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Sample records for dimethylhydrazine-induced colorectal carcinogenesis

  1. Synergistic impact of Lactobacillus fermentum, Lactobacillus plantarum and vincristine on 1,2-dimethylhydrazine-induced colorectal carcinogenesis in mice

    PubMed Central

    ASHA; GAYATHRI, DEVARAJA

    2012-01-01

    Lactobacillus sp. is the most dominant probiotic strain of bacteria. Evidence indicates that the consumption of Lactobacillus sp. reduces the risk of colorectal cancer in animal models. The present study was carried out to determine whether administration of Lactobacillus fermentum/ Lactobacillus plantarum alone or in combination with vincristine have a synergistic impact on the control of colorectal cancer in an animal model. Mice with 1,2 dimethylhydrazine (DMH) hydrochloride-induced colon cancer were fed with L. fermentum and L. plantarum isolated along with vincristine. An increase in body weight, a decrease in ammonia concentration, a decrease in β glucosidase and β glucuronidase enzyme activity and a reduction in the number of crypts in the mice in the pre-carcinogen-induced group was noted when compared to these variables in the post-carcinogen-induced group. The body weight of the mice fed L. fermentum along with vincristine was increased (6.5 g), and was found to be 3.5 times higher compared to that of the control. A marked decrease in the ammonia concentration (240 mg), and β glucosidase (0.0023 IU) and β glucopyranose enzyme activity (0.0027 IU) was observed; 22.59% less ammonia concentration, 73.26% less β glucosidase activity and 56.46% less β glucuronidase enzyme activity was noted when compared to the control. A significant reduction in the number of aberrant crypt foci (ACF) (90%) was observed when compared to the control. Maximum protection was observed in the mice fed the probiotics and vincristine prior to cancer induction. Among the different dietary combinations tested in the present study, L. fermentum and vincristine showed a more extensive reduction in ammonia concentration, β glucosidase, β glucuronidase activity and the number of ACF. PMID:22970015

  2. Polymeric black tea polyphenols inhibit 1,2-dimethylhydrazine induced colorectal carcinogenesis by inhibiting cell proliferation via Wnt/{beta}-catenin pathway

    SciTech Connect

    Patel, Rachana; Ingle, Arvind; Maru, Girish B.

    2008-02-15

    Tea polyphenols like epigallocatechin gallate and theaflavins are established chemopreventive agents for colorectal carcinogenesis. However, studies on evaluating similar chemopreventive properties of thearubigins or polymeric black tea polyphenols (PBPs), the most abundant polyphenols in black tea, are limited. Hence, in the present study we aim to investigate chemopreventive effects along with probable mechanisms of action of PBP extract employing 1,2-dimethylhydrazine (DMH)-induced colorectal carcinogenesis in Sprague-Dawley rats as experimental model. The present study suggests that PBPs, like other tea polyphenols, also inhibit DMH-induced colorectal tumorigenesis by decreasing tumor volume and multiplicity. This study also shows that although the pretreatment with PBP extract could induce detoxifying enzymes in hepatic and colorectal tissue, it did not show any additional chemopreventive effects when compared to treatments with PBP extract after initiation with DMH. Mechanistically, PBP extract may inhibit colorectal carcinogenesis by decreasing DMH-induced cell proliferation via Wnt/{beta}-catenin pathway. Treatments with PBP extract showed decreased levels of COX-2, c-MYC and cyclin D1 proteins which aid cell proliferation probably by regulating {beta}-catenin by maintaining expression of APC and decreasing inactivation of GSK3{beta}. DMH-induced activation of MAP kinases such as ERK and JNK was also found to be inhibited by treatments with PBP extract. In conclusion, the protective effects of PBP extract could be attributed to inhibition of DMH-induced cellular proliferation probably through {beta}-catenin regulation.

  3. Selenium as a modulator of membrane stability parameters and surface changes during the initiation phase of 1,2-dimethylhydrazine induced colorectal carcinogenesis.

    PubMed

    Ghadi, Fereshteh Ezzati; Malhotra, Anshoo; Ghara, Abdollah Ramzani; Dhawan, D K

    2012-10-01

    The present study evaluated the modulatory potential of selenium on colonic surface abnormalities and membrane fluidity changes following 1,2-dimethylhydrazine (DMH) induced colon carcinogenesis. Rats were segregated into four groups viz., normal control, DMH treated, selenium treated, and DMH + selenium treated. Initiation of molecular events leading to colon carcinogenesis was started following weekly subcutaneous injections of DMH (30 mg/Kg body weight) for 10 weeks. Selenium in the form of sodium selenite was supplemented to rats at a dose level of 1 PPM in drinking water, ad libitum for the entire duration of the study. Brush border membranes were isolated from the colon of rats and the viscosity as well as fluidity parameters were assessed using the membrane extrinsic fluorophore pyrene. DMH treatment resulted in a significant increase in lipid peroxidation. Reduced glutathione levels (GSH) and the activities of glutathione reductase (GR), glutathione transferase (GST), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were found to be significantly decreased following DMH treatment. On the other hand, supplementation with selenium to DMH treated rats resulted in a significant decrease in the levels of lipid peroxidation but caused a significant increase in the levels of GSH as well in the activities of GR, GST, SOD, CAT, and GPx. The results further, demonstrated a marked decrease in membrane microviscosity following DMH treatment. On the other hand, a significant increase was observed in the excimer/monomer ratio and fluidity parameter of DMH treated rats when compared to normal control rats. However, the alterations in membrane microviscosity and the fluidity parameters were significantly restored following selenium treatment. Further, histological as well as colon surface alterations were also observed following DMH treatment, which however were greatly prevented upon selenium co-administration. The study, therefore, concludes

  4. Probiotic Dahi containing Lactobacillus acidophilus and Bifidobacterium bifidum modulates the formation of aberrant crypt foci, mucin-depleted foci, and cell proliferation on 1,2-dimethylhydrazine-induced colorectal carcinogenesis in Wistar rats.

    PubMed

    Mohania, Dheeraj; Kansal, Vinod K; Kruzliak, Peter; Kumari, Archana

    2014-08-01

    Aberrant crypt foci (ACF) and mucin-depleted foci (MDF) are pre-neoplastic lesions identified in the colon of carcinogen-treated rodents and in humans at high risk for colon cancer. The present study was carried out to divulge the protective potential of the probiotic Dahi containing Lactobacillus acidophilus LaVK2 and Bifidobacterium bifidum BbVK3 alone or in combination with piroxicam (PXC) on the development of early biomarkers of colorectal carcinogenesis in male Wistar rats administered 1,2-dimethylhydrazine (DMH). DMH was injected subcutaneously at the rate of 40 mg/kg body weight per animal twice a week for 2 weeks. A total of 120 male Wistar rats were randomly allocated to five groups, each group having 24 animals. The rats were fed with buffalo milk or probiotic supplement (20 grams) alone or as an adjunct with PXC in addition to a basal diet ad libitum for 32 weeks. Group I was offered buffalo milk (BM) and served as the control group. Group II was administered DMH along with BM and served as the DMH-control group; group III was administered BM-DMH-PXC, in which besides administering BM-DMH, PXC was also offered. Group IV was offered probiotic LaBb Dahi and DMH, and group V was offered both probiotic LaBb Dahi and PXC along with DMH. The rats were euthanized at the 8(th), 16(th), and 32(nd) week of the experiment and examined for development of ACF, aberrant crypts per ACF (AC/ACF), mucin-depleted foci (MDF), large MDF, and proliferating cell nuclear antigen (PCNA) labeling index. Administration of DMH in rats induced pre-neoplastic lesions (ACF and MDF) and increased the PCNA index in colorectal tissue. A significant (p<0.05) reduction in the number of ACF, AC/ACF, MDF, large MDF, and PCNA labeling index were observed in the probiotic LaBb Dahi group compared with the DMH control group. Feeding rats with LaBb Dahi or treatment with PXC diminished the initiation and progression of DMH-induced pre-neoplastic lesions and the PCNA index, and treatment with

  5. Açai (Euterpe oleracea Mart.) feeding attenuates dimethylhydrazine-induced rat colon carcinogenesis.

    PubMed

    Fragoso, Mariana F; Romualdo, Guilherme R; Ribeiro, Daniel A; Barbisan, Luis F

    2013-08-01

    This study investigated the protective effect of spray-dried açaí powder (AP) intake on colon carcinogenesis induced by 1,2-dimethylhydrazine (DMH) in male Wistar rats. After 4 weeks of DMH administrations, the groups were fed with standard diet, a diet containing 2.5% or 5.0% AP or a diet containing 0.2% N-acetylcysteine (NAC) for 10 weeks, using aberrant crypt foci (ACF) as the endpoint. Additionally, two groups were fed with standard diet or a diet containing 5.0% AP for 20 weeks, using colon tumors as the endpoint. In ACF assay, a reduction in the number of aberrant crypts (ACs) and ACF (1-3 AC) were observed in the groups fed with 5.0% AP (37% AC and 47% ACF inhibition, p=0.036) and 0.2% NAC (39% AC and 41% ACF inhibition, p=0.042). In tumor assay, a reduction in the number of invasive tumors (p<0.005) and tumor multiplicity (p=0.001) was observed in the group fed with 5.0% AP. Also, a reduction in tumor Ki-67 cell proliferation (p=0.003) and net growth index (p=0.001) was observed in the group fed with 5.0% AP. Therefore the findings of this study indicate that AP feeding may reduce the development of chemically-induced rat colon carcinogenesis. PMID:23597449

  6. Luteolin supplementation adjacent to aspirin treatment reduced dimethylhydrazine-induced experimental colon carcinogenesis in rats.

    PubMed

    Osman, Neamt H A; Said, Usama Z; El-Waseef, Ahmed M; Ahmed, Esraa S A

    2015-02-01

    Previous studies have shown that aspirin is used in colon cancer treatment. However, long-term of Aspirin usage is limited to gastric and renal toxicity. Luteolin (LUT) has cancer prevention and anti-inflammatory effects. The present study was designed to investigate the effect of LUT supplementation and Aspirin treatment in dimethylhydrazine (DMH)-induced carcinogenesis in rats. DMH (20 mg/kg BW/week) treated rats received gavages with Aspirin (50 mg/kg BW/week) and LUT (0.2 mg/kg BW/day) for 15 weeks. DMH injections induce colon polyps and renal bleeding, significantly increasing carcinoembryonic antigen (CEA), cyclooxygenase-2 (COX-2), oxidative stress, and kidney function tests and reducing antioxidant markers. Either Aspirin or LUT gavages alone or combined produce a significant decrease in colon polyp number and size, significantly decreasing CEA, COX-2, and oxidative stress and increasing antioxidant markers. In conclusion, the supplementations of LUT adjacent to Aspirin in the treatment of DMH-induced carcinogenesis in rats reflect a better effect than the use of Aspirin alone. PMID:25342594

  7. Chemopreventive effect of sinapic acid on 1,2-dimethylhydrazine-induced experimental rat colon carcinogenesis.

    PubMed

    Balaji, C; Muthukumaran, J; Nalini, N

    2014-12-01

    Sinapic acid (SA) is a naturally occurring phenolic acid found in various herbal plants which is attributed with numerous pharmacological properties. This study was aimed to investigate the chemopreventive effect of SA on 1,2-dimethylhydrazine (DMH)-induced rat colon carcinogenesis. Rats were treated with DMH injections (20 mg kg(-1) bodyweight (b.w.) subcutaneously once a week for the first 4 consecutive weeks and SA (20, 40 and 80 mg kg(-1) b.w.) post orally for 16 weeks. At the end of the 16-week experimental period, all the rats were killed, and the tissues were evaluated biochemically. Our results reveal that DMH alone treatment decreased the levels/activities of lipid peroxidation by-products such as thiobarbituric acid reactive substances, conjugated dienes and antioxidants such as superoxide dismutase, catalase, glutathione reductase, glutathione peroxidase and reduced glutathione in the intestine and colonic tissues which were reversed on supplementation with SA. Moreover, the activities of drug-metabolizing enzymes of phase I (cytochrome P450 and P4502E1) were enhanced and those of phase II (glutathione-S-transferase, DT-diaphorase and uridine diphosphate glucuronosyl transferase) were diminished in the liver and colonic mucosa of DMH alone-treated rats and were reversed on supplementation with SA. All the above changes were supported by the histopathological observations of the rat liver and colon. These findings suggest that SA at the dose of 40 mg kg(-1) b.w. was the most effective dose against DMH-induced colon carcinogenesis, and thus, SA could be used as a potential chemopreventive agent. PMID:24532707

  8. Modulatory efficacy of rosmarinic acid on premalignant lesions and antioxidant status in 1,2-dimethylhydrazine induced rat colon carcinogenesis.

    PubMed

    Karthikkumar, V; Sivagami, G; Vinothkumar, R; Rajkumar, D; Nalini, N

    2012-11-01

    Colorectal cancer is one of the leading causes of cancer related deaths in Western countries and is becoming increasingly common in Asia. Rosmarinic acid (RA), one of the major components of polyphenol possesses attractive remedial features. The purpose of this study is to investigate the possible chemopreventive mechanism of action of RA against 1,2-dimethylhydrazine (DMH) induced rat colon carcinogenesis by evaluating the circulatory antioxidant status and colonic bacterial enzymes activities. Additionally, we analyzed the aberrant crypt foci (ACF) formation and multiplicity in the colon of experimental groups. Wistar male rats were divided into six groups. Group 1 was control rats, group 2 rats received RA (10 mg/kg b.w., p.o. everyday), rats in groups 3-6 received DMH (20 mg/kg b.w., s.c.) for the first 4 weeks. In addition to DMH, groups 4-6 received 2.5, 5, and 10 mg/kg b.w. RA respectively. The results revealed that supplementation with RA significantly reduced the formation of ACF and ACF multiplicity in DMH treated rats. Moreover RA supplementation prevented the alterations in circulatory antioxidant enzymes and colonic bacterial enzymes activities. Overall, our results showed that all three doses of RA inhibited carcinogenesis, though the effect of the intermediary dose of 5 mg/kg b.w. was more pronounced. PMID:22960260

  9. Chemopreventive Effects of Azadirachta indica on Cancer Marker Indices and Ultrastructural Changes During 1,2-Dimethylhydrazine-Induced Colon Carcinogenesis in Rats.

    PubMed

    Liu, Ning; Sun, Bo; Wu, Peiwei; Wei, Xi

    2015-09-01

    The present study elucidated the prospective of Azadirachta indica supplementation, if any, in affording chemoprevention by modulating the altered cancer markers and ultrastructural changes in DMH-induced colorectal carcinogenesis in rats. The rats were segregated into four groups viz., normal control, DMH treated, A. indica treated, and DMH+AI treated. Initiation and induction of colon carcinogenesis were achieved through weekly subcutaneous injections of DMH (30 mg/kg body weight) for both 10 and 20 weeks. A. indica extract was supplemented to rats at a dose rate of 100 mg/kg body weight of animals thrice a week on alternative days, ad libitum for two different time durations of 10 and 20 weeks. The study observed a significant increase in the number of aberrant crypt foci in colons of DMH-treated rats at both the time intervals which were decreased significantly upon AI supplementation. Also, a significant increase was seen in the enzyme activity of alkaline phosphatase, which, however, was moderated upon AI administration to DMH-treated rats. Changes in the ultrastructural architecture of colonic cells were apparent following both the treatment schedules of DMH; however, the changes were prominent following 20 weeks of DMH treatment. The most obvious changes were seen in the form of altered nuclear shape and disruption of cellular integrity, which were appreciably improved upon AI supplementation. In conclusion, the study shows the chemopreventive abilities of AI against DMH-induced colorectal carcinogenesis in rats. PMID:25697750

  10. Chemopreventive effect of Amorphophallus campanulatus (Roxb.) blume tuber against aberrant crypt foci and cell proliferation in 1, 2-dimethylhydrazine induced colon carcinogenesis.

    PubMed

    Ansil, Puthuparampil Nazarudeen; Prabha, Santhibhavan Prabhakaran; Nitha, Anand; Latha, Mukalel Sankunni

    2013-01-01

    Colorectal cancer is one of the leading causes of cancer death, both in men and women. This study investigated the effects of Amorphophallus campanulatus tuber methanolic extract (ACME) on aberrant crypt foci (ACF) formation, colonic cell proliferation, lipid peroxidative damage and the antioxidant status in a long term preclinical model of 1, 2-dimethylhydrazine (DMH) induced colon carcinogenesis in rats. Male Wistar rats were divided into six groups, viz., group I rats served as controls; group II rats treated as drug controls receiving 250 mg/ kg body weight of ACME orally; group III rats received DMH (20 mg/kg body weight) subcutaneously once a week for the first 15 weeks; groups IV, V and VI rats received ACME along with DMH during the initiation, post- initiation stages and the entire period of the study, respectively. All the rats were sacrificed at the end of 30 weeks and the intestinal and colonic tissues from different groups were subjected to biochemical and histological studies. Administration of DMH resulted in significant (p ≤ 0.05) intestinal and colonic lipid peroxidation (MDA) and reduction of antioxidants such as catalase, glutathione peroxidase, glutathione reductase, glutathione-S- transferase and reduced glutathione. Whereas the supplementation of ACME significantly (p ≤ 0.05) improved the intestinal and colonic MDA and reduced glutathione levels and the activities of antioxidant enzymes in DMH intoxicated rats. ACME administration also significantly suppressed the formation and multiplicity of ACF. In addition, the DMH administered rats showed amplified expression of PCNA in the colon and decreased expression of this proliferative marker was clearly noted with initiation, post-initiation and entire period of ACME treatment regimens. These results indicate that ACME could exert a significant chemopreventive effect on colon carcinogenesis induced by DMH. PMID:24175821

  11. The modulatory influence of p-methoxycinnamic acid, an active rice bran phenolic acid, against 1,2-dimethylhydrazine-induced lipid peroxidation, antioxidant status and aberrant crypt foci in rat colon carcinogenesis.

    PubMed

    Sivagami, Gunasekaran; Karthikkumar, Venkatachalam; Balasubramanian, Thangavel; Nalini, Namashivayam

    2012-03-01

    We investigated the chemopreventive effect of p-methoxycinnamic acid (p-MCA), an active phenolic acid of rice bran, turmeric, and Kaemperfia galanga against 1,2-dimethylhydrazine-induced rat colon carcinogenesis. Male albino Wistar rats were randomly divided into six groups. Group 1 consisted of control rats that received a modified pellet diet and 0.1% carboxymethyl cellulose. The rats in Group 2 received a modified pellet diet supplemented with p-MCA [80 mg/kg body weight (b.wt.) post-orally (p.o.)] everyday. The rats in Groups 3-6 received 1,2-dimethylhydrazine (DMH) (20 mg/kg b.wt.) via subcutaneous injections once a week for the first 4 weeks; additionally, the rats in Groups 4, 5 and 6 received p-MCA at doses of 20, 40 and 80 mg/kg b.wt./day p.o., respectively, everyday for 16 weeks. The rats were sacrificed at the end of the experimental period of 16 weeks. The DMH-treated rats exhibited an increased incidence of aberrant crypt foci (ACF) development; an increased crypt multiplicity; decreased concentrations of tissue lipid peroxidation markers such as thiobarbituric acid reactive substances (TBARS), conjugated dienes (CD) and lipid hydroperoxides (LOOH); decreased levels of tissue enzymic antioxidants such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR); and decreased levels of non-enzymic antioxidants such as reduced glutathione (GSH) and vitamins C, E and A in the colon. Supplementation with p-MCA significantly reversed these changes and significantly inhibited the formation of ACF and its multiplicity. Thus, our findings demonstrate that p-MCA exerts a strong chemopreventive activity against 1,2-dimethylhydrazine-induced colon carcinogenesis by virtue of its ability to prevent the alterations in DMH-induced circulatory and tissue oxidative stress and preneoplastic changes. p-MCA was more effective when administered at a dose of 40 mg/kg b.wt. than at the other two doses tested. PMID:22326950

  12. Effects of differing purified cellulose, pectin, and hemicellulose fiber diets on fecal enzymes in 1,2-dimethylhydrazine-induced rat colon carcinogenesis.

    PubMed

    Freeman, H J

    1986-11-01

    The fecal microflora enzymes, beta-glucuronidase and beta-glucosidase, as well as fecal bacterial counts, were examined during colon carcinogenesis in rats administered parenteral 1,2-dimethylhydrazine and fed nutritionally equivalent diets free of fiber or containing one of three single sources of dietary fiber (cellulose, hemicellulose, and pectin). Whereas pectin-fed animals had increased fecal beta-glucuronidase activities, those fed cellulose and hemicellulose, two fibers protective in dimethylhydrazine colon neoplasia, had decreased activities. Although fecal bacterial counts were not significantly changed, similar differential changes in fecal beta-glucosidase activity were noted: cellulose but not pectin or hemicellulose feeding was associated with reduced activity. Although cellulose fiber may cause differing physiological effects resulting in a reduction in colonic neoplasia development in this experimental animal model, decreased bacterial metabolic enzyme activation of carcinogens or cocarcinogens may lead to diminished exposure of colonic cells to exogenous or endogenous mutagens. PMID:3019527

  13. Oral supplementation with troxerutin (trihydroxyethylrutin), modulates lipid peroxidation and antioxidant status in 1,2-dimethylhydrazine-induced rat colon carcinogenesis.

    PubMed

    Vinothkumar, R; Vinoth Kumar, R; Karthikkumar, V; Viswanathan, P; Kabalimoorthy, J; Nalini, N

    2014-01-01

    The present study was aimed to investigate the chemopreventive potential of troxerutin on 1,2-dimethylhydrazine (DMH) induced rat colon carcinogenesis by evaluating the antioxidant and lipid peroxidation (LPO) status. Rats were randomly divided into six groups. Group I rats served as control. Group II rats received troxerutin (50 mg/kgb.w., p.o.) for 16 weeks. Groups III-VI rats received subcutaneous injections of DMH (20 mg/kgb.w., s.c.) once a week, for the first 4 weeks. In addition to DMH, groups IV-VI rats received troxerutin at the doses of 12.5, 25 and 50 mg/kgb.w., respectively. In DMH treated rats, our results showed decreased activities of antioxidants and increased levels of LPO in the liver. Moreover, LPO and antioxidants in the colon were found to be significantly diminished in DMH the treated rats. Furthermore, enhanced activity of colonic vitamin C and vitamin E levels were observed in DMH alone treated rats (group III), which was significantly reversed on troxerutin supplementation. Troxerutin at the dose of 25 mg/kgb.w. had shown profound beneficial effects by exhibiting near normal biochemical profile and well-preserved colon histology as compared to the other two tested doses (12.5 and 50 mg/kgb.w.). These findings suggest that troxerutin could serve as a novel agent for colon cancer chemoprevention. PMID:24355798

  14. The Tumor Microenvironment in Colorectal Carcinogenesis

    PubMed Central

    Peddareddigari, Vijay G.; Wang, Dingzhi

    2010-01-01

    Colorectal cancer is the second leading cause of cancer-related mortality in the United States. Therapeutic developments in the past decade have extended life expectancy in patients with metastatic disease. However, metastatic colorectal cancers remain incurable. Numerous agents that were demonstrated to have significant antitumor activity in experimental models translated into disappointing results in extending patient survival. This has resulted in more attention being focused on the contribution of tumor microenvironment to the progression of a number of solid tumors including colorectal cancer. A more complete understanding of interactions between tumor epithelial cells and their stromal elements will enhance therapeutic options and improve clinical outcome. Here we will review the role of various stromal components in colorectal carcinogenesis and discuss the potential of targeting these components for the development of future therapeutic agents. PMID:21209781

  15. Colorectal Carcinogenesis, Radiation Quality, and the Ubiquitin-Proteasome Pathway

    PubMed Central

    Datta, Kamal; Suman, Shubhankar; Kumar, Santosh; Fornace, Albert J

    2016-01-01

    Adult colorectal epithelium undergoes continuous renewal and maintains homeostatic balance through regulated cellular proliferation, differentiation, and migration. The canonical Wnt signaling pathway involving the transcriptional co-activator β-catenin is important for colorectal development and normal epithelial maintenance, and deregulated Wnt/β-catenin signaling has been implicated in colorectal carcinogenesis. Colorectal carcinogenesis has been linked to radiation exposure, and radiation has been demonstrated to alter Wnt/β-catenin signaling, as well as the proteasomal pathway involved in the degradation of the signaling components and thus regulation of β-catenin. The current review discusses recent progresses in our understanding of colorectal carcinogenesis in relation to different types of radiation and roles that radiation quality plays in deregulating β-catenin and ubiquitin-proteasome pathway (UPP) for colorectal cancer initiation and progression. PMID:26819641

  16. In vitro ¹⁴C-labeled amino acid uptake changes and surface abnormalities in the colon after 1,2-dimethylhydrazine-induced experimental carcinogenesis: protection by zinc.

    PubMed

    Chadha, Vijayta Dani; Dhawan, Devinder K

    2011-01-01

    The present study explored the regulatory role of zinc on the in vitro uptake of ¹⁴C-glucose and ¹⁴C-labeled amino acids and on colonic surface abnormalities after 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis. Rats were segregated into four groups: control, DMH-treated, zinc-treated, and DMH + zinc-treated. Colon carcinogenesis was induced through weekly subcutaneous injections of DMH (30 mg/kg body weight) for 16 weeks. Zinc (in the form of zinc sulfate) was given to rats at a dose level of 227 mg/L in their drinking water. DMH treatment caused a significant decrease in the activities of disaccharidases (sucrase, lactase, and maltase), but a significant increase in the activity of alkaline phosphatase. In vitro uptake of ¹⁴C-D-glucose and the amino acids ¹⁴C-glycine, ¹⁴C-alanine, ¹⁴C-lysine, and ¹⁴C-leucine were significantly higher in the colons of DMH-treated rats. Zinc supplementation of DMH-treated rats resulted in regulating the altered intestinal enzyme activities and in vitro uptake of ¹⁴C-amino acids and ¹⁴C-glucose. Scanning electron microscopy revealed drastic alterations in the colon surface morphology after DMH treatment, which were restored after zinc supplementation. Our results confirm a beneficial effect of zinc against DMH-induced alterations in the colons of rats. PMID:21967455

  17. Colorectal cancer carcinogenesis: a review of mechanisms

    PubMed Central

    Tariq, Kanwal; Ghias, Kulsoom

    2016-01-01

    Colorectal cancer (CRC) is the second most common cancer in women and the third most common in men globally. CRC arises from one or a combination of chromosomal instability, CpG island methylator phenotype, and microsatellite instability. Genetic instability is usually caused by aneuploidy and loss of heterozygosity. Mutations in the tumor suppressor or cell cycle genes may also lead to cellular transformation. Similarly, epigenetic and/or genetic alterations resulting in impaired cellular pathways, such as DNA repair mechanism, may lead to microsatellite instability and mutator phenotype. Non-coding RNAs, more importantly microRNAs and long non-coding RNAs have also been implicated at various CRC stages. Understanding the specific mechanisms of tumorigenesis and the underlying genetic and epigenetic traits is critical in comprehending the disease phenotype. This paper reviews these mechanisms along with the roles of various non-coding RNAs in CRCs. PMID:27144067

  18. Colorectal carcinogenesis-update and perspectives

    PubMed Central

    Raskov, Hans; Pommergaard, Hans-Christian; Burcharth, Jakob; Rosenberg, Jacob

    2014-01-01

    Colorectal cancer (CRC) is a very common malignancy in the Western World and despite advances in surgery, chemotherapy and screening, it is still the second leading cause of cancer deaths in this part of the world. Numerous factors are found important in the development of CRC including colonocyte metbolism, high risk luminal environment, inflammation, as well as lifestyle factors such as diet, tobacco, and alchohol consumption. In recent years focus has turned towards the genetics and molecular biology of CRC and several interesting and promising correlations and pathways have been discovered. The major genetic pathways of CRC are the Chromosome Instability Pathway representing the pathway of sporadic CRC through the K-ras, APC, and P53 mutations, and the Microsatellite Instability Pathway representing the pathway of hereditary non-polyposis colon cancer through mutations in mismatch repair genes. To identify early cancers, screening programs have been initiated, and the leading strategy has been the use of faecal occult blood testing followed by colonoscopy in positive cases. Regarding the treatment of colorectal cancer, significant advances have been made in the recent decade. The molecular targets of CRC include at least two important cell surface receptors: the epidermal growth factor receptor and the vascular endothelial growth factor receptor. The genetic and molecular knowledge of CRC has widen the scientific and clinical perspectives of diagnosing and treatment. However, despite significant advances in the understanding and treatment of CRC, results from targeted therapy are still not convincing. Future studies will determine the role for this new treatment modality. PMID:25561783

  19. Differential colorectal carcinogenesis: Molecular basis and clinical relevance.

    PubMed

    Morán, Alberto; Ortega, Paloma; de Juan, Carmen; Fernández-Marcelo, Tamara; Frías, Cristina; Sánchez-Pernaute, Andrés; Torres, Antonio José; Díaz-Rubio, Eduardo; Iniesta, Pilar; Benito, Manuel

    2010-03-15

    Colorectal cancer (CCR) is one of the most frequent cancers in developed countries. It poses a major public health problem and there is renewed interest in understanding the basic principles of the molecular biology of colorectal cancer. It has been established that sporadic CCRs can arise from at least two different carcinogenic pathways. The traditional pathway, also called the suppressor or chromosomal instability pathway, follows the Fearon and Vogelstein model and shows mutation in classical oncogenes and tumour suppressor genes, such as K-ras, adenomatous polyposis coli, deleted in colorectal cancer, or p53. Alterations in the Wnt pathway are also very common in this type of tumour. The second main colorectal carcinogenesis pathway is the mutator pathway. This pathway is present in nearly 15% of all cases of sporadic colorectal cancer. It is characterized by the presence of mutations in the microsatellite sequences caused by a defect in the DNA mismatch repair genes, mostly in hMLH1 or hMSH2. These two pathways have clear molecular differences, which will be reviewed in this article, but they also present distinct histopathological features. More strikingly, their clinical behaviours are completely different, having the "mutator" tumours a better outcome than the "suppressor" tumours. PMID:21160823

  20. Role of Fusobacteria in the serrated pathway of colorectal carcinogenesis

    PubMed Central

    Park, Chan Hyuk; Han, Dong Soo; Oh, Young-Ha; Lee, A-reum; Lee, Yu-ra; Eun, Chang Soo

    2016-01-01

    Fusobacteria are associated with colorectal cancer (CRC) and are amplified during colorectal carcinogenesis. Compared to the adenoma-carcinoma sequence of carcinogenesis, serrated neoplasm has distinct clinical features and a different molecular background. We aimed to compare the gut microbiome between tubular adenoma (TA) and sessile serrated adenoma/polyp (SSA/P). Patients with TA, SSA/P, or CRC were recruited. Three pieces of colorectal mucosal tissue were obtained from each patient by endoscopic biopsy. 16S rRNA gene pyrosequencing and phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) were performed. Among 26 enrolled patients, 8, 10, and 8 had TA, SSA/P, and CRC, respectively. The relative abundance of Fusobacteria did not differ significantly between the TA and SSA/P groups (4.3% and 1.9%, P = 0.739) but was higher in the CRC group (33.8%) than in the TA or SSA/P group, respectively (TA vs. CRC, P = 0.002, false discovery rate [FDR] = 0.023; SSA/P vs. CRC, P < 0.001, FDR = 0.001). PICRUSt revealed that most functions in the TA metagenome were similar to those in the SSA/P metagenome. The gut microbiome, including relative abundance of Fusobacteria, did not differ between TA and SSA/P, suggesting that Fusobacteria may contribute to both the serrated pathway and the adenoma-carcinoma sequence. PMID:27125587

  1. Role of S100 Proteins in Colorectal Carcinogenesis

    PubMed Central

    Moravkova, Paula; Kohoutova, Darina; Rejchrt, Stanislav; Cyrany, Jiri; Bures, Jan

    2016-01-01

    The family of S100 proteins represents 25 relatively small (9–13 kD) calcium binding proteins. These proteins possess a broad spectrum of important intracellular and extracellular functions. Colorectal cancer is the third most common cancer in men (after lung and prostate cancer) and the second most frequent cancer in women (after breast cancer) worldwide. S100 proteins are involved in the colorectal carcinogenesis through different mechanisms: they enable proliferation, invasion, and migration of the tumour cells; furthermore, S100 proteins increase angiogenesis and activate NF-κβ signaling pathway, which plays a key role in the molecular pathogenesis especially of colitis-associated carcinoma. The expression of S100 proteins in the cancerous tissue and serum levels of S100 proteins might be used as a precise diagnostic and prognostic marker in patients with suspected or already diagnosed colorectal neoplasia. Possibly, in the future, S100 proteins will be a therapeutic target for tailored anticancer therapy. PMID:26880885

  2. Thrombospondin-1 in a Murine Model of Colorectal Carcinogenesis

    PubMed Central

    Lopez-Dee, Zenaida P.; Chittur, Sridar V.; Patel, Hiral; Chinikaylo, Aleona; Lippert, Brittany; Patel, Bhumi; Lawler, Jack; Gutierrez, Linda S.

    2015-01-01

    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. PMID:26461935

  3. Modifier-concept of colorectal carcinogenesis: Lipidomics as a technical tool in pathway analysis

    PubMed Central

    Gassler, Nikolaus; Klaus, Christina; Kaemmerer, Elke; Reinartz, Andrea

    2010-01-01

    In the modifier concept of intestinal carcinogenesis, lipids have been established as important variables and one focus is given to long-chain fatty acids. Increased consumption of long-chain fatty acids is in discussion to modify the development of colorectal carcinoma in humans. Saturated long-chain fatty acids, in particular, are assumed to promote carcinogenesis, whereas polyunsaturated forms are likely to act in the opposite way. At present, the molecular mechanisms behind these effects are not well understood. Recently, it has been demonstrated by lipidomics and associated molecular techniques, that activation and metabolic channeling of long-chain fatty acids are important mechanisms to modify colorectal carcinogenesis. In this Editorial, an overview about the present concept of long-chain fatty acids and its derivatives in colorectal carcinogenesis as well as technical algorithms in lipid analysis is given. PMID:20397257

  4. Mitochondrial D310 mutations in colorectal adenomas: an early but not causative genetic event during colorectal carcinogenesis.

    PubMed

    Legras, Antoine; Lièvre, Astrid; Bonaiti-Pellié, Catherine; Cottet, Vanessa; Pariente, Alexandre; Nalet, Bernard; Lafon, Jacques; Faivre, Jean; Bonithon-Kopp, Claire; Goasguen, Nicolas; Penna, Christophe; Olschwang, Sylviane; Laurent-Puig, Pierre

    2008-05-15

    Somatic mutations of the D310 sequence of the mitochondrial DNA are reported in human cancers, including colorectal cancers (CRC). The presence of these mutations at early or late steps of colorectal carcinogenesis is unknown. Their prevalence increased significantly with the number of cytosines in the D310 sequence of the matched normal tissue (D310 polymorphism), suggesting that this polymorphism could be a risk factor for CRC. The aim of this study was (i) to investigate the prevalence of D310 mutations in 64 colorectal adenomas and 36 liver metastases from 15 CRC patients, (ii) to assess the relation between D310 polymorphism and the risk of colorectal adenoma in a case-control study including 613 cases with colorectal adenoma and 572 polyp-free (PF) controls. D310 mutations were found in colorectal adenomas and liver metastases from CRC patients in 27 and 33%, respectively and so are an early genetic event in colorectal carcinogenesis. The frequency of the mutations increased significantly with the number of cytosines in the matched normal tissue D310 sequence (p < 0.001) but the distribution of D310 polymorphisms was not significantly different between adenoma cases (large (>9 mm) and small (<5 mm) adenomas) and PF controls (C(4)-C(7)TC(6): 47, 52 and 49%; C(8)TC(6): 44, 39 and 41%; C(9)-C(10)TC(6): 9, 9 and 10%, respectively; p > 0.05), suggesting that germline D310 polymorphism is not a risk factor for colorectal adenomas. Considering their high frequency in colorectal adenomas, mitochondrial D310 mutations could represent a biomarker for early detection of CRC although their causative role in colorectal carcinogenesis remains uncertain. PMID:18224678

  5. Cimetidine and Clobenpropit Attenuate Inflammation-Associated Colorectal Carcinogenesis in Male ICR Mice

    PubMed Central

    Tanaka, Takuji; Kochi, Takahiro; Shirakami, Yohei; Mori, Takayuki; Kurata, Ayumi; Watanabe, Naoki; Moriwaki, Hisataka; Shimizu, Masahito

    2016-01-01

    Histamine and histamine receptors (Hrhs) have been identified as critical molecules during inflammation and carcinogenesis. This study was conducted to determine the effects of Hrh1-Hrh3 antagonists on inflammation-associated colorectal carcinogenesis. Male ICR mice were treated with azoxymethane (AOM, 10 mg/kg bw, i.p.) and 1.5% dextran sodium sulfate (DSS, drinking water for 7 days) to induce colorectal carcinogenesis. The mice were then fed diets containing test chemical (500 ppm terfenadine, 500 ppm cimetidine or 10 ppm clobenpropit) for 15 weeks. At week 18, feeding with the diets containing cimetidine (Hrh2 antagonist) and clobenpropit (Hrh3 antagonist/inverse agonist) significantly lowered the multiplicity of colonic adenocarcinoma. Terfenadine (Hrh1 antagonist) did not affect AOM-DSS-induced colorectal carcinogenesis. Adenocarcinoma cells immunohistochemically expressed Hrh1, Hrh2, Hrh3 and Hrh4 with varied intensities. Because clobenpropit is also known to be a Hrh4 receptor agonist, Hrh2, Hrh3 and Hrh4 may be involved in inflammation-related colorectal carcinogenesis. Additional data, including the mRNA expression of pro-inflammatory cytokines and inducible inflammatory enzymes in the colonic mucosa, are also presented. PMID:26907350

  6. A review of dietary factors and its influence on DNA methylation in colorectal carcinogenesis.

    PubMed

    Arasaradnam, R P; Commane, D M; Bradburn, D; Mathers, J C

    2008-01-01

    Colorectal cancer (CRC) is the most common cancer in non-smokers posing a significant health burden in the UK. Observational studies lend support to the impact of environmental factors especially diet on colorectal carcinogenesis. Significant advances have been made in understanding the biology of CRC carcinogenesis in particular epigenetic modifications such as DNA methylation. DNA methylation is thought to occur at least as commonly as inactivation of tumor suppressor genes. In fact compared with other human cancers, promoter gene methylation occurs most commonly within the gastrointestinal tract. Emerging data suggest the direct influence of certain micronutrients for example folic acid, selenium as well as interaction with toxins such as alcohol on DNA methylation. Such interactions are likely to have a mechanistic impact on CRC carcinogenesis through the methylation pathway but also, may offer possible therapeutic potential as nutraceuticals. PMID:18682688

  7. Dissecting characteristics and dynamics of differentially expressed proteins during multistage carcinogenesis of human colorectal cancer

    PubMed Central

    Peng, Fang; Huang, Ying; Li, Mao-Yu; Li, Guo-Qing; Huang, Hui-Chao; Guan, Rui; Chen, Zhu-Chu; Liang, Song-Ping; Chen, Yong-Heng

    2016-01-01

    AIM: To discover novel biomarkers for early diagnosis, prognosis or treatment of human colorectal cancer. METHODS: iTRAQ 2D LC-MS/MS analysis was used to identify differentially expressed proteins (DEPs) in the human colonic epithelial carcinogenic process using laser capture microdissection-purified colonic epithelial cells from normal colon, adenoma, carcinoma in situ and invasive carcinoma tissues. RESULTS: A total of 326 DEPs were identified, and four DEPs (DMBT1, S100A9, Galectin-10, and S100A8) with progressive alteration in the carcinogenic process were further validated by immunohistochemistry. The DEPs were involved in multiple biological processes including cell cycle, cell adhesion, translation, mRNA processing, and protein synthesis. Some of the DEPs involved in cellular process such as “translation” and “mRNA splicing” were progressively up-regulated, while some DEPs involved in other processes such as “metabolism” and “cell response to stress” was progressively down-regulated. Other proteins with up- or down-regulation at certain stages of carcinogenesis may play various roles at different stages of the colorectal carcinogenic process. CONCLUSION: These findings give insights into our understanding of the mechanisms of colorectal carcinogenesis and provide clues for further investigation of carcinogenesis and identification of biomarkers. PMID:27182161

  8. Gut mucosal microbiome across stages of colorectal carcinogenesis

    PubMed Central

    Nakatsu, Geicho; Li, Xiangchun; Zhou, Haokui; Sheng, Jianqiu; Wong, Sunny Hei; Wu, William Ka Kai; Ng, Siew Chien; Tsoi, Ho; Dong, Yujuan; Zhang, Ning; He, Yuqi; Kang, Qian; Cao, Lei; Wang, Kunning; Zhang, Jingwan; Liang, Qiaoyi; Yu, Jun; Sung, Joseph J. Y.

