Mechanism of cell cycle arrest and apoptosis induction by conjugated eicosapentaenoic acid, which is a mammalian DNA polymerase and topoisomerase inhibitor

Yonezawa, Yasuo; Hada, Takahiko; Uryu, Keisuke; Tsuzuki, Toshio; Nakagawa, Kiyotaka; Miyazawa, Teruo; Yoshida, Hiromi; Mizushina, Yoshiyuki

doi:10.3892/ijo.30.5.1197

Cited by 9 publications

(15 citation statements)

References 41 publications

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“…The enzyme activity was dose-dependently From the cell extracts, total pol activity was measured as described previously (7,8). One unit of pol activity is defined as the amount that catalyzes the incorporation of 1 nmol dexyribonucleoside triphosphate (i.e., dTTP) into synthetic template-primers [i.e., poly(dA)/oligo(dT) [12][13][14][15][16][17][18] , A/T=2/1] at 37˚C in 60 min. Values are the means ± SEM of four independent experiments.…”

Section: Resultsmentioning

confidence: 99%

“…Nucleotides and chemically synthesized DNA template primers, such as poly(dA) and oligo(dT) [12][13][14][15][16][17][18] , and radioisotope reagents, such as [ 3 H]-dTTP (2'-deoxythymidine 5'-triphosphate) (43 Ci/mmol), were purchased from GE Healthcare Bio-Science Corp. (Piscataway, NJ, USA). All other reagents were of analytical grade and purchased from Nacalai Tesque Inc. (Kyoto, Japan).…”

Section: Methodsmentioning

confidence: 99%

“…dTTP) into the synthetic DNA template-primers [i.e. poly(dA)/oligo(dT) [12][13][14][15][16][17][18] , A/T=2/1] in 60 min at 37˚C under normal reaction conditions for the enzyme (7,8).…”

Section: Dna Polymerase Assay Of the Cell Extract Hct116 Cells Were mentioning

confidence: 99%

“…The pol activity of the cell extract was measured as described previously (7,8). Poly(dA)/oligo(dT) [12][13][14][15][16][17][18] and dTTP were used as the DNA template-primer and nucleotide substrate, respectively. One unit of pol activity was defined as the amount of enzyme that catalyzed the incorporation of 1 nmol dNTP (2'-deoxyribonucleotide 5'-triphosphate, i.e.…”

Section: Dna Polymerase Assay Of the Cell Extract Hct116 Cells Were mentioning

confidence: 99%

“…We previously realized the importance of the two classes of n-3 PUFA; EPA and DHA, normal and conjugated, and the inhibitory effect of cEPA on pols was stronger than that of EPA, DHA and cDHA (15). Furthermore, cEPA regulates the cell cycle by DNA damage-response proteins, including the ataxia-telangiectasia mutated-and Rad3-related protein kinase (ATR)-Chk1/2 pathway without influencing the proliferation of normal cells (16,17). Radiotherapy is one of the most commonly used therapeutic modalities in cancer treatment.…”

Section: Introductionmentioning

confidence: 99%

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Enhancement of human cancer cell radiosensitivity by conjugated eicosapentaenoic acid - a mammalian DNA polymerase inhibitor

Kumamoto-Yonezawa

Sasaki²,

Suzuki³

et al. 2010

Int J Oncol

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Abstract. We previously found that conjugated eicosapentaenoic acid (cEPA) selectively inhibited the activities of mammalian DNA polymerases (pols), and suppressed human cancer cell growth. The aim of the present study was to evaluate the efficacy of concurrent radiation with cEPA in a human colon carcinoma cell line, HCT 116. Furthermore, we examined the most effective timing of irradiation. The postirradiation addition of cEPA significantly enhanced HCT116 cell radiosensitivity by decreasing the expression of pols ß, ‰ and Â, increasing damaged DNA, such as DNA double-strand breaks, inhibiting clonogenic survival, and inducing apoptosis. However, cells treated by pre-irradiation addition of cEPA did not influence radiosensitive survival and radiation-induced apoptosis. cEPA inhibited the activities of pols needed for DNA repair, thereby DNA damage must be augmented by cEPA and irradiation. These results suggested that the combination of inhibitors of DNA repair-related pols/radiation could be an effective anticancer therapy. IntroductionDNA polymerases (pol, i.e., DNA-dependent DNA polymerases, E.C. 2.7.7.7) catalyze the addition of deoxyribonucleotides to the 3'-hydroxyl terminus of primed doublestranded DNA molecules, and are involved in producing vital cellular processes, such as DNA replication, repair and recombination (1). The human genome encodes at least 15 pols to conduct cellular DNA synthesis (2,3). Eukaryotic cells contain three replicative pols (·, ‰ and Â), mitochondrial pol Á, and at least 13 repair-related pols; ß, ‰, Â, ˙, Ë, ı, È, Î, Ï, Ì, Ó, terminal deoxynucleotidyl transferase (TdT) and REV1 (2-4). Pols have recently emerged as important cellular targets for chemical intervention in the development of anticancer agents.We have been screening for pol inhibitors from natural products (5,6), and found that mammalian pols · and ß are inhibited by linear-chain fatty acids with the following characteristics: 1) C18-or more carbon chains, 2) a free carboxylic group, and 3) double bonds of cis-configuration, n-3 polyunsaturated fatty acid (PUFA) having the strongest inhibitory effect of any fatty acid tested (7,8). Eicosapentaenoic acid (EPA; 5Z8Z11Z14Z17Z-20:5) and docosahexanoic acid (DHA; 4Z7Z10Z13Z16Z19Z-22:6), both n-3 PUFAs, exert significant inhibitory effects on colon carcinoma cell growth at the primary site and metastases (9,10). PUFA are present at high concentrations in some fish oils, and have been evaluated in various clinical trials in which they have proved to be safe and well tolerated.Conjugated fatty acids are positional and geometrical isomers with several conjugated double bonds. Fatty acids with conjugated double bonds exist in nature; seaweeds such as red and green algae contain highly n-3 unsaturated conjugated fatty acids, i.e., conjugated eicosapentaenoic acid (cEPA; 5Z7E9E14Z17Z-20:5), bosseopentaenoic acid (5Z8Z10E12E14Z-20:5) and stellaheptaenoic acid (4Z7Z9 E11E13Z16Z19Z-22:7) (11,12). As n-3 PUFAs have been shown to have anticarcinogenic activity, conjugated fatty ac...

