Resveratrol suppresses IGF-1 induced human colon cancer cell proliferation and elevates apoptosis via suppression of IGF-1R/Wnt and activation of p53 signaling pathways

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Vanamala, Jairam; Reddivari, Lavanya; Radhakrishnan, Sridhar; Tarver, Chris

2010-01-01

Obesity is a global phenomenon and is associated with various types of cancer, including colon cancer. There is a growing interest for safe and effective bioactive compounds that suppress the risk for obesity-promoted colon cancer. Resveratrol (trans-3, 4', 5,-trihydroxystilbene), a stilbenoid found in the skin of red grapes and peanuts suppresses many types of cancers by regulating cell proliferation and apoptosis through a variety of mechanisms, however, resveratrol effects on obesity-promoted colon cancer are not clearly established. We investigated the anti-proliferative effects of resveratrol on HT-29 and SW480 human colon cancer cells in the presence and absence of insulin like growth factor-1 (IGF-1; elevated during obesity) and elucidated the mechanisms of action using IGF-1R siRNA in HT-29 cells which represents advanced colon carcinogenesis. Resveratrol (100-150 μM) exhibited anti-proliferative properties in HT-29 cells even after IGF-1 exposure by arresting G 0 /G 1 -S phase cell cycle progression through p27 stimulation and cyclin D1 suppression. Treatment with resveratrol suppressed IGF-1R protein levels and concurrently attenuated the downstream Akt/Wnt signaling pathways that play a critical role in cell proliferation. Targeted suppression of IGF-1R using IGF-1R siRNA also affected these signaling pathways in a similar manner. Resveratrol treatment induced apoptosis by activating tumor suppressor p53 protein, whereas IGF-1R siRNA treatment did not affect apoptosis. Our data suggests that resveratrol not only suppresses cell proliferation by inhibiting IGF-1R and its downstream signaling pathways similar to that of IGF-1R siRNA but also enhances apoptosis via activation of the p53 pathway. For the first time, we report that resveratrol suppresses colon cancer cell proliferation and elevates apoptosis even in the presence of IGF-1 via suppression of IGF-1R/Akt/Wnt signaling pathways and activation of p53, suggesting its potential role as a

Red Wine and Pomegranate Extracts Suppress Cured Meat Promotion of Colonic Mucin-Depleted Foci in Carcinogen-Induced Rats.

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Bastide, Nadia M; Naud, Nathalie; Nassy, Gilles; Vendeuvre, Jean-Luc; Taché, Sylviane; Guéraud, Françoise; Hobbs, Ditte A; Kuhnle, Gunter G; Corpet, Denis E; Pierre, Fabrice H F

2017-01-01

Processed meat intake is carcinogenic to humans. We have shown that intake of a workshop-made cured meat with erythorbate promotes colon carcinogenesis in rats. We speculated that polyphenols could inhibit this effect by limitation of endogenous lipid peroxidation and nitrosation. Polyphenol-rich plant extracts were added to the workshop-made cured meat and given for 14 days to rats and 100 days to azoxymethane-induced rats to evaluate the inhibition of preneoplastic lesions. Colons of 100-d study were scored for precancerous lesions (mucin-depleted foci, MDF), and biochemical end points of peroxidation and nitrosation were measured in urinary and fecal samples. In comparison with cured meat-fed rats, dried red wine, pomegranate extract, α-tocopherol added at one dose to cured meat and withdrawal of erythorbate significantly decreased the number of MDF per colon (but white grape and rosemary extracts did not). This protection was associated with the full suppression of fecal excretion of nitrosyl iron, suggesting that this nitroso compound might be a promoter of carcinogenesis. At optimized concentrations, the incorporation of these plant extracts in cured meat might reduce the risk of colorectal cancer associated with processed meat consumption.

Dietary Fiber Treatment Corrects the Composition of Gut Microbiota, Promotes SCFA Production, and Suppresses Colon Carcinogenesis

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Faraz Bishehsari

2018-02-01

Full Text Available Epidemiological studies propose a protective role for dietary fiber in colon cancer (CRC. One possible mechanism of fiber is its fermentation property in the gut and ability to change microbiota composition and function. Here, we investigate the role of a dietary fiber mixture in polyposis and elucidate potential mechanisms using TS4Cre × cAPCl°x468 mice. Stool microbiota profiling was performed, while functional prediction was done using PICRUSt. Stool short-chain fatty acid (SCFA metabolites were measured. Histone acetylation and expression of SCFA butyrate receptor were assessed. We found that SCFA-producing bacteria were lower in the polyposis mice, suggesting a decline in the fermentation product of dietary fibers with polyposis. Next, a high fiber diet was given to polyposis mice, which significantly increased SCFA-producing bacteria as well as SCFA levels. This was associated with an increase in SCFA butyrate receptor and a significant decrease in polyposis. In conclusion, we found polyposis to be associated with dysbiotic microbiota characterized by a decline in SCFA-producing bacteria, which was targetable by high fiber treatment, leading to an increase in SCFA levels and amelioration of polyposis. The prebiotic activity of fiber, promoting beneficial bacteria, could be the key mechanism for the protective effects of fiber on colon carcinogenesis. SCFA-promoting fermentable fibers are a promising dietary intervention to prevent CRC.

Colon preneoplasia after carcinogen exposure is enhanced and colonic serotonergic system is suppressed by food deprivation.

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Kannen, Vinicius; Fernandes, Cleverson R; Stopper, Helga; Zanette, Dalila L; Ferreira, Frederico R; Frajacomo, Fernando T; Carvalho, Milene C; Brandão, Marcus L; Elias Junior, Jorge; Jordão Junior, Alceu Afonso; Uyemura, Sérgio Akira; Waaga-Gasser, Ana Maria; Garcia, Sérgio B

2013-10-04

Calorie restriction regimens usually promote health and extend life-span in mammals. This is partially related to their preventive effects against malignancies. However, certain types of nutritional restriction failed to induce beneficial effects. The American Institute of Nutrition defines calorie restriction as diets which have only 40% fewer calories, but provide normal amounts of necessary food components such as protein, vitamins and minerals; whereas, food restriction means 40% less of all dietary ingredients plus 40% less calories. Our study aimed to test the hypothesis that the latter type of food deprivation (40% less food than consumed by standard fed rats) might increase cancer risk instead of reducing it, as is generally assumed for all dietary restrictive regimens. Since the endogenous modulation of the colon serotonergic system has been observed to play a role during the early steps of carcinogenesis we also investigated whether the serotoninergic system could be involved in the food intake modulation of cancer risk. For this, rats were exposed to a carcinogen and subjected to food deprivation for 56 days. Triglyceride levels and visceral adipose tissue were reduced while hepatic and colonic lipid peroxidation was increased. This dietary restriction also decreased serotonin levels in colon, and gene expression of its intestinal transporter and receptors. Finally, the numbers of preneoplastic lesions in the colon tissue of carcinogen-exposed rats were increased. Our data suggest that food deprivation enhances formation of early tumorigenic lesions by suppressing serotonergic activity in colon tissue. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Dose response study of conjugated fatty acid derived from safflower oil on mammary and colon carcinogenesis pretreated with 7,12-dimethylbenz[a]anthracene (DMBA) and 1,2-dimethylhydrazine (DMH) in female Sprague-Dawley rats.

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Cheng, Jing Lei; Futakuchi, Mitsuru; Ogawa, Kumiko; Iwata, Toshio; Kasai, Masaaki; Tokudome, Shinkan; Hirose, Masao; Shirai, Tomoyuki

2003-07-10

To clarify the chemopreventive effects of conjugated fatty acid derived from safflower oil (CFA-S), rich in conjugated linoleic acid (CLA), on mammary and colon carcinogenesis, 6 week old female Sprague-Dawley (SD) rats received diet containing 0.01, 0.05, 0.1, 1, or 2% CFA-S subsequent to five times subcutaneous injections of 1,2-dimethyl-hydrazine (DMH) at a dose of 40 mg/kg b.w. and a single 50 mg/kg b.w. intragastric application of 7,12-dimethylbenz[a]anthracene (DMBA) during the first 11 days. The experiment was terminated at week 36. Numbers of mammary tumors, colon aberrant crypt foci (ACF), and proliferative indices of mammary tumors, and colon epithelium were analyzed. The 1% dose was found to be optimal for suppression of carcinogenesis in both target organs, a good correlation being noted with between data for cell proliferation. These results suggest that a diet containing appropriate levels of CFA-S may be useful for prevention of mammary and colon cancer.

Doenjang prepared with mixed starter cultures attenuates azoxymethane and dextran sulfate sodium-induced colitis-associated colon carcinogenesis in mice

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Ji-Kang Jeong

2014-01-01

Full Text Available Backgrounds: Doenjang is traditional Korean fermented soybean paste and widely known for its various health benefits including anticancer effect. In this study, we manufactured doenjang with the grain-type meju using probiotic mixed starter cultures of Aspegillus oryzae, Bacillus subtilis-SKm, and Lactococcus lactis-GAm to improve the qualities and beneficial properties of doenjang. Materials and Methods: The inhibitory effects of the doenjang prepared with the grain-type meju using mixed starter cultures were investigated in azoxymethane (AOM and dextran sulfate sodium (DSS-induced colon carcinogenesis mice model. AOM and DSS colon carcinogenesis was induced in female C57BL/6 mice, and doenjang was orally administered for 4 weeks. Body weight, colon length, and colon weight of mice were determined, and colonic tissues were histologically evaluated. The serum levels of proinflammatory cytokines as well as the expression of inflammation- and apoptosis-related genes in colonic tissue were also analyzed. Results: Administration of the doenjang using probiotic mixed starter cultures ameliorated the symptoms of colon cancer, and reduced the incidence of neoplasia, and reduced the levels of serum proinflammatory cytokines such as interleukin-6, and tumor necrosis factor-α and inducible nitric oxide synthase and cycloooxygenase-2 expression levels in colonic tissue. In addition, it increased Bax and reduced Bcl-2 expression levels and increased p21 and p53 expression in the colonic tissues. Conclusion: These findings indicate that the doenjang attenuated colon carcinogenesis induced by AOM and DSS by ameliorating the symptoms of colon cancer, reducing the occurrence of neoplasia, regulating proinflammatory cytokine levels, and controlling the expressions of inflammation- and apoptosis-related genes in the colonic tissue.

Colon carcinogenesis: influence of Western diet-induced obesity and targeting stem cells using dietary bioactive compounds.

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Kasdagly, Maria; Radhakrishnan, Sridhar; Reddivari, Lavanya; Veeramachaneni, D N Rao; Vanamala, Jairam

2014-01-01

Colon cancer strikes more than 1 million people annually and is responsible for more than 500,000 cancer deaths worldwide. Recent evidence suggests that the majority of malignancies, including colon cancer are driven by cancer stem cells (CSCs) that are resistant to current chemotherapeutic approaches leading to cancer relapse. Wnt signaling plays a critical role in colon stem cell renewal and carcinogenesis. Leucine-rich repeat-containing G protein-coupled receptor 5 (LGR5), a Wnt target gene, and aldehyde dehydrogenase 1 B1 (ALDH1B1) are good markers for normal and malignant human colon stem cells. Diet contributes to 20% to 42% of all human cancers and 50% to 90% of colon cancer. Recent evidence shows that the Western diet has a causative link to colon cancer; however, mechanisms of action are not fully elucidated. Western diet-induced obesity elevates systemic insulin-like growth factor-1 and insulin levels, which could lead to elevated proliferation and suppressed apoptosis of CSCs through PI3K/AKT/Wnt pathway. Although conventional chemotherapy targets the PI3K/AKT pathways and can significantly reduce tumor size, it fails to eliminate CSCs and has serious side effects. Dietary bioactive compounds such as grape seed extract, curcumin, lycopene, and resveratrol have promising chemopreventive effects, without serious side effects on various types of cancers due to their direct and indirect actions on CSC self-renewal pathways such as the Wnt pathway. Understanding the role of CSCs in diet-induced colon cancer will aid in development of evidence-based dietary chemopreventive strategies and/or therapeutic agents targeting CSCs. Copyright © 2014 Elsevier Inc. All rights reserved.

Chemoprevention of colon carcinogenesis by polyethylene glycol: suppression of epithelial proliferation via modulation of SNAIL/beta-catenin signaling.

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Roy, Hemant K; Kunte, Dhananjay P; Koetsier, Jennifer L; Hart, John; Kim, Young L; Liu, Yang; Bissonnette, Marc; Goldberg, Michael; Backman, Vadim; Wali, Ramesh K

2006-08-01

Polyethylene glycol (PEG) is one of the most potent chemopreventive agents against colorectal cancer; however, the mechanisms remain largely unexplored. In this study, we assessed the ability of PEG to target cyclin D1-beta-catenin-mediated hyperproliferation in the azoxymethane-treated rat model and the human colorectal cancer cell line, HT-29. Azoxymethane-treated rats were randomized to AIN-76A diet alone or supplemented with 5% PEG-8000. After 30 weeks, animals were euthanized and biopsies of aberrant crypt foci and uninvolved crypts were subjected to immunohistochemical and immunoblot analyses. PEG markedly suppressed both early and late markers of azoxymethane-induced colon carcinogenesis (fractal dimension by 80%, aberrant crypt foci by 64%, and tumors by 74%). In both azoxymethane-treated rats and HT-29 cells treated with 5% PEG-3350 for 24 hours, PEG decreased proliferation (45% and 52%, respectively) and cyclin D1 (78% and 56%, respectively). Because beta-catenin is the major regulator of cyclin D1 in colorectal cancer, we used the T-cell factor (Tcf)-TOPFLASH reporter assay to show that PEG markedly inhibited beta-catenin transcriptional activity. PEG did not alter total beta-catenin expression but rather its nuclear localization, leading us to assess E-cadherin expression (a major determinant of beta-catenin subcellular localization), which was increased by 73% and 71% in the azoxymethane-rat and HT-29 cells, respectively. We therefore investigated the effect of PEG treatment on levels of the negative regulator of E-cadherin, SNAIL, and observed a 50% and 75% decrease, respectively. In conclusion, we show, for the first time, a molecular mechanism through which PEG imparts its antiproliferative and hence profound chemopreventive effect.

Lactobacillus salivarius Ren prevent the early colorectal carcinogenesis in 1, 2-dimethylhydrazine-induced rat model.

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Zhu, J; Zhu, C; Ge, S; Zhang, M; Jiang, L; Cui, J; Ren, F

2014-07-01

The objective of this study was to investigate the impact of Lactobacillus salivarius Ren (LS) on modulating colonic micro flora structure and influencing host colonic health in a rat model with colorectal precancerous lesions. Male F344 rats were injected with 1, 2-dimethylhydrazine (DMH) and treated with LS of two doses (5 × 10(8) and 1 × 10(10) CFU kg(-1) body weight) for 15 weeks. The colonic microflora profiles, luminal metabolites, epithelial proliferation and precancerous lesions [aberrant crypt foci (ACF)] were determined. A distinct segregation of colonic microflora structures was observed in LS-treated group. The abundance of one Prevotella-related strain was increased, and the abundance of one Bacillus-related strain was decreased by LS treatment. These changes were accompanied by increased short-chain fatty acid levels and decreased azoreductase activity. LS treatment also reduced the number of ACF by c. 40% and suppressed epithelial proliferation. Lactobacillus salivarius Ren improved the colonic microflora structures and the luminal metabolisms in addition preventing the early colorectal carcinogenesis in DMH-induced rat model. Colonic microflora is an important factor in colorectal carcinogenesis. Modulating the structural shifts of microflora may provide a novel option for preventing colorectal carcinogenesis. This study suggested a potential probiotic-based approach to modulate the intestinal microflora in the prevention of colorectal carcinogenesis. © 2014 The Society for Applied Microbiology.

Chemopreventive effect of Cynodon dactylon (L.) Pers. extract against DMH-induced colon carcinogenesis in experimental animals.

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Albert-Baskar, Arul; Ignacimuthu, Savarimuthu

2010-07-01

The present study was aimed at evaluating the chemopreventive property of Cynodon dactylon. The antioxidant, antiproliferative and apoptotic potentials of the plant were investigated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, nitric oxide radical scavenging activity (NO(-)) and MTT assay on four cancer cell lines (COLO 320 DM, MCH-7, AGS, A549) and a normal cell line (VERO). In vivo chemopreventive property of the plant extract was studied in DMH-induced colon carcinogenesis. The methanolic extract of C. dactylon was found to be antiproliferative and antioxidative at lower concentrations and induced apoptotic cell death in COLO 320 DM cells. Treatment with methanolic extract of C. dactylon increased the levels of antioxidant enzymes and reduced the number of dysplastic crypts in DMH-induced colon of albino rats. The present investigation revealed the anticancer potential of methanolic extract of C. dactylon in COLO 320 DM cells and experimentally induced colon carcinogenesis in rats.

The chemopreventive activity of the histone deacetylase inhibitor tributyrin in colon carcinogenesis involves the induction of apoptosis and reduction of DNA damage

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Heidor, Renato [Laboratory of Diet, Nutrition and Cancer, Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil); Advanced Research Center in Food Science and Nutrition (NAPAN) and Food Research Center (FoRC), Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil); Furtado, Kelly Silva; Ortega, Juliana Festa [Laboratory of Diet, Nutrition and Cancer, Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil); Oliveira, Tiago Franco de [Department of Clinical and Toxicological Analyses, Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil); Tavares, Paulo Eduardo Latorre Martins; Vieira, Alessandra; Miranda, Mayara Lilian Paulino [Laboratory of Diet, Nutrition and Cancer, Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil); Purgatto, Eduardo [Laboratory of Food Chemistry and Biochemistry, Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil); Advanced Research Center in Food Science and Nutrition (NAPAN) and Food Research Center (FoRC), Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil); Moreno, Fernando Salvador, E-mail: rmoreno@usp.br [Laboratory of Diet, Nutrition and Cancer, Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil); Advanced Research Center in Food Science and Nutrition (NAPAN) and Food Research Center (FoRC), Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil)

2014-04-15

The chemopreventive activity of the histone deacetylase inhibitor (HDACi) tributyrin (TB), a prodrug of butyric acid (BA), was evaluated in a rat model of colon carcinogenesis. The animals were treated with TB (TB group: 200 mg/100 g of body weight, b.w.) or maltodextrin (MD isocaloric control group: 300 mg/100 g b.w.) daily for 9 consecutive weeks. In the 3rd and 4th weeks of treatment, the rats in the TB and MD groups were given DMH (40 mg/kg b.w.) twice a week. After 9 weeks, the animals were euthanized, and the distal colon was examined. Compared with the control group (MD group), TB treatment reduced the total number of aberrant crypt foci (ACF; p < 0.05) as well as the ACF with ≥ 4 crypts (p < 0.05), which are considered more aggressive, but not inhibited the formation of DMH-induced O6-methyldeoxyguanosine DNA adducts. The TB group also showed a higher apoptotic index (p < 0.05) and reduced DNA damage (p < 0.05) compared with MD group. TB acted as a HDACi, as rats treated with the prodrug of BA had higher levels of histone H3K9 acetylation compared with the MD group (p < 0.05). TB administration resulted in increased colonic tissue concentrations of BA (p < 0.05) compared with the control animals. These results suggest that TB can be considered a promising chemopreventive agent for colon carcinogenesis because it reduced the number of ACF, including those that were more aggressive. Induction of apoptosis and reduction of DNA damage are cellular mechanisms that appear to be involved in the chemopreventive activity of TB. - Highlights: • Tributyrin is a chemopreventive agent for rat colon aberrant crypt foci. • Tributyrin increased apoptosis in an experimental rat colon carcinogenesis model. • Tributyrin treatment in a rat colon carcinogenesis model decreased DNA damage. • Tributyrin treatment induced H3K9 acetylation in a rat colon carcinogenesis model.

The chemopreventive activity of the histone deacetylase inhibitor tributyrin in colon carcinogenesis involves the induction of apoptosis and reduction of DNA damage

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Heidor, Renato; Furtado, Kelly Silva; Ortega, Juliana Festa; Oliveira, Tiago Franco de; Tavares, Paulo Eduardo Latorre Martins; Vieira, Alessandra; Miranda, Mayara Lilian Paulino; Purgatto, Eduardo; Moreno, Fernando Salvador

2014-01-01

The chemopreventive activity of the histone deacetylase inhibitor (HDACi) tributyrin (TB), a prodrug of butyric acid (BA), was evaluated in a rat model of colon carcinogenesis. The animals were treated with TB (TB group: 200 mg/100 g of body weight, b.w.) or maltodextrin (MD isocaloric control group: 300 mg/100 g b.w.) daily for 9 consecutive weeks. In the 3rd and 4th weeks of treatment, the rats in the TB and MD groups were given DMH (40 mg/kg b.w.) twice a week. After 9 weeks, the animals were euthanized, and the distal colon was examined. Compared with the control group (MD group), TB treatment reduced the total number of aberrant crypt foci (ACF; p < 0.05) as well as the ACF with ≥ 4 crypts (p < 0.05), which are considered more aggressive, but not inhibited the formation of DMH-induced O6-methyldeoxyguanosine DNA adducts. The TB group also showed a higher apoptotic index (p < 0.05) and reduced DNA damage (p < 0.05) compared with MD group. TB acted as a HDACi, as rats treated with the prodrug of BA had higher levels of histone H3K9 acetylation compared with the MD group (p < 0.05). TB administration resulted in increased colonic tissue concentrations of BA (p < 0.05) compared with the control animals. These results suggest that TB can be considered a promising chemopreventive agent for colon carcinogenesis because it reduced the number of ACF, including those that were more aggressive. Induction of apoptosis and reduction of DNA damage are cellular mechanisms that appear to be involved in the chemopreventive activity of TB. - Highlights: • Tributyrin is a chemopreventive agent for rat colon aberrant crypt foci. • Tributyrin increased apoptosis in an experimental rat colon carcinogenesis model. • Tributyrin treatment in a rat colon carcinogenesis model decreased DNA damage. • Tributyrin treatment induced H3K9 acetylation in a rat colon carcinogenesis model

Aberrant crypt foci and colon cancer: comparison between a short- and medium-term bioassay for colon carcinogenesis using dimethylhydrazine in Wistar rats

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Rodrigues M.A.M.

2002-01-01

Full Text Available Aberrant crypt foci (ACF in the colon of carcinogen-treated rodents are considered to be the earliest hallmark of colon carcinogenesis. In the present study the relationship between a short-term (4 weeks and medium-term (30 weeks assay was assessed in a model of colon carcinogenesis induced by dimethylhydrazine (DMH in the rat. Six-week-old male Wistar rats were given subcutaneous injections of DMH (40 mg/kg twice a week for 2 weeks and killed at the end of the 4th or 30th week. ACF were scored for number, distribution pattern along the colon and crypt multiplicity in 0.1% methylene-blue whole-mount preparations. ACF were distinguished from normal crypts by their larger size and elliptical shape. The incidence, distribution and morphology of colon tumors were recorded. The majority of ACF were present in the middle and distal colon of DMH-treated rats and their number increased with time. By the 4th week, 91.5% ACF were composed of one or two crypts and 8.5% had three or more crypts, while by the 30th week 46.9% ACF had three or more crypts. Thus, a progression of ACF consisting of multiple crypts was observed from the 4th to the 30th week. Nine well-differentiated adenocarcinomas were found in 10 rats by the 30th week. Seven tumors were located in the distal colon and two in the middle colon. No tumor was found in the proximal colon. The present data indicate that induction of ACF by DMH in the short-term (4 weeks assay was correlated with development of well-differentiated adenocarcinomas in the medium-term (30 weeks assay.

[In vitro and in vivo effects of mango pulp (Mangifera indica cv. Azucar) in colon carcinogenesis].

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Corrales-Bernal, Andrea; Amparo Urango, Luz; Rojano, Benjamín; Maldonado, Maria Elena

2014-03-01

Mango pulp contains ascorbic acid, carotenoids, polyphenols, terpenoids and fiber which are healthy and could protect against colon cancer. The aim of this study was to evaluate the antiproliferative and preventive capacity of an aqueous extract of Mangifera indica cv. Azúcar on a human colon adenocarcinoma cell line (SW480) and in a rodent model of colorectal cancer, respectively. The content of total phenolics, flavonoids and carotenoids were also analyzed in the extract. SW480 cell growth was inhibited in a dose and time dependent manner by 22.3% after a 72h exposure to the extract (200 µg/ mL). Colon carcinogenesis was initiated in Balb/c mice by two intra-peritoneal injections of azoxymethane (AOM) at the third and fourth week of giving mango in drinking water (0.3%, 0.6%, 1.25%). After 10 weeks of treatment, in the colon of mice receiving 0.3% mango, aberrant crypt foci formation was inhibited more than 60% (p=0,05) and the inhibition was dose-dependent when compared with controls receiving water. These results show that mango pulp, a natural food, non toxic, part of human being diet, contains bioactive compounds able to reduce growth of tumor cells and to prevent the appearance of precancerous lesions in colon during carcinogenesis initiation.

DPEP1, expressed in the early stages of colon carcinogenesis, affects cancer cell invasiveness.

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Toiyama, Yuji; Inoue, Yasuhiro; Yasuda, Hiromi; Saigusa, Susumu; Yokoe, Takeshi; Okugawa, Yoshinaga; Tanaka, Koji; Miki, Chikao; Kusunoki, Masato

2011-02-01

We investigated changes in the gene expression profile in colon cancer in order to identify gene markers that may be useful in the management of this disease. The Cancer Genome Anatomy Project was used to detect differences in gene expression between normal and cancer tissue. The overexpression of dipeptidase-1 (DPEP1) in cancer tissue was confirmed in a sample of 76 patients by real-time PCR. To identify the function of DPEP1, RNA interference (RNAi) was used to inactivate this gene in the colon cancer cell line. Immunohistochemical analysis was performed to characterize the pattern of DPEP1 expression in colon cancer. DPEP1 expression in cancer was significantly higher than that in normal tissue. However, DPEP1 expression decreased with pathological differentiation, lymph-node and distant metastasis. Patients with tumors with decreased DPEP1 expression showed a poorer prognosis, and this was also true of patients with tumors who are treated with curative intent. RNAi-mediated DPEP1 reduction in the colon cancer cell line did not result in cell proliferation or apoptosis, but was associated with an increased invasive ability. DPEP1 protein was observed on the apical side of the cancer cells, and is expressed in the early stages of carcinogenesis, even in adenomas of both sporadic colorectal cancer and familial adenomatous polyposis patients. DPEP1 expression in normal colonic mucosa is very low, but it is highly expressed in colorectal adenoma and cancer specimens and is negatively correlated with parameters of pathological aggressiveness and poor prognosis. DPEP1 is expressed in the early stages of colon carcinogenesis and affects cancer cell invasiveness.

[Changes of expression of miR-155 in colitis-associated colonic carcinogenesis].

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Li, Weiwei; Han, Wenxiao; Zhao, Xinhua; Wang, Hongying

2014-04-01

To investigate the changes of miR-155 and its target genes in colitis-associated carcinogenesis. Colitis-associated colon cancer was induced by azoxymethane (AOM) and dextran sulfate sodium (DSS) in C57BL/6 mice. Mice of three different stages during the development of colon cancer were obtained, named AD1, AD2 and AD3, respectively. A control group of mice without any treatment and a DSS only group representing chronic inflammation without cancer were set up as well. Colon tissue was collected and expression of miR-155 in the colon tissues was measured by real-time fluorescent quantitative PCR. TargetScan and PicTar were used to predict potential target genes of miR-155, which were then preliminarily screened with our gene expression microarray database of AOM-DSS mouse model. Regular PCR was used to confirm the changes of the expression of these potential target genes in AOM-DSS mouse model. Colitis-associated colon cancer was effectively induced by azoxymethane and dextran sulfate sodium in C57BL/6 mice. Histological examination revealed that the evolution process was sequentially from normal, mild dysplasia, moderate dysplasia, and severe dysplasia to adenocarcinoma in the AOM-DSS mouse model. The level of miR-155 was gradually elevated with the formation of colitis-associated colon cancer. There was no significant difference between the levels of miR-155 expression in the DSS group (0.005 6 ± 0.003 7) and control group (0.012 0 ± 0.005 1) (P > 0.05), but the level of miR-155 in the AD3 group (0.054 4 ± 0.027 0) was significantly higher than that of the DSS group (0.005 6 ± 0.003 7)(P Bcorl1, Cacna1c, Rspo2 and Foxo3 were potential target genes of miR-155 in the AOM-DSS mouse model. Changes of Kcna1 and Cacna1c in the AOM-DSS mouse model were validated to be consistent with the changes obtained with the gene expression microarray. The up-regulation of miR-155 is related to colitis-associated carcinogenesis, but is irrelevant to chronic inflammation in the

Differential protective effects of red wine polyphenol extracts (RWEs) on colon carcinogenesis.

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Mazué, Frédéric; Delmas, Dominique; Murillo, Genoveva; Saleiro, Diana; Limagne, Emeric; Latruffe, Norbert

2014-04-01

Various epidemiological studies have shown that a regular and moderate consumption of red wine is correlated with a decreased relative risk of developing coronary heart disease and cancer. These health benefits are commonly attributed to high contents of polyphenols, particularly resveratrol, representing important sources of antioxidants. However, resveratrol does not seem to be the only bioactive compound present in the wine which contains numerous other polyphenols. The present study investigates the efficiency of red wine extracts (RWEs), containing different polyphenols, on colon cancer cell proliferation in vitro and on colonic aberrant crypt foci (ACF) in vivo. Proliferation, cell cycle analysis and incidence of ACF were monitored to examine the effects of RWEs. RWEs derived from a long vinification process exhibit superior anti-proliferative activity in colon cancer cells and prevent the appearance of ACF in mice. Interestingly, quercetin and resveratrol, representing two major bio-active polyphenols, exhibit synergistic anti-proliferative effects. These data suggest that the efficacy of RWEs on colon carcinogenesis may depend on the polyphenolic content, synergistic interaction of bio-active polyphenols and modulation of cellular uptake of polyphenols.

Activation of NF-κB: bridging the gap between inflammation and cancer in colitis-mediated colon carcinogenesis.

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Setia, Shruti; Nehru, Bimla; Sanyal, Sankar Nath

2014-02-01

Several studies have shown the anti-neoplastic effects of non-steroidal anti-inflammatory drugs (NSAIDs) on 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis, but how these drugs act in case of inflammation-augmented tumorigenesis is still not clear. The present study therefore designs an animal model of colitis-associated colon cancer where 3% Dextran sufate sodium (DSS) is used to develop ulcerative colitis and DMH treatment leads to colon carcinogenesis as early as in six weeks. Clinical symptoms for ulcerative colitis were studied using Disease Activity Index (DAI) while myeloperoxidase assay marked the neutrophil infiltration in DSS and DMH treated groups. The present results indicated the upregulation of the activity of inflammatory marker enzyme, cyclooxygenase-2 (cox-2) and pro-inflammatory cytokines such as TNF-α, IL-1β, IL-4 and IFN-γ with the treatment of DSS as well as DMH. The presence of cytokines in the inflammatory milieu might lead to the transformation of cytoplasmic inactive NF-κB (Nuclear Factor κB) to its active nuclear form, thereby leading to tumorigenesis. The administration of celecoxib along with DSS and DMH, revealed its chemopreventive efficacy in colitis as well as colon cancer. The effect of different doses of DMH on mouse colon was also investigated to obtain a minimum dose of DMH which can induce visible lesions in mice colons at a high incidence. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

E-cadherin Mediates the Preventive Effect of Vitamin D3 in Colitis-associated Carcinogenesis.

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Xin, Yu; He, Longmei; Luan, Zijian; Lv, Hong; Yang, Hong; Zhou, Ying; Zhao, Xinhua; Zhou, Weixun; Yu, Songlin; Tan, Bei; Wang, Hongying; Qian, Jiaming

2017-09-01

Vitamin D3 is beneficial in ameliorating or preventing inflammation and carcinogenesis. Here, we evaluated if vitamin D3 has a preventive effect on colitis-associated carcinogenesis. Administration of azoxymethane (AOM), followed with dextran sulfate sodium (DSS), was used to simulate colitis-associated colon cancer in mice. The supplement of vitamin D3 at different dosages (15, 30, 60 IU·g·w), started before AOM or immediately after DSS treatment (post 60), was sustained to the end of the experiment. Dietary vitamin D3 significantly reduced the number of tumors and tumor burden in a dose-dependent manner. Of note, vitamin D3 in high doses showed significant preventive effects on carcinogenesis regardless of administration before or after AOM-DSS treatment. Cell proliferation decreased in vitamin D3 groups compared with the control group after inhibition of expression of β-catenin and its downstream target gene cyclin D1 in the colon. In vitro, vitamin D3 reduced the transcriptional activity and nuclear level of β-catenin, and it also increased E-cadherin expression and its binding affinity for β-catenin. Moreover, repression of E-cadherin was rescued by supplemental vitamin D3 in mouse colons. Taken together, our results indicate that vitamin D3 effectively suppressed colonic carcinogenesis in the AOM-DSS mouse model. Our findings further suggest that upregulation of E-cadherin contributes to the preventive effect of vitamin D3 on β-catenin activity.

Intestinal helminth infection drives carcinogenesis in colitis-associated colon cancer.

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Eva Pastille

2017-09-01

Full Text Available Inflammatory bowel diseases (IBD are chronic inflammatory disorders of the gastrointestinal tract, strongly associated with an increased risk of colorectal cancer development. Parasitic infections caused by helminths have been shown to modulate the host's immune response by releasing immunomodulatory molecules and inducing regulatory T cells (Tregs. This immunosuppressive state provoked in the host has been considered as a novel and promising approach to treat IBD patients and alleviate acute intestinal inflammation. On the contrary, specific parasite infections are well known to be directly linked to carcinogenesis. Whether a helminth infection interferes with the development of colitis-associated colon cancer (CAC is not yet known. In the present study, we demonstrate that the treatment of mice with the intestinal helminth Heligmosomoides polygyrus at the onset of tumor progression in a mouse model of CAC does not alter tumor growth and distribution. In contrast, H. polygyrus infection in the early inflammatory phase of CAC strengthens the inflammatory response and significantly boosts tumor development. Here, H. polygyrus infection was accompanied by long-lasting alterations in the colonic immune cell compartment, with reduced frequencies of colonic CD8+ effector T cells. Moreover, H. polygyrus infection in the course of dextran sulfate sodium (DSS mediated colitis significantly exacerbates intestinal inflammation by amplifying the release of colonic IL-6 and CXCL1. Thus, our findings indicate that the therapeutic application of helminths during CAC might have tumor-promoting effects and therefore should be well-considered.

Strawberry Phytochemicals Inhibit Azoxymethane/Dextran Sodium Sulfate-Induced Colorectal Carcinogenesis in Crj: CD-1 Mice

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Ni Shi

2015-03-01

Full Text Available Human and experimental colon carcinogenesis are enhanced by a pro-inflammatory microenvironment. Pharmacologically driven chemopreventive agents and dietary variables are hypothesized to have future roles in the prevention of colon cancer by targeting these processes. The current study was designed to determine the ability of dietary lyophilized strawberries to inhibit inflammation-promoted colon carcinogenesis in a preclinical animal model. Mice were given a single i.p. injection of azoxymethane (10 mg kg−1 body weight. One week after injection, mice were administered 2% (w/v dextran sodium sulfate in drinking water for seven days and then an experimental diet containing chemically characterized lyophilized strawberries for the duration of the bioassay. Mice fed control diet, or experimental diet containing 2.5%, 5.0% or 10.0% strawberries displayed tumor incidence of 100%, 64%, 75% and 44%, respectively (p < 0.05. The mechanistic studies demonstrate that strawberries reduced expression of proinflammatory mediators, suppressed nitrosative stress and decreased phosphorylation of phosphatidylinositol 3-kinase, Akt, extracellular signal-regulated kinase and nuclear factor kappa B. In conclusion, strawberries target proinflammatory mediators and oncogenic signaling for the preventive efficacies against colon carcinogenesis in mice. This works supports future development of fully characterized and precisely controlled functional foods for testing in human clinical trials for this disease.

Inhibitory effects of meju prepared with mixed starter cultures on azoxymethane and dextran sulfate sodium-induced colon carcinogenesis in mice

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Ji-Kang Jeong

2012-01-01

Full Text Available Backgrounds: Meju is the main ingredient and the starter culture of traditional Korean fermented soybean foods; these fermented soybean products are well-known for their various health benefits, including anticancer effects. We developed the grain-type meju using probiotic mixed starter cultures to improve the qualities and functionalities of fermented soybean products, as well as the meju itself. In this study, the inhibitory effects of the grain-type meju were investigated in azoxymethane (AOM and dextran sulfate sodium (DSS-induced colon carcinogenesis mice model. Materials and Methods: AOM and DSS colon carcinogenesis was induced in female C57BL/6 mice and meju was orally administered for 4 weeks. The body weight, colon length, and colon weight of mice were determined, and colonic tissues were histologically observed. The serum levels of proinflammatory cytokines and the levels of inflammation- and apoptosis-related genes in colonic tissue were also analyzed. Results: The administration of meju using probiotic mixed starter cultures ameliorated the symptoms of colon cancer and reduced number of neoplasia, and reduced serum proinflammatory cytokine levels and iNOS and COX-2 expression levels in colonic tissue. It increased Bax and reduced Bcl-2 expression levels and increased p21 and p53 expression in colonic tissues. Conclusion: The meju showed inhibitory effects on the progression of colon cancer induced by AOM and DSS by ameliorating the symptoms of colon cancer, reducing the number of neoplasias and regulating proinflammatory cytokine levels and the expressions of inflammation- and apoptosis-related genes in the colonic tissue.

Annona crassiflora Mart. fruit pulp effects on biochemical parameters and rat colon carcinogenesis

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Vinícius Paula Venâncio

2013-08-01

Full Text Available A. crassiflora Mart. a Brazilian savannah fruit, is a source of phytochemical compounds that possess a wide array of biological activities, including free radical scavenging. This native fruit proved to potentialize the mutagenic process in previous in vivo investigations. The aim of the present study was to investigate the effects of A. crassiflora Mart. pulp intake on colonic cell proliferation and on the development of Aberrant Crypt Foci (ACF in male Wistar rats. The animals were fed with either a commercial diet or a diet supplemented with A. crassiflora Mart. pulp mixed in 1%, 10% or 20% (w/w for 4 weeks or 20 weeks. The carcinogen 1,2-dimethylhydrazine dihydrochloride (4 doses, 40 mg kg-1 each was used to induce colonic ACF. After euthanasia, the blood, liver and colon samples were collected for biochemical determinations, oxidative stress or ACF development analysis, respectively. Immunohistochemical analyses of the colonic mucosa were performed using antibodies against proliferating cell nuclear antigen (PCNA in normal-appearing colonic crypt and β-catenin in ACF. There was no ACF development in the colon from groups treated with A. crassiflora Mart. pulp. Also, the biochemical and oxidative stress analysis, PCNA labeling and ACF development (number, multiplicity or cellular localization of β-catenin were unchanged as a result of marolo pulp intake. Thus, the present results suggest that A. crassiflora Mart. pulp intake did not exert any protective effect in the colon carcinogenesis induced by DMH in rats.

Cyclooxygenase-2 inhibition in colon experimental carcinogenesis Inhibición de la ciclooxigenasa-2 en la carcinogénesis cólica experimental

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J. F. Noguera Aguilar

2005-09-01

Full Text Available Background: an overexpression of cyclooxygenase-2 (COX-2 has been seen in colon tumors; therefore, COX-2 specific inhibitors may be used as preventive agents. The aim of this study was to investigate the effect of both selective and non-selective COX-2 inhibitors on the incidence of colonic tumors in a model of chemical carcinogenesis in the rat. Design: experimental study with 65 male Sprague-Dawley rats randomly assigned to one of four groups: (a control (n = 20, with chemical carcinogenesis using 1-2 dimethylhydrazine (1-2 DMH; (b acetylsalicylic acid (ASA (n = 15, with chemical carcinogenesis and the addition of ASA at 30 mg/kg; (c low-dose rofecoxib (n = 15, with chemical carcinogenesis and the addition of rofecoxib at a dose of 1.2 mg/kg; (d high-dose rofecoxib (n = 15, with carcinogenesis and the addition of rofecoxib at 3 mg/kg. Carcinogenic induction was performed with 1-2 DMH at a weekly dose of 25 mg/kg for 18 weeks. The main parameter evaluated was percentage of neoplastic colonic tissue, which relates tumor surface area to colon surface area. Results: rofecoxib at a dose of 3 mg/kg significantly reduced chemical colon carcinogenesis in rats (p Introducción: se ha comprobado a nivel clínico y experimental la existencia de sobreexpresión de la ciclooxigenasa-2 (COX-2 en los tumores de colon, por lo que los inhibidores de dicha enzima podrían tener un efecto preventivo. El objetivo del estudio es investigar el efecto de la inhibición de la ciclooxigenasa en un modelo de carcinogénesis cólica farmacológica en la rata. Material y métodos: estudio experimental en 65 ratas Sprague-Dawley macho, asignadas a uno de los grupos: control (n = 20, con carcinogénesis farmacológica con 1-2 dimetilhidrazina; grupo ácido acetilsalicílico (n = 15, con carcinogénesis y adición de AAS, grupo Inhibidores COX-2 a bajas dosis (n = 15, con carcinogénesis y adición de rofecoxib a dosis de 1,2 mg/kg, y grupo Inhibidores COX-2 a altas dosis

Effect of rofecoxib on colon chemical carcinogenesis at colonic anastomotic area in the rat Influencia del rofecoxib en la carcinogénesis cólica perianastomótica inducida en ratas

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J. F. Noguera Aguilar

2005-06-01

Full Text Available Aim: to investigate the effect of the selective cyclooxygenase-2 (COX-2 inhibitor rofecoxib on the incidence of perianastomotic colonic tumors in a model of chemical carcinogenesis in the rat. Experimental design: experimental study with 45 male Sprague-Dawley rats randomly assigned to one of three groups: control (n = 15 with colocolic anastomosis and chemical carcinogenesis with 1-2 dimethylhydrazine (1-2 DMH; rofecoxib 0.0027% (n = 15 with colonic anastomosis, chemical carcinogenesis and the addition of dietary rofecoxib at doses of 27 parts per million (ppm, and rofecoxib 0.0058% (n = 15 with colonic anastomosis, chemical carcinogenesis and the addition of dietary rofecoxib at doses of 58 ppm. Carcinogenic induction was performed with 1-2 DMH at a weekly dose of 25 mg/kg of weight for 18 weeks, and colonic tumors induced were analyzed in postoperative week 20. The main parameter evaluated was the percentage of colonic neoplastic tissue, which relates tumor surface area to the colon's surface area. Results: rofecoxib at doses of 2.5 mg/kg or 0.0058 ppm significantly reduced chemical colon carcinogenesis in rats, both in the perianastomotic area and the rest of the colon (p Objetivo: investigar el efecto de un inhibidor selectivo de la ciclooxigenasa-2, rofecoxib, en la incidencia de tumores cólicos perianastomóticos en un modelo de carcinogénesis farmacológica en ratas. Diseño experimental: estudio experimental con 45 ratas Sprague-Dawley macho, asignadas aleatoriamente a uno de los tres grupos: control (n = 15, con anastomosis colo-cólica y carcinogénesis con 1-2 dimetilhidracina; rofecoxib 0,0027% (n = 15, con anastomosis cólica y carcinogénesis farmacológica y adición de rofecoxib en la dieta a dosis de 27 partes por millón, y rofecoxib 0,0058% (n = 15, con anastomosis, carcinogénesis y adición de rofecoxib en la dieta a dosis de 58 ppm. La inducción carcinogénica se realizó con 1-2 DMH a dosis semanal de 25 mg/kg de peso

Effects of calorie restriction and diet-induced obesity on murine colon carcinogenesis, growth and inflammatory factors, and microRNA expression.

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Susan E Olivo-Marston

Full Text Available Obesity is an established colon cancer risk factor, while preventing or reversing obesity via a calorie restriction (CR diet regimen decreases colon cancer risk. Unfortunately, the biological mechanisms underlying these associations are poorly understood, hampering development of mechanism-based approaches for preventing obesity-related colon cancer. We tested the hypotheses that diet-induced obesity (DIO would increase (and CR would decrease colon tumorigenesis in the mouse azoxymethane (AOM model. In addition, we established that changes in inflammatory cytokines, growth factors, and microRNAs are associated with these energy balance-colon cancer links, and thus represent mechanism-based targets for colon cancer prevention. Mice were injected with AOM once a week for 5 weeks and randomized to: 1 control diet; 2 30% CR diet; or 3 DIO diet. Mice were euthanized at week 5 (n = 12/group, 10 (n = 12/group, and 20 (n = 20/group after the last AOM injection. Colon tumors were counted, and cytokines, insulin-like growth factor 1 (IGF-1, IGF binding protein 3 (IGFBP-3, adipokines, proliferation, apoptosis, and expression of microRNAs (miRs were measured. The DIO diet regimen induced an obese phenotype (∼36% body fat, while CR induced a lean phenotype (∼14% body fat; controls were intermediate (∼26% body fat. Relative to controls, DIO increased (and CR decreased the number of colon tumors (p = 0.01, cytokines (p<0.001, IGF-1 (p = 0.01, and proliferation (p<0.001. DIO decreased (and CR increased IGFBP-3 and apoptosis (p<0.001. miRs including mir-425, mir-196, mir-155, mir-150, mir-351, mir-16, let-7, mir34, and mir-138 were differentially expressed between the dietary groups. We conclude that the enhancing effects of DIO and suppressive effects of CR on colon carcinogenesis are associated with alterations in several biological pathways, including inflammation, IGF-1, and microRNAs.

Suppression of radiation-induced in vitro carcinogenesis by ascorbic acid

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Tauchi, Hiroshi; Sawada, Shozo

1993-01-01

The effects of ascorbic acid on radiation-induced in vitro carcinogenesis have been reported using neoplastic transformation system of C3H 10T1/2 cells. In these reports, no suppressive effect on X-ray-induced transformation was observed with 6 weeks' administration of ascorbic acid (daily addition for 5 days per week) by Kennedy (1984), whereas apparent suppression was observed with daily addition for 7 days by Yasukawa et al (1989). We have tested the effects of ascorbic acid on 60 Co gamma-ray or 252 Cf fission neutron-induced transformation in Balb/c 3T3 cells. The transformation induced by both types of radiations was markedly suppressed when ascorbic acid was daily added to the medium during first 8 days of the post-irradiation period. If ascorbic acid was added for a total of 8 days but with a day's interruption in the middle, the suppression of transformation was decreased. These results suggest that continuous presence of ascorbic acid for a certain number of days is needed to suppress radiation-induced transformation. Since ascorbic acid also suppressed the promotion of radiation-induced transformation by TPA when both chemicals were added together into the medium, ascorbic acid might act on the promotion stage of transformation. Therefore, the effect of ascorbic acid on the distribution of protein kinase C activity was also investigated, and possible mechanisms of suppression of radiation-induced transformation by ascorbic acid will be discussed. (author)

Mushroom Ganoderma lucidum Prevents Colitis-Associated Carcinogenesis in Mice

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Sliva, Daniel; Loganathan, Jagadish; Jiang, Jiahua; Jedinak, Andrej; Lamb, John G.; Terry, Colin; Baldridge, Lee Ann; Adamec, Jiri; Sandusky, George E.; Dudhgaonkar, Shailesh

2012-01-01

Background Epidemiological studies suggest that mushroom intake is inversely correlated with gastric, gastrointestinal and breast cancers. We have recently demonstrated anticancer and anti-inflammatory activity of triterpene extract isolated from mushroom Ganoderma lucidum (GLT). The aim of the present study was to evaluate whether GLT prevents colitis-associated carcinogenesis in mice. Methods/Principal Findings Colon carcinogenesis was induced by the food-borne carcinogen (2-Amino-1-methyl-6-phenylimidazol[4,5-b]pyridine [PhIP]) and inflammation (dextran sodium sulfate [DSS]) in mice. Mice were treated with 0, 100, 300 and 500 mg GLT/kg of body weight 3 times per week for 4 months. Cell proliferation, expression of cyclin D1 and COX-2 and macrophage infiltration was assessed by immunohistochemistry. The effect of GLT on XRE/AhR, PXR and rPXR was evaluated by the reporter gene assays. Expression of metabolizing enzymes CYP1A2, CYP3A1 and CYP3A4 in colon tissue was determined by immunohistochemistry. GLT treatment significantly suppressed focal hyperplasia, aberrant crypt foci (ACF) formation and tumor formation in mice exposed to PhIP/DSS. The anti-proliferative effects of GLT were further confirmed by the decreased staining with Ki-67 in colon tissues. PhIP/DSS-induced colon inflammation was demonstrated by the significant shortening of the large intestine and macrophage infiltrations, whereas GLT treatment prevented the shortening of colon lengths, and reduced infiltration of macrophages in colon tissue. GLT treatment also significantly down-regulated PhIP/DSS-dependent expression of cyclin D1, COX-2, CYP1A2 and CYP3A4 in colon tissue. Conclusions Our data suggest that GLT could be considered as an alternative dietary approach for the prevention of colitis-associated cancer. PMID:23118901

Meat processing and colon carcinogenesis: cooked, nitrite-treated, and oxidized high-heme cured meat promotes mucin-depleted foci in rats.

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Santarelli, Raphaëlle L; Vendeuvre, Jean-Luc; Naud, Nathalie; Taché, Sylviane; Guéraud, Françoise; Viau, Michelle; Genot, Claude; Corpet, Denis E; Pierre, Fabrice H F

2010-07-01

Processed meat intake is associated with colorectal cancer risk, but no experimental study supports the epidemiologic evidence. To study the effect of meat processing on carcinogenesis promotion, we first did a 14-day study with 16 models of cured meat. Studied factors, in a 2 x 2 x 2 x 2 design, were muscle color (a proxy for heme level), processing temperature, added nitrite, and packaging. Fischer 344 rats were fed these 16 diets, and we evaluated fecal and urinary fat oxidation and cytotoxicity, three biomarkers of heme-induced carcinogenesis promotion. A principal component analysis allowed for selection of four cured meats for inclusion into a promotion study. These selected diets were given for 100 days to rats pretreated with 1,2-dimethylhydrazine. Colons were scored for preneoplastic lesions: aberrant crypt foci (ACF) and mucin-depleted foci (MDF). Cured meat diets significantly increased the number of ACF/colon compared with a no-meat control diet (P = 0.002). Only the cooked nitrite-treated and oxidized high-heme meat significantly increased the fecal level of apparent total N-nitroso compounds (ATNC) and the number of MDF per colon compared with the no-meat control diet (P nitrite-treated and oxidized cured meat specifically increased the MDF number compared with similar nonnitrite-treated meat (P = 0.03) and with similar nonoxidized meat (P = 0.004). Thus, a model cured meat, similar to ham stored aerobically, increased the number of preneoplastic lesions, which suggests colon carcinogenesis promotion. Nitrite treatment and oxidation increased this promoting effect, which was linked with increased fecal ATNC level. This study could lead to process modifications to make nonpromoting processed meat. 2010 AACR.

δ- and γ-tocopherols, but not α-tocopherol, inhibit colon carcinogenesis in azoxymethane-treated F344 rats.

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Guan, Fei; Li, Guangxun; Liu, Anna B; Lee, Mao-Jung; Yang, Zhihong; Chen, Yu-Kuo; Lin, Yong; Shih, Weichung; Yang, Chung S

2012-04-01

The cancer preventive activity of vitamin E has been extensively discussed, but the activities of specific forms of tocopherols have not received sufficient attention. Herein, we compared the activities of δ-tocopherol (δ-T), γ-T, and α-T in a colon carcinogenesis model. Male F344 rats, seven weeks old, were given two weekly subcutaneous injections of azoxymethane (AOM) each at a dose of 15 mg/kg body weight. Starting 1 week before the AOM injection, the animals were maintained on a modified AIN76A diet, or the same diet containing 0.2% of δ-T, γ-T, α-T, or a γ-T-rich mixture of tocopherols (γ-TmT), until the termination of the experiment at 8 weeks after the second AOM injection. δ-T treatment showed the strongest inhibitory effect, decreasing the numbers of aberrant crypt foci by 62%. γ-T and γ-TmT were also effective, but α-T was not. Immunohistochemical analysis showed that δ-T and γ-T treatments reduced the levels of 4-hydroxynonenal and nitrotyrosine and the expression of cyclin D1 in the colon, preserved the expression of PPAR-γ, and decreased the serum levels of prostaglandin E2 and 8-isoprostane. Supplementation with 0.2% δ-T, γ-T, or α-T increased the respective levels of tocopherols and their side-chain degradation metabolites in the serum and colon tissues. Rather high concentrations of δ-T and γ-T and their metabolites were found in colon tissues. Our study provides the first evidence for the much higher cancer preventive activity of δ-T and γ-T than α-T in a chemically induced colon carcinogenesis model. It further suggests that δ-T is more effective than γ-T. 2012 AACR

δ- and γ-tocopherols inhibit phIP/DSS-induced colon carcinogenesis by protection against early cellular and DNA damages.

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Chen, Jayson X; Liu, Anna; Lee, Mao-Jung; Wang, Hong; Yu, Siyuan; Chi, Eric; Reuhl, Kenneth; Suh, Nanjoo; Yang, Chung S

2017-01-01

Tocopherols, the major forms of vitamin E, are a family of fat-soluble compounds that exist in alpha (α-T), beta (β-T), gamma (γ-T), and delta (δ-T) variants. A cancer preventive effect of vitamin E is suggested by epidemiological studies. However, past animal studies and human intervention trials with α-T, the most active vitamin E form, have yielded disappointing results. A possible explanation is that the cancer preventive activity of α-T is weak compared to other tocopherol forms. In the present study, we investigated the effects of δ-T, γ-T, and α-T (0.2% in diet) in a novel colon cancer model induced by the meat-derived dietary carcinogen, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and promoted by dextran sodium sulfate (DSS)-induced colitis in CYP1A-humanized (hCYP1A) mice. PhIP/DSS treatments induced multiple polypoid tumors, mainly tubular adenocarcinomas, in the middle to distal colon of the hCYP1A mice after 10 wk. Dietary supplementation with δ-T and γ-T significantly reduced colon tumor formation and suppressed markers of oxidative and nitrosative stress (i.e., 8-oxo-dG and nitrotyrosine) as well as pro-inflammatory mediators (i.e., NF-κB p65 and p-STAT3) in tumors and adjacent tissues. By administering δ-T at different time periods, we obtained results suggesting that the inhibitory effect of δ-T against colon carcinogenesis is mainly due to protection against early cellular and DNA damages caused by PhIP. α-T was found to be ineffective in inhibiting colon tumors and less effective in attenuating the molecular changes. Altogether, we demonstrated strong cancer preventive effects of δ-T and γ-T in a physiologically relevant model of human colon cancer. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

A central role for heme iron in colon carcinogenesis associated with red meat intake.

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Bastide, Nadia M; Chenni, Fatima; Audebert, Marc; Santarelli, Raphaelle L; Taché, Sylviane; Naud, Nathalie; Baradat, Maryse; Jouanin, Isabelle; Surya, Reggie; Hobbs, Ditte A; Kuhnle, Gunter G; Raymond-Letron, Isabelle; Gueraud, Françoise; Corpet, Denis E; Pierre, Fabrice H F

2015-03-01

Epidemiology shows that red and processed meat intake is associated with an increased risk of colorectal cancer. Heme iron, heterocyclic amines, and endogenous N-nitroso compounds (NOC) are proposed to explain this effect, but their relative contribution is unknown. Our study aimed at determining, at nutritional doses, which is the main factor involved and proposing a mechanism of cancer promotion by red meat. The relative part of heme iron (1% in diet), heterocyclic amines (PhIP + MeIQx, 50 + 25 μg/kg in diet), and NOC (induced by NaNO₂+ NaNO₂; 0.17 + 0.23 g/L of drinking water) was determined by a factorial design and preneoplastic endpoints in chemically induced rats and validated on tumors in Min mice. The molecular mechanisms (genotoxicity, cytotoxicity) were analyzed in vitro in normal and Apc-deficient cell lines and confirmed on colon mucosa. Heme iron increased the number of preneoplastic lesions, but dietary heterocyclic amines and NOC had no effect on carcinogenesis in rats. Dietary hemoglobin increased tumor load in Min mice (control diet: 67 ± 39 mm²; 2.5% hemoglobin diet: 114 ± 47 mm², P = 0.004). In vitro, fecal water from rats given hemoglobin was rich in aldehydes and was cytotoxic to normal cells, but not to premalignant cells. The aldehydes 4-hydroxynonenal and 4-hydroxyhexenal were more toxic to normal versus mutated cells and were only genotoxic to normal cells. Genotoxicity was also observed in colon mucosa of mice given hemoglobin. These results highlight the role of heme iron in the promotion of colon cancer by red meat and suggest that heme iron could initiate carcinogenesis through lipid peroxidation. . ©2015 American Association for Cancer Research.

Application of radiotracers in the assessment of prophylactic role of zinc in experimental model of colon carcinogenesis

International Nuclear Information System (INIS)

Dani, Vijayata; Vaiphei, K.; Dhawan, D.K.

2010-01-01

Full text: The present study elucidated the modulatory effects of zinc in 1,2 dimethylhydrazine (DMH) induced colon carcinogenesis using radiotracer techniques. Rats were segregated into four groups viz., untreated control, DMH treated, zinc treated, DMH+zinc treated. Colon carcinogenesis was induced through weekly subcutaneous injections of DMH (30 mg/Kg body weight) for 16 weeks. Zinc was supplemented to rats at a dose level of 227mg/L in drinking water, ad libitum. The prophylactic role of zinc was assessed by following radiotracer techniques viz: whole body biological half life of 65 Zn and 65 Zn biodistribution, subcellular distribution, uptake of 3 H-Thymidine to assess rate of DNA synthesis, radiorespirometric determination of 14 C-D-Glucose metabolism and in-vitro uptake of labeled aminoacids. The statistical significance of the data has been determined by using one way analysis of variance (ANOVA) followed by multiple post - hoc test. The carcinogenic state in the animals was confirmed by histopathological examination, whereby, well-differentiated signs of dysplasia were evident in colonic tissue sections of DMH treated rats. The biokinetics study of zinc revealed a significant decrease in the biological half life of 65 Zn. Also, DMH treatment caused a significant increase in the percent uptake values of 65 Zn in the colon, small intestine, kidney and blood, whereas a significant decrease was observed in the liver. The uptake rates of amino acids viz: 14 C-glycine, 14 C-alanine and 14 C-lysine were significantly higher in the DMH treated colons. Moreover, a significant increase in the uptake and turnover of 14 C-D-Glucose was also observed after DMH treatment. A significant increase in the ( 3 H)-thymidine uptake was observed following 16 weeks DMH treatment. However, supplementation of zinc significantly reversed the proliferative effect of DMH as evidenced by ameliorating the altered parameters. Radiotracer techniques play an important role in assessing

The chemopreventive action of bromelain, from pineapple stem (Ananas comosus L.), on colon carcinogenesis is related to antiproliferative and proapoptotic effects.

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Romano, Barbara; Fasolino, Ines; Pagano, Ester; Capasso, Raffaele; Pace, Simona; De Rosa, Giuseppe; Milic, Natasa; Orlando, Pierangelo; Izzo, Angelo A; Borrelli, Francesca

2014-03-01

Colorectal cancer is an important health problem across the world. Here, we investigated the possible antiproliferative/proapoptotic effects of bromelain (from the pineapple stem Ananas comosus L., family Bromeliaceae) in a human colorectal carcinoma cell line and its potential chemopreventive effect in a murine model of colon cancer. Proliferation and apoptosis were evaluated in human colon adenocarcinoma (Caco-2) cells by the (3) H-thymidine incorporation assay and caspase 3/7 activity measurement, respectively. Extracellular signal-related kinase (ERK) and Akt expression were evaluated by Western blot analysis, reactive oxygen species production by a fluorimetric method. In vivo, bromelain was evaluated using the azoxymethane murine model of colon carcinogenesis. Bromelain reduced cell proliferation and promoted apoptosis in Caco-2 cells. The effect of bromelain was associated to downregulation of pERK1/2/total, ERK, and pAkt/Akt expression as well as to reduction of reactive oxygen species production. In vivo, bromelain reduced the development of aberrant crypt foci, polyps, and tumors induced by azoxymethane. Bromelain exerts antiproliferative and proapoptotic effects in colorectal carcinoma cells and chemopreventive actions in colon carcinogenesis in vivo. Bromelain-containing foods and/or bromelain itself may represent good candidates for colorectal cancer chemoprevention. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Efficacy of geraniol but not of β-ionone or their combination for the chemoprevention of rat colon carcinogenesis

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A. Vieira

2011-06-01

Full Text Available β-ionone (βI, a cyclic isoprenoid, and geraniol (GO, an acyclic monoterpene, represent a promising class of dietary chemopreventive agents against cancer, whose combination could result in synergistic anticarcinogenic effects. The chemopreventive activities of βI and GO were evaluated individually or in combination during colon carcinogenesis induced by dimethylhydrazine in 48 3-week-old male Wistar rats (12 per group weighing 40-50 g. Animals were treated for 9 consecutive weeks with βI (16 mg/100 g body weight, GO (25 mg/100 g body weight, βI combined with GO or corn oil (control. Number of total aberrant crypt foci (ACF and of ACF ≥4 crypts in the distal colon was significantly lower in the GO group (66 ± 13 and 9 ± 2, respectively compared to control (102 ± 9 and 17 ± 3 and without differences in the βI (91 ± 11 and 14 ± 3 and βI+GO groups (96 ± 5 and 19 ± 2. Apoptosis level, identified by classical apoptosis morphological criteria, in the distal colon was significantly higher in the GO group (1.64 ± 0.06 apoptotic cells/mm² compared to control (0.91 ± 0.07 apoptotic cells/mm². The GO group presented a 0.7-fold reduction in Bcl-2 protein expression (Western blot compared to control. Colonic mucosa concentrations of βI and GO (gas chromatography/mass spectrometry were higher in the βI and GO groups, respectively, compared to the control and βI+GO groups. Therefore, GO, but not βI, represents a potential chemopreventive agent in colon carcinogenesis. Surprisingly, the combination of isoprenoids does not represent an efficient chemopreventive strategy.

Prevention of Lung Carcinogenesis by Suppressing Pathogenic CD4 T Cells

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2017-05-01

intestinal inflammation by reducing TH17 cells and preserving group 3 innate lymphoid cells . Nat Med, 2016. 22(3): p. 319-23.   ...stable population of YFP+  cells  similar  to  innate  IL‐17–producing  cells  (e.g., γδ T  cells ) during acute infection (Fig.2) , which is in sharp contrast...AWARD NUMBER: W81XWH-16-1-0100 TITLE: Prevention of Lung Carcinogenesis by Suppressing Pathogenic CD4 T Cells PRINCIPAL INVESTIGATOR: Seon Hee

Methanolic extract of white asparagus shoots activates TRAIL apoptotic death pathway in human cancer cells and inhibits colon carcinogenesis in a preclinical model

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BOUSSEROUEL, SOUAD; LE GRANDOIS, JULIE; GOSSÉ, FRANCINE; WERNER, DALAL; BARTH, STEPHAN W.; MARCHIONI, ERIC; MARESCAUX, JACQUES; RAUL, FRANCIS

2013-01-01

Shoots of white asparagus are a popular vegetable dish, known to be rich in many bioactive phytochemicals reported to possess antioxidant, and anti-inflammatory and antitumor activities. We evaluated the anticancer mechanisms of a methanolic extract of Asparagus officinalis L. shoots (Asp) on human colon carcinoma cells (SW480) and their derived metastatic cells (SW620), and Asp chemopreventive properties were also assessed in a model of colon carcinogenesis. SW480 and SW620 cell proliferation was inhibited by 80% after exposure to Asp (80 μg/ml). We demonstrated that Asp induced cell death through the activation of TRAIL DR4/DR5 death receptors leading to the activation of caspase-8 and caspase-3 and to cell apoptosis. By specific blocking agents of DR4/DR5 receptors we were able to prevent Asp-triggered cell death confirming the key role of DR4/DR5 receptors. We found also that Asp (80 μg/ml) was able to potentiate the effects of the cytokine TRAIL on cell death even in the TRAIL-resistant metastatic SW620 cells. Colon carcinogenesis was initiated in Wistar rats by intraperitoneal injections of azoxymethane (AOM), once a week for two weeks. One week after (post-initiation) rats received daily Asp (0.01%, 14 mg/kg body weight) in drinking water. After 7 weeks of Asp-treatment the colon of rats exhibited a 50% reduction of the number of preneoplastic lesions (aberrant crypt foci). In addition Asp induced inhibition of several pro-inflammatory mediators, in association with an increased expression of host-defense mediators. In the colonic mucosa of Asp-treated rats we also confirmed the pro-apoptotic effects observed in vitro including the activation of the TRAIL death-receptor signaling pathway. Taken together, our data highlight the chemopreventive effects of Asp on colon carcinogenesis and its ability to promote normal cellular homeostasis. PMID:23754197

The Applicability of a Short-term Test for Detection of Modifying Effects of Dietary Factors in Rodent Colon Carcinogenesis

DEFF Research Database (Denmark)

Kristiansen, Eva

The present studies were initiated to develop a short-term rodent model to assess the influence of different dietary components on the development of colon cancer. Diets with different dietary components, i.e. dietary fibre, fat, sucrose, and starches were tested in male rats initiated with DMH-2......HCl or AOM for their modulating effect on the development of aberrant crypt foci (ACF). Furthermore the heterocyclic amines IQ and PhIP were introduced in the assay as inducers of ACF in mice and rats and their role in colon carcinogenesis in mice was investigated. ACF were found to be induced...... in rodent colon by the colon carcinogens DMH-2HC1, AOM, IQ, and PhIP and it was shown that the incidence of the induced ACF could be modulated by dietary components such as sucrose, dietary fibre, and starch....

An apple oligogalactan prevents against inflammation and carcinogenesis by targeting LPS/TLR4/NF-κB pathway in a mouse model of colitis-associated colon cancer.

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Liu, Li; Li, Yu H; Niu, Yin B; Sun, Yang; Guo, Zhen J; Li, Qian; Li, Chen; Feng, Juan; Cao, Shou S; Mei, Qi B

2010-10-01

Evidence strongly supported a link between inflammation and cancer. Patients with colitis have high risk for development of colon cancer. Nuclear factor-kappa B (NF-κB), partially induced by lipopolysaccharide (LPS) binding to Toll-like receptor (TLR) 4, is a vital molecule in supervising the transformation of colitis to colon cancer. It could be a good strategy to prevent colitis carcinogenesis for targeting LPS/TLR4/NF-κB pathway. In the present study, we obtained an oligogalactan composed of five galacturonic acids from apple pectin and evaluated its protective efficacy on intestinal toxicities and carcinogenesis in a mouse model of colitis-associated colon cancer induced by 1,2-dimethylhydrazine and dextran sodium sulfate (DSS). The apple oligogalactan (AOG) was highly effective against intestinal toxicities and carcinogenesis and decreased the elevated levels of TLR4 and tumor necrosis factor-α (TNF-α) induced by inflammation in vivo in this model system. In vitro studies, AOG alone only slightly increased the levels of protein expression and messenger RNA of TLR4, phosphorylation of IκBα and production of TNF-α in HT-29 cells. However, AOG significantly decreased the elevation of all the biomarkers induced by LPS when it was combined with LPS. The effect of AOG may be related to membrane internalization and redistribution of TLR4 from cell membrane to cytoplasm. AOG is active against inflammation and carcinogenesis through targeting LPS/TLR4/NF-κB pathway. Both AOG and LPS are agonists of TLR4 for sharing the same ligand but AOG has a much lower intrinsic activity than that of LPS. AOG may be useful for treatment of colitis and prevention of carcinogenesis in the clinics.

Amelioration of azoxymethane induced-carcinogenesis by reducing oxidative stress in rat colon by natural extracts.

Science.gov (United States)

Waly, Mostafa I; Al-Rawahi, Amani S; Al Riyami, Marwa; Al-Kindi, Mohamed A; Al-Issaei, Halima K; Farooq, Sardar A; Al-Alawi, Ahmed; Rahman, Mohammad S

2014-02-18

Azoxymethane (AOM) is a potent carcinogenic agent commonly used to induce colon cancer in rats; the cytotoxicity of AOM is considered to mediate oxidative stress. This study investigated the chemopreventive effect of three natural extracts [pomegranate peel extract (PomPE), papaya peel extract (PapPE) and seaweed extract (SE)] against AOM-induced oxidative stress and carcinogenesis in rat colon. Eighty Sprague-Dawley rats (aged 4 weeks) were randomly divided into 8 groups (10 rats/group). Control group was fed a basal diet; AOM-treated group was fed a basal diet and received AOM intraperitonial injections for two weeks at a dose of 15 mg/kg bodyweight, whereas the other six groups were received oral supplementation of PomPE, PapPE or SE, in the presence or absence of AOM injection. All animals were continuously fed ad-libitum until aged 16 weeks, then all rats were sacrificed and the colon tissues were examined microscopically for pathological changes and aberrant crypt foci (ACF) development, genotoxicity (induced micronuclei (MN) cells enumeration), and glutathione and lipid peroxidation. Our results showed that AOM-induced ACF development and pathological changes in the colonic mucosal tissues, increased bone marrow MN cells and oxidative stress (glutathione depletion, lipid peroxidation) in rat colonic cells. The concomitant treatment of AOM with PomPE, PapPE or SE significantly ameliorated the cytotoxic effects of AOM. The results of this study provide in-vivo evidence that PomPE, PapPE and SE reduced the AOM-induced colon cancer in rats, through their potent anti-oxidant activities.

Deoxycholate, an Endogenous Cytotoxin/Genotoxin, Induces the Autophagic Stress-Survival Pathway: Implications for Colon Carcinogenesis

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Claire M. Payne

2009-01-01

Full Text Available We report that deoxycholate (DOC, a hydrophobic bile acid associated with a high-fat diet, activates the autophagic pathway in non-cancer colon epithelial cells (NCM-460, and that this activation contributes to cell survival. The DOC-induced increase in autophagy was documented by an increase in autophagic vacuoles (detected using transmission electron microscopy, increased levels of LC3-I and LC3-II (western blotting, an increase in acidic vesicles (fluorescence spectroscopy of monodansycadaverine and lysotracker red probes, and increased expression of the autophagic protein, beclin-1 (immunohistochemistry/western blotting. The DOC-induced increase in beclin-1 expression was ROS-dependent. Rapamycin (activator of autophagy pre-treatment of NCM-460 cells significantly (P<.05 decreased, and 3-MA (inhibitor of autophagy significantly (P<.05 increased the cell loss caused by DOC treatment, alone. Rapamycin pre-treatment of the apoptosis-resistant colon cancer cell line, HCT-116RC (developed in our laboratory, resulted in a significant decrease in DOC-induced cell death. Bafilomycin A1 and hydroxychloroquine (inhibitors of the autophagic process increased the DOC-induced percentage of apoptotic cells in HCT-116RC cells. It was concluded that the activation of autophagy by DOC has important implications for colon carcinogenesis and for the treatment of colon cancer in conjunction with commonly used chemotherapeutic agents.

RBP4-STRA6 Pathway Drives Cancer Stem Cell Maintenance and Mediates High-Fat Diet-Induced Colon Carcinogenesis

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Sheelarani Karunanithi

2017-08-01

Full Text Available The transmembrane protein, STRA6, functions as a vitamin A transporter and a cytokine receptor when activated by vitamin A-bound serum retinol binding protein 4 (RBP4. STRA6 activation transduces a JAK2-STAT3 signaling cascade and promotes tumorigenesis in a xenograft mouse model of colon cancer. We show here that RBP4 and STRA6 expression is associated with poor oncologic prognosis. Downregulating STRA6 or RBP4 in colon cancer cells decreased the fraction of cancer stem cells and their sphere and tumor initiation frequency. Furthermore, we show that high-fat diet (HFD increases LGR5 expression and promotes tumor growth in a xenograft model independent of obesity. HFD increased STRA6 levels, and downregulation of STRA6 delays and impairs tumor initiation, tumor growth, and expression of stemness markers. Together, these data demonstrate a key role of STRA6 and RBP4 in the maintenance of colon cancer self-renewal and that this pathway is an important link through which consumption of HFD contributes to colon carcinogenesis.

Enhancement of colon carcinogenesis by the combination of indole-3 carbinol and synbiotics in hemin-fed rats.

Science.gov (United States)

de Moura, Nelci A; Caetano, Brunno F R; de Moraes, Leonardo N; Carvalho, Robson F; Rodrigues, Maria A M; Barbisan, Luis F

2018-02-01

The risk of developing colorectal cancer (CRC) could be associated with red and processed meat intake. Experimental data supports that hemin iron, found abundantly in red meat, promotes CRC in mice and rats, while indole-3 carbinol (I3C) and synbiotics (syn) exert anti-carcinogenic activities in most studies of colon carcinogenesis. This study aimed to investigate the modifying effects of I3C and syn (inulin + Bifidobacterium lactis), given separately or together, on dimethylhidrazine (DMH)-induced colon carcinogenesis in hemin-fed rats. All animals were given four subcutaneous DMH injections and then, two weeks after carcinogen exposure, they began a basal diet containing hemin, hemin + I3C, hemin + syn, or hemin + I3C + syn for 23 weeks. The combination of I3C + syn significantly increased fecal water genotoxicity, tumor volume and invasiveness when compared to the hemin-fed control group. The groups fed I3C or syn alone had a significant reduction in the number of preneoplastic aberrant crypt foci (ACF) lesions compared to the hemin-fed group. Dietary I3C also reduced fecal water genotoxicity. Gene expression analysis of colorectal tumors demonstrated that the combination of dietary I3C + syn increased transcript levels for Raf1 and decreased tumor progression and invasiveness related to the genes Cdh1 and Appl1. This analysis also revealed that the Tnf and Cdh1 genes were significantly up- and down-regulated, respectively, in tumors of rats that received I3C, in comparison with the hemin-fed group. These findings reveal that the joint administration of I3C and syn enhanced the development of colon tumors induced by DMH in hemin-fed rats, while they potentially reduced ACF development when given alone. Copyright © 2017 Elsevier Ltd. All rights reserved.

Tussilagone suppresses colon cancer cell proliferation by promoting the degradation of β-catenin

International Nuclear Information System (INIS)

Li, Hua; Lee, Hwa Jin; Ahn, Yeon Hwa; Kwon, Hye Jin; Jang, Chang-Young; Kim, Woo-Young; Ryu, Jae-Ha

2014-01-01

Highlights: •Tussilagone (TSL) was purified from plant as an inhibitor of Wnt/β-catenin pathway. •TSL suppressed the β-catenin/T-cell factor transcriptional activity. •The proteasomal degradation of β-catenin was induced by TSL. •TSL suppressed the Wnt/β-catenin target genes, cyclin D1 and c-myc. •TSL inhibit the proliferation of colon cancer cells. -- Abstract: Abnormal activation of the Wnt/β-catenin signaling pathway frequently induces colon cancer progression. In the present study, we identified tussilagone (TSL), a compound isolated from the flower buds of Tussilago farfara, as an inhibitor on β-catenin dependent Wnt pathway. TSL suppressed β-catenin/T-cell factor transcriptional activity and down-regulated β-catenin level both in cytoplasm and nuclei of HEK293 reporter cells when they were stimulated by Wnt3a or activated by an inhibitor of glycogen synthase kinase-3β. Since the mRNA level was not changed by TSL, proteasomal degradation might be responsible for the decreased level of β-catenin. In SW480 and HCT116 colon cancer cell lines, TSL suppressed the β-catenin activity and also decreased the expression of cyclin D1 and c-myc, representative target genes of the Wnt/β-catenin signaling pathway, and consequently inhibited the proliferation of colon cancer cells. Taken together, TSL might be a potential chemotherapeutic agent for the prevention and treatment of human colon cancer

Tussilagone suppresses colon cancer cell proliferation by promoting the degradation of β-catenin

Energy Technology Data Exchange (ETDEWEB)

Li, Hua [College of Pharmacy and Research Center for Cell Fate Control, Sookmyung Women’s University, 52 Hyochangwon-Gil, Yongsan-Gu, Seoul 140-742 (Korea, Republic of); Lee, Hwa Jin [Department of Natural Medicine Resources, Semyung University, 65 Semyung-ro, Jecheon, Chungbuk 390-711 (Korea, Republic of); Ahn, Yeon Hwa; Kwon, Hye Jin; Jang, Chang-Young; Kim, Woo-Young [College of Pharmacy and Research Center for Cell Fate Control, Sookmyung Women’s University, 52 Hyochangwon-Gil, Yongsan-Gu, Seoul 140-742 (Korea, Republic of); Ryu, Jae-Ha, E-mail: ryuha@sookmyung.ac.kr [College of Pharmacy and Research Center for Cell Fate Control, Sookmyung Women’s University, 52 Hyochangwon-Gil, Yongsan-Gu, Seoul 140-742 (Korea, Republic of)

2014-01-03

Highlights: •Tussilagone (TSL) was purified from plant as an inhibitor of Wnt/β-catenin pathway. •TSL suppressed the β-catenin/T-cell factor transcriptional activity. •The proteasomal degradation of β-catenin was induced by TSL. •TSL suppressed the Wnt/β-catenin target genes, cyclin D1 and c-myc. •TSL inhibit the proliferation of colon cancer cells. -- Abstract: Abnormal activation of the Wnt/β-catenin signaling pathway frequently induces colon cancer progression. In the present study, we identified tussilagone (TSL), a compound isolated from the flower buds of Tussilago farfara, as an inhibitor on β-catenin dependent Wnt pathway. TSL suppressed β-catenin/T-cell factor transcriptional activity and down-regulated β-catenin level both in cytoplasm and nuclei of HEK293 reporter cells when they were stimulated by Wnt3a or activated by an inhibitor of glycogen synthase kinase-3β. Since the mRNA level was not changed by TSL, proteasomal degradation might be responsible for the decreased level of β-catenin. In SW480 and HCT116 colon cancer cell lines, TSL suppressed the β-catenin activity and also decreased the expression of cyclin D1 and c-myc, representative target genes of the Wnt/β-catenin signaling pathway, and consequently inhibited the proliferation of colon cancer cells. Taken together, TSL might be a potential chemotherapeutic agent for the prevention and treatment of human colon cancer.

