deoxycholic-acid and Precancerous-Conditions

Topics: Adenoma; Animals; Cell Division; Cell Line; Cells, Cultured; Colonic Neoplasms; Culture Techniques; Deoxycholic Acid; Epidermal Growth Factor; Humans; Models, Biological; Plasminogen Activators; Precancerous Conditions; Tetradecanoylphorbol Acetate

AKR/J mice are resistant to the tumorigenic properties of the colon carcinogen, azoxymethane (AOM). Following AOM exposure, limited numbers of preneoplastic lesions, referred to as aberrant crypt foci (ACF), are formed in the colon, and their progression to tumors rarely occurs. To determine whether genetic resistance can be overcome by exposure to a dietary tumor promoter, AOM-exposed AKR/J mice were fed a diet containing 0.25% deoxycholic acid (DCA). DCA exposure was begun 1 wk prior to or 1 wk after tumor initiation with AOM. Mice placed on the DCA diet prior to AOM treatment developed a significantly higher multiplicity of ACF compared to AOM-exposed mice fed a control diet (15.50 +/- 0.96 vs. 6.17 +/- 0.48, respectively; P < 0.05). When DCA exposure was begun after AOM treatment (post-initiation), ACF formation was further enhanced (34.00 +/- 1.22). Interestingly, increased numbers of ACF were associated with the presence of nuclear beta-catenin, assessed by immunohistochemistry. While approximately 33% of ACF from mice exposed to DCA prior to AOM treatment contained positive nuclear beta-catenin staining, approximately 77% of ACF from mice fed DCA after AOM were positive. Accumulation of nuclear beta-catenin was not associated with a loss of E-cadherin from the plasma membrane, although loss of APC staining was a consistent feature of most AOM-induced ACF, regardless of DCA exposure. These results demonstrate that exposure to DCA, an important digestive component, is sufficient to sensitize the resistant AKR/J colon to formation of high-grade dysplasia, and that nuclear translocation of beta-catenin may play an important role in this process.

Topics: Animals; Azoxymethane; beta Catenin; Cadherins; Carcinogens; Cell Nucleus; Colon; Colonic Neoplasms; Deoxycholic Acid; Detergents; Hyperplasia; Male; Mice; Mice, Inbred AKR; Precancerous Conditions; Protein Transport

We have established a medium-term colorectal carcinogenesis rat model initiated with 1,2-dimethylhydrazine (DMH) followed by dextran sodium sulfate (DSS) treatment, featuring induction of neoplastic lesions within 10 weeks. In the present study, we examined its ability to detect modification of colon lesion development with 10- or 20-week experimental periods. F344 male rats were given three subcutaneous injections of DMH (40 mg/kg b.w.) in a week followed by free access to drinking water containing 1% DSS for a week. One week after this regimen, basal diet alone, basal diet containing 0.04% nimesulide or 2% lactoferrin as known inhibitors, 0.3% deoxycholic acid (DCA) as a promoter or 1.5% 1-hydroxyanthraquinone (1-HA) as a carcinogen were supplied. At week 10, the incidence and multiplicity of combined adenomas and adenocarcinomas were significantly (P < 0.05 or 0.01) decreased by nimesulide and lactoferrin, and values for adenomas were significantly (P < 0.01) increased in the 1-HA group. There was no clear change in the DCA group. At week 20, multiplicity and volume of the tumors were significantly (P < 0.01 or 0.05) decreased by nimesulide, but no effect was now evident with lactoferrin. Multiplicity and volume of tumors were significantly (P < 0.01) increased in 1-HA group and a similar tendency was apparent (P = 0.08) with DCA. It is concluded that this system offers a useful tool for detection of colorectal carcinogenesis modifiers within 10-20 weeks, pending further studies for verification employing other model chemicals.

