• Journal of Life Science
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• v.32 no.3
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• pp.210-221
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• 2022

This study investigated the mechanisms underlying the anti-cancer effects of non-steroidal anti-inflammatory drugs (NSAIDs) in human cancer cells in combination with either N-[N-(3, 5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (DAPT), a γ-secretase inhibitor, or MHY2245, a new synthetic sirtuin 1 inhibitor. The results showed both DAPT and MHY2245 as novel chemosensitizers of human colon cancer KM12 and human hepatocellular carcinoma SNU475 cells to NSAIDs involving celecoxib and 2, 5-dimethyl celecoxib. The NSAID-induced cytotoxicity of these cells was significantly increased by DAPT and MHY2245 in a cyclooxygenase-2 independent manner. In addition, DAPT and MHY2245 reduced levels of p62, Notch1 intracellular domain, and multiple cancer stemness (CS)-related markers including Notch1, CD44, CD133, octamer-binding transcription factor 4, mutated p53 and c-Myc. However, the level of activating transcription factor 4 (ATF4) was enhanced, probably indicating the down-regulation of multiple CS-related markers by DAPT or MHY2245-mediated autophagy induction. Moreover, the NSAID-mediated reduction of p62/nuclear factor erythroid-derived 2-like 2 and CS-related marker proteins and the up-regulation of C/EBP homologous protein (CHOP)/ATF4 were accelerated by DAPT and MHY2245. As such, the combination of NSAID and either DAPT or MHY2245 resulted in higher cytotoxicity than NSAID alone by accelerating the down-regulation of multiple CS-related markers and PARP activation, indicating that both inhibitors promote NSAID-mediated autophagic cell death, possibly through the CHOP/ATF4 pathway. In conclusion, either combination strategy may be useful for the effective treatment of human cancer cells expressing CS-related markers.

• Molecules and Cells
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• v.21 no.3
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• pp.395-400
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• 2006

Glutathione S-transferase P1 (GSTP1) plays an important role in detoxification and the metabolism of xenobiotics. Here we show that GSTP1 also regulates the MEKK1-MKK7 signaling pathway. Over-expression of GSTP1 in HEK293 cells inhibited both ${\Delta}MEKK1$- and etoposide-induced apoptosis, and inhibited procaspase-3 activation and PARP cleavage. MEKK1- induced apoptosis requires both its kinase activity and proteolytic cleavage. ${\Delta}MEKK1$ activity was inhibited by over-expression of GSTP1 in vivo and MEKK1 kinase activity was also inhibited by GSTP1 in vitro when assayed with bacterially-expressed MKK7(KM) protein as substrate. GSTP1 inhibition of etoposide-induced cell apoptosis was mainly due to its ability to suppress MEKK1 kinase activity. The glutathione-conjugating activity of GSTP1 was essential for the above effects. These findings provide insight into the mechanism by which GSTP1 protects cells from genotoxin-induced apoptosis.

• BMB Reports
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• v.44 no.6
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• pp.381-386
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• 2011

In the present study, we characterized the function of HS1-binding protein 3 (HS1BP3), which is mutated in essential tremor and may be involved in lymphocyte activation. We found that HS1BP3 localized to the mitochondria and endoplasmic reticulum partially. Overexpression of HS1BP3 induced apoptosis in HEK293T and HeLa cell lines. When these cell lines were transfected with HS1BP3, they exhibited nuclear DNA condensation, externalization of phosphatidylserine (PS), and cleavage of poly ADP ribose polymerase (PARP). Furthermore, suppression of HS1BP3 or HS1 expression attenuates HS1BP3 induced apoptosis. In addition, HS1BP3 enhanced activator protein 1 (AP-1)-mediated transcription in a dose-dependent manner. Therefore, we conclude that HS1BP3 regulates apoptosis via HS1 and stimulates AP-1-mediated transcription.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.1
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• pp.158-164
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• 2007