Clostridium difficile suppresses colonic vasoactive intestinal peptide associated with altered motility

Directory of Open Access Journals (Sweden)

A. Nassif

1995-01-01

Full Text Available We investigated whether Clostridium difficile toxin alters colonic tissue levels of vasoactive intestinal peptide (VIP at the expense of changes in colonic motility in the isolated perfused rabbit left colon. Colonic inflammation was induced by the intracolonic administration of 10−8 M C. difflcile toxin. Strain gauge transducers were sewn onto the serosal surface of the colon to evaluate colonic motility. C. difflcile administration produced histologic changes consistent with epithelial damage. This was associated with an increased production of prostaglandin E2 and thromboxane B2. Tissue levels of VIP but not substance P were significantly reduced. This was associated with an increased number of contractions per minute and an average force of each colonic contraction. These results suggest that tissue levels of VIP are suppressed by C. difflcile and may participate in colonic dysmotility during active inflammation.

CDB-4124, a progesterone receptor modulator, inhibits mammary carcinogenesis by suppressing cell proliferation and inducing apoptosis.

Science.gov (United States)

Wiehle, Ronald; Lantvit, Daniel; Yamada, Tohru; Christov, Konstantin

2011-03-01

CDB-4124 (Proellex or telapristone acetate) is a modulator of progesterone receptor (PR) signaling, which is currently employed in preclinical studies for prevention and treatment of breast cancer and has been used in clinical studies for treatment of uterine fibroids and endometriosis. Here we provide evidence for its action on steroid hormone-signaling, cell cycle-regulated genes and in vivo on mammary carcinogenesis. When CDB-4124 is given to rats at 200 mg/kg for 24 months, it prevents the development of spontaneous mammary hyperplastic and premalignant lesions. Also, CDB-4124 given as subcutaneous pellets at two different doses suppressed, dose dependently, N-methyl-N-nitrosourea (MNU)-induced mammary carcinogenesis. The high dose (30 mg, over 84 days) increased tumor latency from 66 ± 24 days to 87 ± 20 days (P CDB-4124 inhibited cell proliferation and induced apoptosis in MNU-induced mammary tumors, which correlated with a decreased proportion of PR(+) tumor cells and with decreased serum progesterone. CDB-4124 did not affect serum estradiol. In a mechanistic study employing T47D cells we found that CDB-4124 suppressed G(1)/G(0)-S transition by inhibiting CDK2 and CDK4 expressions, which correlated with inhibition of estrogen receptor (ER) expression. Taken together, these data indicate that CDB-4124 can suppress the development of precancerous lesions and carcinogen-induced ER(+) mammary tumors in rats, and may have implications for prevention and treatment of human breast cancer.

Inhibition of colon carcinogenesis by a standardized Cannabis sativa extract with high content of cannabidiol.

Science.gov (United States)

Romano, Barbara; Borrelli, Francesca; Pagano, Ester; Cascio, Maria Grazia; Pertwee, Roger G; Izzo, Angelo A

2014-04-15

Colon cancer is a major public health problem. Cannabis-based medicines are useful adjunctive treatments in cancer patients. Here, we have investigated the effect of a standardized Cannabis sativa extract with high content of cannabidiol (CBD), here named CBD BDS, i.e. CBD botanical drug substance, on colorectal cancer cell proliferation and in experimental models of colon cancer in vivo. Proliferation was evaluated in colorectal carcinoma (DLD-1 and HCT116) as well as in healthy colonic cells using the MTT assay. CBD BDS binding was evaluated by its ability to displace [(3)H]CP55940 from human cannabinoid CB1 and CB2 receptors. In vivo, the effect of CBD BDS was examined on the preneoplastic lesions (aberrant crypt foci), polyps and tumours induced by the carcinogenic agent azoxymethane (AOM) as well as in a xenograft model of colon cancer in mice. CBD BDS and CBD reduced cell proliferation in tumoral, but not in healthy, cells. The effect of CBD BDS was counteracted by selective CB1 and CB2 receptor antagonists. Pure CBD reduced cell proliferation in a CB1-sensitive antagonist manner only. In binding assays, CBD BDS showed greater affinity than pure CBD for both CB1 and CB2 receptors, with pure CBD having very little affinity. In vivo, CBD BDS reduced AOM-induced preneoplastic lesions and polyps as well as tumour growth in the xenograft model of colon cancer. CBD BDS attenuates colon carcinogenesis and inhibits colorectal cancer cell proliferation via CB1 and CB2 receptor activation. The results may have some clinical relevance for the use of Cannabis-based medicines in cancer patients. Copyright © 2013 Elsevier GmbH. All rights reserved.

Deoxycholate, an Endogenous Cytotoxin/Geno toxin, Induces the Autophagic Stress-Survival Pathway: Implications for Colon Carcinogenesis

International Nuclear Information System (INIS)

Payne, C.M.; Skillicorn, C.C.; Holubec, H.; Bernstein, C.; Dvorak, K.; Bernstein, H.; Moyer, M.P.; Garewal, H.

2009-01-01

We report that deoxycholate (DOC), a hydrophobic bile acid associated with a high-fat diet, activates the autophagic pathway in non-cancer colon epithelial cells (NCM-460), and that this activation contributes to cell survival. The DOC-induced increase in autophagy was documented by an increase in autophagic vacuoles (detected using transmission electron microscopy, increased levels of LC3-I and LC3-II (western blotting), an increase in acidic vesicles (fluorescence spectroscopy of monodansylcadaverine and lyso tracker red probes), and increased expression of the autophagic protein, beclin-1 (immunohistochemistry/western blotting). The DOC-induced increase in beclin-1 expression was ROS-dependent. Rapa mycin (activator of autophagy) pre-treatment of NCM-460 cells significantly (P<.05) decreased, and 3-MA (inhibitor of autophagy) significantly (P<.05) increased the cell loss caused by DOC treatment, alone. Rapa mycin pre-treatment of the apoptosis-resistant colon cancer cell line, HCT-116RC (developed in our laboratory), resulted in a significant decrease in DOC-induced cell death. Bafilomycin A1 and hydroxychloroquine (inhibitors of the autophagic process) increased the DOC-induced percentage of apoptotic cells in HCT-116RC cells. It was concluded that the activation of autophagy by DOC has important implications for colon carcinogenesis and for the treatment of colon cancer in conjunction with commonly used chemotherapeutic agents.

Preclinical Cancer Chemoprevention Studies Using Animal Model of Inflammation-Associated Colorectal Carcinogenesis

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Tanaka, Takuji [Cytopatholgy Division, Tohkai Cytopathology Institute, Cancer Research and Prevention (TCI-CaRP), 5-1-2 Minami-uzura, Gifu 500-8285 (Japan); Department of Tumor Pathology, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu 501-1194 (Japan)

2012-07-16

Inflammation is involved in all stages of carcinogenesis. Inflammatory bowel disease, such as ulcerative colitis and Crohn’s disease is a longstanding inflammatory disease of intestine with increased risk for colorectal cancer (CRC). Several molecular events involved in chronic inflammatory process are reported to contribute to multi-step carcinogenesis of CRC in the inflamed colon. They include over-production of free radicals, reactive oxygen and nitrogen species, up-regulation of inflammatory enzymes in arachidonic acid biosynthesis pathway, up-regulation of certain cytokines, and intestinal immune system dysfunction. In this article, firstly I briefly introduce our experimental animal models where colorectal neoplasms rapidly develop in the inflamed colorectum. Secondary, data on preclinical cancer chemoprevention studies of inflammation-associated colon carcinogenesis by morin, bezafibrate, and valproic acid, using this novel inflammation-related colorectal carcinogenesis model is described.

Effect of dietary fiber on the activity of intestinal and fecal beta-glucuronidase activity during 1,2-dimethylhydrazine induced colon carcinogenesis.

Science.gov (United States)

Manoj, G; Thampi, B S; Leelamma, S; Menon, P V

2001-01-01

The effects of fiber isolated from black gram (Phaseolus mungo) and coconut (Cocos nucifera) kernel on the metabolic activity of intestinal and fecal beta glucuronidase activity during 1,2-dimethylhydrazine induced colon carcinogenesis were studied. The results indicated that the inclusion of fiber from black gram and coconut kernel generally supported lower specific activities and less fecal output of beta-glucuronidase than did the fiber free diet. This study suggests that the fibers isolated from coconut or black gram may potentially play a role in preventing the formation of colon tumors induced by the carcinogen 1,2-dimethylhydrazine by reducing the activity of the intestinal as well as fecal beta-glucuronidase.

End-Binding Protein 1 (EB1) Up-regulation is an Early Event in Colorectal Carcinogenesis

Science.gov (United States)

Stypula-Cyrus, Yolanda; Mutyal, Nikhil N.; Cruz, Mart Angelo Dela; Kunte, Dhananjay P.; Radosevich, Andrew J.; Wali, Ramesh; Roy, Hemant K.; Backman, Vadim

2014-01-01

End-binding protein (EB1) is a microtubule protein that binds to the tumor suppressor adenomatous polyposis coli (APC). While EB1 is implicated as a potential oncogene, its role in cancer progression is unknown. Therefore, we analyzed EB1/APC expression at the earliest stages of colorectal carcinogenesis and in the uninvolved mucosa ("field effect") of human and animal tissue. We also performed siRNA-knockdown in colon cancer cell lines. EB1 is up-regulated in early and field carcinogenesis in the colon, and the cellular/nano-architectural effect of EB1 knockdown depended on the genetic context. Thus, dysregulation of EB1 is an important early event in colon carcinogenesis. PMID:24492008

Polyyne-Enriched Extract from Oplopanax elatus Significantly Ameliorates the Progression of Colon Carcinogenesis in ApcMin/+ Mice

Directory of Open Access Journals (Sweden)

Xin Qiao

2017-09-01

Full Text Available Colorectal cancer (CRC is the third most common cancer in the world. Oplopanax elatus is widely used in traditional medicine. However, little is known about its pharmacological effects and bioactive compounds. We evaluated the effects of the polyyne-enriched extract from O. elatus (PEO on the progression of colon carcinogenesis in ApcMin/+ mice. In addition, these effects were also investigated in HCT116 and SW480 cells. After PEO oral administration (0.2% diet for 12 weeks, PEO significantly improved body weight changes and reduced the tumor burden and tumor multiplicity compared with the untreated mice. Meanwhile, western blot and immunohistochemistry results showed PEO significantly reduced the expression of β-catenin and cyclinD1 in both small intestine and the colon tissues compared with the untreated mice. In addition, PEO treatment significant decreased the cell viability in both HCT116 and SW480 cell lines. It also decreased the levels of β-catenin, cyclinD1, c-myc and p-GSK-3β in HCT116 and SW480 cells at 25 μM. These results indicate that PEO may have potential value in prevention of colon cancer by down-regulating Wnt-related protein.

Review article: loss of the calcium-sensing receptor in colonic epithelium is a key event in the pathogenesis of colon cancer.

LENUS (Irish Health Repository)

Rogers, Ailín C

2012-03-01

The calcium-sensing receptor (CaSR) is expressed abundantly in normal colonic epithelium and lost in colon cancer, but its exact role on a molecular level and within the carcinogenesis pathway is yet to be described. Epidemiologic studies show that inadequate dietary calcium predisposes to colon cancer; this may be due to the ability of calcium to bind and upregulate the CaSR. Loss of CaSR expression does not seem to be an early event in carcinogenesis; indeed it is associated with late stage, poorly differentiated, chemo-resistant tumors. Induction of CaSR expression in neoplastic colonocytes arrests tumor progression and deems tumors more sensitive to chemotherapy; hence CaSR may be an important target in colon cancer treatment. The CaSR has a complex role in colon cancer; however, more investigation is required on a molecular level to clarify its exact function in carcinogenesis. This review describes the mechanisms by which the CaSR is currently implicated in colon cancer and identifies areas where further study is needed.

Suppression of carcinogenesis in mice by adaptive responses to low dose rate irradiation

Energy Technology Data Exchange (ETDEWEB)

Sakai, Kazuo; Iwasaki, Toshiyasu; Hoshi, Yuko; Nomura, Takaharu; Ina, Yasuhiro; Tanooka, Hiroshi [Central Research Institute of Electric Power Industry, Low Dose Radiation Research Center, Komae, Tokyo (Japan)

2003-07-01

Effects of prolonged low-dose-rate irradiation on the process of carcinogenesis were examined in mice treated with chemical carcinogen or irradiated with high doses of X-rays. Female ICR mice, 5 week-old, 35 in each group, were exposed to gamma-rays from a {sup 137}Cs source in the long-term low dose rate irradiation facility at CRIEPI. The dose rate was 2.6 mGy/hr (A), 0.96 mGy/hr (B), or 0.30 mGy/hr (C). Thirty-five days later, the mice were injected into the groin with 0.5 mg of methylcholanthrene (MC) dissolved in olive oil and irradiation was continued. Cumulative tumor incidences after 216 days following MC injection were 89% in group A, 76% in group B, and 94% in group C. That in non-irradiated control group was 94%. The difference in the tumor incidence between the control and position B was statistically significant, indicating the suppressive effect of the low dose rate irradiation on the process of MC-induced carcinogenesis with an optimum dose rate around 1 mGy/hr. In B6C3F1 mice, although the suppression of tumor incidence was not observed, there was a significant delay in tumor appearance in the irradiated mice between 100-150 days after MC injection. A group of 20 female C57BL/6N mice, 5 weeks old, were exposed to gamma-rays at 0.95 mGy/hr for 5 weeks. Then, they were exposed weekly to 1.8 Gy whole body X-irradiation (300 kVp) for consecutive 4 weeks to induce thymic lymphoma. Another group received only the fractionated irradiation. The first mouse died from thymic lymphoma appeared 89 days after the last irradiation in the group received only the fractionated irradiation, while 110 days in the group combined with the low dose rate irradiation. (author)

TAp63 suppress metastasis via miR-133b in colon cancer cells.

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Lin, C W; Li, X R; Zhang, Y; Hu, G; Guo, Y H; Zhou, J Y; Du, J; Lv, L; Gao, K; Zhang, Y; Deng, H

2014-04-29

TAp63 is a tumour-suppressor protein that is often underexpressed in various types of cancer. It has been shown to activate gene transcription depending on the transcription domain and to be closely related with metastasis. In this study, we demonstrate that TAp63 suppresses metastasis in colon cancer cells through microRNA-133b. We evaluated the correlation of TAp63 and miR-133b with HT-29 and SW-620 cells and investigated the roles of TAp63 in the expression of RhoA, E-cadherin and vimentin. We further investigated the roles of TAp63-mediated invasion and migration of colon cancer cells. TAp63 expression is downregulated in colon cancer, and microRNA-133b is a transcriptional target of TAp63. Furthermore, microRNA-133b is essential for the inhibitory effects of TAp63 on RhoA, E-cadherin and vimentin. Moreover, TAp63 inhibits cell migration and invasion through microRNA-133b. Correspondingly, the inhibitory effect of TAp63 on RhoA, E-cadherin, vimentin, migration and invasion can be blocked by the microRNA-133b inhibitor. TAp63 and microRNA-133b were able to suppress the metastasis of colon cancer. Both TAp63 and microRNA-133b may be potential biomarkers for diagnosis in colon cancer metastasis and may provide unique therapeutic targets for this common malignancy.

Up-regulation of CNDP2 facilitates the proliferation of colon cancer.

Science.gov (United States)

Xue, Conglong; Zhang, Zhenwei; Yu, Honglan; Yu, Miao; Yuan, Kaitao; Yang, Ting; Miao, Mingyong; Shi, Hanping

2014-05-21

Cytosolic nonspecific dipetidase (CN2) belongs to the family of M20 metallopeptidases. It was stated in previous articles that higher expression levels of CN2 were observed in renal cell carcinoma and breast cancer. Our study explored the correlation between CN2 and colon carcinogenesis. We analysed the relationship between 183 patients clinicopathological characteristics and its CN2 expression. To detect the levels of CN2 in colon cancer cell lines and colon cancer tissues by western blot. To verify cell proliferation in colon cancer cells with knockdown of CNDP2 and explore the causes of these phenomena. The expression levels of CN2 in clinical colon tumors and colon cancer cell lines were significantly higher than that in normal colon mucosa and colon cell lines. The difference in CN2 levels was associated with tumor location (right- and left-sided colon cancer), but there was no significant association with age, gender, tumor size, tumor grade, tumor stage or serum carcinoembryonic antigen (CEA). Knockdown of CNDP2 inhibited cell proliferation, blocked cell cycle progression and retarded carcinogenesis in an animal model. The signaling pathway through which knockdown of CNDP2 inhibited cell proliferation and tumorigenesis involved in EGFR, cyclin B1 and cyclin E. Knockdown of CNDP2 can inhibit the proliferation of colon cancer in vitro and retarded carcinogenesis in vivo.

Colorectal Carcinogenesis: Role of Oxidative Stress and Antioxidants.

Science.gov (United States)

Carini, Francesco; Mazzola, Margherita; Rappa, Francesca; Jurjus, Abdo; Geagea, Alice Gerges; Al Kattar, Sahar; Bou-Assi, Tarek; Jurjus, Rosalyn; Damiani, Provvidenza; Leone, Angelo; Tomasello, Giovanni

2017-09-01

One of the contributory causes of colon cancer is the negative effect of reactive oxygen species on DNA repair mechanisms. Currently, there is a growing support for the concept that oxidative stress may be an important etiological factor for carcinogenesis. The purpose of this review is to elucidate the role of oxidative stress in promoting colorectal carcinogenesis and to highlight the potential protective role of antioxidants. Several studies have documented the importance of antioxidants in countering oxidative stress and preventing colorectal carcinogenesis. However, there are conflicting data in the literature concerning its proper use in humans, since these studies did not yield definitive results and were performed mostly in vitro on cell populations, or in vivo in experimental animal models. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Black Raspberries Enhance Natural Killer Cell Infiltration into the Colon and Suppress the Progression of Colorectal Cancer

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Pan, Pan; Kang, Siwen; Wang, Youwei; Liu, Ka; Oshima, Kiyoko; Huang, Yi-Wen; Zhang, Jianying; Yearsley, Martha; Yu, Jianhua; Wang, Li-Shu

2017-01-01

Natural killer (NK) cells are an essential component of innate immunity against cancer development. Many studies have been conducted to evaluate immune-modulating effects using dietary compounds. Our laboratory has been investigating the chemopreventive potential of black raspberries (BRBs) and previously demonstrated their beneficial modulation of genetic and epigenetic biomarkers in patients with colorectal cancer (CRC). The current study investigated their potential on modulating NK cells. To avoid the excessive inflammation caused by the dextran sulfate sodium (DSS) treatment that leads to colitis, we treated the mice with overnight DSS so that it would slightly irritate the colon but still promote colon carcinogenesis with 100% incidence in both the ApcMin/+ mice and azoxymethane (AOM)-treated mice. A significant decrease of tissue-infiltrating NK cells along the progression of microadenoma-to-adenoma and adenoma-to-adenocarcinoma was observed in the ApcMin/+/DSS and AOM/DSS mice, respectively. Depletion of NK cells significantly promoted the development of CRC, suggesting a critical role of NK cells in combating CRC progression. BRBs significantly suppressed the CRC progression and increased the number of tissue-infiltrating NK cells in both mouse models. Moreover, we further determined BRBs’ effects on NK cells in the human biopsy specimens collected from our previously completed clinical trial, in which CRC patients consumed BRBs for an average of 4 weeks during a presurgical window. We observed an increased number and an enhanced cytotoxicity of NK cells by BRB intervention. The current study provides evidence that BRBs have the potential to enhance the tumor immunesurveillance of NK cells that can be beneficial in the setting of CRC prevention and treatment. PMID:28861089

A key role of microRNA-29b for the suppression of colon cancer cell migration by American ginseng.

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Deepak Poudyal

Full Text Available Metastasis of colon cancer cells increases the risk of colon cancer mortality. We have recently shown that American ginseng prevents colon cancer, and a Hexane extract of American Ginseng (HAG has particularly potent anti-inflammatory and anti-cancer properties. Dysregulated microRNA (miR expression has been observed in several disease conditions including colon cancer. Using global miR expression profiling, we observed increased miR-29b in colon cancer cells following exposure to HAG. Since miR-29b plays a role in regulating the migration of cancer cells, we hypothesized that HAG induces miR-29b expression to target matrix metalloproteinase-2 (MMP-2 thereby suppressing the migration of colon cancer cells. Results are consistent with this hypothesis. Our study supports the understanding that targeting MMP-2 by miR-29b is a mechanism by which HAG suppresses the migration of colon cancer cells.

The SIRT1 deacetylase suppresses intestinal tumorigenesis and colon cancer growth.

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Ron Firestein

2008-04-01

Full Text Available Numerous longevity genes have been discovered in model organisms and altering their function results in prolonged lifespan. In mammals, some have speculated that any health benefits derived from manipulating these same pathways might be offset by increased cancer risk on account of their propensity to boost cell survival. The Sir2/SIRT1 family of NAD(+-dependent deacetylases is proposed to underlie the health benefits of calorie restriction (CR, a diet that broadly suppresses cancer in mammals. Here we show that CR induces a two-fold increase SIRT1 expression in the intestine of rodents and that ectopic induction of SIRT1 in a beta-catenin-driven mouse model of colon cancer significantly reduces tumor formation, proliferation, and animal morbidity in the absence of CR. We show that SIRT1 deacetylates beta-catenin and suppresses its ability to activate transcription and drive cell proliferation. Moreover, SIRT1 promotes cytoplasmic localization of the otherwise nuclear-localized oncogenic form of beta-catenin. Consistent with this, a significant inverse correlation was found between the presence of nuclear SIRT1 and the oncogenic form of beta-catenin in 81 human colon tumor specimens analyzed. Taken together, these observations show that SIRT1 suppresses intestinal tumor formation in vivo and raise the prospect that therapies targeting SIRT1 may be of clinical use in beta-catenin-driven malignancies.

Calcium and α-tocopherol suppress cured-meat promotion of chemically induced colon carcinogenesis in rats and reduce associated biomarkers in human volunteers123

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Martin, Océane CB; Santarelli, Raphaelle L; Taché, Sylviane; Naud, Nathalie; Guéraud, Françoise; Audebert, Marc; Dupuy, Jacques; Meunier, Nathalie; Attaix, Didier; Vendeuvre, Jean-Luc; Mirvish, Sidney S; Kuhnle, Gunter CG; Cano, Noel; Corpet, Denis E

2013-01-01

Background: Processed meat intake has been associated with increased colorectal cancer risk. We have shown that cured meat promotes carcinogen-induced preneoplastic lesions and increases specific biomarkers in the colon of rats. Objectives: We investigated whether cured meat modulates biomarkers of cancer risk in human volunteers and whether specific agents can suppress cured meat–induced preneoplastic lesions in rats and associated biomarkers in rats and humans. Design: Six additives (calcium carbonate, inulin, rutin, carnosol, α-tocopherol, and trisodium pyrophosphate) were added to cured meat given to groups of rats for 14 d, and fecal biomarkers were measured. On the basis of these results, calcium and tocopherol were kept for the following additional experiments: cured meat, with or without calcium or tocopherol, was given to dimethylhydrazine-initiated rats (47% meat diet for 100 d) and to human volunteers in a crossover study (180 g/d for 4 d). Rat colons were scored for mucin-depleted foci, putative precancer lesions. Biomarkers of nitrosation, lipoperoxidation, and cytotoxicity were measured in the urine and feces of rats and volunteers. Results: Cured meat increased nitroso compounds and lipoperoxidation in human stools (both P meat (P = 0.01). Conclusion: Data suggest that the addition of calcium carbonate to the diet or α-tocopherol to cured meat may reduce colorectal cancer risk associated with cured-meat intake. This trial was registered at clinicaltrials.gov as NCT00994526. PMID:24025632

MicroRNA-449a deficiency promotes colon carcinogenesis.

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Niki, Masanori; Nakajima, Kohei; Ishikawa, Daichi; Nishida, Jun; Ishifune, Chieko; Tsukumo, Shin-Ichi; Shimada, Mitsuo; Nagahiro, Shinji; Mitamura, Yoshinori; Yasutomo, Koji

2017-09-06

MicroRNAs have broad roles in tumorigenesis and cell differentiation through regulation of target genes. Notch signaling also controls cell differentiation and tumorigenesis. However, the mechanisms through which Notch mediates microRNA expression are still unclear. In this study, we aimed to identify microRNAs regulated by Notch signaling. Our analysis found that microRNA-449a (miR-449a) was indirectly regulated by Notch signaling. Although miR-449a-deficient mice did not show any Notch-dependent defects in immune cell development, treatment of miR-449a-deficient mice with azoxymethane (AOM) or dextran sodium sulfate (DSS) increased the numbers and sizes of colon tumors. These effects were associated with an increase in intestinal epithelial cell proliferation following AOM/DSS treatment. In patients with colon cancer, miR-449a expression was inversely correlated with disease-free survival and histological scores and was positively correlated with the expression of MLH1 for which loss-of function mutations have been shown to be involved in colon cancer. Colon tissues of miR-449a-deficient mice showed reduced Mlh1 expression compared with those of wild-type mice. Thus, these data suggested that miR-449a acted as a key regulator of colon tumorigenesis by controlling the proliferation of intestinal epithelial cells. Additionally, activation of miR-449a may represent an effective therapeutic strategy and prognostic marker in colon cancer.

Effects of sucrose and cornstarch on 2-amino-3-methylimidazo[4,5-f]quinoline (IQ)-induced colon and liver carcinogenesis in F344 rats

DEFF Research Database (Denmark)

Lindecrona, R.H.; Dragsted, Lars Ove; Poulsen, Morten

2004-01-01

The purpose of the present study was to compare the effect of sucrose and cornstarch on colon and liver carcinogenesis induced by 0.02% of the food-borne carcinogen 2-amino-3-methylimidazo [4,5-f]quinoline (IQ) in the feed. Male F344 rats were allocated to four groups. Two groups were fed diets...... high in either cornstarch (68%) or sucrose (34% sucrose/34% cornstarch) and were initiated with IQ. The remaining two groups received the same two diets but did not receive any IQ. In both liver and colon, administration of IQ resulted in a higher level of DNA adducts. In animals not dosed with IQ......, sucrose increased the adduct level in both organs but to a lower level than IQ. However, simultaneous administration of IQ and sucrose did not further increase the adduct level. Both IQ and sucrose increased the expression of the DNA-repair enzyme ERCC1 in the liver. In the colon, the number of large...

Influence of rofecoxib on experimental colonic carcinogenesis in rats Influencia del rofecoxib sobre la carcinogénesis cólica experimental en ratas

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J. F. Noguera Aguilar

2004-10-01

Full Text Available Aim: to investigate the effect of a selective cyclooxigenase-2 (COX-2 inhibitor, rofecoxib, in the prevalence of experimental colon tumors in rats. Experimental design: experimental study with 35 male Sprague-Dawley rats, divided into four groups: a control group without experimental manipulation (n = 5; b pharmacological carcinogenesis with 1-2 dimethylhydrazine dihydrocloride (n = 10; c pharmacological carcinogenesis and addition of acetylsalicylic acid (AAS (n = 10; and d carcinogenesis and addition of rofecoxib (n = 10. Carcinogenesis was induced with 1-2 dimethylhydrazine at a weekly dose of 25 mg/kg for 18 weeks. Colon tumors were isolated at 20 weeks. Antiinflammatory agents were given at a dose of AAS 30 mg/kg and rofecoxib at 3 mg/kg. Results: the percentage of colonic tumors was significantly reduced in the rofecoxib group. This result was found for all tumors and for the malignant lesions, adenocarcinomas. Conclusions: rofecoxib, a selective COX-2 inhibitor, reduced the percentage of drug-induced neoplastic glandular tissue in rats.Objetivo: investigar el efecto de un inhibidor selectivo de la ciclooxigenasa-2, rofecoxib, en la incidencia de tumores cólicos a nivel experimental. Diseño experimental: estudio experimental con 35 ratas Sprague-Dawley macho, asignadas aleatoriamente a uno de los cuatro grupos: a control (n=5, sin manipulación experimental; b carcinogénesis farmacológica (n=10; c carcinogénesis farmacológica y ácido acetilsalicílico (n=10, con administración de este fármaco al tiempo de la carcinogénesis farmacológica; y d carcinogénesis farmacológica y rofecoxib (n=10 con administración de este fármaco junto a la carcinogénesis farmacológica. La inducción carcinogénica se realizó con 1-2 dimetilhidrazina dihidrocloruro a dosis semanal de 25 mg/kg de peso durante 18 semanas. Se analizaron los tumores cólicos inducidos en la semana 20. Los antiinflamatorios se administraron por vía oral a razón de �

Chemopreventive Effect of Aster glehni on Inflammation-Induced Colorectal Carcinogenesis in Mice

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Kyung-Sook Chung

2018-02-01

Full Text Available Although Aster glehni is a common dietary herb that has various bioactivities, including anti-diabetic, anti-adipogenic, and anti-inflammatory effects, A. glehni has not been studied in colon cancer. Therefore, we hypothesized the chemopreventive effects of an ethanol extract of A. glehni (AG on azoxymethane/dextran sulfate sodium (AOM/DSS-induced colitis-associated cancer (CAC in mice. In this study, we found that treatment with AG significantly attenuated the AOM/DSS-induced enlargement of the spleen and shortening of the colon. In addition, colonic tumor formation, colonic damage, and increased muscle thickness were significantly reduced in AOM/DSS-induced mice fed AG. Treatment with AG also reduced intestinal interleukin (IL-1β, IL-6, and tumor necrosis factor (TNF-α production and decreased inducible nitric oxide synthase (iNOS and cyclooxygenase (COX-2 protein expression in mice with AOM/DSS-induced CAC. Furthermore, AG reduced nuclear factor (NF-κB activation via phosphorylation and degradation of inhibitor of kappa Bα (IκBα, leading to inhibition of NF-κB p65 nuclear translocation. It also downregulated the expression of NF-κB-related proteins, including the B-cell lymphoma 2 (Bcl-2 family and inhibitors of apoptosis proteins (IAPs, in mice with AOM/DSS-induced CAC. Taken together, these findings suggest that the treatment with AG inhibited colitis-associated colon carcinogenesis in mice, and this chemopreventive effect was strongly mediated by suppression of the NF-κB signaling pathway, indicating that AG could be a promising protective agent against CAC.

Etoricoxib in the Prevention of Rat Mammary Carcinogenesis

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P. Orendáš

2007-01-01

Full Text Available Several experimental studies suggest that non-steroidal antiinflammatory drugs have chemopreventive effects in mammary carcinogenesis. In this study, tumour suppressive effects of a selective inhibitor of cyclooxygenase-2 (COX-2 etoricoxib in the prevention of N-methyl-Nnitrosourea (NMU-induced mammary carcinogenesis in Sprague-Dawley rats were evaluated. Etoricoxib was administered in the diet, at two concentrations: 1 0.01 mg/g (ETO 0.001% and 2 0.025 mg/g (ETO 0.0025%. Although the chemopreventive effects were not statistically significant, remarkable tumour suppressive effects with the concentration of ETO 0.0025% were recorded. The incidence decreased by 4.31% and tumour frequency per group decreased by 6.67% when compared to the control group. Latency (the period from carcinogen administration to the first tumour appearance increased by 7.28% in dose-dependent manner. The results of our experiments point to dose-dependent tumour suppressive effects of a higher concentration of etoricoxib (ETO 0.0025% when compared to the control group. They suggest that higher etoricoxib concentrations may enhance its tumour suppressive effects.

HDAC up-regulation in early colon field carcinogenesis is involved in cell tumorigenicity through regulation of chromatin structure.

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Yolanda Stypula-Cyrus

Full Text Available Normal cell function is dependent on the proper maintenance of chromatin structure. Regulation of chromatin structure is controlled by histone modifications that directly influence chromatin architecture and genome function. Specifically, the histone deacetylase (HDAC family of proteins modulate chromatin compaction and are commonly dysregulated in many tumors, including colorectal cancer (CRC. However, the role of HDAC proteins in early colorectal carcinogenesis has not been previously reported. We found HDAC1, HDAC2, HDAC3, HDAC5, and HDAC7 all to be up-regulated in the field of human CRC. Furthermore, we observed that HDAC2 up-regulation is one of the earliest events in CRC carcinogenesis and observed this in human field carcinogenesis, the azoxymethane-treated rat model, and in more aggressive colon cancer cell lines. The universality of HDAC2 up-regulation suggests that HDAC2 up-regulation is a novel and important early event in CRC, which may serve as a biomarker. HDAC inhibitors (HDACIs interfere with tumorigenic HDAC activity; however, the precise mechanisms involved in this process remain to be elucidated. We confirmed that HDAC inhibition by valproic acid (VPA targeted the more aggressive cell line. Using nuclease digestion assays and transmission electron microscopy imaging, we observed that VPA treatment induced greater changes in chromatin structure in the more aggressive cell line. Furthermore, we used the novel imaging technique partial wave spectroscopy (PWS to quantify nanoscale alterations in chromatin. We noted that the PWS results are consistent with the biological assays, indicating a greater effect of VPA treatment in the more aggressive cell type. Together, these results demonstrate the importance of HDAC activity in early carcinogenic events and the unique role of higher-order chromatin structure in determining cell tumorigenicity.

Microarray Analyses of Genes Differentially Expressed by Diet (Black Beans and Soy Flour) during Azoxymethane-Induced Colon Carcinogenesis in Rats.

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Rondini, Elizabeth A; Bennink, Maurice R

2012-01-01

We previously demonstrated that black bean (BB) and soy flour (SF)-based diets inhibit azoxymethane (AOM)-induced colon cancer. The objective of this study was to identify genes altered by carcinogen treatment in normal-appearing colonic mucosa and those attenuated by bean feeding. Ninety-five male F344 rats were fed control (AIN) diets upon arrival. At 4 and 5 weeks, rats were injected with AOM (15 mg/kg) or saline and one week later administered an AIN, BB-, or SF-based diet. Rats were sacrificed after 31 weeks, and microarrays were conducted on RNA isolated from the distal colonic mucosa. AOM treatment induced a number of genes involved in immunity, including several MHC II-associated antigens and innate defense genes (RatNP-3, Lyz2, Pla2g2a). BB- and SF-fed rats exhibited a higher expression of genes involved in energy metabolism and water and sodium absorption and lower expression of innate (RatNP-3, Pla2g2a, Tlr4, Dmbt1) and cell cycle-associated (Cdc2, Ccnb1, Top2a) genes. Genes involved in the extracellular matrix (Col1a1, Fn1) and innate immunity (RatNP-3, Pla2g2a) were induced by AOM in all diets, but to a lower extent in bean-fed animals. This profile suggests beans inhibit colon carcinogenesis by modulating cellular kinetics and reducing inflammation, potentially by preserving mucosal barrier function.

SPECIAL FEATURES OF CARCINOGENESIS OF COLON ADENOCARCINOMA

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G. A. Raskin

2015-01-01

Full Text Available Colorectal cancer is one of the most common malignancies and the leading cause of cancer-related death. There are 4 basic colon carcinogenic steps: malignant transformation of adenoma into carcinoma; HNPCC (hereditary nonpolyposis colon cancer; cancer «de novo»; chronic colitis malignant transformation. All of them, except for Lynch syndrome, are increasingly focused on stem tissue-committed cells as mutation targets and the source of malignancies. Subsequently, cancer stem cells are considered as the cause of chemoresistance of tumors, metastases and relapses. Thus, the study of the cell population can dramatically change approaches to the treatment of patients with colorectal adenocarcinoma.

The relevance of cell transformation to carcinogenesis in vivo

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Little, J.B.

1989-01-01

Despite the caveats concerning rodent as opposed to human cell transformation systems, the author concludes there are several areas in which cell transformation studies with rodent cells have shown clear relevance to carcinogenesis in vivo, especially studies of carcinogenic effects of high LET radiation, particularly dependence on dose rate. In vitro studies firmly established the generality of promotion by phorbol esters tumour promotors. Initial studies on suppression of transformation, notably by protease inhibitors, has led to the confirmation of this phenomenon in in vivo carcinogenesis; development of inhibitor preparations from natural sources suitable for long-term supplementation in human diet, is under investigation. The potential importance of these modifiers is further emphasized by mechanistic studies suggesting that radiation may initiate a large fraction of exposed cell population, and expression of transformation may be controlled to a large extent by environmental conditions including the presence of promoting or suppressing agents. Finally, cell transformation systems offer the opportunity for mechanistic studies of the initial stages of carcinogenesis. Provocative results have arisen in several areas consistent with findings in experimental animals. (author)

Dietary calcium as a possible anti-promoter of colon carcinogenesis

OpenAIRE

Lapre, J.A.

1992-01-01

SUMMARY
Colon cancer is the second-most common malignancy in both males and females and is strongly related to environmental factors of which diet seems to be the most important one. Dietary fat is positively correlated with the incidence of colon cancer whereas dietary fibre and dietary calcium seem to be negatively associated with the risk of colon cancer. The development of colon cancer can genetically and histologically ...

Vasohibin-1 suppresses colon cancer

OpenAIRE

Liu, Shuai; Han, Bing; Zhang, Qunyuan; Dou, Jie; Wang, Fang; Lin, Wenli; Sun, Yuping; Peng, Guangyong

2015-01-01

Vasohibin-1 (VASH1) is an endogenous angiogenesis inhibitor. However, the clinical relevance of VASH1 in colon cancer and its regulations on cancer angiogenesis and cancer cell biological characteristics are still unknown. Here we showed that stromal VASH1 levels were negatively correlated with tumor size, advanced clinical stage and distant metastases in colon cancer patients. Overexpression of VASH1 in colon cancer cells induced apoptosis and senescence, inhibiting cancer cell growth and co...

Urotensin-II receptor is over-expressed in colon cancer cell lines and in colon carcinoma in humans.

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Federico, Alessandro; Zappavigna, Silvia; Romano, Marco; Grieco, Paolo; Luce, Amalia; Marra, Monica; Gravina, Antonietta Gerarda; Stiuso, Paola; D'Armiento, Francesco Paolo; Vitale, Giovanni; Tuccillo, Concetta; Novellino, Ettore; Loguercio, Carmela; Caraglia, Michele

2014-01-01

Urotensin (U)-II receptor (UTR) has been previously reported to be over-expressed in a number of tumours. Whether UTR-related pathway plays a role in colon carcinogenesis is unknown. We evaluated UTR protein and mRNA expression in human epithelial colon cancer cell lines and in normal colon tissue, adenomatous polyps and colon cancer. U-II protein expression was assessed in cancer cell lines. Moreover, we evaluated the effects of U-II(4-11) (an UTR agonist), antagonists and knockdown of UTR protein expression through a specific shRNA, on proliferation, invasion and motility of human colon cancer cells. Cancer cell lines expressed U-II protein and UTR protein and mRNA. By immunohistochemistry, UTR was expressed in 5-30% of epithelial cells in 45 normal controls, in 30-48% in 21 adenomatous polyps and in 65-90% in 48 colon adenocarcinomas. UTR mRNA expression was increased by threefold in adenomatous polyps and eightfold in colon cancer, compared with normal colon. U-II(4-11) induced a 20-40% increase in cell growth while the blockade of the receptor with specific antagonists caused growth inhibition of 20-40%. Moreover, the knock down of UTR with a shRNA or the inhibition of UTR with the antagonist urantide induced an approximately 50% inhibition of both motility and invasion. UTR appears to be involved in the regulation of colon cancer cell invasion and motility. These data suggest that UTR-related pathway may play a role in colon carcinogenesis and that UTR may function as a target for therapeutic intervention in colon cancer. © 2013 Stichting European Society for Clinical Investigation Journal Foundation.

Sialoglyco proteins trypanosome cruz i. Possible to use for specific active immunotherapy strategies in colon cancer?

International Nuclear Information System (INIS)

Ubillos, L.; Mazal, D.; Chiribao, M.; Berriel, E.; Freire, T.; Robello, C.; Osinaga, E.

2004-01-01

Introduction: The sialyl-Tn structure (SAa2-6GalNAcaSer / Thr) is expressed in cancer colon and not in normal colon tissue, with an intermediate expression in premalignant lesions. Dimethylhydrazine (DMH) induced colon cancer in rats with similar morphology carcinomas human colorectal and express sialyl-Tn similarly. It has been observed that infection of rats the flagellated protozoan Trypanosoma cruzi is associated with a lower incidence colon cancer in this experimental model. There is still no explanation this phenomenon. Recently, our group demonstrated the presence of antigen sialyl-Tn in T. cruzi. Objectives: To evaluate the antitumor effect of immunobiological extracts of T. cruzi in the model of colon carcinogenesis induced by DMH, determining the role of the glycoproteins expressing sialyl Tn. Methodology: was induced colonic carcinogenesis in 16 Wistar rats by injection weekly DMH (15 mg / Kg). The animals were divided into four groups: (A) only treated with the carcinogen; (B) Simultaneous immunization carcinogenesis with extracts of T. cruzi (epimastigotes); (C) Simultaneous immunization carcinogenesis with extracts of T. cruzi I deglycosylated (m-periodate 80 mM); and (D) Carcinogenesis Simultaneous immunization with ovine submaxillary mucin (OSM), rich in antigen sialyl-Tn. After five immunizations (weeks 0, 4, 8, 10 and 12) the animals were sacrificed at week 24 and the colon was evaluated istopathologically. Results: compatible with carcinomas of colon, macroscopic lesions were observed in 3/4 rats from group A, group B in fourth in 4/4 in group C and group D. When 0/4 microscopic analysis, the animals in groups A and C showed lesions more invasive than the lesions observed in animals of group B. Conclusions: These Preliminary results suggest that immunization with T. cruzi extracts can have a protective effect against the development of colon cancer, where the epitopes Carb may be responsible for this effect. He is currently in course further

Chemopreventive potential of β-Sitosterol in experimental colon cancer model - an In vitro and In vivo study

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Paulraj Gabriel M

2010-06-01

Full Text Available Abstract Background Asclepias curassavica Linn. is a traditional medicinal plant used by tribal people in the western ghats, India, to treat piles, gonorrhoea, roundworm infestation and abdominal tumours. We have determined the protective effect of β-sitosterol isolated from A. curassavica in colon cancer, using in vitro and in vivo models. Methods The active molecule was isolated, based upon bioassay guided fractionation, and identified as β-sitosterol on spectral evidence. The ability to induce apoptosis was determined by its in vitro antiradical activity, cytotoxic studies using human colon adenocarcinoma and normal monkey kidney cell lines, and the expression of β-catenin and proliferating cell nuclear antigen (PCNA in human colon cancer cell lines (COLO 320 DM. The chemopreventive potential of β-sitosterol in colon carcinogenesis was assessed by injecting 1,2-dimethylhydrazine (DMH, 20 mg/kg b.w. into male Wistar rats and supplementing this with β-sitosterol throughout the experimental period of 16 weeks at 5, 10, and 20 mg/kg b.w. Results β-sitosterol induced significant dose-dependent growth inhibition of COLO 320 DM cells (IC50 266.2 μM, induced apoptosis by scavenging reactive oxygen species, and suppressed the expression of β-catenin and PCNA antigens in human colon cancer cells. β-sitosterol supplementation reduced the number of aberrant crypt and crypt multiplicity in DMH-initiated rats in a dose-dependent manner with no toxic effects. Conclusion We found doses of 10-20 mg/kg b.w. β-sitosterol to be effective for future in vivo studies. β-sitosterol had chemopreventive potential by virtue of its radical quenching ability in vitro, with minimal toxicity to normal cells. It also attenuated β-catenin and PCNA expression, making it a potential anticancer drug for colon carcinogenesis.

Chemopreventive potential of β-Sitosterol in experimental colon cancer model - an In vitro and In vivo study

Science.gov (United States)

2010-01-01

Background Asclepias curassavica Linn. is a traditional medicinal plant used by tribal people in the western ghats, India, to treat piles, gonorrhoea, roundworm infestation and abdominal tumours. We have determined the protective effect of β-sitosterol isolated from A. curassavica in colon cancer, using in vitro and in vivo models. Methods The active molecule was isolated, based upon bioassay guided fractionation, and identified as β-sitosterol on spectral evidence. The ability to induce apoptosis was determined by its in vitro antiradical activity, cytotoxic studies using human colon adenocarcinoma and normal monkey kidney cell lines, and the expression of β-catenin and proliferating cell nuclear antigen (PCNA) in human colon cancer cell lines (COLO 320 DM). The chemopreventive potential of β-sitosterol in colon carcinogenesis was assessed by injecting 1,2-dimethylhydrazine (DMH, 20 mg/kg b.w.) into male Wistar rats and supplementing this with β-sitosterol throughout the experimental period of 16 weeks at 5, 10, and 20 mg/kg b.w. Results β-sitosterol induced significant dose-dependent growth inhibition of COLO 320 DM cells (IC50 266.2 μM), induced apoptosis by scavenging reactive oxygen species, and suppressed the expression of β-catenin and PCNA antigens in human colon cancer cells. β-sitosterol supplementation reduced the number of aberrant crypt and crypt multiplicity in DMH-initiated rats in a dose-dependent manner with no toxic effects. Conclusion We found doses of 10-20 mg/kg b.w. β-sitosterol to be effective for future in vivo studies. β-sitosterol had chemopreventive potential by virtue of its radical quenching ability in vitro, with minimal toxicity to normal cells. It also attenuated β-catenin and PCNA expression, making it a potential anticancer drug for colon carcinogenesis. PMID:20525330

Diet, microbiota, and microbial metabolites in colon cancer risk in rural Africans and African Americans

NARCIS (Netherlands)

Ou, J.; Carbonero, F.; Zoetendal, E.G.; Delany, J.P.; Wang, M.; Newton, K.; Gaskins, H.R.; O'Keefe, S.F.

2013-01-01

BACKGROUND: Epidemiologic studies have suggested that most cases of sporadic colon cancer can be attributed to diet. The recognition that colonic microbiota have a major influence on colonic health suggests that they might mediate colonic carcinogenesis. OBJECTIVE: To examine the hypothesis that the

Vasohibin-1 suppresses colon cancer

Science.gov (United States)

Liu, Shuai; Han, Bing; Zhang, Qunyuan; Dou, Jie; Wang, Fang; Lin, Wenli; Sun, Yuping; Peng, Guangyong

2015-01-01

Vasohibin-1 (VASH1) is an endogenous angiogenesis inhibitor. However, the clinical relevance of VASH1 in colon cancer and its regulations on cancer angiogenesis and cancer cell biological characteristics are still unknown. Here we showed that stromal VASH1 levels were negatively correlated with tumor size, advanced clinical stage and distant metastases in colon cancer patients. Overexpression of VASH1 in colon cancer cells induced apoptosis and senescence, inhibiting cancer cell growth and colony formation in vitro and tumor growth in vivo. In addition, knockdown of VASH1 in cancer cells promoted cell growth, adhesion and migration in vitro, and enhanced tumorigenesis and metastasis in vivo. PMID:25797264

Vasohibin-1 suppresses colon cancer.

Science.gov (United States)

Liu, Shuai; Han, Bing; Zhang, Qunyuan; Dou, Jie; Wang, Fang; Lin, Wenli; Sun, Yuping; Peng, Guangyong

2015-04-10

Vasohibin-1 (VASH1) is an endogenous angiogenesis inhibitor.However, the clinical relevance of VASH1 in colon cancer and its regulations on cancer angiogenesis and cancer cell biological characteristics are still unknown. Here we showed that stromal VASH1 levels were negatively correlated with tumor size, advanced clinical stage and distant metastases in colon cancer patients. Overexpression of VASH1 in colon cancer cells induced apoptosis and senescence, inhibiting cancer cell growth and colony formation in vitro and tumor growth in vivo. In addition, knockdown of VASH1 in cancer cells promoted cell growth, adhesion and migration in vitro, and enhanced tumorigenesis and metastasis in vivo.

ADA-07 Suppresses Solar Ultraviolet-Induced Skin Carcinogenesis by Directly Inhibiting TOPK.

Science.gov (United States)

Gao, Ge; Zhang, Tianshun; Wang, Qiushi; Reddy, Kanamata; Chen, Hanyong; Yao, Ke; Wang, Keke; Roh, Eunmiri; Zykova, Tatyana; Ma, Weiya; Ryu, Joohyun; Curiel-Lewandrowski, Clara; Alberts, David; Dickinson, Sally E; Bode, Ann M; Xing, Ying; Dong, Zigang

2017-09-01

Cumulative exposure to solar ultraviolet (SUV) irradiation is regarded as the major etiologic factor in the development of skin cancer. The activation of the MAPK cascades occurs rapidly and is vital in the regulation of SUV-induced cellular responses. The T-LAK cell-originated protein kinase (TOPK), an upstream activator of MAPKs, is heavily involved in inflammation, DNA damage, and tumor development. However, the chemopreventive and therapeutic effects of specific TOPK inhibitors in SUV-induced skin cancer have not yet been elucidated. In the current study, ADA-07, a novel TOPK inhibitor, was synthesized and characterized. Pull-down assay results, ATP competition, and in vitro kinase assay data revealed that ADA-07 interacted with TOPK at the ATP-binding pocket and inhibited its kinase activity. Western blot analysis showed that ADA-07 suppressed SUV-induced phosphorylation of ERK1/2, p38, and JNKs and subsequently inhibited AP-1 activity. Importantly, topical treatment with ADA-07 dramatically attenuated tumor incidence, multiplicity, and volume in SKH-1 hairless mice exposed to chronic SUV. Our findings suggest that ADA-07 is a promising chemopreventive or potential therapeutic agent against SUV-induced skin carcinogenesis that acts by specifically targeting TOPK. Mol Cancer Ther; 16(9); 1843-54. ©2017 AACR . ©2017 American Association for Cancer Research.

Tissue distribution of aryl hydrocarbon receptor in the intestine: Implication of putative roles in tumor suppression

International Nuclear Information System (INIS)

Ikuta, Togo; Kurosumi, Masafumi; Yatsuoka, Toshimasa; Nishimura, Yoji

2016-01-01

Intestinal homeostasis is maintained by complex interactions between intestinal microorganisms and the gut immune system. Dysregulation of gut immunity may lead to inflammatory disorders and tumorigenesis. We previously have shown the tumor suppressive effects of aryl hydrocarbon receptor (AhR) in intestinal carcinogenesis. In the present study, we investigated AhR distribution in the mouse and human intestine by histochemical analysis. In the normal intestine, AhR was mainly localized in the stroma containing immune cells in the lamina propria and lymphoid follicles. On the other hand, in the tumor tissue from human colon cancer and that developed in Apc"M"i"n"/"+mice, AhR expression was elevated. AhR immunostaining was found in both stromal and tumor cells. Although AhR was localized in the cytoplasm of tumor cells in most cases, nuclear AhR was also observed in some. AhR knockdown using siRNA resulted in significant promotion of cell growth in colon cancer cell lines. Furthermore, AhR activation by AhR ligands supplemented in culture medium suppressed cell growth. Our study results suggest that tumor suppressive roles of AhR are estimated in two distinct ways: in normal tissue, AhR is associated with tumor prevention by regulating gut immunity, whereas in tumor cells, it is involved in growth suppression. - Highlights: • In the normal intestine, AhR was mainly localized in stroma containing immune cells. • In the tumor tissue, AhR expression was found in both stromal and tumor cells. • AhR knockdown promoted cell growth in colon cancer cell lines.

Tissue distribution of aryl hydrocarbon receptor in the intestine: Implication of putative roles in tumor suppression

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Ikuta, Togo, E-mail: togo@cancer-c.pref.saitama.jp [Department of Cancer Prevention, Research Institute for Clinical Oncology, Saitama Cancer Center, 818 Komuro, Ina-machi, Kitaadachi-gun, Saitama 362-0806 (Japan); Kurosumi, Masafumi, E-mail: mkurosumi@cancer-c.pref.saitama.jp [Division of Pathology, Saitama Cancer Center, 780 Komuro, Ina-machi, Kitaadachi-gun, Saitama 362-0806 (Japan); Yatsuoka, Toshimasa, E-mail: yatsuoka-gi@umin.ac.jp [Division of Gastroenterological Surgery, Saitama Cancer Center, 780 Komuro, Ina-machi, Kitaadachi-gun, Saitama 362-0806 (Japan); Nishimura, Yoji, E-mail: yojinish@cancr-c.pref.saitama.jp [Division of Gastroenterological Surgery, Saitama Cancer Center, 780 Komuro, Ina-machi, Kitaadachi-gun, Saitama 362-0806 (Japan)

2016-05-01

Intestinal homeostasis is maintained by complex interactions between intestinal microorganisms and the gut immune system. Dysregulation of gut immunity may lead to inflammatory disorders and tumorigenesis. We previously have shown the tumor suppressive effects of aryl hydrocarbon receptor (AhR) in intestinal carcinogenesis. In the present study, we investigated AhR distribution in the mouse and human intestine by histochemical analysis. In the normal intestine, AhR was mainly localized in the stroma containing immune cells in the lamina propria and lymphoid follicles. On the other hand, in the tumor tissue from human colon cancer and that developed in Apc{sup Min/+}mice, AhR expression was elevated. AhR immunostaining was found in both stromal and tumor cells. Although AhR was localized in the cytoplasm of tumor cells in most cases, nuclear AhR was also observed in some. AhR knockdown using siRNA resulted in significant promotion of cell growth in colon cancer cell lines. Furthermore, AhR activation by AhR ligands supplemented in culture medium suppressed cell growth. Our study results suggest that tumor suppressive roles of AhR are estimated in two distinct ways: in normal tissue, AhR is associated with tumor prevention by regulating gut immunity, whereas in tumor cells, it is involved in growth suppression. - Highlights: • In the normal intestine, AhR was mainly localized in stroma containing immune cells. • In the tumor tissue, AhR expression was found in both stromal and tumor cells. • AhR knockdown promoted cell growth in colon cancer cell lines.

Stage dependent expression and tumor suppressive function of FAM134B (JK1) in colon cancer.

Science.gov (United States)

Islam, Farhadul; Gopalan, Vinod; Wahab, Riajul; Smith, Robert A; Qiao, Bin; Lam, Alfred King-Yin

2017-01-01

The aims of the present study are to investigate sub-cellular location, differential expression in different cancer stages and functional role of FAM134B in colon cancer development. FAM134B expression was studied and quantified at protein and mRNA levels in cell lines using immunocytochemistry, Western blot and real-time PCR. In vitro functional assays and an in vivo xenotransplantation mouse models were used to investigate the molecular role of FAM134B in cancer cell biology in response to FAM134B silencing with shRNA lentiviral particles. FAM134B protein was noted in both cytoplasm and nuclei of cancer cells. In cancer cells derived from stage IV colon cancer, FAM134B expression was remarkably reduced when compared to non-cancer colon cells and cancer cells derived from stage II colon cancer. FAM134B knockdown significantly (P colon cancer cells following lentiviral transfection. Furthermore, FAM134B suppression significantly increased (34-52%; P cancer suppressor gene in colon cancer. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

miR-136 targets MIEN1 and involves the metastasis of colon cancer by suppressing epithelial-to-mesenchymal transition

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Ren H

2017-12-01

Full Text Available Haipeng Ren,1 Yuanling Qi,1 Xiaoyan Yin,2 Jianfeng Gao1 1Department of Internal Medicine of Oncology, People’s Hospital of Weifang, Weifang, 2Health and Family Planning Bureau of Weifang, Shouguang, People’s Republic of China Abstract: MIEN1 is a novel oncogene, and it involves tumor progression in various cancer types, including colon cancer. However, the definite molecular mechanisms of MIEN1 in colon cancer progression remain to be completely elucidated. In the present study, bioinformatics prediction showed that miR-136 could be an upstream regulator of MIEN1; a luciferase assay and Western blot assay revealed that miR-136 negatively regulates MIEN1 expression via directly targeting its 3'-untranslated region sequence. Moreover, a functional assay using wound healing and transwell invasion showed that overexpressed miR-136 inhibited cell migration and invasion, and overexpression of MIEN1 partly rescued the above-mentioned effects of miR-136 in colon cancer cells. Additionally, a clinical sample assay showed that miR-136 expression was generally downregulated in colon cancer tissue, which was inversely correlated with MIEN1 expression. Furthermore, we found that miR-136 suppressed the Akt/NF-κB signaling pathway and epithelial-to-mesenchymal transition in colon cancer. These results suggest that miR-136, as a tumor suppressor, acts in tumor metastasis by suppressing MIEN1 expression in colon cancer, providing a novel target for the treatment of colon cancer. Keywords: colon cancer, miR-136, MIEN1, migration, invasion

miR-4458 suppresses glycolysis and lactate production by directly targeting hexokinase2 in colon cancer cells

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Qin, Yaguang; Cheng, Chuanyao; Lu, Hong, E-mail: honglu6512@163.com; Wang, Yaqiu

2016-01-01

miR-4458, a new tumor-suppressor, was reported to down-regulated in human hepatocellular carcinoma. The expression status, roles and inhibitory mechanisms of miR-4458 in other tumors still need to be clarified. The aim of this study is to investigate the effects of miR-4458 and to elucidate the potential mechanism in colon cancer cells. Using bioinformatic databases, we predicted that hexokinase2 (HK2), a rate-limiting enzyme in the glycolytic pathway, was a target of miR-4458, so the effects of miR-4458 on glycolysis and lactate production was assessed in colon cancer cells. We found that miR-4458 was down-regulated and HK2 was up-regulated in colon cancer cells. Overexpression of miR-4458 inhibited proliferation, glycolysis, and lactate production under both normoxic and hypoxic conditions. Luciferase activity assays showed that HK2 was a direct target of miR-4458. Moreover, knockdown of HK2 by specific RNAi also suppressed proliferation, glycolysis, and lactate production under both normoxic and hypoxic conditions. In conclusion, our findings suggested that miR-4458 inhibited the progression of colon cancer cells by inhibition of glycolysis and lactate production via directly targeting HK2 mRNA. - Highlights: • miR-4458 is down-regulated in colon cancer cells. • miR-4458 suppresses proliferation, glycolysis, and lactate production. • HK2 is a target of miR-4458. • HK2 knockdown inhibits proliferation, glycolysis, and lactate production.

PPARδ deficiency disrupts hypoxia-mediated tumorigenic potential of colon cancer cells.

Science.gov (United States)

Jeong, Eunshil; Koo, Jung Eun; Yeon, Sang Hyeon; Kwak, Mi-Kyoung; Hwang, Daniel H; Lee, Joo Young

2014-11-01

Peroxisome proliferator-activated receptor (PPAR) δ is highly expressed in colon epithelial cells and closely linked to colon carcinogenesis. However, the role of PPARδ in colon cancer cells in a hypoxic tumor microenvironment is not fully understood. We found that expression of the tumor-promoting cytokines, IL-8 and VEGF, induced by hypoxia (colon cancer cells. Consequently, PPARδ-knockout colon cancer cells exposed to hypoxia and deferoxamine failed to stimulate endothelial cell vascularization and macrophage migration/proliferation, whereas wild-type cells were able to induce angiogenesis and macrophage activation in response to hypoxic stress. Hypoxic stress induced transcriptional activation of PPARδ, but not its protein expression, in HCT116 cells. Exogenous expression of p300 potentiated deferoxamine-induced PPARδ transactivation, while siRNA knockdown of p300 abolished hypoxia- and deferoxamine-induced PPARδ transactivation. PPARδ associated with p300 upon hypoxic stress as demonstrated by coimmunoprecipitation studies. PI3K inhibitors or siRNA knockdown of Akt suppressed the PPARδ transactivation induced by hypoxia and deferoxamine in HCT116 cells, leading to decreased expression of IL-8 and VEGF. Collectively, these results reveal that PPARδ is required for hypoxic stress-mediated cytokine expression in colon cancer cells, resulting in promotion of angiogenesis, macrophage recruitment, and macrophage proliferation in the tumor microenvironment. p300 and the PI3K/Akt pathway play a role in the regulation of PPARδ transactivation induced by hypoxic stress. Our results demonstrate the positive crosstalk between PPARδ in tumor cells and the hypoxic tumor microenvironment and provide potential therapeutic targets for colon cancer. © 2014 Wiley Periodicals, Inc.

Dietary factors and microsatellite instability in sporadic colon carcinomas

NARCIS (Netherlands)

Diergaarde, B.; Braam, H.; Muijen, van G.N.P.; Ligtenberg, M.J.L.; Kok, F.J.; Kampman, E.

2003-01-01

Microsatellite instability (MSI) occurs in 10-20% of the sporadic colon carcinomas and appears to be primarily due to alterations in hMLH1 and hMSH2. Little is known about the role of diet in MSI-related colon carcinogenesis. We used data from a Dutch population-based case-control study on sporadic

Dietary factors and microsatellite instability in sporadic colon carcinomas.

NARCIS (Netherlands)

Diergaarde, B.; Braam, H.; Muijen, G.N.P. van; Ligtenberg, M.J.L.; Kok, F.J.; Kampman, E.

2003-01-01

Microsatellite instability (MSI) occurs in 10-20% of the sporadic colon carcinomas and appears to be primarily due to alterations in hMLH1 and hMSH2. Little is known about the role of diet in MSI-related colon carcinogenesis. We used data from a Dutch population-based case-control study on sporadic

Colon-available raspberry polyphenols exhibit anti-cancer effects on in vitro models of colon cancer

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McDougall Gordon

2007-01-01

Full Text Available Abstract Background There is a probable association between consumption of fruit and vegetables and reduced risk of cancer, particularly cancer of the digestive tract. This anti-cancer activity has been attributed in part to anti-oxidants present in these foods. Raspberries in particular are a rich source of the anti-oxidant compounds, such as polyphenols, anthocyanins and ellagitannins. Methods A "colon-available" raspberry extract (CARE was prepared that contained phytochemicals surviving a digestion procedure that mimicked the physiochemical conditions of the upper gastrointestinal tract. The polyphenolic-rich extract was assessed for anti-cancer properties in a series of in vitro systems that model important stages of colon carcinogenesis, initiation, promotion and invasion. Results The phytochemical composition of CARE was monitored using liquid chromatography mass spectrometry. The colon-available raspberry extract was reduced in anthocyanins and ellagitannins compared to the original raspberry juice but enriched in other polyphenols and polyphenol breakdown products that were more stable to gastrointestinal digestion. Initiation – CARE caused significant protective effects against DNA damage induced by hydrogen peroxide in HT29 colon cancer cells measured using single cell microgelelectrophoresis. Promotion – CARE significantly decreased the population of HT29 cells in the G1 phase of the cell cycle, effectively reducing the number of cells entering the cell cycle. However, CARE had no effect on epithelial integrity (barrier function assessed by recording the trans-epithelial resistance (TER of CACO-2 cell monolayers. Invasion – CARE caused significant inhibition of HT115 colon cancer cell invasion using the matrigel invasion assay. Conclusion The results indicate that raspberry phytochemicals likely to reach the colon are capable of inhibiting several important stages in colon carcinogenesis in vitro.

Chronic ethanol feeding promotes azoxymethane and dextran sulfate sodium-induced colonic tumorigenesis potentially by enhancing mucosal inflammation

International Nuclear Information System (INIS)

Shukla, Pradeep K.; Chaudhry, Kamaljit K.; Mir, Hina; Gangwar, Ruchika; Yadav, Nikki; Manda, Bhargavi; Meena, Avtar S.; Rao, RadhaKrishna

2016-01-01

Alcohol consumption is one of the major risk factors for colorectal cancer. However, the mechanism involved in this effect of alcohol is unknown. We evaluated the effect of chronic ethanol feeding on azoxymethane and dextran sulfate sodium (AOM/DSS)-induced carcinogenesis in mouse colon. Inflammation in colonic mucosa was assessed at a precancerous stage by evaluating mucosal infiltration of neutrophils and macrophages, and analysis of cytokine and chemokine gene expression. Chronic ethanol feeding significantly increased the number and size of polyps in colon of AOM/DSS treated mice. Confocal microscopic and immunoblot analyses showed a significant elevation of phospho-Smad, VEGF and HIF1α in the colonic mucosa. RT-PCR analysis at a precancerous stage indicated that ethanol significantly increases the expression of cytokines IL-1α, IL-6 and TNFα, and the chemokines CCL5/RANTES, CXCL9/MIG and CXCL10/IP-10 in the colonic mucosa of AOM/DSS treated mice. Confocal microscopy showed that ethanol feeding induces a dramatic elevation of myeloperoxidase, Gr1 and CD68-positive cells in the colonic mucosa of AOM/DSS-treated mice. Ethanol feeding enhanced AOM/DSS-induced suppression of tight junction protein expression and elevated cell proliferation marker, Ki-67 in the colonic epithelium. This study demonstrates that chronic ethanol feeding promotes colonic tumorigenesis potentially by enhancing inflammation and elevation of proinflammatory cytokines and chemokines

MicroRNA-98 Suppress Warburg Effect by Targeting HK2 in Colon Cancer Cells.

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Zhu, Weimin; Huang, Yijiao; Pan, Qi; Xiang, Pei; Xie, Nanlan; Yu, Hao

2017-03-01

Warburg effect is a hallmark of cancer cells. Accumulating evidence suggests that microRNAs (miRs) could regulate such metabolic reprograming. Aberrant expression of miR-98 has been observed in many types of cancers. However, its functions and significance in colon cancer remain largely elusive. To investigate miR-98 expression and the biological functions in colon cancer progression. miR-98 expression levels were determined by quantitative RT-PCR in 215 cases of colon cancer samples. miR-98 mimic or inhibitor was used to test the biological functions in SW480 and HCT116 cells, followed by cell proliferation assay, lactate production, glucose uptake, and cellular ATP levels assay and extracellular acidification rates measurement. Western blot and luciferase assay were used to identify the target of miR-98. miR-98 was significantly down-regulated in colon cancer tissues compared to adjacent colon tissues and acted as a suppressor for Warburg effect in cancer cells. miR-98 inhibited glycolysis by directly targeting hexokinase 2, or HK2, illustrating a novel pathway to mediate Warburg effect of cancer cells. In vitro experiments further indicated that HK2 was involved in miR-98-mediated suppression of glucose uptake, lactate production, and cell proliferation. In addition, we detected HK2 expression in colon cancer tissues and found that the expressions of miR-98 and HK2 were negatively correlated. miR-98 acts as tumor suppressor gene and inhibits Warburg effect in colon cancer cells, which provided potential targets for clinical treatments.

Role of microsatellite instability in colon cancer

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M. Yu. Fedyanin

2012-01-01

Full Text Available Coloncancer is among leading causes of cancer morbidity and mortality both inRussiaand worldwide. Development of molecular biology lead to decoding of carcinogenesis and tumor progression mechanisms. These processes require accumulation of genetic and epigenetic alterations in a tumor cell.Coloncancer carcinogenesis is characterized by mutations cumulation in genes controlling growth and differentiation of epithelial cells, which leads to their genetic instability. Microsatellite instability is a type of genetic instability characterized by deterioration of mismatch DNA repair. This leads to faster accumulation of mutations in DNA. Loss of mismatch repair mechanism can easily be diagnosed by length of DNA microsatellites. These alterations are termed microsatellite instability. They can be found both in hereditary and sporadic colon cancers. This review covers the questions of microsatellite instability, its prognostic and predictive value in colon cancer.

Carcinogenesis. Genetics and circumstances

International Nuclear Information System (INIS)

Hino, Okio

2005-01-01

Described are the author's study and aspect concerning carcinogenesis and radiation carcinogenesis, where he thinks cancer is not automatic, has a process and takes time. For radiation carcinogenic studies, he has used a model of the rat with genetically determined kidney cancer which is highly radiosensitive. That is, mutation by the so-called 2nd-hit of the causal gene (tumor suppressing gene Tsc2) is studied in the animal where the 1st-hit has been done by retrotransposon insertion, with and without exposure to radiations (X-ray, heavy particle beam and cosmic ray) for elucidating the mutation spectrum of the causal gene, the carcinogenic target, for the ultimate aim to prevent human cancer. He discusses the drama-type molecular mechanisms leading to cancer, gene abnormality and disease crisis, discontinuity in continuity in cancer formation, and importance of the timely diagnosis and appropriate therapy, and concludes the present age is becoming such one as that the nature of cancer even if genetic can be controlled by circumstances like timely and appropriate intervention. (S.I.)

Influence of the surgical manipulation of the colon in colonic induced carcinogenesis in rats Influencia de la manipulación quirúrgica del colon en la carcinogénesis cólica inducida en ratas

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J. F. Noguera Aguilar

2004-05-01

Full Text Available Aim: to investigate the influence of different experimental manipulations in a model of colonic experimental carcinogenesis with pharmacological induction in the rat. Experimental design: a total of 90 Sprague-Dawley male rats, divided into three groups, were used: non-surgical (n = 30; surgical with colonic trauma (n = 20, and surgical with colo-colonic anastomosis (n = 40. Carcinogenic induction was carried out with 1-2 dimethylhydrazine dihydrochloride. Colonic adenocarcinomas were identified and the number of tumors, as well as tumoral surface and percentage of tumoral surface was established. One-way ANOVA and Chi-square were employed for the statistical analysis. Results: the number of tumors was greater in the surgical group than in the control group, and tumors preferentially develop-ed around the manipulated colon. Surface and tumoral percentage were greater in the surgical group than in the control group, being also greater in the anastomosis group than in the group with colonic trauma. Within anastomosis groups, a greater tumor surface and percentage was found in the group with titanium than in the group with reabsorbable material. Conclusions: the experimental manipulation of the colon in rats enhances drug-induced colon carcingenesis. The creation of an anastomosis further increases the carcinogenic process compared with simulated anastomosis. This process is also enhanced by the quantity of suture material included in the anastomosis, and by the non-reabsorbable nature of the materials used in the anastomotic line.Objetivo: valorar la influencia de las distintas manipulaciones experimentales en un modelo de carcinogénesis cólica experimental con inducción farmacológica en la rata. Diseño experimental: se emplearon 90 ratas Sprague-Dawley macho, divididas en tres grupos: no quirúrgico (n=30; quirúrgico con traumatismo cólico (n=20, y quirúrgico con anastomosis colocólica (n=40. La inducción carcinogénica se realizó con

Effect of various chemicals on the metabolism of benzo(a)pyrene by cultured rat colon

DEFF Research Database (Denmark)

Autrup, Herman; Harris, Curtis C.; Fugaro, Steven

1977-01-01

The effect of various co- and anti-carcinogens of colon carcinogenesis on the metabolism of benzo(a)pyrene (BP) in cultured rat colon is reported. Rat colon enzymatically converted BP into metabolites which bind to cellular macromolecules i.e., DNA and protein. Activity of aryl hydrocarbon...

Inflammatory and redox reactions in colorectal carcinogenesis.

Science.gov (United States)

Guina, Tina; Biasi, Fiorella; Calfapietra, Simone; Nano, Mario; Poli, Giuseppe

2015-03-01

It has been established that there is a relationship between chronic inflammation and cancer development. The constant colonic inflammation typical of inflammatory bowel diseases is now considered a risk factor for colorectal carcinoma (CRC) development. The inflammatory network of signaling molecules is also required during the late phases of carcinogenesis, to enable cancer cells to survive and to metastasize. Oxidative reactions are an integral part of the inflammatory response, and are generally associated with CRC development. However, when the malignant phenotype is acquired, increased oxidative status induces antioxidant defenses in cancer cells, favoring their aggressiveness. This contradictory behavior of cancer cells toward redox status is of great significance for potential anticancer therapies. This paper summarizes the essential background information relating to the molecules involved in regulating oxidative stress and inflammation during carcinogenesis. Understanding more of their function in CRC stages might provide the foundation for future developments in CRC treatment. © 2015 New York Academy of Sciences.

The Effect of Apple Feeding on Markers of Colon Carcinogenesis

DEFF Research Database (Denmark)

Poulsen, Morten; Mortensen, Alicja; Binderup, Mona-Lise

2011-01-01

Regular consumption of fruits and vegetables is associated with reduced risks of certain cancers and other diseases in observational studies and animal models of human diseases. The aim of the present study was to investigate whether feeding of rats with whole raw apple has potentially chemopreve......Regular consumption of fruits and vegetables is associated with reduced risks of certain cancers and other diseases in observational studies and animal models of human diseases. The aim of the present study was to investigate whether feeding of rats with whole raw apple has potentially...... chemopreventive properties by affecting markers of colon cancer. The end-point was preneoplastic changes in the colon known as aberrant crypt foci (ACF). Rats initiated with the colon carcinogen 1,2-dimethylhydrazine dihydrochloride (DMH) were given 0, 5, or 10 g apple/day for 13 wk. The group fed 5 g apple...... but not 10 g had a significantly lower number of ACF (P = 0.009) compared to the initiated control. DNA damage evaluated by the comet assay was significantly increased in leucocytes of DMH-treated animals (P = 0.021). No antigenotoxic effect of apple feeding was apparent in the colon. Apple feeding tended...

Quantification of nanoscale density fluctuations by electron microscopy: probing cellular alterations in early carcinogenesis

International Nuclear Information System (INIS)

Pradhan, Prabhakar; Damania, Dhwanil; Turzhitsky, Vladimir; Subramanian, Hariharan; Backman, Vadim; Joshi, Hrushikesh M; Dravid, Vinayak P; Roy, Hemant K; Taflove, Allen

2011-01-01

Most cancers are curable if they are diagnosed and treated at an early stage. Recent studies suggest that nanoarchitectural changes occur within cells during early carcinogenesis and that such changes precede microscopically evident tissue alterations. It follows that the ability to comprehensively interrogate cell nanoarchitecture (e.g., macromolecular complexes, DNA, RNA, proteins and lipid membranes) could be critical to the diagnosis of early carcinogenesis. We present a study of the nanoscale mass-density fluctuations of biological tissues by quantifying their degree of disorder at the nanoscale. Transmission electron microscopy images of human tissues are used to construct corresponding effective disordered optical lattices. The properties of nanoscale disorder are then studied by statistical analysis of the inverse participation ratio (IPR) of the spatially localized eigenfunctions of these optical lattices at the nanoscale. Our results show an increase in the disorder of human colonic epithelial cells in subjects harboring early stages of colon neoplasia. Furthermore, our findings strongly suggest that increased nanoscale disorder correlates with the degree of tumorigenicity. Therefore, the IPR technique provides a practicable tool for the detection of nanoarchitectural alterations in the earliest stages of carcinogenesis. Potential applications of the technique for early cancer screening and detection are also discussed

Radiation carcinogenesis

International Nuclear Information System (INIS)

1978-01-01

The Cancergram deals with all aspects of radiation carcinogenesis. The term radiation here includes U-V radiation and the entire electromagnetic spectrum, electron and other charged particle beams, neutrons, and alpha and beta radiation from radioactive substances. Abstracts included concern relationships between radiation and carcinogenesis in humans, experimental induction of tumors in animals by irradiation, studies on the mechanism of radiation carcinogenesis at the cellular level, studies of RBE, dose response or dose threshold in relation to radiation carcinogenesis, and methods and policies for control of radiation exposure in the general population. In general, this Cancergram excludes abstracts on radio-therapy, radiologic diagnosis, radiation pathology, and radiation biology, where these articles have no bearing on radiation carcinogenesis

Exercise reduces inflammation and cell proliferation in rat colon carcinogenesis.

Science.gov (United States)

Demarzo, Marcelo Marcos Piva; Martins, Lisandra Vanessa; Fernandes, Cleverson Rodrigues; Herrero, Fábio Augusto; Perez, Sérgio Eduardo de Andrade; Turatti, Aline; Garcia, Sérgio Britto

2008-04-01

There is evidence that the risk of colon cancer is reduced by appropriate levels of physical exercise. Nevertheless, the mechanisms involved in this protective effect of exercise remain largely unknown. Inflammation is emerging as a unifying link between a range of environment exposures and neoplastic risk. The carcinogen dimethyl-hydrazine (DMH) induces an increase in epithelial cell proliferation and in the expression of the inflammation-related enzyme cyclooxigenase-2 (COX-2) in the colon of rats. Our aim was to verify whether these events could be attenuated by exercise. Four groups of eight Wistar rats were used in the experiment. The groups G1 and G3 were sedentary (controls), and the groups G2 and G4 were submitted to 8 wk of swimming training, 5 d.wk. The groups G3 and G4 were given subcutaneous injections of DMH immediately after the exercise protocols. Fifteen days after the neoplasic induction, the rats were sacrificed and the colon was processed for histological examination and immunohistochemistry staining of proliferating cell nuclear antigen (PCNA) and COX-2. We found a significant increase in the PCNA-labeling index in both DMH-treated groups of rats. However, this increase was significantly attenuated in the training group G4 (P < 0.01). Similar results were observed in relation to the COX-2 expression. From our findings, we conclude that exercise training exerts remarkable antiproliferative and antiinflammatory effects in the rat colonic mucosa, suggesting that this may be an important mechanism to explain how exercise protects against colonic cancer.

