(A) RT-PCR demonstrates upregulated expression of MDR1, MRP1, BCRP, and HIF-1α genes important in promoting malignancy and multidrug resistance in 3D spheroids compared to 2D culture. Bar graphs depict densitometry quantitation of MDR1, MRP1, BCRP, and HIF-1α mRNA expression normalized to GAPDH mRNA. (B) RT-PCR demonstrates upregulated expression of Tiam1, Rac1, and c-Myc genes important in tumor progression and chemoresistance in 3D spheroids compared to 2D culture. Bar graphs depict densitometry quantitation of Tiam1, Rac1, and c-Myc mRNA expression normalized to GAPDH mRNA. (C) RT-PCR analysis of EL4 cells for the expression of Tiam1 and Rac1 genes by c-Kit+/Sca-1+ stem cells and c-Kit-/Sca-1- non-stem cells. Bar graphs depict densitometry quantitation of Tiam1 and Rac1 mRNA expression normalized to GAPDH mRNA. Data represent the means ± SD of three independent experiments. *P < 0.05, **P < 0.01, and ***P < 0.001 versus the control.