Number Of Aberrant Crypt Foci Research Articles

Investigation of the Prevalence and Number of Aberrant Crypt Foci Associated with Human Colorectal Neoplasm

Aberrant crypt foci (ACF) are considered to be useful as surrogate biomarker for colorectal cancer (CRC), but the biological significance of ACF remains controversial. We attempted to investigate the relationship between the presence of ACF and human colorectal carcinogenesis using a relatively large sample size. We carried out high-magnification chromoscopic colonoscopy to identify ACFs in 861 subjects undergoing a diagnostic endoscopy at the Yokohama City University Hospital. The present study compared the prevalence and number of ACFs in three subject groups (normal subjects, adenoma cases, and CRC cases). The correlations between the demographic and behavioral characteristics of the subjects and the prevalence of ACFs were also assessed. The prevalence of ACF was 64%, 88%, and 95%, and the mean number of ACF was 3.6, 6.2, and 10.1, in normal subjects, adenoma cases, and CRC cases, respectively. When differences in the prevalence and number of ACFs among age- and sex-stratified subject groups were examined, significant stepwise increments from normal subjects to adenoma cases to CRC cases were apparent (P < 0.001). Moreover, an age- and sex-adjusted multiple logistic regression analysis revealed that smoking and alcohol habits had a synergistic effect, increasing the prevalence of ACFs as well as the risk of CRC (P < 0.001). These results suggested that ACF may serve as a reliable surrogate biomarker for human colorectal carcinogenesis. The use of ACF as an endpoint may enable the size, duration, and cost of CRC chemoprevention studies to be reduced.

Light and Moderate Doses of Ethanol in Chemical Carcinogenesis of the Colon in Rats

The aberrant crypt foci (ACF), cyclooxygenase 2 (COX-2), and the proliferating cell nuclear antigen (PCNA) are putative biomarkers for colon cancer. To study the association between light (1 g of ethanol/kg bw) and moderate (3 g of ethanol/kg bw) doses of ethanol with the chemical carcinogen N-methyl-N′-nitro-N-nitrosoguanidine (MNNG), Wistar rats were divided into 6 groups. The colon fragments were collected for histochemical and immunohistochemical analyses, and the liver samples were collected for oxidative stress analysis, with products of lipid peroxidation (malondialdehyde), antioxidant enzymes (glutathione), and vitamin E. The association of light and moderate doses of ethanol with MNNG did not present differences in the oxidative parameters. However, a reduction in vitamin E levels in the carcinogen groups was observed. The association induced a reduction of the COX-2 and PCNA expression. The number of ACF in the group that received a light dose of ethanol had lower rates, while the group that received a moderate dose had the highest rates compared to the control MNNG, demonstrating that the light dose of ethanol could have a protective effect, while the moderate dose could represent a risk during chemical carcinogenesis in rats.

Randomized Double-Blind Trial of Sulindac and Etodolac to Eradicate Aberrant Crypt Foci and to Prevent Sporadic Colorectal Polyps

On the basis of the results of our preliminary trial suggesting that aberrant crypt foci (ACF) could be eradicated by short-term administration of sulindac, in the present study, we explored the feasibility of using ACF as surrogate markers for chemoprevention of colorectal cancer. Randomly assigned to sulindac (300 mg daily), etodolac (400 mg daily), and placebo groups were 189 subjects without polyps or who had undergone polypectomy. Drugs were administered for 2 months. ACF in the rectal region were counted by magnifying endoscopy. Occurrence of polyps was evaluated at 12 months. A planned interim analysis was conducted. ACF number at 2 months was significantly suppressed in the sulindac group (P = 0.0075), but not in the etodolac group (P = 0.73). In the sulindac group, the numbers of adenomas plus hyperplastic polyps (total polyps) and adenomas at 12 months were significantly (P = 0.02) and marginally (P = 0.064) lower, respectively, in comparison with the placebo group; no such difference was observed in the etodolac group. In analysis of only polypectomized subjects, the numbers of total polyps and adenomas in the sulindac group were even more markedly lower, with P values of 0.014 and 0.034, respectively. A similar tendency was confirmed by analyses of the incidence of polyps at 12 months. Suppression rates of total polyps and adenomas in ACF responders to sulindac were significantly greater than in nonresponders. In all groups, compliance was more than 90% and no intolerable adverse effects were observed. ACF may be useful as surrogate lesions for chemoprevention of colorectal cancer.

