• Title/Summary/Keyword: 발암기전

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Effects of Ultraviolet Radiation on the Skin (자외선에 의한 피부반응)

  • Youn, Jail-Il
    • Journal of Radiation Protection and Research
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    • v.20 no.3
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    • pp.181-186
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    • 1995
  • UV irradiation causes a variety of biologic effects on the skin. These effects can be devided to acute reactuons and chronic reacxtions by duration of UV irradiation. Acute reactions are erythema reaction, pigment reactions and changes in epidermal thickness. Among them erythema reaction is most common and conspicuous acute effects of the skin. Upon exposure to sun or artificial UV soures, a faint redness response of skin may begin. Larger exposure causes sunburn reaction which is exaggerated erythema reactionassociated with pain, swelling, vesicle and dulla. Extent and time course of erythema reaction depend upon several factors including wavelength and dose of UVR, skin conditions likeas skin type, site, color, temperature, humidity and environmental factors. Evaluation of erythema erythema induced by UV irradiation is difficult to quantify. Degree of redness of skin are usually estimated by subjective visual evaluation. The lowest exposure dose required to protuce erythema is called minimal erythema dose (mod). Repeated exposures of UVR result in photaging skin. In this condition we can see wrinkling, skin atrophy, dilated blood vessels and keratoses. In sensitive persons photocarcinogenesis is can Be developed on exposed area of skin. Recently skin canser is increasing now in our country. An effective public education and photopreventive method must be developed.

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Microbial Production of Carotenoids: Biological Functions and Commercial Applications (미생물에 의한 카로티노이드 생산; 생물학적 기능성 및 상업적 적용)

  • Seo, Yong Bae;Kim, Gun-Do
    • Journal of Life Science
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    • v.27 no.6
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    • pp.726-737
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    • 2017
  • Carotenoids are isoprenoids with a long polyene chain containing 3 to 15 conjugated double bonds, which determines their absorption spectrum. They typically consist of a $C_{40}$ hydrocarbon backbone often modified by different oxygen-containing functional groups, to yield cyclic or acyclic xanthophylls. Much work has also been focused on the identification, production, and utilization of natural sources of carotenoid (plants, microorganisms and crustacean by-products) as an alternative to the synthetic pigment which currently covers most of the world markets. Nevertheless, only a few carotenoids (${\beta}-carotene$, lycopene, astaxanthin, canthaxanthin, and lutein) can be produced commercially by fermentation or isolation from the small number of abundant natural sources. The market and demand for carotenoids is anticipated to increase dramatically with the discovery that carotenoids exhibit significant anti-carcinogenic activities and play an important role in the prevention of chronic diseases. The increasing importance of carotenoids in the feed, nutraceutical food and pharmaceutical markets has renewed by efforts to find ways of producing additional carotenoid structures in useful quantities. Because microorganisms and plants synthesize hundreds of different complex chemical carotenoid structures and a number of carotenoid biosynthetic pathways have been elucidated on a molecular level, metabolic and genetic engineering of microorganisms can provide a means towards economic production of carotenoid structures that are otherwise inaccessible. The aim of this article is to review our current understanding of carotenoid formation, to explain the perceived benefits of carotenoid in the diet and review the efforts that have been made to increase carotenoid in certain microorganisms.

Enhanced conversion to cotinine from nicotine by green tea extract (녹차 추출물에 의한 니코틴의 코티닌으로 전이 촉진)

  • Kyung, Yoon-Joo;Lee, Dong-Hee
    • Korean Journal of Environmental Agriculture
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    • v.19 no.2
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    • pp.147-153
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    • 2000
  • Cigarette smoking deals a harmful effect directly to smokers and even to non-smokers through environmental tobacco smoke. The major damaging component in cigarette smoke is nicotine which converts to various carcinogens. Among the carcinogenic metabolites, nitrosamine-4-(methylnitrosamino)-1- (3-pyridyl)-1- butanone (NNK) is responsible for many types of lung cancers. Recent studies report that activation of NNK is markedly inhibited in the presence of cotinine, a safer metabolite from nicotine. It is well known that tea extract have potentials to prevent cancers. This study aims to correlate green tea's potential for cancer prevention with an accelerated formation of cotinine. In the presence of tea extract, a nicotine to cotinine conversion was studied in established cell lines and xenopus oocytes. Among three lines of cell used, PLC/PRF5 and 293 cells showed a fast turnover from nicotine to cotinine while HepG2 cell line showed a marginal difference between groups treated and non-treated with tea extract. A microinjection procedure using Xenopus oocyte was utilized to probe for the effect of tea extract in accelerating nicotine conversion to cotinine. According to this procedure, tea extract's unusual potential for converting nicotine to cotinine is also substantiated. Overall, this present study indicated that tea extract have an unusual effect on conversion of nicotine to cotinine in cells.

