PMC

(A–D) CTCs among blood cells. (A–B) Native images. (C–D) Corresponding fluorescence images after staining with anti-EpCAM-Alexa 488. Note the tip of the capillary used to isolate the CTCs in image A. (E–H) Adherent colonies formed by CTCs 48 h after transfer to in vitro culture dishes. (E–F) Phase contrast microscopy. (G–H) Corresponding fluorescence images (anti-EpCAM-Alexa 488).

(A) Growth kinetics of orthotopically growing HT-29 and HCT116 tumor xenografts in NSG mice. (B) Situs of a NSG mouse bearing a HCT116 xenograft 35 days after tumor inoculation. (C) H & E section of a primary tumor (HCT116). Note the tumor bulk infiltrating the basement membrane (dashed line) and a tumor deposit on the luminal side of the basement membrane (arrow). (D–E) H & E section with immunohistochemical EpCAM staining (brown) of a liver metastasis (D) and a lung metastasis (E).

All data shown are ΔΔCt values comparing gene expression in circulating tumor cells vs. bulk tumor cells derived from hepatic metastases. (A) Gene expression of CTC compared with corresponding liver metastases. Positive values indicate increased expression, negative values reduced expression in CTC. Filled bars indicate significantly upregulated (red) or downregulated (green) genes. p < 0.05 was considered statistically significant. (B) Heat map depicting the individual ΔΔCt values of individual CTC samples compared to their respective liver metastases. Green squares indicate downregulated genes, red squares indicate upregulated genes in CTC, blank squares indicate Ct values > 35, in this case the gene was considered not expressed.