Extracellular L-asparagine pool

The extracellular L-asparagine pool refers to the concentration of the non-essential amino acid L-asparagine circulating in the blood and interstitial fluids (Source: PubMed PMID 30033132). While most normal cells can synthesize asparagine intracellularly via the enzyme asparagine synthetase (ASNS), certain malignant cells, particularly in acute lymphoblastic leukemia (ALL), lack sufficient ASNS activity (Source: StatPearls, Asparaginase). These cells are auxotrophic for L-asparagine and rely entirely on the uptake of the amino acid from the extracellular environment for protein synthesis and survival (Source: PubMed PMID 28233333). Therapeutic intervention involves the administration of the enzyme L-asparaginase, which catalyzes the hydrolysis of extracellular L-asparagine into L-aspartic acid and ammonia (Source: NCI Drug Dictionary). This rapid depletion starves the leukemia cells, leading to cell cycle arrest and apoptosis (Source: PubMed PMID 31513017). This strategy is a cornerstone of pediatric ALL treatment protocols and is also used in some adult regimens and non-Hodgkin lymphomas (Source: FDA, Oncaspar Prescribing Information). However, targeting this pool is associated with significant toxicities, including hypersensitivity reactions, acute pancreatitis, and coagulopathy due to the systemic nature of the depletion (Source: PubMed PMID 26961370). Monitoring of asparaginase activity and asparagine levels is often employed to ensure therapeutic efficacy and manage potential resistance (Source: PubMed PMID 28233333).

Other names

Plasma L-asparagineSerum L-asparagineCirculating L-asparagine pool

Enzymatic depletion of extracellular L-asparagine via hydrolysis into L-aspartic acid and ammonia, leading to nutritional deprivation and apoptosis in asparagine-dependent malignant cells (Source: PubMed PMID 28233333).