• Journal of Periodontal and Implant Science
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• v.30 no.2
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• pp.257-277
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• 2000

New techniques for regenerating the destructed periodontal tissue have been studied for many years. Current acceptable methods of promoting periodontal regeneration are basis of removal of diseased soft tissue, root treatment, guided tissue regeneration, graft materials, and biological mediators. Platelet Rich Plasma has been reported as a biological mediator which regulates activities of wound healing progress including cell proliferation, migration, and metabolism. The purpose of this study is to evaluate the effects of using the Platelet Rich Plasma as a regeneration promoting agent for furcation involvement defect. Five adult beagle dogs were used in this experiment. The dogs were anesthetized with Ketamin HCl(0.1 ml/kg, IV)and Xylazine hydrochloride($Rompun^{(R)}$, Bayer, 0.1 ml/kg, IM) and conventional periodontal prophylaxis were performed with ultrasonic scaler and hand instruments. With intrasulcular and crestal incision, mucoperiosteal flap was elevated. Following decortication with 1/2 high speed round bur, degree II furcation defect was made on mandibular third(P3), forth(P4) and fifth(P5) premolar, and stopping was inserted. After 4 weeks, stopping was removed, and bone graft was performed. Ca-P was grafted in P3(experimental group I), Combination of Ca-P and plasma rich platelet were grafted in P4(experimental group II), and P5 was remained at control group.Systemic antibiotics(gentamicin sulfate)and anlgesics(phenyl butazone) were administrated intramuscular for 2 weeks after surgery. Irrigation with 0.1% Chlorhexidine Gluconate around operate sites was performed during the whole experimental period except one day immediate after surgery. Soft diets were fed through the whole experiment period. After 4, 8 weeks, the animals were sacrificed by perfusion technique. Tissue block was excised including the tooth and prepared for light microscope with Gomori's trichrome staining. At 4 weeks after surgery, there were rapid osteogenesis phenomenon on the defected area of the Platelet Rich Plasma plus Ca-P BBP group and early trabeculation pattern was made with new osteoid tissue produced by activated osteoblast. Bone formation was almost completed to the fornix of furcation by 8 weeks after surgery. In conclusion, Platelet Rich Plasma can promote rapid osteogenesis during healing of periodontalregeneration.

• Applied Microscopy
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• v.27 no.2
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• pp.197-215
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• 1997

A morphologic study on the effect of butylated hydroxytoluene (BHT) on experimental hepatocarcinogenesis induced by 3'-methyl-4-dimethyl aminoazobenzene (3'-MeDAB) was investigated. A total of 110 Sprague-Dowley male rats weighting about 200 g each were used for the experiment, and divided into 4 groups; the 3'-MeDAB, BHT, 3'-MeDAB/BHT treated group, and the control group. Four to eight rats of each group were sacrified on the 4th, 8th, 14th and 16th experimental weeks, with continuous pelletized feeding containing 0.09% 3'-MeDAB and 0.5% BHT. The liver was examined by transmission and scanning electron microscopy. The results were as follows; Electron microscopically, the fine structure of the hepatocytes remained consistently abnormal up to 16 weeks after the 3'-MeDAB treatment. There was no significant difference in the groups observed earlier than in the ones observed later. Many subcellular changes were observed : nuclear change, decreased glycogen, mitochondrial abnormalities, disaggregated rough endoplasmic reticulum, marked proliferation of smooth endoplasmic reticulum, dilatation and distortion of bile canaliculi, increased lysosomes, apoptotic bodies, migration of bile ductule cell. In the BHT treated group, the ultrastructural changes of hepatocytes were not significant, except for the lipid droplets and proliferated smooth endoplasmic reticulum among hepatocytes depending on the experimental duration. The various subcellular changes of 3'-MeDAB/BHT treated groups were simillar to those of the 3'-MeDAB treated group, but the degree of changes in the 3'-MeDAB/ BHT treated group decreased compared with those of the 3'-MeDAB treated group. These results suggest that dietary butylated hydroxytoluene has a protective/inhibitory effect on the hepatocarcinogenesis induced by 3'-methyl-4-dimethyl -aminoazobenzene.

