101
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Daroqui MC, Augenlicht LH. Transcriptional attenuation in colon carcinoma cells in response to butyrate. Cancer Prev Res (Phila) 2010; 3:1292-302. [PMID: 20841488 DOI: 10.1158/1940-6207.capr-10-0083] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The short-chain fatty acid sodium butyrate (NaB), produced in the colonic lumen, induces cell cycle arrest, differentiation, and/or apoptosis in colorectal carcinoma cells in vitro, establishing a potential role for NaB in colon cancer prevention. We have previously shown that butyrate decreases cyclin D1 and c-myc expression, each essential for intestinal tumor development, by transcriptional attenuation. Here, we determined that butyrate-induced transcriptional attenuation of the cyclin D1 and c-myc genes in SW837 human colorectal adenocarcinoma cells occurs at ∼100 nucleotides downstream of the transcription start site, with a similar positioning in Caco-2 cells. A concomitant decrease in RNA polymerase II occupancy at the 5' end of each gene was observed. Because transcriptional regulation is associated with chromatin remodeling, we investigated by chromatin immunoprecipitation whether the histone deacetylase inhibitory activity of butyrate altered chromatin structure at the attenuated loci. Although the distributions of histone H3 trimethylated on K4 and K36 along the cyclin D1 and c-myc genes were consistent with current models, butyrate induced only modest decreases in these modifications, with a similar effect on acetylated H3 and a modest increase in histone H3 trimethylated on K27. Finally, transcriptome analysis using novel microarrays showed that butyrate-induced attenuation is widespread throughout the genome, likely independent of transcriptional initiation. We identified 42 loci potentially paused by butyrate and showed that the transcription patterns are gene specific. The biological functions of these loci encompass a number of effects of butyrate on the physiology of intestinal epithelial cells.
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Affiliation(s)
- Maria C Daroqui
- Department of Oncology, Albert Einstein Cancer Center, Montefiore Medical Center, 111 East 210th Street, Bronx, NY 10467, USA.
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102
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Lunasin promotes apoptosis in human colon cancer cells by mitochondrial pathway activation and induction of nuclear clusterin expression. Cancer Lett 2010; 295:44-53. [DOI: 10.1016/j.canlet.2010.02.010] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2010] [Revised: 02/10/2010] [Accepted: 02/11/2010] [Indexed: 11/21/2022]
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103
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Nasir O, Wang K, Föller M, Bhandaru M, Sandulache D, Artunc F, Ackermann TF, Ebrahim A, Palmada M, Klingel K, Saeed AM, Lang F. Downregulation of Angiogenin Transcript Levels and Inhibition of Colonic Carcinoma by Gum Arabic (Acacia senegal). Nutr Cancer 2010; 62:802-10. [DOI: 10.1080/01635581003605920] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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104
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Hagio M, Matsumoto M, Yajima T, Hara H, Ishizuka S. Voluntary wheel running exercise and dietary lactose concomitantly reduce proportion of secondary bile acids in rat feces. J Appl Physiol (1985) 2010; 109:663-8. [PMID: 20616226 DOI: 10.1152/japplphysiol.00777.2009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
According to epidemiologic studies, a negative correlation exists between exercise amount and subsequent cancer development risk in the large intestine. The proportion of secondary bile acids (SBA) in the large intestine is related to subsequent risk for colorectal carcinogenesis. The aim of this study was to investigate the effects of voluntary wheel running exercise and dietary intervention on bile acid (BA) metabolism in the large intestine. Wistar/ST rats (6 wk old) were divided into two groups, exercise and sedentary, after acclimation. Four days after the animals were assigned to a group, rats in each group were fed diets supplemented with different carbohydrate sources including dextrin, sucrose, and lactose. The wheel running period was 4 wk in the exercise group, whereas rats in the sedentary group remained in individual cages during this period. BA composition in collected feces was analyzed with ultraperformance liquid chromatography-electrospray ionization mass spectrometry. We found that wheel running exercise decreased plasma concentrations of cholesterol, triglyceride, and free fatty acids. These decreases were accompanied by a reduction in the proportion of SBA to primary BA (PBA) in feces; however, daily excretion of BA was comparable regardless of wheel running exercise. In addition, ingestion of lactose decreased the SBA-to-PBA ratio and suppressed production of hyodeoxycholic acid in feces. In conclusion, voluntary wheel running exercise, in combination with dietary intervention, could independently reduce the SBA-to-PBA ratio within the large intestine without changing BA excretion. These changes may contribute to the prevention of colorectal carcinogenesis.
