Aberrant crypt foci as precursors in colorectal cancer progression

Consumption of Feed Supplemented with Oat Beta-Glucan as a Chemopreventive Agent against Colon Cancerogenesis in Rats

Colorectal cancer (CRC) accounts for 30% of all cancer cases worldwide and is the second leading cause of cancer-related deaths. CRC develops over a long period of time, and in the early stages, pathological changes can be mitigated through nutritional interventions using bioactive plant compounds. Our study aims to determine the effect of highly purified oat beta-glucan on an animal CRC model. The study was performed on forty-five male Sprague-Dawley rats with azoxymethane-induced early-stage CRC, which consumed feed containing 1% or 3% low molar mass oat beta-glucan (OBG) for 8 weeks. In the large intestine, morphological changes, CRC signaling pathway genes (RT-PCR), and proteins (Western blot, immunohistochemistry) expression were analyzed. Whole blood hematology and blood redox status were also performed. Results indicated that the histologically confirmed CRC condition led to a downregulation of the WNT/β-catenin pathway, along with alterations in oncogenic and tumor suppressor gene expression. However, OBG significantly modulated these effects, with the 3% OBG showing a more pronounced impact. Furthermore, CRC rats exhibited elevated levels of oxidative stress and antioxidant enzyme activity in the blood, along with decreased white blood cell and lymphocyte counts. Consumption of OBG at any dose normalized these parameters. The minimal effect of OBG in the physiological intestine and the high activity in the pathological condition suggest that OBG is both safe and effective in early-stage CRC.

Listen to Your Gut: Key Concepts for Bioengineering Advanced Models of the Intestine

The intestine performs functions central to human health by breaking down food and absorbing nutrients while maintaining a selective barrier against the intestinal microbiome. Key to this barrier function are the combined efforts of lumen-lining specialized intestinal epithelial cells, and the supportive underlying immune cell-rich stromal tissue. The discovery that the intestinal epithelium can be reproduced in vitro as intestinal organoids introduced a new way to understand intestinal development, homeostasis, and disease. However, organoids reflect the intestinal epithelium in isolation whereas the underlying tissue also contains myriad cell types and impressive chemical and structural complexity. This review dissects the cellular and matrix components of the intestine and discusses strategies to replicate them in vitro using principles drawing from bottom-up biological self-organization and top-down bioengineering. It also covers the cellular, biochemical and biophysical features of the intestinal microenvironment and how these can be replicated in vitro by combining strategies from organoid biology with materials science. Particularly accessible chemistries that mimic the native extracellular matrix are discussed, and bioengineering approaches that aim to overcome limitations in modelling the intestine are critically evaluated. Finally, the review considers how further advances may extend the applications of intestinal models and their suitability for clinical therapies.

Association between Probiotics and Modulation of Gut Microbial Community Composition in Colorectal Cancer Animal Models: A Systematic Review (2010-2021)

Background

Colorectal cancer (CRC) is one of the most prevalent gastrointestinal malignancies and is considered the third major cause of mortality globally. Probiotics have been shown to protect against the CRC cascade in numerous studies.

Aims

The goal of this systematic review was to gather the preclinical studies that examined the impact of probiotics on the alteration of gut microbiota profiles (bacterial communities) and their link to colorectal carcinogenesis as well as the potential processes involved.

Methods

The search was performed using Scopus, Web of Science, and PubMed databases. Five parameters were used to develop search filters: "probiotics," "prebiotics," "synbiotics," "colorectal cancer," and "animal model."

Results

Of the 399 full texts that were screened, 33 original articles met the inclusion criteria. According to the current findings, probiotics/synbiotics could significantly attenuate aberrant crypt foci (ACF) formation, restore beneficial bacteria in the microbiota population, increase short-chain fatty acids (SCFAs), and change inflammatory marker expression.

Conclusions

The present systematic review results indicate that probiotics could modulate the gut microbial composition and immune regulation to combat/inhibit CRC in preclinical models. However, where the evidence is more limited, it is critical to transfer preclinical research into clinical data.

Interaction of lncRNAs with mTOR in colorectal cancer: a systematic review

Colorectal cancer (CRC) is the third most widespread cancer and the fourth leading lethal disease among different societies. It is thought that CRC accounts for about 10% of all newly diagnosed cancer cases with high-rate mortality. lncRNAs, belonging to non-coding RNAs, are involved in varied cell bioactivities. Emerging data have confirmed a significant alteration in lncRNA transcription under anaplastic conditions. This systematic review aimed to assess the possible influence of abnormal mTOR-associated lncRNAs in the tumorigenesis of colorectal tissue. In this study, the PRISMA guideline was utilized based on the systematic investigation of published articles from seven databases. Of the 200 entries, 24 articles met inclusion criteria and were used for subsequent analyses. Of note, 23 lncRNAs were prioritized in association with the mTOR signaling pathway with up-regulation (79.16%) and down-regulation (20.84%) trends. Based on the obtained data, mTOR can be stimulated or inhibited during CRC by the alteration of several lncRNAs. Determining the dynamic activity of mTOR and relevant signaling pathways via lncRNAs can help us progress novel molecular therapeutics and medications.

Colorectal Cancer Chemoprevention: A Dream Coming True?

Colorectal cancer (CRC) is one of the deadliest forms of cancer worldwide. CRC development occurs mainly through the adenoma-carcinoma sequence, which can last decades, giving the opportunity for primary prevention and early detection. CRC prevention involves different approaches, ranging from fecal occult blood testing and colonoscopy screening to chemoprevention. In this review, we discuss the main findings gathered in the field of CRC chemoprevention, focusing on different target populations and on various precancerous lesions that can be used as efficacy evaluation endpoints for chemoprevention. The ideal chemopreventive agent should be well tolerated and easy to administer, with low side effects. Moreover, it should be readily available at a low cost. These properties are crucial because these compounds are meant to be used for a long time in populations with different CRC risk profiles. Several agents have been investigated so far, some of which are currently used in clinical practice. However, further investigation is needed to devise a comprehensive and effective chemoprevention strategy for CRC.

Role of Combination Treatment of Aspirin and Zinc in DMH-DSS-induced Colon Inflammation, Oxidative Stress and Tumour Progression in Male BALB/c Mice

Colitis-associated colorectal cancer serves as a prototype of inflammation-associated cancers which is linked with repeated cycles of inflammation and DNA repair deficits. Several preclinical and clinical data reported that aspirin has a chemo-preventive effect in colorectal cancer and is associated with dose-dependent side effects. Furthermore, it has been reported that zinc supplementation improves the quality of life in patients undergoing chemotherapy by alteration of colonic cancer cell gene expression. However, explication of the detailed molecular mechanisms involved in the combined administration of aspirin and zinc-mediated protection against colitis-associated colorectal cancer deserves further investigation. For the induction of colitis-associated colorectal cancer, male BALB/c mice were administered 1,2-dimethylhydrazine dihydrochloride (DMH) 20 mg/kg/bw thrice before the initiation of every DSS cycle (3%w/v in drinking water). One week after the initiation of DSS treatment, aspirin (40 mg/kg; p.o.) and zinc in the form of zinc sulphate (3 mg/kg; p.o.) were administered for 8 weeks. Combination of aspirin and zinc as intervention significantly ameliorated DAI score, myeloperoxidase activity, histological score, apoptotic cells and protein expression of various inflammatory markers including nuclear factor kappa light chain enhancer of activated B cells (NFκBp65), cycloxygenase-2 (COX-2) and interleukin-6 (IL-6); proliferation markers such as proliferating cell nuclear antigen (PCNA), signal transducer and activator of transcription 3 (STAT3) expression significantly decreased, and antioxidant enzymes nuclear factor erythroid 2-related factor 2 (Nrf-2), metallothionein, catalase and superoxide dismutase (SOD) significantly increased as evaluated by immunohistochemistry and western blot analysis.

