Figure 3.
Cancer cells grown on Glc‐collagen matrix are more tumorigenic and disseminating. A, Migration assay carried out on A549, H460 and LT73 cell lines after cell culturing on collagen films or on plastic culture plates (control) for 72 h. Cells were chemoattracted with 10% FBS. Bars are the mean ± SD of the number of migrated cells counted in 4 random fields of the transwell inserts. One‐way ANOVA was used for statistical analyses *P < 0.05; **P < 0.001. B, LT73 cells grown for 72 h on plate (CTRL) collagen and Glc‐collagen were injected at serial dilutions (1 × 103, 1 × 104, 1 × 105) in the flanks of SCID mice. Tumor take rate, indicated in the table on the left, was evaluated as presence of growing tumor ≥100 mg, 35 days from s.c. injection. ELDA (extreme limiting dilution analysis) software was used to estimate the frequency of cancer stem cells (CSC) after treatments providing confidence intervals for 1/(stem cell frequency) (central table). Pairwise chi‐squared test was carried out between groups to evaluate difference in stem cell frequencies. C, Tumor growth curves of LT73 xenograft generated from s.c. injection of 1 × 105 cells after culturing on collagen films. n = 4 mice/group ***P < 0.0001 calculated by two‐way ANOVA. D, Relative content of CD133+ CSC evaluated by FACS within dissociated LT73 xenografts. Bars are the mean ± SD, n = 4 mice/group, each in duplicate technical analysis. One‐way ANOVA was used for statistical analyses. **P < 0.001. E, Number of disseminated tumor cells (DTC) in lungs of mice bearing LT73 xenografts analyzed in (C). One‐way ANOVA was used for statistical analyses *P < 0.05. DTC were identified as mouse vital, mouse H2Kneg cells by FACS on dissociated lung tissue, n = 4 mice/group