• Journal of Life Science
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• v.26 no.8
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• pp.887-894
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• 2016

The extract from Artemisia annuain L.(AAE) is known as a medicinal herb that is effective against cancer. Apoptosis is the process of programmed cell death, and mitochondria are known to play a central role in cell death control. In this study, we evaluated the p53-independent apoptosis of extract of AAE through downregulation of Bcl-2 and the mitochondrial pathway in A549 (lung cancer cells). AAE may exert cancer cell apoptosis through regulating p-Akt, Cox-2, p53 and mitochondria-mediated apoptotic proteins. p-Akt/cox-2 is known to play an important role in cell proliferation and cell survival. The Bcl-2 pro-apoptotic proteins (such as Bax, Bak and Bim) mediate the permeabilization of the mitochondrial outer membrane. Treatment of AAE reduces p-Akt, p-Mdm2, cox-2 and anti-apoptotic proteins (such as Bcl-2), while tumor suppressor p53 and pro-apoptotic proteins. Activation of Bax/Bak releases cytochrome c from mitochondria to the cytosol to activate a caspase. Caspase-3 is the major effector caspase associated with apoptotic pathways. Caspase-3 generally exists in cytoplasm in the form of a pro-enzyme. In the initiation stage of apoptosis, caspase-3 is activated by proteolytic cleavage and activated caspase-3 cleaves poly (ADP-ribose) polymerase (PARP). We treated Pifithrin-α (p53 inhibitor) and Celecoxib (Cox-2 inhibitor) to learn the relationship between the signal transduction of proteins associated with apoptosis. These results suggest that AAE induces apoptosis through a p53-independent pathway in A549.

• Tuberculosis and Respiratory Diseases
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• v.52 no.5
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• pp.441-452
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• 2002

Background : Anti-apoptotic proteins may be involved in tumor development, progression and the response to treatment, Bcl-2 is by far the most studied anti-apoptotic protein. A novel inhibitor of apoptosis, designated survivin, and the heat shock proteins (HSPs) have recently been found in many human cancers. Immunohistochemical methods were used to determine the expression level of survivin, HSP70 and bcl-2 in non-small cell lung cancer (NSCLC) to evaluate their clinical significance. Materials and Methods : Tissue array slides were obtained from 99 surgically resected NSCLCs. Immunohistochemical staining was performed by an immuno-peroxidase technique using an avidin-biotinylated horseradish peroxidase complex. Anti-survivin rabbit polyclonal antibodies, anti-HSP70 mouse monoclonal antibodies and anti-bcl-2 mouse monoclonal antibodies were used as the primary antibodies. Results : Positive staining of survivin was detected in 33.3% of the cases. Survivin positivity is associated with to females and recurrence. A nonstatistically significant trend toward increased survivin expression was observed in non-smokers, and its expression inversely correlated with the number of cigarettes smoked in smokers. HSP70 was detected in 84.8% but this did not correlated with the clinicopathologic characteristics. Bcl-2 was detected in 18.2% and its expression correlated to tumor recurrence. No significant difference in the median survival time was noted in a comparison of all cases with survivin expression and those without. There was no association between HSP70 or bcl-2 expression and survival. Conclusion : Survivin expression was significantly associated with females and tumor recurrence. In addition its expression was inversely associated with the number of cigarettes smoked. However, HSP70 and bcl-2 expression were not associated with the clinical parameters or survival. This suggests that measuring the survivin levels may be useful in identifying patients at high risk for disease recurrence. Therefore, survivin might be a new diagnostic/therapeutic target in cancer.

• 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.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.6
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• pp.1584-1592
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• 2006

Houttuynia cordata Thunb, well known as 'E-Sung-Cho' in Korea, is traditional medicinal plant generally used in Oriental medicine therapy. We previously reported that the water extract of H. cordata inhibited cell proliferation and induced apoptosis in human breast carcinoma cells. In the present study, we investigated the biochemical mechanisms of anti-proliferative effects by the methanol extract of H. cordata (MEHC) in human lung carcinoma A549 cells. It was found that MEHC could inhibit the cell growth in a dose-dependent manner, which was associated with morphological change and apoptotic cell death as determined by formation of apoptotic bodies, DNA fragmentation and increased populations of apoptotic-sub G1 phase cells. Apoptosis of A549 cells by MEHC was also connected with a down-regulation of anti-apoptotic Bcl-2 and inhibitor of apoptosis proteins (IAPs) expression. MEHC treatment induced the proteolytic activation of caspase-3, caspase-8 and caspase-9, and a concomitant inhibition of poly(ADP-ribose) polymerase (PARP), ${\beta}$-catenin and phospholipase (PLC)-${\gamma}$1 protein expression. Taken together, these findings provide important new insights into the possible molecular mechanisms of the anti-cancer activity of H. cordata.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.10
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• pp.5849-5854
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• 2013

Background: Apoptosis may be induced after Bcl-2 expression is inhibited in proliferative cancer cells. This study focused on the effect of autophagy activation by ABT737 on anti-tumor effects of epirubicin. Methods: Cytotoxic effects of ABT737 on the HepG2 liver cancer cell line were assessed by MTT assay and cell apoptosis through flow cytometry. Mitochondrial membrane potential was measured by fluorescence microscopy. Monodansylcadaverin (MDC) staining was used to detect activation of autophagy. Expression of p53, p62, LC3, and Beclin1, apoptotic or autophagy related proteins, was detected by Western blotting. Results: ABT737 and epirubicin induced growth inhibition in HepG2 cells in a dose- and time-dependent manner. Both ABT737 and epirubicin alone could induce cell apoptosis with a reduction in mitochondrial membrane potential as well as increased apoptotic protein expression. Further increase of apoptosis was detected when HepG2 cells were co-treated with ABT373 and epirubicin. Furthermore, our results demonstrated that ABT373 or epirubicin ccould activate cell autophagy with elevated autophagosome formation, increased expression of autophagy related proteins and LC3 fluorescent puncta. Conclusions: ABT737 influences cancer cells through both apoptotic and autophagic mechanisms, and ABT737 may enhance the effects of epirubicin on HepG2 cells by activating autophagy and inducing apoptosis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.1
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• pp.8-15
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• 2008