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Affiliation(s)
- Masahito Hagio
- Research Faculty of Agriculture, Hokkaido University, Sapporo, Hokkaido 060-8589, Japan
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105
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Terzić J, Grivennikov S, Karin E, Karin M. Inflammation and colon cancer. Gastroenterology 2010; 138:2101-2114.e5. [PMID: 20420949 DOI: 10.1053/j.gastro.2010.01.058] [Citation(s) in RCA: 1435] [Impact Index Per Article: 102.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2009] [Revised: 01/19/2010] [Accepted: 01/25/2010] [Indexed: 02/06/2023]
Abstract
The connection between inflammation and tumorigenesis is well-established and in the last decade has received a great deal of supporting evidence from genetic, pharmacological, and epidemiological data. Inflammatory bowel disease is an important risk factor for the development of colon cancer. Inflammation is also likely to be involved with other forms of sporadic as well as heritable colon cancer. The molecular mechanisms by which inflammation promotes cancer development are still being uncovered and could differ between colitis-associated and other forms of colorectal cancer. Recent work has elucidated the role of distinct immune cells, cytokines, and other immune mediators in virtually all steps of colon tumorigenesis, including initiation, promotion, progression, and metastasis. These mechanisms, as well as new approaches to prevention and therapy, are discussed in this review.
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Affiliation(s)
- Janos Terzić
- Laboratory of Gene Regulation and Signal Transduction, Departments of Pharmacology and Pathology, School of Medicine, University of California, San Diego, La Jolla, California, USA
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106
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Leonardi T, Vanamala J, Taddeo SS, Davidson LA, Murphy ME, Patil BS, Wang N, Carroll RJ, Chapkin RS, Lupton JR, Turner ND. Apigenin and naringenin suppress colon carcinogenesis through the aberrant crypt stage in azoxymethane-treated rats. Exp Biol Med (Maywood) 2010; 235:710-7. [PMID: 20511675 PMCID: PMC2885760 DOI: 10.1258/ebm.2010.009359] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Epidemiological evidence suggests that a diet abundant in fruits and vegetables may protect against colon cancer. Bioactive compounds, including flavonoids and limonoids, have been shown to possess antiproliferative and antitumorigenic effects in various cancer models. This experiment investigated the effects of four citrus flavonoids and one limonoid mixture at the promotion stage of chemically induced colon cancer in rats. Male Sprague-Dawley rats (n = 10 rats/group) were randomly allocated to one of six diets formulated to contain 0.1% apigenin, 0.02% naringenin, 0.1% hesperidin, 0.01% nobiletin, 0.035% limonin glucoside/obacunone glucoside mixture or a control diet (0% flavonoid/limonoid). Rats received experimental diets for 10 weeks and were injected with azoxymethane (15 mg/kg) at weeks 3 and 4. Excised colons were evaluated for aberrant crypt foci (ACF) formation, colonocyte proliferation (proliferating cell nuclear antigen assay), apoptosis (terminal deoxynucleotidyl transferase dUTP nick end labeling assay) and expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) (immunoblotting). When compared with the control diet, apigenin lowered the number of high multiplicity ACF (HMACF >4 aberrant crypts/focus) by 57% (P < 0.05), while naringenin lowered both the number of HMACF by 51% (P < 0.05) and the proliferative index by 32% (P < 0.05). Both apigenin and naringenin increased apoptosis of luminal surface colonocytes (78% and 97%, respectively; P < 0.05) when compared with the control diet. Hesperidin, nobiletin and the limonin glucoside/obacunone glucoside mixture did not affect these variables. The colonic mucosal protein levels of iNOS or COX-2 were not different among the six diet groups. The ability of dietary apigenin and naringenin to reduce HMACF, lower proliferation (naringenin only) and increase apoptosis may contribute toward colon cancer prevention. However, these effects were not due to mitigation of iNOS and COX-2 protein levels at the ACF stage of colon cancer.
