• Molecules and Cells
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• v.25 no.2
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• pp.224-230
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• 2008

Ceramides are well-known second messengers that induce apoptosis in various kinds of cancer cells, and their effects are closely related to radiation sensitivity. Phytoceramides, the yeast counterparts of the mammalian ceramides, are also reported to induce apoptosis. We investigated the effect of a novel ceramide derivative, N-acetylphytosphingosine (NAPS), on the radiosensitivity of NCI-H460 human lung carcinoma cells and its differential cytotoxicity in tumor and normal cells. The combination of NAPS with radiation significantly increased clonogenic cell death and caspase-dependent apoptosis. The combined treatment greatly increased Bax expression and Bid cleavage, but not Bcl-2 expression. However, there was no effect on radiosensitivity and apoptosis in BEAS2B cells, which derive from normal human bronchial epithelium. Cell proliferation and DNA synthesis were significantly inhibited by NAPS in both NCI-H460 and BEAS2B cells, but only the BEAS2B cells recovered by 48h after removal of the NAPS. Furthermore, the NCI-H460 cells underwent more DNA fragmentation than the BEAS2B cells in response to NAPS. Our results indicate that NAPS may be a potential radiosensitizing agent with differential effects on tumor vs. normal cells.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.1
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• pp.157-162
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• 1998

The antimutagenic activity of three kinds of extract such as fresh juice, ethanol extract and water extract of Artemisia iwayomogi against 3 - amino - 1, 4 - dimethyl - 5H - pyrido [4,3-b] indol (Trp-P-1) and N - methyl - N' - nitro - N -nitrosoguanidine(MNNG) was demonstrated with the Salmonella typhimurium assay. The number of revertants per plate decreased significantly when these extracts(0.5ug/plate) added to the assay system system using S. typhimurium TA 100. These extracts also showed prominant cytotoxic activity against four different kinds of human cancer cell as human lung cancer cell (A549), breast cancer cell(MCF7), fibrosacoma cell(HT1080) and gastric cancer cell(KATOIII), respectively.

• YAKHAK HOEJI
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• v.37 no.3
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• pp.278-285
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• 1993

The anticlastogenic effect of N-acetylcysteine was tested in vivo in mouse bone-marrow micronucleus assay. The frequencies of micronuclei induced by adriamycin (5 mg/kg i.p.) in bonemarrow cells were decreased by the oral administration of N-acetylcysteine at 12 h before adriamycin injection. The observed suppressing effect was not a reflection of a delay in the formation of micronuclei by the cytotoxic effect of N-acetylcysteine. The anticlastogenic effects of SH compound including N-acetylcysteine, cysteine, cystine, S-carboxy methylcysteine and glutathione were also investigated by the multiple pretreatment. Each SH compound was administered orally every day for 5 days and adriamycin (5 mg/kg i.p.) was injected at 24h after the last dose of test compound. N-acetylcysteine and glutathione showed significantly the suppressive effect at dose of 10 and 25 mg/kg for N-acetylcysteine and at the dose of 25 mg/kg for glutathione. Our study suggests that N-acetylcysteine is capable of protecting the chromosomal damages in the normal cells during cancer chemotherapy by adriamycin, and may act as an anticlastogen against induction of micronuclei by superoxide generating agent such as adriamycin.

• Archives of Pharmacal Research
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• v.25 no.3
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• pp.293-299
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• 2002

Cytotoxic and antimutagenic effects of a novel cis-$\varepsilon$-viniferin and five known stilbenes, transresveratrol, trans-$\varepsilon$-viniferin, gnetin H, suffruticosols A and B, isolated from the seeds of Paeonia lactiflora Pall. (Paeoniaceae) were determined against five different cancer cell lines, and mutagenicity of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in Salmonella typhimurium TA100, respectively. Six stilbenes showed cytotoxic activity in a dose-dependent manner, and especially did potent cytotoxic activity against C6 (mouse glioma) cancer cell with $IC_{50}$ values ranging from 8.2 to $20.5{\;}{\mu\textrm{g}}/ml$. trans-Resveratrol showed significant cytotoxic activity against HepG2 (liver hepatoma) and HT-29 (colon) human cancer cell lines with $IC_{50}$ values of 11.8 and 25.2 g/ml, respectively. In contrast, trans-$\varepsilon$-viniferin and cis--viniferin, and gnetin H exhibited marked cytotoxic activity against Hela (cervicse) and MCF-7 (breast) human cancer cell lines with $IC_{50}$ values of 20.4, 21.5, and $12.9{\;}{\mu\textrm{g}}/ml$, respectively. However, suffruticosol A and B had less cytotoxic effect against all cancer cells except C6. Meanwhile, six stilbenes exerted antimutagenic activity in a dose-dependent fashion. Of them, trans-resveratrol exhibited the strongest antimutagenic effect against MNNG with $IC_{50}$ value of $27.0{\;}{\mu\textrm{g}}/plate$, while other five resveratrol oligomers also did moderate antimutagenic activity with $IC_{50}$ values ranging from 31.7 to $35.2{\;}{\mu\textrm{g}}/plate$.

