Zofia Porembska

Arginase in patients with breast cancer

The mean arginase activity in breast cancers (n = 80) was significantly higher than in control tissues and it accounted for 0.31 +/- 0.23 U/g wet tissue and 0.083 +/- 0.061 U/g (P < 0.05), respectively. With the cutoff value of 0.1 U/g wet tissue, raised arginase activity was observed in 74% of tumors. The preoperative arginase activity in blood serum from women with breast cancer was 11.2 +/- 7.9 U/l (n = 115), and it was significantly higher than in 70 healthy controls, where it was 5.7 +/- 2.4 U/l (P < 0.05). With the cutoff value for normal serum arginase activity above 8.0 U/l, the activity was raised in 10% of control individuals, and in 63% of women with breast cancer. The sensitivity and specificity of the arginase test in blood serum were 63% and 60%, respectively. Two isoforms immunologically identical to human kidney arginases (L-arginine amidinohydrolase) were found in both normal and cancerous breast tissues. The level of anionic form was similar in control and cancerous tissues, whereas the cationic isoform predominated in breast cancer. The cationic isoform was the only one present in serum of both ill and healthy women, and its level was higher in patients with breast cancer. Thus, it can be concluded that the cationic isoform is responsible for the increase of arginase activity in serum of patients with breast cancer.

Early diagnosis of myocardial infarction by arginase activity determination

In blood serum of healthy persons the activity of arginase (EC 3.5.3.1) is very low, whereas in patients with myocardial infarction it increases within a few hours after the first attack of coronary pain, and returns to normal values after 3-5 days. No increase of arginase activity was observed in sera of patients with angina pectoris, coronary insufficiency or cardiac failure. Determination of arginase activity in blood serum may serve as a useful test in early differential diagnosis of myocardial infarction.

Arginase isoforms in human colorectal cancer.

Arginase (EC 3.5.3.1) activity was determined in 54 colorectal tissues obtained from patients with primary colorectal adenocarcinoma as well as in serum of 45 patients and 65 healthy individuals. In patients, the preoperative values of the mean serum arginase activity and the activity in colorectal tumors were much higher than in serum of healthy subjects and control tissues. Two isoforms of arginase, anionic and cationic, were identified in colorectal tissues (normal and cancerogenous), and only one, the cationic form, in serum. These arginases were different from the main human liver cationic arginase (pI 9.3). The anionic colorectal arginase was identical with the human liver anionic isoform (pI 7.7), and the cationic arginase from colorectal tissues and blood serum with the human kidney cationic enzyme (pI 8.9). The total activity and the level of protein of the cationic arginase in colorectal cancer was higher than in control tissue, and it was also higher in serum of patients with colorectal cancer than in healthy subjects. Thus, it can be concluded that the increased arginase activity in blood serum and colorectal cancer in studied patients was due to the raised level of the cationic arginase and this isoform seems to be a discriminating parameter for assessing the presence of colorectal cancer.

Serum arginase activity in postsurgical monitoring of patients with colorectal carcinoma

Colorectal carcinoma (CRC) is one of the most common malignancies. In the current work, the role of arginase as a diagnostic marker in patients with recurrent CRC and colorectal liver metastases (CRCLM) was studied.

Arginase from human blood serum.

Abstract 1. 1. An isolation and purification procedure for human serum arginase is presented. 2. 2. The specific activity of the purified enzyme was 2400 times greater than that of crude serum arginase. 3. 3. Multiple molecular forms of the enzyme were not detected in serum. 4. 4. The enzyme showed high specificity for l -arginine. K m of the enzyme was 3.3 m m . The enzyme was found to be cationic protein; its molecular weight amounted to 120,000. 5. 5. EDTA inhibited the enzyme. This inhibition could be completely reversed by Mn 2+ ions. The enzyme had an oligomeric structure; upon treatment with EDTA it dissociated into subunits with a molecular weight of 30,000.