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Effect of curcumin and chloropropionic amine on expression of CD44 and Lgr5 in human colon cancer stem-like cells

AIM: To investigate the synergistic effect of curcumin and gastrin receptor antagonist chloropropionic amine on the proliferation of human colon cancer stem-like cells in vitro and the possible mechanisms.

METHODS: Colon cancer SW480 cells in logarithmic growth phase were cultured in complete medium containing 10% serum for 48 h, synchronized by culturing in serum-free medium for 24 h, and then divided into three groups: a curcumin group, a chloropropionic amine group, and a combination group. Each group was further divided into a control group, low-, medium-, and high-concentration groups. After treatment, cells were cultured for another 48 h, and FITC labeled mouse anti-human CD44 monoclonal antibody was added, while the isotype control antibody IgG2b was used in the control group. After incubation at 4 ℃ for 30 min, CD44 expression was detected by flow cytometry. Western blot was used to detect the expression of Lgr5.

RESULTS: Curcumin and chloropropionic amine, alone or in combination, could inhibit SW480 cell growth and proliferation time- and dose-dependently, and they had a synergistic effect. Curcumin and chloropropionic amine alone significantly decreased CD44 and Lgr5 protein expression compared with the normal control group (P < 0.05). Chloropropionic amine combined with curcumin also significantly CD44 and Lgr5 protein expression compared with the normal control group, and the decrease was more significant in the combination group compared with either of them alone (P < 0.05).

CONCLUSION: Both curcumin and chloropropionic amine inhibit the growth and proliferation of SW480 cells time- and dose-dependently. Curcumin and chloropropionic amine may inhibit CD44 and Lgr5 expression to prevent the growth and proliferation of colon cancer stem cells.