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Affiliation(s)
- Tety Leonardi
- Faculty of Nutrition, Texas A&M University, College Station, TX 77843-2253
| | - Jairam Vanamala
- Faculty of Nutrition, Texas A&M University, College Station, TX 77843-2253
- Vegetable and Fruit Improvement Center, Texas A&M University, College Station, TX 77843-2119
| | - Stella S. Taddeo
- Faculty of Nutrition, Texas A&M University, College Station, TX 77843-2253
| | - Laurie A. Davidson
- Faculty of Nutrition, Texas A&M University, College Station, TX 77843-2253
| | - Mary E. Murphy
- Department of Statistics, Texas A&M University, College Station, TX 77843-3143
| | - Bhimanagouda S. Patil
- Vegetable and Fruit Improvement Center, Texas A&M University, College Station, TX 77843-2119
| | - Naisyin Wang
- Department of Statistics, Texas A&M University, College Station, TX 77843-3143
| | - Raymond J. Carroll
- Department of Statistics, Texas A&M University, College Station, TX 77843-3143
| | - Robert S. Chapkin
- Faculty of Nutrition, Texas A&M University, College Station, TX 77843-2253
- Vegetable and Fruit Improvement Center, Texas A&M University, College Station, TX 77843-2119
| | - Joanne R. Lupton
- Faculty of Nutrition, Texas A&M University, College Station, TX 77843-2253
| | - Nancy D. Turner
- Faculty of Nutrition, Texas A&M University, College Station, TX 77843-2253
- Vegetable and Fruit Improvement Center, Texas A&M University, College Station, TX 77843-2119
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107
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Ferguson LR. Recent advances in understanding of interactions between genes and diet in the etiology of colorectal cancer. World J Gastrointest Oncol 2010; 2:125-9. [PMID: 21160819 PMCID: PMC2999172 DOI: 10.4251/wjgo.v2.i3.125] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2009] [Revised: 11/12/2009] [Accepted: 11/19/2009] [Indexed: 02/05/2023] Open
Abstract
At an international level, colorectal cancer (CRC) is a major cause of morbidity and mortality. Diet plays a major etiologic role, and a range of putative dietary carcinogens have been identified. The probability with which these lead to mutations, and thereby cause cancer, is strongly impacted by variants in genes coding for xenobiotic metabolizing or DNA repair enzymes. Nutrient deficiencies also play a role, which will be exacerbated by variants in metabolic genes. However, many of the causal genes in sporadic CRC have hitherto proved elusive. The power of large international collaborations, coupled with genome-wide association studies, has implicated a major functional role of the tumour growth factor-β pathway in CRC susceptibility. Nutrient regulation of gene expression may be especially important here. Future large collaborative studies must consider gene-gene and gene-diet interactions, coupled with high throughput genomic technologies, in order to uncover the relative roles of genetic variants, mutagenic xenobiotics, nutrient imbalance and gene expression in the etiology of CRC.
