• Radiation Oncology Journal
• /
• v.19 no.2
• /
• pp.153-162
• /
• 2001

Purpose : The mechanical insights of death of cancer cells by ionizing radiation are not of yet clearly defined. Recent evidences have demonstrated that radiation therapy may induce cell death via activation of signaling pathway for apoptosis in target cells. This study is designed whether ionizing radiation may activate the signaling cascades of apoptosis including caspase family cysteine pretenses, $Bcl_2/Bax$, cytochrome c and Fas/Fas-L in target cells. Materials and Methods : HL-60 cells were irradiated in vitro with 6 MV X-ray at dose ranges from 2 Gy to 32 Gy. The cell viability was tested by M assay and the extent of apoptosis was determined using agarose gel electrophoresis. The activities of caspase proteases were measured by proteolytic cleavages of substrates. Western blot analysis was used to monitor PARP, Caspase-3, Cytochrome-c, Bcl-2, Bax, Fas and Fas-L. Results : Ionizing radiation decreases the viability of HL-60 cells in a time and dose dependent manner. Ionizing radiation-induced death in HL-60 cells is an apoptotic death which is revealed as characteristic ladder-pattern fragmentation of genomic DNA over 16 Gy at 4 hours. ionizing radiation induces the activation of caspase-2, 3, 6, 8 and 9 of HL-60 cells in a time-dependent manner. The activation of caspase-3 pretense is also evidenced by the digestion of poly (ADP-ribose) polymerase and procaspase 3 with 16Gy ionizing irradiation. Anti-apoptotic Bcl2 expression is decreased but apoptotic Bax expression is increased with mitochondrial cytochrome c release in a time- dependent manner. In addiiton, expression of Fas and Fas-L is also increased in a time dependent manner. Conclusion : These data suggest that ionizing radiation-induced apoptosis is mediated by the activation of various signaling pathways including caspase family cysteine proteases, $Bcl_2/Bax$, Fas and Fas-L in a time and dose dependent manner.

• Proceedings of the Zoological Society Korea Conference
• /
• 1999.04a
• /
• pp.71.1-71
• /
• 1999

No Abstract, See Full Text

• Development and Reproduction
• /
• v.10 no.3
• /
• pp.203-209
• /
• 2006

Ethane 1,2-Dimethane sulfonate(EDS), a toxin which specifically kills Leydig cells(LC), has been widely used to prepare the reversible testosterone(T) depletion rat model. Previous studies including our own clearly demonstrated that the dramatic weight loss of the T-dependent accessory sex organs such as epididymis and seminal vesicle in this 'LC knock-out' rats. These weight loss could be derived from massive and abrupt death of the cells via apoptotic process. The present study was performed to test the effect of EDS administration on the expression of some apoptotic genes in the rat epididymis. Adult male Sprague-Dawley rats($300{\sim}350$ g B.W.) were injected with single dose of EDS(75 mg/kg, i.p.) and sacrificed on Weeks 0, 1, 2, 3, 4, 5, 6 and 7. Tissue weights and the numbers of the epididymal sperm were measured. The transcriptional activities of the bcl-2, bax, Fas and Fas ligand(Fas-L) were evaluated by semi-quantitative RT-PCR. As expected, the weights and the sperm counts of epididymis declined progressively after the EDS treatment during Week 1 and 2. These decrements were discontinued with a gradual return towards normal during Weeks $5{\sim}7$, although the maximal recoveries of the epididymal weights(71%) and sperm count(38%) were subnormal on Week 7. The initial level of bcl-2 transcripts persisted to Week 6 then elevated significantly on Week 7. The level of bax transcripts significantly decreased on Week 6, and no remarkable change was found in the rest of the experimental period. The transcripts for the Fas in epididymis elevated during Weeks $1{\sim}2$, returned to normal on Week 3, and the level persisted to the Week 7. Similarly, the level of Fas-L transcripts elevated during Weeks $1{\sim}3$ and returned to normal after Week 4. Our results demonstrated the transient T depletion by EDS administration could induce the changes in expression of the apoptotic genes in rat epididymis. The activation of Fas and Fas-L in the epididymis of EDS-treated rats might be responsible for the initial apototic process and consequently the tissue damage and the sperm loss. Future studies will attempt to determine the precise molecular mechanism(s) of apoptosis in the rat epididymis.