MicroRNA-215 suppresses cell proliferation, migration and invasion of colon cancer by repressing Yin-Yang 1

International Nuclear Information System (INIS)

Chen, Zehong; Han, Siqi; Huang, Wensheng; Wu, Jialin; Liu, Yuyi; Cai, Shirong; He, Yulong; Wu, Suijing; Song, Wu

2016-01-01

Colorectal cancer is one of the most common malignant tumors worldwide with rising incidence. MicroRNAs are small non-coding RNAs that implicate in multiple physiological or pathological processes. The aberrant expression of miRNA-215 (miR-215) has been illustrated in various types of cancers. However, the expression of miR-215 in human colon cancer and the biological roles of it remain largely unknown. We conducted this study to explore the expression and the function of miR-215 in human colon cancer. The results showed that miR-215 was remarkably downregulated in colon cancer tissues and cell lines. Overexpression of miR-215 by miR-215 mimic significantly inhibited colon cancer cell proliferation, migration and invasion while knockdown of miR-215 by miR-215 inhibitor exerted reverse effects. Furthermore, we newly identified Yin-Yang 1(YY1) as a direct target of miR-215 which could rescue the effects of miR-215 on colon cancer cells. In summary, our investigation revealed that miR-215 was downregulated in colon cancer and it suppressed colon cancer cell proliferation, migration and invasion by directly targeting YY1. - Highlights: • MiR-215 expression was decreased in colon cancer tissues and cell lines. • Mir-215 inhibited colon cancer cell proliferation, migration and invasion. • MiR-215 targeted YY1 directly. • The effects of miR-215 on colon cancer cells were mediated by YY1.

Ulva lactuca polysaccharides prevent Wistar rat breast carcinogenesis through the augmentation of apoptosis, enhancement of antioxidant defense system, and suppression of inflammation

Directory of Open Access Journals (Sweden)

Abd-Ellatef GF

2017-02-01

Full Text Available Gamal-Eldein F Abd-Ellatef,1 Osama M Ahmed,2 Eman S Abdel-Reheim,2 Abdel-Hamid Z Abdel-Hamid,1 1Pharmaceutical and Drug Industries Research Division, Therapeutic Chemistry Department, National Research Centre, Cairo, Egypt; 2Division of Physiology, Department of Zoology, Faculty of Science, Beni-Suef University, Beni-Suef, Egypt Background: Recently, several research studies have been focused on the isolation and function of the polysaccharides derived from different algal species, which revealed multiple biological activities such as antioxidant and antitumor activities. This study assesses the possible breast cancer chemopreventive properties of common seaweeds, sea lettuce, Ulva lactuca (ulvan polysaccharides using in vitro bioassays on human breast cancer cell line (MCF-7 and an in vivo animal model of breast carcinogenesis. Methods: Cytotoxic effect of ulvan polysaccharides on MCF-7 was tested in vitro. For an in vivo investigation, a single dose of 25 mg/kg body weight 7,12-dimethylbenz[a]anthracene (DMBA and ulvan polysaccharides (50 mg/kg body weight every other day for 10 weeks were administered orally to the Wistar rats. Results: Deleterious histopathological alterations in breast tissues including papillary cyst adenoma and hyperplasia of ductal epithelial lining with intraluminal necrotic materials and calcifications were observed in the DMBA-administered group. These lesions were prevented in the DMBA-administered group treated with ulvan polysaccharides. The immunohistochemical sections depicted that the treatment of DMBA-administered rats with ulvan polysaccharides markedly increased the lowered pro-apoptotic protein, p53, and decreased the elevated anti-apoptotic marker, bcl2, expression in the breast tissue. The elevated lipid peroxidation and the suppressed antioxidant enzyme activities in DMBA-administered control were significantly prevented by the treatment with ulvan polysaccharides. The elevated levels of inflammatory

MicroRNA-320a suppresses human colon cancer cell proliferation by directly targeting β-catenin

International Nuclear Information System (INIS)

Sun, Jian-Yong; Huang, Yi; Li, Ji-Peng; Zhang, Xiang; Wang, Lei; Meng, Yan-Ling; Yan, Bo; Bian, Yong-Qian; Zhao, Jing; Wang, Wei-Zhong

2012-01-01

Highlights: ► miR-320a is downregulated in human colorectal carcinoma. ► Overexpression of miR-320a inhibits colon cancer cell proliferation. ► β-Catenin is a direct target of miR-320a in colon cancer cells. ► miR-320a expression inversely correlates with mRNA expression of β-catenin’s target genes in human colon carcinoma. -- Abstract: Recent profile studies of microRNA (miRNA) expression have documented a deregulation of miRNA (miR-320a) in human colorectal carcinoma. However, its expression pattern and underlying mechanisms in the development and progression of colorectal carcinoma has not been elucidated clearly. Here, we performed real-time PCR to examine the expression levels of miR-320a in colon cancer cell lines and tumor tissues. And then, we investigated its biological functions in colon cancer cells by a gain of functional strategy. Further more, by the combinational approaches of bioinformatics and experimental validation, we confirmed target associations of miR-320a in colorectal carcinoma. Our results showed that miR-320a was frequently downregulated in cancer cell lines and colon cancer tissues. And we demonstrated that miR-320a restoration inhibited colon cancer cell proliferation and β-catenin, a functionally oncogenic molecule was a direct target gene of miR-320a. Finally, the data of real-time PCR showed the reciprocal relationship between miR-320a and β-catenin’s downstream genes in colon cancer tissues. These findings indicate that miR-320a suppresses the growth of colon cancer cells by directly targeting β-catenin, suggesting its application in prognosis prediction and cancer treatment.

MicroRNA-320a suppresses human colon cancer cell proliferation by directly targeting {beta}-catenin

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Sun, Jian-Yong [State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology, Fourth Military Medical University, 710032 Xi' an (China); State Key Laboratory of Cancer Biology, Xijing Hospital of Digestive Diseases, Fourth Military Medical University, 710032 Xi' an (China); Huang, Yi [Department of Anesthesiology, Xijing Hospital, Fourth Military Medical University, 710032 Xi' an (China); Li, Ji-Peng [State Key Laboratory of Cancer Biology, Xijing Hospital of Digestive Diseases, Fourth Military Medical University, 710032 Xi' an (China); Zhang, Xiang; Wang, Lei [State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology, Fourth Military Medical University, 710032 Xi' an (China); Meng, Yan-Ling [Department of Immunology, Fourth Military Medical University, 710032 Xi' an (China); Yan, Bo [State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology, Fourth Military Medical University, 710032 Xi' an (China); Bian, Yong-Qian [State Key Laboratory of Cancer Biology, Xijing Hospital of Digestive Diseases, Fourth Military Medical University, 710032 Xi' an (China); Zhao, Jing [State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology, Fourth Military Medical University, 710032 Xi' an (China); Wang, Wei-Zhong, E-mail: weichang@fmmu.edu.cn [State Key Laboratory of Cancer Biology, Xijing Hospital of Digestive Diseases, Fourth Military Medical University, 710032 Xi' an (China); and others

2012-04-20

Highlights: Black-Right-Pointing-Pointer miR-320a is downregulated in human colorectal carcinoma. Black-Right-Pointing-Pointer Overexpression of miR-320a inhibits colon cancer cell proliferation. Black-Right-Pointing-Pointer {beta}-Catenin is a direct target of miR-320a in colon cancer cells. Black-Right-Pointing-Pointer miR-320a expression inversely correlates with mRNA expression of {beta}-catenin's target genes in human colon carcinoma. -- Abstract: Recent profile studies of microRNA (miRNA) expression have documented a deregulation of miRNA (miR-320a) in human colorectal carcinoma. However, its expression pattern and underlying mechanisms in the development and progression of colorectal carcinoma has not been elucidated clearly. Here, we performed real-time PCR to examine the expression levels of miR-320a in colon cancer cell lines and tumor tissues. And then, we investigated its biological functions in colon cancer cells by a gain of functional strategy. Further more, by the combinational approaches of bioinformatics and experimental validation, we confirmed target associations of miR-320a in colorectal carcinoma. Our results showed that miR-320a was frequently downregulated in cancer cell lines and colon cancer tissues. And we demonstrated that miR-320a restoration inhibited colon cancer cell proliferation and {beta}-catenin, a functionally oncogenic molecule was a direct target gene of miR-320a. Finally, the data of real-time PCR showed the reciprocal relationship between miR-320a and {beta}-catenin's downstream genes in colon cancer tissues. These findings indicate that miR-320a suppresses the growth of colon cancer cells by directly targeting {beta}-catenin, suggesting its application in prognosis prediction and cancer treatment.

Transforming growth factor-β suppresses metastasis in a subset of human colon carcinoma cells

International Nuclear Information System (INIS)

Simms, Neka A K; Rajput, Ashwani; Sharratt, Elizabeth A; Ongchin, Melanie; Teggart, Carol A; Wang, Jing; Brattain, Michael G

2012-01-01

TGFβ signaling has typically been associated with suppression of tumor initiation while the role it plays in metastasis is generally associated with progression of malignancy. However, we present evidence here for an anti-metastatic role of TGFβ signaling. To test the importance of TGFβ signaling to cell survival and metastasis we compared human colon carcinoma cell lines that are either non-tumorigenic with TGFβ response (FET), or tumorigenic with TGFβ response (FETα) or tumorigenic with abrogated TGFβ response via introduction of dominant negative TGFβRII (FETα/DN) and their ability to metastasize. Metastatic competency was assessed by orthotopic transplantation. Metastatic colony formation was assessed histologically and by imaging. Abrogation of TGFβ signaling through introduction of a dominant negative TGFβ receptor II (TGFβRII) in non-metastatic FETα human colon cancer cells permits metastasis to distal organs, but importantly does not reduce invasive behavior at the primary site. Loss of TGFβ signaling in FETα-DN cells generated enhanced cell survival capabilities in response to cellular stress in vitro. We show that enhanced cellular survival is associated with increased AKT phosphorylation and cytoplasmic expression of inhibitor of apoptosis (IAP) family members (survivin and XIAP) that elicit a cytoprotective effect through inhibition of caspases in response to stress. To confirm that TGFβ signaling is a metastasis suppressor, we rescued TGFβ signaling in CBS metastatic colon cancer cells that had lost TGFβ receptor expression due to epigenetic repression. Restoration of TGFβ signaling resulted in the inhibition of metastatic colony formation in distal organs by these cells. These results indicate that TGFβ signaling has an important role in the suppression of metastatic potential in tumors that have already progressed to the stage of an invasive carcinoma. The observations presented here indicate a metastasis suppressor role for TGF�

Dietary factors and the occurence of truncating APC mutations in sporadic colon carcinomas: a Dutch population-based study

NARCIS (Netherlands)

Diergaarde, B.; Geloof, van W.L.; Muijen, van G.N.P.; Kok, F.J.; Kampman, E.

2003-01-01

The interactions between environmental factors and the genetic and epigenetic changes that drive colon carcinogenesis are not clear. Dietary factors reported previously to be associated with colon cancer risk may well influence the occurrence of specific somatic alterations in colon tumors. To

Dietary factors and the occurrence of truncating APC mutations in sporadic colon carcinomas: a Dutch population-based study.

NARCIS (Netherlands)

Diergaarde, B.; Geloof, W. van; Muijen, G.N.P. van; Kok, F.J.; Kampman, E.

2003-01-01

The interactions between environmental factors and the genetic and epigenetic changes that drive colon carcinogenesis are not clear. Dietary factors reported previously to be associated with colon cancer risk may well influence the occurrence of specific somatic alterations in colon tumors. To

Lactulose mediates suppression of dextran sodium sulfate-induced colon inflammation by increasing hydrogen production.

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Chen, Xiao; Zhai, Xiao; Shi, Jiazi; Liu, Wen Wu; Tao, Hengyi; Sun, Xuejun; Kang, Zhimin

2013-06-01

Molecular hydrogen (H2) is a potent antioxidant and able to protect organs from oxidative stress injuries. Orally administered lactulose, a potent H2 inducer, is digested by colon microflora and significantly increases H2 production, indicating its potential anti-inflammatory action. To evaluate the anti-inflammatory effects of lactulose on dextran sodium sulfate (DSS)-induced colitis in mice. Mice were randomly assigned into seven groups, receiving regular distilled water, H2-rich saline (peritoneal injection), DSS, oral lactulose (0.1, 0.15, 0.2 ml/10 g, respectively), and lactulose (0.2 ml/10 g) + oral antibiotics. The mouse model of human ulcerative colitis was established by supplying mice with water containing DSS. The H2 breath test was used to determine the exhaled H2 concentration. Body weight, colitis score, colon length, pathological features and tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), maleic dialdehyde (MDA) and marrow peroxidase (MPO) levels in colon lesions were evaluated. After 7 days, DSS-induced loss of body weight, increase of colitis score, shortening of colon length, pathological changes and elevated levels of TNF-α, IL-1β, MDA, and MPO in colon lesions, were significantly suppressed by oral lactulose administration and intraperitoneally injected H2-rich saline. Ingestion of antibiotics significantly compromised the anti-inflammatory effects of lactulose. The H2 breath test showed that lactulose administration significantly induced hydrogen production and that antibiotics administration could inhibit H2 production. Lactulose can prevent the development of DSS-induced colitis and alleviate oxidative stress in the colon, as measured by MDA and MPO, probably by increasing endogenous H2 production.

Prostaglandin E2 Activates YAP and a Positive-Signaling Loop to Promote Colon Regeneration After Colitis but Also Carcinogenesis in Mice.

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Kim, Han-Byul; Kim, Minchul; Park, Young-Soo; Park, Intae; Kim, Tackhoon; Yang, Sung-Yeun; Cho, Charles J; Hwang, DaeHee; Jung, Jin-Hak; Markowitz, Sanford D; Hwang, Sung Wook; Yang, Suk-Kyun; Lim, Dae-Sik; Myung, Seung-Jae

2017-02-01

Prostaglandin E 2 (PGE 2 ) is mediator of inflammation that regulates tissue regeneration, but its continual activation has been associated with carcinogenesis. Little is known about factors in the PGE 2 signaling pathway that contribute to tumor formation. We investigated whether yes-associated protein 1 (YAP1), a transcriptional co-activator in the Hippo signaling pathway, mediates PGE 2 function. DLD-1 and SW480 colon cancer cell lines were transfected with vectors expressing transgenes or small hairpin RNAs and incubated with recombinant PGE 2 , with or without pharmacologic inhibitors of signaling proteins, and analyzed by immunoblot, immunofluorescence, quantitative reverse-transcription polymerase chain reaction, transcriptional reporter, and proliferation assays. Dextran sodium sulfate (DSS) was given to induce colitis in C57/BL6 (control) mice, as well as in mice with disruption of the hydroxyprostaglandin dehydrogenase 15 gene (15-PGDH-knockout mice), Yap1 gene (YAP-knockout mice), and double-knockout mice. Some mice also were given indomethacin to block PGE 2 synthesis. 15-PGDH knockout mice were crossed with mice with intestine-specific disruption of the salvador family WW domain containing 1 gene (Sav1), which encodes an activator of Hippo signaling. We performed immunohistochemical analyses of colon biopsy samples from 26 patients with colitis-associated cancer and 51 age-and sex-matched patients with colorectal cancer (without colitis). Incubation of colon cancer cell lines with PGE 2 led to phosphorylation of cyclic adenosine monophosphate-responsive element binding protein 1 and increased levels of YAP1 messenger RNA, protein, and YAP1 transcriptional activity. This led to increased transcription of the prostaglandin-endoperoxide synthase 2 gene (PTGS2 or cyclooxygenase 2) and prostaglandin E-receptor 4 gene (PTGER4 or EP4). Incubation with PGE 2 promoted proliferation of colon cancer cell lines, but not cells with knockdown of YAP1. Control mice

Up-regulation of CNDP2 facilitates the proliferation of colon cancer

OpenAIRE

Xue, Conglong; Zhang, Zhenwei; Yu, Honglan; Yu, Miao; Yuan, Kaitao; Yang, Ting; Miao, Mingyong; Shi, Hanping

2014-01-01

Background Cytosolic nonspecific dipetidase (CN2) belongs to the family of M20 metallopeptidases. It was stated in previous articles that higher expression levels of CN2 were observed in renal cell carcinoma and breast cancer. Our study explored the correlation between CN2 and colon carcinogenesis. Methods We analysed the relationship between 183 patients clinicopathological characteristics and its CN2 expression. To detect the levels of CN2 in colon cancer cell lines and colon cancer tissues...

Deficiency of the Erc/mesothelin gene ameliorates renal carcinogenesis in Tsc2 knockout mice.

Science.gov (United States)

Zhang, Danqing; Kobayashi, Toshiyuki; Kojima, Tetsuo; Kanenishi, Kenji; Hagiwara, Yoshiaki; Abe, Masaaki; Okura, Hidehiro; Hamano, Yoshitomo; Sun, Guodong; Maeda, Masahiro; Jishage, Kou-ichi; Noda, Tetsuo; Hino, Okio

2011-04-01

Genetic crossing experiments were performed between tuberous sclerosis-2 (Tsc2) KO and expressed in renal carcinoma (Erc) KO mice to analyze the function of the Erc/mesothelin gene in renal carcinogenesis. We found the number and size of renal tumors were significantly less in Tsc2+/-;Erc-/- mice than in Tsc2+/-;Erc+/+ and Tsc2+/-;Erc+/- mice. Tumors from Tsc2+/-;Erc-/- mice exhibited reduced cell proliferation and increased apoptosis, as determined by proliferating cell nuclear antigen (Ki67) and TUNEL analysis, respectively. Adhesion to collagen-coated plates in vitro was enhanced in Erc-restored cells and decreased in Erc-suppressed cells with siRNA. Tumor formation by Tsc2-deficient cells in nude mice was remarkably suppressed by stable knockdown of Erc with shRNA. Western blot analysis showed that the phosphorylation of focal adhesion kinase, Akt and signal transducer and activator of transcription protein 3 were weaker in Erc-deficient/suppressed cells compared with Erc-expressed cells. These results indicate that deficiency of the Erc/mesothelin gene ameliorates renal carcinogenesis in Tsc2 KO mice and inhibits the phosphorylation of several kinases of cell adhesion mechanism. This suggests that Erc/mesothelin may have an important role in the promotion and/or maintenance of carcinogenesis by influencing cell-substrate adhesion via the integrin-related signal pathway. © 2011 Japanese Cancer Association.

Andrographolide suppresses proliferation of human colon cancer SW620 cells through the TLR4/NF-κB/MMP-9 signaling pathway.

Science.gov (United States)

Zhang, Rui; Zhao, Jian; Xu, Jian; Jiao, De-Xin; Wang, Jian; Gong, Zhi-Qiang; Jia, Jian-Hui

2017-10-01

Modern pharmacological research has revealed that andrographolide has various functions, including anti-bacterial, anti-inflammatory and anti-viral effects, immunoregulation, treating cardiovascular and cerebrovascular diseases, and prevention and treatment of alcoholic liver injury. The present study investigated whether andrographolide suppresses the proliferation of human colon cancer cell through the Toll-like receptor 4 (TLR4)/nuclear factor (NF)-κB/matrix metalloproteinase-9 (MMP-9) signaling pathway. The MTT assay and lactate dehydrogenase assay were used to evaluate the anticancer effects of andrographolide on cell proliferation and cytotoxicity in human colon cancer SW620 cells. Flow cytometry was used to analyze the anticancer effects of andrographolide on apoptosis by Annexin V-fluorescein isothiocyanate/propidium iodide kit. The effects of andrographolide on the activity of caspase-3/9 were measured using ELISA. Western blot analysis was also used to analyze the protein expression of TLR4, myeloid differentiation primary response gene 88 (MyD88), NF-κB-p65 and MMP-9. In the present study, it was found that andrographolide suppressed the cell proliferation, augmented cytotoxicity, evoked cell apoptosis and activated caspase-3/9 activities in human colon cancer SW620 cells. The results revealed that the anti-proliferation effects of andrographolide on the SW620 cells was associated with the inhibition of TLR4, MyD88, NF-κB-p65 and MMP-9 signaling activation. The results suggest that andrographolide is a promising drug for treatment of human colon cancer via suppression of the TLR4/NF-κB/MMP-9 signaling pathway.

Effects of dietary beef, pork, chicken and salmon on intestinal carcinogenesis in A/J Min/+ mice.

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Christina Steppeler

Full Text Available The International Agency for Research on Cancer has classified red meat as "probably carcinogenic to humans" (Group 2A. In mechanistic studies exploring the link between intake of red meat and CRC, heme iron, the pigment of red meat, is proposed to play a central role as a catalyzer of luminal lipid peroxidation and cytotoxicity. In the present work, the novel A/J Min/+ mouse was used to investigate the effects of dietary beef, pork, chicken, or salmon (40% muscle food (dry weight and 60% powder diet on Apc-driven intestinal carcinogenesis, from week 3-13 of age. Muscle food diets did not differentially affect carcinogenesis in the colon (flat ACF and tumors. In the small intestine, salmon intake resulted in a lower tumor size and load than did meat from terrestrial animals (beef, pork or chicken, while no differences were observed between the effects of white meat (chicken and red meat (pork and beef. Additional results indicated that intestinal carcinogenesis was not related to dietary n-6 polyunsaturated fatty acids, intestinal formation of lipid peroxidation products (thiobarbituric acid reactive substances, TBARS, or cytotoxic effects of fecal water on Apc-/+ cells. Notably, the amount of heme reaching the colon appeared to be relatively low in this study. The greatest tumor load was induced by the reference diet RM1, underlining the importance of the basic diets in experimental CRC. The present study in A/J Min/+ mice does not support the hypothesis of a role of red meat in intestinal carcinogenesis.

Silencing of the hTERT gene by shRNA inhibits colon cancer SW480 cell growth in vitro and in vivo.

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Ai-Qun Liu

Full Text Available Human telomerase reverse transcriptase (hTERT is the key enzyme responsible for synthesizing and maintaining the telomeres on the ends of chromosomes, and it is essential for cell proliferation. This has made hTERT a focus of oncology research and an attractive target for anticancer drug development. In this study, we designed a small interfering RNA (siRNA targeting the catalytic subunit of hTERT and tested its effects on the growth of telomerase-positive human colon carcinoma SW480 cells in vitro, as well as on the tumorigenicity of these cells in nude mice. Transient and stable transfection of hTERT siRNA into colon cancer SW480 cells suppressed hTERT expression, reduced telomerase activity and inhibited cell growth and proliferation. Knocking down hTERT expression in SW480 tumors xenografted into nude mice significantly slowed tumor growth and promoted tumor cell apoptosis. Our results suggest that hTERT is involved in carcinogenesis of human colon carcinoma, and they highlight the therapeutic potential of a hTERT knock-down approach.

Heme-Induced Biomarkers Associated with Red Meat Promotion of colon Cancer Are Not Modulated by the Intake of Nitrite

Science.gov (United States)

Chenni, Fatima Z; Taché, Sylviane; Naud, Nathalie; Guéraud, Françoise; Hobbs, Ditte A; Kunhle, Gunter G C; Pierre, Fabrice H; Corpet, Denis E

2013-01-01

Red and processed meat consumption is associated with the risk of colorectal cancer. Three hypotheses are proposed to explain this association, via heme/alcenal, heterocyclic amines or N-nitroso compounds. Rats have often been used to study these hypotheses, but the lack of enterosalivary cycle of nitrate in rats casts doubt on the relevance of this animal model to predict nitroso- and heme-associated human colon carcinogenesis. The present study was thus designed to clarify whether a nitrite intake that mimics the enterosalivary cycle can modulate heme-induced nitrosation and fat peroxidation. This study shows that, in contrast with the starting hypothesis, salivary nitrite did not change the effect of hemoglobin on biochemical markers linked to colon carcinogenesis, notably lipid peroxidation and cytotoxic activity in the colon of rat. However, ingested sodium nitrite increased fecal nitroso-compounds level, but their fecal concentration and their nature (iron-nitrosyl) would not be associated with an increased risk of cancer. The rat model could thus be relevant to study the effect of red meat on colon carcinogenesis in spite of the lack of nitrite recycling in rat’s saliva. PMID:23441609

Decreased expression of cytochrome P450 protein in non-malignant colonic tissue of patients with colonic adenoma

DEFF Research Database (Denmark)

Bergheim, I.; Bode, C.; Parlesak, Alexandr

2005-01-01

BACKGROUND: Cytochrome P450 (CYP) enzymes in epithelial cells lining the alimentary tract play an important role in both the elimination and activation of (pro-)carcinogens. To estimate the role of cytochrome P450 in carcinogenesis of the colon, expression patterns and protein levels of four...... representative CYPs (CYP2C, CYP2E1, CYP3A4 and CYP3A5) were determined in colon mucosa of normal and adenomatous colonic tissue of patients with adenomas and disease-free controls. METHODS: Expression of CYP2C, CYP2E1, CYP3A4, and CYP3A5 in colon mucosa of normal and adenomatous colonic tissue of patients...... with adenoma and disease-free controls was determined by RT-PCR. Protein concentration of CYPs was determined using Western blot. RESULTS: With the exception of CYP3A5, expression of CYP mRNA was similar among groups and tissues (e.g. normal colon mucosa and adenoma). CYP3A5 mRNA expression was significantly...

Trypanosomiasis-induced megacolon illustrates how myenteric neurons modulate the risk for colon cancer in rats and humans.

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Vinicius Kannen

2015-04-01

Full Text Available Trypanosomiasis induces a remarkable myenteric neuronal degeneration leading to megacolon. Very little is known about the risk for colon cancer in chagasic megacolon patients. To clarify whether chagasic megacolon impacts on colon carcinogenesis, we investigated the risk for colon cancer in Trypanosoma cruzi (T. cruzi infected patients and rats.Colon samples from T. cruzi-infected and uninfected patients and rats were histopathologically investigated with colon cancer biomarkers. An experimental model for chemical myenteric denervation was also performed to verify the myenteric neuronal effects on colon carcinogenesis. All experiments complied the guidelines and approval of ethical institutional review boards.No colon tumors were found in chagasic megacolon samples. A significant myenteric neuronal denervation was observed. Epithelial cell proliferation and hyperplasia were found increased in chagasic megacolon. Analyzing the argyrophilic nucleolar organiser regions within the cryptal bottom revealed reduced risk for colon cancer in Chagas' megacolon patients. T. cruzi-infected rats showed a significant myenteric neuronal denervation and decreased numbers of colon preneoplastic lesions. In chemical myenteric denervated rats preneoplastic lesions were reduced from the 2nd wk onward, which ensued having the colon myenteric denervation significantly induced.Our data suggest that the trypanosomiasis-related myenteric neuronal degeneration protects the colon tissue from carcinogenic events. Current findings highlight potential mechanisms in tropical diseases and cancer research.

Free radical scavenging and COX-2 inhibition by simple colon metabolites of polyphenols: A theoretical approach.

Science.gov (United States)

Amić, Ana; Marković, Zoran; Marković, Jasmina M Dimitrić; Jeremić, Svetlana; Lučić, Bono; Amić, Dragan

2016-12-01

Free radical scavenging and inhibitory potency against cyclooxygenase-2 (COX-2) by two abundant colon metabolites of polyphenols, i.e., 3-hydroxyphenylacetic acid (3-HPAA) and 4-hydroxyphenylpropionic acid (4-HPPA) were theoretically studied. Different free radical scavenging mechanisms are investigated in water and pentyl ethanoate as a solvent. By considering electronic properties of scavenged free radicals, hydrogen atom transfer (HAT) and sequential proton loss electron transfer (SPLET) mechanisms are found to be thermodynamically probable and competitive processes in both media. The Gibbs free energy change for reaction of inactivation of free radicals indicates 3-HPAA and 4-HPPA as potent scavengers. Their reactivity toward free radicals was predicted to decrease as follows: hydroxyl>alkoxyls>phenoxyl≈peroxyls>superoxide. Shown free radical scavenging potency of 3-HPAA and 4-HPPA along with their high μM concentration produced by microbial colon degradation of polyphenols could enable at least in situ inactivation of free radicals. Docking analysis with structural forms of 3-HPAA and 4-HPPA indicates dianionic ligands as potent inhibitors of COX-2, an inducible enzyme involved in colon carcinogenesis. Obtained results suggest that suppressing levels of free radicals and COX-2 could be achieved by 3-HPAA and 4-HPPA indicating that these compounds may contribute to reduced risk of colon cancer development. Copyright © 2016 Elsevier Ltd. All rights reserved.

De novo expression of human polypeptide N-acetylgalactosaminyltransferase 6 (GalNAc-T6) in colon adenocarcinoma inhibits the differentiation of colonic epithelium

DEFF Research Database (Denmark)

Lavrsen, Kirstine; Dabelsteen, Sally; Vakhrushev, Sergey Y

2018-01-01

Aberrant expression of O-glycans is a hallmark of epithelial cancers. Mucin type O-glycosylation is initiated by a large family of UDP-GalNAc:polypeptide N-acetyl-galactosaminyltransferases (GalNAc-Ts), that target different proteins and are differentially expressed in cells and organs. Here we...... investigated the expression patterns of all of the GalNAc-Ts in colon cancer by analysing transcriptomic data. We found that GalNAc-T6 was highly upregulated in colon adenocarcinomas but absent in normal-appearing adjacent colon tissue. The results were verified by immunohistochemistry, suggesting that Gal......NAc-T6 plays a role in colon carcinogenesis. To investigate the function of GalNAc-T6 in colon cancer, we used precise gene targeting to produce isogenic colon cancer cell lines with a knockout/-rescue system for GalNAc-T6. GalNAc-T6 expression was associated with a cancer-like, dysplastic growth pattern...

Onbaekwon Suppresses Colon Cancer Cell Invasion by Inhibiting Expression of the CXC Chemokine Receptor 4.

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Kim, Buyun; Yoon, Jaewoo; Yoon, Seong Woo; Park, Byoungduck

2017-06-01

Cysteine X cysteine (CXC) chemokine receptor 4 (CXCR4) and C-X-C motif chemokine 12 (CXCL12) were originally identified as chemoattractants between immune cells and sites of inflammation. Since studies have validated an increased level of CXCL12 and its receptor in patients with colorectal cancers, CXCL12/CXCR4 axis has been considered as a valuable marker of cancer metastasis. Therefore, identification of CXCR4 inhibitors has great potential to abrogate tumor metastasis. Onbaekwon (OBW) is a complex herbal formula that is derived from the literature of traditional Korean medicine Dongeuibogam. In this study, we demonstrated that OBW suppressed CXCR4 expression in various cancer cell types in a concentration- and time-dependent manner. Both proteasomal and lysosomal inhibitors had no effect to prevent the OBW-induced suppression of CXCR4, suggesting that the inhibitory effect of OBW was not due to proteolytic degradation but occurred at the transcriptional level. Electrophoretic mobility shift assay further confirmed that OBW could block endogenous activation of nuclear factor kappa B, a key transcription factor that regulates the expression of CXCR4 in colon cancer cells. Consistent with the aforementioned molecular basis, OBW abolished cell invasion induced by CXCL12 in colon cancer cells. Together, our results suggest that OBW, as a novel inhibitor of CXCR4, could be a promising therapeutic agent contributing to cancer treatment.

Detouring the Undesired Route of Helicobacter pylori-Induced Gastric Carcinogenesis

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Ki Baik Hahm

2011-07-01

Full Text Available Epidemiological and experimental evidence has emerged that a dysregulated inflammation is associated with most of the tumors, and many studies have begun to unravel the molecular pathways linking inflammation and cancer. As a typical example linking these associations, Helicobacter pylori (H. pylori infection-associated atrophic gastritis has been recognized as precursor lesion of gastric cancer. The identification of transcription factors such as NF-κB and STAT3, and their gene products such as IL-8, COX-2, iNOS, cytokines, chemokines and their receptors, etc have laid the molecular foundation for our understanding of the decisive role of inflammation in carcinogenesis. In addition to the role as the initiator of cancer, inflammation contributes to survival and proliferation of malignant cells, tumor angiogenesis, and even metastasis. In this review, the fundamental mechanisms of H. pylori-induced carcinogenesis as well as the possibility of cancer prevention through suppressing H. pylori-induced inflammation are introduced. We infer that targeting inflammatory pathways have a potential role to detour the unpleasant journey to H. pylori-associated gastric carcinogenesis.

Detouring the Undesired Route of Helicobacter pylori-Induced Gastric Carcinogenesis

Energy Technology Data Exchange (ETDEWEB)

Kim, Eun-Hee; Hong, Kyung-Sook; Hong, Hua [Lab of Translational Medicine, Lee Gil Ya Cancer and Diabetes Institute, Gachon University of Medicine and Science, 7-45 Songdo-dong, Yeonsu-gu, Incheon 406-840 (Korea, Republic of); Hahm, Ki Baik, E-mail: hahmkb@gachon.ac.kr [Lab of Translational Medicine, Lee Gil Ya Cancer and Diabetes Institute, Gachon University of Medicine and Science, 7-45 Songdo-dong, Yeonsu-gu, Incheon 406-840 (Korea, Republic of); Department of Gastroenterology, Gachon Graduate School of Medicine, Gil Hospital, Incheon 406-840 (Korea, Republic of)

2011-07-25

Epidemiological and experimental evidence has emerged that a dysregulated inflammation is associated with most of the tumors, and many studies have begun to unravel the molecular pathways linking inflammation and cancer. As a typical example linking these associations, Helicobacter pylori (H. pylori) infection-associated atrophic gastritis has been recognized as precursor lesion of gastric cancer. The identification of transcription factors such as NF-κB and STAT3, and their gene products such as IL-8, COX-2, iNOS, cytokines, chemokines and their receptors, etc have laid the molecular foundation for our understanding of the decisive role of inflammation in carcinogenesis. In addition to the role as the initiator of cancer, inflammation contributes to survival and proliferation of malignant cells, tumor angiogenesis, and even metastasis. In this review, the fundamental mechanisms of H. pylori-induced carcinogenesis as well as the possibility of cancer prevention through suppressing H. pylori-induced inflammation are introduced. We infer that targeting inflammatory pathways have a potential role to detour the unpleasant journey to H. pylori-associated gastric carcinogenesis.

Detouring the Undesired Route of Helicobacter pylori-Induced Gastric Carcinogenesis

International Nuclear Information System (INIS)

Kim, Eun-Hee; Hong, Kyung-Sook; Hong, Hua; Hahm, Ki Baik

2011-01-01

Epidemiological and experimental evidence has emerged that a dysregulated inflammation is associated with most of the tumors, and many studies have begun to unravel the molecular pathways linking inflammation and cancer. As a typical example linking these associations, Helicobacter pylori (H. pylori) infection-associated atrophic gastritis has been recognized as precursor lesion of gastric cancer. The identification of transcription factors such as NF-κB and STAT3, and their gene products such as IL-8, COX-2, iNOS, cytokines, chemokines and their receptors, etc have laid the molecular foundation for our understanding of the decisive role of inflammation in carcinogenesis. In addition to the role as the initiator of cancer, inflammation contributes to survival and proliferation of malignant cells, tumor angiogenesis, and even metastasis. In this review, the fundamental mechanisms of H. pylori-induced carcinogenesis as well as the possibility of cancer prevention through suppressing H. pylori-induced inflammation are introduced. We infer that targeting inflammatory pathways have a potential role to detour the unpleasant journey to H. pylori-associated gastric carcinogenesis

Activins and their related proteins in colon carcinogenesis: insights from early and advanced azoxymethane rat models of colon cancer.

Science.gov (United States)

Refaat, Bassem; El-Shemi, Adel Galal; Mohamed, Amr Mohamed; Kensara, Osama Adnan; Ahmad, Jawwad; Idris, Shakir

2016-11-11

Activin-A may exert pro- or anti-tumorigenic activities depending on cellular context. However, little is known about its role, or the other mature activin proteins, in colorectal carcinoma (CRC). This study measured the expression of activin βA- & βB-subunits, activin type IIA & IIB receptors, smads 2/3/4/6/7 and follistatin in CRC induced by azoxymethane (AOM) in rats. The results were compared with controls and disseminated according to the characteristics of histopathological lesions. Eighty male Wistar rats were allocated into 20 controls and the remaining were equally divided between short 'S-AOM' (15 weeks) and long 'L-AOM' (35 weeks) groups following injecting AOM for 2 weeks. Subsequent to gross and histopathological examinations and digital image analysis, the expression of all molecules was measured by immunohistochemistry and quantitative RT-PCR. Activin-A, activin-B, activin-AB and follistatin were measured by ELISA in serum and colon tissue homogenates. Colonic pre-neoplastic and cancerous lesions were identified in both AOM groups and their numbers and sizes were significantly (P colonic epithelial cells. There was a significantly (P cancerous tissues. Oppositely, a significant (P colonic lesions. Normal rat colon epithelial cells are capable of synthesising, controlling as well as responding to activins in a paracrine/autocrine manner. Colonic activin systems are pathologically altered during tumorigenesis and appear to be time and lesion-dependent. Activins could also be potential sensitive markers and/or molecular targets for the diagnosis and/or treatment of CRC. Further studies are required to illustrate the clinical value of activins and their related proteins in colon cancer.

Cadmium carcinogenesis

International Nuclear Information System (INIS)

Waalkes, Michael P.

2003-01-01

Cadmium is a heavy metal of considerable environmental and occupational concern. Cadmium compounds are classified as human carcinogens by several regulatory agencies. The most convincing data that cadmium is carcinogenic in humans comes from studies indicating occupational cadmium exposure is associated with lung cancer. Cadmium exposure has also been linked to human prostate and renal cancer, although this linkage is weaker than for lung cancer. Other target sites of cadmium carcinogenesis in humans, such as liver, pancreas and stomach, are considered equivocal. In animals, cadmium effectively induces cancers at multiple sites and by various routes. Cadmium inhalation in rats induces pulmonary adenocarcinomas, in accord with its role in human lung cancer. Cadmium can induce tumors and/or preneoplastic lesions within the rat prostate after ingestion or injection. At relatively high doses, cadmium induces benign testicular tumors in rats, but these appear to be due to early toxic lesions and loss of testicular function, rather than from a specific carcinogenic effect of cadmium. Like many other metals, cadmium salts will induce mesenchymal tumors at the site of subcutaneous (s.c.) or intramuscular (i.m.) injections, but the human relevance of these is dubious. Other targets of cadmium in rodents include the liver, adrenal, pancreas, pituitary, and hematopoietic system. With the exception of testicular tumors in rodents, the mechanisms of cadmium carcinogenesis are poorly defined. Cadmium can cause any number of molecular lesions that would be relevant to oncogenesis in various cellular model systems. Most studies indicate cadmium is poorly mutagenic and probably acts through indirect or epigenetic mechanisms, potentially including aberrant activation of oncogenes and suppression of apoptosis

Cadmium carcinogenesis

Energy Technology Data Exchange (ETDEWEB)

Waalkes, Michael P

2003-12-10

Cadmium is a heavy metal of considerable environmental and occupational concern. Cadmium compounds are classified as human carcinogens by several regulatory agencies. The most convincing data that cadmium is carcinogenic in humans comes from studies indicating occupational cadmium exposure is associated with lung cancer. Cadmium exposure has also been linked to human prostate and renal cancer, although this linkage is weaker than for lung cancer. Other target sites of cadmium carcinogenesis in humans, such as liver, pancreas and stomach, are considered equivocal. In animals, cadmium effectively induces cancers at multiple sites and by various routes. Cadmium inhalation in rats induces pulmonary adenocarcinomas, in accord with its role in human lung cancer. Cadmium can induce tumors and/or preneoplastic lesions within the rat prostate after ingestion or injection. At relatively high doses, cadmium induces benign testicular tumors in rats, but these appear to be due to early toxic lesions and loss of testicular function, rather than from a specific carcinogenic effect of cadmium. Like many other metals, cadmium salts will induce mesenchymal tumors at the site of subcutaneous (s.c.) or intramuscular (i.m.) injections, but the human relevance of these is dubious. Other targets of cadmium in rodents include the liver, adrenal, pancreas, pituitary, and hematopoietic system. With the exception of testicular tumors in rodents, the mechanisms of cadmium carcinogenesis are poorly defined. Cadmium can cause any number of molecular lesions that would be relevant to oncogenesis in various cellular model systems. Most studies indicate cadmium is poorly mutagenic and probably acts through indirect or epigenetic mechanisms, potentially including aberrant activation of oncogenes and suppression of apoptosis.

Identifying molecular targets of lifestyle modifications in colon cancer prevention

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Molly Marie Derry

2013-05-01

Full Text Available One in four deaths in the United States is cancer-related, and colorectal cancer (CRC is the second leading cause of cancer-associated deaths. Screening strategies are utilized but have not reduced disease incidence or mortality. In this regard, there is an interest in cancer preventive strategies focusing on lifestyle intervention, where specific etiologic factors involved in cancer initiation, promotion, and progression could be targeted. For example, exposure to dietary carcinogens, such as nitrosamines and polycyclic aromatic hydrocarbons influences colon carcinogenesis. Furthermore, dietary deficiencies could alter sensitivity to genetic damage and influence carcinogen metabolism contributing to CRC. High alcohol consumption increases the risk of mutations including the fact that acetaldehyde, an ethanol metabolite, is classified as a group 1 carcinogen. Tobacco smoke exposure is also a risk factor for cancer development; ~20% of CRCs are associated with smoking. Additionally, obese patients have a higher risk of cancer development, which is further supported by the fact that physical activity decreases CRC risk by 55%. Similarly, chronic inflammatory conditions also increase the risk of CRC development. Moreover, the circadian clock alters digestion and regulates other biochemical, physiological and behavioral processes that could positively influence CRC. Taken together, colon carcinogenesis involves a number of etiological factors, and therefore, to create effective preventive strategies, molecular targets need to be identified and beleaguered prior to disease progression. With this in mind, the following is a comprehensive review identifying downstream target proteins of the above lifestyle risk factors, which are modulated during colon carcinogenesis and could be targeted for CRC prevention by novel agents including phytochemicals.

Mechanisms of the intestinal effects of dietary fats and milk products on colon carcinogenesis

NARCIS (Netherlands)

VanderMeer, R; Lapre, JA; Govers, MJAP; Kleibeuker, JH

1997-01-01

Dietary fat may promote colon cancer by increasing fatty acids (FA) and secondary bile acids (BA) in the colonic lumen. These cytotoxic surfactants can damage colonic epithelial cells and thus induce a compensatory hyperproliferation of crypt Cells. Our studies show that the hyperproliferative

Colon cancer modulation by a diabetic environment: A single institutional experience

OpenAIRE

Prieto, Isabel; del Puerto-Nevado, Laura; Gonzalez, Nieves; Portal-Nu?ez, Sergio; Zazo, Sandra; Corton, Marta; Minguez, Pablo; Gomez-Guerrero, Carmen; Arce, Jose Miguel; Sanz, Ana Belen; Mas, Sebastian; Aguilera, Oscar; Alvarez-Llamas, Gloria; Esbrit, Pedro; Ortiz, Alberto

2017-01-01

Background Multiple observational studies suggest an increased risk of colon cancer in patients with diabetes mellitus (DM). This can theoretically be the result of an influence of the diabetic environment on carcinogenesis or the tumor biologic behavior. Aim To gain insight into the influence of a diabetic environment on colon cancer characteristics and outcomes. Material and methods Retrospective analysis of clinical records in an academic tertiary care hospital with detailed analysis of 81...

MiR-30a-5p suppresses tumor growth in colon carcinoma by targeting DTL

DEFF Research Database (Denmark)

Baraniskin, Alexander; Birkenkamp-Demtröder, Karin; Maghnouj, Abdelouahid

2012-01-01

MicroRNAs (miRNAs) are small non-coding RNAs that are involved in different biological processes by suppressing target gene expression. Altered expression of miR-30a-5p has been reported in colon carcinoma. To elucidate its potential biological role in colon cancer, miR-30a-5p was overexpressed via...... with in silico miRNA target prediction, we identified the denticleless protein homolog (DTL) as a potential miRNA-30a-5p target. Subsequent reporter gene assays confirmed the predicted miR-30a-5p binding site in the 3'untranslated region of DTL. Importantly, overexpression of DTL in HCT116 cells partially...... is frequently overexpressed in colorectal cancer. Thus, our data suggest that restoring miR-30a-5p function may prove useful as therapeutic strategy for tumors with reduced miR-30a-5p expression....

Thrombospondin-1 in a Murine Model of Colorectal Carcinogenesis.

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Zenaida P Lopez-Dee

Full Text Available Colorectal Cancer (CRC is one of the late complications observed in patients suffering from inflammatory bowel diseases (IBD. Carcinogenesis is promoted by persistent chronic inflammation occurring in IBD. Understanding the mechanisms involved is essential in order to ameliorate inflammation and prevent CRC. Thrombospondin 1 (TSP-1 is a multidomain glycoprotein with important roles in angiogenesis. The effects of TSP-1 in colonic tumor formation and growth were analyzed in a model of inflammation-induced carcinogenesis. WT and TSP-1 deficient mice (TSP-1-/- of the C57BL/6 strain received a single injection of azoxymethane (AOM and multiple cycles of dextran sodium sulfate (DSS to induce chronic inflammation-related cancers. Proliferation and angiogenesis were histologically analyzed in tumors. The intestinal transcriptome was also analyzed using a gene microarray approach. When the area containing tumors was compared with the entire colonic area of each mouse, the tumor burden was decreased in AOM/DSS-treated TSP-1-/- versus wild type (WT mice. However, these lesions displayed more angiogenesis and proliferation rates when compared with the WT tumors. AOM-DSS treatment of TSP-1-/- mice resulted in significant deregulation of genes involved in transcription, canonical Wnt signaling, transport, defense response, regulation of epithelial cell proliferation and metabolism. Microarray analyses of these tumors showed down-regulation of 18 microRNAs in TSP-1-/- tumors. These results contribute new insights on the controversial role of TSP-1 in cancer and offer a better understanding of the genetics and pathogenesis of CRC.

Inhibitory effects of Baccharis dracunculifolia on 1,2-dimethylhidrazine-induced genotoxicity and preneoplastic lesions in rat colon.

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Munari, Carla C; Furtado, Ricardo A; Santiago, Mirian L; Manhas, Simony S; Bastos, Jairo K; Tavares, Denise C

2014-07-01

Baccharis dracunculifolia (Asteraceae), the main botanical source of green propolis, also known as 'alecrim-do-campo' and 'vassourinha', is a shrub of the Brazilian 'cerrado' and is native to the South and Southeast of Brazil. The effects of B. dracunculifolia ethyl acetate extract (Bd-EAE) were evaluated on the 1,2-dimethylhydrazine (DMH)-induced DNA damage and aberrant crypt foci (ACF) in the colon of male Wistar rats by the comet and ACF assays, respectively. The animals were treated by gavage with doses of 6, 12, and 24 mg/kg body weight/day. Animals were also administered a single subcutaneous injection of 40 mg/kg DMH and were killed after 4 h for evaluation of DNA damage. Also, two doses of 40 mg/kg of DMH were administered weekly for 2 weeks, and animals were killed 2 weeks after the last injection for evaluation of ACF development in the colon. The results showed a significant reduction in the frequency of DNA damage and ACF in the group treated with the Bd-EAE plus DMH in comparison with those treated with DMH alone, suggesting that Bd-EAE reduced DNA damage and suppressed the formation of ACF and also exerted a protective affect against colon carcinogenesis.

Suppression of allene oxide synthase 3 in potato increases degree of arbuscular mycorrhizal fungal colonization.

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Morcillo, Rafael Jorge León; Navarrete, María Isabel Tamayo; Bote, Juan Antonio Ocampo; Monguio, Salomé Prat; García-Garrido, José Manuel

2016-01-15

Arbuscular mycorrhizal (AM) is a mutually beneficial interaction among higher plants and soil fungi of the phylum Glomeromycota. Numerous studies have pointed that jasmonic acid plays an important role in the development of the intraradical fungus. This compound belongs to a group of biologically active compounds known as oxylipins which are derived from the oxidative metabolism of polyunsaturated fatty acids. Studies of the regulatory role played by oxylipins in AM colonization have generally focused on jasmonates, while few studies exist on the 9-LOX pathway of oxylipins during AM formation. Here, the cDNA of Allene oxide synthase 3 (AOS3), a key enzyme in the 9-LOX pathway, was used in the RNA interference (RNAi) system to transform potato plants in order to suppress its expression. Results show increases in AOS3 gene expression and 9-LOX products in roots of wild type potato mycorrhizal plants. The suppression of AOS3 gene expression increases the percentage of root with mycorrhizal colonization at early stages of AM formation. AOS3 RNA interference lead to an induction of LOXA and 13-LOX genes, a reduction in AOS3 derived 9-LOX oxylipin compounds and an increase in jasmonic acid content, suggesting compensation between 9 and 13-LOX pathways. The results in a whole support the hypothesis of a regulatory role for the 9-LOX oxylipin pathway during mycorrhization. Copyright © 2015 Elsevier GmbH. All rights reserved.

Combination Of Aging And Dimethylhydrazine Treatment Causes An Increase In The Stem Cell Population Of Rat Colonic Crypts

OpenAIRE

Levi, Edi; Misra, Sandhya; Du, Jianhua; Patel, Bhaumik B.; Majumdar, Adhip P. N.

2009-01-01

Aging is associated with increased incidence of colon cancers. It is also becoming evident that cancer stem cells (CSC) play a vital role in the pathogenesis and prognosis of colon cancer. Recently, we reported the presence of colon cancer stem-like cells in macroscopically normal mucosa in patients with adenomatous polyps and that they increase with aging, suggesting that aging may predispose the colon to carcinogenesis. In the current study we have examined the combined effects of aging and...

Dietary calcium as a possible anti-promoter of colon carcinogenesis

NARCIS (Netherlands)

Lapre, J.A.

1992-01-01

SUMMARY
Colon cancer is the second-most common malignancy in both males and females and is strongly related to environmental factors of which diet seems to be the most important one. Dietary fat is positively correlated with the

Nucleophosmin in the pathogenesis of arsenic-related bladder carcinogenesis revealed by quantitative proteomics

International Nuclear Information System (INIS)

Chen Shuhui; Wang Yiwen; Hsu Jueliang; Chang Hongyi; Wang Chiyun; Shen Potsun; Chiang Chiwu; Chuang Jingjing; Tsai Hungwen; Gu Powen; Chang Fangchih; Liu Hsiaosheng; Chow Nanhaw

2010-01-01

To investigate the molecular mechanisms of arsenic (As)-associated carcinogenesis, we performed proteomic analysis on E7 immortalized human uroepithelial cells after treatment with As in vitro. Quantitative proteomics was performed using stable isotope dimethyl labeling coupled with two-dimensional liquid chromatography peptide separation and mass spectrometry (MS)/MS analysis. Among 285 proteins, a total of 26 proteins were upregulated (ratio > 2.0) and 18 proteins were downregulated (ratio < 0.65) by As treatment, which are related to nucleotide binding, lipid metabolism, protein folding, protein biosynthesis, transcription, DNA repair, cell cycle control, and signal transduction. This study reports the potential significance of nucleophosmin (NPM) in the As-related bladder carcinogenesis. NPM was universally expressed in all of uroepithelial cell lines examined, implying that NPM may play a role in human bladder carcinogenesis. Upregulation of NPM tends to be dose- and time-dependent after As treatment. Expression of NPM was associated with cell proliferation, migration and anti-apoptosis. On the contrary, soy isoflavones inhibited the expression of NPM in vitro. The results suggest that NPM may play a role in the As-related bladder carcinogenesis, and soybean-based foods may have potential in the suppression of As/NPM-related tumorigenesis.

Derricin and derricidin inhibit Wnt/β-catenin signaling and suppress colon cancer cell growth in vitro.

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Barbara F Fonseca

Full Text Available Overactivation of the Wnt/β-catenin pathway in adult tissues has been implicated in many diseases, such as colorectal cancer. Finding chemical substances that can prevent this phenomenon is an emerging problem. Recently, several natural compounds have been described as Wnt/β-catenin inhibitors and might be promising agents for the control of carcinogenesis. Here, we describe two natural substances, derricin and derricidin, belonging to the chalcone subclass, that show potent transcriptional inhibition of the Wnt/β-catenin pathway. Both chalcones are able to affect the cell distribution of β-catenin, and inhibit Wnt-specific reporter activity in HCT116 cells and in Xenopus embryos. Derricin and derricidin also strongly inhibited canonical Wnt activity in vitro, and rescued the Wnt-induced double axis phenotype in Xenopus embryos. As a consequence of Wnt/β-catenin inhibition, derricin and derricidin treatments reduce cell viability and lead to cell cycle arrest in colorectal cancer cell lines. Taken together, our results strongly support these chalcones as novel negative modulators of the Wnt/β-catenin pathway and colon cancer cell growth in vitro.

Cathelicidin suppresses colon cancer development by inhibition of cancer associated fibroblasts

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Cheng M

2014-12-01

Full Text Available Michelle Cheng,1,* Samantha Ho,1,* Jun Hwan Yoo,1,2,* Deanna Hoang-Yen Tran,1,* Kyriaki Bakirtzi,1 Bowei Su,1 Diana Hoang-Ngoc Tran,1 Yuzu Kubota,1 Ryan Ichikawa,1 Hon Wai Koon1 1Center for Inflammatory Bowel Diseases, Division of Digestive Diseases, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; 2Digestive Disease Center, CHA University Bundang Medical Center, Seongnam, Republic of Korea *These authors share co-first authorship Background: Cathelicidin (LL-37 in humans and mCRAMP in mice represents a family of endogenous antimicrobial and anti-inflammatory peptides. Cancer-associated fibroblasts can promote the proliferation of colon cancer cells and growth of colon cancer tumors. Methods: We examined the role of cathelicidin in the development of colon cancer, using subcutaneous human HT-29 colon-cancer-cell-derived tumor model in nude mice and azoxymethane- and dextran sulfate-mediated colon cancer model in C57BL/6 mice. We also determined the indirect antitumoral mechanism of cathelicidin via the inhibition of epithelial–mesenchymal transition (EMT of colon cancer cells and fibroblast-supported colon cancer cell proliferation. Results: Intravenous administration of cathelicidin expressing adeno-associated virus significantly reduced the size of tumors, tumor-derived collagen expression, and tumor-derived fibroblast expression in HT-29-derived subcutaneous tumors in nude mice. Enema administration of the mouse cathelicidin peptide significantly reduced the size and number of colonic tumors in azoxymethane- and dextran sulfate-treated mice without inducing apoptosis in tumors and the adjacent normal colonic tissues. Cathelicidin inhibited the collagen expression and vimentin-positive fibroblast expression in colonic tumors. Cathelicidin did not directly affect HT-29 cell viability, but did significantly reduce tumor growth factor-ß1-induced EMT of colon cancer cells. Media conditioned by the

Oncogenetic tree model of somatic mutations and DNA methylation in colon tumors.

Science.gov (United States)

Sweeney, Carol; Boucher, Kenneth M; Samowitz, Wade S; Wolff, Roger K; Albertsen, Hans; Curtin, Karen; Caan, Bette J; Slattery, Martha L

2009-01-01

Our understanding of somatic alterations in colon cancer has evolved from a concept of a series of events taking place in a single sequence to a recognition of multiple pathways. An oncogenetic tree is a model intended to describe the pathways and sequence of somatic alterations in carcinogenesis without assuming that tumors will fall in mutually exclusive categories. We applied this model to data on colon tumor somatic alterations. An oncogenetic tree model was built using data on mutations of TP53, KRAS2, APC, and BRAF genes, methylation at CpG sites of MLH1 and TP16 genes, methylation in tumor (MINT) markers, and microsatellite instability (MSI) for 971 colon tumors from a population-based series. Oncogenetic tree analysis resulted in a reproducible tree with three branches. The model represents methylation of MINT markers as initiating a branch and predisposing to MSI, methylation of MHL1 and TP16, and BRAF mutation. APC mutation is the first alteration in an independent branch and is followed by TP53 mutation. KRAS2 mutation was placed a third independent branch, implying that it neither depends on, nor predisposes to, the other alterations. Individual tumors were observed to have alteration patterns representing every combination of one, two, or all three branches. The oncogenetic tree model assumptions are appropriate for the observed heterogeneity of colon tumors, and the model produces a useful visual schematic of the sequence of events in pathways of colon carcinogenesis.

Voluntary exercise prevents colonic inflammation in high-fat diet-induced obese mice by up-regulating PPAR-γ activity

International Nuclear Information System (INIS)

Liu, Wei-Xin; Wang, Ting; Zhou, Feng; Wang, Ying; Xing, Jun-Wei; Zhang, Shen; Gu, Shou-Zhi; Sang, Li-Xuan; Dai, Cong; Wang, Hai-Lan

2015-01-01

Obesity is associated with increased colonic inflammation, which elevates the risk of colon cancer. Although exercise exerts anti-inflammatory actions in multiple chronic diseases associated with inflammation, it is unknown whether this strategy prevents colonic inflammation in obesity. We hypothesized that voluntary exercise would suppress colonic inflammation in high-fat diet (HFD)-induced obesity by modulation of peroxisome proliferator-activated receptor (PPAR)-γ. Male C57Bl/6J mice fed either a control diet (6.5% fat, CON) or a high-fat diet (24% fat, HFD) were divided into sedentary, voluntary exercise or voluntary exercise with PPAR-γ antagonist GW9662 (10 mg/kg/day). All interventions took place for 12 weeks. Compared with CON-sedentary group, HFD-sedentary mice gained significantly more body weight and exhibited metabolic disorders. Molecular studies revealed that HFD-sedentary mice had increased expression of inflammatory mediators and activation of nuclear factor (NF)-κB in the colons, which were associated with decreased expression and activity of PPAR-γ. Voluntary exercise markedly attenuated body weight gain, improved metabolic disorders, and normalized the expression of inflammatory mediators and activation of NF-κB in the colons in HFD-mice while having no effects in CON-animals. Moreover, voluntary exercise significantly increased expression and activity of PPAR-γ in the colons in both HFD- and CON-animals. However, all of these beneficial effects induced by voluntary exercise were abolished by GW9662, which inhibited expression and activity of PPAR-γ. The results suggest that decreased PPAR-γ activity in the colon of HFD-induced obesity may facilitate the inflammatory response and colon carcinogenesis. Voluntary exercise prevents colonic inflammation in HFD-induced obesity by up-regulating PPAR-γ activity. - Highlights: • Obesity down-regulates PPAR-γ in the colon. • Down-regulated colonic PPAR-γ may facilitate inflammatory

Voluntary exercise prevents colonic inflammation in high-fat diet-induced obese mice by up-regulating PPAR-γ activity

Energy Technology Data Exchange (ETDEWEB)

Liu, Wei-Xin, E-mail: weixinliu@yahoo.com [Department of Gastroenterology, First Affiliated Hospital of China Medical University, Shenyang 110001, Liaoning (China); Wang, Ting; Zhou, Feng; Wang, Ying; Xing, Jun-Wei; Zhang, Shen [Department of Gastroenterology, First Affiliated Hospital of China Medical University, Shenyang 110001, Liaoning (China); Gu, Shou-Zhi [Department of Anatomy, Seirei Christopher College, Hamamatsu 433-8558 (Japan); Sang, Li-Xuan [Department of Cadre Ward II, First Affiliated Hospital of China Medical University, Shenyang 110001, Liaoning (China); Dai, Cong [Department of Gastroenterology, First Affiliated Hospital of China Medical University, Shenyang 110001, Liaoning (China); Wang, Hai-Lan [Guangdong Province Hospital for Occupational Disease Prevention and Treatment, Guangzhou 510300, Guangdong (China)

2015-04-10

Obesity is associated with increased colonic inflammation, which elevates the risk of colon cancer. Although exercise exerts anti-inflammatory actions in multiple chronic diseases associated with inflammation, it is unknown whether this strategy prevents colonic inflammation in obesity. We hypothesized that voluntary exercise would suppress colonic inflammation in high-fat diet (HFD)-induced obesity by modulation of peroxisome proliferator-activated receptor (PPAR)-γ. Male C57Bl/6J mice fed either a control diet (6.5% fat, CON) or a high-fat diet (24% fat, HFD) were divided into sedentary, voluntary exercise or voluntary exercise with PPAR-γ antagonist GW9662 (10 mg/kg/day). All interventions took place for 12 weeks. Compared with CON-sedentary group, HFD-sedentary mice gained significantly more body weight and exhibited metabolic disorders. Molecular studies revealed that HFD-sedentary mice had increased expression of inflammatory mediators and activation of nuclear factor (NF)-κB in the colons, which were associated with decreased expression and activity of PPAR-γ. Voluntary exercise markedly attenuated body weight gain, improved metabolic disorders, and normalized the expression of inflammatory mediators and activation of NF-κB in the colons in HFD-mice while having no effects in CON-animals. Moreover, voluntary exercise significantly increased expression and activity of PPAR-γ in the colons in both HFD- and CON-animals. However, all of these beneficial effects induced by voluntary exercise were abolished by GW9662, which inhibited expression and activity of PPAR-γ. The results suggest that decreased PPAR-γ activity in the colon of HFD-induced obesity may facilitate the inflammatory response and colon carcinogenesis. Voluntary exercise prevents colonic inflammation in HFD-induced obesity by up-regulating PPAR-γ activity. - Highlights: • Obesity down-regulates PPAR-γ in the colon. • Down-regulated colonic PPAR-γ may facilitate inflammatory

Nutraceuticals as potential therapeutic agents for colon cancer: a review

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Palaniselvam Kuppusamy

2014-06-01

Full Text Available Colon cancer is a world-wide health problem and the second-most dangerous type of cancer, affecting both men and women. The modern diet and lifestyles, with high meat consumption and excessive alcohol use, along with limited physical activity has led to an increasing mortality rate for colon cancer worldwide. As a result, there is a need to develop novel and environmentally benign drug therapies for colon cancer. Currently, nutraceuticals play an increasingly important role in the treatment of various chronic diseases such as colon cancer, diabetes and Alzheimer׳s disease. Nutraceuticals are derived from various natural sources such as medicinal plants, marine organisms, vegetables and fruits. Nutraceuticals have shown the potential to reduce the risk of colon cancer and slow its progression. These dietary substances target different molecular aspects of colon cancer development. Accordingly, this review briefly discusses the medicinal importance of nutraceuticals and their ability to reduce the risk of colorectal carcinogenesis.

Nutraceuticals as potential therapeutic agents for colon cancer: a review.

Science.gov (United States)

Kuppusamy, Palaniselvam; Yusoff, Mashitah M; Maniam, Gaanty Pragas; Ichwan, Solachuddin Jauhari Arief; Soundharrajan, Ilavenil; Govindan, Natanamurugaraj

2014-06-01

Colon cancer is a world-wide health problem and the second-most dangerous type of cancer, affecting both men and women. The modern diet and lifestyles, with high meat consumption and excessive alcohol use, along with limited physical activity has led to an increasing mortality rate for colon cancer worldwide. As a result, there is a need to develop novel and environmentally benign drug therapies for colon cancer. Currently, nutraceuticals play an increasingly important role in the treatment of various chronic diseases such as colon cancer, diabetes and Alzheimer׳s disease. Nutraceuticals are derived from various natural sources such as medicinal plants, marine organisms, vegetables and fruits. Nutraceuticals have shown the potential to reduce the risk of colon cancer and slow its progression. These dietary substances target different molecular aspects of colon cancer development. Accordingly, this review briefly discusses the medicinal importance of nutraceuticals and their ability to reduce the risk of colorectal carcinogenesis.

Lactobacillus rhamnosus induced epithelial cell apoptosis, ameliorates inflammation and prevents colon cancer development in an animal model.

Science.gov (United States)

Gamallat, Yaser; Meyiah, Abdo; Kuugbee, Eugene D; Hago, Ahmed Musa; Chiwala, Gift; Awadasseid, Annoor; Bamba, Djibril; Zhang, Xin; Shang, Xueqi; Luo, Fuwen; Xin, Yi

2016-10-01

Probiotics have been suggested as prophylactic measure in colon carcinogenesis. This study aimed at determining the potential prophylactic activity of Lactobacillus rhamnosus GG CGMCC 1.2134 (LGG) strain on colorectal carcinogenesis via measuring its effect on Nuclear factor kappa B (NFκB) inflammatory pathway and apoptosis. 64 Sprague Dawley rats were grouped into four as follows; Group 1 (Healthy control), Group 2 (LGG), Group 3 (cancer control Dimethyl hydrazine (DMH)) and Group 4 (LGG+DMH). LGG was administered orally to LGG and LGG+DMH groups. Colon carcinogenesis was chemically induced in LGG+DMH and DMH groups by weekly injection of 40mg/kg DMH. Animals were sacrificed after 25 weeks of experiment and tumor characteristics assessed. The change in expression of NFκB-p65, COX-2, TNFα, Bcl-2, Bax, iNOS, VEGFα, β-catenin, Casp3 and p53 were evaluated by western blotting and qRT-PCR. LGG treatment significantly reduced tumor incidence, multiplicity and volume in LGG+DMH treatment group compared to DMH cancer control group. Also, LGG treatment reduced the expression of β-catenin and the inflammatory proteins NFκB-p65, COX-2 and TNFα; the anti-apoptotic protein Bcl-2, but increased the expression of the pro-apoptotic proteins Bax, casp3 and p53 compared with DMH group. LGG have a potential protection effect against colon carcinogenesis; inducing apoptosis and ameliorating inflammation, and may hold a promise as bio-therapeutic dietary agent. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Carcinogenesis

International Nuclear Information System (INIS)

Anon.

1976-01-01

Progress is reported on studies at the molecular, biochemical, and immunological level of carcinogenesis induced in mice by viruses, radiation, or environmental chemicals alone or in combinations. Emphasis was placed on the identification and assessments of cocarcinogens and studies on their mechanisms of action. Data are included on mechanisms of carcinogenesis in the liver, thyroid, Harderian glands, skin, and lungs. The effects of the food additive butylated hydroxytoluene (BHT), phenobarbitol, DDT, uv irradiation, the herbicide 3-amino-1,2,4-triazole(AT), the pituitary hormone prolactin, topically applied 8-methoxypsoralen (8-MOP), and benzo(a) pyrene(BaP) on tumor induction or enhancement were studied

Null effect of dietary restriction on prostate carcinogenesis in the Wistar-Unilever rat.

Science.gov (United States)

McCormick, David L; Johnson, William D; Haryu, Todd M; Bosland, Maarten C; Lubet, Ronald A; Steele, Vernon E

2007-01-01

Chronic dietary restriction inhibits carcinogenesis in several sites in laboratory animals. To determine the effects of dietary restriction on prostate carcinogenesis, prostate cancers were induced in male Wistar-Unilever rats by a sequential regimen of cyproterone acetate (50 mg/day; 21 days); testosterone propionate (100 mg/kg/day; 3 days); N-methyl-N-nitrosourea [MNU; 30 mg/kg; single dose]; and testosterone (subcutaneous implants of 2 pellets containing 40 mg each). Dietary restriction (0% [ad libitum control], 15%, or 30%) was initiated 2 wk post-MNU, and continued until study termination at 12 mo. Dietary restriction induced a rapid suppression of body weight gain but conferred no protection against prostate carcinogenesis. 74% of carcinogen-treated ad libitum controls developed accessory sex gland cancers, versus cancer incidences of 64% and 72% in groups restricted by 15% and 30%, respectively. Similarly, 44% of dietary controls developed cancers limited to the dorsolateral/prostate, versus incidences of 45% and 53% in groups restricted by 15% and 30%. The results of the present study do not support the hypothesis that prostate carcinogenesis can be prevented by reducing caloric intake. Reducing mean body weight by up to 25% through chronic dietary restriction has no effect on the induction of prostate cancers in the Wistar-Unilever rat model.

Prognostic impact of Metadherin-SND1 interaction in colon cancer.

Science.gov (United States)

Wang, Nan; Du, Xilin; Zang, Li; Song, Nuan; Yang, Tao; Dong, Rui; Wu, Tao; He, Xianli; Lu, Jianguo

2012-12-01

The interaction between Metadherin (MTDH) and Staphylococcal nuclease homology domain containing 1 (SND1) is involved in tumorigenesis and tumor progression of several human malignancies. However, its roles in colon cancer are still unclear. To investigate the clinical value of MTDH and SND1 expression in colon cancer. Immunohistochemical staining was performed to detect the expression of MTDH and SND1 using human colon cancer and their corresponding non-cancerous colon tissues from 196 patients' biopsies. Positive expression of MTDH and SND1 were both increased in colon cancer tissues compared to paired non-cancerous colon tissues. There was a positive correlation between MTDH and SND1 expression in colon cancer tissues (r = 0.86, p colon cancer patients with positive expression of MTDH and SND1 were significantly shorter than those without their expression (both p = 0.01). Furthermore, multivariate Cox regression analysis suggested that positive expression of MTDH and SND1 was an independent poor prognostic predictor in colon cancer. Our data suggest that the increased expression of MTDH and/or SND1 is closely related to carcinogenesis, progression, and prognosis of colon cancer. The co-expression of MTDH/SND1 may be a novel distinctive marker to benefit us in prediction of the prognosis in colon cancer.

Abrogation of Gli3 expression suppresses the growth of colon cancer cells via activation of p53

International Nuclear Information System (INIS)

Kang, Han Na; Oh, Sang Cheul; Kim, Jun Suk; Yoo, Young A.

2012-01-01

p53, the major human tumor suppressor, appears to be related to sonic hedgehog (Shh)–Gli-mediated tumorigenesis. However, the role of p53 in tumor progression by the Shh–Gli signaling pathway is poorly understood. Herein we investigated the critical regulation of Gli3–p53 in tumorigenesis of colon cancer cells and the molecular mechanisms underlying these effects. RT-PCR analysis indicated that the mRNA level of Shh and Gli3 in colon tumor tissues was significantly higher than corresponding normal tissues (P < 0.001). The inhibition of Gli3 by treatment with Gli3 siRNA resulted in a clear decrease in cell proliferation and enhanced the level of expression of p53 proteins compared to treatment with control siRNA. The half-life of p53 was dramatically increased by treatment with Gli3 siRNA. In addition, treatment with MG132 blocked MDM2-mediated p53 ubiquitination and degradation, and led to accumulation of p53 in Gli3 siRNA-overexpressing cells. Importantly, ectopic expression of p53 siRNA reduced the ability of Gli3 siRNA to suppress proliferation of those cells compared with the cells treated with Gli3 siRNA alone. Moreover, Gli3 siRNA sensitized colon cancer cells to treatment with anti-cancer agents (5-FU and bevacizumab). Taken together, our studies demonstrate that loss of Gli3 signaling leads to disruption of the MDM2–p53 interaction and strongly potentiate p53-dependent cell growth inhibition in colon cancer cells, indicating a basis for the rational use of Gli3 antagonists as a novel treatment option for colon cancer.

Light/Dark Shifting Promotes Alcohol-Induced Colon Carcinogenesis: Possible Role of Intestinal Inflammatory Milieu and Microbiota

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Faraz Bishehsari

2016-12-01

Full Text Available Background: Colorectal cancer (CRC is associated with the modern lifestyle. Chronic alcohol consumption—a frequent habit of majority of modern societies—increases the risk of CRC. Our group showed that chronic alcohol consumption increases polyposis in a mouse mode of CRC. Here we assess the effect of circadian disruption—another modern life style habit—in promoting alcohol-associated CRC. Method: TS4Cre × adenomatous polyposis coli (APClox468 mice underwent (a an alcohol-containing diet while maintained on a normal 12 h light:12 h dark cycle; or (b an alcohol-containing diet in conjunction with circadian disruption by once-weekly 12 h phase reversals of the light:dark (LD cycle. Mice were sacrificed after eight weeks of full alcohol and/or LD shift to collect intestine samples. Tumor number, size, and histologic grades were compared between animal groups. Mast cell protease 2 (MCP2 and 6 (MCP6 histology score were analyzed and compared. Stool collected at baseline and after four weeks of experimental manipulations was used for microbiota analysis. Results: The combination of alcohol and LD shifting accelerated intestinal polyposis, with a significant increase in polyp size, and caused advanced neoplasia. Consistent with a pathogenic role of stromal tryptase-positive mast cells in colon carcinogenesis, the ratio of mMCP6 (stromal/mMCP2 (intraepithelial mast cells increased upon LD shifting. Baseline microbiota was similar between groups, and experimental manipulations resulted in a significant difference in the microbiota composition between groups. Conclusions: Circadian disruption by Light:dark shifting exacerbates alcohol-induced polyposis and CRC. Effect of circadian disruption could, at least partly, be mediated by promoting a pro-tumorigenic inflammatory milieu via changes in microbiota.

Curcumin synergizes with resveratrol to inhibit colon cancer.

Science.gov (United States)

Majumdar, Adhip P N; Banerjee, Sanjeev; Nautiyal, Jyoti; Patel, Bhaumik B; Patel, Vaishali; Du, Jianhua; Yu, Yingjie; Elliott, Althea A; Levi, Edi; Sarkar, Fazlul H

2009-01-01

Development and progression of many malignancies, including colorectal cancer, are associated with activation of multiple signaling pathways. Therefore, inhibition of these signaling pathways with noncytotoxic natural products represents a logical preventive and/or therapeutic approach for colon cancer. Curcumin and resveratrol, both of which inhibit the growth of transformed cells and colon carcinogenesis, were selected to examine whether combining them would be an effective preventive and/or therapeutic strategy for colon cancer. Indeed, the combination of curcumin and resveratrol was found to be more effective in inhibiting growth of p53-positive (wt) and p53-negative colon cancer HCT-116 cells in vitro and in vivo in SCID xenografts of colon cancer HCT-116 (wt) cells than either agent alone. Analysis by Calcusyn software showed synergism between curcumin and resveratrol. The inhibition of tumors in response to curcumin and/or resveratrol was associated with the reduction in proliferation and stimulation of apoptosis accompanied by attenuation of NF-kappaB activity. In vitro studies have further demonstrated that the combinatorial treatment caused a greater inhibition of constitutive activation of EGFR and its family members as well as IGF-1R. Our current data suggest that the combination of curcumin and resveratrol could be an effective preventive/therapeutic strategy for colon cancer.

microRNA-365, down-regulated in colon cancer, inhibits cell cycle progression and promotes apoptosis of colon cancer cells by probably targeting Cyclin D1 and Bcl-2.

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Nie, Jing; Liu, Lin; Zheng, Wei; Chen, Lin; Wu, Xin; Xu, Yingxin; Du, Xiaohui; Han, Weidong

2012-01-01

Deregulated microRNAs participate in carcinogenesis and cancer progression, but their roles in cancer development remain unclear. In this study, miR-365 expression was found to be downregulated in human colon cancer tissues as compared with that in matched non-neoplastic mucosa tissues, and its downregulation was correlated with cancer progression and poor survival in colon cancer patients. Functional studies revealed that restoration of miR-365 expression inhibited cell cycle progression, promoted 5-fluorouracil-induced apoptosis and repressed tumorigenicity in colon cancer cell lines. Furthermore, bioinformatic prediction and experimental validation were used to identify miR-365 target genes and indicated that the antitumor effects of miR-365 were probably mediated by its targeting and repression of Cyclin D1 and Bcl-2 expression, thus inhibiting cell cycle progression and promoting apoptosis. These results suggest that downregulation of miR-365 in colon cancer may have potential applications in prognosis prediction and gene therapy in colon cancer patients.

Induction of human breast cell carcinogenesis by triclocarban and intervention by curcumin

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Sood, Shilpa; Choudhary, Shambhunath; Wang, Hwa-Chain Robert, E-mail: hcrwang@utk.edu

2013-09-06

Highlights: •Triclocarban exposure induces breast epithelial cell carcinogenesis. •Triclocarban induces the Erk–Nox pathway, ROS elevation, and DNA damage. •Physiological doses of triclocarban induce cellular carcinogenesis. •Non-cytotoxic curcumin blocks triclocarban-induced carcinogenesis and pathways. -- Abstract: More than 85% of breast cancers are sporadic and attributable to long-term exposure to environmental carcinogens and co-carcinogens. To identify co-carcinogens with abilities to induce cellular pre-malignancy, we studied the activity of triclocarban (TCC), an antimicrobial agent commonly used in household and personal care products. Here, we demonstrated, for the first time, that chronic exposure to TCC at physiologically-achievable nanomolar concentrations resulted in progressive carcinogenesis of human breast cells from non-cancerous to pre-malignant. Pre-malignant carcinogenesis was measured by increasingly-acquired cancer-associated properties of reduced dependence on growth factors, anchorage-independent growth and increased cell proliferation, without acquisition of cellular tumorigenicity. Long-term TCC exposure also induced constitutive activation of the Erk–Nox pathway and increases of reactive oxygen species (ROS) in cells. A single TCC exposure induced transient induction of the Erk–Nox pathway, ROS elevation, increased cell proliferation, and DNA damage in not only non-cancerous breast cells but also breast cancer cells. Using these constitutively- and transiently-induced changes as endpoints, we revealed that non-cytotoxic curcumin was effective in intervention of TCC-induced cellular pre-malignancy. Our results lead us to suggest that the co-carcinogenic potential of TCC should be seriously considered in epidemiological studies to reveal the significance of TCC in the development of sporadic breast cancer. Using TCC-induced transient and constitutive endpoints as targets will likely help identify non-cytotoxic preventive

The nonfermentable dietary fiber lignin alters putative colon cancer risk factors but does not protect against DMH-induced colon cancer in rats.

