• Journal of Life Science
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• v.13 no.1
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• pp.118-127
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• 2003

$\rho$-Fluorophenylalanine (FPA), a phenylalanine analog, is able to induce apoptotic cell death of human acute leukemia Jurkat T cells. To better understand the mechanism by which FPA induces apoptotic cell death, the effect of ectopic expression of antiapoptotic proteins, Bcl-2 and Bcl-xL, on FPA-induced apoptosis was investigated by employing lurkat T cells transfected with Bcl-2 gene (JT/Bcl-2) or Bcl-xL gene (1/Bcl-xL) and Jurkat T cells transfected with vector (JT/Neo or J/Neo). When Jurkat T cells, JT/Neo or J/Neo, were exposed to FPA at concentrations ranging from 0.63 to 5.0 mM, the cell viability determined by MTT assay declined in a dose-dependent manner. In addition, apoptotic DNA fragmentation along with several apoptotic events such as caspase-8 activation, Bid cleavage, mitochondrial cytochrome c release, caspase-9 activation, caspase-3 activation, and degradation of PARP was induced. However, the FPA-induced cytotoxic effect, activation of caspase-8, and cleavage of Bid were significantly abrogated by ectopic expression of Bcl-2 or Bcl-xL. At the same time, there was marked reduction in the level of cytochrome c release from mitorhondria, caspase-9 activation, caspase-3 activation, and degradation of PARP. These results indicate that caspase-8 activation, Bid cleavage, and mitochondrial cytochrome c release with subsequent activation of the caspase cascade are negatively regulated by Bcl-2 or Bcl-xL, and are thus required for FPA-induced apoptosis in Jurkat T cells

• Food Science and Biotechnology
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• v.14 no.3
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• pp.350-354
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• 2005

The effect of the essential oil obtained from Chrysanthemum boreale Makino on the apoptosis of KB cells was investigated. Cytotoxicity and cellular DNA content were analyzed by MTT assay, flow cytometry, agarose gel electrophoresis, and Hoechst 33258 staining. The caspase-3 and poly (ADP-ribose) polymerase (PARP) proteins were estimated by Western blotting method. The various cytotoxic effects of the essential oil which are hallmarks of apoptosis, including DNA fragmentation, apoptotic body formation, and sub-G1 DNA content, all progressed in a dose-dependent manner. Treatment with an apoptosis-inducing concentration of the essential oil caused rapid and transient induction of caspase 3 activity. Further, the efficacious induction of PARP cleavage and caspase-3 activation was observed at an essential oil concentration of 0.1 and 0.2 mg/mL for 12 hr.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.3
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• pp.677-683
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• 2005

The aim of this study was to investigate the apoptotic effect and its mechanism on Radix Aconiti (RA) extract in HL-60 human leukemia cell line. RA extract induced apoptosis as confirmed by discontinuous fragmentation of DNA. To clarify the mechanisms on RA extract-induced apoptosis, we examined the caspase-3, -8 enzyme activity and protein levels including Fas, FasL in HL-60 cells. Treatment with RA extracts resulted in the increase of caspase-3 enzyme activity in a time and dose-dependent manners, which was accompanied by the cleavage of poly-(ADP-ribose) polymerase (PARP). This activation of caspase-3 enzyme resulted from cleavage of procaspase-8, which was followed by increases of FasL, Fas protein expression in RA extracts-treated HL-60 cells. In conclusion, RA extract induced apoptosis of HL-60 human leukemia cell line. This results suggest that the apoptotic mechanisms of RA extract on HL-60 cells involved in FasL, Fas activation, procaspase-8 cleavage, activation of caspase-3 and cleavage of PARP. Collectively, these results suggest that RA may be a valuable agent as a anti-cancer drug.