Topics: 1,2-Dimethylhydrazine; Animals; Anthraquinones; Carcinogenicity Tests; Colorectal Neoplasms; Deoxycholic Acid; Dextran Sulfate; Lactoferrin; Male; Precancerous Conditions; Rats; Rats, Inbred F344

The insoluble 'high-molecular-weight' fraction (HMF) centrifugally separable after digestion of soy protein isolate with a microbial protease of the exo-type, of which about a quarter is regarded as an indigestible 'resistant protein,' was examined for its preventive effect against colonic tumorigenesis in a model system with male F-344 rats. The rats were intraperitoneally injected with azoxymethane (15 mg/kg BW) once a week for 3 wk and were fed a 20.6% HMF diet (+0.4% DL-Met) or 14.7% casein diet (+0.3% DL-Met) supplemented with 0.2% sodium deoxycholate (DCA) or without supplementation. Twelve wk later, 5 rats of each group were inspected for formation of tumors but no tumors were visible to the naked eye. The DCA-fed casein group was conspicuous for a low count of aberrant crypt foci. At 39 wk, 6 rats of the DCA-fed casein group (n = 10) and 3 rats of the DCA-fed HMF group (n = 9) had a total of 18 tumors with a major axis of 4.0 +/- 0.4 mm and 3 tumors with an axis of 2.0 +/- 0.1 mm, respectively, in contrast to only a single tumor for the DCA-unfed casein group (nil for the DCA-unfed HMF group). The difference in tumor number and size was considered significant between these DCA-fed casein and HMF groups; that is to say, HMF feeding retarded tumor development despite the frequent occurrence of pre-neoplastic lesions. In addition, fecal bile acid excretion was much more elevated by HMF feeding than by casein feeding. It can be assumed from these observations that the antitumorigenicity of HMF is due to the inhibitory effect of soybean resistant proteins on reabsorption as well as the mucosal contact of bile acids in the intestine.

Topics: Animals; Azoxymethane; Bile Acids and Salts; Carcinogens; Caseins; Cholesterol; Colonic Neoplasms; Deoxycholic Acid; Feces; Lipids; Male; Molecular Weight; Precancerous Conditions; Rats; Rats, Inbred F344; Soybean Proteins; Steroids

A high-molecular-weight fraction after removal of water-soluble peptides from proteinase-treated soybean protein isolate (referred to as HMF) was examined for its effect on preneoplastic lesions in the rat colon. For this purpose, male Fisher-344 rats 7 wk old were divided into 8 groups (n = 5), of which 6 groups received 3 injections of azoxymethane (AOM, 15 mg/kg of body weight) for 3 wk once a week, while all were fed HMF or casein diets supplemented with or without deoxycholic acid (DCA) over a period of 4 wk. Two groups of AOM-treated rats were allowed free access to HMF or casein diets without supplemental DCA, respectively, while the others were pair-fed so as to be well matched in their food intake. There were no significant differences in growth parameters among the pair-fed groups. Feeding HMF diets raised fecal lipid and acidic steroid excretions to a greater extent than feeding casein diets, secondary bile acids being conspicuous among acidic steroids in the excreta irrespective of the presence or absence of DCA supplementation. As a result of observation for colonic aberrant crypt foci (ACF), the intake of HMF proved to reverse the reduction of ACF appearance by DCA. This result implies that secondary bile acids are caught and brought out by HMF, or rather its derivative "resistant protein," so as not to keep contact with colonic mucosae.

Topics: Animals; Azoxymethane; Bile Acids and Salts; Blood Proteins; Carcinogens; Chromatography, Thin Layer; Colonic Neoplasms; Deoxycholic Acid; Feces; Lipids; Male; Precancerous Conditions; Rats; Rats, Inbred F344; Soybean Proteins

