• Animal cells and systems
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• v.11 no.2
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• pp.129-134
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• 2007

The initiation of eukaryotic DNA replication requires assembly of the pre-replicative complex (Pre-RC) through the concerted action of Orc, Cdc6, Cdt1 and Mcm2-7 complex during G1 phase. The pre-RC assembly licenses individual replication origins for the initiation of DNA replication and sufficient number of the pre-RC is essential for proper progression of S phase. However, it is not well known how cells recognize the completion of the pre-RC assembly before G1-S transition. In order to understand the cellular responses to the defects in pre-RC assembly, we depleted the known components of pre-RC proteins using the small interference RNAs in HeLa cells. Although the defects of pre-RC assembly by the depletion of the pre-RC proteins such as Orc2, Cdt1, Mcm2 & Mcm10 did not elicit the activation of Chk1- or Chk2-dependent checkpoint pathways, these cells still showed significant decrease in the cellular level of Cdc25A proteins. These results suggests that a novel checkpoint pathway exist in HeLa cells, which is not dependent upon Chk1 or Chk2 proteins and play essential roles in the cellular responses to the defects in the pre-RC assembly. Also, among those four proteins tested in this study, the depletion of Mcm10 and Cdt1 proteins significantly increased the apoptotic cell death in HeLa cells, suggesting that these proteins not only play roles in the pre-RC assembly, but also are involved in the checkpoint responses to the defects in the pre-RC assembly.

• Journal of the East Asian Society of Dietary Life
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• v.23 no.6
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• pp.723-732
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• 2013

We investigated the inducing effects of Rubus coreanus extract (RCE) on apoptosis and its related gene expressions in human breast cancer cells. MDA-MB-231 cells were cultured in the presence of 0, 200, 300, and $400{\mu}g/mL$ RCE for 24h. MTT assay demonstrated that relative cell viability measured a decrease in a dose-dependent manner (p<0.05). This dependency was also found in the increasing levels of cell death by a dual staining with Hoechst 33322 and propidium iodide (p<0.05). These close associations was also observed by different stages of apoptotic processes, as shown by an Apoptosis Detection Kit. To determine whether the alterations in such cell activities obtained above cause the induction of apoptotic genes, PT-PCR was performed expressions of both Bcl-2 and Bax mRNAs. The Bcl-2/Bax ratio which is an important indicator of apoptosis, was found to have significantly decreased dose dependence (p<0.05). Western blot analysis also demonstrated that Caspase-3 significantly increases in a dose-dependent manner (p<0.05) in addition to similar alterations of other proteins examined. Taken these results together, the ethanolic RCE used induces a reduction in cell viability along with increased membrane permeability. This leads to a precautious apoptotic process and, subsequently, cell death through the apoptotic pathway involving Bax and Caspase-3 in human breast cancer MDA-MB-231 cells.

• BMB Reports
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• v.35 no.1
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• pp.116-126
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• 2002

Nitric oxide (NO), synthesized from L-arginine by NO synthases, is a small, lipophilic, diffusible, highly reactive molecule with dichotomous regulatory roles in many biological events under physiological and pathological conditions. NO can promote apoptosis (pro-apoptosis) in some cells, whereas it inhibits apoptosis (anti-apoptosis) in other cells. This complexity is a consequence of the rate of NO production and the interaction with biological molecules such as metal ion, thiol, protein tyrosine, and reactive oxygen species. Long-lasting overproduction of NO acts as a pro-apoptotic modulator, activating caspase family proteases through the release of mitochondrial cytochrome c into cytosol, up-regulation of the p53 expression, and alterations in the expression of apoptosis-associated proteins, including the Bcl-2 family. However, low or physiological concentrations of NO prevent cells from apoptosis that is induced by the trophic factor withdrawal, Fas, $TNF{\alpha}$/ActD, and LPS. The anti-apoptotic mechanism is understood on the basis of gene transcription of protective proteins. These include: heat shock protein, hemeoxygenase, or cyclooxygenase-2 and direct inhibition of the apoptotic executive effectors caspase family protease by S-nitrosylation of the cysteine thiol group in their catalytic site in a cell specific way. Our current understanding of the mechanisms by which NO exerts both pro- and anti-apototic action is discussed in this review article.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.4
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• pp.1671-1674
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• 2015

