ABAT, also known as GABA-transaminase, is a key enzyme in the metabolism of gamma-aminobutyric acid (GABA), the most important inhibitory neurotransmitter in the brain. GABA metabolism is crucial for maintaining the balance between neuronal excitation and inhibition, and thus plays a significant role in normal brain function [5]. Mutations in ABAT can lead to GABA-transaminase deficiency, resulting in encephalopathy with symptoms like hypersomnolence, hypotonia, hypomyelination, and seizures [3].

In liver cancer, inactivating ABAT was associated with poor prognosis, and overexpressing ABAT could inhibit cancer cell behaviors and suppress tumorigenesis in nude mice. It was also found that miR-183-5p could target and downregulate ABAT expression in liver cancer [1].

In myelodysplastic syndrome, ABAT gene interference increased the sensitivity of cells to hypomethylating agents treatment, while ABAT overexpression decreased its sensitivity. The downregulation of ABAT gene expression could activate the CXCR4/mTOR signaling pathway, which was related to the sensitivity of hypomethylating agents [2].

In clear cell renal cell carcinoma, downregulated ABAT expression was observed, and overexpression of ABAT significantly attenuated cell proliferation and migration [4].

In conclusion, ABAT is essential for GABA metabolism and normal brain function. Its dysregulation is implicated in multiple diseases, including liver cancer, myelodysplastic syndrome, and clear cell renal cell carcinoma. Studies using in vivo models like nude mice in liver cancer research, and cell-based functional experiments in myelodysplastic syndrome and clear cell renal cell carcinoma, have provided insights into the role of ABAT in disease processes, highlighting its potential as a therapeutic target.