• Biomolecules & Therapeutics
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• 제28권6호
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• pp.561-568
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• 2020

We examined the anticancer effects of a novel sirtuin inhibitor, MHY2256, on HCT116 human colorectal cancer cells to investigate its underlying molecular mechanisms. MHY2256 significantly suppressed the activity of sirtuin 1 and expression levels of sirtuin 1/2 and stimulated acetylation of forkhead box O1, which is a target protein of sirtuin 1. Treatment with MHY2256 inhibited the growth of the HCT116 (TP53 wild-type), HT-29 (TP53 mutant), and DLD-1 (TP53 mutant) human colorectal cancer cell lines. In addition, MHY2256 induced G0/G1 phase arrest of the cell cycle progression, which was accompanied by the reduction of cyclin D1 and cyclin E and the decrease of cyclin-dependent kinase 2, cyclin-dependent kinase 4, cyclin-dependent kinase 6, phosphorylated retinoblastoma protein, and E2F transcription factor 1. Apoptosis induction was shown by DNA fragmentation and increase in late apoptosis, which were detected using flow cytometric analysis. MHY2256 downregulated expression levels of procaspase-8, -9, and -3 and led to subsequent poly(ADP-ribose) polymerase cleavage. MHY2256-induced apoptosis was involved in the activation of caspase-8, -9, and -3 and was prevented by pretreatment with Z-VAD-FMK, a pan-caspase inhibitor. Furthermore, the autophagic effects of MHY2256 were observed as cytoplasmic vacuolation, green fluorescent protein-light-chain 3 punctate dots, accumulation of acidic vesicular organelles, and upregulated expression level of light-chain 3-II. Taken together, these results suggest that MHY2256 could be a potential novel sirtuin inhibitor for the chemoprevention or treatment of colorectal cancer or both.

• 대한한방내과학회지
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• 제30권4호
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• pp.845-857
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• 2009

Background and Objectives : Korean mistletoe lectin (Viscum album coloratum agglutinin, VCA) and bee venom (BV) have been reported to induce apoptosis in various cancer cell lines in vitro and to show antitumor activity against a variety of tumors in animal models. However, the comparative effect of VCA and BV on the anti-cancer effect and mechanisms of action has not been determined. In this study, the effect in a human hepatocellular carcinoma cell line, Hep G2 cells, was examined. Methods : Cytotoxic effects of VCA and BV on Hep G2 cells were determined by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay in litro. The apoptotic cell death was then confirmed by propidium iodide staining and DNA fragmentation analysis. The mechanisms of action were examined by the expression of anti-apoptotic proteins and activation of mitogen-activated protein kinases. The involvement of kinase was examined in VCA or BV-induced apoptosis by using kinase inhibitors. Results : VCA and BV killed Hep G2 cells in a time and dose-dependent manner. Treatment of Hep G2 cells with VCA activated poly (ADP-ribose) polymerase-1 (PARP-1) known as a marker of apoptosis, and mitogen-activated protein kinases signaling pathways including MAPK/ERK, p38 MAPK and JNK. BV also activated PARP-1, MAPK/ERK. and p38 MAPK but not JNK. The expression level of anti-apoptotic molecule, Bcl-X, was decreased by VCA treatment but not by BV. Finally, the phosphorylation level of ERM proteins involved in the cytoskeleton homeostasis was decreased by both stimuli. VCA-induced apoptosis was partially inhibited by in the presence of JNK and p38 inhibitor, but BV only by p38 inhibitor. Conclusions : VCA-induced apoptosis is dependent on the activation of p38 and JNK. while BV-induced apoptosis is mediated by p38 activation in Hep G2 cells.

• Journal of Microbiology and Biotechnology
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• 제14권5호
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• pp.978-984
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• 2004

In the course of screening for a novel inhibitor of CDC2, HY558-1 was isolated from a culture broth of Penicillium minioluteum F558. Moreover, it was found that HY558-1 had an effect on both the cell cycle regulation and apoptosis of human cervical adenocarcinoma HeLa cells. A flow cytometric analysis of HeLa cells revealed appreciable cell cycle arrest at the G1 and G2/M phases following treatment with HY558-1. Furthermore, DNA fragmentation due to apoptosis was observed in HeLa cells treated with HY558-1. To obtain further information on the cell cycle arrest and apoptotic induction induced by HY558-1, the expression of certain cell cycle and apoptosis-associated proteins was examined using a Western blot analysis. The results revealed that HY558-1 inhibited the phosphorylation of pRb and decreased the expression levels of CDK2, CDC2, and cyclin A in the cell cycle progression. It was also shown that the level of $p21^{WAF1/CIP1}$ was increased in HeLa cells treated with 0.52 mM of HY558-1. Accordingly, HY558-1 was found to inhibit the proliferation of HeLa cells through the induction of G1 phase arrest by inhibiting pRb phosphorylation via an upregulation of $p21^{WAF1/CIP1}$, and G2/M phase arrest by directly inhibiting CDC2 and cyclin A. Moreover, HeLa cells treated with 0.52 mM of HY558-1 exhibited apoptotic induction associated with the cleavage of Bid and release of cytochrome c from mitochondria into the cytosol. Subsequent investigation of the activation of caspase-3 and cleavage of poly (ADP-ribose) polymerase (PARP) suggested that the mitochondrial pathway was primarily involved in the HY558-1-induced apoptosis in HeLa cells.

