Modified intranuclear organization of regulatory factors in human acute leukemias: reversal after treatment
Biochemistry & Molecular Pharmacology
Graduate School of Biomedical Sciences; Department of Medicine and Cancer Center; Department of Cell Biology
Medical Subject Headings
Cell Nucleus; DNA-Binding Proteins; *Gene Expression Regulation, Neoplastic; Humans; Leukemia; Microscopy, Fluorescence; Myeloid-Lymphoid Leukemia Protein; Neoplasm Proteins; Nuclear Proteins; *Proto-Oncogenes; Transcription Factors; Tumor Cells, Cultured; Tumor Suppressor Proteins
Life Sciences | Medicine and Health Sciences
Acute leukemias arise secondary to chromosomal aberrations that cause dysfunctions in gene regulation and regulatory factors. Significant differences in morphology between acute leukemic and nonleukemic hematopoietic cells are readily observed. How morphologic changes of the nuclei of acute leukemic cells relate to the underlying functional alterations of gene expression is minimally understood. Spatial modifications in the representation and/or organization of regulatory factors may be functionally linked to perturbations of gene expression in acute leukemic cells. Using in situ immunofluorescence microscopy, we addressed the interrelationships of modifications in nuclear morphology with the intranuclear distribution of leukemia-related regulatory factors (including ALL-1, PML, and AF-9) in cells from patients with acute leukemia. We compared the localization of leukemia-associated proteins with various factors involved in gene transcription and RNA processing (e.g., RNA polymerase II and SC-35). Our findings suggest that there are leukemia-associated aberrations in mechanisms that direct regulatory factors to sites within the nucleus. This misplacement of key cognate factors may contribute to perturbations in gene expression characteristic of leukemias.
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Citation: J Cell Biochem. 2000 Feb;77(1):30-43.