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Affiliation(s)
- Lynnette R Ferguson
- Lynnette R Ferguson, Discipline of Nutrition, University of Auckland, Private Bag 92019, Auckland, New Zealand
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108
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Colorectal cancer: Can nutrients modulate NF-κB and apoptosis? Clin Nutr 2010; 29:42-6. [DOI: 10.1016/j.clnu.2009.06.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2009] [Revised: 05/22/2009] [Accepted: 06/08/2009] [Indexed: 11/18/2022]
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109
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Zhu Y, Suits MDL, Thompson AJ, Chavan S, Dinev Z, Dumon C, Smith N, Moremen KW, Xiang Y, Siriwardena A, Williams SJ, Gilbert HJ, Davies GJ. Mechanistic insights into a Ca2+-dependent family of alpha-mannosidases in a human gut symbiont. Nat Chem Biol 2009; 6:125-32. [PMID: 20081828 DOI: 10.1038/nchembio.278] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2009] [Accepted: 10/30/2009] [Indexed: 11/09/2022]
Abstract
Colonic bacteria, exemplified by Bacteroides thetaiotaomicron, play a key role in maintaining human health by harnessing large families of glycoside hydrolases (GHs) to exploit dietary polysaccharides and host glycans as nutrients. Such GH family expansion is exemplified by the 23 family GH92 glycosidases encoded by the B. thetaiotaomicron genome. Here we show that these are alpha-mannosidases that act via a single displacement mechanism to utilize host N-glycans. The three-dimensional structure of two GH92 mannosidases defines a family of two-domain proteins in which the catalytic center is located at the domain interface, providing acid (glutamate) and base (aspartate) assistance to hydrolysis in a Ca(2+)-dependent manner. The three-dimensional structures of the GH92s in complex with inhibitors provide insight into the specificity, mechanism and conformational itinerary of catalysis. Ca(2+) plays a key catalytic role in helping distort the mannoside away from its ground-state (4)C(1) chair conformation toward the transition state.
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Affiliation(s)
- Yanping Zhu
- Institute for Cell and Molecular Biosciences, The Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, UK
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110
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Dias MC, Vieiralves NFL, Gomes MIFV, Salvadori DMF, Rodrigues MAM, Barbisan LF. Effects of lycopene, synbiotic and their association on early biomarkers of rat colon carcinogenesis. Food Chem Toxicol 2009; 48:772-80. [PMID: 20026158 DOI: 10.1016/j.fct.2009.12.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2009] [Revised: 12/02/2009] [Accepted: 12/12/2009] [Indexed: 12/18/2022]
Abstract
This study evaluated whether a synergy exists for the combined treatment with lycopene and synbiotic on early biomarkers of colon carcinogenesis. Male Wistar rats received a diet containing 300 mg/kg of lycopene and/or synbiotic (Bifidobacterium lactisplus oligofructose/inulin) or their combination 2 weeks before and during carcinogen treatment with 1,2-dimethylhydrazine (DMH). Twenty-four hours after the last DMH application, the colons were processed for immunohistochemical analysis of proliferating cell nuclear antigen (PCNA), p53 protein, hematoxylin-eosin staining for apoptosis analysis and genotoxicity of fecal water by comet assay. Eight weeks after the last DMH application, the colons were analyzed for development of classical aberrant crypt foci (ACF) and mucin-negative ACF. Treatment with lycopene, synbiotic or their combination significantly increased apoptosis, reduced the PCNA and p53 labeling indexes and the development of classical ACF and mucin-negative ACF. Furthermore, a lower genotoxicity of fecal water was also detected in the groups treated with the chemopreventive agents. An additive/synergistic effect of the combined treatment with lycopene/synbiotic was observed only for the fecal water genotoxicity and mucin-negative ACF parameters. These results indicate that an additive/synergistic of the combination of chemopreventive agents on the initiation phase of colon carcinogenesis can be detected using selective early biomarkers.
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Affiliation(s)
- Marcos C Dias
- Department of Morphology, UNESP São Paulo State University, Institute of Biosciences, 18618-000 Botucatu, SP, Brazil
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111
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O'Keefe SJD, Ou J, Aufreiter S, O'Connor D, Sharma S, Sepulveda J, Fukuwatari T, Shibata K, Mawhinney T. Products of the colonic microbiota mediate the effects of diet on colon cancer risk. J Nutr 2009; 139:2044-8. [PMID: 19741203 PMCID: PMC6459055 DOI: 10.3945/jn.109.104380] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2009] [Revised: 04/09/2009] [Accepted: 08/12/2009] [Indexed: 01/19/2023] Open
Abstract
It is estimated that most colon cancers can be attributed to dietary causes. We have hypothesized that diet influences the health of the colonic mucosa through interaction with the microbiota and that it is the milieu interior that regulates mucosal proliferation and therefore cancer risk. To validate this further, we compared colonic contents from healthy 50- to 65-y-old people from populations with high and low risk, specifically low risk Native Africans (cancer incidence <1:100,000; n = 17), high risk African Americans (risk 65:100,000; n = 17), and Caucasian Americans (risk 50:100,000; n = 18). Americans typically consume a high-animal protein and -fat diet, whereas Africans consume a staple diet of maize meal, rich in resistant starch and low in animal products. Following overnight fasting, rapid colonic evacuation was performed with 2 L polyethylene glycol. Total colonic evacuants were analyzed for SCFA, vitamins, nitrogen, and minerals. Total SCFA and butyrate were significantly higher in Native Africans than in both American groups. Colonic folate and biotin content, measured by Lactobacillus rhamnoses and Lactobacillus plantarum ATCC 8014 bioassay, respectively, exceeded normal daily dietary intakes. Compared with Africans, calcium and iron contents were significantly higher in Caucasian Americans and zinc content was significantly higher in African Americans, but nitrogen content did not differ among the 3 groups. In conclusion, the results support our hypothesis that the microbiota mediates the effect diet has on colon cancer risk by their generation of butyrate, folate, and biotin, molecules known to play a key role in the regulation of epithelial proliferation.
