Increased activity of enzymes involved in purine metabolism as one of the factors of rectal cancer pathogenesis

Aim: to study changes in the activities of purine nucleotide degradation enzymes - adenosine deaminase (ADA) and xanthine oxidase (XO) in patients with rectum cancer (RC). Material and Methods. The activity of purine nucleotide degradation enzymes was studied in blood plasma and tissue homogenates: tumor tissue and normal rectal mucosa in 70 patients with stage I-IV RC. The histological type of RC was adenocarcinoma. The levels of ADA and XO activities were measured using spectrophotometry. Results. The activity of ADA and XO in blood serum of RC patients was significantly higher than that of healthy people. A significant increase in the activity of ADA and XO in tumor tissue compared to normal tissue was also found. The relationship between the activities of the enzymes of purine catabolism in blood plasma and tissues were revealed. An increase in purine catabolism depending on the stage of RC was found. Conclusion. The increased ADA and XO activities indicated the enhanced purine catabolism not only in malignant transformation, but also in tumor progression.