Science.gov (United States)

Cameron, I L; Hardman, W E; Heitman, D W

1997-01-01

The effect of supplementation of the diet with autohydrolyzed lignin on 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis was studied using 112 male Sprague-Dawley rats. Rats received eight weekly injections of DMH (9.5 mg/kg s.c.) or the saline vehicle solution and then were maintained on a basal AIN-76 fiber-free diet or the basal fiber-free diet plus 5% or 10% (wt/wt) lignin for 24 weeks. Rats were killed 32 weeks after the start of the experiment. Colon tumor incidence, location, and multiplicity were determined. Body weight, caloric intake, fecal dry weight, gut transit time, pH of cecal contents, and total fecal bile acid excretion were measured. Supplementation of the diet with 5% or 10% lignin resulted in increased fecal dry weight and total fecal bile acid excretion and in decreased gut transit time, colon pH, and fecal bile acid concentration. Dietary lignin did not significantly affect colon tumor incidence or multiplicity compared with the fiber-free diet. Thus dietary supplementation with autohydrolyzed lignin, a food fiber with good bulking characteristics, had a significant effect on several factors that have previously been linked to reduction of colon cancer risk, but the consumption of high levels of lignin did not decrease the risk for colon cancer.

Dietary sucrose and starch affect dysplastic characteristics in carcinogen-induced aberrant crypt foci in rat colon.

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Caderni, G; Lancioni, L; Luceri, C; Giannini, A; Lodovici, M; Biggeri, A; Dolara, P

1997-03-19

To study whether dietary carbohydrates affect dysplasia in aberrant crypt foci (ACF), rats treated with 1,2-dimethilhydrazine (DMH) were fed for three months with diets containing 46% sucrose or corn starch. The number of ACF/colon in the two dietary groups was similar (P = 0.58), but ACF were smaller in the starch than in sucrose group (P colon carcinogenesis while sucrose in the diet is detrimental, promoting the dysplasia of preneoplastic lesions like ACF.

Radiation carcinogenesis

International Nuclear Information System (INIS)

Adams, G.E.

1987-01-01

In this contribution about carcinogenesis induced by ionizing radiation some radiation dose-response relationships are discussed. Curves are shown of the relation between cell survival and resp. low and high LET radiation. The difference between both curves can be ascribed to endogenous repair mechanisms in the cell. The relation between single-gen mutation frequency and the surviving fractions of irradiated cells indicates that these repairing mechanisms are not error free. Some examples of reverse dose-response relationships are presented in which decreasing values of dose-rate (LET) correspond with increasing radiation induced cell transformation. Finally some molecular aspects of radiation carcinogenesis are discussed. (H.W.). 22 refs.; 4 figs

Gene expression profile and genomic alterations in colonic tumours induced by 1,2-dimethylhydrazine (DMH) in rats

International Nuclear Information System (INIS)

Femia, Angelo Pietro; Luceri, Cristina; Toti, Simona; Giannini, Augusto; Dolara, Piero; Caderni, Giovanna

2010-01-01

Azoxymethane (AOM) or 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis in rats shares many phenotypical similarities with human sporadic colon cancer and is a reliable model for identifying chemopreventive agents. Genetic mutations relevant to human colon cancer have been described in this model, but comprehensive gene expression and genomic analysis have not been reported so far. Therefore, we applied genome-wide technologies to study variations in gene expression and genomic alterations in DMH-induced colon cancer in F344 rats. For gene expression analysis, 9 tumours (TUM) and their paired normal mucosa (NM) were hybridized on 4 × 44K Whole rat arrays (Agilent) and selected genes were validated by semi-quantitative RT-PCR. Functional analysis on microarray data was performed by GenMAPP/MappFinder analysis. Array-comparative genomic hybridization (a-CGH) was performed on 10 paired TUM-NM samples hybridized on Rat genome arrays 2 × 105K (Agilent) and the results were analyzed by CGH Analytics (Agilent). Microarray gene expression analysis showed that Defcr4, Igfbp5, Mmp7, Nos2, S100A8 and S100A9 were among the most up-regulated genes in tumours (Fold Change (FC) compared with NM: 183, 48, 39, 38, 36 and 32, respectively), while Slc26a3, Mptx, Retlna and Muc2 were strongly down-regulated (FC: -500; -376, -167, -79, respectively). Functional analysis showed that pathways controlling cell cycle, protein synthesis, matrix metalloproteinases, TNFα/NFkB, and inflammatory responses were up-regulated in tumours, while Krebs cycle, the electron transport chain, and fatty acid beta oxidation were down-regulated. a-CGH analysis showed that four TUM out of ten had one or two chromosomal aberrations. Importantly, one sample showed a deletion on chromosome 18 including Apc. The results showed complex gene expression alterations in adenocarcinomas encompassing many altered pathways. While a-CGH analysis showed a low degree of genomic imbalance, it is interesting to

Experimental Animal Models of Pancreatic Carcinogenesis for Prevention Studies and Their Relevance to Human Disease

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Hitoshi Nakagama

2011-02-01

Full Text Available Pancreatic cancer is difficult to cure, so its prevention is very important. For this purpose, animal model studies are necessary to develop effective methods. Injection of N-nitrosobis(2-oxopropylamine (BOP into Syrian golden hamsters is known to induce pancreatic ductal adenocarcinomas, the histology of which is similar to human tumors. Moreover, K-ras activation by point mutations and p16 inactivation by aberrant methylation of 5’ CpG islands or by homozygous deletions have been frequently observed in common in both the hamster and humans. Thus, this chemical carcinogenesis model has an advantage of histopathological and genetic similarity to human pancreatic cancer, and it is useful to study promotive and suppressive factors. Syrian golden hamsters are in a hyperlipidemic state even under normal dietary conditions, and a ligand of peroxizome proliferator-activated receptor gamma was found to improve the hyperlipidemia and suppress pancreatic carcinogenesis. Chronic inflammation is a known important risk factor, and selective inhibitors of inducible nitric oxide synthase and cyclooxygenase-2 also have protective effects against pancreatic cancer development. Anti-inflammatory and anti-hyperlipidemic agents can thus be considered candidate chemopreventive agents deserving more attention.

Experimental Animal Models of Pancreatic Carcinogenesis for Prevention Studies and Their Relevance to Human Disease

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Takahashi, Mami, E-mail: mtakahas@ncc.go.jp; Hori, Mika; Mutoh, Michihiro [Division of Cancer Development System, Carcinogenesis Research Group, National Cancer Center Research Institute, 1-1, Tsukiji 5-chome, Chuo-ku, Tokyo 104-0045 (Japan); Wakabayashi, Keiji [Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, Yada 52-1, Suruga-ku, Shizuoka 422-8526 (Japan); Nakagama, Hitoshi [Division of Cancer Development System, Carcinogenesis Research Group, National Cancer Center Research Institute, 1-1, Tsukiji 5-chome, Chuo-ku, Tokyo 104-0045 (Japan)

2011-02-09

Pancreatic cancer is difficult to cure, so its prevention is very important. For this purpose, animal model studies are necessary to develop effective methods. Injection of N-nitrosobis(2-oxopropyl)amine (BOP) into Syrian golden hamsters is known to induce pancreatic ductal adenocarcinomas, the histology of which is similar to human tumors. Moreover, K-ras activation by point mutations and p16 inactivation by aberrant methylation of 5′ CpG islands or by homozygous deletions have been frequently observed in common in both the hamster and humans. Thus, this chemical carcinogenesis model has an advantage of histopathological and genetic similarity to human pancreatic cancer, and it is useful to study promotive and suppressive factors. Syrian golden hamsters are in a hyperlipidemic state even under normal dietary conditions, and a ligand of peroxizome proliferator-activated receptor gamma was found to improve the hyperlipidemia and suppress pancreatic carcinogenesis. Chronic inflammation is a known important risk factor, and selective inhibitors of inducible nitric oxide synthase and cyclooxygenase-2 also have protective effects against pancreatic cancer development. Anti-inflammatory and anti-hyperlipidemic agents can thus be considered candidate chemopreventive agents deserving more attention.

Experimental Animal Models of Pancreatic Carcinogenesis for Prevention Studies and Their Relevance to Human Disease

International Nuclear Information System (INIS)

Takahashi, Mami; Hori, Mika; Mutoh, Michihiro; Wakabayashi, Keiji; Nakagama, Hitoshi

2011-01-01

Pancreatic cancer is difficult to cure, so its prevention is very important. For this purpose, animal model studies are necessary to develop effective methods. Injection of N-nitrosobis(2-oxopropyl)amine (BOP) into Syrian golden hamsters is known to induce pancreatic ductal adenocarcinomas, the histology of which is similar to human tumors. Moreover, K-ras activation by point mutations and p16 inactivation by aberrant methylation of 5′ CpG islands or by homozygous deletions have been frequently observed in common in both the hamster and humans. Thus, this chemical carcinogenesis model has an advantage of histopathological and genetic similarity to human pancreatic cancer, and it is useful to study promotive and suppressive factors. Syrian golden hamsters are in a hyperlipidemic state even under normal dietary conditions, and a ligand of peroxizome proliferator-activated receptor gamma was found to improve the hyperlipidemia and suppress pancreatic carcinogenesis. Chronic inflammation is a known important risk factor, and selective inhibitors of inducible nitric oxide synthase and cyclooxygenase-2 also have protective effects against pancreatic cancer development. Anti-inflammatory and anti-hyperlipidemic agents can thus be considered candidate chemopreventive agents deserving more attention

Promoter hypermethylation mediated downregulation of FBP1 in human hepatocellular carcinoma and colon cancer.

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Mingquan Chen

Full Text Available FBP1, fructose-1,6-bisphosphatase-1, a gluconeogenesis regulatory enzyme, catalyzes the hydrolysis of fructose 1,6-bisphosphate to fructose 6-phosphate and inorganic phosphate. The mechanism that it functions to antagonize glycolysis and was epigenetically inactivated through NF-kappaB pathway in gastric cancer has been reported. However, its role in the liver carcinogenesis still remains unknown. Here, we investigated the expression and DNA methylation of FBP1 in primary HCC and colon tumor. FBP1 was lowly expressed in 80% (8/10 human hepatocellular carcinoma, 66.7% (6/9 liver cancer cell lines and 100% (6/6 colon cancer cell lines, but was higher in paired adjacent non-tumor tissues and immortalized normal cell lines, which was well correlated with its promoter methylation status. Methylation was further detected in primary HCCs, gastric and colon tumor tissues, but none or occasionally in paired adjacent non-tumor tissues. Detailed methylation analysis of 29 CpG sites at a 327-bp promoter region by bisulfite genomic sequencing confirmed its methylation. FBP1 silencing could be reversed by chemical demethylation treatment with 5-aza-2'-deoxycytidine (Aza, indicating direct epigenetic silencing. Restoring FBP1 expression in low expressed cells significantly inhibited cell growth and colony formation ability through the induction of G2-M phase cell cycle arrest. Moreover, the observed effects coincided with an increase in reactive oxygen species (ROS generation. In summary, epigenetic inactivation of FBP1 is also common in human liver and colon cancer. FBP1 appears to be a functional tumor suppressor involved in the liver and colon carcinogenesis.

Mechanisms of radiation carcinogenesis

International Nuclear Information System (INIS)

Bekkum, D.W. van

1975-01-01

This speculative review on radiation carcinogenesis deals mainly with its immunological aspects. It need not be emphasized that the role of immunology in carcinogenesis is not yet well understood. Immunological aspects of radiation carcinogenesis comprise a large number of different parameters on the part of the host as well as on the part of the tumor itself. Only two aspects, both related to radiation, will be discussed here. One is the way in which the carcinogenic exposure to ionizing radiation may affect the immune reactivity of the irradiated organism, thereby perhaps changing its responses against the malignant cells. The second aspect is the immunological properties of cells transformed by ionizing irradiation, which may provide the targets for a host-anti-tumor reaction

Role of bacteria in oral carcinogenesis

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R Rajeev

2012-01-01

Full Text Available Oral cancer is the most common cancer diagnosed in Indian men and is the leading cause of cancer deaths. It is considered as a multistep and multifactorial disease. Besides accumulation of genetic mutations, numerous other carcinogens are involved. In this category, viral and chemical carcinogens are well studied and documented. However, in the oral cavity, the role of microbiota in carcinogenesis is not known. Microbial populations on mouth mucosa differ between healthy and malignant sites, and certain oral bacterial species have been linked with malignancies, but the evidence is still weak in this respect. Nevertheless, oral microorganisms inevitably up-regulate cytokines and other inflammatory mediators that affect the complex metabolic pathways, and may thus be involved in carcinogenesis. Poor oral health associates statistically with prevalence of many types of cancer such as pancreatic and gastrointestinal cancer. This review presents possible carcinogenesis pathway involved in bacterial carcinogenesis, commonly implicated bacteria in oral carcinogenesis, and their role in cancer therapeutics as well.

Limited ability of DNA polymerase kappa to suppress benzo[a]pyrene-induced genotoxicity in vivo.

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Masumura, Kenichi; Toyoda-Hokaiwado, Naomi; Niimi, Naoko; Grúz, Petr; Wada, Naoko A; Takeiri, Akira; Jishage, Kou-Ichi; Mishima, Masayuki; Nohmi, Takehiko

2017-12-01

DNA polymerase kappa (Polk) is a specialized DNA polymerase involved in translesion DNA synthesis. To understand the protective roles against genotoxins in vivo, we established inactivated Polk knock-in gpt delta (inactivated Polk KI) mice that possessed reporter genes for mutations and expressed inactive Polk. In this study, we examined genotoxicity of benzo[a]pyrene (BP) to determine whether Polk actually suppressed BP-induced genotoxicity as predicted by biochemistry and in vitro cell culture studies. Seven-week-old inactivated Polk KI and wild-type (WT) mice were treated with BP at doses of 5, 15, or 50 mg/(kg·day) for three consecutive days by intragastric gavage, and mutations in the colon and micronucleus formation in the peripheral blood were examined. Surprisingly, no differences were observed in the frequencies of mutations and micronucleus formation at 5 or 50 mg/kg doses. Inactivated Polk KI mice exhibited approximately two times higher gpt mutant frequency than did WT mice only at the 15 mg/kg dose. The frequency of micronucleus formation was slightly higher in inactivated Polk KI than in WT mice at the same dose, but it was statistically insignificant. The results suggest that Polk has a limited ability to suppress BP-induced genotoxicity in the colon and bone marrow and also that the roles of specialized DNA polymerases in mutagenesis and carcinogenesis should be examined not only by in vitro assays but also by in vivo mouse studies. We also report the spontaneous mutagenesis in inactivated Polk KI mice at young and old ages. Environ. Mol. Mutagen. 58:644-653, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Deficiency of CCAAT/enhancer binding protein family DNA binding prevents malignant conversion of adenoma to carcinoma in NNK-induced lung carcinogenesis in the mouse

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Kimura Shioko

2012-12-01

Full Text Available Abstract Background The CCAAT/enhancer binding proteins (C/EBPs play important roles in carcinogenesis of many tumors including the lung. Since multiple C/EBPs are expressed in lung, the combinatorial expression of these C/EBPs on lung carcinogenesis is not known. Methods A transgenic mouse line expressing a dominant negative A-C/EBP under the promoter of lung epithelial Clara cell secretory protein (CCSP gene in doxycycline dependent fashion was subjected to 4-(methylnitrosamino-1-(3-pyridyl-1-butanone (NNK-induced lung carcinogenesis bioassay in the presence and absence of doxycycline, and the effect of abolition of DNA binding activities of C/EBPs on lung carcinogenesis was examined. Results A-C/EBP expression was found not to interfere with tumor development; however, it suppressed the malignant conversion of adenoma to carcinoma during NNK-induced lung carcinogenesis. The results suggested that Ki67 may be used as a marker for lung carcinomas in mouse. Conclusions The DNA binding of C/EBP family members can be used as a potential molecular target for lung cancer therapy.

Epigenetic mechanism of radiation carcinogenesis

International Nuclear Information System (INIS)

Niwa, Ohtsura

1995-01-01

Carcinogenic action of radiations has long been thought to be due to its mutagenic activity. Since DNA damage is induced and distributes in a stochastic fashion, radiation induction of cancers was also assumed to follow a stochastic kinetics. However, recent progress in radiation research has revealed that some features of radiation carcinogenesis are not explainable by the simple action of radiation as a DNA damaging and mutagenic agent. Firstly, frequencies of radiation-induced transformation in vitro and radiation-induced mammary cancers in rats are too high to be accounted for by the frequency of radiation-induced mutation. Secondly, trans-generation carcinogenesis among F1 mice born to irradiated parents occurs also much more frequently than to be predicted by the frequency of radiation induced germline mutation. Thirdly, multistage carcinogenesis theory predicts that carcinogens give hits to the target cells so as to shorten the latency of cancers. However, latencies of radiation induced solid cancers among atomic bomb survivors are similar to those of the control population. Fourthly, although radiation elevates the frequency of cancers, the induced cancers seem to share the same spectrum of cancer types as in the unirradiated control populations. This suggests that radiation induces cancer by enhancement of the spontaneous carcinogenesis process. These data suggest that the first step of radiation carcinogenesis may not be the direct induction of mutation. Radiation may induce genetic instability which increases the spontaneous mutation rate in the cells to produce carcinogenic mutations. Growth stimulatory effect of radiation may also contribute to the process. Thus, epigenetic, but not genetic effect of radiation might better contribute in the process of carcinogenesis. (author)

Vanillin Differentially Affects Azoxymethane-Injected Rat Colon Carcinogenesis and Gene Expression

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Ho, Ket Li; Chong, Pei Pei; Yazan, Latifah Saiful

2012-01-01

Abstract Vanillin is the substance responsible for the flavor and smell of vanilla, a widely used flavoring agent. Previous studies reported that vanillin is a good antimutagen and anticarcinogen. However, there are also some contradicting findings showing that vanillin was a comutagen and cocarcinogen. This study investigated whether vanillin is an anticarcinogen or a cocarcinogen in rats induced with azoxymethane (AOM). Rats induced with AOM will develop aberrant crypt foci (ACF). AOM-challenged rats were treated with vanillin orally and intraperitoneally at low and high concentrations and ACF density, multiplicity, and distribution were observed. The gene expression of 14 colorectal cancer-related genes was also studied. Results showed that vanillin consumed orally had no effect on ACF. However, high concentrations (300 mg/kg body weight) of vanillin administered through intraperitoneal injection could increase ACF density and ACF multiplicity. ACF were mainly found in the distal colon rather than in the mid-section and proximal colon. The expression of colorectal cancer biomarkers, protooncogenes, recombinational repair, mismatch repair, and cell cycle arrest, and tumor suppressor gene expression were also affected by vanillin. Vanillin was not cocarcinogenic when consumed orally. However, it was cocarcinogenic when being administered intraperitoneally at high concentration. Hence, the use of vanillin in food should be safe but might have cocarcinogenic potential when it is used in high concentration for therapeutic purposes. PMID:23216109

Dietary fish oil modulates the effect of dimethylhydrazine-induced colon cancer in rats

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Rasmy, G. E.; Khalil, W. K. B.; Moharib, S. A.; Kawab, A. A.; Jwanny, E. W.

2011-07-01

This study was conducted to examine the efficacy of fish oil supplementation in male wistar rat colon carcinogenesis. In order to induce colon cancer, the rats were given a weekly subcutaneous injection of 1,2-Dimethylhydrazine (DMH) at a dose of 20 mg/kg b.w. for five weeks. Afterwards, some of the rats ingested fish oil for either 4 weeks (DMH-FO4 group), or 17 weeks (DMH-FO17 group). The remaining rats continued without any supplementation for the same 4 weeks (DMH4 group), or 17 weeks (DMH17 group). Another two groups of rats did not receive the DMH and were given fish oil (FO17 group) or a normal diet only and considered as the control group (CN group). At the end of the experiment, the rats were sacrificed; and were subsequently subjected to biochemical and molecular biological analyses as well as histopathological examinations. The results showed increased levels of lactate dehydrogenase (LDH), malondialdehyde (MDA) and alkaline phosphatase (ALP) activities in the DMH rats compared to the control. The liver and colonic changes that were induced by DMH were significantly improved through fish oil supplementation in the DMH-FO17 group. The molecular analysis revealed that DMH treatment induced the expression alterations of genes p53, p27 and p21 and increased DNA band patterns related to cancer, while both FO17 and DMH-FO17 groups showed much better results. A histopathological examination of the DMH17 group revealed colon adenocarcinoma and several lesions in rat liver tissues. An improvement in the histopathological picture was seen in the livers and colons of groups DMHFO17. In conclusion, the present results demonstrated the anti-carciongenic effect of herring fish oil against DMH induced colon carcinogenesis in rats. The inhibitory effect of FO was due to the modulation of elevated biochemical parameters, DNA damage, gene expression and histopathological lesions caused by DMH. (Author) 70 refs.

Experimental radiation carcinogenesis is studies at NIRS

International Nuclear Information System (INIS)

Sado, Toshihiko

1992-01-01

Experimental radiation carcinogenesis studies conducted during the past decade at NIRS are briefly reviewed. They include the following: 1) Age dependency of susceptibility to radiation carcinogenesis. 2) Radiation-induced myeloid leukemia. 3) Mechanism of fractionated X-irradiation (FX) induced thymic lymphomas. 4) Significance of radiation-induced immunosuppression in radiation carcinogenesis in vivo. 5) Other ongoing studies. (author)

Dietary elevated sucrose modulation of diesel-induced genotoxicity in the colon and liver of Big Blue rats

DEFF Research Database (Denmark)

Risom, L.; Moller, P.; Hansen, Max

2003-01-01

Earlier studies have indicated that sucrose possesses either co-carcinogenic or tumor-promoter effects in colon carcinogenesis induced by genotoxic carcinogens. In this study we investigated the role of sucrose on diesel exhaust particle (DEP)-induced genotoxicity in the colonic mucosa and liver......-breaks and DNA adducts in liver. DEP and sucrose treatment did not have any effect on mutation frequency in colon and liver. Oxidative DNA damage detected as 8-oxodG (8-oxo-7,8-dihydro-2'-deoxyguanosine) and endonuclease III or formamidopyrimidine DNA glycosylase sensitive sites was unaltered in colon and liver....... The mRNA expression levels of the DNA repair enzymes N-methylpurine DNA glycosylase (MPG), 8-oxoguanine DNA glycosylase (OGG1) and ERCC1 (part of the nucleotide excision repair complex) measured by reverse transcription-polymerase chain reaction were increased in liver by DEP feeding. In colon...

Histamine H2 Receptor-Mediated Suppression of Intestinal Inflammation by Probiotic Lactobacillus reuteri.

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Gao, Chunxu; Major, Angela; Rendon, David; Lugo, Monica; Jackson, Vanessa; Shi, Zhongcheng; Mori-Akiyama, Yuko; Versalovic, James

2015-12-15

Probiotics and commensal intestinal microbes suppress mammalian cytokine production and intestinal inflammation in various experimental model systems. Limited information exists regarding potential mechanisms of probiotic-mediated immunomodulation in vivo. In this report, we demonstrate that specific probiotic strains of Lactobacillus reuteri suppress intestinal inflammation in a trinitrobenzene sulfonic acid (TNBS)-induced mouse colitis model. Only strains that possess the hdc gene cluster, including the histidine decarboxylase and histidine-histamine antiporter genes, can suppress colitis and mucosal cytokine (interleukin-6 [IL-6] and IL-1β in the colon) gene expression. Suppression of acute colitis in mice was documented by diminished weight loss, colonic injury, serum amyloid A (SAA) protein concentrations, and reduced uptake of [(18)F]fluorodeoxyglucose ([(18)F]FDG) in the colon by positron emission tomography (PET). The ability of probiotic L. reuteri to suppress colitis depends on the presence of a bacterial histidine decarboxylase gene(s) in the intestinal microbiome, consumption of a histidine-containing diet, and signaling via the histamine H2 receptor (H2R). Collectively, luminal conversion of l-histidine to histamine by hdc(+) L. reuteri activates H2R, and H2R signaling results in suppression of acute inflammation within the mouse colon. Probiotics are microorganisms that when administered in adequate amounts confer beneficial effects on the host. Supplementation with probiotic strains was shown to suppress intestinal inflammation in patients with inflammatory bowel disease and in rodent colitis models. However, the mechanisms of probiosis are not clear. Our current studies suggest that supplementation with hdc(+) L. reuteri, which can convert l-histidine to histamine in the gut, resulted in suppression of colonic inflammation. These findings link luminal conversion of dietary components (amino acid metabolism) by gut microbes and probiotic

Weight loss following diet-induced obesity does not alter colon tumorigenesis in the AOM mouse model.

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Velázquez, Kandy T; Enos, Reilly T; Carson, Meredith S; Cranford, Taryn L; Bader, Jackie E; Chatzistamou, Ioulia; Singh, Udai P; Nagarkatti, Prakash S; Nagarkatti, Mitzi; Davis, J Mark; Carson, James A; Murphy, E Angela

2016-10-01

Obesity presents a significant public health concern given its association with increased cancer incidence, unfavorable prognosis, and metastasis. However, there is very little literature on the effects of weight loss, following obesity, on risk for colon cancer or liver cancer. Therefore, we sought to study whether intentional weight loss through diet manipulation was capable of mitigating colon and liver cancer in mice. We fed mice with a high-fat diet (HFD) comprised of 47% carbohydrates, 40% fat, and 13% protein for 20 wk to mimic human obesity. Subsequently, azoxymethane (AOM) was used to promote colon and liver carcinogenesis. A subset of obese mice was then switched to a low-fat diet (LFD) containing 67.5% carbohydrate, 12.2% fat, and 20% protein to promote intentional weight loss. Body weight loss and excess fat reduction did not protect mice from colon cancer progression and liver dysplastic lesion in the AOM-chemical-cancer model even though these mice had improved blood glucose and leptin levels. Intentional weight loss in AOM-treated mice actually produced histological changes that resemble dysplastic alterations in the liver and presented a higher percentage of F4/80 + CD206 + macrophages and activated T cells (CD4 + CD69 + ) in the spleen and lymph nodes, respectively. In addition, the liver of AOM-treated mice exposed to a HFD during the entire period of the experiment exhibited a marked increase in proliferation and pNF-κB activation. Altogether, these data suggest that intentional weight loss following chemical-induced carcinogenesis does not affect colon tumorigenesis but may in fact negatively impact liver repair mechanisms. Copyright © 2016 the American Physiological Society.

Advancing nutritional therapy: A novel polymeric formulation attenuates intestinal inflammation in a murine colitis model and suppresses pro-inflammatory cytokine production in ex-vivo cultured inflamed colonic biopsies.

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Alhagamhmad, Moftah H; Lemberg, Daniel A; Day, Andrew S; Tan, Li-Zsa; Ooi, Chee Y; Krishnan, Usha; Gupta, Nitin; Munday, John S; Leach, Steven T

2017-04-01

Nutritional therapy is a viable therapeutic option for the treatment of Crohn disease (CD). Therefore improving nutritional therapy would greatly benefit CD patients. The aim of this study was to define the anti-inflammatory properties of a novel nutritional polymeric formula (PF) in comparison to a currently available standard PF. Dextran sodium sulfate (DSS) was utilized to induce colitis in C57BL/6 mice with mice randomized to receive either standard PF or novel PF in addition to control groups. Changes in body weight were recorded and colonic damage was assessed histologically and biochemically. Additional experiments were also included where the cytokine response of colonic biopsies from pediatric CD patients was measured following exposure to standard PF or novel PF. DSS induced significant body weight loss, morphological changes in the colon, increased myeloperoxidase (MPO) activity and up-regulated colonic mRNA expression of tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-12 and monocyte chemoattractant protein (MCP)-1, as well as associated histological changes. Other than histological damage, these inflammatory changes were reversed by both novel and standard PF. However, the novel PF, but not standard PF, completely suppressed TNF-α, IL-6 and IL-8 levels from cultured biopsies. Newly developed nutritional formula reproducibly ameliorated DSS-induced colitis in a murine model, although this response was not measurably different to standard PF. However, the novel PF was significantly superior in suppressing inflammatory cytokine release from cultured colonic biopsies. Collectively, these findings support a possible role for novel PF in advancing nutritional therapy for CD patients. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Deletion of glutathione peroxidase-2 inhibits azoxymethane-induced colon cancer development.

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Mike F Müller

Full Text Available The selenoprotein glutathione peroxidase-2 (GPx2 appears to have a dual role in carcinogenesis. While it protected mice from colon cancer in a model of inflammation-triggered carcinogenesis (azoxymethane and dextran sodium sulfate treatment, it promoted growth of xenografted tumor cells. Therefore, we analyzed the effect of GPx2 in a mouse model mimicking sporadic colorectal cancer (azoxymethane-treatment only. GPx2-knockout (KO and wild-type (WT mice were adjusted to an either marginally deficient (-Se, adequate (+Se, or supranutritional (++Se selenium status and were treated six times with azoxymethane (AOM to induce tumor development. In the -Se and ++Se groups, the number of tumors was significantly lower in GPx2-KO than in respective WT mice. On the +Se diet, the number of dysplastic crypts was reduced in GPx2-KO mice. This may be explained by more basal and AOM-induced apoptotic cell death in GPx2-KO mice that eliminates damaged or pre-malignant epithelial cells. In WT dysplastic crypts GPx2 was up-regulated in comparison to normal crypts which might be an attempt to suppress apoptosis. In contrast, in the +Se groups tumor numbers were similar in both genotypes but tumor size was larger in GPx2-KO mice. The latter was associated with an inflammatory and tumor-promoting environment as obvious from infiltrated inflammatory cells in the intestinal mucosa of GPx2-KO mice even without any treatment and characterized as low-grade inflammation. In WT mice the number of tumors tended to be lowest in +Se compared to -Se and ++Se feeding indicating that selenium might delay tumorigenesis only in the adequate status. In conclusion, the role of GPx2 and presumably also of selenium depends on the cancer stage and obviously on the involvement of inflammation.

Immunohistochemical study of p53 overexpression in radiation-induced colon cancers

International Nuclear Information System (INIS)

Minami, Kazunori; Hayashi, Nobuyuki; Mokarim, A.; Matsuzaki, Sumihiro; Ito, Masahiro; Sekine, Ichiro.

1998-01-01

The expressions of p53 and proliferating cell nuclear antigen (PCNA) were studied immunohistochemically from paraffin sections of 7 cases (9 lesions) of radiation-induced colon cancer and 42 cases of spontaneous colon cancer. Age distribution of radiation-induced and spontaneous colon cancer were 68.1 years (range, 56 to 77 years) and 67.4 years (range, 31 to 85 years), respectively. Among the radiation-induced colon cancers, there were 3 lesions of mucinous carcinoma (33%), a much higher than found for spontaneous mucinous cancer. Immunohistochemically, p53 protein expression was detected in 7/9 (78%) of radiation-induced cancers and in 23/42 (55%) of spontaneous colon cancers. χ 2 analysis found no significant differences between radiation-induced and spontaneous colon cancers in age distribution or p53-positive staining for frequency, histopathology, or Dukes'' classification. In radiation colitis around the cancers including aberrant crypts, spotted p53 staining and abnormal and scattered PCNA-positive staining were observed. In histologically normal cells, p53 staining was almost absent and PCNA-positive staining was regularly observed in the lower half of the crypt. In radiation colitis including aberrant glands, cellular proliferation increased and spotted p53 expression was observed. This study suggests that radiation colitis and aberrant glands might possess malignant potential and deeply associate with carcinogenesis of radiation-induced colon cancer. (author)

Similarities in the Age-Specific Incidence of Colon and Testicular Cancers.

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Soto-Ortiz, Luis; Brody, James P

2013-01-01

Colon cancers are thought to be an inevitable result of aging, while testicular cancers are thought to develop in only a small fraction of men, beginning in utero. These models of carcinogenesis are, in part, based upon age-specific incidence data. The specific incidence for colon cancer appears to monotonically increase with age, while that of testicular cancer increases to a maximum value at about 35 years of age, then declines to nearly zero by the age of 80. We hypothesized that the age-specific incidence for these two cancers is similar; the apparent difference is caused by a longer development time for colon cancer and the lack of age-specific incidence data for people over 84 years of age. Here we show that a single distribution can describe the age-specific incidence of both colon carcinoma and testicular cancer. Furthermore, this distribution predicts that the specific incidence of colon cancer should reach a maximum at about age 90 and then decrease. Data on the incidence of colon carcinoma for women aged 85-99, acquired from SEER and the US Census, is consistent with this prediction. We conclude that the age specific data for testicular cancers and colon cancers is similar, suggesting that the underlying process leading to the development of these two forms of cancer may be similar.

Similarities in the Age-Specific Incidence of Colon and Testicular Cancers.

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Luis Soto-Ortiz

Full Text Available Colon cancers are thought to be an inevitable result of aging, while testicular cancers are thought to develop in only a small fraction of men, beginning in utero. These models of carcinogenesis are, in part, based upon age-specific incidence data. The specific incidence for colon cancer appears to monotonically increase with age, while that of testicular cancer increases to a maximum value at about 35 years of age, then declines to nearly zero by the age of 80. We hypothesized that the age-specific incidence for these two cancers is similar; the apparent difference is caused by a longer development time for colon cancer and the lack of age-specific incidence data for people over 84 years of age. Here we show that a single distribution can describe the age-specific incidence of both colon carcinoma and testicular cancer. Furthermore, this distribution predicts that the specific incidence of colon cancer should reach a maximum at about age 90 and then decrease. Data on the incidence of colon carcinoma for women aged 85-99, acquired from SEER and the US Census, is consistent with this prediction. We conclude that the age specific data for testicular cancers and colon cancers is similar, suggesting that the underlying process leading to the development of these two forms of cancer may be similar.

Expression of Programmed Death-Ligand 1 by Human Colonic CD90+ Stromal Cells Differs Between Ulcerative Colitis and Crohn’s Disease and Determines Their Capacity to Suppress Th1 Cells

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Ellen J. Beswick

2018-05-01

Full Text Available Background and AimsThe role of programmed cell death protein 1 (PD-1 and its ligands in the dysregulation of T helper immune responses observed in the inflammatory bowel disease (IBD is unclear. Recently, a novel concept emerged that CD90+ colonic (myofibroblasts (CMFs, also known as stromal cells, act as immunosuppressors, and are among the key regulators of acute and chronic inflammation. The objective of this study was to determine if the level of the PD-1 ligands is changed in the IBD inflamed colonic mucosa and to test the hypothesis that changes in IBD-CMF-mediated PD-1 ligand-linked immunosuppression is a mechanism promoting the dysregulation of Th1 cell responses.MethodsTissues and cells derived from Crohn’s disease (CD, ulcerative colitis (UC, and healthy individuals (N were studied in situ, ex vivo, and in culture.ResultsA significant increase in programmed death-ligand 1 (PD-L1 was observed in the inflamed UC colonic mucosa when compared to the non-inflamed matched tissue samples, CD, and healthy controls. UC-CMFs were among the major populations in the colonic mucosa contributing to the enhanced PD-L1 expression. In contrast, PD-L1 expression was decreased in CD-CMFs. When compared to CD-CMFs and N-CMFs, UC-CMFs demonstrated stronger suppression of IL-2, Th1 transcriptional factor Tbet, and IFN-γ expression by CD3/CD28-activated CD4+ T cells, and this process was PD-L1 dependent. Similar observations were made when differentiated Th1 cells were cocultured with UC-CMFs. In contrast, CD-CMFs showed reduced capacity to suppress Th1 cell activity and addition of recombinant PD-L1 Fc to CD-CMF:T cell cocultures partially restored the suppression of the Th1 type responses.ConclusionWe present evidence showing that increased PD-L1 expression suppresses Th1 cell activity in UC. In contrast, loss of PD-L1 expression observed in CD contributes to the persistence of the Th1 inflammatory milieu in CD. Our data suggest that

Colon cancer modulation by a diabetic environment: A single institutional experience.

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Prieto, Isabel; Del Puerto-Nevado, Laura; Gonzalez, Nieves; Portal-Nuñez, Sergio; Zazo, Sandra; Corton, Marta; Minguez, Pablo; Gomez-Guerrero, Carmen; Arce, Jose Miguel; Sanz, Ana Belen; Mas, Sebastian; Aguilera, Oscar; Alvarez-Llamas, Gloria; Esbrit, Pedro; Ortiz, Alberto; Ayuso, Carmen; Egido, Jesus; Rojo, Federico; Garcia-Foncillas, Jesus

2017-01-01

Multiple observational studies suggest an increased risk of colon cancer in patients with diabetes mellitus (DM). This can theoretically be the result of an influence of the diabetic environment on carcinogenesis or the tumor biologic behavior. To gain insight into the influence of a diabetic environment on colon cancer characteristics and outcomes. Retrospective analysis of clinical records in an academic tertiary care hospital with detailed analysis of 81 diabetic patients diagnosed of colon cancer matched with 79 non-diabetic colon cancer patients. The impact of streptozotocin-induced diabetes on the growth of colon cancer xenografts was studied in mice. The incidence of DM in 1,137 patients with colorectal cancer was 16%. The diabetic colon cancer cases and non-diabetic colon cancer controls were well matched for demographic and clinical variables. The ECOG Scale Performance Status was higher (worse) in diabetics (ECOG ≥1, 29.1% of controls vs 46.9% of diabetics, p = 0.02), but no significant differences were observed in tumor grade, adjuvant therapy, tumor site, lymphovascular invasion, stage, recurrence, death or cancer-related death. Moreover, no differences in tumor variables were observed between patients treated or not with metformin. In the xenograft model, tumor growth and histopathological characteristics did not differ between diabetic and nondiabetic animals. Our findings point towards a mild or negligible effect of the diabetes environment on colon cancer behavior, once cancer has already developed.

Molecular epidemiology of radiation-induced carcinogenesis

International Nuclear Information System (INIS)

Trosko, J.E.

1996-01-01

The role of ionizing radiation in carcinogenesis is discussed. Every cell contains proto-oncogenes, which if damaged may lead to cell transformation. Every cell also contains tumor suppressor genes, which guard against transformation. Thus, transformation would seem to require a double injury to the DNA in a cell. Ionizing radiation is known to be a relatively weak mutagen, but a good clastogen (inducer of chromosome breaks, deletions and rearrangements). Ionizing radiation may therefore be a 'promoter' of cancer, i.e. a stimulant of the clonal expansion of transformed cells, if it kills enough cells to induce compensatory hyperplasia - i.e. rapid growth of cells. Ionizing radiation may be a 'progressor', if it deactivates tumor suppressor genes tending to suppress the growth of existing clones of transformed cells resulting from any of numerous causes. It may therefore be an oversimplification to say that radiation causes cancer; rather, it seems to be a weak initiator, an indirect promoter, and a late-stage progressor. 2 figs

Use of nonsteroidal antiinflamatory drugs for chemoprevention of colon cancer

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Milić Aleksandra

2013-01-01

Full Text Available Colorectal cancer is in the third most frequent cancer among malignant tumors of both sexes in developed countries. It is predominantly a disease of older persons and occurs mostly after the age of 60. Although the etiology of colon cancer is unknown, it is assumed to arise as a result of unclear and complex interactions between genetic and environmental factors. The main element in the etiology of colorectal cancer is the process of genetic changes in epithelial cells of colon mucosa. It is believed that specific epidemiological factors such as stress, hypoxia, reduced intake of glucose and other nutrients, a hereditary predisposition to mutagenic effects, the meat in the diet, bile acids, reduced intake of minerals and vitamins as well as changes in pH of feces lead to initiation of the process of carcinogenesis in mucosa of the colon. Cancer chemoprevention is defined as the use of chemical agents in order to block, prevent or delay the reversal development or progress of cancer. It is believed that chemoprevention is a key component of cancer control, and numerous studies indicate potential role of NSAIDs in chemoprevention of colon cancer.

Adrenergic factors regulating cell division in the colonic crypt epithelium during carcinogenesis and in colonic adenoma and adenocarcinoma.

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Kennedy, M F; Tutton, P J; Barkla, D H

1985-09-01

Evidence exists implicating adrenergic factors in the control of intestinal epithelial cell proliferation in both normal and diseased states. In this report, attention is focussed on changes in the amine requirements of proliferating cells during the chemical induction of tumours in the colon of mouse. Cell proliferation rates were measured stathmokinetically. Tumours were induced by s.c. injection of dimethylhydrazine (DMH). Results with a series of adrenoceptor agonists and antagonists suggest that there is an alpha 2-adrenoceptor mediated excitatory effect in normal colon but an alpha 2 adrenoceptor mediated inhibitory effect in adenoma and carcinoma. Alpha 1 adrenoceptors, on the other hand, have an inhibitory effect in normal crypts and in adenomas, and an excitatory effect in carcinomas. Beta adrenoceptors have an inhibitory effect in the normal and DMH-treated crypt, and in adenomas, but not in carcinomas. In the crypt epithelium of DMH-treated mice, two regions on cell proliferation, with differing regulatory factors, could be identified. In the upper region of the carcinogen-exposed crypt is a zone where cell proliferation is stimulated by an alpha 2 adrenergic mechanism, thus resembling the basal region of the normal crypt. By contrast, in the basal region of these crypts, cell proliferation is stimulated by an alpha 1 mechanism, thus resembling a malignant tumour.

Differences between right- and left-sided colon cancer in patient characteristics, cancer morphology and histology.

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Nawa, Toru; Kato, Jun; Kawamoto, Hirofumi; Okada, Hiroyuki; Yamamoto, Hiroshi; Kohno, Hiroyuki; Endo, Hisayuki; Shiratori, Yasushi

2008-03-01

Recently, the clinical and biological differences between right- and left-sided colon cancers have been widely debated. However, close analyses of these clinical differences, based on large-scale studies, have been scarcely reported. A total of 3552 consecutive Japanese colorectal cancer cases were examined and the clinical differences between right- and left-sided colon cancer cases were investigated. The proportion of right-sided colon cancer was relatively high in patients aged less than 40 years (33%) and more than 80 years (43%). The proportion of right-sided colon cancer in patients aged 40-59 years was relatively low (male 22% and female 29%). In male patients the proportion increased in the 70-79 years age group (30%), while in female patients the proportion increased in the 60-69 years age group (39%). Right-sided colon cancer was more likely to be detected at an advanced stage (T1 stage; left 22%, right 15%) (P cancer was dominant in the left colon (left 59%; right 40%) (P cancer in the right colon was significantly higher than that in the left colon (left 25%; right 44%) (P colon cancer was observed and the difference between male and female patients was highlighted. Other clinical features also differed between right- and left-sided colon cancer, suggesting that different mechanisms may be at work during right and left colon carcinogenesis.

Hath1 inhibits proliferation of colon cancer cells probably through up-regulating expression of Muc2 and p27 and down-regulating expression of cyclin D1.

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Zhu, Dai-Hua; Niu, Bai-Lin; Du, Hui-Min; Ren, Ke; Sun, Jian-Ming; Gong, Jian-Ping

2012-01-01

Previous studies showed that Math1 homologous to human Hath1 can cause mouse goblet cells to differentiate. In this context it is important that the majority of colon cancers have few goblet cells. In the present study, the potential role of Hath1 in colon carcinogenesis was investigated. Sections of paraffin-embedded tissues were used to investigate the goblet cell population of normal colon mucosa, mucosa adjacent colon cancer and colon cancer samples from 48 patients. Hath1 and Muc2 expression in these samples were tested by immunohistochemistry, quantitative real-time reverse transcription -PCR and Western blotting. After the recombinant plasmid, pcDNA3.1(+)-Hath1 had been transfected into HT29 colon cancer cells, three clones were selected randomly to test the levels of Hath1 mRNA, Muc2 mRNA, Hath1, Muc2, cyclin D1 and p27 by quantitative real-time reverse transcription-PCR and Western blotting. Moreover, the proliferative ability of HT29 cells introduced with Hath1 was assessed by means of colony formation assay and xenografting. Expression of Hath1, Muc2, cyclin D1 and p27 in the xenograft tumors was also detected by Western blotting. No goblet cells were to be found in colon cancer and levels of Hath1 mRNA and Hath1, Muc2 mRNA and Muc2 were significantly down-regulated. Hath1 could decrease cyclin D1, increase p27 and Muc2 in HT29 cells and inhibit their proliferation. Hath1 may be an anti-oncogene in colon carcinogenesis.

Inherent aerobic capacity-dependent differences in breast carcinogenesis.

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Thompson, Henry J; Jones, Lee W; Koch, Lauren G; Britton, Steven L; Neil, Elizabeth S; McGinley, John N

2017-09-01

Although regular physical activity is associated with improvement in aerobic capacity and lower breast cancer risk, there are heritable sets of traits that affect improvement in aerobic capacity in response to physical activity. Although aerobic capacity segregates risk for a number of chronic diseases, the effect of the heritable component on cancer risk has not been evaluated. Therefore, we investigated breast carcinogenesis in rodent models of heritable fitness in the absence of induced physical activity. Female offspring of N:NIH rats selectively bred for low (LIAC) or high (HIAC) inherent aerobic capacity were injected intraperitoneally with 1-methyl-1-nitrosurea (70 mg/kg body wt). At study termination 33 weeks post-carcinogen, cancer incidence (14.0 versus 47.3%; P < 0.001) and multiplicity (0.18 versus 0.85 cancers per rat; P < 0.0001) were significantly decreased in HIAC versus LIAC rats, respectively. HIAC had smaller visceral and subcutaneous body fat depots than LIAC and activity of two proteins that regulated the mammalian target of rapamycin, protein kinase B (Akt), and adenosine monophosphate-activated protein kinase were suppressed and activated, respectively, in HIAC. Although many factors distinguish between HIAC and LIAC, it appears that the protective effect of HIAC against breast carcinogenesis is mediated, at least in part, via alterations in core metabolic signaling pathways deregulated in the majority of human breast cancers. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

GEN-27, a Newly Synthetic Isoflavonoid, Inhibits the Proliferation of Colon Cancer Cells in Inflammation Microenvironment by Suppressing NF-κB Pathway

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Yajing Wang

2016-01-01

Full Text Available Nonresolving inflammation is one of the consistent features of the tumor microenvironment in the intestine and plays a critical role in the initiation and development of colon cancer. Here we reported the inhibitory effects of GEN-27, a new derivative of genistein, on the inflammation-related colon cancer cell proliferation and delineated the mechanism of its action. The results indicated that GEN-27 inhibited the proliferation of human colon tumor HCT116 cells stimulated by culture supernatants of LPS-induced human monocytes THP-1 cells and significantly decreased LPS-induced secretion of proinflammatory cytokines interleukin-6 and interleukin-1β in THP-1 cells. The HCT116 cell proliferation elicited by THP-1-conditioned medium could be blocked by the interleukin-1 receptor antagonist (IL-1RA. Further mechanistic study revealed that GEN-27 remarkably inhibited the nuclear translocation of NF-κB and phosphorylation of IκB and IKKα/β in both HCT116 and THP-1 cells. In addition, GEN-27 markedly suppressed the HCT116 cell proliferation stimulated by IL-1β treatment, which was dependent on the inhibition of NF-κB/p65 nuclear localization, as verified by p65 overexpression and BAY 11-7082, an NF-κB inhibitor. Taken together, our findings established that GEN-27 modulated NF-κB signaling pathway involved in inflammation-induced cancer cells proliferation and therefore could be a potential chemopreventive agent against inflammation-associated colon cancer.

GEN-27, a Newly Synthetic Isoflavonoid, Inhibits the Proliferation of Colon Cancer Cells in Inflammation Microenvironment by Suppressing NF-κB Pathway.

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Wang, Yajing; Lu, Ping; Zhang, Weifeng; Du, Qianming; Tang, Jingjing; Wang, Hong; Lu, Jinrong; Hu, Rong

2016-01-01

Nonresolving inflammation is one of the consistent features of the tumor microenvironment in the intestine and plays a critical role in the initiation and development of colon cancer. Here we reported the inhibitory effects of GEN-27, a new derivative of genistein, on the inflammation-related colon cancer cell proliferation and delineated the mechanism of its action. The results indicated that GEN-27 inhibited the proliferation of human colon tumor HCT116 cells stimulated by culture supernatants of LPS-induced human monocytes THP-1 cells and significantly decreased LPS-induced secretion of proinflammatory cytokines interleukin-6 and interleukin-1β in THP-1 cells. The HCT116 cell proliferation elicited by THP-1-conditioned medium could be blocked by the interleukin-1 receptor antagonist (IL-1RA). Further mechanistic study revealed that GEN-27 remarkably inhibited the nuclear translocation of NF-κB and phosphorylation of IκB and IKKα/β in both HCT116 and THP-1 cells. In addition, GEN-27 markedly suppressed the HCT116 cell proliferation stimulated by IL-1β treatment, which was dependent on the inhibition of NF-κB/p65 nuclear localization, as verified by p65 overexpression and BAY 11-7082, an NF-κB inhibitor. Taken together, our findings established that GEN-27 modulated NF-κB signaling pathway involved in inflammation-induced cancer cells proliferation and therefore could be a potential chemopreventive agent against inflammation-associated colon cancer.

Colon Cancer Chemoprevention by Sage Tea Drinking: Decreased DNA Damage and Cell Proliferation.

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Pedro, Dalila F N; Ramos, Alice A; Lima, Cristovao F; Baltazar, Fatima; Pereira-Wilson, Cristina

2016-02-01

Salvia officinalis and some of its isolated compounds have been found to be preventive of DNA damage and increased proliferation in vitro in colon cells. In the present study, we used the azoxymethane model to test effects of S. officinalis on colon cancer prevention in vivo. The results showed that sage treatment reduced the number of ACF formed only if administered before azoxymethane injection, demonstrating that sage tea drinking has a chemopreventive effect on colorectal cancer. A decrease in the proliferation marker Ki67 and in H2 O2 -induced and azoxymethane-induced DNA damage to colonocytes and lymphocytes were found with sage treatment. This confirms in vivo the chemopreventive effects of S. officinalis. Taken together, our results show that sage treatment prevented initiation phases of colon carcinogenesis, an effect due, at least in part, to DNA protection, and reduced proliferation rates of colon epithelial cell that prevent mutations and their fixation through cell replication. These chemopreventive effects of S. officinalis on colon cancer add to the many health benefits attributed to sage and encourage its consumption. Copyright © 2015 John Wiley & Sons, Ltd.

Crucial involvement of tumor-associated neutrophils in the regulation of chronic colitis-associated carcinogenesis in mice.

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Kun Shang

Full Text Available Ulcerative colitis (UC is a major form of chronic inflammation that can frequently progress to colon cancer. Several studies have demonstrated massive infiltration of neutrophils and macrophages into the lamina propria and submucosa in the progression of UC-associated colon carcinogenesis. Macrophages contribute to the development of colitis-associated colon cancer (CAC. However, the role of neutrophils is not well understood. To better understand the involvement of tumor-associated neutrophils (TANs in the regulation of CAC, we used a mouse CAC model produced by administering azoxymethane (AOM, followed by repeated dextran sulfate sodium (DSS ingestion. This causes severe colonic inflammation and subsequent development of multiple tumors in mice colon. We observed that colorectal mucosal inflammation became increasingly severe with AOM and DSS treatment. Macrophages infiltrated the lamina propria and submucosa, together with a marked increase in neutrophil infiltration. The chemokine CXCL2 increased in the lamina propria and submucosal regions of the colons of the treated mice, together with the infiltration of neutrophils expressing CXCR2, a specific receptor for CXCL2. This process was followed by neoplastic transformation. After AOM and DSS treatment, the mice showed enhanced production of metalloproteinase (MMP-9 and neutrophil elastase (NE, accompanied by excessive vessel generation and cell proliferation. Moreover, CXCL2 promoted neutrophil recruitment and induced neutrophils to express MMP-9 and NE in vitro. Furthermore, administration of neutrophil-neutralizing antibodies after the last DSS cycle markedly reduced the number and size of tumors and decreased the expression of CXCR2, CXCL2, MMP-9, and NE. These observations indicate a crucial role for TANs in the initiation and progression of CAC and suggest that the CXCL2-CXCR2 axis might be useful in reducing the risk of UC-associated colon cancer.

Crucial Involvement of Tumor-Associated Neutrophils in the Regulation of Chronic Colitis-Associated Carcinogenesis in Mice

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Wang, Chen; Wang, Zhen; Gu, Hong-Yu; Du, Xiang; Zhou, Xiao-Yan; Zheng, Chun-Lei; Chi, Ya-Yun; Mukaida, Naofumi; Li, Ying-Yi

2012-01-01

Ulcerative colitis (UC) is a major form of chronic inflammation that can frequently progress to colon cancer. Several studies have demonstrated massive infiltration of neutrophils and macrophages into the lamina propria and submucosa in the progression of UC-associated colon carcinogenesis. Macrophages contribute to the development of colitis-associated colon cancer (CAC). However, the role of neutrophils is not well understood. To better understand the involvement of tumor-associated neutrophils (TANs) in the regulation of CAC, we used a mouse CAC model produced by administering azoxymethane (AOM), followed by repeated dextran sulfate sodium (DSS) ingestion. This causes severe colonic inflammation and subsequent development of multiple tumors in mice colon. We observed that colorectal mucosal inflammation became increasingly severe with AOM and DSS treatment. Macrophages infiltrated the lamina propria and submucosa, together with a marked increase in neutrophil infiltration. The chemokine CXCL2 increased in the lamina propria and submucosal regions of the colons of the treated mice, together with the infiltration of neutrophils expressing CXCR2, a specific receptor for CXCL2. This process was followed by neoplastic transformation. After AOM and DSS treatment, the mice showed enhanced production of metalloproteinase (MMP)-9 and neutrophil elastase (NE), accompanied by excessive vessel generation and cell proliferation. Moreover, CXCL2 promoted neutrophil recruitment and induced neutrophils to express MMP-9 and NE in vitro. Furthermore, administration of neutrophil-neutralizing antibodies after the last DSS cycle markedly reduced the number and size of tumors and decreased the expression of CXCR2, CXCL2, MMP-9, and NE. These observations indicate a crucial role for TANs in the initiation and progression of CAC and suggest that the CXCL2–CXCR2 axis might be useful in reducing the risk of UC-associated colon cancer. PMID:23272179

Correlation between the methylation of APC gene promoter and colon cancer.

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Li, Bing-Qiang; Liu, Peng-Peng; Zhang, Cai-Hua

2017-08-01

The present study was planned to explore the correlation between the methylation of APC (adenomatous polyposis coli) and colon carcinogenesis. Colon cancer tissues and tumor-adjacent normal tissues of 60 colon cancer patients (who received surgical operation in our hospital from January 2012 to December 2014) were collected. SW1116 cells in human colon cancer tissues were selected for culturing. 5-aza-2c-deoxycytidine (5-aza-dC) was utilized as an inhibitor of the methylation for APC gene. Methylation specific PCR (MSP) was utilized for detection of APC methylation in SW1116 cells. The MTT and Transwell assays were performed to detect the effect of the methylation of APC gene on the proliferation and invasive abilities of SW1116 cells. The correlation between the methylation of APC gene and pathological parameters of colon cancer patients was analyzed. MSP results revealed that 41 cases (68.33%) showed methylation of APC gene in colon cancer tissues. No methylation of APC gene was found in tumor-adjacent normal tissues. 5-aza-dC was able to inhibit the methylation of APC gene in SW1116 cells. APC gene methylation was correlated with tumor size, differentiation degree, lymph node metastasis and Dukes staging. In conclusion, the levels of the methylation of APC in colon cancer tissues and SW1116 cells are relatively high. The methylation of APC promoted the proliferation and invasion abilities of SW1116 cells. Furthermore, methylation is correlated with a variety of clinicopathological features of colon cancer patients.

IL33 Promotes Colon Cancer Cell Stemness via JNK Activation and Macrophage Recruitment

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Fang, Min; Li, Yongkui; Huang, Kai; Qi, Shanshan; Zhang, Jian; Zgodzinski, Witold; Majewski, Marek; Wallner, Grzegorz; Gozdz, Stanislaw; Macek, Pawel; Kowalik, Artur; Pasiarski, Marcin; Grywalska, Ewelina; Vatan, Linda; Nagarsheth, Nisha; Li, Wei; Zhao, Lili; Kryczek, Ilona; Wang, Guobin; Wang, Zheng; Zou, Weiping; Wang, Lin

2018-01-01

The expression and biological role of IL33 in colon cancer is poorly understood. In this study, we show that IL33 is expressed by vascular endothelial cells and tumor cells in the human colon cancer microenvironment. Administration of human IL33 and overexpression of murine IL33 enhanced human and murine colon cancer cell growth in vivo, respectively. IL33 stimulated cell sphere formation and prevented chemotherapy-induced tumor apoptosis. Mechanistically, IL33 activated core stem cell genes NANOG, NOTCH3, and OCT3/4 via the ST2 signaling pathway, and induced phosphorylation of c-Jun N terminal kinase (JNK) activation and enhanced binding of c-Jun to the promoters of the core stem cell genes. Moreover, IL33 recruited macrophages into the cancer microenvironment and stimulated them to produce prostaglandin E2, which supported colon cancer stemness and tumor growth. Clinically, tumor IL33 expression associated with poor survival in patients with metastatic colon cancer. Thus, IL33 dually targets tumor cells and macrophages and endows stem-like qualities to colon cancer cells to promote carcinogenesis. Collectively, our work reveals an immune-associated mechanism that extrinsically confers cancer cell stemness properties. Targeting the IL33 signaling pathway may offer an opportunity to treat patients with metastatic cancer. PMID:28249897

Inhibition of beta-catenin and KRAS expressions by Piper betle in azoxymethane-induced colon cancer of male Fischer 344 rats.

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Esa, Faezah; Ngah, Wan Zurinah Wan; Jamal, A Rahman A; Mohd Yusof, Yasmin Anum

2013-12-01

To investigate the chemopreventive effect of Piper betle (PB) on preneoplastic lesions (aberrant crypt foci [ACF]) induced by azoxymethane (AOM) in rats and its effect on colorectal cancer biomarkers (beta-catenin, KRAS, p53 and p21). A total of 32 male Fischer 344 rats were divided into phase 1 and phase 2 groups (8 and 24 weeks of AOM administration, respectively). Each phase was divided into 4 groups: control or normal saline (NS) (1 mL/kg), AOM (15 mg/kg body weight, once weekly for 2 weeks), PB (75 mg/kg body weight) and AOM + PB. PB was force-fed to rats a week after the second dose of AOM and NS. The colon was cut open longitudinally for methylene blue and immunohistochemistry staining. AOM administration showed formation of ACF at 8 and 24 weeks. PB, however, did not reduce ACF formation at either week, but it managed to reduce beta-catenin expression and KRAS found highly expressed in the AOM group of phase 1 rats. No immunoreactivities of p53 and p21 were detected in phase 2 rats, but instead inflammatory cells were visible in between the lesions. PB may act as a potential chemopreventive agent in the early stage of colon carcinogenesis by suppressing the expressions of beta-catenin and KRAS.

Protein Kinases and Transcription Factors Activation in Response to UV-Radiation of Skin: Implications for Carcinogenesis

OpenAIRE

Laurence A. Marchat; Elena Aréchaga Ocampo; Mavil López Casamichana; Carlos Pérez-Plasencia; César López-Camarillo; Elizbeth Álvarez-Sánchez

2011-01-01

Solar ultraviolet (UV) radiation is an important environmental factor that leads to immune suppression, inflammation, photoaging, and skin carcinogenesis. Here, we reviewed the specific signal transduction pathways and transcription factors involved in the cellular response to UV-irradiation. Increasing experimental data supporting a role for p38, MAPK, JNK, ERK1/2, and ATM kinases in the response network to UV exposure is discussed. We also reviewed the participation of NF-?B, AP-1, and NRF2...

Mutagenesis and carcinogenesis resulting from environment pollution

International Nuclear Information System (INIS)

Dimitrov, B.

2001-01-01

The paper reviews different ways of environmental contamination with natural and artificial harmful substances (chemical and radioactive) and their role in the processes of mutagenesis and carcinogenesis. The recent studies of the mechanism of mutagenesis and carcinogenesis due to environmental pollution are discussed

TNF Receptor-2 Facilitates an Immunosuppressive Microenvironment in the Liver to Promote the Colonization and Growth of Hepatic Metastases

DEFF Research Database (Denmark)

Ham, Boram; Wang, Ni; D'Costa, Zarina

2015-01-01

Successful colonization by a cancer cell of a distant metastatic site requires immune escape in the new microenvironment. TNF signaling has been implicated broadly in the suppression of immune surveillance that prevents colonization at the metastatic site and therefore must be blocked. In this st......Successful colonization by a cancer cell of a distant metastatic site requires immune escape in the new microenvironment. TNF signaling has been implicated broadly in the suppression of immune surveillance that prevents colonization at the metastatic site and therefore must be blocked...... chemotherapy-naïve colon cancer patients confirmed the presence of CD33(+)HLA-DR(-)TNFR2(+) myeloid cells in the periphery of hepatic metastases. Overall, our findings implicate TNFR2 in supporting MDSC-mediated immune suppression and metastasis in the liver, suggesting the use of TNFR2 inhibitors...

Inositol Hexaphosphate Inhibits Proliferation and Induces Apoptosis of Colon Cancer Cells by Suppressing the AKT/mTOR Signaling Pathway

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Małgorzata Kapral

2017-10-01

Full Text Available Abstract: AKT, a serine/threonine protein kinase and mammalian target of rapamycin (mTOR plays a critical role in the proliferation and resistance to apoptosis that are essential to the development and progression of colon cancer. Therefore, AKT/mTOR signaling pathway has been recognized as an attractive target for anticancer therapy. Inositol hexaphosphate (InsP6, a natural occurring phytochemical, has been shown to have both preventive and therapeutic effects against various cancers, however, its exact molecular mechanisms of action are not fully understood. The aim of the in vitro study was to investigate the anticancer activity of InsP6 on colon cancer with the focus on inhibiting the AKT1 kinase and p70S6K1 as mTOR effector, in relation to proliferation and apoptosis of cells. The colon cancer Caco-2 cells were cultured using standard techniques and exposed to InsP6 at different concentrations (1 mM, 2.5 mM and 5 mM. Cellular proliferative activity was monitored by 5-bromo-2′-deoxyuridine (BrdU incorporation into cellular DNA. Flow cytometric analysis was performed for cell cycle progression and apoptosis studies. Real-time RT-qPCR was used to validate mRNA levels of CDNK1A, CDNK1B, CASP3, CASP9, AKT1 and S6K1 genes. The concentration of p21 protein as well as the activities of caspase 3, AKT1 and p70S6K1 were determined by the ELISA method. The results revealed that IP6 inhibited proliferation and stimulated apoptosis of colon cancer cells. This effect was mediated by an increase in the expression of genes encoding p21, p27, caspase 3, caspase 9 as well a decrease in transcription of AKT1 and S6K1. InsP6 suppressed phosphorylation of AKT1 and p70S6K1, downstream effector of mTOR. Based on these studies it may be concluded that InsP6 can reduce proliferation and induce apoptosis through inhibition of the AKT/mTOR pathway and mTOR effector followed by modulation of the expression and activity of several key components of these pathways in

A new dietary model to study colorectal carcinogenesis: experimental design, food preparation, and experimental findings.

Science.gov (United States)

Rozen, P; Liberman, V; Lubin, F; Angel, S; Owen, R; Trostler, N; Shkolnik, T; Kritchevsky, D

1996-01-01

Experimental dietary studies of human colorectal carcinogenesis are usually based on the AIN-76A diet, which is dissimilar to human food in source, preparation, and content. The aims of this study were to examine the feasibility of preparing and feeding rats the diet of a specific human population at risk for colorectal neoplasia and to determine whether changes in the colonic morphology and metabolic contents would differ from those resulting from a standard rat diet. The mean daily food intake composition of a previously evaluated adenoma patient case-control study was used for the "human adenoma" (HA) experimental diet. Foods were prepared as for usual human consumption and processed by dehydration to the physical characteristics of an animal diet. Sixty-four female Sprague-Dawley rats were randomized and fed ad libitum the HA or the AIN-76A diet. Every eight weeks, eight rats from each group were sacrificed, and the colons and contents were examined. Analysis of the prepared food showed no significant deleterious changes; food intake and weight gain were similar in both groups. Compared with the controls, the colonic contents of rats fed the HA diet contained significantly less calcium, concentrations of neutral sterols, total lipids, and cholic and deoxycholic acids were increased, and there were no colonic histological changes other than significant epithelial hyperproliferation. This initial study demonstrated that the HA diet can be successfully processed for feeding to experimental animals and is acceptable and adequate for growth but induces significant metabolic and hyperproliferative changes in the rat colon. This dietary model may be useful for studies of human food, narrowing the gap between animal experimentation and human nutritional research.

In vitro studies of human lung carcinogenesis.

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Harris, C C; Lechner, J F; Yoakum, G H; Amstad, P; Korba, B E; Gabrielson, E; Grafstrom, R; Shamsuddin, A; Trump, B F

1985-01-01

Advances in the methodology to culture normal human lung cells have provided opportunities to investigate fundamental problems in biomedical research, including the mechanism(s) of carcinogenesis. Using the strategy schematically shown in Figure 1, we have initiated studies of the effects of carcinogens on the normal progenitor cells of the human cancers caused by these carcinogens. Extended lifespans and aneuploidy were found after exposure of mesothelial cells to asbestos and bronchial epithelial cells to nickel sulfate. These abnormal cells may be considered to be preneoplastic and at an intermediate position in the multistage process of carcinogenesis. Human bronchial epithelial cells can also be employed to investigate the role of specific oncogenes in carcinogenesis and tumor progression. Using the protoplast fusion method for high frequency gene transfection, vHa-ras oncogene initiates a cascade of events in the normal human bronchial cells leading to their apparent immortality, aneuploidy, and tumorigenicity in athymic nude mice. These results suggest that oncogenes may play an important role in human carcinogenesis.

Initiator of carcinogenesis selectively and stably inhibits stem cell differentiation: a concept that initiation of carcinogenesis involves multiple phases

International Nuclear Information System (INIS)

Scott, R.E.; Maercklein, P.B.

1985-01-01

A concept of carcinogenesis was recently devised in our laboratory that suggests the development of defects in the control of cell differentiation is associated with an early phase of carcinogenesis. To test this proposal directly, the effects of an initiator of carcinogenesis (i.e., UV irradiation) on proadipocyte stem cell differentiation and proliferation was assayed. In this regard, 3T3 T proadipocytes represent a nontransformed mesenchymal stem cell line that possesses the ability to regulate its differentiation at a distinct state in the G 1 phase of the cell cycle as well as the ability to regulate its proliferation at two additional G 1 states. The results establish that a slow dosage of 254 nm UV irradiation selectivity and stably inhibits the differentiation of a high percentage of proadipocyte stem cells without significantly altering their ability to regulate cellular proliferation in growth factor-deficient or nutrient-deficient culture conditions. Differentiation-defect proadipocyte stem cells are demonstrated not to be completely transformed but to show an increased spontaneous transformation rate, as evidenced by the formation of type III foci in high density cell cultures. These data support the role of defects in the control of differentiation in the inhibition of carcinogenesis. These observations support a concept that the initiation of carcinogenesis involves multiple phases

Coexistence of K-ras mutations and HPV infection in colon cancer

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Tezol Ayda

2006-05-01

Full Text Available Abstract Background Activation of the ras genes or association with human papillomavirus infection have been extensively studied in colorectal cancer. However, the correlation between K-ras mutations and HPV in colorectal cancer has not been investigated yet. In this study we aimed to investigate the presence of K-ras mutations and their correlation with HPV infection in colon cancer. Methods K-ras mutations were analyzed by a mutagenic PCR assay and digestion with specific restriction enzymes to distinguish the wild-type and mutant codons. HPV infection was analyzed by PCR amplification and hybridization with specific probes by Southern blotting. Stattistical analyses were performed by the chi-square and Fisher's exact tests Results HPV gene fragments were detected in 43 tumors and 17 normal tissue samples. HPV 18 was the prevalent type in the tumor tissue. A mutation at codon 12 of the K-ras gene was present in 31 patients. 56% of the HPV-positive tumors also harbored a K-ras mutation. Codon 13 mutations were not observed. These data indicate that infection with high risk HPV types and mutational activation of the K-ras gene are frequent events in colorectal carcinogenesis. Conclusion Our findings suggest that mutational activation of the K-ras gene is a common event in colon carcinogenesis and that HPV infection may represent an important factor in the development of the premalignant lesions leading to the neoplastic phenotype.

SLC5A8 gene, a transporter of butyrate: a gut flora metabolite, is frequently methylated in African American colon adenomas.

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Hassan Brim

Full Text Available Colon cancer is one of the leading causes of cancer related deaths. Its impact on African Americans (AAs is higher than in the general population both in the incidence and mortality from the disease. Colon cancer aggressiveness in AAs as well as non-frequent check-ups and follow up in this population have been proposed as ways to explain the observed discrepancies. These facts made the detection of early carcinogenesis markers in this population a priority.Here, we analyzed 50 colon adenomas from AA patients for both microsatellite instability (MSI and the methylation status of SLC5A8 gene. This gene's product is involved in the transport of butyrate that has anti-proliferative properties through its effects on histone acetylation and gene expression. A proteomic analysis to check the expressed histones in adenoma and normal tissues was also performed.The analyzed samples displayed 82% (n = 41 methylation level of SLC5A8 gene in adenomas. The MSI-H (high adenoma were about 18% (n = 9 while the rest were mostly MSS (microsatellite stable with few MSI-L (Low. No association was found between SLC5A8 methylation and the MSI status. Also, there was no association between SLC5A8 methylation and the sex and age of the patients. However, there were more right sided adenomas with SLC5A8 methylation than the left sided ones. The proteomic analysis revealed distinct histone expression profiles between normal and adenoma tissues.SLC5A8 is highly methylated in AA colon adenomas which points to its potential use as a marker for early detection. The MSI rate is similar to that found in colon cancer tumors in AAs. These findings suggest that both processes stem from the same epigenetic and genetic events occurring at an early stage in colon carcinogenesis in AAs.

Mutiple simultaneous event model for radiation carcinogenesis

International Nuclear Information System (INIS)

Baum, J.W.

1979-01-01

Theoretical Radiobiology and Risk Estimates includes reports on: Multiple Simultaneous Event Model for Radiation Carcinogenesis; Cancer Risk Estimates and Neutron RBE Based on Human Exposures; A Rationale for Nonlinear Dose Response Functions of Power Greater or Less Than One; and Rationale for One Double Event in Model for Radiation Carcinogenesis

Understanding Carcinogenesis for Fighting Oral Cancer

OpenAIRE

Tanaka, Takuji; Ishigamori, Rikako

2011-01-01

Oral cancer is one of the major global threats to public health. Oral cancer development is a tobacco-related multistep and multifocal process involving field cancerization and carcinogenesis. The rationale for molecular-targeted prevention of oral cancer is promising. Biomarkers of genomic instability, including aneuploidy and allelic imbalance, are able to measure the cancer risk of oral premalignancies. Understanding of the biology of oral carcinogenesis will give us important advances for...

BVES regulates EMT in human corneal and colon cancer cells and is silenced via promoter methylation in human colorectal carcinoma.

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Williams, Christopher S; Zhang, Baolin; Smith, J Joshua; Jayagopal, Ashwath; Barrett, Caitlyn W; Pino, Christopher; Russ, Patricia; Presley, Sai H; Peng, DunFa; Rosenblatt, Daniel O; Haselton, Frederick R; Yang, Jin-Long; Washington, M Kay; Chen, Xi; Eschrich, Steven; Yeatman, Timothy J; El-Rifai, Wael; Beauchamp, R Daniel; Chang, Min S

2011-10-01

The acquisition of a mesenchymal phenotype is a critical step in the metastatic progression of epithelial carcinomas. Adherens junctions (AJs) are required for suppressing this epithelial-mesenchymal transition (EMT) but less is known about the role of tight junctions (TJs) in this process. Here, we investigated the functions of blood vessel epicardial substance (BVES, also known as POPDC1 and POP1), an integral membrane protein that regulates TJ formation. BVES was found to be underexpressed in all stages of human colorectal carcinoma (CRC) and in adenomatous polyps, indicating its suppression occurs early in transformation. Similarly, the majority of CRC cell lines tested exhibited decreased BVES expression and promoter DNA hypermethylation, a modification associated with transcriptional silencing. Treatment with a DNA-demethylating agent restored BVES expression in CRC cell lines, indicating that methylation represses BVES expression. Reexpression of BVES in CRC cell lines promoted an epithelial phenotype, featuring decreased proliferation, migration, invasion, and anchorage-independent growth; impaired growth of an orthotopic xenograft; and blocked metastasis. Conversely, interfering with BVES function by expressing a dominant-negative mutant in human corneal epithelial cells induced mesenchymal features. These biological outcomes were associated with changes in AJ and TJ composition and related signaling. Therefore, BVES prevents EMT, and its epigenetic silencing may be an important step in promoting EMT programs during colon carcinogenesis.

Radiation-induced mammary carcinogenesis in rodent models. What's different from chemical carcinogenesis?

International Nuclear Information System (INIS)

Imaoka, Tatsuhiko; Nishimura, Mayumi; Iizuka, Daisuke; Daino, Kazuhiro; Takabatake, Takashi; Okamoto, Mieko; Kakinuma, Shizuko; Shimada, Yoshiya

2009-01-01

Ionizing radiation is one of a few well-characterized etiologic factors of human breast cancer. Laboratory rodents serve as useful experimental models for investigating dose responses and mechanisms of cancer development. Using these models, a lot of information has been accumulated about mammary gland cancer, which can be induced by both chemical carcinogens and radiation. In this review, we first list some experimental rodent models of breast cancer induction. We then focus on several topics that are important in understanding the mechanisms and risk modification of breast cancer development, and compare radiation and chemical carcinogenesis models. We will focus on the pathology and natural history of cancer development in these models, genetic changes observed in induced cancers, indirect effects of carcinogens, and finally risk modification by reproductive factors and age at exposure to the carcinogens. In addition, we summarize the knowledge available on mammary stem/progenitor cells as a potential target of carcinogens. Comparison of chemical and radiation carcinogenesis models on these topics indicates certain similarities, but it also indicates clear differences in several important aspects, such as genetic alterations of induced cancers and modification of susceptibility by age and reproductive factors. Identification of the target cell type and relevant translational research for human risk management may be among the important issues that are addressed by radiation carcinogenesis models. (author)

A silyl andrographolide analogue suppresses Wnt/β-catenin signaling pathway in colon cancer.

Science.gov (United States)

Reabroi, Somrudee; Chairoungdua, Arthit; Saeeng, Rungnapha; Kasemsuk, Teerapich; Saengsawang, Witchuda; Zhu, Weiming; Piyachaturawat, Pawinee

2018-05-01

Hyperactivation of Wnt/β-catenin signaling implicated in oncogenesis of colorectal cancer (CRC) is a potential molecular target for chemotherapy. An andrographolide analogue, 3A.1 (19-tert-butyldiphenylsilyl-8, 17-epoxy andrographolide) has previously been reported to be potently cytotoxic toward cancer cells by unknown molecular mechanisms. The present study explored the anti-cancer activity of analogue 3A.1 on Wnt/β-catenin signaling in colon cancer cells (HT29 cells) which were more sensitive to the others (HCT116 and SW480 cells). Analogue 3A.1 inhibited viability of HT29 cells with IC 50 value of 11.1 ± 1.4 μM at 24 h, which was more potent than that of the parent andrographolide. Analogue 3A.1 also suppressed the proliferation of HT29 cells and induced cell apoptosis in a dose-dependent manner. Its apoptotic activity was accompanied with increased expressions of proteins related to DNA damages; PARP-1 and γ-H2AX. In addition, analogue 3A.1 significantly inhibited T-cell factor and lymphoid enhancer factor (TCF/LEF) promoter activity of Wnt/β-catenin signaling. Accordingly, the expressions of Wnt target genes and β-catenin protein were suppressed. Moreover, analogue 3A.1 increased the activity of GSK-3β kinase, which is a negative regulator responsible for degradation of intracellular β-catenin. This mode of action was further supported by the absence of the effects after treatment with a GSK-3β inhibitor, and over-expression of a mutant β-catenin (S33Y). Our findings reveal, for the first time, an insight into the molecular mechanism of the anti-cancer activity of analogue 3A.1 through the inhibition of Wnt/β-catenin/GSK-3β pathway and provide a therapeutic potential of the andrographolide analogue 3A.1 in CRC treatment. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Colorectal carcinogenesis: Review of human and experimental animal studies

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Tanaka Takuji

2009-01-01

Full Text Available This review gives a comprehensive overview of cancer development and links it to the current understanding of tumorigenesis and malignant progression in colorectal cancer. The focus is on human and murine colorectal carcinogenesis and the histogenesis of this malignant disorder. A summary of a model of colitis-associated colon tumorigenesis (an AOM/DSS model will also be presented. The earliest phases of colorectal oncogenesis occur in the normal mucosa, with a disorder of cell replication. The large majority of colorectal malignancies develop from an adenomatous polyp (adenoma. These can be defined as well-demarcated masses of epithelial dysplasia, with uncontrolled crypt cell proliferation. When neoplastic cells pass through the muscularis mucosa and infiltrate the submucosa, they are malignant. Carcinomas usually originate from pre-existing adenomas, but this does not imply that all polyps undergo malignant changes and does not exclude de novo oncogenesis. Besides adenomas, there are other types of pre-neoplasia, which include hyperplastic polyps, serrated adenomas, flat adenomas and dysplasia that occurs in the inflamed colon in associated with inflammatory bowel disease. Colorectal neoplasms cover a wide range of pre-malignant and malignant lesions, many of which can easily be removed during endoscopy if they are small. Colorectal neoplasms and/or pre-neoplasms can be prevented by interfering with the various steps of oncogenesis, which begins with uncontrolled epithelial cell replication, continues with the formation of adenomas and eventually evolves into malignancy. The knowledge described herein will help to reduce and prevent this malignancy, which is one of the most frequent neoplasms in some Western and developed countries.