Effect of Tarantula cubensis alcoholic extract on tumour pathways in azoxymethane-induced colorectal cancer in rats

The aim of this study was to determine the effects of Tarantula cubensis alcoholic extract (TCAE) on tumour development pathways in azoxymethane (AOM)-induced colorectal cancer in rats by molecular methods. Eighteen paraffin-embedded intestinal tissues, six from each group, were studied in the healthy control (C), cancer control (CC), cancer + TCAE (C-TCAE) groups. Sections of 5 µm thickness were taken from the paraffin blocks and submitted to staining with haematoxylin-eosin. In the histopathological examination, the number of crypts forming aberrant crypt foci (ACF) and the degree of dysplasia in the crypts were scored. Real-time PCR analysis was completed to determine β-catenin, KRAS (Kirsten rat sarcoma virus), APC (adenomatous polyposis coli) and P53 expressions on samples from each paraffin block. The grading scores of the number of crypts forming ACF and dysplasia in the crypts showed an evident decrease in the C-TCAE group in comparison to the CC group (P < 0.05). In real-time PCR analysis, mRNA expression levels of P53 (P > 0.05) and APC (P < 0.001) genes were found to be increased in the C-TCAE group according to the CC group. The expression levels of KRAS (P < 0.01) and β-catenin (P < 0.005) mRNA were found significantly decreased in the C-TCAE group. In conclusion, the effects of TCAE on AOM-induced colorectal cancer (CRC) in rats were evaluated molecularly; TCAE was found to modulate some changes in CRC developmental pathways, inhibiting tumour development and proliferation, and stimulating non-mutagenic tumour suppressor genes. Thus, it can be stated that TCAE is an effective chemopreventive agent.

Inhibitory Effect of Dietary Defatted Rice Bran in an AOM/DSS-Induced Colitis-Associated Colorectal Cancer Experimental Animal Model

Defatted rice bran (DRB) is gaining immense popularity worldwide because of its nutritional and functional aspects. Emerging evidence suggests that DRB is a potential source of dietary fiber and phenolic compounds with numerous purported health benefits. However, less is known about its chemoprotective efficacy. In the present study, we determined and examined the nutrient composition of DRB and its chemopreventive effect on azoxymethane and dextran sulphate sodium (AOM/DSS)-induced colitis-associated colorectal cancer (CRC) in rats. The results showed the presence of several bioactive compounds, such as dietary fiber, phytic acid, and phenolic acids, in DRB. In addition, DRB supplementation reduced the progression of CRC symptoms, such as colonic shortening, disease activity index (DAI), and histopathological changes. Interestingly, a significant decrease was observed in total numbers of aberrant crypt foci (ACFs) and tumors with DRB supplementation. Furthermore, DRB supplementation suppressed the expression of pro-inflammatory cytokines (IL-6) and inflammatory mediators (NF-κB and COX-2) through the inactivation of the NF-κB signaling pathway. The administration of DRB revealed a negative effect on cancer cell proliferation by repressing the expression of nuclear β-catenin, cyclin D1, and c-Myc. These findings suggest that DRB supplementation mitigates chronic inflammation and cancer cell proliferation and delays tumorigenesis in rat AOM/DSS-induced colitis-associated CRC. Therefore, the establishment of DRB as a natural dietary food-derived chemopreventive agent has the potential to have a significant impact on cancer prevention in the global population.

Dietary Xenobiotics Derived from Food Processing: Association with Fecal Mutagenicity and Gut Mucosal Damage

Whereas the mechanisms underlying the association of toxic dietary xenobiotics and cancer risk are not well established, it is plausible that dietary pattern may affect the colon environment by enhancing or reducing exposure to mutagens. This work aimed to investigate the association between xenobiotics intake and different stages of intestinal mucosal damage and colorectal cancer (CRC) screening and examine whether these associations may be mediated by altered intestinal mutagenicity. This was a case control study with 37 control subjects, 49 patients diagnosed with intestinal polyps, and 7 diagnosed with CRC. Lifestyle, dietary, and clinical information was registered after colonoscopy. For xenobiotics intake estimation the European Prospective Investigation into Cancer (EPIC) and the Computerized Heterocyclic Amines Resource for Research in Epidemiology of Disease (CHARRED) databases were used. The mutagenicity of fecal supernatants was assayed by the Ames test and light microscopy was used for the presence of aberrant crypt formation. Among all the potential carcinogens studied, the polyp group showed higher intakes of ethanol and dibenzo (a) anthracene (DiB(a)A). Besides, intakes between 0.75 and 1.29 µg/d of total polycyclic aromatic hydrocarbons (PAHs) were related with a higher risk of belonging to the polyp group. On the contrary, an intake of wholegrain cereals greater than 50 g/d was associated with a reduction in the relative risk of belonging to the polyp group. Heterocyclic amines (HAs) such as 2-amino-1-methyl-6-phenylimidazo (4,5,b) pyridine (PhIP) were associated with an increased level of mutagenicity in polyps. This study is of great interest for the identification of possible therapeutic targets for the early prevention of colon cancer through diet.

Caffeine and Chlorogenic Acid Combination Attenuate Early-Stage Chemically Induced Colon Carcinogenesis in Mice: Involvement of oncomiR miR-21a-5p

Colorectal cancer (CRC) is one of most common cancers worldwide, with high rates of mortality. Epidemiological findings demonstrate that coffee consumption reduces the risk of developing CRC by ~13%. In general, in vivo and in vitro findings demonstrate the antiproliferative, antioxidant and proapoptotic effects of brewed coffee or major bioavailable coffee compounds. Thus, it was assessed whether caffeine (CAF) and/or chlorogenic acid (CGA) attenuates the early-stage of chemically induced mouse colon carcinogenesis. Male Swiss mice were submitted to a 1,2-dimethylhydrazine/deoxycholic acid (DMH/DCA)-induced colon carcinogenesis model. These animals received CAF (50 mg/kg), CGA (25 mg/kg) or CAF+CGA (50 + 25 mg/kg) intragastrically for five times/week for ten weeks. CAF+CGA had the most pronounced effects on decreasing epithelial cell proliferation (Ki-67) and increasing apoptosis (cleaved caspase-3) in colonic crypts. This treatment also decreased the levels of proinflammatory cytokines IL-6, IL-17 and TNF-α, and downregulated the oncomiR miR-21a-5p in the colon. Accordingly, the analysis of miR-21a-5p targets demonstrated the genes involved in the negative regulation of proliferation and inflammation, and the positive regulation of apoptosis. Ultimately, CAF+CGA attenuated preneoplastic aberrant crypt foci (ACF) development. Our findings suggest that a combination of coffee compounds reduces early-stage colon carcinogenesis by the modulation of miR-21a-5p expression, highlighting the importance of coffee intake to prevent CRC.

Is Sunflower Cooking Oil Beneficial for Colorectal Cancer? In Vivo Studies on Azoxymethane-induced Colon Cancer in Rats

Background:

The incorporation of oils in the diet may have promoting or inhibitory effects on Colorectal Cancer (CRC). In this study, azoxymethane (AOM) was used to mimic CRC in rats, and the effect of sunflower oil on cancer progression in the colon of the rats was tested.

Objective:

This study was conducted to investigate the effect of sunflower oil on preneoplastic cancer properties of the colonic mucosal surface of tumors and the aberrant crypt foci (ACF).

Methods:

Six-week-old Sprague-Dawley male rats were randomized into 4 groups of 6 rats each, namely naïve, positive control, negative control, and sunflower oil-fed. CRC was induced by AOM by subcutaneous injection of 20 mg/kg. After CRC induction, the rats were given the respective treatment of either basal diet (naïve group), 10 mg/kg indomethacin (positive control), 0.9 % saline (negative control), or 7 % sunflower oil (experimental group) daily by oral gavage for 42 days. Rats were sacrificed by cervical dislocation; colon samples were visually observed for any tumors on the colonic mucosal surface and evaluated for ACF; histopathological examinations were also performed.

