Anticarcinogenic activity of methanol extract of Melastoma malabathricum leaves is attributed to the presence of phenolics compounds and the activation of endogenous antioxidant system / Actividad anticancerígena del extracto metanólico de hojas de Melastoma malabathricum atribuida a la presencia de compuestos fenólicos y a la activación del sistema antioxidante endógeno

Melastoma malabathricum (M. malabathricum) extracts have been reported to exert various pharmacological activities including antioxidants, anti-inflammatory and antiproliferative activities. The objective of the present study was to determine the anticarcinogenic activity of its methanol extract (MEMM) against the azoxymethane (AOM)-induced early colon carcinogenesis in rats. Rats were randomly assigned to five groups (n=6) namely normal control, negative control, and treatment (50, 250 or 500 mg/kg of MEMM) groups. Colon tissues were harvested for histopathological analysis and endogenous antioxidant system determination. MEMM was also subjected to HPLC analysis. Findings showed that MEMM significantly (p<0.05) reversed the AOM-induced carcinogenicity by: i) reducing the formation of aberrant crypt foci (ACF) in colon tissues, and; ii) enhancing the endogenous antioxidant activity (catalase, superoxide dismutase and glutathione peroxidase). Moreover, various phenolics has been identified in MEMM. In conclusion, MEMM exerts the in vivo anticarcinogenic activity via the activation of endogenous antioxidant system and synergistic action of phenolics.

Se ha informado que los extractos de Melastoma malabathricum (M. malabathricum) ejercen diversas actividades farmacológicas, incluidas actividades antioxidantes, antiinflamatorias y antiproliferativas. El objetivo del presente estudio fue determinar la actividad anticancerígena de su extracto de metanol (MEMM) contra la carcinogénesis de colon temprana inducida por azoximetano (AOM) en ratas. Las ratas se asignaron al azar a cinco grupos (n=6), a saber, los grupos de control normal, control negativo y tratamiento (50, 250 o 500 mg/kg de MEMM). Tejidos de colon fueron recolectados para análisis histopatológico y determinación del sistema antioxidante endógeno. MEMM también se sometió a análisis de HPLC. Los hallazgos mostraron que MEMM invirtió significativamente (p<0.05) la carcinogenicidad inducida por AOM al: i) reducir la formación de focos de criptas aberrantes (ACF) en los tejidos del colon, y; ii) potenciar la actividad antioxidante endógena (catalasa, superóxido dismutasa y glutatión peroxidasa). Además, se han identificado varios fenólicos en MEMM. En conclusión, MEMM ejerce la actividad anticancerígena in vivo mediante la activación del sistema antioxidante endógeno y la acción sinérgica de los fenólicos.

Topographic, histological and molecular study of aberrant crypt foci identified in human colon in different clinical groups

BACKGROUND/AIMS: Aberrant crypt foci (ACF) are early microscopic lesions of the colonic mucosa, which can be detected by magnified chromoendoscopy. Herein, we have investigated whether ACF identified in different clinical groups can be differentiated based on their characteristics. METHODS: Macroscopically unremarkable mucosal flaps were collected from 270 fresh colectomies and divided into 3 clinical groups: colorectal carcinoma (group A), disease controls having known pre-neoplastic potential (group Bc), and disease controls without risk of carcinoma development (group Bn). Topographic and histologic analysis, immunohistochemistry, and molecular studies (high-resolution melt curve analysis, real-time polymerase chain reaction, and Sanger sequencing) were conducted for certain neoplasia-associated markers. RESULTS: ACF were seen in 107 cases, out of which 72 were left colonic ACF and 35 right colonic ACF (67.2% vs. 32.7%, P=0.02). The overall density of left colonic ACF was 0.97/cm, which was greater than the right colonic ACF density of 0.81/cm. Hypercrinia was present in 41 out of 72 left colonic ACF and in 14 out of 35 right colonic ACF (P=0.01). Immunohistochemical expression of p53 was also greater in left colonic ACF than in right colonic ACF (60.5% vs. 38.2%, P=0.03). However, ACF identified among the 3 clinical groups did not show any distinguishing topographic, histological, or genetic changes. CONCLUSIONS: Left colonic ACF appear to be high-risk based on their morphological and prototypic tumor marker signature. ACF identified in different clinical groups do not show significant genotypic or topographic differences. Further detailed genetic studies are required to elucidate them further.