Initiation-promotion skin carcinogenesis and immunological competence.

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Curtis, G L; Stenbäck, F; Ryan, W L

1975-10-01

The immune competence of mice during initiation-promotion skin carcinogenesis was determined by skin allograft rejection and lymphocyte mitogenesis. The carcinogen 7, 12-dimethylbenzanthracene inhibited the cellular immune competence of mice while lymphocytes from croton oil treated mice had enhanced PWM response. Chlorphenesin, a stimulator of cellular immunity, was found to inhibit tumorigenesis in initiation-promotion skin carcinogenesis when injected during promotion.

Nutraceutical Approach for Preventing Obesity-Related Colorectal and Liver Carcinogenesis

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Hisataka Moriwaki

2012-01-01

Full Text Available Obesity and its related metabolic abnormalities, including insulin resistance, alterations in the insulin-like growth factor-1 (IGF-1/IGF-1 receptor (IGF-1R axis, and the state of chronic inflammation, increase the risk of colorectal cancer (CRC and hepatocellular carcinoma (HCC. However, these findings also indicate that the metabolic disorders caused by obesity might be effective targets to prevent the development of CRC and HCC in obese individuals. Green tea catechins (GTCs possess anticancer and chemopreventive properties against cancer in various organs, including the colorectum and liver. GTCs have also been known to exert anti-obesity, antidiabetic, and anti-inflammatory effects, indicating that GTCs might be useful for the prevention of obesity-associated colorectal and liver carcinogenesis. Further, branched-chain amino acids (BCAA, which improve protein malnutrition and prevent progressive hepatic failure in patients with chronic liver diseases, might be also effective for the suppression of obesity-related carcinogenesis because oral supplementation with BCAA reduces the risk of HCC in obese cirrhotic patients. BCAA shows these beneficial effects because they can improve insulin resistance. Here, we review the detailed relationship between metabolic abnormalities and the development of CRC and HCC. We also review evidence, especially that based on our basic and clinical research using GTCs and BCAA, which indicates that targeting metabolic abnormalities by either pharmaceutical or nutritional intervention may be an effective strategy to prevent the development of CRC and HCC in obese individuals.

Collective studies on carcinogenesis due to exposure to radiation

International Nuclear Information System (INIS)

Yamashita, Hisao

1980-01-01

Carcinogenesis was found in 150 of 25,692 patients who had received radiotherapy for benign diseases. Of primary diseases subjected to radiotherapy, skin diseases were the most. Carcinogenesis was found in 26 of 7,230 patients with skin diseases (0.36%) and 18 in 2286 patients with tuberculous cervical lymphadenitis (0.79%). The sites of carcinogenesis was the skin in 51 patients, the hypopharynx in 43, and the larynx in 18. Carcinogenesis was also found in 140 of 220,361 patients who had received radiotherapy for malignant tumors. As primary cancer, cancer of the cervix uteri was found in 59 of 48,662 patients, and breast cancer was found in 20 of 27,967 patients. As radiation-induced cancer, leukemia was found in 18 patients, soft tissue sarcoma in 18, skin cancer in 10, osteosarcoma in 6, cancer of the hypopharynx in 6, and cancer of the cervical esophagus in 6. It is necessary to differentiate cancer due to exposure to radiation from delayed recurrent cancer and double cancer. Irradiation fields should be restricted as small as possible in order to reduce carcinogenesis. As leukemia and carcinoma were found in a-bomb survivors exposed to very small dose of a-bomb radiation, carcinogenic mechanisms by chromosome aberrations, carcinogenic rates from a viewpoint of epidemiology, and other factors which influenced carcinogenesis are being investigated. (Tsunoda, M.)

Reactive oxygen species mediate Cr(VI)-induced carcinogenesis through PI3K/AKT-dependent activation of GSK-3β/β-catenin signaling

International Nuclear Information System (INIS)

Son, Young-Ok; Pratheeshkumar, Poyil; Wang, Lei; Wang, Xin; Fan, Jia; Kim, Dong-Hern; Lee, Ju-Yeon; Zhang, Zhuo; Lee, Jeong-Chae; Shi, Xianglin

2013-01-01

Cr(VI) compounds are known human carcinogens that primarily target the lungs. Cr(VI) produces reactive oxygen species (ROS), but the exact effects of ROS on the signaling molecules involved in Cr(VI)-induced carcinogenesis have not been extensively studied. Chronic exposure of human bronchial epithelial cells to Cr(VI) at nanomolar concentrations (10–100 nM) for 3 months not only induced cell transformation, but also increased the potential of these cells to invade and migrate. Injection of Cr(VI)-stimulated cells into nude mice resulted in the formation of tumors. Chronic exposure to Cr(VI) increased levels of intracellular ROS and antiapoptotic proteins. Transfection with catalase or superoxide dismutase (SOD) prevented Cr(VI)-mediated increases in colony formation, cell invasion, migration, and xenograft tumors. While chronic Cr(VI) exposure led to activation of signaling cascades involving PI3K/AKT/GSK-3β/β-catenin and PI3K/AKT/mTOR, transfection with catalase or SOD markedly inhibited Cr(VI)-mediated activation of these signaling proteins. Inhibitors specific for AKT or β-catenin almost completely suppressed the Cr(VI)-mediated increase in total and active β-catenin proteins and colony formation. In particular, Cr(VI) suppressed autophagy of epithelial cells under nutrition deprivation. Furthermore, there was a marked induction of AKT, GSK-3β, β-catenin, mTOR, and carcinogenic markers in tumor tissues formed in mice after injection with Cr(VI)-stimulated cells. Collectively, our findings suggest that ROS is a key mediator of Cr(VI)-induced carcinogenesis through the activation of PI3K/AKT-dependent GSK-3β/β-catenin signaling and the promotion of cell survival mechanisms via the inhibition of apoptosis and autophagy. - Highlights: • Chronic exposure to Cr(VI) induces carcinogenic properties in BEAS-2B cells. • ROS play an important role in Cr(VI)-induced tumorigenicity of BEAS-2B cells. • PI3K/AKT/GSK-3β/β-catenin signaling involved in Cr

Reactive oxygen species mediate Cr(VI)-induced carcinogenesis through PI3K/AKT-dependent activation of GSK-3β/β-catenin signaling

Energy Technology Data Exchange (ETDEWEB)

Son, Young-Ok; Pratheeshkumar, Poyil; Wang, Lei; Wang, Xin; Fan, Jia; Kim, Dong-Hern; Lee, Ju-Yeon; Zhang, Zhuo [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States); Lee, Jeong-Chae [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States); School of Dentistry and Institute of Oral Biosciences, Research Center of Bioactive Materials, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Shi, Xianglin, E-mail: xshi5@email.uky.edu [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States)

2013-09-01

Cr(VI) compounds are known human carcinogens that primarily target the lungs. Cr(VI) produces reactive oxygen species (ROS), but the exact effects of ROS on the signaling molecules involved in Cr(VI)-induced carcinogenesis have not been extensively studied. Chronic exposure of human bronchial epithelial cells to Cr(VI) at nanomolar concentrations (10–100 nM) for 3 months not only induced cell transformation, but also increased the potential of these cells to invade and migrate. Injection of Cr(VI)-stimulated cells into nude mice resulted in the formation of tumors. Chronic exposure to Cr(VI) increased levels of intracellular ROS and antiapoptotic proteins. Transfection with catalase or superoxide dismutase (SOD) prevented Cr(VI)-mediated increases in colony formation, cell invasion, migration, and xenograft tumors. While chronic Cr(VI) exposure led to activation of signaling cascades involving PI3K/AKT/GSK-3β/β-catenin and PI3K/AKT/mTOR, transfection with catalase or SOD markedly inhibited Cr(VI)-mediated activation of these signaling proteins. Inhibitors specific for AKT or β-catenin almost completely suppressed the Cr(VI)-mediated increase in total and active β-catenin proteins and colony formation. In particular, Cr(VI) suppressed autophagy of epithelial cells under nutrition deprivation. Furthermore, there was a marked induction of AKT, GSK-3β, β-catenin, mTOR, and carcinogenic markers in tumor tissues formed in mice after injection with Cr(VI)-stimulated cells. Collectively, our findings suggest that ROS is a key mediator of Cr(VI)-induced carcinogenesis through the activation of PI3K/AKT-dependent GSK-3β/β-catenin signaling and the promotion of cell survival mechanisms via the inhibition of apoptosis and autophagy. - Highlights: • Chronic exposure to Cr(VI) induces carcinogenic properties in BEAS-2B cells. • ROS play an important role in Cr(VI)-induced tumorigenicity of BEAS-2B cells. • PI3K/AKT/GSK-3β/β-catenin signaling involved in Cr

Combination of aging and dimethylhydrazine treatment causes an increase in cancer-stem cell population of rat colonic crypts.

Science.gov (United States)

Levi, Edi; Misra, Sandhya; Du, Jianhua; Patel, Bhaumik B; Majumdar, Adhip P N

2009-07-31

Aging is associated with increased incidence of colon cancers. It is also becoming evident that cancer stem cells (CSC) play a vital role in the pathogenesis and prognosis of colon cancer. Recently, we reported the presence of colon cancer stem-like cells in macroscopically normal mucosa in patients with adenomatous polyps and that they increase with aging, suggesting that aging may predispose the colon to carcinogenesis. In the current study we have examined the combined effects of aging and carcinogen exposure on the status of colon CSCs in an experimental model. We used young (4-6 months) and aged (22-24 months) rats and exposed them to the carcinogen, dimethylhydroxide (DMH). We investigated the expression of colon cancer stem cell markers, CD44, CD166, EpCam, and ALDH1 as well as EGFR expression in normal colonic crypt epithelium following carcinogen treatment. Our results demonstrate that aging per se or carcinogen treatment alone causes an increase in the number of colon cancer stems cells, as evidenced by increased immunoreactive-CSC-markers positive cells in the colonic mucosa. In aged rats, carcinogen exposure results in a more pronounced increase in colon cancer stem cells. Our study shows that in aging colon the effects of carcinogens are more pronounced, and an increase in colon CSCs is one of the earliest changes preceding tumor development. Moreover, the current investigation of the use of a panel of immunohistochemical markers of colon CSC can potentially serve as a prognostic marker during screening for colon cancer.

β-Nicotinamide adenine dinucleotide acts at prejunctional adenosine A1 receptors to suppress inhibitory musculomotor neurotransmission in guinea pig colon and human jejunum

Science.gov (United States)

Wang, Guo-Du; Wang, Xi-Yu; Liu, Sumei; Xia, Yun; Zou, Fei; Qu, Meihua; Needleman, Bradley J.; Mikami, Dean J.

2015-01-01

Intracellular microelectrodes were used to record neurogenic inhibitory junction potentials in the intestinal circular muscle coat. Electrical field stimulation was used to stimulate intramural neurons and evoke contraction of the smooth musculature. Exposure to β-nicotinamide adenine dinucleotide (β-NAD) did not alter smooth muscle membrane potential in guinea pig colon or human jejunum. ATP, ADP, β-NAD, and adenosine, as well as the purinergic P2Y1 receptor antagonists MRS 2179 and MRS 2500 and the adenosine A1 receptor agonist 2-chloro-N6-cyclopentyladenosine, each suppressed inhibitory junction potentials in guinea pig and human preparations. β-NAD suppressed contractile force of twitch-like contractions evoked by electrical field stimulation in guinea pig and human preparations. P2Y1 receptor antagonists did not reverse this action. Stimulation of adenosine A1 receptors with 2-chloro-N6-cyclopentyladenosine suppressed the force of twitch contractions evoked by electrical field stimulation in like manner to the action of β-NAD. Blockade of adenosine A1 receptors with 8-cyclopentyl-1,3-dipropylxanthine suppressed the inhibitory action of β-NAD on the force of electrically evoked contractions. The results do not support an inhibitory neurotransmitter role for β-NAD at intestinal neuromuscular junctions. The data suggest that β-NAD is a ligand for the adenosine A1 receptor subtype expressed by neurons in the enteric nervous system. The influence of β-NAD on intestinal motility emerges from adenosine A1 receptor-mediated suppression of neurotransmitter release at inhibitory neuromuscular junctions. PMID:25813057

Decreased Polyunsaturated Fatty Acid Content Contributes to Increased Survival in Human Colon Cancer

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Manuela Oraldi

2009-01-01

Full Text Available Among diet components, some fatty acids are known to affect several stages of colon carcinogenesis, whereas others are probably helpful in preventing tumors. In light of this, our aim was to determine the composition of fatty acids and the possible correlation with apoptosis in human colon carcinoma specimens at different Duke's stages and to evaluate the effect of enriching human colon cancer cell line with the possible reduced fatty acid(s. Specimens of carcinoma were compared with the corresponding non-neoplastic mucosa: a significant decrease of arachidonic acid, PPARα, Bad, and Bax and a significant increase of COX-2, Bcl-2, and pBad were found. The importance of arachidonic acid in apoptosis was demonstrated by enriching a Caco-2 cell line with this fatty acid. It induced apoptosis in a dose- and time-dependent manner via induction of PPARα that, in turn, decreased COX-2. In conclusion, the reduced content of arachidonic acid is likely related to carcinogenic process decreasing the susceptibility of cancer cells to apoptosis.

PLK1 has tumor-suppressive potential in APC-truncated colon cancer cells.

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Raab, Monika; Sanhaji, Mourad; Matthess, Yves; Hörlin, Albrecht; Lorenz, Ioana; Dötsch, Christina; Habbe, Nils; Waidmann, Oliver; Kurunci-Csacsko, Elisabeth; Firestein, Ron; Becker, Sven; Strebhardt, Klaus

2018-03-16

The spindle assembly checkpoint (SAC) acts as a molecular safeguard in ensuring faithful chromosome transmission during mitosis, which is regulated by a complex interplay between phosphatases and kinases including PLK1. Adenomatous polyposis coli (APC) germline mutations cause aneuploidy and are responsible for familial adenomatous polyposis (FAP). Here we study the role of PLK1 in colon cancer cells with chromosomal instability promoted by APC truncation (APC-ΔC). The expression of APC-ΔC in colon cells reduces the accumulation of mitotic cells upon PLK1 inhibition, accelerates mitotic exit and increases the survival of cells with enhanced chromosomal abnormalities. The inhibition of PLK1 in mitotic, APC-∆C-expressing cells reduces the kinetochore levels of Aurora B and hampers the recruitment of SAC component suggesting a compromised mitotic checkpoint. Furthermore, Plk1 inhibition (RNAi, pharmacological compounds) promotes the development of adenomatous polyps in two independent Apc Min/+ mouse models. High PLK1 expression increases the survival of colon cancer patients expressing a truncated APC significantly.

Radiation carcinogenesis in scid mice

Energy Technology Data Exchange (ETDEWEB)

Ishii, Hiroko; Nishimura, Mayumi; Kobayashi, Shigeru; Tsuji, Hideo; Shimada, Yoshiya; Ogiu, Toshiaki [National Inst. of Radiological Sciences, Chiba (Japan); Suzuki, Fumio; Sado, Toshihiko

1999-06-01

Scid mice which have the defect of DNA-dependent protein kinase catalitic subunit, exhibit the limited activities of repair from DNA double strand breaks, and are sensitive to ionizing radiation. In order to study the relationship between repair capacity for DNA double strand breaks and carcinogenesis, the effects of ionizing radiation were studied using scid homozygotes (scid/scid), scid heterozygotes (scid/+) and CB-17 (+/+) mice. Both the Scid bone marrow cells and fibroblast cell lines from Scid embryos were highly sensitivity to acute effects of ionizing radiation. Carcinogenesis experiments showed the high incidence of thymic lymphomas (80 to 90%) in 1 to 3 Gy {sup 137}Cs-{gamma}-ray-irradiated Scid mice. (author)

Diet, lifestyle, and molecular alterations that drive colorectal carcinogenesis

NARCIS (Netherlands)

Diergaarde, B.

2004-01-01

Environmental factors have been repeatedly implicated in the etiology of colorectal cancer, and much is known about the molecular events involved in colorectal carcinogenesis. The relationships between environmental risk factors and the molecular alterations that drive colorectal carcinogenesis are

TRIM45 negatively regulates NF-κB-mediated transcription and suppresses cell proliferation

International Nuclear Information System (INIS)

Shibata, Mio; Sato, Tomonobu; Nukiwa, Ryota; Ariga, Tadashi; Hatakeyama, Shigetsugu

2012-01-01

Highlights: ► NF-κB plays an important role in cell survival and carcinogenesis. ► TRIM45 negatively regulates TNFα-induced NF-κB-mediated transcription. ► TRIM45 overexpression suppresses cell growth. ► TRIM45 acts as a repressor for the NF-κB signal and regulates cell growth. -- Abstract: The NF-κB signaling pathway plays an important role in cell survival, immunity, inflammation, carcinogenesis, and organogenesis. Activation of NF-κB is regulated by several posttranslational modifications including phosphorylation, neddylation and ubiquitination. The NF-κB signaling pathway is activated by two distinct signaling mechanisms and is strictly modulated by the ubiquitin–proteasome system. It has been reported that overexpression of TRIM45, one of the TRIM family ubiquitin ligases, suppresses transcriptional activities of Elk-1 and AP-1, which are targets of the MAPK signaling pathway. In this study, we showed that TRIM45 also negatively regulates TNFα-induced NF-κB-mediated transcription by a luciferase reporter assay and that TRIM45 lacking a RING domain also has an activity to inhibit the NF-κB signal. Moreover, we found that TRIM45 overexpression suppresses cell growth. These findings suggest that TRIM45 acts as a repressor for the NF-κB signal and regulates cell growth.

1-L-MT, an IDO inhibitor, prevented colitis-associated cancer by inducing CDC20 inhibition-mediated mitotic death of colon cancer cells.

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Liu, Xiuting; Zhou, Wei; Zhang, Xin; Ding, Yang; Du, Qianming; Hu, Rong

2018-04-01

Indoleamine 2,3-dioxygenase 1 (IDO1), known as IDO, catabolizes tryptophan through kynurenine pathway, whose activity is correlated with impaired clinical outcome of colorectal cancer. Here we showed that 1-L-MT, a canonical IDO inhibitor, suppressed proliferation of human colorectal cancer cells through inducing mitotic death. Our results showed that inhibition of IDO decreased the transcription of CDC20, which resulted in G2/M cycle arrest of HCT-116 and HT-29. Furthermore, 1-L-MT induced mitochondria injuries and caused apoptotic cancer cells. Importantly, 1-L-MT protected mice from azoxymethane (AOM)/dextran sodium sulfate (DSS)-induced colon carcinogenesis, with reduced mortality, tumor number and size. What is more, IDO1-/- mice exhibited fewer tumor burdens and reduced proliferation in the neoplastic epithelium, while, 1-L-MT did not exhibit any further protective effects on IDO-/- mice, confirming the critical role of IDO and the protective effect of 1-L-MT-mediated IDO inhibition in CRC. Furthermore, 1-L-MT also alleviated CRC in Rag1-/- mice, demonstrating the modulatory effects of IDO independent of its role in modulating adaptive immunity. Taken together, our findings validated that the anti-proliferation effect of 1-L-MT in vitro and the prevention of CRC in vivo were through IDO-induced cell cycle disaster of colon cancer cells. Our results identified 1-L-MT as a promising candidate for the chemoprevention of CRC. © 2018 UICC.

Statistical modeling and extrapolation of carcinogenesis data

International Nuclear Information System (INIS)

Krewski, D.; Murdoch, D.; Dewanji, A.

1986-01-01

Mathematical models of carcinogenesis are reviewed, including pharmacokinetic models for metabolic activation of carcinogenic substances. Maximum likelihood procedures for fitting these models to epidemiological data are discussed, including situations where the time to tumor occurrence is unobservable. The plausibility of different possible shapes of the dose response curve at low doses is examined, and a robust method for linear extrapolation to low doses is proposed and applied to epidemiological data on radiation carcinogenesis

[Curcumin inhibited rat colorectal carcinogenesis by activating PPAR-γ: an experimental study].

Science.gov (United States)

Liu, Liu-bin; Duan, Chang-nong; Ma, Zeng-yi; Xu, Gang

2015-04-01

To explore the chemopreventive effect of curcumin on DMH induced colorectal carcinogenesis and the underlining mechanism. Totally 40 Wistar rats were divided into the model group and the curcumin group by random digit table, 20 in each group. Meanwhile, a normal control group was set up (n =10). A colorectal cancer model was induced by subcutaneously injecting 20 mg/kg DMH. The tumor incidence and the inhibition rate were calculated. The effect of curcumin on the expression of peroxisome proliferator-activated receptor gamma (PPARγ) in rat colon mucosal tissues was observed using immunohistochemistry and Western blot. HT 29 cell line were cultured and divided into a control group, the curcumin + GW9662 (2-chloro-5-nitro-N-4-phenylbenzamide) intervention group, and the curcumin group. The inhibition of different concentrations curcumin on HT29 cell line was detected using MTT. The expression of curcumin on PPARy was also detected using Western blot. The tumor incidence was 80. 00% (12/15 cases) in the model group, obviously higher than that of the curcumin group (58. 82%, 10/17 cases, P manners. The expression of PPARy protein was significantly increased in the GW9662 group and the curcumin group, showing statistical difference when compared with the normal control group (P <0. 01). Compared with the GW9662 group, the expression of PPARγ protein was significantly increased in the curcumin group (P <0. 01). Curcumin could inhibit DMH-induced rat colorectal carcinogenesis and the growth of in vitro cultured HT 29 cell line, which might be achieved by activating PPARy signal transduction pathway.

Muscarinic receptor agonists stimulate matrix metalloproteinase 1-dependent invasion of human colon cancer cells

International Nuclear Information System (INIS)

Raufman, Jean-Pierre; Cheng, Kunrong; Saxena, Neeraj; Chahdi, Ahmed; Belo, Angelica; Khurana, Sandeep; Xie, Guofeng

2011-01-01

Highlights: ► Muscarinic receptor agonists stimulated robust human colon cancer cell invasion. ► Anti-matrix metalloproteinase1 antibody pre-treatment blocks cell invasion. ► Bile acids stimulate MMP1 expression, cell migration and MMP1-dependent invasion. -- Abstract: Mammalian matrix metalloproteinases (MMPs) which degrade extracellular matrix facilitate colon cancer cell invasion into the bloodstream and extra-colonic tissues; in particular, MMP1 expression correlates strongly with advanced colon cancer stage, hematogenous metastasis and poor prognosis. Likewise, muscarinic receptor signaling plays an important role in colon cancer; muscarinic receptors are over-expressed in colon cancer compared to normal colon epithelial cells. Muscarinic receptor activation stimulates proliferation, migration and invasion of human colon cancer cells. In mouse intestinal neoplasia models genetic ablation of muscarinic receptors attenuates carcinogenesis. In the present work, we sought to link these observations by showing that MMP1 expression and activation plays a mechanistic role in muscarinic receptor agonist-induced colon cancer cell invasion. We show that acetylcholine, which robustly increases MMP1 expression, stimulates invasion of HT29 and H508 human colon cancer cells into human umbilical vein endothelial cell monolayers – this was abolished by pre-incubation with atropine, a non-selective muscarinic receptor inhibitor, and by pre-incubation with anti-MMP1 neutralizing antibody. Similar results were obtained using a Matrigel chamber assay and deoxycholyltaurine (DCT), an amidated dihydroxy bile acid associated with colon neoplasia in animal models and humans, and previously shown to interact functionally with muscarinic receptors. DCT treatment of human colon cancer cells resulted in time-dependent, 10-fold increased MMP1 expression, and DCT-induced cell invasion was also blocked by pre-treatment with anti-MMP1 antibody. This study contributes to understanding

Muscarinic receptor agonists stimulate matrix metalloproteinase 1-dependent invasion of human colon cancer cells

Energy Technology Data Exchange (ETDEWEB)

Raufman, Jean-Pierre, E-mail: jraufman@medicine.umaryland.edu [Division of Gastroenterology and Hepatology, University of Maryland School of Medicine, Baltimore, MD (United States); Cheng, Kunrong; Saxena, Neeraj; Chahdi, Ahmed; Belo, Angelica; Khurana, Sandeep; Xie, Guofeng [Division of Gastroenterology and Hepatology, University of Maryland School of Medicine, Baltimore, MD (United States)

2011-11-18

Highlights: Black-Right-Pointing-Pointer Muscarinic receptor agonists stimulated robust human colon cancer cell invasion. Black-Right-Pointing-Pointer Anti-matrix metalloproteinase1 antibody pre-treatment blocks cell invasion. Black-Right-Pointing-Pointer Bile acids stimulate MMP1 expression, cell migration and MMP1-dependent invasion. -- Abstract: Mammalian matrix metalloproteinases (MMPs) which degrade extracellular matrix facilitate colon cancer cell invasion into the bloodstream and extra-colonic tissues; in particular, MMP1 expression correlates strongly with advanced colon cancer stage, hematogenous metastasis and poor prognosis. Likewise, muscarinic receptor signaling plays an important role in colon cancer; muscarinic receptors are over-expressed in colon cancer compared to normal colon epithelial cells. Muscarinic receptor activation stimulates proliferation, migration and invasion of human colon cancer cells. In mouse intestinal neoplasia models genetic ablation of muscarinic receptors attenuates carcinogenesis. In the present work, we sought to link these observations by showing that MMP1 expression and activation plays a mechanistic role in muscarinic receptor agonist-induced colon cancer cell invasion. We show that acetylcholine, which robustly increases MMP1 expression, stimulates invasion of HT29 and H508 human colon cancer cells into human umbilical vein endothelial cell monolayers - this was abolished by pre-incubation with atropine, a non-selective muscarinic receptor inhibitor, and by pre-incubation with anti-MMP1 neutralizing antibody. Similar results were obtained using a Matrigel chamber assay and deoxycholyltaurine (DCT), an amidated dihydroxy bile acid associated with colon neoplasia in animal models and humans, and previously shown to interact functionally with muscarinic receptors. DCT treatment of human colon cancer cells resulted in time-dependent, 10-fold increased MMP1 expression, and DCT-induced cell invasion was also blocked by pre

Expression of Anion Exchanger 1 Sequestrates p16 in the Cytoplasm in Gastric, Colonic Adenocarcinoma

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Wei-Wei Shen

2007-10-01

Full Text Available p16INK4A (p16 binds to cyclin-dependent kinase 4/6, negatively regulates cell growth. Recent studies have led to an understanding of additional biologic functions for p16; however, the detailed mechanisms involved are still elusive. In this article, we show an unexpected expression of anion exchanger 1 (AEi in the cytoplasm in poorly, moderately differentiated gastric, colonic adenocarcinoma cells, in its interaction with p16, thereby sequestrating the protein in the cytoplasm. Genetic alterations of p16, AEi were not detectable. Forced expression of AEi in these cells sequestrated more p16 in the cytoplasm, whereas small interfering RNA-mediated silencing of AEi in the cells induced the release of p16 from the cytoplasm to the nucleus, leading to cell death, growth inhibition of tumor cells. By analyzing tissue samples obtained from patients with gastric, colonic cancers, we found that 83.33% of gastric cancers, 56.52% of colonic cancers coexpressed AEi, p16 in the cytoplasm. We conclude that AEi plays a crucial role in the pathogenesis of gastric, colonic adenocarcinoma, that p16 dysfunction is a novel pathway of carcinogenesis.

A Limited Role of p53 on the Ability of a Hexane Fraction of American Ginseng to Suppress Mouse Colitis

Directory of Open Access Journals (Sweden)

Deepak Poudyal

2012-01-01

Full Text Available Ulcerative colitis (UC is debilitating and carries a high colon cancer risk. Apoptosis of inflammatory cells is a key mechanism regulating UC. We have recently shown that American ginseng (AG, and to a greater extent, a Hexane fraction of AG (HAG can cause apoptosis and suppress mouse colitis through a p53-mediated mechanism. Here, we tested the hypothesis that HAG suppresses colitis through a p53 mechanism. We found only a limited impact of p53 in the ability of HAG to induce inflammatory cell apoptosis and suppress mouse colitis in vitro and in vivo. Finally, we asked whether HAG could cause cell cycle arrest of HCT116 colon cancer cells in vitro. Interestingly, HAG caused a G1 arrest of such cells independent of p53 status. Findings are significant because HAG suppresses colitis and associated colon cancer, and mutation in p53 is observed in most colitis-driven colon cancers. Therefore, HAG might be very effective in targeting the inflammatory cells and cancer cells since it induces apoptosis of inflammatory cells and cell cycle arrest in both p53−/− and WT p53 colon cancer cells.

Lebein, a snake venom disintegrin, suppresses human colon cancer cells proliferation and tumor-induced angiogenesis through cell cycle arrest, apoptosis induction and inhibition of VEGF expression.

Science.gov (United States)

Zakraoui, Ons; Marcinkiewicz, Cezary; Aloui, Zohra; Othman, Houcemeddine; Grépin, Renaud; Haoues, Meriam; Essafi, Makram; Srairi-Abid, Najet; Gasmi, Ammar; Karoui, Habib; Pagès, Gilles; Essafi-Benkhadir, Khadija

2017-01-01

Lebein, is an heterodimeric disintegrin isolated from Macrovipera lebetina snake venom that was previously characterized as an inhibitor of ADP-induced platelet aggregation. In this study, we investigated the effect of Lebein on the p53-dependent growth of human colon adenocarcinoma cell lines. We found that Lebein significantly inhibited LS174 (p53wt), HCT116 (p53wt), and HT29 (p53mut) colon cancer cell viability by inducing cell cycle arrest through the modulation of expression levels of the tumor suppression factor p53, cell cycle regulating proteins cyclin D1, CDK2, CDK4, retinoblastoma (Rb), CDK1, and cyclin-dependent kinase inhibitors p21 and p27. Interestingly, Lebein-induced apoptosis of colon cancer cells was dependent on their p53 status. Thus, in LS174 cells, cell death was associated with PARP cleavage and the activation of caspases 3 and 8 while in HCT116 cells, Lebein induced caspase-independent apoptosis through increased expression of apoptosis inducing factor (AIF). In LS174 cells, Lebein triggers the activation of the MAPK ERK1/2 pathway through induction of reactive oxygen species (ROS). It also decreased cell adhesion and migration to fibronectin through down regulation of α5β1 integrin. Moreover, Lebein significantly reduced the expression of two angiogenesis stimulators, Vascular Endothelial Growth Factor (VEGF) and Neuropilin 1 (NRP1). It inhibited the VEGF-induced neovascularization process in the quail embryonic CAM system and blocked the development of human colon adenocarcinoma in nude mice. Overall, our work indicates that Lebein may be useful to design a new therapy against colon cancer. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Candidate mechanisms accounting for effects of physical activity on breast carcinogenesis.

Science.gov (United States)

Thompson, Henry J; Jiang, Weiqin; Zhu, Zongjian

2009-09-01

Evidence is strong that a reduction in risk for breast cancer is associated with moderate to vigorous physical activity (PA); however, there is limited understanding of the role of type, intensity, duration, and frequency of PA and their mechanisms in accounting for this health benefit. The objective of this review is to stimulate investigations of candidate mechanisms that may account for the effects of the intensity and duration of aerobic PA on breast cancer risk and tumor burden. Three hypotheses are considered: 1) the mTOR network hypothesis: PA inhibits carcinogenesis by suppressing the activation of the mTOR signaling network in mammary carcinomas; 2) the hormesis hypothesis: the carcinogenic response to PA is nonlinear and accounted for by a physiological cellular stress response; and 3) the metabolic reprogramming hypothesis: PA limits the amount of glucose and glutamine available to mammary carcinomas thereby inducing apoptosis because tumor-associated metabolic programming is reversed. To link these hypotheses to systemic effects of PA, it is recommended that consideration be given to determining: 1) what contracting muscle releases into circulation or removes from circulation that would directly modulate the carcinogenic process in epithelial cells; 2) whether the effects of muscle contraction on epithelial cell carcinogenesis are exerted in an endocrine, paracrine, autocrine, or intracrine manner; and 3) if the effects of muscle contraction on malignant cells differ from effects on normal or premalignant cells that do not manifest the hallmarks of malignancy. (c) 2009 IUBMB

BMP Suppresses PTEN Expression via RAS/ERK Signaling

OpenAIRE

Beck, Stayce E.; Carethers, John M.

2007-01-01

Bone morphogenetic protein (BMP), a member of the transforming growth factor β family, classically utilizes the SMAD signaling pathway for its growth suppressive effects, and loss of this signaling cascade may accelerate cell growth. In the colon cancer predisposition syndrome Juvenile Polyposis, as well as in the late progression stages of nonsyndromic colorectal cancers, SMAD4 function is typically abrogated. Here, we utilized the SMAD4-null SW480 colon cancer cell line to examine BMPs effe...

Glucosinolates from pak choi and broccoli induce enzymes and inhibit inflammation and colon cancer differently.

Science.gov (United States)

Lippmann, Doris; Lehmann, Carsten; Florian, Simone; Barknowitz, Gitte; Haack, Michael; Mewis, Inga; Wiesner, Melanie; Schreiner, Monika; Glatt, Hansruedi; Brigelius-Flohé, Regina; Kipp, Anna P

2014-06-01

High consumption of Brassica vegetables is considered to prevent especially colon carcinogenesis. The content and pattern of glucosinolates (GSLs) can highly vary among different Brassica vegetables and may, thus, affect the outcome of Brassica intervention studies. Therefore, we aimed to feed mice with diets containing plant materials of the Brassica vegetables broccoli and pak choi. Further enrichment of the diets by adding GSL extracts allowed us to analyze the impact of different amounts (GSL-poor versus GSL-rich) and different patterns (broccoli versus pak choi) of GSLs on inflammation and tumor development in a model of inflammation-triggered colon carcinogenesis (AOM/DSS model). Serum albumin adducts were analyzed to confirm the up-take and bioactivation of GSLs after feeding the Brassica diets for four weeks. In agreement with their high glucoraphanin content, broccoli diets induced the formation of sulforaphane-lysine adducts. Levels of 1-methoxyindolyl-3-methyl-histidine adducts derived from neoglucobrassicin were the highest in the GSL-rich pak choi group. In the colon, the GSL-rich broccoli and the GSL-rich pak choi diet up-regulated the expression of different sets of typical Nrf2 target genes like Nqo1, Gstm1, Srxn1, and GPx2. GSL-rich pak choi induced the AhR target gene Cyp1a1 but did not affect Ugt1a1 expression. Both colitis and tumor number were drastically reduced after feeding the GSL-rich pak choi diet while the other three diets had no effect. GSLs can act anti-inflammatory and anti-carcinogenic but both effects depend on the specific amount and pattern of GSLs within a vegetable. Thus, a high Brassica consumption cannot be generally considered to be cancer-preventive.

Ultraviolet radiation-induced carcinogenesis: mechanisms and experimental models

International Nuclear Information System (INIS)

Ramasamy, Karthikeyan; Shanmugam, Mohana; Balupillai, Agilan; Govindhasamy, Kanimozhi; Gunaseelan, Srithar; Muthusamy, Ganesan; Robert, Beualah Mary; Nagarajan, Rajendra Prasad

2017-01-01

Ultraviolet radiation (UVR) is a very prominent environmental toxic agent. UVR has been implicated in the initiation and progression of photocarcinogenesis. UVR exposure elicits numerous cellular and molecular events which include the generation of inflammatory mediators, DNA damage, epigenetic modifications, and oxidative damages mediated activation of signaling pathways. UVR-initiated signal transduction pathways are believed to be responsible for tumor promotion effects. UVR-induced carcinogenic mechanism has been well studied using various animal and cellular models. Human skin-derived dermal fibroblasts, epidermal keratinocytes, and melanocytes served as excellent cellular model systems for the understanding of UVR-mediated carcinogenic events. Apart from this, scientists developed reconstituted three-dimensional normal human skin equivalent models for the study of UVR signaling pathways. Moreover, hairless mice such as SKH-1, devoid of Hr gene, served as a valuable model for experimental carcinogenesis. Scientists have also used transgenic mice and dorsal portion shaved Swiss albino mice for UVR carcinogenesis studies. In this review, we have discussed the current progress in the study on ultraviolet B (UVB)-mediated carcinogenesis and outlined appropriate experimental models for both ultraviolet A- and UVB-mediated carcinogenesis. (author)

The influence of surgical transection and anastomosis on the rate of cell proliferation in the colonic epithelium of normal and DMH-treated rats.

Science.gov (United States)

Barkla, D H; Tutton, P M

1983-10-01

Normal and DMH-treated male rats aged 18-20 weeks underwent surgical transection and anastomosis of the transverse colon. Animals were subsequently killed at intervals of 14, 30 and 72 days. Three hours prior to sacrifice animals were injected with vinblastine sulphate and mitotic indices were subsequently estimated in histological sections. Possible differences between experimental and control groups were tested using a Student's t-test. The results show that the accumulated mitotic indices in normal and DMH-treated colon are statistically similar. The results also show that transection and anastomosis stimulates cell division in both normal and DMH-treated colon and that the increase is of greater amplitude and more prolonged duration in the DMH-treated rats. Carcinomas developed close to the line of anastomosis in DMH-treated but not in control rats. The results support the hypothesis that non-specific injury to hyperplastic colonic epithelium promotes carcinogenesis.

Feeding of the water extract from Ganoderma lingzhi to rats modulates secondary bile acids, intestinal microflora, mucins, and propionate important to colon cancer.

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Yang, Yongshou; Nirmagustina, Dwi Eva; Kumrungsee, Thanutchaporn; Okazaki, Yukako; Tomotake, Hiroyuki; Kato, Norihisa

2017-09-01

Consumption of reishi mushroom has been reported to prevent colon carcinogenesis in rodents, although the underlying mechanisms remain unclear. To investigate this effect, rats were fed a high-fat diet supplemented with 5% water extract from either the reishi mushroom (Ganoderma lingzhi) (WGL) or the auto-digested reishi G. lingzhi (AWGL) for three weeks. Both extracts markedly reduced fecal secondary bile acids, such as lithocholic acid and deoxycholic acid (colon carcinogens). These extracts reduced the numbers of Clostridium coccoides and Clostridium leptum (secondary bile acids-producing bacteria) in a per g of cecal digesta. Fecal mucins and cecal propionate were significantly elevated by both extracts, and fecal IgA was significantly elevated by WGL, but not by AWGL. These results suggest that the reishi extracts have an impact on colon luminal health by modulating secondary bile acids, microflora, mucins, and propionate that related to colon cancer.

Meat processing and colon carcinogenesis: cooked, nitrite-treated, and oxidized high-heme cured meat promotes mucin-depleted foci in rats

OpenAIRE

Santarelli, Raphaëlle L; Vendeuvre, Jean-Luc; Naud, Nathalie; Taché, Sylviane; Guéraud, Françoise; Viau, Michelle; Genot, Claude; Corpet, Denis E; Pierre, Fabrice H F

2010-01-01

International audience; Processed meat intake is associated with colorectal cancer risk, but no experimental study supports the epidemiologic evidence. To study the effect of meat processing on carcinogenesis promotion, we first did a 14-day study with 16 models of cured meat. Studied factors, in a 2 x 2 x 2 x 2 design, were muscle color (a proxy for heme level), processing temperature, added nitrite, and packaging. Fischer 344 rats were fed these 16 diets, and we evaluated fecal and urinary ...

Genetic alterations during radiation-induced carcinogenesis

International Nuclear Information System (INIS)

Kodama, Seiji

1995-01-01

This paper reviews radiation-induced genetic alterations and its carcinogenesis, focusing on the previous in vitro assay outcome. A colony formation assay using Syrian hamster fetal cells and focus formation assay using mouse C3H10T1/2 cells are currently available to find malignant transformation of cells. Such in vitro assays has proposed the hypothesis that radiation-induced carcinogenesis arises from at least two-stage processes; i.e., that an early step induced by irradiation plays an important role in promoting the potential to cause the subsequent mutation. A type of genetic instability induced by radiation results in a persistently elevated frequency of spontaneous mutations, so-called the phenomenon of delayed reproductive death. One possible mechanism by which genetic instability arises has been shown to be due to the development of abnormality in the gene group involved in the maintenance mechanism of genome stability. Another possibility has also been shown to stem from the loss of telomere (the extremities of a chromosome). The importance of search for radiation-induced genetic instability is emphasized in view of the elucidation of carcinogenesis. (N.K.)

Refined carbohydrate enhancement of aberrant crypt foci (ACF) in rat colon induced by the food-borne carcinogen 2-amino-3-methyl-imidazo[4,5-f]quinoline (IQ)

DEFF Research Database (Denmark)

Kristiansen, E.; Meyer, Otto A.; Thorup, I.

1996-01-01

,2-dimethylhydrazine dihydrochloride (DMH) and azoxymethane (AOM), the use of a diet-related colon cancer initiator, such as the heterocyclic amine 2-amino-3-methyl-imidazo[4,5-f]quinoline (IQ) formed during meat cooking, would probably give a more relevant insight into diet-related colon carcinogenesis......The aberrant crypt foci (ACF) bioassay has been used extensively to study the early effects of different dietary components on the colonic mucosa of laboratory rodents. ACF are proposed to represent preneoplastic lesions of colon cancer. Compared to the normally used initiators 1....... In the present study it is shown that a feeding regimen with continuous low IQ doses (0.03% in the diet) throughout a study period of 10 weeks has a significant effect on the induction of ACF in the colon of male F344 rats. In addition, the study illustrates that the incidence of the IQ-induced ACF can...

Ursodeoxycholic acid inhibits the proliferation of colon cancer cells by regulating oxidative stress and cancer stem-like cell growth

Science.gov (United States)

Kim, EuiJoo

2017-01-01

Introduction The regulation of reactive oxygen species (ROS) exists as a therapeutic target for cancer treatments. Previous studies have shown that ursodeoxycholic acid (UDCA) suppresses the proliferation of colon cancer cells. The aim of this study was to evaluate the effect of UDCA upon the proliferation of colon cancer cells as a direct result of the regulation of ROS. Method Colon cancer cell lines (HT29 and HCT116) were treated with UDCA. The total number of cells and the number of dead cells were determined using cell counters. A fluorescein isothiocyanate-bromodeoxyuridine flow kit was used to analyze cell cycle variations. Upon exposure to UDCA, the protein levels of p27, p21, CDK2, CDK4 and CDK6 were determined using western blotting, and qRT-PCR was used to determine levels of mRNA. We preformed dichlorofluorescindiacetate (DCF-DA) staining to detect alteration of intracellular ROS using fluorescence activated cell sorting (FACS). Colon cancer stem-like cell lines were generated by tumorsphere culture and treated with UDCA for seven days. The total number of tumorspheres was determined using microscopy. Results We found that UDCA reduced the total number of colon cancer cells, but did not increase the number of dead cells. UDCA inhibited the G1/S and G2/M transition phases in colon cancer cells. UDCA induced expression of cell cycle inhibitors such as p27 and p21. However, it was determined that UDCA suppressed levels of CDK2, CDK4, and CDK6. UDCA regulated intracellular ROS generation in colon cancer cells, and induced activation of Erk1/2. Finally, UDCA inhibited formation of colon cancer stem-like cells. Conclusion Our results indicate that UDCA suppresses proliferation through regulation of oxidative stress in colon cancer cells, as well as colon cancer stem-like cells. PMID:28708871

Present status of theories and data analyses of mathematical models for carcinogenesis

International Nuclear Information System (INIS)

Kai, Michiaki; Kawaguchi, Isao

2007-01-01

Reviewed are the basic mathematical models (hazard functions), present trend of the model studies and that for radiation carcinogenesis. Hazard functions of carcinogenesis are described for multi-stage model and 2-event model related with cell dynamics. At present, the age distribution of cancer mortality is analyzed, relationship between mutation and carcinogenesis is discussed, and models for colorectal carcinogenesis are presented. As for radiation carcinogenesis, models of Armitage-Doll and of generalized MVK (Moolgavkar, Venson, Knudson, 1971-1990) by 2-stage clonal expansion have been applied to analysis of carcinogenesis in A-bomb survivors, workers in uranium mine (Rn exposure) and smoking doctors in UK and other cases, of which characteristics are discussed. In analyses of A-bomb survivors, models above are applied to solid tumors and leukemia to see the effect, if any, of stage, age of exposure, time progression etc. In miners and smokers, stages of the initiation, promotion and progression in carcinogenesis are discussed on the analyses. Others contain the analyses of workers in Canadian atomic power plant, and of patients who underwent the radiation therapy. Model analysis can help to understand the carcinogenic process in a quantitative aspect rather than to describe the process. (R.T.)

Effect of Dendrobium officinale Extraction on Gastric Carcinogenesis in Rats

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Yi Zhao

2016-01-01

Full Text Available Dendrobium officinale (Tie Pi Shi Hu in Chinese has been widely used to treat different diseases in China. Anticancer effect is one of the important effects of Dendrobium officinale. However, the molecular mechanism of its anticancer effect remains unclear. In the present study, gastric carcinogenesis in rats was used to evaluate the effect of Dendrobium officinale on cancer, and its pharmacological mechanism was explored. Dendrobium officinale extracts (4.8 and 2.4 g/kg were orally administered to the rats of the gastric carcinogenesis model. Compared with the cancer model group, the high dose of Dendrobium officinale extracts significantly inhibited the rate of carcinogenesis. Further analysis revealed that Dendrobium officinale extracts could regulate the DNA damage, oxidative stress, and cytokines related with carcinogenesis and induce cell apoptosis in order to prevent gastric cancer.

Oral Carcinogenesis and Oral Cancer Chemoprevention: A Review

OpenAIRE

Tanaka, Takuji; Tanaka, Mayu; Tanaka, Takahiro

2011-01-01

Oral cancer is one of the major global threats to public health. The development of oral cancer is a tobacco-related multistep and multifocal process involving field cancerization and carcinogenesis. The rationale for molecular-targeted prevention of oral cancer is promising. Biomarkers of genomic instability, including aneuploidy and allelic imbalance, are possible to measure the cancer risk of oral premalignancies. Understanding of the biology of oral carcinogenesis will yield important adv...

Wnt5a is associated with cigarette smoke-related lung carcinogenesis via protein kinase C.

Science.gov (United States)

Whang, Young Mi; Jo, Ukhyun; Sung, Jae Sook; Ju, Hyun Jung; Kim, Hyun Kyung; Park, Kyong Hwa; Lee, Jong Won; Koh, In Song; Kim, Yeul Hong

2013-01-01

Wnt5a is overexpressed during the progression of human non-small cell lung cancer. However, the roles of Wnt5a during smoking-related lung carcinogenesis have not been clearly elucidated. We investigated the associations between Wnt5a and the early development of cigarette smoke related lung cancer using human bronchial epithelial (HBE) cells (NHBE, BEAS-2B, 1799, 1198 and 1170I) at different malignant stages established by exposure to cigarette smoke condensate (CSC). Abnormal up-regulation of Wnt5a mRNA and proteins was detected in CSC-exposed transformed 1198 and tumorigenic 1170I cells as compared with other non-CSC exposed HBE cells. Tumor tissues obtained from smokers showed higher Wnt5a expressions than matched normal tissues. In non-CSC exposed 1799 cells, treatment of recombinant Wnt5a caused the activations of PKC and Akt, and the blockage of Wnt5a and PKC significantly decreased the viabilities of CSC-transformed 1198 cells expressing high levels of Wnt5a. This reduced cell survival rate was associated with increased apoptosis via the down-regulation of Bcl2 and the induction of cleaved poly ADP-ribose polymerase. Moreover, CSC-treated 1799 cells showed induction of Wnt5a expression and enhanced colony-forming capacity. The CSC-induced colony forming efficiency was suppressed by the co-incubation with a PKC inhibitor. In conclusion, these results suggest that cigarette smoke induces Wnt5a-coupled PKC activity during lung carcinogenesis, which causes Akt activity and anti-apoptosis in lung cancer. Therefore, current study provides novel clues for the crucial role of Wnt5a in the smoking-related lung carcinogenesis.

Wnt5a is associated with cigarette smoke-related lung carcinogenesis via protein kinase C.

Directory of Open Access Journals (Sweden)

Young Mi Whang

Full Text Available Wnt5a is overexpressed during the progression of human non-small cell lung cancer. However, the roles of Wnt5a during smoking-related lung carcinogenesis have not been clearly elucidated. We investigated the associations between Wnt5a and the early development of cigarette smoke related lung cancer using human bronchial epithelial (HBE cells (NHBE, BEAS-2B, 1799, 1198 and 1170I at different malignant stages established by exposure to cigarette smoke condensate (CSC. Abnormal up-regulation of Wnt5a mRNA and proteins was detected in CSC-exposed transformed 1198 and tumorigenic 1170I cells as compared with other non-CSC exposed HBE cells. Tumor tissues obtained from smokers showed higher Wnt5a expressions than matched normal tissues. In non-CSC exposed 1799 cells, treatment of recombinant Wnt5a caused the activations of PKC and Akt, and the blockage of Wnt5a and PKC significantly decreased the viabilities of CSC-transformed 1198 cells expressing high levels of Wnt5a. This reduced cell survival rate was associated with increased apoptosis via the down-regulation of Bcl2 and the induction of cleaved poly ADP-ribose polymerase. Moreover, CSC-treated 1799 cells showed induction of Wnt5a expression and enhanced colony-forming capacity. The CSC-induced colony forming efficiency was suppressed by the co-incubation with a PKC inhibitor. In conclusion, these results suggest that cigarette smoke induces Wnt5a-coupled PKC activity during lung carcinogenesis, which causes Akt activity and anti-apoptosis in lung cancer. Therefore, current study provides novel clues for the crucial role of Wnt5a in the smoking-related lung carcinogenesis.

Prevalence of colonic polyp and its predictors in patients with acromegaly

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Purnima Agarwal

2016-01-01

Full Text Available Background: There are conflicting data regarding the prevalence of colorectal polyp in patients with acromegaly. Subjects and Methods: Consecutive forty-seven acromegalic patients (21 men, 26 women, with a mean age of (40 ± 12 years attending endocrinology outpatient department underwent full colonoscopy. All the patients underwent clinical and biochemical evaluation (glucose suppressed growth hormone (GH, Insulin-like growth factor-1 [IGF-1], fasting insulin, and glucose. The control group (n = 120 for colonoscopy was adult subjects undergoing evaluation for symptoms of irritable bowel syndrome. Clinical and biochemical parameters in acromegalic patients with colonic polyp were compared to those without a polyp. Results: Patients with acromegaly had significantly higher prevalence of colonic polyp as compared to control subjects (10.6% vs. 0.8%. None of the patients with polyp had skin tags. There was no significant difference between subjects with and without colonic polyp in duration of illness, basal, and glucose-suppressed GH and most recent IGF-1. Fasting blood sugar was significantly higher (P < 0.05 in adenoma group after adjusting for age, body mass index (BMI, and insulin levels. Patients in adenoma group showed a trend toward male gender and younger age as compared to those without adenoma. Conclusions: Subjects with acromegaly as compared to control have a higher prevalence of colonic polyps. There was no association of polyps seen with age, BMI, skin tags, homeostasis model assessment of insulin resistance index, duration of disease, and basal and glucose-suppressed GH and IGF-1 levels. There were no specific predictive factors detected. Screening full colonoscopy is recommended in all cases with acromegaly.

Diet-induced obesity elevates colonic TNF-α in mice and is accompanied by an activation of Wnt signaling: a mechanism for obesity-associated colorectal cancer.

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Liu, Zhenhua; Brooks, Ryan S; Ciappio, Eric D; Kim, Susan J; Crott, Jimmy W; Bennett, Grace; Greenberg, Andrew S; Mason, Joel B

2012-10-01

Inflammation associated with obesity may play a role in colorectal carcinogenesis, but the underlying mechanism remains unclear. This study investigated whether the Wnt pathway, an intracellular signaling cascade that plays a critical role in colorectal carcinogenesis, is activated by obesity-induced elevation of the inflammatory cytokine tumor necrosis factor-alpha (TNF-α). Animal studies were conducted on C57BL/6 mice, and obesity was induced by utilizing a high-fat diet (60% kcal). An inflammation-specific microarray was performed, and results were confirmed with real-time polymerase chain reaction. The array revealed that diet-induced obesity increased the expression of TNF-α in the colon by 72% (P=.004) and that of interleukin-18 by 41% (P=.023). The concentration of colonic TNF-α protein, determined by ex vivo culture assay, was nearly doubled in the obese animals (P=.002). The phosphorylation of glycogen synthase kinase 3 beta (GSK3β), an important intermediary inhibitor of Wnt signaling and a potential target of TNF-α, was quantitated by immunohistochemistry. The inactivated (phosphorylated) form of GSK3β was elevated in the colonic mucosa of obese mice (P<.02). Moreover, β-catenin, the key effector of canonical Wnt signaling, was elevated in the colons of obese mice (P<.05), as was the expression of a downstream target gene, c-myc (P<.05). These data demonstrate that diet-induced obesity produces an elevation in colonic TNF-α and instigates a number of alterations of key components within the Wnt signaling pathway that are protransformational in nature. Thus, these observations offer evidence for a biologically plausible avenue, the Wnt pathway, by which obesity increases the risk of colorectal cancer. Copyright © 2012 Elsevier Inc. All rights reserved.

Ethanol Does Not Promote MeIQx-initiated Rat Colon Carcinogenesis Based on Evidence from Analysis of a Colon Cancer Surrogate Marker

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Kushida, Masahiko; Wanibuchi, Hideki; Wei, Min; Kakehashi, Anna; Ozaki, Keisuke; Sukata, Tokuo; Miyata, Kaori; Ogata, Keiko; Uwagawa, Satoshi; Fukushima, Shoji

2009-01-01

Epidemiological studies suggest that alcohol consumption increases the risk of developing colorectal cancer. However, the data are confounded by numerous cosegregating variables. To cast further light on the relationships between alcohol intake and colon cancer development, 21-day-old male F344/DuCrj rats were fed 200 ppm 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) in their diet for 8 weeks and doses of 0, 0.1, 0.3, 1, 3, 10 and 20% of ethanol in their drinking water ad libitum for ...

α-lipoic acid suppresses neuronal excitability and attenuates colonic hypersensitivity to colorectal distention in diabetic rats

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Sun Y

2017-07-01

Full Text Available Yan Sun,1,* Pan-Pan Yang,1,* Zhen-Yuan Song,2 Yu Feng,1 Duan-Min Hu,1 Ji Hu,1 Guang-Yin Xu,3 Hong-Hong Zhang1,3 1Department of Endocrinology, The Second Affiliated Hospital of Soochow University, Suzhou, People’s Republic of China; 2Department of Endocrinology, The East District of Suzhou Municipal Hospital, Suzhou, People’s Republic of China; 3Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases, Institute of Neuroscience, Soochow University, Suzhou, People’s Republic of China *These authors contributed equally to this work Aim: Patients with long-standing diabetes often demonstrate intestinal dysfunction, characterized as constipation or colonic hypersensitivity. Our previous studies have demonstrated the roles of voltage-gated sodium channels NaV1.7 and NaV1.8 in dorsal root ganglion (DRG in colonic hypersensitivity of rats with diabetes. This study was designed to determine roles of antioxidant α-lipoic acid (ALA on sodium channel activities and colonic hypersensitivity of rats with diabetes. Methods: Streptozotocin was used to induce diabetes in adult female rats. Colonic sensitivity was measured by behavioral responses to colorectal distention in rats. The excitability and sodium channel currents of colon projection DRG neurons labeled with DiI were measured by whole-cell patch-clamp recordings. The expressions of NaV1.7 and NaV1.8 of colon DRGs were measured by western blot analysis. Results: ALA treatment significantly increased distention threshold in responding to colorectal distension in diabetic rats compared with normal saline treatment. ALA treatment also hyperpolarized the resting membrane potentials, depolarized action potential threshold, increased rheobase, and decreased frequency of action potentials evoked by ramp current stimulation. Furthermore, ALA treatment also reduced neuronal sodium current densities of DRG neurons innervating the colon from rats with diabetes. In addition, ALA

Human colon tissue in organ culture: calcium and multi-mineral-induced mucosal differentiation.

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Dame, Michael K; Veerapaneni, Indiradevi; Bhagavathula, Narasimharao; Naik, Madhav; Varani, James

2011-01-01

We have recently shown that a multi-mineral extract from the marine red algae, Lithothamnion calcareum, suppresses colon polyp formation and inflammation in mice. In the present study, we used intact human colon tissue in organ culture to compare responses initiated by Ca(2+) supplementation versus the multi-mineral extract. Normal human colon tissue was treated for 2 d in culture with various concentrations of calcium or the mineral-rich extract. The tissue was then prepared for histology/immunohistochemistry, and the culture supernatants were assayed for levels of type I procollagen and type I collagen. At higher Ca(2+) concentrations or with the mineral-rich extract, proliferation of epithelial cells at the base and walls of the mucosal crypts was suppressed, as visualized by reduced Ki67 staining. E-cadherin, a marker of differentiation, was more strongly expressed at the upper third of the crypt and at the luminal surface. Treatment with Ca(2+) or with the multi-mineral extract influenced collagen turnover, with decreased procollagen and increased type I collagen. These data suggest that calcium or mineral-rich extract has the capacity to (1) promote differentiation in human colon tissue in organ culture and (2) modulate stromal function as assessed by increased levels of type I collagen. Taken together, these data suggest that human colon tissue in organ culture (supporting in vivo finding in mice) will provide a valuable model for the preclinical assessment of agents that regulate growth and differentiation in the colonic mucosa.

Radiation-induced colon cancer with high frequency microsatellite instability (MSI-H), report of a case

International Nuclear Information System (INIS)

Arai, Masami; Ueno, Masashi; Koizumi, Koichi

2002-01-01

We report a 67-year-old female with radiation-induced colon cancer which developed 23 years after radiation therapy for cancer of the endometrium. She was strongly suspected to be a case of hereditary nonpolyposis colorectal cancer (HNPCC) due to her clinical manifestations, i.e. metachronous multiple cancer developed in the endometrium and colon. MSI test and immunohistochemistry for mismatch repair (MMR) proteins revealed that MSI was highly positive and expression of hMSH2 was lost in the colon cancers. Further, on examining the genetic change, the point mutation, ACG→ATG, responsible for amino acid change, was detected in codon8 (exon1) of the hMSH2 gene. The change, however, could be a polymorphism of this gene and further analyses were necessitated to confirm the genetic background for HNPCC. Interestingly, three cancers with adenoma were located in the mucosa of radiation colitis, in which several atypical glands were also found. This is the only case of radiation-induced colorectal cancer with MSI-H in our hospital. Because of our previous studies, we believe that the genetic pathway in carcinogenesis of the radiation-induced colon cancer is different from that of HNPCC, despite their having several kinds of clinical and pathological features in common. (author)

Radiation-induced colon cancer with high frequency microsatellite instability (MSI-H), report of a case

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Arai, Masami; Ueno, Masashi; Koizumi, Koichi [Japanese Foundation for Cancer Research, Tokyo (Japan). Hospital] [and others

2002-07-01

We report a 67-year-old female with radiation-induced colon cancer which developed 23 years after radiation therapy for cancer of the endometrium. She was strongly suspected to be a case of hereditary nonpolyposis colorectal cancer (HNPCC) due to her clinical manifestations, i.e. metachronous multiple cancer developed in the endometrium and colon. MSI test and immunohistochemistry for mismatch repair (MMR) proteins revealed that MSI was highly positive and expression of hMSH2 was lost in the colon cancers. Further, on examining the genetic change, the point mutation, ACG{yields}ATG, responsible for amino acid change, was detected in codon8 (exon1) of the hMSH2 gene. The change, however, could be a polymorphism of this gene and further analyses were necessitated to confirm the genetic background for HNPCC. Interestingly, three cancers with adenoma were located in the mucosa of radiation colitis, in which several atypical glands were also found. This is the only case of radiation-induced colorectal cancer with MSI-H in our hospital. Because of our previous studies, we believe that the genetic pathway in carcinogenesis of the radiation-induced colon cancer is different from that of HNPCC, despite their having several kinds of clinical and pathological features in common. (author)

Combinational Effects of Prebiotics and Soybean against Azoxymethane-Induced Colon Cancer In Vivo

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V. P. Gourineni

2011-01-01

Full Text Available Prebiotic fructans are nondigestible carbohydrates with numerous health benefits. Soybean is a rich source of phytonutrients such as isoflavones. The objective of this study was to evaluate the chemopreventive effects of prebiotics (Synergy1 and soybean meal (SM at 5% and 10% levels alone and in combination on azoxymethane- (AOM- induced colon carcinogenesis. After one wk of acclimatization, Fisher 344 male rats (N=90 were randomly assigned to 9 groups (n=10. Control rats (C were fed AIN-93G/M. Two s/c injections of AOM were administered to rats at 7 and 8 wk of age at 16 mg/kg body weight. Rats were killed by CO2 asphyxiation at 45 wk. Tumor incidence (% in treatment groups ranged from 40 to 75 compared to 100 in C. Results indicate that feeding prebiotics and soybean in combination significantly reduced incidence of AOM-induced colon tumors with implications for food industry in the food-product development.

Deletion of epidermal Rac1 inhibits HPV-8 induced skin papilloma formation and facilitates HPV-8- and UV-light induced skin carcinogenesis.

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Deshmukh, Jayesh; Pofahl, Ruth; Pfister, Herbert; Haase, Ingo

2016-09-06

Overexpression and increased activity of the small Rho GTPase Rac1 has been linked to squamous cell carcinoma of the epidermis and mucosa in humans. Targeted deletion of Rac1 or inhibition of Rac1 activity in epidermal keratinocytes reduced papilloma formation in a chemical skin carcinogenesis mouse model. However, a potential role of Rac1 in HPV- and UV-light induced skin carcinogenesis has not been investigated so far, solar UV radiation being an important carcinogen to the skin.To investigate this, we deleted Rac1 or modulated its activity in mice with transgenic expression of Human papilloma virus type-8 (HPV-8) in epidermal keratinocytes. Our data show that inhibition or deletion of Rac1 results in reduced papilloma formation upon UV-irradiation with a single dose, whereas constitutive activation of Rac1 strongly increases papilloma frequency in these mice. Surprisingly, we observed that, upon chronic UV-irradiation, the majority of mice with transgenic expression of HPV-8 and epidermis specific Rac1 deletion developed squamous cell carcinomas. Taken together, our data show that Rac1 exerts a dual role in skin carcinogenesis: its activation is, on one hand, required for HPV-8- and UV-light induced papilloma formation but, on the other, suppresses the development of squamous cell carcinomas.

Spectroscopic microvascular blood detection from the endoscopically normal colonic mucosa: biomarker for neoplasia risk.

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Roy, Hemant K; Gomes, Andrew; Turzhitsky, Vladimir; Goldberg, Michael J; Rogers, Jeremy; Ruderman, Sarah; Young, Kim L; Kromine, Alex; Brand, Randall E; Jameel, Mohammed; Vakil, Parmede; Hasabou, Nahla; Backman, Vadim

2008-10-01

We previously used a novel biomedical optics technology, 4-dimensional elastically scattered light fingerprinting, to show that in experimental colon carcinogenesis the predysplastic epithelial microvascular blood content is increased markedly. To assess the potential clinical translatability of this putative field effect marker, we characterized the early increase in blood supply (EIBS) in human beings in vivo. We developed a novel, endoscopically compatible, polarization-gated, spectroscopic probe that was capable of measuring oxygenated and deoxygenated (Dhb) hemoglobin specifically in the mucosal microcirculation through polarization gating. Microvascular blood content was measured in 222 patients from the endoscopically normal cecum, midtransverse colon, and rectum. If a polyp was present, readings were taken from the polyp tissue along with the normal mucosa 10-cm and 30-cm proximal and distal to the lesion. Tissue phantom studies showed that the probe had outstanding accuracy for hemoglobin determination (r(2) = 0.99). Augmentation of microvasculature blood content was most pronounced within the most superficial ( approximately 100 microm) layer and dissipated in deeper layers (ie, submucosa). EIBS was detectable within 30 cm from the lesion and the magnitude mirrored adenoma proximity. This occurred for both oxygenated hemoglobin and DHb, with the effect size being slightly greater for DHb. EIBS correlated with adenoma size and was not engendered by nonneoplastic (hyperplastic) polyps. We show, herein, that in vivo microvascular blood content can be measured and provides an accurate marker of field carcinogenesis. This technological/biological advance has numerous potential applications in colorectal cancer screening such as improved polyp detection and risk stratification.

Prevention of colonic neoplasia with polyethylene glycol: A short term randomized placebo-controlled double-blinded trial.

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Wali, Ramesh K; Bianchi, Laura; Kupfer, Sonia; De La Cruz, Mart; Jovanovic, Borko; Weber, Christopher; Goldberg, Michael J; Rodriguez, L M; Bergan, Raymond; Rubin, David; Tull, Mary Beth; Richmond, Ellen; Parker, Beth; Khan, Seema; Roy, Hemant K

2018-01-01

Chemoprevention represents an attractive modality against colorectal cancer (CRC) although widespread clinical implementation of promising agents (e.g. aspirin/NSAIDS) have been stymied by both suboptimal efficacy and concerns over toxicity. This highlights the need for better agents. Several groups, including our own, have reported that the over-the-counter laxative polyethylene glycol (PEG) has remarkable efficacy in rodent models of colon carcinogenesis. In this study, we undertook the first randomized human trial to address the role of PEG in prevention of human colonic neoplasia. This was a double-blind, placebo-controlled, three-arm trial where eligible subjects were randomized to 8g PEG-3350 (n = 27) or 17g PEG-3350 (n = 24), or placebo (n = 24; maltodextrin) orally for a duration of six months. Our initial primary endpoint was rectal aberrant crypt foci (ACF) but this was changed during protocol period to rectal mucosal epidermal growth factor receptor (EGFR). Of the 87 patients randomized, 48 completed study primary endpoints and rectal EGFR unchanged PEG treatment. Rectal ACF had a trend suggesting potentially reduction with PEG treatment (pre-post change 1.7 in placebo versus -0.3 in PEG 8+ 17g doses, p = 0.108). Other endpoints (proliferation, apoptosis, expression of SNAIL and E-cadherin), previously noted to be modulated in rodent models, appeared unchanged with PEG treatment in this clinical trial. We conclude that PEG was generally well tolerated with the trial failing to meet primary efficacy endpoints. However, rectal ACFs demonstrated a trend (albeit statistically insignificant) for suppression with PEG. Moreover, all molecular assays including EGFR were unaltered with PEG underscoring issues with lack of translatability of biomarkers from preclinical to clinical trials. This data may provide the impetus for future clinical trials on PEG using more robust biomarkers of chemoprevention. ClinicalTrials.gov NCT00828984.

Radiation and multistage carcinogenesis

International Nuclear Information System (INIS)

Day, N.E.

1984-01-01

Epidemiological data are insufficient at present to define with much precision the shape of the dose-response curve for radiation carcinogenesis at low or moderate dose levels, for different organs. The available data have to be supplemented with theoretical models for the mode of action. These models, however, often seem not to take into account the complex nature of the process of carcinogenesis. They relate more to mutational events, rather than the long process of cancer induction. In addition, they ignore the fact that in the human situation radiation is one among a large number of exposures, and even the basic form of the dose response may be dependent on the presence or absence of other factors. Information on modes of action usually comes from experimental results, where the requisite combination of exposures can be chosen in advance. Epidemiology, however, also provides information on mechanisms. The purpose of this paper is to consider some of the information that epidemiology provides on the role of radiation in increasing cancer risk in humans

Human colon cancers as a major problem in poland and in the world – medical and environmental issues

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Sylwia Katarzyna Król

2011-12-01

Full Text Available Many epidemiological data have shown an increasing incidence and mortality of colon cancer cases in the past several years, not only in Poland but all over the world as well. Each year, approximately a million new cases of colon cancer are diagnosed and that is the cause of death of almost half a million patients in the world. The aim of this article is to present the epidemiology and the current state of scientific knowledge concerning etiology and pathogenesis of neoplastic diseases in human large intestine. Furthermore, this short review describes the essential risk factors and suggests the simple and effective ways of colon cancer prevention.Colorectal cancer is one of the most frequently diagnosed cancers in EU countries. Scientific studies have proved that genetic and hereditary factors have a strong influence on carcinogenesis in human colon. Moreover, environmental factors, such as dietary contribute to the development of colon neoplasm. The most useful tool to reduce high morbidity and mortality is a prevention. Screening tests in nonsymptomatic people from high-risk groups or populations enable diagnosis in the early stage of colorectal cancer. Many publications have reported that modification of lifestyle and daily diet also play a significant role in prevention.

Apoptotic block in colon cancer cells may be rectified by lentivirus mediated overexpression of caspase-9.

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Xu, D; Wang, C; Shen, X; Yu, Y; Rui, Y; Zhang, D; Zhou, Z

2013-12-01

At present, the inhibition of apoptosis during pathogenesis of colorectal cancer is widely recognized while the role of caspase-9 in this process remains controversial. We aimed to investigate the differential expression of caspase-9 and evaluate the therapeutic potential of expression intervention in this study. We first examined the different expression of caspase-9 in normal colon mucosa, adenoma and cancer, investigating the relationship between its expression and clinico-pathological characteristics. Secondly, overexpression of caspase-9 was established in colon cancer cell lines by lentivirus infection to study the changes in growth, proliferation and apoptosis. Compared with normal colon mucosa, the expression of caspase-9 was higher in adenoma while lower in cancer both at mRNA and protein level (P expression is more common in poorly differentiated cancers (P expression of caspase-9, poorer colony formation and slower cell proliferation. In terms of apoptosis related indicators, caspase-9 overexpression leads to higher apoptosis rate and GO/G1 arrest, while up-regulating the expression of caspase-3 (P expression from colon mucosa, adenoma to cancer suggested it may be involved in the carcinogenesis of colon cancer. The overexpression of caspase-9 exhibits an inhibitory role in cancer growth and proliferation while promoting apoptosis. However, a non-apoptotic role of caspase-9 facilitating differentiation was also implied.

Experimental, statistical, and biological models of radon carcinogenesis

International Nuclear Information System (INIS)

Cross, F.T.

1991-09-01

Risk models developed for underground miners have not been consistently validated in studies of populations exposed to indoor radon. Imprecision in risk estimates results principally from differences between exposures in mines as compared to domestic environments and from uncertainties about the interaction between cigarette-smoking and exposure to radon decay products. Uncertainties in extrapolating miner data to domestic exposures can be reduced by means of a broad-based health effects research program that addresses the interrelated issues of exposure, respiratory tract dose, carcinogenesis (molecular/cellular and animal studies, plus developing biological and statistical models), and the relationship of radon to smoking and other copollutant exposures. This article reviews experimental animal data on radon carcinogenesis observed primarily in rats at Pacific Northwest Laboratory. Recent experimental and mechanistic carcinogenesis models of exposures to radon, uranium ore dust, and cigarette smoke are presented with statistical analyses of animal data. 20 refs., 1 fig

Hypoxia-inducible factor 1 alpha expression increases during colorectal carcinogenesis and tumor progression

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Simiantonaki, Nektaria; Taxeidis, Marios; Jayasinghe, Caren; Kurzik-Dumke, Ursula; Kirkpatrick, Charles James

2008-01-01

Hypoxia-inducible factor 1 alpha (HIF-1α) is involved in processes promoting carcinogenesis of many tumors. However, its role in the development of colorectal cancer is unknown. To investigate the significance of HIF-1α during colorectal carcinogenesis and progression we examined its expression in precursor lesions constituting the conventional and serrated pathways, as well as in non-metastatic and metastatic adenocarcinomas. Immunohistochemistry and Western blot is used to analyse HIF-1α expression in normal colonic mucosa, hyperplastic polyps (HPP), sessile serrated adenomas (SSA), low-grade (TA-LGD) and high-grade (TA-HGD) traditional adenomas as well as in non-metastatic and metastatic colorectal adenocarcinomas. Eight colorectal carcinoma cell lines are tested for their HIF-1α inducibility after lipopolysaccharide (LPS) stimulation using western blot and immunocytochemistry. In normal mucosa, HPP and TA-LGD HIF-1α was not expressed. In contast, perinuclear protein accumulation and nuclear expression of HIF-1α were shown in half of the examined SSA and TA-HGD. In all investigated colorectal carcinomas a significant nuclear HIF-1α overexpression compared to the premalignant lesions was observed but a significant correlation with the metastatic status was not found. Nuclear HIF-1α expression was strongly accumulated in perinecrotic regions. In these cases HIF-1α activation was seen in viable cohesive tumor epithelia surrounding necrosis and in dissociated tumor cells, which subsequently die. Enhanced distribution of HIF-1α was also seen in periiflammatory regions. In additional in vitro studies, treatment of diverse colorectal carcinoma cell lines with the potent pro-inflammatory factor lipopolysaccharide (LPS) led to HIF-1α expression and nuclear translocation. We conclude that HIF-1α expression occurs in early stages of colorectal carcinogenesis and achieves a maximum in the invasive stage independent of the metastatic status. Perinecrotic

A challenge to mutation theory of radiation carcinogenesis

International Nuclear Information System (INIS)

Watanabe, Masami

2006-01-01

This paper presents an objection against the commonly accepted mutation theory in radiation carcinogenesis. First, author's studies of X-ray irradiated syrian hamster embryo (SHE) cells on malignant morphological changes and mutational change of HGPRT gene showed that the changing patterns were quite different, and as well, other studies in mice gave the essentially similar results. Thus radiation-induced carcinogenesis in cells does not simply occur by an accumulation of radiation-induced mutation. Second, as cultured cells usually used for oncogenesis studies already have the infinitively proliferative ability, the author used the primary cell culture obtained from the rodent embryo. Even those cells became immortal to be cancerous after repeated culture passage with the higher frequency of 10 3 -10 4 relative to somatic cell mutation. Cells thus seem to be easily changeable to cancerous ones. Bystander effect can cause transformation in non-irradiated cells and genetic instability by radiation can form the potentially unstable chromatin region, which induces telomere instability. The author has found that, while short-lived radicals yielded by X-ray irradiation attack DNA to induce cell death and chromosome aberration, long-lived radicals in biomolecules do not, but can cause mutation and carcinogenesis, which are reduced by vitamine C supplementation. The author concludes that the primary target in the radiation carcinogenesis in cells and even in the whole individuals is conceivably protein and not DNA. (T.I.)

Exhaustive physical exercise increases the number of colonic preneoplastic lesions in untrained rats treated with a chemical carcinogen.

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Demarzo, Marcelo Marcos Piva; Garcia, Sérgio Britto

2004-12-08

Aberrant crypt foci (ACF) have been used for early detection of factors that influence colorectal carcinogenesis in rats. It has been observed that exhaustive exercise increases free radical DNA oxidative damage and depresses immune function, events also related to the increased risk for cancer development. Fifteen days after a single exhaustive swimming bout in untrained rats treated with a colon carcinogen, we observed a statistically significant increased number of ACF when compared to the non-exercised group. Thus, we concluded that exhaustive exercise increased the susceptibility for colon cancer in rats. From our finding and literature data, we hypothesize that, similarly to the suggested relationship between exercise and infections, exercise could be protective against cancer or it could increase the risk for this disease depending on its type, dose and duration.

Inhibitory effect of vitamin D-binding protein-derived macrophage activating factor on DMBA-induced hamster cheek pouch carcinogenesis and its derived carcinoma cell line.

