• BMB Reports
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• v.51 no.2
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• pp.92-97
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• 2018

B cell leukemia/lymphoma 3 (Bcl3) plays a pivotal role in immune homeostasis, cellular proliferation, and cell survival, as a co-activator or co-repressor of transcription of the $NF-{\kappa}B$ family. Recently, it was reported that Bcl3 positively regulates pluripotency genes, including Oct4, in mouse embryonic stem cells (mESCs). However, the role of Bcl3 in the maintenance of pluripotency and self-renewal activity is not fully established. Here, we report the dynamic regulation of the proliferation, pluripotency, and self-renewal of mESCs by Bcl3 via an influence on Nanog transcriptional activity. Bcl3 expression is predominantly observed in immature mESCs, but significantly decreased during cell differentiation by LIF depletion and in mESC-derived EBs. Importantly, the knockdown of Bcl3 resulted in the loss of self-renewal ability and decreased cell proliferation. Similarly, the ectopic expression of Bcl3 also resulted in a significant reduction of proliferation, and the self-renewal of mESCs was demonstrated by alkaline phosphatase staining and clonogenic single cell-derived colony assay. We further examined that Bcl3-mediated regulation of Nanog transcriptional activity in mESCs, which indicated that Bcl3 acts as a transcriptional repressor of Nanog expression in mESCs. In conclusion, we demonstrated that a sufficient concentration of Bcl3 in mESCs plays a critical role in the maintenance of pluripotency and the self-renewal of mESCs via the regulation of Nanog transcriptional activity.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.105-105
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• 2003

In previous reports, pVPSV.IGR2.1 transgenic mouse were described that brain tumor and lymphoma by reason of Vasopressin-SV40 T antigen. In this study, we produced pVPSV.IGR3.6 transgenic mouse that used pVPSV.IGR3.6 vector. Expression of transgene was vary different in transgenic mouse. We obtained 6 transgenic mouse line, moreover they had died at the age of 2-6 weeks without transmitting the transgene to their offspring, and had tumorigenesis on same location with pVPSV.IGR2.1 transgenic mouse. Only a founder mouse was investigated for expression of fusion gene. Here we extended this transgenic approach to the study of tumor progression. From the mouse, we confirmed brain tumor cell, after then cultured for investigate characterization. In this report, we demonstrate that reduction of survival rate in transgenic mouse fused vasopressin gene length, acquisition of brain tumor cell, composition with astrocyte cells and neuronal cells. Finally, cells had no change with increase of passage.

• Molecular & Cellular Toxicology
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• v.3 no.1
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• pp.23-30
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• 2007

The effects of high energy short wave solar radiation on human skin have received much publicity as the major cause of accelerated skin ageing and of skin cancers. To meet public demand, the cosmetic industry has developed sun protection factor products, which contain a variety of so-called "UV filters", among others benzophenone (BP) and its metabolites are the widely used UV filters. UV filters are also used to prevent UV light from damaging scents and colors in a variety of cosmetics products and to protect of plastic products against light-induced degradation. There are many variants of BP in use. In this respect, to regulate and to evaluate the hazardous effect of BP-type UV filters will be important to environment and human health. The genotoxicity of 7 BP-type UV filters was evaluated in L5178Y $(tk^{+/-})$ mouse lymphoma cells in vitro. BP, benzhydrol, 4-hydroxybenzophenone 2-hydroxy-4-methoxybenzophenone and 2, 4-dihydroxybenzophenone did not induce significant mutation frequencies both in the presence and absence of metabolic activation system. 2, 2'-Dihydroxy-4-methoxybenzophenone appeared the positive results at the highest dose, i.e. 120.4 ${\mu}g/mL$ only in the absence of metabolic activation system. And also, 2, 3, 4-trihydroxybenzophenone revealed a significant increase of mutation frequencies in the range of 138.1-207.2 ${\mu}g/mL$ in the absence of metabolic activation system and 118.3-354.8 ${\mu}g/mL$ in the presence of metabolic activation system. Through the results of MLA with 7 BP-type UV filters in L5178Y cells in vitro, we may provide the important clues on the genotoxic potentials of these BP-type UV filters.

• Environmental Mutagens and Carcinogens
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• v.21 no.2
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• pp.89-94
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• 2001