Carcinogenesis in rats subjected to a new model ureterosigmoidostomy and treated with L-lysine

ABSTRACT PURPOSE: To evaluate the effects of L-lysine on the intestinal and urothelial epithelium of rats subjected to ureterosigmoidostomy (new model for surgical carcinogenesis). METHODS: Forty-two rats, 9 weeks of age, were divided into 6 groups. Animals in groups A, B, C were subjected to ureterosigmoidostomy (US) and treated with L-lysine, celecoxib and H2O, respectively. Groups D, E and F (non-operated controls) received L-lysine, celecoxib and H2O, respectively. The L-lysine dose was 150 mg/kg and that of celecoxib was 20 mg/kg. The colon was analyzed for the presence of aberrant crypt foci (ACF) under a stereomicroscope.The tissue was stained with hematoxylin and eosin and PAS alcian blue. RESULTS: There were rare ACF, and there was no statistically significant difference between the groups. Histopathologic study of the ureteral epithelium identified moderate to severe urothelial hyperplasia in rats with ureterosigmoidostomy. Transitional hyperplasia in the ureters of animals receiving L-lysine (A) showed an apparent difference compared to the control (C) (P=0.2424). There was no dysplasia or atypia CONCLUSION: L-lysine does not promote carcinogenesis of the intestinal and urethelial epithelium of rats subjected to ureterosigmoidostomy at the doses and times studied.

Chemopreventive effect of alpha-viniferin in azoxymethane-induced mouse colorectal tumor and Caco-2 cells / 동물의과학연구지

alpha-Viniferin (AVF), a trimer of resveratrol, is known to have an anti-inflammatory effect via inhibition of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). It has been reported that up-regulated COX-2 and iNOS are expressed in colon cancer tissues of humans and rodents as well as pre-neoplastic aberrant crypt foci (ACF) of rodents. In this study, chemopreventive effects of AVF were assessed in Caco-2 cells as well as azoxymethane (AOM)-induced colorectal tumorigenesis in mice. Anti-tumor effect of AVF with regards to apoptotic induction was assessed by TUNEL and caspase-3 expression in human colon cancer Caco-2 cells. For development of ACF, AOM was administered with to mice intraperitoneally at a dose of 10 mg/kg once a week for 3 weeks. To induce colitis-related colon cancer, mice were administered a single dose of AOM (10 mg/kg) and 2% dextran sodium sulfate in drinking water. Mice treated with 0.05 and/or 0.1 mg of AVF by gavage showed significantly reduced development of ACF and colorectal tumors. Immunofluorescence detection in Caco-2 cells showed reduced COX-2 and iNOS expression, whereas cleavage of caspase-3 and apoptotic cell numbers increased upon AVF treatment. Immunostaining showed reduced expression levels of COX-2 and iNOS expression along with increased cleaved caspase-3 expression increased upon AVF treatment. These results suggest that AVF has chemopreventive effects on colorectal cancer via anti-inflammatory potential and pro-apoptotic activity.

Use of defatted flaxseed meal reduces precancerous colon lesions in C57BL/6 mice

PURPOSE: To investigate the hemopreventive effect of defatted flaxseed meal in C57BL/6 mice after induction of precancerous colon lesions with 1.2-dimethylhydrazine (DMH). METHODS: Thirty-six 12-week-old C57BL/6 mice were divided into three treatment groups(n=12 in each group): (1) diet with 10% defatted flaxseed meal; (2) diet with defatted flaxseed meal and precancerous colon lesions induced by DMH; and (3) precancerous colon lesions induced by DMH, without defatted flaxseed meal. The incidence of aberrant crypt foci (ACF), oxidative processes, expression of tumor suppressor proteins and cyclins, as well as the profile of short-chain fatty acids (SCFA) in animal feces were investigated in the presence and absence of DMH. RESULTS: The rats consuming defatted flaxseed meals showed lesions with lower multiplicity and a reduced incidence of lesions. No changes in the expression of tumor suppressor proteins and those involved in cell cycle control were detected. CONCLUSION: Defatted flaxseed meal protected the distal colon of mice from precancerous lesions.