    2015-01-01

    Gut microbial dysbiosis contributes to the development of colorectal cancer (CRC). Here we catalogue the microbial communities in human gut mucosae at different stages of colorectal tumorigenesis. We analyse the gut mucosal microbiome of 47 paired samples of adenoma and adenoma-adjacent mucosae, 52 paired samples of carcinoma and carcinoma-adjacent mucosae and 61 healthy controls. Probabilistic partitioning of relative abundance profiles reveals that a metacommunity predominated by members of the oral microbiome is primarily associated with CRC. Analysis of paired samples shows differences in community configurations between lesions and the adjacent mucosae. Correlations of bacterial taxa indicate early signs of dysbiosis in adenoma, and co-exclusive relationships are subsequently more common in cancer. We validate these alterations in CRC-associated microbiome by comparison with two previously published data sets. Our results suggest that a taxonomically defined microbial consortium is implicated in the development of CRC. PMID:26515465

  9. Molecular biomarkers of colorectal carcinogenesis and their role in surveillance and early intervention.

    PubMed

    Garcea, G; Sharma, R A; Dennison, A; Steward, W P; Gescher, A; Berry, D P

    2003-05-01

    Modern medicine is increasingly focused towards population surveillance for disease, coupled with the implementation of preventative measures applied to 'at-risk' patients. Surveillance in colorectal cancer is limited by the cost and risk of endoscopy. Trials of putative chemopreventive agents in colorectal cancer are hampered by difficulties in following up large cohorts of patients over long periods of time to ascertain the clinical effect. Research into possible pathways of colorectal carcinogenesis has revealed a range of biological intermediates which could be used in surveillance, the identification of high risk populations and early diagnosis of cancer. The aim of this paper was to review the possible role of biomarkers in surveillance and the timing of intervention. A literature review using both Medline and Web of Science was performed from 1995 onwards using keywords: biomarkers, colorectal cancer, carcinogenesis, chemoprevention, surveillance and screening. Research has identified many potential biomarkers, such as cyclooxygenase-2 (COX-2), oxidative DNA adducts and glutathione S-transferase (GST) polymorphisms, which could be applied in a clinical setting to screen for and detect colorectal cancer. Molecular biomarkers, such as COX-2, oxidative DNA adducts and GST polymorphisms offer new prospects in the detection of early colorectal cancer, surveillance of high-risk populations and prediction of the clinical effectiveness of chemopreventive drugs. Their role could be extended into surgical surveillance for potentially operable disease and post-operative follow-up for disease recurrence. Research should be directed at assessing complementary biomarkers to increase clinical effectiveness in determining management options for patients. PMID:12736102

  10. Characterization of hERG1 channel role in mouse colorectal carcinogenesis.

    PubMed

    Fiore, Antonella; Carraresi, Laura; Morabito, Angela; Polvani, Simone; Fortunato, Angelo; Lastraioli, Elena; Femia, Angelo P; De Lorenzo, Emanuele; Caderni, Giovanna; Arcangeli, Annarosa

    2013-10-01

    The human ether-à-go-go-related gene (hERG)1 K(+) channel is upregulated in human colorectal cancer cells and primary samples. In this study, we examined the role of hERG1 in colorectal carcinogenesis using two mouse models: adenomatous polyposis coli (Apc(min/+) ) and azoxymethane (AOM)-treated mice. Colonic polyps of Apc(min/+) mice overexpressed mERG1 and their formation was reverted by the hERG1 blocker E4031. AOM was applied to either hERG1-transgenic (TG) mice, which overexpress hERG1 in the mucosa of the large intestine, or wild-type mice. A significant increase of both mucin-depleted foci and polyps in the colon of hERG1-TG mice was detected. Both the intestine of TG mice and colonic polyps of Apc(min/+) showed an upregulation of phospho-Protein Kinase B (pAkt)/vascular endothelial growth factor (VEGF-A) and an increased angiogenesis, which were reverted by treatment with E4031. On the whole, this article assigns a relevant role to hERG1 in the process of in vivo colorectal carcinogenesis. PMID:24403225

  11. Colorectal carcinogenesis: a cellular response to sustained risk environment.

    PubMed

    Fung, Kim Y C; Ooi, Cheng Cheng; Zucker, Michelle H; Lockett, Trevor; Williams, Desmond B; Cosgrove, Leah J; Topping, David L

    2013-01-01

    The current models for colorectal cancer (CRC) are essentially linear in nature with a sequential progression from adenoma through to carcinoma. However, these views of CRC development do not explain the full body of published knowledge and tend to discount environmental influences. This paper proposes that CRC is a cellular response to prolonged exposure to cytotoxic agents (e.g., free ammonia) as key events within a sustained high-risk colonic luminal environment. This environment is low in substrate for the colonocytes (short chain fatty acids, SCFA) and consequently of higher pH with higher levels of free ammonia and decreased mucosal oxygen supply as a result of lower visceral blood flow. All of these lead to greater and prolonged exposure of the colonic epithelium to a cytotoxic agent with diminished aerobic energy availability. Normal colonocytes faced with this unfavourable environment can transform into CRC cells for survival through epigenetic reprogramming to express genes which increase mobility to allow migration and proliferation. Recent data with high protein diets confirm that genetic damage can be increased, consistent with greater CRC risk. However, this damage can be reversed by increasing SCFA supply by feeding fermentable fibre as resistant starch or arabinoxylan. High protein, low carbohydrate diets have been shown to alter the colonic environment with lower butyrate levels and apparently greater mucosal exposure to ammonia, consistent with our hypothesis. Evidence is drawn from in vivo and in vitro genomic and biochemical studies to frame experiments to test this proposition. PMID:23807509

  12. Mitotic crossover--an evolutionary rudiment which promotes carcinogenesis of colorectal carcinoma.

    PubMed

    Rovcanin, Branislav; Ivanovski, Ivan; Djuric, Olivera; Nikolic, Dimitrije; Petrovic, Jelena; Ivanovski, Petar

    2014-09-21

    Mitotic crossover is a natural mechanism that is a main source of the genetic variability of primitive organisms. In complex organisms such as mammals, it represents an evolutionary rudiment which persisted as one of the numerous DNA repair mechanisms, and results in the production of homozygous allele combinations in all heterozygous genes located on the chromosome arm distal to the crossover. This event is familiar as loss of heterozygosity, which is one of the key mechanisms responsible for the development and progression of almost all cancers. We propose the hypothesis in which mitotic crossover is a principal source of the increased loss of heterozygosity that leads to the initiation and progression of colorectal carcinoma. The hypothesis could be tested by in vitro inhibition of Rad51 protein, orthotopic grafting of human colon cancer tissue into the gut of mice, and treatment with potential inhibitors. After these procedures, the frequency of mitotic crossover would be estimated. The development of selective inhibitors of mitotic crossover could stop further carcinogenesis of colorectal carcinoma, as well as many other neoplastic events. Loss of heterozygosity is an event responsible for carcinogenesis, its reduction by selective inhibitors of mitotic crossover could have a positive effect on cancer chemoprevention, as well as on growth reduction and a cessation in the progression of earlier developed tumors. PMID:25253953

  13. Kimchi Protects Against Azoxymethane/Dextran Sulfate Sodium–Induced Colorectal Carcinogenesis in Mice

    PubMed Central

    Kim, Hee-Young; Song, Jia-Le; Chang, Hee-Kyung; Kang, Soon-Ah

    2014-01-01

    Abstract The chemopreventive effects of different types and quantities of kimchi prepared with different subingredients, including commercial kimchi (CK), standardized kimchi (SK), cancer-preventive kimchi (CPK), and anticancer kimchi (ACK), on colorectal carcinogenesis in mice were evaluated. The development of colon cancer was induced in male BALB/c mice with a single intraperitoneal injection of azoxymethane (AOM, 10 mg/kg body weight) and subsequent treatment with 2% dextran sulfate sodium (DSS) in drinking water for 7 days for two cycles. After exposure to AOM and DSS, treatment with the methanolic extracts from different kimchis, particularly 1.89 g/kg of ACK, significantly increased colon length, decreased the ratio of colon weight/length, and resulted in the lowest number of tumors compared with the other kimchi-treated groups. Histological observation revealed that ACK was able to suppress AOM- and DSS-induced colonic mucosal damage and neoplasia. ACK also significantly decreased the mRNA levels of proinflammatory cytokines (TNF-α, IL-6, and IFN-γ) as well as the mRNA and protein expression of inducible nitric oxide synthase and cyclooxygenase-2 (COX-2). In addition, the mRNA and protein expression of p53 and p21 was elevated in colon tissues from the ACK-treated mice compared with the other kimchi-treated groups. Our results suggest that kimchi exerted a suppressive effect on AOM- and DSS-induced colorectal carcinogenesis in the BALB/c mice. The anticancer effects of ACK were particularly potent. Thus, it is possible that the health-promoting subingredients added to ACK might be used to prevent colon carcinogenesis in humans. PMID:25029638

  14. TGF-beta during human colorectal carcinogenesis: the shift from epithelial to mesenchymal signaling.

    PubMed

    Matsuzaki, K; Seki, T; Okazaki, K

    2006-12-01

    Transforming growth factor-beta (TGF-beta) activates not only TGF-beta type I receptor (Tbeta RI) but also c-Jun N-terminal kinase (JNK), converting the mediator Smad3 to two distinct phosphoisoforms: C-terminally phosphorylated Smad3 (pSmad3C) and linker phosphorylated Smad3 (pSmad3L). While Tbeta RI/pSmad3C pathway inhibits growth of normal epithelial cells, the activated mesenchymal cells invade via JNK/pSmad3L pathway. During sporadic human colorectal carcinogenesis, TGF-beta signaling confers a selective advantage upon tumor cells by shifting from epithelial Tbeta RI/pSmad3C pathway to mesenchymal JNK/pSmad3L pathway. Loss of epithelial homeostasis and acquisition of a migratory, mesenchymal phenotype are essential for tumor invasion. In a future, specific inhibition of the JNK/pSmad3L pathway will become a therapy for human colorectal cancer that restores the lost tumor-suppressive function observed in normal colorectal epithelial cells at the expense of effects promoting the aggressive behavior. PMID:17093904

  15. Smad3 phosphoisoform-mediated signaling during sporadic human colorectal carcinogenesis.

    PubMed

    Matsuzaki, K

    2006-06-01

    Transforming growth factor-beta (TGF-beta) signaling occurring during human colorectal carcinogenesis involves a shift in TGF-beta function, reducing the cytokine's antiproliferative effect, while increasing actions that promote invasion and metastasis. TGF-beta signaling involves phosphorylation of Smad3 at serine residues 208 and 213 in the linker region and serine residues 423 and 425 in the C-terminal region. Exogenous TGF-beta activates not only TGF-beta type I receptor (TbetaRI) but also c-Jun N-terminal kinase (JNK), changing unphosphorylated Smad3 to its phosphoisoforms: C-terminally phosphorylated Smad3 (pSmad3C) and linker phosphorylated Smad3 (pSmad3L). Either pSmad3C or pSmad3L oligomerizes with Smad4, and translocates into nuclei. While the TbetaRI/pSmad3C pathway inhibits growth of normal epithelial cells in vivo, JNK/pSmad3L-mediated signaling promotes tumor cell invasion and extracellular matrix synthesis by activated mesenchymal cells. Furthermore, hepatocyte growth factor signaling interacts with TGF-beta to activate the JNK/pSmad3L pathway, accelerating nuclear transport of cytoplasmic pSmad3L. This reduces accessibility of unphosphorylated Smad3 to membrane-anchored TbetaRI, preventing Smad3C phosphorylation, pSmad3C-mediated transcription, and antiproliferative effects of TGF-beta on epithelial cells. As neoplasia progresses from normal colorectal epithelium through adenoma to invasive adenocarcinoma with distant metastasis, nuclear pSmad3L gradually increases while pSmad3C decreases. The shift from TbetaRI/pSmad3C-mediated to JNK/pSmad3L-mediated signaling is a major mechanism orchestrating a complex transition of TGF-beta signaling during sporadic human colorectal carcinogenesis. This review summarizes the recent understanding of Smad3 phosphoisoform-mediated signaling, particularly 'cross-talk' between Smad3 and JNK pathways that cooperatively promote oncogenic activities. Understanding of these actions should help to develop more effective

  16. Morphological and cell kinetic effects of dietary manipulation during colorectal carcinogenesis.

    PubMed Central

    Galloway, D J; Jarrett, F; Boyle, P; Indran, M; Carr, K; Owen, R W; George, W D

    1987-01-01

    The effect of dietary manipulation of fat and fibre on the structural and cell kinetic characteristics of colonic mucosa was studied before and during experimental carcinogenesis in 232 male Albino Swiss rats. Carcinogen treated animals were given 12 weekly injections of azoxymethane (10 mg/kg/week). The animals were divided between four dietary groups (1) high fat, high fibre, (2) low fat, high fibre, (3) high fat, low fibre and (4) low fat, low fibre. Pathological and cell kinetic information together with details of certain faecal characteristics was collected when the animals were killed 4, 20, and 28 weeks after starting their experimental diet. Tumour induction was significantly influenced by diet. The highest risk of colorectal tumour development was found in groups fed diet 3: high fat, low fibre (p less than 0.03). In contrast, diet 2: low fat, high fibre was associated with the lowest risk. The proportion of histologically proven colonic tumours occurring in each dietary group was: diet 1-10.9%, diet 2-3.6%, diet 3-63.7%, diet 4-21.8%. Scanning electron microscopic (SEM) studies done on selected samples indicated both dietary and azoxymethane related alterations in crypt unit integrity. The most marked surface architectural changes were seen in carcinogen treated animals maintained on diet 3 (high fat, low fibre). Stathmokinetic analysis revealed considerable intergroup variability. Both fat and fibre produced significant effects, principally during the preneoplastic phase of carcinogenesis. Faster proliferative activity tended to be found in animals at low risk of tumour induction (diet 2), slower proliferation being more characteristic of animals at high risk (p less than 0.05). The findings suggest that both topographical and cell kinetic parameters have an important relationship with promoting and protecting dietary factors during the development of colorectal cancer. Images Fig. 1 Fig. 2 Fig. 4 PMID:3040544

  17. Effect of dioctyl sodium sulfosuccinate feeding on rat colorectal 1,2-dimethylhydrazine carcinogenesis.

    PubMed

    Karlin, D A; O'Donnell, R T; Jensen, W E

    1980-04-01

    The 1,2-dimethylhydrazine (DMH) rodent model for colorectal carcinogenesis was used to explore the effect of dietary dioctyl sodium sulfosuccinate (DSS) on carcinogenesis. Inbred male F344 rats were divided into two groups of 84 each and fed the following diets: ground chow and 5% corn oil (control group) and ground chow, 5% corn oil, and 1% DSS (experimental group). All rats received high-dose DMH base, 20 mg/kg/week sc for 20 weeks. Twenty rats per group were killed after 3, 4, 5, and 6 months. Duodenum, small intestine, colon, and rectum were dissected out. Each tumor was measured for size and location and evaluated histologically. The percentage of rats bearing tumors in the control and experimental groups did not differ significantly. In each rat there were fewer gastrointestinal tumors in the DSS-fed group of all histologic types combined, at all organ sites, at 5 and 6 months. This difference between the control and DSS-fed rats reached the level of statistical significance for tumors of the duodenum, colon, and rectum and for total gastrointestinal tumors at the 5th month. PMID:6154162

  18. DNA repair by MGMT, but not AAG, causes a threshold in alkylation-induced colorectal carcinogenesis.

    PubMed

    Fahrer, Jörg; Frisch, Janina; Nagel, Georg; Kraus, Alexander; Dörsam, Bastian; Thomas, Adam D; Reißig, Sonja; Waisman, Ari; Kaina, Bernd

    2015-10-01

    Epidemiological studies indicate that N-nitroso compounds (NOC) are causally linked to colorectal cancer (CRC). NOC induce DNA alkylations, including O (6)-methylguanine (O (6)-MeG) and N-methylated purines, which are repaired by O (6)-MeG-DNA methyltransferase (MGMT) and N-alkyladenine-DNA glycosylase (AAG)-initiated base excision repair, respectively. In view of recent evidence of nonlinear mutagenicity for NOC-like compounds, the question arises as to the existence of threshold doses in CRC formation. Here, we set out to determine the impact of DNA repair on the dose-response of alkylation-induced CRC. DNA repair proficient (WT) and deficient (Mgmt (-/-), Aag (-/-) and Mgmt (-/-)/Aag (-/-)) mice were treated with azoxymethane (AOM) and dextran sodium sulfate to trigger CRC. Tumors were quantified by non-invasive mini-endoscopy. A non-linear increase in CRC formation was observed in WT and Aag (-/-) mice. In contrast, a linear dose-dependent increase in tumor frequency was found in Mgmt (-/-) and Mgmt (-/-)/Aag (-/-) mice. The data were corroborated by hockey stick modeling, yielding similar carcinogenic thresholds for WT and Aag (-/-) and no threshold for MGMT lacking mice. O (6)-MeG levels and depletion of MGMT correlated well with the observed dose-response in CRC formation. AOM induced dose-dependently DNA double-strand breaks in colon crypts including Lgr5-positive colon stem cells, which coincided with ATR-Chk1-p53 signaling. Intriguingly, Mgmt (-/-) mice displayed significantly enhanced levels of γ-H2AX, suggesting the usefulness of γ-H2AX as an early genotoxicity marker in the colorectum. This study demonstrates for the first time a non-linear dose-response for alkylation-induced colorectal carcinogenesis and reveals DNA repair by MGMT, but not AAG, as a key node in determining a carcinogenic threshold. PMID:26243310

  19. Toll-like receptor signaling in colorectal cancer: Carcinogenesis to cancer therapy

    PubMed Central

    Li, Ting-Ting; Ogino, Shuji; Qian, Zhi Rong

    2014-01-01

    Toll-like receptors (TLRs) are germ line encoded innate immune sensors that recognize conserved microbial structures and host alarmins, and signal expression of major histocompatibility complex proteins, costimulatory molecules, and inflammatory mediators by macrophages, neutrophils, dendritic cells, and other cell types. These protein receptors are characterized by their ability to respond to invading pathogens promptly by recognizing particular TLR ligands, including flagellin and lipopolysaccharide of bacteria, nucleic acids derived from viruses, and zymosan of fungi. There are 2 major TLR pathways; one is mediated by myeloid differentiation factor 88 (MYD88) adaptor proteins, and the other is independent of MYD88. The MYD88-dependent pathway involves early-phase activation of nuclear factor of kappa light polypeptide gene enhancer in B-cells 1 (NF-κB1) and all the TLRs, except TLR3, have been shown to activate this pathway. TLR3 and TLR4 act via MYD88-independent pathways with delayed activation of NF-κB signaling. TLRs play a vital role in activating immune responses. TLRs have been shown to mediate inflammatory responses and maintain epithelial barrier homeostasis, and are highly likely to be involved in the activation of a number of pathways following cancer therapy. Colorectal cancer (CRC) is one of the most common cancers, and accounts for almost half a million deaths annually worldwide. Inflammation is considered a risk factor for many common malignancies including cancers of the colorectum. The key molecules involved in inflammation-driven carcinogenesis include TLRs. As sensors of cell death and tissue remodeling, TLRs may have a universal role in cancer; stimulation of TLRs to activate the innate immune system has been a legitimate therapeutic strategy for some years. TLRs 3/4/7/8/9 are all validated targets for cancer therapy, and a number of companies are developing agonists and vaccine adjuvants. On the other hand, antagonists may favor inhibition

  20. Genomic lesions and colorectal carcinogenesis: the effects of protein-calorie restriction and inulin supplementation on deficiency statuses.

    PubMed

    Cantero, W B; Takahachi, N A; Mauro, M O; Pesarini, J R; Rabacow, A P M; Antoniolli, A C M B; Oliveira, R J

    2015-01-01

    The present study investigated the effects of restricting protein and calories and supplementation of inulin, a fiber comprising a linear type of polydisperse carbohydrates composed primarily of fructil-fructose bonds (β-(2→1), on the deficiency statuses of animals in which genomic lesion development and colorectal carcinogenesis had been induced. This experiment involved adult male Swiss mice (N = 11/group). The experimental groups were as follows: Negative Control (vehicle), Positive Control, 1,2-dimethylhydrazine (DMH), Inulin, and Associate. DMH, which promoted colorectal cancer, was administered intraperitoneally in 4 20-mg/kg body weight (bw) doses during a 2-week period; inulin was administered orally at a daily dose of 50 mg/kg bw. Each group was bifurcated; half of each group was fed a normal protein diet and the other half was fed a low-protein diet. The results indicated that a correlation existed between malnutrition and an increased frequency of genomic lesions but that malnutrition did not predispose animals to colorectal cancer development. Inulin exhibited genotoxic activity, which requires further investigation, and low anti-genotoxic activity. Moreover, inulin reduced the levels of intestinal carcinogenesis biomarkers in both malnourished and healthy animals. These data suggest that inulin holds therapeutic potential and is a strong candidate for inclusion among the functional foods used for cancer prevention in both properly nourished and malnourished individuals. PMID:25867388

  1. The MUTYH base excision repair gene protects against inflammation-associated colorectal carcinogenesis

    PubMed Central

    Grasso, Francesca; Di Meo, Serena; De Luca, Gabriele; Pasquini, Luca; Rossi, Stefania; Boirivant, Monica; Biffoni, Mauro; Bignami, Margherita; Di Carlo, Emma

    2015-01-01

    MUTYH DNA glycosylase removes mismatched adenine opposite 7, 8-dihydro-8-oxoguanine (8-oxoG), which is the major mutagenic lesion induced by oxidative stress. Biallelic mutations in MUTYH are associated with MUTYH-Associated polyposis (MAP) and increased risk in colorectal cancer (CRC). We investigated cancer susceptibility associated with MUTYH inactivation in a mouse model of inflammation-dependent carcinogenesis induced by azoxymethane (AOM) and dextran sulphate (DSS). Mutyh−/− mice were more sensitive than wild-type (WT) animals to AOM/DSS toxicity and accumulated DNA 8-oxoG in their gastrointestinal tract. AOM/DSS-induced colonic adenomas were significantly more numerous in Mutyh−/− than in WT animals, and frequently showed a tubulo-villous feature along with high-grade dysplasia and larger size lesions. This condition resulted in a greater propensity to develop adenocarcinomas. The colon of untreated Mutyh−/− mice expressed higher basal levels of pro-inflammatory cytokines GM-CSF and IFNγ, and treatment with AOM/DSS induced an early decrease in circulating CD4+ and CD8+ T lymphocytes and an increase in myeloid-derived suppressor cells (MDSCs). Adenomas from Mutyh−/− mice had a greater infiltrate of Foxp3+ T regulatory cells, granulocytes, macrophages, MDSCs and strong expression of TGF-β-latency-associated peptide and IL6. Our findings indicate that MUTYH loss is associated with an increase in CRC risk, which involves immunosuppression and altered inflammatory response. We propose that the AOM/DSS initiation/promotion protocol in Mutyh−/− mice provides a good model for MAP. PMID:26109431

  2. The MUTYH base excision repair gene protects against inflammation-associated colorectal carcinogenesis.

    PubMed

    Grasso, Francesca; Di Meo, Serena; De Luca, Gabriele; Pasquini, Luca; Rossi, Stefania; Boirivant, Monica; Biffoni, Mauro; Bignami, Margherita; Di Carlo, Emma

    2015-08-14

    MUTYH DNA glycosylase removes mismatched adenine opposite 7, 8-dihydro-8-oxoguanine (8-oxoG), which is the major mutagenic lesion induced by oxidative stress. Biallelic mutations in MUTYH are associated with MUTYH-Associated polyposis (MAP) and increased risk in colorectal cancer (CRC). We investigated cancer susceptibility associated with MUTYH inactivation in a mouse model of inflammation-dependent carcinogenesis induced by azoxymethane (AOM) and dextran sulphate (DSS). Mutyh-/- mice were more sensitive than wild-type (WT) animals to AOM/DSS toxicity and accumulated DNA 8-oxoG in their gastrointestinal tract. AOM/DSS-induced colonic adenomas were significantly more numerous in Mutyh-/- than in WT animals, and frequently showed a tubulo-villous feature along with high-grade dysplasia and larger size lesions. This condition resulted in a greater propensity to develop adenocarcinomas. The colon of untreated Mutyh-/- mice expressed higher basal levels of pro-inflammatory cytokines GM-CSF and IFNγ, and treatment with AOM/DSS induced an early decrease in circulating CD4+ and CD8+ T lymphocytes and an increase in myeloid-derived suppressor cells (MDSCs). Adenomas from Mutyh-/- mice had a greater infiltrate of Foxp3+ T regulatory cells, granulocytes, macrophages, MDSCs and strong expression of TGF-β-latency-associated peptide and IL6. Our findings indicate that MUTYH loss is associated with an increase in CRC risk, which involves immunosuppression and altered inflammatory response. We propose that the AOM/DSS initiation/promotion protocol in Mutyh-/- mice provides a good model for MAP. PMID:26109431

  3. Increased expression of multidrug resistance related proteins Pgp, MRP1, and LRP/MVP occurs early in colorectal carcinogenesis.

    PubMed Central

    Meijer, G A; Schroeijers, A B; Flens, M J; Meuwissen, S G; van der Valk, P; Baak, J P; Scheper, R J

    1999-01-01

    AIM: To analyse the expression of multidrug resistance (MDR) related proteins at different steps in colorectal carcinogenesis. METHODS: The presence of three MDR related proteins (Pgp, MRP1, and LRP/MVP) was studied by means of immunohistochemistry in normal, adenomatous, and malignant colorectal epithelium. Formaldehyde fixed, paraffin embedded tissue sections of 17 samples of colorectal tissue were used (normal mucosa, n = 4; adjacent mucosa, n = 5; adenoma, n = 5; carcinoma, n = 3). RESULTS: For all three proteins, expression was found in the surface epithelium and the upper parts of the crypts in normal colon. In the adenomas, staining was seen along the complete length of the crypts. In the carcinomas analysed, all epithelium showed positive staining. Mucosa adjacent to either carcinoma or adenoma showed staining patterns mostly resembling those of normal mucosa, but sometimes some extension of staining was seen along the crypt. CONCLUSIONS: These proteins already show increased expression in the adenoma stage. In the absence of adequate mucin production in adenomas, MDR related proteins could be an important factor in protecting the epithelium against further environmentally induced genetic damage. This could be one of the reasons why only about 5% of colorectal adenomas will actually progress to carcinomas. Images PMID:10562814

  4. Calcium inhibits promotion by hot dog of 1,2-dimethylhydrazine-induced mucin-depleted foci in rat colon.

    PubMed

    Santarelli, Raphaelle L; Naud, Nathalie; Taché, Sylviane; Guéraud, Françoise; Vendeuvre, Jean-Luc; Zhou, Lin; Anwar, Muhammad M; Mirvish, Sidney S; Corpet, Denis E; Pierre, Fabrice H F

    2013-12-01

    Epidemiology suggests that processed meat is associated with colorectal cancer risk, but few experimental studies support this association. We have shown that a model of cured meat made in a pilot workshop promotes preneoplastic lesions, mucin-depleted foci (MDF) in the colon of rats. This study had two aims: to check if real store-bought processed meats also promote MDF, and to test if calcium carbonate, which suppresses heme-induced promotion, can suppress promotion by processed meat. A 14-day study was done to test the effect of nine purchased cured meats on fecal and urinary biomarkers associated with heme-induced carcinogenesis promotion. Fecal water from rats given hot dog or fermented raw dry sausage was particularly cytotoxic. These two cured meats were thus given to rats pretreated with 1,2-dimethylhydrazine, to evaluate their effect on colorectal carcinogenesis. After a 100-days feeding period, fecal apparent total N-nitroso compounds (ATNC) were assayed and colons were scored for MDF. Hot dog diet increased fecal ATNC and the number of MDF per colon compared with the no-meat control diet (3.0 ± 1.7 vs. 1.2 ± 1.4, p < 0.05). In a third study, addition of calcium carbonate (150 µmol/g) to the hot dog diet decreased the number of MDF/colon and fecal ATNC compared with the hot dog diet without calcium carbonate (1.2 ± 1.1 vs. 2.3 ± 1.4, respectively, p < 0.05). This is the first experimental evidence that a widely consumed processed meat promotes colon carcinogenesis in rats. It also shows that dietary prevention of this detrimental effect is possible. PMID:23712585

  5. Fatty acid metabolism pathway play an important role in carcinogenesis of human colorectal cancers by Microarray-Bioinformatics analysis.

    PubMed

    Yeh, Ching-Sheng; Wang, Jaw-Yuan; Cheng, Tian-Lu; Juan, Chin-Hung; Wu, Chan-Han; Lin, Shiu-Ru

    2006-02-28

    The present study systematically explored metabolic pathways and altered expressions of genes speculatively participating in colorectal carcinogenesis by using a Microarray-Bioinformatic analysis methods. The results revealed that 157 genes were up-regulated and 281 genes were down-regulated in colorectal cancer (CRC). Gene Ontology (GO) and relevant bioinformatics tools indicated that the functional category to which 438 genes (12%; 438/3800) of the most frequent alteration belonged was metabolism. The analysis of 10 colorectal cancer tissue specimens demonstrated that genes involved in fatty acid metabolic pathways had high rates of overexpression. In addition, we stimulated CRL-1790 cell line with linoleic acid (a polyunsaturated fatty acid) for 12, 24, 48 and 72 h. Cell proliferation was elevated by 5, 25, 28 and 31% (P<0.05), respectively. Further analyses revealed that the genes increasingly expressed in the cell line included enoyl-Coenzyme A, hydratase/3-hydroxyacyl Coenzyme A dehydrogenase (EHHADH), enoyl Coenzyme A hydratase, short chain, 1, mitochondrial (ECHS1); glutaryl-Coenzyme A dehydrogenase (GCDH), acyl-Coenzyme A oxidase 2, branched chain (ACOX2); acyl-Coenzyme A dehydrogenase, C-2 to C-3 short chain precursor (ACADS); carnitine palmitoyltransferase 1B (CPT1B), acyl-CoA synthetase long-chain family member 5 (ACSL5), and cytochrome P450, family 4, subfamily A, and polypeptide 11 (CYP4A11) genes. This indicated that the stimulating effect of linoleic acid on cell proliferation was due to interference with the metabolic pathway of fatty acid metabolism. In conclusion, genes with altered expression levels in CRC were mainly associated with fatty acid metabolic pathways speculated to have an important role linked to carcinogenesis. PMID:15885896

  6. Slit-Robo signaling induces malignant transformation through Hakai-mediated E-cadherin degradation during colorectal epithelial cell carcinogenesis

    PubMed Central

    Zhou, Wei-Jie; Geng, Zhen H; Chi, Shan; Zhang, Wenli; Niu, Xiao-Feng; Lan, Shu-Jue; Ma, Li; Yang, Xuesong; Wang, Li-Jing; Ding, Yan-Qing; Geng, Jian-Guo

    2011-01-01

    The Slit family of guidance cues binds to Roundabout (Robo) receptors and modulates cell migration. We report here that ectopic expression of Slit2 and Robo1 or recombinant Slit2 treatment of Robo1-expressing colorectal epithelial carcinoma cells recruited an ubiquitin ligase Hakai for E-cadherin (E-cad) ubiquitination and lysosomal degradation, epithelial-mesenchymal transition (EMT), and tumor growth and liver metastasis, which were rescued by knockdown of Hakai. In contrast, knockdown of endogenous Robo1 or specific blockade of Slit2 binding to Robo1 prevented E-cad degradation and reversed EMT, resulting in diminished tumor growth and liver metastasis. Ectopic expression of Robo1 also triggered a malignant transformation in Slit2-positive human embryonic kidney 293 cells. Importantly, the expression of Slit2 and Robo1 was significantly associated with an increased metastatic risk and poorer overall survival in colorectal carcinoma patients. We conclude that engagement of Robo1 by Slit2 induces malignant transformation through Hakai-mediated E-cad ubiquitination and lysosomal degradation during colorectal epithelial cell carcinogenesis. PMID:21283129

  7. Aged garlic extract inhibits 1,2-dimethylhydrazine-induced colon tumor development by suppressing cell proliferation.

    PubMed

    Jikihara, Hiroshi; Qi, Guangying; Nozoe, Koichiro; Hirokawa, Mayumi; Sato, Hiromi; Sugihara, Yuka; Shimamoto, Fumio

    2015-03-01

    Garlic and its constituents are reported to have a preventive effect against colorectal cancer in animal models. Aged garlic extract (AGE), which is produced by natural extraction from fresh garlic for more than 10 months in aqueous ethanol, also has reputed chemopreventive effects on colon carcinogenesis, but has never been studied for its effects on colon cancer development. We investigated the antitumor effects of AGE in rats with 1,2-dimethylhydrazine (DMH)-induced carcinogenesis, and the mechanism of AGE in human colon cancer cell proliferation. F344 rats randomly divided into three groups were administered DMH (20 mg/kg weight) subcutaneously once a week for 8 weeks in a basal diet. After the last injection, one group of rats was then moved onto a basal diet containing 3% wt/wt AGE, and rats were sacrificed at 8 or 31 weeks. The number of aberrant crypt foci (ACF), histological type of tumor and proliferative activity of the tumor lesions were analyzed by macroscopic, pathological and immunohistochemical methods. DLD-1 human colon cancer cells were utilized to investigate the effect of AGE on anti-cell proliferation. AGE decreased the number of ACF but had no effect on gross tumor pathology. AGE showed a lower number of adenoma and adenocarcinoma lesions by histological analysis. Immunohistochemical staining indicated that AGE suppressed the proliferative activity in adenoma and adenocarcinoma lesions, but showed no effect on normal colon mucosa. Moreover, we demonstrated that AGE delayed cell cycle progression by downregulating cyclin B1 and cdk1 expression via inactivation of NF-κB in the human colorectal cancer cells but did not induce apoptosis. These findings suggest that AGE has an antitumor effect through suppression of cell proliferation. PMID:25573280

  8. Acceleration of Smad2 and Smad3 phosphorylation via c-Jun NH(2)-terminal kinase during human colorectal carcinogenesis.

    PubMed

    Yamagata, Hideo; Matsuzaki, Koichi; Mori, Shigeo; Yoshida, Katsunori; Tahashi, Yoshiya; Furukawa, Fukiko; Sekimoto, Go; Watanabe, Toshihiko; Uemura, Yoshiko; Sakaida, Noriko; Yoshioka, Kazuhiko; Kamiyama, Yasuo; Seki, Toshihito; Okazaki, Kazuichi

    2005-01-01

    Conversion of normal epithelial cells to tumors is associated with a shift in transforming growth factor-beta (TGF-beta) function: reduction of tumor suppressor activity and increase of oncogenic activity. However, specific mechanisms of this functional alteration during human colorectal carcinogenesis remain to be elucidated. TGF-beta signaling involves Smad2/3 phosphorylated at linker regions (pSmad2/3L) and COOH-terminal regions (pSmad2/3C). Using antibodies specific to each phosphorylation site, we herein showed that Smad2 and Smad3 were phosphorylated at COOH-terminal regions but not at linker regions in normal colorectal epithelial cells and that pSmad2/3C were located predominantly in their nuclei. However, the linker regions of Smad2 and Smad3 were phosphorylated in 31 sporadic colorectal adenocarcinomas. In particular, late-stage invasive and metastatic cancers typically showed a high degree of phosphorylation of Smad2/3L. Their extent of phosphorylation in 11 adenomas was intermediate between those in normal epithelial cells and adenocarcinomas. Whereas pSmad2L remained in the cytoplasm, pSmad3L was located exclusively in the nuclei of Ki-67-immunoreactive adenocarcinomas. In contrast, pSmad3C gradually decreased as the tumor stage progressed. Activated c-Jun NH(2)-terminal kinase in cancers could directly phosphorylate Smad2/3L. Although Mad homology 2 region sequencing in the Smad4 gene revealed a G/A substitution at codon 361 in one adenocarcinoma, the mutation did not correlate with phosphorylation. No mutations in the type II TGF-beta receptor and Smad2 genes were observed in the tumors. In conclusion, pSmad3C, which favors tumor suppressor activity of TGF-beta, was found to decrease, whereas c-Jun NH(2)-terminal kinase tended to induce the phosphorylation of Smad2/3L in human colorectal adenoma-carcinoma sequence. PMID:15665291

  9. Genotoxicity of Cytolethal Distending Toxin (CDT) on Isogenic Human Colorectal Cell Lines: Potential Promoting Effects for Colorectal Carcinogenesis

    PubMed Central

    Graillot, Vanessa; Dormoy, Inge; Dupuy, Jacques; Shay, Jerry W.; Huc, Laurence; Mirey, Gladys; Vignard, Julien

    2016-01-01

    The composition of the human microbiota influences tumorigenesis, notably in colorectal cancer (CRC). Pathogenic Escherichia coli possesses a variety of virulent factors, among them the Cytolethal Distending Toxin (CDT). CDT displays dual DNase and phosphatase activities and induces DNA double strand breaks, cell cycle arrest and apoptosis in a broad range of mammalian cells. As CDT could promote malignant transformation, we investigated the cellular outcomes induced by acute and chronic exposures to E. coli CDT in normal human colon epithelial cells (HCECs). Moreover, we conducted a comparative study between isogenic derivatives cell lines of the normal HCECs in order to mimic the mutation of three major genes found in CRC genetic models: APC, KRAS, and TP53. Our results demonstrate that APC and p53 deficient cells showed impaired DNA damage response after CDT exposure, whereas HCECs expressing oncogenic KRASV12 were more resistant to CDT. Compared to normal HCECs, the precancerous derivatives exhibit hallmarks of malignant transformation after a chronic exposure to CDT. HCECs defective in APC and p53 showed enhanced anchorage independent growth and genetic instability, assessed by the micronucleus formation assay. In contrast, the ability to grow independently of anchorage was not impacted by CDT chronic exposure in KRASV12 HCECs, but micronucleus formation is dramatically increased. Thus, CDT does not initiate CRC by itself, but may have promoting effects in premalignant HCECs, involving different mechanisms in function of the genetic alterations associated to CRC. PMID:27047802

  10. Antiproliferative efficacy of hesperetin (citrus flavanoid) in 1,2-dimethylhydrazine-induced colon cancer.

    PubMed

    Aranganathan, Selvaraj; Nalini, Namasivayam

    2013-07-01

    Cancer is the second leading cause of death worldwide and is increasing at an alarming rate. The present study was to evaluate the antiproliferative effects of hesperetin, a flavonoid commonly found in many herbal medicines and foods, on aberrant crypt foci (ACF), argyrophylic nucleolar organizer regions (AgNORs) and proliferating cell nuclear antigen (PCNA) in 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis in rats. Rats were given subcutaneous injections of DMH (20 mg/kg body weight) weekly for 15 weeks to induce carcinogenesis, and hesperetin was administered orally at the dose of 20 mg/kg body weight. DMH exposure alone produced a high incidence of ACF and showed positive staining for PCNA and AgNORs in colonic tissues. Supplementation with hesperetin lowered the PCNA labeling index and suppressed the formation of ACF in the rats with colon cancer. These results clearly reveal that dietary hesperetin possesses antiproliferative ability against chemically induced colon tumourigenesis. PMID:22899565

  11. Exenatide suppresses 1,2-dimethylhydrazine-induced colon cancer in diabetic mice: Effect on tumor angiogenesis and cell proliferation.

