• Biomedical Science Letters
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• v.14 no.4
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• pp.263-267
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• 2008

Photodynamic therapy (PDT) is a treatment utilizing the generation of singlet oxygen and other reactive oxygen species (ROS), which selectively accumulate in target cells. Peroxiredoxin (prx) plays an important role in eliminating peroxides generated during metabolism. Prx exert protective antioxidant role in cells though peroxidase activity. The aim of present work is to investigate the cytotoxicity of photofrin-mediated PDT in prx IV-transfectant AMC-HN3 cell lines. We confirmed that PDT has an effect on ROS generation in prx IV-induced cell lines. Treatment of PDT in prx IV-HN3 cell lines inhibits cytotoxic effects. Prx IV-induced HN3 cell lines resists in cell death during PDT. Also, prx IV-HN3 cell lines treated PDT inhibited ROS generation in contrast with vector control. We indicated that prx IV-induced AMC-HN3 cell lines have a function as inhibitors during PDT.

• Biomedical Science Letters
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• v.14 no.2
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• pp.83-89
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• 2008

We have compared the antitumor effect of photodynamic therapy (PDT), using 5-aminolevulinic acid (ALA) as the photosensitizer, combined with cisplatin (CDDP) on AMC-HN3 human squamous cell carcinoma. AMC-HN3 cells were cultured and then incubated with various concentrations of CDDP and ALA. 632 nm diode laser was given at $6.0J/cm^2$ followed by incubation for 24 hours. The evaluation of cell viability was done by MTT assay. In vivo CDDP was injected intraperitoneally 24 hours prior to PDT. The anti-tumor effects of each treatment were measured by tumor volume change. Cell viability were 44.29% for the cisplatin-mediated chemotherapy group $(6.25{\mu}g/ml)$, 77.22% for ALA-PDT group, and 15.06% for the Combination therapy group. In vivo, the antitumor effect of photodynamic therapy was enhanced by combination of Cisplatin-mediated chemotherapy. Photodynamic therapy combined with administration of Cisplatin appears to enhance antitumor effect and to be a useful treatment modality.

• Journal of Life Science
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• v.29 no.3
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• pp.318-324
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• 2019

Squamous cell carcinoma is the primary tumor type in head and neck cancers, the fifth most common malignant neoplasm world-wide. Survivin, a member of the inhibitor of apoptosis family, is highly expressed in head and neck carcinoma patients and correlated with more aggressive forms. In this study, we investigated whether YM155, a specific survivin inhibitor, could induce apoptosis in head and neck AMC-HN4 cells. YM155 was found to markedly induce apoptosis and cleavage of PARP, a marker of apoptosis. Furthermore, YM155 promoted apoptosis in other cancer cells, such as glioma (U251MG) and renal carcinoma (Caki) cells. In contrast, YM155 had no effect on apoptosis in normal mesangial cells. YM155 significantly induced caspase activation, and pan caspase inhibitor z-VAD-fmk markedly blocked apoptosis, PARP cleavage, and caspase-3 cleavage. Therefore, YM155 was seen to instigate caspase-dependent apoptosis in head and neck AMC-HN4 cells, inducing downregulation of survivin as well as other apoptotic proteins such as c-FLIP and Mcl-1. In addition, the induction of apoptosis and PARP cleavage by YM155 treatment was effectively inhibited in survivin-, c-FLIP- and Mcl-1-over-expressing head and neck AMC-HN4 cells. In conclusion, YM155 is a potent candidate for inducing cell death in head and neck AMC-HN4 cells.

• Radiation Oncology Journal
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• v.22 no.3
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• pp.208-216
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• 2004

Purpose: DNA-dependent protein kinase (DNA-PK) is a serine/threonine kinase consisting of a 470 kDa catalytic subunit (DNA-PKcs) and a heterodimeric regulatory complex, called Ku, which is composed of 70 kDa(Ku 70) and 86 kDa (Ku 80) proteins. The DNA-PK has been shown to play a pivotal role in rejoining DNA double-strand-breaks (dsb) in mammalian cells. The purpose of this study is to examine the relationship between the level of Ku expression and radiation sensitivity. Methods and Materials: Nine head and neck, cancer cell lines showed various intrinsic radiation sensitivities. Among the nine, AMC-HN-3 cell was the most sensitive for X-ray irradiation and AMC-HN-9 cell was the most resistance. The most sensitive and resistant cell lines were selected and the test sensitivity of radiation and expression of Ku were measured. Radiation sensitivity was obtained by colony forming assay and Ku protein expression using Western blot analysis. Results: Ku80 increased expression by radiation, wheres Ku70 did not. Overexpression of Ku80 protein increased radiation resistance in AMC-HN9 cell line. There was a correlation between Ku8O expression and radiation resistance. Ku80 was shown to play an important role in radiation damage response. Conclusion: Induction of Ku80 expression had an important role in DNA damage repair by radiation. Ku80 expression may be an effective predictive assay of radiosensitivity on head and neck cancer.

• Journal of Life Science
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• v.18 no.9
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• pp.1257-1262
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• 2008

Photodynamic therapy (PDT) is a treatment utilizing the generation of singlet oxygen and other reactive oxygen species (ROS), which selectively accumulated in target cells. Genistein, soy-derived phytoestrogen, is one of the anticancer agents found in soybean. In the current study, we investigated the effect of photofrin-induced PDT and genistein on apoptotic cell death in head and neck cell line (AMC-HN3) to confirm the photodynamic therapy of genistein. It was determined by MTT assay that the combination group had more cytotoxicity effect than PDT group alone. Combination of photofrin PDT and genistein induced apoptosis more when comparing with PDT alone. Our data also showed that ROS was increased in combination therapy, indicating apoptosis by mitochondrial damage. These results indicated that the combination of photofrin PDT and genistein showed more cytotoxic effect and induced apoptosis in head and neck cancer cell line.

