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        검색결과 279

        142.
        2008.03 구독 인증기관 무료, 개인회원 유료
        Inhibition of proteasome activity may reduce many types of cancer, so it's pathway is effective in cancer as well as in clinical fields. Here the author has carried out experiment targeting on the elevation of apoptosis in oral cancer cells by combination of proteasome inhibitor, lactacystin, and DNA replication inhibitor, etoposide. The growth of KB cells was measured by MTT methods and apoptosis was analyzed by DNA fragmentation and Hochest nucleus staining. The proteasome activity was analyzed by fluorescent tagged peptide and cellular protein expression was detected by Western hybridization. Though lactacystin and etoposide inhibited KB cell growth alone, but low combined doses inhibited cell growth more strongly and induced apoptosis. The proteasome activity was also seriously inhibited by the combination of both chemicals. Tumor suppressor proteins and apoptosis inducing proteins were highly increased under the combination of both chemicals. From above studies we can conclude that proteasome inhibitors may be used for the treatment of oral cancer and proteasome inhibitors with DNA replication inhibitors may be effective in clinical trials of oral cancer.
        4,000원
        144.
        2008.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The prominent side effect of cyclosporin A, immunosuppressive agent, in oral tissues is gingival overgrowth(GO). It is characterized by the gingival enlargement with epithelial thickening, a large number of proliferating fibroblasts and overproduction of ECM components. Fibroblast accumulation in Cs A induced GO is caused by the Inhibition of apoptosis. But CsA effect on normal human oral keratinocyte(NHOK) remains unclear. Transglutaminase 2(TGase 2) which is expressed and activated in tissue where epithelial cells undergo apoptosis has been used as a marker for apoptotic cells. The purpose of this study were to study the effect of CsA on the proliferation and apoptosis of cultured NHOK by TGase 2 expression. After primary cultured NHOK was treated by 0.1, 1.0 and 10ug/ml Cs A, growth curve, MTT assay for succinyl dehydrogenase activity and RT-PCR for TGase 2 mRNA expression were done. The obtained results were as follows. MTT assay showed about 65% cell viability at 1.0μg/ml and 40% at 10μg/ml CsA. Growth curve showed normal S curve on control & DMSO, while decreased growth rate after 3 days of higher CsA tx. TGase 2 mRNA expression of cultured NHOK was the highest at 10μg/ml Cs A. TEM showed chromosome margination, and vacuole formation and clustered mitochodria in cytoplasm of cultured NHOK after CsA tx. It suggested that higher CsA might induce apoptosis of NHOK correlated with increased TGase 2 mRNA expression
        4,000원
        145.
        2007.12 구독 인증기관 무료, 개인회원 유료
        Oral squamous cell carcinoma (OSCC) is the most common malignancy and is a major cause of worldwide cancer mortality. The proto-oncogene c-myb plays an important role in regulation of cell growth and differentiation, and it is expressed at high levels in hematopoietic cells and many other types of cancers. However, the function of c-myb is not well known in OSCC. The present study aimed to reveal the function of c-myb and to test the alternation of cell growth and signaling by c-myb in OSCC. In this study, c-myb and dominant-negatibe myb(DNmyb) were expressed in an adenovirus-mediated gene delivery system to KB cells. The over-expressed c-myb brought increased cellular proliferation compared with control cells. However, DN-myb infected KB cells showed significant reduction of cell growth and enhanced induction of apoptosis to activate PARP and caspase 9. c-myb induced increase of IGF-I, -II and IGF-IR expressions while DN-myb down-regulated these expression. Activation of ERK and Akt/PKB pathway was shown only in c-myb transduced cells. These findings suggest that the role of c-myb in cell growth of oral cancer cells is partially mediated through the modulation of IGFs, ERK and Akt/PKB. From this results, DN-myb is strongly recommended as a curable gene for the treatment of c-myb dependent malignancies such as OSCC.
        4,000원
        146.