Science.gov (United States)

Toyohara, Yukiyo; Hashitani, Susumu; Kishimoto, Hiromitsu; Noguchi, Kazuma; Yamamoto, Nobuto; Urade, Masahiro

2011-07-01

This study investigated the inhibitory effect of vitamin D-binding protein-derived macrophage-activating factor (GcMAF) on carcinogenesis and tumor growth, using a 9,10-dimethyl-1,2-benzanthracene (DMBA)-induced hamster cheek pouch carcinogenesis model, as well as the cytocidal effect of activated macrophages against HCPC-1, a cell line established from DMBA-induced cheek pouch carcinoma. DMBA application induced squamous cell carcinoma in all 15 hamsters of the control group at approximately 10 weeks, and all 15 hamsters died of tumor burden within 20 weeks. By contrast, 2 out of the 14 hamsters with GcMAF administration did not develop tumors and the remaining 12 hamsters showed a significant delay of tumor development for approximately 3.5 weeks. The growth of tumors formed was significantly suppressed and none of the hamsters died within the 20 weeks during which they were observed. When GcMAF administration was stopped at the 13th week of the experiment in 4 out of the 14 hamsters in the GcMAF-treated group, tumor growth was promoted, but none of the mice died within the 20-week period. On the other hand, when GcMAF administration was commenced after the 13th week in 5 out of the 15 hamsters in the control group, tumor growth was slightly suppressed and all 15 hamsters died of tumor burden. However, the mean survival time was significantly extended. GcMAF treatment activated peritoneal macrophages in vitro and in vivo, and these activated macrophages exhibited a marked cytocidal effect on HCPC-1 cells. Furthermore, the cytocidal effect of activated macrophages was enhanced by the addition of tumor-bearing hamster serum. These findings indicated that GcMAF possesses an inhibitory effect on tumor development and growth in a DMBA-induced hamster cheek pouch carcinogenesis model.

Identification of colonic fibroblast secretomes reveals secretory factors regulating colon cancer cell proliferation.

Science.gov (United States)

Chen, Sun-Xia; Xu, Xiao-En; Wang, Xiao-Qing; Cui, Shu-Jian; Xu, Lei-Lei; Jiang, Ying-Hua; Zhang, Yang; Yan, Hai-Bo; Zhang, Qian; Qiao, Jie; Yang, Peng-Yuan; Liu, Feng

2014-10-14

Stromal microenvironment influences tumor cell proliferation and migration. Fibroblasts represent the most abundant stromal constituents. Here, we established two pairs of normal fibroblast (NF) and cancer-associated fibroblast (CAF) cultures from colorectal adenocarcinoma tissues and the normal counterparts. The NFs and CAFs were stained positive for typical fibroblast markers and inhibited colon cancer (CC) cell proliferation in in vitro cocultures and in xenograft mouse models. The fibroblast conditioned media were analyzed using LC-MS and 227 proteins were identified at a false discovery rate of 1.3%, including 131 putative secretory and 20 plasma membrane proteins. These proteins were enriched for functional categories of extracellular matrix, adhesion, cell motion, inflammatory response, redox homeostasis and peptidase inhibitor. Secreted protein acidic and rich in cysteine, transgelin, follistatin-related protein 1 (FSTL1) and decorin was abundant in the fibroblast secretome as confirmed by Western blot. Silencing of FSTL1 and transgelin in colonic fibroblast cell line CCD-18Co induced an accelerated proliferation of CC cells in cocultures. Exogenous FSTL1 attenuates CC cell proliferation in a negative fashion. FSTL1 was upregulated in CC patient plasma and cancerous tissues but had no implication in prognosis. Our results provided novel insights into the molecular signatures and modulatory role of CC associated fibroblasts. In this study, a label-free LC-MS was performed to analyze the secretomes of two paired primary fibroblasts, which were isolated from fresh surgical specimen of colorectal adenocarcinoma and adjacent normal colonic tissues and exhibited negative modulatory activity for colon cancer cell growth in in vitro cocultures and in vivo xenograph mouse models. Follistatin-related protein 1 was further revealed to be one of the stroma-derived factors of potential suppression role for colon cancer cell proliferation. Our results provide novel

Vitamin D receptor gene polymorphisms, dietary promotion of insulin resistance, and colon and rectal cancer.

Science.gov (United States)

Murtaugh, Maureen A; Sweeney, Carol; Ma, Khe-Ni; Potter, John D; Caan, Bette J; Wolff, Roger K; Slattery, Martha L

2006-01-01

Modifiable risk factors in colorectal cancer etiology and their interactions with genetic susceptibility are of particular interest. Functional vitamin D receptor (VDR) gene polymorphisms may influence carcinogenesis through modification of cell growth, protection from oxidative stress, cell-cell matrix effects, or insulin and insulin-like growth factor pathways. We investigated interactions between foods (dairy products, red and processed meat, and whole and refined grains) and dietary patterns (sucrose-to-fiber ratio and glycemic index) associated with insulin resistance with the FokI polymorphism of the VDR gene and colon and rectal cancer risk. Data (diet, anthropometrics, and lifestyle) and DNA came from case-control studies of colon (1,698 cases and 1,861 controls) and rectal cancer (752 cases and 960 controls) in northern California, Utah, and the Twin Cities metropolitan area, Minnesota (colon cancer study only). Unconditional logistic regression models were adjusted for smoking, race, sex, age, body mass index, physical activity, energy intake, dietary fiber, and calcium. The lowest colon cancer risk was observed with the Ff/ff FokI genotypes and a low sucrose-to-fiber ratio. Rectal cancer risk decreased with greater consumption of dairy products and increased with red or processed meat consumption and the FF genotype. Modifiable dietary risk factors may be differentially important among individuals by VDR genotype and may act through the insulin pathway to affect colon cancer risk and through fat, calcium, or other means to influence rectal cancer risk.

Complex of MUC1, CIN85 and Cbl in Colon Cancer Progression and Metastasis

International Nuclear Information System (INIS)

Cascio, Sandra; Finn, Olivera J.

2015-01-01

We previously reported that CIN85, an 85 KDa protein known to be involved in tumor cell migration and metastasis through its interaction with Cbl, associates with MUC1 in tumor cells. MUC1/CIN85 complex also regulates migration and invasion of tumor cells in vitro. Here, we examined specifically human colon carcinoma tissue microarrays (TMA) by immunohistochemistry for the expression of MUC1 and CIN85 and their potential role in cancer progression and metastasis. We detected a significant increase in expression of both MUC1 and CIN85 associated with advanced tumor stage and lymph node metastasis. We further investigated if Cbl could also be present in the MUC1/CIN85 complex. Co-immunoprecipitation assay showed that Cbl co-localized both with CIN85 and with MUC1 in a human colon cancer cell line. To begin to investigate the in vivo relevance of MUC1 overexpression and association with CIN85 and Cbl in cancer development and progression, we used human MUC1 transgenic mice that express MUC1 on the colonic epithelial cells, treated with azoxymethane to initiate and dextran sulfate sodium (AOM/DSS) to promote colorectal carcinogenesis. MUC1.Tg mice showed higher tumor incidence and decreased survival when compared with wild-type mice. Consistent with the in vitro data, the association of MUC1, CIN85 and Cbl was detected in colon tissues of AOM/DSS-treated MUC1 transgenic mice. MUC1/CIN85/Cbl complex appears to contribute to promotion and progression of colon cancer and thus increased expression of MUC1, CIN85 and Cbl in early stage colon cancer might be predictive of poor prognosis

Complex of MUC1, CIN85 and Cbl in Colon Cancer Progression and Metastasis

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Cascio, Sandra, E-mail: sac131@pitt.edu [Department of Immunology, University of Pittsburgh School of Medicine, E1040 Biomedical Science Tower, Pittsburgh, PA 15261 (United States); Fondazione Ri.Med, via Bandiera, Palermo 90133 (Italy); Finn, Olivera J., E-mail: sac131@pitt.edu [Department of Immunology, University of Pittsburgh School of Medicine, E1040 Biomedical Science Tower, Pittsburgh, PA 15261 (United States)

2015-02-10

We previously reported that CIN85, an 85 KDa protein known to be involved in tumor cell migration and metastasis through its interaction with Cbl, associates with MUC1 in tumor cells. MUC1/CIN85 complex also regulates migration and invasion of tumor cells in vitro. Here, we examined specifically human colon carcinoma tissue microarrays (TMA) by immunohistochemistry for the expression of MUC1 and CIN85 and their potential role in cancer progression and metastasis. We detected a significant increase in expression of both MUC1 and CIN85 associated with advanced tumor stage and lymph node metastasis. We further investigated if Cbl could also be present in the MUC1/CIN85 complex. Co-immunoprecipitation assay showed that Cbl co-localized both with CIN85 and with MUC1 in a human colon cancer cell line. To begin to investigate the in vivo relevance of MUC1 overexpression and association with CIN85 and Cbl in cancer development and progression, we used human MUC1 transgenic mice that express MUC1 on the colonic epithelial cells, treated with azoxymethane to initiate and dextran sulfate sodium (AOM/DSS) to promote colorectal carcinogenesis. MUC1.Tg mice showed higher tumor incidence and decreased survival when compared with wild-type mice. Consistent with the in vitro data, the association of MUC1, CIN85 and Cbl was detected in colon tissues of AOM/DSS-treated MUC1 transgenic mice. MUC1/CIN85/Cbl complex appears to contribute to promotion and progression of colon cancer and thus increased expression of MUC1, CIN85 and Cbl in early stage colon cancer might be predictive of poor prognosis.

Radiation carcinogenesis: radioprotectors and photosensitizers

International Nuclear Information System (INIS)

Fry, R.J.M.

1982-01-01

This paper outlines 1) some of the salient features of radiation carcinogenesis that are pertinent to the questions of how the carcinogenic effects might be influenced, 2) the effects of radioprotectors on ionizing radiation-induced cancer, and 3) the effect of photosensitizers on UVR-induced skin cancer

Radiation carcinogenesis: radioprotectors and photosensitizers

Energy Technology Data Exchange (ETDEWEB)

Fry, R.J.M.

1982-01-01

This paper outlines 1) some of the salient features of radiation carcinogenesis that are pertinent to the questions of how the carcinogenic effects might be influenced, 2) the effects of radioprotectors on ionizing radiation-induced cancer, and 3) the effect of photosensitizers on UVR-induced skin cancer.

Cell Transformation by PTP1B Truncated Mutants Found in Human Colon and Thyroid Tumors.

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Mei, Wenhan; Wang, Kemin; Huang, Jian; Zheng, Xinmin

2016-01-01

Expression of wild-type protein tyrosine phosphatase (PTP) 1B may act either as a tumor suppressor by dysregulation of protein tyrosine kinases or a tumor promoter through Src dephosphorylation at Y527 in human breast cancer cells. To explore whether mutated PTP1B is involved in human carcinogenesis, we have sequenced PTP1B cDNAs from human tumors and found splice mutations in ~20% of colon and thyroid tumors. The PTP1BΔE6 mutant expressed in these two tumor types and another PTP1BΔE5 mutant expressed in colon tumor were studied in more detail. Although PTP1BΔE6 revealed no phosphatase activity compared with wild-type PTP1B and the PTP1BΔE5 mutant, its expression induced oncogenic transformation of rat fibroblasts without Src activation, indicating that it involved signaling pathways independent of Src. The transformed cells were tumourigenic in nude mice, suggesting that the PTP1BΔE6 affected other molecule(s) in the human tumors. These observations may provide a novel therapeutic target for colon and thyroid cancer.

Expression of cholecystokinin receptors in colon cancer and the clinical correlation in Taiwan.

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Huang, Bee-Piao; Lin, Chun-Hsiang; Chen, Yi-Ching; Kao, Shao-Hsuan

2016-04-01

Cholecystokinin and gastrin receptors are upregulated in many human digestive malignancies; however, the correlation of their expressions with severity of colon carcinoma remains sketchy. Here, we determined the expression of cholecystokinin-1 and cholecystokinin-2 receptor, CCK1R and CCK2R, in colon carcinomas and investigated their correlations with clinicopathological characteristics and 1-year survival rate. Expression of CCK1R and CCK2R was determined by immunohistochemical assay in tissue samples obtained from 97 surgical specimens. Clinicopathological character analysis revealed that higher expression of cytoplasmic CCK1R and CCK2R was significantly associated with several variables including the depth of tumor invasion (P = 0.001), venous invasion (P = 0.023), and progression stage (P = 0.013). In addition, immunohistochemical staining revealed statistically significant associations of nuclear CCK1R expression with higher lymphatic invasion (P = 0.042), progression stage (P = 0.025), and unfavorable survival (P = 0.025). Interestingly, we found no link between nuclear CCK2R expression and all the clinicopathological characteristics examined. Taken these, our findings indicate that nuclear CCK1R represents a potential biomarker for poor prognosis, and CCK1R may play a role differing from CCK2R in colon carcinogenesis.

Stage III & IV colon and rectal cancers share a similar genetic profile: a review of the Oregon Colorectal Cancer Registry.

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Gawlick, Ute; Lu, Kim C; Douthit, Miriam A; Diggs, Brian S; Schuff, Kathryn G; Herzig, Daniel O; Tsikitis, Vassiliki L

2013-05-01

Determining the molecular profile of colon and rectal cancers offers the possibility of personalized cancer treatment. The purpose of this study was to determine whether known genetic mutations associated with colorectal carcinogenesis differ between colon and rectal cancers and whether they are associated with survival. The Oregon Colorectal Cancer Registry is a prospectively maintained, institutional review board-approved tissue repository with associated demographic and clinical information. The registry was queried for any patient with molecular analysis paired with clinical data. Patient demographics, tumor characteristics, microsatellite instability status, and mutational analysis for p53, AKT, BRAF, KRAS, MET, NRAS, and PIK3CA were analyzed. Categorical variables were compared using chi-square tests. Continuous variables between groups were analyzed using Mann-Whitney U tests. Kaplan-Meier analysis was used for survival studies. Comparisons of survival were made using log-rank tests. The registry included 370 patients: 69% with colon cancer and 31% with rectal cancer. Eighty percent of colon cancers and 68% of rectal cancers were stages III and IV. Mutational analysis found no significant differences in detected mutations between colon and rectal cancers, except that there were significantly more BRAF mutations in colon cancers compared with rectal cancers (10% vs 0%, P colon versus rectal cancers when stratified by the presence of KRAS, PIK3CA, and BRAF mutations. Stage III and IV colon and rectal cancers share similar molecular profiles, except that there were significantly more BRAF mutations in colon cancers compared with rectal cancers. Copyright © 2013 Elsevier Inc. All rights reserved.

Suppression of microRNA-31 increases sensitivity to 5-FU at an early stage, and affects cell migration and invasion in HCT-116 colon cancer cells

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Sun Xiao-Feng

2010-11-01

Full Text Available Abstract Background MicroRNAs (miRNAs are endogenously expressed noncoding RNAs with important biological and pathological functions. Although several studies have shown that microRNA-31 (miR-31 is obviously up-regulated in colorectal cancer (CRC, there is no study on the functional roles of miR-31 in CRC. Methods Anti-miR™ miRNA 31 inhibitor (anti-miR-31 is a sequence-specific and chemically modified oligonucleotide to specifically target and knockdown miR-31 molecule. The effect of anti-miR-31 transfection was investigated by real-time PCR. HCT-116p53+/+ and HCT-116p53-/-colon cancer cells were treated by anti-miR-31 with or without 5-fluorouracil (5-FU, cell proliferation was determined by MTT assay; apoptosis was detected by DAPI staining; cell cycle was evaluated by flow cytometry; colony formation, migration and invasion assays were performed to investigate the effect of suppression of miR-31 on the cell lines. Results Real-time PCR results showed that anti-miR-31 was efficiently introduced into the cells and reduced miR-31 levels to 44.1% in HCT-116p53+/+ and 67.8% in HCT-116p53-/-cell line (p = 0.042 and 0.046. MTT results showed that anti-miR-31 alone had no effect on the proliferation of HCT-116p53+/+ or HCT-116p53-/-. However, when combined with 5-FU, anti-miR-31 inhibited the proliferation of the two cell lines as early as 24 h after exposure to 5-FU (p = 0.038 and 0.044. Suppression of miR-31 caused a reduction of the migratory cells by nearly 50% compared with the negative control in both HCT-116p53+/+ and HCT-116p53-/-(p = 0.040 and 0.001. The invasive ability of the cells were increased by 8-fold in HCT-116p53+/+ and 2-fold in HCT-116p53-/- (p = 0.045 and 0.009. Suppression of miR-31 had no effect on cell cycle and colony formation (p > 0.05. Conclusions Suppression of miR-31 increases sensitivity to 5-FU at an early stage, and affects cell migration and invasion in HCT-116 colon cancer cells.

BMP suppresses PTEN expression via RAS/ERK signaling.

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Beck, Stayce E; Carethers, John M

2007-08-01

Bone morphogenetic protein (BMP), a member of the transforming growth factor beta family, classically utilizes the SMAD signaling pathway for its growth suppressive effects,and loss of this signaling cascade may accelerate cell growth. In the colon cancer predisposition syndrome Juvenile Polyposis, as well as in the late progression stages of nonsyndromic colorectal cancers, SMAD4 function is typically abrogated. Here, we utilized the SMAD4-null SW480 colon cancer cell line to examine BMPs effect on a potential target gene, PTEN, and how its expression might be regulated. Initial treatment of the SMAD4-null cells with BMP resulted in mild growth suppression, but with prolonged exposure to BMP, the cells become growth stimulatory, which coincided with observed decreases in transcription and translation of PTEN, and with corresponding increases in phospho-AKT protein levels. BMP-induced PTEN suppression was mediated via the RAS/ERK pathway, as pharmacologic inhibition of RAS/ERK, or interference with protein function in the cytosol by DN-RAS prevented BMP-induced growth promotion and changes in PTEN levels, as did treatment with noggin, a BMP ligand inhibitor. Thus, BMP downregulates PTEN via RAS/ERK in a SMAD4-null environment that contributes to cell growth, and constitutes a SMAD4-independent but BMP-responsive signaling pathway.

Comfrey (Symphytum officinale. L. and Experimental Hepatic Carcinogenesis: A Short-Term Carcinogenesis Model Study

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Maria Fernanda Pereira Lavieri Gomes

2010-01-01

Full Text Available Comfrey or Symphytum officinale (L. (Boraginaceae is a very popular plant used for therapeutic purposes. Since the 1980s, its effects have been studied in long-term carcinogenesis studies, in which Comfrey extract is administered at high doses during several months and the neoplastic hepatic lesions are evaluated. However, the literature on this topic is very poor considering the studies performed under short-term carcinogenesis protocols, such as the ‘resistant hepatocyte model’ (RHM. In these studies, it is possible to observe easily the phenomena related to the early phases of tumor development, since pre-neoplastic lesions (PNLs rise in about 1–2 months of chemical induction. Herein, the effects of chronic oral treatment of rats with 10% Comfrey ethanolic extract were evaluated in a RHM. Wistar rats were sequentially treated with N-nitrosodiethylamine (ip and 2-acetilaminofluorene (po, and submitted to hepatectomy to induce carcinogenesis promotion. Macroscopic/microscopic quantitative analysis of PNL was performed. Non-parametric statistical tests (Mann–Whitney and χ2 were used, and the level of significance was set at P ≤ 0.05. Comfrey treatment reduced the number of pre-neoplastic macroscopic lesions up to 1 mm (P ≤ 0.05, the percentage of oval cells (P = 0.0001 and mitotic figures (P = 0.007, as well as the number of Proliferating Cell Nuclear Antigen (PCNA positive cells (P = 0.0001 and acidophilic pre-neoplastic nodules (P = 0.05. On the other hand, the percentage of cells presenting megalocytosis (P = 0.0001 and vacuolar degeneration (P = 0.0001 was increased. Scores of fibrosis, glycogen stores and the number of nucleolus organizing regions were not altered. The study indicated that oral treatment of rats with 10% Comfrey alcoholic extract reduced cell proliferation in this model.

Comfrey (Symphytum Officinale. l.) and Experimental Hepatic Carcinogenesis: A Short-term Carcinogenesis Model Study.

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Gomes, Maria Fernanda Pereira Lavieri; de Oliveira Massoco, Cristina; Xavier, José Guilherme; Bonamin, Leoni Villano

2010-06-01

Comfrey or Symphytum officinale (L.) (Boraginaceae) is a very popular plant used for therapeutic purposes. Since the 1980s, its effects have been studied in long-term carcinogenesis studies, in which Comfrey extract is administered at high doses during several months and the neoplastic hepatic lesions are evaluated. However, the literature on this topic is very poor considering the studies performed under short-term carcinogenesis protocols, such as the 'resistant hepatocyte model' (RHM). In these studies, it is possible to observe easily the phenomena related to the early phases of tumor development, since pre-neoplastic lesions (PNLs) rise in about 1-2 months of chemical induction. Herein, the effects of chronic oral treatment of rats with 10% Comfrey ethanolic extract were evaluated in a RHM. Wistar rats were sequentially treated with N-nitrosodiethylamine (ip) and 2-acetilaminofluorene (po), and submitted to hepatectomy to induce carcinogenesis promotion. Macroscopic/microscopic quantitative analysis of PNL was performed. Non-parametric statistical tests (Mann-Whitney and χ(2)) were used, and the level of significance was set at P ≤ 0.05. Comfrey treatment reduced the number of pre-neoplastic macroscopic lesions up to 1 mm (P ≤ 0.05), the percentage of oval cells (P = 0.0001) and mitotic figures (P = 0.007), as well as the number of Proliferating Cell Nuclear Antigen (PCNA) positive cells (P = 0.0001) and acidophilic pre-neoplastic nodules (P = 0.05). On the other hand, the percentage of cells presenting megalocytosis (P = 0.0001) and vacuolar degeneration (P = 0.0001) was increased. Scores of fibrosis, glycogen stores and the number of nucleolus organizing regions were not altered. The study indicated that oral treatment of rats with 10% Comfrey alcoholic extract reduced cell proliferation in this model.

Lymphotoxin prevention of diethylnitrosamine carcinogenesis in vivo

International Nuclear Information System (INIS)

Ransom, J.H.; Evans, C.H.; DiPaolo, J.A.

1982-01-01

Development of intervention measures to control cancer would be facilitated by being able to monitor in vivo carcinogenesis by in vitro quantitation of early indices of neoplastic transformation to assess the in vivo effectiveness of preventive-therapeutic measures. Pregnant Syrian golden hamsters were used in an in vivo-in vitro transplacental model of carcinogenesis to determine the extent that in vivo administration of immunologic hormone preparations along with chemical carcinogen would prevent morphologic transformation assessed in vitro. Pregnant hamsters at 10-11 days of gestation were given injections ip of 3 mg diethylnitrosamine (DENA)/100 g body weight and were killed 2 days later when fetal cells were seeded for colony formation. The frequency of morphologically transformed colonies was assessed after 7 days of growth. Cloning efficiency and mean transformation frequency after DENA exposure were 3.6% and 1 X 10(-4) per cell seeded, respectively. The ip injection of an immunologic hormone preparation reduced the transformation frequency by 46%. The hormone preparation, containing 10,000 U of lymphotoxin but no detectable interferon, was the ultrafiltered lymphokines (greater than 10,000 mol wt) from phytohemagglutinin-stimulated hamster peritoneal leukocytes. The effect of lymphotoxin on cocarcinogenic exposure of fetal cells to DENA in vivo followed by X-irradiation in vitro was also determined. Cells exposed to 250 rad in vitro had a cloning efficiency of 0.5% and a transformation frequency of 0.4 X 10(-4) per cell seeded. After DENA injection and X-irradiation, the transformation frequency increased to 1 X 10(-4) and was inhibited 64% by lymphotoxin in vivo. Thus immunologic hormones (e.g., lymphotoxin) can prevent carcinogenesis in vivo. Furthermore, in vitro quantitation of transformation is a rapid means for evaluating therapeutic and autochthonous effector mechanisms for their ability to prevent or otherwise modulate carcinogenesis in vivo

Slc5a8, a Na+-coupled high-affinity transporter for short-chain fatty acids, is a conditional tumour suppressor in colon that protects against colitis and colon cancer under low-fibre dietary conditions.

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Gurav, Ashish; Sivaprakasam, Sathish; Bhutia, Yangzom D; Boettger, Thomas; Singh, Nagendra; Ganapathy, Vadivel

2015-07-15

Mammalian colon harbours trillions of bacteria under physiological conditions; this symbiosis is made possible because of a tolerized response from the mucosal immune system. The mechanisms underlying this tolerogenic phenomenon remain poorly understood. In the present study we show that Slc5a8 (solute carrier gene family 5a, member 8), a Na(+)-coupled high-affinity transporter in colon for the bacterial fermentation product butyrate, plays a critical role in this process. Among various immune cells in colon, dendritic cells (DCs) are unique not only in their accessibility to luminal contents but also in their ability to induce tolerogenic phenotype in T-cells. We found that DCs exposed to butyrate express the immunosuppressive enzymes indoleamine 2,3-dioxygenase 1 (IDO1) and aldehyde dehydrogenase 1A2 (Aldh1A2), promote conversion of naive T-cells into immunosuppressive forkhead box P3(+) (FoxP3(+)) Tregs (regulatory T-cells) and suppress conversion of naive T-cells into pro-inflammatory interferon (IFN)-γ-producing cells. Slc5a8-null DCs do not induce IDO1 and Aldh1A2 and do not generate Tregs or suppress IFN-γ-producing T-cells in response to butyrate. We also provide in vivo evidence for an obligatory role for Slc5a8 in suppression of IFN-γ-producing T-cells. Furthermore, Slc5a8 protects against colitis and colon cancer under conditions of low-fibre intake but not when dietary fibre intake is optimal. This agrees with the high-affinity nature of the transporter to mediate butyrate entry into cells. We conclude that Slc5a8 is an obligatory link between dietary fibre and mucosal immune system via the bacterial metabolite butyrate and that this transporter is a conditional tumour suppressor in colon linked to dietary fibre content. © 2015 Authors; published by Portland Press Limited.

Adlay (薏苡 yì yĭ; “soft-shelled job's tears”; the seeds of Coix lachryma-jobi L. var. ma-yuen Stapf is a Potential Cancer Chemopreventive Agent toward Multistage Carcinogenesis Processes

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Ching-Chuan Kuo, Ph.D.

2012-10-01

Full Text Available Adlay (薏苡 yì yĭ; “soft-shelled job’s tears”, the seeds of Coix lachryma-jobi L. var. ma-yuen Stapf is a grass crop that has long been used in traditional Chinese medicine (TCM and as a nourishing food in China for the treatment of warts, chapped skin, rheumatism, neuralgia, inflammatory, and neoplastic diseases. In addition, adlay also has been said to have stomachic, diuretic, antipholgistic, anodynic, and antispasmodic effects. Carcinogenesis is a multistage process that begins with exposure of viruses or chemicals that are found in the environment. Chemoprevention refers to the use of natural or synthetic, non-toxic chemical substances to reverse, repress, or prevent carcinogenesis. In this review, we summarize recent research attempting to study the chemopreventive blocking and suppressing potential of adlay and its active components in scavenging electrophiles and reactive oxygen species, antimutagenicity, enhancing Nrf2-mediated detoxification and antioxidant effect, altering carcinogen metabolism, suppressing proliferation, decreasing inflammation, and enhancing antitumor immunity. In addition, several active components with diverse chemopreventive properties have been also mentioned in this review article.

Radiation carcinogenesis, laboratory studies

International Nuclear Information System (INIS)

Shellabarger, C.J.

1974-01-01

Laboratory studies on radioinduced carcinogenesis are reviewed. Some topics discussed are: radioinduced neoplasia in relation to life shortening; dose-response relationships; induction of skin tumors in rats by alpha particles and electrons; effects of hormones on tumor response; effects of low LET radiations delivered at low dose-rates; effects of fractionated neutron radiation; interaction of RBE and dose rate effects; and estimates of risks for humans from animal data. (U.S.)

Lactobacillus rhamnosus ATCC 7469 exopolysaccharides synergizes with low level ionizing radiation to modulate signaling molecular targets in colorectal carcinogenesis in rats.

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Zahran, Walid E; Elsonbaty, Sawsan M; Moawed, Fatma S M

2017-08-01

Combination therapy that targets cellular signaling pathway represents an alternative therapy for the treatment of colon cancer (CRC). The present study was therefore aimed to investigate the probable interaction of Lactobacillus rhamnosus ATCC 7469 exopolysaccharides (EPS) with low level ionizing γ radiation (γ-R) exposure against dimethylhydrazine (DMH)- induced colorectal carcinogenesis in rats. Colon cancer was induced with 20mg DMH/kg BW. Rats received daily by gastric gavage 100mg EPS/Kg BW concomitant with 1Gy γ-R over two months. Colonic oxidative and inflammatory stresses were assessed. The change in the expression of p-p38 MAPK, p-STAT3, β-catenin, NF-kB, COX-2 and iNOS was evaluated by western blotting and q-PCR. It was found that DMH treatment significantly induced colon oxidative injury accompanied by inflammatory disturbance along with increased protein expression of the targeted signaling factors p-p38 MAPK, p-STAT3 and β-catenin. The mRNA gene expression of NF-kB, COX-2 and iNOS was significantly higher in DMH-treated animals. It's worthy to note that colon tissues with DMH treatment showed significant dysplasia and anaplasia of the glandular mucosal lining epithelium with loses of goblet cells formation, pleomorphism in the cells and hyperchromachia in nuclei. Interestingly, EPS treatment with γ-R exposure showed statistically significant amelioration of the oxidative and inflammatory biomarkers with modulated signaling molecular factors accompanied by improved histological structure against DMH-induced CRC. In conclusion, our findings showed that Lactobacillus rhamnosus ATCC 7469 EPS with low level γ-R in synergistic interaction are efficacious control against CRC progression throughout the modulation of key signaling growth factors associated with inflammation via antioxidant mediated anti-inflammatory and anti-proliferative activities. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Breast cancer as heterogeneous disease: contributing factors and carcinogenesis mechanisms.

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Kravchenko, Julia; Akushevich, Igor; Seewaldt, Victoria L; Abernethy, Amy P; Lyerly, H Kim

2011-07-01

The observed bimodal patterns of breast cancer incidence in the U.S. suggested that breast cancer may be viewed as more than one biological entity. We studied the factors potentially contributing to this phenomenon, specifically focusing on how disease heterogeneity could be linked to breast carcinogenesis mechanisms. Using empirical analyses and population-based biologically motivated modeling, age-specific patterns of incidence of ductal and lobular breast carcinomas from the SEER registry (1990-2003) were analyzed for heterogeneity and characteristics of carcinogenesis, stratified by race, stage, grade, and estrogen (ER)/progesterone (PR) receptor status. The heterogeneity of breast carcinoma age patterns decreased after stratification by grade, especially for grade I and III tumors. Stratification by ER/PR status further reduced the heterogeneity, especially for ER(+)/PR(-) and ER(-)/(-) tumors; however, the residual heterogeneity was still observed. The number of rate-limiting events of carcinogenesis and the latency of ductal and lobular carcinomas differed, decreasing from grade I to III, with poorly differentiated tumors associated with the least number of carcinogenesis stages and the shortest latency. Tumor grades play important role in bimodal incidence of breast carcinoma and have distinct mechanisms of carcinogenesis. Race and cancer subtype could play modifying role. ER/PR status contributes to the observed heterogeneity, but is subdominant to tumor grade. Further studies on sources of "remaining" heterogeneity of population with breast cancer (such as genetic/epigenetic characteristics) are necessary. The results of this study could suggest stratification rather than unification of breast cancer prevention strategies, risk assessment, and treatment.

Bone Marrow Cell Therapy on 1,2-Dimethylhydrazine (DMH)-Induced Colon Cancer in Rats.

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El-Khadragy, Manal F; Nabil, Heba M; Hassan, Basmaa N; Tohamy, Amany A; Waaer, Hanaa F; Yehia, Hany M; Alharbi, Afra M; Moneim, Ahmed Esmat Abdel

2018-01-01

Stem cell based therapies are being under focus due to their possible role in treatment of various tumors. Bone marrow stem cells believed to have anticancer potential and are preferred for their activities by stimulating the immune system, migration to the site of tumor and ability for inducting apoptosis in cancer cells. The current study was aimed to investigate the tumor suppressive effects of bone marrow cells (BMCs) in 1,2-dimethylhydrazine (DMH)-induced colon cancer in rats. The rats were randomly allocated into four groups: control, BMCs alone, DMH alone and BMCs with DMH. BMCs were injected intrarectally while DMH was injected subcutaneously at 20 mg/kg body weight once a week for 15 weeks. Histopathological examination and gene expression of survivin, β-catenin and multidrug resistance-1 (MDR-1) by real-time reverse transcription-polymerase chain reaction (RT-PCR) in rat colon tissues. This is in addition to oxidative stress markers in colon were performed across all groups. The presence of aberrant crypt foci was reordered once histopathological examination of colon tissue from rats which received DMH alone. Administration of BMCs into rats starting from zero-day of DMH injection improved the histopathological picture which showed a clear improvement in mucosal layer, few inflammatory cells infiltration periglandular and in the lamina propria. Gene expression in rat colon tissue demonstrated that BMCs down-regulated survivin, β-catenin, MDR-1 and cytokeratin 20 genes expression in colon tissues after colon cancer induction. Amelioration of the colon status after administration of MSCs has been evidenced by a major reduction of lipid peroxidation, nitric oxide, and increasing of glutathione content and superoxide dismutase along with catalase activities. Our findings demonstrated that BMCs have tumor suppressive effects in DMH-induced colon cancer as evidenced by down-regulation of survivin, β-catenin, and MDR-1 genes and enhancing the antioxidant

Radiogenic cell transformation and carcinogenesis

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Yang, T. C.; Georgy, K. A.; Mei, M.; Durante, M.; Craise, L. M.

1995-01-01

Radiation carcinogenesis is one of the major biological effects considered important in the risk assessment for space travel. Various biological model systems, including both cultured cells and animals, have been found useful for studying the carcinogenic effects of space radiations, which consist of energetic electrons, protons and heavy ions. The development of techniques for studying neoplastic cell transformation in culture has made it possible to examine the cellular and molecular mechanisms of radiation carcinogenesis. Cultured cell systems are thus complementary to animal models. Many investigators have determined the oncogenic effects of ionizing and nonionizing radiation in cultured mammalian cells. One of the cell systems used most often for radiation transformation studies is mouse embryonic cells (C3H10T1/2), which are easy to culture and give good quantitative dose-response curves. Relative biological effectiveness (RBE) for heavy ions with various energies and linear energy transfer (LET) have been obtained with this cell system. Similar RBE and LET relationship was observed by investigators for other cell systems. In addition to RBE measurements, fundamental questions on repair of sub- and potential oncogenic lesions, direct and indirect effect, primary target and lesion, the importance of cell-cell interaction and the role of oncogenes and tumor suppressor genes in radiogenic carcinogenesis have been studied, and interesting results have been found. Recently several human epithelial cell systems have been developed, and ionizing radiation have been shown to transform these cells. Oncogenic transformation of these cells, however, requires a long expression time and/or multiple radiation exposures. Limited experimental data indicate high-LET heavy ions can be more effective than low-LET radiation in inducing cell transformation. Cytogenetic and molecular analyses can be performed with cloned transformants to provide insights into basic genetic

Liver Development, Regeneration, and Carcinogenesis

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Janet W. C. Kung

2010-01-01

Full Text Available The identification of putative liver stem cells has brought closer the previously separate fields of liver development, regeneration, and carcinogenesis. Significant overlaps in the regulation of these processes are now being described. For example, studies in embryonic liver development have already provided the basis for directed differentiation of human embryonic stem cells and induced pluripotent stem cells into hepatocyte-like cells. As a result, the understanding of the cell biology of proliferation and differentiation in the liver has been improved. This knowledge can be used to improve the function of hepatocyte-like cells for drug testing, bioartificial livers, and transplantation. In parallel, the mechanisms regulating cancer cell biology are now clearer, providing fertile soil for novel therapeutic approaches. Recognition of the relationships between development, regeneration, and carcinogenesis, and the increasing evidence for the role of stem cells in all of these areas, has sparked fresh enthusiasm in understanding the underlying molecular mechanisms and has led to new targeted therapies for liver cirrhosis and primary liver cancers.

Butyrate and bioactive proteolytic form of Wnt-5a regulate colonic epithelial proliferation and spatial development

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Uchiyama, Kazuhiko; Sakiyama, Toshio; Hasebe, Takumu; Musch, Mark W.; Miyoshi, Hiroyuki; Nakagawa, Yasushi; He, Tong-Chuan; Lichtenstein, Lev; Naito, Yuji; Itoh, Yoshito; Yoshikawa, Toshikazu; Jabri, Bana; Stappenbeck, Thaddeus; Chang, Eugene B.

2016-01-01

Proliferation and spatial development of colonic epithelial cells are highly regulated along the crypt vertical axis, which, when perturbed, can result in aberrant growth and carcinogenesis. In this study, two key factors were identified that have important and counterbalancing roles regulating these processes: pericrypt myofibroblast-derived Wnt-5a and the microbial metabolite butyrate. Cultured YAMC cell proliferation and heat shock protein induction were analzyed after butryate, conditioned medium with Wnt5a activity, and FrzB containing conditioned medium. In vivo studies to modulate Hsp25 employed intra-colonic wall Hsp25 encoding lentivirus. To silence Wnt-5a in vivo, intra-colonic wall Wnt-5a silencing RNA was used. Wnt-5a, secreted by stromal myofibroblasts of the lower crypt, promotes proliferation through canonical β-catenin activation. Essential to this are two key requirements: (1) proteolytic conversion of the highly insoluble ~40 kD Wnt-5a protein to a soluble 36 mer amino acid peptide that activates epithelial β-catenin and cellular proliferation, and (2) the simultaneous inhibition of butyrate-induced Hsp25 by Wnt-5a which is necessary to arrest the proliferative process in the upper colonic crypt. The interplay and spatial gradients of these factors insures that crypt epithelial cell proliferation and development proceed in an orderly fashion, but with sufficient plasticity to adapt to physiological perturbations including inflammation. PMID:27561676

Oncogenic KRAS activates an embryonic stem cell-like program in human colon cancer initiation.

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Le Rolle, Anne-France; Chiu, Thang K; Zeng, Zhaoshi; Shia, Jinru; Weiser, Martin R; Paty, Philip B; Chiu, Vi K

2016-01-19

Colorectal cancer is the third most frequently diagnosed cancer worldwide. Prevention of colorectal cancer initiation represents the most effective overall strategy to reduce its associated morbidity and mortality. Activating KRAS mutation (KRASmut) is the most prevalent oncogenic driver in colorectal cancer development, and KRASmut inhibition represents an unmet clinical need. We apply a systems-level approach to study the impact of KRASmut on stem cell signaling during human colon cancer initiation by performing gene set enrichment analysis on gene expression from human colon tissues. We find that KRASmut imposes the embryonic stem cell-like program during human colon cancer initiation from colon adenoma to stage I carcinoma. Expression of miR145, an embryonic SC program inhibitor, promotes cell lineage differentiation marker expression in KRASmut colon cancer cells and significantly suppresses their tumorigenicity. Our data support an in vivo plasticity model of human colon cancer initiation that merges the intrinsic stem cell properties of aberrant colon stem cells with the embryonic stem cell-like program induced by KRASmut to optimize malignant transformation. Inhibition of the embryonic SC-like program in KRASmut colon cancer cells reveals a novel therapeutic strategy to programmatically inhibit KRASmut tumors and prevent colon cancer.

A paraptosis-like cell death induced by δ-tocotrienol in human colon carcinoma SW620 cells is associated with the suppression of the Wnt signaling pathway

International Nuclear Information System (INIS)

Zhang, Jing-Shu; Li, Da-Ming; He, Ning; Liu, Ying-Hua; Wang, Chun-Hua; Jiang, Shu-Qing; Chen, Bing-Qing; Liu, Jia-Ren

2011-01-01

Tocotrienol is considered a beneficial effect agent on inhibition of tumor development. In this study, we focused on the effects of δ-tocotrienol and its possible mechanism on induction of death in human colon cancer SW620 cells. δ-Tocotrienol inhibited proliferation of SW620 cell in a dose-dependent manner. Our findings showed that δ-tocotrienol effectively induced paraptosis-like death in SW620 cells, correlated with the vacuolation that may be from welling and fusion of mitochondria and/or the endoplasmic reticulum (ER) as well as caspase-3 nonactivated. However, there were no changes in apoptosis based on flow cytometry analysis. Of being noted, δ-tocotrienol reduced the expression of β-catenin and wnt-1 proteins by about 50% at the highest dose (20 μmol/L). δ-Tocotrienol also decreased cyclin D1, c-jun and MMP-7 protein levels in SW620 cells. Altogether, these data indicate that δ-tocotrienol induces paraptosis-like cell death, which is associated with the suppression of the Wnt signaling pathway. Thus, our findings may provide a novel application in treatment of human colon carcinoma.

Introduction to Genetic Mechanisms of Carcinogenesis

International Nuclear Information System (INIS)

Yang, W.K.

1983-01-01

Recent technical advances in nucleic acid research and molecular biology have made it possible to explore the complicated genetic systems of eukaryotic cells. One of the fields showing rapid progress concerns genes and gene regulatory functions related to neoplastic processes. Thus, the 35th Annual Conference of the Biology Division of Oak Ridge National Laboratory, held at Gatlinburg, April 12-15, 1982, was organized with the intention to bring together investigators working on seemingly diverse fields of cancer research to discuss and exchange their views on the genetic mechanisms of carcinogenesis. The meeting was attended by workers from chemical, physical as well as biological carcinogenesis fields, by classical geneticists as well as by molecular biologists, and by researchers interested in experimental as well as in human cancers. Included in this volume are papers by the invited speakers of the symposium as well as by those presenting poster papers at the meeting

Rhizosphere Colonization and Control of Meloidogyne spp. by Nematode-trapping Fungi

Science.gov (United States)

Persson, Christina; Jansson, Hans-Börje

1999-01-01

The ability of nematode-trapping fungi to colonize the rhizosphere of crop plants has been suggested to be an important factor in biological control of root-infecting nematodes. In this study, rhizosphere colonization was evaluated for 38 isolates of nematode-trapping fungi representing 11 species. In an initial screen, Arthrobotrys dactyloides, A. superba, and Monacrosporium ellipsosporum were most frequently detected in the tomato rhizosphere. In subsequent pot experiments these fungi and the non-root colonizing M. geophyropagum were introduced to soil in a sodium alginate matrix, and further tested both for establishment in the tomato rhizosphere and suppression of root-knot nematodes. The knob-forming M. ellipsosporum showed a high capacity to colonize the rhizosphere both in the initial screen and the pot experiments, with more than twice as many fungal propagules in the rhizosphere as in the root-free soil. However, neither this fungus nor the other nematode-trapping fungi tested reduced nematode damage to tomato plants. PMID:19270886

Effects of Lactobacillus salivarius Ren on cancer prevention and intestinal microbiota in 1, 2-dimethylhydrazine-induced rat model.

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Zhang, Ming; Fan, Xing; Fang, Bing; Zhu, Chengzhen; Zhu, Jun; Ren, Fazheng

2015-06-01

Probiotics have been suggested as a prophylactic measure in colon cancer. The aim of this study was to investigate the impact of Lactobacillus salivarius Ren (Ren) in modulating colonic microbiota structure and colon cancer incidence in a rat model after injection with 1,2-dimethyl hydrazine (DMH). The results indicated that oral administration of Ren could effectively suppress DMH-induced colonic carcinogenesis. A significant decrease in cancer incidence (87.5% to 25%) was detected in rats fed with a dose of 5 × 10(10) CFU/kg bodyweight per day. Using denaturing gradient gel electrophoresis and Real-time PCR combined with multivariate statistical methods, we demonstrated that injection with DMH significantly altered the rat gut microbiota, while Ren counteracted these DMH-induced adverse effects and promoted reversion of the gut microbiota close to the healthy state. Tvalue biplots followed by band sequencing identified 21 bacterial strains as critical variables affected by DMH and Ren. Injection of DMH significantly increased the amount of Ruminococcus species (sp.) and Clostridiales bacteria, as well as decreasing the Prevotella sp. Administration of Ren reduced the amount of Ruminococcus sp., Clostridiales bacteria, and Bacteroides dorei, and increased the amount of Prevotella. Real-time PCR results were consistent with the results derived by t-value biplots. These findings suggested that Ren is a potential agent for colon cancer prevention. In conclusion, the results in the present study suggest a potential therapeutic approach based on the modulation of intestinal microflora by probiotics may be beneficial in the prevention of colorectal carcinogenesis.

The Indolic Diet-Derivative, 3,3′-Diindolylmethane, Induced Apoptosis in Human Colon Cancer Cells through Upregulation of NDRG1

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A. Lerner

2012-01-01

Full Text Available N-myc downstream regulated gene-1 participates in carcinogenesis, angiogenesis, metastases, and anticancer drug resistance. In the present study, we analyzed the expression pattern of N-myc downstream regulated gene-1 following treatment of human colonic cancer cell lines; HCT-116 (well differentiated with wild-type p53 gene and Colo-320 (poorly differentiated with mutant p53 gene, with 3,3′-diindolylmethane, a well-established proapoptotic agent product derived from indole-3-carbinol. Treatment of Colo-320 and HCT-116 with 3,3′-diindolylmethane disclosed inhibition of cell viability in a dose-dependent manner, mediated through apoptosis induction. The increased expression of N-myc downstream regulated gene-1 was detected only in poorly differentiated colon cancer cells, Colo-320 cell line. Our results suggest that N-myc downstream regulated gene-1 expression is enhanced by 3,3′-diindolylmethane in poorly differentiated cells and followed by induction of apoptosis. 3,3′-diindolylmethane induced apoptosis may represent a new regulator of N-myc downstream regulated gene-1 in poorly differentiated colonic cancer cells.

Growth-inhibitory effects of the chemopreventive agent indole-3-carbinol are increased in combination with the polyamine putrescine in the SW480 colon tumour cell line

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Gescher Andreas

2003-01-01

Full Text Available Abstract Background Many tumours undergo disregulation of polyamine homeostasis and upregulation of ornithine decarboxylase (ODC activity, which can promote carcinogenesis. In animal models of colon carcinogenesis, inhibition of ODC activity by difluoromethylornithine (DFMO has been shown to reduce the number and size of colon adenomas and carcinomas. Indole-3-carbinol (I3C has shown promising chemopreventive activity against a range of human tumour cell types, but little is known about the effect of this agent on colon cell lines. Here, we investigated whether inhibition of ODC by I3C could contribute to a chemopreventive effect in colon cell lines. Methods Cell cycle progression and induction of apoptosis were assessed by flow cytometry. Ornithine decarboxylase activity was determined by liberation of CO2 from 14C-labelled substrate, and polyamine levels were measured by HPLC. Results I3C inhibited proliferation of the human colon tumour cell lines HT29 and SW480, and of the normal tissue-derived HCEC line, and at higher concentrations induced apoptosis in SW480 cells. The agent also caused a decrease in ODC activity in a dose-dependent manner. While administration of exogenous putrescine reversed the growth-inhibitory effect of DFMO, it did not reverse the growth-inhibition following an I3C treatment, and in the case of the SW480 cell line, the effect was actually enhanced. In this cell line, combination treatment caused a slight increase in the proportion of cells in the G2/M phase of the cell cycle, and increased the proportion of cells undergoing necrosis, but did not predispose cells to apoptosis. Indole-3-carbinol also caused an increase in intracellular spermine levels, which was not modulated by putrescine co-administration. Conclusion While indole-3-carbinol decreased ornithine decarboxylase activity in the colon cell lines, it appears unlikely that this constitutes a major mechanism by which the agent exerts its antiproliferative

Tissue misrepair hypothesis for radiation carcinogenesis

International Nuclear Information System (INIS)

Kondo, Sohei

1991-01-01

Dose-response curves for chronic leukemia in A-bomb survivors and liver tumors in patients given Thorotrast (colloidal thorium dioxide) show large threshold effects. The existence of these threshold effects can be explained by the following hypothesis. A high dose of radiation causes a persistent wound in a cellrenewable tissue. Disorder of the injured cell society partly frees the component cells from territorial restraints on their proliferation, enabling them to continue development of their cellular functions toward advanced autonomy. This progression might be achieved by continued epigenetic and genetic changes as a result of occasional errors in the otherwise concerted healing action of various endogeneous factors recruited for tissue repair. Carcinogenesis is not simply a single-cell problem but a cell-society problem. Therefore, it is not warranted to estimate risk at low doses by linear extrapolation from cancer data at high doses without knowledge of the mechanism of radiation carcinogenesis. (author) 57 refs

Blueberry inhibits invasion and angiogenesis in 7,12-dimethylbenz[a]anthracene (DMBA)-induced oral squamous cell carcinogenesis in hamsters via suppression of TGF-β and NF-κB signaling pathways.

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Baba, Abdul Basit; Kowshik, Jaganathan; Krishnaraj, Jayaraman; Sophia, Josephraj; Dixit, Madhulika; Nagini, Siddavaram

2016-09-01

Aberrant activation of oncogenic signaling pathways plays a pivotal role in tumor initiation and progression. The purpose of the present study was to investigate the chemopreventive and therapeutic efficacy of blueberry in the hamster buccal pouch (HBP) carcinogenesis model based on its ability to target TGF-β, PI3K/Akt, MAPK and NF-κB signaling and its impact on invasion and angiogenesis. Squamous cell carcinomas were induced in the HBP by 7,12-dimethylbenz[a]anthracene (DMBA). The effect of blueberry on the oncogenic signaling pathways and downstream events was analyzed by quantitative real-time PCR and immunoblotting. Experiments with the ECV304 cell line were performed to explore the mechanism by which blueberry regulates angiogenesis. Blueberry supplementation inhibited the development and progression of HBP carcinomas by abrogating TGF-β and PI3K/Akt pathways. Although blueberry failed to influence MAPK, it suppressed NF-κB activation by preventing nuclear translocation of NF-κB p65. Blueberry also modulated the expression of the oncomiR miR-21 and the tumor suppressor let-7. Collectively, these changes induced a shift to an anti-invasive and anti-angiogenic phenotype as evidenced by downregulating matrix metalloproteinases and vascular endothelial growth factor. Blueberry also inhibited angiogenesis in ECV304 cells by suppressing migration and tube formation. The results of the present study suggest that targeting oncogenic signaling pathways that influence acquisition of cancer hallmarks is an effective strategy for chemointervention. Identification of modulatory effects on phosphorylation, intracellular localization of oncogenic transcription factors and microRNAs unraveled by the present study as key mechanisms of action of blueberry is critical from a therapeutic perspective. Copyright © 2016 Elsevier Inc. All rights reserved.

The American ''colonization'' of Northwest European social psychology after World War II

NARCIS (Netherlands)

vanStrien, PJ

1997-01-01

The term colonization as used in this article does not refer to the suppression of one culture by another, but to a voluntary intellectual submission, eventually resulting in a ''neo-colonial'' relationship in which, in spite of a ''decolonization'' movement, much of the dominant culture has been

Experimental gastric carcinogenesis in Cebus apella nonhuman primates.

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Joana de Fátima Ferreira Borges da Costa

Full Text Available The evolution of gastric carcinogenesis remains largely unknown. We established two gastric carcinogenesis models in New-World nonhuman primates. In the first model, ACP03 gastric cancer cell line was inoculated in 18 animals. In the second model, we treated 6 animals with N-methyl-nitrosourea (MNU. Animals with gastric cancer were also treated with Canova immunomodulator. Clinical, hematologic, and biochemical, including C-reactive protein, folic acid, and homocysteine, analyses were performed in this study. MYC expression and copy number was also evaluated. We observed that all animals inoculated with ACP03 developed gastric cancer on the 9(th day though on the 14(th day presented total tumor remission. In the second model, all animals developed pre-neoplastic lesions and five died of drug intoxication before the development of cancer. The last surviving MNU-treated animal developed intestinal-type gastric adenocarcinoma observed by endoscopy on the 940(th day. The level of C-reactive protein level and homocysteine concentration increased while the level of folic acid decreased with the presence of tumors in ACP03-inoculated animals and MNU treatment. ACP03 inoculation also led to anemia and leukocytosis. The hematologic and biochemical results corroborate those observed in patients with gastric cancer, supporting that our in vivo models are potentially useful to study this neoplasia. In cell line inoculated animals, we detected MYC immunoreactivity, mRNA overexpression, and amplification, as previously observed in vitro. In MNU-treated animals, mRNA expression and MYC copy number increased during the sequential steps of intestinal-type gastric carcinogenesis and immunoreactivity was only observed in intestinal metaplasia and gastric cancer. Thus, MYC deregulation supports the gastric carcinogenesis process. Canova immunomodulator restored several hematologic measurements and therefore, can be applied during/after chemotherapy to increase the

Colon cancer

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Colorectal cancer; Cancer - colon; Rectal cancer; Cancer - rectum; Adenocarcinoma - colon; Colon - adenocarcinoma; Colon carcinoma ... eat may play a role in getting colon cancer. Colon cancer may be linked to a high-fat, ...

Rhein induces apoptosis of HCT-116 human colon cancer cells via ...

African Journals Online (AJOL)

Rhein, a major compound in rhubarb, has been found to have anti-tumor properties in many human cancer cells. However, the details about rhein suppressing the growth of human colon cancer cells remained elusive. In this paper, we explored the potential of rhein as a chemotherapeutic agent on HCT- 116 cells and ...

ColoLipidGene: signature of lipid metabolism-related genes to predict prognosis in stage-II colon cancer patients

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Vargas, Teodoro; Moreno-Rubio, Juan; Herranz, Jesús; Cejas, Paloma; Molina, Susana; González-Vallinas, Margarita; Mendiola, Marta; Burgos, Emilio; Aguayo, Cristina; Custodio, Ana B.; Machado, Isidro; Ramos, David; Gironella, Meritxell; Espinosa-Salinas, Isabel; Ramos, Ricardo; Martín-Hernández, Roberto; Risueño, Alberto; De Las Rivas, Javier; Reglero, Guillermo; Yaya, Ricardo; Fernández-Martos, Carlos; Aparicio, Jorge; Maurel, Joan; Feliu, Jaime; de Molina, Ana Ramírez

2015-01-01

Lipid metabolism plays an essential role in carcinogenesis due to the requirements of tumoral cells to sustain increased structural, energetic and biosynthetic precursor demands for cell proliferation. We investigated the association between expression of lipid metabolism-related genes and clinical outcome in intermediate-stage colon cancer patients with the aim of identifying a metabolic profile associated with greater malignancy and increased risk of relapse. Expression profile of 70 lipid metabolism-related genes was determined in 77 patients with stage II colon cancer. Cox regression analyses using c-index methodology was applied to identify a metabolic-related signature associated to prognosis. The metabolic signature was further confirmed in two independent validation sets of 120 patients and additionally, in a group of 264 patients from a public database. The combined analysis of these 4 genes, ABCA1, ACSL1, AGPAT1 and SCD, constitutes a metabolic-signature (ColoLipidGene) able to accurately stratify stage II colon cancer patients with 5-fold higher risk of relapse with strong statistical power in the four independent groups of patients. The identification of a group of 4 genes that predict survival in intermediate-stage colon cancer patients allows delineation of a high-risk group that may benefit from adjuvant therapy, and avoids the toxic and unnecessary chemotherapy in patients classified as low-risk group. PMID:25749516

HIF1α deficiency reduces inflammation in a mouse model of proximal colon cancer

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Dessislava N. Mladenova

2015-09-01

Full Text Available Hypoxia-inducible factor 1α (HIF1α is a transcription factor that regulates the adaptation of cells to hypoxic microenvironments, for example inside solid tumours. Stabilisation of HIF1α can also occur in normoxic conditions in inflamed tissue or as a result of inactivating mutations in negative regulators of HIF1α. Aberrant overexpression of HIF1α in many different cancers has led to intensive efforts to develop HIF1α-targeted therapies. However, the role of HIF1α is still poorly understood in chronic inflammation that predisposes the colon to carcinogenesis. We have previously reported that the transcription of HIF1α is upregulated and that the protein is stabilised in inflammatory lesions that are caused by the non-steroidal anti-inflammatory drug (NSAID sulindac in the mouse proximal colon. Here, we exploited this side effect of long-term sulindac administration to analyse the role of HIF1α in colon inflammation using mice with a Villin-Cre-induced deletion of Hif1α exon 2 in the intestinal epithelium (Hif1αΔIEC. We also analysed the effect of sulindac sulfide on the aryl hydrocarbon receptor (AHR pathway in vitro in colon cancer cells. Most sulindac-treated mice developed visible lesions, resembling the appearance of flat adenomas in the human colon, surrounded by macroscopically normal mucosa. Hif1αΔIEC mice still developed lesions but they were smaller than in the Hif1α-floxed siblings (Hif1αF/F. Microscopically, Hif1αΔIEC mice had significantly less severe colon inflammation than Hif1αF/F mice. Molecular analysis showed reduced MIF expression and increased E-cadherin mRNA expression in the colon of sulindac-treated Hif1αΔIEC mice. However, immunohistochemistry analysis revealed a defect of E-cadherin protein expression in sulindac-treated Hif1αΔIEC mice. Sulindac sulfide treatment in vitro upregulated Hif1α, c-JUN and IL8 expression through the AHR pathway. Taken together, HIF1α expression augments inflammation

Down-regulation of LRP1B in colon cancer promoted the growth and migration of cancer cells.

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Wang, Zhiqiang; Sun, Peng; Gao, Chun; Chen, Ji; Li, Jun; Chen, Zhonghao; Xu, Ming; Shao, Jun; Zhang, Yunpeng; Xie, Jiang

2017-08-01

Aberrant activation of beta-catenin/TCF signaling is one of the hallmarks of colon cancer. It is of great interest to study the mechanism for the regulation of beta-catenin/TCF signaling. In this study, it was found that LRP1B was down-regulated in colon cancer tissues and inhibited the growth, migration and metastasis of colon cancer cells. The molecular mechanism study revealed that LRP1B interacted with DVL2, inhibited the interaction between DVL2 and Axin, and negatively regulated beta-catenin/TCF signaling. Taken together, our study demonstrated the suppressive roles of LRP1B in the progression of colon cancer, implicating that restoring the function of LRP1B would be a promising strategy for the treatment of colon cancer. Copyright © 2017. Published by Elsevier Inc.

Dietary chromium and nickel enhance UV-carcinogenesis in skin of hairless mice

International Nuclear Information System (INIS)

Uddin, Ahmed N.; Burns, Fredric J.; Rossman, Toby G.; Chen, Haobin; Kluz, Thomas; Costa, Max

2007-01-01

The skin cancer enhancing effect of chromium (in male mice) and nickel in UVR-irradiated female Skh1 mice was investigated. The dietary vitamin E and selenomethionine were tested for prevention of chromium-enhanced skin carcinogenesis. The mice were exposed to UVR (1.0 kJ/m 2 3x weekly) for 26 weeks either alone, or combined with 2.5 or 5.0 ppm potassium chromate, or with 20, 100 or 500 ppm nickel chloride in drinking water. Vitamin E or selenomethionine was added to the lab chow for 29 weeks beginning 3 weeks before the start of UVR exposure. Both chromium and nickel significantly increased the UVR-induced skin cancer yield in mice. In male Skh1 mice, UVR alone induced 1.9 ± 0.4 cancers/mouse, and 2.5 or 5.0 ppm potassium chromate added to drinking water increased the yields to 5.9 ± 0.8 and 8.6 ± 0.9 cancers/mouse, respectively. In female Skh1 mice, UVR alone induced 1.7 ± 0.4 cancers/mouse, and the addition of 20, 100 or 500 ppm nickel chloride increased the yields to 2.8 ± 0.9, 5.6 ± 0.7 and 4.2 ± 1.0 cancers/mouse, respectively. Neither vitamin E nor selenomethionine reduced the cancer yield enhancement by chromium. These results confirm that chromium and nickel, while not good skin carcinogens per se, are enhancers of UVR-induced skin cancers in Skh1 mice. Data also suggest that the enhancement of UVR-induced skin cancers by chromate may not be oxidatively mediated since the antioxidant vitamin E as well as selenomethionine, found to prevent arsenite-enhanced skin carcinogenesis, failed to suppress enhancement by chromate

Predicting the time to colonization of the parasitoid Diadegma semiclausum: the importance of the shape of spatial dispersal kernels for biological control

NARCIS (Netherlands)

Bianchi, F.J.J.A.; Schellhorn, N.A.; Werf, van der W.

2009-01-01

The time at which natural enemies colonize crop fields is an important determinant of their ability to suppress pest populations. This timing depends on the distance between source and sink habitats in the landscape. Here we estimate the time to colonization of sink habitats from a distant source

Radiation carcinogenesis: Epidemiology and biological significance

International Nuclear Information System (INIS)

Boice, J.D.; Fraumeni, J.F.

1984-01-01

Epidemiologic studies of populations exposed to radiation have led to the identification of a preventable cause of cancer, but in the long run perhaps the most important contribution of radiation studies will be to provide insights into the basic processes of human carcinogenesis. In this volume, key investigators of major epidemiologic projects summarize their observations to date, including information to help assess the effects of low-level exposures. Experimentalists and theorists emphasize the relevance of laboratory and epidemiologic data in elucidating carcinogenic risks and mechanisms in man. This volume was prepared with several objectives in mind: (a) organize and synthesize knowledge on radiation carcinogenesis through epidemiologic and experimental approaches; (b) illustrate and explore ways of utilizing this information to gain insights into the fundamental mechanisms of cancer development; (c) stimulate the formation of hypotheses suited to experimental or epidemiologic testing, theoretical modeling, and multidisciplinary approaches; and (d) identify recent advances that clarify dose-response relationships and the influence of low-dose exposures, provide leads to carcinogenic mechanisms and host-environmental interactions, and suggest strategies for future research and preventive action

γ-Aminobutyric acid inhibits the proliferation and increases oxaliplatin sensitivity in human colon cancer cells.

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Song, Lihua; Du, Aiying; Xiong, Ying; Jiang, Jing; Zhang, Yao; Tian, Zhaofeng; Yan, Hongli

2016-11-01

γ-Aminobutyric acid (GABA) is a natural non-protein amino acid, which broadly exists in many plant parts and is widely used as an ingredient in the food industry. In mammals, it is widely distributed in central nervous system and non-neural tissues. In addition to a primary inhibitory neurotransmitter in the central nervous system, endogenous GABA content has been found to be elevated in neoplastic tissues in colon cancer. However, the effect of extraneous GABA on colon cancer has rarely been reported. In this study, we found the inhibitory effects of GABA on the proliferation of colon cancer cells (CCCs). The amino acid also suppressed metastasis of SW480 and SW620 cells. To further study the correlated mechanism, we analyzed the changes in cell cycle distribution and found that GABA suppressed cell cycle progression through G2/M or G1/S phase. Furthermore, RNA sequencing analysis revealed GABA-induced changes in the mRNA expression of 30 genes, including EGR1, MAPK4, NR4A1, Fos, and FosB, in all the three types of CCC. Importantly, GABA enhanced the anti-tumor efficacy of oxaliplatin (OXA) in subcutaneous xenograft tumor model in nude mice. The data suggest that GABA inhibits colon cancer cell proliferation perhaps by attenuating EGR1-NR4A1 axis, EGR1-Fos axis, and by disrupting MEK-EGR1 signaling pathway. This work reveals the pharmacological value of GABA derived from food and suggests that exogenous GABA might play an auxiliary role in polychemotherapy of colon cancer.

Towards a systemic paradigm in carcinogenesis: linking epigenetics and genetics.

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Burgio, Ernesto; Migliore, Lucia

2015-04-01

For at least 30 years cancer has been defined as a genetic disease and explained by the so-called somatic mutation theory (SMT), which has dominated the carcinogenesis field. Criticism of the SMT has recently greatly increased, although still not enough to force all SMT supporters to recognize its limits. Various researchers point out that cancer appears to be a complex process concerning a whole tissue; and that genomic mutations, although variably deleterious and unpredictably important in determining the establishment of the neoplastic phenotype, are not the primary origin for a malignant neoplasia. We attempt to describe the inadequacies of the SMT and demonstrate that epigenetics is a more logical cause of carcinogenesis. Many previous models of carcinogenesis fall into two classes: (i) in which some biological changes inside cells alone lead to malignancy; and (ii) requiring changes in stroma/extracellular matrix. We try to make clear that in the (ii) model genomic instability is induced by persistent signals coming from the microenvironment, provoking epigenetic and genetic modifications in tissue stem cells that can lead to cancer. In this perspective, stochastic mutations of DNA are a critical by-product rather then the primary cause of cancer. Indirect support for such model of carcinogenesis comes from the in vitro and vivo experiments showing apparent 'reversion' of cancer phenotypes obtained via physiological factors of cellular differentiation (cytokines and other signaling molecules) or drugs, even if the key mutations are not 'reversed'.

Molecular mechanisms in radiation carcinogenesis: introduction

International Nuclear Information System (INIS)

Setlow, R.B.

1975-01-01

Molecular studies of radiation carcinogenesis are discussed in relation to theories for extrapolating from cellular and animal models to man. Skin cancer is emphasized because of sunlight-induced photochemical damage to DNA. It is emphasized that cellular and animal models are needed as well as molecular theories for quantitative evaluation of hazardous environmental agents. (U.S.)

Inoculation effects on root-colonizing arbuscular mycorrhizal fungal communities spread beyond directly inoculated plants

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Krak, Karol; Vosátka, Miroslav; Püschel, David; Štorchová, Helena

2017-01-01

Inoculation with arbuscular mycorrhizal fungi (AMF) may improve plant performance at disturbed sites, but inoculation may also suppress root colonization by native AMF and decrease the diversity of the root-colonizing AMF community. This has been shown for the roots of directly inoculated plants, but little is known about the stability of inoculation effects, and to which degree the inoculant and the inoculation-induced changes in AMF community composition spread into newly emerging seedlings that were not in direct contact with the introduced propagules. We addressed this topic in a greenhouse experiment based on the soil and native AMF community of a post-mining site. Plants were cultivated in compartmented pots with substrate containing the native AMF community, where AMF extraradical mycelium radiating from directly inoculated plants was allowed to inoculate neighboring plants. The abundances of the inoculated isolate and of native AMF taxa were monitored in the roots of the directly inoculated plants and the neighboring plants by quantitative real-time PCR. As expected, inoculation suppressed root colonization of the directly inoculated plants by other AMF taxa of the native AMF community and also by native genotypes of the same species as used for inoculation. In the neighboring plants, high abundance of the inoculant and the suppression of native AMF were maintained. Thus, we demonstrate that inoculation effects on native AMF propagate into plants that were not in direct contact with the introduced inoculum, and are therefore likely to persist at the site of inoculation. PMID:28738069

Inoculation effects on root-colonizing arbuscular mycorrhizal fungal communities spread beyond directly inoculated plants.

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Martina Janoušková

Full Text Available Inoculation with arbuscular mycorrhizal fungi (AMF may improve plant performance at disturbed sites, but inoculation may also suppress root colonization by native AMF and decrease the diversity of the root-colonizing AMF community. This has been shown for the roots of directly inoculated plants, but little is known about the stability of inoculation effects, and to which degree the inoculant and the inoculation-induced changes in AMF community composition spread into newly emerging seedlings that were not in direct contact with the introduced propagules. We addressed this topic in a greenhouse experiment based on the soil and native AMF community of a post-mining site. Plants were cultivated in compartmented pots with substrate containing the native AMF community, where AMF extraradical mycelium radiating from directly inoculated plants was allowed to inoculate neighboring plants. The abundances of the inoculated isolate and of native AMF taxa were monitored in the roots of the directly inoculated plants and the neighboring plants by quantitative real-time PCR. As expected, inoculation suppressed root colonization of the directly inoculated plants by other AMF taxa of the native AMF community and also by native genotypes of the same species as used for inoculation. In the neighboring plants, high abundance of the inoculant and the suppression of native AMF were maintained. Thus, we demonstrate that inoculation effects on native AMF propagate into plants that were not in direct contact with the introduced inoculum, and are therefore likely to persist at the site of inoculation.

Deficient Pms2, ERCC1, Ku86, CcOI in field defects during progression to colon cancer.

Science.gov (United States)

Nguyen, Huy; Loustaunau, Cristy; Facista, Alexander; Ramsey, Lois; Hassounah, Nadia; Taylor, Hilary; Krouse, Robert; Payne, Claire M; Tsikitis, V Liana; Goldschmid, Steve; Banerjee, Bhaskar; Perini, Rafael F; Bernstein, Carol

2010-07-28

In carcinogenesis, the "field defect" is recognized clinically because of the high propensity of survivors of certain cancers to develop other malignancies of the same tissue type, often in a nearby location. Such field defects have been indicated in colon cancer. The molecular abnormalities that are responsible for a field defect in the colon should be detectable at high frequency in the histologically normal tissue surrounding a colonic adenocarcinoma or surrounding an adenoma with advanced neoplasia (well on the way to a colon cancer), but at low frequency in the colonic mucosa from patients without colonic neoplasia. Using immunohistochemistry, entire crypts within 10 cm on each side of colonic adenocarcinomas or advanced colonic neoplasias were found to be frequently reduced or absent in expression for two DNA repair proteins, Pms2 and/or ERCC1. Pms2 is a dual role protein, active in DNA mismatch repair as well as needed in apoptosis of cells with excess DNA damage. ERCC1 is active in DNA nucleotide excision repair. The reduced or absent expression of both ERCC1 and Pms2 would create cells with both increased ability to survive (apoptosis resistance) and increased level of mutability. The reduced or absent expression of both ERCC1 and Pms2 is likely an early step in progression to colon cancer. DNA repair gene Ku86 (active in DNA non-homologous end joining) and Cytochrome c Oxidase Subunit I (involved in apoptosis) had each been reported to be decreased in expression in mucosal areas close to colon cancers. However, immunohistochemical evaluation of their levels of expression showed only low to modest frequencies of crypts to be deficient in their expression in a field defect surrounding colon cancer or surrounding advanced colonic neoplasia. We show, here, our method of evaluation of crypts for expression of ERCC1, Pms2, Ku86 and CcOI. We show that frequency of entire crypts deficient for Pms2 and ERCC1 is often as great as 70% to 95% in 20 cm long areas

The influence of hormone therapies on colon and rectal cancer.

Science.gov (United States)

Mørch, Lina Steinrud; Lidegaard, Øjvind; Keiding, Niels; Løkkegaard, Ellen; Kjær, Susanne Krüger

2016-05-01

Exogenous sex hormones seem to play a role in colorectal carcinogenesis. Little is known about the influence of different types or durations of postmenopausal hormone therapy (HT) on colorectal cancer risk. A nationwide cohort of women 50-79 years old without previous cancer (n = 1,006,219) were followed 1995-2009. Information on HT exposures was from the National Prescription Register and updated daily, while information on colon (n = 8377) and rectal cancers (n = 4742) were from the National Cancer Registry. Potential confounders were obtained from other national registers. Poisson regression analyses with 5-year age bands included hormone exposures as time-dependent covariates. Use of estrogen-only therapy and combined therapy were associated with decreased risks of colon cancer (adjusted incidence rate ratio 0.77, 95 % confidence interval 0.68-0.86 and 0.88, 0.80-0.96) and rectal cancer (0.83, 0.72-0.96 and 0.89, 0.80-1.00), compared to never users. Transdermal estrogen-only therapy implied more protection than oral administration, while no significant influence was found of regimen, progestin type, nor of tibolone. The benefit of HT was stronger for long-term hormone users; and hormone users were at lower risk of advanced stage of colorectal cancer, which seems supportive for a causal association between hormone therapy and colorectal cancer.

Colonic lymphoid follicles associated with colonic neoplasms

International Nuclear Information System (INIS)

Glick, S.N.; Teplick, S.K.; Ross, W.M.

1986-01-01

The authors prospectively evaluated 62 patients over 40 years old in whom lymphoid follicles were demonstrated on double-contrast enema examinations. Eighteen patients (29%) had no current radiographic evidence of, or history of, colonic neoplasms. Forty-four patients (71%) had an associated neoplasm. Fourteen patients had associated colonic carcinoma, and ten patients had a history of a previously resected colon cancer. One patient had previously undergone resection for ''polyps.'' Twenty-two patients had an associated ''polyp.'' There were no clinical or radiographic features that could reliably distinguish the neoplastic from the nonneoplastic groups. However, lymphoid follicles in the left colon or diffusely involving the colon were more likely to be associated with a colonic neoplasm. Lymphoid follicles were almost always identified near a malignant lesion

Time- and dose-dependent effects of curcumin on gene expression in human colon cancer cells

Directory of Open Access Journals (Sweden)

van Erk Marjan J

2004-05-01

Full Text Available Abstract Background Curcumin is a spice and a coloring food compound with a promising role in colon cancer prevention. Curcumin protects against development of colon tumors in rats treated with a colon carcinogen, in colon cancer cells curcumin can inhibit cell proliferation and induce apoptosis, it is an anti-oxidant and it can act as an anti-inflammatory agent. The aim of this study was to elucidate mechanisms and effect of curcumin in colon cancer cells using gene expression profiling. Methods Gene expression changes in response to curcumin exposure were studied in two human colon cancer cell lines, using cDNA microarrays with four thousand human genes. HT29 cells were exposed to two different concentrations of curcumin and gene expression changes were followed in time (3, 6, 12, 24 and 48 hours. Gene expression changes after short-term exposure (3 or 6 hours to curcumin were also studied in a second cell type, Caco-2 cells. Results Gene expression changes (>1.5-fold were found at all time points. HT29 cells were more sensitive to curcumin than Caco-2 cells. Early response genes were involved in cell cycle, signal transduction, DNA repair, gene transcription, cell adhesion and xenobiotic metabolism. In HT29 cells curcumin modulated a number of cell cycle genes of which several have a role in transition through the G2/M phase. This corresponded to a cell cycle arrest in the G2/M phase as was observed by flow cytometry. Functional groups with a similar expression profile included genes involved in phase-II metabolism that were induced by curcumin after 12 and 24 hours. Expression of some cytochrome P450 genes was downregulated by curcumin in HT29 and Caco-2 cells. In addition, curcumin affected expression of metallothionein genes, tubulin genes, p53 and other genes involved in colon carcinogenesis. Conclusions This study has extended knowledge on pathways or processes already reported to be affected by curcumin (cell cycle arrest, phase

Gene-diet-interactions in folate-mediated one-carbon metabolism modify colon cancer risk.

Science.gov (United States)

Liu, Amy Y; Scherer, Dominique; Poole, Elizabeth; Potter, John D; Curtin, Karen; Makar, Karen; Slattery, Martha L; Caan, Bette J; Ulrich, Cornelia M

2013-04-01

The importance of folate-mediated one-carbon metabolism (FOCM) in colorectal carcinogenesis is emphasized by observations that high dietary folate intake is associated with decreased risk of colon cancer (CC) and its precursors. Additionally, polymorphisms in FOCM-related genes have been repeatedly associated with risk, supporting a causal relationship between folate and colorectal carcinogenesis. We investigated ten candidate polymorphisms with defined or probable functional impact in eight FOCM-related genes (SHMT1, DHFR, DNMT1, MTHFD1, MTHFR, MTRR, TCN2, and TDG) in 1609 CC cases and 1974 controls for association with CC risk and for interaction with dietary factors. No polymorphism was statistically significantly associated with overall risk of CC. However, statistically significant interactions modifying CC risk were observed for DNMT1 I311V with dietary folate, methionine, vitamin B2 , and vitamin B12 intake and for MTRR I22M with dietary folate, a predefined one-carbon dietary pattern, and vitamin B6 intake. We observed statistically significant gene-diet interactions with five additional polymorphisms. Our results provide evidence that FOCM-related dietary intakes modify the association between CC risk and FOCM allelic variants. These findings add to observations showing that folate-related gene-nutrient interactions play an important role in modifying the risk of CC. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

CT Findings of Colonic Complications Associated with Colon Cancer

International Nuclear Information System (INIS)

Kim, Sang Won; Shin, Hyeong Cheol; Kim, Il Young; Kim, Young Tong; Kim, Chang Jin

2010-01-01

A broad spectrum of colonic complications can occur in patients with colon cancer. Clinically, some of these complications can obscure the presence of underlying malignancies in the colon and these complications may require emergency surgical management. The complications of the colon that can be associated with colon cancer include obstruction, perforation, abscess formation, acute appendicitis, ischemic colitis and intussusception. Although the majority of these complications only rarely occur, familiarity with the various manifestations of colon cancer complications will facilitate making an accurate diagnosis and administering prompt management in these situations. The purpose of this pictorial essay is to review the CT appearance of the colonic complications associated with colon cancer

CT Findings of Colonic Complications Associated with Colon Cancer

Energy Technology Data Exchange (ETDEWEB)

Kim, Sang Won; Shin, Hyeong Cheol; Kim, Il Young; Kim, Young Tong; Kim, Chang Jin [Cheonan Hospital, Soonchunhyang University, Cheonan (Korea, Republic of)

2010-04-15

A broad spectrum of colonic complications can occur in patients with colon cancer. Clinically, some of these complications can obscure the presence of underlying malignancies in the colon and these complications may require emergency surgical management. The complications of the colon that can be associated with colon cancer include obstruction, perforation, abscess formation, acute appendicitis, ischemic colitis and intussusception. Although the majority of these complications only rarely occur, familiarity with the various manifestations of colon cancer complications will facilitate making an accurate diagnosis and administering prompt management in these situations. The purpose of this pictorial essay is to review the CT appearance of the colonic complications associated with colon cancer.

MicroRNAs Induce Epigenetic Reprogramming and Suppress Malignant Phenotypes of Human Colon Cancer Cells.

