Analysis of immunophenotype, genotype, and lineage fidelity in blastic transformation of chronic myelogenous leukemia: a study of 20 cases.
ABSTRACT We have examined the immunophenotype and genotype of leukemic cells from 20 patients with the blastic phase of chronic myelogenous leukemia (CML), which is known to arise from a pluripotential hematopoietic stem cell. The phenotypic analysis of surface antigens with a panel of lineage-specific monoclonal antibodies revealed that six of 20 cases expressed phenotypes of lymphoid blastic transformation with pre-B cell markers. One of these cases was shown to coexpress cluster designation 2 of T cell marker on the same cells by two-color immunofluorescence analysis. Eight cases, including two cases that also had a megakaryocytic component, showed phenotypes expressing differentiation antigens of myeloid series. Three expressed a phenotype of megakaryoblastic transformation. The remaining three cases had no surface marker characteristic of any cellular lineage. The genotypic analysis by Southern blot hybridization showed that immunoglobulin heavy chain genes were rearranged in all of six lymphoid blastic transformations and that rearrangement of a T cell receptor beta chain gene was present in only one lymphoid blastic transformation that had no T cell surface marker. DNA samples in all cases of nonlymphoid blastic transformation were retained in the germ line configuration for both immunoglobulin and T cell receptor genes.(ABSTRACT TRUNCATED AT 250 WORDS)
Article: Absence of the human retinoblastoma gene product in the megakaryoblastic crisis of chronic myelogenous leukemia.[show abstract] [hide abstract]
ABSTRACT: The human retinoblastoma gene (RB) product, which is involved in the control of cell cycle and tumor suppression, is constitutively expressed as a nuclear phosphoprotein in normal human cells. We examined leukemic cells from 22 patients with blast crisis of chronic myelogenous leukemia (CML) for alterations of the RB expression. Western blotting and flow cytometry with anti-RB-protein antibodies showed that all of five cases with megakaryoblastic crisis lacked the expression of the RB-encoded protein, whereas none of 17 cases with the other phenotypes such as myeloblastic or lymphoblastic crisis showed any abnormality. These findings suggest that megakaryoblastic transformation of CML might be lineage-specifically associated with loss of the RB protein.Blood 12/1991; 78(9):2178-81. · 9.90 Impact Factor