        2007.12 구독 인증기관 무료, 개인회원 유료
        This study was conducted to examine the mRNA expression of apoptosis-related and imprinted genes and methylation pattern of the differentially methylated region (DMR) of H19 gene in day 35 of SCNT pig fetuses. The day 35 of natural mating (control) or cloned (clone) pig fetuses were recovered from uterus. Endometrium from dam and liver from fetus were obtained, respectively. mRNA expression was evaluated by real-time PCR and methylation pattern was analyzed by bisulfite sequencing method. The Bcl-2 mRNA expression in clone was significantly lower than that of control (p<0.05). The mRNA expression of H19 gene in both endometrium and liver was significantly higher in clone than that of control, respectively (p<0.05). The level of IGF-2 mRNA in liver of clone was significantly lower than that of control (p<0.05), whereas the mRNA expression of IGF2-R gene in liver of clone was significantly higher than that of control (p<0.05). The DMR of H19 was lower methylation pattern in clone than that of control. These results suggest that the aberrant mRNA expression of apoptosis-related and imprinted genes and the lower DMR methylation pattern of imprinted gene may be closely related to the inadequate fetal development of cloned fetus.
        4,000원
        147.
        2007.12 KCI 등재 구독 인증기관·개인회원 무료
        Cordyceps militaris is well known as a traditional herbal ingredient, which has been used for patients suffering from cancer in oriental medicine. In this study we have investigated the biochemical mechanisms of anti-proliferative effects by C. militaris extract(CBE) in human breast cancer MDA-MB-231 cells. It was found that CBE treatment induced chromatin condensation, mitochondrial energization, annexin V staining and sub-G1 phase DNA content. These indicators of apoptosis correlate with the mitochondrial dependent pathway, which results in the activation of caspase-3 activity. Both the cytotoxic effect by CBE treatment were significantly inhibited by z-DEVD-fmk, a caspase-3 inhibitor, demonstrating the important role of caspase-3 in the observed cytotoxic effect. Co-treatment of CBE and LY294002, resulted in significantly induction of apoptosis. These results indicate that caspase-3 is a key regulator of apoptosis in response to CBE in human breast cancer MDA-MB-231 through down regulation of Akt, and that the C. militaris extract may therefore have therapeutic potential against human breast cancer.
        148.
        2007.10 KCI 등재 구독 인증기관·개인회원 무료
        Glycyrrhiza ura lensis (Leguminosae) has long been known as an ant i-i nflammatory agent for gastric 띠cers , arthri t is, and rheumaLism. 1'he f1avonoid glycyr ol isolated from Glycyrrhiza uralensis dramatically inhibits phorbol ester (PMA)-induced NF-kB-dependent transcriptional activity, as determined by luciferase activity in HEK293T cells To in vestigate the global gene expression profiling by glycyrol, we performed high-density oligonucleotide microarrays, Our microarray analysis showed that gl ycY I 이 inhi bited phorbol ester-induced NF-kB-dependent transcriptional activity in inflarnmatory-related gene expression, RT-PCR analysis based on microarry data showed that NF-kB-dependent genes such as CCL2‘ CCL7. CD44, and HSPB8 in addition to NF-kB itself were significantly down-regulated by glycyrol Treatment with glycyrol inhibited ]-kB degradation induced by PMA, suggesting that glycyrol has a potential anti-in flammatory activity by modulating NF-kB-dependent pathways. Also, the microarray data showed that glycyr이 appears to induce gene expression related to p53-dependent apoptosis t hrough ENDO G instead of CAD/DFF and AlF/PDCD8 as down stream apoptosis factor in HEK293T tumor cell s and to induce an added function as oncogenes in connection with apoptoslS
        149.
        2007.09 구독 인증기관 무료, 개인회원 유료
        Treatment of oral cancers with chemotherapeutic agents become evaluated as an effective method to reduce cancer cell proliferation. Anti-proliferative and anti-oral cancer activities of momordin I on oral cancer cells were evaluated in this study. Momordin I was originally purified from a natural product, Ampelopsis radix and showed the antiproliferative activity against oral carcinoma, KB cells. Obtained value was approximately 104μM/mℓ. Time-and dose-dependent chromosomal DNA fragmentations were observed in momordin I-treated KB cells. Flow cytometry analysis showed time-dependent apoptotic cell appearance after treatment of momordin I. Approximately 18.6% apoptotic cells were observed at 72 hours after of momordin I treatment. These observation were consistent with the results obtained in DNA fragmentation analysis. These data suggest that momordin I has anti-proliferative effect and induces cell death in KB cells through apoptosis.
        4,000원
        150.
