Oleifolioside A mediates caspase-independent human cervical carcinoma HeLa cell apoptosis involving nuclear relocation of mitochondrial apoptogenic factors AIF and EndoG.
ABSTRACT Apoptosis, the main type of programmed cell death, plays an essential role in a variety of biological events. Whereas "classical" apoptosis is dependent on caspase activation, caspase-independent death is increasingly recognized as an alternative pathway. To develop new anticancer agents, oleifolioside A was isolated from Dendropanax morbifera Leveille and the biochemical mechanisms of oleifolioside A-induced apoptosis in HeLa cells were investigated. Exposure to oleifolioside A resulted in caspase activation and typical features of apoptosis, although cell death was not prevented by caspase inhibition. Oleifolioside A treatment induced up-regulation of Bad, loss of mitochondrial membrane potential, nuclear relocation of mitochondrial factors, apoptosis-inducing factor (AIF), endonuclease G (EndoG), and apoptosis induction. This is the first report of anticancer activity of oleifolioside A, and nuclear translocation of AIF and EndoG in oleifolioside A-treated HeLa cells might represent an alternative death signaling pathway in the absence of caspase activity.
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ABSTRACT: Cratoxylum formosum (Jack) Dyer ssp. pruniflorum (Kurz) Gogel. (Hong ya mu) (CF) has been used for treatment of fever, cough, and peptic ulcer. Previously, a 50% ethanol-water extract from twigs of CF was shown highly selective in cytotoxicity against cancer cells. This study aims to investigate the molecular mechanisms underlying the apoptosis-inducing effect of CF. The cytotoxicity of CF was evaluated in the human hepatocellular carcinoma (HCC) HepG2 cell line in comparison with a non-cancerous African green monkey kidney epithelial cell line (Vero) by a neutral red assay. The apoptosis induction mechanisms were investigated through nuclear morphological changes, DNA fragmentation, mitochondrial membrane potential alterations, and caspase enzyme activities. CF selectively induced HepG2 cell death compared with non-cancerous Vero cells. A 1.5-fold higher apoptotic effect compared with melphalan was induced by 120 mug/mL of the 50% ethanol-water extract of CF. The apoptotic cell death in HepG2 cells occurred via extrinsic and intrinsic caspase-dependent pathways in dose- and time-dependent manners by significantly increasing the activities of caspase 3/7, 8, and 9, decreasing the mitochondrial membrane potential, and causing apoptotic body formation and DNA fragmentation. CF extract induced a caspase-dependent apoptosis in HepG2 cells.Chinese Medicine 04/2014; 9(1):12. · 2.34 Impact Factor
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ABSTRACT: To develop new anticancer agents, we prepared a sulfated polysaccharide (SCGLP1) from the fruiting bodies of Ganoderma lucidum, and the effect of SCGLP1 on human osteosarcoma MG63 cell line was investigated. Our result showed that treatment with SCGLP1 resulted in a significant inhibitory effect on cell proliferation and cell viability of MG63 cells in a dose- and time-dependent manner and caused apoptotic death in MG63 cells through an increase in G0/G1 phase arrest, but had minor cytotoxic effect on human normal osteoblast (NHOst) cells. Western blot analysis identified that SCGLP1-induced apoptosis was associated with an increased protein expression of proapoptotic Bax and Bad, decreased expression of antiapoptotic Bcl-2 and Bcl-XL, loss of mitochondrial membrane potential (Δψm), the release of mitochondrial cytochrome c to cytosol, and cleavage of caspase-9, caspase-3, and poly(ADP-ribose) polymerase (PARP). In addition, pretreatment with the pan-caspase inhibitor (z-VAD-fmk) blocked the SCGLP1-induced apoptosis in MG63 cells. The data indicate that SCGLP1-induced apoptosis is primarily associated with caspase-3- and caspase-9-dependent apoptotic pathway.Tumour biology : the journal of the International Society for Oncodevelopmental Biology and Medicine. 07/2014;
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ABSTRACT: Dioscin, a saponin extracted from the roots of Polygonatum zanlanscianense, shows several bioactivities such as antitumor, antifungal, and antiviral properties. Although, dioscin is already known to induce cell death in variety cancer cells, the molecular basis for dioscin-induced cell death was not definitely known in cancer cells. In this study, we found that dioscin treatment induced cell death in dose-dependent manner in breast cancer cells such as MDA-MB-231, MDA-MB-453, and T47D cells. Dioscin decreased expressions of Bcl-2 and cIAP-1 proteins, which were down-regulated at the transcriptional level. Conversely, Mcl-1 protein level was down-regulated by facilitating ubiquitin/proteasome-mediated Mcl-1 degradation in dioscin-treated cells. Pretreatment with z-VAD fails to attenuate dioscin-induced cell death as well as caspase-mediated events such as cleavages of procaspase-3 and PARP. In addition, dioscin treatment increased the population of annexin V positive cells and induced DNA fragmentation in a dose-dependent manner in MDA-MB-231 cells. Furthermore, apoptosis inducing factor (AIF) was released from the mitochondria and translocated to the nucleus. Suppression in AIF expression by siRNA reduced dioscin-induced apoptosis in MDA-MB-231 cells. Taken together, our results demonstrate that dioscin-induced cell death was mediated via AIF-facilitating caspase-independent pathway as well as down-regulating anti-apoptotic proteins such as Bcl-2, cIAP-1, and Mcl-1 in breast cancer cells.Apoptosis 04/2014; · 3.61 Impact Factor