• Korean Journal of Head & Neck Oncology
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• v.33 no.1
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• pp.21-29
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• 2017

Methylation of CpG islands in the promoter region of genes acts as a significant mechanism of epigenetic gene silencing in head and neck squamous cell carcinoma (HNSCC). DNA methylation markers are particularly advantageous because DNA methylation is an early event in tumorigenesis, and the epigenetic modification, 5-methylcytosine, is a stable mark. In the present study, we assessed the genome-wide preliminary screening and were to identify novel methylation biomarker candidate in HNSCC. Genome-wide methylation analysis was performed on 10 HNSCC tumors using the Methylated DNA Isolation Assay (MeDIA) CpG island microarray. Validation was done using immunohistochemistry using tissue microarray of 135 independent HNSCC tumors. In addition, in vitro proliferation, migration/invasion assays, RT-PCR and immunoblotting were performed to elucidate molecular regulating mechanisms. Our preliminary validation using CpG microarray data set, immunohisto-chemistry for HNSCC tumor tissues and in vitro functional assays revealed that methylation of the Homeobox B5 (HOXB5) and H6 Family Homeobox 2 (HMX2) could be possible novel methylation biomarkers in HNSCC.

• Toxicological Research
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• v.29 no.1
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• pp.43-52
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• 2013

Zearalenone (ZEN) is a non-steroidal estrogenic mycotoxin produced by several species of Fusarium that are found in cereals and agricultural products. ZEN has been implicated in mycotoxicosis in farm animals and in humans. The toxic effects of ZEN are well known, but the ability of an alkaline Comet assay to assess ZEN-induced oxidative DNA damage in Chang liver cells has not been established. The first aim of this study was to evaluate the Comet assay for the determination of cytotoxicity and extent of DNA damage induced by ZEN toxin, and the second aim was to investigate the ability of N-acetylcysteine amide (NACA) to protect cells from ZEN-induced toxicity. In the Comet assay, DNA damage was assessed by quantifying the tail extent moment (TEM; arbitrary unit) and tail length (TL; arbitrary unit), which are used as indicators of DNA strand breaks in SCGE. The cytotoxic effects of ZEN in Chang liver cells were mediated by inhibition of cell proliferation and induction of oxidative DNA damage. Increasing the concentration of ZEN increased the extent of DNA damage. The extent of DNA migration, and percentage of cells with tails were significantly increased in a concentration-dependent manner following treatment with ZEN toxin (p < 0.05). Treatment with a low concentration of ZEN toxin (25 ${\mu}M$) induced a relatively low level of DNA damage, compared to treatment of cells with a high concentration of ZEN toxin (250 ${\mu}M$). Oxidative DNA damage appeared to be a key determinant of ZEN-induced toxicity in Chang liver cells. Significant reductions in cytolethality and oxidative DNA damage were observed when cells were pretreated with NACA prior to exposure to any concentration of ZEN. Our data suggest that ZEN induces DNA damage in Chang liver cells, and that the antioxidant activity of NACA may contribute to the reduction of ZEN-induced DNA damage and cytotoxicity via elimination of oxidative stress.

• Analytical Science and Technology
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• v.25 no.5
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• pp.333-338
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• 2012

IQ motif-containing GTPase-activating proteins (IQGAPs), which are well-known $Ca^{2+}$-independent calmodulin (CaM) binding proteins, are involved in various cellular functions such as cell proliferation, carcinogenesis and cell migration. The IQGAP3 similar to IQGAP1 has four repeated IQ motifs, which are crucial for CaM binding. It has been recently shown that all four IQ motifs of the IQGAP1 could bind to CaM, while not clear the binding of four IQ motifs of the IQGAP3. In this study, we examined the binding between CaM and each IQ motif of IQGAP3. As a result, we found that IQ2 and IQ3, but not IQ1 and IQ4, have a $Ca^{2+}$-independent CaM binding activity. We also found that IQ(3.5-4.4) on the IQGAP3 has $Ca^{2+}$-dependent CaM binding activity as similar with that of IQGAP1. This finding indicates that IQ motifs of the IQGAP3 plays a dynamic role via different interaction of IQ motifs with $Ca^{2+}$/CaM or apoCaM.

