TMI-1 targeting of cancer stem cells.

<p><b>A</b>: TMI-1 inhibits primary tumorspheres formation. SUM149 cells were treated with TMI-1 (2 µM) for 3 days. Cells were then cultured for 5 days to allow tumorsphere formation (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0043409#s2" target="_blank">material and methods</a>). Results are presented as the mean of tumorspheres counted. Bars represent the mean +/− s.e.m.. **<i>P</i><0.005 as calculated using Mann-Whitney test. <b>B</b>: TMI-1 inhibits secondary tumorspheres formation. Dissociated primary tumorspheres were cultured for 5 days. Results are presented as the mean of tumorspheres counted. Bars represent the mean +/− s.e.m.. **<i>P</i><0.005 as calculated using Mann-Whitney test. <b>C</b>: TMI-1 affects the pool of the ALDH-1 positive population. SUM149 cells were treated with TMI-1 (2 µM), TMI-005 (2 µM) or doxorubicin (0.352 µM) for 3 days. Cells were stained with Aldefluor kit and analyzed by flow cytometry. DEAB inhibitor was used to block aldehyde dehydrogenase activity. <b>D</b>: Overall results are represented as ratio between percent ALDH+ cells in treated conditions vs percent ALDH+ cells in DMSO. These results are representative of four experiments.