Expression of EVI1 and the Retinoblastoma genes in acute myelogenous leukemia with t(3;13)(q26;q13-14).

The EVI1 DNA-binding protein gene on chromosome 3q26 has been reported to be activated in some leukemia cells with alterations in 3q26. We present an acute myelogenous leukemia (AML) patient with a rare chromosomal translocation, t(3;13)(q26.2;q13-14). By reverse transcription-polymerase chain reaction, we detected active transcription of the EVI1 gene in the patient's leukemia cells. The retinoblastoma susceptibility (Rb) gene, a tumor-suppressor gene, is located at chromosome 13ql4 and is within the other translocation breakpoint in this patient. The expression of the Rb gene product was found to be substantially decreased in the patient's leukemia cells by Western blotting. Southern blot analysis, however, revealed no gross abnormalities of the Rb gene. Although it is unlikely that the Rb gene is directly involved in this translocation, the loss of the Rb gene product combined with the activation of the EVI1 gene may have led to the development of leukemia.