• Toxicological Research
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• 제19권2호
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• pp.141-146
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• 2003

A nonspecific immunostimulator $BARODON^{\circledR}$ was tested for mutagenicity using Ames Salmonella tester strains TA98, TA1 00, TA 102, TA 1535 and TA 1537 with or without metabolic activation (59 mix). None of the fresh species showed mutagenicity. In the reverse mutation test using Salmonella phimurium TA98, TA100, TA102, TA1535 and TA1537 did not increase the number of revertants at all doses tested (5, 2.5 or 1.25 mg/ml). Chromosome aberration test was carried out in Chinese hamster lung (CHL) cell line. The cells were treated with $BARODON^{\circledR}$ (1, 0.5 or 0.25 mg/ml), while positive control group was treated with Mitomycin C (0.1 mg/ml). The results show that there is no statistically significant difference between positive control and treatment groups. In mouse micronucleus test, there was significant increase in the ratio of micronucleated polychromatic erythrocyte (MNPCE) in the high dose group (10% $BARODON^{\circledR}$), while there is no significance between control and low (2.5% $BARODON^{\circledR}$) or middle (5% $BARODON^{\circledR}$ dose groups. Taken together, this results suggest that below 5% $BARODON^{\circledR}$ might not have mutagenic potential in vitro and vivo systems.

• Journal of Microbiology and Biotechnology
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• 제20권1호
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• pp.30-38
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• 2010

The contribution of a type II restriction-modification system (R-M system) to genome integrity and cell viability was investigated. We established experimental conditions that enabled the achievement of hemimethylated and unmethylated states for the specific bases of the recognition sequences of the host's DNA. To achieve this, we constructed the MboII R-M system containing only one (i.e., M2.MboII) out of two functional MboII methyltransferases found in Moraxella bovis. Using the incomplete R-M system, we were able to perturb the balance between methylation and restriction in an inducible manner. We demonstrate that upon the SOS-induced DNA repair in mitomycin C treated cells, restriction significantly reduces cell viability. Similar results for the well-studied wild-type EcoRI R-M system, expressed constitutively in Escherichia coli, were obtained. Our data provide further insights into the benefits and disadvantages of maintaining of a type II R-M system, highlighting its impact on host cell fitness.

• 한국미생물·생명공학회지
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• 제25권2호
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• pp.144-150
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• 1997

After DNA damage, umuDC is the only SOS operon that must be induced to promote SOS mutagenesis in Escherichia coli. The recombinant plasmid pBC401 and pBC402 were constructed to fuse the lac structural genes with promoter region of umuDC operon to induce the expression of lacZ gene by DNA damage. We transformed the plasmid pBC401 and pBC402 into E. coli MC1061, lacZ deleted strain and determined the activity of $\beta$-galactosidase for various mutagen; UV, mitomycin C (MMC), N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), 4-nitroqunoline-1-oxide (NQO), ethyl methanesulfonate (EMS). The $\beta$-galactosidase activities of PBC401 and pBC402 for UV, MMC, and NQO were increased in proportion to expression time until 3 hours thereafter, the activities were constant or slightly decreased. The activities for MNNG and EMS were not so high as for UV, MMC, and NQO. When MNNG and EMS were treated, $\beta$-galactosidase activity of pBC402 was slightly lower than pBC401 but when UV, MMC, and NQO were treated in pBC402, $\beta$-galactosidase activity was slightly higher than in pBC401. Therefore, the pBC402 was better than the pBC401 in terms of sensitivity for frameshift mutagen. We suggest that the plasmid pBC401 and pBC402 are easy to detect mutagens which cause frameshift mutation rather than point mutation.

• 한국자원식물학회지
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• 제1권1호
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• pp.8-22
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• 1988