Sex Differences in Associations Between Psychosocial Factors and Aberrant Crypt Foci Among Patients at Risk for Colon Cancer

Psychosocial factors may impact cancer risk but sex differences in this domain are understudied. Examining psychosocial factors, such as depression and social support, among colon cancer patients allows for a unique opportunity to study sex differences in the association between psychosocial factors and colon cancer risk in this population. The primary aim of this study was to evaluate sex differences in the association between key psychosocial factors and aberrant crypt foci (ACF), a putative biomarker of colon cancer risk. We hypothesized that higher levels of depression in women and lower levels of social support in men were associated with greater numbers of ACF among individuals at heightened risk for colon cancer. Participants were self-referred or referred by physicians for routine colonoscopy. Within 2 weeks before colonoscopy, participants completed standardized measures assessing psychosocial factors. At colonoscopy, individuals were examined for ACF frequency in the distal 20 cm of the colorectum. Regression β weights were used to examine the association between the psychosocial factors and ACF. A total of 93 individuals (51% women, 49% men) consented to the study. Among women, higher levels of depressive symptoms were associated with greater numbers of ACF; among men, lower levels of social support were associated with greater numbers of ACF. These results suggest that although colon cancer affects men and women equally with regard to morbidity and mortality rates, there were important sex differences in how psychosocial variables were related to colon cancer risk. Psychosocial interventions aimed at targeting these types of factors are warranted but need to consider the role of sex.

The Protective Role of Lychnophora ericoides Mart. (Brazilian Arnica) in 1,2-Dimethylhydrazine-Induced Experimental Colon Carcinogenesis

Aberrant crypt foci (ACF) and colon rectal mucosal epithelial cell proliferation have been shown to be increased in patients with colon cancer and have been largely used for early detection of factors that influence colorectal carcinogenesis in rats. Fifty male Wistar rats were randomly divided into 5 groups. The groups G1 to G4 were given 4 injections of the carcinogen 1,2-dimethylhydrazine (DMH). The G2 group received Lychnophora ericoides (LE) extracts for 6 wk. The groups G3 and G4 received LE for 4 wk and 2 wk, respectively, at the postinitiation and initiation phases of colonic carcinogenesis. The group G5 was the control. Forty-two days after the first injections of DMH for the neoplasic induction, we observed a statistically significant decrease in the number of aberrant crypt foci (ACF) and an attenuation of the increase in cell proliferation induced by DMH in all the LE-treated groups. Thus, we concluded that Lychnophora ericoides extracts were effective against the development of cancer. These data suggest that LE has a protective influence on the process of colon carcinogenesis, suppressing both the initiation and the promotion of colonic carcinogenesis.

Abstract 1866: (−)-Epigallocatechin gallate suppresses azoxymethane-induced colonic preneoplastic lesions in rats by inhibiting the expression and activation of indoleamine 2,3-dioxygenase

Abstract Immune escape is involved in the development and progression of several types of tumors. Indoleamine 2,3-dioxygenase (IDO) plays a critical role in the induction of immune tolerance. (−)-Epigallocatechin gallate (EGCG), the major biologically active component of green tea, exerts cancer chemopreventive and anti-carcinogenic effects in various organs. In the present study, we examined the effects of EGCG and 1-methyl-tryptophan (1-MT), an IDO inhibitor, on the development of azoxymethane (AOM)-induced colonic preneoplastic lesions in F344 rats by focusing on the inhibition of IDO activation. To induce colonic premalignant lesions, male F344 rats were given two weekly subcutaneous injections of AOM (20 mg/kg body weight). They also received drinking water containing 0.1% EGCG or 0.2% 1-MT for 4 weeks, starting 1 week before the first dose of AOM. At sacrifice, drinking water with EGCG and 1-MT significantly decreased the total number of aberrant crypt foci and β-catenin accumulated crypts, which overexpresses IDO protein, compared with the control untreated-rats. Drinking EGCG decreased the expression levels of IDO mRNA on the colonic mucosa of experimental rats. In addition, the enzyme activity of IDO, which was estimated by measuring the serum concentration of kynurenine and tryptophan, was also significantly inhibited by treatment with EGCG and 1-MT. These findings suggest that the up-regulation of IDO is associated with colon carcinogenesis and EGCG prevents this carcinogenesis by inhibiting the expression and activation of IDO. Targeting IDO by using EGCG or IDO inhibitor might be, therefore, a promising strategy for the prevention of colon cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1866. doi:10.1158/1538-7445.AM2011-1866

