Colonic Precancerous Lesions Research Articles

Bifidobacterium lactis ameliorates AOM/DSS-induced inflammation, dysbiosis, and colonic precancerous lesions

Bowel cancer is the third most common malignancy of tumors and one of the major causes of cancer-related death. Bowel precancerous conditions can develop without any symptoms, which either makes it difficult for early diagnosis or poses a poor prognosis/gloomy relapse. This study aimed to investigate the effects of Bifidobacterium animalis subsp. lactis TCI604 (B. lactis) on inflammatory responses, gut microbiome, and protectiveness against azoxymethane (AOM)/dextran sodium sulfate (DSS)-induced colonic precancerous lesions. The AOM/DSS-induced colonic precancerous lesion murine model was studied with 24 female C57BL/6 J mice assigned to the control group, AOM/DSS-induced colonic precancerous lesion group (AOM/DSS), AOM/DSS treated with B. lactis probiotic group (B. lactis P), and AOM/DSS treated with B. lactis cell-free supernatant group (B. lactis S). The results showed that both B. lactis P and B. lactis S could attenuate AOM/DSS-induced body weight loss and intestine damage, reduce aberrant crypt foci (ACF) and the formation of colonic polyps, and significantly inhibit pro-inflammatory cytokines and the NF-κB signaling pathway, in which the B. lactis S group outperformed others. Further analysis using 16S rDNA sequencing suggested that both B. lactis P and B. lactis S optimize gut microbiota. Several bacteria, including Muribaculaceae, Prevotellaceae_UCG-001, Anaerostipes, Ruminococcaceae, Mucispirillum, Clostridia_UCG-014, and Clostridia_vadinBB60 that were known in close relation to colonic precancerous lesions, were sequenced at taxonomic level. Our results indicated that both B. lactis P and B. lactis S improved AOM/DSS-induced colonic precancerous lesions by regulating inflammation as well as optimizing gut microbiota, thereby establishing reciprocally cooperative net benefits between probiotics/postbiotics and mice with colonic precancerous lesions.Key points• Prophylactic administration of probiotic and postbiotic of B. lactis is capable of alleviating the AOM/DSS-induced body weight loss and colon shortening, as well as diminishing the development of colonic precancerous lesions, such as the formation of ACF and colonic polyps, in an AOM/DSS mouse model• Either probiotic or postbiotic of B. lactis has a positive role in mediating immune imbalance and colonic inflammation via suppression of inflammatory immune cells, pro-inflammatory cytokines, and the NF-κB signaling pathway• AOM/DSS-induced dysbiosis can be reversed with the probiotic and postbiotic of B. lactis supplementation

Co-Delivery of Glycyrrhizin and Paclitaxel via Gelatin-Based Core-Shell Nanoparticles Ameliorates 1,2-Dimethylhydrazine-Induced Precancerous Lesions in Colon.

Colorectal cancer is a lethal malignancy that begins from acquired/inherent premalignant lesions. Thus, targeting these lesions at an early stage of the disease could impede the oncogenesis and maximize the efficacy. The present work underscores a combinatorial therapy of paclitaxel (PTX) and glycyrrhizin (GL) delivered via gelatin-derived core-shell nanoparticles [AC-PCL(GL + PTX)-GNPs] for effective management of precancerous lesions. The desolvation method was adopted to prepare GL-loaded gelatin nanoparticles (GL-GNPs), which were coated with PTX and AC-PCL. The prepared NPs exhibited optimal physical attributes and had spherical morphology, as analyzed by transmission electron microscopy and field-emission scanning electron microscopy. In vitro release studies revealed sustained release for ∼96 h. Cell culture studies in HTC 116, and HT-29 cells showed synergistic action with CI < 0.9 and DRI > 1. Moreover, AC-PCL(GL + PTX)-GNPs exhibited amplified intracellular uptake and thus significantly reduced IC50. Pharmacokinetic studies revealed substantiated pharmacokinetic parameters (AUC0-∞, Cmax, etc.). In vivo studies in a 1,2-dimethyl hydrazine-induced model revealed a decrease in the number of lesions, mucin depletion, and subside infiltrations. An immunohistochemical study revealed elevated expression of caspase-9 and suppressed expression of VEGF and Ki-67. Toxicity studies showed insignificant changes in systemic biomarkers along with no alterations in organ morphology and hemocompatibility. In essence, AC-PCL(GL + PTX)-GNPs render a competent and safer tactic to regulate early-stage precancerous lesions.