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Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

“…dTTP) into the synthetic DNA template-primers [i.e. poly(dA)/oligo(dT) [12][13][14][15][16][17][18] , A/T=2/1] in 60 min at 37˚C under normal reaction conditions for the enzyme (7,8).…”

Section: Dna Polymerase Assay Of the Cell Extract Hct116 Cells Were mentioning

confidence: 99%

Section: Dna Polymerase Assay Of the Cell Extract Hct116 Cells Were mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Enhancement of human cancer cell radiosensitivity by conjugated eicosapentaenoic acid - a mammalian DNA polymerase inhibitor

Kumamoto-Yonezawa

Sasaki²,

Suzuki³

et al. 2010

Int J Oncol

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A Novel DNA Topoisomerase I Inhibitor with Different Mechanism from Camptothecin Induces G2/M Phase Cell Cycle Arrest to K562 Cells

Agama

et al. 2010

Biochemistry

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DNA topoisomerase I (Top1) is an essential nuclear enzyme and a validated target for anticancer agent screening. In a previous study, we found that indolizinoquinoline-5,12-dione derivatives show significant biological activity against several human cancer cell lines. To understand their mechanism of inhibition of cancer cell growth, one indolizinoquinoline-5,12-dione derivative, CY13II, was further studied as lead. Our present results indicate that CY13II shows more potent antiproliferative activity against K562 cells than camptothecin. Additionally, K562 cells were arrested in G2/M and their growth rate decreased after treatment with CY13II at micromolar concentration. Biochemical Top1 assays indicate that CY13II exhibits a different inhibitory mechanism from camptothecin. Unlike camptothecin, CY13II specifically inhibits the catalytic cleavage activity of Top1 instead of forming drug-enzyme-DNA covalent ternary complex.

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Effect of oxindolimine copper(ii) and zinc(ii) complexes on human topoisomerase I activity

Katkar¹,

Coletta²,

Castelli³

et al. 2014

Metallomics

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The ability of oxindolimine copper(II) and zinc(II) complexes, known to have antitumor activity, to inhibit human topoisomerase IB has been tested through enzymatic kinetic assays and molecular docking simulations. These copper and zinc compounds are able to inhibit remarkably the cleavage reaction and only partially the religation step, the copper compound being more efficient than the zinc one. A complete inhibition activity of the cleavage is only obtained when the enzyme is pre-incubated with the compound, the inhibition being irreversible and reversible for the copper and zinc compounds, respectively. The relative stability of such complexes was estimated by competitive equilibria with human serum albumin (HSA), monitored by CD spectroscopy. The copper species shows a log KCuL = 17.2, while the analogous zinc complex exhibits a log KZnL = 7.2. Molecular docking simulation studies show that the almost square planar geometry of the copper compound allows a direct coordination of the metal with two amino acids (Glu492, Asp563) of the enzyme at variance of the zinc compound which has a more tetrahedral geometry. Altogether, the data indicate that the different coordination geometry achieved by the two transition metal ions has an important role in modulating their efficiency as topoisomerase I inhibitors.

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Mechanism of cell cycle arrest and apoptosis induction by conjugated eicosapentaenoic acid, which is a mammalian DNA polymerase and topoisomerase inhibitor

Cited by 9 publications

References 41 publications

Enhancement of human cancer cell radiosensitivity by conjugated eicosapentaenoic acid - a mammalian DNA polymerase inhibitor

Enhancement of human cancer cell radiosensitivity by conjugated eicosapentaenoic acid - a mammalian DNA polymerase inhibitor

A Novel DNA Topoisomerase I Inhibitor with Different Mechanism from Camptothecin Induces G2/M Phase Cell Cycle Arrest to K562 Cells

Effect of oxindolimine copper(ii) and zinc(ii) complexes on human topoisomerase I activity

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