The Expression Of Prame Gene In Leukemia,Multiple Myeloma And Its Clinical Significance

Objective: To elucidate the expression of Prame (preferentially expressed antigen of melanoma) in leukemia and MM , and its clinical significance.Method: Expression of Prame mRNA was detected in 23 AML ,15 ALL ,20 CML ,8 MM , 10 non-blood disease patients and 10 heathy subjects by using RT-PCR,and compared with the expression of Wilm's tumor gene (WT1) in leukemias.Result: Prame mRNA was revealed in 12 of 23 AML(67%),10 of 15 ALL (52%),5 of 9 CML patients in blast crisis,1 of 8 MM.Prame mRNA was undetected in bone marrow cells from non-blood disease patients and in PBMNC from 10 healthy subjects . The expression of Prame and WT1 had no significant difference in AML,ALL and CML,but both had correlated witheach other(p<0.01). however,one AML,five ALL with Prame expression had no WTl detectable. Only 1 MM was detected the expression of Prame mRNA, it's no different with normal group(P>0.05) .Comparing the expressed level of Prame between AML and ALL by semiquantitative RT-PCR(0.752 0.157 and 0.823 0.231 respectively), there were no significant difference to be found .2 Prame-positive patients and 4 patients with the expression of the both Prame and WT1 genes were monitored using semiquantitative RT-PCR in short follow-up.The lowed level of Prame were detected in all patients after chemotherapy.One with high Prame expression at dignosis became negative after CR ,she doesn't relapse until now,and another one remaining Pramepositive in early days of CR ,which decreased to negative after several intensivechemotherapy.One patient had been increased Prame expression after one month of CR ,after two months this patient relapsed and thereafter WTl turned up. The other paitents with Prame-and-WT1-positive had consistent change in both genes .Conclution: Immunogenic antigen Prame is a special gene expressed in leukemias,and no significant difference in AML and ALL. It's involved in human leukemogeneses and immunize change.it may be a good tumor marker ,combinding with WTl gene, to cover wider range in mornitoring MRD in patients with leukemia,and Prame may also be useful as target antigen for immunotherapy of leukemia.