Directory of Open Access Journals (Sweden)

Hisataka Ogawa

Full Text Available Although cancer is a genetic disease, epigenetic alterations are involved in its initiation and progression. Previous studies have shown that reprogramming of colon cancer cells using Oct3/4, Sox2, Klf4, and cMyc reduces cancer malignancy. Therefore, cancer reprogramming may be a useful treatment for chemo- or radiotherapy-resistant cancer cells. It was also reported that the introduction of endogenous small-sized, non-coding ribonucleotides such as microRNA (miR 302s and miR-369-3p or -5p resulted in the induction of cellular reprogramming. miRs are smaller than the genes of transcription factors, making them possibly suitable for use in clinical strategies. Therefore, we reprogrammed colon cancer cells using miR-302s and miR-369-3p or -5p. This resulted in inhibition of cell proliferation and invasion and the stimulation of the mesenchymal-to-epithelial transition phenotype in colon cancer cells. Importantly, the introduction of the ribonucleotides resulted in epigenetic reprogramming of DNA demethylation and histone modification events. Furthermore, in vivo administration of the ribonucleotides in mice elicited the induction of cancer cell apoptosis, which involves the mitochondrial Bcl2 protein family. The present study shows that the introduction of miR-302s and miR-369s could induce cellular reprogramming and modulate malignant phenotypes of human colorectal cancer, suggesting that the appropriate delivery of functional small-sized ribonucleotides may open a new avenue for therapy against human malignant tumors.

Prevention of mammary carcinogenesis by short-term estrogen and progestin treatments

International Nuclear Information System (INIS)

Rajkumar, Lakshmanaswamy; Guzman, Raphael C; Yang, Jason; Thordarson, Gudmundur; Talamantes, Frank; Nandi, Satyabrata

2004-01-01

Women who have undergone a full-term pregnancy before the age of 20 have one-half the risk of developing breast cancer compared with women who have never gone through a full-term pregnancy. This protective effect is observed universally among women of all ethnic groups. Parity in rats and mice also protects them against chemically induced mammary carcinogenesis. Seven-week-old virgin Lewis rats were given N-methyl-N-nitrosourea. Two weeks later the rats were treated with natural or synthetic estrogens and progestins for 7–21 days by subcutaneous implantation of silastic capsules. In our current experiment, we demonstrate that short-term sustained exposure to natural or synthetic estrogens along with progestins is effective in preventing mammary carcinogenesis in rats. Treatment with 30 mg estriol plus 30 mg progesterone for 3 weeks significantly reduced the incidence of mammary cancer. Short-term exposure to ethynyl estradiol plus megesterol acetate or norethindrone was effective in decreasing the incidence of mammary cancers. Tamoxifen plus progesterone treatment for 3 weeks was able to confer only a transient protection from mammary carcinogenesis, while 2-methoxy estradiol plus progesterone was effective in conferring protection against mammary cancers. The data obtained in the present study demonstrate that, in nulliparous rats, long-term protection against mammary carcinogenesis can be achieved by short-term treatments with natural or synthetic estrogen and progesterone combinations

Piroxicam and C-phycocyanin mediated apoptosis in 1,2-dimethylhydrazine dihydrochloride induced colon carcinogenesis: exploring the mitochondrial pathway.

Science.gov (United States)

Saini, Manpreet Kaur; Sanyal, Sankar Nath; Vaiphei, Kim

2012-04-01

Apoptosis is a synchronized procedure of cell death that is regulated by caspases and proapoptotic proteins. During apoptosis, translocation of cytochrome c, an electron carrier, from mitochondria into the cytosol is regulated by Bcl-2 family members. Cytochrome c in association with an apoptotic protease activating factor (Apaf), a proapoptotic protein essential for cell differentiation and procaspase-9 form the apoptosome complex, which consecutively activates effector caspase, caspase-3, and coordinate the implementation of apoptosis. In the current study, an attempt has been made to gain insight into piroxicam, a traditional nonsteroidal antiinflammatory drug and c-phycocyanin, a biliprotein from Spirulina platensis (cyanobacterium) mediated apoptosis in DMH-induced colon cancer. Male Sprague-Dawley rats were segregated into 5 groups: control, DMH, DMH + piroxicam, DMH + c-phycocyanin, and DMH + piroxicam + c-phycocyanin. Results illustrated that piroxicam and c-phycocyanin treatments stimulate cytochrome c release by downregulating the Bcl-2 (an antiapoptotic protein) expression significantly, while promoting the level of Bax (a proapoptotic protein), thereby activating caspases (caspases-9 and -3) and Apaf-1. The outcomes of the present study clearly signify that piroxicam and c-phycocyanin may mediate mitochondrial-dependent apoptosis in DMH-induced colon cancer. Moreover, apoptosis induction was more apparent in the combination regimen of piroxicam and c-phycocyanin than the individual drugs alone.

2-Dodecylcyclobutanone, a radiolytic product of palmitic acid, is genotoxic in primary human colon cells and in cells from preneoplastic lesions

International Nuclear Information System (INIS)

Knoll, Nadine; Weise, Anja; Claussen, Uwe; Sendt, Wolfgang; Marian, Brigitte; Glei, Michael; Pool-Zobel, Beatrice L.

2006-01-01

The irradiation of fat results in the formation of 2-alkylcyclobutanones, a new class of food contaminants. Results of previous in vitro studies with primary human colon cells and in vivo experiments with rats fed with 2-alkylcyclobutanones indicated that these radiolytic derivatives may be genotoxic and enhance the progression of colon tumors. The underlying mechanisms of these effects, however, are not clearly understood. Therefore we performed additional investigations to elucidate the genotoxic potential of 2-dodecylcyclobutanone (2dDCB) that is generated from palmitic acid. In particular, we explored the relative sensitivities of human colon cells, representing different stages of tumor development and healthy colon tissues, respectively. HT29clone19A cells, LT97 adenoma cells and primary human epithelial cells were exposed to 2dDCB (150-2097 μM). We determined cytotoxic effects using trypan blue exclusion. Genotoxicity, reflected as strand breaks, was assessed using the alkaline version of the comet assay and chromosomal abnormalities were investigated by 24-color fluorescence-in-situ-hybridization. 2dDCB was cytotoxic in a time- and dose-dependent manner in LT97 adenoma cells and in freshly isolated primary cells but not in the human colon tumor cell line. Associated with this was a marked induction of DNA damage by 2dDCB in LT97 adenoma cells and in freshly isolated colonocytes, whereas in the HT29clone19A cells no strand breaks were detectable. A long-term incubation of LT97 adenoma cells with lower concentrations of 2dDCB revealed cytogenetic effects. In summary, 2dDCB was clearly genotoxic in healthy human colon epithelial cells and in cells representing preneoplastic colon adenoma. These findings provide additional evidence that this compound may be regarded as a possible risk factor for processes in colon carcinogenesis related to initiation and progression

Biological Complexities in Radiation Carcinogenesis and Cancer Radiotherapy: Impact of New Biological Paradigms

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Hossein Mozdarani

2012-01-01

Full Text Available Although radiation carcinogenesis has been shown both experimentally and epidemiologically, the use of ionizing radiation is also one of the major modalities in cancer treatment. Various known cellular and molecular events are involved in carcinogenesis. Apart from the known phenomena, there could be implications for carcinogenesis and cancer prevention due to other biological processes such as the bystander effect, the abscopal effect, intrinsic radiosensitivity and radioadaptation. Bystander effects have consequences for mutation initiated cancer paradigms of radiation carcinogenesis, which provide the mechanistic justification for low-dose risk estimates. The abscopal effect is potentially important for tumor control and is mediated through cytokines and/or the immune system (mainly cell-mediated immunity. It results from loss of growth and stimulatory and/or immunosuppressive factors from the tumor. Intrinsic radiosensitivity is a feature of some cancer prone chromosomal breakage syndromes such as ataxia telangectiasia. Radiosensitivity is manifested as higher chromosomal aberrations and DNA repair impairment is now known as a good biomarker for breast cancer screening and prediction of prognosis. However, it is not yet known whether this effect is good or bad for those receiving radiation or radiomimetic agents for treatment. Radiation hormesis is another major concern for carcinogenesis. This process which protects cells from higher doses of radiation or radio mimic chemicals, may lead to the escape of cells from mitotic death or apoptosis and put cells with a lower amount of damage into the process of cancer induction. Therefore, any of these biological phenomena could have impact on another process giving rise to genome instability of cells which are not in the field of radiation but still receiving a lower amount of radiation. For prevention of radiation induced carcinogenesis or risk assessment as well as for successful radiation

Interaction Between Dietary Factors and Inflammation in Prostate Carcinogenesis

National Research Council Canada - National Science Library

De Marzo, Angelo M

2007-01-01

We are investigating whether inflammation can enhance prostate carcinogenesis in a rat model of dietary charred meat carcinogen induced cancers, and, whether antioxidant and other chemopreventative...

Interactions between Dietary Factors and Inflammation in Prostate Carcinogenesis

National Research Council Canada - National Science Library

DeMarzo, Angelo M

2006-01-01

We are investigating whether inflammation can enhance prostate carcinogenesis in a rat model of dietary charred meat carcinogen induced cancers, and, whether antioxidant and other chemopreventative...

Dietary fish oil modulates the effect of dimethylhydrazine- induced colon cancer in rats

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Rasmy, G. E.

2011-09-01

Full Text Available This study was conducted to examine the efficacy of fish oil supplementation in male wistar rat colon carcinogenesis. In order to induce colon cancer, the rats were given a weekly subcutaneous injection of 1,2-Dimethylhydrazine (DMH at a dose of 20 mg/kg b.w. for five weeks. Afterwards, some of the rats ingested fish oil for either 4 weeks (DMH-FO4 group, or 17 weeks (DMH-FO17 group. The remaining rats continued without any supplementation for the same 4 weeks (DMH4 group, or 17 weeks (DMH17 group. Another two groups of rats did not receive the DMH and were given fish oil (FO17 group or a normal diet only and considered as the control group (CN group. At the end of the experiment, the rats were sacrificed; and were subsequently subjected to biochemical and molecular biological analyses as well as histopathological examinations. The results showed increased levels of lactate dehydrogenase (LDH, malondialdehyde (MDA and alkaline phoshatase (ALP activities in the DMH rats compared to the control. The liver and colonic changes that were induced by DMH were significantly improved through fish oil supplementation in the DMH-FO17 group. The molecular analysis revealed that DMH treatment induced the expression alterations of genes p53, p27 and p21 and increased DNA band patterns related to cancer, while both FO17 and DMH-FO17 groups showed much better results. A histopathological examination of the DMH17 group revealed colon adenocarcinoma and several lesions in rat liver tissues. An improvement in the histopathological picture was seen in the livers and colons of groups DMHFO17. In conclusion, the present results demonstrated the anti-carciongenic effect of herring fish oil against DMH induced colon carcinogenesis in rats. The inhibitory effect of FO was due to the modulation of elevated biochemical parameters, DNA damage, gene expression and histopathological lesions caused by DMH.

Este estudio fue realizado para examinar la eficacia de la

Cellular adaptation as an important response during chemical carcinogenesis

International Nuclear Information System (INIS)

Farber, E.

1992-01-01

Since disease processes are largely expressions of how living organisms react and respond to perturbations in the external and internal environments, adaptive or protective responses and their modulations and mechanisms are of the greatest concern in fundamental studies of disease pathogenesis. Such considerations are also of the greatest relevance in toxicology, including how living organisms respond to low levels of single and multiple xenobiotics and radiations. As the steps and mechanisms during cancer development are studied in greater depth, phenomena become apparent that suggest that adaptive reactions and responses may play important or even critical roles in the process of carcinogenesis. The question becomes whether the process of carcinogenesis is fundamentally an adversarial one (i.e., an abnormal cell in a vulnerable host), or is it more in the nature of a physiological selection or differentiation, which has survival value for the host as an adaptive phenomena? The very early initial interactions of mutagenic chemical carcinogens, radiations and viruses with DNA prejudice most to consider the adversarial 'abnormal' view as the appropriate one. Yet, the unusually common nature of the earliest altered rare cells that appear during carcinogenesis, their unusually bland nature, and their spontaneous differentiation to normal-appearing adult liver should be carefully considered

Promoter hypermethylation of KLF4 inactivates its tumor suppressor function in cervical carcinogenesis.

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Wen-Ting Yang

Full Text Available OBJECTIVE: The KLF4 gene has been shown to be inactivated in cervical carcinogenesis as a tumor suppressor. However, the mechanism of KLF4 silencing in cervical carcinomas has not yet been identified. DNA methylation plays a key role in stable suppression of gene expression. METHODS: The methylation status of the KLF4 promoter CpG islands was analyzed by bisulfite sequencing (BSQ in tissues of normal cervix and cervical cancer. KLF4 gene expression was detected by RT-PCR, immunohistochemistry and western blot. KLF4 promoter methylation in cervical cancer cell line was determined by BSQ and methylation-specific polymerase chain reaction (MS-PCR. Cell proliferation ability was detected by cell growth curve and MTT assay. RESULTS: The methylated allele was found in 41.90% of 24 cervical cancer tissues but only in 11.11% of 11 normal cervix tissues (P<0.005. KLF4 mRNA levels were significantly reduced in cervical cancer tissues compared with normal cervix tissues (P<0.01 and KLF4 mRNA expression showed a significant negative correlation with the promoter hypermethylation (r = -0.486, P = 0.003. Cervical cancer cell lines also showed a significant negative correlation between KLF4 expression and hypermethylation. After treatment with the demethylating agent 5-Azacytidine (5-Aza, the expression of KLF4 in the cervical cancer cell lines at both mRNA and protein levels was drastically increased, the cell proliferation ability was inhibited and the chemosensitivity for cisplatin was significantly increased. CONCLUSION: KLF4 gene is inactivated by methylation-induced silencing mechanisms in a large subset of cervical carcinomas and KLF4 promoter hypermethylation inactivates the gene's function as a tumor suppressor in cervical carcinogenesis.

Effect of vitamin C on azoxymethane (AOM)/dextran sulfate sodium (DSS)-induced colitis-associated early colon cancer in mice.

Science.gov (United States)

Jeon, Hee-Jin; Yeom, Yiseul; Kim, Yoo-Sun; Kim, Eunju; Shin, Jae-Ho; Seok, Pu Reum; Woo, Moon Jea; Kim, Yuri

2018-04-01

The objective of this study was to investigate the effects of vitamin C on inflammation, tumor development, and dysbiosis of intestinal microbiota in an azoxymethane (AOM)/dextran sulfate sodium (DSS)-induced inflammation-associated early colon cancer mouse model. Male BALB/c mice were injected intraperitoneally with AOM [10 mg/kg body weight (b.w)] and given two 7-d cycles of 2% DSS drinking water with a 14 d inter-cycle interval. Vitamin C (60 mg/kg b.w. and 120 mg/kg b.w.) was supplemented by gavage for 5 weeks starting 2 d after the AOM injection. The vitamin C treatment suppressed inflammatory morbidity, as reflected by disease activity index (DAI) in recovery phase and inhibited shortening of the colon, and reduced histological damage. In addition, vitamin C supplementation suppressed mRNA levels of pro-inflammatory mediators and cytokines, including cyclooxygenase-2, microsomal prostaglandin E synthase-2, tumor necrosis factor-α, Interleukin (IL)-1β , and IL-6 , and reduced expression of the proliferation marker, proliferating cell nuclear antigen, compared to observations of AOM/DSS animals. Although the microbial composition did not differ significantly between the groups, administration of vitamin C improved the level of inflammation-related Lactococcus and JQ084893 to control levels. Vitamin C treatment provided moderate suppression of inflammation, proliferation, and certain inflammation-related dysbiosis in a murine model of colitis associated-early colon cancer. These findings support that vitamin C supplementation can benefit colonic health. Long-term clinical studies with various doses of vitamin C are warranted.

Chemoprevention of DMH-induced rat colon carcinoma initiation by combination administration of piroxicam and C-phycocyanin.

Science.gov (United States)

Saini, Manpreet Kaur; Vaiphei, Kim; Sanyal, Sankar Nath

2012-02-01

Cancer research illustrated that combinatorial studies can provide significant improvement in safety and effectiveness over the monotherapy regimens. A combination of two drugs may restrain precancerous colon polyps, opening a new possible opportunity for chemoprevention of colon cancer. In this context, chemopreventive efficacy of a combination regimen of C-phycocyanin, a biliprotein present in Spirulina platensis, a cyanobacterium, which is a selective cycloxygenase-2 (COX-2) inhibitor and piroxicam, a traditional non-steroidal anti-inflammatory drug was considered in 1,2 dimethylhyadrazine (DMH)-induced colon carcinogenesis in rats. Western blotting, immunohistochemistry, DNA fragmentation, fluorescent staining, PGE(2) enzyme immunoassay, and carrageenan-induced paw edema test were performed along with morphological and histological analysis. DMH treatment showed a rich presence of preneoplastic lesions such as multiple plaque lesions, aberrant crypt foci, and well-characterized dysplasia. These features were reduced with piroxicam and C-phycocyanin administration. The number of apoptotic cells was featured prominently in all the groups compared with DMH. DMH treatment revealed intact high molecular weight genomic DNA with no signs of laddering/DNA fragmentation while it was noticeable significantly in control and DMH + piroxicam + C-phycocyanin. DMH group showed highest COX-2 expression and PGE(2) level in comparison with other groups. Doses of piroxicam and C-phycocyanin used in the present study were established at an anti-inflammatory range. A combination regimen of piroxicam and C-phycocyanin, rather than individually has the much greater potential for reduction of DMH-induced colon cancer development and COX-2 being the prime possible target in such chemoprevention.

FXR silencing in human colon cancer by DNA methylation and KRAS signaling.

Science.gov (United States)

Bailey, Ann M; Zhan, Le; Maru, Dipen; Shureiqi, Imad; Pickering, Curtis R; Kiriakova, Galina; Izzo, Julie; He, Nan; Wei, Caimiao; Baladandayuthapani, Veerabhadran; Liang, Han; Kopetz, Scott; Powis, Garth; Guo, Grace L

2014-01-01

Farnesoid X receptor (FXR) is a bile acid nuclear receptor described through mouse knockout studies as a tumor suppressor for the development of colon adenocarcinomas. This study investigates the regulation of FXR in the development of human colon cancer. We used immunohistochemistry of FXR in normal tissue (n = 238), polyps (n = 32), and adenocarcinomas, staged I-IV (n = 43, 39, 68, and 9), of the colon; RT-quantitative PCR, reverse-phase protein array, and Western blot analysis in 15 colon cancer cell lines; NR1H4 promoter methylation and mRNA expression in colon cancer samples from The Cancer Genome Atlas; DNA methyltransferase inhibition; methyl-DNA immunoprecipitation (MeDIP); bisulfite sequencing; and V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) knockdown assessment to investigate FXR regulation in colon cancer development. Immunohistochemistry and quantitative RT-PCR revealed that expression and function of FXR was reduced in precancerous lesions and silenced in a majority of stage I-IV tumors. FXR expression negatively correlated with phosphatidylinositol-4, 5-bisphosphate 3 kinase signaling and the epithelial-to-mesenchymal transition. The NR1H4 promoter is methylated in ~12% colon cancer The Cancer Genome Atlas samples, and methylation patterns segregate with tumor subtypes. Inhibition of DNA methylation and KRAS silencing both increased FXR expression. FXR expression is decreased early in human colon cancer progression, and both DNA methylation and KRAS signaling may be contributing factors to FXR silencing. FXR potentially suppresses epithelial-to-mesenchymal transition and other oncogenic signaling cascades, and restoration of FXR activity, by blocking silencing mechanisms or increasing residual FXR activity, represents promising therapeutic options for the treatment of colon cancer.

Modulation of Estrogen Chemical Carcinogenesis by Botanical Supplements used for Postmenopausal Women’s Health

Science.gov (United States)

Snelten, Courtney S.; Dietz, Birgit; Bolton, Judy L.

2012-01-01

Breast cancer risk has been associated with long-term estrogen exposure including traditional hormone therapy (HT, formally hormone replacement therapy). To avoid traditional HT and associated risks, women have been turning to botanical supplements such as black cohosh, red clover, licorice, hops, dong gui, and ginger to relieve menopausal symptoms despite a lack of efficacy evidence. The mechanisms of estrogen carcinogenesis involve both hormonal and chemical pathways. Botanical supplements could protect women from estrogen carcinogenesis by modulating key enzymatic steps [aromatase, P4501B1, P4501A1, catechol-O-methyltransferase (COMT), NAD(P)H quinone oxidoreductase 1 (NQO1), and reactive oxygen species (ROS) scavenging] in estradiol metabolism leading to estrogen carcinogenesis as outlined in Figure 1. This review summarizes the influence of popular botanical supplements used for women’s health on these key steps in the estrogen chemical carcinogenesis pathway, and suggests that botanical supplements may have added chemopreventive benefits by modulating estrogen metabolism. PMID:24223609

Pomegranate exerts chemoprevention of experimentally induced mammary tumorigenesis by suppression of cell proliferation and induction of apoptosis.

Science.gov (United States)

Bishayee, Anupam; Mandal, Animesh; Bhattacharyya, Piyali; Bhatia, Deepak

2016-01-01

Breast cancer is the second leading cause of cancer-related death in women in the United States and discovery and development of safe chemopreventive drugs is urgently needed. The fruit pomegranate (Punica granatum) is gaining importance because of its various health benefits. This study was initiated to investigate chemopreventive potential of a pomegranate emulsion (PE) against 7,12-dimethylbenz(a)anthracene (DMBA) rat mammary carcinogenesis. The animals were orally administered with PE (0.2-5.0 g/kg), starting 2 wk before and 16 wk following DMBA treatment. PE exhibited a striking reduction of DMBA-induced mammary tumor incidence, total tumor burden, and reversed histopathological changes. PE dose-dependently suppressed cell proliferation and induced apoptosis in mammary tumors. Immunohistochemical studies showed that PE increased intratumor Bax, decreased Bcl2 and manifested a proapoptotic shift in Bax/Bcl2 ratio. In addition, our gene expression study showed PE-mediated upregulation of Bad, caspase-3, caspase-7, caspase-9, poly (ADP ribose) polymerase and cytochrome c in mammary tumors. Thus, PE exerts chemoprevention of mammary carcinogenesis by suppressing cell proliferation and inducing apoptosis mediated through upregulation of Bax and downregulation of Bcl2 in concert with caspase cascades. Pomegranate bioactive phytoconstituents could be developed as a chemopreventive drug to reduce the risk of breast cancer.

Role of Stat in Skin Carcinogenesis: Insights Gained from Relevant Mouse Models

International Nuclear Information System (INIS)

Macias, E.; Rao, D.; DiGiovanni, J.; DiGiovanni, J.; DiGiovanni, J.

2013-01-01

Signal transducer and activator of transcription 3 (Stat) is a cytoplasmic protein that is activated in response to cytokines and growth factors and acts as a transcription factor. Stat plays critical roles in various biological activities including cell proliferation, migration, and survival. Studies using keratinocyte-specific Stat-deficient mice have revealed that Stat plays an important role in skin homeostasis including keratinocyte migration, wound healing, and hair follicle growth. Use of both constitutive and inducible keratinocyte-specific Stat-deficient mouse models has demonstrated that Stat is required for both the initiation and promotion stages of multistage skin carcinogenesis. Further studies using a transgenic mouse model with a gain of function mutant of Stat (Stat3C) expressed in the basal layer of the epidermis revealed a novel role for Stat in skin tumor progression. Studies using similar Stat-deficient and gain-of-function mouse models have indicated its similar roles in ultraviolet B (UVB) radiation-mediated skin carcinogenesis. This paper summarizes the use of these various mouse models for studying the role and underlying mechanisms for the function of Stat in skin carcinogenesis. Given its significant role throughout the skin carcinogenesis process, Stat is an attractive target for skin cancer prevention and treatment.

Retinoic acid morpholine amide (RAMA) inhibits expression of Fas ligand through EP1 receptor in colon cancer cells.

Science.gov (United States)

Chen, Shao-Xuan; Du, Shi-Yu; Wang, Yun-Ting; Zhao, Hong-Chuan; Zhang, Yan-Li; Yao, Li

2016-01-01

Among the members of tumour necrosis factor family Fas ligand on binding to its receptor strongly induces apoptosis of tumour-infiltrating lymphocytes (TIL). Thus, FasL acts as an inhibitor of anti-tumour immune response. The present study demonstrates that retinoic acid morpholine amide (RAMA) significantly suppresses FasL expression in colon cancer cells in a dose- and time-dependent manner. The suppression of FasL mRNA and proteins was significant at a concentration of 30 μM after 48 h in CLT85 and HT26 colon cancer cells. There was around 2.6- and 3.2-fold decrease in FasL mRNA after incubation with 30 μM of RAMA in CLT85 cells and HT26 cells, respectively. The results from Western blot showed a decrease in FasL mRNA and protein expression in both CLT85 and HT26 cells after suppression of cyclooxygenase (COX)-2 and COX-1 by RNAi. However, when COX-2-specific silencer RNA (siCOX-2)- and siCOX-1-treated CLT85 and HT26 cells were exposed to RAMA, inhibition of FasL expression was further suppressed. The siCOX-2-treated CLT85 and HT26 cells on exposure to RAMA showed ∼87 and ∼54 % reduction in FasL mRNA, respectively. Co-culture of Jurkat T cells with RAMA-treated HT26 and CLT85 cells decreased the viability of Jurkat T cells by only 2 and 4.3 %, respectively, compared to 19.5 and 37.3 % in control HT26 and CLT85 cells. The results from real-time reverse transcription polymerase chain reaction (RT-PCR) and immunoblotting showed that suppression of EP1 prevented RAMA-induced FasL suppression in CLT85 cells at both the mRNA and protein levels. Thus, RAMA can be a potent therapeutic agent for the treatment of colon tumours.

Combining fluorescent Pseudomonas spp. strains to enhance suppression of fusarium wilt of radish

NARCIS (Netherlands)

Boer, Marjan de; Sluis, Ientse van der; Loon, L.C. van; Bakker, P.A.H.M.

1999-01-01

Fusarium wilt diseases, caused by the fungus Fusarium oxysporum, lead to significant yield losses of crops. One strategy to control fusarium wilt is the use of antagonistic, root-colonizing Pseudomonas spp. It has been demonstrated that different strains of these bacteria suppress disease by

Mouse Models of the Skin: Models to Define Mechanisms of Skin Carcinogenesis

International Nuclear Information System (INIS)

Wheeler, D. L.; Verma, A. K.; Denning, M. F.

2013-01-01

The multistep model of mouse skin carcinogenesis has facilitated identification of irreversible genetic events of initiation and progression, and epigenetic events of tumor promotion. Mouse skin tumor initiation can be accomplished by a single exposure to a sufficiently small dose of a carcinogen, and this step is rapid and irreversible. However, promotion of skin tumor formation requires a repeated and prolonged exposure to a promoter, and that tumor promotion is reversible. Investigations focused on the mechanisms of mouse carcinogenesis have resulted in the identifications of potential molecular targets of cancer induction and progression useful in planning strategies for human cancer prevention trials. This special issue contains eight papers that focus on mouse models used to study individual proteins expressed in the mouse skin and the role they play in differentiation, tissue homeostasis, skin carcinogenesis, and chemo prevention of skin cancer.

Cadmium induces carcinogenesis in BEAS-2B cells through ROS-dependent activation of PI3K/AKT/GSK-3β/β-catenin signaling

Energy Technology Data Exchange (ETDEWEB)

Son, Young-Ok; Wang, Lei; Poyil, Pratheeshkumar; Budhraja, Amit; Hitron, J. Andrew; Zhang, Zhuo [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY (United States); Lee, Jeong-Chae [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY (United States); School of Dentistry and Institute of Oral Biosciences (BK21 program), Research Center of Bioactive Materials, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Shi, Xianglin, E-mail: xshi5@email.uky.edu [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY (United States)

2012-10-15

Cadmium has been widely used in industry and is known to be carcinogenic to humans. Although it is widely accepted that chronic exposure to cadmium increases the incidence of cancer, the mechanisms underlying cadmium-induced carcinogenesis are unclear. The main aim of this study was to investigate the role of reactive oxygen species (ROS) in cadmium-induced carcinogenesis and the signal transduction pathways involved. Chronic exposure of human bronchial epithelial BEAS-2B cells to cadmium induced cell transformation, as evidenced by anchorage-independent growth in soft agar and clonogenic assays. Chronic cadmium treatment also increased the potential of these cells to invade and migrate. Injection of cadmium-stimulated cells into nude mice resulted in the formation of tumors. In contrast, the cadmium-mediated increases in colony formation, cell invasion and migration were prevented by transfection with catalase, superoxide dismutase-1 (SOD1), or SOD2. In particular, chronic cadmium exposure led to activation of signaling cascades involving PI3K, AKT, GSK-3β, and β-catenin and transfection with each of the above antioxidant enzymes markedly inhibited cadmium-mediated activation of these signaling proteins. Inhibitors specific for AKT or β-catenin almost completely suppressed the cadmium-mediated increase in total and active β-catenin proteins and colony formation. Moreover, there was a marked induction of AKT, GSK-3β, β-catenin, and carcinogenic markers in tumor tissues formed in mice after injection with cadmium-stimulated cells. Collectively, our findings suggest a direct involvement of ROS in cadmium-induced carcinogenesis and implicate a role of AKT/GSK-3β/β-catenin signaling in this process. -- Highlights: ► Chronic exposure to cadmium induces carcinogenic properties in BEAS-2B cells. ► ROS involved in cadmium-induced tumorigenicity of BEAS-2B cells. ► Cadmium activates ROS-dependent AKT/GSK-3β/β-catenin-mediated signaling. ► ROS

Effect of soy saponin on the growth of human colon cancer cells

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Tsai, Cheng-Yu; Chen, Yue-Hwa; Chien, Yi-Wen; Huang, Wen-Hsuan; Lin, Shyh-Hsiang

2010-01-01

AIM: To investigate the effect of extracted soybean saponins on the growth of human colon cancer cells. METHODS: WiDr human colon cancer cells were treated with 150, 300, 600 or 1200 ppm of soy saponin to determine the effect on cell growth, cell morphology, alkaline phosphatase (AP) and protein kinase C (PKC) activities, and P53 protein, c-Fos and c-Jun gene expression. RESULTS: Soy saponin decreased the number of viable cells in a dose-dependent manner and suppressed 12-O-tetradecanol-phorbol-13-acetate-stimulated PKC activity (P saponins developed cytoplasmic vesicles and the cell membrane became rougher and more irregular in a dose-dependent manner, and eventually disassembled. At 600 and 1200 ppm, the activity of AP was increased (P saponin. CONCLUSION: Soy saponin may be effective in preventing colon cancer by affecting cell morphology, cell proliferation enzymes, and cell growth. PMID:20632438

[Histologic study on impeding leukoplakia carcinogenesis of golden hamster cheek pouch about Erigeron breviscapus (Vant) Hand-Mazz].

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Zhou, C T; Zhong, W J; Hua, L; Hu, H F; Jin, Z G

2000-06-01

To observe the effect of Erigeron breviscapus (Vant) Hand Mazz (HEr) in impeding oral leukoplakia carcinogenesis, and to seek effective Chinese herb medicine that can impede precarcinoma of oral mucosas. 132 golden hamsters were randomly divided into model group (60 animals), HEr group (60 animals), and control group 12 animals. Salley's leukoplakia carcinogenesis model of golden hamster cheek pouch was used in this study. HEr was injected into the stomach to impede evolution of carcinogenesis. Pathological specimens were observed via naked eye and light microscope between model group and HEr group. Results were compared. Observation via naked-eye showed that leukoplakia rate of HEr group (18.2%) was lower than that of model group (27.3%). Observation via light microscope showed that carcinogenesis rate descended one fold and displasia rate descended 0.4 fold in HEr group. HEr has exact effect in impeding leukoplakia carcinogenesis.

Experimental radiation carcinogenesis: what have we learned

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Fry, R.J.M.

1980-01-01

The author reviews the need for animal experiments in development of a biological model for radioinduced carcinogenesis. He concludes they are vital for: (1) study of mechanisms; (2) establishment of generalizations; (3) elucidation of dose-response and time-dose relationships; and (4) determination of dose-distributions and their results, particularly for radionuclides. (PSB)

Experimental radiation carcinogenesis: what have we learned

International Nuclear Information System (INIS)

Fry, R.J.M.

1980-01-01

The author reviews the need for animal experiments in development of a biological model for radioinduced carcinogenesis. He concludes they are vital for: (1) study of mechanisms; (2) establishment of generalizations; (3) elucidation of dose-response and time-dose relationships; and (4) determination of dose-distributions and their results, particularly for radionuclides

Longevity in mice is promoted by probiotic-induced suppression of colonic senescence dependent on upregulation of gut bacterial polyamine production.

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Mitsuharu Matsumoto

Full Text Available BACKGROUND: Chronic low-grade inflammation is recognized as an important factor contributing to senescence and age-related diseases. In mammals, levels of polyamines (PAs decrease during the ageing process; PAs are known to decrease systemic inflammation by inhibiting inflammatory cytokine synthesis in macrophages. Reductions in intestinal luminal PAs levels have been associated with intestinal barrier dysfunction. The probiotic strain Bifidobacterium animalis subsp. lactis LKM512 is known to increase intestinal luminal PA concentrations. METHODOLOGY/PRINCIPAL FINDINGS: We supplemented the diet of 10-month-old Crj:CD-1 female mice with LKM512 for 11 months, while the controls received no supplementation. Survival rates were compared using Kaplan-Meier survival curves. LKM512-treated mice survived significantly longer than controls (P<0.001; moreover, skin ulcers and tumors were more common in the control mice. We then analyzed inflammatory and intestinal conditions by measuring several markers using HPLC, ELISA, reverse transcription-quantitative PCR, and histological slices. LKM512 mice showed altered 16S rRNA gene expression of several predominant intestinal bacterial groups. The fecal concentrations of PAs, but not of short-chain fatty acids, were significantly higher in LKM512-treated mice (P<0.05. Colonic mucosal function was also better in LKM512 mice, with increased mucus secretion and better maintenance of tight junctions. Changes in gene expression levels were evaluated using the NimbleGen mouse DNA microarray. LKM512 administration also downregulated the expression of ageing-associated and inflammation-associated genes and gene expression levels in 21-month-old LKM512-treated mice resembled those in 10-month-old untreated (younger mice. CONCLUSION/SIGNIFICANCE: Our study demonstrated increased longevity in mice following probiotic treatment with LKM512, possibly due to the suppression of chronic low-grade inflammation in the colon

Tea polyphenols EGCG and TF restrict tongue and liver carcinogenesis simultaneously induced by N-nitrosodiethylamine in mice

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Sur, Subhayan, E-mail: subhayansur18@gmail.com [Dept. of Oncogene Regulation, Chittaranjan National Cancer Institute, 37, S.P. Mukherjee Road, Kolkata 700 026, West Bengal (India); Pal, Debolina; Roy, Rituparna; Barua, Atish [Dept. of Oncogene Regulation, Chittaranjan National Cancer Institute, 37, S.P. Mukherjee Road, Kolkata 700 026, West Bengal (India); Roy, Anup [North Bengal Medical College and Hospital, West Bengal (India); Saha, Prosenjit [Dept. of Oncogene Regulation, Chittaranjan National Cancer Institute, 37, S.P. Mukherjee Road, Kolkata 700 026, West Bengal (India); Panda, Chinmay Kumar, E-mail: ckpanda.cnci@gmail.com [Dept. of Oncogene Regulation, Chittaranjan National Cancer Institute, 37, S.P. Mukherjee Road, Kolkata 700 026, West Bengal (India)

2016-06-01

The aim of this study is to understand the molecular mechanisms of N-nitrosodiethylamine (NDEA) induced multi-organ carcinogenesis in tongue and liver of the same mouse and restriction of carcinogenesis by Epigallocatechin gallate (EGCG) and Theaflavin (TF), if any. For that purpose, cellular proliferation/apoptosis, prevalence of CD44 positive stem cell population and expressions of some key regulatory genes of self renewal Wnt and Hedgehog (Hh) pathways and some of their associated genes were analyzed in the NDEA induced tongue and liver lesions in absence or presence of EGCG/TF. Chronic NDEA exposure in oral cavity could decrease mice body weights and induce tongue and liver carcinogenesis with similar histological stages (severe dysplasia up to 30th weeks of NDEA administration). Increasing mice body weights were seen in continuous and post EGCG/TF treated groups. EGCG/TF treatment could restrict both the carcinogenesis at similar histological stages showing potential chemopreventive effect in continuous treated groups (mild dysplasia) followed by pre treatment (moderate dysplasia) and therapeutic efficacy in post treated groups (mild dysplasia) up to 30th week. The mechanism of carcinogenesis by NDEA and restriction by the EGCG/TF in both tongue and liver were similar and found to be associated with modulation in cellular proliferation/apoptosis and prevalence of CD44 positive population. The up-regulation of self renewal Wnt/β-catenin, Hh/Gli1 pathways and their associated genes Cyclin D1, cMyc and EGFR along with down regulation of E-cadherin seen during the carcinogenesis processes were found to be modulated during the restriction processes by EGCG/TF. - Highlights: • Simultaneous tongue and liver carcinogenesis in mice by oral NDEA administration • Restriction of both carcinogenesis by EGCG and TF at early pre-malignant stages • The mechanisms of carcinogenesis and restriction were similar in both the organs. • Changes in proliferation

Tea polyphenols EGCG and TF restrict tongue and liver carcinogenesis simultaneously induced by N-nitrosodiethylamine in mice

International Nuclear Information System (INIS)

Sur, Subhayan; Pal, Debolina; Roy, Rituparna; Barua, Atish; Roy, Anup; Saha, Prosenjit; Panda, Chinmay Kumar

2016-01-01

The aim of this study is to understand the molecular mechanisms of N-nitrosodiethylamine (NDEA) induced multi-organ carcinogenesis in tongue and liver of the same mouse and restriction of carcinogenesis by Epigallocatechin gallate (EGCG) and Theaflavin (TF), if any. For that purpose, cellular proliferation/apoptosis, prevalence of CD44 positive stem cell population and expressions of some key regulatory genes of self renewal Wnt and Hedgehog (Hh) pathways and some of their associated genes were analyzed in the NDEA induced tongue and liver lesions in absence or presence of EGCG/TF. Chronic NDEA exposure in oral cavity could decrease mice body weights and induce tongue and liver carcinogenesis with similar histological stages (severe dysplasia up to 30th weeks of NDEA administration). Increasing mice body weights were seen in continuous and post EGCG/TF treated groups. EGCG/TF treatment could restrict both the carcinogenesis at similar histological stages showing potential chemopreventive effect in continuous treated groups (mild dysplasia) followed by pre treatment (moderate dysplasia) and therapeutic efficacy in post treated groups (mild dysplasia) up to 30th week. The mechanism of carcinogenesis by NDEA and restriction by the EGCG/TF in both tongue and liver were similar and found to be associated with modulation in cellular proliferation/apoptosis and prevalence of CD44 positive population. The up-regulation of self renewal Wnt/β-catenin, Hh/Gli1 pathways and their associated genes Cyclin D1, cMyc and EGFR along with down regulation of E-cadherin seen during the carcinogenesis processes were found to be modulated during the restriction processes by EGCG/TF. - Highlights: • Simultaneous tongue and liver carcinogenesis in mice by oral NDEA administration • Restriction of both carcinogenesis by EGCG and TF at early pre-malignant stages • The mechanisms of carcinogenesis and restriction were similar in both the organs. • Changes in proliferation

Exogenous regucalcin suppresses the growth of human liver cancer HepG2 cells in vitro.

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Yamaguchi, Masayoshi; Murata, Tomiyasu

2018-04-05

Regucalcin, which its gene is localized on the X chromosome, plays a pivotal role as a suppressor protein in signal transduction in various types of cells and tissues. Regucalcin gene expression has been demonstrated to be suppressed in various tumor tissues of animal and human subjects, suggesting a potential role of regucalcin in carcinogenesis. Regucalcin, which is produced from the tissues including liver, is found to be present in the serum of human subjects and animals. This study was undertaken to determine the effects of exogenous regucalcin on the proliferation in cloned human hepatoma HepG2 cells in vitro. Proliferation of HepG2 cells was suppressed after culture with addition of regucalcin (0.01 – 10 nM) into culture medium. Exogenous regucalcin did not reveal apoptotic cell death in HepG2 cells in vitro. Suppressive effects of regucalcin on cell proliferation were not enhanced in the presence of various signaling inhibitors including tumor necrosis factor-α (TNF-α), Bay K 8644, PD98059, staurosporine, worthomannin, 5,6-dichloro-1-β-D-ribofuranosylbenzimidazole (DRB) or gemcitabine, which were found to suppress the proliferation. In addition, exogenous regucalcin suppressed the formation of colonies of cultured hepatoma cells in vitro. These findings demonstrated that exogenous regucalcin exhibits a suppressive effect on the growth of human hepatoma HepG2 cells, proposing a strategy with the gene therapy for cancer treatment.

Suppression of epithelial ovarian cancer invasion into the omentum by 1α,25-dihydroxyvitamin D3 and its receptor.

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Lungchukiet, Panida; Sun, Yuefeng; Kasiappan, Ravi; Quarni, Waise; Nicosia, Santo V; Zhang, Xiaohong; Bai, Wenlong

2015-04-01

Epithelial ovarian cancer (EOC) is the leading cause of gynecological cancer death in women, mainly because it has spread to intraperitoneal tissues such as the omentum in the peritoneal cavity by the time of diagnosis. In the present study, we established in vitro assays, ex vivo omental organ culture system and syngeneic animal tumor models using wild type (WT) and vitamin D receptor (VDR) null mice to investigate the effects of 1α,25-dihydroxyvitamin D3 (1,25D3) and VDR on EOC invasion. Treatment of human EOC cells with 1,25D3 suppressed their migration and invasion in monolayer scratch and transwell assays and ability to colonize the omentum in the ex vivo system, supporting a role for epithelial VDR in interfering with EOC invasion. Furthermore, VDR knockdown in OVCAR3 cells increased their ability to colonize the omentum in the ex vivo system in the absence of 1,25D3, showing a potential ligand-independent suppression of EOC invasion by epithelial VDR. In syngeneic models, ID8 tumors exhibited an increased ability to colonize omenta of VDR null over that of WT mice; pre-treatment of WT, not VDR null, mice with EB1089 reduced ID8 colonization, revealing a role for stromal VDR in suppressing EOC invasion. These studies are the first to demonstrate a role for epithelial and stromal VDR in mediating the activity of 1,25D3 as well as a 1,25D3-independent action of the VDR in suppressing EOC invasion. The data suggest that VDR-based drug discovery may lead to the development of new intervention strategies to improve the survival of patients with EOC at advanced stages. This article is part of a Special Issue entitled "Vitamin D Workshop". Copyright © 2014 Elsevier Ltd. All rights reserved.

Mechanisms underlying 3-bromopyruvate-induced cell death in colon cancer.

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Sun, Yiming; Liu, Zhe; Zou, Xue; Lan, Yadong; Sun, Xiaojin; Wang, Xiu; Zhao, Surong; Jiang, Chenchen; Liu, Hao

2015-08-01

3-Bromopyruvate (3BP) is an energy-depleting drug that inhibits Hexokinase II activity by alkylation during glycolysis, thereby suppressing the production of ATP and inducing cell death. As such, 3BP can potentially serve as an anti-tumorigenic agent. Our previous research showed that 3BP can induce apoptosis via AKT /protein Kinase B signaling in breast cancer cells. Here we found that 3BP can also induce colon cancer cell death by necroptosis and apoptosis at the same time and concentration in the SW480 and HT29 cell lines; in the latter, autophagy was also found to be a mechanism of cell death. In HT29 cells, combined treatment with 3BP and the autophagy inhibitor 3-methyladenine (3-MA) exacerbated cell death, while viability in 3BP-treated cells was enhanced by concomitant treatment with the caspase inhibitor benzyloxycarbonyl-Val-Ala-Asp fluoromethylketone (z-VAD-fmk) and the necroptosis inhibitor necrostatin (Nec)-1. Moreover, 3BP inhibited tumor growth in a SW480 xenograft mouse model. These results indicate that 3BP can suppress tumor growth and induce cell death by multiple mechanisms at the same time and concentration in different types of colon cancer cell by depleting cellular energy stores.

Radiation carcinogenesis and related radiobiology. Special listing

International Nuclear Information System (INIS)

1980-01-01

The special listing of Current Cancer Research Projects is a publication of the International Cancer Research Data Bank (ICRDB) Program of the National Cancer Institute. Each Listing contains descriptions of ongoing projects in one selected cancer research area. The research areas include: Human cancer and exposure to radiation; Experimental radiation carcinogenesis and radiation biology

Overexpression of RBBP6, alone or combined with mutant TP53, is predictive of poor prognosis in colon cancer.

Directory of Open Access Journals (Sweden)

Jian Chen

Full Text Available Retinoblastoma binding protein 6 (RBBP6 plays an important role in chaperone-mediated ubiquitination and interacts with TP53 in carcinogenesis. However, the clinicopathologic significance of RBBP6 expression in colon cancer is unknown; in particular, the prognostic value of RBBP6 combined with TP53 expression has not been explored. Therefore, quantitative real-time PCR and western blot analyses were performed to detect RBBP6 expression in colon cancer tissues. RBBP6 and TP53 expression were assessed by immunohistochemistry in a tissue microarray format, in which the primary colon cancer tissue was paired with noncancerous tissue. Tissue specimens were obtained from 203 patients. We found that RBBP6 was overexpressed in colon tumorous tissues and was significantly associated with clinical stage, depth of tumor invasion, lymph node metastasis (LNM, distant metastasis, and histologic grade. Further studies revealed that a corresponding correlation between RBBP6 overexpression and mutant TP53 was evident in colon cancer (r = 0.450; P<0.001. RBBP6 expression was an independent prognostic factor for overall survival (OS and disease free survival (DFS. Interestingly, patients with tumors that had both RBBP6 overexpression and mutant TP53 protein accumulation relapsed and died within a significantly short period after surgery (P<0.001. Multivariate analysis showed that patients with LNM and patients with both RBBP6- and TP53-positive tumors had extremely poor OS (HR 6.75; 95% CI 2.63-17.35; P<0.001 and DFS (HR 8.08; 95% CI 2.80-23.30; P<0.001. These clinical findings indicate that the assessment of both RBBP6 and mutant TP53 expression will be helpful in predicting colon cancer prognosis.

A Case of Sigmoid Colon Tuberculosis Mimicking Colon Cancer

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Yu, Seong-Min; Park, Jong-Hwan; Kim, Min-Dae; Lee, Hee-Ryong; Jung, Peel; Ryu, Tae-Hyun; Choi, Seung-Ho; Lee, Il-Seon

2012-01-01

Tuberculosis of the sigmoid colon is a rare disorder. An 80-year-old man visited Bongseng Memorial Hospital for medical examination. A colonoscopy was performed, and a lesion in the sigmoid colon that was suspected to be colon cancer was found. A biopsy was performed, and tuberculous enteritis with chronic granulomatous inflammation was diagnosed. Intestinal tuberculosis is most frequent in the ileocecal area, followed by the ascending colon, transverse colon, duodenum, stomach, and sigmoid c...

The effect of parenteral immunisation on antibody production in the pig colon.

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Rees, A S; Lysons, R J; Stokes, C R; Bourne, F J

1989-11-30

Local and systemic antibody production was studied in pigs to compare responses to live and killed bacterial antigen and purified protein antigen, with and without prior mucosal stimulation. Recovery from challenge with live bacteria and intramuscular injection with killed bacteria gave rise to similar high levels of serum IgG antibody, but the ratio of specific IgA to IgG in the colon was significantly higher after infection than following vaccination with killed bacteria. Vaccination with a protein antigen gave rise to serum and local antibody production. Prior feeding of the antigen had a tolerising effect on the serum antibody response, but production of IgG and IgA antibody by the colon was not suppressed.

Composts containing fluorescent pseudomonads suppress fusarium root and stem rot development on greenhouse cucumber.

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Bradley, Geoffrey G; Punja, Zamir K

2010-11-01

Three composts (Ball, dairy, and greenhouse) were tested for the ability to suppress the development of Fusarium root and stem rot (caused by Fusarium oxysporum f. sp. radicis-cucumerinum) on greenhouse cucumber. Dairy and greenhouse composts significantly reduced disease severity (P = 0.05), while Ball compost had no effect. Assessment of total culturable microbes in the composts showed a positive relationship between disease suppressive ability and total population levels of pseudomonads. In vitro antagonism assays between compost-isolated bacterial strains and the pathogen showed that strains of Pseudomonas aeruginosa exhibited the greatest antagonism. In growth room trials, strains of P. aeruginosa and nonantagonistic Pseudomonas maculicola, plus 2 biocontrol strains of Pseudomonas fluorescens, were tested for their ability to reduce (i) survival of F. oxysporum, (ii) colonization of plants by the pathogen, and (iii) disease severity. Cucumber seedlings grown in compost receiving P. aeruginosa and P. fluorescens had reduced disease severity index scores after 8 weeks compared with control plants without bacteria. Internal stem colonization by F. oxysporum was significantly reduced by P. aeruginosa. The bacteria colonized plant roots at 1.9 × 10(6) ± 0.73 × 10(6) CFU·(g root tissue)-1 and survival was >107 CFU·(g compost)-1 after 6 weeks. The locus for 2,4-diacetylphloroglucinol production was detected by Southern blot analysis and confirmed by PCR. The production of the antibiotic 2,4-diacetylphloroglucinol in liquid culture by P. aeruginosa was confirmed by thin layer chromatography. These results demonstrate that composts containing antibiotic-producing P. aeruginosa have the potential to suppress diseases caused by Fusarium species.

shRNA-Mediated XRCC2 Gene Knockdown Efficiently Sensitizes Colon Tumor Cells to X-ray Irradiation in Vitro and in Vivo

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Qin Wang

2014-01-01

Full Text Available Colon cancer is one of the most common tumors of the digestive tract. Resistance to ionizing radiation (IR decreased therapeutic efficiency in these patients’ radiotherapy. XRCC2 is the key protein of DNA homologous recombination repair, and its high expression is associated with enhanced resistance to DNA damage induced by IR. Here, we investigated the effect of XRCC2 silencing on colon tumor cells’ growth and sensitivity to X-radiation in vitro and in vivo. Colon tumor cells (T84 cell line were cultivated in vitro and tumors originated from the cell line were propagated as xenografts in nude mice. The suppression of XRCC2 expression was achieved by using vector-based short hairpin RNA (shRNA in T84 cells. We found that the knockdown of XRCC2 expression effectively decreased T84 cellular proliferation and colony formation, and led to cell apoptosis and cell cycle arrested in G2/M phase induced by X-radiation in vitro. In addition, tumor xenograft studies suggested that XRCC2 silencing inhibited tumorigenicity after radiation treatment in vivo. Our data suggest that the suppression of XRCC2 expression rendered colon tumor cells more sensitive to radiation therapy in vitro and in vivo, implying XRCC2 as a promising therapeutic target for the treatment of radioresistant human colon cancer.

Chemopreventive effects of PBI-Se, a selenium-containing analog of PBIT, on AOM-induced aberrant crypt foci in F344 rats.

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Janakiram, Naveena B; Mohammed, Altaf; Ravillah, Durgadevi; Choi, Chang In; Zhang, Yuting; Desai, Dhimant; Amin, Shantu; Rao, Chinthalapally V

2013-08-01

Inducible nitric oxide synthase (iNOS) is a potential target for the treatment of inflammation and cancer. Previously, we showed that the selective iNOS inhibitor S,S'-1,4-phenylenebis(1,2-ethanediyl)bis-isothiourea (PBIT) caused significant inhibition of colon carcinogenesis induced by azoxymethane (AOM), although it did not completely abrogate NO production due to the exogenous bioavailability of NO and NO generation by eNOS in tumor tissues. To create an iNOS-targeting molecule that may have additional benefits, a novel isosteric analog of PBIT, PBI-Se, was developed, in which sulfur was replaced with selenium. Chemopreventive efficacy of PBI-Se was evaluated in an AOM-induced rat colon carcinogenesis model using aberrant crypt foci (ACF) as the endpoint. At 7 weeks of age, rats (12/group) were fed the control diet (AIN 76A) and then colonic ACF were induced with two AOM treatments. Three days later, rats were fed diets containing PBI-Se (0-20 ppm) for 8 weeks, and then ACF were evaluated histopathologically. Dietary administration of 10 or 20 ppm of PBI-Se significantly suppressed AOM-induced total colonic ACF formation (32 or 41%, pPBI-Se was dose-dependent and was half the dose of PBIT for inhibiting total ACF in rats. Both PBIT and PBI-Se induced dose-dependent apoptosis in CaCo2 cells and caused a significant decrease in the cell cycle proteins cyclin D1 (70%, pPBI-Se (2 and 4  µM) significantly decreased the LPS-induced cytokine interleukin-6 level. Incorporation of selenium into the structure of PBIT provided the agent with additional novel cytotoxic and immunologic properties. Results from the in vitro and in vivo bioassays suggest that PBI-Se could be developed further for the prevention and treatment of colon cancer.

Toxicology and carcinogenesis study of senna in C3B6.129F1-Trp53 tm1Brd N12 haploinsufficient mice.

Science.gov (United States)

Surh, Inok; Brix, Amy; French, John E; Collins, Bradley J; Sanders, J Michael; Vallant, Molly; Dunnick, June K

2013-07-01

Senna is a pod or leaf of Senna alexandrina P. Mill and is used as a stimulant laxative. In the large intestine, bacterial enzymes reduce sennosides to rhein-9-anthrone, the active form for the laxative effect. To determine the potential toxic effects of senna, a 5-week dose range finding study in the C57BL/6N mouse and a 40-week toxicology and carcinogenesis study in the C3B6.129F1-Trp53 (tm1Brd) N12 haploinsufficient (p53(+/-)) mouse were conducted. In the 5-week study, C57BL/6N mice were exposed to up to 10,000 ppm senna in feed. Increased incidences of epithelial hyperplasia of the cecum and colon were observed in males and females exposed to 5,000 or 10,000 ppm senna. These intestinal lesions were not considered to be of sufficient severity to cause mortality and, thus, in the p53(+/-) mouse 40-week study, the high dose of 10,000 ppm was selected. Significant increases in the incidences of epithelial hyperplasia of the colon and cecum were observed at 10,000 ppm in p53(+/-) males and females, and the incidence of hyperplasia of the colon was significantly increased at 3,000 ppm in females. In conclusion, the large intestine was the major target of senna-induced toxicity in both wild-type and the p53(+/-) mouse model. There was no neoplastic change when senna was administered to p53(+/-) mouse.

Telmisartan attenuates colon inflammation, oxidative perturbations and apoptosis in a rat model of experimental inflammatory bowel disease.

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Hany H Arab

Full Text Available Accumulating evidence has indicated the implication of angiotensin II in the pathogenesis of inflammatory bowel diseases (IBD via its proinflammatory features. Telmisartan (TLM is an angiotensin II receptor antagonist with marked anti-inflammatory and antioxidant actions that mediated its cardio-, reno- and hepatoprotective actions. However, its impact on IBD has not been previously explored. Thus, we aimed to investigate the potential alleviating effects of TLM in tri-nitrobenezene sulphonic acid (TNBS-induced colitis in rats. Pretreatment with TLM (10 mg/kg p.o. attenuated the severity of colitis as evidenced by decrease of disease activity index (DAI, colon weight/length ratio, macroscopic damage, histopathological findings and leukocyte migration. TLM suppressed the inflammatory response via attenuation of tumor necrosis factor-α (TNF-α, prostaglandin E2 (PGE2 and myeloperoxidase (MPO activity as a marker of neutrophil infiltration besides restoration of interleukin-10 (IL-10. TLM also suppressed mRNA and protein expression of nuclear factor kappa B (NF-κB p65 and mRNA of cyclo-oxygenase-2 (COX-2 and inducible nitric oxide synthase (iNOS proinflammatory genes with concomitant upregulation of PPAR-γ. The alleviation of TLM to colon injury was also associated with inhibition of oxidative stress as evidenced by suppression of lipid peroxides and nitric oxide (NO besides boosting glutathione (GSH, total anti-oxidant capacity (TAC and the activities of superoxide dismutase (SOD and glutathione peroxidase (GPx. With respect to apoptosis, TLM downregulated the increased mRNA, protein expression and activity of caspase-3. It also suppressed the elevation of cytochrome c and Bax mRNA besides the upregulation of Bcl-2. Together, these findings highlight evidences for the beneficial effects of TLM in IBD which are mediated through modulation of colonic inflammation, oxidative stress and apoptosis.

The Skin Microbiome: Is It Affected by UV-induced Immune Suppression?

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Patra, VijayKumar; Byrne, Scott N.; Wolf, Peter

2016-01-01

Human skin apart from functioning as a physical barricade to stop the entry of pathogens, also hosts innumerable commensal organisms. The skin cells and the immune system constantly interact with microbes, to maintain cutaneous homeostasis, despite the challenges offered by various environmental factors. A major environmental factor affecting the skin is ultraviolet radiation (UV-R) from sunlight. UV-R is well known to modulate the immune system, which can be both beneficial and deleterious. By targeting the cells and molecules within skin, UV-R can trigger the production and release of antimicrobial peptides, affect the innate immune system and ultimately suppress the adaptive cellular immune response. This can contribute to skin carcinogenesis and the promotion of infectious agents such as herpes simplex virus and possibly others. On the other hand, a UV-established immunosuppressive environment may protect against the induction of immunologically mediated skin diseases including some of photodermatoses such as polymorphic light eruption. In this article, we share our perspective about the possibility that UV-induced immune suppression may alter the landscape of the skin’s microbiome and its components. Alternatively, or in concert with this, direct UV-induced DNA and membrane damage to the microbiome may result in pathogen associated molecular patterns (PAMPs) that interfere with UV-induced immune suppression. PMID:27559331

The skin microbiome: Is it affected by UV-induced immune suppression?

Directory of Open Access Journals (Sweden)

Vijaykumar Patra

2016-08-01

Full Text Available Human skin apart from functioning as a physical barricade to stop the entry of pathogens, also hosts innumerable commensal organisms. The skin cells and the immune system constantly interact with microbes, to maintain cutaneous homeostasis, despite the challenges offered by various environmental factors. A major environmental factor affecting the skin is ultraviolet radiation UV-R from sunlight. UV-R is well known to modulate the immune system, which can be both beneficial and deleterious. By targeting the cells and molecules within skin, UV-R can trigger the production and release of antimicrobial peptides (AMPs, affect the innate immune system and ultimately suppress the adaptive cellular immune response. This can contribute to skin carcinogenesis and the promotion of infectious agents such as herpes simplex virus and possibly others. On the other hand, a UV-established immunosuppressive environment may protect against the induction of immunologically mediated skin diseases including some of photodermatoses such as polymorphic light eruption. In this article, we share our perspective about the possibility that UV-induced immune suppression may alter the landscape of the skin's microbiome and its components. Alternatively, or in concert with this, direct UV-induced DNA and membrane damage to the microbiome may result in pathogen associated molecular patterns (PAMPs that interfere with UV-induced immune suppression.

Meat and cancer: haemoglobin and haemin in a low-calcium diet promote colorectal carcinogenesis at the aberrant crypt stage in rats

Science.gov (United States)

Pierre, Fabrice; Taché, Sylviane; Petit, Claude R; Van Der Meer, Roelof; Corpet, Denis E

2003-01-01

High intake of red meat, but not of white meat, is associated with an increased risk of colon cancer. However, red meat does not promote cancer in rodents. Haemin, added to low-calcium diets, increases colonic proliferation, and haemoglobin, added to high-fat diets, increases the colon tumour incidence in rats, an effect possibly due to peroxyl radicals. We thus speculated that haem might be the promoting agent in meat, and that prevention strategies could use calcium and antioxidants. These hypotheses were tested in rats at the aberrant crypt foci (ACF) stage at 100 days. F344 rats (n=124) were given an injection of azoxymethane and were then randomised to 11 groups fed with low-calcium (20μmol/g) AIN76-based diets, containing 5% safflower oil. Haemin (0.25, 0.5 and 1.5μmol/g) or haemoglobin (1.5 and 3 μmol haem/g) was added to five experimental diets, compared to a control diet without haem. Three other high-haemin diets (1.5μmol/g) were supplemented with calcium (250μmol/g), antioxidant butylated hydroxyanisole and rutin (0.05% each), and olive oil, which replaced safflower oil. Faecal water was assayed for lipid peroxidation by thiobarbituric acid reactive substances (TBARs) test, and for cytolytic activity. Haemin strikingly increased the ACF size, dose-dependently, from 2.6 to 11.4 crypts/ACF (all p<0.001). The high-haemin diet also increased the number of ACF per colon (p<0.001). Promotion was associated with increased faecal water TBARs and cytotoxicity. Calcium, olive oil, and antioxidants each inhibited the haemin-induced ACF promotion, and normalised the faecal TBARs and cytotoxicity. The haemoglobin diets increased the number of ACF and faecal TBARs, but not the ACF size or the faecal cytotoxicity. In conclusion, dietary haemin is the most potent known ACF promoter. Haemoglobin is also a potent promoter of colorectal carcinogenesis. The results suggest that myoglobin in red meat could promote colon cancer. Diets high in calcium, or in oxidation

Estrogen receptor beta, a possible tumor suppressor involved in ovarian carcinogenesis

Science.gov (United States)

Lazennec, Gwendal

2006-01-01

Ovarian cancer is one of the leading cause of death from gynecological tumors in women. Several lines of evidence suggest that estrogens may play an important role in ovarian carcinogenesis, through their receptors, ERα and ERβ. Interestingly, malignant ovarian tumors originating from epithelial surface constitute about 90% of ovarian cancers and expressed low levels of ERβ, compared to normal tissues. In addition, restoration of ERβ in ovarian cancer cells, leads to strong inhibition of their proliferation and invasion, while apoptosis is enhanced. In this manuscript, recent data suggesting a possible tumor-suppressor role for ERβ in ovarian carcinogenesis are discussed. PMID:16399219

IFNγ Induces DNA Methylation-Silenced GPR109A Expression via pSTAT1/p300 and H3K18 Acetylation in Colon Cancer.

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Bardhan, Kankana; Paschall, Amy V; Yang, Dafeng; Chen, May R; Simon, Priscilla S; Bhutia, Yangzom D; Martin, Pamela M; Thangaraju, Muthusamy; Browning, Darren D; Ganapathy, Vadivel; Heaton, Christopher M; Gu, Keni; Lee, Jeffrey R; Liu, Kebin

2015-07-01

Short-chain fatty acids, metabolites produced by colonic microbiota from fermentation of dietary fiber, act as anti-inflammatory agents in the intestinal tract to suppress proinflammatory diseases. GPR109A is the receptor for short-chain fatty acids. The functions of GPR109A have been the subject of extensive studies; however, the molecular mechanisms underlying GPR109A expression is largely unknown. We show that GPR109A is highly expressed in normal human colon tissues, but is silenced in human colon carcinoma cells. The GPR109A promoter DNA is methylated in human colon carcinoma. Strikingly, we observed that IFNγ, a cytokine secreted by activated T cells, activates GPR109A transcription without altering its promoter DNA methylation. Colon carcinoma grows significantly faster in IFNγ-deficient mice than in wild-type mice in an orthotopic colon cancer mouse model. A positive correlation was observed between GPR109A protein level and tumor-infiltrating T cells in human colon carcinoma specimens, and IFNγ expression level is higher in human colon carcinoma tissues than in normal colon tissues. We further demonstrated that IFNγ rapidly activates pSTAT1 that binds to the promoter of p300 to activate its transcription. p300 then binds to the GPR109A promoter to induce H3K18 hyperacetylation, resulting in chromatin remodeling in the methylated GPR109A promoter. The IFNγ-activated pSTAT1 then directly binds to the methylated but hyperacetylated GPR109 promoter to activate its transcription. Overall, our data indicate that GPR109A acts as a tumor suppressor in colon cancer, and the host immune system might use IFNγ to counteract DNA methylation-mediated GPR109A silencing as a mechanism to suppress tumor development. ©2015 American Association for Cancer Research.

IFNγ induces DNA methylation-silenced GPR109A expression via pSTAT1/p300 and H3K18 acetylation in colon cancer

Science.gov (United States)

Bardhan, Kankana; Paschall, Amy V.; Yang, Dafeng; Chen, May R.; Simon, Priscilla S.; Bhutia, Yangzom; Martin, Pamela M.; Thangaraju, Muthusamy; Browning, Darren D.; Ganapathy, Vadivel; Heaton, Christopher M.; Gu, Keni; Lee, Jeffrey R.; Liu, Kebin

2015-01-01

Short-chain fatty acids, metabolites produced by colonic microbiota from fermentation of dietary fiber, act as anti-inflammatory agents in the intestinal tract to suppress proinflammatory diseases. GPR109A is the receptor for short-chain fatty acids. The functions of GPR109A has been the subject of extensive studies, however, the molecular mechanisms underlying GPR109A expression is largely unknown. We show that GPR109A is highly expressed in normal human colon tissues, but is silenced in human colon carcinoma cells. The GPR109A promoter DNA is methylated in human colon carcinoma. Strikingly, we observed that IFNγ, a cytokine secreted by activated T cells, activates GPR109A transcription without altering its promoter DNA methylation. Colon carcinoma grows significantly faster in IFNγ-deficient mice than in wildtype mice in an orthotopic colon cancer mouse model. A positive correlation was observed between GPR109A protein level and tumor-infiltrating T cells in human colon carcinoma specimens, and IFNγ expression level is higher in human colon carcinoma tissues than in normal colon tissues. We further demonstrated that IFNγ rapidly activates pSTAT1 that binds to the promoter of p300 to activate its transcription. p300 then binds to the GPR109A promoters to induce H3K18 hyperacetylation, resulting in chromatin remodeling in the methylated GPR109A promoter. The IFNγ-activated pSTAT1 then directly binds to the methylated but hyperacetylated GPR109 promoters to activate its transcription. Overall, our data indicate that GPR109A acts as a tumor suppressor in colon cancer and the host immune system might use IFNγ to counteract DNA methylation-mediated GPR109A silencing as a mechanism to suppress tumor development. PMID:25735954

Hypoxia and cell cycle deregulation in endometrial carcinogenesis

NARCIS (Netherlands)

Horrée, N.

2007-01-01

Because uterine endometrial carcinoma is the most common malignancy of the female genital tract and 1 of every 5 patients dies of this disease, understanding the mechanisms of carcinogenesis and progression of endometrial carcinoma is important. In general, this thesis can be summarized as a study

Experimental Hepatic Carcinogenesis: Oxidative Stress and Natural Antioxidants

Directory of Open Access Journals (Sweden)

Velid Unsal

2017-08-01

Full Text Available Hepatocellular carcinoma is one of the most common cancers in the world, and it is influenced by agents such as DEN, 2-AAF, phenobarbital, alcohol, aflatoxin B1 metabolite or hepatitis viruses (B and C. Oxidative stress is becoming recognized as a key factor in the progression of hepatocarcinogenesis. Reactive oxygen species can play a leading role in initiation and promotion of hepatic carcinogenesis. The metabolites of DEN Diethylnitrosamine (DEN mediate the binding of tumour promoters by covalently binding to the DNA with one or two oxidation-providing electrons. 2-AAF is the inducer of DEN, and it is involved in tumour formation in the bladder and liver. Reactive Oxygen species (ROS; carbohydrates, lipids, DNA and enzymes, such as affect all important structures. Additionally, an excessive amount of ROS is highly toxic to cells. Antioxidants are protects against ROS, toxic substances, carcinogens. This review focuses on the literature on studies of Hepatic Carcinogenesis, oxidative stress and antioxidant therapy.

Palytoxin: exploiting a novel skin tumor promoter to explore signal transduction and carcinogenesis.

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Wattenberg, Elizabeth V

2007-01-01

Palytoxin is a novel skin tumor promoter, which has been used to help probe the role of different types of signaling mechanisms in carcinogenesis. The multistage mouse skin model indicates that tumor promotion is an early, prolonged, and reversible phase of carcinogenesis. Understanding the molecular mechanisms underlying tumor promotion is therefore important for developing strategies to prevent and treat cancer. Naturally occurring tumor promoters that bind to specific cellular receptors have proven to be useful tools for investigating important biochemical events in multistage carcinogenesis. For example, the identification of protein kinase C as the receptor for the prototypical skin tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) (also called phorbol 12-myristate 13-acetate, PMA) provided key evidence that tumor promotion involves the aberrant modulation of signaling cascades that govern cell fate and function. The subsequent discovery that palytoxin, a marine toxin isolated from zoanthids (genus Palythoa), is a potent skin tumor promoter yet does not activate protein kinase C indicated that investigating palytoxin action could help reveal new aspects of tumor promotion. Interestingly, the putative receptor for palytoxin is the Na(+),K(+)-ATPase. This review focuses on palytoxin-stimulated signaling and how palytoxin has been used to investigate alternate biochemical mechanisms by which important targets in carcinogenesis can be modulated.

Biologically based modelling and simulation of carcinogenesis at low doses

International Nuclear Information System (INIS)

Ouchi, Noriyuki B.

2003-01-01

The process of the carcinogenesis is studied by computer simulation. In general, we need a large number of experimental samples to detect mutations at low doses, but in practice it is difficult to get such a large number of data. To satisfy the requirements of the situation at low doses, it is good to study the process of carcinogenesis using biologically based mathematical model. We have mainly studied it by using as known as 'multi-stage model'; the model seems to get complicated, as we adopt the recent new findings of molecular biological experiments. Moreover, the basic idea of the multi-stage model is based on the epidemiologic data of log-log variation of cancer incidence with age, it seems to be difficult to compare with experimental data of irradiated cell culture system, which has been increasing in recent years. Taking above into consideration, we concluded that we had better make new model with following features: 1) a unit of the target system is a cell, 2) the new information of the molecular biology can be easily introduced, 3) having spatial coordinates for checking a colony formation or tumorigenesis. In this presentation, we will show the detail of the model and some simulation results about the carcinogenesis. (author)

BG-4, a novel anticancer peptide from bitter gourd (Momordica charantia), promotes apoptosis in human colon cancer cells.

Science.gov (United States)

Dia, Vermont P; Krishnan, Hari B

2016-09-15

Momordica charantia is a perennial plant with reported health benefits. BG-4, a novel peptide from Momordica charantia, was isolated, purified and characterized. The trypsin inhibitory activity of BG-4 is 8.6 times higher than purified soybean trypsin inhibitor. The high trypsin inhibitory activity of BG-4 may be responsible for its capability to cause cytotoxicity to HCT-116 and HT-29 human colon cancer cells with ED50 values of 134.4 and 217.0 μg/mL after 48 h of treatment, respectively. The mechanism involved in the cytotoxic effect may be associated with induction of apoptosis as evidenced by increased percentage of HCT-116 and HT-29 colon cancer cells undergoing apoptosis from 5.4% (untreated) to 24.8% (BG-4 treated, 125 μg/mL for 16 h) and 8.5% (untreated) to 31.9% (BG-4 treated, 125 μg/mL for 16 h), respectively. The molecular mechanistic explanation in the apoptosis inducing property of BG-4 is due to reduced expression of Bcl-2 and increased expression of Bax leading to increased expression of caspase-3 and affecting the expression of cell cycle proteins p21 and CDK2. This is the first report on the anti-cancer potential of a novel bioactive peptide isolated from Momordica charantia in vitro supporting the potential therapeutic property of BG-4 against colon cancer that must be addressed using in vivo models of colon carcinogenesis.

Suppression of gross chromosomal rearrangements by a new alternative replication factor C complex

International Nuclear Information System (INIS)

Banerjee, Soma; Sikdar, Nilabja; Myung, Kyungjae

2007-01-01

Defects in DNA replication fidelity lead to genomic instability. Gross chromosomal rearrangement (GCR), a type of genomic instability, is highly enhanced by various initial mutations affecting DNA replication. Frequent observations of GCRs in many cancers strongly argue the importance of maintaining high fidelity of DNA replication to suppress carcinogenesis. Recent genome wide screens in Saccharomyces cerevisiae identified a new GCR suppressor gene, ELG1, enhanced level of genome instability gene 1. Its physical interaction with proliferating cell nuclear antigen (PCNA) and complex formation with Rfc2-5p proteins suggest that Elg1 functions to load/unload PCNA onto DNA during a certain DNA metabolism. High level of DNA damage accumulation and enhanced phenotypes with mutations in genes involved in cell cycle checkpoints, homologous recombination (HR), or chromatin assembly in the elg1 strain suggest that Elg1p-Rfc2-5p functions in a fundamental DNA metabolism to suppress genomic instability

Estimating radiation-induced cancer risk using MVK two-stage model for carcinogenesis

International Nuclear Information System (INIS)

Kai, M.; Kusama, T.; Aoki, Y.

1993-01-01

Based on the carcinogenesis model as proposed by Moolgavkar et al., time-dependent relative risk models were derived for projecting the time variation in excess relative risk. If it is assumed that each process is described by time-independent linear dose-response relationship, the time variation in excess relative risk is influenced by the parameter related with the promotion process. The risk model based carcinogenesis theory would play a marked role in estimating radiation-induced cancer risk in constructing a projection model or transfer model

Intestinal tumor suppression in ApcMin/+ mice by prostaglandin D2 receptor PTGDR

International Nuclear Information System (INIS)

Tippin, Brigette L; Kwong, Alan M; Inadomi, Michael J; Lee, Oliver J; Park, Jae Man; Materi, Alicia M; Buslon, Virgilio S; Lin, Amy M; Kudo, Lili C; Karsten, Stanislav L; French, Samuel W; Narumiya, Shuh; Urade, Yoshihiro; Salido, Eduardo; Lin, Henry J

2014-01-01

Our earlier work showed that knockout of hematopoietic prostaglandin D synthase (HPGDS, an enzyme that produces prostaglandin D 2 ) caused more adenomas in Apc Min/+ mice. Conversely, highly expressed transgenic HPGDS allowed fewer tumors. Prostaglandin D 2 (PGD 2 ) binds to the prostaglandin D 2 receptor known as PTGDR (or DP1). PGD 2 metabolites bind to peroxisome proliferator-activated receptor γ (PPARG). We hypothesized that Ptgdr or Pparg knockouts may raise numbers of tumors, if these receptors take part in tumor suppression by PGD 2 . To assess, we produced Apc Min/+ mice with and without Ptgdr knockouts (147 mice). In separate experiments, we produced Apc Min/+ mice expressing transgenic lipocalin-type prostaglandin D synthase (PTGDS), with and without heterozygous Pparg knockouts (104 mice). Homozygous Ptgdr knockouts raised total numbers of tumors by 30–40% at 6 and 14 weeks. Colon tumors were not affected. Heterozygous Pparg knockouts alone did not affect tumor numbers in Apc Min/+ mice. As mentioned above, our Pparg knockout assessment also included mice with highly expressed PTGDS transgenes. Apc Min/+ mice with transgenic PTGDS had fewer large adenomas (63% of control) and lower levels of v-myc avian myelocytomatosis viral oncogene homolog (MYC) mRNA in the colon. Heterozygous Pparg knockouts appeared to blunt the tumor-suppressing effect of transgenic PTGDS. However, tumor suppression by PGD 2 was more clearly mediated by receptor PTGDR in our experiments. The suppression mechanism did not appear to involve changes in microvessel density or slower proliferation of tumor cells. The data support a role for PGD 2 signals acting through PTGDR in suppression of intestinal tumors

Molecular Basis of Alcohol-Related Gastric and Colon Cancer.

Science.gov (United States)

Na, Hye-Kyung; Lee, Ja Young

2017-05-24

Many meta-analysis, large cohort studies, and experimental studies suggest that chronic alcohol consumption increases the risk of gastric and colon cancer. Ethanol is metabolized by alcohol dehydrogenases (ADH), catalase or cytochrome P450 2E1 (CYP2E1) to acetaldehyde, which is then further oxidized to acetate by aldehyde dehydrogenase (ALDH). Acetaldehyde has been classified by the International Agency for Research on Cancer (IARC) as a Group 1 carcinogen to humans. The acetaldehyde level in the stomach and colon is locally influenced by gastric colonization by Helicobacter pylori or colonic microbes, as well as polymorphisms in the genes encoding tissue alcohol metabolizing enzymes, especially ALDH2. Alcohol stimulates the uptake of carcinogens and their metabolism and also changes the composition of enteric microbes in a way to enhance the aldehyde level. Alcohol also undergoes chemical coupling to membrane phospholipids and disrupts organization of tight junctions, leading to nuclear translocation of β-catenin and ZONAB, which may contributes to regulation of genes involved in proliferation, invasion and metastasis. Alcohol also generates reactive oxygen species (ROS) by suppressing the expression of antioxidant and cytoprotective enzymes and inducing expression of CYP2E1 which contribute to the metabolic activation of chemical carcinogens. Besides exerting genotoxic effects by directly damaging DNA, ROS can activates signaling molecules involved in inflammation, metastasis and angiogenesis. In addition, alcohol consumption induces folate deficiency, which may result in aberrant DNA methylation profiles, thereby influencing cancer-related gene expression.

