Fig. 7

Human lung cancer-derived mesenchymal stem cells inhibit CTL-mediated tumor cell destruction in vitro. A Tumor cells were cultured in ordinary medium for 24 h in the presence or absence of hLC-MSCs, at hLC-MSC:CTLs ratios of 1:5 and 1:10 in a contact system. The in vitro cell viability ratios of the indicated cells are shown (n = 5). B hLC-MSCs did not affect the kinetics of CT-26, A549 or HepG2 tumor cells in vitro following 24 h of exposure in a contact system. The histograms show the luciferase activity of the indicated cells cultured in the presence or absence of hLC-MSCs (n = 5). The data are expressed as the mean ± SD from three independent replicates. *P ≤ 0.05, **P ≤ 0.001, n.s. > 0.05 by Student’s t-test. The error bars represent SD of three independent experiments. CTL cytotoxic T lymphocytes; hLC-MSCs human lung cancer-derived mesenchymal stem cells; CT-26 an undifferentiated colon carcinoma cell line; A549 lung carcinoma epithelial cell line; HepG2 a human liver cancer cell line; SD standard deviation; n.s. not significant