Recently, single cell gel electrophoresis, also known as comet assay, is widely used for the detection and measurement of DNA strand breaks in vitro and in vivo in many toxicological fields such as radiation exposure, human monitoring and toxicity evaluation. As well defined, comet assay is a sensitive, rapid and visual method for the detection of DNA strand breaks in individual cells. Briefly, a small number of damaged cells suspended in a thin agarose gel on a microscope slide were lysed, unwinded, electrophoresed, and stained with a fluorescent DNA binding dye. The electric current pulled the charged DNA from the nucleus such that relaxed and broken DNA fragments migrated further. The resulting images which were subsequently named for their appearance as comets, were measured to determine the extent of DNA damages. However, some variations could be occurred in procedures, laboratories's conditions and kind of cells used. Hence, to overcome and to harmonize these matters in comet assay, International Workshop on Genotoxicity Test Procedure (IWGTP) was held with several topics including comet assay at Washington D.C. on March, 1999. In spite of some consensus in procedures and conditions in IWGTP, there are some problems still remained to be solved. In this respect, we attempted to set the practical optimal conditions in the experimental procedures such as lysis, unwinding, electrophoresis and neutralization conditions and so on. First of all, we determined optimal lysis and unwinding time by using 150 $\mu$M methyl methanesulfonate (MMS) which is usually used concentration. And then, we determined optimal positive control concentrations of benzo(a)pyrene (BaP) and MMS in the presence and absence of S9 metabolic activation system, respectively.

• Archives of Pharmacal Research
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• v.17 no.6
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• pp.480-482
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• 1994

A number of 5-substituted pyrimidine acyclic nucleosides were synthesized and tested for invitor cytotoxicity against four cell lines (j-82 cell, p-388 cell, FM-3A cell and U-938 cell lines). Synthesis of 1-cyanomethyl-5-substituted pyrimidines (1a-e) and 1-(4-cyanobutyl)-5-substituted pyrimidines (2a-e) was acomplished from the series of alkylation reactions ofl 5-substituted uracils with the corresponding chloacetonitrile and 5-chlorovaleronitile in DMSO under $50^{\circ}C$ temperature. These 5-substituted pyrimidine acylic nucleosides (1a-e and 2a-e) exhibited moderate to significant acitivity aginst four cell lines.

• Archives of Pharmacal Research
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• v.17 no.3
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• pp.135-138
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• 1994

Acyclonucleoside homologues of 1-$(\omega$-cyabnoalkyl)-and 1, 3-bis $(\omega$-cyanoalkyl) uracils were synthesized by the series of alkylation reactions of uracil with the $\omega$-chloroalkyl nitrile ${(Cl-(CH}_2)_n$-CN;n=1, 2, 3, 4) in DMSO under $50-70^circ{C}$ temperature. The 1-$(\omega$-cyanoalkyl)-and 1, 3-bis$(\omega$-cyanoalkyl) uracils were separated either by the fractional crystallization or column chromatography. The antitumor activities for these synthesized compounds were determined against four cell lines (J-82 cell, P388 cell, FM-3A cell and U-937 cell lines). These compounds failed to exhibit any significant antitumor activity.

• Archives of Pharmacal Research
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• v.19 no.1
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• pp.62-65
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• 1996

A homologous series of twenty, hitherto unreported, analogues of 5-halosubstituted $1, 3-Bis(\omega-cyanoalkyl)uracil$acyclic nucleosides were synthesized by the series of alkylation reactions of 5-halouracils with the corresponding chloroacetonitrile, chloropropionitrile, chlorobutyronitrile and 5-chlorovaleronitrile $(Cl-(C_ 2)_n-CN: n=l, 2, 3, 4)\; in\; anhydrous\; DMSO\; (or DMF)/K_2CO_3(or NaH)\; under\; 75^{\circ}C$ temperature. Antitumor activities for the synthesized compounds were determined against three cell lines (FM-3A cell, P-388 cell and U-938 cell lines). The compounds that exhibited moderate activity to significant activity, included la-b, 2a-b, 3a-c, and 4a, whose compounds were active against P-388, FM-3A and U-937 cell lines with the compounds la, lb, and 2a, showing significant antitumor activity (inhibitory concentrations $(IC_{50})$ ranged from 2.2 to $7.0\mug/ml$). Their strucrure-activity relationship did not show any activity differences in their effective chain length (methyl, ethyl, propyl, butyl) in 1, 3-bis(.omega.-cyanoalkyl) uracils.

• Molecular & Cellular Toxicology
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• v.2 no.3
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• pp.176-184
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• 2006