• Journal of Life Science
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• v.21 no.7
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• pp.923-931
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• 2011

In the present study, we investigated the effect of indole-3-carbinol (I3C), a natural compound present in vegetables, on the cell migration and invasion of OVCAR-3 ovarian cancer cells. Our results indicated that I3C inhibited the proliferation of OVCAR-3 cells, a process which was associated with inhibition of cell motility as determined by wound healing experiments and cell invasion studies. I3C treatment increased the tightness of the tight junctions (TJs), which was demonstrated by an increase in transepithelial electrical resistance and a decrease in paracellular permeability. The RT-PCR and immunoblotting results indicated that I3C repressed the levels of claudin-3 as well as claudin-4, proteins that comprise a major part of TJs and play a key role in the control and selectivity of paracellular transport. Furthermore, the activities of matrix metalloproteinase (MMP)-2 and MMP-9 were also decreased by treatment with I3C, which was connected with the down-regulation of their mRNAs and protein expression. The results suggest that I3C may be expected to inhibit cancer cell metastasis and invasion by restoring TJs and decreasing MMP activity in ovarian cancer cell line OVCAR-3.

• Journal of Life Science
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• v.20 no.6
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• pp.914-921
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• 2010

In this study, we carried out a series of experiments to know whether melatonin, an anti-oxidative and immunosuppressive agent, played an important role in endothelial cells. It was revealed that melatonin had little or no effect on endothelial proliferation, cell death or migration. Additionally, melatonin had no effect on adhesion of THP-1 leukocytes to bovine aortic endothelial cells (BAECs) and THP-1 homotypic cell aggregation. In contrast, it was shown that melatonin diminished the basal level of nitric oxide by PP2A-mediated dephosphorylation of endothelial nitric oxide synthase (eNOS), leading to enhanced detachment of BAEC from the extracellular matrix. Collectively, melatonin in high doses decreases the NO production via regulations of PP2A and eNOS activities, inducing detachment of endothelial cells, a possible initial step for thrombosis.

• Journal of Life Science
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• v.25 no.6
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• pp.724-731
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• 2015

Mesenchymal stem cells (MSCs) are characterized by their multipotency capacity, which allows them to differentiate into diverse cell types (bone, cartilage, fat, tendon, and neuron-like cells) and secrete a variety of trophic factors (ANG, FGF-2, HGF, IGF-1, PIGF, SDF-1α, TGF-β, and VEGF). MSCs can be easily isolated from human bone-marrow, fat, and umbilical-cord tissues. These features indicate that MSCs might be of use in stem-cell therapy. However, MSCs undergo cellular senescence during long-term expansion, and this is accompanied by functional declines in stem-cell potency. In the human body, because of their senescence and declines in their microenvironmental niches stem cells fail to maintain tissue homeostasis, and as a result, senescent cells accumulate in tissues. This can lead to age-related diseases, including degenerative disorders and cancers. Recent studies suggest that the number of histone modifications to stem cells’ genomes and aberrant alterations to their DNA methylation increase as stem cells progress into senescence. These epigenetic alterations have been partly reversed with treatments in which DNA methyltransferase (DNMT) inhibitors or histone deacetylase (HDAC) inhibitors are introduced into replicative senescent-MSCs. This review focuses on epigenetic alteration in replicative senescent-MSCs and explains how epigenetic modifications are widely associated with stem-cell senescences such as differentiation, proliferation, migration, calcium signaling, and apoptosis.

