Over-expression of short isoforms of Helios in patients with adult T-cell leukaemia/lymphoma


Fumihiko Ishimaru, MD, Department of Medicine, University of Okayama, 2-5-1 Shikatacho, Okayama 700–8558, Japan. E-mail: ishimaru@md.okayama-u.ac.jp


Summary. In previous studies, we demonstrated an over-expression of the dominant-negative isoform of the transcription factor Ikaros in patients with blast crisis of both chronic myelogenous leukaemia and B-cell acute lymphoblastic leukaemia (ALL). Recently, we reported an over-expression of the short isoforms of Helios, which is one of the members of the Ikaros gene family, in a patient with T-cell ALL. In the present study, we found over-expression of short isoforms of Helios in human T lymphotropic virus-I (HTLV1)-infected patients who had developed chronic and acute forms of adult T-cell leukaemia/lymphoma. In contrast, we could not detect any over-expression of short isoforms of Helios in healthy HTLV1 carriers. By Southern blotting, we detected a small deletion in the Helios gene locus of adult T-cell leukaemia/lymphoma patients. The present results suggest that Helios gene abnormalities might be one of the important mechanisms in the disease progression of HTLV1 infection.