• Journal of Microbiology and Biotechnology
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• 제27권1호
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• pp.197-205
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• 2017

Exposure of Jurkat T cell clone (J/Neo cells) to acacetin (5,7-dihydroxy-4'-methoxyflavone), which is present in barnyard millet (Echinochloa esculenta (A. Braun)) grains, caused cytotoxicity, enhancement of apoptotic $sub-G_1$ rate, Bak activation, loss of mitochondrial membrane potential (${\Delta}{\Psi}m$), activation of caspase-9 and caspase-3, degradation of poly(ADP-ribose) polymerase, and FITC-Annexin V-stainable phosphatidylserine exposure on the external surface of the cytoplasmic membrane without accompanying necrosis. These apoptotic responses were abrogated in Jurkat T cell clone (J/Bcl-xL) overexpressing Bcl-xL. Under the same conditions, cellular autophagic responses, including suppression of the Akt-mTOR pathway and p62/SQSTM1 down-regulation, were commonly detected in J/Neo and J/Bcl-xL cells; however, formation of acridine orange-stainable acidic vascular organelles, LC3-I/II conversion, and Beclin-1 phosphorylation (Ser-15) were detected only in J/Neo cells. Correspondingly, concomitant treatment with the autophagy inhibitor (3-methyladenine or LY294002) appeared to enhance acacetin-induced apoptotic responses, such as Bak activation, ${\Delta}{\Psi}m$ loss, activation of caspase-9 and caspase-3, and apoptotic $sub-G_1$ accumulation. This indicated that acacetin could induce apoptosis and cytoprotective autophagy in Jurkat T cells simultaneously. Together, these results demonstrate that acacetin induces not only apoptotic cell death via activation of Bak, loss of ${\Delta}{\Psi}m$, and activation of the mitochondrial caspase cascade, but also cytoprotective autophagy resulting from suppression of the Akt-mTOR pathway. Furthermore, pharmacologic inhibition of the autophagy pathway augments the activation of Bak and resultant mitochondrial damage-mediated apoptosis in Jurkat T cells.

• Asian Pacific Journal of Cancer Prevention
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• 제15권6호
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• pp.2591-2596
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• 2014

Purpose: To evaluate the prognostic value of the expression of excision repair cross-complementation group l (ERCC1), MutS protein homolog 2 (MSH2) and poly ADP-ribose polymerase 1 (PARP1) in non-small-cell lung cancer patients receiving platinum-based postoperative adjuvant chemotherapy. Methods: Immunohistochemistry was applied to detect the expression of ERCC1, MSH2 and PARP1 in 111 cases of non-small cell lung cancer paraffin embedded surgical specimens. Through og-rank survival analysis, we evaluated the prognostic value of the ERCC1, MSH2, PARP1 and the related clinicopathological factors. COX regression analysis was used to determine whether ERCC1, MSH2 and PARP1 were independent prognostic factors. Results: In the enrolled 111 non-small cell lung cancer patients, the positive expression rate of ERCC1, MSH2 and RARP1 was 33.3%, 36.9% and 55.9%, respectively. ERCC1 (P<0.001) and PARP1 (P=0.033) were found to be correlated with the survival time while there was no correlation for MSH2 (P=0.298). Patients with both ERCC1 and PARP1 negative cancer had significantly longer survival time than those with ERCC1 (P=0.042) or PARP1 (P=0.027) positive alone. Similalry, the survival time of patients with both ERCC1 and PARP1 positive cancer was shorter than those with ERCC1 (P=0.048) or PARP1 (P=0.01) positive alone. Conclusion: Patients with ERCC1 or PARP1 negative non-small cell lung cancer appear to benefit from platinum-based postoperative adjuvant chemotherapy.

