• Title/Summary/Keyword: G2 cell cycle arrest

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Induction of Apoptosis Signaling by a Glycoprotein of Capsosiphon fulvescens in AGS Cell (매생이 (Capsosiphon fulvescens) 당단백질에 의한 인간 위암세포 사멸기전)

  • Kim, Young-Min;Kim, In-Hye;Nam, Taek-Jeong
    • 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.

Novel strategy for isolating suppressors of meiosis-deficient mutants and its application for isolating the bcy1 suppressor

  • Shin, Deug-Yong;Yun, Jean-Ho;Yoo, Hyang-Sook
    • Journal of Microbiology
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    • v.35 no.1
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    • pp.61-65
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    • 1997
  • A novel strategy was developed for isolating suppressors from sporulation-deficient mutants. The mutation in the BCY1 gene, which codes for the regulatory subunit of cAMP-dependent protein kinase, when homozygous, results in diploids being meiosis and sporulation deficient. Two plasmids, YCp-MAT.alpha. and YEp-SPOT7-lacZ, were introduced into MAT.alpha. BCY1$\^$+/ or MAT.alpha. bcy1 haploid cells. The transformant of the BCY1$\^$+/ haploid cell produced .betha.-galactosidase under nutrient starvation, but the bcy1 transformant did not. Using this system, the mutagenesis experiment performed on the bcy1 transformant strain resulted in a number of sporulation mutants that produced .betha.-galactosidase under nutrient starvation. One complementation group, sob1, was identified from the isoalted suppressor mutants and characterized as a single recessive mutation by tetrad analysis. Genetic analysis revealed that the sob1 mutation suppressed the sporulation deficiency, the failure to arrest at the G1 phase of the cell cecle, and the sensitivity to heat or nitrogen starvation caused by the bcy1 mutation. However, the sob1 mutation did not suppress the sporulation deficiency of ime1 and of ime2 diploids. These results suggest that the sob1 mutation affects a gene which functions as a downstream regulator in both meiosis and cell cycle regulation.

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Water Extract of Allium sativum L. Induces Apoptosis in Human Leukemia U937 Cells through Reactive Oxygen Species Generation (마늘 열수 추출물의 활성산소중 생성을 통한 인체백혈병세포의 apoptosis 유발)

  • Choi, Yung-Hyun
    • Food preservation and processing industry
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    • v.7 no.1
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    • pp.9-18
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    • 2008
  • The health benefits of garlic (Allium sativum L.) are derived from a wide variety of components and from the different ways it is administered. The known health benefits of garlic include cardiovascular protective effects, stimulation of immune function, reduction of blood glucose level, protection against microbial, viral and fungal infections, as well as anticancer effects. In the present study, it was examined the effects of water extract of A. sativum (WEAS) on the growth of cultured human tumor cells in order to investigate its anti-proliferative mechanism. Treatment of WEAS to tumor cells resulted in the growth inhibition, especially in leukemia cells, which was associated with induction of G2/M arrest of the cell cycle and apoptosis. In order to further explore the critical events leading to apoptosis in WEAS-treated U937 human leukemia cells, the following effects of WEAS on components of the mitochondrial apoptotic pathway were examined: generation of reactive oxygen species (ROS), alteration of the mitochondrial membrane potential (MMP), and the expression changes of Bcl-2 and IAP family proteins. The cytotoxic effect of WEAS was mediated by its induction of apoptosis as characterized by the occurrence of DNA ladders, apoptotic bodies and chromosome condensation in U937 cells. The WEAS-induced apoptosis in U937 cells was correlated with the generation of intracellular ROS, collapse of MMP, activation of caspase-3 and down-regulation of anti-apoptotic proteins. The quenching of ROS generation with antioxidant N-acetyl-L-cysteine conferred significant protection against WEAS-elicited ROS generation, caspase-3 activation, G2/M arrest and apoptosis. In conclusion, the present study reveals that the cellular ROS generation plays a pivotal role in the initiation of WEAS-triggered apoptotic death in U937 cells.

