from H&E stained sections. DNA extraction was then performed using standard techniques. The integrity of each DNA sample was cofirmed by beta-actin PCR. The K-ras gene was then amplified by PCR and then sequenced by standard radiolabelling methods. The sequence was then manually read and examined for evidence of mutation. Results: Two of the 24 samples (8%) showed evidence of mutation; one in the codon 11 region, the other in the codon 12 region. Both mutations were G>A transitions. Conclusions: The K-ras oncogene, though frequently mutated in other tumors, appears to play a lesser role in squamous cell carcinoma of the conjunctiva. To our knowledge this is the first documentation of any specific mutations within this class of tumors.

Keywords: oncology • conjunctiva • mutations