Figure 1

Expression of c-raf, c-myc, EpCAM, CD44, and CD133. (A) Expression of c-raf in A2C12 cells (lane 2) was markedly stronger than that in non-neoplastic lung tissue (lane 1), A549 cells (lane 3), or Caco-2 cells (lane 4). Expression of c-myc was detected in non-neoplastic lung tissue (lane 1) as well as in A2C12 cells (lane 2), A549 cells (lane 3), and Caco-2 cells (lane 4). Epithelial cell adhesion molecule was found to be expressed in the cancer cell lines A2C12 (lane 2), A549 (lane 3), and Caco-2 (lane 4), but not in non-cancerous lung tissue (lane 1) as determined by western blot analysis. (B) Epithelial cell adhesion molecule expression in A2C12, A549, and Caco-2 cells was determined by flow cytometry using anti-EpCAM antibody G8.8. The mean fluorescence of EpCAM-labelled cells (filled curve) was increased 1.98-fold for A2C12 cells, 1.92-fold for A549 cells, and 1.46-fold for Caco-2 cells as compared with the respective controls (black line). (C) CD44 was found to be highly expressed in the mouse lung carcinoma cell line A2C12 (lane 2), but not in non-cancerous lung tissue (lane 1), as determined by western blot analysis. A low CD44 expression was found in the cell lines A549 (lane 3) and Caco-2 (lane 4). CD133 was found to be expressed in Caco-2 cells (lane 4) only, but not in non-cancerous lung tissue (lane 1), A1C12 cells (lane 2), and A549 cells (lane 3). Expression signal intensities for CD133 and CD44 of control cells (white columns) and G8.8 antibody-treated cells (black columns), as determined by microarray analysis. In the case of more than one probe set per gene (CD44), highest intensities of the probe sets, which are specific for only one transcript designated as number_at, are shown. Signal intensities of probe sets 1419700_a_at (mouse CD133), 204304_s_at (human CD133), 1423760_at (mouse CD44), and 212063_at (human CD44) are shown. (D) CD44 expression was confirmed for A2C12, A549, and Caco-2 cells by flow cytometry. Cells were stained with the rat anti-human CD44 antibody (filled curve) or isotypic control antibody (black line) and secondary FITC-labelled anti-rat antibody. Results of one representative experiment each are shown. EpCAM=epithelial cell adhesion molecule.