• Microbiology and Biotechnology Letters
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• v.32 no.1
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• pp.72-77
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• 2004

Previously, we synthesized a novel Cyclin-dependent kinase inhibitor, MCS-5A. Also, we investigated the involvement of cell cycle regulatory events during MCS-5A-mediated apoptosis in HL-60(+p16/-p53) cells with up-regulation of p16 protein expression. In contrast, apoptosis was not observed in A549(-p16/+p53) cells. Therefore we propose that $p16^{INK4A}$ is a key enzyme for inducing apoptosis. In the present studies, we have explored the mechanism of $p16^{INK4A}$ -mediated cytotoxicity and the role of p16.sup INK4A/ overexpression in the induction of apoptosis in human tumor cells. The tumor suppressor gene $p16^{INK4A}$ is known as a cyclin-dependent kinase inhibitor (CKI) and cell cycle regulator. We expressed wild type $p16^{INK4A}$ in pcDNA3.1 vector and then transfected into non-small cell lung cancer (NSCLC) cell expressing different statue of p16$^{INK4A}$, p53 gene〔A549(-p16/+p53), H1299(-p16/-p53) and HeLa(+pl6/+p53) cell line〕. TUNEL assay (including propidium iodide staining following transfection of these cell line with pcDNA3.1-pl6) indicate that p16$^{INK4A}$-mediated cytotoxicity was associated with apoptosis. This is supported by studies demonstrating an induction of caspase 3 cleavage due to the transfection of A549, H1299 and HeLa cells with pcDNA3.1-pl6. These results suggest that p16$^{INK4A}$ has a new function of inducing apoptosis which is not related with the function of tumor suppressor gene p53.

• The Korean Journal of Physiology and Pharmacology
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• v.9 no.4
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• pp.247-253
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• 2005

The present study assessed the effect of calmodulin antagonists trifluoperazine and W-7 against the cytotoxicity of $MPP^+$ and 6-bydroxydoparnine (6-OHDA) in relation to the mitochondrial dysfunction and cell death in PC12 cells. Trifluoperazine (an inhibitor of the mitochondrial permeability transition and calmodulin antagonist) and W-7 (a specific calmodulin antagonist) significantly attenuated the $MPP^+-induced$ cell viability loss in PC12 cells with a maximum inhibition at $0.5{\sim}1{\mu}M$; beyond these concentrations the inhibitory effect declined. Both compounds at this concentration range did not cause cell death significantly. In contrast to $MPP^+$, the trifluoperazine and W-7 did not depress the cytotoxic effect of 6-OHDA. Addition of trifluoperazine and W-7 inhibited the cytosolic accumulation of cytochrome c and caspase-3 activation in PC12 cells treated with $MPP^+$ and attenuated the formation of reactive oxygen species and the depletion of GSH, whereas both compounds did not reduce the effect of 6-OHDA. The results show that trifluoperazine and W-7 may attenuate the cytotoxicity of $MPP^+$ by inhibition of the mitochondrial permeability transition and calmodulin. Meanwhile, the cytotoxic effect of 6-OHDA seems to be mediated by the actions, which are different from $MPP^+$.

• The Korean Journal of Physiology and Pharmacology
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• v.10 no.4
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• pp.207-212
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• 2006

Mitochondrial permeability transition has been shown to be involved in neuronal cell death. Mitochondrial monoamine oxidase (MAO)-B is considered to play a part in the progress of nigrostriatal cell death. The present study examined the effect of MAO inhibitors against the toxicity of 1-methyl-4-phenylpyridinium $(MPP^+)$ in relation to the mitochondrial permeability transition. Chlorgyline (a selective inhibitor of MAO-A), deprenyl (a selective inhibitor of MAO-B) and tranylcypromine (nonselective inhibitor of MAO) all prevented cell viability loss, cytochrome c release, caspase-3 activation, formation of reactive oxygen species and depletion of GSH in differentiated PC12 cells treated with $500\;{\mu}M$$MPP^+$. The MAO inhibitors at $10\;{\mu}M$ revealed a maximal inhibitory effect and beyond this concentration the inhibitory effect declined. On the basis of concentration, the inhibitory potency was tranylcypromine, deprenyl and chlorgyline order. The results suggest that chlorgyline, deprenyl and tranylcypromine attenuate the toxicity of $MPP^+$ against PC12 cells by suppressing the mitochondrial permeability transition that seems to be mediated by oxidative stress.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.12
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• pp.6233-6237
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• 2012

