• Tuberculosis and Respiratory Diseases
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• v.44 no.3
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• pp.547-558
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• 1997

Background : Tumor necrosis factor(TNF) has been considered as an important candidate for cancer gene therapy based on its potent anti-tumor activity. However, since the efficiency of current techniques of gene transfer is not satisfactory, the majorities of current protocols is aiming the in vitro gene transfer to cancer cells and re-introducing genetically modified cancer cells to hoot. In previous study, it was shown that TNF-sensitive cancer cells transfected with TNF-$\alpha$ cDNA would become highly resistant to TNF. Understanding the mechanisms of TNF-resistance in TNF-$\alpha$ gene transfected cancer cells would be an important step for improving the efficacy of cancer gene therapy as well as for better understandings of tumor biology. This study was designed to evaluate the role of new protective protein synthesis in the acquired resistance to TNF of TNF-$\alpha$ gene transfected cancer cells. Method : We transfected TNF-$\alpha$ c-DNA to WEHI164, a murine fibrosarcoma cell line, using retroviral vector(pLT12SN(TNF)) and confirm the expression of TNF with PCR, ELISA, MIT assay. Then we determined the TNF resistance of TNF gene transfected cells(WEHI164-TNF) and the changes of TNF sensitivities after treatments with actinomycin D(transcription inhibitor) and cycloheximide ( translation inhibitor). Results : WEHI164 which was sensitive to TNF became resistant to TNF after being transfected with TNF-$\alpha$ gene and the resistance to TNF was partially reversed after treatment with actinomycin D, but not with cycloheximide. Conclusion : The acquired resistance to TNF after TNF-$\alpha$ gene transfection may be associated with synthesis of some protective proteins.

• Tuberculosis and Respiratory Diseases
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• v.41 no.2
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• pp.87-96
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• 1994

Background : Since tumor necrosis factor was discovered in 1975, TNF has been well known about its cytotoxic effect on tumor cells in vivo and in vitro. According to the recent improvement of molecular biological techinques, it is possible that exogenous TNF gene is transferred to tumor cells and is expressed in theirs. By virtue of TNF gene transfer, we have expected that TNF expressed in TNF-gene-transferred tumor cells would kill tumor cells in vivo without systemic side effect. The expected mechanisms in which antitumor effects of TNF expressed in TNF-gene-transferred tumor cells are working would be as followings. In the first mechanism, TNF expressed in TNF-gene-transferred tumor cells would kill tumor cells around(like homicide). In the second mechanism, TNF expressed in TNF-gene-transferred tumor cells would kill themselves(like suicide). In the third mechanism, TNF expressed in TNF-gene-transferred tumor cells would recruit immune effector cells and kill tumor cells indirectly. In the last mechanism, TNF expressed in TNF-gene-transferred tumor cells would augment cytokine such as interferon-$\gamma$ to kill tumor cells. Among these four mechanisms of antitumor effect, only the second mechanism has not been established yet. Therefore, to elucidate the second mechanism, We performed this study. Method : We transferred TNF-$\alpha$ gene to NCI-H2058, a human mesothelioma cell line and WEHI164, a murine fibrosarcoma cell line by using retroviral vector(pLT12SNTNF). And, We determined by using MTT assay whether TNF expressed in TNF-gene-transferred tumor cell lines would kill themselves like suicide or not. Then, if TNF-gene-transferred tumor cell lines would not suicide themselves, I would know more about the TNF sensitivity of TNF-gene-transferred tumor cell lines to exogenous TNF also by MTT assay. Result : NCI-H2058 and WEHI164 which were sensitive to TNF, became far less sensitive to endogenous and exogenous TNF after being transferred TNF-$\alpha$ gene to. Conclusion : TNF-gene-transfer to NCI-H2058 and WEHI164 gave them resistance to TNF.