Cancer genomics and proteomics have undergone considerable broadening in the past decades and increasingly it is being realized that solid/liquid phase microarrays and high-throughput resequencing have provided platforms to improve our existing knowledge of determinants of cancer development, progression and survival. Loss of apoptosis is a widely and deeply studied process and different approaches are being used to restore apoptosis in resistant cancer phenotype. Modulating the balance between pro-apoptotic and anti-apoptotic proteins is essential to induce apoptosis. It is becoming more understood that pharmacological inhibition of the proteasome might prove to be an effective option in improving TRAIL induced apoptosis in cancer cells. Keeping in view rapidly accumulating evidence of carcinogenesis, metastasis, resistance against wide ranging therapeutics and loss of apoptosis, better knowledge regarding tumor suppressors, oncogenes, pro-apoptotic and anti-apotptic proteins will be helpful in translating the findings from benchtop to bedside.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.5
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• pp.2095-2100
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• 2012

Sulforaphane (SFN) an isothiocyanate formed by hydrolysis of glucosinolates found in Brassica oleraceae is reported to possess anticancer and antioxidant activities. In this study, we isolated SFN from red cabbage (Brassica oleraceae var rubra) and evaluated the comparative antiproliferative activity of various fractions (standard SFN, extract and purified SFN) by MTT assay in human epithelial carcinoma HEp -2 and and Vero cells. Probable apoptotic mechanisms mediated through p53, bax and bcl-2 were also examined. The SFN fraction was collected by HPLC, enriched for its SFN content and confirmed. Expression of apoptosis-related proteins was detected by western blotting and RT PCR. Results showed that Std SFN and purified SFN concentration found to have closer $IC_{50}$ which is equal to 58.96 microgram/ml (HEp-2 cells), 61.2 microgram/ml (Vero cells) and less than the extract which is found to be 113 microgram/ml (HEp-2 cells) and 125 microgram/ml (Vero cells). Further studies on apoptotic mechanisms showed that purified SFN down-regulated the expression of bcl-2 (antiapoptotic), while up-regulating p53 and Bax (proapoptotic) proteins, as well as caspase-3. This study indicates that purified SFN possesses antiproliferative effects the same as Std SFN and its apoptotic mechanism in HEp-2 cells could be mediated through p53 induction, bax and bcl-2 signaling pathways.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.6
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• pp.1423-1430
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• 2009

Rosmarinic acid frequently found as a secondary metabolite in herbs and medicinal plants, has exhibited antimicrobial, antiviral, antioxidative, and anti-inflammatory activities. The proliferation and migration of human aortic smooth muscle cells (HASMC) in response to activation by various stimuli plays a critical role in the initiation and development of atherosclerosis. This study was conducted to examine the effects of Rosmarinic acid on the proliferation and migration of HASMC. Rosmarinic acid suppressed the proliferation of HASMC via induction of the expression of apoptotic proteins including cleaved poly ADP-ribose polymerase (PARP), and caspase-3. Rosmarinic acid decreased anti-apoptotic Bcl-2 and increased pro-apoptotic Bax. Moreover, treatment of rosmarinic acid decreased the G1/S cycle regulation proteins (cyclin D1, cyclin E, CDK2, CDK4 and CDK6) and increased p21, p27 and p53. Rosmarinic acid also blocked HASMC migration via suppression of MMP-9 and MMP-2. Taken together, these results indicate that rosmarinic acid has the potential for use as an anti-atherosclerosis agent.