• Biomolecules & Therapeutics
• /
• v.20 no.2
• /
• pp.177-182
• /
• 2012

Tetrazolium violet is a tetrazolium salt and has been proposed as an antitumor agent. In this study, we reported for the first time that tetrazolium violet not only inhibited human lung cancer A549 cell proliferation but also induced apoptosis and blocked cell cycle progression in the G1 phase. The results showed that tetrazolium violet significantly decreased the viability of A549 cells at $5-15{\mu}M$. Tetrazolium violet -induced apoptosis in A549 cells was confirmed by H33258 staining assay. In A549, tetrazolium violet blocked the progression of the cell cycle at G1 phase by inducing p53 expression and further up-regulating p21/WAF1 expression. In addition, an enhancement in Fas/APO-1 and its two forms of ligands, membrane-bound Fas ligand (mFasL) and soluble Fas ligand (sFasL), as well as caspase, were responsible for the apoptotic effect induced by tetrazolium violet. The conclusion of this study is that tetrazolium violet induced p53 expression which caused cell cycle arrest and apoptosis. These findings suggest that tetrazolium violet has strong potential for development as an agent for treatment lung cancer.

• Food Science of Animal Resources
• /
• v.39 no.3
• /
• pp.430-445
• /
• 2019

Natural edible waxes mixed with plant oils, containing high levels of unsaturated fatty acids (FAs), are known as oleogels. Oleogels are used for replacing saturated FAs in animal-derived food with unsaturated FAs. However, the health effects of edible waxes are not yet clearly defined. The purpose of this study was to investigate the effect of FAs and natural waxes on the adipogenesis in 3T3-L1 cells. The 3T3-L1 cells were differentiated and treated with FAs and waxes. These FAs [Palmitic acid (PA), Stearic acid (SA), Oleic acid (OA), Linoleic acid (LA), and Alpha-linolenic acid (ALA)] and waxes [beeswax (BW) and carnauba wax (CW)] were prepared at varying concentrations, and cell toxicity, triglyceride accumulation, lipid droplets size, and distribution inside of cells were determined. Adipogenic gene expression including $PPAR{\gamma}$, FASN, $C/EBP{\alpha}$, SREBP-1, and CPT-1 was determined. Results showed that increasing the concentration of FAs and waxes led to a decrease in the adipocyte cells viability and metabolic performance. SA showed the highest level of triglyceride accumulation (p<0.05), whereas ALA showed the lowest (p<0.05). Both BW and CW at 3.0 ppm showed significantly higher lipid accumulation than in the control and other groups (p<0.05). ALA had significantly downregulated adipogenic gene expression levels, excluding those of CPT-1, compared to the other treatment groups (p<0.05). Moreover, BW demonstrated similar adipogenic gene expression levels as ALA compared to CW. Consequently, ALA and BW may have health benefits by reducing adipogenesis and can be used in processed meat.

• The Korean Journal of Physiology and Pharmacology
• /
• v.10 no.3
• /
• pp.111-121
• /
• 2006

Neuroprotective properties of lithium were evaluated by using in vivo NMDA excitotoxicity model. Systemic injection of NMDA to young mice induced neuronal apoptosis mediated by both TNFR-l and Fas ligand, and long-term lithium treatment showed noticeable neuroprotection against NMDA-induced excitotoxicity: NMDA-damaged neurons expressed several apoptosis-related gene products such as TNFR-l, Fas ligand, and caspase-3, and these gene expressions were not found in the brain of mice chronically treated with lithium. Therefore, it is highly likely that the protection offered by chronic lithium treatment occurred at far upstream of caspase activation, since the chronic lithium treatment increased the expression of Bcl-2, an important antiapoptotic gene known to act upstream of caspase cascade. Timm's histochemistry indicated the complete blockade of the NMDA insults by the treatment. There was no indication of axonal regeneration, which follows synaptic degeneration induced by neuronal damage. Furthermore, this study reports for the first time that TNFR-l and Fas ligand are involved in neuroprotective effects of lithium in NMDA-induced neuronal apoptosis.

