[Up-Regulation of Bax/BCL-2 Ratio by 2-Methoxyestradiol Induces Apoptosis in Lymphoma Raji Cells]

Abstract

Objective: To investigate the effect of 2-methoxyestradiol (2-ME2) to lymphoma Raji cells and its mechanism.

Methods: Different concentrations of 2-ME2 were used to treat lymphoma Raji cells. CCK8 method was used to detect the effect of 2-ME2 to proliferation of Raji cells. Flow cytometry FITC/PI double labeling method was used to detect early apoptosis of the cells. Western blotting was used to detect the effect of 2-ME2 to the expression of BCL-2, Bax, Caspase-3 and C-myc proteins in Raji cells.

Results: 2-ME2 significantly inhibited the proliferation of Raji cells. The inhibition rate increased with the increasing of drug concentration, and increased significantly with the prolongation of drug treatment time (r=0.9215). Flow cytometry FITC/PI double staining showed that the apoptotic rate of 2.5 μmol/L 2-ME2 treatment group was (33.79±1.63) %, while the apoptosis rate of the 48 h group was (51.90±2.72) %, and that of the control group was (7.08±0.36) %. After treated with 2.5 μmol/L 2-ME2 for 12 h, the expression of Bax protein was up-regulated, BCL-2 protein was down-regulated, caspase-3 protein expression was up-regulated, and C-myc protein expression was down-regulated, all of them showed a time-dependent relationship.

Conclusion: 2-ME2 shows obvious inhibitory effect on lymphoma Raji cells in a dose- and time-dependent manner. Its mechanism of treatment on lymphoma Raji cells may be related to up-regulation of Bax/BCL-2 ratio and activation of Caspase-3 to induce apoptosis in cancer cells. Down-regulation of C-myc protein expression also participates in the apoptotic process.