        2007.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Disruption of cell - matrix attachment results in a loss of prosurvival signals and culminates in programmed cell death, referred to as anoikis , Apoptosis signal- regulating kinase 1(ASKl)/MKK5 is a ubiquitously expressed enzyme that acti vates c-Jun N-terminal kinase/stress-activated protein kinase JNK/SAPK and p38 pathways by direct site specific Ser/Thr phosphoryl ation of their respective MKKs-MKK4/MKK7 for JNK and MKK3/MKK6 for p38 kinases, The kinase activity of ASKl is stimulated by a variety of death signals, including TNF, Fas ligation, reactive oxygen species, and antineoplastic agents , The aim of this study was to investigate the relative importance of ASKl in anOlkls 1n the present study cells which lost their adhesion showed higher rate of cell death in compared to cells which maintained anchorage. 1nterestingly the res ult showed that suspended cells expressing ASK1 were more susceptible to anoikis than suspended cells having no ASK1 1n addition, cellu lar attachment seems to have significant effect on ASKl activity and p38 MAPK protein rather than serum stimulation
        4,000원
        155.
        2007.06 구독 인증기관·개인회원 무료
        Cordyceps militaris is well known as a traditional herbal ingredient, which has been used for patients suffering from cancer in oriental medicine. In this study we have investigated the biochemical mechanisms of anti-proliferative effects by C. militaris extract(CBE) in human breast cancer MDA-MB-231 cells. It was found that CBE treatment induced chromatin condensation, mitochondrial energization, annexin V staining and sub-G1 phase DNA content. These indicators of apoptosis correlate with the mitochondrial dependent pathway, which results in the activation of caspase-3 activity. Both the cytotoxic effect by CBE treatment were significantly inhibited by z-DEVD-fmk, a caspase-3 inhibitor, demonstrating the important role of caspase-3 in the observed cytotoxic effect. Co-treatment of CBE and LY294002, resulted in significantly induction of apoptosis. These results indicate that caspase-3 is a key regulator of apoptosis in response to CBE in human breast cancer MDA-MB-231 through down regulation of Akt, and that the C. militaris extract may therefore have therapeutic potential against human breast cancer.
        156.
        2007.04 KCI 등재 구독 인증기관·개인회원 무료
        Apoptos is s ignal- regulating kinase 1 (ASKl) is a rnitogen-activated protein kinase kinase kinase(MAP3K) 떼 th proapoptotic functlOn 1'he kinase activity of ASKl is stimulated by a variety of death signals , including 1'NFα • Fas ligation, reactive oxygen species, and antineoplastic agents, ASKl promotes cell death by activating the c- Jun N-termina l kinase/stress-activated protein kinase MKK4/MKK7-JNK/SAPK pathway and MKK3/ 1\αCK6-p38 pathway‘ ASKl activity is highly controlled in cells by multiple mechanisms, including phosphorylation, oligome ri zation, and protein- protein ll1 teractlOns Epigallocatechin-3-galla te(EGCG) is the major bioactive polyphenol present in green tea, It possesses anti-oxida nt , a nti - mutagenic‘ a n ti - prote이 ytic , and anti-proliferative activity, In addition. it has been shown to inhibit cyclin activity, and inhibit cell cycle progression 1n the present study, we exarnined the effect of EGCG on ASKl- overexpressed cells , We expected that EGCG contributes to cell a poptos is by activating ASKl functlOn However, EGCG showed no suppressive effect on cell s urvival of ASKl-overexpressed cells and seemed to promote cell survlval Importantly, the EGCG treatment in creased Akt activity when cells expressed enough amount of ASKl protein, These results s uggest that the presence of ASKl may modify the inhibitory effect of EGCG on cell survival through Akt pathway,
        157.
        2007.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Indirubin is the active ingredient 0 1' a traditional Chinese herbal medicine, Danggui Longhui Wan, used for the t reatment of chronic myelocytic leu kelma The author reports that novel indirubin derivative, 5'-nitro-indirubinox ime (5'-NIO) , has potent a nti -proliferative activity on human o1'al cancer cells , Treatment of KB cells with 5’ NIO s howed a s t rong cell growth inhibit ion during indicated time point , A typical apoptosis pattern was obtained with DNA fragmenta tion and i mmunofl uorescence analysis of annelxn-v-f!ous Western blot data revealed that p53 and p21CIP1/Waf- l level increased strongJy upon 5'-NIO treatment , The a uthor next tested whether 5'-NIO could activate apoptos is related proteins s uch as caspase-3/-7/-9, [n cells exposed to 5‘-NIO, activation of caspase-3 and -7 was observed, Interesti ngly‘ caspase-9 and cytochrome c cou ld s li ghtly activate in response to 5’-NIO. These results indicate that 5’-NIO strongly induces oral cancer cells apoptosis via a Mi tochondria-mediated cas pase cascade pathway, These observations together s uggest that 5’ NTO may have a possible therapeutic potentia[ to oral cancer
        4,000원
        158.
