• Asian Pacific Journal of Cancer Prevention
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• 제15권1호
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• pp.475-481
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• 2014

Background: Pereskia sacharosa is a genus of cacti widely used in folk medicine for cancer-related treatment. Anti-proliferative effects have been studied in recent years against colon, breast, cervical and lung cancer cell lines, with promising results. We here extended study of anti-proliferative effects to a blood malignancy, leukemia. Materials and Methods: Two leukemic cell lines, MV4-11 (acute myeloid leukemia) and K562 (chronic myeloid leukemia), were studied. $IC_{50}$ concentrations were determined and apoptosis and cell cycle regulation were studied by flow cytometric analysis. The expression of apoptosis and cell-cycle related regulatory proteins was assessed by Western blotting. Results: P sacharosa inhibited growth of MV4-11 and K562 cells in a dose-dependent manner. The mode of cell death was via induction of intrinsic apoptotic pathways and cell cycle arrest. There was profound up-regulation of cytochrome c, caspases, p21 and p53 expression and repression of Akt and Bcl-2 expression in treated cells. Conclusions: These results suggest that P sacharosa induces leukemic cell death via apoptosis induction and changes in cell cycle checkpoint, thus deserves further study for anti-leukemic potential.

• Asian Pacific Journal of Cancer Prevention
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• 제14권12호
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• pp.7339-7344
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• 2013

To analyze the effects of a new unknown peptide DEF on the growth of tumor cells, a fused polypeptide TAT-DV1-DEF was designed and synthesized. The lung adenocarcinoma cell line GLC-82 treated with TAT-DV1-DEF was analyzed with a cell counting kit 8, and the location of polypeptides in cells was observed under laser confocal microscopy. The efficiency of polypeptide transfection and changes in nuclear morphology were analyzed by flow cytometry and fluorescence microscopy, respectively. Finally, the mechanism of tumor cell growth inhibition was evaluated by Western blotting. We found that TAT-DV1-DEF could significantly inhibit the growth of the lung adenocarcinoma cell line GLC-82, but not the normal human embryonic kidney cell line HEK-293. Polypeptides were found to be mostly localized in the cytoplasm and some mitochondria. The efficiency of polypeptide transfection in the two cell types was approximately 99%. Apoptotic nuclei were observed under fluorescence microscopy upon treatment with polypeptides and DAPI staining. Western blot analyses indicated that the polypeptide inhibition of tumor cell growth was apoptosis dependent. In the present study, we demonstrated that fused polypeptides could induce apoptosis of the lung adenocarcinoma cell line GLC-82, indicating that the new unknown peptide DEF has antitumor effects.

• The Korean Journal of Physiology and Pharmacology
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• 제9권1호
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• pp.63-68
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• 2005

Hydrogen peroxide ($H_2O_2$) causes oxidative stress and is considered as an inducer of cell death in various tissues. Two-pore domain $K^+$ ($K_{2p}$) channels may mediate $K^+$ efflux during apoptotic volume decreases (AVD) in zygotes and in mouse embryos. In the present study, we sought to elucidate linkage between $K_{2p}$ channels and cell death by $H_2O_2$. Thus $K_{2p}$ channels (TASK-1, TASK-3, TREK-1, TREK-2) were stably transfected in HEK-293 cells, and cytotoxicity assay was preformed using cell counting kit-8 (CCK-8). Cell survival rates were calculated using the cytotoxicity assay data and dose-response curve was fitted to the $H_2O_2$ concentration. Ionic currents were recorded in cell-attached mode. The bath solution was the normal Ringer solution and the pipette solution was high $K^+$ solution. In HEK-293 cells expressing TREK-1, TREK-2, TASK-3, $H_2O_2$ induced cell death did not change in comparison to non-transfected HEK-293. In HEK-293 cells expressing TASK-1, however, dose-response curve was significantly shifted to the left. It means that $H_2O_2$ induced cell death was increased. In cell attached-mode recording, application of $H_2O_2$ (300μM) increased activity of all $K_{2p}$ channels. However, a low concentration of $H_2O_2$ ($50{\mu}M$) increased only TASK-1 channel activity. These results indicate that TASK-1 might participate in $K^+$ efflux by $H_2O_2$ at low concentration, thereby inducing AVD.

