• Biomolecules & Therapeutics
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• v.17 no.1
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• pp.17-24
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• 2009

Histone deacetylase (HDAC) inhibitors are a promising class of anticancer agents that inhibit cancer cell growth in vitro and in vivo. Previous report has shown that apicidin inhibited SK-OV-3 cells proliferation and down-regulation of cyclin B1 and CDK1, and up-regulation of $p21^{WAF1}$ and p27. However, the mechanism of apicidin-mediated apoptotic cell death is not clearly understood. For this study, we investigated the mechanism of apoptotic pathway induced by apicidin in human ovarian cancer cell. We found that SK-OV-3 cells treated with apicidin caused an increase in the percentage of cells in the G2/M phase, which preceded apoptosis characterized by the appearance of cells with sub-G1 population. To further investigate the mechanism of apoptosis induction by apicidin, we measured TUNEL assay, poly-ADP ribose polymerase (PARP) cleavage, and caspase activity in SK-OV-3 cells treated with apicidin for 48 h. Apicidin significantly enhanced apoptosis as measured by TUNEL positive apoptotic cells, PARP cleavage, and increased Bax/Bcl-2 ratio. Induction of apoptosis was confirmed by the release of cytochrome c to cytosol. Our data suggest that apicidin-induced apoptosis in SK-OV-3 cells was accompanied by caspase-3 activation and the increase in Bax/Bcl-2 ratio. These data suggest that apicidin may be effective in the treatment of ovarian cancer through activation of intrinsic apoptotic pathway.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.5
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• pp.1370-1374
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• 2005

The Tosyl-JM3 (TJM3) is a modified compound from one of 1,2,3,4-Tetra- hydroisoquinoline (THIQ) derivatives. The THIQs include potent cytotoxic agents that display a range of anti-tumor activities, antimicrobial activity, and other biological properties. In this study, we investigated the effect of TJM3 on the cytotoxicity, induction of apoptosis in human promyelocytic leukemia cells (HL-60 cells). TJM3 showed a significant cytotoxic activity in HL-60 cells (IC50 = approximately $60{\mu}g/m{\ell}$) after a 24 hr incubation. Treatment of HL-60 cells with TJM3 exhibited several features of apoptosis, including formation of DNA ladders in agarose gel electrophoresis, morphological changes of HL-60 cells with DAPI stain. Here we observed that TJM3 caused a decrease of procaspase-3 protein. Further molecular analysis demonstrated that TJM3 led to cleavage of poly(ADP-ribose) polymerase (PARP) by western blot and increase of hypodiploid (Sub-G1) population in the flow cytometric analysis. In conclusion, these above results indicate that TJM3 dramatically suppresses HL-60 cell growth and induces apoptosis. These data may support a possibility for the use of TJM3 in the prevention and treatment of leukemia.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.6
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• pp.1563-1567
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• 2005

Mori Cortex Radicis is distributed in Northwestern China, northern Asia, northern Europe, North America, and Korea. This extracts drops sugar in bloods and inhibits cyclic AMP phophodiesterase. In this study, we investigated whether Mori Cortex Radicis would cause apoptotic death of A549 lung cancer cells. To examine the apoptotic effect of Mori Cortex Radicis, cytotoxicity assay, DNA fragmentation analysis, caspase-3 activity assay, and Western blotting for caspase-3, caspase-9 and poly(ADP-ribose) polymerase (PARP) and cytochrome c were performed. Treatment of cells with Mori Cortex Radicis was shown to induce cell death in a dose-dependent manner. DNA fragmentation was made in response to Mori Cortex Radicis. The active fragments of caspase-3, caspase-9 and PARP were almost completely induced and cytochrome c was released following exposure to Mori Cortex Radicis. To elucidate the apoptotic mechanisms, RT-PCR and Western blot analyses for the expression of Bcl-2, Bu and Cox-2 were carried out. Treatment with Mori Cortex Radicis was expressed the reduction of Bcl-2 and Cox-2 and the induction of Bax. Especially p21 and p53 were increased prior to untreated control, while cyclin E and cyclin D1 decreased in the cytosol. These results suggest that the effect Mori Cortex Radicis is associated with the cell cycle arrest and pro-apoptotic cell death in A549 lung cancer cells.

