• Title/Summary/Keyword: Carcinogenesis

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A Study on the Effect of Indomethacin on Distribution of Langerhans Cells and T-lym-phocytes in 4-Nitroquinoline-1-oxide(4NQO) induced Carcinogenesis at the Palate and Tongue of Albino Rat (4-Nitroquinoline-1-oxide(4NQO)유도 백서 구강암 발암과정에서 Indomethacin 이 Langerhans 세포와 T-임파구의 발현에 미치는 영향에 관한 연구)

  • Rho, Soo-Young
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.12 no.1
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    • pp.41-61
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    • 1990
  • This study was undertaken to investigate the effect of indomethacin on the distribution of Langerhans cells and T-lymphocytes related with immune response of 4-Nitroquinoline-1-oxide induced carcinogenesis at the palate and tongue of albino rat. 54 Sprague-Dawley strain 10 weeks old albino rats, about 150gm weighted, divided into a normal group of 6 rats without treatment, a control group of 12 rats given indomethacin, a carcinogenesis group of 18 whose palatal mucosa were appiled with 4-Nitroquinoline-1-oxide three times a week, and experimental group of 18 rats were treated with indomethacin and whose palatal mucosa were applied 4-Nitroquinoline-1-oxide. All these 54 rats were subjected to be observed as being ATPase stained specimens, specimens for the observation of light and electron microscope, and T-lymphocyte stained specimens. The obtained results were summarized as follows; 1. In carcinogenesis group, proliferation of epithelial layer and rete peg were observed early period of the experiment and showed parakeratosis, individual cell keratinization, acanthosis, and lymphocyte infiltration from 13th week of the experiment on lightmicroscopically, while experimental group showed less reaction than that of carcinagenesis group. 2. The number of Langerhans cells in normal group rarely changed until 21st week of the experiment, while the Langerhans cells increased markedly from 3rd week of the experiment in control group. 3. The number of Langerhans cells were decreased markedly and persistantly until 21st week of the experiment both in carcinogenesis and experimental groups. 4. Appearance of the T-helper cells and T-suppressor cells were minimal and irregullar in number both in normal and control groups. Thus it is assumed that administration of indomethacin and distribution of Langerhans cells showed close relation. 5. In carcinogenesis and experimental groups, the number of the T-helper cells was apparently inereased than that of the T-suppressor cells, but increasing pattern in experimental group was less than in carcinogenesis group. These cells increased most in the 21st week, decreased from the 23rd week and the appearance of these cells were irregular in general throughout the experiment.

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Long Non-coding RNAs are Differentially Expressed in Hepatocellular Carcinoma Cell Lines with Differing Metastatic Potential

  • Fang, Ting-Ting;Sun, Xiao-Jing;Chen, Jie;Zhao, Yan;Sun, Rui-Xia;Ren, Ning;Liu, Bin-Bin
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.23
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    • pp.10513-10524
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    • 2015
  • Background: Metastasis is a major reason for poor prognosis in patients with cancer, including hepatocellular carcinoma (HCC). A salient feature is the ability of cancer cells to colonize different organs. Long non-coding RNAs (lncRNAs) play important roles in numerous cellular processes, including metastasis. Materials and Methods: In this study, the lncRNA expression profiles of two HCC cell lines, one with high potential for metastasis to the lung (HCCLM3) and the other to lymph nodes (HCCLYM-H2) were assessed using the Arraystar Human LncRNA Array v2.0, which contains 33,045 lncRNAs and 30,215 mRNAs. Coding-non-coding gene co-expression (CNC) networks were constructed and gene set enrichment analysis (GSEA) was performed to identify lncRNAs with potential functions in organ-specific metastasis. Levels of two representative lncRNAs and one representative mRNA, RP5-1014O16.1, lincRNA-TSPAN8 and TSPAN8, were further detected in HCC cell lines with differing metastasis potential by qRT-PCR. Results: Using microarray data, we identified 1,482 lncRNAs and 1,629 mRNAs that were differentially expressed (${\geq}1.5$ fold-change) between the two HCC cell lines. The most upregulated lncRNAs in H2 were RP11-672F9.1, RP5-1014O16.1, and RP11-501G6.1, while the most downregulated ones were lincRNA-TSPAN8, lincRNA-CALCA, C14orf132, NCRNA00173, and CR613944. The most upregulated mRNAs in H2 were C15orf48, PSG2, and PSG8, while the most downregulated ones were CALCB, CD81, CD24, TSPAN8, and SOST. Among them, lincRNA-TSPAN8 and TSPAN8 were found highly expressed in high lung metastatic potential HCC cells, while lowly expressed in no or low lung metastatic potential HCC cells. RP5-1014O16.1 was highly expressed in high lymphatic metastatic potential HCC cell lines, while lowly expressed in no lymphatic metastatic potential HCC cell lines. Conclusions: We provide the first detailed description of lncRNA expression profiles related to organ-specific metastasis in HCC. We demonstrated that a large number of lncRNAs may play important roles in driving HCC cells to metastasize to different sites; these lncRNAs may provide novel molecular biomarkers and offer a new basis for combating metastasis in HCC cases.