    PubMed

    Tawfik, Mona K; Mohamed, Magda I

    2016-08-01

    Colon cancer is the third leading cause of cancer mortality worldwide, which results from interactions of different factors. It is frequently a pathological consequence of persistent inflammation. Diabetes affects several cancers and is positively correlated with the incidence of colon cancer. This study aimed to study the effect of exenatide in ameliorating inflammation, angiogenesis and cell proliferation in 1,2-dimethyl hydrazine (DMH) induced colorectal carcinoma in diabetic mice. Mice were randomly allocated into six groups, 8 mice each. Group 1: vehicle control group. Group 2: diabetic control group. Group 3: DMH control group: diabetic mice treated with DMH (20mg/kg/week,s.c.) for 15 week. Group 4: DMH-cisplatin group: mice received cisplatin (4mg/kg/week, i.p.). Groups 5 & 6: DMH-exenatide (10 and 20μg/kg) group: mice received exenatide (10 or 20μg/kg/day,s.c.), respectively. The present results highlighted an increase in angiogenic markers and cell proliferation in the DMH-diabetic group in comparison with the control group with greater expression of endothelial marker (CD34) and Ki-67 in colon tissue. Monotherapy with cisplatin or exenatide (10 and 20μg/kg) downregulated these markers to different extents. The current results provided evidence that exenatide represents a promising chemopreventive effect against DMH-induced colon carcinogenesis in diabetic mice, at least in part, attributed to its anti-angiogenic and anti-proliferative mechanisms. PMID:27470345

  12. Inhibition of SALL4 suppresses carcinogenesis of colorectal cancer via regulating Gli1 expression

    PubMed Central

    Cheng, Ji; Deng, Rui; Wu, Chuanqing; Zhang, Peng; Wu, Ke; Shi, Liang; Liu, Xinghua; Bai, Jie; Deng, Meizhou; Gao, Jinbo; Shuai, Xiaoming; Wang, Guobin; Tao, Kaixiong

    2015-01-01

    Background: SALL4 is a novel oncogene mediating tumorigenesis in multiple carcinomas. However, its actual role and mechanisms participating in the development of colorectal cancer remains unclear. Methods: Immunohistochemical staining and Western blot were conducted to detect the expression of SALL4 and other molecules. siRNA of SALL4 was transfected to silence SALL4 expression in Caco-2 cell line. Flow cytometry was used for cell cycle and apoptosis analysis. Wound healing and transwell assay were used for invasion test. CCK-8 test was employed for cell proliferation and drug sensitivity assessment. Results: By inhibition of SALL4 expression, the proliferation, invasiveness and drug resistance were dramatically reduced while apoptosis rate was up-regulated. Gli1 was found to decrease its expression in SALL4 silencing cells. Moreover, the inhibition on tumorigenesis of Caco-2 by SALL4 silencing was antagonized by Gli1 up-regulation, suggesting Gli1 as a downstream target of SALL4 in cancer development. Conclusion: SALL4 inhibition limited oncogenesis on colorectal cancer by reducing Gli1 expression. PMID:26617716

  13. Molecular evolution of colorectal cancer: from multistep carcinogenesis to the big bang.

    PubMed

    Amaro, Adriana; Chiara, Silvana; Pfeffer, Ulrich

    2016-03-01

    Colorectal cancer is characterized by exquisite genomic instability either in the form of microsatellite instability or chromosomal instability. Microsatellite instability is the result of mutation of mismatch repair genes or their silencing through promoter methylation as a consequence of the CpG island methylator phenotype. The molecular causes of chromosomal instability are less well characterized. Genomic instability and field cancerization lead to a high degree of intratumoral heterogeneity and determine the formation of cancer stem cells and epithelial-mesenchymal transition mediated by the TGF-β and APC pathways. Recent analyses using integrated genomics reveal different phases of colorectal cancer evolution. An initial phase of genomic instability that yields many clones with different mutations (big bang) is followed by an important, previously not detected phase of cancer evolution that consists in the stabilization of several clones and a relatively flat outgrowth. The big bang model can best explain the coexistence of several stable clones and is compatible with the fact that the analysis of the bulk of the primary tumor yields prognostic information. PMID:26947218

  14. Prevention of preneoplastic lesions by dietary vitamin D in a mouse model of colorectal carcinogenesis.

    PubMed

    Hummel, Doris Maria; Thiem, Ursula; Höbaus, Julia; Mesteri, Ildiko; Gober, Lukas; Stremnitzer, Caroline; Graça, João; Obermayer-Pietsch, Barbara; Kallay, Enikö

    2013-07-01

    Colorectal cancer (CRC) is one of the leading causes of cancer morbidity and mortality in Western countries. One of the risk factors for colorectal tumorigenesis is vitamin D insufficiency. The aim of this study was to establish whether increasing dietary vitamin D intake can prevent or delay development of chemically induced preneoplastic lesions in the colon of mice. We fed six weeks old female C57BL/6J mice (n=28) with increasing vitamin D3 concentrations (100, 400, 1000, 2500, 5000IU/kg diet). To induce dysplasia, a preneoplastic lesion, we injected mice with the carcinogen azoxymethane (10mg/kg) intraperitoneally, followed by three cycles of 2% dextran sodium sulfate salt, a tumor promoter, in the drinking water. To test our hypothesis that high vitamin D intake prevents formation of preneoplastic lesions, we have investigated the effect of increasing dietary vitamin D on development of premalignant colorectal lesions, serum 25-hydroxyvitamin D3 (25-D3) levels, and expression of renal vitamin D system genes. Dietary vitamin D concentration correlated inversely with dysplasia score (Spearman's correlation coefficient, ρ: -0.579, p=0.002) and positively with serum 25-D3 levels (ρ: 0.752, p=0.001). Increasing dietary vitamin D concentration beyond 1000IU/kg led to no further increase in circulating 25-D3 levels, while the dysplasia score leveled out at ≥2500IU/kg vitamin D. High dietary vitamin D intake led to increased renal mRNA expression of the vitamin D catabolizing enzyme cyp24a1 (ρ: 0.518, p=0.005) and decreased expression of the vitamin D activating enzyme cyp27b1 (ρ: -0.452, p=0.016), protecting the body from toxic serum levels of the active vitamin D metabolite 1,25-dihydroxyvitamin D3 (1,25-D3). Our data showed that increasing dietary vitamin D intake is able to prevent chemically induced preneoplastic lesions. The maximum impact was achieved when the mice consumed more than 2500IU vitamin D/kg diet. This article is part of a Special Issue

  15. Implication of K-ras and p53 in colorectal cancer carcinogenesis in Tunisian population cohort.

    PubMed

    Ines, Chaar; Donia, Ounissi; Rahma, Boughriba; Ben Ammar, Azza; Sameh, Amara; Khalfallah, Taher; Abdelmajid, Ben Hmida; Sabeh, Mzabi; Saadia, Bouraoui

    2014-07-01

    According to the multistep route of genetic alterations in the colorectal adenoma-carcinoma sequence, the complex K-ras/p53 mutation is one of the first alterations to occur and represent an important genetic event in colorectal cancer (CRC). An evaluation of the mutation spectra in K-ras and p53 gene was effected in 167 Tunisian patients with sporadic CRC to determine whether our populations have similar pattern of genetic alteration as in Maghrebin's population. Mutation patterns of codon 12-13 of K-ras and exon 5-8 of p53 were analyzed by immunohistochemistry and PCR-SSCP and confirmed by sequencing. Mutations in the K-ras gene were detected in 31.13 % and affect the women more than the men (p = 0.008). Immunostaining showed that expression of p21 ras was correlated with the advanced age (p = 0.004), whereas loss of signal was associated with mucinous histotype (p = 0.003). Kaplan-Meier survival curve found that patients with the K-ras mutation had a shorter survival compared with patients without mutation (p = 0.005). Alteration in p53 was seen in 17.4 % of patients and affects three hot spot codons such as 175, 245, and 248. Overexpression of p53 was seen in 34.1 % and correlated with tumor node metastasis (TNM) advanced stage (p = 0.037) and mucinous histotype (p = 0.001). A high concordance between p53 expression and alteration (p<0.005) was shown. Concomitant mutations in K-ras and p53 gene were detected in only 4 % of tumors. K-ras and p53 undergo separate pathways in colorectal tumorogenesis. Interestingly, mutations in the K-ras gene might be considered a valuable prognostic factor correlated to poor outcome. p53 gene alterations were rather low in our set, and methylation pattern of p53 is required to elucidate the molecular basis of this protein in CRC. PMID:24763823

  16. Therapeutic effect of hydroxychloroquine on colorectal carcinogenesis in experimental murine colitis.

    PubMed

    Yao, Junlin; Xie, Jiansheng; Xie, Binbin; Li, Yiran; Jiang, Liming; Sui, Xinbing; Zhou, Xiaoyun; Pan, Hongming; Han, Weidong

    2016-09-01

    Chronic inflammation in the intestine is a strong risk factor for colitis-associated colorectal cancer (CAC). Hydroxychloroquine (HCQ) is widely used as an anti-inflammatory drug in the treatment of immune-mediated inflammatory disorders and various tumors. However, little is known regarding the effects of HCQ on colitis-associated tumorigenesis. In this study, mice treated with HCQ showed a significant reduction in early-stage colitis following azoxymethane (AOM)/dextran sodium sulfate (DSS) administration, as well as a remarkable inhibition of colonic tumorigenesis and tumor growth at late stages of CAC. Mechanistically, the therapeutic effects of HCQ were attributed to inhibition of inflammatory responses and production of mutagenic reactive oxygen species (ROS) in immune cells and subsequent promotion of apoptosis and cell cycle arrest in tumor cells. Furthermore, we found that HCQ inhibited the production of inflammatory cytokines and ROS in response to toll-like receptor 4 (TLR4) activation in macrophages. Our data presented herein may help guide the clinical use of HCQ as a prevention and treatment strategy for CAC. PMID:27288548

  17. Mutator/Hypermutable Fetal/Juvenile Metakaryotic Stem Cells and Human Colorectal Carcinogenesis

    PubMed Central

    Kini, Lohith G.; Herrero-Jimenez, Pablo; Kamath, Tushar; Sanghvi, Jayodita; Gutierrez, Efren; Hensle, David; Kogel, John; Kusko, Rebecca; Rexer, Karl; Kurzweil, Ray; Refinetti, Paulo; Morgenthaler, Stephan; Koledova, Vera V.; Gostjeva, Elena V.; Thilly, William G.

    2013-01-01

    Adult age-specific colorectal cancer incidence rates increase exponentially from maturity, reach a maximum, then decline in extreme old age. Armitage and Doll (1) postulated that the exponential increase resulted from “n” mutations occurring throughout adult life in normal “cells at risk” that initiated the growth of a preneoplastic colony in which subsequent “m” mutations promoted one of the preneoplastic “cells at risk” to form a lethal neoplasia. We have reported cytologic evidence that these “cells at risk” are fetal/juvenile organogenic, then preneoplastic metakaryotic stem cells. Metakaryotic cells display stem-like behaviors of both symmetric and asymmetric nuclear divisions and peculiarities such as bell shaped nuclei and amitotic nuclear fission that distinguish them from embryonic, eukaryotic stem cells. Analyses of mutant colony sizes and numbers in adult lung epithelia supported the inferences that the metakaryotic organogenic stem cells are constitutively mutator/hypermutable and that their contributions to cancer initiation are limited to the fetal/juvenile period. We have amended the two-stage model of Armitage and Doll and incorporated these several inferences in a computer program CancerFit v.5.0. We compared the expectations of the amended model to adult (15–104 years) age-specific colon cancer rates for European-American males born 1890–99 and observed remarkable concordance. When estimates of normal colonic fetal/juvenile APC and OAT gene mutation rates (∼2–5 × 10−5 per stem cell doubling) and preneoplastic colonic gene loss rates (∼8 × 10−3) were applied, the model was in accordance only for the values of n = 2 and m = 4 or 5. PMID:24195059

  18. KAG-308, a newly-identified EP4-selective agonist shows efficacy for treating ulcerative colitis and can bring about lower risk of colorectal carcinogenesis by oral administration.

    PubMed

    Watanabe, Yusuke; Murata, Takahiko; Amakawa, Masahiro; Miyake, Yoshihide; Handa, Tango; Konishi, Katsuhiko; Matsumura, Yasushi; Tanaka, Takuji; Takeuchi, Koji

    2015-05-01

    Agonists for EP4 receptor, a prostaglandin E2 receptor subtype, appear to be a promising therapeutic strategy for ulcerative colitis (UC) due to their anti-inflammatory and epithelial regeneration activities. However, the clinical development of orally-available EP4 agonists for mild to moderate UC has not yet been reported. Furthermore, the possibility of an increased risk of colitis-associated cancer (CAC) through direct proliferative effects on epithelial cells via EP4 signaling has not been ruled out. Recently, we identified KAG-308 as an orally-available EP4-selective agonist. Here, we investigated the pharmacological and pharmacokinetic profiles of KAG-308. Then, we compared KAG-308 and sulfasalazine (SASP) for their abilities to prevent colitis and promote mucosal healing in a mouse model of dextran sulfate sodium (DSS)-induced colitis. Finally, the effect of KAG-308 treatment on CAC was evaluated in an azoxymethane (AOM)/DSS-induced CAC mouse model. KAG-308 selectively activated EP4 and potently inhibited tumor necrosis factor-α production in peripheral whole blood and T cells. Oral administration of KAG-308, which showed relatively high bioavailability, suppressed the onset of DSS-induced colitis and promoted histological mucosal healing, while SASP did not. KAG-308 also prevented colorectal carcinogenesis by inhibiting colitis development and consequently decreasing mortality in a CAC model, whereas SASP had marginal effects. In contrast, MF-482, an EP4 antagonist, increased mortality. These results indicated that orally-administered KAG-308 suppressed colitis development and promoted mucosal healing. Moreover, it exhibited preventive effects on colorectal carcinogenesis, and thus may be a new therapeutic strategy for the management of UC that confers a reduced risk of colorectal carcinogenesis. PMID:25704618

  19. Ethanolic Extract of Bark from Salix aegyptiaca Ameliorates 1,2-dimethylhydrazine-induced Colon Carcinogenesis in Mice by Reducing Oxidative Stress.

    PubMed

    Bounaama, Abdelkader; Enayat, Shabnam; Ceyhan, Muserref Seyma; Moulahoum, Hichem; Djerdjouri, Bahia; Banerjee, Sreeparna

    2016-01-01

    We have previously shown that ethanolic extract from bark (EEB) of Salix aegyptiaca (Musk Willow) can inhibit proliferation and motility and induce apoptosis in colon cancer cells. Tandem mass spectrometry revealed EEB to be rich in catechin, catechol, and salicin. The present study investigated the chemopreventive effect of HPLC-fingerprinted EEB on 1,2-dimethylhydrazine (DMH)-induced aberrant crypt foci (ACF) formation in mice. DMH (20 mg/kg body weight) was weekly injected subcutaneously to mice for the first 2 weeks. EEB (100 and 400 mg/kg body weight) was provided orally from the 7th to 14th week, after which colon tissues were evaluated histologically and biochemically. DMH treatment induced high number of ACF; EEB significantly reduced the number and multiplicity of ACF, along with a restoration in goblet cells and mucin accumulation. EEB supplementation improved the markers of inflammation (myeloperoxidase and neutrophil infiltration) and oxidative stress. More importantly, EEB amplified apoptosis of neoplastic cells in the colon mucosa of DMH-treated mice. It also lowered levels of markers for early transformation events such as EGFR, nuclear β-catenin, and COX-2 in colon cancer cell lines HT-29 and HCT-116. The innocuity of EEB (up to 1600 mg/kg) to mice reinforces its potential as a chemopreventive agent. PMID:27093594

  20. Strawberry phytochemicals inhibit azoxymethane/dextran sodium sulfate-induced colorectal carcinogenesis in Crj: CD-1 mice.

    PubMed

    Shi, Ni; Clinton, Steven K; Liu, Zhihua; Wang, Yongquan; Riedl, Kenneth M; Schwartz, Steven J; Zhang, Xiaoli; Pan, Zui; Chen, Tong

    2015-03-01

    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. PMID:25763529

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

    PubMed Central

    Shi, Ni; Clinton, Steven K.; Liu, Zhihua; Wang, Yongquan; Riedl, Kenneth M.; Schwartz, Steven J.; Zhang, Xiaoli; Pan, Zui; Chen, Tong

    2015-01-01

    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. PMID:25763529

  2. NF-κB and Nrf2 signaling pathways contribute to wogonin-mediated inhibition of inflammation-associated colorectal carcinogenesis

    PubMed Central

    Yao, J; Zhao, L; Zhao, Q; Zhao, Y; Sun, Y; Zhang, Y; Miao, H; You, Q-D; Hu, R; Guo, Q-L

    2014-01-01

    The transcriptional factors nuclear factor-κB (NF-κB) and NF-E2-related factor 2 (Nrf2) have been recently reported to have critical roles in protecting various tissues against inflammation and colitis-associated colorectal cancer (aberrant crypt foci). Our previous studies showed that wogonin (5,7-dihydroxy-8-methoxyflavone) possessed anti-neoplastic and anti-inflammatory activities. The present study extended these important earlier findings by exploring the effect of wogonin on the initiation and development of colitis-associated cancer. Wogonin lowered tumor incidence and inhibited the development of colorectal adenomas in azoxymethane- or dextran sulfate sodium-induced mice. We found that wogonin significantly decreased the secretion and expression of IL-6 and IL-1β, reduced cell proliferation and nuclear expression of NF-κB in adenomas and surrounding tissues and promoted Nrf2 nuclear translocation in surrounding tissues, although overexpressed Nrf2 in tumor tissues was independent of wogonin administration. Furthermore, wogonin inhibited the interaction between human monocytic THP-1 cells and human colon cancer HCT116 cells, and significantly downregulated lipopolysaccharide-induced secretion of prototypical pro-inflammatory cytokines IL-6 and IL-1β in THP-1 cells. Further mechanism research revealed that wogonin inhibited the nuclear translocation of NF-κB and phosphorylation of IκB and IKKα/β, and promoted Nrf2 signaling pathway in HCT116 cells and THP-1 cells. Taken together, the present results indicated that wogonin effectively suppressed inflammation-associated colon carcinogenesis and cancer development, suggesting its potential as a chemopreventive agent against colitis-associated colon cancer. PMID:24901054

  3. Molecular Genetic Changes Associated With Colorectal Carcinogenesis Are Not Prognostic for Tumor Regression Following Preoperative Chemoradiation of Rectal Carcinoma

    SciTech Connect

    Zauber, N. Peter Marotta, Steven P.; Berman, Errol; Grann, Alison; Rao, Maithili; Komati, Naga; Ribiero, Kezia; Bishop, D. Timothy

    2009-06-01

    Purpose: Preoperative chemotherapy and radiation has become the standard of care for many patients with rectal cancer. The therapy may have toxicity and delays definitive surgery. It would therefore be desirable to identify those cancers that will not regress with preoperative therapy. We assessed a series of rectal cancers for the molecular changes of loss of heterozygosity of the APC and DCC genes, K-ras mutations, and microsatellite instability, changes that have clearly been associated with rectal carcinogenesis. Methods and Materials: Diagnostic colonoscopic biopsies from 53 patients who received preoperative chemotherapy and radiation were assayed using polymerase chain reaction techniques followed by single-stranded conformation polymorphism and DNA sequencing. Regression of the primary tumor was evaluated using the surgically removed specimen. Results: Twenty-three lesions (45%) were found to have a high degree of regression. None of the molecular changes were useful as indicators of regression. Conclusions: Recognized molecular changes critical for rectal carcinogenesis including APC and DCC loss of heterozygosity, K-ras mutations, and microsatellite instability are not useful as indicators of tumor regression following chemoradiation for rectal carcinoma.

  4. Effect of alterations in the quality and quantity of dietary fat on 1,2-dimethylhydrazine-induced colon tumorigenesis in rats.

    PubMed

    Nauss, K M; Locniskar, M; Newberne, P M

    1983-09-01

    The effect of alterations in the quality and quantity of dietary fat on 1,2-dimethylhydrazine-induced colon cancer in rats was studied. Weanling Sprague-Dawley rats were fed semipurified diets containing 24% beef fat, 24% corn oil, 24% Crisco, or the three fats in equal parts to make a total of 5% fat with other macronutrients and micronutrients adjusted to balance the ratios of nutrient to calorie. After 4 weeks of dietary treatment, all rats, except vehicle-treated animals, received 1,2-dimethylhydrazine (15 mg/kg) by gavage, once a week for 5 weeks. The animals were fed the experimental diets until intestinal tumors developed, and surviving animals were sacrificed at 60 weeks. There was no effect of any of the high-fat diets tested on intestinal tumor incidence, latency, size, or frequency. All groups contained the same proportion of adenomas (less than 3%) as well as adenocarcinomas classified as mucinous. In the group fed 24% Crisco, tumors occurred with greater frequency in the proximal section of the colon than in lower segments, but the distribution was approximately uniform in the other groups. Cumulative probability of death with colon carcinoma was lowest in the 24% Crisco group, but the other high-fat groups did not differ significantly from the 5% mixed fat group nor from one another. PMID:6871849

  5. CD24 knockout prevents colorectal cancer in chemically induced colon carcinogenesis and in APC(Min)/CD24 double knockout transgenic mice.

    PubMed

    Naumov, Inna; Zilberberg, Alona; Shapira, Shiran; Avivi, Doran; Kazanov, Dina; Rosin-Arbesfeld, Rina; Arber, Nadir; Kraus, Sarah

    2014-09-01

    Increased expression of CD24 is seen in a large variety of solid tumors, including up to 90% of gastrointestinal (GI) tumors. Stable derivatives of SW480 colorectal cancer (CRC) cells that overexpress CD24 proliferate faster, and increase cell motility, saturation density, plating efficiency, and growth in soft agar. They also produce larger tumors in nude mice as compared to the parental SW480 cells. Most significantly, even depletion of one copy of the CD24 allele in the APC(Min/+) mice of a transgenic mouse model led to a dramatic reduction in tumor burden in all sections of the small intestine. Homozygous deletion of both CD24 alleles resulted in complete abolishment of tumor formation. Moreover, CD24 knockout mice exhibited resistance to chemically induced inflammation-associated CRC. Finally, a new signal transduction pathway is suggested: namely, CD24 expression downstream to COX2 and PGE2 synthesis, which is directly regulated by β-catenin. CD24 is shown in vitro and in vivo as being an important oncogene in the gut, and one that plays a critical role in the initiation and progression of carcinogenesis. PMID:24500912

  6. Time-serial Assessment of Drug Combination Interventions in a Mouse Model of Colorectal Carcinogenesis Using Optical Coherence Tomography

    PubMed Central

    LeGendre-McGhee, Susan; Rice, Photini S.; Wall, R. Andrew; Sprute, Kyle J.; Bommireddy, Ramireddy; Luttman, Amber M.; Nagle, Raymond B.; Abril, Edward R.; Farrell, Katrina; Hsu, Chiu-Hsieh; Roe, Denise J.; Gerner, Eugene W.; Ignatenko, Natalia A.; Barton, Jennifer K.

    2015-01-01

    Optical coherence tomography (OCT) is a high-resolution, nondestructive imaging modality that enables time-serial assessment of adenoma development in the mouse model of colorectal cancer. In this study, OCT was utilized to evaluate the effectiveness of interventions with the experimental antitumor agent α-difluoromethylornithine (DFMO) and a nonsteroidal anti-inflammatory drug sulindac during early [chemoprevention (CP)] and late stages [chemotherapy (CT)] of colon tumorigenesis. Biological endpoints for drug interventions included OCT-generated tumor number and tumor burden. Immunochistochemistry was used to evaluate biochemical endpoints [Ki-67, cleaved caspase-3, cyclooxygenase (COX)-2, β-catenin]. K-Ras codon 12 mutations were studied with polymerase chain reaction-based technique. We demonstrated that OCT imaging significantly correlated with histological analysis of both tumor number and tumor burden for all experimental groups (P < 0.0001), but allows more accurate and full characterization of tumor number and burden growth rate because of its time-serial, nondestructive nature. DFMO alone or in combination with sulindac suppressed both the tumor number and tumor burden growth rate in the CP setting because of DFMO-mediated decrease in cell proliferation (Ki-67, P < 0.001) and K-RAS mutations frequency (P = 0.04). In the CT setting, sulindac alone and DFMO/sulindac combination were effective in reducing tumor number, but not tumor burden growth rate. A decrease in COX-2 staining in DFMO/sulindac CT groups (COX-2, P < 0.01) confirmed the treatment effect. Use of nondestructive OCT enabled repeated, quantitative evaluation of tumor number and burden, allowing changes in these parameters to be measured during CP and as a result of CT. In conclusion, OCT is a robust minimally invasive method for monitoring colorectal cancer disease and effectiveness of therapies in mouse models. PMID:26396545

  7. P21 and CEA expression and AgNOR counts in dimethylhydrazine-induced colon carcinoma in rats

    PubMed Central

    Zhang, Zhi-Gang; Wu, Jing-Ying; Fu, Xiang-Dong; Gu, Da-Kun; Fang, Fang

    1997-01-01

    AIM: To study P21 and carcinoembryonic antigen (CEA) expression and to measure argyrophilic nucleolar organizer region (AgNOR) counts in various lesions of colonic mucosa and the mechanism of carcinogenesis. METHODS: Thirty-eight male Wistar rats were injected with dimethylhydrazine (DMH) once a week for 25 wk. P21 and CEA expression was detected by immunohistochemical methods, and AgNOR was counted by silver staining paraffin sections from various colonic lesions. RESULTS: The incidence of colonic carcinoma in DMH-treated rats was 71.05% (27/38), and lymph node metastasis occurred in six rats. Immunohistochemical studies showed that P21 was primarily expressed in dysplasia and carcinomas, while CEA was expressed in carcinomas and metastatic tumors. AgNOR counts were higher in dysplasia and carcinomas. There were significant differences in P21 and CEA expression between benign and malignant lesions (P < 0.05). The difference in AgNOR counts was also significant between normal and dysplastic tissues, and between dysplasia and malignant lesions (P < 0.05). CONCLUSION: Dysplasia is a premalignant change of colonic carcinoma. The detection of P21 via immunohistochemistry and AgNOR counting may be an important clinical screening technique for colon carcinoma and premalignant lesions.

  8. Trivalent Chromium has no Effect on Delaying Azoxymethane-Induced Colorectal Cancer in FVB/NJ Mice.

    PubMed

    White, Pandora E; Deng, Ge; Kuykendall, M Kaitlyn; Tadros, Abbey M; Dyroff, Samantha L; Honan, Rachel E; Robertson, Preshus M; Vincent, John B; Rasco, Jane F

    2015-11-01

    As Cr(III) compounds have been shown to increase insulin sensitivity and decrease plasma cholesterol and triglycerides in rodent models of diabetes and insulin resistance and as colorectal cancer risk has been associated with insulin resistance and diabetes, the effects of the Cr(III) compound Cr3 ([Cr3O(O2CCH2CH3)6(H2O)3](+)) were investigated in male and female FVB/NJ mice with azoxymethane-induced colorectal cancer. In contrast to a previous study on the effects of Cr3 on 1,2-dimethylhydrazine-induced colorectal cancer in Sprague Dawley rats, no effects of Cr3 at daily doses of 1 and 10 mg Cr/kg body mass were observed, leaving in question whether administration of Cr(III) compounds can delay or prevent the onset of colorectal cancer. PMID:25910900

  9. β-sitosterol prevents lipid peroxidation and improves antioxidant status and histoarchitecture in rats with 1,2-dimethylhydrazine-induced colon cancer.

    PubMed

    Baskar, Arul Albert; Al Numair, Khalid S; Gabriel Paulraj, Micheal; Alsaif, Mohammed A; Muamar, May Al; Ignacimuthu, Savarimuthu

    2012-04-01

    Oxidative stress has become widely viewed as an underlying condition in diseases such as ischemia/reperfusion disorders, central nervous system disorders, cardiovascular disease, cancer, diabetes, etc. The role that antioxidants play in the process of carcinogenesis has recently gained considerable attention. β-Sitosterol, a naturally occurring sterol molecule, is a relatively mild to moderate antioxidant and exerts beneficial effects in vitro by decreasing the level of reactive oxygen species. The present study evaluated the antioxidant potential of β-sitosterol in 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis. The enzymatic and nonenzymatic antioxidants and lipid peroxides in colonic and hepatic tissues were evaluated. Generation of reactive oxygen species, beyond the body's endogenous antioxidant capacity, causes a severe imbalance of cellular antioxidant defense mechanisms. Elevated levels of liver lipid peroxides by DMH induction were effectively decreased by β-sitosterol supplementation. β-Sitosterol also exhibited a protective action against DMH-induced depletion of antioxidants such as catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase, glutathione S-transferase, and reduced glutathione in colonic and hepatic tissues of experimental animals. Supplementation with β-sitosterol restored the levels of nonenzymatic antioxidants (vitamin C, vitamin E, and glutathione). Histopathological alterations in DMH-induced animals were restored to near normal in rats treated with β-sitosterol. Thus, β-sitosterol by virtue of its antioxidant potential may be used as an effective agent to reduce DMH-induced oxidative stress in Wistar rats and may be an effective chemopreventive drug for colon carcinogenesis. PMID:22353013

  10. In vivo measurement of the shape of the tissue-refractive-index correlation function and its applicationto detection of colorectal field carcinogenesis

    PubMed Central

    Gomes, Andrew J.; Ruderman, Sarah; DelaCruz, Mart; Wali, Ramesh K.; Roy, Hemant K.

    2012-01-01

    Abstract. Polarization-gated spectroscopy is an established method to depth-selectively interrogate the structural properties of biological tissue. We employ this method in vivo in the azoxymethane (AOM)-treated rat model to monitor the morphological changes that occur in the field of a tumor during early carcinogenesis. The results demonstrate a statistically significant change in the shape of the refractive-index correlation function for AOM-treated rats versus saline-treated controls. Since refractive index is linearly proportional to mass density, these refractive-index changes can be directly linked to alterations in the spatial distribution patterns of macromolecular density. Furthermore, we found that alterations in the shape of the refractive-index correlation function shape were an indicator of both present and future risk of tumor development. These results suggest that noninvasive measurement of the shape of the refractive-index correlation function could be a promising marker of early cancer development. PMID:22559696

  11. Nutritional factors in carcinogenesis.

    PubMed

    Wahlqvist, M L

    1993-09-01

    There have been varying estimates of the role of nutritional as opposed to other contributors to carcinogenesis. Several considerations probably account for the different estimates: (1) genetic overestimates because of foetal and early life rearing practices and the nutritional modulation of genetic expression (2) errors in food intake methodology (3) the limitations of nutrient carcinogenesis hypotheses, ie models which are too naive and do not allow for non-nutrients in food, food patterns and the overall package which is food culture (4) indirect pathways connecting nutrition and cancer such as that via immunosurveillance. Examples of cancers where rapid change in nutritional thinking is underway are breast, prostatic, colorectal and pancreatic. With breast cancer, weakly oestrogenic compounds from foods may be comparable to tamoxifen. Changing food culture away from that rich in phyto-oestrogens may increase the risk of prostatic cancer in men as well. Colorectal cancer incidence has continued at high rates in urbanized society despite an awareness of dietary contribution comparable to the knowledge of diet and coronary heart disease is the analysis sufficiently stratified for large bowel site or nutritionally sophisticated enough to allow for aggregate food pattern effects? Pancreatic cancer on the rise presents questions about unidentified changes continuing in the diets of industrialized societies, possibly from an early age, and even during infant feeding. Nutritional surveillance with mathematical modelling of food intake at a more sophisticated level will be required to understand present food-cancer relationships, and those which may emerge with newer food technologies, especially those related to designer foods. PMID:24352145

  12. Thymoquinone subdues tumor growth and potentiates the chemopreventive effect of 5-fluorouracil on the early stages of colorectal carcinogenesis in rats

    PubMed Central

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

    2016-01-01

    Colorectal cancer (CRC) is one of the most prevalent cancers and has a high mortality rate. Insensitivity and the limited therapeutic efficacy of its standard chemotherapeutic drug, 5-fluorouracil (5-FU), represents an important challenge in CRC treatment. The robust antitumor properties of thymoquinone (TQ), the main bioactive constituent of Nigella sativa, have recently been demonstrated on different cancers. We investigated whether TQ could potentiate the chemopreventive effect of 5-FU to eradicate the early stages of CRC and elucidated its underlying mechanisms. An intermediate-term (15 weeks) model of colorectal tumorigenesis was induced in male Wistar rats by azoxymethane (AOM), and the animals were randomly and equally divided into five groups: control, AOM, AOM/5-FU, AOM/TQ, and AOM/5-FU/TQ. TQ (35 mg/kg/d; 3 d/wk) was given during the seventh and 15th weeks post-AOM injection, while 5-FU was given during the ninth and tenth weeks (12 mg/kg/d for 4 days; then 6 mg/kg every other day for another four doses). At week 15, the resected colons were subjected to macroscopic, histopathological, molecular, and immunohistochemical examinations. Interestingly, 5-FU/TQ combination therapy resulted in a more significant reduction on AOM-induced colorectal tumors and large aberrant crypts foci than treatment with the individual drugs. Mechanistically, 5-FU and TQ remarkably cooperated to repress the expression of procancerous Wnt, β-catenin, NF-κB, COX-2, iNOS, VEGF, and TBRAS and upregulate the expression of anti-tumorigenesis DKK-1, CDNK-1A, TGF-β1, TGF-βRII, Smad4, and GPx. Overall, our findings present the first report describing the in vivo enhancement effect of combined TQ and 5-FU against early stages of CRC; however, further studies are required to determine the value of this combination therapy in an advanced long-term model of CRC and also to realize its clinical potential. PMID:27468227

  13. Endothelins and carcinogenesis.

    PubMed

    Olender, Jacek; Nowakowska-Zajdel, Ewa; Walkiewicz, Katarzyna; Muc-Wierzgoń, Małgorzata

    2016-01-01

    Endothelins are a family of four endogenous peptides (ET-1, ET-2, ET-3, ET-4) secreted primarily in an inactive form by the endothelium. They are activated with the participation of converting enzyme. Numerous studies have described their pleiotropic biological activity. These peptides are involved, inter alia, in the regulation of processes such as cell proliferation, migration, angiogenesis and apoptosis. Their important role in the regulation of blood pressure, tissue perfusion (especially in the central nervous system), and myocardial systolic function is also known. Moreover, changes in transcriptional activity of endothelin and its receptors may be involved, with the participation of a number of signaling pathways, in carcinogenesis, and the pathogenesis of numerous diseases (heart, kidney, lung and skin disorders, especially with the component of fibrosis). Their role has been documented in the development of breast, prostatic, colorectal, ovarian, lung, kidney, and endometrial cancer, and in melanoma. In this article we present a brief description of the endothelin group and the participation of them and their receptors in carcinogenesis. We also try to show their role as prognostic and predictive factors in human malignant tumors. The article also refers to clinical trials on the use of preparations of endothelin receptor antagonists in the design of molecular therapeutic strategies in human malignancies. PMID:27594562

  14. Bixin protects hepatocytes against 1,2-dimethylhydrazine-induced genotoxicity but does not suppress DNA damage and pre-neoplastic lesions in the colon of Wistar rats.

    PubMed

    de Oliveira, Pollyanna Francielli; de Andrade, Kelly Jacqueline Barbosa; Paula, Marcela Cristina Ferreira; Oliveira Acésio, Nathália; da Silva Moraes, Thais; Borges, Priscilla Scalon Freitas; Barcelos, Gustavo Rafael Mazzaron; Tavares, Denise Crispim

    2014-01-01

    Bixin is a carotenoid found in the seeds of Bixa orellana L., a plant native to tropical America that is used in the food industry. The aim of this study was to investigate the effect of bixin on DNA damage and pre-neoplastic lesions induced by 1,2-dimethylhydrazine (DMH) in the liver and colon of Wistar rats. The animals received bixin at daily doses of 0.1, 1.0 and 10mg/kg body weight (bw) by gavage. For the assessment of DNA damage in hepatocytes and colon cells with the comet assay, the administration of bixin was for 7 days. The animals received a single subcutaneous injection of 25mg/kg bw of DMH, and were euthanized 4h later. For the evaluation of the frequency of aberrant crypt foci (ACF), the animals were treated with the different doses of bixin for 4 weeks. Four doses of 40mg/kg bw DMH, two doses in the first week and two doses in the second week, were administered and euthanasia occurred at 4 weeks after the beginning of treatment. Bixin reduced the frequency of DNA damage in hepatocytes at the highest two doses tested (1.0 and 10mg/kg bw). On the other hand, no differences in the frequency of DNA damage in colon cells were observed between animals treated with bixin plus DMH and those treated with DMH alone. In addition, the frequency of ACF did not differ significantly between the group treated with bixin plus DMH and the DMH group. The results suggest that bixin does not suppress the formation of ACF, indicating the absence of a protective effect against colon carcinogenesis. PMID:24246722

  15. A randomized trial on folic acid supplementation and risk of recurrent colorectal adenoma

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Evidence from observational studies suggests that inadequate folate status enhances colorectal carcinogenesis, but results from some randomized trials do not support this hypothesis. Objective: To assess the effect of folic acid supplementation on recurrent colorectal adenoma, we conduc...

  16. Chemoprevention of colorectal cancer.

    PubMed

    Lang, Michaela; Gasche, Christoph

    2015-01-01

    Colorectal cancer has become one of the most prevalent malignant diseases for both men and women. Patients with inflammatory bowel diseases or certain inherited cancer syndromes are at high risk of developing colorectal cancer and have naturally the highest need for cancer prevention. In familial adenomatous polyposis (FAP) and Lynch syndrome, most of the underlying germline mutations can be detected by DNA sequencing, and medical counselling of affected individuals involves both surveillance tests and chemopreventive measures. However, as the mechanisms leading to colorectal cancer differ in these high-risk groups, the molecular action of chemopreventive drugs needs to be adjusted to the certain pathway of carcinogenesis. In the last decades, a number of drugs have been tested, including sulindac, aspirin, celecoxib, and mesalazine, but some of them are still controversially discussed. This review summarizes the advances and current standards of colorectal cancer prevention in patients with inflammatory bowel disease, FAP and Lynch syndrome. PMID:25531498

  17. Dietary fibres may protect or enhance carcinogenesis.

    PubMed

    Harris, P J; Ferguson, L R

    1999-07-15

    Dietary fibre (DF) is widely considered to protect against cancer, especially colorectal cancer. However, a large prospective epidemiological study has shown no apparent effect of DF intake on the development of colorectal cancer. We suggest that this may be because the term DF represents a wide range of materials, some able to protect, but some able to enhance carcinogenesis. This is consistent with data from animal carcinogenesis experiments. Most of the DF in western diets is in the form of plant cell walls, but these vary in their composition and it is unlikely that all types are protective. The few data available indicate that plant cell walls containing suberin or lignin may be the most protective, although they are present in only small amounts in food plants. DFs are also added to foods. These include components obtained from plant cell walls, such as pectins, as well as soluble DFs from other sources. In general, animal carcinogenesis experiments indicate that soluble DFs do not protect and some may enhance carcinogenesis. Few human intervention studies have been done on DF or sources of DF, with the exception of wheat bran, a good source of DF, which has been shown to protect. Possible mechanisms whereby DF may enhance carcinogenesis are discussed. In addition to DFs, resistant starches and non-digestible oligosaccharides are added to foods; these, like DF, escape digestion in the small intestine. However, so far only a few animal carcinogenesis experiments have been reported using these materials, and no human intervention studies. We believe caution should be exercised in the addition of such materials to food. PMID:10415434

  18. Plasminogen activators in experimental colorectal neoplasia: a role in the adenoma-carcinoma sequence?

    PubMed Central

    Gelister, J S; Lewin, M R; Driver, H E; Savage, F; Mahmoud, M; Gaffney, P J; Boulos, P B

    1987-01-01

    An important step in the transition from adenomatous polyp to invasive carcinoma is the degradation of the epithelial basement membrane. By the generation of plasmin, plasminogen activators may play an important role in regulating the extracellular protease activity required for this event to occur. The production of biofunctional urokinase and of tissue plasminogen activator was therefore investigated in the dimethylhydrazine induced rat model of colorectal neoplasia. Both adenomatous polyps (p values less than 0.001) and colorectal carcinomas (p values less than 0.001) were demonstrated to produce a significant excess of both urokinase and tissue plasminogen activator when compared with macroscopically normal colon. There was, however, no increased production of either enzyme by macroscopically normal preneoplastic colon when compared with control colon. This enhanced capacity of colorectal tumours to produce plasminogen activators and generate plasmin is thus a feature of both the premalignant as well as the malignant phenotype. These enzymes may contribute to the malignant potential of adenomatous polyps and to the invasive capacity of established carcinomas. PMID:3115868

  19. Nutrients, Foods, and Colorectal Cancer Prevention

    PubMed Central

    Song, Mingyang; Garrett, Wendy S.; Chan, Andrew T.

