The Experimental and Clinical Study on the Effect of Curcumin on Cell Cycle Proteins and Regulating Proteins of Apoptosis in Acute Myelogenous Leukemia

摘要

To investigate whether the Bcl-2 gene family is involved in modulating mechanism of apoptosis and change of cell cycle protein induced by curcumin in acute myeloid leukemia HL-60 cell line and primary acute myelogenous leukemic cells, the Bcl-2 family member Mcl-1, Bax and Bak and cell cycle proteins including P27~(kipl), P21~(wafl), cyclin D_3 and pRb~(p-) were selected and their expression detected by SABC immuno-histochemical stain method. The attitude of sub-G_1 peak in DNA histogram was determined by FCM. The TUNEL positive cell percentage was identified by terminal deoxynucleotidyl transferase ( TdT )-mediated Biotin dUNP end labeling technique. It was found that when HL-60 cells were treated with 25 μmol/L curcumin for 24 h, the expression level of Mcl-1 was down-regulated, but that of Bax and Bak up-regulated time-dependently. There was significant difference in the expression level of Mcl-1, Bax and Bak between the curcumin-treated groups and control group (P<0. 05 - 0. 01). At the same time, curcumin had no effect on progress of cell cycle in primaty acute myelogenous leukemia at newly diagnosis, but could increase the peak of Sub-G_1(P<0. 05), and down-regulate the expression of Mcl-1 and up-regulate the expression of Bax and Bak with the difference being statistically significant. The expression of P27~(kipl), P21~(wafl) and pRb~(p-) were elevated and that of cyclin D_3 decreased in the presence of curcumin. These findings suggested that the Bcl-2 gene family indeed participated in the regulatory process of apoptosis induced by curcumin in HL-60 cells and AML cells. Curcumin can induce apoptosis of primary acute myelogenous leukemic cells and disturb cell cycle progression of HL-60 cells. The mechanism appeared to be mediated by perturbing G_0/G_1 phases checkpoints which associated with up-regulation of P27~(kipl), P21~(wafl) and pRb~(p-) expression, and down-regulation of cyclin D_3.