Effect of probiotics on the development of dimethylhydrazine-induced preneoplastic lesions in the mice colon

PURPOSE: To determine the effect of probiotics on the development of chemically induced (1, 2-dimethylhydrazine) colonic preneoplastic lesions, in mice. METHODS: The animals were divided into five groups. The control group was injected with carcinogen alone and the other groups also received probiotics (1- Lactobacillus delbrueckii UFV-H2b20; 2- Bifidobacterium animalis var. lactis Bb12; 3- L. delbrueckii UFV-H2b20 plus B. animalis var. lactis Bb12; and 4- Saccharomyces boulardii) administered orally in drinking water throughout fourteen weeks. RESULTS: Consumption of lactobacilli and bifidobacteria alone resulted in a significant reduction of the total number of aberrant crypt foci (55.7% and 45.1%, respectively). Significant reduction in the number of these small foci (<3 aberrant crypts) was only observed in the group treated with lactobacilli (52.2%) in comparison to control group. The number of larger foci (>3 aberrant crypts) crypts had no significant reduction. CONCLUSION: L. delbrueckii UFV-H2b20 and B. animalis var. lactis Bb12 administered alone protect colonic preneoplastic lesions in mice, while the combined treatment of these bacteria and the administration of S.boulardii were not effective in reducing such colonic lesions.

Effect of a hyperlipidic diet rich in omegas 3, 6 and 9 on aberrant crypt formation in rat colonic mucosa / Efeito de uma dieta hiperlipídica rica em ômegas 3, 6 e 9 na formação de criptas aberrantes em mucosa cólica de ratos

PURPOSE: To determine whether a hypercaloric and hyperlipidic diet enriched with polyunsaturated fatty acids influences the formation of aberrant crypt foci (ACF) in colonic mucosa of Wistar rats treated with azoxymethane (AOM). METHODS: At eight weeks of life, the rats were assigned to four groups: Group I―standard diet (STD) not treated with AOM; Group II―hypercaloric and hyperlipidic diet (FED), not treated with AOM; Group III―STD, treated with AOM; Group IV―FED, treated with AOM. At 16 weeks, the animals were injected intraperitoneal with 0.9 percent saline solution (Group I and II) or AOM at 15mg/Kg (Groups III and IV) once a week for two weeks. Fifteen weeks later, the animals were euthanized. RESULTS: FED promoted weight gain in Groups II and IV compared to Groups I and III, respectively. The groups did not differ with regard to the total number of ACF. The Chi-square test revealed no predominance of the presence of foci with <4 crypts. However, foci with ≥5 crypts were proportionally more prevalent in Group III than in Group IV (p=0.043). CONCLUSION: The administration of polyunsaturated fatty acids did not interfere with the formation of aberrant crypt foci, but reduced ACF multiplicity, exercising an attenuating effect on carcinogenesis.

OBJETIVO: Determinar se uma dieta hipercalórica, hiperlipídica, rica em ácidos graxos poliinsaturados (FED) tem influência na formação de focos de cripta aberrante (FCA) em mucosa cólica de ratos Wistar expostos ao azoximetano (AOM). MÉTODOS: Com oito semanas de vida, os ratos foram distribuídos em quatro grupos: Grupo I: Dieta padrão (SD) sem AOM; Grupo II: FED, sem AOM; Grupo III: SD, com AOM; Grupo IV: FED com AOM. Com 16 semanas, os animais dos grupos I e II receberam injeções intraperitoneais de solução salina 0,9 por cento, enquanto os dos grupos III e IV receberam AOM na dose de 15mg/Kg de peso, 1 vez por semana por duas semanas. Quinze semanas após, os animais foram mortos. RESULTADOS: FED promoveu aumento de peso nos grupos II e IV em relação aos grupos I e III. Não houve aumento significante no número total de FCA entre os grupos. Em relação à multiplicidade das criptas por FCA, o teste do qui-quadrado mostrou que não houve predominância da presença <4 criptas por foco. Contudo, focos ≥5 criptas foram proporcionalmente mais prevalentes no grupo III que no grupo IV (p=0,043). CONCLUSÃO: Os ácidos graxos poliinsaturados não interferem na formação de focos de cripta aberrante, contudo reduz sua multiplicidade, exercendo efeito atenuador na carcinogênese.

