• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.6
• /
• pp.2527-2532
• /
• 2012

Objectives: The aim of the present study was to explore mechanisms underlying the effects of down-regulating ${\beta}$-catenin expression on esophageal carcinoma (EC) cells. Methods: Cell cycle distribution and apoptosis were determined using flow cytometry and annexin V apoptosis assay, respectively. Transmission electron microscopy (TEM) was used to examine changes in ultrastructure, while expression of cyclin D1 protein and mRNA was detected by western blot and real-time PCR. Proliferating cell nuclear antigen (PCNA) and extracellular signal-regulated kinase (ERK) 1-2 were evaluated by Western blot analysis. PCNA labeling index (LI) was determined by immunocytochemistry. Results: Compared with pGen-3-con transfected and Eca-109 cells, the percentage of G0/G1-phase pGen-3-CTNNB1 transfected cells was obviously increased (P<0.05), with no significant difference among the three groups with regard to apoptosis (P>0.05). pGen-3-CTNNB1 transfected cells exhibited obvious decrease in cyclin D1 mRNA and protein expression (P<0.05) and the ultrastructure of Eca-109 cells underwent a significant change after being transfected with pGen-3-CTNNB1, suggesting that down-regulating ${\beta}$-catenin expression can promote the differentiation and maturation. The expression of PCNA and the ERKI/2 phosphorylation state were also down-regulated in pGen-3-CTNNB1 transfected cells (P<0.05). At the same time, the PCNA labeling index was decreased accordingly (P<0.05). Conclusion: Inhibition of EC Eca-109 cellproliferation by down-regulating ${\beta}$-catenin expression could improve cell ultrastructure by mediating blockade in G0/G1 through inhibiting cyclin D1, PCNA and the MAPK pathway (p-ERK1/2).

• The Journal of Korean Medicine
• /
• v.39 no.1
• /
• pp.35-43
• /
• 2018

Objectives: In the brain, glutamate is the most important excitable neurotransmitter in physiological and pathological conditions. However, the high level of glutamate induces neuronal cell death due to exitotoxicity and oxidative stress. The present study investigated to evaluate a possible neuroprotective effect of furosin isolated from Euphorbia helioscopia against glutamate-induced HT22 cell death. Methods: Furosin was isolated from methanol extract of Euphorbia helioscopia and examined whether it protects glutamate-induced neuronal cell death. The cell viability was determined using Ez-Cytox assay. Anti-oxidative effect of furosin was determined by DPPH scavenging activities, and the levels of intracellular reactive oxygen species (ROS) were determined by the fluorescent intensity after staining the cells with $H_2DCFDA$. To evaluate apoptotic cell death, we performed nuclear staining and image-based cytometeric analysis. Results: The cell viability was significantly increased by treatement with furosin compared with the treatment with glutamate. Furosin showed a strong DPPH radical scavenging activity ($EC50=1.83{\mu}M$) and prevented the accumulation of intra cellular ROS. Finally, the presence of 50 and $100{\mu}M$ furosin significantly the percentage of apoptotic cells compared with glutamate treatment. Conclusion: The present study found that furosin is a potent neuroprotectant against glutamate-induced oxidative stress through inhibition of apoptotic cell death induced by glutamate. Therefore, the present study suggests that furosin as a bioactive compound of E. helioscopia can be a useful source to develop a drug for the treatment of neurodegenerative diseases and acute brain injuries.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.31 no.4 s.54
• /
• pp.349-357
• /
• 2005