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The Relationship of Plasma Visfatin Level and Anorexia in Terminal Cancer Patients (말기암환자의 혈중 Visfatin 농도와 식욕부진의 관계)

  • Lee, So Jin;Lee, Joon Yong;Choi, Youn Seon;Lee, June Young
    • Journal of Hospice and Palliative Care
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    • v.17 no.1
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    • pp.18-26
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    • 2014
  • Purpose: Anorexia is a common symptom in terminal cancer patients. Some data have suggested a role of visfatin in regulating feeding behavior. We studied the relationship of a serum visfatin level and anorexia in cancer patients provided with hospice care. Methods: After informed consent was obtained, 69 cancer patients over 20 years old at a hospice center were enrolled in the study from July 2009 to July 2010. We characterized patients by age, sex, body mass index, primary cancer site, and Eastern Cooperative Oncology Group (ECOG) performance status, etc. Also, blood tests were performed to measure the level of hemoglobin, white blood cell (WBC), C-reactive protein (CRP), total cholesterol, albumin, lymphocyte count, glucose, blood urea nitrogen (BUN), creatinine, tumor necrosis factor-alpha (TNF-${\alpha}$), interukin-6, leptin and visfatin. Results: The mean age of subjects was 65.5 years old, According to univariate analysis, pulse, ECOG performance scale, opioid use and visfatin level were different between the anorexia and non-anorexic group (P<0.05). The median visfatin level was higher in the anorexia group than the good appetite group (P=0.0323). Serum visfatin concentrations were not related with either body mass index or serum leptin or total cholesterol levels, but it was negatively correlated with serum albumin levels (P=0.0198) and lymphocyte counts (P=0.0013). Conclusion: This study did not identify a novel link between visfatin levels and anorexia in cancer patients at a hospice.

Effect of Evodiae fructus Methanol Extract on Virulence-Related Genes' Expression of Helicobacter pylori (오수유 메탄올 추출물이 Helicobacter pylori 병원성 관련 유전자 발현에 미치는 영향)

  • Yang, Ji Yeong;Lee, Pyeongjae;Kim, Jong-Bae
    • Korean Journal of Clinical Laboratory Science
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    • v.51 no.3
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    • pp.316-322
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    • 2019
  • Helicobacter pylori, a gram-negative bacterium, is one of the risk factors that induces gastritis and gastric cancer. Therefore, much attention has been paid to the compounds that inhibit bacterial growth or eradicate bacteria. Evodiae fructus (EF), the fruit of Evodia rutaecarpa, has been used for treating diarrhea and abdominal pain. EF extract was already found to inhibit the growth of H. pylori. However, to the best of our knowledge, the effect of EF on the virulence factors of H. pylori has not been reported. In this study, when comparing the minimum inhibitory concentration (MIC) of the different methanol concentration extracts, the 95% methanol extract (EF95) showed the lowest MIC value. EF95 extract suppressed the expressions of cagA, vacA and ureB, but interestingly, it up-regulated the expression of ureA. A decrease in production of ammonia in the culture medium and the cell lysates indicated that EF95 inhibited the urease activity in H. pylori, which was the result of EF95 inhibiting the ureB expression. Although the mechanism by which EF95 extract regulates the virulence factors in H. pylori needs further study, EF95 could be used for treatment of gastric troubles induced by H. pylori.

