Fig. 4

Suppressing Spry4 expression enhances cancer stem cell subpopulation and cancer stem cell features of MDA-MB-231 cells. a Representative images from mammosphere assays show S4kd cells formed more and larger mammospheres. b Quantification of mammosphere assays. c Allocation of different sized mammoshperes. d Representative results of FACS analysis of CD44 and CD133 expression. e Quantification of CD133⁺CD44⁺ population from three independent experiments. f In vivo LDA of tumor initiating capacity shows that S4kd MDA-MB-231 cells had higher chance to form palpable tumor compared to NT cells in vivo. h Representative images of clonogenic analysis of NT and S4kd MDA-MB-231 cell upon single high dosage Paclitaxel treatment. i Quantification of colonies formed from three independent experiments. j NT and S4kd cells were treated with Paclitaxel at an increasing dosage from 0 to 5 μM, survival cells were estimated with MTT measurement. The Paclitaxel killing curve shows that suppressing Spry4 decreased the sensitivity of MDA-MB-231 cell to Paclitaxel treatment. *p < 0.05