Results:

The mean body weights of the rats were similar in all groups as per one-way ANOVA. A total of 3 ACF were found in the negative group, while none were observed in other groups. The crypts appeared regular with circular luminal openings and were closely packed together in the naïve group. Crypts in the positive and treated group had a similar appearance to the naïve group.

Conclusion:

Sunflower oil inhibition of the preneoplastic cancer ACF properties were tested but were found to be insignificant when administered during CRC treatment or management. However, long-term experiments with a greater number of days will yield better development of tumor and ACF development and will be useful in identifying the molecular mechanism.

Transcriptomic and proteomic insights into patulin mycotoxin-induced cancer-like phenotypes in normal intestinal epithelial cells

Patulin (PAT) is a natural contaminant of fruits (primarily apples) and their products. Significantly, high levels of contamination have been found in fruit juices all over the world. Several in vitro studies have demonstrated PAT's ability to alter intestinal structure and function. However, in real life, the probability of low dose long-term exposure to PAT to humans is significantly higher through contaminated food items. Thus, in the present study, we have exposed normal intestinal cells to non-toxic levels of PAT for 16 weeks and observed that PAT had the ability to cause cancer-like properties in normal intestinal epithelial cells after chronic exposure. Here, our results showed that chronic exposure to low doses of PAT caused enhanced proliferation, migration and invasion ability, and the capability to grow in soft agar (anchorage independence). Moreover, an in vivo study showed the appearance of colonic aberrant crypt foci (ACFs) in PAT-exposed Wistar rats, which are well, establish markers for early colon cancer. Furthermore, as these neoplastic changes are consequences of alterations at the molecular level, here, we combined next-generation RNA sequencing with liquid chromatography mass spectrometry-based proteomic analysis to investigate the possible underlying mechanisms involved in PAT-induced neoplastic changes.

Ameliorative effect of fluvoxamine against colon carcinogenesis via COX-2 blockade with oxidative and metabolic stress reduction at the cellular, molecular and metabolic levels

Fluvoxamine's (FLX's) anticancer potential was investigated in pre-clinical research utilizing a DMH-induced colorectal cancer (CRC) rat model. qRT-PCR and immunoblotting validated the mechanistic investigation. The CRC condition was induced in response to COX-2 and IL-6, however, following FLX therapy, the condition returned to normal. FLX's anti-CRC potential may be attributable to COX-2 inhibition since this molecular activity was more apparent for COX-2 than IL-6. FLX repaired the altered metabolites linked to CRC rats, according to ¹H-NMR analysis. FLX was shown to be similar to 5-FU in terms of tumor protection, which may be useful in future medication development.

Amelioration of DMH-induced colon cancer by eupafolin through the reprogramming of apoptosis-associated p53/Bcl2/Bax signaling in rats

Introduction: Colorectal cancer is the third most common malignancy and the second most deadly cancer worldwide. In this present study, the effects of eupafolin on DMH-induced colon cancer in rats were assessed.

Methods: The acute and sub-acute oral toxicity study in the balb/c mice was performed to evaluate the LD50 dose and the chemotherapeutic doses of eupafolin. The colon cancer was induced in the animals through a single intraperitoneal injection (i.p) of 30 mg/kg of dimethylhydrazine followed by 2% DSS for 7 days in the drinking water in male Wistar rats. The rats were treated with eupafolin (50, 100, and 200 mg/kg) through oral route for 18 weeks. The animals were sacrificed and colon tissues were subsequently investigated for aberrant crypt foci (ACF), in vivo antioxidant studies, histology and immunohistochemical analysis, and apoptosis by TUNNEL technique after 18 weeks of eupafolin therapy.

Results: The acute oral toxicity data represented the LD50 dose of eupafolin which was found to be 500 mg/kg body weight. Along with that, the sub-acute toxicity study suggested the chemotherapeutic doses of eupafolin, that is, 50, 100, and 200 mg/kg body weight. Eupafolin therapy inhibits ACF development in rat colon mucosa efficiently. Additionally, eupafolin has improved the colonic lesions and the structural integrity of the colonic mucosa. Eupafolin therapy causes anti-oxidant enzymes such as superoxide dismutase, catalase, and glutathione to increase as well. Increased levels of P53, BAX, and PCNA and a simultaneous decrease in Bcl2 and IL-6 expressions show eupafolin therapy successfully regulated these biological markers in colorectal cancer. Eupafolin also induced apoptosis efficiently in the rat colon mucous membrane.

Conclusion: These results show that eupafolin can improve colon cancer by modulating the p53, Bcl2, BAX, and IL-6 pathways in rats.

Antitumor and hepatoprotective effect of Cuscuta reflexa Roxb. in a murine model of colon cancer

ETHNOPHARMACOLOGICAL RELEVANCE

Cuscuta reflexa Roxb. (C. reflexa) is a well-known traditional herbal plant, with numerous inherent therapeutic potentials including anticancer, antitumor, antibacterial, analgesic, anthelmintic, laxative and others. Moreover, the anticancer and antitumor potentials of this herb are ongoing with several trails, thus an attempt was made to assess the anticancer and hepatoprotective potentials of traditional C. reflexa herbs.

METHOD

The dried ethanolic extract of C. reflexa was tested for acute oral toxicity in the treated animals subsequently their behavioral, neurological, and autonomic profiles changes were observed. The preliminary anti-cancer effects of extracts against 1, 2- Dimethyl hydrazine (DMH) induced animals were assessed through barium enema X-ray, colonoscopy, and Aberrant crypt foci (ACF) studies. The blood samples of the animals (treated and untreated) were collected and their in-vitro histological parameters were evaluated by the experienced technician.

RESULTS

It was observed that C. reflexa significantly reduced Disease activity indexing (DAI) level and ACF counting, as well as demonstrated similar activity as of the standard drug 5-Fluorouracil (5-FU). Histopathological results revealed that the apoptotic bodies decreased in the DMH-induced group (group II) during cancer progression while in 5-FU treated (group III) and C. reflexa treated (group IV and V) animals the apoptotic bodies were increased. Inversely, the mitotic bodies increased in group II animals and reduced in group III, IV, and V animals. In the colonic section, DMH-induced cancer assay exhibited significant effects on the levels of hemoglobin, Packed cell volume (PCV), Red blood cell (RBC) counts, Mean corpuscular hemoglobin concentration (MCHC), Mean corpuscular volume (MCV), and Mean cell hemoglobin (MCH), and was found to be less in group II animals whereas administration of C. reflexa efficiently recovered back the loss probably by healing the colon damage/depletion of cancer progression. Moreover, compared to the group II animals, the neutrophil count was within the normal range in C. reflexa administered group.

CONCLUSIONS

In the present study, the major hematological parameters significantly increased within DMH treated animals and exhibited extensive damage in the hepatic regions. Moreover, the histopathological findings demonstrated that the C. reflexa extracts potentially reduced the cell proliferation, with no toxicity. The C. reflexa extracts exhibited impending anti-cancer activity as well as protected the hepatic cells and thus could be potentially used in the management of colon or colorectal cancer and hepatic impairments.

