The retinoblastoma gene product in acute myeloid leukemia: A possible involvement in promyelocytic leukemia

The retinoblastoma susceptibility gene in leukemia and lymphoma has been investigated using different approaches involving either gene or protein analysis. In this study, a novel method, which evaluates the functional status of the retinoblastoma gene product by a binding assay to an in vitro- translated viral oncoprotein, has been applied to leukemic cells from acute myeloid leukemia patients. One hundred twenty-two cases were considered, and 42 of them were also analyzed by Western blot. Results obtained with the two methods were comparable, with the exception of few cases, where the retinoblastoma protein appeared detectable but unable to bind to the vital oncoprotein. The retinoblastoma protein has been found defective mostly in the M3 promyelocytic subtype.