Abstract 2983: Sgo1 haploinsufficiency contributes to enhanced colon carcinogenesis in mice and yet associated with high colonic epithelial apoptosis

Abstract Inactivation of Shugoshin-1 (Sgo1) function or depletion of Sgo1 in mammalian cells causes missegregation of chromosome. Sgo1 plays an obligate role in chromosome cohesion and its defect is implicated in high chromosome instability. Recent studies indicate that Sgo1 levels were significantly decreased in human colonic tumors, suggesting a role in colon carcinogenesis. Here, we report for first time that depletion of Sgo1 lead to the enhanced colorectal carcinogenesis in mice. To understand the role of Sgo1 in colorectal cancer, we have established haploinsufficient Sgo1+/- mouse model. We tested whether Sgo1 deficiency would enhance the colon carcinogenesis in animal exposed to colonic specific carcinogen. At eight weeks of age mice Sgo1+/+ and Sgo1+/- were treated with azoxymethane (AOM), s.c., 4 mg/kg BW, twice weekly for four weeks. Upon treatment with AOM, we analyzed for colonic crypt cell-cycle modifications and later stage colonic ACF and tumor formation. Sgo1-/+ mice showed higher acute cell death rate than Sgo1+/+ mice soon after the AOM-treatment. However, at the endpoint, the number of aberrant crypt foci [Sgo1+/+, 4±1.41 vs Sgo1+/- 12.2 ±1.5, mean ±SD, p&amp;lt;0.0002] and multiplicity of aberrant crypts/foci [Sgo1+/+ 0.4±0.32 vs Sgo1+/- 3.8 ±0.57, mean ±SD, p&amp;lt;0.0001]. Importantly, mean number of colonic microadenoma were 5-fold higher in haploinsufficient mice [Sgo1+/+, 0.8 ±0.45 vs Sgo1+/- 5.0 ± 1.2, p&amp;lt;0001]. Normal-looking colonic mucosa in AOM-treated Sgo1-/+ mice expressed higher Bcl2, p53 and COX-2 proteins compared with Sgo1+/+ type. These results suggest the notion that defect in mitotic machinery can serve both oncogenic and enhance cell death by apoptosis in an environment-dependent manner; Sgo1-/+ mice may be latently antagonizing carcinogenesis by removing damaged cells in higher rate with cell death. Our results for the first time provide functional evidence of Sgo1 in enhancement of precancerous lesions, and their progression to colonic tumors. (Supported by R01-CA-113349 and R01-CA-102942) Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2983. doi:10.1158/1538-7445.AM2011-2983

Abstract LB-21: Taraxacum officinale (common dandelion) inhibits azoxymethane-induced aberrant crypt foci formation in C67BL/6 mice and regulates apoptosis in mice and in human colorectal carcinoma HCT-116 cells

Abstract Taraxacum officinale (TO), the common dandelion, has been used traditionally as a diuretic and as a treatment for jaundice and other liver disorders. Recent studies have substantiated its diuretic effect; in addition, it exhibits considerable antimicrobial, anti-inflammatory, antioxidant, hypolipidemic, and anti-breast and anti-prostate cancer-cell properties. In this study, the effects of TO as a chemopreventive agent of early-stage colon cancer development were evaluated. In the in vivo investigation, C57BL/6 mice between 6–10 wk old were randomized into negative control (N = 10), positive control (N = 10), and experimental (N = 10) groups. Aberrant crypt foci (ACF), putative precursors of colon cancer, were induced in positive control and experimental mice by intraperitoneal injection of azoxymethane (AOM; 5 mg/kg body mass) at the beginning of the first and second weeks, while the negative control mice received none. The experimental group was daily fed TO extract (1 mL/mouse; 84.22 mg/mL) by gavage throughout the duration of the 8-wk study while the control groups received a sterilized-water placebo. Mice in all three groups were sacrificed at the end of the 8-wk period and 25 mm of the proximal colon were resected and analyzed for ACF development after staining with methylene blue. Histological preparations of the proximal colon samples were used to determine apoptotic index, mitotic index, and caspase induction. Oral TO administration significantly reduced the number of AOM-induced ACF in the proximal colon in the experimental group in comparison to the positive control group (10.67 ± 3.75 &amp;lt; 32.10 ± 9.86; P &amp;lt; 0.00016), which indicates a 68.9 % inhibition of ACF formation by TO and a potency index of 3.01. The mice in all three groups experienced weight gain (negative: 7.0% &amp;lt; positive: 7.5% &amp;lt; experimental: 8.1%). Colon samples from the experimental group revealed a higher apoptotic index (AI) (1.34 &amp;gt; 0.60; P &amp;lt; 0.0002) and a lower mitotic index (MI) (1.13 &amp;lt; 2.80; P &amp;lt; 0.25) than the positive control group (AOM only). Caspase 3 and 9 induction was detected in human colorectal carcinoma HCT-116 cells treated with TO (.05 mg/mL) in chamber slides, using a specific carboxyfluorecein (FAM) labeled peptide fluoromethyl ketone (FMK) caspase inhibitor (FAM-peptide-FMK). Caspase 3 and 9 activation was also observed in TO-treated mouse colon tissues using the same caspase inhibitor. The data suggests that TO possesses potential chemopreventive effects on colon cancer development through the inhibition of AOM-induced ACF formation via C3/C9-regulated apoptosis. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-21. doi:10.1158/1538-7445.AM2011-LB-21