• Korean Journal of Plant Resources
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• v.28 no.3
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• pp.297-304
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• 2015

The flower buds of Sophora japonica L (SF), as a well-known traditional Chinese medicinal herb, have been used to treat bleeding-related disorders such as hematochezia, hemorrhoidal bleeding, dysfunctional uterine bleeding, and diarrhea. However, no specific anti-cancer effect and its molecular mechanism of SF have been described. Thus, we performed in vitro study to investigate if treatment of SF affects activating transcription factor 3 (ATF3) expression and ATF3-mediated apoptosis in human colorectal cancer cells. The effects of SF on cell viability and apoptosis were measured by MTT assay and Western blot analysis against cleaved poly (ADP-ribose) polymerase (PARP). ATF3 activation induced by SF was evaluated using Western blot analysis, RT-PCR and ATF3 promoter assay. SF treatment caused decrease of cell viability and increase of apoptosis in a dose-dependent manner in HCT116 and SW480 cells. Exposure of SF activated the levels of ATF3 protein and mRNA via transcriptional regulation in HCT116 and SW480 cells. Inhibition of extracellular signal-regulated kinases (ERK) 1/2 by PD98059 and p38 by SB203580 attenuated SF-induced ATF3 expression and transcriptional activation. Ectopic ATF3 overexpression accelerated SF-induced cleavage of PARP. These findings suggest that SF-mediated apoptosis may be the result of ATF3 expression through ERK1/2 and p38-mediated transcriptional activation.

• Journal of Microbiology and Biotechnology
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• v.16 no.9
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• pp.1399-1404
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• 2006

The roots of Aralia continentalis (AC) have been used traditionally in Korean as a folk medicine for anti-inflammation and as an anti-rheumatic. In this study, we report that the ethyl acetate-soluble traction (ACE) of the methanolic extract of AC root inhibited the cell growth of various human cancer cell lines and induced apoptosis of HL-60, human promyelocytic leukemia cells. Its $IC_{50}$ values on growth inhibition were estimated to be $56.3{\mu}g/ml$ on HL-60, $87.2{\mu}g/ml$ on HepG2, $93.2{\mu}g/ml$ on HeLa, $135.5{\mu}g/ml$ on DU-145, and $135.8{\mu}g/ml$ on HT-29 cells. Interestingly, ACE showed no antiproliferative effect on normal lymphocyte cells used as control. Furthermore, nuclear DAPI staining revealed the typical nuclear features of apoptosis in the HL-60 cells exposed to $80{\mu}g/ml$ ACE, and a flow cytometric analysis of the HL-60 cells using propidium iodide showed that the apoptotic cell population increased gradually from 5% at 0 h to 16% at 12 h and 20% at 24 h after treated with $50{\mu}g/ml$ of ACE. TUNEL assay also revealed the apoptotic induction of the HL-60 cells treated with ACE. To obtain further information on the ACE-induced apoptosis, the expression level of certain apoptosis-associated proteins was examined using a Western blot analysis. Treatment of the HL-60 cells with ACE resulted in the activation of caspase-3, and subsequent proteolytic cleavage of poly(ADP-ribose) polymerase (PARP). The above results confirmed that the apoptosis in the HL-60 cells was induced by ACE, and that caspase-3-mediated PARP cleavage was involved in the process.

