Morphological and functional responses of three-dimensional-cultured colorectal cancer spheres to anticancer drugs

Figure 9 Quantitative reverse transcriptase PCR analysis of cancer stem cell and epithelial-mesenchymal transition markers on colorectal adenocarcinoma spheres. HCT-15 and SW480 cells were cultured in 96-well low-attachment plates, and anticancer drugs (30 μM) were added on day 3. Total RNA was extracted on day 7 post-treatment, and quantitative reverse transcriptase PCR was performed to assess the expressions of cancer stem cell markers (CD44, ALDH1A1, and PROM1) and epithelial-mesenchymal transition markers (CDH1, VIM, and ZEB1). Gene expression levels were normalized to GAPDH and expressed relative to the control group (set to 1.0). Data represent the means ± SD from three independent experiments, each analyzed in duplicate (biological replicates, n = 3). ^aP < 0.001 vs control group; ^bP < 0.0001 vs control group. 5-FU: 5-fluorouracil; CSC: Cancer stem cell; EMT: Epithelial-mesenchymal transition.