• Natural Product Sciences
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• v.9 no.3
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• pp.161-166
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• 2003

In the course of our studies for new anticancer medicinal plants, we evaluated the effects of an alcohol-water (1:1, V/V) extract of Dendrostellera lesserii (Thymelaeaceae) leaves on the growth rates of breast tumors of rats. The breast tumors were induced in a group of rats by Dimethylbenz[a]anthracene (DMBA) injection. Our data showed that daily oral feeding of the crude extract to the rats, for 20 consecutive weeks, significantly repressed the growth rates of the breast tumors. In addition, the probable effect of D. lessertii crude extract or one of its purified active components on metastasis was evaluated using wehi-164 cells. Treatment of the cells with a single nontoxic dose of the purified active component for 48 hours inhibited the adhesion of the cells to the immobilized fibronectin molecules by almost 80% compared to the untreated control cells.

• Tuberculosis and Respiratory Diseases
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• v.44 no.6
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• pp.1353-1365
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• 1997

Background : Tumor necrosis factor(TNF) has been considered as an important candidate for cancer gene therapy based on its potent anti-tumor activity. However, since the efficiency of current techniques of gene transfer is not satisfactory, the majority of current protocols is aiming the in vitro gene transfer to cancer cells and re-introducing genetically modified cancer cells to host. In the previous study, it was shown that TNF-sensitive cancer cells transfected with TNF-$\alpha$ cDNA would become highly resistant to TNF, and the probability was shown that the acquired resistance to TNF might be associated with synthesis of some protective protein. Understanding the mechanisms of TNF -resistance in TNF-$\alpha$ cDNA transfected cancer cells would be. an important step for improving the efficacy of cancer gene therapy as well as for better understandings of tumor biology. This study was designed to evaluate the role of MnSOD, an antioxidant enzyme, in the acquired resistance to TNF of TNF-$\alpha$ cDN A transfected cancer cells. Method : We transfected TNF-$\alpha$ c-DNA to WEHI164(murine fibrosarcoma cell line), NCI-H2058(human mesothelioma cell line), A549(human non-small cell lung cancer cell line), ME180(human cervix cancer cell line) cells using retroviral vector(pLT12SN(TNF)) and confirm the expression of TNF with PCR, ELISA, MIT assay. Then we determined the TNF resistance of TNF-$\alpha$ cDNA transfected cells(WEHI164-TNF, NCIH2058-TNF, A549-TNF, ME180-TNF) and the changes of MnSOD mRNA expressions with Northern blot analysis. Results : The MnSOD mRNA expressions of parental cells and genetically modified cells of WEHI164 and ME180 cells(both are naturally TNF sensitive) were not significantly different The MnSOD mRNA expressions of genetically modified cells of NCI-H2058 and A549(both are naturally TNF resistant) were higher than those of the parental cells, while those of parental cells with exogenous TNF were also elevated. Conclusion : The acquired resistance to TNF after TNF-$\alpha$ cDNA transfection may not be associated with the change in the MnSOD expression, but the difference in natural TNF sensitivity of each cell may be associated with the level of the MnSOD expression.

• Parasites, Hosts and Diseases
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• v.47 no.2
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• pp.175-177
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• 2009

Cancer is the main cause of death in developed countries. However, in underdeveloped countries infections and parasitic diseases are the main causes of death. There are raising scientific evidences indicating that parasitic infections induce antitumor activity against certain types of cancers. In this study, the effects of Toxoplasma gondii and Toxocara canis egg antigens in comparison with Bacillus Calmette Guerin (BCG) (known to have anticancer distinctive) on WEHI-164 fibosarcoma transplanted to BALB/c mice was investigated. Groups of 6 male BALB/c mice injected with T. gondii antigen, BCG, or T. canis egg antigen as case groups and alum alone as control groups. All mice were then challenged with WEHI-164 fibrosarcoma cells. The mice were examined for growth of the solid tumor and the tumor sizes were measured every other day up to 4wk. The mean tumor area in T. gondii, BCG, or alum alone injected mice in 4 different days of measurements was $25\;mm^2$, $23\;mm^2$, and $186\;mm^2$ respectively, Also the mean tumor area in T. canis injected mice in 4 different days was $25.5\;mm^2$ compared to the control group (alum treated) which was $155\;mm^2$. T. gondii parasites and T. canis egg antigens induced inhibition of the tumor growth in the fibrosarcoma mouse model. We need further study to clarify the mechanisms of anti-cancer effects.

