Streptococcus gallolyticus subsp. gallolyticus promotes colorectal tumor development
A. Sg-treated cells developed larger tumors in nude mice. ~ 1x 106 HCT116 cells were treated with TX20005 or L. lactis, mixed with Matrigel and injected into the dorsal flap of nude mice (n = 5/group) as described in the Methods and Materials section. Tumor size was measured at the indicated time point with a digital caliper. B-C. Sg-treated xenografts had higher levels of β-catenin, c-Myc and PCNA compared to L. lactis-treated ones. Tumors were collected on day 21. Three tumors were randomly selected from each group. Protein extracts were analyzed by western blot assays (B). Protein level was normalized to β-actin first and then to L. lactis-treated controls (C). Data is presented as the mean ± SEM. Statistical analysis was done using unpaired, two-tailed t test. *, p < 0.05; **, p < 0.01. Significance shown in panel A is of comparison between TX20005-treated and L. lactis-treated HCT116 cells at day 13 and 19, respectively.