Uterine leiomyoma is the most common tumor in the female genital tract. Although the tumor is benign, it is a matter of paramount importance since it often causes profuse menstrual bleeding, pressure symptoms and infertility. Nevertheless, the etiology and pathophysiology of this abnormality remain poorly understood. The traditional definitive treatment for uterine leiomyomas is hysterectomy and, even today, symptomatic leiomyomas are the leading cause of hysterectomy in Korea. Clearly, the development of a safe, effective, and nonsurgical method of treatment for leiomyoma would be of great benefit to many women. This study demonstrated growth inhibition of uterine leiomyoma cells using Haeohyultang (HT). When human leiomyoma cells were treated with Haeohyultang, cells showed dose-dependent growth inhibitory effect. Cell growth was inhibited by over 40% as determined by both cell counts and MTS assay. Reduction of cellular viability as a consequence of exposure to Haeohyultang resulted from induction of apoptosis, as assessed by DNA fragmentation, PARP cleavage, caspase 9 and caspase 3 assay. Flow cytometry analysis with uterine leiomyoma cells demonstrated sub G1 cell cycle arrest after treatment with drug Haeohyultang. But, the expression levels of p27 and p21 were not changed in Haeohyultang treated cells compared with control. However, the expression levels of clAP1 were reduced by Haeohyultang compared with control. This reduction of clAP1 data means activation of the caspase family, and then induction of PARP cleavage and apoptosis. These results suggest that Haeohyultang may be potential therapeutic approach in the clinical management of uterine leiomyoma.

• Journal of Life Science
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• v.28 no.1
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• pp.50-57
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• 2018

Millettia erythrocalyx, a species of plant in the Fabaceae family, is widely distributed in the tropical and subtropical regions of the world, such as the Indies, China, and Thailand. The antiviral activity of flavonoids from M. erythrocalyx has been reported; however, the antioxidative and anticancer activities of M. erythrocalyx remain unclear. In this study, we evaluated the antioxidative and anticancer effects of ethanol extract of M. erythrocalyx (EEME) and the molecular mechanism of its anticancer activity in human hepatocellular carcinoma HepG2 cells. EEME exhibited significant antioxidative effects, with a concentration at 50% inhibition ($IC_{50}$) value of $2.74{\mu}g/ml$, as measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay; moreover, it inhibited cell proliferation in a dose-dependent manner in HepG2 cells. Cell cycle analyses showed that EEME induced HepG2 cell accumulation in the subG1 phase in a dose-dependent manner. EEME also induced apoptosis of HepG2 cells, with increases in apoptotic cells and apoptotic bodies, as detected by Annexin V and 4,6-diamidino-2-phenylindole (DAPI) staining, respectively. Treatment with EEME resulted in increased expression of First apoptosis signal (Fas), a death receptor, and Bcl-2-associated X protein (Bax), a proapoptotic protein, and the activation of caspase-3, 8, and 9, resulting in the cleavage of poly (Adenosine diphosphate-ribose) polymerase (PARP). Collectively, these results suggest that EEME may exert an anticancer effect in HepG2 cells by inducing apoptosis via both the intrinsic and extrinsic pathways.

• Journal of Life Science
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• v.24 no.12
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• pp.1356-1363
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• 2014

Ghrelin is a 28 amino acid orexigenic peptide hormone that is secreted predominantly by tX/A cells in the stomach, and it plays a major role in energy homeostasis. Activated ghrelin has an n-octanoyl group covalently linked to the hydroxyl group of the Ser3 residue, which is critical for its binding to the G-protein coupled growth hormone secretagogue receptor-1a (GHS-R1a). According to recent reports, both ghrelin and its receptor, GHS-R1a, are expressed by a variety of immune cells, including T- and B-lymphocytes, monocytes, and dendritic cells, and ghrelin stimulation of leukocytes provides a potent immunomodulatory signal controlling systemic and age-associated inflammation and thymic involution. Here, we report that ghrelin protected murine thymocytes from dexamethasone (DEX)-induced cell death both in vivo and in vitro. Subsequently, we explored the molecular mechanisms of the antiapoptotic effect of ghrelin. According to our experiments, ghrelin inhibited the expression of proapoptotic proteins via the regulation of glucocorticoid receptor (GR) phosphorylation. As a result, ghrelin inhibited the proapoptotic activation of proteins, such as Caspase-3, PARP, and Bim. These data suggest that ghrelin, through GHS-R, inhibits the pathway to apoptosis by regulation of the proapoptotic protein activation signal pathway. They provide evidence that blocking apoptosis is an essential function of ghrelin during the development of thymocytes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.6
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• pp.657-662
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• 2009

Antioxidant and anticancer activities of water and ethanol extracts of defatted soybean grits (DSG) fermented Bacillus subtilis NUC1 were determined and compared with those of the raw DSG. The fermented defatted soybean grits (FDSG) exhibited higher total polyphenols and flavonoids contents than DSG. The ethanol extracts of FDSG (FD-E) showed the highest polyphenol and flavonoid contents with 23.35 mg/g and 3.48 mg/g, respectively. Particularly, FD-E showed higher DPPH radical scavenging activities with $RC_{50}$ of 0.32 mg/mL than other samples with $RC_{50}$ of 1.10${\sim}$3.89 mg/mL. The water and ethanol extracts of FDSG and DSG showed growth inhibitory effects against AGS, A549 and Hela cancer cells in a dose-dependent manner, and especially FD-E showed the highest growth inhibition effects. FD-E induced apoptosis in Hela cells through an increased activation of caspase-3 and caspase-3 target protein, PARP, but rarely affected caspase-7.

