THE EXPRESSION OF IMMUNOPROTEASOME SUBUNITSβ AND PRO-TEASOME ACTIVATORS AND THEIRS RELATION TO LINICAL AND BIOLOGICAL CHARACTERISTICS IN CHILDHOOD ACUTE LEUKEMIA

Xie J-J1, Hu Y-M1, Lu Y-Y2, Li W-M2, Gong W-Y1, Li J1

1 Beijing Children's Hospital, Beijing, China

2 Clinical College of Tumor, Beijing University, Beijing, China

 

Objective: To investigate whether the function of antigen processing and presentation is deficient and related to clinical and biological characteristics in childhood acute leukemia(AL)

Methods: (1)The clinical and biological data and anti-coagulated bone marrow from 50 inpatients with childhood AL were collected. And then mononuclear cells were separated. (2) Western Blotting was performed for the detection of LMP2(low-molecular mass polypeptide), LMP7, TAP1(transporter1 associated with antigen processing), PA28α and PA28β(proteasome activator) expression.

Results:  (1) The ratios of intensively positive, weakly positive and negative expression of LMP7 in AL were 23.3%, 38.9% and 44.4% respectively, and were significantly different from those in control (p<0.05). d Negative expression of LMP7 was seen in 70% of inpatients with relapsed AL, which was significantly different from that in 18.8% of inpatients with de novo AL; (2)The expression of LMP2, TAP1, PA28αand PA28βin AL were not significantly different from those in control (p>0.05); (3)The decrease or loss of LMP7 expression was related to relapse (p<0.05).,and the expressions of LMP2, PA28α, PA28β and TAP1 were not related to clinical and biological characteristics (p>0.05).

Conclusion: (1) Decreased generation of endogenous antigen pepetide resulting from LMP7 deficiency exits in leukemic cell, which will possibly be related to the escape of leukemic cells from immune surveillance in childhood AL. (2) Decrease or loss of LMP7 expression is possibly related to relapsed leukemia.

 

 
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