• Radiation Oncology Journal
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• v.19 no.2
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• pp.171-180
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• 2001

Purpose : Expression of TIMP, intrinsic inhibitor of MMP, is regulated by signal transduction in response to genotoxins and is likely to be an important step in metastasis, angiogenesis and wound healing after ionizing radiation. Therefore, we studied radiation mediated TIMP expression and its mechanism in head and neck cancer cell lines. Materials and Methods : Human head and neck cancer cell lines established at Asan Medical Center were used and radiosensitivity $(D_0)$, radiation cytotoxicity and metastatic potential were measured by clonogenic assay, n assay and invasion assay, respectively. The conditioned medium was prepared at 24 hours and 48 hours after 2 Gy and 10 Gy irradiation and expression of TIMP protein was measured by Elisa assay with specific antibodies against human TIMP. hTIMP1 promoter region was cloned and TIMP1 luciferase reporter vector was constructed. The reporter vector was transfected to AMC-HN-1 and -HN-9 cells with or without expression vector Ras, then the cells were exposed to radiation or PMA, PKC activator. EMSA was peformed with oligonucleotide (-59/-53 element and SP1) of TIMP1 promoter. Results : $D_0$ of HN-1, -2, -3, -5 and -9 cell lines were 1.55 Gy, 1.8 Gy, 1.5 Gt, 1.55 Gy and 2.45 Gy respectively. n assay confirmed cell viability, over $94\%$ at 24hrs, 48hrs after 2 Gy irradiation and over 73% after 10 Gy irradiation. Elisa assay confirmed that cells secreted TIMP1, 2 proteins continuously. After 2 Gy irradiation, TIMP2 secretion was decreased at 24hrs in HN-1 and HN-9 cell lines but after 10 Gy irradiation, it was increased in all cell lines. At 48hrs after irradiation, it was increased in HN-1 but decreased in HN-9 cells. But the change in TIMP secretion by RT was mild. The transcription of TIMP1 gene in HN-1 was induced by PMA but in HN-9 cell lines, it was suppressed. Wild type Ras induced the TIMP-1 transcription by 20 fold and 4 fold in HN-1 and HN-9 respectively. The binding activity to -59/-53, AP1 motif was increased by RT, but not to SP1 motif in both cell lines. Conclusions : We observed the difference of expression and activity of TIMPs between radiosensitive and radioresistant cell line and the different signal transduction pathway between in these cell lines may contribute the different radiosensitivity. Further research to investigate the radiation response and its signal pathway of TIMPs is needed.

• Radiation Oncology Journal
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• v.25 no.4
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• pp.227-232
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• 2007

Purpose: To investigate the flavopiridol effect on radiation-induced apoptosis and expression of apoptosisrelated genes of human laryngeal and lung cancer cells. Materials and Methods: A human laryngeal cancer cell line, AMC-HN3 and a human lung cancer cell line, NCI-H460, were used in the study. The cells were divided into four groups according to the type of treatment: 1) control groups; 2) cells that were only irradiated; 3) cells treated only with flavopiridol; 4) cells treated with flavopiridol and radiation simultaneously. The cells were irradiated with 10 Gy of X-rays using a 4 MV linear accelerator. Flavopiridol was administered to the media at a concentration of 100 nM for 24 hours. We compared the fraction of apoptotic cells of each group 24 hours after the initiation of treatment. The fraction of apoptotic cells was detected by measurement of the sub-G1 fractions from a flow cytometric analysis. The expression of apoptosis-regulating genes, including cleaved caspase-3, cleaved PARP (poly (ADP-ribose) polymerase), p53, p21, cyclin D1, and phosphorylated Akt (protein kinase B) were analyzed by Western blotting. Results: The sub-G1 fraction of cells was significantly increased in the combination treatment group, as compared to cells exposed to radiation alone or flavopiridol alone. Western blotting also showed an increased expression of cleaved caspase-3 and cleaved PARP expression in cells of the combination treatment group, as compared with cells exposed to radiation alone or flavopiridol alone. Treatment with flavopiridol down regulated cyclin 01 expression of both cell lines but its effect on p53 and p21 expression was different according to each individual cell line. Flavopiridol did not affect the expression of phophorylated Akt in both cell lines. Conclusion: Treatment with flavopiridol increased radiation-induced apoptosis of both the human laryngeal and lung cancer cell lines. Flavopiridol effects on p53 and p21 expression were different according to the individual cell line and it did not affect Akt activation of both cell lines.

• Journal of the Korean Chemical Society
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• v.54 no.4
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• pp.451-459
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• 2010

The fluorescence detection of intracellular metal ions are high interest in the fields of organic molecular chemistry and cellular biology. This study was purposed to detection for mercury and zinc in the cell using fluorescent chemosensor (FS). FS exhibits a weak fluorescence, but emits strong fluorescence upon Zn$^{2+}$ complexation. The increased fluorescence of the 2FS/Zn$^{2+}$ can be quenched completely by addition of only 1 equiv of Hg$^{2+}$ with the formation of complex FS-Hg$^{2+}$. Four cell lines (LLC-MK2, Hela, HT29 and AMC-HN3) were used for fluorescence imaging by confocal microscope. The cell viability MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was evaluated after cell treatment of FS, Zn$^{2+}$, FS-Zn$^{2+}$, Hg$^{2+}$ on LLC-MK2 cell line. The cytotoxicity of FS was showed to viability over 80%. This study has shown that FS can be detected for selective imaging of Zn$^{2+}$ and Hg$^{2+}$ in living cells.