The Relation of Serum Arginine Levels with Serum Arginase and Nitric Oxide Synthase Activity in Patients with Breast Cancer BC11-BC14
Dr. Shelgikar Prachi Jayant,
PhD Student, Department of Biochemistry, B.J. Government Medical College, Pune-411001, Maharashtra, India.
Introduction: There is a significant disparity between metabolism in normal individuals and cancer patients which have resulted in metabolism based diagnosis. Several types of tumours have abnormalities in arginine and arginine metabolic enzymes. It is now becoming apparent that the two key enzymes of arginine metabolism: arginase and Nitric Oxide Synthase (NOS) in mammals play key roles in regulation of most aspects of arginine metabolism in cancer.
Aim: To evaluate arginine levels, arginase and nitric oxide synthase activity from serum of breast cancer patients of different stages and healthy controls and to find out the diagnostic use of these parameters for early breast cancer detection.
Materials and Methods: Fifty histopathologically proved cases of breast cancer of any stage (Stage I to Stage IV) in the age group of 35-70 years and 25 age and sex matched healthy controls were recruited for this prospective case control study. Intravenous blood sample was obtained to evaluate study parameters. Serum arginine levels were estimated by Sakaguchi method, serum arginase activity was estimated by Roman and Ray method while serum NOS activity was measured by Cortas and Wakid method.
Results: The results of this study showed significant decrease in serum arginine levels and significant increase in the activities of serum arginase and NOS in patients of all stages when compared with controls (p<0.01). Serum arginine levels further decreased (p<0.05) and activity of serum arginase (p<0.01) and of serum nitric oxide synthase (p<0.05) was found to be significantly increased in final stage (Stage III+IV) patients when compared with patients of initial stage (Stage I+II).
Conclusion: Complex interrelationship exists between the two important arginine metabolic pathways: arginase and NOS which may profoundly influence tumour growth and biology. The estimation of these parameters can give additional insight regarding disease progression.