Fig. 1

LPS-induced inflammasome activation promotes CRC progression. a Relative mRNA level of IL-1β in tumor and corresponding normal tissues of the breast, colon, liver, lung, stomach, and thyroid from TCGA dataset. b Relative mRNA level of IL-1β in tumor and matched normal tissues from 83 CRC cases. mRNA level was determined by real-time PCR, and logarithmic transformed data were used. c Inflammasome activation level in nine CRC tissue samples. Protein expression was determined by western blotting. d Detection of LPS receptor TLR4, and markers of inflammasome activation by western blotting in eight CRC cell lines, including SW480, SW620, DLD1, HT-29, HCT116, RKO, HCT8 and LoVo. e Western blotting was performed to detect Caspase-1-P20 and IL-1β-P17 expression in whole cell lysates (lys) and supernatants (Sup). Cells were pretreated with 3μM caspase-1 inhibitor Ac-YVAD-CHO (cas) for 3h, and then stimulated with 1μg/ml LPS for 24h. f LPS enhanced migration and invasion of CRC cells by transwell assay, which could be blocked by Ac-YVAD-CHO (cas). OD values were measured by a microplate reader at 570 nm. g Representative images (H&E staining) presented number of metastatic foci of lung in mice with tail-vein injection of untreated (UT) or LPS-treated RKO cells; the stars indicated the metastatic foci. h Statistical analysis of numbers of lung metastatic foci in mice. Data are presented as mean±SEM. *P < 0.05, **P < 0.01, ***P < 0.001