• 제목/요약/키워드: DNA damage

검색결과 1,448건 처리시간 0.031초

Hypertonicity Down-regulates the $1{\alpha},25(OH)_2$ Vitamin $D_3$-induced Osteoclastogenesis Via the Modulation of RANKL Expression in Osteoblast

  • Jeong, Hyun-Joo;Yushun, Tian;Kim, Bo-Hye;Nam, Mi-Young;Lee, Hyun-A;Yoo, Yun-Jung;Seo, Jeong-Taeg;Shin, Dong-Min;Ohk, Seung-Ho;Lee, Syng-Ill
    • International Journal of Oral Biology
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    • 제30권1호
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    • pp.23-30
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    • 2005
  • Bone remodeling is a process controlled by the action of two major bone cells; the bone forming osteoblast and the bone resorbing osteoclast. In the process of osteoclastogenesis, stromal cells and osteoblast produce RANKL, OPG, and M-CSF, which in turn regulate the osteoclastogenesis. During the bone resorption by activated osteoclasts, extracellular $Ca^{2+}/{PO_4}^{2-}$ concentration and degraded organic materials goes up, providing the hypertonic microenvironment. In this study, we tested the effects of hypertonicity due to the degraded organic materials on osteoclastogenesis in co-culture system. It was examined the cellular response of osteoblastic cell in terms of osteoclastogenesis by applying the sucrose, and mannitol, as a substitute of degraded organic materials to co-culture system. Apart from the sucrose, mannitol, and NaCl was tested to be compared to the effect of organic osmotic particles. The addition of sucrose and mannitol (25, 50, 100, 150, or 200 mM) to co-culture medium inhibited the number of tartrate-resistant acid phosphatase (TRAP) positive multinucleated cells induced by 10 nM $1{\alpha},25(OH)_2vitaminD_3$ ($1{\alpha},25(OH)_2D_3$). However, NaCl did exert harmful effect upon the cells in this co-culture system, which is attributed to DNA damage in high concentration of NaCl. To further investigate the mechanism by which hypertonicity inhibits $1{\alpha},25(OH)_2D_3$-induced osteoclastogenesis, the mRNA expressions of receptor activator of nuclear factor (NF)-kB ligand (RANKL) and osteoprotegerin (OPG) were monitored by RT-PCR. In the presence of sucrose (50 mM), RANKL mRNA expression was decreased in a dose-dependent manner, while the change in OPG and M-CSF mRNA were not occurred in significantly. The RANKL mRNA expression was inhibited for 48 hours in the presence of sucrose (50 mM), but such a decrement recovered after 72 hours. However, there were no considerable changes in the expression of OPG and M-CSF mRNA. Conclusively, these findings strongly suggest that hypertonic stress down-regulates $1{\alpha},25(OH)_2D_3$-induced osteoclastogenesis via RANKL signal pathway in osteoblastic cell, and may playa pivotal role as a regulator that modulates osteoclastogenesis.

벼도열병균에서의 methionine sulfoxide reductase B 유전자의 분자적 특성 (Identification and Molecular Characterization of Methionine Sulfoxide Reductase B Gene in Rice Blast Fungus, Magnaporthe oryzae)

  • 김정환;김진수;정미연;최우봉
    • 생명과학회지
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    • 제19권3호
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    • pp.343-348
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    • 2009
  • 벼도열병균은 벼의 주요 병해인 벼도열병의 원인균이다. 식물병원균의 침입 시 식물체로부터 발생하는 ROS는 식물의 방어기작으로 중요하며, 특히 아미노산의 하나인 methionine은 ROS에 의해 산화되어 methionine sulfoxide로 변화될 수 있다. 식물병원균은 식물체로 부터의 ROS에 의한 산화반응을 회피하기 위해 methionine sulfoxide reductase B (MSRB)와 같은 항산화 효소를 가지는데 본 연구에서는 벼도열병균에서의 MSRB 유전자를 동정하고 분자적 특성을 살펴보았다. MSRB 유전자는 벼도열병균의 게놈 상에 단일 유전자로 존재하며 과산화수소 처리에 의해 유전자발현이 다소 증가하는 경향을 보였다. 이러한 결과로 MSRB 유전자는 벼도열병균의 항산화 기작에 관여할 가능성이 높다고 판단된다.

