OBJECTIVETo investigate the effect of c-Met inhibitor cabozantinib (XL-184) in inhibiting Listeria monocytogenes (LM) from invading Caco-2 cells to reduce the cell injury.

METHODSThe cell invasion capacity of LM was assayed in Caco-2 cells incubated with different doses of XL-184 for different durations. Caco-2 cells incubated with XL-184 were seeded on the upper room of the transwell chamber, and the cell monolayer was exposed to LM infection followed by addition of horseradish peroxidase (HRP). The trans-epithelial electric resistance (TEER), HRP concentration and LM colony-forming unit (CFU) were measured in the cell monolayer. Fluorescent staining was used to evaluate the cell viability, and LDH release from the cells was examined to assess the changes in cell membrane permeability.

RESULTSXL-184 significantly decreased LM invasion rate in Caco-2 cells in a dose- and time-dependent manner (P=0.000), and this effect was enhanced by co-incubation of the cells with ampicillin (P<0.05). In the cell membrane permeability assay in the monolayer cells, XL-184 markedly inhibited LM-induced reduction of TEER (P<0.05) and significantly suppressed LM-induced enhancement of cell membrane permeability shown by reduced HRP concentration and LM count in the lower chamber (P=0.000). The cells infected with LM showed significantly lowered cell viability, which was rescued by XL-184 (P<0.01); XL-184 also dose-dependently reduced LDH release from the cells (P<0.05).

CONCLUSIONSXL-184 can suppress LM invasion in Caco-2 cells to reduce the cell injury, suggesting its value as a promising candidate agent for prevention and treatment of LM infections.