• BMB Reports
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• v.39 no.6
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• pp.649-655
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• 2006

The NSAID activated gene (NAG-1), a member of the TGF-$\beta$ superfamily, is involved in tumor progression and development. The over-expression of NAG-1 in cancer cells results in growth arrest and increase in apoptosis, suggesting that NAG-1 has anti-tumorigenic activity. This conclusion is further supported by results of experiments with transgenic mice that ubiquitously express human NAG-1. These transgenic mice are resistant to the development of intestinal tumors following treatment with azoxymethane or by introduction of a mutant APC gene. In contrast, other data suggest a pro-tumorigenic role for NAG-1, for example, high expression of NAG-1 is frequently observed in tumors. NAG-1 may be like other members of the TGF-$\beta$ superfamily, acting as a tumor suppressor in the early stages, but acting pro-tumorigenic at the later stages of tumor progression. The expression of NAG-1 can be increased by treatment with drugs and chemicals documented to prevent tumor formation and development. Most notable is the increase in NAG-1 expression by the inhibitors of cyclooxygenases that prevent human colorectal cancer development. The regulation of NAG-1 is complex, but these agents act through either p53 or EGR-1 related pathways. In addition, an increase in NAG-1 is observed in inhibition of the AKT/GSK-$3{\beta}$ pathway, suggesting NAG-1 alters cell survival. Thus, NAG-1 expression is regulated by tumor suppressor pathways and appears to modulate tumor progression.

• Journal of Life Science
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• v.28 no.1
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• pp.37-42
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• 2018

Non-steroidal anti-inflammatory drug-activated gene-1 (NAG-1) is a transforming growth factor beta (TGF-${\beta}$) superfamily gene associated with pro-apoptotic and anti-tumorigenic activities. In the present study, we investigated if caffeic acid phenethyl ester (CAPE) derived from propolis could induce the expression of anti-tumorigenic gene NAG-1. Our results indicate that CAPE significantly induced NAG-1 expression in a time- and concentration-dependent manner in HCT116 cells. We also found that CAPE induced NAG-1 expression in a concentration-dependent manner in another human colorectal cancer cell line, LOVO. In addition, CAPE triggered apoptosis, which was detected with Western blot analysis using poly-(ADP-ribose) polymerase antibody. NAG-1 induction by CAPE was not dependent on transcription factor p53, which was confirmed with Western blot analysis using p53 null HCT116 cells. The luciferase assay results indicated that the new cis-elements candidates were located between -474 and -1,086 of the NAG-1 gene promoter. CAPE dramatically induced activating transcription factor 3 (ATF3) expression, but not cAMP response element-binding protein (CREB), which shares the same binding sites with ATF3. The co-transfection experiment with pCG-ATF3 and pCREB showed that only ATF3 was associated with NAG-1 up-regulation by CAPE, whereas CREB had no effect. In conclusion, the results suggest that CAPE could induce the expression of anti-tumorigenic gene NAG-1 mainly through ATF3.

• Journal of Life Science
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• v.29 no.10
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• pp.1080-1085
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• 2019

Nelumbo nucifera, also known as sacred lotus, has mainly been used as a food throughout the Asian countries. In the present study, we prepared the ethanol extracts from leaf (NL), seed (NS), and seedpod (NSP) of Nelumbo nucifera and investigated their anti-proliferative and pro-apoptotic activities in human colorectal cancer HCT116 cells. NL, NS, and NSP decreased cell viabilities in a dose-dependent manner. All extracts increased the expression of non-steroidal anti-inflammatory drug (NSAID)-activated gene (NAG-1) as well as NAG-1 protein. And also, NL induced the expression of pro-apoptotic NAG-1 protein and PARP cleavage in a time-dependent manner. The PARP cleavage induced by NL treatment, was recovered in part by the transfection of NAG-1 siRNA. We also evaluated the effects of neferine, one of bioactive components of Nelumbo nucifera, on the proliferation and apoptosis in HCT116 cells. It also decreased cell viability in a dose-dependent manner, and induced the expression of pro-apoptotic NAG-1 protein and PARP cleavage in a dose- and time-dependent manner. In addition, PARP cleavage was recovered in part by the transfection of NAG-1 siRNA, indicating that NAG-1 may be one of the genes responsible for apoptosis induced by neferine. Overall, our findings may contribute to understand the molecular mechanisms of anti-proliferative and pro-apoptotic effects mediated by Nelumbo nucifera and neferine.

• Journal of Life Science
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• v.22 no.3
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• pp.360-365
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• 2012

We investigated the anti-proliferative activity of sulforaphane and expression changes of NAG-1 and p21 genes in response to sulforaphane treatment in human colorectal HCT116 cells. The results showed that sulforaphane decreased cell viabilities in a dose-dependent manner and induced expression of NAG-1 and p21 proteins in a dose-dependent and time-dependent manner. In addition, we found that NAG-1 expression by sulforaphane was not dependent on the presence of p53, whereas p21 expression was dependent on p53 presence. The results indicated that up-regulation of NAG-1 was not related with the activity of a dietary histone deacetylase inhibitor of sulforaphane. ATF3 induction was detected from 2 hr after sulforaphane treatment, indicating that ATF3 could be a transcription factor to up-regulate NAG-1 expression. The results of this study may help to increase our understanding of the molecular mechanism of anti-cancer activity mediated by sulforaphane in human colorectal cancer cells.

