染料木黄酮对人结肠癌SW620细胞生长的抑制

Mechanisms underlying suppressive effect of lutein on cell proliferation in human colon cancer cell line HT29

AIM: To study the anti-proliferative effect of lutein on human colon cancer HT29 cells and to explore the possible mechanisms involved.

METHODS: HT29 cells were treated with different concentrations of lutein (20, 40, 80, 160 mg/L) for 24, 48 or 72 h. After treatment, cell proliferation was detected by SRB assay, cell cycle progression was analyzed by flow cytometry, cell apoptosis was detected by fluorescence microscopy and Hoechst 33342/PI staining, and the levels of p-ERK and p-p38 proteins were determined by Western blot.

RESULTS: Lutein treatment inhibited the proliferation of HT29 cells in a dose- and time-dependent manner. After treatment of HT29 cells with lutein (80 mg/L) for 48 h, the percentage of cells at G₀/G₁ phase cells increased from 58.67% to 63.23%, and with the increase in drug concentration, the percentage of cells at G₀/G₁ phase increased significantly. When the lutein concentration was 160 mg/L, the percentage of cells at G₀/G₁ phase increased to 70.81%, indicating that lutein arrested HT29 cells in G₀/G₁ phase. Fluorescence microscopy and Hoechst 33342/PI staining suggested that lutein induced HT29 cell apoptosis in a dose-dependent manner. Western blot analysis showed that lutein down-regulated the expression of p-ERK and up-regulated the expression of p-p38 protein in dose-dependent manner (both P < 0.01).

CONCLUSION: Lutein could significantly inhibit the proliferation of HT29 cells, induce apoptosis, and arrest cell cycle in G0/G1 phase. Down-regulation of p-ERK protein expression and up-regulation of p-p38 protein expression may be important mechanisms responsible for the apoptosis-inducing effect of lutein.