Suppressive Effect of Zinc on the Formation of Colonic Preneoplastic Lesions in the Mouse Fed High Levels of Dietary Iron

We investigated the effect of zinc on the formation of colonic aberrant crypt foci induced by azoxymethane (AOM) followed by dextran sodium sulfate (DSS) in mice with high iron diet (HFe; 450 ppm iron). Six-week old ICR mice were fed on high iron diets with combination of three different levels of zinc in diets, low-zinc (LZn; 0.01 ppm), medium-zinc (MZn; 0.1 ppm), and high-zinc (HZn; 1 ppm) for 12 weeks. Animals were received weekly intraperitoneal injections of AOM (10 mg/kg B.W. in saline) for 3 weeks followed by 2% DSS (molecular weight 36,000~50,000) in the drinking water for a week. To confirm the iron storage in the body, the hepatic iron concentration has been determine chemically and compared with histological assessment visualized by Prussian blue reaction. Aberrant crypt (AC) and aberrant crypt foci (ACF) were analyzed in the colonic mucosa of mouse fed high dietary iron. Superoxide dismutase (SOD) activity and thiobarbituric acid-reactive substances (TBARS) level were also investigated. Apoptosis in the preneoplastic lesion was determined by terminal deoxynucleotidyl transferase-mediated dUTP nickend labeling (TUNEL). In addition, immunohistochemistry of beta-catenin was also performed on the mucous membrane of colon. The number of large ACF (> or = 4 AC/ACF), which possess greater tumorigenic potential, was significantly lower in MZn and HZn groups compared with LZn group. Cytosolic SOD activity in the liver was significantly higher in HZn group compared with LZn group. Hepatic MDA level was decreased significantly in HZn group compared with MZn and LZn groups. Apoptotic index was significantly higher in HZn group. Taken together, these findings indicate that dietary zinc might exert a protective effect against colonic preneoplastic lesion induced by AOM/DSS in ICR mice with high iron status, and suggest that dietary supplement of zinc might play a role in suppressing colon carcinogenesis in mice.

Sequential Changes in Aberrant Crypt Foci and Lectin Expression in the Early and Late Stages of DMH-Induced Colon Carcinogenesis in Rats

BACKGROUND/AIMS: The purpose of this study was to investigate the malignant potential of aberrant crypt foci (ACF) by measuring the multiplicity of crypts and lectin expression in the early and late stages of 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis. METHODS: Six-week-old Wistar rats were injected subcutaneously with DMH for 27 weeks. We classified ACF according to the number of crypts per ACF as a few crypts ( or =4 crypts, NC ACF). Immunohistochemistry was used to evaluate lectin expression. RESULTS: In the early stage, FC ACF (590/1,902, 31.0%) occurred more frequently than NC ACF (35/449, 7.8%); whereas in the late stage, NC ACF (176/449, 39.2%) occurred more frequently than FC ACF (324/1,902, 17.0%). The number of ACF peaked at 15 to 20 weeks. The ratio of NC/FC ACF increased gradually during carcinogenesis. The expression of both UEA1 and PNA was higher in NC ACF than FC ACF. Lectin expression increased in the late stage compared with the early stage. CONCLUSIONS: The expression of lectin was higher in NC ACF and ACF in the late stage. Therefore, ACF with higher multiplicities in the late stage may have more malignant potential in DMH-induced colon carcinogenesis.

