Comparison of the activity and tissue distribution of thioredoxin reductase enzyme in the tumoral tissue of pancreatic carcinoma with its cancer-free adjacent tissue

Pancreatic cancer is one of the common types of cancer in Iran which accounts for a large number of patients hospitalized in the surgical ward who need surgical resection. Its highest prevalence is between the ages of 55 and 85 years. The real cause of this cancer is not yet known.Thioredoxin (Trx), NADPH and Thioredoxin reductase (TrxR) form the Thioredoxin system which exists in all living cells.Thioredoxin reductase as part of thethiol regulatory system allows for oxidation-reduction metabolism to regulate the cell needs. This enzyme plays various roles including the involvement in the development of cancer in mammalian cells. Since oxidant agents have a major role in the pathogenesis of this cancer, studying the oxidant compounds like Thioredoxin reductase enzyme is not only a new topic but also enjoys great importance to increase our knowledge about the molecular mechanisms involved in the pathogenesis of the disease and ultimately design more effective treatments. Given that the research conducted on this issue is very limited, we intend in this study to compare tissue distribution and activity of Thioredoxin reductase enzyme in the tumor tissue of pancreatic cancer and its healthy margin.This study was performed on 30 patients suffering from pancreatic cancer that referred to Imam Reza Hospital in Mashhad and had the inclusion criteria. After selecting the subjects, a tissue sample was taken from the tumor and its healthy margin. The rate of enzyme tissue distribution was determined based on immunohistochemical staining and using a separate rating for the percentage of stained cells and staining intensity and finally the product of the two scores for tumor healthy tissues. Then the scores were compared.To measure the enzyme activity in the tissue, the samples were sent to the biochemistry laboratory of Faculty of Medicine and were homogenized. Afterwards, the liquid obtained from homogenizing the samples which contained enzyme was kept at -80° C. After completion of the samples, the measurement kit was opened and the enzyme activity was assessed based on catalyzing a specific reaction and creating a colored material (yellow) and measuring the amount of this material according to optical absorption at 405 nm for tumor and healthy tissues and then, they were compared.The obtained results demonstrated that there is no statistically significant difference between the tumor tissue of pancreatic cancer and its normal surrounding environment in terms of Thioredoxin reductase enzyme activity level (P-value= 0.56). But if we consider the different stages of the disease, this difference can be observed. A statistically significant relationship exists between staining intensity of the tumor and disease stage (P-value= 0.022). No statistically significant difference was observed between staining percentage, staining intensity and tissue distribution of the sampling site.In the present study, no difference was observed between the tumor tissue of pancreatic cancer and tissue of the healthy margin in terms of activity and tissue distribution of Thioredoxin Reductase. With regard to the limitations of this study, it is recommended to continue the research to collect a greater sample and have an equal number of patients in each stage

Keywords:

Cancer Diagnosis , Cancer Prevention , Solid Tumors , Cancer Treatment and Management , Targeted Cancer Therapy