• Journal of Life Science
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• v.26 no.2
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• pp.212-219
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• 2016

Glioblastoma multiforme is the most common and most aggressive type of primary brain tumor in humans. Despite intensive treatment, including surgery, radiation, and chemotherapy, most patients die of the disease. Although the anti-cancer activity of resveratrol has been demonstrated in various cancer cell types, its underlying mechanism in glioma cells is not fully elucidated. The present study was undertaken to investigate the effect of resveratrol on cell viability and to determine the molecular mechanism in A172 human glioma cells. Resveratrol caused the generation of reactive oxygen species (ROS), and resveratrol-induced cell death was prevented by antioxidants (N-acetylcysteine and catalase), suggesting that an oxidative mechanism is responsible for resveratrol-induced cell death. Resveratrol-induced phosphorylation of extracellular signal-regulated kinase (ERK), p38 kinase, and c-Jun N-terminal kinase (JNK), and resveratrol-induced cell death were prevented by inhibitors of these kinases. Resveratrol-induced activation of caspase-3 and cell death were prevented by the caspase inhibitors. ERK activation and caspase-3 activation induced by resveratrol was blocked by N-acetylcysteine. Taken together, these results suggest that resveratrol causes a caspase-dependent cell death via activation of ERK, p38, and JNK, mediated by ROS generation, in human glioma cells.

• Journal of Life Science
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• v.34 no.2
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• pp.94-104
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• 2024

β-Lapachone is a natural quinone compound originally obtained from the bark of the lapacho tree (Tabebuia vellanedae), which has been used in traditional medicine in several South and Central American countries for treating various diseases. Although β-lapachone has been reported to have potent anticancer activity in many types of cancer cells, its effect on the proliferation of hepatocellular carcinoma (HCC) cells is still unclear. Therefore, in this study, we investigated the effect of β-lapachone on the proliferation of human HCC Hep3B cells. According to our results, the decrease in cell viability of Hep3B cells caused by β-lapachone was closely related to the induction of apoptosis, which was confirmed through changes in nuclear morphology and flow cytometry. In addition, in Hep3B cells treated with β-lapachone, the expression of Bcl-2, an anti-apoptotic factor, was decreased, while the expression of Bax, an apoptosis inducer, was increased, and the activity of the caspase cascade was also increased. However, in the presence of a pan-caspase inhibitor, β-lapachone-induced apoptosis was weakened, indicating that the induction of apoptosis by β-lapachone was caspase-dependent. Moreover, β-lapachone treatment activated extracellular-regulated kinase (ERK) signaling while inhibiting activation of the phosphoinositide 3 kinase (PI3K)/Akt pathway. Furthermore, the effect of the ERK inhibitor on suppressing the induction of apoptosis by β-lapachone was minimal, and the PI3K inhibitor significantly increased β-lapachone-induced apoptosis. The findings from this study will contribute to a better understanding of the anticancer activity of β-lapachone in HCC cells.

• BMB Reports
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• v.47 no.8
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• pp.457-462
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• 2014

The pathogenesis of non-alcoholic steatohepatitis (NASH) is not fully understood. In the present study, both in vitro and in vivo vimentin expression and secretion in NASH were investigated. The exposure of palmitate and lipopolysaccharide (LPS) to HepG2 cells enhanced caspase-3 activity and vimentin expression, respectively. The combined effects of both treatments on vimentin expression and caspase-3 activation appeared to be synergic. In contrast, blockade of caspase-3 activity by zVADfmk resulted in a significant reduction of cleaved vimentin and secreted vimentin into the culture supernatant. Similarly, lipid accumulation and inflammation occurred in mice fed a methionine-choline-deficient diet; thus, vimentin expression and serum cleaved vimentin levels were increased. However, vimentin was not significantly upregulated, and no cleavage occurred in mice fed a high-fat diet. It was conclusively determined that lipid accumulation in hepatocytes induces apoptosis through a caspase-3 dependent pathway; whereas, LPS stimulates vimentin expression, leading to its cleavage and secretion. Increased vimentin fragment levels indicated the existence of substantial hepatocellular death via an apoptotic mechanism.