New antioxidative substances for cosmeceuticals were screened from natural resources such as microbial metabolites, mushrooms, and medicinal plants. Four antioxidants were isolated from the fungal metabolite of Eupenicillium shearii and their structures were determined to be new phenolic compounds. The compounds were designated as melanocins A, B, C, and D. Melanocins $A{\sim}D$ exhibited free radical scavenging activity on DPPH and superoxide with $EC_{50}$ values of $21{\sim}94\;and\;7{\sim}84{\mu}M$, respectively, which were stronger activity than those of ${\alpha}-tocopherol$ and BHA. Melanocin A showed anti-wrinkle effects on the UV-irrated hairless mouse skin. A novel hispidin antioxidative compound designated as inoscavin A was isolated from the fruiting body of the mushroom, Inonotus xeranticus. Inoscavin A scavenged superoxide radical with $EC_{50}$ values of $0.03{\mu}g/mL$, and inhibited rat liver microsomal lipid peroxidation with $EC_{50}$ values of $0.3{\mu}g/mL$. Benzastatins $A{\sim}G$, the novel antioxidants isolated from the culture of Streptomyces nitrosporeus showed potent lipid peroxidation inhibitory activity with $EC_{50}$ values of $3{\sim}30{\mu}M$. A cyclopentene compound with strong hypopigmentary effect was isolated from the fungal metabolite of Penicillium sp. and identifed as terrein. Terrein significantly reduced melanin levels in a melanomacyte cell line, Mel-Ab. It showed 10 times stronger activity than kojic acid, but exhibited no cytotoxic effect even in $100{\mu}M$. It was suggested that terrein reduced melanin synthesis by reducing tyrosinase production by MITF down-regulation.

• Proceedings of the IEEK Conference
• /
• 2000.11a
• /
• pp.73-76
• /
• 2000

We investigate the stepwise parallel processing of the serial search which can success the co]1 search at low Ec/Io. The single path Rayleigh fading channel which is worst-case channel model is considered. The typical 3-step cell search is used. The probabilities of detection, miss and false alarm for each step are used in closed forms based on the statistics of CDMA noncoherent demodulator output. The optimal power allocation to each channel and The optimal number of post-detection integrations for each step is obtained. Also, the cumulative probability distribution of the average eel] search time for serial search methods are compared.

• Journal of Microbiology and Biotechnology
• /
• v.16 no.12
• /
• pp.2000-2003
• /
• 2006

A gene (GenBank AF096282) coding for a $\alpha$-glucosidase (TcaAG, EC 3.2.1.20) from Thermus caldophilus GK24 was expressed in Saccharomyces cerevisiae, a generally recognized as safe (GRAS) host. The thermostable $\alpha$-glucosidase was produced inside of the GRAS host at 0.04 unit/mg-dry cell by the constitutively expressing ADH1 promoter and at 1.2 unit/mg-dry cell by the inductively expressing GALl0 promoter, respectively. No $\alpha$-glucosidase activities were found in the medium when the MF-alpha signal sequence from S. cerevisiae or $\alpha$-amylase signal sequence from Aspergillus oryzae were fused before the $\alpha$-glucosidase gene for the secretion.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 2001.11a
• /
• pp.113-113
• /
• 2001

Stable MCF-7-ERE cells, in which pERE-Luc reporter gene has been stably integrated into the genome of the MCF-7 cells, were used to detect the estrogenic activity of various dietary flavonoids in either pure chemical or mixtures. Estradiol (E2) induced luciferase activity in dose dependent manner and this activity was inhibited by tamoxifen (Tam) concomitant treatment. A large series of flavonoids showed estrogenic activities, corresponding to EC5O values between 0.2 and 9 microM and their mixtures didn't show additive or synergistic effects. And we could find some structure and activity relationship. First, 4-methoxylation and catechol structure decreased estrogenic activities. Second, hydroxylation of 3 position reduced estrogenic effect. Third glycosides of flavonoids showed weak estrogenic activity or no activity. Interestingly, when tested at high concentrations, genistein, kaempferol, biochanin A and chrysin elicited luciferase induction higher than that of the maximum induction by estradiol. And these effects of genistein and kaempferol could not be fully inhibited with tamoxifen

• The Korean Journal of Nuclear Medicine
• /
• v.38 no.2
• /
• pp.190-197
• /
• 2004

Apoptosis plays a role in the pathophysiology of many kinds of diseases and in the response of treatment. Compared to the necrosis, the apoptosis is a genetically controlled and energy-dependent process which removes the unwanted cells from the body; programmed cell death or cell suicide. During the apoptosis, phosphatidylserine is expressed in the cytoplasmic outer membrane in the early phase. Annexin V, an endogenous human protein (MW=35 kD), has an affinity of about $10^{-9}\;M$ for the phosphatidylserine exposed on the outer membrane of apoptotic cells. Annexin V can be radiolabeled with $^{99m}Tc$ by HYNIC or EC chelators, which can be used as an radiotracer for the in vivo imaging of apoptosis. In this article, we reviewed the apoptosis, radiolabeling of annexin V, and the experimental and clinical data using annexin V imaging.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.11 no.10
• /
• pp.768-772
• /
• 1998

