Fig. 2
Collagen gels mediated TICs characteristics through ITGB1 signaling in gastric cancer. A Relative expression of ITGB1–8 in SGC-7901/BGC-823 cells cultured in dish or 3D gels, which was determined by real-time quantitative PCR. B Western blotting of ITGB1 in SGC-7901/BGC-823 cells cultured in dish or 3D gels. C Western blotting of ITGB1 in SGC-7901/BGC-823 (SCR) and ITGB1 KO SGC-7901/BGC-823 (KO1, KO2). D The colony growth curve of SGC-7901/BGC-823 and ITGB1 KO SGC-7901/BGC-823 cells in 3D collagen gels. The scale bar is 50 μm. E The cell apoptosis of SGC-7901/BGC-823 and ITGB1 KO SGC-7901/BGC-823 cells in 3D collagen gels on day 5. F SGC-7901/BGC-823 and ITGB1 KO SGC-7901/BGC-823 cells were cultured in 3D collagen gels for 5 days. Then tumor cells were collected and the colony formation capability was examined. G Tumor cells in (F) were collected and the tumorigenic capability was examined in mice. 105 SGC-7901 or BGC-823 cells were subcutaneously injected into NOD-SCID mice (n = 10 in each group, day 30). The tumor diameter > 1 mm were determined as tumorigenicity. The percentage of mice with tumorigenicity in 10 mice was determined as tumorigenesis rate. H Tumor cells in (F) were collected and the cell migration was examined by transwell (24 h). I Tumor cells in (F) were collected and treated with 5-FU (1 µg/ml) for 48 h. The cell apoptosis was examined using Annexin/PI staining. J Tumor cells in (F) were collected and treated with PTX (2 µg/ml) for 48 h. The cell apoptosis was examined using Annexin/PI staining. K Immunohistochemical staining of ITGB1 in gastric tumor tissues from high stage (H-S, stage T3–4) and low stage (L-S, stage T1–2) patients (n=10 in each group). The scale bar is 50 μm. L Overall survival of gastric cancer patients with high/low ITGB1 expression (low expression, n= 95 and high expression, n= 297)