• IMMUNE NETWORK
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• v.12 no.5
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• pp.213-216
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• 2012

Our previous report showed that polyacetylene compound, 1-Heptadecene-11, 13-diyne-8, 9, 10-triol (PA) from the root of Cirsium japonicum var. ussuriense has anti-inflammatory activity. In this study we investigated the role of the PA as inhibitor of caspase-1, which converts prointerleukin-$1{\beta}$ (proIL-$1{\beta}$) to active IL-$1{\beta}$ and is activated by inflammasome involved in the inflammatory process. We tested the effect of PA on the production of pro-inflammatory cytokines, IL-$1{\beta}$ in murine macrophage cell line, RAW264.7. PA inhibited lipopolysaccharide (LPS)-induced IL-$1{\beta}$ production by macrophages at a dose dependent manner. PA also suppressed the activation of caspase-1. The mRNA level of ASC (apoptosis-associated spec-like protein containing a CARD), an important adaptor protein of inflammasome, was decreased in the PA treated group. Therefore our results suggest that the anti-inflammatory effect of PA is due to inhibit the caspase-1 activation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.3
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• pp.216-224
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• 2011

Capsosiphon fulvescens is well-known green sea algae that, in recent years, has been proposed as a potential anticancer drug. In this study, we found that C. fulvescens glycoprotein (Cf-GP) had pro-apoptotic effects on human gastric carcinoma cells. By SDS-PAGE, we confirmed that C. fulvescens extract contained a glycoprotein. Using H33342 staining, we found that the Cf-GP caused cell death in a does-dependent manner, while an MTS assay showed decreased cellular viability due to induction of apoptosis. To determine the effect of Cf-GP on apoptosis-related cellular events, cells were treated with Cf-GP and the expression of several apoptosis-related protein was determined by Western blotting. Our results indicate that Cf-GP activated both a caspase cascade and PARP, which is a substrate of caspase-3, caspase-8 and the Bcl-2 family proteins. In addition, we assessed caspase-3, and -8 activation and annexin V staining. Our results revealed a cell cycle arrest, itself leading to an increased percentage of sub-G1 cells. Our findings indicate that Cf-GP may be a source of bio-functional material with therapeutic effects on human gastrointestinal cancer.

• International Journal of Oral Biology
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• v.30 no.4
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• pp.111-116
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• 2005

Resveratrol (3,4',5-trihydroxy-trans-stilbene), a naturally occuring polyphenol compound which present in the skin of grapes and red wine has been considered to posses chemopreventive and antioxidant properties. However, little is known about the cellular actions by which resveratrol mediates its therapeutic effects. In this study, the effect of resveratrol on cell proliferation and induction of apoptosis in human osteogenic sarcoma (HOS) cells was investigated. $IC_{50}$ value was determined to be approximately $6.0{\mu}g/ml$. Chromosomal DNA framgmentation analysis showed the appearance degraded DNA in time-and dose-dependent manner upon treatment of resveratrol. In order to observe the molecular mechanism involved in resveratrol-induced apoptosis, Western blot analysis was performed. We observed the decrease in the level of procaspase-3, the zymogen form of active caspase-3 in resveratrol-treated cells. This result implies that caspase-3 is activated upon treatment of resveratrol. The activation of caspase-3 was confirmed by the cleavage of poly(ADP-ribose) polymerase. Taken together, our data demonstrate that resveratrol has anti-proliferative effect on HOS cells and induced apoptosis through activation of caspase-3 and PARP cleavage.