Saussurea lappa (SL) has been used to reduce abdominal pain and tenesmus in traditional oriental medicine. SL and major compounds of SL, sesquiterpene lactones, have been suggested to possess various biological effects, including anti-tumor, anti-ulcer, anti-inflammatory, anti-viral and cardiotonic activities. Recently, it has been reported that ethanol extracts from roots of SL have antiproliferative effects on gastric cancer cells. To explore the possibility that SL has chemopreventive effects on prostate cancer, we examined whether the hexane extract of SL (HESL) inhibits the growth of LNCaP human prostate cancer cells. Cells were incubated with various concentrations ($0{\sim}4$ mg/L) of HESL in DMEM/F12 containing 5% charcoal stripped fetal bovine serum. HESL substantially decreased viable cell numbers and induced apoptosis of LNCaP cells in dose-dependent manners. HESL increased the levels of cleaved caspase-8, -9, -7 and -3, and poly (ADP-ribose) polymerase. HESL increased the levels of the pro-apoptotic Bak and truncated-Bid proteins whereas it had no effect on the anti-apoptotic Bcl-2, Bcl-xL, or Mcl-1. The present results indicate that HESL inhibits the growth of human prostate cancer cells by inducing apoptosis, which involves the activation of the caspase cascades.

• Journal of Life Science
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• v.22 no.6
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• pp.815-822
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• 2012

Piceatannol (trans-3,4,3',5'-tetrahydroxystilbene), a natural stilbene, is an analogue of resveratrol. Although recent experimental data have revealed the health benefit potency of piceatannol, the molecular mechanisms underlying the anti-cancer activity have not yet been studied in detail. In the present study, the further possible mechanisms by which piceatannol exerts its pro-apoptotic action in cultured human lung cancer A549 cells were investigated. Exposure of A549 cells to piceatannol resulted in growth inhibition and induction of apoptosis. Apoptosis induction of A549 cells by piceatannol showed correlation with proteolytic activation of caspase-3, -8, and -9, and concomitant degradation of activated caspase-3 target proteins such as poly (ADP-ribose) polymerase, phospholipase C-${\gamma}1$, ${\beta}$-catenin, and Inhibitor caspase-activated DNase. The increase in apoptosis by piceatannol treatment was also associated with an increase of pro-apoptotic Bax expression and decrease of anti-apoptotic Bcl-2 and Bcl-xL expression, and caused down-regulation of the inhibitor of apoptosis protein family members and up-regulation of Fas and Fas legend. In addition, piceatannol treatment markedly inhibited the expression of mRNA and proteins of inducible nitric oxide (NO) synthase, and the levels of NO production were progressively down-regulated by piceatannol treatment in a dose-dependent fashion. The results indicate that piceatannol may have therapeutic potential against human gastric cancer 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.

• BMB Reports
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• v.54 no.3
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• pp.176-181
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• 2021

Bcl-x, a member of the Bcl-2 family, plays a key role in apoptosis. Alternative splicing of Bcl-x pre-mRNA through alternative 5' splice-site selection produces an anti-apoptotic mRNA isoform that includes exon 2b and a pro-apoptotic Bcl-x mRNA isoform that excludes exon 2b. Here we used Bcl-x minigene and identified SRSF2 and SRSF6 as two regulatory factors of 5' splice-site selection of Bcl-x pre-mRNA. We selected binding clusters closer to 5' splice-sites from multiple potential binding sites of SRSF2 and SRSF6 to perform loss of functions analysis through site-directed mutagenesis. Our results demonstrated that these mutations did not abolish regulatory functions of SRSF2 or SRSF6, indicating that a single binding motif or a cluster was not a functional target of these proteins in Bcl-x pre-mRNA splicing. Random deletion mutagenesis did not disrupt the role of SRSF2 and SRSF6. Importantly, mutagenesis of 5' splice-site to a conserved or a weaker score demonstrated that the weaker strength of the target 5' splice-site or higher strength of the other 5' splice-site strength limited the role of SRSF2 and SRSF6 in 5' splice-site activation.

• Journal of Pharmaceutical Investigation
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• v.37 no.5
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• pp.287-290
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• 2007

Intrinsic or acquired resistance to chemotherapeutic drugs is one of the major obstacles to effective cancer treatment. Hypoxia is widespread in solid tumors as a consequence of decreased blood flow in the tumor-derived neovasculature. The recent finding of a link between hypoxia and chemoresistance prompted us to investigate whether hypoxia induces doxorubicin resistance in human MCF-7 breast cancer cells. Low oxygen concentration decreased the doxorubicin sensitivity in MCF-7 cells. The expression of p-glycoprotein, a major MDR-related transporter, and those of apoptosis-related proteins (anti-apoptotic Bcl-2, Bcl-XL and pro-apoptotic Bax) were not altered by hypoxia in MCF-7 cells. Intracellular uptake of doxorubicin was significantly decreased under hypoxic conditions. Decreased cellular uptake of doxorubicin under hypoxia may contribute to causing doxorubicin resistance in these cells. The use of agents that can modulate the doxorubicin uptake for adjuvant therapy may contribute to improving the therapeutic efficacy of doxorubicin in breast cancer patients.