Promotion of adenoma growth by dietary inulin is associated with increase in cyclin D1 and decrease in adhesion proteins in Min/+ mice mucosa

Inulin-based formulations as an emerging therapeutic strategy for cancer: A comprehensive review

Cancer stands as the second leading cause of death in the United States (US). Most chemotherapeutic agents exhibit severe adverse effects that are attributed to exposure of drugs to off-target tissues, posing a significant challenge in cancer therapy management. In recent years, inulin, a naturally occurring prebiotic fiber has gained substantial attention for its potential in cancer treatment owing to its multitudinous health values. Its distinctive structure, stability, and nutritional properties position it as an effective adjuvant and carrier for drug delivery in cancer therapy. To address some of the above unmet clinical issues, this review summarizes the recent efforts towards the development of inulin-based nanomaterials and nanocomposites for healthcare applications with special emphasis on the multifunctional role of inulin in cancer therapy as a synergist, signaling molecule, immunomodulatory and anticarcinogenic molecule. Furthermore, the review provides a concise overview of ongoing clinical trials and observational studies associated with inulin-based therapy. In conclusion, the current review offers insights on the significant role of inulin interventions in exploring its potential as a therapeutic agent to treat cancer.

Metastatic Colon Cancer in an Individual Following Prolonged Daily Inulin Consumption

Studies in rodents suggest that inulin supplements may be carcinogenic. We present a case implicating that this risk extends to humans. A healthy male from a family lacking history of cancer had his first cancer-screening colonoscopy at age 56. No intestinal polyps/abnormalities were detected. A second colonoscopy, performed 7 years later, revealed a tumor in the cecum, with evidence of metastasis to lymph nodes. The only known change in patient's lifestyle during that seven-year period was the addition of 4g of inulin powder as a daily supplement during the last 2 years. Such inulin consumption is a plausible contributor to his disease.

Effect of inulin-type fructans in patients undergoing cancer treatments: A systematic review

Background and Objective

Current studies give us inconsistent results regarding the inulin consumption in cancer patients. The results of to-date studies are summarized in this systematic review.

Methods

Web of Science (Science citation index expanded), PubMed (Medline), Embase and CENTRAL Science direct, Google scholar, Scopus and Cochrane were searched. Cochrane Collaboration's 'Risk of Bias' tool was used to assess the quality of included articles.

Results

Our search yielded 2652 studies after the elimination of duplicates. Three randomized controlled trials (RCTs), reporting results from 197 patients, were eligible for inclusion in the present systematic review. Risk of bias in these studies was assessed as high and moderate.

Conclusion

The available evidence is inconclusive regarding the effect of inulin and oligofructose on cancer outcomes. Nonetheless, possible inulin positive effects including improved stool consistency after abdomen radiotherapy and increased stool butyrate content which is involved in controlling tumor cells proliferation and apoptosis should not be denied. Further research is needed in this area before strong conclusions can be drawn.

Plant stanols induce intestinal tumor formation by up-regulating Wnt and EGFR signaling in Apc Min mice

The rate of APC mutations in the intestine increases in middle-age. At the same period of life, plant sterol and stanol enriched functional foods are introduced to diet to lower blood cholesterol. This study examined the effect of plant stanol enriched diet on intestinal adenoma formation in the Apc(Min) mouse. Apc(Min) mice were fed 0.8% plant stanol diet or control diet for nine weeks. Cholesterol, plant sterols and plant stanols were analyzed from the caecum content and the intestinal mucosa. Levels of β-catenin, cyclin D1, epidermal growth factor receptor (EGFR) and extracellular signal-regulated kinase 1/2 (ERK1/2) were measured from the intestinal mucosa by Western blotting. Gene expression was determined from the intestinal mucosa using Affymetrix and the data were analyzed for enriched categories and pathways. Plant stanols induced adenoma formation in the small intestine, however, the adenoma size was not affected. We saw increased levels of nuclear β-catenin, phosphorylated β-catenin (Ser675 and Ser552), nuclear cyclin D1, total and phosphorylated EGFR and phosphorylated ERK1/2 in the intestinal mucosa after plant stanol feeding. The Affymetrix data demonstrate that several enzymes of cholesterol synthesis pathway were up-regulated, although the cholesterol level in the intestinal mucosa was not altered. We show that plant stanols induce adenoma formation by activating Wnt and EGFR signaling. EGFR signaling seems to have promoted β-catenin phosphorylation and its translocation into the nucleus, where the expression of cyclin D1 was increased. Up-regulated cholesterol synthesis may partly explain the increased EGFR signaling in the plant stanol-fed mice.