• Journal of Microbiology and Biotechnology
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• v.12 no.1
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• pp.89-95
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• 2002

Telomerase is a ribonucleoprotein complex, whose function is to add telomeric repeats $(TTAGGG)_n$ to chromosomal ends and is also known to play an important role in cellular immortalization. Telomerase is highly active in most tumor cells, yet not in normal cells. Therefore, it may have possible applications in cancer gene therapy. Telomerase consists of two essential components; a telomerase RNA template (hTR) and a catalytic subunit (hTERT). The current study attempted to inhibit the "open" part of the human telomerase RNA (hTR) with an antisense sequence-expressing adenovirus. It was found that the antisense telomerase adenovirus suppressed the telomerase activity, tumor cell growth, and survival in vitro. Furthermore, FACS analysis and TUNEL assay suggested that the reduce viability was mediated through the induction of apoptosis, indicating that this approach might be a useful method for suppressing cancer growth in targeted cancer gene therapy.

• Clinical and Experimental Pediatrics
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• v.55 no.12
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• pp.474-480
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• 2012

Purpose: For evaluating the immunogenicity of an influenza vaccine, the microneutralization (MN) test has a higher sensitivity and specificity as compared to the hemagglutination inhibition (HI) test. However, the MN test is more time consuming and is difficult to standardize. We performed the MN test to determine its usefulness as an alternative or complementary test to the HI test for evaluating the immunogenicity of influenza vaccines. Methods: We compared the MN test with the HI test using 50 paired samples taken from a previous clinical study (2008-2009) in Korean children under 18 years of age. Results: The linear correlation coefficients of the 2 tests for H3N2, H1N1, and influenza B were 0.69, 0.70, and 0.66, respectively. We identified a high index of coincidence between the 2 tests. For an influenza vaccine, the postvaccination seroprotection rates and seroconversion rates determined by the MN test were 78.0% and 96.0%, 90% and 42.0%, and 42.0% and 48.0% for H3N2, H1N1, and influenza B, respectively. Geometric mean titer fold increases of H3N2, H1N1, and influenza B were 2.89, 5.04, and 4.29, respectively, and were 2.5-fold higher. We obtained good results in the evaluation of the immunogenicity of the 2008-2009 seasonal influenza vaccines. Conclusion: We found that the MN test was as effective as the HI test. Therefore, we suggest that the MN test can be used as an alternative or complementary test to the HI test for evaluating the immunogenicity of influenza vaccines.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.16
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• pp.7003-7006
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• 2015

Background: Nanoparticles of gold and silver are offering revolutionary changes in the field of cancer therapy. N-heterocyclic carbene (NHC) metal complexes possess diverse biological activities and are being investigated as potential chemotherapeutic agents. The purpose of this study was to examine the cytotoxicity and possible mechanisms of action of two types of newly synthesized nanofiber composites containing BIAN N-heterocyclic gold carbene complexes in two types of human cancer cells, namely breast cancer (MCF7) and liver cancer (HepG2) cells and also in normal human embryonic kidney cells (HEK 293). Materials and Methods: Cytotoxicity was assessed by MTT cell viability assay and oxidative stress by checking the total glutathione level. Results: Both compounds affected the cell survival of the tested cell lines at very low concentrations (IC50 values in the micro molar range) as compared to a well-known anti-cancer drug, 5 fluorouracil. A 60-80% depletion in total glutathione level was detected in treated cells. Conclusions: Reduction in total glutathione level is one of the biochemical pathways for the induction of oxidative stress which in turn could be a possible mechanism of action by which these compounds induce cytotoxicity in cancer cell lines. The in vitro toxicity towards cancer cells found here means that these molecules could be potential anticancer candidates.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.05a
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• pp.156-156
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• 2001

One of the most frequent defects in human cancer is the uncontroled activation of the ras-signaling pathway. We have previously shown that H-rasm but not N-ras, induces an invasiveness. Here, we show that cell motility was greatly increased by H-ras, but not by N-ras, suggesting that H-ras-induced invasive phnotype involves enhanced cell motility.(omitted)

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.5
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• pp.2279-2283
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• 2012

Human Papillomavirus (HPV) infection is one of the most common sexually transmitted infections and oncogenic HPV is the main cause of cervical cancer. However, HPV vaccination is already available as the primary preventive method against cervical cancer. The objective of this study was to determine the level of knowledge, attitude and practice of HPV vaccination among Universiti Kebangsaan Malaysia (UKM) and Universiti Malaya (UM) students. This study was conducted from March until August 2009. Pre-tested and validated questionnaires were filled by the third year UKM (n=156) and UM (n=149) students from medical, dentistry and pharmacy faculties. The results showed that the overall level of knowledge on HPV infection, cervical cancer and its prevention among respondents was high and the majority of them had positive attitude towards HPV vaccination. Medical students had the highest level of knowledge (p<0.05). Very few students (3.6%) had already taken the vaccine with no significant difference between the two Universities (p=0.399). In conclusion, the knowledge and attitude of the respondents were high and positive, respectively. Only few students took HPV vaccination. Thus, more awareness campaigns and HPV vaccination services should be provided at universities' campuses with the price of the HPV vaccine reduced for the students.

• Proceedings of the PSK Conference
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• 2000.04a
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• pp.157-157
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• 2000