IKKγ Facilitates the Activation of NF-κB by Hsp90 (Hsp90에 의한 NF-κB의 활성화를 촉진하는 IKKγ의 역할)

  • Lee, Jeong Ah;Kim, Dong Wan
    • Journal of Life Science
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    • v.32 no.3
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    • pp.241-248
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    • 2022
  • NF-κB acts as a critical transcription factor in inflammation and innate immunity, and it is also closely involved in cell survival and tumorigenesis via induction of anti-apoptotic genes. In these processes, NF-κB cooperates with multiple other signaling molecules and pathways, and although many studies have demonstrated that Hsp90 regulates NF-κB activity, the exact mechanism is unclear. In this study, we investigated the relationship between Hsp90 and IKKγ in the regulation of NF-κB using expression plasmids of IKK complex components. Wild-type and deletion mutants of IKKγ were expressed together with Hsp90, and the combined regulatory effect of Hsp90 and IKKγ on NF-κB activation was assayed. The results show that Hsp90 activates NF-κB by promoting the phosphorylation and degradation of IκBα and that activation of NF-κB by NIK and LPS was increased by Hsp90. IKKγ elevated the effect of Hsp90 on NF-κB activation by increasing phosphorylation and degradation of IκBα. The positive regulation on NF-κB by Hsp90 and IKKγ was also proved in analysis with IKKβ-EE, the constitutively active form of IKKβ. In experiments with the deletion mutants of IKKγ, the N-terminal IKKβ binding domain, C-terminal leucine zipper, and zinc finger domains of IKKγ were found not necessary for the positive regulation of NF-κB activity. Additionally, the expression of pro-inflammatory cytokines was synergistically elevated by Hsp90 and IKKγ. These results indicate that inhibiting the interaction between Hsp90 and IKKγ is a possible strategic method for controlling NF-κB and related diseases.

Biomarkers for Canine Mammary Tumors (반려견 유선종양 바이오 마커)

  • Chan-Ho Lee;Young Sun Choi;Suk Jun Lee;Sung-Hak Kim
    • Journal of Life Science
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    • v.34 no.6
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    • pp.434-441
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    • 2024
  • Mammary gland tumors are the most common tumors detected in non-spayed female dogs and pose a significant clinical challenge. Due to the strong similarity between canine mammary tumors (CMT) and human breast cancer (HBC), biomarkers identified in HBC can also be detected in CMT. These biomarkers have been shown to offer valuable insights into early diagnosis, prognosis, and treatment strategies. The purpose of this article is to provide a concise overview of CMT biomarkers based on the current literature. Traditional treatments for CMT in dogs typically begin with surgery, followed by chemotherapy, radiotherapy, or hormonal therapy. However, these treatments alone are not always fully effective. A diagnostic biomarker can detect the presence of a disease or the characteristics of a disease and classify an individual's status. Prognostic biomarkers focus on predicting the expected progression, recurrence, or survival of the disease in patients. By utilizing advances in understanding the mechanism of canine-specific mammary gland tumors, the estimation of biomarkers offers hope for improved outcomes in cancer patients. Novel technologies, such as single-cell RNA sequencing analysis, could provide a valuable resource for deciphering intra- and inter-tumoral heterogeneity. This review paper explores current research on CMT biomarkers and suggests directions for their development.

Perspectives on Glutaminase Inhibitors as Metabolic Anti-cancer Agents (Glutamine 대사항암제의 개발과 전망)

  • Ho-Yeon Jeon;Chae-Ryeong Seo;Jaeho Bae;Soon-Cheol Ahn
    • Journal of Life Science
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    • v.34 no.10
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    • pp.744-754
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    • 2024
  • Cancer cells exhibit a unique metabolic process for uncontrolled cell division, providing bioenergy and intermediates, which are significantly different from normal cells. Here an aerobic glycolysis converts most of the pyruvate produced from glucose into lactate and inefficiently produced ATP. Cancer cells counter their lack of energy through glutamine metabolism, together with glucose. Glutamine is the most abundant amino acid in the blood and is used for the synthesis of amino acids, nucleotides, and lipids, as well as bioenergy through glutaminolysis. Cancer cells rely on glutamine rather than normal cells, showing more than half of the tricarboxylic acid cycle metabolites derived from glutamine, called glutamine addiction. Oncogenes c-Myc also regulates the expression of various genes involved in glutamine metabolism and promotes the absorption of glutamine. Whether glutaminase (GLS) causes or inhibits tumors is controversial. However, GLS1 is a promising treatment target due to its higher carcinogenic incidence, whereas GLS2 is known to act as a tumor suppressor. The 4th-generation metabolic anti-cancer therapy, which has been actively investigated since the mid-2010s, is based on a complex and sophisticated network of cancer metabolites. These drugs directly regulate the energy metabolism of cancer cells to maximize anti-cancer effects without side effects. GLS is a crucial enzyme for cancer metabolism and tumor progression that catalyzes the first stage in the process of glutaminolysis. The development of anti-cancer drugs targeting GLS enzymes has emerged as a promising strategy.