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112
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Decreased polyunsaturated Fatty Acid content contributes to increased survival in human colon cancer. JOURNAL OF ONCOLOGY 2009; 2009:867915. [PMID: 19841681 PMCID: PMC2762309 DOI: 10.1155/2009/867915] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2009] [Revised: 07/24/2009] [Accepted: 07/27/2009] [Indexed: 12/14/2022]
Abstract
Among diet
components, some fatty acids are known to affect
several stages of colon carcinogenesis, whereas
others are probably helpful in preventing
tumors. In light of this, our aim was to
determine the composition of fatty acids and the
possible correlation with apoptosis in human
colon carcinoma specimens at different
Duke's stages and to evaluate the effect of
enriching human colon cancer cell line with the
possible reduced fatty acid(s). Specimens of
carcinoma were compared with the corresponding
non-neoplastic mucosa: a significant decrease of
arachidonic acid, PPARα, Bad, and Bax and a significant increase of COX-2,
Bcl-2, and pBad were found. The importance of arachidonic acid in
apoptosis was demonstrated by enriching a Caco-2 cell line with
this fatty acid. It induced apoptosis in a dose- and
time-dependent manner via induction of PPARα that, in turn, decreased COX-2. In conclusion, the
reduced content of arachidonic acid is likely related to
carcinogenic process decreasing the susceptibility of cancer cells
to apoptosis.
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113
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Bhatnagar N, Li X, Chen Y, Zhou X, Garrett SH, Guo B. 3,3'-diindolylmethane enhances the efficacy of butyrate in colon cancer prevention through down-regulation of survivin. Cancer Prev Res (Phila) 2009; 2:581-9. [PMID: 19470789 DOI: 10.1158/1940-6207.capr-08-0142] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Butyrate is an inhibitor of histone deacetylase (HDAC) and has been extensively evaluated as a chemoprevention agent for colon cancer. We recently showed that mutations in the adenomatous polyposis coli (APC) gene confer resistance to HDAC inhibitor-induced apoptosis in colon cancers. Here, we show that APC mutation rendered colon cancer cells resistant to butyrate-induced apoptosis due to the failure of butyrate to down-regulate survivin in these cells. Another cancer-preventive agent, 3,3'-diindolylmethane (DIM), was identified to be able to down-regulate survivin in colon cancers expressing mutant APC. DIM inhibited survivin mRNA expression and promoted survivin protein degradation through inhibition of p34(cdc2)-cyclin B1-mediated survivin Thr(34) phosphorylation. Pretreatment with DIM enhanced butyrate-induced apoptosis in colon cancer cells expressing mutant APC. DIM/butyrate combination treatment induced the expression of proapoptotic Bax and Bak proteins, triggered Bax dimerization/activation, and caused release of cytochrome c and Smac proteins from mitochondria. Whereas overexpression of survivin blocked DIM/butyrate-induced apoptosis, knocking down of survivin by small interfering RNA increased butyrate-induced apoptosis in colon cancer cells. We further showed that DIM was able to down-regulate survivin and enhance the effects of butyrate in apoptosis induction and prevention of familial adenomatous polyposis in APC(min/+) mice. Thus, the combination of DIM and butyrate is potentially an effective strategy for the prevention of colon cancer.
