ABSTRACT
OBJECTIVE@#To investigate the effect of etoposide (ETO) on elimination of chronic myeloid leukemia (CML) stem cells by imatinib mesylate(IM) in vivo.@*METHODS@#SCL-tTA/BCR-ABL mice were used as CML animal model. Flow cytometry was used to assess the effect of ETO alone or in combination with IM on the number of leukemia stem cell （LSC） in bone marrow and spleen, and peripheral blood neutrophils in CML mice and normal control FVB mice.@*RESULTS@#The results showed that in CML mice, the number and proportion of LSC in bone marrow and the proportion of neutrophils in peripheral blood decreased significantly after ETO and IM combined treatment, and the degree of decrease was more significant than that of both alone. While in wild type FVB mice, the combination of ETO and IM showed no significant effect on the number and proportion of LSK cells in bone marrow and the proportion of neutrophils in spleen.@*CONCLUSION@#ETO can selectively enhance elimination of CML LSC by IM in vivo.
Subject(s)
Animals , Mice , Drug Resistance, Neoplasm , Etoposide , Fusion Proteins, bcr-abl , Imatinib Mesylate , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy , Stem CellsABSTRACT
This study was to investigate the effect of RORα activator SR1078 on ovarian cancer cells and its molecular mechanism in vitro. The survival rate of HeyA8 and Hey cells was detected by MTS assay; the apoptosis and cells cycle distribution after SR1078 treatment and the effect of p53 siRNA or PFT-α and PFT-β of p53 inhibitors on SR1078-induced apoptosis of HeyA8 or Hey cells were analyzed by flow cytometry. Western blot was used to detect the effect of SR1078 and p53 siRNA on the expression of p53 protein and the effect of p53 inhibitors alone or in combination with SR1078 on the expression of p53, p-p53 and its downstream pro-apoptotic protein Noxa. The results showed that SR1078 significantly reduced the cell viability and induced apoptosis in HeyA8 and Hey cells. In addition, SR1078 up-regulated the protein expression of p53 and Noxa, and p53 suppression led to significant inhibition of SR1078-induced apoptosis and the expression of Noxa in ovarian cancer cells. In summary, SR1078 induced apoptosis of ovarian cancer cells by activation of p53 signaling pathway.
ABSTRACT
The present study is to elucidate the mechanisms underlying Gleevec-induced apoptosis of chronic myeloid leukemia (CML) K562 cells in vitro. The apoptotic cell death and cell cycle distribution after Gleevec treatment and the effect of PDCD4 siRNA on Gleevec-induced apoptosis of K562 cells were analyzed by flow cytometry. The effect of Gleevec on p-Crkl, caspase-3, PARP and PDCD4 protein levels, and the knockdown efficacy of PDCD4 siRNA were detected by Western blotting. The results showed that Gleevec dramatically suppressed the phosphorylation level of Crkl in a dose-dependent manner and induced significant apoptosis and G0/G1 cell cycle arrest of K562 cells in time- and dose-dependent manners. In addition, Gleevec activated caspase-3 and its downstream substrates PARP, and the caspase pan inhibitor Z-VAD-FMK (50 micromol x L(-1)) markedly reduced Gleevec-induced apoptosis from 47.97% +/- 10.56% to 31.05% +/- 9.206% (P < 0.05). Moreover, Gleevec significantly increased the protein expression of programmed cell death 4 (PDCD4). PDCD4 knockdown by siRNA reduced Gleevec-induced apoptosis from 46.97% +/- 14.32% to 42.8% +/- 11.43%. In summary, Gleevec induced apoptosis in K562 cells via caspase-3 activation.
Subject(s)
Humans , Amino Acid Chloromethyl Ketones , Apoptosis , Benzamides , Pharmacology , Caspase 3 , Metabolism , Cell Cycle , Imatinib Mesylate , K562 Cells , Phosphorylation , Piperazines , Pharmacology , Pyrimidines , PharmacologyABSTRACT
The effect of curcumin on JAK-STAT signaling pathway was investigated in hepatoma cell lines Huh7 and Hep3B. Curcumin inhibited cell proliferation and induced apoptosis of both cell lines, but Huh7 cells were more sensitive to curcumin than Hep3B cells. Curcumin (50 micromol x L(-1)) significantly increased phosphorylations of p38 (T180/Y182) and STAT-1 (S727) in Huh7 and Hep3B cells, and caused relocalization of phosphorylated-STAT-1 (Y701) from cytoplasm to nucleus in Hep3B cells. In addition, curcumin (25 and 50 micromol x L(-1)) dramatically suppressed the phosphorylation level of STAT-1 (Y701) and resulted in a significant reduction of nuclear phosphorylated-STAT-1 (Y701) in Huh7 cells.
Subject(s)
Humans , Antineoplastic Agents, Phytogenic , Pharmacology , Apoptosis , Carcinoma, Hepatocellular , Metabolism , Pathology , Cell Line, Tumor , Cell Proliferation , Curcuma , Chemistry , Curcumin , Pharmacology , Janus Kinases , Metabolism , Liver Neoplasms , Metabolism , Pathology , Phosphorylation , Plants, Medicinal , Chemistry , STAT1 Transcription Factor , Metabolism , Signal Transduction , p38 Mitogen-Activated Protein Kinases , MetabolismABSTRACT
In the present study, shRNA plasmid of pSi-p21 targeting p21 mRNA was constructed and the effect of p21 shRNA on curcumin-induced apoptosis of human hepatoma Huh7 cells was investigated. The effect of curcumin on the expression of p21 mRNA and protein and the silence efficiency of pSi-p21 were detected with RT-PCR and Western blotting. The effect of pSi-p21 on curcumin-induced apoptosis of Huh7 cells was evaluated with DAPI staining. The results showed that curcumin significantly upregulated p21 mRNA and protein expression, which was knocked down by pSi-p21 of Huh7 cells. DAPI staining results showed that pSi-p21 significantly decreased curcumin-induced apoptosis of Huh7 cells. The data suggested that curcumin induced apoptosis of Huh7 cells via upregulation of p21 expression.