Harmol alleviates dimethylhydrazine induced colon cancer by downregulating Bcl2/IL-6/TNF-α expression in association with p53 mediated apoptosis

Objectives: Colorectal cancer is the world’s third most prevalent cancer. Herbal drugs are increasingly being used to treat a variety of disorders, including cancer, due to the severe adverse effects. Harmol, natural molecule containing β-carboline alkaloids, has aroused the interest of researchers due to its diverse biological functions, including anticancer properties. Methods: In this study, the chemotherapeutic effects of harmol have been investigated on HT-29 colon cancer cell line and a rat model of colon cancer. In the in vitro study the cytotoxicity assay, DAPI analysis and the flow cytometric analysis was performed to assess the anticancer efficacy of harmol in HT-29 cell. The colorectal cancer was developed in male Wistar rats through the administration of DMH followed by treatment with DSS. The rats were treated with harmol (100, 200 and 400 mg/kg) for 18 weeks. At the end of therapy, the colon tissues were assessed for ACF, in vivo antioxidant activity, histopathology, immunohistochemistry, immunofluorescence analysis and apoptosis assay. Results: The in vitro data suggested that the harmol therapy would significantly increase the percentage of early apoptosis in HT-29 cells through halting of G0/G1 phase. Furthermore, inhibition of ACF development with improved colonic abrasion and morphological features in colonic mucosal region were noted. Harmol treatment also increased the levels of antioxidants and p53 and downregulated Bcl2, IL-6 and TNF-α expression. Conclusion: These outcomes signify that harmol successfully recover colorectal carcinoma by reprogramming the p53, Bcl2, IL-6 and TNF-α pathway in rats.

Promising effects of gingerol against toxins: A review article

Ginger is a medicinal and valuable culinary plant. Gingerols, as an active constituent in the fresh ginger rhizomes of Zingiber officinale, exhibit several promising pharmacological properties. This comprehensive literature review was performed to assess gingerol's protective and therapeutic efficacy against the various chemical, natural, and radiational stimuli. Another objective of this study was to investigate the mechanism of anti-inflammatory, antioxidant, and antiapoptotic properties of gingerol. It should be noted that the data were gathered from in vivo and in vitro experimental studies. Gingerols can exert their protective activity through different mechanisms and cell signaling pathways. For example, these are mitogen-activated protein kinase (MAPK), nuclear factor-kappa B (NF-kB), Wnt/β-catenin, nuclear factor erythroid 2-related factor 2/antioxidant response element (Nrf2/ARE), transforming growth factor beta1/Smad3 (TGF-β1/Smad3), and extracellular signal-related kinase/cAMP-response element-binding protein (ERK/CREB). We hope that more researchers can benefit from this review to conduct preclinical and clinical studies, treat cancer, inflammation, and attenuate the side effects of drugs and industrial pollutants.

Selenium and the 15kDa Selenoprotein Impact Colorectal Tumorigenesis by Modulating Intestinal Barrier Integrity

Selenoproteins play important roles in many cellular functions and biochemical pathways in mammals. Our previous study showed that the deficiency of the 15 kDa selenoprotein (Selenof) significantly reduced the formation of aberrant crypt foci (ACF) in a mouse model of azoxymethane (AOM)-induced colon carcinogenesis. The objective of this study was to examine the effects of Selenof on inflammatory tumorigenesis, and whether dietary selenium modified these effects. For 20 weeks post-weaning, Selenof-knockout (KO) mice and littermate controls were fed diets that were either deficient, adequate or high in sodium selenite. Colon tumors were induced with AOM and dextran sulfate sodium. Surprisingly, KO mice had drastically fewer ACF but developed a similar number of tumors as their littermate controls. Expression of genes important in inflammatory colorectal cancer and those relevant to epithelial barrier function was assessed, in addition to structural differences via tissue histology. Our findings point to Selenof's potential role in intestinal barrier integrity and structural changes in glandular and mucin-producing goblet cells in the mucosa and submucosa, which may determine the type of tumor developing.

The chemopreventive effects of Huangqin-tea against AOM-induced preneoplastic colonic aberrant crypt foci in rats and omics analysis

Despite that colorectal cancer (CRC) is a severe global health problem, effective chemopreventive strategies against CRC are still lacking. Huang-qin tea (HQT), a healthy herbal tea, is prepared from the aerial parts of Scutellaria baicalensis Georgi and has been consumed in China for thousands of years. HQT contains abundant flavonoids, which display potent anticancer effects, but no research studies have investigated the cancer-preventive effects of HQT on CRC in vivo. Here, we found that HQT inhibits azoxymethane-induced aberrant crypt foci (ACF) formation in a preneoplastic colonic ACF rat model. The essential role of the gut microbiota in the chemopreventive effect of HQT on CRC in a pseudo-germ-free rat model was confirmed. Besides, HQT modulates inflammatory cytokine expression by significantly decreasing IL-1β, IL-6, IL-10, and TNF-α expression, and elevating IFN-γ production. 16S rDNA sequencing analysis indicated that HQT regulated the gut microbiota by increasing the abundance of beneficial bacteria (Lachnoclostridium, Alistipes, Roseburia, and Lactococcus) and reducing the levels of Bacteroides, Parasutterella, and unidentified_Clostridiales. Fecal metabolomics showed that HQT modulated the AOM-induced metabolomic disorder, and these altered metabolites were almost involved in the lipid metabolic pathways. The Spearman correlation analysis revealed a correlation between the gut microbiota and fecal metabolites. Collectively, these results suggested that HQT exerted beneficial effects on host health by inhibiting inflammation, and by regulating the gut microbiota profile and certain metabolic pathways. In conclusion, HQT inhibits AOM-induced ACF formation by modulating the gut microbiota composition and improving metabolomic disorders, indicating the potential of HQT as a functional beverage candidate for the prevention and treatment of CRC.

Identification of key candidate genes and pathways associated with colorectal aberrant crypt foci-to-adenoma-to-carcinoma progression

AIM

The present study aimed to detect key candidate genes and pathways involved in colorectal aberrant crypt foci-to-adenoma-to-carcinoma progression.

BACKGROUND

Although colorectal cancer (CRC) is the third most common type of cancer, the involved signaling pathways and driver-genes remain largely unclear. CRC begins with the malignant transformation of precancerous lesions including aberrant crypt foci (ACF) and benign adenomatous polyp or adenoma.

METHODS

A list of formerly reported ACF, adenoma, and CRC-associated proteins was obtained from GeneCards, and then the data in online David Bioinformatics Resources was analyzed. The protein-protein interactions were surveyed utilizing String database and Cytoscape software. After hubs and bottlenecks were recognized, the key genes and pathways were identified through different bioinformatics analysis.

RESULTS

The most important pathways associated with colorectal aberrant crypt foci-to-adenoma progression were attributed to "pathways in cancer" and "chemokine signaling pathway" and those in adenoma-to-carcinoma progression were related to "pathways in cancer," "chemokine signaling pathway," and "Ras signaling pathway." The genes participating in these pathways are key ones. Furthermore, PRKACB, CUL2, and GSK3B were significant as the seed in the clusters related to adenoma and GNB1, RALBP1, ROCK1, and IKBKG in the clusters related to cancer.

CONCLUSION

The key candidate genes and pathways in progress CRC formed precursor lesions were identified by integrated bioinformatics analysis. The results could lead to a better understanding of the cause and underlying molecular events as well as detection of therapeutic targets for CRC.