Dietary zinc inhibits the formation of colonic preneoplastic lesion induced by azoxymethane and dextran sodium sulfate in mice / 대한수의학회지

Colorectal cancer (CRC) is one of the leading causes of cancer death in western countries or in the developed countries. Zinc intake has been associated with decreased risk of CRC. We investigated the effect of zinc on the formation of colonic aberrant crypt foci (ACF) induced by azoxymethane followed by dextran sodium sulfate in mice. Five-week old ICR mice were fed with the different zinc levels (0.01, 0.1, 1 ppm) for 12 weeks. The numbers of ACF were measured in the colonic mucosa. The ACF number of HZn group was significantly low compared with LZn group or MZn group. Cytosolic superoxide dismutase activity was the highest in HZn group, while thiobarbituric acid reactive substance level for lipid peroxidation was the highest in LZn group. There was no difference in number of PCNA-positive proliferative cells among the groups. TUNEL-positive apoptotic cells were increased in HZn group compared with LZn group. The HZn group exhibited a decrease of beta-catenin immunostaining areas compared with the LZn or MZn group. These findings indicate that dietary zinc might exert a protecting effect against colon carcinogenesis by inhibiting the development of ACF in the mice.

Sodium butyrate does not decrease the evolution of precancerous lesions in rats / Butirato de sódio não diminui a evolução de lesões pré-neoplásicas em ratos

PURPOSE: To evaluate the preventive effect of sodium butyrate in the appearance of aberrant crypt foci (ACF) in rats after induction with the carcinogen 1,2-dimethylhydrazine (DMH). METHODS: Forty Wistar rats were separated into four groups (n=10) distributed as follows: control 1, control 2, butyrate 1 and butyrate 2. The groups control 1 and butyrate 1 remained under experimentation for 4 weeks, while the groups control 2 and butyrate 2 remained for 8 weeks. In the first four weeks, the animals of the control groups received water ad libitum and the animals of the butyrate groups received a sodium butyrate solution (3.4 percent) ad libitum. Injections of the drug 1,2-dimethylhydrazine were applied during the two first weeks of the experiment in all the animals, concurrently with the application of sodium butyrate. The large intestine of the animals was removed, for the analysis of the ACF and of the content of polyamines. The animal feces were collected for the analysis of the SCFA profile. RESULTS: The spermidine presented a higher concentration in the group butyrate 2 in comparison to the group control 2. There was a significant difference in the concentration value (µmol/mL) of acetate in comparison to the groups control 2 and butyrate 2. CONCLUSION: The use of sodium butyrate together with the induction of colorectal cancer was not effective in the prevention of the disease progression.

OBJETIVO: Avaliar o efeito preventivo do butirato de sódio no surgimento de focos de cripta aberrante (FCA) em ratos após a indução com o carcinógeno 1,2-dimetilhidrazina. MÉTODOS: Quarenta ratos foram divididos em quatro grupos, com dez animais em cada. Os grupos controle 1 e butirato 1 ficaram em experimentação por 4 semanas e os grupos controle 2 e butirato 2 por oito semanas. Nas primeiras quatro semanas, os animais dos grupos controle receberam água ad libitum e os animais dos grupos butirato receberam solução de butirato de sódio (3,4 por cento) ad libitum. Em todos os animais foram aplicadas quatro injeções subcutâneas da droga 1,2-dimetilhidrazina nas duas primeiras semanas, concomitante a administração do butirato de sódio. Foi retirado o intestino grosso dos animais, para análise dos FCA e do teor de poliaminas. As fezes dos animais foram recolhidas para análise do perfil de AGCC. RESULTADOS: A espermidina apresentou maior concentração no grupo butirato 2 em relação ao grupo controle 2. Foi encontrada diferença significativa no valor da concentração de acetato quando comparado os grupos controle 2 e butirato 2. CONCLUSÃO: A utilização do butirato de sódio concomitante à indução do câncer colorretal não se mostrou efetiva na prevenção da progressão da doença.

Optimization of visibility and quantification of aberrant crypt foci in colonic mucosa in Wistar rats / Otimização da visibilidade e quantificação de focos de criptas aberrantes em mucosa cólica de ratos Wistar

Purpose: Test immersion of microscopy samples in water as an aid to visualizing and quantifying aberrant crypt foci (ACF) in rat colon mucosa. Methods: Carcinogenesis was induced with azoxymethane in Wistar rats kept on a conventional diet or a hypercaloric diet containing unsaturated fat. Fifteen weeks after induction, colon samples were retrieved and fixated in a 10 percent formaldehyde solution. The samples were divided into segments (distal, middle, proximal) and stained with 1 percent toluidine blue. The technique tested in the study consisted of immersing microscopy samples in distilled water in order to eliminate the problem of light reflection known from conventional microscopy. Results: When samples were immersed in water during microscopy, significantly more ACF could be visualized in all colon segments than with the conventional method proposed by Bird. Conclusion: Immersing microscopy samples in water aids the visualization and quantification of aberrant crypt foci in rat colon mucosa fixed in formaldehyde.

