Safrole induces G 0/G 1 phase arrest via inhibition of cyclin E and provokes apoptosis through endoplasmic reticulum stress and mitochondrion-dependent pathways in human leukemia HL-60 cells

School of Pharmacy, China Medical University, Taichung, Taiwan, ROC.
Anticancer research (Impact Factor: 1.83). 05/2012; 32(5):1671-9.
Source: PubMed


Safrole, a component of Piper betle inflorescence, is a carcinogen which has been demonstrated to induce apoptosis on human oral cancer HSC-3 cells in vitro and to inhibit HSC-3 cells in xenograft tumor cells in vivo. In our previous study, safrole promoted phagocytosis by macrophages and natural killer cell cytotoxicity in normal BALB/c mice. The cytotoxic effects of safrole on HL-60 cells were investigated by using flow cytometric analysis, comet assay, 4',6-diamidino-2-phenylindole (DAPI) staining, western blotting and confocal laser microscopy. The obtained results indicate that safrole induced a cytotoxic response through reducing the percentage of viable cells and induction of apoptosis in HL-60 cells in a dose-dependent manner. DAPI staining and comet assay also showed that safrole induced apoptosis (chromatin condensation) and DNA damage in HL-60 cells. The flow cytometric assay showed that safrole increased the production of reactive oxygen species (ROS) and Ca(2+) and reduced the mitochondrial membrane potential in HL-60 cells. Safrole enhanced the levels of the pro-apoptotic protein BAX, inhibited those of the anti-apoptotic protein BCL-2 and promoted the levels of apoptosis-inducing factor (AIF) and endonuclease G (Endo G) in HL-60 cells. Furthermore, safrole promoted the expression of glucose-regulated protein 78 (GRP78), growth arrest- and DNA damage-inducible gene 153 (GADD153) and of activating transcription factor 6α (ATF-6α). Based on these findings, we suggest that safrole-induced apoptosis in HL-60 cells is mediated through the ER stress and intrinsic signaling pathways.

1 Follower
10 Reads
  • [Show abstract] [Hide abstract]
    ABSTRACT: Amentoflavone, isolated from an ethyl acetate extract of the whole plant of Selaginella tamariscina, a traditional herb, may exhibit antitumor activity. The aim of this study was to investigate the anticancer mechanism(s) of amentoflavone, such as mitochondria-mediated apoptotic cell death, in typical breast cancer MCF-7 cells. Cells treated with amentoflavone exhibited a series of cellular alterations related to apoptosis, including DNA and nuclear fragmentation, and de-regulation of intracellular reactive oxygen species (ROS) and calcium. In addition, markers of mitochondrial-mediated apoptosis, including the reduction of mitochondrial inner-membrane potential, the release of cytochrome c from mitochondria, and activation of caspase 3, were observed. In conclusion, our results present, to our knowledge, the first evidence that amentoflavone induces apoptosis of MCF-7 breast cancer cells, and that this is closely related to mitochondrial dysfunction. Amentoflavone may be a potential therapeutic agent for breast cancer treatment.
    In vivo (Athens, Greece) 11/2012; 26(6):963-970. · 0.97 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Numerous studies have demonstrated that triptolide induces cell cycle arrest and apoptosis in human cancer cell lines. However, triptolide-induced DNA damage and inhibition of DNA repair gene expression in human skin cancer cells has not previously been reported. We sought the effects of triptolide on DNA damage and associated gene expression in A375.S2 human malignant melanoma cells in vitro. Comet assay, DAPI staining and DNA gel electrophoresis were used for examining DNA damage and results indicated that triptolide induced a longer DNA migration smear based on single cell electrophoresis and DNA condensation and damage occurred based on the examination of DAPI straining and DNA gel electrophoresis. The real-time PCR technique was used to examine DNA damage and repair gene expression (mRNA) and results indicated that triptolide led to a decrease in the ataxia telangiectasia mutated (ATM), ataxia-telangiectasia and Rad3-related (ATR), breast cancer 1, early onset (BRCA-1), p53, DNA-dependent serine/threonine protein kinase (DNA-PK) and O6-methylguanine-DNA methyltransferase (MGMT) mRNA expression. Thus, these observations indicated that triptolide induced DNA damage and inhibited DNA damage and repair-associated gene expression (mRNA) that may be factors for triptolide-mediated inhibition of cell growth in vitro in A375.S2 cells.
    Oncology Reports 12/2012; 29(2). DOI:10.3892/or.2012.2170 · 2.30 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Citric acid is an alpha-hydroxyacid (AHA) widely used in cosmetic dermatology and skincare products. However, there is concern regarding its safety for the skin. In this study, we investigated the cytotoxic effects of citric acid on the human keratinocyte cell line HaCaT. HaCaT cells were treated with citric acid at 2.5-12.5 mM for different time periods. Cell-cycle arrest and apoptosis were investigated by 4,6-diamidino-2-phenylindole dihydrochloride (DAPI) staining, flow cytometry, western blot and confocal microscopy. Citric acid not only inhibited proliferation of HaCaT cells in a dose-dependent manner, but also induced apoptosis and cell cycle-arrest at the G2/M phase (before 24 h) and S phase (after 24 h). Citric acid increased the level of Bcl-2-associated X protein (BAX) and reduced the levels of B-cell lymphoma-2 (BCL-2), B-cell lymphoma-extra large (BCL-XL) and activated caspase-9 and caspase-3, which subsequently induced apoptosis via caspase-dependent and caspase-independent pathways. Citric acid also activated death receptors and increased the levels of caspase-8, activated BH3 interacting-domain death agonist (BID) protein, Apoptosis-inducing factor (AIF), and Endonuclease G (EndoG). Therefore, citric acid induces apoptosis through the mitochondrial pathway in the human keratinocyte cell line HaCaT. The study results suggest that citric acid is cytotoxic to HaCaT cells via induction of apoptosis and cell-cycle arrest in vitro.
    Anticancer research 10/2013; 33(10):4411-4420. · 1.83 Impact Factor
Show more