The Effect of Smoking on the Number and Type of Rectal Aberrant Crypt Foci (ACF)-First Identifiable Precursors of Colorectal Cancer (CRC)

Background: The problem of smoking and its influence on the occurrence of precursors and advanced colorectal cancer is often discussed in the medical literature. Tobacco smoke can provide a non-nutritional source of polycyclic hydrocarbons and other substances which, when combined with an incorrect diet, may play a role in promoting carcinogenesis at the level of the genetic control mechanism. The aim of our study was to assess the effect of smoking on the frequency and type of aberrant crypt foci (ACF) in the rectum and polyps in the large intestine in people who smoke more than 20 cigarettes a day for more than 20 years. Methods and Findings: A colonoscopy combined with rectal mucosa staining with 0.25% methylene blue was performed in 131 patients. Each of the study participants gave informed consent to participate in the study. Three bioptates were collected from the foci defined macroscopically as ACF; in cases where there were fewer foci, the number of collected foci was respectively lower. On the colonoscopy day, patients completed the questionnaire regarding epidemiological data used for analysis of factors affecting the occurrence of ACF in the study group. The number of ACF in the colon was divided into three groups: −ACF < 5, 5 < ACF < 10, ACF > 10. In the statistical analysis, numerical data were presented and real numbers, range of arrhythmic means, mean standard deviation, and results of probability distribution. The Student’s test, U test, and chi2 were applied in order to determine the significance of differences of means and frequency of events in both groups. The level of significance was set at α = 0.05. Statistica 7.1 and Excel 2010 were used. Most smokers are in the age groups between 51–70 years. In the youngest (31–40 years), single ACF appear first (ACF <5) ACF in the number of 5–10 appear a little later (around 50 years of age) and dynamically increase, reaching a maximum at the age of 60–65.ACF in the number >10 appear at the latest age (55 years old) and their number gradually increases with age (linear growth). The probability of occurrence of ACF in all groups is greater in smokers, and the difference for the ACF group 5-10 and ACF >10 is statistically significant with a significance level of p < 0.05. Apart from ACF normal, all types of ACF are more likely in this group than in non-smokers and these differences are statistically significant with p < 0.05. Conclusions: Smoking has a significant impact on the number and type of rectal ACF. Smokers have a greater number of ACFs in the rectum than non-smokers, and the most common type is hyperplastic ACF. Smokers are more likely to develop polyps in all sections of the colon compared to non-smokers.

Early stage colon cancer: Current treatment standards, evolving paradigms, and future directions

Colon cancer continues to be one of the leading causes of mortality and morbidity throughout the world despite the availability of reliable screening tools and effective therapies. The majority of patients with colon cancer are diagnosed at an early stage (stages I to III), which provides an opportunity for cure. The current treatment paradigm of early stage colon cancer consists of surgery followed by adjuvant chemotherapy in a select group of patients, which is directed at the eradication of minimal residual disease to achieve a cure. Surgery alone is curative for the vast majority of colon cancer patients. Currently, surgery and adjuvant chemotherapy can achieve long term survival in about two-thirds of colon cancer patients with nodal involvement. Adjuvant chemotherapy is recommended for all patients with stage III colon cancer, while the benefit in stage II patients is not unequivocally established despite several large clinical trials. Contemporary research in early stage colon cancer is focused on minimally invasive surgical techniques, strategies to limit treatment-related toxicities, precise patient selection for adjuvant therapy, utilization of molecular and clinicopathologic information to personalize therapy and exploration of new therapies exploiting the evolving knowledge of tumor biology. In this review, we will discuss the current standard treatment, evolving treatment paradigms, and the emerging biomarkers, that will likely help improve patient selection and personalization of therapy leading to superior outcomes.

Rectal aberrant crypt foci (ACF) as a predictor of benign and malignant neoplastic lesions in the large intestine

Background

The importance of ACF is not fully explained, however, their number may be a good predictor of synchronous and metachronic adenoma or other polyps whose removal reduces the risk of CRC. Due to the epidemiological and genetic association of ACF with pre-cancer lesions, they may be a potential CRC biomarker. The aim of our study was to show that the number and type of rectal ACF may be a good predictive factor for the presence of polyps located proximally from the splenic flexure and that the type and number of ACF can correlate with the number and specific types of polyps in the large intestine.

Methods

The study included 131 patients who underwent colonoscopy combined with rectal mucosa staining with 0.25% methylene blue. The number of rectal ACF was determined and bioptats were sampled for histopathological examination to assess the type of ACF. Endoscopic ACF assessment criteria given by L. Roncucci were used. The obtained material was subjected to statistical analysis using probability distribution, U-test, t-student test, and chi ² as well as the Statistica 7.1 software package.

Results

The study population was divided into three subgroups according to the number of ACF observed, i.e. ACF < 5, 5–10 and > 10. ACF < 5 were found in 35 patients (29.41%), 5–10 ACF in 70 (58.82%) and ACF > 10 in 14 individuals (11.76%).

The study revealed the presence of normal ACF (p = 0.49), hyperplastic ACF (p = 0.34), dysplastic ACF (p = 0.11), and mixed ACF (p = 0.06). A single type of ACF was most commonly observed (n = 88, p = 0.74). In the researched group a larger number of ACF is concurrent with adenomas and hyperplastic polyps. The number of ACF clearly correlates with the dysplasia advancement in the adenoma and the number of polyps found.

Conclusions

Rectal ACF are a useful marker for the presence of cancerous lesions in the proximal and distal sections of the large intestine.

Efficacy of Difluoromethylornithine and Aspirin for Treatment of Adenomas and Aberrant Crypt Foci in Patients with Prior Advanced Colorectal Neoplasms

Difluoromethylornithine (DFMO), an inhibitor of polyamine synthesis, was shown to act synergistically with a NSAID for chemoprevention of colorectal neoplasia. We determined the efficacy and safety of DFMO plus aspirin for prevention of colorectal adenomas and regression of rectal aberrant crypt foci (ACF) in patients with prior advanced adenomas or cancer. A double-blinded, placebo-controlled trial was performed in 104 subjects (age 46-83) randomized (1:1) to receive daily DFMO (500 mg orally) plus aspirin (325 mg) or matched placebos for one year. All polyps were removed at baseline. Adenoma number (primary endpoint) and rectal ACF (index cluster and total) were evaluated at a one year colonoscopy. ACF were identified by chromoendoscopy. Toxicity was monitored, including audiometry. Eighty-seven subjects were evaluable for adenomas or ACF modulation (n = 62). At one year of treatment, adenomas were detected in 16 (38.1%) subjects in the DFMO plus aspirin arm (n = 42) versus 18 (40.9%) in the placebo arm (n = 44; P = 0.790); advanced adenomas were similar (n = 3/arm). DFMO plus aspirin was associated with a statistically significant reduction in the median number of rectal ACF compared with placebo (P = 0.036). Total rectal ACF burden was also reduced in the treatment versus the placebo arm relative to baseline (74% vs. 45%, P = 0.020). No increase in adverse events, including ototoxicity, was observed in the treatment versus placebo arms. While adenoma recurrence was not significantly reduced by one year of DFMO plus aspirin, the drug combination significantly reduced rectal ACF number consistent with a chemopreventive effect.

Preventive Effect of an Infusion of the Aqueous Extract of Chaya Leaves (Cnidoscolus aconitifolius) in an Aberrant Crypt Foci Rat Model Induced by Azoxymethane and Dextran Sulfate Sodium

Aberrant crypt foci (ACF) is the precursor lesion of colorectal carcinogenesis (CRC), one of the most common malignancies in the world. Many studies have reported that people with higher phytochemical intake are at a reduced risk of developing ACF. One example of the botanical potential of preventive plant products is Cnidoscolus aconitifolius (CA), commonly known as Chaya. This study evaluated the phenolic profile of CA and the effects of the daily consumption of CA leaf infusion on the formation of ACF, histopathological lesions, and molecular biomarkers after azoxymethane (AOM) and dextran sulfate sodium (DSS) induced premalignant colon lesions in rats treated with for 16 and 32 weeks. The phenolic composition of the CA infusion was identified by reversed phase-high performance liquid chromatography-diode array detection (RP-HPCC-DAD). After sacrifice, a 4 cm segment was collected from the distal part of the colon and stained with methylene blue to look for ACF. Furthermore, 4 μm of colon, liver, and kidney was collected and stained with hematoxylin and eosin for histopathological analysis, along with 7 μm of colon for immunohistochemistry analysis. Eleven phenolic compounds were identified in the infusions, and ACF formation was reduced by 29.5% at the subchronic and by 64.6% at chronic stages. Lesions on kidney, liver, and colon tissue were also reduced. Our data suggest that CA treatment has preventive effects against AOM-/DSS-induced premalignant colon lesions in colon rats at the promotion level, inhibiting the cell proliferation of early neoplastic lesions and colonic inflammation through the decrease of β-catenin by 41.8% at the subchronic stage and 29% at the chronic stage, along with a 46.2% reduction of cyclooxygenase 2 (COX-2) at long term, despite a high expression of NF-κB (30.3% at the subchronic stage and 22.8% at the chronic stage).

