门冬酰胺酶 (Rylaze, Spectrila)

概览

Asparaginase Escherichia coli is an asparaginase enzyme from E. coli used as part of treatment regimens for acute lymphoblastic leukemias.

作用机制

Asparagine is a non-essential amino acid that maintains DNA, RNA and protein synthesis and promotes cell growth. While healthy and normal cells are capable of obtaining asparagine via dietary intake or synthesizing the asparagine from aspartate via asparagine synthetase activity, lymphoblastic leukemic cells lack the asparagine synthetase enzyme and cannot produce asparagine de novo . Thus, leukemic cells rely on exogenous source of asparagine for protein synthesis and cell survival . L-asparagine from E. coli serves to deplete plasma levels of asparagine in leukemic cells by converting L-asparagine to L-aspartic acid and ammonia , leading to reduced reduced DNA, RNA and protein synthesis; inhibition of cell growth; and ultimately the activation of apoptotic cell-death mechanisms . Normal cells, however, are able to synthesize asparagine and thus are affected less by the rapid depletion produced by treatment with the enzyme asparaginase .

适应症

Indicated as a component of a multi-agent chemotherapeutic regimen for the treatment of patients with acute lymphoblastic leukemia (ALL).

• Acute Lymphoblastic Leukaemias (ALL)