Lack of Association of the NPAS2 Gene Ala394Thr Polymorphism (rs2305160:G>A) with Risk of Chronic Lymphocytic Leukemia

  • Rana, Sobia;Shahid, Adeela;Ullah, Hafeez;Mahmood, Saqib
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권17호
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    • pp.7169-7174
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    • 2014
  • Background: NPAS2 is a product of the circadian clock gene. It acts as a putative tumor suppressor by playing an important role in DNA damage responses, cell cycle control and apoptosis. Chronic lymphocytic leukemia (CLL) appears to be an apoptosis related disorder and alteration in the NPAS2 gene might therefore be directly involved in the etiology of CLL. Here, the Ala394Thr polymorphism (rs2305160:G>A) in the NPAS2 gene was genotyped and melatonin concentrations were measured in a total of seventy-four individuals, including thirty-seven CLL cases and an equal number of age- and sex-matched healthy controls in order to examine the effect of NPAS2 polymorphism and melatonin concentrations on CLL risk in a Pakistani population. Materials and Methods: Genotyping of rs2305160:G>A polymorphism at NPAS2 locus was carried out by amplification refractory mutation system-polymerase chain reaction (ARMS-PCR). Melatonin concentrations were determined by enzyme linked immunosorbent assay (ELISA). Statistical analysis was performed using Statistical Package for Social Sciences software. Results: Our results demonstrated no association of the variant Thr genotypes (Ala/Thr and Thr/Thr) with risk of CLL. Similarly, no association of rs2305160 with CLL was observed in either females or males after stratification of study population on a gender basis. Moreover, when the subjects with CLL were further stratified into shift-workers and non-shift-workers, no association of rs2305160 with CLL was seen in either case. However, significantly low serum melatonin levels were observed in CLL patients as compared to healthy subjects (p<0.05). Also, lower melatonin levels were seen in shift-workers as compared to non-shift-workers (p<0.05). There was no significant difference (p>0.05) in the melatonin levels across NPAS2 genotypes in all subjects, subjects with CLL who were either shift workers or non-shift-workers. General Linear Model (GLM) univariate analysis revealed no significant association (p>0.05) of the rs2305160 polymorphism of the NPAS2 gene with melatonin levels in any of the groups. Conclusions: While low melatonin levels and shift-work can be considered as one of the risk factors for CLL, the NPAS2 rs2305160 polymorphism does not appear to have any association with risk of CLL in our Pakistani population.

Serum 8 Hydroxydeoxyguanosine and Cytotoxin Associated Gene A as Markers for Helicobacter pylori Infection

  • Yeniova, Abdullah Ozgur;Uzman, Metin;Kefeli, Ayse;Basyigit, Sebahat;Ata, Naim;Dal, Kursat;Guresci, Servet;Nazligul, Yasar
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권13호
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    • pp.5199-5203
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    • 2015
  • Background: Helicobacter pylori (H.pylori) is associated with chronic gastritis, peptic ulcers, gastric adenocarcinomas and mucosa associated tissue lymphomas. Cytotoxin associated gene A (CagA) is one of the virulence factors of H.pylori. It is hypothesized that reactive oxygen species (ROS) play roles in H.pylori associated disease especially in development of gastric adenocarcinoma. Individuals infected with H.pylori bearing CagA produce more ROS than others. 8-hydroxydeoxyguanosine (8OHdG) is an in vitro marker of DNA damage and oxidative stress. The aim of this study was to investigate the relationship between 8OHdG level, H.pylori infection and CagA and alterations of serum 8OHdG level after H.pylori eradication. Materials and Methods: Patients admitted with dyspeptic complaints and upper gastrointestinal endoscopy were assessed. H.pylori was determined from histopathology of specimens. Serum 8OHdG levels of three groups (H.pylori negative, H. pylori positive CagA negative and H.pylori positive CagA positive) were compared. Patients with H.pylori infection received eradication therapy. Serum 8OHdG levels pretreatment and posttreatment were also compared. Results: In total, 129 patients (M/F, 57/72) were enrolled in the study. Serum 8OHdG level of H.pylori negative, H. pylori positive CagA negative and H.pylori positive CagA positive groups were significantly different ($5.77{\pm}1.35ng/ml$, $5.43{\pm}1.14ng/ml$ and $7.57{\pm}1.25ng/ml$ respectively, p=0.05). Furthermore, eradication therapy reduced serum 8OHdG level ($6.10{\pm}1.54ng/ml$ vs $5.55{\pm}1.23ng/ml$, p=0.05). Conclusions: Individuals infected with H.pylori bearing CagA strains have the highest serum 8OHdG level and eradication therapy decreases the serum 8OHdG level. To the best of our knowledge this is the first study that evaluated the effect of CagA virulence factor on serum 8OHdG level and the effect of eradication therapy on serum 8OHdG levels together. Eradication of CagA bearing H.pylori may prevent gastric adenocarcinoma by decreasing ROS. 8OHdG level may thus be a good marker for prevention from gastric adenocarcinoma.

