Possible new genetic marker for human lymphoid leukemias as detected by ribosomal protein S14 cDNA

Two polymorphic restriction fragments (bands) were detected in human lymphoid leukemias using restriction enzyme HindIII and a DNA probe coding for the human ribosomal protein S14 gene. Seventy-four leukemia samples of either fresh or cultured cells (54 lymphoid and 20 non-lymphoid) and 28 normal leukocyte samples as controls were examined. Southern blot analysis of their genomic DNA showed that, in addition to seven distinct and invariant bands, two new bands of 3.0 kb and 1.8 kb were detected in 19 of 20 cases (95%) of T-cell leukemias and in 20 of 34 cases (59%) of B-cell and B-precursor-cell leukemias tested. These two new bands were not detected, however, in any of the 20 cases of myeloid leukemias, nor in any of the 28 cases of normal control samples. A fragment of approximately 400 bp sequences can be enzymatically amplified from the 3.0 kb and 1.8 kb size-selected genomic DNA by polymerase chain reaction. A processed pseudogene seems to be involved, as judged by the size of the amplified product. These results suggest this could be a genetic marker for lymphoid leukemias and may provide new insight into the heterogeneity of the genetic changes taking place in human hematopoietic malignancies.