Fig. 1.

High expression of FZD6 in liver cancer and liver TICs. a Heatmap of Wnt receptors (FZD1-FZD10) in 214 peri-tumor samples and 224 tumor samples derived from GSE14520. The average expression levels in peri-tumor samples were defined as 1. FZD6 is highly expressed during liver tumorigenesis. b Thirty-two peri-tumor samples and 32 HCC samples were examined for expression levels of the indicated genes. Ten FZD members and two Wnt/β-catenin target genes (Axin2, c-Myc) were analyzed. c, d Samples were divided into two groups according to sample origin c or metastasis d, and FZD6 intensity were analyzed and shown as box and whisker plot. Boxes indicate interquartile ranges (IQR); upper and lower edges are the 75th and 25th percentiles. Horizontal lines within boxes are median intensity. Whiskers are 5th and 95th percentiles. e Samples were divided into two groups according to FZD6 expression levels, followed by Kaplan–Meier survival analysis. f, g Peri-tumor, early hepatocellular carcinoma (eHCC) and advanced hepatocellular carcinoma (aHCC) samples were collected, and FZD6 expression levels were detected using real-time PCR f and western blot g. h, i FZD6 mRNA expression levels were detected using CD133 enriched liver TICs h or oncospheres i. FZD6 expression in non-TICs was served as control. j, k liver TICs j and oncospheres k were enriched and FZD6 protein levels were examined with western blot. l, m FZD6 overexpressed (oeFZD6) and control (oeVec) cells were treated with β-catenin/TCF inhibitors (PNU-74654, LF3), and tumor invasion l and self-renewal capacities m were examined. Typical images and calculated numbers (or ratios) were shown. For b, f, h, i, data were shown as means ± s.d. For c, d, data are shown as box and whisker plot. *P < 0.05; **P < 0.01; ***P < 0.001 by two-tailed Student’s t-test. Data are representative of three independent experiments