Increased Sox2 copy number in lung squamous cell carcinomas

Abstract

The transcription factor Sox2 is necessary for foregut morphogenesis. Sox2 is also required for the normal development of the trachea and lung. Recently, Sox2 amplifications were investigated using large-scale single nucleotide polymorphism arrays in esophageal and lung cancer. We hypothesized that Sox2 overexpression might be correlated with clinicopathological features of lung cancers. The increased copy number of the Sox2 gene was analyzed by real-time polymerase chain reaction amplifications in 127 surgically treated non-small cell lung cancer cases from Nagoya City University Hospital, Japan. A total of 87 squamous cell carcinoma (SCC) cases were involved. An increased Sox2 gene copy number was found in 42 (33.1%) lung cancer patients. Increased Sox2 copy number status was significantly correlated with gender (females, 9.5% vs. males, 34.1%; p=0.0026), smoking status (never smoker, 4.8% vs. smoker, 32.9%; p=0.0003) and pathological subtypes (squamous cell carcinoma, 44.8% vs. non-squamous cell carcinoma, 7.5%; p<0.0001). However, among the SCCs, the Sox2 copy number status was not significantly correlated with gender, smoking status, pathological stage or differentiation status. An increased Sox2 copy number is common within SCC.