Objetivo: Otimizar a visibilização de focos de criptas aberrantes (FCA) em mucosa cólica de ratos Wistar. Métodos: Colo de rato Wistar, sob diferentes dietas e submetidos a iniciação de carcinogênese pelo azoximetano há 4 meses, foram previamente lavados, abertos e fixados em solução de formalina a 10 por cento por 24 horas. Após serem corados em azul de toluidina a 1 por cento, foram divididos em segmentos distal, médio e proximal e imersos em água destilada para quantificação de FCA. Resultados: No método de imersão foi visibilizado maior quantidade de focos de criptas aberrantes em todos os segmentos cólicos, com diferença significante, quando comparado com o método de Bird. Conclusão: O método de imersão otimiza a visibilização e quantificação de focos de criptas aberrantes em mucosa cólica (ratos Wistar) fixada em solução de formalina a 10 por cento.

Histomorphology of aberrant crypt foci in colorectal carcinoma

Colorectal carcinogenesis is a complex multistep process that includes changes in histomorphological appearance of the colonic mucosa and changes at molecular level. Aberrant crypt foci (ACF) was first described by Bird in 1987 on examination of methylene-blue-stained colonic mucosa of azoxymethane-treated mice under light microscopy. Since then ACF was considered as the earliest preneoplastic change that can be seen in the colonic mucosa. The aim of this study was to look at the histomorphology and distribution of ACF in colorectal carcinoma. 50 formalin-fixed archival colectomy specimens for colorectal carcinoma were examined under light microscopy after staining with 0.2% methylene blue. ACF was identified by larger and darker crypts with thickened epithelium, and often elevated from adjacent normal mucosa. ACF was found in 41 of 50 colectomy specimens examined. There were 328 ACF consisting of 36 (11.0%) ACF without hyperplasia or dysplasia, 263 (80.2%) ACF with hyperplasia and 29 (8.8%) ACF with dysplasia. Of these 29 ACF with dysplasia, 25 showed low grade dysplasia and four high grade dysplasia. The density of ACF was higher in the left colon, those older than 65 years of age and among males but these findings were statistically not significant. The crypt multiplicity of hyperplastic ACF (30.149, SD 28.395) was larger than dysplastic ACF (20.613, SD 40.128). The spectrum of histological changes observed probably represent the evolution of ACF in colorectal carcinogenesis.

Preventive effects of berberine on experimental colon cancer and relationship with cyclooxygenase-2 expression / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the anti-colon cancer effects of berberine and possible relationship with cyclooxygenase-2.</p><p><b>METHOD</b>Wistar rat colon cancer model was induced by 1-2 dimethylhydrazine (DMH) (40 mg x kg(-1), sc) + 1% dextran sodium sulfate solution (DSS) (freely drinking). All rats were randomly divided into 3 groups: Control (DMH + DSS + solvant), meloxicam (Mel) (DMH + DSS + Mel 1.35 mg x kg(-1)), berberine (Ber) (DMH + DSS + Ber 100 mg x kg(-1)). The drugs were given orally once a day for 5 day per week. The body weight, the number of colon ACFs, the incidence and number of colon cancer in rats, as well as the morphological changes of rat colon tissues were evaluated. Human colon cancer lovo cell line was treated by either Ber or Mel in various concentrations (1 10(-6) mol x L(-1), 1 x 10(-5) mol x L(-1), 1 x 10(-4) mol x L(-1), 1 x 10(-3) mol x L(-1)) for 6, 12 and 24 h, respectively, and the cell growth was assayed by MTT method. RT-PCR and western-blot were used to evaluate the mRNA and protein expressions of COX-2 from lovo cells treated with Ber and Mel.</p><p><b>RESULT</b>Ber significantly improved the dyscrasia induced by DMH + DSS, the both of body weight and general condition were better than control group. Ber also significantly inhibited ACF and colon cancer incidence in the rats treated by DMH + DSS for 10 weeks or 20 weeks, which was similar to that of Mel. Ber inhibited the proliferation of lovo cells in concentration- and time-dependent manners, and the IC50 values were significantly smaller than that of Mel at 6, 12 and 24 h after lovo cells were treated by either Ber or Mel. Ber also concentration-dependently decreased expressions of COX-2 mRNA and COX-2 protein from lovo cells.</p><p><b>CONCLUSION</b>Ber can inhibit ACF and tumor formation induced by DMH + DSS, and decrease the lovo cell proliferation index. The anti-tumor effects of Ber may involve in an unknown pathway through which the expressions of COX-2 mRNA and protein were inhibited.</p>