• The Korean Journal of Physiology and Pharmacology
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• 제12권4호
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• pp.185-191
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• 2008

Activation of c-Jun N-terminal kinase (JNK), a member of the mitogen-activated protein kinase family, is an important cellular response that modulates the outcome of the cells which are exposed to the tumor necrosis factor (TNF) or the genotoxic stress including DNA damaging agents. Although it is known that JNK is activated in response to genotoxic stress, neither the pathways to transduce signals to activate JNK nor the primary sensors of the cells that trigger the stress response have been identified. Here, we report that the receptor interacting protein (RIP), a key adaptor protein of TNF signaling, was required to activate JNK in the cells treated with certain DNA damaging agents such as adriamycin (Adr) and 1-${\beta}$-D-arabinofuranosylcytosine (Ara-C) that cause slow and sustained activation, but it was not required when treated with N-methyl-N-nitro-N-nitrosoguanidine (MNNG) and short wavelength UV, which causes quick and transient activation. Our findings revealed that this sustained JNK activation was not mediated by the TNF (tumor necrosis factor) receptor signaling, but it required a functional ATM (ataxia telangiectasia) activity. In addition, JNK inhibitor SP-600125 significantly blocked the Adr-induced cell death, but it did not affect the cell death induced by MNNG. These findings suggest that the sustained activation of JNK mediated by RIP plays an important role in the DNA damage-induced cell death, and that the duration of JNK activation relays a different stress response to determine the cell fate.

• Nutrition Research and Practice
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• 제14권5호
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• pp.438-452
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• 2020

BACKGROUND/OBJECTIVES: Brain senescence causes cognitive impairment and neurodegeneration. It has also been demonstrated that curcumin (Cur) and hesperetin (Hes), both antioxidant polyphenolic compounds, mediate anti-aging and neuroprotective effects. Therefore, the objective of this study was to investigate whether Cur, Hes, and/or their combination exert anti-aging effects in D-galactose (Dg)-induced aged neuronal cells and rats. MATERIALS/METHODS: SH-SY5Y cells differentiated in response to retinoic acid were treated with Cur (1 μM), Hes (1 μM), or a combination of both, followed by 300 mM Dg. Neuronal loss was subsequently evaluated by measuring average neurite length and analyzing expression of β-tubulin III, phosphorylated extracellular signal-regulated kinases, and neurofilament heavy polypeptide. Cellular senescence and related proteins, p16 and p21, were also investigated, including their regulation of antioxidant enzymes. In vivo, brain aging was induced by injecting 250 mg/kg body weight (b.w.) Dg. The effects of supplementing this model with 50 mg/kg b.w. Cur, 50 mg/kg b.w. Hes, or a combination of both for 3 months were subsequently evaluated. Brain aging was examined with a step-through passive avoidance test and apoptosis markers were analyzed in brain cortex tissues. RESULTS: Cur, Hes, and their combination improved neuron length and cellular senescence by decreasing the number of β-gal stained cells, down-regulated expression of p16 and p21, and up-regulated expression of antioxidant enzymes, including superoxide dismutase 1, glutathione peroxidase 1, and catalase. Administration of Cur, Hes, or their combination also tended to ameliorate cognitive impairment and suppress apoptosis in the cerebral cortex by down-regulating Bax and poly (ADP-ribose) polymerase expression and increasing Bcl-2 expression. CONCLUSIONS: Cur and Hes appear to attenuate Dg-induced brain aging via regulation of antioxidant enzymes and apoptosis. These results suggest that Cur and Hes may mediate neuroprotective effects in the aging process, and further study of these antioxidant polyphenolic compounds is warranted.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2018년도 추계학술대회
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• pp.103-103
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• 2018

Oenothera biennis, commonly known as evening primrose, a potential source of natural bioactive substances: flavonoids, steroids, tannins, fatty acids and terpenoids responsible for a diverse range of pharmacological functions. However, whether extract prepared from aerial part of O. biennis (APOB) protects skin against oxidative stress remains unknown. To investigate the protective effects of APOB against oxidative stress-induced cellular damage and elucidated the underlying mechanisms in the HaCaT human skin keratinocytes. Our results revealed that treatment with APOB prior to hydrogen peroxide ($H_2O_2$) exposure significantly increased viability, and the highest DPPH radical-scavenging activities and reducing power of HaCaT cells. APOB also effectively attenuated H2O2-induced comet tail formation and inhibited the $H_2O_2$-induced phosphorylation levels of the histone ${\gamma}H2AX$, as well as the number of apoptotic bodies and Annexin V-positive cells. In addition, APOB exhibited scavenging activity against intracellular reactive oxygen species (ROS) accumulation and restored the mitochondrial membrane potential loss by $H_2O_2$. Moreover, $H_2O_2$ enhanced the cleavage of caspase-3 and degradation of poly (ADP-ribose)-polymerase (PARP), a typical substrate protein of activated caspase-3, as well as DNA fragmentation; however, these events were almost totally reversed by pretreatment with APOB. Furthermore, APOB increased the levels of heme oxygenase-1 (HO-1), which is a potent antioxidant enzyme, associated with the induction of nuclear factor-erythroid 2-related factor 2 (Nrf2). According to our data, APOB is able to protect HaCaT cells from $H_2O_2$-induced DNA damage and cell death through blocking cellular damage related to oxidative stress through a mechanism that would affect ROS elimination and activating the Nri2/HO-1 signaling pathway.