Functional foods for dyslipidaemia and cardiovascular risk prevention

A food can be regarded as ‘functional’ if it can demonstrate a beneficial efficacy on one or more target functions in the body in a convincing way. Beyond adequate nutritional qualities, functional foods should either improve the state of health and wellbeing and/or reduce the risk of disease. Functional foods that are marketed with claims of heart disease reduction focus primarily on the major risk factors, i.e. cholesterol, diabetes and hypertension. Some of the most innovative products are designed to be enriched with ‘protective’ ingredients, believed to reduce risk. They may contain, for example, soluble fibre (from oat and psyllium), useful both for lowering cholesterol and blood pressure, or fructans, effective in diabetes. Phytosterols and stanols lower LDL-cholesterol in a dose-dependent manner. Soya protein is more hypocholesterolaemic in subjects with very high initial cholesterol and recent data indicate also favourable activities in the metabolic syndrome.n-3 Fatty acids appear to exert significant hypotriacylglycerolaemic effects, possibly partly responsible for their preventive activity. Dark chocolate is gaining much attention for its multifunctional activities, useful both for the prevention of dyslipidaemia as well as hypertension. Finally, consensus opinions about tea and coffee have not emerged yet, and the benefits of vitamin E, garlic, fenugreek and policosanols in the management of dyslipidaemia and prevention of arterial disease are still controversial.

Loss of EphA2 receptor tyrosine kinase reduces ApcMin/+ tumorigenesis

The Eph receptor A2 (EphA2) is overexpressed in a range of human epithelial cancers, a phenotype that is associated with cancer cell proliferation, progression and angiogenesis. Mouse models of mammary neoplasia have confirmed the role of EphA2 as mice carrying a knockout allele of EphA2 were resistant to breast cancer, a phenotype that was associated with interactions between EphA2 and ErbB2. We investigated in vivo the role of EphA2 in GI cancer. To determine whether EphA2 influences intestinal tumorigenesis, we used qRT-PCR to examine the mRNA expression levels of EphA2 in tumors from the small intestine and colon of Apc(Min/+) mice. We found that EphA2 was significantly up-regulated in tumors from both regions when compared with normal control tissues. We then evaluated the spatial expression patterns of EphA2 protein using immunohistochemistry in both the small intestine and colon and found that in normal tissues EphA2 was robustly expressed in highly differentiated cells, such as cells of the villi, but that EphA2 expression was largely absent from the stem cell niche and proliferative zones of intestinal crypts. In contrast, in tumors EphA2 was broadly expressed. Finally, we created a strain of Apc(Min/+) mice carrying a genetic knockout of the EphA2 gene. These mice developed significantly fewer and smaller tumors in both the small and large intestine. Overall, our results indicate that EphA2 plays an oncogenic role in the mammalian intestine suggesting that strategies to target EphA2 activity may offer new therapeutic modalities for colorectal cancer.

Diet and epigenetics in colon cancer

Over the past few years, evidence has accumulated indicating that apart from genetic alterations, epigenetic alterations, through e.g. aberrant promoter methylation, play a major role in the initiation and progression of colorectal cancer (CRC). Even in the hereditary colon cancer syndromes, in which the susceptibility is inherited dominantly, cancer develops only as the result of the progressive accumulation of genetic and epigenetic alterations. Diet can both prevent and induce colon carcinogenesis, for instance, through epigenetic changes, which regulate the homeostasis of the intestinal mucosa. Food-derived compounds are constantly present in the intestine and may shift cellular balance toward harmful outcomes, such as increased susceptibility to mutations. There is strong evidence that a major component of cancer risk may involve epigenetic changes in normal cells that increase the probability of cancer after genetic mutation. The recognition of epigenetic changes as a driving force in colorectal neoplasia would open new areas of research in disease epidemiology, risk assessment, and treatment, especially in mutation carriers who already have an inherited predisposition to cancer.

Chemoprevention by white currant is mediated by the reduction of nuclear beta-catenin and NF-kappaB levels in Min mice adenomas

BACKGROUND

Berries are a good natural source of phenolic compounds and many berries or their compounds have been shown to be chemopreventive. White currant is an interesting berry, as it contains low levels of dominant berry phenolics such as ellagic acid, anthocyanins and other flavonoids.

AIMS OF THE STUDY

To study if white currant is chemopreventive in an experimental model for intestinal tumorigenesis and further study the effects on beta-catenin and NF-kappaB signaling pathways.