Effects of astragalosides on induction of colorectal aberrant crypt foci by dimethylhydrazine and metabolizing enzymes in liver microsomes in rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the effects of astragalosides on content of rat liver microsomal cytochrome P450 (CYP450), activity of glutathione-S-transferase (GST) and dimethylhydrazine (DMH)-induced aberrant crypt foci formation in rats.</p><p><b>METHODS</b>Forty SD rats were randomly and equally divided into control group, Astragalus group, DMH group, Astragalus+DMH group. The animals were killed by off neck and the colorectal and liver tissues taken after treatment with astragalosides and dimethyl hydrazine . The colorectal tissues were stained by methylene blue, ACFs observed and counted, and liver microsomes isolated by differential centrifugation. The total enzyme content was detected by using differential spectrometry for carbon monoxide reduction. The glutathione (GSH) level was detected by using spectrophotometry to reflect the activity of the GST.</p><p><b>RESULTS</b>The numbers of ACF and large ACF in Astragalus+DMH group were more significantly decreased than the DMH group (P<0.05). Compared with the control group, Astragalus group and Astragalus+DMH group, CYP450 level was decreased significantly, and GST activity increased significantly in DMH group (P<0.05).</p><p><b>CONCLUSION</b>Astragalosides might reduce the number of colorectal aberrant crypt foci induced by dimethylhydrazine possibly by reducing the content of hepatic CYP450 and increasing GST activity in rats.</p>

Dose-response assessment of the anti-cancer efficacy of soy isoflavones in dimethylhydrazine-treated rats fed 6% fructooligosaccharide

We investigated the combinatorial effects of different doses of dietary soy isoflavones (SI) and fructooligosaccharide (FOS) in a rat model of colon cancer. We hypothesized that increased bioavailability of SI metabolites due to dietary FOS may increase production of bioactive equol and affect colon carcinogenesis in a dose-dependent manner. Sprague-Dawley male rats were injected with 12-dimethylhydrazine (DMH) and were provided experimental diets that contained 0, 10, 50, 150, or 500 mg SI per kg of diet and 6% FOS for 12 weeks. The number of aberrant crypt foci (ACF) and the expression of cyclooxygenase-2 (COX-2) in colonic tissues were significantly decreased in the 6% FOS-fed groups compared to the control group. Gut transit time and fecal pH were significantly lower, and fecal concentrations of bifidobacteria were increased with 6% FOS. However, dietary SI supplementation in combination with 6% dietary FOS did not affect ACF formation or COX-2 expression. Plasma equol concentrations were dose-dependently increased by supplementation of SI up to 500 mg/kg of diet. In conclusion, SI supplementation up to 500 mg/kg of diet appeared to have no additive beneficial effects in rats with chemically-induced colon cancer that were fed 6% FOS, although plasma equol was dose-dependently increased.

