Evaluation of total glutathione-s-transferase levels in serum of patients with oral malignancy.

Abstract

Squamous cell carcinoma-related antigen is not always sensitive enough for the early detection of oral cancer which is why a new marker has been desired as a substitute to be applied for serum diagnosis of oral cancer. Reactive oxygen species (ROS) has been known to play an important role in carcinogenesis. Glutathione-s-transferases (GSTs) are a family of eukaryotic and prokaryotic phase-II metabolic isoenzymes involved in xenobiotic detoxification. This correlation of the ROS species function and their role in initiation and progression of cancer could be exploited as of diagnostic value. The biologic function of the GSTs in human head-and-neck squamous cell carcinomas has been studied by researchers at gross as well as molecular levels. Taking into consideration this scientific background, future scope and perspectives, we initiated this study. This study was performed as a prospective case-control in vitro analytical study with subjects (n = 40) fulfilling the prerequisite conditions and were compliant. The case group (n = 20) was subjects with histopathologically proven cases of oral malignancy and age- and sex-matched control group (n = 20). The enzyme GST was evaluated in sera of all participants and then comparison was done between two groups as well as correlation with histopathologic grading for oral malignancy. The mean serum GST activity in oral cancer patients was significantly higher than that of the control group. The present study has compared the alterations of enzyme in relation to histopathological grading of oral malignancy and found increased serum GST activity of well-differentiated and moderately differentiated carcinomas than the poorly differentiated carcinoma in terms of mean. Increased expression of the enzyme, as reported in the present study, can be due to tumor burden which attributes to overproduction of GST by cancer cells. The major clinical significance of the present study is that it gives important information regarding a new tumor progression and prognosis marker.