Chemopreventive efficacy zingerone (4-[4-hydroxy-3-methylphenyl] butan-2-one) in experimental colon carcinogenesis in Wistar rats

Colorectal cancer is one of the most common cancers worldwide. Development of naturally occurring inexpensive and safe alternatives can be effective in suppressing colon related proliferations. Zingerone (4-[4-hydroxy-3-methylphenyl] butan-2-one), a polyphenolic alkanone of ginger, has massive pharmacological properties and thus can be used as promising candidate against various ailments. In the current study, we aimed at demonstrating the protective effect of zingerone against experimental colon carcinogenesis and elucidating its possible mechanism by studying inflammatory and Nrf-2 signaling cascade. Four groups of animals (I-IV) were made with six animals each. Group I (control) was given normal saline orally. Group II was given 1,2-dimethylhydrazine (DMH) at the dose rate of 20 mg/kg body weight. Group III and IV were treated with DMH at the dose rate of 20 mg/kg body weight and also received oral treatment of zingerone at a dose rate of 50 and 100 mg/kg body weight, respectively, for first 5 weeks and animals were euthanized after 16 weeks. Our results reveal that DMH treated rats exhibited elevated ROS and MDA levels, increased activity of cytochrome P450 2E1 and serum marker enzyme carcinoembreyonic antigen (CEA), increased no of aberrant crypts of foci (ACF), and elevated expression of inflammatory and proliferative proteins. Nrf-2 was downregulated by DMH treatment. Treatment with zingerone to DMH treated rats, resulted in alterations in the activity of the cytochrome P450 2E1 and CEA. In addition, immunostaining of NF-kB-p65, COX-2, iNOS, and PCNA, Ki-67 was suppressed by zingerone. Furthermore, zingerone administration also attenuated the level of IL-6 and TNF-α and it also helps in preserving mucous layer. Thus, zingerone could be considered as a good chemopreventive agent in experimental model of colon carcinogenesis. Further studies are required to study other pathways involved in colon carcinogenesis and their modulation buy zingerone.

Proximal Aberrant Crypt Foci Associate with Synchronous Neoplasia and Are Primed for Neoplastic Progression

Aberrant crypt foci (ACF) are the earliest morphologically identifiable lesion found within the human colon. Despite their relatively high frequency in the distal colon, few studies have examined the molecular characteristics of ACF within the proximal colon. In the following study, clinical participants (n = 184) were screened for ACF using high-definition chromoendoscopy with contrast dye-spray. Following pathologic confirmation, ACF biopsies were subjected to laser capture microdissection (LCM), and epithelial cells were evaluated for somatic mutations with a customized colorectal cancer mutation panel using DNA-mass spectrometry. Samples were further characterized for microsatellite instability (MSI). Logistic models were used to associate proximal ACF with synchronous (detected during the same procedure) neoplasia. Thirty-nine percent of participants had at least one histologically confirmed proximal ACF. Individuals with a proximal ACF were significantly more likely to present with a synchronous neoplasm (P = 0.001), and specifically, a proximal, tubular, or tubulovillous adenoma (multivariable OR = 2.69; 95% confidence interval, 1.12-6.47; P = 0.027). Proximal ACF were more likely to be dysplastic (52%) compared with distal ACF (13%; P < 0.0001). Somatic mutations to APC, BRAF, KRAS, NRAS, and ERBB2 were detected in 37% of proximal ACF. Hyperplastic ACF were more often MSI-high, but there were no differences in MSI status observed by colonic location. In summary, ACF are identified in the proximal colons of approximately 40% of individuals undergoing chromoendoscopy and more often in patients with synchronous proximal adenomas.Implications: This study provides the most complete set of data, to date, that ACF represent the earliest step in the adenoma-carcinoma sequence but remain below the detection limit of conventional endoscopy.Visual Overview: http//mcr.accrjournals.org/content/molcanres/16/3/486/F1.large.jpg Mol Cancer Res; 16(3); 486-95. ©2017 AACR.

Fish Oil Contaminated with Persistent Organic Pollutants Induces Colonic Aberrant Crypt Foci Formation and Reduces Antioxidant Enzyme Gene Expression in Rats

Background: Epidemiologic, clinical, and experimental studies have suggested that fish oil (FO), a rich source of n-3 (ω-3) polyunsaturated fatty acids, protects against colon cancer. However, this message is confounded by the FDA's warning that the consumption of certain types of fish should be restricted because of contamination with persistent organic pollutants (POPs), such as polychlorinated biphenyls (PCBs) and organochlorine pesticides.Objective: We examined FO contaminated with POPs (PCBs, dichlorodiphenyltrichloroethane, and chlordane) compared with unmodified FO on the risk factors of colon cancer development.Methods: Male Sprague-Dawley rats aged 28 d (n = 30) were allocated into 3 groups and fed 15% corn oil (CO), FO, or POP-contaminated FO for 9 wk with a subcutaneous injection of colon carcinogen azoxymethane at weeks 3 and 4. Colonic aberrant crypt foci (ACF) and cell proliferation were enumerated, and the gene expression of inflammation, antioxidant enzymes, and repair enzymes were determined with the use of real-time quantitative polymerase chain reaction analysis.Results: FO-fed rats had a lower number of ACF (mean ± SE: 29 ± 4.0 for FO compared with 53 ± 8.4 for CO and 44 ± 4.6 for POP FO) and higher-multiplicity ACF than the CO and POP FO groups (4.7 ± 0.9 for FO compared with 11 ± 1.5 for CO and 9.6 ± 1.8 for POP FO) (P < 0.05). FO feeding lowered the proliferation index compared with the CO and POP FO feeding groups (18% ± 1.1% for FO compared with 25% ± 1.6% for CO and 23% ± 0.7% for POP FO) (P = 0.009). Superoxide dismutase [2.4 ± 0.6 relative quantification (RQ) for FO compared with 1.2 ± 0.2 RQ for CO and 1.3 ± 0.3 RQ for POP FO] and catalase gene expression (10 ± 2.0 RQ for FO compared with 5.4 ± 1.1 RQ for CO and 6.6 ± 1.5 RQ for POP FO) were higher in the FO group than in the CO and POP FO groups (P < 0.05). There were no differences between CO and POP FO on the variables.Conclusion: These results indicate that POPs in FO reduce the preventive effects of FO on colon carcinogenesis by increasing preneoplastic lesion formation through the downregulation of antioxidant enzyme expression and increasing cell proliferation in rats.

Bladder carcinogenesis in rats subjected to ureterosigmoidostomy and treated with L-lysine

OBJECTIVE

to evaluate the effect of L-lysine in the bladder and intestinal epithelia in rats submitted to vesicosigmoidostomy.

METHODS

we divided forty Wistar rats into four groups: group I - control group (Sham); group II - submitted to vesicosigmoidostomy and treated with L-lysine 150mg/kg; group III - submitted only to vesicosigmoidostomy; and group IV - received L-lysine 150mg/kg. After eight weeks the animals were sacrificed.

RESULTS

in the bladders of all operated animals we observed simple, papillary and nodular hyperplasia of transitional cells, transitional cell papillomas and squamous metaplasia. As for the occurrence of aberrant crypt foci in the colons of operated animals, we did not observe statistically significant differences in any of the distal, proximal and medium fragments, or in all fragments together (p=1.0000).