Early screening of colorectal cancer using feature engineering with artificial intelligence-enhanced analysis of nanoscale chromatin modifications

Colonoscopy is accurate but inefficient for colorectal cancer (CRC) prevention due to the low (~ 7 to 8%) prevalence of target lesions, advanced adenomas. We leveraged rectal mucosa to identify patients who harbor CRC field carcinogenesis by evaluating chromatin 3D architecture. Supranucleosomal disordered chromatin chains (~ 5 to 20 nm, ~1 kbp) fold into chromatin packing domains (~ 100 to 200 nm, ~ 100 to 1000 kbp). In turn, the fractal-like conformation of DNA within chromatin domains and the folding of the genome into packing domains has been shown to influence multiple facets of gene transcription, including the transcriptional plasticity of cancer cells. We deployed an optical spectroscopic nanosensing technique, chromatin-sensitive partial wave spectroscopic microscopy (csPWS), to evaluate the packing density scaling D of the chromatin chain conformation within packing domains from rectal mucosa in 256 patients with varying degrees of progression to colorectal cancer. We found average packing scaling D of chromatin domains was elevated in tumor cells, histologically normal-appearing cells 4 cm proximal to the tumor, and histologically normal-appearing rectal mucosa compared to cells from control patients (p < 0.001). Nuclear D had a robust correlation with the model of 5-year risk of CRC with r2 = 0.94. Furthermore, rectal D was evaluated as a screening biomarker for patients with advanced adenomas presenting an AUC of 0.85 and 85% sensitivity and specificity. artificial intelligence-enhanced csPWS improved diagnostic performance with AUC = 0.90. Considering the low sensitivity of existing CRC tests, including liquid biopsies, to early-stage cancers our work highlights the potential of chromatin biomarkers of field carcinogenesis in detecting early, significant precancerous colon lesions.

Loss of symbiotic and increase of virulent bacteria through microbial networks in Lynch syndrome colon carcinogenesis.

Through a pilot study, we performed whole gut metagenomic analysis in 17 Lynch syndrome (LS) families, including colorectal cancer (CRC) patients and their healthy first-degree relatives. In a second asymptomatic LS cohort (n=150) undergoing colonoscopy-screening program, individuals with early precancerous lesions were compared to those with a normal colonoscopy. Since bacteria are organized into different networks within the microbiota, we compared related network structures in patients and controls. Fecal prokaryote DNA was extracted prior to colonoscopy for whole metagenome (n=34, pilot study) or 16s rRNA sequencing (validation study). We characterized bacteria taxonomy using Diamond/MEGAN6 and DADA2 pipelines and performed differential abundances using Shaman website. We constructed networks using SparCC inference tools and validated the construction's accuracy by performing qPCR on selected bacteria. Significant differences in bacterial communities in LS-CRC patients were identified, with an enrichment of virulent bacteria and a depletion of symbionts compared to their first-degree relatives. Bacteria taxa in LS asymptomatic individuals with colonic precancerous lesions (n=79) were significantly different compared to healthy individuals (n=71). The main bacterial network structures, constructed based on bacteria-bacteria correlations in CRC (pilot study) and in asymptomatic precancerous patients (validation-study), showed a different pattern than in controls. It was characterized by virulent/symbiotic co-exclusion in both studies and illustrated (validation study) by a higher Escherichia/Bifidobacterium ratio, as assessed by qPCR. Enhanced fecal virulent/symbiotic bacteria ratios influence bacterial network structures. As an early event in colon carcinogenesis, these ratios can be used to identify asymptomatic LS individual with a higher risk of CRC.

Effects of Soybean and Tempeh Water Extracts on Regulation of Intestinal Flora and Prevention of Colon Precancerous Lesions in Rats

Soybean bioactivity is significantly enhanced during tempeh fermentation. This study aimed to evaluate the efficacy of tempeh on colorectal cancer cells in vitro and colon precancerous lesions (aberrant crypt foci, ACF) in vivo. In the in vitro assay, tempeh water extract (WET) could inhibit the proliferation of Caco-2 cells. In the animal assay using 1,2-dimethylhydrazine (DMH)-induced Sprague–Dawley (SD) rats, 12-weeks daily feeding of tempeh could decrease the level of Clostridium perfringens in cecum contents and reduce the number of large (≥4 foci) ACF in the colon of treated rats, compared to the DMH control. By the results of TOF-MS and Edman degradation, the isolated antioxidant dipeptide, tripeptides, and tetrapeptides from WET might contain methionine, proline, and lysine. The bioactive peptides in tempeh might inhibit colon cancer by suppressing the growth of C. perfringens in the intestinal tract.

