Normal structure of NPKB2, C-REL and BCL-3 gene loci in lymphoproliferative and myeloproliferative disorders

NF-kappa B/rel transcription factors are crucial regulators of development, differentiation and apoptosis of both lymphoid and myeloid lineages. There is increasing evidence for an involvement of NF-kappa B/rel proteins in lymphomagenesis and resistance of lymphoid tumors to the induction of apoptosis. Structural alterations of the NF-kappa B/rel genes NFKB2, c-rel and bcl-3 have been shown to result in increased NF-kappa B/rel activity. Because we observed strong constitutive NF-kappa B/rel binding activity in chronic lymphocytic leukemia of the B-cell type (B-CLL) which may contribute to resistance against cytotoxic drugs we studied the genomic organisation of NFKB2, c-rel and bcl-3 gene loci in a panel of lymphoproliferative disorders (n=81) with an emphasis on B-CLL (n=47). The method of genomic Southern blotting using cDNAs of the respective genes was used. In spite of the role of NF-kappa B/rel in myeloid maturation there is no data available as to the occurrence of NF-kappa B/rel rearrangements in chronic myeloproliferative syndromes (cMPS). For this reason we included a small panel of cMPS patients (n=16). Southern Blotting revealed a germline configuration of NFKB2, c-rel and bcl-3 loci in all NHL and cMPS patients examined. Our results demonstrate that structural alterations of NFKB2, c-rel and bcl-3 genes at the Southern Blotting level are rare events that do not contribute to lymphoid or myeloid transformation in the majority of NHL or cMPS patients.