ARG Cancer Research Results

Arginine is a semi-essential amino acid involved in protein synthesis, nitric oxide production, the urea cycle, creatine synthesis, polyamine production, immune-cell function, and cellular metabolism. Its availability is regulated partly by arginase-1 (ARG1), arginase-2 (ARG2), nitric oxide synthases, and enzymes involved in arginine synthesis and recycling.
-higher ARG1/ARG2 activity → lower available arginine

In cancer, arginine has context-dependent effects. Some tumours are dependent on extracellular arginine because they have reduced expression of argininosuccinate synthetase 1 (ASS1) or other arginine-synthesis enzymes. Arginine depletion may therefore inhibit the growth of arginine-auxotrophic tumours. In contrast, adequate arginine can support T-cell proliferation, cytotoxic activity, and antitumour immune responses. Increased ARG1 or ARG2 activity may deplete arginine in the tumour microenvironment and suppress T-cell function.

In neurodegenerative disease, arginine metabolism influences nitric oxide production, vascular function, mitochondrial activity, oxidative stress, and neuroinflammation. Excessive arginase activity may reduce arginine availability for nitric oxide synthase, while dysregulated nitric oxide production may contribute to oxidative and nitrosative stress.

Direction: context-dependent. Increased arginine availability may support immune and vascular function, whereas arginine depletion may be beneficial in arginine-dependent tumours. Arginine is a direction-neutral metabolite target, with the favourable direction recorded at the individual study or disease-context level.