Loss of DNA-dependent Protein Kinase Catalytic Subunit (DNA- PKcs) Expression in Gastric Cancers / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: DNA-PKcs is one of the DNA repair genes. It was recently found that hyperplasia and dysplasia of the intestinal mucosa and the production of aberrant crypt foci were developed in DNA-PKcs-null mice, and this suggests a suppressive role for DNA-PKcs in tumorigenesis. MATERIALS AND METHODS: To investigate the possible relationship between the clinico-pathologic characteristics and the survival of gastric cancer patients, the expression status of DNA-PKcs was determined in 279 consecutive gastric cancers. Immunohistochemical analysis was performed to evaluate the expression levels of DNA-PKcs protein by using the tissue array method. RESULTS: Out of 279 consecutive gastric cancers, 63 cases (22.6%) showed the loss of DNA-PKcs expression. The loss of DNA-PKcs expression was significantly associated with advanced cancer (p <0.001), lymphatic invasion (p=0.001), lymph node metastasis (p=0.009), and advanced pTNM stage (p=0.009). Univariate survival analysis revealed that patients with the loss of DNA-PKcs expression had significantly poorer survival than those patients with intact DNA-PKcs expression (p=0.004). Moreover, the loss of DNA-PKcs expression was identified to correlate with a lower survival in the subgroup of stage I gastric cancer patients (p=0.037). CONCLUSION: The loss of DNA-PKcs expression was found in 23% of human gastric cancers and this was identified to significantly correlate with poor patient survival, especially for stage I gastric cancer patients.

Aberrant Crypt Foci in the Background Mucosa of Colorectal Adenocarcinoma / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: This study was performed in order to determine the histologic features, incidence & frequency of the Aberrant Crypt Foci (ACFs) including mucosal abnormalities arising in the sporadic colonic cancer. MATERIALS AND METHODS: We investigated the proximal and distal colonic mucosa surrounding the tumor in 22 cases (right colon 7 cases and left colon 15 cases) of resected colonic adenocarcinoma specimen. The methylene blue- stained colonic mucosa was examined in en face preparations and rolled totally. The rolled colonic mucosa was embedded in paraffin and examined by using 4micrometer thick serial sections. RESULTS: We found one hundred twenty two ACFs. The 97 foci (78.7%) were simple hypertrophic foci (SH), composed of more elongated and larger crypts than normal with apical branching associated with goblet cell hyperplasia. The 17 foci (13.9%) were hyperplastic foci (HP) resembling hyperplastic polyp, and 7 (5.7%) were adeno matous foci (AD) while 2 (1.6%) were adenomatous foci with dysplasia (Dys). The mean number of ACFs/cm of the examined mucosa were 0.18+/-0.21 and were higher in the left colon than in the right colon (0.22+/-0.24 vs. 0.10+/-0.10). Immunohistochemical stains for p53 and Ki-67 in these foci revealed strong and upper cryptal staining patterns in AD and Dys of ACFs, like that of neoplasia or preneoplastic condition. However, the staining intensities in SH and HP of ACFs were equal to or lower than that of normal crypts. CONCLUSION: These results suggest that grossly defined ACFs include reactive process and the majority of ACFs are induced by simple reactive alteration without preneoplastic potential; and two types of ACFs (AD and Dys) are more likely to be direct precursors of colon tumors than SH or HP.

Aberrant Crypt Foci: Histopathologic Classification and Profiles of Mucin Secretion

Aberrant crypt foci (ACF) are grossly unidentifiable lesions of the colon and visible only with low-power microscopic examinations after methylene blue stain. To establish the role of ACF in colorectal carcinogenesis, we evaluated the distribution, frequency, histopathological classification, and patterns of mucin secretion of ACF in the colon. A total of 142 aberrant crypt foci were found in 41 colectomy specimen for adenocarcinoma (36 cases) and benign diseases of colon (5 cases). Ten of 142 ACFs were in the ascending and transverse colon, 39 in the descending and sigmoid colon, and 93 in the rectum. The mean number of ACFs in the rectum (0.13 0.11/cm2) was higher than in the ascending and transverse colons (0.019 0.018/ cm2) and descending and sigmoid colon (0.10 0.14/cm2). ACFs were found only in cancer patients. One hundred and twenty ACFs among 142 ACFs identified by topology, were identified on histological examination. We classified ACFs into simple (48.3%), hyperplastic (42.5%), and dysplastic (9.2%) types. All ACFs were infiltrated by the lymphocytes in the stroma and 18 of these accompanied the lymphoid follicles. ACFs have variable histopathologic features and mucin profiles. Some variants of ACFs are at the early stage of the spectrum between benign and malignant.