• Journal of Life Science
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• v.13 no.2
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• pp.154-162
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• 2003

Platycodi Radix, the root of Platycodon grandiflorum, commonly known as Doraji, is used as a traditional oriental medicine. Extracts from the roots of P grandiflorum have been reported to have wide ranging health benefits. In the present study, we investigated the effects of an aqueous extract from the roots of P. grandiflorum (AEPG) on the growth of human lung carcinoma A549 cells. Upon treatment with AEPG, a concentration-dependent inhibition of cell growth was observed and cells developed many of the hallmark features of apoptosis, including condensation of chromatin. Flow cytometry analysis confirmed that AEPG increased populations of apoptotic-sub Gl phase. Immunoblot and quantitative RT-PCR analyses indicated that the expressions of Bcl-2 was down-regulated but Bax was up-regulated in AEPG-treated A549 cells. The expression of active form of caspase-3 by AEPG treatment was markedly increased, and the levels of poly(ADP-ribose) polymerase (PARP) and $\beta$-catenin, its target proteins, were decreased in a concentration dependent manner. Taken together, these findings suggest that P. grandiflorum has strong potential for development as an agent for prevention against human lung cancer.

• Archives of Pharmacal Research
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• v.26 no.9
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• pp.739-746
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• 2003

Ultraviolet B (UVB) is known to induce apoptosis in human melanocytes. Here we show the cytoprotective effect of sphingosine-1-phosphate (S1P) against UVB-induced apoptosis. We also show that UVB-induced apoptosis of melanocytes is mediated by caspase-3 activation and poly(ADP-ribose) polymerase (PARP) cleavage, and that S1P prevents apoptosis by inhibiting this apoptotic pathway. We further investigated three major mitogen-activated protein (MAP) kinases after UVB irradiation. UVB gradually activated c-Jun N-terminal kinase (JNK) and p38 MAP kinase, while extracellular signal-regulated protein kinase (ERK) was inactivated transiently. Blocking of the p38 MAP kinase pathway using SB203580 promoted cell survival and inhibited the activation of caspase-3 and PARP cleavage. These results suggest that p38 MAP kinase activation may play an important role in the UVB-induced apoptosis of human melanocytes. To explain this cytoprotective effect, we next examined whether S1P could inhibit UVB-induced JNK and p38 MAP kinase activation. However, S1P was not found to have any influence on UVB-induced JNK or p38 MAP kinase activation. In contrast, S1P clearly stimulated the phosphorylation of ERK, and the specific inhibition of the ERK pathway using PD98059 abolished the cytoprotective effect of S1P. Based on these results, we conclude that the activation of p38 MAP kinase plays an important role in UVB-induced apoptosis, and that S1P may show its cytoprotective effect through ERK activation in human melanocytes.

• Biomedical Science Letters
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• v.29 no.2
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• pp.66-74
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• 2023

Triglyceride (TG) accumulation can cause monocytic death and suppress innate immunity. However, the signaling pathways involved in this phenomenon are not fully understood. This study aimed to examine whether inducible nitric oxide synthase (iNOS) is involved in the TG-induced death of THP-1 monocytes. Results showed that iNOS was upregulated in TG-treated THP-1 monocytes, and iNOS inhibition blocked TG-induced monocytic death. In addition, TG-induced poly (ADP-ribose) polymerase (PARP) cleavage and caspase-3 and -7 activation were suppressed by iNOS inhibition. Furthermore, the expression of X-linked inhibitor of apoptosis protein (XIAP) and survivin, which inhibit caspase-3 and -7, was reduced in TG-treated THP-1 monocytes, but iNOS inhibition recovered the TG-induced downregulation of XIAP and survivin expression. Considering that TG-induced monocytic death is triggered by caspase2 and -8, we investigated whether caspase-2 and -8 are linked to the TG-induced expression of iNOS in THP-1 monocytes. When the activities of caspase-2 and -8 were inhibited by specific inhibitors, the TG-induced upregulation of iNOS and downregulation of XIAP and survivin were restored in THP-1 monocytes. These results suggest that TG-induced monocytic death is mediated by the caspase-2/caspase-8/iNOS/XIAP and survivin/executioner caspase/PARP pathways.