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Affiliation(s)
- Namrata Bhatnagar
- Department of Pharmaceutical Sciences, College of Pharmacy, North Dakota State University, Fargo, North Dakota 58105, USA
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114
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Dale OB, Tørud B, Kvellestad A, Koppang HS, Koppang EO. From Chronic Feed-Induced Intestinal Inflammation to Adenocarcinoma with Metastases in Salmonid Fish. Cancer Res 2009; 69:4355-62. [DOI: 10.1158/0008-5472.can-08-4877] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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115
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Ishikawa SI, Asano T, Takenoshita S, Nozawa Y, Arihara K, Itoh M. Egg yolk proteins suppress azoxymethane-induced aberrant crypt foci formation and cell proliferation in the colon of rats. Nutr Res 2009; 29:64-9. [PMID: 19185779 DOI: 10.1016/j.nutres.2008.12.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2008] [Revised: 12/04/2008] [Accepted: 12/11/2008] [Indexed: 10/21/2022]
Abstract
Dietary proteins can influence colonic carcinogenesis; some proteins have a promotional effect, whereas others exhibit a preventive effect. Dietary egg yolk proteins have been reported to suppress the expression of colon tumors in rats. In this study, we investigated the effect of consumption egg yolk proteins on cell proliferation in a rat model of azoxymethane (AOM)-induced colon cancer. We hypothesize, based on the literature of egg yolk protein actions, that they protect against colon tumor development. Therefore, male F344 rats were fed a purified AIN-93G diet containing either 20% casein (control) or 20% egg yolk proteins for 5 weeks. After 1 week on the experimental diet, the rats were administered weekly subcutaneous injections of saline or AOM for 2 weeks to induce aberrant crypt foci. Rats were administered an intraperitoneal injection of 5-bromo-2'-deoxyuridine 1 hour before being euthanized for examination of DNA synthesis in the colonic mucosa. The contents of the cecum were analyzed for the presence of short-chain fatty acids (SCFAs). In the AOM-injected rats, the yolk protein diet suppressed aberrant crypt foci formation and reduced the proliferative 5-bromo-2'-deoxyuridine-labeling index in the proximal colon when compared with the control diet. A significant increase in cecal SCFAs was observed in the rats that were fed egg yolk proteins. These results indicate that dietary egg yolk proteins have a preventive effect on AOM-induced large bowel carcinogenesis in rats; it exerts this effect by altering cell proliferation through SCFA production. This study suggests that the consumption of egg yolk proteins might be protective against colon carcinogenesis.
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Affiliation(s)
- Shin-Ichi Ishikawa
- School of Veterinary Medicine, Kitasato University, Towada, Aomori 034-8628, Japan.
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116
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Warren CA, Paulhill KJ, Davidson LA, Lupton JR, Taddeo SS, Hong MY, Carroll RJ, Chapkin RS, Turner ND. Quercetin may suppress rat aberrant crypt foci formation by suppressing inflammatory mediators that influence proliferation and apoptosis. J Nutr 2009; 139:101-5. [PMID: 19056647 PMCID: PMC2714375 DOI: 10.3945/jn.108.096271] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The flavonoid quercetin suppresses cell proliferation and enhances apoptosis in vitro. In this study, we determined whether quercetin protects against colon cancer by regulating the protein level of phosphatidylinositol 3-kinase (PI 3-kinase) and Akt or by suppressing the expression of proinflammatory mediators [cyclooxygenase (COX)-1, COX-2, inducible nitric oxide synthase (iNOS)] during the aberrant crypt (AC) stage. Forty male rats were randomly assigned to receive diets containing quercetin (0 or 4.5 g/kg) and injected subcutaneously with saline or azoxymethane (AOM; 2 times during wk 3 and 4). The colon was resected 4 wk after the last AOM injection and samples were used to determine high multiplicity AC foci (HMACF; foci with >4 AC) number, colonocyte proliferation and apoptosis by immunohistochemistry, expression of PI 3-kinase (p85 and p85alpha subunits) and Akt by immunoblotting, and COX-1, COX-2, and iNOS expression by real time RT-PCR. Quercetin-fed rats had fewer (P = 0.033) HMACF. Relative to the control diet, quercetin lowered the proliferative index (P = 0.035) regardless of treatment and diminished the AOM-induced elevation in crypt column cell number (P = 0.044) and expansion of the proliferative zone (P = 0.021). The proportion of apoptotic colonocytes in AOM-injected rats increased with quercetin treatment (P = 0.014). Levels of p85 and p85alpha subunits of PI 3-kinase and total Akt were unaffected by dietary quercetin. However, quercetin tended to suppress (P < 0.06) the expression of COX-1 and COX-2. Expression of iNOS was elevated by AOM injection (P = 0.0001). In conclusion, quercetin suppresses the formation of early preneoplastic lesions in colon carcinogenesis, which occurred in concert with reductions in proliferation and increases in apoptosis. It is possible the effects on proliferation and apoptosis resulted from the tendency for quercetin to suppress the expression of proinflammatory mediators.
