• Biomolecules & Therapeutics
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• v.19 no.2
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• pp.174-180
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• 2011

Experiments were carried out to determine the role of Raf-1 kinase in the development of drug resistance to paclitaxel in v-H-ras transformed NIH 3T3 fibroblasts (Ras-NIH 3T3). We established a multidrug-resistant cell line (Ras-NIH 3T3/Mdr) from Ras-NIH 3T3 cells by stepwise increases in paclitaxel. Drug sensitivity assays indicated that the $IC_{50}$ value for drug-resistant Ras-NIH 3T3/Mdr cells was more than 1 ${\mu}M$ paclitaxel, 10- or more-fold higher than for the parental Ras-NIH 3T3 cells. Western blot and RT-PCR analysis showed that the drug efflux pump a P-glycoprotein were highly expressed in Ras-NIH 3T3/Mdr cells, while not being detectable in Ras-NIH 3T3 cells. Additionally, verapamil, which appears to inhibit drug efflux by acting as a substrate for P-glycoprotein, completely reversed resistance to paclitaxel in Ras-NIH 3T3/Mdr cell line, indicating that resistance to paclitaxel is associated with overexpression of the multidrug resistance gene. Interestingly, Ras-NIH 3T3/Mdr cells have higher basal Raf-1 activity compared to Ras-NIH 3T3 cells. Unexpectedly, however, the colocalization of Raf-1 and its negative regulator Spry2 was less observed in cytoplasm of Ras-NIH 3T3/Mdr cells due to translocation of Spry2 around the nucleus in the perinuclear zone, implying that Raf-1 may be released from negative feedback inhibition by interacting with Spry2. We also showed that shRNA-mediated knockdown of Raf-1 caused a moderate increase in cell susceptibility to paclitaxel. Thus, the results presented here suggest that a Raf-1-dependent pathway plays an important role in the development of acquired drug-resistance.

• The Korea Journal of Herbology
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• v.21 no.4
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• pp.143-148
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• 2006

Objectives : It is demonstrated that oxygen free radicals have cytotoxic effect on NIH3T3 fibroblast cells. Recently, many of herb extracts have an effect of antioxidant in oxygen free radical-induced cytotoxicity. But, the toxic mechanism of oxygen free radical is left unknown. The purpose of this study was to examine the cytotoxicity of hydrogen peroxide ($H_2O_2$) and antioxidant effect of Citri reticulatae pericarpium (CRP) on NIH3T3 fibroblasts. Methods : The cytotoxicy was measured by cell viability by XTT assay in NIH3T3 fibroblasts. XTT assay is regarded as a very sensitive screening method for the determination of the cell viability on various chemicals. Results : In this study, H2O2 decreased cell viability according to the dose- and time dependent manners after NIH3T3 fibroblasts were treated with various concentrations of H2O2 for 4 hours. And also, CRP showed the effect of antioxidant on $H_2O_2-induced $ cytotoxicity in cultured NIH3T3 fibroblasts. Conclusion : These results suggest that $H_2O_2$ has highly cytotoxic effect on cultured NIH3T3 fibroblasts by the decrease of cell viavility, and the herb extract such as CRP was showed the effect of antioxidant on $H_2O_2-induced$ cytotoxicity in these cultures.

• Korean Journal of Microbiology
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• v.27 no.1
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• pp.10-15
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• 1989

The plasmid pKOneo, containing SV40 transcriptional promoter, has been used in the mouse tumorigenicity assay for oncogene studies. This assay employs a cotransfection of NIG3T3 fibroblast cells with the desired DNA and the plasmid pKOneo. This oncogene assay, however, has been speculated due to the SV40 transcriptional promoter in the plasmid pKOneo. This research was designed to investigate if the plasmid pKOneo alone is capable of transforming NiH3T3 fibroblast cells. The NIH3T3 subclones were established after the NIH3T3 cells were transfected with the plasmid pKOneo alone. The estabilished NIH3T3 subclones, containing the exogeneous plasmid pKOneo in their chromosomes, were examined for their expression of transformation-associated parameters. The results indicate that this plasmid pKOneo alone has positive effects on transformation of NIH3T3 cells after integration into cellular chromosomes.