CONCLUSION

Although statistically there was no promotion of carcinogenesis in the epithelia of rats treated with L-lysine in the observed time, it was clear the histogenesis of bladder carcinogenesis in its initial phase in all operated rats, this being probably associated with chronic infection and tiny bladder stones.

OBJETIVO

o objetivo deste trabalho é avaliar o efeito da L-lisina nos epitélios vesical e intestinal de ratas submetidas à vesicossigmoidostomia.

MÉTODOS

quarenta ratas Wistar, foram divididas em quatro grupos: grupo I- grupo controle (Sham); grupo II- submetido à vesicossigmoidostomia e tratado com L-lisina 150mg/kg; grupo III- submetido apenas à vesicossigmoidostomia; e grupo IV- recebeu L-lisina 150mg/kg. Após oito semanas os animais foram sacrificados.

RESULTADOS

na bexiga de todos os animais operados observou-se hiperplasia simples, papilar e nodular de células transicionais, papiloma de células transicionais e metaplasia escamosa. Quanto à ocorrência de focos de criptas aberrantes nos colos dos animais operados, não foi evidenciado diferença estatística significante em nenhum dos fragmentos distal, proximal e médio, e todos juntos (P=1,0000).

CONCLUSÃO

apesar de, estatisticamente, não ter havido promoção de carcinogênese nos epitélios dos ratos tratados com L-lisina, no tempo observado, é nítida a histogênese da carcinogênese de bexiga em sua fase inicial, no epitélio vesical, em todos os ratos operados, estando esta provavelmente associada à infecção crônica e aos diminutos cálculos vesicais.

Detection and characterization of oncogene mutations in preneoplastic and early neoplastic lesions

While it has been nearly 30 years since its discovery, the ras family of genes has not yet lost its impact on basic and clinical oncology. These genes remain central to the field of molecular oncology as tools for investigating carcinogenesis and oncogenic signaling, as powerful biomarkers for the identification of those who have or are at high risk of developing cancer, and as oncogene targets for the design and development of new chemotherapeutic drugs. Mutational activation of the K-RAS proto-oncogene is an early event in the development and progression of the colorectal, pancreatic, and lung cancers that are the major causes of cancer death in the world. The presence of point mutational "hot spots" at sites necessary for the activation of this proto-oncogene has led to the development of a number of highly sensitive PCR-based methods that are feasible for the early detection of K-RAS oncogene mutations in the clinical setting. In light of these facts, mutation at the K-RAS oncogene has the potential to serve as a useful biomarker in the early diagnosis and risk assessment of cancers with oncogenic ras signaling. This chapter describes a highly sensitive method for detecting mutant K-RAS, enriched PCR, and its application to early detection of alterations in this oncogene in preneoplastic and early neoplastic lesions of the colon and rectum.

Predictive value of rectal aberrant crypt foci for intraepithelial neoplasia in ulcerative colitis - a cross-sectional study

BACKGROUND

Ulcerative colitis (UC) is associated with an increased risk of colorectal cancer (CRC). Aberrant crypt foci (ACF) are important biomarkers of sporadic CRC risk. Their correlation with the risk of intraepithelial neoplasia (IN) in UC remains unclear.

AIMS

To assess whether ACF are a risk factor for IN in long-standing UC and to investigate any correlation between the clinico-epidemiological characteristics and prevalence/number of ACF in these patients.

METHODS

Seventy-six patients with long-standing UC were prospectively screened by colonoscopy with chromoendoscopy-guided endomicroscopy. ACF were sought in the lower rectum.

RESULTS

Eight INs were detected in seven (9.2%) patients. The ACF prevalence and mean number were 60.5% and 2.4 ± 2.8, respectively. The number of ACF was independently associated with the risk of having IN (odds ratio = 1.338; 95% confidence interval 1.030-1.738). ACF number revealed a good calibration (area under the receiver operating characteristic curve = 0.829) and discriminative ability (p = 0.205, Hosmer-Lemeshow test) for the prediction of synchronous IN. Patients with ≥3 ACF have a significantly higher prevalence of IN than patients with <3 ACF (22.6% vs. 0%, p = 0.001). Using this cut-off value, the performance of ACF in predicting the presence of IN was as follows: sensitivity = 100%, specificity = 65.2%, positive predictive value = 22.6%, and negative predictive value = 100%. Age >40 years, family history of CRC, and increased body mass index (BMI) were associated with a significantly higher number of ACF.

CONCLUSION

Long-standing UC patients with ≥3 ACF have a significantly higher likelihood of having IN. Age >40 years, family history of CRC, and increased BMI have significant positive associations with the number of ACF.

Aberrant crypt focus and fragile histidine triad protein in sporadic colorectal carcinoma

AIM: To characterize aberrant crypt focus (ACF) in adjoining mucosa in sporadic colorectal carcinoma and to evaluate fragile histidine triad (Fhit) protein and Ki67.

METHODS: ACF was identified grossly and classified histologically in 75 resected specimens. ACF was typed into hyperplastic ACF (HACF) and dysplastic ACF (DACF). Sections of ACF, carcinoma and normal colonic mucosa as control were studied for Fhit and Ki67 expressions by immunohistochemistry and were grouped according to staining intensity and the number of positive stained cells observed in different histological groups. Comparison was done between the different groups by Pearson’s χ² test and γ test for the ordinal data. P value < 0.05 was considered as significant.

RESULTS: Age range was 40 to 86 years in males (mean = 43.36) and 45 to 70 years in females (mean = 56). HACF was identified in all cases studied in the non-tumorous colonic mucosa; ACF was observed as non-contiguous scattered foci, which supports the hypothesis of acquisition of single focus monoclonality by colonic epithelial cells in tumor generation. Twenty-four (32%) had DACF and were observed as closure to carcinoma foci. Intensity of Fhit expression: (1) HACF - 40% exhibited strong intensity, similar to normal, moderate in 36% and weak in 24%; (2) DACF - strong in 25%, moderate in 37.5% and weak in 37.5%; and (3) carcinoma - negative in 16%, strong in 43% and moderate and weak in 28.5% each. Significant difference was observed in intensity of the Fhit protein expressions by HACF and DACF (P < 0.05). Tumor in older patients showed a stronger Fhit intensity compared to younger patients (P = 0.036). Vegetarian diet intake and non-smokers showed stronger Fhit intensities. Advanced stage tumor, non-vegetarian diet and younger age was associated with loss of Fhit protein. Ki67 positivity was an extended crypt pattern in HACF and DACF showed extension up to the neck region of the crypts and surface epithelium. Carcinomas showed a marked increase in Ki67 expression (P < 0.05). Fhit protein had an inverse association with Ki67 expression.

CONCLUSION: Weaker Fhit intensity was associated with smoking, non-vegetarian diet intake and increasing Ki67 expression. Loss of Fhit protein expression is possibly influenced by environmental factors like smoking and non-vegetarian diet intake.

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 (≤3 crypts, FC ACF) or numerous crypts (≥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.

Epigenetic markers of early tumor development

Cancer patients' outcome and survival depends on the early diagnosis of malignant lesions. Several investigation methods used for the prevention and early detection strategies have specific limitations. More recently, epigenetic changes have been considered one of the most promising tools for the early diagnosis of cancer. Some of these epigenetic alterations including promoter hypermethylation of genes like P16INK4a, BRCA1, BRCA2, ERα and RARβ2, APC, and RASSF1A have been associated with early stages of mammary gland tumorigenesis and have been suggested to be included in the models that evaluate individual breast cancer risk. In lung cancer, P16INK4a and MGMT gene hypermethylation was observed in sputum years before clinical manifestation of the squamous cell carcinoma among smokers. Loss of GSTP1 function by DNA hypermethylation together with changes in the methylation levels of repetitive elements like LINE-1 and Sat2 was reported in prostatic preneoplastic lesions. Also, DNA hypermethylation for hMLH1 and MGMT DNA repair genes was reported in precursor lesions to colorectal cancer. These epigenetic alterations may be influenced by factors such as xenoestrogens, folate, and multivitamins. Detection of these changes may help determining cancer susceptibility and early diagnosis.

