Zinc Finger Protein SALL4 Functions through an AT-Rich Motif to Regulate Gene Expression

Area of Science:

• Molecular Biology
• Cancer Biology
• Epigenetics

Background:

• The zinc finger transcription factor SALL4 is highly expressed in embryonic stem cells and reactivated in aggressive cancers.
• SALL4's unique expression pattern presents it as a potential therapeutic target in oncology.
• The precise DNA-binding mechanism and cancer-specific gene targets of SALL4 remain largely uncharacterized.

Purpose of the Study:

• To elucidate the direct DNA-binding mechanism of the transcription factor SALL4.
• To identify novel SALL4-regulated genes in aggressive liver cancer.
• To uncover potential therapeutic targets in SALL4-dependent tumors.

Main Methods:

• Utilized protein binding microarray (PBM) to identify SALL4 DNA-binding domains and consensus sequences.
• Employed cleavage under targets and release using nuclease (CUT&RUN) for in vivo DNA-binding validation.
• Performed RNA sequencing (RNA-seq) following SALL4 knockdown to identify target genes.

Main Results:

• Identified and validated the DNA-binding domain and consensus binding sequence of SALL4.
• Discovered hundreds of new direct SALL4 target genes in aggressive liver cancer cells.
• Found that SALL4 directly regulates genes encoding histone 3 lysine 9-specific demethylases (KDMs).

Conclusions:

• Elucidated the direct DNA-binding mechanism of SALL4.
• Revealed novel SALL4 target genes and pathways critical in aggressive liver cancer.
• Provided insights into potential therapeutic strategies for SALL4-dependent cancers.