• Journal of Microbiology and Biotechnology
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• v.28 no.6
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• pp.1007-1021
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• 2018

Cancer represents one of the most significant threats to human health on a global scale. Hence, the development of effective cancer prevention strategies, as well as the discovery of novel therapeutic agents against cancer, is urgently required. In light of this challenge, this research aimed to evaluate the effects of several potent bioactive peptides and proteins contained in crocodile white blood cell extract (cWBC) against LU-1, LNCaP, PC-3, MCF-7, and CaCo-2 cancer cell lines. The results demonstrate that 25, 50, 100, and $200{\mu}g/ml$ cWBC exhibits a strong cytotoxic effect against all investigated cell lines ($IC_{50}$ $70.34-101.0{\mu}g/ml$), while showing no signs of cytotoxicity towards noncancerous Vero and HaCaT cells. Specifically, cWBC treatment caused a significant reduction in the cancerous cells' colony forming ability. A remarkable suppression of cancerous cell migration was observed after treatment with cWBC, indicating potent antimetastatic properties. The mechanism involved in the cancer cell cytotoxicity of cWBC may be related to apoptosis induction, as evidenced by typical apoptotic morphology features. Moreover, certain cWBC concentrations induced significant overproduction of ROS and significantly inhibited the $S-G_2/M$ transition in the cancer cell. The molecular mechanisms of cWBC in apoptosis induction were to decrease Bcl-2 and XIAP expression levels and increase the expression levels of caspase-3, caspase-8, and p53. These led to a decrease in the expression level of the cell cycle-associated gene cyclin-B1 and the arrest of cell population growth. Consequently, these findings demonstrate the prospect of the use of cWBC for cancer therapy.

• Journal of Periodontal and Implant Science
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• v.26 no.2
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• pp.429-447
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• 1996

Transforming growth factor $-{\beta}$ is one of the polypeptide growth factors that mediate the activity of mesenchymal cells and regulate wound healing process via cell proliferation, migration and extracellular matrix formation. The purposes of this study is to evaluate the effects of transforming growth factor $-{\beta}$ on the protein synthetic activity of human periodontal ligament cells and human gingival fibroblasts. The cells which were prepared were primary cultured gingival fibroblasts and periodontal ligament cells from humans, and the fourth or sixth subpassage were used in the experiments. Cells were seeded and at a confluent state, 0, 0.5, I, 2.5, 5, 10 ng/ml $TGF-{\beta}$ and $2{\mu]Ci/ml\;[^3H]$ proline were added to the cells and cultured for 24 hours. Then, 1 and 5 ng/ml concentrations were selected and added to confluent cells and cultured for 24 and 48 hours. They were labeled with $2{\mu}Ci/ml\;[^3H]$ proline for 24 hours and a collagen assay was done by the Peterkofsky and Diegelman method. The results were presented as the mean disintegration per minute (dpm) per well and S.D. of four determinations, The results were as follows. : The total protein, collagen and noncollagenous protein synthesis in periodontal ligament cells and gingival fibroblasts were increased dose- dependently by transforming growth factor-p to 2.5-5 ng/ml concentration and decreased at 10 ng/ml concentration. The percent of collagen was slightly changed according to the concentration of transforming growth factor-po The effect of transforming growth $factor-{\beta}$ was not specific for collagen synthesis since it increased the total, noncollagenous and collagenous protein, simultaneously. In the comparison of protein synthetic activity between the human periodontal ligament cells and human gingival fibroblasts, the human gingival fibroblasts had higher activities than the human periodontal ligament cells at all times and concentrations of $TGF-{\beta}$. In the comparison of protein synthetic activity between the 24 hour effect and the 48 hour effect of $TGF-{\beta}$, the 48 hour cultured cells' synthetic activity decreased more than the 24 hour cultured cells at human periodontal ligament cells and human gingival fibroblasts. In conclusion, $TGF-{\beta}$ has important roles in the stimulation of protein synthesis in human periodontal ligament cells and human gingival fibroblasts. Thus, it may be useful for clinical application in periodontal regenerative procedures.