• Microbiology and Biotechnology Letters
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• v.51 no.3
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• pp.243-249
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• 2023

We recently found that the insect-derived antimicrobial peptide CopA3 (LLCIALRKK) directly binds to and inhibits the proteolytic activation of caspases, which play essential roles in apoptotic processes. However, the mechanism of CopA3 binding to caspases remained unknown. Here, using recombinant GST-caspase-3 and -6 proteins, we investigated the mechanism by which CopA3 binds to caspases. We showed that replacement of cysteine in CopA3 with alanine caused a marked loss in its binding activity towards caspase-3 and -6. Exposure to DTT, a reducing agent, also diminished their interaction, suggesting that this cysteine plays an essential role in caspase binding. Experiments using deletion mutants of CopA3 showed that the last N-terminal leucine residue of CopA3 peptide is required for binding of CopA3 to caspases, and that C-terminal lysine and arginine residues also contribute to their interaction. These conclusions are supported by binding experiments employing direct addition of CopA3 deletion mutants to human colonocyte (HT29) extracts containing endogenous caspase-3 and -6 proteins. In summary, binding of CopA3 to caspases is dependent on a cysteine in the intermediate region of the CopA3 peptide and a leucine in the N-terminal region, but that both an arginine and two adjacent lysines in the C-terminal region of CopA3 also contribute. Collectively, these results provide insight into the interaction mechanism and the high selectivity of CopA3 for caspases.

• Journal of Life Science
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• v.25 no.4
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• pp.385-389
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• 2015

In this study, it is reported that a large polyprotein can be stoichiometrically cleaved by the use of caspase-3-dependent proteolysis. Previously, it has been shown that the proteolytic IETD motif was partially processed when treated with caspase-3, while the DEVD motif was completely cleaved. The cleavage efficiency of the DEVD-based substrate was approximately 2.0 times higher than that of the IETD substrate, in response to caspase-3. Based on this, 3 protein genes of interest were genetically linked to each other by adding two proteolytic cleavage sequences, DEVD and IETD, for caspase-3. Particularly, glutathione-S transferase (GST), maltose binding protein (MBP), and red fluorescent protein (RFP) were chosen as model proteins due to the variation in their size. The expressed polyprotein was purified by immobilized metal ion affinity chromatography (IMAC) via a hexa-histidine tag at the C-terminal end, showing 93 kDa of a chimeric GST:MBP:RFP fusion protein. In response to caspase-3, cleavage products, such as MBP:RFP (68 kDa), MBP (42 kDa), RFP (26 kDa), and GST (25 kDa), were separated from a large precursor GST:MBP:RFP (93 kDa) via SDS-PAGE. The results obtained from this study indicate that a multi-protein can be stoichiometrically produced from a large poly-protein by using proteolytic recognition motifs, such as DEVD and IETD tetra-peptides, for caspase-3.

• Proceedings of the Korean Society of Life Science Conference
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• 2007.10a
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• pp.42.2-42.2
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• 2007

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• Food Science and Preservation
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• v.14 no.6
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• pp.655-661
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• 2007

The biological activities of methanol extracts of Angelica gigas Nakai, such as antioxidation, anticancer and immuno-activity, were investigated in relation to development of functional foods. Anti-oxidation activity in the methanol extracts were assessed by hydrogen donating activity, reducing power and hydroxyl radical scavenging activity. Activities were dose-dependent over concentrations of 0.1, 0.5 and 1 mg/mL, with thehydrogen donating activity being over 50% at 1 mg/mL concentration. The methanol extracts inhibited the proliferation of SW480 cells in a dose-dependent manner, and chromatin condensation and apoptotic bodies were observed by fluorescence microcopy in the cells treated with the extracts for 24 hr. Caspase-3 activity was also increased in a dose-dependent manner in cells treated with the extracts relative to control cells. The extracts did not induce the proliferation of mouse spleen cells or NO production in macrophage cells (RAW 264.7). These results show that the methanol extract had slight anti-oxidative activity and did not increase immuno-activity, but inhibited proliferation of SW480 through apoptosis via a caspase dependent pathway.