Thrombotic events (TEs) are serious secondary complications in children with acute lymphoblastic leukemia (ALL) who receive L-asparaginase (ASP) therapy; however, the prevalence of TEs has not been established.
In this study tumor cell P-170 expression was assessed in 29 patients suffering from acute leukemia (17 acute myeloid leukemia (AML) and 12 acute lymphoblastic leukemia (ALL)) using three different techniques: flow cytometry measuring rhodamine 123 (Rh123) efflux (functional level), immunocytochemistry (protein level) and RT-PCR (mRNA level).
Immunocytochemical detection of the multidrug resistance (MDR)-associated membrane protein (P-170) was performed at time of diagnosis in a series of 36 children and 23 adults with acute lymphoblastic leukemia (ALL) using two monoclonal antibodies JSB1 and C219.
From these observations it appears that overexpression without gene amplification of mdr-1/P-170 may be one mechanism of clinical drug resistance in ALL.
Therefore, the objective of this study was to assess the effect of metformin on the treatment regimen in patients with ALL who exhibited high levels of ABCB1 gene expression and to determine its impact on overall survival.
In this study, we have shown that changes in the expression of MDR1 gene after short-term incubation of lymphoblasts with prednisolone may have prognostic value in pediatric de novo ALL patients.
There were no relations between the presence of P-gp, clinical characteristics (age, sex, hepatomegaly, and splenomegaly) and initial laboratory parameters (immunophenotype, white blood cells count, and serum lactate dehydrogenase) in ALL.
The expression of P-glycoprotein, multidrug-resistance protein, and lung-resistance protein (LRP) was not higher in infants compared to older c/preB ALL patients, but LRP was higher in proB ALL and MLL-rearranged ALL of all ages.
From these observations it appears that overexpression without gene amplification of mdr-1/P-170 may be one mechanism of clinical drug resistance in ALL.
To explore this phenomenon we investigated N6/ADR, a doxorubicin-selected, P-gp-positive variant of the human acute lymphoblastic leukemia (ALL) cell line NALM6.
Since the resistance of BALL‑1/VCR cells is potentially attributed to the overexpression of MDR‑associated protein 1 (MRP1), the development of drug resistance in relapsed ALL may associated with the overexpression of MRP1 and P‑glycoprotein.
The ABCB1 and ABCG2 gene expression levels were analyzed using real-time polymerase chain reaction in 61 patients diagnosed with ALL and 99 healthy donors as controls.
We found a concomitant increase in mdr1 and mrp gene expression combined with a decreased expression of topoisomerase II alpha in the course of the second relapse of an acute lymphoblastic leukemia (ALL).
High expression of MDR1 and BCL-2 in AML and MRP1 gene in ALL was associated with response to induction chemotherapy (p=0.001, p=0.02 and p=0.007 respectively).
In the present study, we determined the effect of dasatinib which was approved for imatinib resistant chronic myelogenous leukemia (CML) and (Ph(+)) acute lymphoblastic leukemia (ALL) treatment on P-gp-mediated MDR.