Fig. 4
Isolation and molecular analysis of sialyl-glycolipid stage-specific embryonic antigen 4 (SSEA4)-positive and SSEA4-negative tumor subpopulations. a and b Flow cytometric analysis of cells before and after cell sorting. c Correlation matrices showing the relationship of mRNA- and miRNA-based gene expression profiles in all experiments. Correlation coefficients are indicated by their color from 0.9 (black) to 1.0 (yellow) for mRNA-based and from 0.75 (black) to 1.0 (yellow) for miRNA-based clustering. d Cluster analysis of miRNAs identified as differentially expressed by discriminatory gene analysis in combination with a paired t test (p < 0.05) of the SSEA4-positive versus SSEA4-negative tumor subpopulation. Resulting genes were grouped by similarities in gene expression patterns using hierarchical clustering (Pearson correlation, average linkage). Levels of log2-transformed expression ratios are indicated from −3 (green) to 3 (red). FITC fluorescein isothiocyanate, FSC forward scatter FSC-A forward scatter area, FSC-H forward scatter height, miRNA microRNA, mRNA messenger RNA, PE pleural effusions, PI propidium iodide, SSC side scatter