    2015-01-01

    Diet has an important role in the development of colorectal cancer. In the past few decades, findings from extensive epidemiologic and experimental investigation have linked consumption of several foods and nutrients to the risk of colorectal neoplasia. Calcium, fiber, milk, and whole grain have been associated with a lower risk of colorectal cancer, and red meat and processed meat with an increased risk. There is substantial evidence for the potential chemopreventive effects of vitamin D, folate, fruits and vegetables. Nutrients and foods may also interact, as a dietary pattern, to influence colorectal cancer risk. Diet likely influences colorectal carcinogenesis through several interacting mechanisms. These include the direct effects on immune responsiveness and inflammation, and the indirect effects of over-nutrition and obesity—risk factors for colorectal cancer. Emerging evidence also implicates the gut microbiota as an important effector in the relationship between diet and cancer. Dietary modification therefore has the promise of reducing colorectal cancer incidence. PMID:25575572

  20. Gut microbiota imbalance and colorectal cancer

    PubMed Central

    Gagnière, Johan; Raisch, Jennifer; Veziant, Julie; Barnich, Nicolas; Bonnet, Richard; Buc, Emmanuel; Bringer, Marie-Agnès; Pezet, Denis; Bonnet, Mathilde

    2016-01-01

    The gut microbiota acts as a real organ. The symbiotic interactions between resident micro-organisms and the digestive tract highly contribute to maintain the gut homeostasis. However, alterations to the microbiome caused by environmental changes (e.g., infection, diet and/or lifestyle) can disturb this symbiotic relationship and promote disease, such as inflammatory bowel diseases and cancer. Colorectal cancer is a complex association of tumoral cells, non-neoplastic cells and a large amount of micro-organisms, and the involvement of the microbiota in colorectal carcinogenesis is becoming increasingly clear. Indeed, many changes in the bacterial composition of the gut microbiota have been reported in colorectal cancer, suggesting a major role of dysbiosis in colorectal carcinogenesis. Some bacterial species have been identified and suspected to play a role in colorectal carcinogenesis, such as Streptococcus bovis, Helicobacter pylori, Bacteroides fragilis, Enterococcus faecalis, Clostridium septicum, Fusobacterium spp. and Escherichia coli. The potential pro-carcinogenic effects of these bacteria are now better understood. In this review, we discuss the possible links between the bacterial microbiota and colorectal carcinogenesis, focusing on dysbiosis and the potential pro-carcinogenic properties of bacteria, such as genotoxicity and other virulence factors, inflammation, host defenses modulation, bacterial-derived metabolism, oxidative stress and anti-oxidative defenses modulation. We lastly describe how bacterial microbiota modifications could represent novel prognosis markers and/or targets for innovative therapeutic strategies. PMID:26811603

  1. Carcinogenesis and aging

    SciTech Connect

    Anisimov, V.N.; Petrov, N.N.

    1987-01-01

    This 2-voluem set discusses the problem of inter-relation between carcinogenesis and aging, and the phenomenon of age-related increase in cancer incidence in animals and humans. Covered topics include current concepts in mechanisms of carcinogenesis and aging; data on chemical, radiation, ultraviolet-light, hormonal and viral carcinogenesis in aging; data on the role of age-related shifts in the activity of carcinogen-metabolizing enzymes; binding of carcinogens with macromolecules; DNA repair; tissue proliferation; and immunity and homono-metabolic patterns in realization of initiation and promotion of carcinogenesis.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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-induce...

  3. Animal Models of Colorectal Cancer

    PubMed Central

    Johnson, Robert L.; Fleet, James C.

    2012-01-01

    Colorectal cancer is a heterogeneous disease that afflicts a large number of people in the United States. The use of animal models has the potential to increase our understanding of carcinogenesis, tumor biology, and the impact of specific molecular events on colon biology. In addition, animal models with features of specific human colorectal cancers can be used to test strategies for cancer prevention and treatment. In this review we provide an overview of the mechanisms driving human cancer, we discuss the approaches one can take to model colon cancer in animals, and we describe a number of specific animal models that have been developed for the study of colon cancer. We believe that there are many valuable animal models to study various aspects of human colorectal cancer. However, opportunities for improving upon these models exist. PMID:23076650

  4. Colorectal Cancer

    MedlinePlus

    ... and rectum are part of the large intestine. Colorectal cancer occurs when tumors form in the lining of ... both men and women. The risk of developing colorectal cancer rises after age 50. You're also more ...

  5. Colorectal polyps

    MedlinePlus

    ... SJ, et al. United States Multi-Society Task Force on Colorectal Cancer. Guidelines for colonoscopy surveillance after ... consensus update by the US Multi-Society Task Force on Colorectal Cancer. Gastroenterology . 2012;143:844-857. ...

  6. Colorectal Cancer

    MedlinePlus

    ... rectum are part of the large intestine. Colorectal cancer occurs when tumors form in the lining of ... men and women. The risk of developing colorectal cancer rises after age 50. You're also more ...

  7. Mechanism of carcinogenesis in familial tumors.

    PubMed

    Tamura, Kazuo; Utsunomiya, Joji; Iwama, Takeo; Furuyama, Jun-ichi; Takagawa, Tetsuya; Takeda, Naohisa; Fukuda, Yoshihiro; Matsumoto, Takayuki; Nishigami, Takashi; Kusuhara, Kiyoshi; Sagayama, Ken; Nakagawa, Kazuhiko; Yamamura, Takehira

    2004-08-01

    It is thought that malignant tumors occur through interactions of multiple environmental factors and a personal genetic factor. A normal somatic cell having an intrinsic function is able to acquire the characteristics of a malignant cell under the influence of many factors. A small percentage of all tumors have obvious familial aggregation. These entities are called familial cancer. The familial cancer syndrome is well defined for colorectal cancer, breast cancer, endocrine neoplasia, and so on. Traits of familial tumors are sequentially inherited by offspring through gametes in a Mendelian fashion, most commonly in an autosomal-dominant manner. Carcinogenesis requires multiple genetic events. A patient with a familial tumor is ahead of an individual without any germline mutation in the carcinogenesis process. In such a situation, patients frequently suffer from multiple malignant tumors at a young age. It is well known that three major genes are closely related to the cell cycle and tumorigenesis. These gene types are protooncogenes, tumor suppressor genes, and DNA mismatch repair genes. Proto-oncogenes function to accelerate cells during the G1 or growth phase of the cell cycle. Tumor suppressor genes act as blocks against cell growth and proliferation. Inactivation of tumor suppressor genes requires alterations in both alleles. These phenomena are known as Knudson's two-hits theory. However, DNA mismatch repair genes are known as caretaker genes and correct mismatch pair generation during DNA replication. Germline mutation of DNA mismatch repair genes causes hereditary nonpolyposis colorectal cancer. The tumor phenotype from patients with hereditary nonpolyposis colorectal cancer is demonstrated to be microsatellite instability positive. PMID:15375699

  8. Carcinogenesis and aging

    SciTech Connect

    Anisimov, V.N.

    1983-01-01

    A suggested mechanism of carcinogenesis is presented. This scheme takes into account the effect of carcinogens at different integration levels: subcellular, tissue, and organism. Any of these levels may be age dependent. Age-associated changes in the activity of enzymes responsible for activation and inactivation of carcinogens, and variations in concentrations of lipids and proteins contributing to the transport of carcinogenic agents into cells, may play an important role in the modifying effect of age on carcinogenesis. The effects of age-associated changes in DNA repair need clarification. However, they are thought to exert a permissive influence on the age-associated rise in tumor incidence. It seems that proliferative activity of target tissues is the important modifying factor of carcinogenesis. Age-related changes of regulation at tissue and organism levels are also powerful factors in carcinogenesis modification. Age-dependent changes in the neuroendocrine system provide conditions for metabolic immunodepression and promotion of carcinogenesis. On the other hand, carcinogens per se (especially chemical and radiological) may intensify aging processes in the organism. Normalization, by drugs, of age-associated shifts requiring synthetic and energetic changes of a transformed tumor cells, and of immunological shifts, may exert both antitumor and geroprotective effects.

  9. Hormones and endometrial carcinogenesis.

    PubMed

    Kamal, Areege; Tempest, Nicola; Parkes, Christina; Alnafakh, Rafah; Makrydima, Sofia; Adishesh, Meera; Hapangama, Dharani K

    2016-02-01

    Endometrial cancer (EC) is the commonest gynaecological cancer in the Western World with an alarmingly increasing incidence related to longevity and obesity. Ovarian hormones regulate normal human endometrial cell proliferation, regeneration and function therefore are implicated in endometrial carcinogenesis directly or via influencing other hormones and metabolic pathways. Although the role of unopposed oestrogen in the pathogenesis of EC has received considerable attention, the emerging role of other hormones in this process, such as androgens and gonadotropin-releasing hormones (GnRH) is less well recognised. This review aims to consolidate the current knowledge of the involvement of the three main endogenous ovarian hormones (oestrogens, progesterone and androgens) as well as the other hormones in endometrial carcinogenesis, to identify important avenues for future research. PMID:26966933

  10. [Colorectal carcinoma in Cronkhite-Canada syndrome].

    PubMed

    Zügel, N P; Hehl, J A; Jechart, G; Tannapfel, A; Wienbeck, M; Witte, J

    2001-05-01

    We report a 63-year-old lady with Cronkhite-Canada syndrome, who developed colorectal cancer. A hemicolectomy was performed, and the tumor specimen was prepared for DNA-analysis and immunohistochemical screening. We found a mutation of p53 gene without APC- and ras-gene alteration and expression of erbB2-protooncogen. The polyps in non-hereditary Cronkhite-Canada-syndrom are neither adenomatous nor hyperplastic, but patients often develop colorectal cancers. The steps of mutation do not follow the adenoma-carcinoma sequence, first described by Vogelstein 1988. This and previous observations suggest that carcinogenesis in Cronkhite-Canada syndrome follows another independent sequence. PMID:11413916

  11. Cadmium carcinogenesis in review.

    PubMed

    Waalkes, M P

    2000-04-01

    Cadmium is an inorganic toxicant of great environmental and occupational concern which was classified as a human carcinogen in 1993. Occupational cadmium exposure is associated with lung cancer in humans. Cadmium exposure has also, on occasion, been linked to human prostate cancer. The epidemiological data linking cadmium and pulmonary cancer are much stronger than for prostatic cancer. Other target sites for cadmium carcinogenesis in humans (liver, kidney, stomach) are considered equivocal. In rodents, cadmium causes tumors at several sites and by various routes. Cadmium inhalation in rats results in pulmonary adenocarcinomas, supporting a role in human lung cancer. Prostate tumors and preneoplastic proliferative lesions can be induced in rats after cadmium ingestion or injection. Prostatic carcinogenesis in rats occurs only at cadmium doses below those that induce chronic degeneration and dysfunction of the testes, a well-known effect of cadmium, confirming the androgen dependency of prostate tumors. Other targets of cadmium in rodents include the testes, adrenals, injection sites, and hematopoietic system. Various treatments can modify cadmium carcinogenesis including supplemental zinc, which prevents cadmium-induced injection site and testicular tumors while facilitating prostatic tumors. Cadmium is poorly mutagenic and probably acts through indirect mechanisms, although the precise mechanisms remain unknown. PMID:10830873

  12. Dietary modifiers of carcinogenesis.

    PubMed Central

    Kohlmeier, L; Simonsen, N; Mottus, K

    1995-01-01

    Dietary components express a wide range of activities that can affect carcinogenesis. Naturally occurring substances in foods have been shown in laboratory experiments to serve as dietary antimutagens, either as bioantimutagens or as desmutagens. Dietary desmutagens may function as chemical inactivaters, enzymatic inducers, scavengers, or antioxidants. Dietary components may also act later in the carcinogenic process as tumor growth suppressors. Examples of dietary factors acting in each of these stages of carcinogenesis are presented, and potential anticarcinogens such as the carotenoids, tocopherols, phenolic compounds, glucosinolates, metal-binding proteins, phytoestrogens, and conjugated linoleic acid are discussed. Individual foods typically contain multiple potential anticarcinogens. Many of these substances can influence carcinogenesis through more than one mechanism. Some substances exhibit both anticarcinogenic and carcinogenic activity in vitro, depending on conditions. Epidemiologic research indicates that high fruit and vegetable consumption is associated with lower cancer risk. Little research has focused on the effects of single substances or single foods in man. Realization of the potential of foodborne substances to reduce the human burden of cancer will only be achieved with better measurement of dietary exposures and funding of multidisciplinary research in this area commensurate with its importance. PMID:8741780

  13. microRNAs and Colorectal Cancer.

    PubMed

    Ress, Anna Lena; Perakis, Samantha; Pichler, Martin

    2015-01-01

    Colorectal cancer (CRC) is one of the most common types of human cancer with high cancer-related morbidity and mortality rates. The development and clinical validation of novel therapeutic avenues have improved the clinical outcome, but metastatic CRC still remains an incurable disease in most cases. The interest in discovering novel pathophysiological drivers in CRC is intensively ongoing and the search for novel biomarkers for early diagnosis, for patient's stratification for prognostic purposes or for predicting treatment response are warranted. microRNAs are small RNA molecules that regulate the expression of larger messenger RNA species by different mechanisms with the final consequence to provide a fine tuning tool for global gene expression patterns. First discovered in worms, around 15 years ago it became clear that microRNAs are also existing in humans and that they are widely involved in human carcinogenesis. Within the last years, tremendous progress in the understanding of microRNAs and their role in CRC carcinogenesis has been developed. In this book chapter, several examples of previously identified microRNAs and how they influence colorectal carcinogenesis will be discussed. The information starting at the underlying molecular mechanisms towards clinical applications will be depicted and an overview what great potential these small molecules might carry in future colorectal cancer medicine, will be discussed. PMID:26658998

  14. Relationship between intestinal microbiota and colorectal cancer

    PubMed Central

    Cipe, Gokhan; Idiz, Ufuk Oguz; Firat, Deniz; Bektasoglu, Huseyin

    2015-01-01

    The human gastrointestinal tract hosts a complex and vast microbial community with up to 1011-1012 microorganisms colonizing the colon. The gut microbiota has a serious effect on homeostasis and pathogenesis through a number of mechanisms. In recent years, the relationship between the intestinal microbiota and sporadic colorectal cancer has attracted much scientific interest. Mechanisms underlying colonic carcinogenesis include the conversion of procarcinogenic diet-related factors to carcinogens and the stimulation of procarcinogenic signaling pathways in luminal epithelial cells. Understanding each of these mechanisms will facilitate future studies, leading to the development of novel strategies for the diagnosis, treatment, and prevention of colorectal cancer. In this review, we discuss the relationship between colorectal cancer and the intestinal microbiota. PMID:26483877

  15. Diet and supplements and their impact on colorectal cancer

    PubMed Central

    Pericleous, Marinos; Mandair, Dalvinder

    2013-01-01

    Background Colorectal cancer is the third commonest cancer and the third leading cause of cancer death among men and women. It has been proposed that dietary factors are responsible for 70-90% of colorectal cancer and diet optimization may prevent most cases. Aim To evaluate the role of dietary components and supplements in colorectal cancer. Methods Bibliographical searches were performed in Pubmed for the terms “diet and colorectal cancer”, “diet and colon cancer”, “diet and rectal cancer”, “nutrition and colorectal cancer”, “probiotics and colorectal cancer”, “prebiotics and colorectal cancer”, “alcohol and cancer” and “colorectal cancer epidemiology”. Results Consumption of processed or red meat, especially when cooked at high temperatures may be associated with increased risk of colorectal cancer. The evidence for dietary fibre is unclear but foods that contain high amounts of fibre are usually rich in polyphenols which have been shown to alter molecular processes that can encourage colorectal carcinogenesis. Meta-analyses provide evidence on the benefits of circulating, diet-derived and supplemented, vitamin D and Calcium. We also found that diets rich in Folate may prevent colorectal carcinoma. The evidence on dietary micronutrients such as Zinc and Selenium in association with colorectal cancer is not conclusive. It has been suggested that there may be a direct association between alcohol intake and colorectal cancer. In vitro and in vivo studies have highlighted a possible protective role of prebiotics and probiotics. Conclusions The lack of randomized trials and the presence of confounding factors including smoking, physical activity, obesity and diabetes may often yield inconclusive results. Carefully designed randomized trials are recommended. PMID:24294513

  16. Sawmill chemicals and carcinogenesis.

    PubMed Central

    Huff, J

    2001-01-01

    Workers in wood industries are exposed to variable medleys of chemicals, both natural and synthetic. Additional exposures include fungi, bacteria, bark and wood dusts, solvents, paints, and various other wood coatings. These individual and conglomerate exposures have been associated with diverse occupational illnesses and hazards, including cancers. In this commentary, I summarize both experimental and epidemiologic carcinogenesis results for several chemicals used in the wood industry, as well as for wood dust. Working in the wood industries entails excess risks of cancers, among other diseases and workplace injuries. A key to preventing occupationally and environmentally associated cancers, as in the wood industries, is avoiding exposures to chemicals and wood dusts and, in particular, chemicals known to cause cancer in animals or/and humans. PMID:11333179

  17. FXR and liver carcinogenesis

    PubMed Central

    Huang, Xiong-fei; Zhao, Wei-yu; Huang, Wen-dong

    2015-01-01

    Farnesoid X receptor (FXR) is a member of the nuclear receptor family and a ligand-modulated transcription factor. In the liver, FXR has been considered a multi-functional cell protector and a tumor suppressor. FXR can suppress liver carcinogenesis via different mechanisms: 1) FXR maintains the normal liver metabolism of bile acids, glucose and lipids; 2) FXR promotes liver regeneration and repair after injury; 3) FXR protects liver cells from death and enhances cell survival; 4) FXR suppresses hepatic inflammation, thereby preventing inflammatory damage; and 5) FXR can directly increase the expression of some tumor-suppressor genes and repress the transcription of several oncogenes. However, inflammation and epigenetic silencing are known to decrease FXR expression during tumorigenesis. The reactivation of FXR function in the liver may be a potential therapeutic approach for patients with liver cancer. PMID:25500874

  18. [Iron function and carcinogenesis].

    PubMed

    Akatsuka, Shinya; Toyokuni, Shinya

    2016-07-01

    Though iron is an essential micronutrient for humans, the excess state is acknowledged to be associated with oncogenesis. For example, iron overload in the liver of the patients with hereditary hemocromatosis highly increases the risk of hepatocellular carcinoma. Also, as to asbestos-related mesothelioma, such kinds of asbestos with a higher iron content are considered to be more carcinogenic. Iron is a useful element, which enables fundamental functions for life such as oxygen carrying and electron transport. However, in the situation where organisms are unable to have good control of it, iron turns into a dangerous element which catalyzes generation of reactive oxygen. In this review, I first outline the relationships between iron and cancer in general, then give an explanation about iron-related animal carcinogenesis models. PMID:27455808

  19. Combined therapeutic efficacy of carvacrol and X-radiation against 1,2-dimethyl hydrazine-induced experimental rat colon carcinogenesis.

    PubMed

    Arivalagan, Sivaranjani; Thomas, Nisha Susan; Chandrasekaran, Balaji; Mani, Vijay; Siddique, Aktarul Islam; Kuppsamy, Thayalan; Namasivayam, Nalini

    2015-12-01

    Colon cancer is one of the most commonly diagnosed cancers, and is a major cause of cancer morbidity and mortality worldwide. The objective of the present study is to evaluate the combined therapeutic efficacy of carvacrol (CVC) and X-radiation against 1,2-dimethylhydrazine-induced colon cancer. Male albino Wistar rats were randomly divided into six groups. Group 1 served as control; group 2 received 40 mg/kg b.wt of CVC orally everyday throughout the experimental period (32 weeks); groups 3-6 received subcutaneous injections of DMH (20 mg/kg b.wt), once a week for the first 15 weeks; group 4 received a single dose of X-radiation at the 31st week; group 5 received CVC (40 mg/kg b.wt) two days after the last injection of DMH and continued everyday till the end of the experimental period; group 6 received CVC as in group 5 and radiation as in group 4. DMH-treated rats showed increased incidence of aberrant crypt foci (ACF), dysplastic aberrant crypt foci (DACF), mast cell number, argyrophilic nucleolar organizer regions; elevated activities of phase I enzymes, decreased activities of phase II enzymes, decreased mucin content and altered colonic and liver histology as compared to control rats. Though the individual treatments with CVC and X-radiation to DMH-treated rats reversed the above changes, the combined treatment with both CVC and X-radiation showed a marked effect. Our findings emphasize the potential role of combined therapeutic effect of CVC and X-radiation against DMH-induced colon carcinogenesis. PMID:26264073

  20. An investigation into the mechanism of co-carcinogenesis of dietary cholesterol during the induction of colon cancer in rats by 1,2 dimethylhydrazine.

    PubMed

    Cruse, J P; Lewin, M R; Clark, C G

    1984-09-01

    The mechanism by which dietary cholesterol facilities colon carcinogenesis was investigated in the dimethylhydrazine-induced rat colon cancer model. Fifty female Wistar rats received a standard course of dimethylhydrazine (DMH) injections (40 mg/kg/week subcutaneously for ten weeks) while being fed Vivonex, a cholesterol-free elemental diet. Animals were allocated to one of five dietary regimens. One control group received Vivonex with added cholesterol (10 mg/100 ml Vivonex/rat/day) throughout the experiment, while another group received Vivonex alone. The remaining three groups received added cholesterol exclusively before, during or after the ten week DMH induction period. The experiment continued for over 500 days, and was evaluated by comparing, between groups, the time taken for the development of objective signs of colonic disease (time to tumour presentation or TTP). Animals either died spontaneously or were killed and autopsied. Colon cancers were confirmed histologically in every animal. The results showed that cholesterol feeding throughout the experiment or during the DMH induction period reduced the TTP compared to controls (p less than 0.05). Cholesterol prefeeding had no such effect. In the after group, the TTP was correspondingly delayed (p less than 0.05). Cholesterol-fed controls and groups receiving cholesterol during or after the DMH induction had more colon tumours and/or a greater incidence of metastases than cholesterol-free controls or those pre-fed cholesterol. The findings indicate a direct relationship between timing of cholesterol exposure and signs of colon cancer, and demonstrate that dietary cholesterol has promoter-like characteristics. PMID:6478681

  1. Primary prevention of colorectal cancer. The WHO Collaborating Centre for the Prevention of Colorectal Cancer.

    PubMed Central

    Shike, M.; Winawer, S. J.; Greenwald, P. H.; Bloch, A.; Hill, M. J.; Swaroop, S. V.

    1990-01-01

    Colorectal cancer is the third most common malignant neoplasm worldwide. Epidemiological and laboratory animal studies have established a link between various nutritional factors and the etiology of this cancer. Recent studies in genetic epidemiology and molecular biology have shown that inherited genetic factors also play an important role in colorectal carcinogenesis. Thus, genetic-nutritional interactions may form the basis for the development of this cancer. Nutritional factors that appear to promote or attenuate the carcinogenic process in the colon include fat, excess calories, fibre, calcium, selenium, and various vitamins. Strategies for primary prevention of colorectal cancer should therefore be targeted to all populations who are at risk because of dietary and hereditary predisposition. Based on current knowledge, recommended nutrition guidelines for reducing the risk of colon cancer include decreased fat consumption, adequate amounts of fruits, vegetables, and calcium, and avoidance of overweight. Research to further elucidate the role of diet in colorectal carcinogenesis should include randomized studies in humans, testing of various nutritional regimens, and the use of colonic adenomas and markers of cell proliferation and differentiation as end-points. PMID:2203551

  2. Hypermutability in carcinogenesis.

    PubMed Central

    Strauss, B S

    1998-01-01

    The presence of numerous chromosomal changes and point mutations in tumors is well established. At least some of these changes play a role in the development of the tumors. It has been suggested that the number of these genetic changes requires that tumorigenesis involves an increase in mutation rate. However, the presence of numerous changes can also be accounted for by efficient selection. What is required to settle the issue is some measure of nonselected mutations in tumors. In order to determine whether the tumor suppressor TP53 (coding for the protein p53) is hypermutable at some stage of carcinogenesis, the frequency of silent and multiple mutations in this gene has been examined. Silent mutations make up approximately 3% of the total recorded but constitute 9.5% of the mutations found in tumors with multiple mutations. Multiple closely linked mutations are also observed. Such multiple mutations suggest the operation of an error-prone replication process in a subclass of cells. The published data indicate that TP53 is hypermutable at some stage of tumor development. It is not yet clear whether TP53 is unique or whether other genes display a similar pattern of silent and multiple mutations. PMID:9560381

  3. Ionizing radiation, inflammation, and their interactions in colon carcinogenesis in Mlh1-deficient mice

    PubMed Central

    Morioka, Takamitsu; Miyoshi-Imamura, Tomoko; Blyth, Benjamin J; Kaminishi, Mutsumi; Kokubo, Toshiaki; Nishimura, Mayumi; Kito, Seiji; Tokairin, Yutaka; Tani, Shusuke; Murakami-Murofushi, Kimiko; Yoshimi, Naoki; Shimada, Yoshiya; Kakinuma, Shizuko

    2015-01-01

    Genetic, physiological and environmental factors are implicated in colorectal carcinogenesis. Mutations in the mutL homolog 1 (MLH1) gene, one of the DNA mismatch repair genes, are a main cause of hereditary colon cancer syndromes such as Lynch syndrome. Long-term chronic inflammation is also a key risk factor, responsible for colitis-associated colorectal cancer; radiation exposure is also known to increase colorectal cancer risk. Here, we studied the effects of radiation exposure on inflammation-induced colon carcinogenesis in DNA mismatch repair-proficient and repair-deficient mice. Male and female Mlh1−/− and Mlh1+/+ mice were irradiated with 2 Gy X-rays when aged 2 weeks or 7 weeks and/or were treated with 1% dextran sodium sulfate (DSS) in drinking water for 7 days at 10 weeks old to induce mild inflammatory colitis. No colon tumors developed after X-rays and/or DSS treatment in Mlh1+/+ mice. Colon tumors developed after DSS treatment alone in Mlh1−/− mice, and exposure to radiation prior to DSS treatment increased the number of tumors. Histologically, colon tumors in the mice resembled the subtype of well-to-moderately differentiated adenocarcinomas with tumor-infiltrating lymphocytes of human Lynch syndrome. Immunohistochemistry revealed that expression of both p53 and β-catenin and loss of p21 and adenomatosis polyposis coli proteins were observed at the later stages of carcinogenesis, suggesting a course of molecular pathogenesis distinct from typical sporadic or colitis-associated colon cancer in humans. In conclusion, radiation exposure could further increase the risk of colorectal carcinogenesis induced by inflammation under the conditions of Mlh1 deficiency. PMID:25529563

  4. Strong correlation between diet and development of colorectal cancer.

    PubMed

    Cappellani, Alessandro; Zanghì, Antonio; Di Vita, Maria; Cavallaro, Andrea; Piccolo, Gaetano; Veroux, Pierfrancesco; Lo Menzo, Emanuele; Cavallaro, Vincenzo; de Paoli, Paolo; Veroux, Massimiliano; Berretta, Massimiliano

    2013-01-01

    Multiple factors have been described among the causes of non-hereditary colorectal cancer. In Western countries, the most common risk factors include upper-middle socioeconomic status and dietary regimens rich in proteins and animal fats. High consumption of red meats, smoked foods, cold cuts, or canned foods is believed to contribute to carcinogenesis as they directly affect epithlial turnover and cause metabolism of biliary acids. Dietary fibers have protective effects in that they capture the fats and biliary acids, thereby inhibiting their activity. Tobacco smoking acts both locally and systemically on the colorectal mucosa through the production of carcinogenic agents. Finally, the action of alcohol, in association with nicotine addiction, also increases the risk of developing colorectal tumors. Knowledge of dietary and environmental factors is of paramount importance in implementing preventive strategies for colorectal cancer. PMID:23276917

  5. Role of micro-RNA in colorectal cancer screening.

    PubMed

    Rodríguez-Montes, José Antonio; Menéndez Sánchez, Pablo

    2014-12-01

    MicroRNAs are involved in carcinogenesis through postranscriptional gene regulatory activity. These molecules are involved in various physiological and pathological functions, such as apoptosis, cell proliferation and differentiation, which indicates their functionality in carcinogenesis as tumour suppressor genes or oncogenes. Several studies have determined the presence of microRNAs in different neoplastic diseases such as colon, prostate, breast, stomach, pancreas, and lung cancer. There are promising data on the usefulness of quantifying microRNAs in different organic fluids and tissues. We have conducted a review of the determinations of microRNAs in the diagnosis of colorectal cancer. PMID:25088411

  6. Helicobacter pylori in gastric carcinogenesis

    PubMed Central

    Ahn, Hyo Jun; Lee, Dong Soo

    2015-01-01

    Gastric cancer still is a major concern as the third most common cancer worldwide, despite declining rates of incidence in many Western countries. Helicobacter pylori (H. pylori) is the major cause of gastric carcinogenesis, and its infection insults gastric mucosa leading to the occurrence of atrophic gastritis which progress to intestinal metaplasia, dysplasia, early gastric cancer, and advanced gastric cancer consequently. This review focuses on multiple factors including microbial virulence factors, host genetic factors, and environmental factors, which can heighten the chance of occurrence of gastric adenocarcinoma due to H. pylori infection. Bacterial virulence factors are key components in controlling the immune response associated with the induction of carcinogenesis, and cagA and vacA are the most well-known pathogenic factors. Host genetic polymorphisms contribute to regulating the inflammatory response to H. pylori and will become increasingly important with advancing techniques. Environmental factors such as high salt and smoking may also play a role in gastric carcinogenesis. It is important to understand the virulence factors, host genetic factors, and environmental factors interacting in the multistep process of gastric carcinogenesis. To conclude, prevention via H. pylori eradication and controlling environmental factors such as diet, smoking, and alcohol is an important strategy to avoid H. pylori-associated gastric carcinogenesis. PMID:26690981

  7. Helicobacter pylori in gastric carcinogenesis.

    PubMed

    Ahn, Hyo Jun; Lee, Dong Soo

    2015-12-15

    Gastric cancer still is a major concern as the third most common cancer worldwide, despite declining rates of incidence in many Western countries. Helicobacter pylori (H. pylori) is the major cause of gastric carcinogenesis, and its infection insults gastric mucosa leading to the occurrence of atrophic gastritis which progress to intestinal metaplasia, dysplasia, early gastric cancer, and advanced gastric cancer consequently. This review focuses on multiple factors including microbial virulence factors, host genetic factors, and environmental factors, which can heighten the chance of occurrence of gastric adenocarcinoma due to H. pylori infection. Bacterial virulence factors are key components in controlling the immune response associated with the induction of carcinogenesis, and cagA and vacA are the most well-known pathogenic factors. Host genetic polymorphisms contribute to regulating the inflammatory response to H. pylori and will become increasingly important with advancing techniques. Environmental factors such as high salt and smoking may also play a role in gastric carcinogenesis. It is important to understand the virulence factors, host genetic factors, and environmental factors interacting in the multistep process of gastric carcinogenesis. To conclude, prevention via H. pylori eradication and controlling environmental factors such as diet, smoking, and alcohol is an important strategy to avoid H. pylori-associated gastric carcinogenesis. PMID:26690981

  8. Biomarkers in Colorectal Cancer Screening.

    PubMed

    Nguyen, Minhhuyen T; Weinberg, David S

    2016-08-01

    Colorectal cancer (CRC) is the third most common cause of cancer death in men and women in the United States. The main goals of screening are to prevent carcinogenesis (via adenoma detection and removal) and detect cancer at an early, curable stage. CRC mortality is steadily dropping in the United States, partly because of greater screening utilization. However, nearly 1 in 3 average-risk people are not up to date with standard CRC screening recommendations. This review surveys a wide range of CRC biomarkers in various stages of development, which may offer attractive risk stratification tools; a few have reached the commercial stage. If widely accepted, these tools may contribute to shift CRC screening practices away from 1-step colonoscopy to a 2-step risk stratification process of predictive biomarker measurements followed by colonoscopy for lower-risk patients with a positive result. Such strategies could potentially increase the rate of CRC screening. PMID:27496118

  9. Helicobacter pylori and colorectal neoplasia: Is there a causal link?

    PubMed

    Papastergiou, Vasilios; Karatapanis, Stylianos; Georgopoulos, Sotirios D

    2016-01-14

    Ever since Helicobacter pylori (H. pylori) was recognized as an infectious cause of gastric cancer, there has been increasing interest in examining its potential role in colorectal carcinogenesis. Data from case-control and cross-sectional studies, mostly relying on hospital-based samples, and several meta-analyses have shown a positive statistical relationship between H. pylori infection and colorectal neoplasia. However, the possibility exists that the results have been influenced by bias, including the improper selection of patients and disparities with respect to potential confounders. While the evidence falls short of a definitive causal link, it appears that infection with H. pylori/H. pylori-related gastritis is associated with an increased, although modest, risk of colorectal adenoma and cancer. The pathogenic mechanisms responsible for this association remain uncertain. H. pylori has been detected in colorectal malignant tissues; however, the possibility that H. pylori is a direct activator of colonic carcinogenesis remains purely hypothetical. On the other hand, experimental data have indicated a series of potential oncogenic interactions between these bacteria and colorectal mucosa, including induction and perpetuation of inflammatory responses, alteration of gut microflora and release of toxins and/or hormonal mediators, such as gastrin, which may contribute to tumor formation. PMID:26811614

  10. Helicobacter pylori and colorectal neoplasia: Is there a causal link?

    PubMed Central

    Papastergiou, Vasilios; Karatapanis, Stylianos; Georgopoulos, Sotirios D

    2016-01-01

    Ever since Helicobacter pylori (H. pylori) was recognized as an infectious cause of gastric cancer, there has been increasing interest in examining its potential role in colorectal carcinogenesis. Data from case-control and cross-sectional studies, mostly relying on hospital-based samples, and several meta-analyses have shown a positive statistical relationship between H. pylori infection and colorectal neoplasia. However, the possibility exists that the results have been influenced by bias, including the improper selection of patients and disparities with respect to potential confounders. While the evidence falls short of a definitive causal link, it appears that infection with H. pylori/H. pylori-related gastritis is associated with an increased, although modest, risk of colorectal adenoma and cancer. The pathogenic mechanisms responsible for this association remain uncertain. H. pylori has been detected in colorectal malignant tissues; however, the possibility that H. pylori is a direct activator of colonic carcinogenesis remains purely hypothetical. On the other hand, experimental data have indicated a series of potential oncogenic interactions between these bacteria and colorectal mucosa, including induction and perpetuation of inflammatory responses, alteration of gut microflora and release of toxins and/or hormonal mediators, such as gastrin, which may contribute to tumor formation. PMID:26811614

  11. Serrated colorectal cancer: Molecular classification, prognosis, and response to chemotherapy

    PubMed Central

    Murcia, Oscar; Juárez, Miriam; Hernández-Illán, Eva; Egoavil, Cecilia; Giner-Calabuig, Mar; Rodríguez-Soler, María; Jover, Rodrigo

    2016-01-01

    Molecular advances support the existence of an alternative pathway of colorectal carcinogenesis that is based on the hypermethylation of specific DNA regions that silences tumor suppressor genes. This alternative pathway has been called the serrated pathway due to the serrated appearance of tumors in histological analysis. New classifications for colorectal cancer (CRC) were proposed recently based on genetic profiles that show four types of molecular alterations: BRAF gene mutations, KRAS gene mutations, microsatellite instability, and hypermethylation of CpG islands. This review summarizes what is known about the serrated pathway of CRC, including CRC molecular and clinical features, prognosis, and response to chemotherapy. PMID:27053844

  12. Serrated colorectal cancer: Molecular classification, prognosis, and response to chemotherapy.

    PubMed

    Murcia, Oscar; Juárez, Miriam; Hernández-Illán, Eva; Egoavil, Cecilia; Giner-Calabuig, Mar; Rodríguez-Soler, María; Jover, Rodrigo

    2016-04-01

    Molecular advances support the existence of an alternative pathway of colorectal carcinogenesis that is based on the hypermethylation of specific DNA regions that silences tumor suppressor genes. This alternative pathway has been called the serrated pathway due to the serrated appearance of tumors in histological analysis. New classifications for colorectal cancer (CRC) were proposed recently based on genetic profiles that show four types of molecular alterations: BRAF gene mutations, KRAS gene mutations, microsatellite instability, and hypermethylation of CpG islands. This review summarizes what is known about the serrated pathway of CRC, including CRC molecular and clinical features, prognosis, and response to chemotherapy. PMID:27053844

  13. Nrf2-dependent suppression of azoxymethane/dextran sulfate sodium-induced colon carcinogenesis by the cinnamon-derived dietary factor cinnamaldehyde.

    PubMed

    Long, Min; Tao, Shasha; Rojo de la Vega, Montserrat; Jiang, Tao; Wen, Qing; Park, Sophia L; Zhang, Donna D; Wondrak, Georg T

    2015-05-01

    The progressive nature of colorectal cancer and poor prognosis associated with the metastatic phase of the disease create an urgent need for the development of more efficacious strategies targeting colorectal carcinogenesis. Cumulative evidence suggests that the redox-sensitive transcription factor Nrf2 (nuclear factor-E2-related factor 2), a master regulator of the cellular antioxidant defence, represents a promising molecular target for colorectal cancer chemoprevention. Recently, we have identified cinnamon, the ground bark of Cinnamomum aromaticum (cassia cinnamon) and Cinnamomum verum (Ceylon cinnamon), as a rich dietary source of the Nrf2 inducer cinnamaldehyde (CA) eliciting the Nrf2-regulated antioxidant response in human epithelial colon cells, conferring cytoprotection against electrophilic and genotoxic insult. Here, we have explored the molecular mechanism underlying CA-induced Nrf2 activation in colorectal epithelial cells and have examined the chemopreventive potential of CA in a murine colorectal cancer model comparing Nrf2(+/+) with Nrf2(-/-) mice. In HCT116 cells, CA caused a Keap1-C151-dependent increase in Nrf2 protein half-life via blockage of ubiquitination with upregulation of cytoprotective Nrf2 target genes and elevation of cellular glutathione. After optimizing colorectal Nrf2 activation and target gene expression by dietary CA-supplementation regimens, we demonstrated that CA suppresses AOM/DSS-induced inflammatory colon carcinogenesis with modulation of molecular markers of colorectal carcinogenesis. Dietary suppression of colorectal cancer using CA supplementation was achieved in Nrf2(+/+) but not in Nrf2(-/-) mice confirming the Nrf2 dependence of CA-induced chemopreventive effects. Taken together, our data suggest feasibility of colorectal cancer suppression by dietary CA, an FDA-approved food additive derived from the third most consumed spice in the world. PMID:25712056

  14. Potential Targets for Colorectal Cancer Prevention

    PubMed Central

    Temraz, Sally; Mukherji, Deborah; Shamseddine, Ali

    2013-01-01

    The step-wise development of colorectal neoplasia from adenoma to carcinoma suggests that specific interventions could delay or prevent the development of invasive cancer. Several key factors involved in colorectal cancer pathogenesis have already been identified including cyclooxygenase 2 (COX-2), nuclear factor kappa B (NF-κB), survivin and insulin-like growth factor-I (IGF-I). Clinical trials of COX-2 inhibitors have provided the “proof of principle” that inhibition of this enzyme can prevent the formation of colonic adenomas and potentially carcinomas, however concerns regarding the potential toxicity of these drugs have limited their use as a chemopreventative strategy. Curcumin, resveratrol and quercetin are chemopreventive agents that are able to suppress multiple signaling pathways involved in carcinogenesis and hence are attractive candidates for further research. PMID:23975167

  15. Iron homeostasis and distal colorectal adenoma risk in the prostate, lung, colorectal, and ovarian cancer screening trial.