Abstract LB-436: Rectal aberrant crypt foci for estimate of colorectal tumor recurrence: 3-year follow up study

Abstract Background and Aims: Endoscopic screening and removal of colorectal tumor can reduce colorectal cancer, although surveillance colonoscopy is currently recommended after the initial screening and removal of colorectal tumor due to the possibility of newly developing tumor. Aberrant crypt foci (ACF) serve as surrogate biomarkers of human colorectal carcinogenesis. In this study we aimed to investigate the relationship between ACF and the recurrence of colorectal tumor after endoscopic polypectomy. Methods: We performed high-magnification chromoscopic colonoscopy to identify lower rectal ACF on 82 subjects who underwent endoscopic polypectomy, and surveillance colonoscopy 3 years after baseline polypectomy at Yokohama City University Hospital. Results: Marked elevation of the ACF number at baseline findings was observed in the tumor recurrence patients in comparison with the non recurrence patients (p &amp;lt; 0.01). ROC analysis showed high specificity of the number of ACF for diagnosis of any tumor recurrence. Conclusion: This is the first study to investigate relation between ACF and the recurrence of colorectal tumor after endoscopic polypectomy. These results suggested that ACF is useful for predictive factors for the recurrence of tumor. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-436. doi:10.1158/1538-7445.AM2011-LB-436

The Effect of Apple Feeding on Markers of Colon Carcinogenesis

Regular consumption of fruits and vegetables is associated with reduced risks of certain cancers and other diseases in observational studies and animal models of human diseases. The aim of the present study was to investigate whether feeding of rats with whole raw apple has potentially chemopreventive properties by affecting markers of colon cancer. The end-point was preneoplastic changes in the colon known as aberrant crypt foci (ACF). Rats initiated with the colon carcinogen 1,2-dimethylhydrazine dihydrochloride (DMH) were given 0, 5, or 10 g apple/day for 13 wk. The group fed 5 g apple but not 10 g had a significantly lower number of ACF (P = 0.009) compared to the initiated control. DNA damage evaluated by the comet assay was significantly increased in leucocytes of DMH-treated animals (P = 0.021). No antigenotoxic effect of apple feeding was apparent in the colon. Apple feeding tended to lower DNA damage in the liver (P = 0.136 in DMH-initiated and P = 0.284 in noninitiated rats). Liver alanine aminotransferase was significantly increased in rats fed apples (P = 0.008 in DMH-initiated and P = 0.019 in noninitiated rats). In conclusion, feeding whole fresh apple may affect the occurrence of preneoplastic changes in the rat colon, but the effect was not gradual.