• 대한한방부인과학회지
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• 제20권2호
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• pp.139-154
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• 2007

Purpose: This study examined the Cell differentiation and the anti-oxidative effect of Dioscoreae Rhizoma on HeLa cells. We are interested in whether Dioscoreae Rhizoma is capable of causing apoptosis processes on HeLa cell, and whether cotreatment of NCS with Dioscoreae Rhizoma reduces cell viability. Methods: We used aqueous extract to treat HeLa cell with different concentrations treated with a water or a MeOH extract of Dioscoreae Rhizoma (0, x10, x20, x40, x80). The MTT (3, (4, 5-dimethyl-thiazol) 2, 5-diphenyl-tetraxolium bromide) reduction assay was employed to quantify the differences in cell activity and viability. Cells were stained with DAPI and visualized by fluorescent Microscope. The caspase-3, Bcl-2, PARP, p53 expression level was monitored using western-blotting techniques. The patterns of the changes in expression were scanned and analyzed. Results: The survival rate of cells treated with Dioscoreae Rhizoma extracts increased by 20% at specific concentration. The other side Dioscoreae Rhizoma extracts induced apoptotic features including chromatin condensation and fragmentation. And Dioscoreae Rhizoma extracts increased the expression of caspase-3, p53 and the cleavage of PARP protein. However, co-treatment with Dioscoreae Rhizoma with NCS attenuated the activations of p53 and PARP protein that were mediated by NCS treatment alone. This is indicated Dioscoreae batatas extracts attenuated cytotoxicity induced by oxidative agents including NCS. Conclusion: Our results suggest Dioscoreae Rhizoma extracts induce cell differentiation or apoptosis connected with concentration. Further elucidation of concentration of Dioscoreae Rhizoma awaits many other biochemical investigative studies.

• Journal of Chest Surgery
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• 제45권1호
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• pp.1-10
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• 2012

Background: ${\alpha}$-Lipoic acid (${\alpha}$-LA) has been studied as an anticancer agent as well as a therapeutic agent for diabetes and obesity. We performed this study to evaluate the anticancer effects and mechanisms of ${\alpha}$-LA in a lung cancer cell line, A549. Materials and Methods: ${\alpha}$-LA-induced apoptosis of A549 cells was detected by fluorescence-activated cell sorting analysis and a DNA fragmentation assay. Expression of apoptosis-related genes was analyzed by western blot and reverse transcription.polymerase chain reaction analyses. Results: ${\alpha}$-LA induced apoptosis and DNA fragmentation in A549 cells in a dose- and time-dependent manner. ${\alpha}$-LA increased caspase activity and the degradation of poly (ADP-ribose) polymerase. It induced expression of endoplasmic reticulum (ER) stress-related genes, such as glucose-regulated protein 78, C/EBP-homologous protein, and the short form of X-box binding protein-1, and decreased expression of the anti-apoptotic protein, X-linked inhibitor of apoptosis protein. Reactive oxygen species (ROS) production was induced by ${\alpha}$-LA, and the antioxidant N-acetyl-L-cysteine decreased the ${\alpha}$-LA-induced increase in expression of apoptosis and ER stress-related proteins. Conclusion: ${\alpha}$-LA induced ER stress-mediated apoptosis in A549 cells via ROS. ${\alpha}$-LA may therefore be clinically useful for treating lung cancer.

• IMMUNE NETWORK
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• 제3권4호
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• pp.268-275
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• 2003

Background: Hemopoietic cells require the constant presence of growth factors for survival in vitro and in vivo. Caspases have been known as central executors of apoptotic cell death. We have, therefore, investigated the pathways that regulate caspase activity and apoptosis using the $CD34^+$ cell line, TF-1 which requires GM-CSF for survival. Methods: Apoptosis was measured by annexin V staining and mitochondrial membrane potential was measured by DiOC6 labelling. Intracellular pH was measured using pH sensitive fluorochrome, BCECF or SNARF-1, followed by flow cytometry analysis. Caspase activation was analyzed by PARP cleavage using anti-PARP antibody. Results: Removal of GM-CSF induceed PARP cleavage, a hallmark of caspase activity, concomitant with pHi acidification and a drop in mitochondrial potential. Treatment with ZVAD, a competitive inhibitor of caspases, partially rescued cell death without affecting pHi acidification and the reduction of mitochondrial potential, suggesting that both these events act upstream of caspases. Overexpression of Bcl-2 prevented cell death induced by GM-CSF deprivation as well as pHi acidification and the reduction in mitochondrial membrane potential. In parental cells maintained with GM-CSF, EIPA, a competitive inhibitor of $Na^+/H^+$ antiporter induced apoptosis, accompanied by a drastic reduction in mitochondrial potential. In contrast, EIPA induced apoptosis in Bcl-2 transfectants without causing mitochondrial membrane depolarization. Conclusion: Taken together, our results suggest that the regulation of $H^+$fluxes, either through a mitochondriondependent or independent pathway, is central to caspase activation and apoptosis.