To elucidate the role of fecal steroids in the malignant tumor formation of colonic epithelial cells, we examined the effects of dietary deoxycholic acid (DCA) and cholesterol (CHL) on fecal steroid concentrations and their impact on colonic crypt cell proliferation. Twenty 5-week-old male Fischer 344 rats were provided with either a control semisynthetic diet or the same diet supplemented with 0.15% DCA and 1% CHL (steroid diet) over a 5-week period. The effects of these two diets were compared among rats that were either injected with azoxymethane (AOM), a known gastrointestinal carcinogen, or saline. In a 2 x 2 factorial design, rats fed each of these diets were given two weekly subcutaneous injections of either AOM (15 mg/kg b.w.) or saline at 6 and 7 weeks of age. At 9 weeks of age, fecal samples were obtained for analysis of bile acids, CHL and its bacterial metabolites of intestinal microflora. At 10 weeks of age, animals were sacrificed and colonic proliferation was assessed as vincristine-accumulated mitotic figures per crypt. Rats fed the steroid diet had significantly elevated fecal bile acid (5x, P < 0.001) and neutral steroid (10x, P < 0.01) levels when compared to those fed the control diet. AOM treatment did not appear to influence these levels. However, rats injected with AOM had a significant increase (P < 0.001) in their rate of colonic cell proliferation as compared to saline-injected control animals on both diets. Furthermore, rats fed the steroid diet had a significantly higher (P < 0.001) cell proliferation rate than animals fed the control diet. The effects of AOM treatment and the steroid diet on cell proliferation were additive. Our results demonstrate that high concentrations of neutral and acid steroids in the colonic lumen can enhance carcinogen-induced elevated cell proliferation and thus may play a key role in the etiology of colon cancer.

Topics: Animals; Azoxymethane; Bile Acids and Salts; Body Weight; Carcinogens; Cell Division; Cholesterol, Dietary; Cocarcinogenesis; Colon; Colonic Neoplasms; Deoxycholic Acid; Eating; Feces; Male; Precancerous Conditions; Rats; Rats, Inbred F344; Steroids

A high-fat and low-fiber diet is regarded as a major risk factor for colon cancer by increasing luminal contents of secondary bile acids. Calcium, on the other hand, has been implicated as a possible preventive agent in colon tumor development. In in vitro studies with human colonic epithelium, incubation with the secondary bile acid deoxycholic acid (DCA) induced hyperproliferation of colonic crypt cells which is regarded as a sign of preneoplastic transformation. In the present study the effects of calcium chloride (CaCl2) on DCA-induced hyperproliferation were tested at different stages of DCA-induced cell injury. Colonic biopsies from 36 patients (no tumors, polyps or IBD) were incubated with CaCl2 (1 and 10 mM) and 5 microM DCA which was added to the incubation medium either together with (experiment A), after (experiment B), or before CaCl2 (experiment C). Coincubation of the biopsies with DCA and 10 mM CaCl2 at the same time (experiment A) resulted in a significant reduction of whole crypt labeling index by 12% (p < 0.05), whereas in the other incubation experiments no significant growth-inhibitory effects could be demonstrated for CaCl2. These findings may best be explained by the formation of calcium-bound bile acid salts which lost most of their toxicity for the colonic cells.

Topics: Adult; Aged; Aged, 80 and over; Biopsy; Calcium; Cell Division; Cells, Cultured; Colon; Colonic Neoplasms; Deoxycholic Acid; Dose-Response Relationship, Drug; Female; Humans; Immunohistochemistry; Male; Middle Aged; Precancerous Conditions; Risk Factors

Modifying effects of fibrosis or a cirrhotic state, caused by treatment with swine serum (SS), on the induction of preneoplastic focal lesions were assessed in a rat medium-term liver bioassay model for the detection of environmental carcinogens, in which the test compound is administered during the promotion phase after initiation with diethylnitrosamine. In experiment I, repeated intraperitoneal administration of SS concomitantly with the hepatopromoting agent deoxycholic acid (DCA) or phenobarbital (PB) resulted in a cirrhotic state and a significant increase in the number or size of preneoplastic glutathione S-transferase placental form (GST-P)-positive liver cell foci as compared to the corresponding DCA or PB alone groups. In experiment II, SS was given prior to commencement of the same medium-term bioassay system, in which a known hepatopromoting agent, DCA, 17-alpha-ethynylestradiol, or 2-acetylaminofluorene, was applied. In this case, the liver did not show obvious cirrhotic change and, rather than any enhancement, slight inhibition of promotion occurred. The results indicate that a coexisting, but not a pre-existing, cirrhotic condition acts to increase growth pressure on GST-P+ preneoplastic foci, and suggest that concomitant administration of SS with the promoting agent could be applied to improve the sensitivity of the assay protocol.