Survivin, a new member of the inhibitor of apoptosis protein (IAP) family, both inhibits apoptosis and regulates the cell cycle. It is overexpressed in breast tumor tissues. In this study, we designed two survivin specific DNAzymes (DRz1 and DRz2) targeting survivin mRNA. The results showed that DRz1 could decrease the expression of survivin by nearly 60%. Furthermore, DRz1 significantly inhibited cell proliferation, induced apoptosis and inhibited migration in MCF-7 cells. In addition, down-regulation of survivin expression was associated with increased caspase-3 and -9 activities in MCF-7 cells after 24 h transfection. In our experiments, the efficacy of DRz1 to influence survivin levels and associated effects were better than DRz2. Survivin-DRz1 might have anti-tumorigenic activity and may potentially provide the basis for a novel therapeutic intervention in breast cancer treatment.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2020.10a
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• pp.219-219
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• 2020

Kaempferol (3,4',5,7-tetrahydroxyflavone), a flavonoid found in beans, broccoli, garlic, etc., has been used in natural medicine as an anti-inflammatory and antioxidant. This experiment was carried out to evaluate the anti-apoptotic effect of kaempferol in 12-O-tetradecanoylphorbol 13-acetate (TPA)-treated Normal Human Dermal Fibroblast (NHDF). Kaempferol inhibited the production of intracellular Reactive Oxygen Species (ROS) induced by TPA in NHDF. Kaempferol significantly blocks the phosphorylation of extracellular signal-regulated kinase responsible for the activation of nuclear factor-kappa B. In addition, kaempferol significantly attenuated the expression of Bax and cleaved caspase-3 as regulated by the phosphorylation of nuclear factor-kappa B during its blockage of TPA-induced apoptotic cell death. These findings suggest that kaempferol protects the apoptotic signaling pathway induced by TPA through modulating intracellular ROS in NHDF.

• Journal of Life Science
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• v.19 no.9
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• pp.1209-1217
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• 2009

Many cancer cells are sensitive to the TNF-related apoptosis-inducing ligand (TRAIL)-induced apoptosis. However, some cancer cells show either partial or complete resistance to TRAIL. Human colon carcinoma KM12 cells have been shown to be insensitive to TRAIL-induced apoptosis. To overcome TRAIL resistance in KM12 cells, we targeted key anti-apoptotic molecules involved in the modulation of TRAIL resistance in the cells, and evaluated the effects of quercetin as a TRAIL sensitizer in the cells. We found that quercetin acted in synergy with TRAIL to enhance TRAIL-induced apoptosis in KM12 cells by the down-regulation of c-FLIP and DNA-PKcs/Akt and up-regulation of death receptors (DR4/DR5), which led to the enhancement of TRAIL-mediated activation of caspases and subsequent cleavage of PARP, as well as up-regulation of Bax. These findings suggest that the DNA-PKcs/Akt signaling pathway, as well as c-FLIP, play essential roles in regulating cells in the escape from TRAIL-induced apoptosis. Based on these results, this study provides a potential application of quercetin in combination with TRAIL in the treatment of human colon cancer.

• Food Science and Preservation
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• v.31 no.2
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• pp.298-306
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• 2024

This study evaluated the differentiation and protective effects of mixed plant-extract powder in C2C12 muscle cells. Cells were differentiated into myotubes in 2% horse serum (HS)-containing medium with mixed plant-extract powder (MPEP) for 6 days. Treatment with MPEP increased the expression of myogenin and myosin heavy chain (MHC) protein in cells compared with non-treated cells. Differentiated cells were pretreated with MPEP, and hydrogen peroxide (H₂O₂). Our results revealed that treatment with MPEP before H₂O₂ treatment increased cell viability and decreased H₂O₂-induced lactate dehydrogenase (LDH) and creatine kinase (CK). In addition, MPEP attenuated H₂O₂-induced upregulation of Bax, downregulation of Bcl-2, and activation of caspase-9 and -3. These results suggest the MPEP can stimulate C2C12 muscle cell differentiation into myotubes and observe the protective effect of mixed plant-extract powder against muscle oxidative stress. In conclusion, MPEP may be useful as a prevention and treatment material for skeletal muscle disease caused by age-related diseases.