    PubMed

    Cross, Amanda J; Sinha, Rashmi; Wood, Richard J; Xue, Xiaonan; Huang, Wen-Yi; Yeager, Meredith; Hayes, Richard B; Gunter, Marc J

    2011-09-01

    Red meat consumption has been positively associated with colorectal cancer; however, the biological mechanism underlying this relationship is not understood. Red meat is a major source of iron, which may play a role in colorectal carcinogenesis via increased crypt cell proliferation, cytotoxicity, and endogenous N-nitrosation. In a nested case-control study within the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, we prospectively evaluated multiple iron exposure parameters, including dietary intake and serum measures of iron, ferritin, transferrin, total iron binding capacity (TIBC), and unsaturated iron binding capacity (UIBC) in relation to incident colorectal adenoma in 356 cases and 396 matched polyp-free controls. We also investigated variation in eight key genes involved in iron homeostasis in relation to colorectal adenoma in an additional series totaling 1,126 cases and 1,173 matched controls. We observed a positive association between red meat intake and colorectal adenoma [OR comparing extreme quartiles (OR(q4-q1)) = 1.59, 95% CI = 1.02-2.49, P(trend) = 0.03]. Serum TIBC and UIBC were inversely associated with colorectal adenoma (OR(q4-q1) = 0.57, 95% CI = 0.37-0.88, P(trend) = 0.03; and OR(q4-q1) = 0.62, 95% CI = 0.40-0.95, P(trend) = 0.04, respectively). Colorectal adenoma was not associated with serum ferritin, iron, or transferrin saturation or with polymorphisms in genes involved in iron homeostasis. Serum TIBC and UIBC, parameters that have a reciprocal relationship with overall iron load, were inversely related to colorectal adenoma, suggesting that individuals with lower iron status have a reduced risk of developing colorectal adenoma. PMID:21685236

  16. Radiation carcinogenesis: radioprotectors and photosensitizers

    SciTech Connect

    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.

  17. Five Myths about Colorectal Cancer

    MedlinePlus

    ... ACS » Your Local Offices Close + - Text Size Five Myths About Colorectal Cancer In many cases, colorectal cancer ... screening tests you need, when you need them. Myth: Colorectal cancer is a man’s disease. Truth: Colorectal ...

  18. Mouse models for the study of colon carcinogenesis

    PubMed Central

    Rosenberg, Daniel W.; Giardina, Charles; Tanaka, Takuji

    2009-01-01

    The study of experimental colon carcinogenesis in rodents has a long history, dating back almost 80 years. There are many advantages to studying the pathogenesis of carcinogen-induced colon cancer in mouse models, including rapid and reproducible tumor induction and the recapitulation of the adenoma–carcinoma sequence that occurs in humans. The availability of recombinant inbred mouse panels and the existence of transgenic, knock-out and knock-in genetic models further increase the value of these studies. In this review, we discuss the general mechanisms of tumor initiation elicited by commonly used chemical carcinogens and how genetic background influences the extent of disease. We will also describe the general features of lesions formed in response to carcinogen treatment, including the underlying molecular aberrations and how these changes may relate to the pathogenesis of human colorectal cancer. PMID:19037092

  19. IRON AND COLORECTAL CANCER RISK IN THE ALPHA-TOCOPHEROL, BETA-CAROTENE CANCER PREVENTION STUDY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In vitro and in vivo studies have associated iron with both the initiation and promotional stages of carcinogenesis. We investigated whether iron was associated with colorectal cancer in a nested case-control study within the a-tocopherol, b-carotene cancer prevention study cohort. Exposure was asse...

  20. Folate and carcinogenesis-mechanisms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A large and growing body of both pre-clinical and clinical studies pertaining to colorectal neoplasms constitutes the most compelling evidence for the protective effect of folate against the development of cancer, although evidence is also accruing in this regard for cancers of the breast, lung, pan...

  1. Ultrastructural alterations in field carcinogenesis measured by enhanced backscattering spectroscopy

    PubMed Central

    Mutyal, Nikhil N.; Yi, Ji; Stypula-Cyrus, Yolanda; Rogers, Jeremy D.; Goldberg, Michael J.; Bianchi, Laura K.; Bajaj, Shailesh; Roy, Hemant K.; Backman, Vadim

    2013-01-01

    Abstract. Optical characterization of biological tissue in field carcinogenesis offers a method with which to study the mechanisms behind early cancer development and the potential to perform clinical diagnosis. Previously, low-coherence enhanced backscattering spectroscopy (LEBS) has demonstrated the ability to discriminate between normal and diseased organs based on measurements of histologically normal-appearing tissue in the field of colorectal (CRC) and pancreatic (PC) cancers. Here, we implement the more comprehensive enhanced backscattering (EBS) spectroscopy to better understand the structural and optical changes which lead to the previous findings. EBS provides high-resolution measurement of the spatial reflectance profile P(rs) between 30 microns and 2.7 mm, where information about nanoscale mass density fluctuations in the mucosa can be quantified. A demonstration of the length-scales at which P(rs) is optimally altered in CRC and PC field carcinogenesis is given and subsequently these changes are related to the tissue’s structural composition. Three main conclusions are made. First, the most significant changes in P(rs) occur at short length-scales corresponding to the superficial mucosal layer. Second, these changes are predominantly attributable to a reduction in the presence of subdiffractional structures. Third, similar trends are seen for both cancer types, suggesting a common progression of structural alterations in each. PMID:24008865

  2. Modeling intercellular interactions during carcinogenesis.

    PubMed

    Sachs, Rainer K; Chan, Michael; Hlatky, Lynn; Hahnfeldt, Philip

    2005-09-01

    By modulating the microenvironment of malignant or premalignant cells, inhibitory or stimulatory signals from nearby cells can play a key role in carcinogenesis. However, current commonly used quantitative models for induction of cancers by ionizing radiation focus on single cells and their progeny. Intercellular interactions are neglected or assumed to be confined to unidirectional radiation bystander effect signals from cells of the same tissue type. We here formulate a parsimoniously parameterized two-stage logistic (TSL) carcinogenesis model that incorporates some effects of intercellular interactions during the growth of premalignant cells. We show that for baseline tumor rates, involving no radiation apart from background radiation, this TSL model gives acceptable fits to a number of data sets. Specifically, it gives the same baseline hazard function, using the same number of adjustable parameters, as does the commonly used two-stage clonal expansion (TSCE) model, so it is automatically applicable to the many data sets on baseline cancer that have been analyzed using the TSCE model. For perturbations of baseline rates due to radiation, the models differ. We argue from epidemiological and laboratory evidence, especially results for the atomic bomb survivors, that for radiation carcinogenesis the TSL model gives results at least as realistic as the TSCE or similar models, despite involving fewer adjustable parameters in many cases. PMID:16137206

  3. Colorectal Cancer Prevention

    MedlinePlus

    ... Genetics of Colorectal Cancer Colorectal cancer is the second leading cause of death from cancer in the ... professional versions have detailed information written in technical language. The patient versions are written in easy-to- ...

  4. Radiogenic cell transformation and carcinogenesis

    NASA Technical Reports Server (NTRS)

    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

  5. A microenvironmental model of carcinogenesis.

    PubMed

    Gatenby, Robert A; Gillies, Robert J

    2008-01-01

    We propose that carcinogenesis requires tumour populations to surmount six distinct microenvironmental proliferation barriers that arise in the adaptive landscapes of normal and premalignant populations growing from epithelial surfaces. Somatic evolution of invasive cancer can then be viewed as a sequence of phenotypical adaptations to these barriers. The genotypical and phenotypical heterogeneity of cancer populations is explained by an equivalence principle in which multiple strategies can successfully adapt to the same barrier. This model provides a theoretical framework in which the diverse cancer genotypes and phenotypes can be understood according to their roles as adaptive strategies to overcome specific microenvironmental growth constraints. PMID:18059462

  6. High Prevalence of Human Papillomavirus in Colorectal Cancer in Hispanics: A Case-Control Study

    PubMed Central

    Bernabe-Dones, Raul D.; Gonzalez-Pons, Maria; Villar-Prados, Alejandro; Lacourt-Ventura, Mercedes; Rodríguez-Arroyo, Heriberto; Fonseca-Williams, Sharon; Velazquez, Francisco E.; Diaz-Algorri, Yaritza; Lopez-Diaz, Sofia M.; Rodríguez, Nayra; Yamamura, Yasuhiro; Cruz-Correa, Marcia

    2016-01-01

    The role of Human Papillomavirus (HPV) in colorectal carcinogenesis remains elusive. Based on the high incidence of HPV-associated malignancies among Puerto Rican Hispanics, this study aimed to assess the prevalence of HPV infection and viral integration in colorectal tissues in order to evaluate its putative role in colorectal cancer (CRC). In this case-control study, the prevalence of HPV infection in CRC (cases n = 45) and normal colon mucosa from cancer-free subjects (controls n = 36) was assessed by a nested PCR strategy. HPV-16 genotyping was performed in HPV-positive tissues and the physical status of the HPV-16 genome was determined by E2 detection. HPV was detected in 19 of 45 (42.2%) CRC cases (mean age 61.1 ± 10.7 years, 24 males) and in 1 of 36 (2.8%) controls (mean age 60.9 ± 9.6 years, 24 males) with an OR = 25.58 (95% CI 3.21 to 203.49). HPV-16 was detected in 63.2% of the HPV-positive colorectal tumors; genome integration was observed in all HPV-16 positive cases. This is the first report showing the high prevalence of HPV infections in Caribbean Hispanic colorectal tumors. Despite evidence of HPV integration into the host genome, further mechanistic analysis examining HPV oncoprotein expression and the putative role of these oncoproteins in colorectal carcinogenesis is warranted. PMID:26904111

  7. Dynamic microbe and molecule networks in a mouse model of colitis-associated colorectal cancer.

    PubMed

    Liang, Xujun; Li, Huiying; Tian, Geng; Li, Shao

    2014-01-01

    Bacterial colonisation of the gut is involved in the development of colitis-associated colorectal cancer. However, it remains unclear how the gut microbiota dynamically shifts correlating with colorectal carcinogenesis. Here, we reveal the longitudinal shifts in the microbial community that occur with colitis-associated colorectal cancer. High-throughput sequencing results for the bacterial 16S rRNA gene (V3 region) were compared for azoxymethane/dextran sodium sulphate-treated mice and control mice. We found that microbial community structure was significantly altered by chronic colitis. Microbes in the species Streptococcus luteciae, Lactobacillus hamster, Bacteroides uniformis and Bacteroides ovatus were increased during colorectal carcinogenesis. Histological measurements for a molecular network including six interconnected key factors from inflammation to cancer, namely p65, p53, COX-2, PPARγ, CCR2 and β-catenin, indicated that the microbiome modifications were correlated with molecular pathogenesis of colitis-associated colorectal cancer. Phylotype modifications after each AOM/DSS cycle were identified. A longitudinal microbial network was then constructed for the gut microbiome and showed that the phylotype shifts during this process were complex and highly dynamic. This work may provide a deeper understanding of the role of the microbiota and microbe-host interactions in colitis-associated colorectal cancer. PMID:24828543

  8. High Prevalence of Human Papillomavirus in Colorectal Cancer in Hispanics: A Case-Control Study.

    PubMed

    Bernabe-Dones, Raul D; Gonzalez-Pons, Maria; Villar-Prados, Alejandro; Lacourt-Ventura, Mercedes; Rodríguez-Arroyo, Heriberto; Fonseca-Williams, Sharon; Velazquez, Francisco E; Diaz-Algorri, Yaritza; Lopez-Diaz, Sofia M; Rodríguez, Nayra; Yamamura, Yasuhiro; Cruz-Correa, Marcia

    2016-01-01

    The role of Human Papillomavirus (HPV) in colorectal carcinogenesis remains elusive. Based on the high incidence of HPV-associated malignancies among Puerto Rican Hispanics, this study aimed to assess the prevalence of HPV infection and viral integration in colorectal tissues in order to evaluate its putative role in colorectal cancer (CRC). In this case-control study, the prevalence of HPV infection in CRC (cases n = 45) and normal colon mucosa from cancer-free subjects (controls n = 36) was assessed by a nested PCR strategy. HPV-16 genotyping was performed in HPV-positive tissues and the physical status of the HPV-16 genome was determined by E2 detection. HPV was detected in 19 of 45 (42.2%) CRC cases (mean age 61.1 ± 10.7 years, 24 males) and in 1 of 36 (2.8%) controls (mean age 60.9 ± 9.6 years, 24 males) with an OR = 25.58 (95% CI 3.21 to 203.49). HPV-16 was detected in 63.2% of the HPV-positive colorectal tumors; genome integration was observed in all HPV-16 positive cases. This is the first report showing the high prevalence of HPV infections in Caribbean Hispanic colorectal tumors. Despite evidence of HPV integration into the host genome, further mechanistic analysis examining HPV oncoprotein expression and the putative role of these oncoproteins in colorectal carcinogenesis is warranted. PMID:26904111

  9. Dynamic microbe and molecule networks in a mouse model of colitis-associated colorectal cancer

    PubMed Central

    Liang, Xujun; Li, Huiying; Tian, Geng; Li, Shao

    2014-01-01

    Bacterial colonisation of the gut is involved in the development of colitis-associated colorectal cancer. However, it remains unclear how the gut microbiota dynamically shifts correlating with colorectal carcinogenesis. Here, we reveal the longitudinal shifts in the microbial community that occur with colitis-associated colorectal cancer. High-throughput sequencing results for the bacterial 16S rRNA gene (V3 region) were compared for azoxymethane/dextran sodium sulphate-treated mice and control mice. We found that microbial community structure was significantly altered by chronic colitis. Microbes in the species Streptococcus luteciae, Lactobacillus hamster, Bacteroides uniformis and Bacteroides ovatus were increased during colorectal carcinogenesis. Histological measurements for a molecular network including six interconnected key factors from inflammation to cancer, namely p65, p53, COX-2, PPARγ, CCR2 and β-catenin, indicated that the microbiome modifications were correlated with molecular pathogenesis of colitis-associated colorectal cancer. Phylotype modifications after each AOM/DSS cycle were identified. A longitudinal microbial network was then constructed for the gut microbiome and showed that the phylotype shifts during this process were complex and highly dynamic. This work may provide a deeper understanding of the role of the microbiota and microbe-host interactions in colitis-associated colorectal cancer. PMID:24828543

  10. TNIK inhibition abrogates colorectal cancer stemness.

    PubMed

    Masuda, Mari; Uno, Yuko; Ohbayashi, Naomi; Ohata, Hirokazu; Mimata, Ayako; Kukimoto-Niino, Mutsuko; Moriyama, Hideki; Kashimoto, Shigeki; Inoue, Tomoko; Goto, Naoko; Okamoto, Koji; Shirouzu, Mikako; Sawa, Masaaki; Yamada, Tesshi

    2016-01-01

    Canonical Wnt/β-catenin signalling is essential for maintaining intestinal stem cells, and its constitutive activation has been implicated in colorectal carcinogenesis. We and others have previously identified Traf2- and Nck-interacting kinase (TNIK) as an essential regulatory component of the T-cell factor-4 and β-catenin transcriptional complex. Consistent with this, Tnik-deficient mice are resistant to azoxymethane-induced colon tumorigenesis, and Tnik(-/-)/Apc(min/+) mutant mice develop significantly fewer intestinal tumours. Here we report the first orally available small-molecule TNIK inhibitor, NCB-0846, having anti-Wnt activity. X-ray co-crystal structure analysis reveals that NCB-0846 binds to TNIK in an inactive conformation, and this binding mode seems to be essential for Wnt inhibition. NCB-0846 suppresses Wnt-driven intestinal tumorigenesis in Apc(min/+) mice and the sphere- and tumour-forming activities of colorectal cancer cells. TNIK is required for the tumour-initiating function of colorectal cancer stem cells. Its inhibition is a promising therapeutic approach. PMID:27562646

  11. TNIK inhibition abrogates colorectal cancer stemness

    PubMed Central

    Masuda, Mari; Uno, Yuko; Ohbayashi, Naomi; Ohata, Hirokazu; Mimata, Ayako; Kukimoto-Niino, Mutsuko; Moriyama, Hideki; Kashimoto, Shigeki; Inoue, Tomoko; Goto, Naoko; Okamoto, Koji; Shirouzu, Mikako; Sawa, Masaaki; Yamada, Tesshi

    2016-01-01

    Canonical Wnt/β-catenin signalling is essential for maintaining intestinal stem cells, and its constitutive activation has been implicated in colorectal carcinogenesis. We and others have previously identified Traf2- and Nck-interacting kinase (TNIK) as an essential regulatory component of the T-cell factor-4 and β-catenin transcriptional complex. Consistent with this, Tnik-deficient mice are resistant to azoxymethane-induced colon tumorigenesis, and Tnik−/−/Apcmin/+ mutant mice develop significantly fewer intestinal tumours. Here we report the first orally available small-molecule TNIK inhibitor, NCB-0846, having anti-Wnt activity. X-ray co-crystal structure analysis reveals that NCB-0846 binds to TNIK in an inactive conformation, and this binding mode seems to be essential for Wnt inhibition. NCB-0846 suppresses Wnt-driven intestinal tumorigenesis in Apcmin/+ mice and the sphere- and tumour-forming activities of colorectal cancer cells. TNIK is required for the tumour-initiating function of colorectal cancer stem cells. Its inhibition is a promising therapeutic approach. PMID:27562646

  12. MTDH genetic variants in colorectal cancer patients

    PubMed Central

    Gnosa, Sebastian; Ticha, Ivana; Haapaniemi, Staffan; Sun, Xiao-Feng

    2016-01-01

    The colorectal carcinogenesis is a complex process encompassing genetic alterations. The oncoprotein AEG-1, encoded by the MTDH gene, was shown previously to be involved in colorectal cancer (CRC). The aim of this study was to determine the frequency and the spectrum of MTDH variants in tumor tissue, and their relationship to clinicopathological variables in CRC patients. The study included tumors from 356 unselected CRC patients. Mutation analysis of the MTDH gene, including coding region and adjacent intronic sequences, was performed by direct DNA sequencing. The corresponding normal colorectal tissue was analyzed in the carriers of exonic variant to confirm germline or somatic origin. We detected 42 intronic variants, where 25 were novel. Furthermore, we found 8 exonic variants of which four, one missense (c.977C > G-germline) and three frameshift mutations (c.533delA-somatic, c.1340dupA-unknown origin, c.1731delA-unknown origin), were novel. In silico prediction analyses suggested four deleterious variants (c.232G > T, c.533delA, c.1340dupA, and c.1731delA). There were no correlations between the MTDH variants and tumor stage, differentiation or patient survival. We described several novel exonic and intronic variants of the MTDH gene. The detection of likely pathogenic truncating mutations and alterations in functional protein domains indicate their clinical significance, although none of the variants had prognostic potential. PMID:26983693

  13. Molecular mechanism of cholangiocarcinoma carcinogenesis.

    PubMed

    Maemura, Kosei; Natsugoe, Shoji; Takao, Sonshin

    2014-10-01

    Cholangiocarcinoma (CCA) is a highly malignant cancer of the biliary tract with a poor prognosis, which often arises from conditions causing long-term inflammation, injury, and reparative biliary epithelial cell proliferation. Several conditions are known to be major risk factors for cancer in the biliary tract or gallbladder, including primary sclerosing cholangitis, liver fluke infection, pancreaticobiliary maljunction, and chemical exposure in proof-printing workers. Abnormalities in various signaling cascades, molecules, and genetic mutations are involved in the pathogenesis of CCA. CCA is characterized by a series of highly recurrent mutations in genes, including KRAS, BRF, TP53, Smad, and p16(INK4a) . Cytokines that are affected by inflammatory environmental conditions, such as interleukin-6 (IL-6), transforming growth factor-β (TGF-β), tumor necrosis factor-α (TNF-α), and platelet-derived growth factor (PDGF), play an important role in cancer pathogenesis. Prominent signaling pathways important in carcinogenesis include TGF-β/Smad, IL-6/STAT-3, PI3K/AKT, Wnt, RAF/MEK/MAPK, and Notch. Additionally, some microRNAs regulate targets in critical pathways of CCA development and progression. This review article provides the understanding of the genetic and epigenetic mechanism(s) of carcinogenesis in CCA, which leads to the development of new therapeutic targets for the prevention and treatment of this devastating cancer. PMID:24895231

  14. Pancreatic carcinogenesis: apoptosis and angiogenesis.

    PubMed

    Onizuka, Shinya; Kawakami, Shunsuke; Taniguchi, Ken; Fujioka, Hikaru; Miyashita, Kosei

    2004-04-01

    Apoptosis and angiogenesis are critical biologic processes that are altered during carcinogenesis. Both apoptosis and angiogenesis may play an important role in pancreatic carcinogenesis. Despite numerous advances in the diagnosis and treatment of pancreatic cancer, its prognosis remains dismal and a new therapeutic approach is much needed. Recent research has revealed that apoptosis and angiogenesis are closely interrelated. Several reports show that a tumor suppresser gene that is expressed in pancreatic carcinoma and related to malignant potential can induce apoptosis and also inhibit angiogenesis. At present, it is generally accepted that tumor growth in cancers, including pancreatic cancer, depends on angiogenesis. We have identified 2 new angiogenesis inhibitors from a conditioned medium of human pancreatic carcinoma cell line (BxPC-3): antiangiogenic antithrombin III (aaAT-III) and vitamin D binding protein-macrophage activating factor (DBP-maf). These molecules were able to regress tumors in severe combined immunodeficiency disease (SCID) mice, demonstrating potent inhibition of endothelial cell proliferation. Moreover, the angiogenesis inhibitors induced tumor dormancy in the animal model. These results suggest that antiangiogenic therapy using angiogenesis inhibitors may become a new strategy for treatment of pancreatic cancer in the near future. PMID:15084979

  15. Expression of TMEM207 in Colorectal Cancer: Relation between TMEM207 and Intelectin-1

    PubMed Central

    Maeda, Kenichi; Saigo, Chiemi; Kito, Yusuke; Sakuratani, Takuji; Yoshida, Kazuhiro; Takeuchi, Tamotsu

    2016-01-01

    Recent research advances highlighted an intestinal goblet cell-produced lectin, intelectin-1 (also known as omentin-1), as a tumor suppressor. One study indicated that downregulation of intelectin-1 may be related to the unfavorable prognosis among patients with colorectal carcinoma at an advanced stage. The present study was aimed at analyzing the expression of a hitherto uncharacterized transmembrane protein TMEM207 in colorectal carcinoma, and we found that the TMEM207 function is linked to intelectin-1 processing. With specific antibodies, TMEM207 immunoreactivity was detected in 38 of 216 colorectal cancer tissue samples. TMEM207 immunoreactivity correlated inversely with lymph node metastatic status (p < 0.01). TMEM207 expression significantly correlated with the mucinous phenotype of colorectal carcinoma. A coimmunoprecipitation assay revealed an interaction between intelectin-1 and TMEM207 in colorectal cancer cells. A proximal ligation assay indicated that intelectin-1 and TMEM207 were colocalized to the cytoplasm of the colorectal cancer cells. A small-interfering-RNA-mediated knockdown of TMEM207 increased polyubiquitination and proteasome degradation of intelectin-1 in cultured colorectal cancer cells and decreased intelectin-1 secretion. These findings indicate that a loss of TMEM207 expression leads to insufficient intelectin-1 production thus promoting colorectal carcinogenesis. PMID:26819645

  16. Clinical applications of next-generation sequencing in colorectal cancers

    PubMed Central

    Kim, Tae-Min; Lee, Sug-Hyung; Chung, Yeun-Jun

    2013-01-01

    Like other solid tumors, colorectal cancer (CRC) is a genomic disorder in which various types of genomic alterations, such as point mutations, genomic rearrangements, gene fusions, or chromosomal copy number alterations, can contribute to the initiation and progression of the disease. The advent of a new DNA sequencing technology known as next-generation sequencing (NGS) has revolutionized the speed and throughput of cataloguing such cancer-related genomic alterations. Now the challenge is how to exploit this advanced technology to better understand the underlying molecular mechanism of colorectal carcinogenesis and to identify clinically relevant genetic biomarkers for diagnosis and personalized therapeutics. In this review, we will introduce NGS-based cancer genomics studies focusing on those of CRC, including a recent large-scale report from the Cancer Genome Atlas. We will mainly discuss how NGS-based exome-, whole genome- and methylome-sequencing have extended our understanding of colorectal carcinogenesis. We will also introduce the unique genomic features of CRC discovered by NGS technologies, such as the relationship with bacterial pathogens and the massive genomic rearrangements of chromothripsis. Finally, we will discuss the necessary steps prior to development of a clinical application of NGS-related findings for the advanced management of patients with CRC. PMID:24187453

  17. Molecular mechanisms of pancreatic carcinogenesis.

    PubMed

    Furukawa, Toru; Sunamura, Makoto; Horii, Akira

    2006-01-01

    Pancreatic ductal adenocarcinoma is one of the most fatal malignancies. Intensive investigation of molecular pathogenesis might lead to identifying useful molecules for diagnosis and treatment of the disease. Pancreatic ductal adenocarcinoma harbors complicated aberrations of alleles including losses of 1p, 6q, 9p, 12q, 17p, 18q, and 21q, and gains of 8q and 20q. Pancreatic cancer is usually initiated by mutation of KRAS and aberrant expression of SHH. Overexpression of AURKA mapping on 20q13.2 may significantly enhance overt tumorigenesity. Aberrations of tumor suppressor genes synergistically accelerate progression of the carcinogenic pathway through pancreatic intraepithelial neoplasia (PanIN) to invasive ductal adenocarcinoma. Abrogation of CDKN2A occurs in low-grade/early PanIN, whereas aberrations of TP53 and SMAD4 occur in high-grade/late PanIN. SMAD4 may play suppressive roles in tumorigenesis by inhibition of angiogenesis. Loss of 18q precedes SMAD4 inactivation, and restoration of chromosome 18 in pancreatic cancer cells results in tumor suppressive phenotypes regardless of SMAD4 status, indicating the possible existence of a tumor suppressor gene(s) other than SMAD4 on 18q. DUSP6 at 12q21-q22 is frequently abrogated by loss of expression in invasive ductal adenocarcinomas despite fairly preserved expression in PanIN, which suggests that DUSP6 works as a tumor suppressor in pancreatic carcinogenesis. Restoration of chromosome 12 also suppresses growths of pancreatic cancer cells despite the recovery of expression of DUSP6; the existence of yet another tumor suppressor gene on 12q is strongly suggested. Understanding the molecular mechanisms of pancreatic carcinogenesis will likely provide novel clues for preventing, detecting, and ultimately curing this life-threatening disease. PMID:16367914

  18. Metabolites of tobacco smoking and colorectal cancer risk.

    PubMed

    Cross, Amanda J; Boca, Simina; Freedman, Neal D; Caporaso, Neil E; Huang, Wen-Yi; Sinha, Rashmi; Sampson, Joshua N; Moore, Steven C

    2014-07-01

    Colorectal cancer is not strictly considered a tobacco-related malignancy, but modest associations have emerged from large meta-analyses. Most studies, however, use self-reported data, which are subject to misclassification. Biomarkers of tobacco exposure may reduce misclassification and provide insight into metabolic variability that potentially influences carcinogenesis. Our aim was to identify metabolites that represent smoking habits and individual variation in tobacco metabolism, and investigate their association with colorectal cancer. In a nested case-control study of 255 colorectal cancers and 254 matched controls identified in the Prostate, Lung, Colorectal and Ovarian cancer screening trial, baseline serum was used to identify metabolites by ultra-high-performance liquid-phase chromatography and mass spectrometry, as well as gas chromatography with tandem mass spectrometry. Odds ratios (OR) and 95% confidence intervals (CI) were estimated by logistic regression. Self-reported current smoking was associated with serum cotinine, O-cresol sulfate and hydroxycotinine. Self-reported current smoking of any tobacco (OR = 1.90, 95% CI: 1.02-3.54) and current cigarette smoking (OR = 1.51, 95% CI: 0.75-3.04) were associated with elevated colorectal cancer risks, although the latter was not statistically significant. Individuals with detectable levels of hydroxycotinine had an increased colorectal cancer risk compared with those with undetectable levels (OR = 2.68, 95% CI: 1.33-5.40). Although those with detectable levels of cotinine had a suggestive elevated risk of this malignancy (OR = 1.81, 95% CI: 0.98-3.33), those with detectable levels of O-cresol sulfate did not (OR = 1.16, 95% CI: 0.57-2.37). Biomarkers capturing smoking behavior and metabolic variation exhibit stronger associations with colorectal cancer than self-report, providing additional evidence for a role for tobacco in this malignancy. PMID:24648381

  19. Aberrant DNA methylation of WNT pathway genes in the development and progression of CIMP-negative colorectal cancer.

    PubMed

    Galamb, Orsolya; Kalmár, Alexandra; Péterfia, Bálint; Csabai, István; Bodor, András; Ribli, Dezső; Krenács, Tibor; Patai, Árpád V; Wichmann, Barnabás; Barták, Barbara Kinga; Tóth, Kinga; Valcz, Gábor; Spisák, Sándor; Tulassay, Zsolt; Molnár, Béla

    2016-08-01

    The WNT signaling pathway has an essential role in colorectal carcinogenesis and progression, which involves a cascade of genetic and epigenetic changes. We aimed to analyze DNA methylation affecting the WNT pathway genes in colorectal carcinogenesis in promoter and gene body regions using whole methylome analysis in 9 colorectal cancer, 15 adenoma, and 6 normal tumor adjacent tissue (NAT) samples by methyl capture sequencing. Functional methylation was confirmed on 5-aza-2'-deoxycytidine-treated colorectal cancer cell line datasets. In parallel with the DNA methylation analysis, mutations of WNT pathway genes (APC, β-catenin/CTNNB1) were analyzed by 454 sequencing on GS Junior platform. Most differentially methylated CpG sites were localized in gene body regions (95% of WNT pathway genes). In the promoter regions, 33 of the 160 analyzed WNT pathway genes were differentially methylated in colorectal cancer vs. normal, including hypermethylated AXIN2, CHP1, PRICKLE1, SFRP1, SFRP2, SOX17, and hypomethylated CACYBP, CTNNB1, MYC; 44 genes in adenoma vs. NAT; and 41 genes in colorectal cancer vs. adenoma comparisons. Hypermethylation of AXIN2, DKK1, VANGL1, and WNT5A gene promoters was higher, while those of SOX17, PRICKLE1, DAAM2, and MYC was lower in colon carcinoma compared to adenoma. Inverse correlation between expression and methylation was confirmed in 23 genes, including APC, CHP1, PRICKLE1, PSEN1, and SFRP1. Differential methylation affected both canonical and noncanonical WNT pathway genes in colorectal normal-adenoma-carcinoma sequence. Aberrant DNA methylation appears already in adenomas as an early event of colorectal carcinogenesis. PMID:27245242

  20. Gestational mutations in radiation carcinogenesis

    NASA Astrophysics Data System (ADS)

    Meza, R.; Luebeck, G.; Moolgavkar, S.

    Mutations in critical genes during gestation could increase substantially the risk of cancer. We examine the consequences of such mutations using the Luebeck-Moolgavkar model for colorectal cancer and the Lea-Coulson modification of the Luria-Delbruck model for the accumulation of mutations during gestation. When gestational mutation rates are high, such mutations make a significant contribution to cancer risk even for adult tumors. Furthermore, gestational mutations ocurring at distinct times during emryonic developmemt lead to substantially different numbers of mutated cells at birth, with early mutations leading to a large number (jackpots) of mutated cells at birth and mutation occurring late leading to only a few mutated cells. Thus gestational mutations could confer considerable heterogeneity of the risk of cancer. If the fetus is exposed to an environmental mutagen, such as ionizing radiation, the gestational mutation rate would be expected to increase. We examine the consequences of such exposures during gestation on the subsequent development of cancer.

  1. The gastrointestinal microbiota and colorectal cancer

    PubMed Central

    Dulal, Santosh; Deveaux, April; Jovov, Biljana; Han, Xuesong

    2014-01-01

    The human gut is home to a complex and diverse microbiota that contributes to the overall homeostasis of the host. Increasingly, the intestinal microbiota is recognized as an important player in human illness such as colorectal cancer (CRC), inflammatory bowel diseases, and obesity. CRC in itself is one of the major causes of cancer mortality in the Western world. The mechanisms by which bacteria contribute to CRC are complex and not fully understood, but increasing evidence suggests a link between the intestinal microbiota and CRC as well as diet and inflammation, which are believed to play a role in carcinogenesis. It is thought that the gut microbiota interact with dietary factors to promote chronic inflammation and CRC through direct influence on host cell physiology, cellular homeostasis, energy regulation, and/or metabolism of xenobiotics. This review provides an overview on the role of commensal gut microbiota in the development of human CRC and explores its association with diet and inflammation. PMID:25540232

  2. Clonal origins and parallel evolution of regionally synchronous colorectal adenoma and carcinoma

    PubMed Central

    Rhee, Je-Keun; Jung, Seung-Hyun; Lee, Sung Hak; Baek, In-Pyo; Kim, Min Sung; Lee, Sug Hyung; Chung, Yeun-Jun

    2015-01-01

    Although the colorectal adenoma-to-carcinoma sequence represents a classical cancer progression model, the evolution of the mutational landscape underlying this model is not fully understood. In this study, we analyzed eight synchronous pairs of colorectal high-grade adenomas and carcinomas, four microsatellite-unstable (MSU) and four -stable (MSS) pairs, using whole-exome sequencing. In the MSU adenoma-carcinoma pairs, we observed no subclonal mutations in adenomas that became fixed in paired carcinomas, suggesting a ‘parallel’ evolution of synchronous adenoma-to-carcinoma, rather than a ‘stepwise’ evolution. The abundance of indel (in MSU and MSS pairs) and microsatellite instability (in MSU pairs) was noted in the later adenoma- or carcinoma-specific mutations, indicating that the mutational processes and functional constraints operative in early and late colorectal carcinogenesis are different. All MSU cases exhibited clonal, truncating mutations in ACVR2A, TGFBR2, and DNA mismatch repair genes, but none were present in APC or KRAS. In three MSS pairs, both APC and KRAS mutations were identified as both early and clonal events, often accompanying clonal copy number changes. An MSS case uniquely exhibited clonal ERBB2 amplification, followed by APC and TP53 mutations as carcinoma-specific events. Along with the previously unrecognized clonal origins of synchronous colorectal adenoma-carcinoma pairs, our study revealed that the preferred sequence of mutational events during colorectal carcinogenesis can be context-dependent. PMID:26336987

  3. Clonal origins and parallel evolution of regionally synchronous colorectal adenoma and carcinoma.

    PubMed

    Kim, Tae-Min; An, Chang Hyeok; Rhee, Je-Keun; Jung, Seung-Hyun; Lee, Sung Hak; Baek, In-Pyo; Kim, Min Sung; Lee, Sug Hyung; Chung, Yeun-Jun

    2015-09-29

    Although the colorectal adenoma-to-carcinoma sequence represents a classical cancer progression model, the evolution of the mutational landscape underlying this model is not fully understood. In this study, we analyzed eight synchronous pairs of colorectal high-grade adenomas and carcinomas, four microsatellite-unstable (MSU) and four-stable (MSS) pairs, using whole-exome sequencing. In the MSU adenoma-carcinoma pairs, we observed no subclonal mutations in adenomas that became fixed in paired carcinomas, suggesting a 'parallel' evolution of synchronous adenoma-to-carcinoma, rather than a 'stepwise' evolution. The abundance of indel (in MSU and MSS pairs) and microsatellite instability (in MSU pairs) was noted in the later adenoma- or carcinoma-specific mutations, indicating that the mutational processes and functional constraints operative in early and late colorectal carcinogenesis are different. All MSU cases exhibited clonal, truncating mutations in ACVR2A, TGFBR2, and DNA mismatch repair genes, but none were present in APC or KRAS. In three MSS pairs, both APC and KRAS mutations were identified as both early and clonal events, often accompanying clonal copy number changes. An MSS case uniquely exhibited clonal ERBB2 amplification, followed by APC and TP53 mutations as carcinoma-specific events. Along with the previously unrecognized clonal origins of synchronous colorectal adenoma-carcinoma pairs, our study revealed that the preferred sequence of mutational events during colorectal carcinogenesis can be context-dependent. PMID:26336987

  4. High occurrence of Fusobacterium nucleatum and Clostridium difficile in the intestinal microbiota of colorectal carcinoma patients

    PubMed Central

    Fukugaiti, Márcia H.; Ignacio, Aline; Fernandes, Miriam R.; Ribeiro, Ulysses; Nakano, Viviane; Avila-Campos, Mario J.

