Fig. 1
3D collagen gels culture promoted TICs phenotypes of gastric cancer cells. A Top overexpression genes in stomach adenocarcinoma (STAD) tissues (n = 156) compared to normal tissues (n = 34) from TCGA database. B The presentative image and cell apoptosis of SGC-7901/BGC-823 in collagen gels (1–2 mg/ml) on day5. The scale bar is 50 μm. C The colony growth curve of SGC-7901/BGC-823 in collagen gels (0.5 mg/ml). The scale bar is 50 μm. D, the cell apoptosis of SGC-7901/BGC-823 in collagen gels (0.5 mg/ml) on day 5. E The colony formation capability of SGC-7901/BGC-823 cultured in dish or 3D collagen gels. F The tumorigenic capability of SGC-7901/BGC-823 cultured in dish or 3D collagen gels. 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. G The CD44 expression of SGC-7901/BGC-823 cultured in dish or 3D collagen gels, which was determined by flow cytometry. H Cell migration of SGC-7901/BGC-823 cultured in dish or 3D collagen gels (24 h), which was determined by transwell assay. I SGC-7901/BGC-823 were cultured in dish or 3D collagen gels for 5 days, then treated with 5-FU (1 µg/ml) for 48 h. The cell apoptosis was examined using Annexin/PI staining. J SGC-7901/BGC-823 were cultured in dish or 3D collagen gels for 5 days, then treated with PTX (2 µg/ml) for 48 h. The cell apoptosis was examined using Annexin/PI staining. K Immunohistochemical staining of collagen I 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