Topics: 2-Acetylaminofluorene; Animals; Blood; Chemical and Drug Induced Liver Injury; Cocarcinogenesis; Deoxycholic Acid; Ethinyl Estradiol; Glutathione Transferase; Injections, Intraperitoneal; Liver; Liver Cirrhosis, Experimental; Liver Diseases; Male; Organ Size; Phenobarbital; Precancerous Conditions; Rats; Rats, Inbred F344; Swine

The aim of this study was to determine whether changes in serum free radicals may be useful for the early detection of precancerous conditions in the rat colon after treatment with a direct carcinogen (N-Methyl-N'-Nitro-N-Nitrosoguanidine, MNNG) and a secondary bile acid (deoxycholic acid, DCA) as a tumor promoter. It was shown that a significant increase in the concentrations of free radicals in sera of rats following their treatment with MNNG and DCA was observed as early as the 18th week after the beginning of the treatment. Since our results have shown that these alterations occurred in parallel with neoplastic transformations in the rat colon, it suggests that the increase in serum free radicals reflected the precancerous situation in the animals and may be useful in the early detection of cancer development. The possible role of free radicals in deoxycholate-induced liver toxicity was discussed.

Topics: Animals; Colonic Neoplasms; Deoxycholic Acid; Free Radicals; Gentisates; Hydroxybenzoates; Male; Methylnitronitrosoguanidine; Precancerous Conditions; Rats; Rats, Sprague-Dawley

The development of tumorigenic conditions in the carcinogen-exposed rat colon was studied using selected morphological, histochemical, immunohistochemical and biochemical methods of analysis. Rats were treated with two carcinogens: 1,2-dimethylhydrazine and N-methyl-N'-nitro-N-nitrosoguanidine alone or with deoxycholic acid as a tumor promoter. It was found that 3 months after treatment of animals with the carcinogens the following changes were developed in colonic tissue: infiltration of lymphocytes in the mucous membrane, high increase in mitotic index among epithelial cells, negative reactions of colonic cells for neutral mucopolysaccharides and sulfomucins and positive reactions to carboxyl groups, nonsulfated acid mucosubstances and tissue polypeptide antigens. An increase in the activity of ornithine decarboxylase in colonic tissue was developed within the same time period and has been seen only in those tissues which were characterized by the development of precancerous conditions. Individual variations were observed in the manifestation of the studied parameters in rat neoplastic colonic tissues. It is suggested that these differences reflect an individual sensitivity of animals to carcinogens and the magnitude of the dysplastic processes induced in the colon.

Topics: 1,2-Dimethylhydrazine; Animals; Biomarkers, Tumor; Carcinogens; Colonic Neoplasms; Deoxycholic Acid; Dimethylhydrazines; Histocytochemistry; Immunohistochemistry; Male; Methylnitronitrosoguanidine; Mitotic Index; Ornithine Decarboxylase; Peptides; Precancerous Conditions; Rats; Rats, Sprague-Dawley; Tissue Polypeptide Antigen