• Tuberculosis and Respiratory Diseases
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• v.46 no.5
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• pp.636-644
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• 1999

Background : Tumor necrosis factor(TNF) has been considered as an important candidate for cancer gene therapy based on its potent anti-tumor activity. The mechanisms of TNF cytotoxicity are not clearly understood and some has reported that reactive oxygen species(ROS) might be associated with them, but there is controversy about antioxidant effect on TNF cytotoxicity. This study was designed to compare the TNF cytotoxicity after antioxidant pretreatment with that of control to evaluate the role of ROS in the mechanism of TNF cytotoxicity. Method : We compared the TNF cytotoxicies to WEHI164(murine fibrosarcoma cell line) and ME180(human cervix cancer cell line) after antioxidant pretreatment with those of control by MIT(dimethylthiazolyl-diphenyltetrazolium bromide) assay. Results : In the control group, the TNF cytotoxicities were $92.2{\pm}2.8%$(WEHI164) and $59.9{\pm}7.0%$(MEl80). In the TMTU(tetramethyl thiourea) pretreatment group, those were $91.4{\pm}3.7%$ and $74.6{\pm}7.0%$. In the PMZ(promethazine) pretreatment group, those were $90.2{\pm}2.5%$ and $62.5{\pm}5.7%$. In the BHT(butylated hydroxytoluene) pretreatment group, those were $93.2{\pm}1.3%$ and $66.3{\pm}6.1%$. So there was no reduction in TNF cytotoxicity after antioxidants pretreatment. Conclusion : The ROS may not have major role in the mechanisms of TNF cytotoxicity.

• Tuberculosis and Respiratory Diseases
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• v.42 no.3
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• pp.302-313
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• 1995

Background: Tumor necrosis factor(TNF) showed antitumor cytolytic effects on sensitive tumor cells in numerous in vivo and in vitro studies. But it could not be administered systemically to human because of severe systemic adverse effects at effective concentrations against tumor cells. Many studies showed that a high concentrations of TNF in the local milieu may evoke in vivo TNF-responsive mechanisms sufficient to suppress tumor growth. Recently developed technique of TNF gene transfer to tumor cells using retrovirus vector could be a good candidate for local TNF administration. TNF is also known to synergistically enhance in vitro cytotoxicity of chemotherapeutic drugs targeted to DNA topoisomerase II against TNF-sensitive tumor cell lines. In this study the in vitro chemosensitivity against DNA topoisomerase II targeted chemotherapeutic drugs was evaluated using some respiratory cancer cell lines to which TNF gene had been transferred. Method: NCI-H2058, a human mesothelioma cell line, A549, a human lung adenocarcinoma cell line and WEHI 164 cell line, a murine fibrosarcoma cell line were treated with etoposide and doxorubicin, which are typical topoisomerase II - targeted chemotherapeutic agents, at different concentration. The resultant cytotoxicity was measured by MIT assay. Then the cytotoxicity of the same chemotherapeutic agents was measured after TNF-$\alpha$ gene-transfer and the two results were compared. Results: The cytotoxicity was not increased significantly in WEHI164 cell line and A549 cell line but statistically significant increase was observed in H2058 cell line when TNF-$\alpha$ gene was transferred(p<0.05). Conclusion: These findings show that TNF-$\alpha$ gene transfer to respiratory cancer cell lines results in variable effects on chemosensitivity against topoisomerase II inhibitor among different cell lines in vitro and can be additively cytotoxic in certain selective tumor cell lines.