Genetic Alteration of Tumor Suppressor Gene and Microsatellite in Nonsmall Cell Lung Cancer (비소세포폐암에서 종양억제유전자와 극소위성 변이에 관한 연구)

  • Shin, Tae-Rim;Hong, Young-Sook;Kim, Jhin-Gook;Chang, Jung-Hyun
    • Tuberculosis and Respiratory Diseases
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    • v.49 no.4
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    • pp.453-465
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    • 2000
  • Background : Lung carcinogenesis is a multistage process involving alterations in multiple genes and diverse pathway. Mutational activation of oncogenes and inactivation of tumor suppressor genes, and subsequent increased genetic instability are the major genetic events. The p53 gene and FHIT gene as tumor suppressor genes contribute to the pathogenesis of lung cancer, evidenced by mutation, microsatellite instability(MI) and loss of heterozygosity(LOH). Methods : We analysed genetic mutations of p53 and FHIT gene in 29 surgical specimens of nonsmall cell lung cancer using PCR-single strand conformation polymorphism, DNA sequencing and RT-PCR. MI and LOH were analyzed in loci of D3S1285, D9S171, and TP53. Results : In 2 cases, point mutation of p53 gene was observed on exon 5. MI of 3 times and LOH of 14 times were observed in at least one locus. In terms of the location of microsatellite, D3S1285 as a marker of FH1T was observed in 5 cases out of 26 specimens; D9S171 as a marker of p16 in 5 out of 17; and TP53 as a marker of p53 in 7 out of 27. In view of histologic type, squamous cell carcinoma presented higher frequency of microsatellite alteration, compared to others. Mutation of FHIT gene was observed in 11 cases and 6 cases of those were point mutation as a silent substitution on exon 8. FHIT mRNA expression exhibited deletion on exon 6 to 9 in 4 cases among 15 specimens, presenting beta-actin normally. Conclusion : Our results show comparable frequency of genetic alteration in nonsmall cell lung cancer to previous studies of Western countries. Microsatellite analysis might have a role as a tumor marker especially in squamous cell carcinoma. Understanding molecular abnormalities involved in the pathogenesis could potentially lead to prevention, earlier diagnosis and the development of novel investigational approaches to the treatment of lung cancer.

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Mutations of p53 Tumor Suppressor Gene in Human Lung Cancer Cell Lines (사람 폐암세포주에서 p53 종양억제유전자의 변이)

  • Hong, Weon-Seon;Hong, Seok-Il;Lee, Dong-Soon;Son, Young-Sook;Lee, Choon-Taek
    • Tuberculosis and Respiratory Diseases
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    • v.40 no.6
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    • pp.653-658
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    • 1993
  • Background: Recent advancement of molecular genetics has revealed that malignant transformation of a cell may be a complex multistep process and this process is grouped, in general, into two distinct categories, activation of protooncogenes and inactivation of tumor suppressor genes. This study was focused on the mutation of p53 tumor suppressor gene, because p53 gene mutation is now generally accepted to be one of the most frequent genetic changes in a variety of human cancers. Although lung cancer is one of the common cancers in Korea, the genetic change in the carcinogenesis process is not yet known clearly. To investigate the role of p53 gene mutation in lung cancer, we examined the mutations of exon 4-8 of the p53 gene in humna lung cancer cell lines, because most of the mutations of p53 gene have been reported to develop in exon 4-8. Method: Genomic DNA was obtained by the digestion of proteinase K and the extraction by phenol-chloroform-ethanol method from two human pulmonary adenocarcinoma cell lines, PC-9 and PC-14, and one human small cell lung cancer cell line, H69. To detect the mutations of exon 4-8 of the p53 gene, polymerase chain reaction single-strand conformation polymorphism(PCR-SSCP) analysis was performed with the DNA extracted from the cells. Results: The mutation of p53 gene was present in all three cell lines tested. In PC-9, PC-14 and H69, the altered mobility was detected in exon 7, 7 and 5, respectively. Conclusion: These results suggest that p53 gene mutation plays an important role in certain steps of the carcinogenesis of human non-small cell and small cell lung cancer.

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