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Molecular Prognostic Profile of Egyptian HCC Cases Infected with Hepatitis C Virus

  • Zekri, Abdel-Rahman N.;Hassan, Zeinab K.;Bahnassy, Abeer A.;Sherif, Ghada M.;ELdahshan, Dina;Abouelhoda, Mohamed;Ali, Ahmed;Hafez, Mohamed M.
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.11
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    • pp.5433-5438
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    • 2012
  • Background: Hepatocellular carcinoma (HCC) is a common and aggressive malignancy. Despite of the improvements in its treatment, HCC prognosis remains poor due to its recurrence after resection. This study provides complete genetic profile for Egyptian HCC. Genome-wide analyses were performed to identify the predictive signatures. Patients and Methods: Liver tissue was collected from 31 patients with diagnosis of HCC and gene expression levels in the tumours and their adjacent non-neoplastic tissues samples were studied by analyzing changes by microarray then correlate these with the clinico-pathological parameters. Genes were validated in an independent set by qPCR. The genomic profile was associated with genetic disorders and cancer focused on gene expression, cell cycle and cell death. Molecular profile analysis revealed cell cycle progression and arrest at G2/M, but progression to mitosis; unregulated DNA damage check-points, and apoptosis. Result: Nine hundred fifty eight transcripts out of the 25,000 studied cDNAs were differentially expressed; 503 were up-regulated and 455 were down-regulated. A total of 19 pathways were up-regulated through 27 genes and 13 pathways were down-regulated through 19 genes. Thirty-seven genes showed significant differences in their expression between HCC cases with high and low Alpha Feto Protein ($AFP{\geq}600$ IU/ml). The validation for the microarray was done by real time PCR assay in which PPP3CA, ATG-5, BACE genes showed down-regulation and ABCG2, RXRA, ELOVL2, CXR3 genes showed up-regulation. cDNA microarrays showed that among the major upregulated genes in HCC are sets. Conclusion: The identified genes could provide a panel of new diagnostic and prognostic aids for HCC.

Identification of a Novel PGE2 Regulated Gene in SNU1 Gastric Cancer Cell

  • Park, Min-Seon;Kim, Hong-Tae;Min, Byung-Re;Kimm, Ku-Chan;Nam, Myeong-Jin
    • BMB Reports
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    • v.33 no.2
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    • pp.184-187
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    • 2000
  • Prostaglandin $E_2$ ($PGE_2$) plays an important role in the regulation of various gastric functions, and the growth-inhibitory activities on tumor cells are studied in vitro and in vivo. Although the mechanisms have attracted many researchers in the past decade, the molecular mechanisms of cell cycle arrest, or induction of apoptosis by $PGE_2$, is unclear. We investigated the effects of $PGE_2$ on the growth of the human gastric carcinoma cell line SNU1 and genes that are regulated by $PGE_2$ and isolated them using differential display RT-PCR (DD RT-PCR). FACS analysis suggested that SNU1 cells were arrested at the G1 phase by $PGE_2$ treatment. This growth inhibitory effect was in a time- and dose-dependent manner. Treatment of SNU1 cells with $10\;{\mu}g/ml$ $PGE_2$, followed by DD RT-PCR analysis, revealed differently expressed bands patterns from the control. Among the differently expressed clones, we found an unidentified cDNA clone (HGP-27) overexpressed in $PGE_2$-treated cells. The full-length cDNA of HGP-27 was isolated using RACE, which consisted of a 30-nt 5'-noncoding region, a 891-nt ORF encoding the 296 amino acid protein, and a 738-nt 3'-noncoding region including a poly(a) signal. This gene was localized on the short arm of chromosome number 11. Using the Motif Finder program, a myb-DNA binding repeat signature was detected on the ORF region. The COOH-terminal half was shown to have similarity with the $NH_3$-terminal domain of thioredoxin (Trx). This relation between HGP-27 and Trx implied a potential role for HGP-27 in modulating the DNA binding function of a transcription factor, myb.

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Anti-cancer Effects of Samultang-Gami on HeLa, HepG2, AGS Cells (사물탕가미방(四物湯加味方)의 항암효과에 대한 실험적 연구)

