Expression of CSC marker in human primary tumors and tumor cell lines.

(A) The percentage of CSC marker positive cells from human primary tumors (n = 10 for each type) and tumor cell lines. Single cell suspensions were prepared, followed by flow cytometric analysis. Dots represent the percentage of CD34+CD38− cells in AML, APL, and CML, CD44+CD24− cells in breast cancer, CD133+ cells in glioblastoma and colon cancer, and CD271+ cells in melanoma samples. (B–F) The CSC marker mRNA expression level of cells (CSC+ and CSC− cells from CSC marker expressing tumor cell lines, and cells from non-expression tumor cell lines) was analyzed by qRT-PCR and normalized to GAPDH. The level of CD34 mRNA in KG-1 CSC+ cells, CD44 mRNA in MCF-7 CSC+ cells, CD133 mRNA in SHG-44 and Caco-2 CSC+ cells, CD271 mRNA in A375 CSC+ cells, was arbitrarily designated as 1.0 for leukemia, breast cancer, glioblastoma, colon cancer, melanoma samples, respectively. Photographs show the RT-PCR products and histograms show the CSC marker mRNA expression level of cells from leukemia (B), breast cancer (C), glioblastoma (D), colon cancer (E), and melanoma (F) cell lines. Note that cells from CSC marker non-expressing tumor cell lines (U37, U81, COLO320, LoVo, LS174T) do not express CSC marker mRNA.