• Biomedical Science Letters
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• v.14 no.3
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• pp.187-192
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• 2008

To clerify the protective effect of omega-3 of polyunsaturated fatty acid docosahexaenoic acid (DHA) on the cytotoxicity induced by organic mercury in cultured NIH3T3 fibroblasts. The measurement of cell viability on ogranic mercury wad done by XTT assay after NIH3T3 fibroblasts were cultured with various concentrations of methyl mercuric chloride (MMC). And also, the effect of DHA on the MMC-mediated cytotoxicity was examined by cell viability, and antioxidant effect of DHA was also assessed by superoxide dismutase (SOD)-like activity and the lipid peroxidation activity in cultured NIH3T3 fibroblasts. In this study, MMC decreased cell viability and $XTT_{50}$ value was determined at $50{\mu}M$ of MMC in these culture. In the effect of DHA against the cytotoxicity induced by MMC, DHA significantly increased the cell viability damaged by MMC in cultured NIH3T3 fibroblasts. And also, DHA showed the antioxidant effect by showing the increase of SOD-like activity and the decrease of lipid peroxidation activity. From these results, it is suggested that organic mercury such as MMC has highly toxic effect on cultured NIH3T3 fibroblasts, and also, omega-3 of polyunsaturated fatty acid, DHA showed the protection on MMC-induced cytotoxicity and antioxidant effect.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.20 no.1 s.32
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• pp.145-153
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• 2007

Objecgtive : The aim of present study was to investigate inhibition effect of Whakijogyung-Tang(WJT) on the tumor cell lines. This study estimated the cytotoxicity of WJT about viability of S-180 and NlH3T3. Methods : The cytotoxicity of WJT about viability of cells were tested using a colorimetric tetrazoliun assay(MTT assay) Results and Conclusion : 1. Water extract of WJT had $IC_{50}$ of 863 ${\mu}g/ml$ in S-180 cell lines, but cytotoxicity of NIH3T3 was not significant difference compare with S-180. 2. n-Hexane fraction of WJT had similar cytotoxicity between S-180 and NIH3T3, but that could not have $IC_{50}$ in S-180 cell lines. 3. Ethyl acetate fraction of WJT had low degree cytotoxicity both S-180 and NIH3T3 cell lines. 4. Significantly, Butanol fraction of WJT had differenct citotoxicity between S-180 and NIH3T3. 5. $H_2O_2$ fraction of WJT had no cytotoxicity both S-180 and NIH3T3.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.20 no.1 s.32
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• pp.169-176
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• 2007

Objectives : The purpose of this study was to investigate inhibitory effect of Gagamtongsung-San(GTS) on the cancer. Methods : This study estimated the cytotoxicity of GTS about L1210 and NIH3T3. We used GTS extract distilled with water, n-Hexane, Ethyl acetate and Butanol. The cytotoxicitys of GTS about cancer cells and normal cells were tested using a colorimetric tetrazoliun assay(MTT assay). Results : The results of this study were obtained as follow ; l. Cytotoxicity of water extract of GTS in L1210 cell lines was significantly increased, compared with NIH3T3. 2. n-Hexane fraction of GTS had similar cytotoxicity between L1210 and NIH3T3, and that have similar $IC_{50}$ of water extract of GTS at 276 ${\mu}g/ml$ 3. Ethyl acetate fraction of GTS had low degree cytotoxicity both L1210 and NIH3T3 cell lines. 4. Butanol fraction of GTS had cytotoxicity between L1210 and NIH3T3. Significantly, Cytotoxicity of GTS in L1210 cell lines was significant increased. 5. $H_2O$ fraction of GTS had no cytotoxicity both L1210 and NIH3T3.

• Korean Journal of Veterinary Research
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• v.30 no.4
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• pp.459-464
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• 1990

Inhibitory effect of caffeine on NIH3T3 cell proliferation was studied by using [$^3H$]thymidine incorporation and a modified one-step silver staining technique. The latter technique shows argyrophilic nucleolar organizer region-associated proteins (Ag-NORs), which are seen in nuclei as black dots. The result was compared with the counts of [$^3H$] thymidine incorporation. The results were summarized as follows; 1. The Ag-NORs numbers of NIH3T3 cells were $6.81{\pm}1.38$ at 24 hrs, $7.13{\pm}1.26$ at 48 hrs, $8.50{\pm}2.04$ at 72 hrs after incubation. 2. The numbers of Ag-NORs were significantly decrease in caffeine treated groups (p<0.01). 3. The counts of [$^3H$] thymidine incorporation were similar to the result of using Ag-NORs staining technique. It is concluded that Ag-NOR is a rapid, simple and compatible method to quantitate cell proliferation as compared with [$^3H$]thymidine incorporation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.4
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• pp.633-640
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• 2004

