Specific
immunotherapies for patients with
acute myeloid leukemia (AML) using
leukemia-associated
antigens (LAA) as target structures might be a therapeutic option to enhance the graft-vs.-leukemia effect observed after allogeneic
stem cell transplantation or to prolong a complete remission (CR) achieved by
chemotherapy. Significant
mRNA expression of LAA is a prerequisite for such
immunotherapies. Here, previously characterized
antigens associated with solid
tumors (TAA) and newly characterized LAA were investigated for their expression in up to 60 AML patients and in
leukemia cell lines. To investigate their specificity for leukemic blasts, the
mRNA expression was also characterized in PBMN and CD34 positive cells of healthy volunteers and in a panel of normal tissues. The following
antigens showed high
mRNA expression in AML patients: MPP11 was detected in 43/50 (86%), RHAMM in 35/50 (70%), WT1 in 40/60 (67%), PRAME in 32/50 (64%), G250 in 18/35 (51%), hTERT in 7/25 (28%) and BAGE in 8/30 (27%) of AML patients. Real-time RT-PCR showed a
tumor-specific expression of the
antigens BAGE, G250 and hTERT, as well as highly
tumor-restricted expression for RHAMM, PRAME and WT1. The
antigen MPP11 was overexpressed. These
antigens might be candidates for
immunotherapies of
leukemia patients and, because of their simultaneous expression, also for
polyvalent vaccines.