A novel role of stem cell factor SALL4 as an oncofetal protein in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related deaths worldwide. Treatment of HCC remains abysmal; discovery of novel pathways implicated in hepatocarcinogenesis is needed for more effective therapeutics. SALL4 is a stem cell factor essential for the maintenance of embryonic stem cell self-renewal properties and expressed in fetal liver, but silenced in normal adult liver. We observed that expression of SALL4 in murine liver in a transgenic model led to development of HCC. In humans, SALL4 is re-expressed as an oncofetal protein in a subgroup of HCC patients with unfavorable prognoses. Loss-of-function studies demonstrated that SALL4 is essential for human HCC cell survival and tumorigenicity. We demonstrated that a peptide can block the oncogenic function of SALL4 in HCC by modulating the PTEN/AKT pathway. Our findings reveal a novel role of SALL4 in HCC with important implications for understanding disease mechanisms and development of innovative therapeutics. Cultured cells from HCC cell line SNU-398 with scrambled or SALL4 shRNA knockdown were used for RNA extraction and hybridization on Affymetrix microarrays.