Resveratrol inhibits cell proliferation and up-regulates MICA/B expression in human colon cancer stem cells

Objective: To investigate the effect of resveratrol (Res) on the proliferation, apoptosis and immunogenicity of colorectal cancer stem cells (CCSCs).

Methods: The CCSCs were induced from colon cancer cell line HCT116 in serum-free medium (SFM). The expressions of CD133 and CD44 were detected by flow cytometry to identify CCSCs. After treatment with Res at (12.5-200.0) μmol/L, the effect of Res on CCSC proliferation was detected by MTT assay ; cell apoptosis was examined by flow cytometry combined with annexin V-FITC/PI staining; cell cycle and the expression of major histocompatibility complex class I-related chain A and B (MICA/B) were assessed by flow cytometry.

Results: HCT116 cells formed cancer stem cell spheres in SFM. The proportion of CD133⁺ cells in cell spheres was (91.07 ± 1.79)%, and CD44⁺ cells was (90.33 ± 1.78)%. Compared with control groups, Res significantly inhibited CCSC proliferation in a time- and dose-depended manner. After treatment with Res for 48 hours, the proportion of cells increased in the G0/G1 phase and decreased in the S phase, both in a dose-depended manner. Apoptosis rate of CCSCs and the expression of MICA/B were raised with the increasing concentration of Res.

Conclusions: CCSCs were successfully induced from HCT116 colon cancer cell line. Res could depress CCSC proliferation in a time-and dose-depended manner, arrest cell cycle in the G0/G1 phase and promote cell apoptosis. Res could up-regulate the expression of MICA/B in CCSCs and enhance cell immunogenicity.