Anti-tumor Initiating Potential of Andrographolide in 7,12-dimethylbenz[a]anthracene Induced Hamster Buccal Pouch Carcinogenesis

  • Manoharan, S.;Singh, Arjun Kumar;Suresh, K.;Vasudevan, K.;Subhasini, R.;Baskaran, N.
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.11
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    • pp.5701-5708
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    • 2012
  • The aim of the study was to investigate the chemopreventive potential of andrographolide in 7,12-dimethylbenz(a) anthracene (DMBA)-induced hamster buccal pouch carcinogenesis. Oral tumors developed in the buccal pouch of golden Syrian hamsters at a 100% incidence on painting with 0.5% DMBA in liquid paraffin three times a week for 14 weeks. Marked abnormalities in the status of detoxification enzymes, lipid perxodiation and antioxidants were noticed in hamsters treated with DMBA alone. Oral administration of andrographolide at a dose of 50 mg/kg bw to hamsters treated with DMBA not only completely prevented the tumor formation but also restored the status of the above mentioned biomarkers. The present study thus demonstrates the chemopreventive potential of andrographolide in DMBA-induced hamster buccal pouch carcinogenesis, which is probably due to its antioxidant potential as well as modulating effect on xenobiotic metabolising enzymes during DMBA-induced oral carcinogenesis.

Inhibitory Effects of Opuntia humifusa on 7, 12-Dimethyl-benz[a]anthracene and 12-O-tetradecanoylphorbol-13-acetate Induced Two-stage Skin Carcinogenesis

  • Lee, Jin-A;Jung, Bock-Gie;Lee, Bong-Joo
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.9
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    • pp.4655-4660
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    • 2012
  • Opuntia humifusa, member of the Cactaceae family, was previously demonstrated to have radical scavenging, anti-inflammatory and anti-proliferative effects in in vitro models. It was suggested that O. humifusa could function in the prevention of carcinogenesis. To investigate the in vivo chemopreventive effect of O. humifusa, mice were fed a diet containing either 1% or 3% following 7, 12-dimethylbenz[a] anthracene (DMBA) and 12-O-tetradecanoylphorbol-13-acetate (TPA) induction of skin carcinogenesis. Significant decrease in the numbers of papilloma and epidermal hyperplasia were observed in mice fed with O. humifusa, compared to the control group. O. humifusa also upregulated high total antioxidant capacity and level of phase II detoxifying enzyme such as superoxide dismutase and glutathione S-transferase activity in the skin. Lipid peroxidation activity level was measured in skin cytosol and significantly inhibited in 3% OH fed group compared to the control group. These results suggest that O. humifusa exerts chemopreventive effects on chemical carcinogenesis in mouse skin and that prevention effects are associated with reduction of oxidative stress via the modulation of cutaneous lipid peroxidation, enhancing of total antioxidant capacity especially in phase II detoxifying enzyme system and partial apoptotic influence.

Histone Deacetylase in Carcinogenesis and Its Inhibitors as Anti-cancer Agents

  • Kim, Dong-Hoon;Kim, Min-Jung;Kwon, Ho-Jeong
    • BMB Reports
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    • v.36 no.1
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    • pp.110-119
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    • 2003
  • The acetylation state of histone is reversibly regulated by histone acetyltransferase (HAT) and deacetylase (HDAC). An imbalance of this reaction leads to an aberrant behavior of the cells in morphology, cell cycle, differentiation, and carcinogenesis. Recently, these key enzymes in the gene expression were cloned. They revealed a broad use of this modification, not only in histone, but also other proteins that involved transcription, nuclear transport, and cytoskeleton. These results suggest that HAT/HDAC takes charge of multiple-functions in the cell, not just the gene expression. HDAC is especially known to play an important role in carcinogenesis. The enzyme has been considered a target molecule for cancer therapy. The inhibition of HDAC activity by a specific inhibitor induces growth arrest, differentiation, and apoptosis of transformed or several cancer cells. Some of these inhibitors are in a clinical trial at phase I or phase II. The discovery and development of specific HDAC inhibitors are helpful for cancer therapy, and decipher the molecular mode of action for HDAC.