Genetic Control of Plant Root Colonization by the Biocontrol agent, Pseudomonas fluorescens

Energy Technology Data Exchange (ETDEWEB)

Cole, Benjamin J.; Fletcher, Meghan; Waters, Jordan; Wetmore, Kelly; Blow, Matthew J.; Deutschbauer, Adam M.; Dangl, Jeffry L.; Visel, Axel

2015-03-19

Plant growth promoting rhizobacteria (PGPR) are a critical component of plant root ecosystems. PGPR promote plant growth by solubilizing inaccessible minerals, suppressing pathogenic microorganisms in the soil, and directly stimulating growth through hormone synthesis. Pseudomonas fluorescens is a well-established PGPR isolated from wheat roots that can also colonize the root system of the model plant, Arabidopsis thaliana. We have created barcoded transposon insertion mutant libraries suitable for genome-wide transposon-mediated mutagenesis followed by sequencing (TnSeq). These libraries consist of over 105 independent insertions, collectively providing loss-of-function mutants for nearly all genes in the P.fluorescens genome. Each insertion mutant can be unambiguously identified by a randomized 20 nucleotide sequence (barcode) engineered into the transposon sequence. We used these libraries in a gnotobiotic assay to examine the colonization ability of P.fluorescens on A.thaliana roots. Taking advantage of the ability to distinguish individual colonization events using barcode sequences, we assessed the timing and microbial concentration dependence of colonization of the rhizoplane niche. These data provide direct insight into the dynamics of plant root colonization in an in vivo system and define baseline parameters for the systematic identification of the bacterial genes and molecular pathways using TnSeq assays. Having determined parameters that facilitate potential colonization of roots by thousands of independent insertion mutants in a single assay, we are currently establishing a genome-wide functional map of genes required for root colonization in P.fluorescens. Importantly, the approach developed and optimized here for P.fluorescens>A.thaliana colonization will be applicable to a wide range of plant-microbe interactions, including biofuel feedstock plants and microbes known or hypothesized to impact on biofuel-relevant traits including biomass productivity

Apoptotic effects of inositol hexaphosphate on biomarker Itpr3 in induced colon rat carcinogenesis Efeito de apoptose do inositol hexafosfato no marcador biológico Itpr3 em carcinogênese induzida de colo em ratos

Directory of Open Access Journals (Sweden)

Marks Guido

2008-04-01

Full Text Available PURPOSE: To study the effect of the modulation of inositol hexaphosphate (IP6 in the biological immunohistochemistry expression of cellular signaling marker apoptosis, in model of carcinogenesis of colon induced by azoxymethane (AOM. METHODS: Wistar rats (N=112 distributed in 4 groups (n=28: Control; B, AOM (5 mg kg-1, 2x, to break week 3; C, IP6 (in water 1%, six weeks; D, IP6+AOM. Weekly euthanasia (n=7, from week three. Immunohistochemistry of ascendant colon with biological marker inositol 1,4,5 triphosphate receptor type III (Itpr3. Quantification of the immune-expression with use of computer-assisted image processing. Analysis statistics of the means between groups, weeks in groups, groups in weeks, and established significance when pOBJETIVO: Estudar os efeitos da modulação do inositol hexafosfato (IP6 na expressão imunoistoquímica de marcador biológico de sinalização celular de apoptose, em modelo de carcinogênese induzida pelo azoximetano (AOM. MÉTODOS: Ratos Wistar (N=112 distribuídos em 4 grupos (n=28: A, controle; B, AOM (5 mg Kg-1, 2x, a partir semana 3; C, IP6 (em água a 1%, seis semanas; D, IP6+AOM. Eutanásia semanal (n=7, a partir de semana três. Imunoistoquímica de colo ascendente com marcador biológico inositol 1,4,5 trisphosphate receptor type III (Itpr3. Quantificação da imunoexpressão com uso de processamento imagem assistida computador. Análise estatística da expressão média entre grupos, semanas em grupos e grupos em semanas, e estabelecido significância quando p<0.05. RESULTADOS: Evidenciou-se diferença significante entre grupos na expressão de Itpr3, p<0.0001; com diminuição Itpr3 de grupo BxD, p<0.001. CONCLUSÃO: O inositol hexafostato promove a modulação de marcador biológico com diminuição Itpr3 em carcinogênese de colo.

MiR-34a inhibits colon cancer proliferation and metastasis by inhibiting platelet-derived growth factor receptor α.

Science.gov (United States)

Li, Chunyan; Wang, Yulin; Lu, Shuming; Zhang, Zhuqing; Meng, Hua; Liang, Lina; Zhang, Yan; Song, Bo

2015-11-01

The microRNA (miRNA), miR‑34a is significant in colon cancer progression. In the present study, the role of miR‑34a in colon cancer cell proliferation and metastasis was investigated. It was found that the expression of miR‑34a in colon cancer tissues and cell lines was lower when compared with that of normal tissues and cells. Further research demonstrated that miR‑34a inhibited cell proliferation, induced G1 phase arrest, and suppressed metastasis and epithelial mesenchymal transition in colon cancer cells. Bioinformatic prediction indicated that platelet‑derived growth factor receptor α (PDGFRA) was a potential target gene of miR‑34a and a luciferase assay identified that PDGFRA was a novel direct target gene of miR‑34a. In addition, assays of western blot analyses and quantitative reverse‑transcription polymerase chain reaction confirmed that miR‑34a decreased PDGFRA mRNA expression and protein levels in colon cancer cells. Assessment of cellular function indicated that miR‑34a inhibited colon cancer progression via PDGFRA. These findings demonstrate that miR‑34a may act as a negative regulator in colon cancer by targeting PDGFRA.

Toxicology and Carcinogenesis Study of Senna in the C3B6.129F1-Trp53tm1Brd N12 haploinsufficient mice

Science.gov (United States)

Surh, Inok; Brix, Amy; French, John E.; Collins, Bradley J.; Sanders, J. Michael; Vallant, Molly; Dunnick, June K.

2013-01-01

Senna is a pod or leaf of Senna alexandrina P. Mill and is used as a stimulant laxative. In the large intestine, bacterial enzymes break sennosides and release rhein-9-anthrone, the active form for the laxative effect. To determine potential toxic effects of senna, a 5-week dose range finding study in the C57BL/6N mouse and a 40-week toxicology and carcinogenesis study in the C3B6.129F1-Trp53tm1Brd N12 haploinsufficient (p53+/−) mouse were conducted. In the 5-week study, C57BL/6N mice were exposed up to 10,000 ppm senna in feed. Increased incidences of epithelial hyperplasia of the cecum and colon were observed in males and females exposed to 5,000 or 10,000 ppm senna. These intestinal lesions were not considered to be of sufficient severity to cause mortality and, thus, in the p53+/− mouse 40-week study, the high dose of 10,000 ppm was selected. Significant increases in the incidences of epithelial hyperplasia of the colon and cecum were observed at 10,000 ppm in p53(+/−) males and females, and the incidence of hyperplasia of the colon was significantly increased at 3,000 ppm in females. In conclusion, the large intestine was the major target of senna-induced toxicity in both wild-type and the p53+/− mouse model. There was no neoplastic change, when senna was administered to p53 +/− mouse. PMID:23125117

Experimental studies on lung carcinogenesis and their relationship to future research on radiation-induced lung cancer in humans

International Nuclear Information System (INIS)

Cross, F.T.

1991-03-01

The usefulness of experimental systems for studying human lung carcinogenesis lies in the ease of studying components of a total problem. As an example, the main thrust of attack on possible synergistic interactions between radiation, cigarette smoke, and other irritants must be by means of research on animals. Because animals can be serially sacrificed, a systematic search can be made for progressive lung changes, thereby improving our understanding of carcinogenesis. The mechanisms of radiation-induced carcinogenesis have not yet been delineated, but modern concepts of molecular and cellular biology and of radiation dosimetry are being increasingly applied to both in vivo and in vitro exposure to determine the mechanisms of radiation-induced carcinogenesis, to elucidate human data, and to aid in extrapolating experimental animal data to human exposures. In addition, biologically based mathematical models of carcinogenesis are being developed to describe the nature of the events leading to malignancy; they are also an essential part of a rational approach to quantitative cancer risk assessment. This paper summarizes recent experimental and modeling data on radon-induced lung cancer and includes the confounding effects of cigarette-smoke exposures. The applicability of these data to understanding human exposures is emphasized, and areas of future research on human radiation-induced carcinogenesis are discussed. 7 refs., 2 figs., 3 tabs

Trigonella foenum-graecum (fenugreek-mediated suppression of Meloidogyne javanica in mungbean

Directory of Open Access Journals (Sweden)

Tayyaba Zia

2013-12-01

Full Text Available Soil amendments with powdered seeds of Trigonella foenum - graecum (fenugreek caused soil suppressiveness against Meloidogyne javanica. Decomposed seeds of fenugreek caused marked reduction in nematode population densities and subsequent root-knot development as compared to the aqueous extract of the seeds indicating that some indirect factors are involved in the suppression of root-knot nematode. Both decomposed seeds and aqueous extracts enhanced plant height and fresh weights of shoot whereas root growth remained uninfluenced. Changes in fungal communities associated with nematode control were studied by comparing population numbers of fungi in the soil and in internal root tissues (endorhiza in non-amended and fenugreekamended soils. Acremonium sp., Chaetomium globosum, Fusarium solani, Macrophomina phaseolina and Rhizoctonia solani were found to colonize inner root tissues of mungbean. Acremonium sp., C. globosum and F.solani were isolated in a relatively higher frequency from roots growing in the amended soils while M. phaseolina and R. solani colonized greatly in roots growing in non-amended soil. Of the fungi isolated from soils, Penicillium brefaldianum caused maximum juvenile mortality of M.javanica whereas F.solani caused greatest inhibition of egg hatch.

Carcinogenesis related to intense pulsed light and UV exposure

DEFF Research Database (Denmark)

Hedelund, L; Lerche, C; Wulf, H C

2006-01-01

This study examines whether intense pulsed light (IPL) treatment has a carcinogenic potential itself or may influence ultraviolet (UV)-induced carcinogenesis. Secondly, it evaluates whether UV exposure may influence IPL-induced side effects. Hairless, lightly pigmented mice (n=144) received three...

Tamoxifen Forms DNA Adducts In Human Colon After Administration Of A Single [14C]-Labeled Therapeutic Dose.

Energy Technology Data Exchange (ETDEWEB)

Brown, K; Tompkins, E M; Boocock, D J; Martin, E A; Farmer, P B; Turteltaub, K W; Ubick, E; Hemingway, D; Horner-Glister, E; White, I H

2007-05-23

Tamoxifen is widely prescribed for the treatment of breast cancer and is also licensed in the U.S. for the prevention of this disease. However, tamoxifen therapy is associated with an increased occurrence of endometrial cancer in women and there is also evidence that it may elevate the risk of colorectal cancer. The underlying mechanisms responsible for tamoxifen-induced carcinogenesis in women have not yet been elucidated but much interest has focussed on the role of DNA adduct formation. We investigated the propensity of tamoxifen to bind irreversibly to colorectal DNA when given to ten women as a single [{sup 14}C]-labeled therapeutic (20 mg) dose, {approx}18 h prior to undergoing colon resections. Using the sensitive technique of accelerator mass spectrometry, coupled with HPLC separation of enzymatically digested DNA, a peak corresponding to authentic dG-N{sup 2}-tamoxifen adduct was detected in samples from three patients, at levels ranging from 1-7 adducts/10{sup 9} nucleotides. No [{sup 14}C]-radiolabel associated with tamoxifen or its major metabolites was detected. The presence of detectable CYP3A4 protein in all colon samples suggests this tissue has the potential to activate tamoxifen to {alpha}-hydroxytamoxifen, in addition to that occurring in the systemic circulation, and direct interaction of this metabolite with DNA could account for the binding observed. Although the level of tamoxifeninduced damage displayed a degree of inter-individual variability, when present it was {approx}10-100 times higher than that reported for other suspect human colon carcinogens such as PhIP. These findings provide a mechanistic basis through which tamoxifen could increase the incidence of colon cancers in women.

Human Colon Tumors Express a Dominant-Negative Form of SIGIRR That Promotes Inflammation and Colitis-Associated Colon Cancer in Mice.

Science.gov (United States)

Zhao, Junjie; Bulek, Katarzyna; Gulen, Muhammet F; Zepp, Jarod A; Karagkounis, Georgio; Martin, Bradley N; Zhou, Hao; Yu, Minjia; Liu, Xiuli; Huang, Emina; Fox, Paul L; Kalady, Matthew F; Markowitz, Sanford D; Li, Xiaoxia

2015-12-01

Single immunoglobulin and toll-interleukin 1 receptor (SIGIRR), a negative regulator of the Toll-like and interleukin-1 receptor (IL-1R) signaling pathways, controls intestinal inflammation and suppresses colon tumorigenesis in mice. However, the importance of SIGIRR in human colorectal cancer development has not been determined. We investigated the role of SIGIRR in development of human colorectal cancer. We performed RNA sequence analyses of pairs of colon tumor and nontumor tissues, each collected from 68 patients. Immunoblot and immunofluorescence analyses were used to determine levels of SIGIRR protein in primary human colonic epithelial cells, tumor tissues, and colon cancer cell lines. We expressed SIGIRR and mutant forms of the protein in Vaco cell lines. We created and analyzed mice that expressed full-length (control) or a mutant form of Sigirr (encoding SIGIRR(N86/102S), which is not glycosylated) specifically in the intestinal epithelium. Some mice were given azoxymethane (AOM) and dextran sulfate sodium to induce colitis-associated cancer. Intestinal tissues were collected and analyzed by immunohistochemical and gene expression profile analyses. RNA sequence analyses revealed increased expression of a SIGIRR mRNA isoform, SIGIRR(ΔE8), in colorectal cancer tissues compared to paired nontumor tissues. SIGIRR(ΔE8) is not modified by complex glycans and is therefore retained in the cytoplasm-it cannot localize to the cell membrane or reduce IL1R signaling. SIGIRR(ΔE8) interacts with and has a dominant-negative effect on SIGIRR, reducing its glycosylation, localization to the cell surface, and function. Most SIGIRR detected in human colon cancer tissues was cytoplasmic, whereas in nontumor tissues it was found at the cell membrane. Mice that expressed SIGIRR(N86/102S) developed more inflammation and formed larger tumors after administration of azoxymethane and dextran sulfate sodium than control mice; colon tissues from these mutant mice expressed

MiR-145 regulates PAK4 via the MAPK pathway and exhibits an antitumor effect in human colon cells

International Nuclear Information System (INIS)

Wang, Zhigang; Zhang, Xiaoping; Yang, Zhili; Du, Hangxiang; Wu, Zhenqian; Gong, Jianfeng; Yan, Jun; Zheng, Qi

2012-01-01

Highlights: ► MiR-145 targets a putative binding site in the 3′UTR of PAK4. ► MiR-145 played an important role in inhibiting cell growth by directly targeting PAK4. ► MiR-145 may function as tumor suppressors. -- Abstract: MicroRNAs (miRNAs) are regulators of numerous cellular events; accumulating evidence indicates that miRNAs play a key role in a wide range of biological functions, such as cellular proliferation, differentiation, and apoptosis in cancer. Down-regulated expression of miR-145 has been reported in colon cancer tissues and cell lines. The molecular mechanisms underlying miR-145 and the regulation of colon carcinogenesis remain unclear. In this study, we investigated the levels of miR-145 in human colon cancer cells using qRT-PCR and found markedly decreased levels compared to normal epithelial cells. We identified PAK4 as a novel target of miR-145 using informatics screening. Additionally, we demonstrated that miR-145 targets a putative binding site in the 3′UTR of PAK4 and that its abundance is inversely associated with miR-145 expression in colon cancer cells; we confirmed this relationship using the luciferase reporter assay. Furthermore, restoration of miR-145 by mimics in SW620 cells significantly attenuated cell growth in vitro, in accordance with the inhibitory effects induced by siRNA mediated knockdown of PAK4. Taken together, these findings demonstrate that miR-145 downregulates P-ERK expression by targeting PAK4 and leads to inhibition of tumor growth.

Hydrogen sulfide-releasing naproxen suppresses colon cancer cell growth and inhibits NF-κB signaling

Directory of Open Access Journals (Sweden)

Kodela R

2015-08-01

Full Text Available Ravinder Kodela,1 Niharika Nath,2 Mitali Chattopadhyay,1 Diandra E Nesbitt,1 Carlos A Velázquez-Martínez,3 Khosrow Kashfi11Department of Physiology, Pharmacology and Neuroscience, Sophie Davis School of Biomedical Education, City University of New York Medical School, 2Department of Life Sciences, New York Institute of Technology, New York, NY, USA; 3Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada Abstract: Colorectal cancer (CRC is the second leading cause of death due to cancer and the third most common cancer in men and women in the USA. Nuclear factor kappa B (NF-κB is known to be activated in CRC and is strongly implicated in its development and progression. Therefore, activated NF-κB constitutes a bona fide target for drug development in this type of malignancy. Many epidemiological and interventional studies have established nonsteroidal anti-inflammatory drugs (NSAIDs as a viable chemopreventive strategy against CRC. Our previous studies have shown that several novel hydrogen sulfide-releasing NSAIDs are promising anticancer agents and are safer derivatives of NSAIDs. In this study, we examined the growth inhibitory effect of a novel H2S-releasing naproxen (HS-NAP, which has a repertoire as a cardiovascular-safe NSAID, for its effects on cell proliferation, cell cycle phase transitions, and apoptosis using HT-29 human colon cancer cells. We also investigated its effect as a chemopreventive agent in a xenograft mouse model. HS-NAP suppressed the growth of HT-29 cells by induction of G0/G1 arrest and apoptosis and downregulated NF-κB. Tumor xenografts in mice were significantly reduced in volume. The decrease in tumor mass was associated with a reduction of cell proliferation, induction of apoptosis, and decreases in NF-κB levels in vivo. Therefore, HS-NAP demonstrates strong anticancer potential in CRC. Keywords: nonsteroidal anti-inflammatory drugs, cell cycle, apoptosis, xenograft, NF

Chronology of p53 protein accumulation in gastric carcinogenesis

NARCIS (Netherlands)

Craanen, M. E.; Blok, P.; Dekker, W.; Offerhaus, G. J.; Tytgat, G. N.

1995-01-01

p53 Protein accumulation in early gastric carcinoma was studied in relation to the histological type (Lauren classification) and the type of growth pattern, including the chronology of p53 protein accumulation during carcinogenesis. Forty five, paraffin embedded gastrectomy specimens from early

Mechanisms of carcinogenesis prevention by flavonoids

Directory of Open Access Journals (Sweden)

G. A. Belitsky

2014-01-01

Full Text Available The mechanisms of anticancerogenic effects of flavanoids and isocyanates from the plants widely consumed in the midland belt of Russia were reviewed. Data of studies both in vitro and in vivo were analyzed. Special attention was paid to inhibition of targets responsible for carcinogen metabolic activation, carcinogenesis promotion and tumor progression as well as neoangiogenesis. Besides that the antioxidant properties of flavonoids and their effects on cell cycle regulation, apoptosis initiation and cell mobility were considered.

External radiation carcinogenesis

International Nuclear Information System (INIS)

Fry, R.J.M.; Storer, J.B.

1987-01-01

There have been many reviews of the subject of radiation carcinogenesis in general and of specific radiation-induced cancers. The aim of this article is not to give an exhaustive, and perhaps exhausting, review of all that has been published since the thorough treatise of Walburg in volume 4 of this series but rather to concentrate on the questions that still remain of importance and recent contributions to the answers. In the years since 1974 a vast amount of information has been reported, and the authors assess what gain there has been in knowledge. For example, it is in the 13 years since the last review that the great majority of data for the carcinogenic effects of neutrons has appeared. It is over 50 years since the discovery of the neutron, and yet knowledge of the carcinogenic effects of neutrons is far from adequate

The novel HDAC inhibitor AR-42-induced anti-colon cancer cell activity is associated with ceramide production

International Nuclear Information System (INIS)

Xu, Weihong; Xu, Bin; Yao, Yiting; Yu, Xiaoling; Shen, Jie

2015-01-01

In the current study, we investigated the potential activity of AR-42, a novel histone deacetylase (HDAC) inhibitor, against colon cancer cells. Our in vitro results showed that AR-42 induced ceramide production, exerted potent anti-proliferative and pro-apoptotic activities in established (SW-620 and HCT-116 lines) and primary human colon cancer cells. Exogenously-added sphingosine 1-phosphate (S1P) suppressed AR-42-induced activity, yet a cell-permeable ceramide (C4) facilitated AR-42-induced cytotoxicity against colon cancer cells. In addition, AR-42-induced ceramide production and anti-colon cancer cell activity were inhibited by the ceramide synthase inhibitor fumonisin B1, but were exacerbated by PDMP, which is a ceramide glucosylation inhibitor. In vivo, oral administration of a single dose of AR-42 dramatically inhibited SW-620 xenograft growth in severe combined immunodeficient (SCID) mice, without inducing overt toxicities. Together, these results show that AR-42 dramatically inhibits colon cancer cell proliferation in vitro and in vivo, and ceramide production might be the key mechanism responsible for its actions. - Highlights: • AR-42 is anti-proliferative against primary/established colon cancer cells. • AR-42 induces significant apoptotic death in primary/established colon cancer cells. • Ceramide production mediates AR-42-induced cytotoxicity in colon cancer cells. • AR-42 oral administration potently inhibits SW-620 xenograft growth in SCID mice

The novel HDAC inhibitor AR-42-induced anti-colon cancer cell activity is associated with ceramide production

Energy Technology Data Exchange (ETDEWEB)

Xu, Weihong; Xu, Bin; Yao, Yiting; Yu, Xiaoling [Department of Clinical Laboratory, Tongren Hospital, Shanghai (China); Shen, Jie, E-mail: tongrensj163@163.com [Department of Administrative, Tongren Hospital, No. 786 Yuyuan Road, Changning District, Shanghai (China)

2015-08-07

In the current study, we investigated the potential activity of AR-42, a novel histone deacetylase (HDAC) inhibitor, against colon cancer cells. Our in vitro results showed that AR-42 induced ceramide production, exerted potent anti-proliferative and pro-apoptotic activities in established (SW-620 and HCT-116 lines) and primary human colon cancer cells. Exogenously-added sphingosine 1-phosphate (S1P) suppressed AR-42-induced activity, yet a cell-permeable ceramide (C4) facilitated AR-42-induced cytotoxicity against colon cancer cells. In addition, AR-42-induced ceramide production and anti-colon cancer cell activity were inhibited by the ceramide synthase inhibitor fumonisin B1, but were exacerbated by PDMP, which is a ceramide glucosylation inhibitor. In vivo, oral administration of a single dose of AR-42 dramatically inhibited SW-620 xenograft growth in severe combined immunodeficient (SCID) mice, without inducing overt toxicities. Together, these results show that AR-42 dramatically inhibits colon cancer cell proliferation in vitro and in vivo, and ceramide production might be the key mechanism responsible for its actions. - Highlights: • AR-42 is anti-proliferative against primary/established colon cancer cells. • AR-42 induces significant apoptotic death in primary/established colon cancer cells. • Ceramide production mediates AR-42-induced cytotoxicity in colon cancer cells. • AR-42 oral administration potently inhibits SW-620 xenograft growth in SCID mice.

The S100P/RAGE signaling pathway regulates expression of microRNA-21 in colon cancer cells.

Science.gov (United States)

Mercado-Pimentel, Melania E; Onyeagucha, Benjamin C; Li, Qing; Pimentel, Angel C; Jandova, Jana; Nelson, Mark A

2015-08-19

S100P signaling through the receptor for advanced glycation end-products (RAGE) contributes to colon cancer invasion and metastasis, but the mechanistic features of this process are obscure. Here, we investigate whether activation of S100P/RAGE signaling regulates oncogenic microRNA-21 (miR-21). We show that exogenous S100P up-regulates miR-21 levels in human colon cancer cells, whereas knockdown of S100P results in a decrease of miR-21. Furthermore, blockage of RAGE with anti-RAGE antibody suppresses S100P induction of miR-21. In addition, we found that S100P induction of miR-21 expression involves ERK and is suppressed by the MEK inhibitor U0126. Also, S100P treatment stimulates the enrichment of c-Fos, and AP-1 family members, at the miR-21 gene promoter. Copyright © 2015 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Different effects of ERβ and TROP2 expression in Chinese patients with early-stage colon cancer.

Science.gov (United States)

Fang, Yu-Jing; Wang, Guo-Qiang; Lu, Zhen-Hai; Zhang, Lin; Li, Ji-Bin; Wu, Xiao-Jun; Ding, Pei-Rong; Ou, Qing-Jian; Zhang, Mei-Fang; Jiang, Wu; Pan, Zhi-Zhong; Wan, De-Sen

2012-12-01

Estrogen receptor beta (ERβ) and TROP2 expressed in colon carcinoma and might play an important role there. We explored the relationship of ERβ and TROP2 expression with the prognosis of early-stage colon cancer. ERβ and TROP2 levels were assessed by immunohistochemistry in normal mucosa and tumoral tissues from 220 Chinese patients with T(3)N(0)M(0) (stage IIa) and T(4)N(0)M(0) (stage IIb) colon cancer in the Cancer Center, Sun Yat-sen University, who underwent curative surgical resection between 1995 and 2003. The Cox proportional hazards regression model was applied to analyze the overall survival (OS) data, and the ROC curve, Kaplan-Meier estimate, log rank test, and Jackknife method were used to show the effect of ERβ and TROP2 expression at different stages of cancer. The 5-year survival rates were not significantly different between the patients with stage IIa and stage IIb colon cancer (83 vs. 80 %, respectively). The high expression of ERβ was related to decreasing OS in stage IIa and stage IIb colon cancer, while the high expression of TROP2 was related to decreasing OS in stage IIb colon cancer. The expression of ERβ and TROP2 has tumor-suppressive and tumor-promoting effect in stage IIa and stage IIb colon cancer, respectively.

Neurotensin receptor 1 gene activation by the Tcf/beta-catenin pathway is an early event in human colonic adenomas.

Science.gov (United States)

Souazé, Frédérique; Viardot-Foucault, Véronique; Roullet, Nicolas; Toy-Miou-Leong, Mireille; Gompel, Anne; Bruyneel, Erik; Comperat, Eva; Faux, Maree C; Mareel, Marc; Rostène, William; Fléjou, Jean-François; Gespach, Christian; Forgez, Patricia

2006-04-01

Alterations in the Wnt/APC (adenomatous polyposis coli) signalling pathway, resulting in beta-catenin/T cell factor (Tcf)-dependent transcriptional gene activation, are frequently detected in familial and sporadic colon cancers. The neuropeptide neurotensin (NT) is widely distributed in the gastrointestinal tract. Its proliferative and survival effects are mediated by a G-protein coupled receptor, the NT1 receptor. NT1 receptor is not expressed in normal colon epithelial cells, but is over expressed in a number of cancer cells and tissues suggesting a link to the outgrowth of human colon cancer. Our results demonstrate that the upregulation of NT1 receptor occurring in colon cancer is the result of Wnt/APC signalling pathway activation. We first established the functionality of the Tcf response element within the NT1 receptor promoter. Consequently, we observed the activation of NT1 receptor gene by agents causing beta-catenin cytosolic accumulation, as well as a strong decline of endogenous receptor when wt-APC was restored. At the cellular level, the re-establishment of wt-APC phenotype resulted in the impaired functionality of NT1 receptor, like the breakdown in NT-induced intracellular calcium mobilization and the loss of NT pro-invasive effect. We corroborated the Wnt/APC signalling pathway on the NT1 receptor promoter activation with human colon carcinogenesis, and showed that NT1 receptor gene activation was perfectly correlated with nuclear or cytoplasmic beta-catenin localization while NT1 receptor was absent when beta-catenin was localized at the cell-cell junction in early adenomas of patients with familial adenomatous polyposis, hereditary non-polyposis colorectal cancer and loss of heterozygosity tumours. In this report we establish a novel link in vitro between the Tcf/beta-catenin pathway and NT1 receptor promoter activation.

Curcumin and salsalate suppresses colonic inflammation and procarcinogenic signaling in high-fat-fed, azoxymethane-treated mice

Science.gov (United States)

High-fat diets (HFDs) and excess adiposity increase proinflammatory cytokines in the colon, altering gene expression in a manner that promotes the development of colorectal cancer (CRC). Thus, compounds that reduce this biochemical inflammation are potential chemopreventive agents. Curcumin (CUR), a...

Interaction of renin-angiotensin system and adenosine monophosphate-activated protein kinase signaling pathway in renal carcinogenesis of uninephrectomized rats.

Science.gov (United States)

Yang, Ke-Ke; Sui, Yi; Zhou, Hui-Rong; Zhao, Hai-Lu

2017-05-01

Renin-angiotensin system and adenosine monophosphate-activated protein kinase signaling pathway both play important roles in carcinogenesis, but the interplay of renin-angiotensin system and adenosine monophosphate-activated protein kinase in carcinogenesis is not clear. In this study, we researched the interaction of renin-angiotensin system and adenosine monophosphate-activated protein kinase in renal carcinogenesis of uninephrectomized rats. A total of 96 rats were stratified into four groups: sham, uninephrectomized, and uninephrectomized treated with angiotensin-converting enzyme inhibitor or angiotensin receptor blocker. Renal adenosine monophosphate-activated protein kinase and its downstream molecule acetyl coenzyme A carboxylase were detected by immunohistochemistry and western blot at 10 months after uninephrectomy. Meanwhile, we examined renal carcinogenesis by histological transformation and expressions of Ki67 and mutant p53. During the study, fasting lipid profiles were detected dynamically at 3, 6, 8, and 10 months. The results indicated that adenosine monophosphate-activated protein kinase expression in uninephrectomized rats showed 36.8% reduction by immunohistochemistry and 89.73% reduction by western blot. Inversely, acetyl coenzyme A carboxylase expression increased 83.3% and 19.07% in parallel to hyperlipidemia at 6, 8, and 10 months. The histopathology of carcinogenesis in remnant kidneys was manifested by atypical proliferation and carcinoma in situ, as well as increased expressions of Ki67 and mutant p53. Intervention with angiotensin-converting enzyme inhibitor or angiotensin receptor blocker significantly prevented the inhibition of adenosine monophosphate-activated protein kinase signaling pathway and renal carcinogenesis in uninephrectomized rats. In conclusion, the novel findings suggest that uninephrectomy-induced disturbance in adenosine monophosphate-activated protein kinase signaling pathway resulted in hyperlipidemia and

Radiation carcinogenesis and related radiobiology. Special listing

International Nuclear Information System (INIS)

1978-01-01

This Special Listing of Current Cancer Research Projects is a service of the International Cancer Research Data Bank (ICRDB) program of the National Cancer Institute. Each listing contains descriptions of ongoing projects in one selected cancer research area. The descriptions are provided by cancer scientists in about 50 different countries. Research areas covered in this listing are: Human cancer and exposure to radiation; experimental radiation carcinogenesis and radiation biology

Sodium 4-phenylbutyrate suppresses the development of dextran sulfate sodium-induced colitis in mice.

Science.gov (United States)

Ono, Kazuhiko; Nimura, Satoshi; Nishinakagawa, Takuya; Hideshima, Yuko; Enjyoji, Munechika; Nabeshima, Kazuki; Nakashima, Manabu

2014-03-01

Sodium 4-phenylbutyrate (PBA) exhibits anti-inflammatory effects by suppressing nuclear factor-κB (NF-κB) activation. In the present study, the effects of PBA on a mouse model of dextran sulfate sodium (DSS)-induced colitis were investigated. The therapeutic efficacy of PBA (150 mg/kg body weight) in DSS-induced colitis was assessed based on the disease activity index (DAI), colon length, the production of inflammatory cytokines and histopathological examination. The results showed an increase in the median survival time in the PBA-treated group compared with that of the untreated DSS control group. DAI scores were lower in the PBA-treated group than in the DSS control group during the 12 days of the experiment. Additionally, PBA treatment inhibited shortening of the colon and the production of the inflammatory cytokines tumor necrosis factor-α, interleukin-1β and IL-6, which were measured in the colonic lavage fluids. Histopathological examination of the DSS control group showed diffused clusters of chronic inflammatory cells infiltrating the lamina propria, partial exfoliation of the surface epithelium and decreased numbers of mature goblet cells. By contrast, in the PBA-treated group the histopathological findings were the same as those of the normal healthy controls. These results suggest that PBA strongly prevents DSS-induced colitis by suppressing the mechanisms involved in its pathogenesis.

The level of claudin-7 is reduced as an early event in colorectal carcinogenesis

DEFF Research Database (Denmark)

Lange, Jette Bornholdt; Friis, Stine; Godiksen, Sine

2011-01-01

-regulation of the oncogenic serine protease, matriptase, induces leakiness in epithelial barriers both in vivo and in vitro. We found in an in-silico search tight co-regulation between matriptase and claudin-7 expression. We have previously shown that the matriptase expression level decreases during colorectal carcinogenesis....... In the present study we investigated whether claudin-7 expression is likewise decreased during colorectal carcinogenesis, thereby causing or contributing to the compromised epithelial leakiness of dysplastic tissue....

Metabolomics analysis identifies intestinal microbiota-derived biomarkers of colonization resistance in clindamycin-treated mice.

Directory of Open Access Journals (Sweden)

Robin L P Jump

Full Text Available The intestinal microbiota protect the host against enteric pathogens through a defense mechanism termed colonization resistance. Antibiotics excreted into the intestinal tract may disrupt colonization resistance and alter normal metabolic functions of the microbiota. We used a mouse model to test the hypothesis that alterations in levels of bacterial metabolites in fecal specimens could provide useful biomarkers indicating disrupted or intact colonization resistance after antibiotic treatment.To assess in vivo colonization resistance, mice were challenged with oral vancomycin-resistant Enterococcus or Clostridium difficile spores at varying time points after treatment with the lincosamide antibiotic clindamycin. For concurrent groups of antibiotic-treated mice, stool samples were analyzed using quantitative real-time polymerase chain reaction to assess changes in the microbiota and using non-targeted metabolic profiling. To assess whether the findings were applicable to another antibiotic class that suppresses intestinal anaerobes, similar experiments were conducted with piperacillin/tazobactam.Colonization resistance began to recover within 5 days and was intact by 12 days after clindamycin treatment, coinciding with the recovery bacteria from the families Lachnospiraceae and Ruminococcaceae, both part of the phylum Firmicutes. Clindamycin treatment caused marked changes in metabolites present in fecal specimens. Of 484 compounds analyzed, 146 (30% exhibited a significant increase or decrease in concentration during clindamycin treatment followed by recovery to baseline that coincided with restoration of in vivo colonization resistance. Identified as potential biomarkers of colonization resistance, these compounds included intermediates in carbohydrate or protein metabolism that increased (pentitols, gamma-glutamyl amino acids and inositol metabolites or decreased (pentoses, dipeptides with clindamycin treatment. Piperacillin

EGF signalling pathway regulates colon cancer stem cell proliferation and apoptosis.

Science.gov (United States)

Feng, Y; Dai, X; Li, X; Wang, H; Liu, J; Zhang, J; Du, Y; Xia, L

2012-10-01

Cancer stem cells (CSCs) compose a subpopulation of cells within a tumour that can self-renew and proliferate. Growth factors such as epidermal growth factor (EGF) and basic fibroblast growth factor (b-FGF) promote cancer stem cell proliferation in many solid tumours. This study assesses whether EGF, bFGF and IGF signalling pathways are essential for colon CSC proliferation and self-renewal. Colon CSCs were cultured in serum-free medium (SFM) with one of the following growth factors: EGF, bFGF or IGF. Characteristics of CSC gene expression were evaluated by real time PCR. Tumourigenicity of CSCs was determined using a xenograft model in vivo. Effects of EGF receptor inhibitors, Gefitinib and PD153035, on CSC proliferation, apoptosis and signalling were evaluated using fluorescence-activated cell sorting and western blotting. Colon cancer cell HCT116 transformed to CSCs in SFM. Compared to other growth factors, EGF was essential to support proliferation of CSCs that expressed higher levels of progenitor genes (Musashi-1, LGR5) and lower levels of differential genes (CK20). CSCs promoted more rapid tumour growth than regular cancer cells in xenografts. EGFR inhibitors suppressed proliferation and induced apoptosis of CSCs by inhibiting autophosphorylation of EGFR and downstream signalling proteins, such as Akt kinase, extracellular signal-regulated kinase 1/2 (ERK 1/2). This study indicates that EGF signalling was essential for formation and maintenance of colon CSCs. Inhibition of the EGF signalling pathway may provide a useful strategy for treatment of colon cancer. © 2012 Blackwell Publishing Ltd.

Resistant Starch Induces Catabolic but Suppresses Immune and Cell Division Pathways and Changes the Microbiome in Proximal Colon of Male Pigs

NARCIS (Netherlands)

Haenen, D.; Souza Da Silva, C.; Zhang, J.; Koopmans, S.J.; Bosch, G.; Vervoort, J.J.M.; Gerrits, W.J.J.; Kemp, B.; Smidt, H.; Müller, M.R.; Hooiveld, G.J.E.J.

2013-01-01

Consumption of resistant starch (RS) has been associated with various intestinal health benefits, but knowledge on its effects on global gene expression in the colon is limited. The main objective of the current study was to identify genes affected by RS in the proximal colon to infer which biologic

Resistant starch induces catabolic but suppresses immune and cell division pathways and changes the microbiome in proximal colon of male pigs

NARCIS (Netherlands)

Haenen, Danielle; Muller, Michael; Hooiveld, Guido

2013-01-01

Consumption of resistant starch (RS) has been associated with various intestinal health benefits, but knowledge on its effects on global gene expression in the colon is limited. The main objective of the current study was to identify genes affected by RS in the proximal colon to infer which biologic

Curcumin: the spicy modulator of breast carcinogenesis.

Science.gov (United States)

Banik, Urmila; Parasuraman, Subramani; Adhikary, Arun Kumar; Othman, Nor Hayati

2017-07-19

Worldwide breast cancer is the most common cancer in women. For many years clinicians and the researchers are examining and exploring various therapeutic modalities for breast cancer. Yet the disease has remained unconquered and the quest for cure is still going on. Present-day strategy of breast cancer therapy and prevention is either combination of a number of drugs or a drug that modulates multiple targets. In this regard natural products are now becoming significant options. Curcumin exemplifies a promising natural anticancer agent for this purpose. This review primarily underscores the modulatory effect of curcumin on the cancer hallmarks. The focus is its anticancer effect in the complex pathways of breast carcinogenesis. Curcumin modulates breast carcinogenesis through its effect on cell cycle and proliferation, apoptosis, senescence, cancer spread and angiogenesis. Largely the NFkB, PI3K/Akt/mTOR, MAPK and JAK/STAT are the key signaling pathways involved. The review also highlights the curcumin mediated modulation of tumor microenvironment, cancer immunity, breast cancer stem cells and cancer related miRNAs. Using curcumin as a therapeutic and preventive agent in breast cancer is perplexed by its diverse biological activity, much of which remains inexplicable. The information reviewed here should point toward potential scope of future curcumin research in breast cancer.

Bladder carcinogenesis in rats subjected to ureterosigmoidostomy and treated with L-lysine.

Science.gov (United States)

Dornelas, Conceição Aparecida; Santos, Alessandra Marques Dos; Correia, Antonio Lucas Oliveira; Juanes, Camila de Carvalho; Coelho, João Paulo Ferreira; Cunha, Bianca Lopes; Maciel, André Vinicius Vieira; Jamacaru, Francisco Vagnaldo Fechine

2016-01-01

to evaluate the effect of L-lysine in the bladder and intestinal epithelia in rats submitted to vesicosigmoidostomy. we divided forty Wistar rats into four groups: group I - control group (Sham); group II - submitted to vesicosigmoidostomy and treated with L-lysine 150mg/kg; group III - submitted only to vesicosigmoidostomy; and group IV - received L-lysine 150mg/kg. After eight weeks the animals were sacrificed. in the bladders of all operated animals we observed simple, papillary and nodular hyperplasia of transitional cells, transitional cell papillomas and squamous metaplasia. As for the occurrence of aberrant crypt foci in the colons of operated animals, we did not observe statistically significant differences in any of the distal, proximal and medium fragments, or in all fragments together (p=1.0000). Although statistically there was no promotion of carcinogenesis in the epithelia of rats treated with L-lysine in the observed time, it was clear the histogenesis of bladder carcinogenesis in its initial phase in all operated rats, this being probably associated with chronic infection and tiny bladder stones. o objetivo deste trabalho é avaliar o efeito da L-lisina nos epitélios vesical e intestinal de ratas submetidas à vesicossigmoidostomia. quarenta ratas Wistar, foram divididas em quatro grupos: grupo I- grupo controle (Sham); grupo II- submetido à vesicossigmoidostomia e tratado com L-lisina 150mg/kg; grupo III- submetido apenas à vesicossigmoidostomia; e grupo IV- recebeu L-lisina 150mg/kg. Após oito semanas os animais foram sacrificados. na bexiga de todos os animais operados observou-se hiperplasia simples, papilar e nodular de células transicionais, papiloma de células transicionais e metaplasia escamosa. Quanto à ocorrência de focos de criptas aberrantes nos colos dos animais operados, não foi evidenciado diferença estatística significante em nenhum dos fragmentos distal, proximal e médio, e todos juntos (P=1,0000). apesar de

Isoreserpine promotes {beta}-catenin degradation via Siah-1 up-regulation in HCT116 colon cancer cells

Energy Technology Data Exchange (ETDEWEB)

Gwak, Jungsug; Song, Taeyun [PharmacoGenomics Research Center, Inje University, Busan 614-735 (Korea, Republic of); Song, Jie-Young; Yun, Yeon-Sook [Laboratory of Radiation Cancer Science, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of); Choi, Il-Whan [Department of Microbiology, Center for Viral Disease Research, Inje University College of Medicine, Busan 614-735 (Korea, Republic of); Jeong, Yongsu [Department of Genetic Engineering, and Graduate School of Biotechnology, Kyung Hee University, Yongin 446-701 (Korea, Republic of); Shin, Jae-Gook [PharmacoGenomics Research Center, Inje University, Busan 614-735 (Korea, Republic of); Department of Clinical Pharmacology, Inje University Busan Paik Hospital, Busan 614-735 (Korea, Republic of); Oh, Sangtaek, E-mail: ohsa@inje.ac.kr [PharmacoGenomics Research Center, Inje University, Busan 614-735 (Korea, Republic of)

2009-09-25

Aberrant accumulation of intracellular {beta}-catenin in intestinal epithelial cells is a frequent early event during the development of colon cancer. To identify small molecules that decrease the level of intracellular {beta}-catenin, we performed cell-based chemical screening using genetically engineered HEK293 reporter cells to detect compounds that inhibit TOPFlash reporter activity, which was stimulated by Wnt3a-conditioned medium. We found that isoreserpine promoted the degradation of intracellular {beta}-catenin by up-regulation of Siah-1 in HEK293 and HCT116 colon cancer cells. Moreover, isoreserpine repressed the expression of {beta}-catenin/T-cell factor (TCF)-dependent genes, such as cyclin D1 and c-myc, resulting in the suppression of HCT116 cell proliferation. Our findings suggest that isoreserpine can potentially be used as a chemotherapeutic agent against colon cancer.

Modulation of expression of Programmed Death-1 by administration of probiotic Dahi in DMH-induced colorectal carcinogenesis in rats.

Science.gov (United States)

Mohania, Dheeraj; Kansal, Vinod K; Kumar, Manoj; Nagpal, Ravinder; Yamashiro, Yuichiro; Marotta, Francesco

2013-09-01

Interaction of probiotic bacteria with the host immune system elicits beneficial immune modulating effects. Although, there are many published studies on interaction of probiotics with immune system focusing on activation of immune system by bacterial cell wall through the engagement of Toll-like receptor family; very few studies have focused on molecules involved in the T-cell activation, and not much work has been executed to study the correlation of probiotics and programmed death-1 in colorectal carcinogenesis in animal models. Hence, the present study was carried out to assess the effect of probiotic Dahi on expression of programmed death (PD-1) in colorectum of 1, 2-dimethylhydrazine treated Wistar rats. DMH was injected subcutaneously at the rate of 40 mg/kg body weight per animal twice a week for 2 weeks. A total of 168 male Wistar rats were randomly allocated to seven groups, each group having twenty-four animals. The rats were euthanized at the 8th, 16th and 32nd week of the experiment and examined for the expression of PD-1 in colorectal tissues by immunohistochemical staining. Expression of PD-1 was observed in colorectal tissues of normal and DMH-treated rats. Feeding rats with probiotic Dahi or the treatment with piroxicam decreased the expression of PD-1 in DMH-induced colorectal mucosa, and the combined treatment with probiotic Dahi and piroxicam was significantly more effective in reducing the expression of PD-1. PD-1 expressed independent of carcinogen administration in normal colonic mucosa and may play a role in modulation of immune response in DMH-induced colorectal carcinogenesis. The present study suggests that probiotic Dahi can be used as an effective chemopreventive agent in the management of colorectal cancer.

Gemifloxacin, a Fluoroquinolone Antimicrobial Drug, Inhibits Migration and Invasion of Human Colon Cancer Cells

Directory of Open Access Journals (Sweden)

Jung-Yu Kan

2013-01-01

Full Text Available Gemifloxacin (GMF is an orally administered broad-spectrum fluoroquinolone antimicrobial agent used to treat acute bacterial exacerbation of pneumonia and bronchitis. Although fluoroquinolone antibiotics have also been found to have anti-inflammatory and anticancer effects, studies on the effect of GMF on treating colon cancer have been relatively rare. To the best of our knowledge, this is the first report to describe the antimetastasis activities of GMF in colon cancer and the possible mechanisms involved. Results have shown that GMF inhibits the migration and invasion of colon cancer SW620 and LoVo cells and causes epithelial mesenchymal transition (EMT. In addition, GMF suppresses the activation of NF-κB and cell migration and invasion induced by TNF-α and inhibits the TAK1/TAB2 interaction, resulting in decreased IκB phosphorylation and NF-κB nuclear translocation in SW620 cells. Furthermore, Snail, a critical transcriptional factor of EMT, was downregulated after GMF treatment. Overexpression of Snail by cDNA transfection significantly decreases the inhibitory effect of GMF on EMT and cell migration and invasion. In conclusion, GMF may be a novel anticancer agent for the treatment of metastasis in colon cancer.

Kaempferol targets RSK2 and MSK1 to suppress ultraviolet radiation-induced skin cancer

Science.gov (United States)

Langfald, Alyssa; Yang, Ge; Zhang, Yi; Yu, Dong Hoon; Kim, Myoung Ok; Lee, Mee-Hyun; Li, Haitao; Bae, Ki Beom; Kim, Hong-Gyum; Ma, Wei-Ya; Bode, Ann M.; Dong, Ziming; Dong, Zigang

2014-01-01

Solar ultraviolet (SUV) irradiation is a major factor in skin carcinogenesis, the most common form of cancer in the USA. The mitogen-activated protein (MAP) kinase cascades are activated by SUV irradiation. The 90 kDa ribosomal S6 kinase (RSK) and mitogen and stress activated protein kinase (MSK) proteins constitute a family of protein kinases that mediate signal transduction downstream of the MAP kinase cascades. In this study, phosphorylation of RSK and MSK1 was up-regulated in human squamous cell carcinoma (SCC) and solar UV-treated mouse skin. Kaempferol, a natural flavonol, found in tea, broccoli, grapes, apples and other plant sources, is known to have anticancer activity, but its mechanisms and direct target(s) in cancer chemoprevention are unclear. Kinase array results revealed that kaempferol inhibited RSK2 and MSK1. Pull-down assay results, ATP competition and in vitro kinase assay data revealed that kaempferol interacts with RSK2 and MSK1 at the ATP-binding pocket and inhibits their respective kinase activities. Mechanistic investigations showed that kaempferol suppresses RSK2 and MSK1 kinase activities to attenuate solar UV-induced phosphorylation of CREB and histone H3 in mouse skin cells. Kaempferol was a potent inhibitor of solar UV-induced mouse skin carcinogenesis. Further analysis showed that skin from the kaempferol-treated group exhibited a substantial reduction in solar UV-induced phosphorylation of cAMP response element-binding protein (CREB), c-Fos and histone H3. Overall, our results identify kaempferol as a safe and novel chemopreventive agent against solar UV-induced skin carcinogenesis that acts by targeting RSK2 and MSK1. PMID:24994661

Kaempferol targets RSK2 and MSK1 to suppress UV radiation-induced skin cancer.

Science.gov (United States)

Yao, Ke; Chen, Hanyong; Liu, Kangdong; Langfald, Alyssa; Yang, Ge; Zhang, Yi; Yu, Dong Hoon; Kim, Myoung Ok; Lee, Mee-Hyun; Li, Haitao; Bae, Ki Beom; Kim, Hong-Gyum; Ma, Wei-Ya; Bode, Ann M; Dong, Ziming; Dong, Zigang

2014-09-01

Solar UV (SUV) irradiation is a major factor in skin carcinogenesis, the most common form of cancer in the United States. The MAPK cascades are activated by SUV irradiation. The 90 kDa ribosomal S6 kinase (RSK) and mitogen and stress-activated protein kinase (MSK) proteins constitute a family of protein kinases that mediate signal transduction downstream of the MAPK cascades. In this study, phosphorylation of RSK and MSK1 was upregulated in human squamous cell carcinoma (SCC) and SUV-treated mouse skin. Kaempferol, a natural flavonol, found in tea, broccoli, grapes, apples, and other plant sources, is known to have anticancer activity, but its mechanisms and direct target(s) in cancer chemoprevention are unclear. Kinase array results revealed that kaempferol inhibited RSK2 and MSK1. Pull-down assay results, ATP competition, and in vitro kinase assay data revealed that kaempferol interacts with RSK2 and MSK1 at the ATP-binding pocket and inhibits their respective kinase activities. Mechanistic investigations showed that kaempferol suppresses RSK2 and MSK1 kinase activities to attenuate SUV-induced phosphorylation of cAMP-responsive element binding protein (CREB) and histone H3 in mouse skin cells. Kaempferol was a potent inhibitor of SUV-induced mouse skin carcinogenesis. Further analysis showed that skin from the kaempferol-treated group exhibited a substantial reduction in SUV-induced phosphorylation of CREB, c-Fos, and histone H3. Overall, our results identify kaempferol as a safe and novel chemopreventive agent against SUV-induced skin carcinogenesis that acts by targeting RSK2 and MSK1. ©2014 American Association for Cancer Research.

15-Hydroxyprostaglandin dehydrogenase inactivation as a mechanism of resistance to celecoxib chemoprevention of colon tumors.

LENUS (Irish Health Repository)

Yan, Min

2009-06-09

Pharmacologic inhibitors of the prostaglandin-synthesizing COX-2 oncogene prevent the development of premalignant human colon adenomas. However, resistance to treatment is common. In this study, we show that the adenoma prevention activity of the COX-2 inhibitor celecoxib requires the concomitant presence of the 15-hydroxyprostaglandin dehydrogenase (15-PGDH) tumor suppressor gene, and that loss of 15-PGDH expression imparts resistance to celecoxib\\'s anti-tumor effects. We first demonstrate that the adenoma-preventive activity of celecoxib is abrogated in mice genetically lacking 15-PGDH. In FVB mice, celecoxib prevents 85% of azoxymethane-induced tumors >1 mm in size, but is essentially inactive in preventing tumor induction in 15-PGDH-null animals. Indeed, celecoxib treated 15-PGDH null animals develop more tumors than do celecoxib naive WT mice. In parallel with the loss of tumor prevention activity, celecoxib-mediated suppression of colonic PGE(2) levels is also markedly attenuated in 15-PGDH-null versus WT mice. Finally, as predicted by the murine models, humans with low colonic 15-PGDH levels also exhibit celecoxib resistance. Specifically, in a colon adenoma prevention trial, in all cases tested, individuals who developed new adenomas while receiving celecoxib treatment were also found as having low colonic 15-PGDH levels.

Overexpression of UbcH10 alternates the cell cycle profile and accelerate the tumor proliferation in colon cancer

Directory of Open Access Journals (Sweden)

Hatoh Shinji

2009-03-01

Full Text Available Abstract Background UbcH10 participates in proper metaphase to anaphase transition, and abrogation of UbcH10 results in the premature separation of sister chromatids. To assess the potential role of UbcH10 in colon cancer progression, we analyzed the clinicopathological relevance of UbcH10 in colon cancer. Methods We firstly screened the expression profile of UbcH10 in various types of cancer tissues as well as cell lines. Thereafter, using the colon cancer cells line, we manipulated the expression of UbcH10 and evaluated the cell cycle profile and cellular proliferations. Furthermore, the clinicopathological significance of UbcH10 was immunohistologically evaluated in patients with colon cancer. Statistical analysis was performed using the student's t-test and Chi-square test. Results Using the colon cancer cells, depletion of UbcH10 resulted in suppression of cellular growth whereas overexpression of UbcH10 promoted the cellular growth and oncogenic cellular growth. Mitotic population was markedly alternated by the manipulation of UbcH10 expression. Immunohistochemical analysis indicated that UbcH10 was significantly higher in colon cancer tissue compared with normal colon epithelia. Furthermore, the clinicopathological evaluation revealed that UbcH10 was associated with high-grade histological tumors. Conclusion The results show the clinicopathological significance of UbcH10 in the progression of colon cancer. Thus UbcH10 may act as a novel biomarker in patients with colon cancer.

Age and Space Irradiation Modulate Tumor Progression: Implications for Carcinogenesis Risk

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National Aeronautics and Space Administration — Age plays a major role in tumor incidence and is an important consideration when modeling the carcinogenesis process or estimating cancer risks. Epidemiological data...

Dietary tomato and lycopene impact androgen signaling- and carcinogenesis-related gene expression during early TRAMP prostate carcinogenesis

Science.gov (United States)

Wan, Lei; Tan, Hsueh-Li; Thomas-Ahner, Jennifer M.; Pearl, Dennis K.; Erdman, John W.; Moran, Nancy E.; Clinton, Steven K.

2014-01-01

Consumption of tomato products containing the carotenoid lycopene is associated with a reduced risk of prostate cancer. To identify gene expression patterns associated with early testosterone-driven prostate carcinogenesis, which are impacted by dietary tomato and lycopene, wild type (WT) and transgenic adenocarcinoma of the mouse prostate (TRAMP) mice were fed control or tomato- or lycopene-containing diets from 4-10 wk-of-age. Eight-week-old mice underwent sham surgery, castration, or castration followed by testosterone-repletion (2.5 mg/kg/d initiated 1 wk after castration). Ten-wk-old intact TRAMP mice exhibit early multifocal prostatic intraepithelial neoplasia (PIN). Of the 200 prostate cancer-related genes measured by quantitative NanoString®, 189 are detectable, 164 significantly differ by genotype, 179 by testosterone status, and 30 by diet type (Plycopene feeding (Srd5a1) and by tomato-feeding (Srd5a2, Pxn, and Srebf1). Additionally, tomato-feeding significantly reduced expression of genes associated with stem cell features, Aldh1a and Ly6a, while lycopene-feeding significantly reduced expression of neuroendocrine differentiation-related genes, Ngfr and Syp. Collectively, these studies demonstrate a profile of testosterone-regulated genes associated with early stages of prostate carcinogenesis that are potential mechanistic targets of dietary tomato components. Future studies on androgen signaling/metabolism, stem cell features, and neuroendocrine differentiation pathways may elucidate the mechanisms by which dietary tomato and lycopene impact prostate cancer risk. PMID:25315431

Outcomes of colon resection in patients with metastatic colon cancer.

Science.gov (United States)

Moghadamyeghaneh, Zhobin; Hanna, Mark H; Hwang, Grace; Mills, Steven; Pigazzi, Alessio; Stamos, Michael J; Carmichael, Joseph C

2016-08-01

Patients with advanced colorectal cancer have a high incidence of postoperative complications. We sought to identify outcomes of patients who underwent resection for colon cancer by cancer stage. The National Surgical Quality Improvement Program database was used to evaluate all patients who underwent colon resection with a diagnosis of colon cancer from 2012 to 2014. Multivariate logistic regression analysis was performed to investigate patient outcomes by cancer stage. A total of 7,786 colon cancer patients who underwent colon resection were identified. Of these, 10.8% had metastasis at the time of operation. Patients with metastatic disease had significantly increased risks of perioperative morbidity (adjusted odds ratio [AOR]: 1.44, P = .01) and mortality (AOR: 3.72, P = .01). Patients with metastatic disease were significantly younger (AOR: .99, P colon cancer have metastatic disease. Postoperative morbidity and mortality are significantly higher than in patients with localized disease. Published by Elsevier Inc.

Information dynamics in carcinogenesis and tumor growth.

Science.gov (United States)

Gatenby, Robert A; Frieden, B Roy

2004-12-21

The storage and transmission of information is vital to the function of normal and transformed cells. We use methods from information theory and Monte Carlo theory to analyze the role of information in carcinogenesis. Our analysis demonstrates that, during somatic evolution of the malignant phenotype, the accumulation of genomic mutations degrades intracellular information. However, the degradation is constrained by the Darwinian somatic ecology in which mutant clones proliferate only when the mutation confers a selective growth advantage. In that environment, genes that normally decrease cellular proliferation, such as tumor suppressor or differentiation genes, suffer maximum information degradation. Conversely, those that increase proliferation, such as oncogenes, are conserved or exhibit only gain of function mutations. These constraints shield most cellular populations from catastrophic mutator-induced loss of the transmembrane entropy gradient and, therefore, cell death. The dynamics of constrained information degradation during carcinogenesis cause the tumor genome to asymptotically approach a minimum information state that is manifested clinically as dedifferentiation and unconstrained proliferation. Extreme physical information (EPI) theory demonstrates that altered information flow from cancer cells to their environment will manifest in-vivo as power law tumor growth with an exponent of size 1.62. This prediction is based only on the assumption that tumor cells are at an absolute information minimum and are capable of "free field" growth that is, they are unconstrained by external biological parameters. The prediction agrees remarkably well with several studies demonstrating power law growth in small human breast cancers with an exponent of 1.72+/-0.24. This successful derivation of an analytic expression for cancer growth from EPI alone supports the conceptual model that carcinogenesis is a process of constrained information degradation and that malignant

Antegrade Colonic Lavage in Acute Colonic Obstruction

OpenAIRE

Foster, Michael E.; Johnson, Colin D.

1986-01-01

Conventional management of acute left sided colonic obstruction employs some form of proximal colostomy. Intraoperative antegrade colonic irrigation relieves proximal faecal loading and may permit safer primary resection and anastomosis. The results of a pilot study are presented, and are shown to be favourable.

MiR-145 regulates PAK4 via the MAPK pathway and exhibits an antitumor effect in human colon cells

Energy Technology Data Exchange (ETDEWEB)

Wang, Zhigang [Department of General Surgery, Shanghai Jiaotong University Affiliated 6th People' s Hospital, Shanghai (China); Zhang, Xiaoping [Department of Nuclear Medicine, Shanghai 10th People' s Hospital, Tongji University School of Medicine (China); Yang, Zhili; Du, Hangxiang; Wu, Zhenqian; Gong, Jianfeng; Yan, Jun [Department of General Surgery, Shanghai Jiaotong University Affiliated 6th People' s Hospital, Shanghai (China); Zheng, Qi, E-mail: zhengqi1957@yahoo.com.cn [Department of General Surgery, Shanghai Jiaotong University Affiliated 6th People' s Hospital, Shanghai (China)

2012-10-26

Highlights: Black-Right-Pointing-Pointer MiR-145 targets a putative binding site in the 3 Prime UTR of PAK4. Black-Right-Pointing-Pointer MiR-145 played an important role in inhibiting cell growth by directly targeting PAK4. Black-Right-Pointing-Pointer MiR-145 may function as tumor suppressors. -- Abstract: MicroRNAs (miRNAs) are regulators of numerous cellular events; accumulating evidence indicates that miRNAs play a key role in a wide range of biological functions, such as cellular proliferation, differentiation, and apoptosis in cancer. Down-regulated expression of miR-145 has been reported in colon cancer tissues and cell lines. The molecular mechanisms underlying miR-145 and the regulation of colon carcinogenesis remain unclear. In this study, we investigated the levels of miR-145 in human colon cancer cells using qRT-PCR and found markedly decreased levels compared to normal epithelial cells. We identified PAK4 as a novel target of miR-145 using informatics screening. Additionally, we demonstrated that miR-145 targets a putative binding site in the 3 Prime UTR of PAK4 and that its abundance is inversely associated with miR-145 expression in colon cancer cells; we confirmed this relationship using the luciferase reporter assay. Furthermore, restoration of miR-145 by mimics in SW620 cells significantly attenuated cell growth in vitro, in accordance with the inhibitory effects induced by siRNA mediated knockdown of PAK4. Taken together, these findings demonstrate that miR-145 downregulates P-ERK expression by targeting PAK4 and leads to inhibition of tumor growth.

Can arbuscular mycorrhiza fungi and NPK fertilizer suppress nematodes and improve tuber yield of yam (Dioscorea rotundata ‘cv’ ewuru?

Directory of Open Access Journals (Sweden)

Gani Oladejo Kolawole

2018-04-01

Full Text Available Poor soil fertility and nematodes limit yam tuber yield and quality. Arbuscular mycorrhizal fungi (AMF and fertilizers may suppress nematodes and improve yam productivity. We evaluated the extent AMF and fertilizer suppressed nematodes and improved yam performance. Tuber weight, mycorrhizal colonization of roots and nematode populations were evaluated with eight treatments; Control (No amendments, 90-50-75, kg N- P2O5-K2O ha-1 (NPK, (AMF (2g/kg soil, nematodes (5000 juvenile/pot, and their combinations. Tuber weight was higher in NPK+AMF and NPK+nematode treatments than AMF+nematode. NPK+AMF improved tuber weight by 17.5% and 32% compared with sole NPK or AMF respectively. Compared with control, nematodes did not reduce tuber weight but, AMF+nematode reduced it by 49.4%. NPK reduced AMF colonization of roots and reduced nematode population on tuber, in roots and soil by 34%, 42.6% and 41% respectively. NPK+AMF treatment was superior to either NPK or AMF in improving tuber yield while NPK was superior to AMF in suppressing nematodes in roots, soil, and tuber.

Gibberellins interfere with symbiosis signaling and gene expression and alter colonization by arbuscular mycorrhizal fungi in Lotus japonicus.

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Takeda, Naoya; Handa, Yoshihiro; Tsuzuki, Syusaku; Kojima, Mikiko; Sakakibara, Hitoshi; Kawaguchi, Masayoshi

2015-02-01

Arbuscular mycorrhiza is a mutualistic plant-fungus interaction that confers great advantages for plant growth. Arbuscular mycorrhizal (AM) fungi enter the host root and form symbiotic structures that facilitate nutrient supplies between the symbionts. The gibberellins (GAs) are phytohormones known to inhibit AM fungal infection. However, our transcriptome analysis and phytohormone quantification revealed GA accumulation in the roots of Lotus japonicus infected with AM fungi, suggesting that de novo GA synthesis plays a role in arbuscular mycorrhiza development. We found pleiotropic effects of GAs on the AM fungal infection. In particular, the morphology of AM fungal colonization was drastically altered by the status of GA signaling in the host root. Exogenous GA treatment inhibited AM hyphal entry into the host root and suppressed the expression of Reduced Arbuscular Mycorrhization1 (RAM1) and RAM2 homologs that function in hyphal entry and arbuscule formation. On the other hand, inhibition of GA biosynthesis or suppression of GA signaling also affected arbuscular mycorrhiza development in the host root. Low-GA conditions suppressed arbuscular mycorrhiza-induced subtilisin-like serine protease1 (SbtM1) expression that is required for AM fungal colonization and reduced hyphal branching in the host root. The reduced hyphal branching and SbtM1 expression caused by the inhibition of GA biosynthesis were recovered by GA treatment, supporting the theory that insufficient GA signaling causes the inhibitory effects on arbuscular mycorrhiza development. Most studies have focused on the negative role of GA signaling, whereas our study demonstrates that GA signaling also positively interacts with symbiotic responses and promotes AM colonization of the host root. © 2015 American Society of Plant Biologists. All Rights Reserved.

Sewage sludge does not induce genotoxicity and carcinogenesis

Science.gov (United States)

Silva, Paula Regina Pereira; Barbisan, Luis Fernando; Dagli, Maria Lúcia Zaidan; Saldiva, Paulo Hilário Nascimento

2012-01-01

Through a series of experiments, the genotoxic/mutagenic and carcinogenic potential of sewage sludge was assessed. Male Wistar rats were randomly assigned to four groups: Group 1 - negative control; Group 2 - liver carcinogenesis initiated by diethylnitrosamine (DEN; 200 mg/kg i.p.); Group 3 and G4-liver carcinogenesis initiated by DEN and fed 10,000 ppm or 50,000 ppm of sewage sludge. The animals were submitted to a 70% partial hepatectomy at the 3rd week. Livers were processed for routine histological analysis and immunohistochemistry, in order to detect glutathione S-transferase positive altered hepatocyte foci (GST-P+ AHF). Peripheral blood samples for the comet assay were obtained from the periorbital plexus immediately prior to sacrificing. Polychromatic erythrocytes (PCEs) were analyzed in femoral bone-marrow smears, and the frequencies of those micronucleated (MNPCEs) registered. There was no sewage-sludge-induced increase in frequency of either DNA damage in peripheral blood leucocytes, or MNPCEs in the femoral bone marrow. Also, there was no increase in the levels of DNA damage, in the frequency of MNPCEs, and in the development of GST-P AHF when compared with the respective control group. PMID:23055806

Roles of stromal microenvironment in colon cancer progression.

Science.gov (United States)

Taketo, Makoto Mark

2012-05-01

Although our understanding of epithelial cancer cells has advanced significantly, our understanding of the cancer microenvironment is still fragmentary. In contrast to our intuitive impression that our body always suppresses cancer growth, recent pieces of evidence show that cancer often exploits our body reactions to expand, invade local tissues and metastasize to distant organs. Accordingly, investigations of such body reactions in the tumour microenvironment should help us to design novel therapeutic strategies that can be combined with the traditional therapeutics targeted at the cancer cells themselves. In this article, I am going to review our recent efforts in search of novel therapeutic strategies against colon cancer using mouse models.

Chemical peeling by SA-PEG remodels photo-damaged skin: suppressing p53 expression and normalizing keratinocyte differentiation.

Science.gov (United States)

Dainichi, Teruki; Amano, Satoshi; Matsunaga, Yukiko; Iriyama, Shunsuke; Hirao, Tetsuji; Hariya, Takeshi; Hibino, Toshihiko; Katagiri, Chika; Takahashi, Motoji; Ueda, Setsuko; Furue, Masutaka

2006-02-01

Chemical peeling with salicylic acid in polyethylene glycol vehicle (SA-PEG), which specifically acts on the stratum corneum, suppresses the development of skin tumors in UVB-irradiated hairless mice. To elucidate the mechanism through which chemical peeling with SA-PEG suppresses skin tumor development, the effects of chemical peeling on photodamaged keratinocytes and cornified envelopes (CEs) were evaluated in vivo. Among UVB-irradiated hairless mice, the structural atypia and expression of p53 protein in keratinocytes induced by UVB irradiation were intensely suppressed in the SA-PEG-treated mice 28 days after the start of weekly SA-PEG treatments when compared to that in the control UVB-irradiated mice. Incomplete expression of filaggrin and loricrin in keratinocytes from the control mice was also improved in keratinocytes from the SA-PEG-treated mice. In photo-exposed human facial skin, immature CEs were replaced with mature CEs 4 weeks after treatment with SA-PEG. Restoration of photodamaged stratum corneum by treatment with SA-PEG, which may affect remodeling of the structural environment of the keratinocytes, involved the normalization of keratinocyte differentiation and suppression of skin tumor development. These results suggest that the stratum corneum plays a protective role against carcinogenesis, and provide a novel strategy for the prevention of photo-induced skin tumors.

Time factors in radiation carcinogenesis

International Nuclear Information System (INIS)

Sasaki, Shunsaku

1995-01-01

Results of experiments using B6C3F 1 female mice were made subject of analysis on the time factors in radiation carcinogenesis. In the experiment for examination of influence of age at irradiation on the lifetime risk and on distribution of ages at death, mice were irradiated at day 12, 14 or 17 of the prenatal period, or day 0, 7, 35, 105, 240 or 365 of the postnatal period with doses ranging from 0.48 to 5.7 Gy gamma-rays from 137 Cs. In the experiment to examine the reduction factor for carcinogenic effect by multiple fractionation of gamma-rays dose 1.9 or 3.8 Gy was divided into 10 fractions, which were delivered once a week during period from 5 to 15 weeks of age. All mice were allowed to live out their life spans under a specific pathogen free condition. The cumulative relative risk for mortality from all causes except lymphoma and leukemia was shown to decrease with age when mice were irradiated at the fetal, neonatal, suckling, adolescent or young adult period, whereas, the decrease in the cumulative relative risk was very little when gamma-rays were given at the intermediate adult period. The lifetime risk for the increase in mortality and for the induction of solid tumors was highest in mice irradiated during neonatal, suckling or adolescent period. Age-dependence of susceptibility to radiation carcinogenesis was different for each type of neoplasm. However, the most susceptible period for induction of each type of neoplasm concentrated in the age from neonatal to adolescent period. Radiation-induced late effects were apparently reduced by multiple fractionation of radiation dose, but the reduction factor for the increase in the long-term mortality did not exceed 2.0. (author)

A novel NSAID derivative, phospho-ibuprofen, prevents AOM-induced colon cancer in rats

Science.gov (United States)

OUYANG, NENGTAI; JI, PING; WILLIAMS, JENNIE L.

2013-01-01

The cancer chemopreventive properties and gastrointestinal toxicity of ibuprofen are well documented. Modification of existing NSAIDs has improved on the chemopreventive efficacy of this agent and reduced its toxicity. In this study, ibuprofen and a modified derivative (phospho-modified ibuprofen or p-ibuprofen) were used in a chemically induced model of colon cancer. Fisher 344 rats were injected with azoxymethane then treated with either ibuprofen (500 ppm) or p-ibuprofen (900 ppm) for 20 weeks to observe aberrant crypt foci (ACF) or 40 weeks to evaluate tumor incidence and multiplicity. β-catenin and p65 were measured in colonic tissues by immunofluorescence staining. Equal molar doses of ibuprofen (75 and 670 mg/kg) and p-ibuprofen (135 and 1,215 mg/kg) were administered to rats for 7 days to assess acute toxicity. The in vitro effect of p-ibuprofen on COX-2 and PGE2 synthesis, β-catenin expression and NF-κB activity were examined in RAW 264.7 macrophage and HCT 116 colon cancer cells. At week 20, p-ibuprofen and ibuprofen significantly reduced the multiplicity of ACF compared with control (pibuprofen and ibuprofen reduced the multiplicity of colon tumors compared with control (pibuprofen (670 mg/kg) and p-ibuprofen (1,215 mg/kg) resulted in stomach ulceration in 85.7% (6 out of 7) and 14.3% (1 out of 7) of rats, respectively, with pibuprofen and p-ibuprofen suppressed β-catenin nuclear translocation in colon cancer cells. In addition, p-ibuprofen but not ibuprofen inhibited NF-κB activation in colon cancer cells. Collectively, these results suggest that p-ibuprofen is a potential effective novel drug for long-term use in colon cancer prevention. PMID:23291777

Uropathogenic E. coli Exploit CEA to Promote Colonization of the Urogenital Tract Mucosa

Science.gov (United States)

Muenzner, Petra; Kengmo Tchoupa, Arnaud; Klauser, Benedikt; Brunner, Thomas; Putze, Johannes; Dobrindt, Ulrich; Hauck, Christof R.

2016-01-01

Attachment to the host mucosa is a key step in bacterial pathogenesis. On the apical surface of epithelial cells, members of the human carcinoembryonic antigen (CEA) family are abundant glycoproteins involved in cell-cell adhesion and modulation of cell signaling. Interestingly, several gram-negative bacterial pathogens target these receptors by specialized adhesins. The prototype of a CEACAM-binding pathogen, Neisseria gonorrhoeae, utilizes colony opacity associated (Opa) proteins to engage CEA, as well as the CEA-related cell adhesion molecules CEACAM1 and CEACAM6 on human epithelial cells. By heterologous expression of neisserial Opa proteins in non-pathogenic E. coli we find that the Opa protein-CEA interaction is sufficient to alter gene expression, to increase integrin activity and to promote matrix adhesion of infected cervical carcinoma cells and immortalized vaginal epithelial cells in vitro. These CEA-triggered events translate in suppression of exfoliation and improved colonization of the urogenital tract by Opa protein-expressing E. coli in CEA-transgenic compared to wildtype mice. Interestingly, uropathogenic E. coli expressing an unrelated CEACAM-binding protein of the Afa/Dr adhesin family recapitulate the in vitro and in vivo phenotype. In contrast, an isogenic strain lacking the CEACAM-binding adhesin shows reduced colonization and does not suppress epithelial exfoliation. These results demonstrate that engagement of human CEACAMs by distinct bacterial adhesins is sufficient to blunt exfoliation and to promote host infection. Our findings provide novel insight into mucosal colonization by a common UPEC pathotype and help to explain why human CEACAMs are a preferred epithelial target structure for diverse gram-negative bacteria to establish a foothold on the human mucosa. PMID:27171273

Environmental carcinogenesis and genetic variability

International Nuclear Information System (INIS)

Knudsen, A.G. Jr

1977-01-01

It was found that carcinogenesis in man may involve the interaction of genetic and environmental forces, and that mutation, whether germinal or somatic, seems to be involved in the origin of many, perhaps all cancers. The cancers of man may be visualized as occurring in four groups of individuals according to whether (1) neither genetic nor environmental factors are dominant, i.e. 'background' or 'spontaneous' cancer, (2) heredity alone is dominant, (3) environment alone is important, or (4) both are operating (Knudsen, 1977). The last two groups together are widely thought to contribute 70-80% of cancer cases in the United States; the relative contribution of each group is a major question to be answered

Identification of downstream metastasis-associated target genes regulated by LSD1 in colon cancer cells.

Science.gov (United States)

Chen, Jiang; Ding, Jie; Wang, Ziwei; Zhu, Jian; Wang, Xuejian; Du, Jiyi

2017-03-21

This study aims to identify downstream target genes regulated by lysine-specific demethylase 1 (LSD1) in colon cancer cells and investigate the molecular mechanisms of LSD1 influencing invasion and metastasis of colon cancer. We obtained the expression changes of downstream target genes regulated by small-interfering RNA-LSD1 and LSD1-overexpression via gene expression profiling in two human colon cancer cell lines. An Affymetrix Human Transcriptome Array 2.0 was used to identify differentially expressed genes (DEGs). We screened out LSD1-target gene associated with proliferation, metastasis, and invasion from DEGs via Gene Ontology and Pathway Studio. Subsequently, four key genes (CABYR, FOXF2, TLE4, and CDH1) were computationally predicted as metastasis-related LSD1-target genes. ChIp-PCR was applied after RT-PCR and Western blot validations to detect the occupancy of LSD1-target gene promoter-bound LSD1. A total of 3633 DEGs were significantly upregulated, and 4642 DEGs were downregulated in LSD1-silenced SW620 cells. A total of 4047 DEGs and 4240 DEGs were upregulated and downregulated in LSD1-overexpressed HT-29 cells, respectively. RT-PCR and Western blot validated the microarray analysis results. ChIP assay results demonstrated that LSD1 might be negative regulators for target genes CABYR and CDH1. The expression level of LSD1 is negatively correlated with mono- and dimethylation of histone H3 lysine4(H3K4) at LSD1- target gene promoter region. No significant mono-methylation and dimethylation of H3 lysine9 methylation was detected at the promoter region of CABYR and CDH1. LSD1- depletion contributed to the upregulation of CABYR and CDH1 through enhancing the dimethylation of H3K4 at the LSD1-target genes promoter. LSD1- overexpression mediated the downregulation of CABYR and CDH1expression through decreasing the mono- and dimethylation of H3K4 at LSD1-target gene promoter in colon cancer cells. CABYR and CDH1 might be potential LSD1-target genes in colon

Carcinogenesis

International Nuclear Information System (INIS)

Fry, R.J.M.

1975-01-01

The long-term aims are concerned with various aspects of the natural history and biology of cancer, the mechanism of induction and of the advancement of time of appearance of tumors, the development of systems suitable for the assay of oncogenesis and cocarcinogenesis, and the elucidation of some of the factors important to the problem of extrapolation of estimates of risk made in experimental systems to the estimate of risk in man. It is necessary to have a number of test systems in order to study the various factors related to cocarcinogenesis; some of these are clearly tissue specific. The liver tumor system is clearly useful for certain compounds, and the liver is an excellent tissue for the study of the mechanisms of cocarcinogenesis. This year we report on the relatively rapid induction of what appears histologically to be carcinoma of the thyroid by aminotriazole. In a collaborative study with the Neutron and Gamma-Ray Toxicity Group, we have established a new example of synergism in carcinogenesis, namely between radiation and pituitary hormone(s) in the production of Harderian gland tumors. Not only does a synergistic effect on incidence occur, but also on the degree of malignancy of the tumor induced. We thus have three different model systems for the study of various aspects of cocarcinogenesis: various chemicals, including nononcogenic polycyclic hydrocarbons, in liver tumorigenesis; ionizing radiation and aminotriazole in thyroid tumorigenesis; and in conjunction with the JANUS Program, the interaction of radiation and hormones in the production of Harderian gland, mammary gland, and other tumors