• International Journal of Oral Biology
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• 제45권3호
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• pp.107-114
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• 2020

Acacetin, which is present in damiana (Turnera diffusa) and black locust (Robinia pseudoacacia), has several pharmacologic activities such as antioxidant, anti-inflammatory, and anti-proliferative effects on cancer cells. However, the effect of acacetin on head and neck cancers has not been clearly established. This study aimed to examine the effects of acacetin on cell growth and apoptosis induction in FaDu human pharyngeal carcinoma cells. These were investigated by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay, Live/Dead cell assay, 4',6-diamidino-2-phenylindole dihydrochloride staining, caspase-3 and caspase-7 activation assay, and immunoblotting in FaDu cells. Acacetin induced FaDu cell death in a dose-dependent manner, with an estimated IC₅₀ value of 41.9 µM, without affecting the viability of L-929 mouse fibroblasts as normal cells. Acacetin treatment resulted in nuclear condensation in the FaDu cells. It promoted the proteolytic cleavage of procaspase-3, -7, -8, and -9 with increasing amounts of the cleaved caspase isoforms in FaDu cells. Acacetin-induced apoptosis in FaDu cells was mediated by the expression of Fas and activation of caspase-8, caspase-3, and poly (ADP-ribose) polymerase. Immunoblotting showed downregulation of the anti-apoptotic mitochondrial proteins Bcl-2 and Bcl-xL, but upregulation of the mitochondria-dependent pro-apoptotic proteins Bax and Badin FaDu cells after acacetin treatment. These findings indicate that acacetin inhibits cell proliferation and induces apoptotic cell death in FaDu human pharyngeal carcinoma cells via both the death receptor-mediated extrinsic apoptotic pathway and the mitochondria-mediated intrinsic apoptotic pathway.

• 대한본초학회지
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• 제21권2호
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• pp.37-46
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• 2006

Objectives : The purpose of this study was to investigate the effect of Dangguibohyultang (DB) and its combination (DB-I; Astragali membraneus BUNGE : Angelica gigas NAKAI=5:1, DB-II; Astragali membraneus BUNGE:Angelica gigas NAKAI=1:1, DB-III; Astragali membraneus BUNGE:Angelica gigas NAKAI=1:5,) on apoptosis in human colorectal adenocarcinoma HCT116 cells. Methods : To study the cytotoxic effect of methanol extract of DB-I, DB-II and DB-III on HCT116 cells, the cell viability was determined by XTT reduction method and ttypan blue exclusion assay. To confirm the induction of apoptosis, the cleavage of poly ADP-ribose polymerase (PARP), a substrate for caspase-3 and a typical sign of apoptosis, and the activation of procaspase-3, -8 and -9 were examined by western blot analysis. Furthermore, DB-induced apoptosis was confirmed by DNA fragmentation. The release of cytochrome C from mitochondria to cytosol, the level of Bcl-2 and Bax, and the expressions of Raf/MEK/ERK were examined by western blot analysis. Results : DB-I and DB-II reduced proliferation of HCT116 cells in a dose-dependent manner. DB-I and DB-II decreased procaspase-3, -8, -9 levels in a dose-dependent manner and induced the clevage of PARP. DB-I and DB-II also triggered the mitochondrial apoptotic signaling by increasing the release of cytochrome C from mitochondria to cytosol, decreasing of anti-apoptotic Bcl-2, and increasing of pro-apoptotic Bax. DB-I and DB-II decreased the activation of Ras/Raf/MEK/ERK cascade in a dose-dependent manner. Conclusion : These results suggest that DB-I and DB-II induce apoptosis via mitochondrial pathway in HCT116 cells. Furthermore, Raf/MEK/ERK cascade is involved in DB-induced apoptosis. These results suggest that DB is potentially useful as a chemotherapeutic agent in human liver cancer.