Food, Nutrition and Cancer (식품, 영양과 암의 관계)

  • Rhew, Tae-Hyong
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.14 no.3
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    • pp.305-313
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    • 1985
  • There is a trend that the total number of cancer cases is steadily increasing as the population grows. It has been estimated that 85% of the cancer rate in the U.S. is attributed to environmental factors. Among the environmental factors, diet and nutrition appear to be related to the largest number of human cancers. Diet and nutrition might be related to cancer by several mechanisms. Food may contain a direct carcinogen or precursors that become carcinogens by spontanous reactions, or by host metabolism, or through the actions of microbial flora. Chemicals that cause cancers generally have reactive electrophilic centers which can combine with electron-rich atoms in nucleic acids and cause cancers by changing the genetic activity of the cells. A variety of factors in foods might be involved in the etiology of carcinogenesis. Chemicals in food that cause cancers include carcinogens of plants and animal origin and also those in drinking water. Other then these, fungal metabolites alcohol, asbestos, heavy metals, pesticides, and food additives might be included as food carcinogenesis. The method of cooking foods also might contribute to carcinogenesis. Some chemicals in foods act as promoters in carcinogenesis. Prevention of cancers by dietary practises have received much interest. Consumption of certain vegetables or cellulose can reduce carcinogenic activity of several compounds. A variety of antioxidants or micronutrients may be effective anticarciongens. Glutathione in the soluble fraction of the cells, is a major defense against oxidative and alkylating carcinogens. Recently anticarcinogenic activity of chlorophyll was demonstrated. Daily consumption of milk appears to effectively reduce stomach cancer.

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Investigation of Carcinogenic Potential of TCDD in the Human Breast Epithelial Cell line (사람의 유방상피세포에서 TCDD에 의한 발암성 연구)

  • 김정환;나혜경;서영준
    • Environmental Mutagens and Carcinogens
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    • v.22 no.4
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    • pp.312-318
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    • 2002
  • Dioxin represents a group of halogenated aromatic hydrocarbons of which 2,3,7,8-tetrachlorod-ibenzo-p-dioxin (TCDD) is well known for its extremely toxic properties as well as ubiquitous presence in our environment and ecosystems. In order to better assess the carcinogenic mechanism of dioxin, we should utilize the reliable biomarkers that can precisely and correctly reflect multi-stage carcinogenesis. When MCF10A cells were exposed to TCDD (10 nM), expression of both CYP1A1 and CYP1B1 was induced in a time-related manner. The expression as well as activity of ornithine decarboxylase was transiently induced by TCDD treatment. In contrast, the induction of COX-2 that is implicated in carcinogenesis as well as inflammation, was not induced by TCDD. In another study, gap-junctional intercellular communication (GJIC) was attenuated by TCDD treatment as revealed by the dye-transfer assay. Based on these findings, TCDD has both tumor initiating and promoting potential in human breast epithelial cells in culture. Also, treatment of MCF10A cells with the carcinogen 7,12-dimethylbenz[a]anthracene plus TCDD resulted in malignant cell transformation as revealed by increased anchorage-independent growth of exposed cells. Additional studies may be necessary to assess the effects of TCDD on multi-stage carcinogenesis in vivo.

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Cancer Chemoprevention by Dietary Phytochemicals: Rationale and Mechanisms (Dietary Phytochemical을 이용한 화학적 암에방과 그 작용 기전)

  • Surh, Young-Joon;Lee, Jong-Min
    • Environmental Mutagens and Carcinogens
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    • v.18 no.1
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    • pp.1-8
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    • 1998
  • Chemoprevention refers to the use of non-toxic chemical agents to prevent the neoplastic development by inhibiting, delaying, or reversing a multi-stage carcinogenesis. The primary goal of chemoprevention research is to identify or produce effective agents and strategies for clinical trials for applications to normal or high risk human populations. A large number of compounds have been tested for their possible chemopreventive activities, and it is of interest to note that many of them are naturally occurring substances. Thus, a variety of plant and vegetable constituents, particularly those included in our daily diet, have been found to possess substantial protective properties against experimental carcinogenesis. These substances, collectively known as dietary phytochemicals, exert their chemopreventive effects by influencing specific step(s) of multi-stage carcinogenesis: some inhibit metabolic activation or enhance detoxification of carcinogens, others interfere with covalent interactions between ultimate eloctrophilic carcinogens and the target cell DNA and still others may exert anti-promoting or anti-progressing effects. Mechanism-based interventions by use of safe dietary phytochemicals may provide one of the most practical and promising cancer chemopreventive strategies.

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