Lifelong genistein feeding reduces colon neoplasia by affecting the expression profile of WNT signaling in AOM‐treated rats

Colon cancer is a leading cancer worldwide. We investigated the effects of genistein (GEN) and soy protein isolate on the development of colon neoplasia in azoxymethane (AOM)-induced rats. Male Sprague-Dawley rats were exposed to a control (0 mg/kg of GEN), soy protein isolate (SPI, contains 140 mg/kg of GEN, aglycone equivalent), or genistein (140 mg/kg) diet throughout life, including gestation, lactation, and after weaning until the end of the study. Colon samples were collected at 6 w of age and analyzed for the baseline profile. The rest of rats were induced by AOM injection at 7 w of age and colon samples were collected at 13 w of age. Numbers of aberrant crypt foci (ACF) was determined in the descending colon. Offspring from all three dietary groups developed ACF. GEN and SPI diets decreased the numbers of total ACF/cm of colon, especially the numbers of higher multiplicity ACF/cm. Nuclear β-catenin level was not different between three diet groups at 6 w. However, SPI and GEN repressed AOM-induced Nuclear β-catenin accumulation at 13 w. Moreover, SPI and GEN maintained lower expression of WNT signaling including Wnt1, Wnt5a and WNT antagonists sFRP1, sFRP2 and sFRP5 compared to control after AOM treatment. Our results suggest that lifelong exposure to genistein reduces descending colon neoplasia by affecting WNT signaling and suppressing β-catenin accumulation in the AOM-induced rat model. Grant Funding Source: NIH

Dietary acrylamide does not increase colon aberrant crypt foci formation in male F344 rats

Acrylamide, a known rodent and a probable human carcinogen, is spontaneously formed in foods cooked at high temperature. We studied the role of dietary acrylamide in modulating the early stages of colon carcinogenesis and assessed if dietary fat level was critical in altering the effects of acrylamide. Male F344 rats were subcutaneously injected with azoxymethane and were simultaneously randomized into 8 dietary groups (n=8 rats/group). Diets were based on AIN-93G semi-synthetic formula modified to contain either low fat (7% corn oil) or high fat (23.9% corn oil) and acrylamide at 0, 5, 10 or 50mg/kg diet (wt/wt). All rats received the experimental diets ad libitum for 8weeks, after which they were killed and their colons assessed for aberrant crypt foci (ACF), putative precancerous lesions. Irrespective of dietary fat level, rats with the highest tested dose of acrylamide (50mg/kg diet) had significantly lower total ACF (p<0.05) and lower large ACF (those with 4 or more crypts/focus; p<0.001) compared with their respective controls (0mg/kg diet). A significantly lower number of large ACF (p=0.046) was noted in rats treated with 10mg/kg diet acrylamide exclusively in the high fat group, compared to the high fat control. This short-term bio-assay to test carcinogenicity of dietary acrylamide in the colon demonstrates that acrylamide, when administered through the diet at doses known to cause rat tumors, does not increase the risk of developing azoxymethane-induced precancerous lesions of the colon in rats. On the contrary, a high dose of dietary acrylamide decreased the growth of precancerous lesions in both low and high fat diet regimens in this model.

Phase IIa Clinical Trial of Curcumin for the Prevention of Colorectal Neoplasia

Curcumin is derived from the spice tumeric and has antiinflammatory and antineoplastic effects in vitro and in animal models, including preventing aberrant crypt foci (ACF) and adenomas in murine models of colorectal carcinogenesis. Inhibiting the production of the procarcinogenic eicosanoids prostaglandin E₂ (PGE₂) and 5-hydroxyeicosatetraenoic acid (5-HETE) can suppress carcinogenesis in rodents. Curcumin reduces mucosal concentrations of PGE₂ (via inhibition of cyclooxygenases 1 and 2) and 5-HETE (via inhibition of 5-lipoxygenase) in rats. Although preclinical data support curcumin activity in many sites, the poor bioavailability reported for this agent supports its use in the colorectum. We assessed the effects of oral curcumin (2 g or 4 g per day for 30 days) on PGE₂ within ACF (primary endpoint), 5-HETE, ACF number, and proliferation in a nonrandomized, open-label clinical trial in 44 eligible smokers with eight or more ACF on screening colonoscopy. We assessed pre- and posttreatment concentrations of PGE₂ and 5-HETE by liquid chromatography tandem mass spectroscopy in ACF and normal-tissue biopsies; ACF number via rectal endoscopy; proliferation by Ki-67 immunohistochemistry; and curcumin concentrations by high-performance liquid chromatography in serum and rectal mucosal samples. Forty-one subjects completed the study. Neither dose of curcumin reduced PGE₂ or 5-HETE within ACF or normal mucosa or reduced Ki-67 in normal mucosa. A significant 40% reduction in ACF number occurred with the 4-g dose (P < 0.005), whereas ACF were not reduced in the 2-g group. The ACF reduction in the 4-g group was associated with a significant, five-fold increase in posttreatment plasma curcumin/conjugate levels (versus pretreatment; P = 0.009). Curcumin was well tolerated at both 2 g and 4 g. Our data suggest that curcumin can decrease ACF number, and this is potentially mediated by curcumin conjugates delivered systemically.