METHODS

Multiple intestinal neoplasia (Min) mice were fed an AIN-93G based control diet or a diet containing 10% freeze dried white currant (Ribes x pallidum) for 10 weeks. Cell signaling parameters were analysed from intestinal adenomas and surrounding mucosa by Western blotting and immunohistochemistry.

RESULTS

The white currant diet reduced the number of adenomas from 81 (min-max 47-114) to 51 (36-84) in the total small intestine of Min mice (P<0.02). Most of the adenomas develop in the distal part of the small intestine, and in this area white currant reduced the number from 49 to 29.5 (P<0.01) and also the size of the adenomas from 0.88 mm to 0.70 mm (P<0.02). In the colon white currant increased the number of adenomas (0.3+/-0.6 vs. 0.8+/-0.6, mean +/- SD, P<0.05), but did not affect the size. White currant reduced nuclear beta-catenin and NF-kappaB protein levels in the adenomas (P<0.05 and P<0.02, respectively). They were correlated with the size of adenomas (P<0.01).

CONCLUSIONS

This study shows that white currant is effective in preventing cancer initiation and progression in the Min mouse. Whether the positive effects are due to its special phenolic composition needs to be studied in more detail.

Effect of exercise on biological pathways in ApcMin/+ mouse intestinal polyps

Many epidemiological studies have demonstrated that level of exercise is associated with reduced colorectal cancer risk. Treadmill training can decrease Apc(Min/+) mouse intestinal polyp number and size, but the mechanisms remain unclear. Understanding the molecular changes in the tumor following exercise training may provide insight on the mechanism by which exercise decreases Apc(Min/+) mouse polyp formation and growth. The purpose of this study was to determine if exercise can modulate Apc(Min/+) mouse intestinal polyp cellular signaling related to tumor formation and growth. Male Apc(Min/+) mice were randomly assigned to control (n = 20) or exercise (n = 20) treatment groups. Exercised mice ran on a treadmill at a moderate intensity (18 m/min, 60 min, 6 days/wk, 5% grade) for 9 wk. Polyps from Apc(Min/+) mice were used to quantify markers of polyp inflammation, apoptosis, and beta-catenin signaling. Exercise decreased the number of macrophages in polyps by 35%. Related to apoptosis, exercise decreased the number of terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL)-positive cells by 73% in all polyps. Bax protein expression in polyps was decreased 43% by exercise. beta-Catenin phosphorylation was elevated 3.3-fold in polyps from exercised mice. Moderate-intensity exercise training alters cellular pathways in Apc(Min/+) mouse polyps, and these changes may be related to the exercise-induced reduction in polyp formation and growth.

Inulin results in increased levels of beta-catenin and cyclin D1 as the adenomas increase in size from small to large in the Min/+ mouse

The mechanism that drives the growth of some colonic adenomas towards malignancy, while permitting others to remain for decades in quiescence, remains unknown. Diets can alter the growth rate of intestinal tumours but it is still unknown whether diets are able to alter the molecular biology of these adenomas in a way that predicts further outcome. To address this issue we fed Min/+ mice with two diets known to lead to different adenoma outcomes: a high-fat control diet (n 15) or a high-fat inulin-enriched (10 % w/w) diet (n 13). To study the effect of diet on cell signalling during adenoma growth, the adenomas of each Min/+ mouse were divided into three size-categories, and the levels of beta-catenin, E-cadherin, cyclin D1 and matrix metalloproteinase-9, which are known to be involved in colon tumorigenesis, were determined. The growth-promoting inulin diet resulted in more large adenomas than the control feeding (P = 0.003) and doubled the total area of the adenomas (P = 0.008). The inulin diet increased the expression of nuclear beta-catenin (P = 0.004) and its target cyclin D1 (P = 0.017) as the adenomas increased in size from small to large, indicating the presence of an accelerated cancerous process. Neither phenomenon was seen in the control group during adenoma growth. Our results suggest that in addition to the number, size, and growth rate of adenomatous polyps, the signalling pattern of the adenomas should also be considered when evaluating preventive dietary strategies.

