[Abnormalities of the retinoblastoma susceptibility gene (RB) in hematologic malignancies]

The retinoblastoma susceptibility gene (RB) is expressed in all lineages of normal hematopoietic cells and plays an important role in controlling cell cycle progression at G1/S. Abnormalities of the RB gene may, therefore, predispose to the development of hematologic malignancies. DNA rearrangement was reported to be present in 1.5-12.1% of cases with primary leukemias and the absence of the RB gene product was also observed in 6.3-23.2%. The abnormalities were frequently observed in blastic crisis of CML, especially of the megakaryoblastic phenotype, AML with monocytic differentiation and Ph1-positive leukemias. These results indicate that abnormalities of RB are relatively common in hematologic malignancies and loss of RB function may contribute to the altered growth of these cells.