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Affiliation(s)
- Cynthia A. Warren
- Faculty of Nutrition and Deptartment of Statistics Texas A&M University, College Station, TX 77843
| | - Kimberly J. Paulhill
- Faculty of Nutrition and Deptartment of Statistics Texas A&M University, College Station, TX 77843
| | - Laurie A. Davidson
- Faculty of Nutrition and Deptartment of Statistics Texas A&M University, College Station, TX 77843
| | - Joanne R. Lupton
- Faculty of Nutrition and Deptartment of Statistics Texas A&M University, College Station, TX 77843
| | - Stella S. Taddeo
- Faculty of Nutrition and Deptartment of Statistics Texas A&M University, College Station, TX 77843
| | - Mee Young Hong
- Faculty of Nutrition and Deptartment of Statistics Texas A&M University, College Station, TX 77843
| | - Raymond J. Carroll
- Faculty of Nutrition and Deptartment of Statistics Texas A&M University, College Station, TX 77843
| | - Robert S. Chapkin
- Faculty of Nutrition and Deptartment of Statistics Texas A&M University, College Station, TX 77843
| | - Nancy D. Turner
- Faculty of Nutrition and Deptartment of Statistics Texas A&M University, College Station, TX 77843,To whom correspondence should be addressed. E-mail:
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117
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Payne CM, Bernstein C, Dvorak K, Bernstein H. Hydrophobic bile acids, genomic instability, Darwinian selection, and colon carcinogenesis. Clin Exp Gastroenterol 2008; 1:19-47. [PMID: 21677822 PMCID: PMC3108627 DOI: 10.2147/ceg.s4343] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Sporadic colon cancer is caused predominantly by dietary factors. We have selected bile acids as a focus of this review since high levels of hydrophobic bile acids accompany a Western-style diet, and play a key role in colon carcinogenesis. We describe how bile acid-induced stresses cause cell death in susceptible cells, contribute to genomic instability in surviving cells, impose Darwinian selection on survivors and enhance initiation and progression to colon cancer. The most likely major mechanisms by which hydrophobic bile acids induce stresses on cells (DNA damage, endoplasmic reticulum stress, mitochondrial damage) are described. Persistent exposure of colon epithelial cells to hydrophobic bile acids can result in the activation of pro-survival stress-response pathways, and the modulation of numerous genes/proteins associated with chromosome maintenance and mitosis. The multiple mechanisms by which hydrophobic bile acids contribute to genomic instability are discussed, and include oxidative DNA damage, p53 and other mutations, micronuclei formation and aneuploidy. Since bile acids and oxidative stress decrease DNA repair proteins, an increase in DNA damage and increased genomic instability through this mechanism is also described. This review provides a mechanistic explanation for the important link between a Western-style diet and associated increased levels of colon cancer.