Реакция нейроэндокринных клеток и макрофагов селезенки на развитие опухоли в толстой кишке

Introduction. High cancer incidence requires finding new ways for comprehensive studying car-cinogenesis. Therefore, it is crucial to understand immune organ cell response and cell interaction in tumor development. The aim of the research was to study Synaptophysin+-, CD68+-cells, and biogenic amines in rat spleens during tumor development in the colon during dysplasia stages and adenocarcinoma formation. Materials and methods. Spleen histological slides of 110 mature male rats were studied 1 and 4 months after 1,2-dimethylhydrazine carcinogen administration using immunohistochemical, morphometric, and luminescent histochemical methods. Results. We found imbalanced production of biogenic amines (serotonin, histamine, and catecholamines) in the spleen and, therefore, a decrease in the cellular activity of the germinal centers of the lymphoid nodules. We also observed activation of periarteriolar lymphoid sheath (PALS) and red pulp in rats with precancerous colon lesions (1 month after carcinogen administration). At the same time, there was an increase in the number of CD68+ macrophages and Synaptophysin+ cells in the red pulp. In animals with adenocarcinoma (4 months after carcinogen introduction), the level of catecholamines in the luminescent granular cells of the PALS and the functional activity of these cells increased significantly. Simultaneously, the number of macrophages decreased in all the studied spleen compartments. Amid the decreased level of all biogenic amines in the red pulp, the quantity of Synaptophysin+ cells grew even more. Conclusion. The cells of all spleen compartments react to colon carcinogenesis, with reactivity of PALS cells and the red pulp being the most pronounced. The population of spleen macrophages undergoes rapid changes: their number increases in the red pulp in animals with precancerous lesions, while it decreases in all the splenic structures of rats with adenocarcinoma. Synaptophysin+ neuroendocrine cells of the red pulp play an important role in the reaction of the spleen to tumor development, and the number of these cells rises over time. Biogenic amines participate in the interaction of spleen cells with each other and with tumor-associated cells. Keywords: spleen, biogenic amines, neuroendocrine cells, synaptophysin, carcinogenesis

Abstract IA025: Stem and metaplastic cell states and their influences on the tumor immune microenvironment in colonic pre-cancerous lesions

Abstract The immune microenvironment is critical to colorectal cancer (CRC) pathogenesis, regarding both prognosis and therapeutic responses. While much work has been done to characterize tumor microenvironments, less is known about those environments are established following transformation of epithelial cells. We hypothesize that mapping routes towards CRCs, from normal human colonic tissues and precursor polyps, will uncover additional mechanisms that define the CRC cellular landscape and identify targets with diagnostic or therapeutic utility. Here, we present a comparative atlas of the two most common colorectal precursor lesions, conventional adenomas and serrated polyps, and their resulting CRC counterparts using single-cell transcriptomics and multiplex imaging across two cohorts of human participants. Integrative analysis reveals adenomas arise from dysregulated WNT-driven expansion of stem cells, while serrated polyps are depleted of stem cell populations and are derived from differentiated cells transitioning through a pyloric metaplasia program. Mucosal damage associated with metaplasia is coupled to a cytotoxic immune microenvironment that precedes hypermutation. Mouse and organoid experiments validate the importance of the differentiation states of colonic tumor cells in driving cytotoxic immunity partly through increased expression of antigen-presentation machinery. These data provide constitute a rich resource into malignant progression of colorectal polyps and their microenvironments, serving as a framework for precision surveillance and prevention of CRC. Citation Format: Ken S. Lau. Stem and metaplastic cell states and their influences on the tumor immune microenvironment in colonic pre-cancerous lesions [abstract]. In: Proceedings of the AACR Special Conference on Colorectal Cancer; 2022 Oct 1-4; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;82(23 Suppl_1):Abstract nr IA025.

Meta-Analysis and Validation of a Colorectal Cancer Risk Prediction Model Using Deep Sequenced Fecal Metagenomes.

Simple SummaryColorectal cancer (CRC) is the third most common cancer in the world. The gut microbiome, which includes a collection of microbes, is a potential modifiable risk factor. The study of the microbiome is complex and many issues remain unsolved despite the scientific efforts that have been recently made. The present study aimed to build a CRC predictive model performing a meta-analyses of previously published shotgun metagenomics data, and to validate it in a new study. For that purpose, 156 participants of a CRC screening program were recruited, with an even distribution of CRCs, high-risk colonic precancerous lesions, and a control group with normal colonic mucosa. We have identified a signature of 32 bacterial species that have a good predictive accuracy to identify CRC but not precancerous lesions. This suggests that the identified microbes that were enriched or depleted in CRC are merely a consequence of the tumor. The gut microbiome is a potential modifiable risk factor for colorectal cancer (CRC). We re-analyzed all eight previously published stool sequencing data and conducted an MWAS meta-analysis. We used cross-validated LASSO predictive models to identify a microbiome signature for predicting the risk of CRC and precancerous lesions. These models were validated in a new study, Colorectal Cancer Screening (COLSCREEN), including 156 participants that were recruited in a CRC screening context. The MWAS meta-analysis identified 95 bacterial species that were statistically significantly associated with CRC (FDR < 0.05). The LASSO CRC predictive model obtained an area under the receiver operating characteristic curve (aROC) of 0.81 (95%CI: 0.78–0.83) and the validation in the COLSCREEN dataset was 0.75 (95%CI: 0.66–0.84). This model selected a total of 32 species. The aROC of this CRC-trained model to predict precancerous lesions was 0.52 (95%CI: 0.41–0.63). We have identified a signature of 32 bacterial species that have a good predictive accuracy to identify CRC but not precancerous lesions, suggesting that the identified microbes that were enriched or depleted in CRC are merely a consequence of the tumor. Further studies should focus on CRC as well as precancerous lesions with the intent to implement a microbiome signature in CRC screening programs.

