BACKGROUND: The proteasome chymotrypsin-like (Cht-L) activity was determined in plasma of children with acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) in correlation to baseline leukocytosis, immunophenotype, LDH at the time of diagnosis and after remission induction. PROCEDURE: The activity was assayed using the fluorogenic peptide substrate in the presence of an artificial activator sodium dodecyl sulfate (SDS) in the plasma of healthy donors (n=25), acute lymphoblastic leukemia, ALL (n=95) and AML (n=17) patients. RESULTS: As compared to healthy subjects, the plasma proteasome ChT-L activity was significantly increased (p=0.001) in ALL patients prior to treatment, especially in those with T-ALL immunophenotype and with high LDH activity. Similarly, in AML patients the plasma proteasome ChT-L activity was elevated (p=0.001). Following remission-inducing chemotherapy, the activity of the ChT-L proteasome was significantly reduced both in ALL and AML patients. CONCLUSION: Plasma proteasome ChT-L activity may serve as an additional marker in monitoring anticancer therapy.
BACKGROUND: The proteasome chymotrypsin-like (Cht-L) activity was determined in plasma of children with acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) in correlation to baseline leukocytosis, immunophenotype, LDH at the time of diagnosis and after remission induction. PROCEDURE: The activity was assayed using the fluorogenic peptide substrate in the presence of an artificial activator sodium dodecyl sulfate (SDS) in the plasma of healthy donors (n=25), acute lymphoblastic leukemia, ALL (n=95) and AML (n=17) patients. RESULTS: As compared to healthy subjects, the plasma proteasome ChT-L activity was significantly increased (p=0.001) in ALL patients prior to treatment, especially in those with T-ALL immunophenotype and with high LDH activity. Similarly, in AMLpatients the plasma proteasome ChT-L activity was elevated (p=0.001). Following remission-inducing chemotherapy, the activity of the ChT-L proteasome was significantly reduced both in ALL and AMLpatients. CONCLUSION: Plasma proteasome ChT-L activity may serve as an additional marker in monitoring anticancer therapy.