    2015-01-01

    Abstract Colorectal carcinoma is considered the fourth leading cause of cancer deaths worldwide. Several microorganisms have been associated with carcinogenesis, including Enterococcus spp., Helicobacter pylori, enterotoxigenic Bacteroides fragilis, pathogenic E. coli strains and oral Fusobacterium. Here we qualitatively and quantitatively evaluated the presence of oral and intestinal microorganisms in the fecal microbiota of colorectal cancer patients and healthy controls. Seventeen patients (between 49 and 70 years-old) visiting the Cancer Institute of the Sao Paulo State were selected, 7 of whom were diagnosed with colorectal carcinoma. Bacterial detection was performed by qRT-PCR. Although all of the tested bacteria were detected in the majority of the fecal samples, quantitative differences between the Cancer Group and healthy controls were detected only for F. nucleatum and C. difficile. The three tested oral microorganisms were frequently observed, suggesting a need for furthers studies into a potential role for these bacteria during colorectal carcinoma pathogenesis. Despite the small number of patients included in this study, we were able to detect significantly more F. nucleatum and C. difficile in the Cancer Group patients compared to healthy controls, suggesting a possible role of these bacteria in colon carcinogenesis. This finding should be considered when screening for colorectal cancer. PMID:26691472

  5. Anti-cancer properties of phenolics from apple waste on colon carcinogenesis in vitro.

    PubMed

    McCann, M J; Gill, C I R; O' Brien, G; Rao, J R; McRoberts, W C; Hughes, P; McEntee, R; Rowland, I R

    2007-07-01

    Colorectal cancer is one of the most common cancers in Western countries. The World Health Organisation identifies diet as a critical risk factor in the development and progression of this disease and the protective role of high levels of fruit and vegetable consumption. Several studies have shown that apples contain several phenolic compounds that are potent anti-oxidants in humans. However, little is known about other beneficial properties of apple phenolics in cancer. We have used the HT29, HT115 and CaCo-2 cell lines as in vitro models to examine the effect of apple phenolics (0.01-0.1% apple extract) on key stages of colorectal carcinogenesis, namely; DNA damage (Comet assay), colonic barrier function (TER assay), cell cycle progression (DNA content assay) and invasion (Matrigel assay). Our results indicate that a crude extract of apple phenolics can protect against DNA damage, improve barrier function and inhibit invasion (p<0.05). The anti-invasive effects of the extract were enhanced with twenty-four hour pretreatment of cells (p<0.05). We have shown that a crude apple extract from waste, rich in phenolic compounds, beneficially influences key stages of carcinogenesis in colon cells in vitro. PMID:17300861

  6. Somatic gene copy number alterations in colorectal cancer: new quest for cancer drivers and biomarkers.

    PubMed

    Wang, H; Liang, L; Fang, J-Y; Xu, J

    2016-04-21

    Colorectal cancer (CRC) results from the accumulation of genetic alterations, and somatic copy number alterations (CNAs) are crucial for the development of CRC. Genome-wide survey of CNAs provides opportunities for identifying cancer driver genes in an unbiased manner. The detection of aberrant CNAs may provide novel markers for the early diagnosis and personalized treatment of CRC. A major challenge in array-based profiling of CNAs is to distinguish the alterations that play causative roles from the random alterations that accumulate during colorectal carcinogenesis. In this view, we systematically discuss the frequent CNAs in CRC, focusing on functional genes that have potential diagnostic, prognostic and therapeutic significance. PMID:26257062

  7. Mechanisms of non-genotoxic carcinogenesis.

    PubMed

    Shaw, I C; Jones, H B

    1994-03-01

    Until recently, the mechanism of carcinogenesis has been regarded as a two-stage phenomenon involving damage to the genetic material, which initiates the process, followed by a cell-division stimulus, which promotes the development of the tumour. However, exposure to some chemicals has been shown to result in carcinogenesis without involvement of the initiation step. The mechanism of non-genotoxic carcinogenesis is not fully understood, but is believed to involve stimulation of cell division with a consequent increased probability of a mutation occurring spontaneously. In this article, Ian Shaw and Huw Jones review the theories of non-genotoxic carcinogenesis with reference to specific examples of known non-genotoxic carcinogens. PMID:8184492

  8. Targeting cell death signaling in colorectal cancer: Current strategies and future perspectives

    PubMed Central

    Koehler, Bruno Christian; Jäger, Dirk; Schulze-Bergkamen, Henning

    2014-01-01

    The evasion from controlled cell death induction has been considered as one of the hallmarks of cancer cells. Defects in cell death signaling are a fundamental phenomenon in colorectal cancer. Nearly any non-invasive cancer treatment finally aims to induce cell death. However, apoptosis resistance is the major cause for insufficient therapeutic success and disease relapse in gastrointestinal oncology. Various compounds have been developed and evaluated with the aim to meet with this obstacle by triggering cell death in cancer cells. The aim of this review is to illustrate current approaches and future directions in targeting cell death signaling in colorectal cancer. The complex signaling network of apoptosis will be demonstrated and the “druggability” of targets will be identified. In detail, proteins regulating mitochondrial cell death in colorectal cancer, such as Bcl-2 and survivin, will be discussed with respect to potential therapeutic exploitation. Death receptor signaling and targeting in colorectal cancer will be outlined. Encouraging clinical trials including cell death based targeted therapies for colorectal cancer are under way and will be demonstrated. Our conceptual understanding of cell death in cancer is rapidly emerging and new types of controlled cellular death have been identified. To meet this progress in cell death research, the implication of autophagy and necroptosis for colorectal carcinogenesis and therapeutic approaches will also be depicted. The main focus of this topic highlight will be on the revelation of the complex cell death concepts in colorectal cancer and the bridging from basic research to clinical use. PMID:24587670

  9. The TNF family member APRIL promotes colorectal tumorigenesis

    PubMed Central

    Lascano, V; Zabalegui, L F; Cameron, K; Guadagnoli, M; Jansen, M; Burggraaf, M; Versloot, M; Rodermond, H; van der Loos, C; Carvalho-Pinto, C E; Kalthoff, H; Medema, J P; Hahne, M

    2012-01-01

    The tumor necrosis factor (TNF) family member APRIL (A proliferation inducing ligand) is a disease promoter in B-cell malignancies. APRIL has also been associated with a wide range of solid malignancies, including colorectal cancer (CRC). As evidence for a supportive role of APRIL in solid tumor formation was still lacking, we studied the involvement of APRIL in CRC. We observed that ectopic APRIL expression exacerbates the number and size of adenomas in ApcMin mice and in a mouse model for colitis-associated colon carcinogenesis. Furthermore, knockdown of APRIL in primary spheroid cultures of colon cancer cells and both mouse and human CRC cell lines reduced tumor clonogenicity and in vivo outgrowth. Taken together, our data therefore indicate that both tumor-derived APRIL and APRIL produced by non-tumor cells is supportive in colorectal tumorigenesis. PMID:22705846

  10. Role of MGMT as biomarker in colorectal cancer

    PubMed Central

    Inno, Alessandro; Fanetti, Giuseppe; Di Bartolomeo, Maria; Gori, Stefania; Maggi, Claudia; Cirillo, Massimo; Iacovelli, Roberto; Nichetti, Federico; Martinetti, Antonia; de Braud, Filippo; Bossi, Ilaria; Pietrantonio, Filippo

    2014-01-01

    O6-methylguanine DNA methyltransferase (MGMT) gene promoter methylation plays an important role in colorectal carcinogenesis, occurring in about 30%-40% of metastatic colorectal cancer. Its prognostic role has not been defined yet, but loss of expression of MGMT, which is secondary to gene promoter methylation, results in an interesting high response to alkylating agents such as dacarbazine and temozolomide. In a phase 2 study on heavily pre-treated patients with MGMT methylated metastatic colorectal cancer, temozolomide achieved about 30% of disease control rate. Activating mutations of RAS or BRAF genes as well as mismatch repair deficiency may represent mechanisms of resistance to alkylating agents, but a dose-dense schedule of temozolomide may potentially restore sensitivity in RAS-mutant patients. Further development of temozolomide in MGMT methylated colorectal cancer includes investigation of synergic combinations with other agents such as fluoropyrimidines and research for additional biomarkers, in order to better define the role of temozolomide in the treatment of individual patients. PMID:25516857

  11. Nrf2-dependent suppression of azoxymethane/dextran sulfate sodium-induced colon carcinogenesis by the cinnamon-derived dietary factor cinnamaldehyde

    PubMed Central

    Long, Min; Tao, Shasha; de la Vega, Montserrat Rojo; Jiang, Tao; Wen, Qing; Park, Sophia L.; Zhang, Donna D.; Wondrak, Georg T.

    2015-01-01

    The progressive nature of colorectal cancer (CRC) and poor prognosis associated with the metastatic phase of the disease create an urgent need for the development of more efficacious strategies targeting colorectal carcinogenesis. Cumulative evidence suggests that the redox-sensitive transcription factor Nrf2 (nuclear factor-E2-related factor 2), a master regulator of the cellular antioxidant defence, represents a promising molecular target for CRC chemoprevention. Recently, we have identified cinnamon, the ground bark of Cinnamomum aromaticum (cassia cinnamon) and Cinnamomum verum (Ceylon cinnamon), as a rich dietary source of the Nrf2 inducer cinnamaldehyde (CA) eliciting the Nrf2-regulated antioxidant response in human epithelial colon cells, conferring cytoprotection against electrophilic and genotoxic insult. Here, we have explored the molecular mechanism underlying CA-induced Nrf2 activation in colorectal epithelial cells and have examined the chemopreventive potential of CA in a murine CRC model comparing Nrf2+/+ and Nrf2−/− mice. In HCT116 cells, CA caused a Keap1-C151-dependent increase in Nrf2 protein half-life via blockage of ubiquitination with upregulation of cytoprotective Nrf2 target genes and elevation of cellular glutathione. After optimizing colorectal Nrf2 activation and target gene expression by dietary CA-supplementation regimens, we demonstrated that CA suppresses AOM/DSS-induced inflammatory colon carcinogenesis with modulation of molecular markers of colorectal carcinogenesis. Dietary suppression of CRC using CA supplementation was achieved in Nrf2+/+ but not in Nrf2−/− mice confirming the Nrf2-dependence of CA-induced chemopreventive effects. Taken together, our data suggest feasibility of CRC suppression by dietary CA, an FDA-approved food additive derived from the third most consumed spice in the world. PMID:25712056

  12. The AOM/DSS murine model for the study of colon carcinogenesis: From pathways to diagnosis and therapy studies

    PubMed Central

    Robertis, Mariangela De; Massi, Emanuela; Poeta, Maria Luana; Carotti, Simone; Morini, Sergio; Cecchetelli, Loredana; Signori, Emanuela; Fazio, Vito Michele

    2011-01-01

    Colorectal cancer (CRC) is a major health problem in industrialized countries. Although inflammation-linked carcinogenesis is a well accepted concept and is often observed within the gastrointestinal tract, the underlying mechanisms remain to be elucidated. Inflammation can indeed provide initiating and promoting stimuli and mediators, generating a tumour-prone microenvironment. Many murine models of sporadic and inflammation-related colon carcinogenesis have been developed in the last decade, including chemically induced CRC models, genetically engineered mouse models, and xenoplants. Among the chemically induced CRC models, the combination of a single hit of azoxymethane (AOM) with 1 week exposure to the inflammatory agent dextran sodium sulphate (DSS) in rodents has proven to dramatically shorten the latency time for induction of CRC and to rapidly recapitulate the aberrant crypt foci–adenoma–carcinoma sequence that occurs in human CRC. Because of its high reproducibility and potency, as well as the simple and affordable mode of application, the AOM/DSS has become an outstanding model for studying colon carcinogenesis and a powerful platform for chemopreventive intervention studies. In this article we highlight the histopathological and molecular features and describe the principal genetic and epigenetic alterations and inflammatory pathways involved in carcinogenesis in AOM/DSS–treated mice; we also present a general overview of recent experimental applications and preclinical testing of novel therapeutics in the AOM/DSS model. PMID:21483655

  13. Transplacental arsenic carcinogenesis in mice

    SciTech Connect

    Waalkes, Michael P. Liu, Jie; Diwan, Bhalchandra A.

    2007-08-01

    Our work has focused on the carcinogenic effects of in utero arsenic exposure in mice. Our data show that a short period of maternal exposure to inorganic arsenic in the drinking water is an effective, multi-tissue carcinogen in the adult offspring. These studies have been reproduced in three temporally separate studies using two different mouse strains. In these studies pregnant mice were treated with drinking water containing sodium arsenite at up to 85 ppm arsenic from days 8 to 18 of gestation, and the offspring were observed for up to 2 years. The doses used in all these studies were well tolerated by both the dam and offspring. In C3H mice, two separate studies show male offspring exposed to arsenic in utero developed liver carcinoma and adrenal cortical adenoma in a dose-related fashion during adulthood. Prenatally exposed female C3H offspring show dose-related increases in ovarian tumors and lung carcinoma and in proliferative lesions (tumors plus preneoplastic hyperplasia) of the uterus and oviduct. In addition, prenatal arsenic plus postnatal exposure to the tumor promoter, 12-O-tetradecanoyl phorbol-13-acetate (TPA) in C3H mice produces excess lung tumors in both sexes and liver tumors in females. Male CD1 mice treated with arsenic in utero develop tumors of the liver and adrenal and renal hyperplasia while females develop tumors of urogenital system, ovary, uterus and adrenal and hyperplasia of the oviduct. Additional postnatal treatment with diethylstilbestrol or tamoxifen after prenatal arsenic in CD1 mice induces urinary bladder transitional cell proliferative lesions, including carcinoma and papilloma, and enhances the carcinogenic response in the liver of both sexes. Overall this model has provided convincing evidence that arsenic is a transplacental carcinogen in mice with the ability to target tissues of potential human relevance, such as the urinary bladder, lung and liver. Transplacental carcinogenesis clearly occurs with other agents in humans

  14. Decorin deficiency promotes hepatic carcinogenesis

    PubMed Central

    Horváth, Zsolt; Kovalszky, Ilona; Fullár, Alexandra; Kiss, Katalin; Schaff, Zsuzsa; Iozzo, Renato V.; Baghy, Kornélia

    2014-01-01

    experimental carcinogenesis by providing an environment devoid of this potent pan-RTK inhibitor. Thus, our results support future utilization of decorin as an antitumor agent in liver cancer. PMID:24361483

  15. Modeling Multiple Causes of Carcinogenesis

    SciTech Connect

    Jones, T D

    1999-01-24

    multiple causes of carcinogenesis and shifts the risk-assessment logic to considerations of "what dose does?" in contrast to the current process of the substance-specific question of "what dose is?" Whether reactive oxygen is the proximate or contributing cause of disease or simply a better estimate of biologically effective dose, it has enormous advantages for improved risk- and policy-based decisions. Various estimates of immune system modulation will be given based on radiobiology.

  16. Radiation carcinogenesis: lessons from Chernobyl.

    PubMed

    Williams, D

    2008-12-01

    Radiation is a carcinogen, interacting with DNA to produce a range of mutations. Irradiated cells also show genomic instability, as do adjacent non-irradiated cells (the bystander effect); the importance to carcinogenesis remains to be established. Current knowledge of radiation effects is largely dependent on evidence from exposure to atomic bomb whole body radiation, leading to increases in a wide range of malignancies. In contrast, millions of people were exposed to radioactive isotopes in the fallout from the Chernobyl accident, within the first 20 years there was a large increase in thyroid carcinoma incidence and a possible radiation-related increase in breast cancer, but as yet there is no general increase in malignancies. The increase in thyroid carcinoma, attributable to the very large amounts of iodine 131 released, was first noticed in children with a strong relationship between young age at exposure and risk of developing papillary thyroid carcinoma (PTC). The extent of the increase, the reasons for the relationship to age at exposure, the reduction in attributable fraction with increasing latency and the role of environmental factors are discussed. The large number of radiation-induced PTCs has allowed new observations. The subtype and molecular findings change with latency; most early cases were solid PTCs with RET-PTC3 rearrangements, later cases were classical PTCs with RET-PTC1 rearrangements. Small numbers of many other RET rearrangements have occurred in 'Chernobyl' PTCs, and also rearrangement of BRAF. Five of the N-terminal genes found in papillary carcinoma rearrangements are also involved in rearrangements in hematological malignancies; three are putative tumor suppressor genes, and two are further genes fused to RET in PTCs. Radiation causes double-strand breaks; the rearrangements common in these radiation-induced tumors reflect their etiology. It is suggested that oncogenic rearrangements may commonly involve both a tumor-suppressor gene

  17. What Is Colorectal Cancer?

    MedlinePlus

    ... on staging, see “ Colorectal cancer stages ” The normal colon and rectum The colon and rectum are parts ... through the anus . Types of cancer in the colon and rectum Adenocarcinomas make up more than 95% ...

  18. Colorectal Cancer Coalition

    MedlinePlus

    ... Million Strong Shop Join the Movement Share Your Story Check our Calendar Colorectal Support Community Latest News Help Wanted Read Blogs Get Social Free Printable Coloring Sheets Action Alerts About Our ...

  19. Tests for Colorectal Cancer

    MedlinePlus

    ... to look for colorectal cancer Imaging tests use sound waves, x-rays, magnetic fields, or radioactive substances to ... has spread to the liver. Ultrasound Ultrasound uses sound waves and their echoes to create images of the ...

  20. Epidemiology of colorectal cancer.

    PubMed

    Boyle, Peter; Leon, Maria Elena

    2002-01-01

    Colorectal cancer is a important public health problem: there are nearly one million new cases of colorectal cancer diagnosed world-wide each year and half a million deaths. Recent reports show that, in the US, it was the most frequent form of cancer among persons aged 75 years and older. Given that the majority of cancers occur in elder people and with the ageing of the population in mind, this observation gives further impetus to investigating prevention and treatment strategies among this subgroup of the population. Screening research, recommendations and implementation is an obvious priority. While there are many questions to be resolved, it is apparent that many facets of colorectal cancer are becoming increasingly understood and prospects for prevention are becoming apparent. Achieving colorectal cancer control is the immediate challenge. PMID:12421722

  1. Anticancer Effect of Lycopene in Gastric Carcinogenesis

    PubMed Central

    Kim, Mi Jung; Kim, Hyeyoung

    2015-01-01

    Gastric cancer ranks as the most common cancer and the second leading cause of cancer-related death in the world. Risk factors of gastric carcinogenesis include oxidative stress, DNA damage, Helicobacter pylori infection, bad eating habits, and smoking. Since oxidative stress is related to DNA damage, smoking, and H. pylori infection, scavenging of reactive oxygen species may be beneficial for prevention of gastric carcinogenesis. Lycopene, one of the naturally occurring carotenoids, has unique structural and chemical features that contributes to a potent antioxidant activity. It shows a potential anticancer activity and reduces gastric cancer incidence. This review will summarize anticancer effect and mechanism of lycopene on gastric carcinogenesis based on the recent experimental and clinical studies. PMID:26151041

  2. Anticancer Effect of Lycopene in Gastric Carcinogenesis.

    PubMed

    Kim, Mi Jung; Kim, Hyeyoung

    2015-06-01

    Gastric cancer ranks as the most common cancer and the second leading cause of cancer-related death in the world. Risk factors of gastric carcinogenesis include oxidative stress, DNA damage, Helicobacter pylori infection, bad eating habits, and smoking. Since oxidative stress is related to DNA damage, smoking, and H. pylori infection, scavenging of reactive oxygen species may be beneficial for prevention of gastric carcinogenesis. Lycopene, one of the naturally occurring carotenoids, has unique structural and chemical features that contributes to a potent antioxidant activity. It shows a potential anticancer activity and reduces gastric cancer incidence. This review will summarize anticancer effect and mechanism of lycopene on gastric carcinogenesis based on the recent experimental and clinical studies. PMID:26151041

  3. [Colorectal foreign bodies].

    PubMed

    Thim, Troels; Laurberg, Søren

    2006-09-25

    A patient with a retained anally introduced colorectal foreign body or complications hereof needs appropriate treatment. The patient may be in danger and is certainly in discomfort. The problem is relatively rare; however, its incidence may be expected to increase. Guidelines for handling of the situation are lacking in many textbooks. Here, a suggestion for handling of a patient with a retained colorectal foreign body or complications hereof is presented. PMID:17032594

  4. Colorectal cancer in adolescents.

    PubMed Central

    Shankar, A.; Renaut, A. J.; Whelan, J.; Taylor, I.

    1999-01-01

    Colorectal cancer, one of the most common malignancies among adults, is rare in adolescence. This low incidence coupled with non-specific symptoms and aggressive natural history leads to a poorer prognosis than in reported adult series. This article describes two cases of colorectal cancer in adolescents and reviews the literature regarding this rare condition. Earlier diagnosis and a greater understanding of the natural history may lead to improved treatment with concomitant improvements in survival. Images Figure 1 Figure 2 PMID:10364965

  5. Colorectal carcinoma: Pathologic aspects

    PubMed Central

    Fleming, Matthew; Ravula, Sreelakshmi; Tatishchev, Sergei F.

    2012-01-01

    Colorectal carcinoma is one of the most common cancers and one of the leading causes of cancer-related death in the United States. Pathologic examination of biopsy, polypectomy and resection specimens is crucial to appropriate patient managemnt, prognosis assessment and family counseling. Molecular testing plays an increasingly important role in the era of personalized medicine. This review article focuses on the histopathology and molecular pathology of colorectal carcinoma and its precursor lesions, with an emphasis on their clinical relevance. PMID:22943008

  6. Screening for colorectal cancer.

    PubMed Central

    Campbell, W. J.; Moorehead, R. J.

    1997-01-01

    Colorectal carcinoma represents a major cause of cancer deaths in the United Kingdom. Tumours detected at an early or even premalignant stage have a better prognosis. In this review we consider the argument for screening for colorectal carcinomas and discuss the means available and the implications of implementing screening programmes using some of these methods. A suggestion is made for the more rational use of limited resources to target those at greatest risk. PMID:9185482

  7. Screening for colorectal cancer.

    PubMed

    He, Jin; Efron, Jonathan E

    2011-01-01

    March is national colorectal cancer awareness month. It is estimated that as many as 60% of colorectal cancer deaths could be prevented if all men and women aged 50 years or older were screened routinely. In 2000, Katie Couric's televised colonoscopy led to a 20% increase in screening colonoscopies across America, a stunning rise called the "Katie Couric Effect". This event demonstrated how celebrity endorsement affects health behavior. Currently, discussion is ongoing about the optimal strategy for CRC screening, particularly the costs of screening colonoscopy. The current CRC screening guidelines are summarized in Table 2. Debates over the optimum CRC screening test continue in the face of evidence that 22 million Americans aged 50 to 75 years are not screened for CRC by any modality and 25,000 of those lives may have been saved if they had been screened for CRC. It is clear that improving screening rates and reducing disparities in underscreened communities and population subgroups could further reduce colorectal cancer morbidity and mortality. National Institutes of Health consensus identified the following priority areas to enhance the use and quality of colorectal cancer screening: Eliminate financial barriers to colorectal cancer screening and appropriate follow-up of positive results of colorectal cancer screening. Develop systems to ensure the high quality of colorectal cancer screening programs. Conduct studies to determine the comparative effectiveness of the various colorectal cancer screening methods in usual practice settings. Encouraging population adherence to screening tests and allowing patients to select the tests they prefer may do more good (as long as they choose something) than whatever procedure is chosen by the medical profession as the preferred test. PMID:21954677

  8. [Epidemiology of colorectal cancer].

    PubMed

    Bouvier, Anne-Marie; Launoy, Guy

    2015-06-01

    The incidence of colorectal cancer increased in France until the 2000s' then decreased. Time trends in incidence for this cancer varied according to its sublocation along the gut. Incidence increased for right and left colon cancers, whereas it remained stable for sigmoid cancers in males and decreased in females. Incidence decreased over time for rectal cancers. The proportion of colorectal cancer in the overall French cancer prevalence is 12%. In 2008, 121,000 patients had a colorectal cancer diagnosed in the 5 previous years. The cumulative risk of colorectal cancer increased from 3.9% for males born around 1900 to 4.9% for those born around 1930 and then slightly decreased, being 4.5% among those born around 1950. It remained at the same level for females and was 2.9% for those born around 1950. The prognosis of colorectal cancer improved over time. Net 5-year survival increased in males from 53% for cancers diagnosed between 1989 and 1991 to 58% for those diagnosed between 2001 and 2004. The highest improvement of 10 year survival rates concerned left colon and rectosigmoid junction (+19% in a decade). The progressive set up of national colorectal screening since the early 2000's and the introduction of recent immunological tests in 2015 should decrease the mortality for this cancer and, at term, should decrease its incidence too. PMID:26298897

  9. Inflammation and colorectal cancer, when microbiota-host mutualism breaks

    PubMed Central

    Candela, Marco; Turroni, Silvia; Biagi, Elena; Carbonero, Franck; Rampelli, Simone; Fiorentini, Carla; Brigidi, Patrizia

    2014-01-01

    Structural changes in the gut microbial community have been shown to accompany the progressive development of colorectal cancer. In this review we discuss recent hypotheses on the mechanisms involved in the bacteria-mediated carcinogenesis, as well as the triggering factors favoring the shift of the gut microbiota from a mutualistic to a pro-carcinogenic configuration. The possible role of inflammation, bacterial toxins and toxic microbiota metabolites in colorectal cancer onset is specifically discussed. On the other hand, the strategic role of inflammation as the keystone factor in driving microbiota to become carcinogenic is suggested. As a common outcome of different environmental and endogenous triggers, such as diet, aging, pathogen infection or genetic predisposition, inflammation can compromise the microbiota-host mutualism, forcing the increase of pathobionts at the expense of health-promoting groups, and allowing the microbiota to acquire an overall pro-inflammatory configuration. Consolidating inflammation in the gut, and favoring the bloom of toxigenic bacterial drivers, these changes in the gut microbial ecosystem have been suggested as pivotal in promoting carcinogenesis. In this context, it will become of primary importance to implement dietary or probiotics-based interventions aimed at preserving the microbiota-host mutualism along aging, counteracting deviations that favor a pro-carcinogenic microbiota asset. PMID:24574765

  10. Fecal DNA testing for colorectal cancer screening: Molecular targets and perspectives

    PubMed Central

    Dhaliwal, Amaninder; Vlachostergios, Panagiotis J; Oikonomou, Katerina G; Moshenyat, Yitzchak

    2015-01-01

    The early detection of colorectal cancer with effective screening is essential for reduction of cancer-specific mortality. The addition of fecal DNA testing in the armamentarium of screening methods already in clinical use launches a new era in the noninvasive part of colorectal cancer screening and emanates from a large number of previous and ongoing clinical investigations and technological advancements. In this review, we discuss the molecular rational and most important genetic alterations hallmarking the early colorectal carcinogenesis process. Also, representative DNA targets-markers and key aspects of their testing at the clinical level in comparison or/and association with other screening methods are described. Finally, a critical view of the strengths and limitations of fecal DNA tests is provided, along with anticipated barriers and suggestions for further exploitation of their use. PMID:26483873

  11. Get Tested for Colorectal Cancer

    MedlinePlus

    ... section Colorectal Cancer 4 of 6 sections Take Action! Take Action: Get Tested The best way to prevent colorectal ... I at Risk? 5 of 6 sections Take Action: Healthy Habits Quit smoking. People who smoke are ...

  12. 6 Common Cancers - Colorectal Cancer

    MedlinePlus

    ... Home Current Issue Past Issues 6 Common Cancers - Colorectal Cancer Past Issues / Spring 2007 Table of Contents For ... of colon cancer. Photo: AP Photo/Ron Edmonds Colorectal Cancer Cancer of the colon (large intestine) or rectum ( ...

  13. Risks of Colorectal Cancer Screening

    MedlinePlus

    ... Genetics of Colorectal Cancer Colorectal cancer is the second leading cause of death from cancer in the ... professional versions have detailed information written in technical language. The patient versions are written in easy-to- ...

  14. Developments in Colorectal Cancer Screening

    MedlinePlus

    ... on. Feature: Colorectal Cancer Developments in Colorectal Cancer Screening Summer 2016 Table of Contents Dr. Asad Umar, ... know to help determine the best colon cancer screening test for them? Colonoscopy is considered the gold ...

  15. Endobronchial metastases of colorectal cancer.

    PubMed

    Rosado Dawid, Natalia-Zuberoa; Villegas Fernández, Francisco Ramón; Rodríguez Cruz, María Del Mar; Ramos Meca, Asunción

    2016-04-01

    Colorectal metastases affecting trachea or bronchi are highly unusual. Up to 26% of endotracheal/endobronchial metastases are due to colorectal cancer. Treatment and palliative management rely on a multidisciplinary team to improve their quality of life. PMID:26856850

  16. 6 Common Cancers - Colorectal Cancer

    MedlinePlus

    ... Bar Home Current Issue Past Issues 6 Common Cancers - Colorectal Cancer Past Issues / Spring 2007 Table of Contents For ... colon cancer. Photo: AP Photo/Ron Edmonds Colorectal Cancer Cancer of the colon (large intestine) or rectum ( ...

  17. Absence of somatic alterations of the EB1 gene adenomatous polyposis coli-associated protein in human sporadic colorectal cancers.

    PubMed Central

    Jaïs, P.; Sabourin, J. C.; Bombled, J.; Rougier, P.; Lasser, P.; Duvillard, P.; Bénard, J.; Bressac-de Paillerets, B.

    1998-01-01

    The human EB1 gene product was recently found, by a yeast two-hybrid screening, to be associated with the carboxy terminus of the APC (adenomatous polyposis coli) protein, the product of a tumour-suppressor gene thought to act as a gatekeeper in colorectal carcinogenesis. Because virtually all of the APC mutations result in the synthesis of carboxy-terminal truncated proteins, mutant APC proteins are expected to lose their ability to interact with EB1 gene product. Thus, the interaction between APC and EB1 proteins may be important for the tumour-suppressor activity of APC protein, and raises the hypothesis that EB1 is also involved in sporadic colorectal tumorigenesis. To investigate this hypothesis, somatic mutations in the entire coding sequence of EB1 cDNA were searched by reverse transcriptase single-strand conformational polymorphism (SSCP) analysis in 21 sporadic colorectal cancers and seven adenomas. None of these tumours contained somatic mutation, whereas a silent cDNA variant was identified in 14% of alleles. Furthermore, to investigate whether EB1 locus was included within a region subjected to losses of heterozygosity, four polymorphism markers surrounding EB1 locus were surveyed. Only one out of 28 colorectal tumours contained a loss of heterozygosity at the D20S107 marker. In conclusion, the present findings strongly suggest that EB1 gene is not involved in somatic colorectal carcinogenesis. Images Figure 2 Figure 3 PMID:9823979

  18. ORGAN AND SPECIES SPECIFICITY IN CHEMICAL CARCINOGENESIS

    EPA Science Inventory

    The focus of the Symposium and this volume is the relative susceptibility of specific animal species strains and organs to various carcinogens. For the first time, investigators in chemical carcinogenesis are able to pool their discoveries in this area. Once analyzed, this data c...

  19. A Systems Approach to Radiation Carcinogenesis

    NASA Astrophysics Data System (ADS)

    Hlatky, Lynn

    Understanding carcinogenesis risk is complicated by a number of factors, among these the lack of a common platform to integrate and analyze the available data, and the inherently systemsbiologic nature of the problem. We have investigated mechanistic approaches to radiogenic risk estimation that draw on unifying biological principles and incorporate data from multiscale sources. The resultant modeling takes into account that carcinogenesis is a multi-scale phenomenon, critically influenced by determinants not only at the molecular level, but at the cell and tissue-levels as well. To account for cell-level carcinogenesis progression as influenced by inter-tissue signaling, we have developed a dynamic carrying capacity construct that couples the growth of a tumor with the degree of induced vascularization. We have also characterized the molecular responses to radiation incorporating tissue-level angiogenesis implications, and have found striking radiation-quality-dependent responses. The molecular-level events of initiation and promotion are considered in our Two-Stage Logistic model, while incorporating in a rudimentary way the larger-scale growth-limiting role of cell-cell interactions. These and other recent studies undertaken to elaborate radiation-induced carcinogenesis are discussed, in pursuit of a more complete paradigm for understanding radiation induction of cancer and the consequent risk.

  20. Experimental radiation carcinogenesis: what have we learned

    SciTech Connect

    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)

  1. Curcumin ameliorates the tumor-enhancing effects of a high-protein diet in an azoxymethane-induced mouse model of colon carcinogenesis.

    PubMed

    Byun, So-Young; Kim, Dan-Bi; Kim, Eunjung

    2015-08-01

    An increasing number of reports suggest that a high-protein diet (HPD) is associated with an increased risk for colorectal cancer (CRC). One of the proposed mechanisms is that an HPD increases the delivery of protein to the colon and generates various toxic metabolites that contribute to colon carcinogenesis. Curcumin was shown to exert significant preventive properties against CRC. We therefore hypothesized that curcumin can reverse the tumor-enhancing effects of an HPD. This study examined the effects of curcumin on the development of azoxymethane (AOM)-induced colorectal tumors in HPD-fed mice. A total of 30 female Balb/c mice were randomly divided into 3 groups: those fed a normal diet (20% casein), those fed an HPD (HPD; 50% casein), and those fed an HPD supplemented with curcumin (HPDC; 0.02% curcumin). The mice were subjected to an AOM-dextran sodium sulfate colon carcinogenesis protocol. Mice in the HPDC group exhibited a significant (40%) reduction in colorectal tumor multiplicity when compared with those in the HPD group. The expression of colonic inflammatory proteins (cyclooxygenase-2 and inducible nitric oxide synthase), the levels of plasma inflammatory markers (nitric oxide and tumor necrosis factor-α), fecal ammonia, short- and branched-chain fatty acid levels, and the rate of colonocyte proliferation were significantly lower in the HPDC than the HPD group. In conclusion, curcumin inhibited the development of colorectal tumors in an AOM-induced mouse model of colon carcinogenesis by attenuating colonic inflammation, proliferation, and toxic metabolite production. Curcumin might be useful in the chemoprevention of CRC in individuals consuming an HPD. PMID:26094212

  2. Expression profile of mucin-associated sialyl-Tn antigen in Chinese patients with different colorectal lesions (adenomas, carcinomas)

    PubMed Central

    Xu, Feng; Fan, Cuizhen; Fan, Shanshan; Liu, Fuquan; Wen, Tao; An, Guangyu; Feng, Guosheng

    2015-01-01

    Background: The sialyl-Tn (sTn) antigen is a mucin-associated carbohydrate antigen expressed by numerous human carcinomas, and is also claimed to be a prognostic factor in colorectal cancer. But the associations between sTn and colorectal cancer remain elusive and controversial. Here, we investigated the expression profile of sTn antigen in a series of human colorectal tissue samples including normal colon, colorectal adenomas, and colorectal carcinomas (CRCs), with an aim to analyzing whether sTn plays a role in the progression and development of Chinese patients with CRCs. Methods: Immunohistochemical staining of sTn antigen was performed in formalin-fixed, paraffin-embedded colonic sections from 4 healthy controls, 44 patients with colorectal adenomas, and 186 patients with primary CRCs. Results: No sTn antigen was detected in normal colonic tissues. There were 41 of 44 patients with colorectal adenomas (93.2%), and 141 of 186 patients with CRCs (75.8%) found to express sTn antigen. The patterns of sTn localization were different in adenomas and carcinomas of colonic tissues. Colorectal adenomas showed predominant supranuclear distribution of sTn antigen, while carcinomas revealed apical membrane, mucin droplet and diffuse cytoplasmic localization. Notably, sTn was significantly associated with the degree of differentiation (P = 0.006) and perineural invasion (P = 0.041) of the tumors, but was independent of age, gender, tumor location, depth of penetration, status of lymph nodes, lymphovascular invasion and TNM stage. Conclusions: These results indicate that sTn may play a role in initiating colorectal carcinogenesis and promoting tumor progression. Determination of sTn expression and localization may assist in evaluating malignant status of colorectal lesions. PMID:26617889

  3. Association of Fusobacterium nucleatum with immunity and molecular alterations in colorectal cancer

    PubMed Central

    Nosho, Katsuhiko; Sukawa, Yasutaka; Adachi, Yasushi; Ito, Miki; Mitsuhashi, Kei; Kurihara, Hiroyoshi; Kanno, Shinichi; Yamamoto, Itaru; Ishigami, Keisuke; Igarashi, Hisayoshi; Maruyama, Reo; Imai, Kohzoh; Yamamoto, Hiroyuki; Shinomura, Yasuhisa

    2016-01-01

    The human intestinal microbiome plays a major role in human health and diseases, including colorectal cancer. Colorectal carcinogenesis represents a heterogeneous process with a differing set of somatic molecular alterations, influenced by diet, environmental and microbial exposures, and host immunity. Fusobacterium species are part of the human oral and intestinal microbiota. Metagenomic analyses have shown an enrichment of Fusobacterium nucleatum (F. nucleatum) in colorectal carcinoma tissue. Using 511 colorectal carcinomas from Japanese patients, we assessed the presence of F. nucleatum. Our results showed that the frequency of F. nucleatum positivity in the Japanese colorectal cancer was 8.6% (44/511), which was lower than that in United States cohort studies (13%). Similar to the United States studies, F. nucleatum positivity in Japanese colorectal cancers was significantly associated with microsatellite instability (MSI)-high status. Regarding the immune response in colorectal cancer, high levels of infiltrating T-cell subsets (i.e., CD3+, CD8+, CD45RO+, and FOXP3+ cells) have been associated with better patient prognosis. There is also evidence to indicate that molecular features of colorectal cancer, especially MSI, influence T-cell-mediated adaptive immunity. Concerning the association between the gut microbiome and immunity, F. nucleatum has been shown to expand myeloid-derived immune cells, which inhibit T-cell proliferation and induce T-cell apoptosis in colorectal cancer. This finding indicates that F. nucleatum possesses immunosuppressive activities by inhibiting human T-cell responses. Certain microRNAs are induced during the macrophage inflammatory response and have the ability to regulate host-cell responses to pathogens. MicroRNA-21 increases the levels of IL-10 and prostaglandin E2, which suppress antitumor T-cell-mediated adaptive immunity through the inhibition of the antigen-presenting capacities of dendritic cells and T-cell proliferation in

  4. Human colon carcinogenesis is associated with increased interleukin-17-driven inflammatory responses

    PubMed Central

    Xie, Zhaohui; Qu, Yine; Leng, Yanli; Sun, Wenxiu; Ma, Siqi; Wei, Jingbo; Hu, Jiangong; Zhang, Xiaolan

    2015-01-01

    Inflammation is known to contribute to carcinogenesis in human colorectal cancer. Proinflammatory cytokine interleukin-17 (IL-17 or IL-17A) has been shown to play a critical role in colon carcinogenesis in mouse models. However, few studies have investigated IL-17A in human colon tissues. In the present study, we assessed IL-17-driven inflammatory responses in 17 cases of human colon adenocarcinomas, 16 cases of human normal colon tissues adjacent to the resected colon adenocarcinomas, ten cases of human ulcerative colitis tissues from biopsies, and eight cases of human colon polyps diagnosed as benign adenomas. We found that human colon adenocarcinomas contained the highest levels of IL-17A cytokine, which was significantly higher than the IL-17A levels in the adenomas, ulcerative colitis, and normal colon tissues (P<0.01). The levels of IL-17 receptor A (IL-17RA) were also the highest in human colon adenocarcinomas, followed by adenomas and ulcerative colitis. The increased levels of IL-17A and IL-17RA were accompanied with increased IL-17-driven inflammatory responses, including activation of extracellular signal-regulated kinase (ERK)1/2 and c-Jun N-terminal kinase (JNK) pathways, increase in expression of matrix metalloproteinase (MMP)9, MMP7, MMP2, B-cell lymphoma (Bcl-2), and cyclin D1, decrease in Bcl-2-associated X protein (BAX) expression, and increase in vascular endothelial growth factor (VEGF) and VEGF receptor (VEGFR) expression that were associated with increased angiogenesis. These findings suggest that IL-17 and its signaling pathways appear as promising new targets in the design and development of drugs for cancer prevention and treatment, particularly in colorectal cancer. PMID:25834404

  5. Genomic Landscape of Colorectal Mucosa and Adenomas.

    PubMed

    Borras, Ester; San Lucas, F Anthony; Chang, Kyle; Zhou, Ruoji; Masand, Gita; Fowler, Jerry; Mork, Maureen E; You, Y Nancy; Taggart, Melissa W; McAllister, Florencia; Jones, David A; Davies, Gareth E; Edelmann, Winfried; Ehli, Erik A; Lynch, Patrick M; Hawk, Ernest T; Capella, Gabriel; Scheet, Paul; Vilar, Eduardo

    2016-06-01

    The molecular basis of the adenoma-to-carcinoma transition has been deduced using comparative analysis of genetic alterations observed through the sequential steps of intestinal carcinogenesis. However, comprehensive genomic analyses of adenomas and at-risk mucosa are still lacking. Therefore, our aim was to characterize the genomic landscape of colonic at-risk mucosa and adenomas. We analyzed the mutation profile and copy number changes of 25 adenomas and adjacent mucosa from 12 familial adenomatous polyposis patients using whole-exome sequencing and validated allelic imbalances (AI) in 37 adenomas using SNP arrays. We assessed for evidence of clonality and performed estimations on the proportions of driver and passenger mutations using a systems biology approach. Adenomas had lower mutational rates than did colorectal cancers and showed recurrent alterations in known cancer driver genes (APC, KRAS, FBXW7, TCF7L2) and AIs in chromosomes 5, 7, and 13. Moreover, 80% of adenomas had somatic alterations in WNT pathway genes. Adenomas displayed evidence of multiclonality similar to stage I carcinomas. Strong correlations between mutational rate and patient age were observed in at-risk mucosa and adenomas. Our data indicate that at least 23% of somatic mutations are present in at-risk mucosa prior to adenoma initiation. The genomic profiles of at-risk mucosa and adenomas illustrate the evolution from normal tissue to carcinoma via greater resolution of molecular changes at the inflection point of premalignant lesions. Furthermore, substantial genomic variation exists in at-risk mucosa before adenoma formation, and deregulation of the WNT pathway is required to foster carcinogenesis. Cancer Prev Res; 9(6); 417-27. ©2016 AACR. PMID:27221540

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

    PubMed

    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. PMID:25796713

  7. Apple polysaccharide reduces NF-Kb mediated colitis-associated colon carcinogenesis.

    PubMed

    Zhang, Dian; Mi, Man; Jiang, Fengliang; Sun, Yang; Li, Yuhua; Yang, Libin; Fan, Lei; Li, Qian; Meng, Jin; Yue, Zhenggang; Liu, Li; Mei, Qibing

    2015-01-01

    Nuclear factor-kappa B (NF-κB) is an important molecule in mediating inflammatory colitis, which can lead to colorectal cancer (CRC). The aim of this study was to evaluate the chemopreventive efficacy of apple polysaccharide extract (AP) in inhibiting NF-κB-mediated inflammation pathways in CRC. We evaluated AP in vitro in HT-29 and SW620 human CRC cells. We also used the azoxymethane and dextran sodium sulphate (AOM/DSS) model to induce colon carcinogenesis in vivo. The chemoprotective effects of AP were assessed using Western blot, immunofluorescence assay, real-time PCR, electrophoretic mobility shift assay, and flow cytometry. AP reduced AOM/DSS-associated toxicities, prevented carcinogenesis, and decreased the expression of TLR4, MD2, MyD88, TRAM, TRIF-related adapter molecule, interferon-β, tumor necrosis factor-α, and interleukin-6. The protective effects of AP may be related to the inhibition of TLR4/MD2-mediated signaling, including MyD88 and TRIF, as well as the inhibition of NF-κB-mediated inflammatory signaling pathways. Therefore, AP could be used in combination therapy for the prevention of colitis-associated colon cancer. PMID:25412264

  8. Inflammation-Related Carcinogenesis: Current Findings in Epidemiological Trends, Causes and Mechanisms

    PubMed Central

    Okada, Futoshi

    2014-01-01

    Inflammation is a definite cancer-causing factor as revealed by cumulative basic, clinical and epidemiological studies. It is mostly induced by infectious agents. For instance, infection with papillomaviruses associates with anogenital cancers, especially cervical cancers; Helicobacter pylori infection of the stomach tends to increase the risk of stomach cancer; chronic hepatitis B & C viruses and fluke infections of the liver increase liver cancers; autoimmune diseases, e.g., inflammatory bowel diseases, associate with development of colorectal cancer, and aerial irritants (foreign bodies) such as asbestos or fine particulate matter (PM2.5) in outdoor air increase malignant pleural mesotheliomas or lung cancers. These are typical examples of inflammation-related carcinogenesis. It is apparent that the pathogens to induce inflammatory reactions in specific organs are not related to each other. However, the underlying pathogenesis in common is to induce and/or sustain inflammation. In this article, I would like to review the up-to-date findings of epidemiological trends, causes and mechanisms of inflammation-related carcinogenesis. PMID:25324587

  9. Apc-driven colon carcinogenesis in Pirc rat is strongly reduced by polyethylene glycol.

    PubMed

    Femia, Angelo Pietro; Becherucci, Caterina; Crucitta, Stefania; Caderni, Giovanna

    2015-11-01

    Polyethylene glycol (PEG) is one of the most powerful agents in reducing chemically induced carcinogenesis in rat colon. However, contrasting results in Min mice dampened the enthusiasm on this potentially strong and virtually safe, cancer chemopreventing agent. Pirc (F344/NTac-Apc (am1137) ) rats carrying a germline heterozygous mutation in the Apc gene, spontaneously develop multiple tumours in the colon thus modelling both familial adenomatous polyposis (FAP) and sporadic colorectal cancer (CRC). Given this similarity, we thought that these rats could be appropriate to test the efficacy of PEG 8000 in reducing carcinogenesis. Pirc male rats aged one month were treated with 5% PEG in drinking water for 2 or 6 months. Precancerous lesions were dramatically reduced after 2 months of PEG treatment (Mucin depleted foci (MDF)/colon were 99 ± 17 and 12 ± 8 in Controls and PEG-treated rats, respectively; p < 0.001; mean ± SD). Similarly, colon tumors were significantly reduced after 6 months of treatment (tumors/rat were 8.1 ± 2.3 and 3.6 ± 2.2 in Controls and PEG-treated rats, respectively; p < 0.05; mean ± SD). Colon proliferation, a parameter correlated to cancer risk, was also significantly lower in PEG-treated rats than in Controls, while apoptosis was not significantly affected. In conclusion, PEG markedly reduces colon carcinogenesis in Pirc rats mutated in Apc; we thus suggest that PEG may be used as chemopreventive agent to reduce cancer risk in FAP and CRC patients. PMID:25912754

  10. Study of chemical and radiation induced carcinogenesis

    SciTech Connect

    Chmura, A.