Randomized Phase II Trial of Sulindac, Atorvastatin, and Prebiotic Dietary Fiber for Colorectal Cancer Chemoprevention

Sulindac, atorvastatin, or prebiotic dietary fiber may reduce colorectal cancer (CRC) risk. However, clinical trial data are currently limited. We conducted a randomized, phase II chemoprevention trial involving subjects 40 years or older, with previously resected colon cancer or multiple/advanced colorectal adenomas. Magnification chromoendoscopy (MCE) was performed to identify and characterize rectal aberrant crypt foci (ACF); eligibility criteria required five or more rectal ACFs at baseline. Intervention assignments were as follows: (a) atorvastatin 20 mg qd; (b) sulindac 150 mg bid; (c) oligofructose-enriched inulin (as ORAFTI®Synergy1) 6 gm bid; or (d) control (maltodextrin) 6 gm bid, for 6 months. Percent change in rectal ACF number (%ΔACF) within arm was the primary endpoint. Secondary endpoints included changes in proliferation (Ki67) and apoptosis (caspase-3), as measured from normal mucosa biopsy samples. Among 85 eligible randomized subjects, 76 (86%) completed the trial per protocol. The median (range) of rectal ACF was 9 (5-34) and 8 (0-37) at baseline and postintervention, respectively. The median (SD) for %ΔACF was 5.6 (-69% to 143%), -18.6 (-83% to 160%), -3.6 (-88% to 83%), and -10.0 (-100% to 117%) in the atorvastatin, sulindac, ORAFTI®Synergy1 and control arms, respectively. Neither within-arm (P = 0.12-0.59) nor between-arm (P = 0.30-0.92) comparisons of %ΔACF were statistically significant. The active and control interventions also seemed to have similar effects on mucosal proliferation and apoptosis (P > 0.05 for each comparison). Data from this multicenter, phase II trial do not provide convincing evidence of CRC risk reduction from 6-month interventions with atorvastatin, sulindac, or ORAFTI®Synergy1, although statistical power was limited by the relatively small sample size.

Abnormal Savda Munziq, an Herbal Preparation of Traditional Uighur Medicine, May Prevent 1,2‐dimethylhydrazine‐Induced Rat Colon Carcinogenesis

The study tried to assess the chemoprotective effect of abnormal Savda Munziq (ASMq) on 1,2-dimethylhydrazine (DMH)-induced rat colon carcinogenesis. Male F344 rats were randomized into eight groups: Group 1 was served as control, no DMH injection was given and treated daily with normal saline. Rats in Groups 2–8 were given a single intraperitoneal injection of DMH (20 mg/kg body weight) at the beginning of the study. Group 2 was served as negative control, administered with normal saline until the end of the experiment after the single DMH injection. Groups 3–5 were served as pretreatment group, administered with ASMq ethanol extract at 400, 800 and 1600 mg/kg body weight, respectively, until the 45th day, continued by normal saline administration for another 45 days. Groups 6–8 were served as the treatment group, administered with normal saline for the first 45 days from the day of DMH injection, ASMq ethanol extract at three different doses to be administered until the end of the second 45th day. All rats were sacrificed at 91st day and the colons were analyzed for aberrant crypt foci (ACF) formation and crypt multiplicity. Results showed that ASMq ethanol extract reduced the number of ACF, AC and crypt multiplicity significantly (P < .05). It suggested that ASMq ethanol extract had chemoprotective effects on DMH-induced colon carcinogenesis, by suppressing the development of preneoplastic lesions, and probably exerted protection against the initiation and promotion steps of colon carcinogenesis.

