PRAME, A GENE ENCODING AN ANTIGEN RECOGNIZED ON A HUMAN-MELANOMA BY CYTOLYTIC T-CELLS, IS EXPRESSED IN ACUTE-LEUKEMIA CELLS

Gene PRAME was found to encode an antigen recognized on a human melano ma cell Line by an autologous cytolytic T-lymphocyte clone. This gene is expressed at a high level in a very large fraction of tumours, such as melanomas, non-small-cell lung carcinomas, sarcomas, head and neck tumours and renal carcinomas. It is therefore a candidate for tumour immunotherapy even though some low expression is found in certain norm al tissues. We tested by RT-PCR the expression of PRAME on more than 2 50 bone marrow or blood samples from patients with a haematological ma lignancy, Approximately 25% of the acute leukaemia samples were positi ve, Remarkably, all acute myeloblastic leukaemias that carried the chr omosomal translocation t(8;21), which fuses the genes AML1 and ETO, ex pressed PRAME at a high level.