• Journal of Nutrition and Health
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• v.50 no.5
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• pp.415-425
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• 2017

Purpose: Many studies have suggested that neuronal cells protect against oxidative stress-induced apoptotic cell death by polyphenolic compounds. We investigated the neuroprotective effects and the mechanism of action of Momordica charantia ethanol extract (MCE) against $H_2O_2-induced$ cell death of human neuroblastoma SK-N-MC cells. Methods: The antioxidant activity of MCE was measured by the quantity of total phenolic acid compounds (TPC), quantity of total flavonoid compounds (TFC), and 2,2-Diphenyl-1-pycrylhydrazyl (DPPH) radical scavenging activity. Cytotoxicity and cell viability were determined by CCK-8 assay. The formation of reactive oxygen species (ROS) was measured using 2,7-dichlorofluorescein diacetate (DCF-DA) assay. Antioxidant enzyme (SOD-1,2 and GPx-1) expression was determined by real-time PCR. Mitogen-activated protein kinases (MAPK) pathway and apoptosis signal expression was measured by Western blotting. Results: The TPC and TFC quantities of MCE were 28.51 mg gallic acid equivalents/extract g and 3.95 mg catechin equivalents/extract g, respectively. The $IC_{50}$ value for DPPH radical scavenging activity was $506.95{\mu}g/ml$ for MCE. Pre-treatment with MCE showed protective effects against $H_2O_2-induced$ cell death and inhibited ROS generation by oxidative stress. SOD-1,2 and GPx-1 mRNA expression was recovered by pre-treatment with MCE compared with the presence of $H_2O_2$. Pre-treatment with MCE inhibited phosphorylation of p38 and the JNK pathway and down-regulated cleaved caspase-3 and cleaved PARP by $H_2O_2$. Conclusion: The neuroprotective effects of MCE in terms of recovery of antioxidant enzyme gene expression, down-regulation of MAPK pathways, and inhibition apoptosis is associated with reduced oxidative stress in SK-N-MC cells.

• BMB Reports
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• v.44 no.1
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• pp.46-51
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• 2011

Osteosarcoma is a primary bone cancer which occurs mainly in children. Neuroguidin/CANu1 is a nucleolar protein involved in the maintenance of ribosomal structure. In this study, we investigated the effect of Neuroguidin/CANu1 depletion on the response of osteosarcoma cells to doxorubicin. In normal circumstances, Neuroguidin/CANu1 is localized at nucleoli, which translocates to nuclear foci in the presence of doxorubicin. shRNA knockdown of Neuroguidin/CANu1 did not affect cell viability in the absence of doxorubicin, but led to enhanced cytotoxicity in doxorubicin-treated cells. Doxorubicin increased the population of apoptotic cells by 3-fold in Neuroguidin/CANu1-depleted cells compared to that in control cells. Depletion of Neuroguidin/CANu1 mRNA induced the expression of p21 and the cleavage of PARP, leading to increased caspase-3/7 activity. Together, these results suggest that Neuroguidin/CANu1 is required for maintaining cellular homeostasis and may contribute to the improved efficiency of chemotherapy.

• Journal of Microbiology and Biotechnology
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• v.25 no.3
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• pp.418-422
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• 2015

In the course of screening for novel cell cycle inhibitors and apoptotic inducers, CR389, elucidated as 5-(1H-benzoimidazol-2-yl)-1H-pyridin-2-one, was generated as a new hit compound. Flow cytometric analysis and western blots of PA-1 cells treated with $60{\mu}M$ CR389 revealed an appreciable cell cycle arrest at the G2/M phase through direct inhibition of the CDK1 complex. In addition, activation of p53 via phosphorylation at Ser15 and subsequent up-regulation of p21^CIP1 showed that CR389 also induces p53-dependent-p21^CIP1-mediated cell cycle arrest. Furthermore, apoptotic induction in $60{\mu}M$ CR389-treated PA-1 cells is associated with the release of cytochrome c from mitochondria through up-regulation of the proapoptotic Bax protein, which results in the activation of procaspase-9 and -3, and the cleavage of poly(ADP-ribose) polymerase (PARP). Accordingly, CR389 seems to have multiple mechanisms of antiproliferative activity through p53-mediated pathways against human ovarian cancer cells. Therefore, we conclude that CR389 is a candidate therapeutic agent for the treatment of human ovarian cancer via the activation of p53.