ABSTRACT
The aim of this study was to investigate the effects of gemcitabine(GEM) on apoptosis and c-myc gene expression of HL-60 cells, and feasibility of using GEM in therapy of leukemia. The HL-60 cells were cultured in vitro. The expressions of the c-myc mRNA and C-MYC protein were detected by RT-PCR and Western-blot respectively. The cell apoptosis was analyzed by TUNEL staining. The results showed that after the HL-60 cells were treated with 1.0 microg/ml GEM for 12, 24, 36 and 48 hours, the expression of c-myc mRNA was inhibited to various degree. This inhibitory effect displayed time-dependent manner and the most optimal effective time was 24 hours. Compared GEM group with Ara-C group and blank control group, there were statistical differences (p<0.05). After the HL-60 cells were treated with 1.0 microg/ml GEM for 24, 48, 72 hours, C-MYC protein significantly decreased, and the expression of C-MYC protein reached to lowest level at 48 hours after treating with GEM, and with inhibition rate of 94.16%. Compared GEM group with Ara-C group and blank control group, the differences were significant (p<0.01). There was significant difference between cells treated with GEM for 24, 48 and 72 hours (p<0.01). After the HL-60 cells were treated with 1.0 microg/ml GEM for 24 hours, the apoptotic cells increased obviously. The positive rate was 83.67% in GEM-treated group. Compared GEM group with Ara-C group (positive rate 10.67%) and untreated group (positive rate 3.00%), the differences had statistical significance (p<0.01). It is concluded that GEM can induce the apoptosis and down-regulate c-myc gene expression significantly in HL-60 cells and it may be used as a new therapeutic drug for leukemia.