Anti-metastatic Effects on B16F10 Melanoma Cells of Extracts and Two Prenylated Xanthones Isolated from Maclura amboinensis Bl. Roots

  • Siripong, Pongpun;Rassamee, Kitiya;Piyaviriyakul, Suratsawadee;Yahuafai, Jantana;Kanokmedhakul, Kwanjai
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권7호
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    • pp.3519-3528
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    • 2012
  • Inhibitory effects of Maclura amboinenesis Bl, one plant used traditionally for the treatment of cancers, on metastatic potential of highly metastatic B16F10 melanoma cells were investigated in vitro. Cell proliferation was assessed using the MTT colorimetric assay. Details of metastatic capabilities including invasion, migration and adhesion of B16F10 melanoma cells were examined by Boyden Chamber invasion and migration, scratch motility and cell attachment assays, respectively. The results demonstrated that n-hexane and chloroform extracts exhibited potent anti-proliferative effects (p<0.01), whereas the methanol and aqueous extracts had less pronounced effects after 24 h exposure. Bioactivity-guided chromatographic fractionation of both active n-hexane and chloroform extracts led to the isolation of two main prenylated xanthones and characterization as macluraxanthone and gerontoxanthone-I, respectively, their structures being identified by comparison with the spectral data. Interestingly, both exhibited potent effective effects. At non-toxic effective doses, n-hexane and chloroform extracts (10 and $30{\mu}g/ml$) as well as macluraxanthone and gerontoxanthone-I (3 and $10{\mu}M$) significantly inhibited B16F10 cell invasion, to a greater extent than $10{\mu}m$ doxorubicin, while reducing migration of cancer cells without cellular cytotoxicity. Moreover, exposure of B16F10 melanoma cells to high concentrations of chloroform ($30{\mu}g/ml$) and geratoxanthone-I ($20{\mu}M$) for 24 h resulted in delayed adhesion and retarded colonization. As insights into mechanisms of action, typical morphological changes of apoptotic cells e.g. membrane blebbing, chromatin condensation, nuclear fragmentation, apoptotic bodies and loss of adhesion as well as cell cycle arrest in the G1 phase with increase of sub-G1 cell proportions, detected by Hoechst 33342 staining and flow cytometry were observed, suggesting DNA damage and subsequent apoptotic cell death. Taken together, our findings indicate for the first time that active n-hexane and chloroform extracts as well as macluraxanthone and gerontoxanthone-I isolated from Maclura amboinensis Bl. roots affect multistep of cancer metastasis processes including proliferation, adhesion, invasion and migration, possibly through induction of apoptosis of highly metastatic B16F10 melanoma cells. Based on these data, M. amboinensis Bl. represents a potential candidate novel chemopreventive and/or chemotherapeutic agent. Additionally, they also support its ethno-medicinal usage for cancer prevention and/or chemotherapy.

Mn-SOD와 GST 유전자 다형성에 따른 유아의 산화손상지표의 분포 (Oxidative damage biomarker levels according to Mn-SOD and GST gene polymorphisms in preschool children)

  • 신유경;최지원;오세영;정자용
    • Journal of Nutrition and Health
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    • 제48권6호
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    • pp.468-475
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    • 2015
  • 우리나라 일부 건강한 유아를 대상으로 Mn-SOD Val16Ala, GSTP1 Ile105Val, GSTT1 present/null, GSTM1 present/null 유전자 다형성 분포를 살펴본 결과, Mn-SOD Val/Val형, GSTP1 Ile/Ile형, GSTT1 null 형, GSTM1 null 형이 주된 (major) 유전자형인 것으로 나타났다. 이 중 Mn-SOD Val/Val형은 Val/Ala 또는 Ala/Ala형에 비해 소변 8-OHdG 수준이 유의적이지는 않으나 높은 경향을 나타내었고, GSTP1 Ile/Ile형은 Ile/Val 또는 Val/Val형에 비해 소변 8-OHdG 수준이 유의적으로 낮았다. 간접흡연에의 노출 여부와 간접흡연-유전자 다형성의 상호 작용이 산화손상지표에는 유의적인 영향을 미치지 않는 것으로 나타났다. 이상의 결과로 볼 때 건강한 유아에서 GSTP1 Val allele 보유한 경우 산화적 손상에 대해 취약할 수 있음을 제시하며, 추후 대규모 연구를 통한 검증 및 이들 유전자형을 보유한 대상자를 위한 효과적인 영양 중재방안에 대한 고려가 필요할 것으로 사료된다.