The initiating potential of the secondary bile acids, deoxycholic acid (DCA) and lithocholic acid (LCA), for rat hepatocarcinogenesis was investigated using the development of hyperplastic nodules and/or glutathione S-transferase placental form (GST-P)-positive liver foci as the end point. Five week old male F344 rats were given either basal diet, or diets containing 0.5% DCA or 0.5% LCA for 3 weeks in conjunction with partial hepatectomy performed midway, followed by a selection regimen consisting of 2 weeks feeding of 0.02% 2-acetylaminofluorene diet and a single gastric intubation of carbon tetrachloride. The animals were then placed on either basal diet or a diet containing 0.05% phenobarbital (PB) for 52 weeks. Significantly higher numbers of hyperplastic liver nodules developed in the DCA-treated rats irrespective of PB promotion as compared with the respective control groups. No such increase was evident in the LCA-treated rats. In contrast, both DCA and LCA treatments enhanced the development of GST-P-positive liver foci with or without subsequent PB promotion. Only one hepatocellular carcinoma was diagnosed in a control group animal. The present data indicate that a short period of feeding of DCA and LCA in the initiation stage in conjunction with partial hepatectomy results in enhanced development of preneoplastic liver lesions under selection pressure conditions with or without subsequent PB promotion. They thus confirm and extend our previous finding of enhanced gamma-glutamyltranspeptidase-positive liver foci development in a short-term assay of DCA and LCA, and suggest that these secondary bile acids either possess possible initiating activity or some other priming effect for rat hepatocarcinogenesis.

Topics: Animals; Body Weight; Deoxycholic Acid; gamma-Glutamyltransferase; Glutathione Transferase; Lithocholic Acid; Liver Neoplasms, Experimental; Male; Phenobarbital; Precancerous Conditions; Rats; Rats, Inbred F344

The effect of deoxycholic acid (DCA) treatment subsequent to initiation of F344 male rats with N-methyl-N-nitrosourea (MNU), a wide spectrum carcinogen inducing tumors in many organs, was investigated. Rats were initially given four doses of MNU (50 mg/kg) i.p. within a 2-week period combined with a two-thirds partial hepatectomy performed at day 7 and then placed on basal diet containing DCA at concentrations of 0.313, 0.125, 0.050 and 0.020% for 21 weeks prior to final sacrifice. All organs studied were carefully examined histologically and histochemically for development of neoplastic and pre-neoplastic lesions. DCA enhanced the induction of glutathione S-transferase positive (GST-P+) liver cell foci in a dose-related manner. Furthermore groups of rats given DCA without prior MNU administration also developed dose-dependent numbers of pre-neoplastic liver lesions. In addition, increased numbers of small intestine tumors were apparent in DCA-treated animals although the difference was not significant. Induction of tumors in the thyroids, Zymbal glands, skin and peripheral nerves was not affected. The results indicate that DCA is a strong promoter of hepatocarcinogenesis with possible complete carcinogenicity in the liver and promotion potential for tumor development in the small intestine.

Topics: Animals; Deoxycholic Acid; Diet; Dose-Response Relationship, Drug; Liver Neoplasms, Experimental; Male; Methylnitrosourea; Precancerous Conditions; Rats; Rats, Inbred F344

Initiating activities of the secondary bile acids, deoxycholic acid (DCA) and lithocholic acid (LCA), were examined in terms of the induction of gamma-glutamyltranspeptidase (GGT)-positive foci in rat liver. A rapid induction model of enzyme-altered foci was utilized. GGT-positive foci were clearly induced by DCA ranging from 0.05% to 0.5% in the diet. In contrast, the induction of GGT-positive foci by LCA was less pronounced and was not dose-dependent. These results suggest that DCA possesses initiating activity.

