Arginase isoforms in human colorectal cancer

Area of Science:

• Biochemistry
• Oncology
• Clinical Chemistry

Background:

• Arginase (EC 3.5.3.1) plays a role in arginine metabolism.
• Altered enzyme activity is implicated in various cancers, including colorectal adenocarcinoma.
• Understanding arginase isoforms in colorectal cancer is crucial for diagnostic development.

Purpose of the Study:

• To quantify arginase activity in colorectal cancer tissues and patient serum.
• To identify and characterize arginase isoforms present in colorectal tissues and serum.
• To evaluate the potential of arginase as a biomarker for colorectal cancer detection.

Main Methods:

• Arginase activity assays were performed on 54 colorectal tumor tissues and 65 healthy control tissues.
• Serum arginase activity was measured in 45 colorectal cancer patients and 65 healthy individuals.
• Isoelectric focusing and Western blotting were used to identify and characterize arginase isoforms.

Main Results:

• Significantly higher arginase activity was found in colorectal tumors and serum of cancer patients compared to controls.
• Two arginase isoforms, anionic and cationic, were identified in colorectal tissues; only the cationic form was detected in serum.
• The cationic arginase isoform, distinct from the main liver isoform, was elevated in both tumor tissue and serum of patients with colorectal cancer.

Conclusions:

• Increased serum and tumor arginase activity in colorectal cancer patients is attributed to elevated levels of the cationic arginase isoform.
• The cationic arginase isoform shows promise as a discriminating biomarker for assessing the presence of colorectal cancer.