5-fluorouracil과 curcumin의 복합투여에 의한 자궁암세포의 성장억제와 p53유전자 발현의 상승 효과 (Synergistic Effects of 5-Fluorouracil (FU) and Curcumin on Human Cervical Cancer Cells)

  • 안성호;김동희;강정훈;이명선
    • Applied Microscopy
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    • 제40권4호
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    • pp.229-235
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    • 2010
  • 암은 전 세계적으로 사망률이 높은 질병으로 현재 자궁암 치료는 cisplatin, 5-fluorouracil (5FU) 등의 항암화학요법과 방사선 요법 등을 복합적으로 병행하고 있다. 최근 항암효과를 가지고 있는 자연식품의 섭취에 관심이 커지면서 커리의 주성분인 curcumin (CMN), 녹차의 주성분인 카테킨, 토마토의 주성분인 리코펜 등의 약리효과에 대한 연구가 활성화되고 있다. CMN은 동물실험 결과 항염증의 활성이 있고, 피부, 대장, 유방, 전립선 등에서 암으로의 진행을 억제한다는 보고가 있으나 인체 자궁암에서는 그 효과가 밝혀져 있지않다. 본 연구는 항암제 5FU와 CMN이 인체 자궁암세포 HeLa에 미치는 영향을 apoptosis의 유도로 평가하고, p53유전자 발현율과의 상관관계로 확인하고자 시행하였다. CMN은 HeLa 세포의 성장을 억제하였으며, 5FU로 유도된 apoptosis의 발생률과 p53유전자의 발현률을 현저하게 증가시키는 것으로 나타났다(p<0.05). 이러한 연구결과는 CMN이 자궁암 치료제의 가능성이 있으며, 또한 5FU와 복합적으로 사용하면 항암제를 단독으로 투여하는 경우보다 자궁암 치료에 보다 효과적임을 강력히 시사하는 것이다.

Molecular Mechanism of Tetrabromobisphenol A (TBBPA)-induced Target Organ Toxicity in Sprague-Dawley Male Rats

  • Choi, Jae-Seok;Lee, Young-Jun;Kim, Tae-Hyung;Lim, Hyun-Jung;Ahn, Mee-Young;Kwack, Seung-Jun;Kang, Tae-Seok;Park, Kui-Lea;Lee, Jae-Won;Kim, Nam-Deuk;Jeong, Tae-Cheon;Kim, Sang-Geum;Jeong, Hye-Gwang;Lee, Byung-Mu;Kim, Hyung-Sik
    • Toxicological Research
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    • 제27권2호
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    • pp.61-70
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    • 2011
  • Brominated flame retardants (BFRs) are present in many consumer products ranging from fabrics to plastics and electronics. Wide use of flame retardants can pose an environmental hazard, which makes it important to determine the mechanism of their toxicity. In the present study, dose-dependent toxicity of tetrabromobisphenol A (TBBPA), a flame retardant, was examined in male prepubertal rats (postnatal day 18) treated orally with TBBPA at 0, 125, 250 or 500 mg/kg for 30 days. There were no differences in body weight gain between the control and TBBPA-treated groups. However, absolute and relative liver weights were significantly increased in high dose of TBBPA-treated groups. TBBPA treatment led to significant induction of CYP2B1 and constitutive androstane receptor (CAR) expression in the liver. In addition, serum thyroxin (T4) concentration was significantly reduced in the TBBPA treated group. These results indicate that repeated exposure to TBBPA induces drug-metabolising enzymes in rats through the CAR signaling pathway. In particular, TBBPA efficiently produced reactive oxygen species (ROS) through CYP2B1 induction in rats. We measured 8-hydroxy-2'-deoxyguanosine (8-OHdG), a biomarker of DNA oxidative damage, in the kidney, liver and testes of rats following TBBPA treatment. As expected, TBBPA strongly induced the production of 8-OHdG in the testis and kidney. These observations suggest that TBBPA-induced target organ toxicity may be due to ROS produced by metabolism of TBBPA in Sprague-Dawley rats.