• Animal cells and systems
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• 제12권1호
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• pp.15-21
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• 2008

Nitric oxide(NO) has been known to play important roles in numerous physiologic processes including neurotransmission, vasorelaxation, and cellular apoptosis. Using a mouse cDNA gene chip, we examined expression patterns and time course of NO-dependent genes in mouse macrophage RAW264.7 cells. Genes shown to be upregulated more than two fold or at least at two serial time points were further selected and validated by RT-PCR. Finally, 81 selected genes were classified by function as signaling, apoptosis, inflammation, transcription, translation, ionic homeostasis and metabolism. Among those, genes related with signaling, apoptosis and inflammation, such as guanylate cyclase 1, soluble, alpha3(Gucy1a3); protein kinase C, alpha($Pkc{\alpha}$); lymphocyte protein tyrosine kinase(Lck); BCL2/adenovirus E1B 19 kDa-interacting protein(Bnip3); apoptotic protease activating factor 1(Apaf1); X-linked inhibitor of apoptosis(Xiap); cyclin G1(Ccng1); chemokine(C-C motif) ligand 4(Ccl4); B cell translocation gene 2, anti-proliferative(Btg2); lysozyme 2(Lyz2); secreted phosphoprotein 1(Spp1); heme oxygenase(decycling) 1(Hmox1); CD14 antigen(Cd14); and granulin(Grn) may play important roles in NO-dependent responses in murine macrophages.

• Journal of Acupuncture Research
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• 제18권1호
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• pp.129-145
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• 2001

Objectives : To characterize the antitumorigenic potential of three representative bee venom components, Melittin, Apamin, and Phospholipase A2, their effects on cell proliferation and apotosis of the human melanoma cell line SK-MEL-2 were analyzed using molecular biological approaches. Methodes & Results : To determine the doses of the drugs that do not induce cytotoxic damage to this cell line, cell viability was examined by MTT assay. While SK-MEL-2 cells treated with 0.5 - 2.0㎍/㎖ of each drug showed no recognizable cytotoxic effect, marked reductions of cell viability were detected at concentrations over 5.0㎍/㎖. [3H]thymidine incorporation assay for cell proliferation demonstrated that DNA replication of SK-MEL-2 cells is inhibited by Apamin and Phospholipase A2 in a dose-dependent manner. Consistent with this result, the cells were accumulated at the G1 phase of the cell cycle after treatment with Apamin and Phospholipase A2, whereas no detectable change in cell proliferation was identified by Melittin treatment. In addition, tryphan blue exclusion and flow cytometric analyses showed that all of these drugs can trigger apoptotic cell death of SK-MEL-2, suggesting that Melittin, Apamin, and Phospholipase A2 have antitumorigenic potential through the suppression of cell growth and/or induction of apoptosis. Qantitative RT-PCR analysis revealed that Apamin and Phospholipase A2 inhibit expression of growth-promoting genes such as c-Jun, c-Fos, and Cyciin D1. Furthermore, Phospholipase A2 induced tumor suppressors p53 and p21/Wafl. In addition, all three drugs were found to activate expression of a representative apoptosis-inducing gene Bax while expression of apoptosis-suppressing Bcl-2 and Bcl-XL genes was not changed. Taken together, this study strongly suggests that Metittin, Apamin, and Phosphalipase A2 may have antitumorigenic activities, which are associated with its growth-inhibiting and/or apoptosis-inducing potentials.

• BMB Reports
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• 제47권4호
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• pp.221-226
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• 2014

Drug-resistance and imbalance of apoptotic regulation limit chemotherapy clinical application for the human hepatocellular carcinoma (HCC) treatment. The reactivation of p53 is an attractive therapeutic strategy in cancer with disrupted-p53 function. Nutlin-3, a MDM2 antagonist, has antitumor activity in various cancers. The post-translational modifications of p53 are a hot topic, but there are some controversy ideas about the function of phospho-$Ser^{392}$-p53 protein in cancer cell lines in response to Nutlin-3. Therefore, we investigated the relationship between Nutlin-3 and phospho-$Ser^{392}$-p53 protein expression levels in SMMC-7721 (wild-type TP53) and HuH-7 cells (mutant TP53). We demonstrated that Nutlin-3 induced apoptosis through down-regulation phospho-$Ser^{392}$-p53 in two HCC cells. The result suggests that inhibition of p53 phosphorylation on $Ser^{392}$ presents an alternative for HCC chemotherapy.

• BMB Reports
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• 제51권6호
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• pp.296-301
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• 2018

Mitochondrial DNA (mtDNA) mutations are often observed in various cancer types. Although the correlation between mitochondrial dysfunction and cancer malignancy has been demonstrated by several studies, further research is required to elucidate the molecular mechanisms underlying accelerated tumor development and progression due to mitochondrial mutations. We generated an mtDNA-depleted cell line, ${\rho}^0$, via long-term ethidium bromide treatment to define the molecular mechanisms of tumor malignancy induced by mitochondrial dysfunction. Mitochondrial dysfunction in ${\rho}^0$ cells reduced drug-induced cell death and decreased the expression of pro-apoptotic proteins including p53. The p53 expression was reduced by activation of nuclear $factor-{\kappa}B$ that depended on elevated levels of free calcium in $HCT116/{\rho}^0$ cells. Overall, these data provide a novel mechanism for tumor development and drug resistance due to mitochondrial dysfunction.