Topics: Animals; Deoxycholic Acid; Dose-Response Relationship, Drug; gamma-Glutamyltransferase; Lithocholic Acid; Liver; Liver Neoplasms, Experimental; Male; Precancerous Conditions; Rats; Rats, Inbred F344

Bile acids and cholesterol metabolites may play a role in large bowel carcinogenesis. Currently, the bile acids chenodeoxycholic (CDCA) and ursodeoxycholic acid (UDCA) are being used for dissolution of cholesterol gallstones in surgical high-risk patients. The effect of prolonged exogenous bile acid intake on rectal epithelial cell proliferation, as a marker for preneoplasia, was evaluated in 19 patients selected for treatment. They were divided into two groups: nine patients received CDCA, 15 mg/kg/day for a mean duration of 11.0 months, while 11 patients received UDCA, 10 mg/kg/day for a mean duration of 9.2 months. Rectal biopsies taken before treatment and at one, three, six, and 12 months of treatment were analyzed and evaluated by three proliferative parameters including labeling index (LI), distribution of labeled cells, and total cells per crypt column. No significant alterations in epithelial cell proliferation were observed among patients treated with UDCA or CDCA with the exception of the number of cells per crypt column which, in the latter instance, deviated only slightly from the predicted values. The lack of major persistent alterations in the proliferative behavior of rectal epithelial cells does not justify any change in the selection of patients for gallstone therapy, but cannot exclude the potentially deleterious long-term effects of bile acid treatment.

Topics: Autoradiography; Biopsy; Cell Division; Chenodeoxycholic Acid; Cholelithiasis; Deoxycholic Acid; Drug Evaluation; Epithelium; Humans; Precancerous Conditions; Rectal Neoplasms; Rectum; Time Factors; Ursodeoxycholic Acid

The effects of two agents, 12-O-tetradecanoylphorbol-13-acetate (TPA) and deoxycholic acid (DOC), which act as tumor promoters in the gastrointestinal epithelium of experimental animals, were compared using primary cultures of human premalignant colonic epithelial cells at different stages in tumor progression. Both DOC and TPA enhanced the size of the proliferative fraction in colonies of early-stage premalignant cells, with DOC providing more stimulation. TPA-treated intermediate- and late-stage premalignant cells elongated and then disrupted the monolayer by forming rills several cells in thickness and then multicellular clusters. This multilayering was reminiscent of the areas of carcinoma found within adenomas. DOC had no such effects on morphology. Cell clustering was concomitant with secretion of a protease with characteristics of a plasminogen activator. Premalignant cells secreted severalfold higher levels of protease in response to TPA than did either TPA-treated primary cultures of colonic adenocarcinomas or established colon carcinoma cell lines. These results suggest that (a) DOC and TPA act sequentially during tumor promotion and (b) cell clustering and protease release may be associated with the transition of premalignant epithelial cells to colonic carcinoma.

Topics: Cell Division; Cell Line; Cell Transformation, Neoplastic; Cells, Cultured; Colonic Neoplasms; Deoxycholic Acid; DNA Replication; Epithelium; Humans; Peptide Hydrolases; Phorbols; Plasminogen Activators; Precancerous Conditions; Protease Inhibitors; Tetradecanoylphorbol Acetate

The protein in microsomal membranes of hyperplastic nodules of livers from rats fed a diet containing 2-acetyl-aminofluorene referred to as the preneoplastic antigen has been purified to a nearly homogeneous state. A protein sharing identical immunodeterminants based on double agarose diffusion and immunoelectrophoresis has also been detected in deoxycholate-solubilized microsomes from normal liver, but it cannot be detected by gel immunodiffusion in the absence of detergent. There is approximately 4 times as much of this antigen in hyperplastic nodule microsomes as there is in normal microsomes as determined by electroimmunoassay. The antigen from nodules is not more than one-half the molecular weight of the antigen derived from normal microsomes in 0.2% deoxycholate. These findings are consistent with the hypothesis that an altered state of membranes exists in hyperplastic nodule endoplasmic reticulum, resulting in increased amounts of immunoreactive preneoplastic antigen. The nodule protein has a decreased association with its membrane matrix.

Topics: 2-Acetylaminofluorene; Animals; Antigens, Neoplasm; Deoxycholic Acid; Hyperplasia; Immunosorbent Techniques; Liver Neoplasms; Male; Microsomes, Liver; Neoplasms, Experimental; Precancerous Conditions; Rats