Targeting the Oncofetal Transcription Factor Protein SALL4 in Cancer By a Non-IMiD Degrader

Sal-like protein 4 (SALL4) is a C2H2 zinc finger transcription factor (TF) with two naturally occurring isoforms; SALL4A and SALL4B. It is typically detected in fetal tissues and silenced in most normal adult tissues. It is therefore intriguing that SALL4 is aberrantly re-expressed in about one-third of almost all primary human malignancies, presumably by demethylation dependent mechanisms. Direct evidence of the causative role of SALL4 in cancer has been demonstrated in SALL4 transgenic mice, which developed myelodysplastic syndrome (MDS), acute myeloid leukemia (AML) and/or liver tumors. Loss-of-function studies by SALL4 knock-down using shRNA showed cell growth inhibition and death in leukemias and solid tumors in culture and in in vivoxenotransplants.