    1995-11-01

    The study of chemical and radiation induced carcinogenesis has up to now based many of its results on the detection of genetic aberrations using the fluorescent in situ hybridization (FISH) technique. FISH is time consuming and this tends to hinder its use for looking at large numbers of samples. We are currently developing new technological advances which will increase the speed, clarity and functionality of the FISH technique. These advances include multi-labeled probes, amplification techniques, and separation techniques.

  11. Lesser-Known Molecules in Ovarian Carcinogenesis

    PubMed Central

    Lozneanu, Ludmila; Cojocaru, Elena; Giuşcă, Simona Eliza; Cărăuleanu, Alexandru; Căruntu, Irina-Draga

    2015-01-01

    Currently, the deciphering of the signaling pathways brings about new advances in the understanding of the pathogenic mechanism of ovarian carcinogenesis, which is based on the interaction of several molecules with different biochemical structure that, consequently, intervene in cell metabolism, through their role as regulators in proliferation, differentiation, and cell death. Given that the ensemble of biomarkers in OC includes more than 50 molecules the interest of the researchers focuses on the possible validation of each one's potential as prognosis markers and/or therapeutic targets. Within this framework, this review presents three protein molecules: ALCAM, c-FLIP, and caveolin, motivated by the perspectives provided through the current limited knowledge on their role in ovarian carcinogenesis and on their potential as prognosis factors. Their structural stability, once altered, triggers the initiation of the sequences characteristic for ovarian carcinogenesis, through their role as modulators for several signaling pathways, contributing to the disruption of cellular junctions, disturbance of pro-/antiapoptotic equilibrium, and alteration of transmission of the signals specific for the molecular pathways. For each molecule, the text is built as follows: (i) general remarks, (ii) structural details, and (iii) particularities in expression, from different tumors to landmarks in ovarian carcinoma. PMID:26339605

  12. Management of Colorectal Trauma

    PubMed Central

    2011-01-01

    Although the treatment strategy for colorectal trauma has advanced during the last part of the twentieth century and the result has improved, compared to other injuries, problems, such as high septic complication rates and mortality rates, still exist, so standard management for colorectal trauma is still a controversial issue. For that reason, we designed this article to address current recommendations for management of colorectal injuries based on a review of literature. According to the reviewed data, although sufficient evidence exists for primary repair being the treatment of choice in most cases of nondestructive colon injuries, many surgeons are still concerned about anastomotic leakage or failure, and prefer to perform a diverting colostomy. Recently, some reports have shown that primary repair or resection and anastomosis, is better than a diverting colostomy even in cases of destructive colon injuries, but it has not fully established as the standard treatment. The same guideline as that for colonic injury is applied in cases of intraperitoneal rectal injuries, and, diversion, primary repair, and presacral drainage are regarded as the standards for the management of extraperitoneal rectal injuries. However, some reports state that primary repair without a diverting colostomy has benefit in the treatment of extraperitoneal rectal injury, and presacral drainage is still controversial. In conclusion, ideally an individual management strategy would be developed for each patient suffering from colorectal injury. To do this, an evidence-based treatment plan should be carefully developed. PMID:21980586

  13. OTX1 promotes colorectal cancer progression through epithelial-mesenchymal transition

    SciTech Connect

    Yu, Kun; Cai, Xin-Yi; Li, Qiang; Yang, Zhi-Bin; Xiong, Wei; Shen, Tao; Wang, Wei-Ya; Li, Yun-Feng

    2014-01-31

    Highlights: • OTX1 is overexpression in colorectal cancer tissues. • Overexpression of OTX1 promotes colorectal cancer cell proliferation and invasion in vitro and tumor growth in vivo. • Depletion of OTX1 inhibits colorectal cancer cell proliferation and invasion in vitro. • Overexpression of OTX1 is linked to the EMT-like phenotype. - Abstract: Orthodenticle homeobox 1 (OTX1), a transcription factor containing a bicoid-like homeodomain, plays a role in brain and sensory organ development. In this study, we report that OTX1 is overexpressed in human colorectal cancer (CRC) and OTX1 overexpression is associated with higher stage. Functional analyses reveal that overexpression of OTX1 results in accumulation of CRC cell proliferation and invasion in vitro and tumor growth in vivo, whereas ablation of OTX1 expression significantly inhibits the proliferative and invasive capability of CRC cells in vitro. Together, our results indicate that OTX1 is involved in human colon carcinogenesis and may serve as a potential therapeutic target for human colorectal cancer.

  14. [Nutrition and colorectal cancer].

    PubMed

    Ströhle, Alexander; Maike, Wolters; Hahn, Andreas

    2007-01-01

    Diet plays an important role in the pathogenesis of colorectal cancer. Current prospective cohort studies and metaanalysis enable a reevaluation of how food or nutrients such as fiber and fat influence cancer risk. Based on the evidence criteria of the WHO/FAD, risk reduction by a high intake of fruit is assessed as possible, while a lowered risk by a high vegetable intake is probable. Especially raw vegetables and fruits seem to exert anticancer properties. The evidence of a risk reducing effect of whole grain relating to colorectal cancer is assessed as probable whereas the evidence of an increased risk by high consumption of refined white flour products and sweets is (still) insufficient despite some evidences. There is a probable risk reducing effect of milk and dairy products. e available data on eggs and red meat indicate a possible risk increasing influence. Stronger clues for a risk increasing effect have been shown for meat products leading to an evidence assessed as probable. Owing to varied interpretations of the data on fiber, the evidence of a risk reducing effect relating to colorectal cancer is assessed as possible or insufficient. The available data on alcohol consumption indicate a possible risk increasing effect. In contrast to former evaluations, diets rich in fat seem to increase colorectal cancer risk only indirectly as part of a hypercaloric diet by advancing the obesity risk. Thus, the evidence of obesity, especially visceral obesity, as a risk of colorectal cancer is judged as convincing today. Prospective cohort studies suggest that people who get higher than average amounts of folic acid from multivitamin supplements have lower risks of colorectal cancer. The evidence for a risk reducing effect of calcium, selenium, vitamin D and vitamin E on colorectal cancer is insufficient. As primary prevention, a diet rich in vegetables, fruits, whole grain products, and legumes added by low-fat dairy products, fish, and poultry can be recommended. In

  15. Radioimmunodetection of colorectal cancer

    SciTech Connect

    Kim, E.E.; Deland, F.H.; Casper, S.; Corgan, R.L.; Primus, F.J.; Goldenberg, D.M.

    1980-03-15

    This study examines the accuracy of colorectal cancer radioimmunodetection. Twenty-seven patients with a history of histologically-confirmed colonic or rectal carcinoma received a high-titer, purified goat anti-CEA IgG labelled with /sup 131/I at a total dose of at least 1.0 ..mu..Ci. Various body views were scanned at 24 and 48 hours after administration of the radioantibody. Three additional cases were evaluated; one had a villous adenoma in the rectum and received the /sup 131/I-labeled anti-CEA IgG, while two colonic carcinoma patients received normal goat IgG labelled with /sup 131/I. All of the 7 cases with primary colorectal cancer showed true-positive tumor localization, while 20 of 25 sites of metastatic colorectal cancer detected by immune scintigraphy were corroborated by other detection measures. The sensitivity of the radioimmunodetection of colorectal cancers (primary and metastatic) was found to be 90% (true-positive rate), the putative specificity (true-negative rate) was 94%, and the apparent overall accuracy of the technique was 93%. Neither the case of a villous adenoma receiving the anti-CEA IgG nor the two cases of colonic cancer receiving normal goat IgG showed tumor radiolocalization. Very high circulating CEA titers did not appear to hinder successful tumor radiolocalization. These findings suggest that in colorectal cancers the method of CEA radioimmunodetection may be of value in preoperatively determining the location and extent of disease, in assessing possible recurrence or spread postoperatively, and in localizing the source of CEA production in patients with rising or elevated CEA titers. An ancilliary benefit could be a more tumor-specific detection test for confirming the findings of other, more conventional diagnostic measures.

  16. Polymorphisms in Alcohol Metabolism Genes ADH1B and ALDH2, Alcohol Consumption and Colorectal Cancer

    PubMed Central

    Crous-Bou, Marta; Rennert, Gad; Cuadras, Daniel; Salazar, Ramon; Cordero, David; Saltz Rennert, Hedy; Lejbkowicz, Flavio; Kopelovich, Levy; Monroe Lipkin, Steven; Bernard Gruber, Stephen; Moreno, Victor

    2013-01-01

    Background Colorectal cancer (CRC) is a leading cause of cancer death worldwide. Epidemiological risk factors for CRC included alcohol intake, which is mainly metabolized to acetaldehyde by alcohol dehydrogenase and further oxidized to acetate by aldehyde dehydrogenase; consequently, the role of genes in the alcohol metabolism pathways is of particular interest. The aim of this study is to analyze the association between SNPs in ADH1B and ALDH2 genes and CRC risk, and also the main effect of alcohol consumption on CRC risk in the study population. Methodology/Principal Findings SNPs from ADH1B and ALDH2 genes, included in alcohol metabolism pathway, were genotyped in 1694 CRC cases and 1851 matched controls from the Molecular Epidemiology of Colorectal Cancer study. Information on clinicopathological characteristics, lifestyle and dietary habits were also obtained. Logistic regression and association analysis were conducted. A positive association between alcohol consumption and CRC risk was observed in male participants from the Molecular Epidemiology of Colorectal Cancer study (MECC) study (OR = 1.47; 95%CI = 1.18-1.81). Moreover, the SNPs rs1229984 in ADH1B gene was found to be associated with CRC risk: under the recessive model, the OR was 1.75 for A/A genotype (95%CI = 1.21-2.52; p-value = 0.0025). A path analysis based on structural equation modeling showed a direct effect of ADH1B gene polymorphisms on colorectal carcinogenesis and also an indirect effect mediated through alcohol consumption. Conclusions/Significance Genetic polymorphisms in the alcohol metabolism pathways have a potential role in colorectal carcinogenesis, probably due to the differences in the ethanol metabolism and acetaldehyde oxidation of these enzyme variants. PMID:24282520

  17. Mechanisms of diet and colon carcinogenesis.

    PubMed

    Hill, M J

    1999-12-01

    There is consistent and strong evidence that a high risk of colorectal cancer is associated with obesity and with a low intake of vegetables, of whole grain cereals and of fish. Many other food groups or nutrients have been associated with this cancer, but the evidence for them is inconsistent and therefore untenable. Vegetables contain a wide range of protective agents that protect against cancer at many other sites as well as the large bowel. The same is true of whole grain cereals; these can also protect against colorectal cancer by mechanisms specific to the large bowel. Fish are rich in n-3 polyunsaturated fatty acids that are thought to protect the colon against malignancy via the prostaglandin pathway. Overweight is the result of an excess of energy intake over energy output, and there is good evidence to suggest that overweight might be a surrogate measure of lack of exercise. PMID:10772423

  18. miRNA-144 suppresses proliferation and migration of colorectal cancer cells through GSPT1.

    PubMed

    Xiao, Ruilin; Li, Cui; Chai, Baofeng

    2015-08-01

    MicroRNAs play a key role in carcinogenesis or tumor progression, which negatively and posttranscriptionally regulate gene expression and function as oncogenes or tumor suppressors, as well as regulators of cell cycle, proliferation, apoptosis, migration and other processes. A number of miRNAs are reported be related to the occurrence and development of colorectal cancer (CRC). However, these studies were not involved in the effect of miRNA 144 of CRC, whose function remains unclear. In this study, we demonstrated that the expression level of miRNA 144 was markedly down-regulated in colorectal cancer HCT116 cells compared with normal control FHC cells. Meanwhile, we found that GSPT1 was over-expressed in human colorectal cancer HCT116 cells. Subsequently, GSPT1 was identified as a target of miRNA 144 through bioinformatics and luciferase reporter assays. Besides, we also confirmed that miRNA 144 can inhibit the proliferation and migration of colorectal cancer HCT116 cells . Next, we observed RNA-mediated knockdown of GSPT1 can also inhibit the proliferation and migration of colorectal cancer cells. Thus, we concluded that miRNA 144 inhibits cell proliferation and migration through GSPT1 in CRC. In addition, further mechanic investigations revealed that miRNA-144 suppressed the expression of GSPT1 to regulate the expression of c-myc, survivin and Bcl2L15 which are involved in cell proliferation, and that metastasis related factor MMP28 was also down-regulated by miRNA144. Our findings suggested that microRNA 144 might be an important element to control the status of colorectal cancer, which has provided a new insight into the mechanism of proliferation and migration and a new target in therapy against colorectal cancer. PMID:26349975

  19. Worldwide variations in colorectal cancer.

    PubMed

    Center, Melissa M; Jemal, Ahmedin; Smith, Robert A; Ward, Elizabeth

    2009-01-01

    Previous studies have documented significant international variations in colorectal cancer rates. However, these studies were limited because they were based on old data or examined only incidence or mortality data. In this article, the colorectal cancer burden and patterns worldwide are described using the most recently updated cancer incidence and mortality data available from the International Agency for Research on Cancer (IARC). The authors provide 5-year (1998-2002), age-standardized colorectal cancer incidence rates for select cancer registries in IARC's Cancer Incidence in Five Continents, and trends in age-standardized death rates by single calendar year for select countries in the World Health Organization mortality database. In addition, available information regarding worldwide colorectal cancer screening initiatives are presented. The highest colorectal cancer incidence rates in 1998-2002 were observed in registries from North America, Oceania, and Europe, including Eastern European countries. These high rates are most likely the result of increases in risk factors associated with "Westernization," such as obesity and physical inactivity. In contrast, the lowest colorectal cancer incidence rates were observed from registries in Asia, Africa, and South America. Colorectal cancer mortality rates have declined in many longstanding as well as newly economically developed countries; however, they continue to increase in some low-resource countries of South America and Eastern Europe. Various screening options for colorectal cancer are available and further international consideration of targeted screening programs and/or recommendations could help alleviate the burden of colorectal cancer worldwide. PMID:19897840

  20. Fusobacterium nucleatum and T-cells in Colorectal Carcinoma

    PubMed Central

    Mima, Kosuke; Sukawa, Yasutaka; Nishihara, Reiko; Qian, Zhi Rong; Yamauchi, Mai; Inamura, Kentaro; Kim, Sun A; Masuda, Atsuhiro; Nowak, Jonathan A.; Nosho, Katsuhiko; Kostic, Alecsandar D.; Giannakis, Marios; Watanabe, Hideo; Bullman, Susan; Milner, Danny A.; Harris, Curtis C.; Giovannucci, Edward; Garraway, Levi A.; Freeman, Gordon J.; Dranoff, Glenn; Chan, Andrew T.; Garrett, Wendy S.; Huttenhower, Curtis; Fuchs, Charles S.; Ogino, Shuji

    2015-01-01

    -cells (for a unit increase in quartile categories of CD3+ T-cells as an outcome: multivariable odds ratio, 0.47; 95% confidence interval, 0.26 to 0.87; Ptrend = 0.006). The amount of Fusobacterium nucleatum was not significantly associated with the density of CD8+, CD45RO+, or FOXP3+ T-cells (Ptrend > 0.013). Conclusions and relevance The amount of tissue Fusobacterium nucleatum is inversely associated with CD3+ T-cell density in colorectal carcinoma tissue. Upon validation, our human population data may provide an impetus for further investigations on potential interactive roles of Fusobacterium and host immunity in carcinogenesis. PMID:26181352

  1. [Colorectal cancer screening].

    PubMed

    Castells, Antoni

    2013-10-01

    Colorectal cancer is the paradigm of tumoral growth that is susceptible to preventive measures, especially screening. Various screening strategies with demonstrated efficacy and efficiency are currently available, notable examples being the fecal occult blood test and endoscopic tests. In addition, new modalities have appeared in the last few years that could become viable alternatives in the near future. The present article reviews the most important presentations on colorectal screening at the annual congress of the American Gastroenterological Association held in Orlando in May 2013, with special emphasis on the medium- and long-term results of strategies using the fecal occult blood test and flexible sigmoidoscopy, as well as initial experiences with the use of new biomarkers. PMID:24160954

  2. Historical origins of current concepts of carcinogenesis.

    PubMed

    Lawley, P D

    1994-01-01

    The first attempts to understand the causes of cancer were based on generalizations of what might now be termed a "holistic" nature, and hereditary influences were recognized at an early stage; these views survive principally through a supposed positive connection between psychological factors such as stress and diminished ability to combat the progressive development of tumors through some form of immunologically mediated rejection of potentially cancerous cells. While evidence for immunosurveillance is generally accepted, it is now widely regarded as almost wholly confined to instances where tumor viruses are involved as causative agents. The earliest theorists drew an analogy between the processes of carcinogenesis and of evolution; the cancer cells acquired the ability to outstrip their normal counterparts in their capacity for proliferation. This was even before evolution had been interpreted as involving a continuous succession of mutations. Evidence was already to hand before the end of the 18th century that exogenous agents, notably soot, a product of the "industrial revolution," could cause skin cancer. Somewhat over 100 years later, another industrial innovation, the manufacture of synthetic dyestuffs, implicated specific chemical compounds that could act systemically to cause bladder cancer. Meanwhile, the 19th century saw the establishment of the fundamentals of modern medical science; of particular relevance to cancer was the demonstration that it involved abnormalities in the process of cell division. The commencement of the 20th century was marked by a rediscovery of the concept of mutation; and it was proposed that cancer originated through uncontrolled division of somatically mutated cells. At around this time, two further important exogenous causative agents were discovered: X-rays and tumor viruses. In the late 1920s, x-radiation became the first established exogenous cause of mutagenesis. The discoverer of this phenomenon, H. J. Muller

  3. Oxidative stress in prostate hyperplasia and carcinogenesis.

    PubMed

    Udensi, Udensi K; Tchounwou, Paul B

    2016-01-01

    Prostatic hyperplasia (PH) is a common urologic disease that affects mostly elderly men. PH can be classified as benign prostatic hyperplasia (BPH), or prostate cancer (PCa) based on its severity. Oxidative stress (OS) is known to influence the activities of inflammatory mediators and other cellular processes involved in the initiation, promotion and progression of human neoplasms including prostate cancer. Scientific evidence also suggests that micronutrient supplementation may restore the antioxidant status and hence improve the clinical outcomes for patients with BPH and PCa. This review highlights the recent studies on prostate hyperplasia and carcinogenesis, and examines the role of OS on the molecular pathology of prostate cancer progression and treatment. PMID:27609145

  4. [Epigenetics and colorectal cancer].

    PubMed

    Menéndez, Pablo; Villarejo, Pedro; Padilla, David; Menéndez, José María; Rodríguez Montes, José Antonio

    2012-05-01

    The epigenetic and physiological mechanisms that alter the structure of chromatin include the methylation of DNA, changes in the histones, and changes in RNA. A literature review has been carried out using PubMed on the evidence published on the association between epigenetics and colorectal cancer. The scientific literature shows that epigenetic changes, such as genetic modifications may be very significant in the origin of neoplastic disease, contributing both to the development and progression of the disease. PMID:22425513

  5. Techniques for colorectal anastomosis

    PubMed Central

    Ho, Yik-Hong; Ashour, Mohamed Ahmed Tawfik

    2010-01-01

    Colorectal anastomotic leak remains one of the most feared post-operative complications, particularly after anterior resection of the rectum with, the shift from abdomino-peritoneal resections to total mesorectal excision and primary anastomosis. The literature fails to demonstrate superiority of stapled over hand-sewn techniques in colorectal anastomosis, regardless of the level of anastomosis, although a high stricture rate was noted in the former technique. Thus, improvements in safety aspects of anastomosis and alternatives to hand-sewn and stapled techniques are being sought. Here, we review alternative anastomotic techniques used to fashion bowel anastomosis. Compression anastomosis using compression anastomotic clips, endoluminal compression anastomotic rings, AKA-2, biofragmental anastomotic rings, or Magnamosis all involve the concept of creating a sutureless end-to-end anastomosis by compressing two bowel ends together, leading to a simultaneous necrosis and healing process that joins the two lumens. Staple line reinforcement is a new approach that reduce the drawbacks of staplers used in colorectal practice, i.e. leakage, bleeding, misfiring, and inadequate tissue approximation. Various non-absorbable, semi or fully absorbable materials are now available. Two other techniques can provide alternative anastomotic support to the suture line: a colorectal drain and a polyester stent, which can be utilized in ultra-low rectal excision and can negate the formation of a defunctioning stoma. Doxycycline coated sutures have been used to overcome the post-operative weakness in anastomosis secondary to rapid matrix degradation mediated by matrix metalloproteinase. Another novel technique, the electric welding system, showed promising results in construction of a safe, neat, smooth sutureless bowel anastomosis. Various anastomotic techniques have been shown to be comparable to the standard techniques of suturing and stapling. However, most of these alternatives need

  6. Effects of calcium supplementation on biomarkers of inflammation and oxidative stress in colorectal adenoma patients: a randomized controlled trial.

    PubMed

    Yang, Baiyu; Gross, Myron D; Fedirko, Veronika; McCullough, Marjorie L; Bostick, Roberd M

    2015-11-01

    Inflammation and oxidative stress play important roles in colorectal carcinogenesis. There is strong evidence that calcium reduces risk for colorectal neoplasms, possibly through its ability to bind bile acids and prevent their colonic toxicity (which occurs via an oxidative mechanism and results in an inflammatory response). In a previously reported pilot, randomized, controlled trial among sporadic colorectal adenoma patients we found that those on 2.0 g/day of calcium, relative to those on placebo, had an estimated drop in a combined cytokine z-score of 48% (P = 0.18) over 6 months. To follow-up these promising preliminary findings, we tested the efficacy of two doses of supplemental calcium (1.0 or 2.0 g/day) relative to placebo on modulating circulating biomarkers of inflammation [C-reactive protein (CRP) and 10 cytokines] and oxidative stress (F2-isoprostanes) over a 4-month treatment period among 193 patients with previous sporadic, colorectal adenoma in a randomized, double-blinded, placebo-controlled clinical trial. The inflammation markers were measured in plasma using electrochemiluminescence detection-based immunoassays, and F2-isoprostanes were measured in plasma using gas chromatography-mass spectrometry. Over a 4-month treatment period, we found no appreciable effects of calcium on CRP, cytokines, or F2-isoprostanes (P > 0.4), overall or within strata of several major risk factors for colorectal carcinogenesis, such as body mass index and regular use of nonsteroidal anti-inflammatory drugs. Overall, our results provide no evidence that calcium supplementation favorably modulates concentrations of circulating biomarkers of inflammation or oxidative stress over 4 months among patients with a previous colorectal adenoma. PMID:26304464

  7. Methylator phenotype in colorectal cancer: A prognostic factor or not?

    PubMed

    Gallois, C; Laurent-Puig, P; Taieb, J

    2016-03-01

    Colorectal cancer (CRC) is due to different types of genetic alterations that are translated into different phenotypes. Among them, CpG island methylator phenotype (CIMP+) is the most recently involved in carcinogenesis of some CRC. The malignant transformation in this case is mainly due to the transcriptional inactivation of tumor suppressor genes. CIMP+ are reported to be more frequently found in the elderly and in women. The tumors are more frequently located in the proximal part of the colon, BRAF mutated and are associated with microsatellite instability (MSI) phenotype. All sporadic MSI CRC belong to the methylator phenotype, however some non MSI CRC may also harbor a methylator phenotype. The prognostic value of CIMP is not well known. Most studies show a worse prognosis in CIMP+ CRC, and adjuvant treatments seem to be more efficient. We review here the current knowledge on prognostic and predictive values in CIMP+ CRC. PMID:26702883

  8. Biology of colorectal cancer

    PubMed Central

    Arvelo, Francisco; Sojo, Felipe; Cotte, Carlos

    2015-01-01

    Colorectal cancer is a serious health problem, a challenge for research, and a model for studying the molecular mechanisms involved in its development. According to its incidence, this pathology manifests itself in three forms: family, hereditary, and most commonly sporadic, apparently not associated with any hereditary or familial factor. For the types having inheritance patterns and a family predisposition, the tumours develop through defined stages ranging from adenomatous lesions to the manifestation of a malignant tumour. It has been established that environmental and hereditary factors contribute to the development of colorectal cancer, as indicated by the accumulation of mutations in oncogenes, genes which suppress and repair DNA, signaling the existence of various pathways through which the appearance of tumours may occur. In the case of the suppressive and mutating tracks, these are characterised by genetic disorders related to the phenotypical changes of the morphological progression sequence in the adenoma/carcinoma. Moreover, alternate pathways through mutation in BRAF and KRAS genes are associated with the progression of polyps to cancer. This review surveys the research done at the cellular and molecular level aimed at finding specific alternative therapeutic targets for fighting colorectal cancer. PMID:25932044

  9. Epidemiological transition of colorectal cancer in developing countries: Environmental factors, molecular pathways, and opportunities for prevention

    PubMed Central

    Bishehsari, Faraz; Mahdavinia, Mahboobeh; Vacca, Michele; Malekzadeh, Reza; Mariani-Costantini, Renato

    2014-01-01

    Colorectal cancer (CRC) is one of the leading causes of cancer and cancer-related mortality worldwide. The disease has been traditionally a major health problem in industrial countries, however the CRC rates are increasing in the developing countries that are undergoing economic growth. Several environmental risk factors, mainly changes in diet and life style, have been suggested to underlie the rise of CRC in these populations. Diet and lifestyle impinge on nuclear receptors, on the intestinal microbiota and on crucial molecular pathways that are implicated in intestinal carcinogenesis. In this respect, the epidemiological transition in several regions of the world offers a unique opportunity to better understand CRC carcinogenesis by studying the disease phenotypes and their environmental and molecular associations in different populations. The data from these studies may have important implications for the global prevention and treatment of CRC. PMID:24876728

  10. Colonic perianastomotic carcinogenesis in an experimental model

    PubMed Central

    Pérez-Holanda, Sergio; Rodrigo, Luis; Pinyol-Felis, Carme; Vinyas-Salas, Joan

    2008-01-01

    Background To examine the effect of anastomosis on experimental carcinogenesis in the colon of rats. Methods Forty-three 10-week-old male and female Sprague-Dawley rats were operated on by performing an end-to-side ileorectostomy. Group A:16 rats received no treatment. Group B: 27 rats received 18 subcutaneous injections weekly at a dose of 21 mg/kg wt of 1–2 dimethylhydrazine (DMH), from the eighth day after the intervention. Animals were sacrificed between 25–27 weeks. The number of tumours, their localization, size and microscopic characteristics were recorded. A paired chi-squared analysis was performed comparing tumoral induction in the perianastomotic zone with the rest of colon with faeces. Results No tumours appeared in the dimethylhydrazine-free group. The percentage tumoral area was greater in the perianastomotic zone compared to tumours which had developed in the rest of colon with faeces (p = 0.014). Conclusion We found a cocarcinogenic effect due to the creation of an anastomosis, when using an experimental model of colonic carcinogenesis induced by DMH in rats. PMID:18667092

  11. Multistage carcinogenesis in the urinary bladder.

    PubMed Central

    Cohen, S M; Greenfield, R E; Ellwein, L B

    1983-01-01

    The induction of cancer of the urinary bladder is a multi-stage process involving multiple exogenous and endogenous factors. Based on the classical initiation-promotion model, we have used N-[4-(5-nitro-2-furyl)-2-thiazolyl]formamide (FANFT) as initiator and sodium saccharin (SAC) or tryptophan as promoters. These latter chemicals have the properties expected of promoters: induction of hyperplasia, reversibility and nonmutagenicity. Also, tumors were induced whether the promoter was administered immediately after FANFT or beginning 6 weeks after FANFT was discontinued, but no tumors resulted if either promoter was given without initiation with FANFT. Factor(s) present in normal urine also are involved in the promotion process, in addition to the role of urine as a carrier of carcinogens. However, administration of SAC to animals with a rapidly proliferating bladder mucosa, induced by ulceration, pellet insertion, or in utero, resulted in bladder tumor induction, even without prior initiation with FANFT. To better understand the complex interaction of the multiple variables in bladder carcinogenesis, a stochastic computer model has been formulated based on long-term carcinogenicity and tissue kinetic studies in vivo. This model indicates the importance of cell proliferation and the development of hyperplasia in carcinogenesis. PMID:6832093

  12. Carcinogenesis--a new point of view.

    PubMed

    Gevorkyan, L; Gambashidze, K

    2014-04-01

    Presented article suggests the novel hypothesis of carcinogenesis, where the key moment for all types (biological, physical, chemical) of carcinogenesis has been discussed. For confirmation of the hypothesis thorough theoretical analysis of the mechanisms of malignant transformation of cells after influence of any type of carcinogens and results of experiments have been presented. Hypothesis highlights are formulated as follows: 1) Covalent bond disorders between S+-methionine and Fe3+ atoms in cytochrome; 2) Electron transport chain blockade with certain ligand after its penetration in cytochrome pocket with further formation of 6th coordination bond between ligand and Fe atom (in one case increase in mitochondrial pH precede-, and in other, it follows electron transport chain blockade in cytochromes); 3) Fe3+ reduction up to Fe2+ leading to blockade of aerobic glycolysis; 4) Decrease in enzyme (Е1-TDP, oxidases etc.) activity due to mitochondrial pH alterations; 5) Production of S-adenosylmethionine owing to lipoic acid amide leading to accumulation of homocysteine in cytoplasm with further penetration in cell nucleus producing DNA mutations; 6) Fe2+ wash-out from cytochrome and its deposition in ferritin. PMID:24850610

  13. THE REACTIVE OXYGEN SPECIES (ROS) THEORY OF ARSENIC CARCINOGENESIS

    EPA Science Inventory

    At this time, there is not a scientific consensus on the mechanisms/modes of action for arsenic carcinogenesis. Proposed mechanisms/modes of action for arsenic carcinogenesis include but are not limited to clastogenic effects, mutation, oxidative stress (via ROS and other chemic...

  14. THE REACTIVE OXYGEN SPECIES (ROS) THEORY OF ARSENIC CARCINOGENESIS

    EPA Science Inventory



    Arsenic is a human carcinogen in skin, lung, liver, urinary bladder
    and kidney. At this time, there is not a scientific consensus on the
    mechanisms/modes of action for arsenic carcinogenesis. Proposed
    mechanisms/modes of action for arsenic carcinogenesi...

  15. Other 1-carbon micronutrients and age modulate the effects of folate on colorectal carcinogenesis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Considerable evidence arising from both pre-clinical and clinical studies indicates that a habitually low intake of folate increases the risk of malignant transformation. Moreover, the pre-clinical observations convincingly substantiate true causation. The data in this regard is most compelling for ...

  16. Recent Developments in Colorectal Imaging

    PubMed Central

    Pickhardt, Perry J.

    2014-01-01

    Purpose of review The aim of this review is to provide an update on important recent advances in radiologic colorectal imaging, with emphasis on detection, staging, and surveillance of colorectal neoplasia. Recent findings Colorectal imaging advances with magnetic resonance (MR), CT colonography (CTC), and positron emission tomography (PET) over the past year or so have been substantial. Progress in MR imaging for rectal cancer was most notable in terms of assessment of response to neoadjuvant therapy. Continued maturation and clinical validation of CTC was observed for the evaluation of advanced neoplasia, among other areas. Multimodality approaches to colorectal imaging that incorporate functional PET data have also made impressive strides forward. Summary Recent advances in cross-sectional and functional radiologic imaging of the colorectum will positively impact the clinical capabilities for noninvasive evaluation of colorectal neoplasia PMID:25394232

  17. Dietary Intakes of Red Meat, Poultry, and Fish During High School and Risk of Colorectal Adenomas in Women

    PubMed Central

    Nimptsch, Katharina; Bernstein, Adam M.; Giovannucci, Edward; Fuchs, Charles S.; Willett, Walter C.; Wu, Kana

    2013-01-01

    Adolescent diet may be etiologically relevant for colorectal carcinogenesis. We examined the association between meat and fish intakes during adolescence and the risk of colorectal adenomas later in life among 19,771 women participating in the Nurses' Health Study II. Subjects had completed a validated food frequency questionnaire in 1998 (when aged 34–51 years) about their diets during high school and subsequently underwent at least 1 lower-bowel endoscopy during the study period (1998–2007). During this period, 1,494 subjects were diagnosed with colorectal adenomas. Intake of red meat during adolescence was not associated with colorectal adenoma risk when comparing those in the highest versus lowest category of intake (odds ratio (OR) = 1.04, 95% confidence interval (CI): 0.81, 1.35). Similarly, intake of fish during adolescence was not associated with colorectal adenoma risk (OR = 0.96, 95% CI: 0.78, 1.17). Intake of poultry during adolescence was associated with a lower risk of total colorectal (OR = 0.80, 95% CI: 0.64, 0.99), distal (OR = 0.71, 95% CI: 0.51, 0.99), rectal (OR = 0.51, 95% CI: 0.29, 0.90), and advanced (OR = 0.60, 95% CI: 0.38, 0.93) adenomas. Replacement of 1 serving per day of red meat with 1 serving per day of poultry or fish was associated with 41% and 35% decreased risks for rectal adenomas and advanced adenomas, respectively. Our findings do not suggest an association between red meat intake during adolescence and colorectal adenomas later in life, but higher poultry intake during this time was associated with a lower risk of colorectal adenomas. PMID:23785116

  18. Current targeted therapies in the treatment of advanced colorectal cancer: a review

    PubMed Central

    Moriarity, Andrew; O’Sullivan, Jacintha; Kennedy, John; Mehigan, Brian; McCormick, Paul

    2016-01-01

    Treatment strategies for metastatic colorectal cancer (mCRC) patients have undergone dramatic changes in the past decade and despite improved patient outcomes, there still exist areas for continued development. The introduction of targeted agents has provided clinicians with additional treatment options in mCRC, however, results have been mixed at best. These novel therapies were designed to interfere with specific molecules involved in the cellular carcinogenesis pathway and ultimately deliver a more focused treatment. Currently, their use in mCRC has been limited primarily as an adjunct to conventional chemotherapy regimens. This review explores the relevant cell-signaling networks in colorectal cancer, provides focus on the current targeted agent armamentarium approved for use in mCRC and explores the usefulness of predictive mCRC biomarkers. PMID:27482287

  19. Metal interactions in carcinogenesis: enhancement, inhibition

    PubMed Central

    Nordberg, Gunnar F.; Andersen, Ole

    1981-01-01

    Metals constitute a fundamentally important part of the total human environment. Since human exposure often involves complex mixtures of metal compounds and, possibly, organic compounds which may be carcinogenic per se, interactions between these compounds may add significantly to human cancer risk. Our present knowledge about these kinds of interactions is very limited. The best investigated area is benzo(a)pyrene (BP)-metal oxide particle interactions in respiratory carcinogenesis in the hamster. Metal oxide particles were also shown to modify the carcinogenic effect of nitrosamines. Several reports describe experiments in which selenium compounds exerted a generally anticarcinogenic and antimutagenic activity. Inorganic arsenic compounds, which are accepted to be carcinogenic in man, have so far been negative in animal experiments except for one recent suggested report. Several authors have, however, suggested that these compounds may act as cocarcinogens due to their inhibition of DNA repair, although animal experiments to demonstrate a cocarcinogenic effect of arsenic compounds have been negative so far, except for one preliminary report. The concentration of zinc in the diet seemed to influence both transplanted tumor growth and the carcinogenicity of several organic compounds, and the possibility of a correlation between dietary zinc and certain cancer forms in man has been suggested. Protection against development of Leydigiomas usually induced by cadmium injection was afforded by simultaneous injection of zinc salts. Nickel carcinogenesis has been reported to be antagonized by manganese, and synergism between Ni and organic carcinogens, e.g. BP, has been demonstrated. There is no firm evidence that lead may be a cocarcinogen, although some limited experimental evidence is available. Oxidizing agents have been demonstrated to increase, and reducing agents to antagonize, the mutagenic effect of chromium compounds in vitro. The content of carcinogenic and

  20. Identification of diagnostic markers in colorectal cancer via integrative epigenomics and genomics data

    PubMed Central

    KOK-SIN, TEOW; MOKHTAR, NORFILZA MOHD; HASSAN, NUR ZARINA ALI; SAGAP, ISMAIL; ROSE, ISA MOHAMED; HARUN, ROSLAN; JAMAL, RAHMAN

    2015-01-01

    contribute to colorectal carcinogenesis. PMID:25997610

  1. Urinary total isothiocyanates and colorectal cancer: a prospective study of men in Shanghai, China

    PubMed Central

    Moy, Kristin A.; Yuan, Jian-Min; Chung, Fung-Lung; Van Den Berg, David; Wang, Renwei; Gao, Yu-Tang; Yu, Mimi C.