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Affiliation(s)
- Claire M Payne
- Department of Cell Biology and Anatomy, College of Medicine, University of Arizona, Tucson, Arizona, USA
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Abstract
UNLABELLED Preventing many chronic diseases in North America requires substantial changes in dietary habits. Achieving a better balance of grain-based foods through the inclusion of whole grains is one scientifically supported dietary recommendation. Epidemiological and other types of research continue to document health benefits for diverse populations who have adequate intakes of both folic acid-fortified grain foods and whole grains. Folic acid fortification of grains is associated with reduced incidence of neural tube and other birth defects and may be related to decreased risk of other chronic disease. Whole grain intake is associated with reduced risk of chronic disease. Specifically, there is a decreased risk of obesity, coronary heart disease, hypertension, stroke, metabolic syndrome, type 2 diabetes, and some cancers observed among the highest whole grain eaters compared with those eating little or no whole grains. Nationally promulgated dietary recommendations such as those in the US Dietary Guidelines or by health promotion organizations such as the American Heart Association have incorporated the science on whole grains, recommending that consumers increase their whole grain intake. The US Dietary Guidelines state that consumers select half of the recommended bread and cereal servings as whole grain. Thus, the recommendations recognize the importance of adequate folic acid intake from refined, fortified grains to reduce the risk of birth defects and other disorders and to reflect the existing science on whole grains. The association between whole grains and decreased chronic disease is not surprising because whole grains are a source of vitamins, minerals, fatty acids, anti oxidants, and other phytochemicals and dietary fiber. Each of these components can act singly or in tandem to contribute to specific health-maintaining and disease-preventing mechanisms. Health professionals should be aware of these benefits and advocate these dietary strategies to help prevent chronic disease and to improve overall health. KEYWORDS nutrition; whole grain; folic acid; disease prevention; diet; mortality; diabetes; cereal; pseudocereal; phytochemicals; anti-oxidants.
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119
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Rajamanickam S, Agarwal R. Natural products and colon cancer: current status and future prospects. Drug Dev Res 2008; 69:460-471. [PMID: 19884979 DOI: 10.1002/ddr.20276] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Carcinogenesis is a multistage process consisting of initiation, promotion and progression phases. Thus, the multistage sequence of events has many phases for prevention and intervention. Chemoprevention, a novel approach for controlling cancer, involves the use of specific natural products or synthetic chemical agents to reverse, suppress or prevent premalignancy before the development of invasive cancer. Several natural products, such as, grains, nuts, cereals, spices, fruits, vegetables, beverages, medicinal plants and herbs and their various phytochemical constituents including, phenolics, flavonoids, carotenoids, alkaloids, nitrogen containing as well as organosulfur compounds confer protective effects against wide range of cancers including colon cancer. Since diet has an important role in the etiology of colon cancer, dietary chemoprevention received attention for colon cancer prevention. However, identification of an agent with chemopreventive potential requires in vitro studies, efficacy and toxicity studies in animal models before embarking on human clinical trials. A brief introduction about colon cancer and the role of some recent natural products in colon cancer chemoprevention with respect to multiple molecular mechanisms in various in vitro, in vivo and clinical studies are described in this review.
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Affiliation(s)
- Subapriya Rajamanickam
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Colorado Denver, Denver, Colorado, USA
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Ivanov NA, Kholodok GN, Kulish ID. [Comparative analysis of antibiotic sensitivity of Streptococcus pneumoniae strains isolated from patients and carriers]. THE LANCET. INFECTIOUS DISEASES 1990; 13:719-24. [PMID: 2383142 DOI: 10.1016/s1473-3099(13)70107-5] [Citation(s) in RCA: 107] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The data on antibiotic sensitivity of 38 strains of S. pneumoniae isolated from children and 46 strains isolated from carriers are presented. The isolates from the carriers had significantly higher sensitivity to benzylpenicillin, ampicillin, methicillin, oxacillin, cefazolin, erythromycin, oleandomycin and lincomycin. Resistance to gentamicin was more frequent in the strains isolated from the carriers. Among the strains of S. pneumoniae isolated from the patients and carriers representatives of serovar K19 were more frequent. There were no statistically reliable difference in them by sensitivity to benzylpenicillin, ampicillin, cefazolin, lincomycin and rifampicin. Still, the isolates from the carriers were much more sensitive to methicillin, oxacillin, oleandomycin and erythromycin.
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