  • Jung, Jae-Joong;Goo, Sun-Young;Goo, Sun-Young;Sung, Jung-Suk;Kim, Dong-Il
    • The Journal of Korean Obstetrics and Gynecology
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    • v.23 no.3
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    • pp.38-55
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    • 2010
  • Purpose: This study was designed to find out the anti-cancer effects of Samultang-Gami which was composed of Rehmanniae Radix(RR), Angelicae Gigantis Radix(AGR), Cnidii Rhizoma(CR), Paeoniae Radix(PR), Cortex Moutan Radicis(CMR), Hedyotis Diffusa(HD) and Caesalpinia Sappan on HeLa, HepG2 and AGS cells. Methods: Various cancer cell lines including HeLa, HepG2 and AGS cells, were used. In vitro anti-cancer effects were measured by MTT assay using cancer cell lines treated with various concentrations of 70% ethanol extract of Samultang-Gami. Expression of cell cycle arrest mediators including Bax, Bcl-2, p53 and DARP-1 proteins were measured by Western blot analysis. Results: 1. Samultang-Gami decreased the viability of HeLa and HepG cells in a dosedependent manner. 2. AGR, CMR, PR and HD decreased the viability of HeLa, HepG2 and AGS cells. 3. We could observe that the decreased Bax and Bcl-2 expression level and the increased PARP-1 expression level by Samultang-Gami extracts treated in HeLa cells. 4. We could observe that the decreased Bcl-2 expression level and the increased Bax, p53 and PARP-1 expression level by RR extracts treated in HeLa cells. and also could observe that the reduction of the protein level of Bcl-2, p53 and PARP-1 and the increase of the protein level of Bax by PR in HeLa cells. 5. We could observe that the increased p53 expression level, the decreased PARP-1's that and the unchanged Bax and Bcl-2's that by Samultang-Gami extracts treated in HepG2 cells. 6. We could observe that the reduced Bcl-2 expression level by each of RR extracts and PR extracts in HepG2 cells. 7. The treatment of Samultang-Gami in AGS cells didn't have any effect on the expression level of Bax, Bcl-2, p53 and PARP-1. 8. We could observe that the increased p53 and PARP-1 expression level by each of CR, RR and PR extracts in AGS cells. Conclusion: Taken together, we suggest that Samultang-Gami exhibits cytotoxic effects on HeLa, HepG2 and AGS cells, causing apoptosis. The results showed that Samultang-Gami may do so by regulating the expression of specific target molecules that promote efficient apoptotic cell death in a dose-dependent manner.

Effects of Arsenic Compounds $(AS_2O_3\;and\;AS_4O_6)$ on the Induction of Apoptotic Cell Death in A549 Human Non-small Cell Lung Cancer Cells (비소화합물에 의한 A549 폐암세포의 증식억제에 관한 연구)

  • Choi, Yung-Hyun;Choi, Woo-Young;Choi, Byung-Tae;Lee, Yong-Tae;Lee, Won-Ho
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.19 no.4
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    • pp.1050-1054
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    • 2005
  • Recently, arsenic compounds were considered as novel agents for treatment of acute promyelocytic leukemia and malignant tumors. However, it showed severe toxicity effect on normal tissue at the same time. In this study, to investigate the possible molecular mechanism (s) of arsenic compounds as candidate of anti-cancer drugs, we compared the abilities of two arsenic compounds, tetraarsenic oxide $(AS_4O_6)$ and arsenic trioxide (diarsenic oxide, $As_2O_3$), to induce cell growth inhibition as well as apoptosis induction in A549 human non-small cell lung cancer cells. Both $As_4O_6\;and\;As_2O_3$ treatment declined the cell growth and viability of A549 cells in a concentration-dependent manner, which was associated with induction of G1 arrest of the cell cycle and apoptotic cell death. However, $As_4O_6$ induced growth inhibition and apoptosis in A549 cells at much lower concentrations than $As_2O_3.\;As_4O_6$ down-regulated the levels of anti-apoptotic Bcl-2 protein, however, the levels of Bax, a pro-apoptotic protein, were up-regulated in a dose-dependent manner. In conclusion, $As_4O_6$ might be a new arsenic compound which may induce apoptosis in A549 cells by modulation the Bcl-2 family and deserves further evaluation.

