Nuclear localization of translocation partners in differentiating B-cells.

We studied the nuclear localization and relative position in the nuclear space of malignant translocation partner genes c-Myc, CCND1, and IGH locus in naive and differentiating B cells. We have shown that, during B-cell maturation, c-Myc and IGH loci become closer to each other. In differentiating lymphocytes, those alleles of c-Myc and IGH that are in close spatial proximity to each other are closer to the nucleolus. For the CCND1 locus, no correlation between the proximity of loci and nuclear localization was found. These data suggest that the close spatial proximity of c-Myc and IGH loci during B-cell maturation increase the probability of malignant translocation.