The new type polymer electrolyte composed of polymethyl methacrylate(PMMA) - polyethy leneoxide(PEO) contain $LiClO_4$ -EC/PC was developed for the weightless and long or life time of lithium polymer batery system with using polyaniline electrode. the gel type electrolytes were prepared by PMMA with PEO at different lithium salts in the glove box. The minimum thickness of PMMA-PEO gel electrolyte for the slim type is about(400~450$\mu\textrm{m}$. These gel electrolyte showed good compatibility with lithium electrode. The test cell Li/polymer electrolyte/polyaniline solid state cell which was prepared by different lithium salt was researched by electrochemical technique.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.1
• /
• pp.169-173
• /
• 2012

Objective: This study aimed to explore the differences in the curative and side effects of chemoradiotherapy on esophageal cancer (EC) among Xinjiang Han, Uigur and Kazakh patients. Methods: 170 patients with IIA stage-IV of esophageal squamous cell carcinoma were analyzed retrospectively. Based on different nationalities, they were divided into the Han, Uigur and Kazakh groups. The 1-, 2- and 3-year survival rates, incidence of the side effects (including hematological toxicities, radioactive esophagitis and percutaneous reactions) and application of antibiotics and harmonics were compared among the groups. There was no significant difference in the short-term curative effects among the Han, Uigur and Kazakh groups. The 1- 2- and 3-year survival rates of the three groups were 84%, 40%, 26%; 78%, 27%, 18%; and 60%, 21%, 12% ($x^2$=14.497, P<0.05). The incidence rate of hamatological toxicity ${\geq}$Grade 2 in the Kazakh group was significantly lower than that in the Han or Uigur group. Results: The incidence rates of radioactive esophagitis and percutaneous reactions Grade 2 in the Han group were significantly higher than those in the Uigur or Kazakh group. There was no significant difference in the types of applied antibiotics among the groups, but there were significant differences in the days of antibiotic application and proportion of patients receiving harmonics between the Hans and either of other groups. Conclusion: Chemoradiotherapy shows a better effect in the long-term survival rate among Han EC patients compared with Uigur or Kazakh EC patients. Uigur and Kazakh patients show a better tolerance to the side effects of chemoradiotherapy compared with Hans.

• Development and Reproduction
• /
• v.12 no.2
• /
• pp.159-168
• /
• 2008

Nanog is a newly identified member of the homeobox family of DNA binding transcription factors that functions to maintain the undifferentiated state of stem cells. However, molecular mechanisms underlying the function of Nanog remain largely unknown. To elucidate the regulatory roles of Nanog involved in maintenance of P19 embryonal carcinoma (EC) stem cells, we transfected three small interfering RNA (siRNA) duplexes targeted against different regions of the Nanog gene into P19 cells. The Nanog siRNA-100 duplexes effectively decreased the expression of Nanog up to 30.7% compared to other two Nanog siRNAs, the Nanog siRNA-400 (67.9 %) and -793 (53.0%). When examined by RT-PCR and real-time PCR, the expression of markers for pluripotency such as Fgf4, Oct3/4, Rex1, Sox1 and Yes was downregulated at 48 h after transfection with Nanog siRNA-100. Furthermore, expression of the ectodermal markers, Fgf5 and Isl1 was reduced by Nanog knockdown. By contrast, the expression of other markers for pluripotency such as Cripto, Sox2 and Zfp57 was not affected by Nanog knockdown at this time. On the other hand, the expression of Lif/Stat3 pathway molecules and of the endoderm markers including Dab2, Gata4, Gata6 and the germ cell nuclear factor was not changed by Nanog knockdown. The results of this study demonstrated that the knockdown of Nanog expression by RNA interference in P19 cells was sufficient to modulate the expression of pluripotent markers involved in the self-renewal of EC stem cells. These results provide the valuable information on potential downstream targets of Nanog and add to our understanding of the function of Nanog in P19 EC stem cells.