Constitutive expression of the putative transcription factor SCL associated with proviral insertion in the myeloid leukemic cell line WEHI-3BD-

Abstract

The murine myeloid leukemia WEHI-3B contains an intracisternal A-particle insertion in a growth factor gene (IL-3) and a homeobox gene (Hox 2.4). Southern blot analysis of the differentiation unresponsive subline WEHI-3BD- demonstrated a rearrangement of the SCL gene, a gene that encodes a protein of the helix-loop-helix class of transcription factors. Northern blot analysis demonstrated an abnormal SCL transcript in the WEHI-3BD- cells, although SCL expression was not detected in the parental cells. The rearrangement was cloned and confirmed as an insertion of an intracisternal A-particle in the 3' untranslated region of the SCL gene. Although SCL is implicated in up to 25% of human T-cell acute lymphoblastic leukemia, this is the first example of SCL involvement in a myeloid leukemia.