Vincristine and vinblastine isolated from Vinco spp. , and podophyllotoxine derivatives isolated from Podophyllum spp. are usefulas anticancerous components obtaned from higher plants. More thanten antineoplastic compounds are now following them as anticancerousagents from higher plants. In my laboratory, Sarcoma 180A has beenused as the first screening test. By this method, I have found outsome kinds of antineoplastic constituents from active plants extracts .For instance, bisaborane type compounds were isolated from Curcumaxanthorrhiza, one of Indonesian plants; a morphinane type compoundfromCocculus trilobus; cyclic hexapeptides from Rubia akane and R.cordiorta. Seven components having antineoplastic actirity wereisolated from Rubia spp. except. R. tinctoria. Their structures wereelucidated except RA-Vl by chemical reaction and variovs instrumentalanalysis as shown in Fig. Among of them, RA-Vll showed strong activityagainst P388 Lymphocytic leukemia, L2O, B16 melanoma, Lewis lungcarcinoma, colon 38 and Ehrlich carcinoma. RA-V revealed excellentactivity against MM2 mammary carcinoma. The· value of acute LD5O ofRA-ViI were 10. Omg/kg( iP) and 16.5mg/kg( po ) respectiveIy . Therapruticratio was 400, compared with 10 of mitomycin C. QSAR was also appliedto these compounds by elongation of ether and ester side chains atR'. Mechanism of action of RA-Vll was also investigated and wasassumed to be inhibition of protein biosynthesis .

• 한국환경성돌연변이발암원학회지
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• 제22권2호
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• pp.106-111
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• 2002

AG6O, the complex of acriflavine and guanosine, has been shown to possess the synergistic antitumorigenic activity in the previous paper (J. Pharm. Pharmacol. 1997, 49:216). In this study, we have investigated the genotoxic properties of AG60 using in vitro and in vivo system such as Ames bacterial reversion test, chromosomal aberration assay and micronucleus assay. In Ames reverse mutation test, AG60 treatment at the dose range up to 250 $\mu\textrm{g}$/plate caused the dose-independent random induction of the mutagenic colony formation in S. typhimurium TA98, TA100, TA1537, and E. coli WP2uvrA, while any mutagenic effect of AG60 wasn't observed in S. typhimurium TA1535. Any significant chromosomal aberration wasn't observed in chinese hamster lung (CHL) fibroblast cells incubated with PBS or AG60 at the concentrations of 2.5, 5, 10 $\mu\textrm{g}$/$m\ell$ for 24 hours without but even with 59 metabolic activation system for 6 hours. In vivo ICR mice, the intramuscular injection of AG60 at the doses of 7.15, 14.3, and 28.6 mg/kg did not induce the frequency of micronucleus formation. However, mitomycin C, as one of the positive controls at the dose of 2 mg/kg caused the 8.4% induction in the frequency of micronucleus and 24% increase in the chromosomal aberration.

• BMB Reports
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• 제48권11호
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• pp.609-617
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• 2015

NAD(P)H:quinone oxidoreductase (NQO1), an obligatory two-electron reductase, is a ubiquitous cytosolic enzyme that catalyzes the reduction of quinone substrates. The NQO1- mediated two-electron reduction of quinones can be either chemoprotection/detoxification or a chemotherapeutic response, depending on the target quinones. When toxic quinones are reduced by NQO1, they are conjugated with glutathione or glucuronic acid and excreted from the cells. Based on this protective effect of NQO1, the use of dietary compounds to induce the expression of NQO1 has emerged as a promising strategy for cancer prevention. On the other hand, NQO1-mediated two-electron reduction converts certain quinone compounds (such as mitomycin C, E09, RH1 and β-lapachone) to cytotoxic agents, leading to cell death. It has been known that NQO1 is expressed at high levels in numerous human cancers, including breast, colon, cervix, lung, and pancreas, as compared with normal tissues. This implies that tumors can be preferentially damaged relative to normal tissue by cytotoxic quinone drugs. Importantly, NQO1 has been shown to stabilize many proteins, including p53 and p33ING1b, by inhibiting their proteasomal degradation. This review will summarize the biological roles of NQO1 in cancer, with emphasis on recent findings and the potential of NQO1 as a therapeutic target for the cancer therapy.

• 한국임상수의학회지
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• 제35권4호
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• pp.161-165
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• 2018

A 12-year-old gelding Warmblood Horse was presented with a corneolimbal mass in the right eye (OD) of 6 months duration. Clinical signs included ocular discomfort, persistent mucoid ocular discharge, and conjunctival hyperemia. The mass was excised by superficial keratectomy under sedation in a standing position, followed by a topical application of 0.04% mitomycin C (MMC), and a placement of a conjunctival advancement graft. The histopathological diagnosis was squamous cell carcinoma. One month after surgery, recurrence of the mass was suspected upon examination of the eye. Topical MMC and 5-fluorouracil followed by cryotherapy were applied as adjunctive therapies after debulking of the mass. The surgical site healed without complications and with a cosmetically acceptable result. No recurrence of the mass was noted four years following the second procedure.