Protective effect of lactofermented beetroot juice against aberrant crypt foci formation and genotoxicity of fecal water in rats

The aim of the study was to investigate the effects of beetroot juice fermented by Lactobacillus brevis 0944 and Lactobacillus paracasei 0920 (FBJ) on carcinogen induction of aberrant crypt foci (ACF) in rat colon. N-Nitroso-N-methylurea (MNU) was used as carcinogen, which was administrated intragastrically at a dose of 50 mg/kg on the 23rd and 26th day of the experiment. Additionally, we investigated the cytotoxicity and genotoxicity of fecal water from experimental animals in the Caco 2 cell line, evaluated by MTT/NRU tests and the comet assay, respectively, as well as by the count of bacteria adhered to colon epithelium assessed by fluorescence in situ hybridization and DAPI staining. The experimental rats were divided into four groups based on diet type: basal diet, basal diet supplemented with FBJ, basal diet and MNU treatment, and basal diet supplemented with FBJ and MNU treatment. FBJ significantly reduced the number of ACF in MNU-treated rats (from 55±18 to 21±6). Moreover, the number of extensive aberrations (more than 4 crypts in a focus) decreased from 45±21 to 7±4. Fecal water obtained from rats fed with an MNU-containing diet induced pronounced cytotoxic and genotoxic effects in Caco 2 cells, but FBJ supplementation of the diet abolished these effects. The presence of FBJ in the diet significantly increased the count of bacteria, including Lactobacillus/Enterococcus, adhered to colonic epithelium. In conclusion, supplementation of the diet with lactofermented beetroot juice may provide protection against precancerous aberrant crypt formation and reduce the cytotoxic and genotoxic effects of fecal water.

Abstract B37: Relationship of human rectal aberrant crypt foci and formation of colorectal polyp

Abstract In experimental models of colonic carcinogenesis, aberrant crypt foci (ACF) are the earliest detectable abnormality and precede adenomas. Herein, we wanted to determine the adenoma incidence over a 1-year period after polypectomy. Eighty-nine subjects were recruited from the population of Japanese individuals who underwent polypectomy at Yokohama City University Hospital. All patients had baseline adenomas (&amp;gt; 6mm) removed at year 0 colonoscopy. ACF were defined as lesions in which the crypts were more darkly stained with methylene blue than normal crypts and had larger diameters, often with oval or slit-like lumens and a thicker epithelial lining. A total of 366 ACFs were identified in 89 patients; all had baseline adenomas (&amp;gt; 6mm) removed at the first examination (year 0) colonoscopy and returned for the second (year 1). ACF in the lower rectum were assessed at year 0 and study group were divided into two groups depend on ACF numbers, 0-3 or over 4. All participants were examined in the number and maximum size of adenoma. There was no statistical difference in number and maximum size of ACF at year 0, however, maximum size of adenoma was larger in over 4 group than 0-3 group at year 1. The meaning of the number of ACF is not elucidated; however, the number of ACF may be a predictive factor of relatively large adenoma incidence in the pilot phase study. Citation Information: Cancer Prev Res 2010;3(12 Suppl):B37.

Abstract B53: Metformin treatment suppresses colorectal aberrant crypt foci in humans: Results from a short-term feasibility study

Abstract Metformin is a biguanide derivative that has been widely used for diabetic treatment. Previously, we reported the chemopreventive effect of metformin in two rodent models of colorectal carcinogenesis. However, besides epidemiologic studies, little is known about the effects of metformin on human colorectal carcinogenesis. The objective of this pilot study was to evaluate the chemopreventive effects of metformin on rectal aberrant crypt foci (ACF), which are the endoscopic surrogate marker of colorectal cancer. We prospectively randomized 30 non-diabetic patients with ACF to treatment with metformin (250 mg/day; n = 15) or no treatment (control; n = 15); 27 patients were evaluable for endpoint analyses (12 metformin; 15 control); the two groups were similar in ACF number and other baseline clinical characteristics. Magnifying colonoscopy determined the number of rectal ACF in each patient at baseline and after 1 month in a blinded fashion (as were all laboratory-endpoint analyses). In addition, the proliferative activity of the colonic epithelium was examined by determining the proliferating cell nuclear antigen labeling index, and the apoptotic activity by terminal deoxynucleotidyl transferase dUTP nick end labeling. At 1 month, significant decrease in the mean number of ACF per person was observed in the metformin group (8.54 ± 6.37 before treatment versus 5.32 ± 4.87 at 1 month; P = 0.009), whereas in the control group the mean number of ACF did not change significantly. The proliferating cell nuclear antigen index was significantly decreased and the apoptotic cell index remained unaltered in normal rectal epithelium in metformin patients. The present study demonstrated that metformin has the potential to suppress colonic epithelial proliferation and rectal ACF formation in humans, suggesting that its promise for the chemoprevention of colorectal cancer. Citation Information: Cancer Prev Res 2010;3(12 Suppl):B53.