Randomized double-blind trial of sulindac and etodolac to eradicate aberrant crypt foci and to prevent sporadic colorectal polyps

PURPOSE

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.

EXPERIMENTAL DESIGN

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.

RESULTS

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.

CONCLUSIONS

ACF may be useful as surrogate lesions for chemoprevention of colorectal cancer.

Role of different inflammatory and tumor biomarkers in the development of ulcerative colitis-associated carcinogenesis

BACKGROUND

Colorectal cancer (CRC) is the most severe complication in inflammatory bowel disease (IBD). In the present study we investigated different mechanistic links between chronic colonic inflammation and its progression to adenocarcinoma. Along these lines, given that adrenomedullin (AM) has been implicated in carcinogenesis, we also analyzed changes in its colonic expression.

METHODS

Mice were exposed to 5, 10, and 15 cycles of dextran sulfate sodium (DSS); each cycle consisted of 0.7% DSS for 1 week followed by distilled water for 10 days. After each period, macroscopic and histological studies, as well as characterization of inflammatory and tumor biomarkers, were carried out.

RESULTS

The disease activity index (DAI) showed that the disease was present from the third cycle and it gradually increased during the course of DSS treatment. Macroscopic tumors were only seen after 15 cycles, and microscopic study showed that inflammation, dysplasia, and adenocarcinomas correlated with DSS cycles. β-Catenin and proliferating cell nuclear antigen expressions progressively increased in animals treated with the different cycles of DSS. TNF-α and IFN-γ showed the highest production at the tenth cycle. COX-2, mPGES-1, and iNOS levels were also appreciably higher at the fifth and tenth cycles. Moreover, we observed a progressive enhancement in AM expression and changes in its intracellular location during the progression of the disease.

CONCLUSIONS

Our results show an early induction of proinflammatory factors, which may contribute to the development of colon cancer, as well as demonstrate, for the first time, the expression of AM in IBD-derived CRC.

Morphological and molecular alterations in 1,2 dimethylhydrazine and azoxymethane induced colon carcinogenesis in rats

The dimethyhydrazine (DMH) or azoxymethane (AOM) model is a well-established, well-appreciated, and widely used model of experimental colon carcinogenesis. It has many morphological as well as molecular similarities to human sporadic colorectal cancer (CC), which are summarized and discussed in this paper. In addition, the paper combines present knowledge of morphological and molecular features in the multistep development of CC recognized in the DMH/AOM rat model. This understanding is necessary in order to accurately identify and interpret alterations that occur in the colonic mucosa when evaluating natural or pharmacological compounds in DMH/AOM rat colon carcinogenesis. The DMH/AOM model provides a wide range of options for investigating various initiating and environmental factors, the role of specific dietary and genetic factors, and therapeutic options in CC. The limitations of this model and suggested areas in which more research is required are also discussed.

Aberrant crypt foci: the case for inclusion as a biomarker for colon cancer

Aberrant crypt foci (ACF) are one of the earliest histopathological manifestations of colon cancer. In this review, we critically present the molecular, cellular, histopathological, and chemopreventive evidence that ACF are relevant biomarkers for colon cancer. The laboratory and clinical evidence are highly suggestive that ACF are in the pathway leading to colon cancer, but not all ACF will do so. The possible fate and outcome of ACF in the progression toward colon cancer may be dependent on a number of features that define their predictive power for the prevention or progression of cancer.

A novel clinically relevant animal model for studying galectin-3 and its ligands during colon carcinogenesis

Galectin-3 (Gal-3) is a multifunctional protein that plays different roles in cancer biology. To better understand the role of Gal-3 and its ligands during colon carcinogenesis, we studied its expression in tumors induced in rats treated with 1,2-dimethylhydrazine (DMH) and in human tissues. Normal colon from untreated rats showed no staining using two specific monoclonal antibodies. In contrast, morphologically normal colon from DMH-treated rats and dysplastic aberrant crypt foci were strongly stained, indicating that increased Gal-3 expression is an early event during the neoplastic transformation in colon cells. Gal-3 was weakly expressed in adenocarcinomas. Overall, the Gal-3 expression pattern observed in the DMH rat model closely resembles that displayed by human colon stained with the same antibodies. We also found that Gal-3 phosphorylation diminishes in serines while increasing in tyrosines during rat colon carcinogenesis. Finally, we showed that Gal-3-ligands expression is strikingly similar in rat and human malignant colon and in non-malignant tissues. In conclusion, the DMH-induced rat colon cancer model displays expression patterns of Gal-3 and its ligands very similar to those observed in human samples. This animal model should contribute to clarifying the role of Gal-3 in colon carcinogenesis and also to finding effective preventive cancer agents based on Gal-3 targeting.

Molecular identification of "latent precancers" for endometrial serous carcinoma in benign-appearing endometrium

Alteration of p53 is an early event in the development of endometrial serous carcinoma (ESC). We have recently identified a group of benign-looking endometria with p53 overexpression, designated "p53 signatures." In this study, we investigated these p53 signatures and evaluated whether they represented "latent" precancers for ESC. The p53 signatures were specifically associated with ESC, frequently found in the benign-appearing endometrium adjacent to the ESC and only rarely in either the endometrium adjacent to endometrioid carcinomas or in non-cancerous uteri. Forty-two percent of the p53 signature samples showed at least one p53 gene mutation. There were eight ESC uteri with p53 signatures that revealed p53 gene mutations. In four (50%) of these cases, at least one identical p53 gene mutation was found in the signature glands, precancerous regions, and cancerous areas within the same uterus. We concluded that p53 gene mutations apparently precede the morphological changes in affected endometrial cells. The finding of identical p53 mutations in the p53 signatures, precancerous regions, and ESCs in a subset of the uteri provides further evidence of a probable shared lineage between these lesions and suggests that the epithelia that display these p53 signatures are likely latent ESC precancerous regions. These findings underscore the significance of the p53 signature as a target for further research in the early detection and prevention of ESC.

Azoxymethane-induced rat aberrant crypt foci: Relevance in studying chemoprevention of colon cancer

The pathogenesis of colon cancer involves sequential and multistep progression of epithelial cells initiated to a cancerous state with defined precancerous intermediaries. Aberrant crypt foci (ACF) represent the earliest identifiable intermediate precancerous lesions during colon carcinogenesis in both laboratory animals and humans. ACF are easily induced by colon-specific carcinogens in rodents and can be used to learn more about the process of colon carcinogenesis. For over two decades, since its first discovery, azoxymethane (AOM)-induced rodent ACF have served as surrogate biomarkers in the screening of various anticarcinogens and carcinogens. Several dietary constituents and phytochemicals have been tested for their colon cancer chemopreventive efficacy using the ACF system. There has been substantial effort in defining and refining ACF in terms of understanding their molecular make-up, and extensive research in this field is currently in progress. In chemoprevention studies, AOM-induced rat ACF have been very successful as biomarkers, and have provided several standardized analyses of data. There have been several studies that have reported that ACF data do not correlate to actual colon tumor outcome, however, and hence there has been an ambiguity about their role as biomarkers. The scope of this mini-review is to provide valuable insights and limitations of AOM-induced rat ACF as biomarkers in colon cancer chemoprevention studies. The role of the dynamics and biological heterogeneity of ACF is critical in understanding them as biomarkers in chemoprevention studies.