Three Nordic berries inhibit intestinal tumorigenesis in multiple intestinal neoplasia/+ mice by modulating beta-catenin signaling in the tumor and transcription in the mucosa

Berries contain a number of compounds that are proposed to have anticarcinogenic properties. We studied the effects and molecular mechanisms of wild berries with different phenolic profiles on intestinal tumorigenesis in multiple intestinal neoplasia/+ mice. The mice were fed a high-fat AIN93-G diet (Con) or AIN93-G diets containing 10% (w:w) freeze-dried bilberry, lingonberry (LB), or cloudberry (CB) for 10 wk. All 3 berries significantly inhibited the formation of intestinal adenomas as indicated by a 15-30% reduction in tumor number (P < 0.05). CB and LB also reduced tumor burden by over 60% (P < 0.05). Compared to Con, CB and LB resulted in a larger (P < 0.05) proportion of small adenomas (43, 69, and 64%, respectively) and a smaller proportion of large adenomas (56, 29, and 33%, respectively). Beta-catenin and cyclin D1 in the small and large adenomas and in the normal-appearing mucosa were measured by Western blotting and immunohistochemistry. CB resulted in decreased levels of nuclear beta-catenin and cyclin D1 and LB in the level of cyclin D1 in the large adenomas (P < 0.05). Early changes in gene expression in the normal-appearing mucosa were analyzed by Affymetrix microarrays, which revealed changes in genes implicated in colon carcinogenesis, including the decreased expression of the adenosine deaminase, ecto-5'-nucleotidase, and prostaglandin E2 receptor subtype EP4. Our results indicate that berries are potentially a rich source of chemopreventive components.

A mixture of prebiotic oligosaccharides reduces the incidence of atopic dermatitis during the first six months of age

BACKGROUND

Oligosaccharides may alter postnatal immune development by influencing the constitution of gastrointestinal bacterial flora.

AIMS

To investigate the effect of a prebiotic mixture of galacto- and long chain fructo-oligosaccharides on the incidence of atopic dermatitis (AD) during the first six months of life in formula fed infants at high risk of atopy.

METHODS

Prospective, double-blind, randomised, placebo controlled trial; 259 infants at risk for atopy were enrolled. A total of 102 infants in the prebiotic group and 104 infants in the placebo group completed the study. If bottle feeding was started, the infant was randomly assigned to one of two hydrolysed protein formula groups (0.8 g/100 ml prebiotics or maltodextrine as placebo). All infants were examined for clinical evidence of atopic dermatitis. In a subgroup of 98 infants, faecal flora was analysed.

RESULTS

Ten infants (9.8%; 95 CI 5.4-17.1%) in the intervention group and 24 infants (23.1%; 95 CI 16.0-32.1%) in the control group developed AD. The severity of the dermatitis was not affected by diet. Prebiotic supplements were associated with a significantly higher number of faecal bifidobacteria compared with controls but there was no significant difference in lactobacilli counts.

CONCLUSION

Results show for the first time a beneficial effect of prebiotics on the development of atopic dermatitis in a high risk population of infants. Although the mechanism of this effect requires further investigation, it appears likely that oligosaccharides modulate postnatal immune development by altering bowel flora and have a potential role in primary allergy prevention during infancy.

Nuclear factor kappaB is downregulated and correlates with p53 in the Min mouse mucosa during an accelerated tumor growth

The nuclear factor kappaB signaling pathway has gained attention for its role in the carcinogenic process. We have measured the protein levels of the p65 subunit during a growth of adenomas in the Min mouse model for colon cancer. To study how an accelerated growth of adenomas affect cell signalling, adenoma growth was increased by an inulin diet (10%) that we have shown previously to be a promotor of adenoma formation. In our study, the association between NF-kappaB, p53, beta-catenin, Fas and COX-2 were evaluated by measuring their protein levels in 9- and 15-week old Min mouse adenomas and surrounding mucosa. The amount of p65 rouse between 9- and 15-weeks in the mucosa of the control-fed mice (p = 0.032). The inulin-fed mice had less p65 in the nucleus of the mucosa at 15 weeks of age compared to the control (p = 0.064), although the adenomas were significantly larger (1.46 mm +/- 0.12 for inulin, 0.97 mm +/- 0.12 for control, p < 0.001). Nuclear p65 correlated positively with nuclear p53 in the mucosa (p < 0.001) and adenoma (p < 0.001) tissues. Also, p65 correlated positively with nuclear beta-catenin in the mucosa (p = 0.012) and the adenoma (p = 0.001). Fas expression increased in the inulin group between 9-15 weeks (p = 0.034) and correlated negatively with p65 (p = 0.03). The amount of COX-2 in the adenoma tissue increased between 9-15 weeks and did not correlate with p65. The results suggest that p65 is involved in a p53-dependent apoptotic response in the Min mouse.