This study was performed to investigate the cytotoxic effect of the water-extract from Chaga mushroom (Inonotus obliquus) compositions containing powdered green tea in HCT-15 human colon carcinoma, AGS human gastric carcinoma and NIH3T3 mouse normal fibroblast cells using viable cell count and MTT assay. The water-extract from Chaga mushroom compositions induced inhibitory effects on proliferation of HCT-15 and AGS cells in the MTT assay and viable cell count. However, mouse normal NIH3T3 cells were exhibited 80% survival under the same condition. Chaga mushroom compositions showed highly antiproliferative effect in human cancer cell line HCT-15 and AGS, but not in mouse normal cell line NIH3T3. These results suggest that Chaga mushroom (Inonotus obliquus) compositions containing powdered green tea are the candidate for chemoprevention in colon and gastric cancer.

• Toxicological Research
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• v.16 no.2
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• pp.173-178
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• 2000

This study was carried out to investigate cytotoxicity of several herbicides (Bentazone, Butachlor. Paraquat and Ethalfluralin) in cultured mouse NIH 3T3 fibroblasts. Tetrazolium (MTT), neutral red (NR) and sulforhodamine protein B (SRB) of the colorimetric assays were performed to evaluate the cytotoxicity on cell organelles. 2 x 10$^4$cell/$m\ell$ of NIH 3T3 fibroblast in each well of 24 multidish were cultured. After 24 hours, the cells were treated with solution (1, 25, 50 or 100 $\mu$M) of each herbicide. After the NIH 3T3 fibroblasts of all groups were cultured in the same condition for 48 hours, MTT, NR and SRB assays were performed to evaluate the cytotoxicity. The light microscopic study was carried out to examine morphological changes of cultured NIH 3T3 fibroblasts. The MTT$_{50}$ of Bentazone, Butachlor, Paraquat and Ethalfluralin were 1560.97 $\mu$M, 56.15 $\mu$M, 3138.81 $\mu$M and 1301.82 $\mu$M, respectively. The NR$_{50}$ of Bentazone, Butachlor. Paraquat and Ethalfluralin were 1763.93 $\mu$M, 45.98 $\mu$M, 1030.85 $\mu$M and 1808.29 $\mu$M, respectively. The SRB$_{50}$ of Bentazone, Butachlor. Paraquat and Ethalfluralin were 1913.38 $\mu$M, 65.30 $\mu$M, 1860.73 $\mu$M and 1086.93 $\mu$M, respectively. The morphological changes of NIH 3T3 fibroblasts showed severe degeneration in Butachlor 50 $\mu$M and 100 $\mu$M concentrations. These results indicate that Butachlor has high cytotoxicity, Bentazone, Paraquat and Ethalfluralin very weak cytotoxicity against NIH 3T3 fibroblasts.lasts.

• The Korea Journal of Herbology
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• v.21 no.1
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• pp.101-107
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• 2006

Objectives : It is well known that hexavalent chromium has toxic effect on normal cells. Recently, toxic effect of hexavalent chromium is diminished by the some extracts derived from herbs or plants. But, the toxic or protective mechanism of hexavalent chromium is well unknown. This study was performed to examine the protective effect of poncirin against $Na_2Cr_2O_7$-induced cytotoxicity on NIH3T3 fibroblasts. Methods : The protective effect of the cytotoxicity induced by $Na_2Cr_2O_7$ was measured by the cell viability after NIH3T3 fibroblasts were cultured with or without $Na_2Cr_2O_7$ for 48 hours. Antitoxic effects of poncirin on the cytotoxicity induced by $Na_2Cr_2O_7$ were examined by colorimetric assays such as MTT or XTT assay. Results : $Na_2Cr_2O_7$ decreased cell viability by the decreased absorbance in MTT or XTT assay, but, the poncirin increased cell viability which was decreased by $Na_2Cr_2O_7$-induced cytotoxicity on NIH3T3 fibroblasts. Conclusion : These results suggest that $Na_2Cr_2O_7$ showed cytotoxicity effect on NIH3T3 fibroblasts by the decrease of cell viavility, and poncirin was effective in the protection of $Na_2Cr_2O_7$-induced cytotoxicity in these cultures.