Arginase-1

Arginase-1 (ARG1) is a binuclear manganese metalloprotease in liver cells, which can catalyze the hydrolysis of arginine to ornithine and urea, thus becoming a key enzyme in the urea cycle. In clinical practice, ARG1 is an essential diagnostic biomarker with high specificity and sensitivity for hepatocellular carcinoma (HCC). Especially, ARG1 is highly expressed in primary liver cancer but lowly expressed in liver metastatic cancer, which makes it become a differential indicator. Moreover, the expression level of ARG1 is down-regulated with the decreased HCC differentiation degree, indicating that it plays a negative regulatory role in the tumor. This may be because the arginine accumulation caused by ARG1 deficiency will indirectly induce an increase in NO, leading to the inactivation of tumor suppressor genes and stimulating anti-apoptosis gene expression and tumor angiogenesis. However, some scholars found that ARG1 can be expressed in gastric cancer, and it is associated with the high malignancy of the tumor, speculated that arginine consumption by ARG1 may inhibit T cell proliferation and promote the production of polyamines that are necessary for cell growth.