    2008-01-01

    Laboratory and epidemiological evidence suggest that dietary isothiocyanates (ITCs) may have a chemopreventive effect on cancer. Humans are exposed to ITCs primarily through ingestion of cruciferous vegetables which contain glucosinolates, the precursors to ITCs. The association between urinary total ITC level and colorectal cancer risk was examined in a cohort of 18,244 men in Shanghai, China, with 16 years of follow-up. Urinary total ITCs were quantified on 225 incident cases of colorectal cancer and 1119 matched controls. Odds ratios (ORs) and their 95% confidence intervals (95% CIs) were calculated using logistic regression models. High levels of urinary total ITCs were associated with a reduced risk of colorectal cancer five years after baseline measurements of ITCs whereas a statistically nonsignificant increase in the risk of colorectal cancer was observed for cases within five years of post-enrollment (OR=1.93; 95% CI =0.85, 4.39 for the upper three quartiles of urinary ITCs versus the lowest quartile). The inverse ITC-colorectal cancer association became stronger with a longer duration of follow-up. Compared with the first quartile, ORs (95% CIs) for the second, third, and fourth quartiles of total ITCs in urine collected 10 or more years before cancer diagnosis were 0.61 (0.35, 1.05), 0.51 (0.29, 0.92), and 0.46 (0.25, 0.83), respectively, for risk of colorectal cancer (P for trend = 0.006). The present study suggests that dietary ITCs may exert tumor inhibitory effects, especially during earlier stages of the multistage process of carcinogenesis. PMID:18559550

  2. Identification of GABRA1 and LAMA2 as new DNA methylation markers in colorectal cancer.

    PubMed

    Lee, Sunwoo; Oh, Taejeong; Chung, Hyuncheol; Rha, Sunyoung; Kim, Changjin; Moon, Youngho; Hoehn, Benjamin D; Jeong, Dongjun; Lee, Seunghoon; Kim, Namkyu; Park, Chanhee; Yoo, Miae; An, Sungwhan

    2012-03-01

    Aberrant methylation of CpG islands in the promoter region of genes is a common epigenetic phenomenon found in early cancers. Therefore conducting genome-scale methylation studies will enhance our understanding of the epigenetic etiology behind carcinogenesis by providing reliable biomarkers for early detection of cancer. To discover novel hypermethylated genes in colorectal cancer by genome-wide search, we first defined a subset of genes epigenetically reactivated in colon cancer cells after treatment with a demethylating agent. Next, we identified another subset of genes with relatively down-regulated expression patterns in colorectal primary tumors when compared with normal appearing-adjacent regions. Among 29 genes obtained by cross-comparison of the two gene-sets, we subsequently selected, through stepwise subtraction processes, two novel genes, GABRA1 and LAMA2, as methylation targets in colorectal cancer. For clinical validation pyrosequencing was used to assess methylation in 134 matched tissue samples from CRC patients. Aberrant methylation at target CpG sites in GABRA1 and LAMA2 was observed with high frequency in tumor tissues (92.5% and 80.6%, respectively), while less frequently in matched tumor-adjacent normal tissues (33.6% for GABRA1 and 13.4% for LAMA2). Methylation levels in primary tumors were not significantly correlated with clinico-pathological features including age, sex, survival and TNM stage. Additionally, we found that ectopic overexpression of GABRA1 in colon cancer cell lines resulted in strong inhibition of cell growth. These results suggest that two novel hypermethylated genes in colorectal cancer, GABRA1 and LAMA2, may have roles in colorectal tumorigenesis and could be potential biomarkers for the screening and the detection of colorectal cancer in clinical practice. PMID:22038115

  3. Toward a Molecular Classification of Colorectal Cancer: The Role of MGMT

    PubMed Central

    Minoo, Parham

    2013-01-01

    O6-methylguanine DNA methyltransferase (MGMT) is a DNA repair enzyme with the ability to protect cells from DNA mutations by removing alkyl groups from the O6 position of guanine. Colon mucosa is exposed to the direct effects of environmental carcinogens and therefore maintaining a proficient DNA repair system is very important to stay protected against DNA mutagenesis. Loss of MGMT expression is almost exclusively associated with methylation of CpG islands in the MGMT gene promoter region which is found in approximately 40% of colorectal cancers. The role of MGMT loss in colorectal tumorigenesis is complex but numerous studies have documented methylation of this gene even in the normal appearing mucosa as well as in aberrant crypt foci, suggesting that MGMT methylation can be regarded as an early event or “field defect” in colon cancer neoplasia. The focus of this perspective is the role of MGMT in different pathways of colorectal carcinogenesis as well as the implication of this molecule in treatment decisions in colorectal cancer patients. PMID:24151575

  4. miR-506 inhibits cell proliferation and invasion by targeting TET family in colorectal cancer

    PubMed Central

    Wu, Minghao; Zhang, Yu; Tang, Anliu; Tian, Li

    2016-01-01

    Objective(s): Ten-eleven translocation (TET) family members have been shown to be involved in the development of many tumors. However, the biological role of the TET family and its mechanism of action in colorectal carcinogenesis and progression remain poorly understood. Materials and Methods: We measured the expression levels of TET family members in colorectal cancer (CRC) specimens, in the corresponding normal tissues and in cell lines using quantitative real-time PCR (qRT-PCR) and in situ hybridization (ISH). Both the protein function and the protein-independent role of TETs were investigated by cell viability assays and cell invasion assays using in vitro and in vivo models. Results: We found that all three TET genes were strongly up-regulated at the transcript level in CRC samples compared to matched normal tissues. The same results were observed in colorectal cancer cell lines. Knockdown of TETs by shTET1/2/3 showed that TET family members inhibited CRC growth and metastasis. We showed that TET family member degradation by miR-506 inhibits cell proliferation and invasion in colorectal cancer. Conclusion: Through this study, we advance our understanding of the expression levels TETs and miR-506 in CRC and further clarify the internal regulatory mechanism of miR-506 by targeting TET during CRC processes. These findings may contribute to a novel avenue for researching and developing targeted therapies for CRC. PMID:27114802

  5. FAM172A is a tumor suppressor in colorectal carcinoma.

    PubMed

    Cui, Chunhui; Ye, Lili; Huang, Zonghai; Huang, Shuxin; Liu, Hao; Yu, Jinlong

    2016-05-01

    The present study was designed to elucidate the regulatory role of a novel protein FAM172A in carcinogenesis of colorectal carcinoma (CRC). Investigation of clinical samples using Western blotting showed that expression of FAM172A is significantly lower in cancerous tissues than in adjacent tissues. Furthermore, we constructed in vitro model for continuous overexpression and silencing of FAM172A with a retroviral vector system. FAM172A suppressed the proliferative and invasive potentials of LOVO cells as shown in MTT test, transwell migration assay, wound healing assay, 3D-culture morphologic study, and xenograft experiment. RT-PCR and Western blotting showed that FAM172A overexpression inhibited expressions of Cyclin D1, CDK2, MMP-2, MMP-9, PERK, elF2α, ATF6, XBP1, and GRP78, while FAM172A silencing induced their expressions. FAM172A might regulate ERS through PERK-elF2α, ATF6-XBP1-GRP78 signal pathway. The results implicated that FAM172A functioned as a tumor suppressor in colorectal carcinoma. PMID:26637224

  6. Bowman-Birk inhibitors from legumes as colorectal chemopreventive agents

    PubMed Central

    Clemente, Alfonso; Arques, Maria del Carmen

    2014-01-01

    Aberrant functioning of serine proteases in inflammatory and carcinogenic processes within the gastrointestinal tract (GIT) has prompted scientists to investigate the potential of serine protease inhibitors, both natural and synthetic, as modulators of their proteolytic activities. Protease inhibitors of the Bowman-Birk type, a major protease inhibitor family in legume seeds, which inhibit potently and specifically trypsin- and chymotrypsin-like proteases, are currently being investigated as colorectal chemopreventive agents. Physiologically relevant amounts of Bowman-Birk inhibitors (BBI) can reach the large intestine in active form due to their extraordinary resistance to extreme conditions within the GIT. Studies in animal models have proven that dietary BBI from several legume sources, including soybean, pea, lentil and chickpea, can prevent or suppress carcinogenic and inflammatory processes within the GIT. Although the therapeutic targets and the action mechanism of BBI have not yet been elucidated, the emerging evidence suggests that BBI exert their preventive properties via protease inhibition; in this sense, serine proteases should be considered as primary targets in early stages of carcinogenesis. The validation of candidate serine proteases as therapeutic targets together with the identification, within the wide array of natural BBI variants, of the most potent and specific protease inhibitors, are necessary to better understand the potential of this protein family as colorectal chemopreventive agents. PMID:25132747

  7. Proteomics for discovery of candidate colorectal cancer biomarkers

    PubMed Central

    Álvarez-Chaver, Paula; Otero-Estévez, Olalla; Páez de la Cadena, María; Rodríguez-Berrocal, Francisco J; Martínez-Zorzano, Vicenta S

    2014-01-01

    Colorectal cancer (CRC) is the second most common cause of cancer-related deaths in Europe and other Western countries, mainly due to the lack of well-validated clinically useful biomarkers with enough sensitivity and specificity to detect this disease at early stages. Although it is well known that the pathogenesis of CRC is a progressive accumulation of mutations in multiple genes, much less is known at the proteome level. Therefore, in the last years many proteomic studies have been conducted to find new candidate protein biomarkers for diagnosis, prognosis and as therapeutic targets for this malignancy, as well as to elucidate the molecular mechanisms of colorectal carcinogenesis. An important advantage of the proteomic approaches is the capacity to look for multiple differentially expressed proteins in a single study. This review provides an overview of the recent reports describing the different proteomic tools used for the discovery of new protein markers for CRC such as two-dimensional electrophoresis methods, quantitative mass spectrometry-based techniques or protein microarrays. Additionally, we will also focus on the diverse biological samples used for CRC biomarker discovery such as tissue, serum and faeces, besides cell lines and murine models, discussing their advantages and disadvantages, and summarize the most frequently identified candidate CRC markers. PMID:24744574

  8. Chemoprevention of colorectal cancer

    PubMed Central

    LANGMAN, M; BOYLE, P

    1998-01-01

    Department of Medicine, Queen Elizabeth Hospital, Birmingham B15 2TH, UK P BOYLE Colorectal cancer is the fourth commonest form of cancer in men with 678 000 estimated new cases per year worldwide, representing 8.9% of all new cancers. The disease is most frequent in Occidental countries and particularly so in North America, Australia, New Zealand, and parts of Europe. Prospects for colorectal cancer control are bright and a number of possible approaches could prove fruitful. Among these, pharmaceutical measures seem to be valid and logical approaches to the prevention of colorectal cancer and diminishing its impact. Such approaches could concentrate in primary prevention in at-risk subjects or be applied in altering the course of precursor or established disease. Treatments used must fulfil basic requirements of biological plausibility and safety in continued use in large numbers of subjects. Those available include vitamins and minerals, and other drugs with potential as antioxidants, immune modulators or promoters of cell differentiation or apoptosis. Of the various regimens suggested, vitamin A supplementation may even predispose to adverse outcomes, and antioxidant vitamins in general have no coherent body of evidence to support their use. N-acetylcysteine and ursodeoxycholic acid have promising characteristics but there are as yet no clinical data to support the use of the former in gut epithelial cancer, and formal dose ranging studies must be carried out before the latter is submitted to large scale trial. Folate shows promising characteristics but non-steroidal anti-inflammatory drugs and vitamin D seem the most promising agents. Both seem to reduce the incidence of disease, and to reduce growth rates and/or induce differentiation or apoptosis in gut epithelial cancer cells. Both are also well understood pharmacologically. They may be preferred to newer selective compounds in the same class until these newer compounds are confirmed as safe for widespread

  9. Familial colorectal cancer.

    PubMed

    Lung, M S; Trainer, A H; Campbell, I; Lipton, L

    2015-05-01

    Identifying individuals with a genetic predisposition to developing familial colorectal cancer (CRC) is crucial to the management of the affected individual and their family. In order to do so, the physician requires an understanding of the different gene mutations and clinical manifestations of familial CRC. This review summarises the genetics, clinical manifestations and management of the known familial CRC syndromes, specifically Lynch syndrome, familial adenomatous polyposis, MUTYH-associated neoplasia, juvenile polyposis syndrome and Peutz-Jeghers syndrome. An individual suspected of having a familial CRC with an underlying genetic predisposition should be referred to a familial cancer centre to enable pre-test counselling and appropriate follow up. PMID:25955461

  10. [Recent advances in bladder urothelial carcinogenesis].

    PubMed

    Pignot, Géraldine; le Goux, Constance; Bieche, Ivan

    2015-12-01

    Bladder cancer is the sixth cause of cancer mortality in France and prognosis of muscle-invasive tumors remains poor due to lack of effective treatments. Recent advances in molecular biology applied to tumors and results of recent genome-wide studies have brought a important impact on the understanding of bladder carcinogenesis. Main molecular alterations concern FGFR3, TP53 and HER2, and it is now possible to distinguish three subgroups of tumors according to molecular profile. This paper proposes a review of different genetic and epigenetic alterations in bladder cancer, their potential role as theranostic markers in clinical oncology and new targeted therapies according to the concept of personalized medicine. PMID:26617115

  11. (Radiation carcinogenesis in the whole body system)

    SciTech Connect

    Fry, R.J.M.

    1990-12-14

    The objectives of the trip were: to take part in and to give the summary of a Symposium on Radiation Carcinogenesis at Tokyo, and to give a talk at the National Institute of Radiological Sciences at Chiba. The breadth of the aspects considered at the conference was about as broad as is possible, from effects at the molecular level to human epidemiology, from the effects of tritium to cancer induction by heavy ions. The events induced by cancer that lead to cancer and the events that are secondary are beginning to come into better focus but much is still not known. Interest in suppressor genes is increasing rapidly in the studies of human tumors and many would predict that the three or four suppressor genes associated with cancer are only the first sighting of a much larger number.

  12. Chemical basis of inflammation-induced carcinogenesis.

    PubMed

    Ohshima, Hiroshi; Tatemichi, Masayuki; Sawa, Tomohiro

    2003-09-01

    Chronic inflammation induced by biological, chemical, and physical factors has been associated with increased risk of human cancer at various sites. Inflammation activates a variety of inflammatory cells, which induce and activate several oxidant-generating enzymes such as NADPH oxidase, inducible nitric oxide synthase, myeloperoxidase, and eosinophil peroxidase. These enzymes produce high concentrations of diverse free radicals and oxidants including superoxide anion, nitric oxide, nitroxyl, nitrogen dioxide, hydrogen peroxide, hypochlorous acid, and hypobromous acid, which react with each other to generate other more potent reactive oxygen and nitrogen species such as peroxynitrite. These species can damage DNA, RNA, lipids, and proteins by nitration, oxidation, chlorination, and bromination reactions, leading to increased mutations and altered functions of enzymes and proteins (e.g., activation of oncogene products and/or inhibition of tumor-suppressor proteins) and thus contributing to the multistage carcinogenesis process. Appropriate treatment of inflammation should be explored further for chemoprevention of human cancers. PMID:12921773

  13. Primary Prevention of Colorectal Cancer

    PubMed Central

    Chan, Andrew T.; Giovannucci, Edward L.

    2010-01-01

    Colorectal cancer has been strongly associated with a Western lifestyle. In the past several decades, much has been learned about the dietary, lifestyle, and medication risk factors for this malignancy. Although there is controversy about the role of specific nutritional factors, consideration of the dietary pattern as a whole appears useful for formulating recommendations. For example, several studies have shown that high intake of red and processed meats, highly refined grains and starches, and sugars is related to increased risk of colorectal cancer. Replacing these factors with poultry, fish, and plant sources as the primary source of protein; unsaturated fats as the primary source of fat; and unrefined grains, legumes and fruits as the primary source of carbohydrates is likely to lower risk of colorectal cancer. Although a role for supplements, including vitamin D, folate, and vitamin B6, remains uncertain, calcium supplementation is likely to be at least modestly beneficial. With respect to lifestyle, compelling evidence indicates that avoidance of smoking and heavy alcohol use, prevention of weight gain, and the maintenance of a reasonable level of physical activity are associated with markedly lower risks of colorectal cancer. Medications such as aspirin and non-steroidal anti-inflammatory drugs and post-menopausal hormones for women are associated with significant reductions in colorectal cancer risk, though their utility is affected by associated risks. Taken together, modifications in diet and lifestyle should substantially reduce the risk of colorectal cancer and could complement screening in reducing colorectal cancer incidence. PMID:20420944

  14. Oxidative DNA damage accumulation in gastric carcinogenesis

    PubMed Central

    Farinati, F; Cardin, R; Degan, P; Rugge, M; Di, M; Bonvicini, P; Naccarato, R

    1998-01-01

    Background—Gastric carcinogenesis is a multifactorial, multistep process, in which chronic inflammation plays a major role. 
Aims—In order to ascertain whether free radical mediated oxidative DNA damage is involved in such a process, concentrations of 8-hydroxydeoxyguanosine (8OHdG), a mutagenic/carcinogenic adduct, and thiobarbituric acid reactive substances (TBARS), as an indirect measure of free radical mediated damage, were determined in biopsy specimens from patients undergoing endoscopy. 
Patients—Eighty eight patients were divided into histological subgroups as follows: 27 with chronic non-atrophic gastritis, 41 with atrophic gastritis, six with gastric cancer, and 14 unaffected controls. 
Methods—Intestinal metaplasia, Helicobacter pylori infection, and disease activity were semiquantitatively scored. 8OHdG concentrations were assessed by HPLC with electrochemical detection, and TBARS concentrations were fluorimetrically assayed. 
Results—8OHdG concentrations (mean number of adducts/105 dG residues) were significantly higher in chronic atrophic gastritis (p=0.0009). Significantly higher concentrations were also detected in the presence of severe disease activity (p=0.02), intestinal metaplasia (p=0.035), and H pylori infection (p=0.001). TBARS concentrations were also higher in atrophic gastritis, though not significantly so. In a multiple logistic regression analysis, 8OHdG concentrations correlated best with the presence and severity of H pylori infection (r=0.53, p=0.002). 
Conclusions—Chronic gastritis is characterised by the accumulation of oxidative DNA damage with mutagenic and carcinogenic potential. H pylori infection is the major determinant for DNA adduct formation. 

 Keywords: free radicals; oxidative DNA damage; gastric carcinogenesis; precancerous changes; peroxidative damage PMID:9577340

  15. Cathepsin B promotes colorectal tumorigenesis, cell invasion, and metastasis

    PubMed Central

    Bian, Benjamin; Mongrain, Sébastien; Cagnol, Sébastien; Langlois, Marie‐Josée; Boulanger, Jim; Bernatchez, Gérald; Carrier, Julie C.; Boudreau, François

    2015-01-01

    Cathepsin B is a cysteine proteinase that primarily functions as an endopeptidase within endolysosomal compartments in normal cells. However, during tumoral expansion, the regulation of cathepsin B can be altered at multiple levels, thereby resulting in its overexpression and export outside of the cell. This may suggest a possible role of cathepsin B in alterations leading to cancer progression. The aim of this study was to determine the contribution of intracellular and extracellular cathepsin B in growth, tumorigenesis, and invasion of colorectal cancer (CRC) cells. Results show that mRNA and activated levels of cathepsin B were both increased in human adenomas and in CRCs of all stages. Treatment of CRC cells with the highly selective and non‐permeant cathepsin B inhibitor Ca074 revealed that extracellular cathepsin B actively contributed to the invasiveness of human CRC cells while not essential for their growth in soft agar. Cathepsin B silencing by RNAi in human CRC cells inhibited their growth in soft agar, as well as their invasion capacity, tumoral expansion, and metastatic spread in immunodeficient mice. Higher levels of the cell cycle inhibitor p27Kip1 were observed in cathepsin B‐deficient tumors as well as an increase in cyclin B1. Finally, cathepsin B colocalized with p27Kip1 within the lysosomes and efficiently degraded the inhibitor. In conclusion, the present data demonstrate that cathepsin B is a significant factor in colorectal tumor development, invasion, and metastatic spreading and may, therefore, represent a potential pharmacological target for colorectal tumor therapy. © 2015 The Authors. Molecular Carcinogenesis, published by Wiley Periodicals, Inc. PMID:25808857

  16. Academic colorectal surgery job search.

    PubMed

    Kalady, Matthew F

    2014-06-01

    The field of academic colorectal surgery encompasses a vast array of possibilities. Clinical care accompanied by research, teaching, innovation, and/or administration provides the foundation for what is considered an academic career. For those choosing academic colorectal surgery, the process of finding and selecting a first job can provoke much angst. This article describes some strategies to approach the academic colorectal job search and provides insight into deciding a career focus, exploring relevant positions, weighing specific factors, and negotiating your first offer. PMID:25067918

  17. Academic Colorectal Surgery Job Search

    PubMed Central

    Kalady, Matthew F.

    2014-01-01

    The field of academic colorectal surgery encompasses a vast array of possibilities. Clinical care accompanied by research, teaching, innovation, and/or administration provides the foundation for what is considered an academic career. For those choosing academic colorectal surgery, the process of finding and selecting a first job can provoke much angst. This article describes some strategies to approach the academic colorectal job search and provides insight into deciding a career focus, exploring relevant positions, weighing specific factors, and negotiating your first offer. PMID:25067918

  18. IL-15 suppresses colitis-associated colon carcinogenesis by inducing antitumor immunity

    PubMed Central

    Bahri, Rajia; Pateras, Ioannis S; D’Orlando, Orietta; Goyeneche-Patino, Diego A; Campbell, Michelle; Polansky, Julia K; Sandig, Hilary; Papaioannou, Marilena; Evangelou, Kostas; Foukas, Periklis G; Gorgoulis, Vassilis G; Bulfone-Paus, Silvia

    2015-01-01

    IL-15 regulates the development, survival, and proliferation of multiple innate and adaptive immune cells and plays a dual role, inducing both tumor cell growth and antitumor immunity. However, the role of IL-15 in inflammation-induced cancer remains unclear. To explore this, we have compared the colon carcinoma burden of Il15−/− and Il15rα−/− mice with wild type (WT) mice after induction of colitis-associated colon carcinogenesis utilizing the AOM/DSS model. Compared to WT mice, Il15−/− but not Il15rα−/− mice showed reduced survival, along with higher tumor incidence, colon weight, and tumor size. This suggests that low affinity IL-15 signaling via the shared IL-2Rβ/γc decreases the risk for developing colitis-associated cancer. CD11c-Il15 mice, in which IL-15 expression is reconstituted in Il15−/− mice under the control of the CD11c-promoter, showed that selective reconstitution of IL-15 in antigen-presenting cells restored the CD8+ T and NK cell compartments, serum levels of IFNγ, G-CSF, IL-10, and CXCL1 and reduced tumor burden. After demonstrating IL-15 expression in human colorectal cancer (CRC) cells in situ, we investigated the role of this cytokine in the modulation of key colonic oncogenic pathways in the tumor. While these pathways were found to be unaltered in the absence of IL-15, tumor transcriptome analysis showed that the loss of IL-15 upregulates key inflammatory mediators associated with colon cancer progression, such as IL-1β, IL-22, IL-23, Cxcl5, and Spp1. These findings provide evidence that IL-15 suppresses colitis-associated colon carcinogenesis through regulation of antitumor cytotoxicity, and modulation of the inflammatory tumor micromilieu. PMID:26405589

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

    PubMed

    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. . PMID:25592152

  20. Genetic polymorphisms of MMP1, MMP3 and MMP7 gene promoter and risk of colorectal adenoma

    PubMed Central

    Lièvre, Astrid; Milet, Jacqueline; Carayol, Jérôme; Le Corre, Delphine; Milan, Chantal; Pariente, Alexandre; Nalet, Bernard; Lafon, Jacques; Faivre, Jean; Bonithon-Kopp, Claire; Olschwang, Sylviane; Bonaiti-Pellié, Catherine; Laurent-Puig, Pierre

    2006-01-01

    Background Matrix metalloproteinases (MMP) have been shown to play a role in colorectal cancer (CRC). More recently, MMP1, MMP3 and MMP7 functional gene promoter polymorphisms have been found to be associated with CRC occurrence and prognosis. To document the role of MMP polymorphisms in the early step of colorectal carcinogenesis, we investigated their association with colorectal adenoma risk in a case-control study comprising 295 patients with large adenomas (LA), 302 patients with small adenomas (SA) and 568 polyp-free (PF) controls. Methods Patients were genotyped using automated fragment analysis for MMP1 -1607 ins/del G and MMP3 -1612 ins/delA (MMP3.1) polymorphisms and allelic discrimination assay for MMP3 -709 A/G (MMP3.2) and MMP7 -181 A/G polymorphisms. Association between MMP genotypes and colorectal adenomas was first tested for each polymorphism separately and then for combined genotypes using the combination test. Adjustment on relevant variables and estimation of odds ratios were performed using unconditional logistic regression. Results No association was observed between the polymorphisms and LA when compared to PF or SA. When comparing SA to PF controls, analysis revealed a significant association between MMP3 -1612 ins/delA polymorphism and SA with an increased risk associated with the 6A/6A genotype (OR = 1.67, 95%CI: 1.20–2.34). Using the combination test, the best association was found for MMP3.1-MMP1 (p = 0.001) with an OR of 1.88 (95%CI: 1.08–3.28) for the combined genotype 2G/2G-6A/6A estimated by logistic regression. Conclusion These data show a relation between MMP1 -1607 ins/del G and MMP3 -1612 ins/delA combined polymorphisms and risk of SA, suggesting their potential role in the early steps of colorectal carcinogenesis. PMID:17125518

  1. Transforming growth factor-beta during carcinogenesis: the shift from epithelial to mesenchymal signaling.

    PubMed

    Matsuzaki, Koichi; Okazaki, Kazuichi

    2006-04-01

    Transforming growth factor-beta (TGF-beta) activates not only TGF-beta type I receptor (TbetaRI) but also c-Jun N-terminal kinase (JNK), changing unphosphorylated Smad3 to its phosphoisoforms: C-terminally phosphorylated Smad3 (pSmad3C) and linker phosphorylated Smad3 (pSmad3L). While the TbetaRI/pSmad3C pathway inhibits growth of normal epithelial cells, JNK/pSmad3L-mediated signaling is involved in invasion by activated mesenchymal cells. During sporadic human colorectal carcinogenesis, TGF-beta signaling confers a selective advantage on tumor cells by shifting from the TbetaRI/pSmad3C pathway characteristic of mature epithelial cells to the JNK/pSmad3L pathway, which is more characteristic of the state of flux shown by the activated mesenchymal cells. JNK acts as a regulator of TGF-beta signaling by increasing the basal level of pSmad3L available for action in the nuclei of the invasive adenocarcinoma, in the meantime shutting down TGF-beta-dependent nuclear activity of pSmad3C. Loss of epithelial homeostasis and acquisition of a migratory, mesenchymal phenotype are essential for tumor invasion. From the viewpoint of TGF-beta signaling, a key therapeutic aim in cancer would be restoration of the lost tumor suppressor function observed in normal colorectal epithelial cells at the expense of effects promoting aggressive behavior of the adenocarcinoma. Specific inhibitors of the JNK/pSmad3L pathway might prove useful in this respect. In the case of molecularly targeted therapy for human cancer, pSmad3L and pSmad3C could be assessed as biomarkers to evaluate the likely benefit from specific inhibition of the JNK/pSmad3L pathway. PMID:16741607

  2. Get Tested for Colorectal Cancer

    MedlinePlus

    ... of fiber . Talk with your doctor about taking aspirin every day. Taking aspirin every day can lower your risk of colorectal ... 50 to 59, ask your doctor if daily aspirin is right for you . Previous section Get Tested ...

  3. Primary prevention: phytoprevention and chemoprevention of colorectal cancer.

    PubMed

    Turini, Marco E; DuBois, Raymond N

    2002-08-01

    Considering the various stages of carcinogenesis and the numerous tumor types and available chemoprevention agents, knowledge of the etiology and the type of cancer to be treated, or possibly prevented, and understanding of the mechanisms by which agents exert their chemoprevention benefits may provide for improved strategy in designing therapeutic regimens. Because cancer usually develops over a 10- to 20-year period, it may be necessary for some agents to be provided before or early in the initiation steps of carcinogenesis to have beneficial effects. On the other hand, some agents may be more suitable for CRC prevention if provided at a later stage of carcinogenesis. Gene array, genomics, and proteomics are useful tools in advancing our understanding of the molecular events involved in carcinogenesis and in identifying markers of risk and surrogate end-points for colorectal cancer progression. These techniques may also serve for screening, identifying, and providing treatment targets for high-risk patients populations. Treatment could be developed depending on a patient's individual needs and genomic tumor profile. Clinical markers and surrogate end-points should be considered, together with molecular measurements, to more accurately assess risk. NSAIDs and COXIBs are clinically recognized as chemoprevention agents, and clinical trials evaluating their efficacy are ongoing. Treatment protocols, including dose and timing, remain to be determined, however. DFMO may best be used in combination with other chemoprevention agents. Dietary fiber and calcium supplements, as part of an overall low-fat diet, may decrease CRC risk. Long-term compliance with this regimen may be necessary to effect a beneficial outcome. Folate holds promise but needs further investigation, especially because its beneficial effects may depend on cancer type. Phytochemicals have been identified as strong candidates for use as agents to prevent colorectal cancer in cell culture and in rodent

  4. Effect of meat (beef, chicken, and bacon) on rat colon carcinogenesis

    PubMed Central

    Parnaud, Géraldine; Peiffer, Ginette; Taché, Sylviane; Corpet, Denis E.

    1998-01-01

    High intake of red meat or processed meat is associated with increased risk of colon cancer. In contrast, consumption of white meat (chicken) is not associated with risk and might even reduce the occurrence of colorectal cancer. We speculated that a diet containing beef or bacon would increase and a diet containing chicken would decrease colon carcinogenesis in rats. One hundred female Fischer 344 rats were given a single injection of azoxymethane (20 mg/kg i.p.), then randomized to 10 different AIN-76-based diets. Five diets were adjusted to 14% fat and 23% protein and five other diets to 28% fat and 40% protein. Fat and protein were supplied by 1) lard and casein, 2) olive oil and casein, 3) beef, 4) chicken with skin, and 5) bacon. Meat diets contained 30% or 60% freeze-dried fried meat. The diets were given ad libitum for 100 days, then colon tumor promotion was assessed by the multiplicity of aberrant crypt foci [number of crypts per aberrant crypt focus (ACF)]. The ACF multiplicity was nearly the same in all groups, except bacon-fed rats, with no effect of fat and protein level or source (p = 0.7 between 8 groups by analysis of variance). In contrast, compared with lard- and casein-fed controls, the ACF multiplicity was reduced by 12% in rats fed a diet with 30% bacon and by 20% in rats fed a diet with 60% bacon (p < 0.001). The water intake was higher in bacon-fed rats than in controls (p < 0.0001). The concentrations of iron and bile acids in fecal water and total fatty acids in feces changed with diet, but there was no correlation between these concentrations and the ACF multiplicity. Thus the hypothesis that colonic iron, bile acids, or total fatty acids can promote colon tumors is not supported by this study. The results suggest that, in rats, beef does not promote the growth of ACF and chicken does not protect against colon carcinogenesis. A bacon-based diet appears to protect against carcinogenesis, perhaps because bacon contains 5% NaCl and increased

  5. Residual-QSAR. Implications for genotoxic carcinogenesis

    PubMed Central

    2011-01-01

    Introduction Both main types of carcinogenesis, genotoxic and epigenetic, were examined in the context of non-congenericity and similarity, respectively, for the structure of ligand molecules, emphasizing the role of quantitative structure-activity relationship ((Q)SAR) studies in accordance with OECD (Organization for Economic and Cooperation Development) regulations. The main purpose of this report involves electrophilic theory and the need for meaningful physicochemical parameters to describe genotoxicity by a general mechanism. Residual-QSAR Method The double or looping multiple linear correlation was examined by comparing the direct and residual structural information against the observed activity. A self-consistent equation of observed-computed activity was assumed to give maximum correlation efficiency for those situations in which the direct correlations gave non-significant statistical information. Alternatively, it was also suited to describe slow and apparently non-noticeable cancer phenomenology, with special application to non-congeneric molecules involved in genotoxic carcinogenesis. Application and Discussions The QSAR principles were systematically applied to a given pool of molecules with genotoxic activity in rats to elucidate their carcinogenic mechanisms. Once defined, the endpoint associated with ligand-DNA interaction was used to select variables that retained the main Hansch physicochemical parameters of hydrophobicity, polarizability and stericity, computed by the custom PM3 semiempirical quantum method. The trial and test sets of working molecules were established by implementing the normal Gaussian principle of activities that applies when the applicability domain is not restrained to the congeneric compounds, as in the present study. The application of the residual, self-consistent QSAR method and the factor (or average) method yielded results characterized by extremely high and low correlations, respectively, with the latter resembling

  6. Molecular genetics of colorectal cancer.

    PubMed

    Bogaert, Julie; Prenen, Hans

    2014-01-01

    Approximately 90% of colorectal cancer cases are sporadic without family history or genetic predisposition, while in less than 10% a causative genetic event has been identified. Historically, colorectal cancer classification was only based on clinical and pathological features. Many efforts have been made to discover the genetic and molecular features of colorectal cancer, and there is more and more evidence that these features determine the prognosis and response to (targeted) treatment. Colorectal cancer is a heterogeneous disease, with three known major molecular groups. The most common is the chromosomal instable group, characterized by an accumulation of mutations in specific oncogenes and tumor suppressor genes. The second is the microsatellite instable group, caused by dysfunction of DNA mismatch repair genes leading to genetic hypermutability. The CpG Island Methylation phenotype is the third group, distinguished by hypermethylation. Colorectal cancer subtyping has also been addressed using genome-wide gene expression profiling in large patient cohorts and recently several molecular classification systems have been proposed. In this review we would like to provide an up-to-date overview of the genetic aspects of colorectal cancer. PMID:24714764

  7. Diet-related DNA adduct formation in relation to carcinogenesis.

    PubMed

    Hemeryck, Lieselot Y; Vanhaecke, Lynn

    2016-08-01

    The human diet contributes significantly to the initiation and promotion of carcinogenesis. It has become clear that the human diet contains several groups of natural foodborne chemicals that are at least in part responsible for the genotoxic, mutagenic, and carcinogenic potential of certain foodstuffs. Electrophilic chemicals are prone to attack nucleophilic sites in DNA, resulting in the formation of altered nucleobases, also known as DNA adducts. Since DNA adduct formation is believed to signal the onset of chemically induced carcinogenesis, the DNA adduct-inducing potential of certain foodstuffs has been investigated to gain more insight into diet-related pathways of carcinogenesis. Many studies have investigated diet-related DNA adduct formation. This review summarizes work on known or suspected dietary carcinogens and the role of DNA adduct formation in hypothesized carcinogenesis pathways. PMID:27330144

  8. Wound-healing error model for radon carcinogenesis

    SciTech Connect

    Kondo, Sohei

    1995-12-31

    Epidemiological studies of lung cancer in uranium miners exposed to radon suggest that radon is a tumor promoter. I will refine this notion by applying the wound-healing error model proposed for radiation carcinogenesis in general.

  9. The Dose Response Relationship for Radiation Carcinogenesis

    NASA Astrophysics Data System (ADS)

    Hall, Eric

    2008-03-01

    Recent surveys show that the collective population radiation dose from medical procedures in the U.S. has increased by 750% in the past two decades. It would be impossible to imagine the practice of medicine today without diagnostic and therapeutic radiology, but nevertheless the widespread and rapidly increasing use of a modality which is a known human carcinogen is a cause for concern. To assess the magnitude of the problem it is necessary to establish the shape of the dose response relationship for radiation carcinogenesis. Information on radiation carcinogenesis comes from the A-bomb survivors, from occupationally exposed individuals and from radiotherapy patients. The A-bomb survivor data indicates a linear relationship between dose and the risk of solid cancers up to a dose of about 2.5 Sv. The lowest dose at which there is a significant excess cancer risk is debatable, but it would appear to be between 40 and 100 mSv. Data from the occupation exposure of nuclear workers shows an excess cancer risk at an average dose of 19.4 mSv. At the other end of the dose scale, data on second cancers in radiotherapy patients indicates that cancer risk does not continue to rise as a linear function of dose, but tends towards a plateau of 40 to 60 Gy, delivered in a fractionated regime. These data can be used to estimate the impact of diagnostic radiology at the low dose end of the dose response relationship, and the impact of new radiotherapy modalities at the high end of the dose response relationship. In the case of diagnostic radiology about 90% of the collective population dose comes from procedures (principally CT scans) which involve doses at which there is credible evidence of an excess cancer incidence. While the risk to the individual is small and justified in a symptomatic patient, the same is not true of some screening procedures is asymptomatic individuals, and in any case the huge number of procedures must add up to a potential public health problem. In the

  10. Suppressed rate of carcinogenesis and decreases in tumour volume and lung metastasis in CXCL14/BRAK transgenic mice.

    PubMed

    Hata, Ryu-Ichiro; Izukuri, Kazuhito; Kato, Yasumasa; Sasaki, Soichiro; Mukaida, Naofumi; Maehata, Yojiro; Miyamoto, Chihiro; Akasaka, Tetsu; Yang, Xiaoyan; Nagashima, Yoji; Takeda, Kazuyoshi; Kiyono, Tohru; Taniguchi, Masaru

    2015-01-01

    Cancer progression involves carcinogenesis, an increase in tumour size, and metastasis. Here, we investigated the effect of overexpressed CXC chemokine ligand 14 (CXCL14) on these processes by using CXCL14/BRAK (CXCL14) transgenic (Tg) mice. The rate of AOM/DSS-induced colorectal carcinogenesis in these mice was significantly lower compared with that for isogenic wild type C57BL/6 (Wt) mice. When tumour cells were injected into these mice, the size of the tumours that developed and the number of metastatic nodules in the lungs of the animals were always significantly lower in the Tg mice than in the Wt ones. Injection of anti-asialo-GM1 antibodies to the mice before and after injection of tumour cells attenuated the suppressing effects of CXCL14 on the tumor growth and metastasis, suggesting that NK cell activity played an important role during CXCL14-mediated suppression of tumour growth and metastasis. The importance of NK cells on the metastasis was also supported when CXCL14 was expressed in B16 melanoma cells. Further, the survival rates after tumour cell injection were significantly increased for the Tg mice. As these Tg mice showed no obvious abnormality, we propose that CXCL14 to be a promising molecular target for cancer suppression/prevention. PMID:25765541