Abstract B59: The effect of resveratrol on azoxymethane (AOM)-induced colon carcinogenesis in mice with aberrant crypt foci (ACF)

Abstract Introduction: Resveratrol (trans-3,4,5-trihydroxy-trans-stilbene) is a naturally occurring phytoalexin with antioxidant and antiinflammatory properties. Moreover, recent studies suggest that resveratrol possesses anticancer effects on the major stages (initiation, promotion and progression) of malignant transformation. The present study was designed to investigate the effect of resveratrol on azoxymethane (AOM)-induced colon carcinogenesis in mice with aberrant crypt foci (ACF). Methods and Results: 8-week-old male C57/BL6 mice were randomly assorted into experimental five groups and administered several doses resveratrol (0.1, 1, 10, 50mg/kg/day). All mice were injected twice (1 week apart) of 10 mg/kg AOM, and sacrificed 6weeks after the first injection of AOM. Colon and rectum were stained with methylene blue for the determination of ACF. The number of ACF was significantly decreased in groups of mice treated with resveratrol in dose-dependent manner. Discussion: Colorectal cancer (CRC) poses a major clinical challenge in the developed world where the disease is common. However chemoprevention is defined as the use of natural, synthetic or chemical agents to reverse, suppress or prevent carcinogenic progress. No drug is confirmed for CRC chemoprevention. Present study demonstrated resveratrol may have chemopreventive effect for CRC. Resveratrol considered to be a food supplement and a relatively safe natural medication, so seems to be tolerated to long-term administration for CRC chemoprevention. Citation Information: Cancer Prev Res 2010;3(12 Suppl):B59.

Abstract A50: Plantago major inhibits azoxymethane-induced aberrant crypt foci in C57BL/6 mice and modulates apoptosis in mice and human colon cancer cells

Abstract Plantago major (PM), commonly known as common plantain, is a temperate perennial herb. Traditionally, its seeds and leaves have been ingested or applied externally to treat inflammation and infection. Studies showed PM possesses inhibitory effects towards a variety of tumors and cancer cell lines, including mice Ehrlich ascites carcinoma and breast adenocarcinoma, gastric, leukaemia, ovary, melanoma, and renal human cell lines. While PM has been shown to exhibit selective cytotoxic activity against cancer cells, its quantitative potential as a chemopreventive agent on colon cancer has yet to be elucidated. In this study, C57BL/6 mice (N = 30) of 9 wk old were randomized into three groups (N = 10). Positive and experimental mice groups were injected with Azoxymethane (AOM; 5 mg/kg body weight) at the onset and second wk of the 8-wk duration of the in vivo study while the negative group received no injection. The mice in the experimental group were given daily oral feedings of 20 mg/ml of PM from the onset of the study while the negative and positive control groups were given a sterilized water placebo. All groups were sacrificed after 8 wks and 25 mm cuts of the proximal colon were analyzed for aberrant crypt foci (ACF). PM feeding significantly reduced the number of AOM-induced ACF in the proximal colon compared to the water-fed positive control AOM-induced group (7.02 ± 2.61 &amp;lt; 32.1 ± 9.86; P &amp;lt; 0.0003). The negative control, water placebo group had minimal ACF (2.0 ± 1.56) compared to the experimental and positive control groups. The potency index of the herb was calculated as 4.57. Percent inhibition of AOM-induced ACF formation of 78.1% was obtained with the PM treatment. On average, all three groups gained weight (calculated as % increase) through the course of the experiment (experimental, 6.93 &amp;lt; negative control 15.6 &amp;lt; positive control 39.4). Histological (H&amp;E) slides of the proximal colon displayed a significantly higher apoptotic index than the positive control (AOM only) (2.0 &amp;gt; 0.6) and a lower mitotic index (MI) than control (1.5 &amp;lt; 2.8). Caspase 3 induction was identified in human colon cancer cells (COLO-205) treated with PM (5mg/ml) in chamber slides, using a specific carboxyfluorecein (FAM) labeled peptide fluoromethyl ketone (FMK) caspase inhibitor (FAM-Peptide-FMK). Caspase 3 activation was also observed in immunofluorescent slides of PM treated proximal colon tissues. Through inhibition of AOM-induced ACF via apoptosis, our data suggests PM to be a prospective chemopreventive and potential therapeutic agent for colon cancer. Citation Information: Cancer Prev Res 2010;3(12 Suppl):A50.