• International Journal of Oral Biology
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• v.40 no.4
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• pp.223-228
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• 2015

6-Gingerol exerts anti-tumor effects in various cancer cell models. We evaluated the effect of 6-gingerol on the growth of MCF-7 breast cancer cells and MCF-10A breast epithelial cells to determine whether any growth-inhibitory effects found were attributable to apoptosis, and to elucidate the underlying mechanism of action. 6-Gingerol inhibited the viability of both cell lines in a dose- and time-dependent manner; however, the degree of inhibition was greater in MCF-7 than MCF-10A cells. By flow cytometry, induction of dose- and time-dependent apoptosis was found, and the magnitude of apoptosis was also markedly greater in MCF-7 than MCF-10A cells. Expression of caspase-3 and poly (ADP-ribose) polymerase (PARP) was observed in MCF-7 cells treated with 6-gingerol, and further cleavage of PARP occurred in these cells. We suggest that 6-gingerol induces apoptosis in human breast cancer cells mainly by promoting caspase-3 expression and subsequent degradation of PARP.

• Molecules and Cells
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• v.21 no.2
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• pp.218-223
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• 2006

The effect of poly(ADP-ribosyl)ation on the stability of p53 in SK-HEP1 cells treated with UV light was examined. Intracellular levels of p53 increased in cells treated with a low dose of UV light ($20J/m^2$), whereas they increased but then declined after a higher dose of UV ($100J/m^2$). Intracellular levels of p53 in the UV treated SK-HEP1 cells were dependent on the UV dose. Use of proteasome inhibitors revealed that p53 is degraded by proteasomal proteolysis after high doses of UV light. We present evidence that, at low doses, poly(ADP-ribose)polymerase (PARP) poly(ADP-ribosyl) ates p53 and protects it from proteasomal degradation before caspase-3 is activated, whereas at high doses the cells undergo UV induced apoptosis and PARP is cleaved by caspase-3 before it can protect p53 from degradation. Destabilization of p53 by cleavage of PARP may be important in cell fate decision favoring apoptosis.

• Toxicological Research
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• v.25 no.3
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• pp.113-118
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• 2009

Cell death induced by menadione (vitamin K-3,2-methyl-1,4-naphthoquinone) has been investigated in human promyelocytic leukemia HL-60 cells. Menadione was found to induce both apoptosis and necrosis in HL-60 cells. Low concentration ($1{\sim}$50 ${\mu}$M) of menadione induced apoptotic cell death, which was demonstrated by typical DNA ladder patterns on agarose gel electrophoresis and flow cytometry analysis. In contrast, a high concentration of menadione (100 ${\mu}$M) induced necrotic cell death, which was demonstrated by DNA smear pattern in agarose gel electrophoresis. Necrotic cell death was accompanied with a great reduction of cell viability. Menadione activated caspase-3, as evidenced by both increased protease activity and proteolytic cleavage of 116 kDa poly(ADP-ribose) polymerase (PARP) into 85 kDa cleavage product. Caspase-3 activity was maximum at 50 ${\mu}$M of menadione, and very low at 100 ${\mu}$M of menadione. Taken together, our results showed that menadione induced mixed types of cell death, apoptosis at low concentrations and necrosis at high concentrations in HL-60 cells.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.1
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• pp.20-27
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• 2007

Eugenol is commonly used in dentistry for the sedation of toothache, pulpitis, and dental hyperalgesia. This study was performed to investigate the apoptotic effect of eugenol to human osteosarcoma (HOS) cells and the potential use of this compound in osteosarcoma cells. Eugenol showed the apoptotic effect in HOS cells in dose- and time-dependent manner. Fragmentation and condensation of DNA were showed by TUNEL assay, Hemacolor stain and Hoechst stain. In the DNA electrophoresis analysis, cells showed DNA degradation characteristic of apoptosis with a ladder pattern of DNA fragments. Apoptosis-related factors were analyzed by western blotting. Cells treated with eugenol showed caspase-3, PARP, lamin A and DFF-45 cleavage. Eugenol treatment induced caspase-3 cleavage and activation. Cleavages of PARP, DFF-45 and lamin A were accompanied with activation of caspase triggered by eugenol in HOS cells. Though this study needs more investigations, these results suggest that eugenol induce apoptosis via caspase dependent pathway in HOS cells and eugenol may constitute a potential antitumor compound against osteosarcoma cells.