• The Korean Journal of Physiology and Pharmacology
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• v.9 no.4
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• pp.231-238
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• 2005

Neuronal apoptotic events, which result in cell death, are occurred in hypoxic/ischemic conditions. Estradiol is a female sex hormone with steroid structure known to provide neuroprotection through multiple mechanisms in the central nervous system. This study was aimed to investigate the signal transduction pathway of $CoCl_2$-induced neuronal cell death and the inhibitory effects of estradiol. Administration of $CoCl_2$ decreased cell viability in both a dose- and time-dependent manner in PC12 cells. $CoCl_2$-induced cell death produced genomic DNA fragmentation and morphologic changes such as cell shrinkage and condensed nuclei. It was found that $CoCl_2$-treated cells increased the reactive oxygen species (ROS) as well as caspase-8, -9 and -3 activities. However, pretreatment with estradiol before exposure to $CoCl_2$ prevented the reduction in cell viability reduction and attenuated DNA fragmentation and morphologic changes caused by $CoCl_2$. Furthermore, the $CoCl_2$-induced increases of ROS levels and caspases activities were attenuated by estradiol. Gene expression analysis revealed that estradiol blocked the underexpression of the Bcl-2 and ameliorated the increase in the release of cytochrome c from mitochondria into cytoplasm and Fas-ligand (Fas-L) upregulated by $CoCl_2$. These results suggest that $CoCl_2$ induce apoptosis in PC12 cells through both mitochondria- and death receptor-mediated cell death pathway. Estradiol was found to have a neuroprotective effect against $CoCl_2$-induced apoptosis through the inhibition of ROS production and by modulating apoptotic effectors associated with the mitochondria- and death-dependent pathway in PC12 cells.

• Korean Journal of Agricultural Science
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• v.49 no.2
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• pp.175-184
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• 2022

The present study investigated the neuroprotective effects of Coreopsis lanceolate extract against hydrogen-peroxide (H₂O₂)-induced oxidative damage and cell death in pheochromocytoma 12 (PC12) cells. Reactive oxygen species (ROS), 2,2'-azinobis (3-ethylbebzothiazoloine-6-sulfonic acid) diammonium salt, and 1,1-diphenyl-2-picrrylhydrazyl radical scavenging activities, as well as the expression levels of proteins associated with oxidative damage and cell death were investigated. According to the results, C. lanceolate extract exhibited inhibitory activity against intracellular ROS generation and cell-damaging effects induced by hydroxyl radicals in a dose-dependent manner. Total phenolic and flavonoid contents were 22.3 mg·g^-1 gallic acid equivalent and 16.2 mg·g^-1 catechin equivalent, respectively. Additionally, a high-performance liquid chromatography (HPLC) assay based on the internal standard method used to detect phenolic compounds. The phenolic compounds identified in C. lanceolata extract contained (+)-catechin hydrate (5.0 ± 0.0 mg·g^-1), ferulic acid (1.6 ± 0.0 mg·g^-1), chlorogenic acid (1.5 ± 0.0 mg·g^-1), caffeic acid (1.2 ± 0.0 mg·g-1), naringin (0.9 ± 0.0 mg·g^-1), and p-coumaric acid (0.5 ± 0.0 mg·g^-1). C. lanceolata extract attenuated pro-apoptotic Bax expression levels and enhanced the expression levels of anti-apoptotic Bcl-2, caspase-3, and caspase-9 proteins. Therefore, C. lanceolata is a potential source of materials with neuroprotective properties against neurodegenerative disorders, such as Alzheimer's and Parkinson's diseases.

• Korean Journal of Food Science and Technology
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• v.46 no.5
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• pp.609-615
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• 2014

The cytoprotective effect of Moringa oleifera Lam. (drumstick tree) on neuronal cells was investigated to confirm the physiological benefits associated with this natural food resource. First, the drumstick tree extract was chemically analyzed to determine inherent nutritional constituents. Calcium and potassium were identified as the major mineral constituents, and palmitic acid (C16:0, 16.33%) and gadoleic acid (C20:01, 66.34%) were detected as the major fatty acids. Moreover, drumstick tree extract contained 94.78 mg/100 g vitamin E and 112.61 mg/100 g niacin. PC12 cells were used to study the cytoprotective effects of drumstick tree extract. Intracellular accumulation of reactive oxygen species was significantly reduced when $H_2O_2$ treated-neuronal cells were cultured in a medium containing the methanolic extract of drumstick tree, compared to cells treated with only $H_2O_2$. Cell viability assay using MTT showed that the extract protected cells against $H_2O_2$-induced neurotoxicity and inhibited LDH leakage from the cell membrane. Caspase assay showed that the extract exerted cytoprotective effect against apoptosis. Consequently, these data suggest that drumstick tree is a useful natural resource with positive effects on human health.