• Journal of Life Science
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• v.19 no.12
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• pp.1787-1793
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• 2009

To investigate whether caffeic acid phenethyl ester (CAPE) could affect cancer cell viabilities and gene expression, human colorectal HCT116 cells were incubated with CAPE. CAPE decreased cancer cell viabilities and induced apoptosis in a dose-dependent manner. To analyse differently expressed genes by CAPE, we performed oligo DNA microarray analysis. We found that 266 genes were up-regulated more than twofold, whereas 143 genes were down-regulated more than twofold by 24 hr of treatment with $20{\mu}M$ CAPE. Among the up-regulated genes, we selected 3 genes (NSAID activated gene-1 [NAG-1], cyclin-dependent kinase inhibitor 1A [CDKN1A, p21] and growth arrest and DNA-damage-inducible alpha [GADD45A]) and performed reverse-transcription PCR to confirm microarray data. In addition, we found that CAPE increased NAG-1 gene and NAG-1 protein expression in a dose-dependent manner. And, several other phytochemicals (resveratrol, genistein, daidzein and capsaicin) also could induce NAG-1 expression in human colorectal HCT116 cells. However, CAPE was the highest inducer of NAG-1, even in low concentrations. Overall, these results imply that cancer cell death by CAPE is closely related with over-expression of NAG-1.

• Journal of Life Science
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• v.28 no.4
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• pp.415-420
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• 2018

Schisandra chinensis (Turcz.) Baill. (omija) is often used in Chinese medicine to treat various human diseases, and is known to possess various bioactive components such as schizandrin and gomisin A. In the present study, we prepared ethanol extracts of pomace of Schisandra chinensis (PSC) and investigated their effects on cell viability and expression changes of pro-apoptotic genes such as ATF3, NAG-1 and p21 in human colorectal cancer HCT116 cells. PSC significantly reduced cell viability in a dose-dependent manner, and also dramatically induced the expression of ATF3, NAG-1 and p21 genes, with resveratrol used as a positive control. We also assessed the effects of pure compound schizandrin (SZ) derived from Schisandra chinensis on cell viability and expression of pro-apoptotic genes such as ATF3, NAG-1 and p21. The results showed that SZ also decreased cell viabilities in a dose-dependent manner and increased the expression of ATF3, NAG-1 and p21 genes. In addition, apoptosis was detected in SZ-treated HCT116 cells, which was confirmed with PARP cleavage. PARP cleavage was recovered in part by the transfection of NAG-1 siRNA. The results indicate that NAG-1 is one of the genes responsible for apoptosis induced by SZ. Overall, our findings may contribute to understanding the molecular mechanisms of anti-proliferative and pro-apoptotic activities mediated by PSC and SZ.

• Journal of Life Science
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• v.28 no.5
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• pp.615-620
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• 2018

Epigallocatechin-3-gallate (EGCG), one of catechins of green tea, has been known to possess anti-oxidation, anti-inflammation, and anti-cancer effects. The present study analyzed global gene expression changes in EGCG-treated HCT116 cells and p53-null HCT116 cells by oligo DNA microarray analysis. Among the differentially expressed genes in EGCG-treated HCT116 cells, four were selected that are known as tumor suppressor genes (activating transcription factor 3 [ATF3], cyclin dependent kinase inhibitor 1A [CDKN1A], DNA damage-inducible transcript 3 [DDIT3] and non-steroidal anti-inflammatory drug activated gene [NAG-1]) and their expression was compared to the expression of genes in p53-null HCT116 cells. We found that the expression of these genes was not dependent on their p53 status except for NAG-1, which was only up-regulated in HCT116. The results of RT-PCR and Western blot analysis showed that ATF3 up-regulation by EGCG was not affected by the presence of p53, whereas NAG-1 expression was not induced in p53-null HCT116 cells. We also detected ATF3 and NAG-1 expression changes through genistein and resveratrol treatment. Interestingly, genistein could not up-regulate ATF3 regardless of p53 status, but genistein could induce NAG-1 only in HCT116 cells. Resveratrol could significantly induce NAG-1 as well as ATF3 independent of p53 presence. These results indicate that EGCG, genistein and resveratrol may have different anti-cancer effects. Overall, the results of this study may help to increase our understandings of molecular mechanisms on anti-cancer activities mediated by EGCG, genistein and resveratrol in human colorectal cancer cells.