• Animal cells and systems
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• v.4 no.4
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• pp.381-388
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• 2000

Using a murine T cell hybridoma, activation-induced cell death (AICD) was studied. As an in vitro model system for the AICD, 1 cell hybridoma expressing TCR/CD3 complex was incubated onto the immobilized purified anti-CD3 antibody. The immobilized anti-CD3 antibody induced AICD effectively up to 40%. At 1-100 $\mu$M range of SNP, an exogenous source of nitric oxide (NO), the cell proliferation was not affected, but at 1 mM SNP, cell proliferation was significantly reduced. The AICD of T cell hybridoma was inhibited by exogenous NO at non-cytotoxic concentration, In the cells undergoing AICD, the expressions of caspase-3 and FasL were detected, but not iNOS. Similar result was recognized in the apoptosis induced by dexamethasone, an apoptosis-inducing agent. However, the conversion from the inactive form of caspase-3 (32 kDa) to the active form (17 kDa) was significantly reduced in the cells in AICD induced by anti-CD3 antibody, With the result of increased PARP cleavage in the cells, we propose that another PARP cleavage pathway not involving caspase-3 may function in the anti-CD3 antibody induced AICD in the T cell hybridoma.

• Journal of Life Science
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• v.29 no.3
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• pp.318-324
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• 2019

Squamous cell carcinoma is the primary tumor type in head and neck cancers, the fifth most common malignant neoplasm world-wide. Survivin, a member of the inhibitor of apoptosis family, is highly expressed in head and neck carcinoma patients and correlated with more aggressive forms. In this study, we investigated whether YM155, a specific survivin inhibitor, could induce apoptosis in head and neck AMC-HN4 cells. YM155 was found to markedly induce apoptosis and cleavage of PARP, a marker of apoptosis. Furthermore, YM155 promoted apoptosis in other cancer cells, such as glioma (U251MG) and renal carcinoma (Caki) cells. In contrast, YM155 had no effect on apoptosis in normal mesangial cells. YM155 significantly induced caspase activation, and pan caspase inhibitor z-VAD-fmk markedly blocked apoptosis, PARP cleavage, and caspase-3 cleavage. Therefore, YM155 was seen to instigate caspase-dependent apoptosis in head and neck AMC-HN4 cells, inducing downregulation of survivin as well as other apoptotic proteins such as c-FLIP and Mcl-1. In addition, the induction of apoptosis and PARP cleavage by YM155 treatment was effectively inhibited in survivin-, c-FLIP- and Mcl-1-over-expressing head and neck AMC-HN4 cells. In conclusion, YM155 is a potent candidate for inducing cell death in head and neck AMC-HN4 cells.

• IMMUNE NETWORK
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• v.3 no.4
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• pp.268-275
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• 2003

Background: Hemopoietic cells require the constant presence of growth factors for survival in vitro and in vivo. Caspases have been known as central executors of apoptotic cell death. We have, therefore, investigated the pathways that regulate caspase activity and apoptosis using the $CD34^+$ cell line, TF-1 which requires GM-CSF for survival. Methods: Apoptosis was measured by annexin V staining and mitochondrial membrane potential was measured by DiOC6 labelling. Intracellular pH was measured using pH sensitive fluorochrome, BCECF or SNARF-1, followed by flow cytometry analysis. Caspase activation was analyzed by PARP cleavage using anti-PARP antibody. Results: Removal of GM-CSF induceed PARP cleavage, a hallmark of caspase activity, concomitant with pHi acidification and a drop in mitochondrial potential. Treatment with ZVAD, a competitive inhibitor of caspases, partially rescued cell death without affecting pHi acidification and the reduction of mitochondrial potential, suggesting that both these events act upstream of caspases. Overexpression of Bcl-2 prevented cell death induced by GM-CSF deprivation as well as pHi acidification and the reduction in mitochondrial membrane potential. In parental cells maintained with GM-CSF, EIPA, a competitive inhibitor of $Na^+/H^+$ antiporter induced apoptosis, accompanied by a drastic reduction in mitochondrial potential. In contrast, EIPA induced apoptosis in Bcl-2 transfectants without causing mitochondrial membrane depolarization. Conclusion: Taken together, our results suggest that the regulation of $H^+$fluxes, either through a mitochondriondependent or independent pathway, is central to caspase activation and apoptosis.