摘要
Objective: The aim of our study was to detect whether Vitamin E Succinic Acid (VES) could regulate the expression level of DR5 in the cells and further elucidate the potential mechanisms involving that VES enhances the effect of mDRA-6 to eradicate leukemia Raji and K562 cells. Methods: MTT method was used to detect the growth inhibition of VES and mDRA-6 to Raji and K562 cells. Annexin V-FITC/PI double staining assay was used to analysis the apoptosis of leukemia cell. Flow cytometry was used to detect the cell surface DR5 expression. Immunoblotting technique was used to detect the DR5 protein expression. Results: MTT detection showed that 10 μmol/L mDRA-6 on the cell death rates of Raji and K562 cells were 21.98% and 5.23%, respectively. While increasing concentration of VES (5 μmol/L, 10 μmol/L, 20 μmol/L) and mDRA-6 both on the cell viability of Raji or K562 cells, the mortality of Raji cells elevated to 24.67%, 35.65% (P<0.01) and 40.22% (P<0.01), respectively. Similarly, the mortality of K562 cells increase to 6%, 7.89% (P<0.01) and 8.67% (P<0.01), respectively. To further specify the increased cell death rate induced by mDRA-6 and VES, the treated cells were analyzed by Annexin-V/PI staining assay. As shown in Fig. 1, the apoptosis rates of Raji and K562 cells treated with 2 μg/mL mDRA-6 for 12 h were 20.79% and 7.74%. Compared with this, the proportion of apoptotic cells increased upon exposure to 2 μg/mL mDRA-6 combination with 10 μmol/L VES, the apoptosis rates of Raji and K562 cells were 43.18% and 16.99%, respectively. To examine the anticancer effects of a combination strategy based on mDRA-6 and VES. We analyzed whether VES could elevated the expression level of DR5 on Raji and K562 cytomembrane by FACS. Interestingly, after treated with 10 μmol/L VES for 12 h, the expression level of DR5 on Raji and K562 cell surface increased from 50.66% to 70.08%, and 15.02% to 16.38%, respectively. Immune imprinting technology test showed that, different concentrations of VES could increase Raji and K562 cell DR5 protein expression. Conclusion: VES enhances the effect of mDRA-6 to eradicate leukemia Raji and K562 cells. The proper mechanism is VES could enhance the Raji and K562 cell membrane expression of DR5, and VES can also enhance the DR5 protein expression of cells.
基金
Supported by grants from the National "863 Plan" (No. 2006AA02A254)
Outstanding Talent Program of Henan Province (No. 074200510014)