• Journal of Life Science
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• v.26 no.2
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• pp.241-246
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• 2016

In the present study, ethanol extracts and their subsequent organic solvent fractions were extracted from the lees of Ehwa Makgeolli containing oriental herbs, a commercialized traditional Korean rice wine, and the prepared lees samples were designated as from KSD-E3-1 to KSD-E3-5. First, their effects on cell viability and on the expression of pro-apoptotic ATF3 and NAG-1 genes in human colorectal HCT116 cells were investigated. Among the treated lees samples, the hexane fraction (KSD-E3-2) and the ethyl acetate fraction (KSD-E3-3) of lees extracts from Ehwa Makgeolli significantly reduced cell viabilities, in a dose dependent manner. The treatment with KSD-E3-2 and KSD-E3-3 also increased the expression of pro-apoptotic NAG-1 and ATF-3 genes and their proteins, which were detected with RT-PCR and Western blot analysis, respectively. In addition, poly-(ADP-ribose) polymerase (PARP) cleavage was detected by treatment with the fraction KSD-E3-3, indicating that KSD-E3-3 could induce apoptosis in HCT116 cells. Interestingly, this PARP cleavage was recovered by transfection of NAG-1 small interfering RNA. The results indicate that NAG-1 is one of the genes responsible for apoptosis induced by the fraction KSD-E3-3 from Ehwa Makgeolli. Overall, the findings may help in understanding the molecular mechanisms of the anti-proliferative and pro-apoptotic activities mediated by the lees of Ehwa Makgeolli.

• Journal of Preventive Medicine and Public Health
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• v.26 no.1 s.41
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• pp.49-64
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• 1993

To provide the basic data for assessment of renal dysfunction related to silicosis, urinary N-acetyl-$\beta$-D-giucobarninidase(NAG) activity known as a sensitive markers for early renal damage were measured in 58 silicosis patients, and control subjects of 40 pulmonary tuberculosis Patients and 51 official workers. The results were summarized as fellows. 1. The values of blood urea nitrogen and serum creatinine in all subjects were within reference limits. But the mean value of urinary NAG activity($7.25{\pm}7.31U/g\;creatinine$) was beyond reference value and more sensitive test than others. 2. The mean value of urinary NAG activity in silicosis group was $11.98{\pm}9.05U/g\;creatinine$ and significantly higher than in tuberculosis and healthy group(p<0.01), but the mean values of NAG activity in tuberculosis and healthy group were not different(p>0.05). 3. The value of NAG activity in tuberculosis had a tendency to be increased according to severity of disease, but that was not significant(p>0.05). The value of NAG activity was increased significantly by use of nephrotoxic antituberculosis drugs(p<0.05). 4. The value of NAG activity in silicosis had a tendecy to be increased according to the size of nodule, use of nephrotoxic antituberculosis drugs and shortness of onset duration, but the increase was not significant(p>0.05). 5. After excluding the users of nephrotoxic antituberculosis drugs, the mean values of NAG activity in healthy control and in tuberculosis control were same as 3.63 U/g creatinine and 3.60 U/g creatinine, respectively. But the mean value of NAG activity in silicosis group was remarkably increased as 10.90 U/g creatinine(p<0.01). As above results, even though there are no abnormal finding in screening renal function test, silicosis can be related with renal dysfunction. And it will be very useful to apply urinary NAG activity in health management of workers exposed to dust.

• The Journal of Advanced Prosthodontics
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• v.10 no.3
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• pp.177-183
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• 2018

PURPOSE. The purpose of the current study was to evaluate the effect of incorporating nanoparticles of silver (NAg) and amorphous calcium phosphate (NACP) into a self-etching primer of a resin cement on the microtensile bond strength of dentin, regarding the proven antibacterial feature of NAg and remineralizing effect of NACP. MATERIALS AND METHODS. Flat, mid-coronal dentin from 20 intact extracted human third molars were prepared for cementation using Panavia F2.0 cement. The teeth were randomly divided into the four test groups (n=5) according to the experimental cement primer composition: cement primer without change (control group), primer with 1% (wt) of NACP, primer with 1% (wt) of physical mixture of NACP+Nag, and primer with 1% (wt) of chemical mixture of NACP+Nag. The resin cement was used according to the manufacturer's instructions. After storage in distilled water at $37^{\circ}C$ for 24 h, the bonded samples were sectioned longitudinally to produce $1.0{\times}1.0mm$ beams for micro-tensile bond strength testing in a universal testing machine. Failure modes at the dentin-resin interface were observed using a stereomicroscope. The data were analyzed by one-way ANOVA and Tukey's post-hoc tests and the level of significance was set at 0.05. RESULTS. The lowest mean microtensile bond strength was obtained for the NACP group. Tukey's test showed that the bond strength of the control group was significantly higher than those of the other experimental groups, except for group 4 (chemical mixture of NACP and NAg; P=.67). CONCLUSION. Novel chemical incorporation of NAg-NACP into the self-etching primer of resin cement does not compromise the dentin bond strength.