• The Journal of Korean Medicine
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• v.39 no.4
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• pp.158-170
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• 2018

Objectives: The objective of this study is Korean mistletoe lectin (Viscum album coloratum agglutinin, VCA) and bee venom (BV) to experimental prove comparative study of VCA and BV on the anti-cancer effect and mechanisms of action. Methods: In this study, it was examined in a human hepatocellular carcinoma cell line, Hep G2 cells. 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 vitro. VCA and BV killed Hep G2 cells in a time- and dose-dependent manner. Results: The apoptotic cell death was then confirmed by propidium iodide staining and DNA fragmentation analysis. The mechanisms of action was examined by the expression of anti-apoptotic proteins and activation of mitogen-activated protein kinases. 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 SAPK/JNK, MAPK and p38. BV also activated PARP-1, MAPK, p38 but not JNK. The expression level of anti-apoptotic molecule, Bcl-X, was decreased by VCA treatment but not BV. Finally, the phosphorylation level of ERM proteins involved in the cytoskeleton homeostasis was decreased by both stimuli. Conclusion: We examined the involvement of kinase in VCA or BV - induced apoptosis by using kinase inhibitors. VCA-induced apoptosis was partially inhibited by in the presence.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2004.06a
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• pp.297-301
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• 2004

The purpose of the present study was to investigate the anti-proliferative and apoptotic effects of MCS-C2, a novel analogue of toyocamycin and sangivamycin, in human promyelocytic leukemia (HL-60) cells. When treated with MCS-C2, inhibited proliferation associated with cell cycle arrest and apoptotic induction was found in the HL-60 cells in a concentration-dependent and time-dependent manner. This apoptotic induction was associated with the cleavage of Bid and a release of cytochrome c from mitochondria into the cytosol, followed by the activation of caspase-3 and inactivation of poly (ADP-ribose) polymerase (PARP). However, there was no significant change in any other mitochondrial membrane proteins, such as Bcl-2 and Bax. Consequently, the current findings suggest that the mitochondrial pathway was primarily involved in the MCS-C2-induced apoptosis in the human promyelocytic leukemia HL-60 cells.

• International Journal of Oral Biology
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• v.31 no.3
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• pp.81-86
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• 2006

SET (Suppressor of variegation, Enhancer of zeste, and the Trithorax) domain-containing proteins are known to have methyltransferase activity at lysine residues of histone proteins. In this study, we identified a novel SET domain-containing protein from mouse and named Kodo7. Indeed, Kodo7 has methyltransferase activity at K9 residue of the H3 protein as demonstrated by a histone methyl-transferse activity assay using GST-tagged Kodo7. Confocal microscopy showed that Kodo7 is co-localized with histones in the nucleus. Interestingly, ectopic expression of Kodo7 by transient transfection induced cell death and treatment of the transfectants with a caspase-3 inhibitor, Ac-DEVD-AFC decreased Kodo7-induced apoptosis. These results suggest that Kodo7 induces apoptotic cell death through increased methylation of histones leading to transcriptional repression.

• Biomolecules & Therapeutics
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• v.27 no.1
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• pp.41-47
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• 2019

The apoptotic effects of shikonin (5,8-dihydroxy-2-[(1R)-1-hydroxy-4-methylpent-3-enyl]naphthalene-1,4-dione) on the human colon cancer cell line SNU-407 were investigated in this study. Shikonin showed dose-dependent cytotoxic activity against SNU-407 cells, with an estimated $IC_{50}$ value of $3{\mu}M$ after 48 h of treatment. Shikonin induced apoptosis, as evidenced by apoptotic body formation, sub-G_1$ phase cells, and DNA fragmentation. Shikonin induced apoptotic cell death by activating mitogen-activated protein kinase family members, and the apoptotic process was mediated by the activation of endoplasmic reticulum (ER) stress, leading to activation of the $PERK/elF2{\alpha}/CHOP$ apoptotic pathway, and mitochondrial $Ca^{2+}$ accumulation. Shikonin increased mitochondrial membrane depolarization and altered the levels of apoptosis-related proteins, with a decrease in B cell lymphoma (Bcl)-2 and an increase in Bcl-2-associated X protein, and subsequently, increased expression of cleaved forms of caspase-9 and -3. Taken together, we suggest that these mechanisms, including MAPK signaling and the ER- and mitochondria-mediated pathways, may underlie shikonin-induced apoptosis related to its anticancer effect.