The wt peptide reduces tumor cell viability in a SALL4/PTEN-dependent manner. (A) SALL4 expression in various tumor cell lines. SALL4 RNA expression was measured by quantitative RT-PCR and normalized to GAPDH. Expression of SALL4 in KBM5 cells was set as 1. (B) Reduced viability of tumor cells treated with wt peptide and TSA at various concentrations was observed in SALL4-expressing THP1, HL-60, SNU-398, and HuH-7 cell lines, but not in non-SALL4–expressing KBM5 cells at 72 hours. Surprisingly, AN3CA, a uterine cancer cell line with high SALL4 expression did not respond to wt peptide treatment. Cell viability (y axis) represents the relative result of the MTS assay. The value for each cell line with Pep-1 treatment alone was set as 1 (n = 3). *P < .05. (C) Western blot on endogenous PTEN protein expression in various untreated cancer cell lines. AN3CA has no detectable endogenous PTEN. (D) Peptide treatment can affect the PTEN/AKT pathway. Shown is a Western blot of the protein expression levels of PTEN, pAKT, and total AKT after peptide treatments. (E) A PTEN inhibitor (SF1670) can reverse wt peptide effects on viability of THP1 (SALL4⁺) cells, but has no effect on KBM5 (SALL4⁻) cells. The graph shows the results of MTS analysis of cells treated with wt peptide, scr peptide, TSA (100nM), or wt peptide + PTEN inhibitor SF1670 (wt + inh; n = 3). *P < .05.