• Tuberculosis and Respiratory Diseases
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• v.44 no.6
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• pp.1271-1284
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• 1997

Background : Tumor necrosis factor(TNF) has been considered as an important candidate for cancer gene therapy based on its potent anti-tumor activity. However, since the efficiency of current techniques of gene transfer is not satisfactory, the majority of current protocols is aiming the in vitro gene transfer to cancer cells and re-introducing genetically modified cancer cells to host. In the previous study, it was shown that TNF-sensitive cancer cells transfected with TNF-$\alpha$ cDNA would become highly resistant to TNF, and the probability was shown that the acquired resistance to TNF might be associated with synthesis of some protective protein. Understanding the mechanisms of TNF-resistance in TNF-$\alpha$ cDNA transfected cancer cells would be an important step for improving the efficacy of cancer gene therapy as well as for better understandings of tumor biology. This study was designed to evaluate whether the levels of TNF receptor mRNA expression and soluble TNF receptor release from cancer cells are changed after TNF-$\alpha$ cDNA transfection. Method : We transfected TNF-$\alpha$ c-DNA to WEHI164(murine fibrosarcoma cell line), NCI-H2058(human mesothelioma cell line), A549(human non-small cell lung cancer cell line), ME180(human cervix cancer cell line) cells using retroviral vector(pLT12SN(TNF)) and confirm the expression of TNF with PCR, EUSA, MTT assay. Then we determined the TNF resistance of TNF-$\alpha$ cDNA transfected cells(WEHI164-TNF, NCIH2058-TNF, A549-TNF, ME180-TNF) and evaluated the TNF receptor mRNA expression with Northern blot analysis and soluble TNF receptor release with EUSA. Results : The TNF receptor mRNA expressions of parental cells and genetically modified cells were not significantly different. The soluble TNF receptor levels of media from genetically modified cells were lower than those from parental cells. Conclusion : The acquired resistance to TNF after TNF-$\alpha$ cDNA transfection may not be associated with the change in the TNF receptor and the soluble TNF receptor expression.

• YAKHAK HOEJI
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• v.46 no.2
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• pp.113-119
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• 2002

The composition of monosaccharides of acidic polysaccharide isolated from ethanol-insoluble and water-soluble fractions of red ginseng roots was analysed and its immunological activities were investigated. Red ginseng acidic polysaccharide (RGAP) was composed of glucose (26.1 mole %), arabinose (1.6 mole %), glucuroninc acid (51.8 mol %) and galacturonic acid (5.1 mole %) as determined by gas liquid chromatography. Addition of RGAP increased production of nitric oxide (NO) and tumor necrosis factor (TNF)-$\alpha$ in the rodent macrophage cultures. Peritoneal macrophages from RGAP-treated mice exhibited potent tumoricidal activities toward P815 and WEHI 164 tumor cells. It was also observed that concentrations of NO and TNF-$\alpha$ were high in the culture medium of macrophages from the mice administered with RGAP. Moreover, treatment of RGAP in vivo stimulated tumoricidal activities of natural killer (NK) cells. Treatment with RGAP increased life span of sarcoma 180-bearing mice and decreased tumor weights of B16-tumor-bearing mice. These results suggest that activation of macrophages and NK cells serve to enhance in vivo anticancer activities of RGAP.

• Journal of Microbiology and Biotechnology
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• v.16 no.1
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• pp.136-140
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• 2006

In this study, we investigated the synergistic effects of Staphylococcus aureus extracts (membranes and walls) and lipopolysaccharide (LPS) derived from Escherichia coli on tumor necrosis factor (TNF) production in the pathogenesis of silica-induced inflammation. The synergistic induction of TNF by silica particles $(<20\;{\mu}m)$ in combination with either S. aureus extracts or LPS was examined in J774A.1 cell cultures. Media from the treated and untreated cell cultures were assayed for TNF, using the mouse WEHI 164 cell cytotoxicity assay and enzyme immunoassay. Cells exposed simultaneously to silica and $0.5\;{\mu}g/ml$ S. aureus extracts (or 0.5 ng/ml of LPS) produced a significantly higher level of TNF than those produced by the inducer alone. Our results indicate that device-associated infections (or pyrogen contamination) could enhance inflammatory responses, because of particles produced by the wear of medical implants or particulate biomaterials used for clinical purposes.