Abstract
BACKGROUND: Glutathione peroxidase 1 (GPX1) and GPX4 are abundant antioxidant enzymes within the cytosol in mammalian tissues. These enzymes have the capacity to scavenge free radicals, and they play roles in various cancers, especially oral squamous cell carcinoma (OSCC). OBJECTIVES: 1. To compare the expression levels of GPX1 and GPX4 among different pathological stages for OSCC primary tumors. 2. To assess the associations of GPX1 and GPX4 expression with other independent variables (age, gender, site of lesion, laterality, histopathological grades, and lymph node involvement of OSCC tumor). METHODS: In total, 133 prospective OSCC tissue specimens were selected from Dow Diagnostic Research and Referral Laboratory of Dow University. Expression levels of GPX1 and GPX4 were evaluated by immunohistochemistry. Immunoreactive score (IRS) values were obtained using ImageJ software. The IRS values for GPX1 and GPX4 were compared according to the pathological stages of cancer and other independent variables. Data were statistically analyzed by using SPSS version 21 and STATA. RESULTS: Among the 133 samples, GPX4 was present in all stages of oral cancer and high IRS values mostly corresponded to moderate to strong staining intensity. By contrast, GPX1 was not found in all stages of oral cancer, and low IRS values mostly corresponded to weak staining intensity. No relationships were found with other variables. CONCLUSION: GPX4 was present in all stages of oral cancer and in all tissue samples, whereas GPX1 was not found in all cases. The IRS values for GPX1 and GPX4 had significant relationships with pathological stages of oral cancer.