• Asian Pacific Journal of Cancer Prevention
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• 제13권7호
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• pp.3343-3347
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• 2012

The aim of this study was to investigate the anticlastogenicity as well as the clastogenicity of Eryngium foetidum leaf (EF) using the in vivo mouse peripheral blood erythrocyte micronucleus assay. Eighty ICR male mice were fed AIN-76 diet supplemented with ground freeze-dried EF at 0.0%, 0.8%, 1.6% and 3.2% for 2 weeks prior to the administration of both direct-acting, mitomycin C (MMC), and indirect-acting, 7, 12-dimethylbenz(a) anthracene (DMBA) clastogens. Peripheral blood samples were collected from mice just before administration of clastogen and at 24 and 48 h thereafter for MMC. Blood samples were collected at the same times and after 72 h for DMBA. Then, reticulocytes in blood samples were counted using fluorescent microscopy. The results indicated that EF had no clastogenic effect in mice. All doses of diets supplemented with EF decreased the number of micronucleated peripheral reticulocytes in all the MMC-treated groups in a dose dependent manner, but significant reduction was found only at 1.6% and 3.2% EF in the DMBA-treated groups. It can be concluded that EF has no clastogenicity, but possesses anticlastogenic potential against both direct- and indirect-acting types of clastogen in mice.

• Molecules and Cells
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• 제22권2호
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• pp.203-209
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• 2006

TBP (TATA-binding protein)-related factor 2 (TRF2) regulates transcription during a nuber of cellular processes. We previously demonstrated that it is localized in the cytoplasm and is translocated to the nucleus by DNA-damaging agents. However, the cytoplasmic localization of TRF2 is controversial. In this study, we reconfirmed its cytoplasmic localization in various ways and examined its nuclear migration. Stresses such as heat shock, redox agents, heavy metals, and osmotic shock did not affect localization whereas genotoxins such as methyl methanesulfonate (MMS), cisplatin, etoposide, and hydroxyurea caused it to migrate to the nucleus. Adriamycin, mitomycin C and ${\gamma}$-rays had no obvious effect. We determined optimal conditions for the nuclear migration. The proportions of cells with nuclei enriched for TRF2 were 25-60% and 5-10% for stressed cells and control cells, respectively. Nuclear translocation was observed after 1 h, 4 h and 12 h for cisplatin, etoposide and MMS and hydroxyurea, respectively. The association of TRF2 with the chromatin and promoter region of the proliferating cell nuclear antigen (PCNA) gene, a putative target of TRF2, was increased by MMS treatment. Thus TRF2 may be involved in genotoxin-induced transcriptional regulation.

• 한국동물학회지
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• 제37권2호
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• pp.232-239
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• 1994

RecA protein plans a central role in homologous recombination and DNA repair in Escherichia cofi (E. colD. The function 8nd structure of this protein are universal in prokarvotes and also conserved in eukaryotes such as yeast. The RecA-like protein with 74 lInDa in size has already been identified and purified from a fission yeast Schizosaccharomyces pombe (5. pommel (Lee, 19911. From this study it was revealed that the RecA-like protein of 5. pombe was highly inducible to various DNA damaging agents and inhibitors of nucleotide pool svnthesizins enzymes. The cellular level of the 5. pombe RecA-like protein wi,u markedly increased, upto 5- to 10-fold, by treatment with various DNA-damains agents including ultraviolet (UV) light, methyl methanesulfonate WS),4-nitroquinoline-1-oxide (4-NQO), and mitomycin-C (MMC), similar to E. cofi RecA protein. Interestingly, the protein level was also increased by inhibitors of nucleotide pool forming enzlwnes such as methotrexate (MTX) and hvdroxvurea (HU). The most effective doses for the inducibility of 4-NQO, MMS, W, MMC, MTX, and HU were 0.2 Ug/ml, 30 mM, 200 J/ma, 0.4 $\mus/ml,$ 1 Ug/ml, and 100 mM, respectively. The range of effective duration time for the inducibilitv of RecA-like protein was from 270 to 450 mins. These results suggest that the 5. pombe RecA-like protein also platys an imortant role in cellular responses to DNA damage as in E. coli system.