솔잎착즙액을 첨가한 설기떡의 가열조리에 따른 항산화 및 항유전독성 효능 검증 (Changes in the Antioxidative and Antigenotoxic Effects After the Cooking Process of Sulgidduk Containing Pine Needle Juice)

  • 이현정;김소윤;박재희;김래영;정현숙;박은주
    • 한국식품조리과학회지
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    • 제29권5호
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    • pp.453-462
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    • 2013
  • Recently, two formulas of sulgidduk added to pine needle juice (PNJ) with various physiological activities were developed for metabolic syndrome patients in our lab. According to previous studies, cooking may alter antioxidant properties by initiating destruction, release or transformation of antioxidant compounds contained in food. Therefore, the aim of this study was to compare the antioxidant activities and antigenotixic effects of sulgidduk with/without PNJ and to note changes in these activities after cooking. The ingredients of sulgidduk was added on the basis of 100% rice flour as follows: conventional sulgidduk (S): 1.5% salt, 30.0% sugar; PNJ added to sulgidduk A (PS-A): 1.4% salt, 30.0% sugar, and 1.0% PNJ; PNJ added to sulgidduk B (PS-B): 1.5% salt, 21.4% sugar, and 1.4% PNJ. Ethanol and water extracts of sulgidduk were analyzed for the total phenolic content (TPC), DPPH radical scavenging activity (DPPH RSA), total radical-trapping antioxidant potential (TRAP), oxygen radical absorbance capacity (ORAC), and antigenotoxic effect by comet assay. The ethanol extracts PS-A and PS-B showed higher TPC and antioxidant activities (DPPH RSA, TRAP, and ORAC) than did the S ethanol extract before cooking. The more PNJ was added, the higher TPC and anitoxidant activities were observed in sulgidduk (PS-A$200{\mu}M$ of $H_2O_2$. Taken together, this study suggests that sulgidduk added to 1.44% of pine needle juice may be a good option antioxidant and antigenotoxic source.

미국 담배소송의 변천과 보건법정책 효과 (The Development of Tobacco Litigation in USA and it's Impact of Law and Politics in Public Health)

  • 김운묵;김지현
    • 의료법학
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    • 제12권1호
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    • pp.133-173
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    • 2011
  • Since mid-1960s the reports from the Surgeon General, the World Health Organization, and other health experts state that there is no risk-free level exposure to smoking and secondhand smoke. Tobacco smoke is made up of more than 7,000 chemicals. Hundreds are toxic, and at least 70 are carcinogens. The chemicals in tobacco smoke reach smoker's lungs quickly every time smoker inhale causing damages immediately. Inhaling even the smallest amount of tobacco smoke can also damage smoker's DNA, which can lead to cancers. Smoking is responsible for more than 87% of lung cancers, but there are a host of other chronic diseases directly related to exposure to tobacco smoke. It's also a major cause of heart disease, stroke, aortic aneurysm, peripheral arterial disease and most of the other diseases. In the United States, each year with more than from 440,000 to 520,000 deaths caused by smoking and exposure to involuntary smoke. They conclude that smoking is the single most important source of preventable morbidity and mortality. The United States of America have about 60-year history of tobacco litigation. Tobacco litigation has been an important tool in tobacco control strategies aimed at limiting the activities of tobacco companies and providing redress to people who have become ill as a result of their use of tobacco products. Tobacco litigation is a kind of tort litigation. Quite often, as in the asbestos and other mass tort litigation episodes, tobacco litigation can play an educational role, warning the public about the magnitude of health risks that might otherwise be less clearly perceived. Tobacco litigation allows smokers, their families or other victims of smoking to sue tobacco companies in order to be compensated for the harm they have suffered. Potential benefits of tobacco litigation include compensation for smoking-related damages, strengthening regulatory activity, publicity, documents disclosure and changing tobacco industry behavior. And also tobacco litigation can limit the political activities of tobacco industry, protect human rights of smokers and non-smokers, increase burden to tobacco price-up and enhance the effects of law and politics in public health.

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