Differentially expressed nuclear proteins in human CCRF‐CEM, HL‐60, MEC‐1 and Raji cells correlate with cellular properties

The human cell lines CCRF‐CEM (T‐cell acute lymphocytic leukemia), HL‐60 (acute myeloid leukemia), MEC‐1 (B‐cell chronic lymphocytic leukemia) and Raji (Burkitt's B‐cell lymphoma) have been analysed for differences in their nuclear proteomes. Using 2‐D DIGE, 55 nuclear proteins have been identified that are differentially expressed ( p <0.025) between the four cell lines, including proteins associated with transcription, proliferation, DNA repair and apoptosis. Of these 55 proteins, 22 were over‐expressed in just one cell line, and four were down‐regulated in one cell line. Proteins uniquely over‐expressed between myeloid and lymphoid cell lines include those that may have use as markers for diagnosis, disease progression and B‐cell maturation and differentiation. Expression of various proliferation‐associated nuclear proteins correlated with relative growth rates of the cell lines, giving these proteins potential diagnostic applications for distinction of chronic versus acute subtypes of haematological malignancies. Identification of these differentially expressed nuclear proteins should facilitate elucidation of the molecular mechanisms underlying leukocyte differentiation and transformation to leukemias and lymphomas. The nuclear expression profiles should enable classification of subtypes of leukemia, and identify potential nuclear protein targets for development of diagnostic and therapeutic strategies.