• International Journal of Molecular Medicine
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• v.46 no.5
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• pp.1923-1937
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• 2020

It has been suggested that oxidative stress involving reactive oxygen species (ROS) induces granulosa cell apoptosis, leading to follicular atresia, and that T-lymphokine-activated killer cell-originated protein kinase (TOPK) suppresses cancer cell apoptosis induced by several stimuli. However, it remains to be determined whether TOPK affects oxidative stress-induced granulosa cell apoptosis. The present study demonstrates that TOPK inhibition increases human granulosa COV434 cell apoptosis induced by hydrogen peroxide (H₂O₂). Co-treatment with the TOPK inhibitor, OTS514, in combination with H₂O₂ increased p53 acetylation and its expression, whereas it decreased Sirtuin 1 (SIRT1) expression, contributing to the promotion of apoptosis. In addition, the SIRT1 activator, resveratrol, or the SIRT1 inhibitor, Ex527, reduced or elevated H₂O₂-induced COV434 cell apoptosis, respectively. Furthermore, the p53 inhibitor, Pifithrin-μ, diminished the augmentation in poly(ADP-ribose) polymerase (PARP) cleavage induced by OTS514 plus H₂O₂, while the Mdm2 antagonist, Nutlin 3, increased PARP cleavage. Moreover, OTS514 further decreased the SIRT1 transcriptional activity decreased by H₂O₂, but promoted the H₂O₂-induced p53 or p21 transcriptional activity. Notably, the expression of exogenous p53 reduced SIRT1 transcriptional activity. Taken together, the findings of the present study demonstrate that TOPK inhibition promotes p53-mediated granulosa cell apoptosis through SIRT1 downregulation in response to H₂O₂. Therefore, it can be concluded that TOPK suppresses H₂O₂-induced apoptosis through the modulation of the p53/SIRT1 axis, suggesting a potential role of TOPK in the regulation of human granulosa cell apoptosis, leading to the promotion of abnormal follicular development.

• Radiation Oncology Journal
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• v.25 no.4
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• pp.227-232
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• 2007

Purpose: To investigate the flavopiridol effect on radiation-induced apoptosis and expression of apoptosisrelated genes of human laryngeal and lung cancer cells. Materials and Methods: A human laryngeal cancer cell line, AMC-HN3 and a human lung cancer cell line, NCI-H460, were used in the study. The cells were divided into four groups according to the type of treatment: 1) control groups; 2) cells that were only irradiated; 3) cells treated only with flavopiridol; 4) cells treated with flavopiridol and radiation simultaneously. The cells were irradiated with 10 Gy of X-rays using a 4 MV linear accelerator. Flavopiridol was administered to the media at a concentration of 100 nM for 24 hours. We compared the fraction of apoptotic cells of each group 24 hours after the initiation of treatment. The fraction of apoptotic cells was detected by measurement of the sub-G1 fractions from a flow cytometric analysis. The expression of apoptosis-regulating genes, including cleaved caspase-3, cleaved PARP (poly (ADP-ribose) polymerase), p53, p21, cyclin D1, and phosphorylated Akt (protein kinase B) were analyzed by Western blotting. Results: The sub-G1 fraction of cells was significantly increased in the combination treatment group, as compared to cells exposed to radiation alone or flavopiridol alone. Western blotting also showed an increased expression of cleaved caspase-3 and cleaved PARP expression in cells of the combination treatment group, as compared with cells exposed to radiation alone or flavopiridol alone. Treatment with flavopiridol down regulated cyclin 01 expression of both cell lines but its effect on p53 and p21 expression was different according to each individual cell line. Flavopiridol did not affect the expression of phophorylated Akt in both cell lines. Conclusion: Treatment with flavopiridol increased radiation-induced apoptosis of both the human laryngeal and lung cancer cell lines. Flavopiridol effects on p53 and p21 expression were different according to the individual cell line and it did not affect Akt activation of both cell lines.