        2007.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Chromosomal abnormality s uch as aneuploidy is one of the main factors to cause cancers This abnormality is caused by defects in centrosomal duplication‘ and most cancer cells have extra copies of centrosomes, r esulting in t he formation of multipolar spindles. Several kinases playing in mitotic phase have been implicated in regulating the centrosomal cycle‘ spindle checkpoint‘ and chromosome co ndensation and segregation. They also have Lhe ability to act as oncogenes. FOl studying the relationship between rnitotic kinase and oral cancers, the kinase activity of polo-like kinase-1, which is one of mitosis-specific kinases, is analyzed in oral carcinoma cells originated differently. Kinase activity was increased in these cancer cells compared to normal human gingival fibroblast primary cultured cells Moreover. the mitotic cell populations were a lso increased in these cell lines. Whereas the inhibition of Polo-like kinase-1 by C-terrninal domain in human gingival fibroblast cells induced multiploidy‘ the apoptotic cell population was increased in oral cancer cells overexpressed C-terminal domain 0 1' Polo- Ii ke kinase-1. These data suggested that polo-like kinase-1 might be involved in the on cogenic effect in oral cancer like other solid human carcinomas, and be target molecules for anti-cancer drug.
        4,000원
        159.
        2006.12 구독 인증기관 무료, 개인회원 유료
        Many naturally occurring plant extracts are studied for their beneficial effects for health and particularly on cancer. Apoptosis, or programmed cell death, occurs in both normal and pathological conditions, including cancer Dysregulation of apoptosis allows transformed cells to continually and uninhibitedly enter the cell cycle, thus perpetuating the sequence of mutation, genomic instability and, finally, oncogenesis. To investigate the apoptosis-inducing effect of the extract of Fructus Trichosanthis (EFT) on leukemic HL-60 cells and its mechanism, HL-60 cells in vitro in culture medium were given different doses of the extract. The inhibitory rate of cells were measured by microculture tetrazolium assay, cell apoptotic rate was detected by flow cytometry, morphology of cell apoptosis was observed by DAPI fluorescence staining, and the activations of caspases and PARP were detected using Western blotting analysis. The extract could activate the caspase-3 and caspase-8, induce PARP cleavage, inhibit growth of HL-60 cells, and cause apoptosis significantly The suppression was in dose-dependent manner. Marked morphological changes of cell apoptosis including condensation of chromatin and nuclear fragmentation were observed clearly by DAPI fluorescence staining especially. These results will provide strong laboratory evidence of EFT for clinical treatment of acute leukemia.
        4,000원
        160.
        2006.06 KCI 등재 구독 인증기관·개인회원 무료
        Agaricus blazeiMurill is an edible mushroom distributed in Brazil and presently cultivated in other areas, including Korea, Japan, and China. Its chemical components, including steroids and lectin and various polysaccharides have been widely studied. For this, we used U937/vector and U937/Bcl-2 cells, which were generated by transfection of the cDNA of the Bcl-2 gene. As compared with U937/vector, U937/Bcl-2 cells exhibited a 4-fold greater expression of Bcl-2. Treatment with 0.5 or 4 mg/ml A. blazei Murill for 24 h produced morphological features of apoptosis in U937/vector cells, respectively. This was associated with caspase-3 activation and PARP degradation. In contrast, A. blazei Murill-induced caspase-3 activation and PARP degradation and apoptosis were significantly inhibited by z-DEVD-fmk in U937 cells. Bcl-2 overexpressing cells exhibited sustained caspase-3 activation and expression levels of the Bcl-2 proteins during A. blazei Murill-induced apoptosis. In addition, these findings indicate that Bcl-2 inhibits A. blazei Murill-induced apoptosis by a mechanism that interferes with Bcl-2 degradation and activity of caspase-3 that is involved in the execution of apoptosi.