• Journal of Life Science
• /
• v.19 no.11
• /
• pp.1529-1537
• /
• 2009

To elucidate further the antitumor effects of a natural L-arginine analogue, L-canavanine, the mechanism underlying apoptogenic activity of L-canavanine and its modulation by protein tyrosine kinase $p56^{lck}$ was investigated in human Jurkat T cells. When the cells were treated with 1.25 to 2.5 mM L-canavanine for 36 h, several apoptotic events including mitochondrial membrane potential (${\Delta\Psi}m$) loss, activation of caspase-9, -3, -8, and -7, poly (ADP-ribose) polymerase (PARP) degradation, and DNA fragmentation were induced without alteration in the levels of Fas or FasL. These apoptotic changes were more significant in $p56^{lck}$-deficient Jurkat clone JCaM1.6 than in $p56^{lck}$-positive Jurkat clone E6.1. The L-canavanine-induced apoptosis observed in $p56^{lck}$-deficient JCaM1.6 cells was significantly reduced by introducing $p56^{lck}$ gene into JCaM1.6 cells by stable transfection. Treatment of JCaM1.6/lck cells with L-canavanine caused a transient 1.6-fold increase in the kinase activity of $p56^{lck}$. Both FADD-positive wild-type Jurkat T cell clone A3 and FADD-deficient Jurkat T cell clone I2.1 exhibited a similar susceptibility to the cytotoxicity of L-canavanine, excluding involvement of Fas/FasL system in triggering L-canavanine-induced apoptosis. The L-canavanine-induced apoptotic sub-$G_1$ peak and activation of caspase-3, -8, and -7 were abrogated by pan-caspase inhibitor (z-VAD-fmk), whereas L-canavanine-induced activation of caspase-9 was not affected. These results demonstrated that L-canavanine caused apoptosis of Jurkat T cells via the loss of ${\Delta\Psi}m$, and the activation of caspase-9, -3, -8, and -7, leading to PARP degradation, and that the $p56^{lck}$ kinase attenuated the ${\Delta\Psi}m$ loss and activation of caspases, and thus contributed as a negative regulator to L-canavanine-induced apoptosis.

• Proceedings of the PSK Conference
• /
• 2001.10a
• /
• pp.205.1-205.1
• /
• 2001

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.23
• /
• pp.10407-10412
• /
• 2015

Background: ${\beta}$-elemene, extracted from herb medicine Curcuma wenyujin has potent anti-tumor effects in various cancer cell lines. However, the activity of ${\beta}$-elemene against glioma cells remains unclear. In the present study, we assessed effects of ${\beta}$-elemene on human glioma cells and explored the underlying mechanism. Materials and Methods: Human glioma U87 cells were used. Cell proliferation was determined with MTT assay and colony formation assay to detect the effect of ${\beta}$-elemene at different doses and times. Fluorescence microscopy was used to observe cell apoptosis with Hoechst 33258 staining and change of glioma apoptosis and cell cycling were analyzed by flow cytometry. Real-time quantitative PCR and Western-blotting assay were performed to investigated the influence of ${\beta}$-elemene on expression levels of Fas/FasL, caspase-3, Bcl-2 and Bax. The experiment was divided into two groups: the blank control group and ${\beta}$-elemne treatment group. Results: With increase in the concentration of ${\beta}$-elemene, cytotoxic effects were enhanced in the glioma cell line and the concentration of inhibited cell viability ($IC_{50}$) was $48.5{\mu}g/mL$ for 24h. ${\beta}$-elemene could induce cell cycle arrest in the G0/G1 phase. With Hoechst 33258 staining, apoptotic nuclear morphological changes were observed. Activation of caspase-3,-8 and -9 was increased and the pro-apoptotic factors Fas/FasL and Bax were upregulated, while the anti-apoptotic Bcl-2 was downregulated after treatment with ${\beta}$-elemene at both mRNA and protein levels. Furthermore, proliferation and colony formation by U87 cells were inhibited by ${\beta}$-elemene in a time and does-dependent manner. Conclusions: Our results indicate that ${\beta}$-elemene inhibits growth and induces apoptosis of human glioma cells in vitro. The induction of apoptosis appears to be related with the upregulation of Fas/FasL and Bax, activation of caspase-3,-8 and -9 and downregulation of Bcl-2, which then trigger major apoptotic cascades.

• The Korean Journal of Physiology and Pharmacology
• /
• v.7 no.1
• /
• pp.29-31
• /
• 2003

It is well known that different expression of Apo-1/Fas (CD95) plays important roles in various tumors and hepatocellular carcinoma (HCC) pathogenesis. Apo-1/Fas mediated apoptosis is one of the important pathways of apoptosis and is known to mediate apoptotic cell death by fas ligand (FasL). To examine the possible relationship between Apo-1/Fas gene polymorphism and HCC susceptibility, MvaI restriction fragment length polymorphism (RFLP) of Apo-1/Fas gene was examined in 94 Korean HCC patients and 240 control subjects. No statistically significant difference in the genotypic distribution and allelic frequencies was found between the control and the HCC. It is, therefore, concluded that Apo-1/Fas gene polymorphism is not associated with HCC susceptibility. Further studies are needed in order to clarify the relationships between genotypes of Apo-1/Fas gene and HCC pathogenesis.