Hepatic leukemia factor (HLF)

Hepatic leukemia factor (HLF) is a member of the PAR bZIP (proline and acidic-rich, basic leucine zipper) family of transcription factors, characterized by a bZIP domain that mediates DNA binding and dimerization[1][2][4][5]. HLF plays an important role in gene expression regulation, notably in circadian rhythm and cell differentiation processes[2][4][5]. It can act as a homodimer or heterodimer with other PAR bZIP proteins such as TEF and DBP, binding to a specific DNA consensus sequence to activate transcription[3][4]. HLF gains oncogenic function in acute lymphoblastic leukemia when a chromosomal translocation t(17;19) creates an E2A-HLF fusion protein, which alters normal transcriptional regulation and is associated with a specific subtype of leukemia[2][3][4][5]. The E2A-HLF fusion is a well-recognized biomarker in diagnosis of this leukemia subtype. HLF itself is considered a proto-oncogene due to its role in malignancy when abnormally regulated[4][5]. Currently, no drugs are known to directly target HLF, and there are no mechanism-of-action or safety data for HLF-targeted therapies in clinical use.

Other names

Hepatic leukemia factorHLFMGC33822E2A-HLF fusion transcript proteinPAR bZIP transcription factorPAR bZIP family member