Involvement of the MLL gene in T-ALL.

Southern blot analysis performed on genomic DNA extracted from leukemic cells from 5 patients with T-ALL (P1, P2, P3, P4, and P5) compared with human placenta used as a negative control (C). The enzymes used to digest the DNA are indicated. The filter was assayed for hybridization to the MLL PCR-amplified cDNA probes: E3E7 (nucleotides 3137-4125), E15E22 (nucleotides 5171-6130), and 0.85 (nucleotides 3750-4614); nucleotide numbering is with respect to the MLLcDNA sequence (Genbank accession no. NM_005933). The numbers indicate band size (kbp). The rearranged fragments are indicated by arrows. Southern blot analysis of the MLL gene revealed rearranged DNA fragments, with at least 2 restriction endonucleases in 5 of the 47 adults studied.