Inhibition Effects of Lamellarin D on Human Leukemia K562 Cell Proliferation and Underlying Mechanisms

  • Zhang, Nan;Wang, Dong;Zhu, Yu;Wang, Jian;Lin, Hong
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.22
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    • pp.9915-9919
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    • 2014
  • Lamellarin D (LamD) is a marine alkaloid with a pronounced cytotoxicity against a large panel of cancer cells, affecting cell growth and inducing apoptosis. However, the molecular mechanisms of action of this compound are poorly understood. In this study, the anticancer efficacy of LamD was investigated in human leukemia K562 cells. The results showed suppressed cell proliferation and induction of G0/G1-phase arrest,while expression of CDK1, and activity of smad3 and smad5 were reduced, but that of p27, p53 and STGC3 was increased. LamD induced cell apoptosis through activation of caspases-8/-3, inhibition of survivin and Bcl-2, suggesting that this compound may also act through a caspase-independent pathway. Moreover, LamD inhibited the secretion of TGF-${\beta}$, IL-$1{\beta}$, IL-6, IL-8 and other inflammatory cytokines and the transcriptional activity of transcription factor NF-${\kappa}B$ in human leukemia K562 cells.Taken together, our results suggest that LamD-mediated inhibition of leukemia cell proliferation may be related to the induction of apoptosis and the regulation of cell cycle, tumor-related gene expression and cytokine expression, which may provide a new way of thinking for the treatment leukemia.

Silencing of Rac3 Inhibits Proliferation and Induces Apoptosis of Human Lung Cancer Cells

  • Liu, Tie-Qin;Wang, Ge-Bang;Li, Zheng-Jun;Tong, Xiang-Dong;Liu, Hong-Xu
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.7
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    • pp.3061-3065
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    • 2015
  • Background: Rac3, a member of the Rac family of small guanosine triphosphatases (GTPases), regulates a variety of cell functions, including the organization of the cytoskeleton, cell migration, and invasion. Overexpression of Rac3 has been reported in several human cancers. However, the role of Rac3 in lung cancer (LC) has not been determined in detail. The purpose of this study was to investigate the effect of silencing of Rac3 expression in human LC cells and the consequences for cell survival. Materials and Methods: Lentivirus small hairpin RNA (shRNA) interference techniques were utilized to knock down the Rac3 gene. Gene and protein expression was quantified by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting. LC cell apoptosis was examined by annexin V-APC /propidium iodide staining. Results: Efficient silencing of Rac3 strongly inhibited A549 cell proliferation and colony formation ability, and significantly decreased tumor growth. Moreover, flow cytometry analysis showed that knockdown of Rac3 led to G2/M phase cell cycle arrest as well as an excess accumulation of cells in the G1 and S phase. Conclusions: Thus, functional analysis using shRNAs revealed a critical role for Rac3 in the tumor growth of LC cells. shRNA silencing of Rac3 could provide an effective strategy to treat LC.

Evaluation of Glucosinolate Content and Composition Contained in Korean Leaf Mustard (Brassica juncea var. integrifolia) Germplasm Using Liquid Chromatography Electrospray Ionization Mass Spectrometry(LC-ESI-MS/MS)

  • Kim, Jung-Bong;Kim, Heon-Woong;Ko, Ho-Cheol;Kim, So-Young;Kim, Se-Na;Jin, Yong-Xie;Kim, Jae-Hyun
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2010.05a
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    • pp.18-18
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    • 2010
  • Glucosinolates(GSLs) are major secondary products($\beta$-thioglucoside N-hydroxysulfates) containing sulfates that are found mainly in Cruciferae family such as cabbage, broccoli, radish, turnip, kale, mustard and rapeseed as the important crops in agronomic and economic aspects. Especially, isothiocyanates(ITCs) have been shown to inhibit carcinogenesis with regulation cancer cell development followed by regulating target enzymes, inducing cell cycle arrest and apoptosis against various human cancer cell lines. Total desulfo(DS)-GSLs of nine type in 210 Korean leaf mustard accessions were isolated and confirmed using electrospray ionization mass spectrometric(ESI-MS/MS) method and DS-GSLs powerful library maked from several reference data. The isolated individual DS-GSLs were identified by removed $\beta$-D-glucopyranose residue ($C_6H_{11}O_5$, MW 163) from MS/MS data. Among them sinigrin(41.7%), glucoiberverin(21.7%) and gluconasturtiin(12.6%) were major components, Especially, despite gluconapin was minor component, accession K046197-1 and K046197-2 showed higher content of 4.11 and 3.31 mg/g(DW), respectively. The total GSLs contents in 210 accessions were ranged from 5.3 to 23.2 mg/g(DW) with a mean value of 13.0 mg/g(DW). As a result of principal component analysis(PCA), the individual GSLs loading plots were composed of three groups and components belonged to each group showed correlationship in quantitative pattern.

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