The controversy on genotoxicity of molinate, an herbicide, has been reported in bacterial system, and in vitro and in vivo mammalian systems. To clarify the genotoxicity of molinate, we performed bacterial gene mutation test, in vitro chromosome aberration and mouse lymphoma $tk^{+/-}$ gene assay, and in vivo micronucleus assay using bone marrow cells and peripheral reticulocytes of mice. In bacterial gene mutation assay, no mutagenicity of molinate ($12-185{\mu}g/plate$) was observed in Salmonella typhimurium TA 98, 100, 1535 and 1537 both in the absence and in the presence of S-9 metabolic activation system. The clastogenicity of molinate was observed in the presence ($102.1-408.2\;{\mu}g/mL$) of metabolic activation system in mammalian cell system using Chinese hamster lung fibroblast. However, no clastogenicity was observed in the absence ($13.6-54.3\;{\mu}g/mL$) of metabolic activation system. It is suggested that the genotoxicity of molinate was derived some metabolites by metabolic activation. Molinate was also subjected to mouse lymphoma L5178Y $tk^{+/-}$ cells using microtiter cloning technique. In the absence of S-9 mixture, mutation frequencies (MFs) were revealed $1.4-1.9{\times}10^{-4}$ with no statistical significance. However, MFs in the presence of metabolic activation system revealed $3.2-3.4{\times}10^{-4}$ with statistical significance (p<0.05). In vivo micronucleus (MN) assay using mouse bone marrow cells, molinate revealed genotoxic potential in the dose ranges of 100-398 mg/kg of molinate when administered orally. Molinate also subjected to acridine orange MN assay with mouse peripheral reticulocytes. The frequency of micronucleated reticulocytes (MNRETs) induced 48 hr after i.p. injection at a single dose of 91, 182 and 363 mg/kg of molinate was dose-dependently increased as $10.2{\pm}4.7,\;14.6{\pm}3.9\;and\;28.6{\pm}6.3\;(mean{\pm}SD\;of\;MNRETs/2,000\;reticulocytes)$ with statistical significance (p<0.05), respectively. Consequently, genotoxic potential of molinate was observed in in vitro mammalian mutagenicity systems only in the presence of metabolic activation system and in vivo MN assay using both bone marrow cells and peripheral reticulocytes in the dose ranges used in this experiment. These results suggest that metabolic activation plays a critical role to express the genotoxicity of molinate in in vitro and in vivo mammalian system.

• Molecular & Cellular Toxicology
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• v.2 no.3
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• pp.151-158
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• 2006

Khal was a synthetic congener of halocidin, a heterodimeric peptide consisting of 19 and 15 amino acid residues detected in Halocynthia aurantium. This compound was considered a candidate for the development of a novel peptide antibiotic. The genotoxicity of Khal was subjected to high throughput toxicity screening (HTTS) because they revealed strong antibacterial effects. Mouse lymphoma thymidine kinase ($tk^{+/-}$) gene assay (MOLY), single cell gel electrophoresis (Comet) assay and chromosomal aberration assay in mammalian cells and Ames reverse mutation assay in bacterial system were used as simplified, inexpensive, short-term in vitro screening tests in our laboratory. These compounds are not mutagenic in S. typhimurium TA98 and TA100 strains both in the presence and absence of metabolic activation. Before performing the comet assay, $IC_{20}$ of Khal was determined the concentration of $25.51\;{\mu}/mL\;and\;21.99\;{\mu}g/mL$ with and without S-9, respectively. In the comet assay, Khal was not induced DNA damage in mouse lymphoma cell line. Also, the mutation frequencies in the Khal-treated cultures were similar to the vehicle controls. It is suggests that Khal is non-mutagenic in MOLY assay. And no clastogenicity was observed in Khal-treated Chinese hamster lung cells. The results of this battery of assays indicate that Khal has no genotoxic potential in bacterial or mammalian cell systems. Therefore, we suggest that Khal, as the optimal candidates with both no genotoxic potential and antibacterial effects must be chosen.

• Environmental Analysis Health and Toxicology
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• v.22 no.3
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• pp.263-269
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• 2007

Chitosan is a depolymerized and partially deacetylated derivative of chitin. We investigated the cytotoxicity of chitosan in cancer cell lines, such as P388, L1210, HCT-15, SK-HepG-1 and mouse splenocytes as a normal cell by MTT assay. To clarify whether chitosan enhances cytotoxicity of anticancer drugs, we also examined the cytotoxicity of combined treatment with chitosan and anticancer drugs, such as cisplatin, mitomycin C, and 5-fluorouracil in cancer cell lines in vitro. Chitosan ($37.5\;{\mu}g/mL,\;75\;{\mu}g/mL,\;112.5\;{\mu}g/mL,\;and\;150\;{\mu}g/mL$) showed concentration-dependent cytotoxicity in the cancer cell lines. In addition, chitosan showed relatively lower cytotoxicity in normal cells than in the cancer cell lines. Particularly, this trend was significant at high doses of chitosan, i.e. $112.5\;{\mu}g/mL,\;and\;150\;{\mu}g/mL$. Thus, these results suggest that chitosan may selectively induce the growth inhibition in cancer cell lines, compared to normal cells. Furthermore. the co-treatment of chitosan and anticancer drugs exhibited an apparant synergistic cytotoxicity in murine lymphoma cell lines, i.e. P388 and L1210 at $37.5\;{\mu}g/mL$ of chitosan rather than at $75\;{\mu}g/mL$ of chitosan, but such phenomenon could not be observed in solid tumor cell lines, i.e. HCT-15 and SK-HepG-1. However, chitosan did'nt reduced the cytotoxicity against normal mouse splenocytes induced by anticancer drugs. Therefore, it is concluded that the combination of chitosan and anticancer drugs might be useful for the cancer chemotherapy.