Possible role of nuclear factor erythroid 2–related factor 2 in the progression of human colon precancerous lesions

Possible role of nuclear factor erythroid 2–related factor 2 in the progression of human colon precancerous lesions

Colorectal Cancer in Egypt: Clinical, Life-Style, and Socio-Demographic Risk Factors

Background: Colorectal cancer (CRC) is cancer of the colon and rectum. It arises from the mucosa that lining the colon, rectum or both. Aim of the work: Determination of the clinical, lifestyle, and socio-demographic risk factors of colorectal cancer in Egypt. Patients and Methods: A hospital-based, case-control study design was performed. 160 cases with CRC and 300 healthy subjects were recruited in this study. An endoscopic, radiological and pathological methods and clinical examinations had been done for the collection of data. Results: The most significant risk factors for medical and family were obesity, DM, bowel habit change, inflammatory bowel disease (IBD), precancerous colonic lesions, no NSAIDs use, no HRT use, cholecystectomy, and family history of CRC (ORs=2.12, 2.13, 1.97, 4.91, 5.46, 3.69, 6.3, 3.84, and 8.88; respectively). Conclusion: The most important risk factors of CRC were obesity, DM, IBD, precancerous colonic lesions, and family history of CRC. Risk factors of CRC are commonly controllable.

Red Wheat Alters Colon Cancer Risk, Oxidative Stress, and the Gut Microbiome

Red Wheat Alters Colon Cancer Risk, Oxidative Stress, and the Gut Microbiome

Colon Cancer Risk of a Westernized Diet Is Reduced in Mice by Feeding Cruciferous or Apiaceous Vegetables at a Lower Dose of Carcinogen but Not a Higher Dose.

Western-style diets (WD) are associated with greater risk of colon cancer. Exposure to 2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine (PhIP), a food-borne carcinogen, is linked to increased colon cancer risk. In contrast, intake of apiaceous and cruciferous vegetables (APIs and CRUs) is associated with reduced risk. Here we evaluated effects of a WD alone or a WD containing API or CRU, relative to a purified diet (basal), on colon cancer risk in mice. All diets were fed at one of two concentrations of PhIP (100 or 400 ppm). The activity of the hepatic PhIP-activating enzyme, cytochrome P450 (CYP) 1A2, was examined at week 4 and colonic precancerous lesions (aberrant crypt foci, ACF) were enumerated at week 12. In low PhIP-fed groups, CYP1A2 activity was greater for CRU than all other groups, which did not differ from one another. WD had a significantly greater effect on the formation of ACF than the basal diet. In groups fed API or CRU, the ACF number was reduced to the level observed in the basal diet-fed group. In high PhIP-fed groups, all WD-based diets had greater CYP1A2 activity than the basal diet-fed group. Surprisingly, the basal diet group had more ACF than the WD group, and API and CRU groups did not differ from the WD alone group. Thus, at the lower dose of PhIP, the WD increased colon cancer risk in mice, compared to a purified diet, and APIs and CRUs reduced the risk of the WD. However, at the higher dose of PhIP, the enhancement of colon cancer risk by the WD was not evident, nor was the chemopreventive effect of these vegetables.

Zinc dyshomeostasis in azoxymethane-induced colonic precancerous and cancerous lesions in Fischer rats.

Zinc is an essential micronutrient involved in various biological processes. It is also argued that tumors need zinc for maintenance and proliferation and tumor cell apoptosis. Zinc homeostasis is regulated by the gastrointestinal tract and involves interplay of host, dietary, environmental and social factors such as alcohol consumption. The DNA alkylation agent azoxymethane (AOM), which is primarily activated in the liver, induces a high incidence of initiation and promotion steps of precancerous lesions in the colon of rats. The altered expression of hepatic zinc transporters by AOM may lead to zinc dyshomeostasis in liver. Decreased serum zinc concentration, despite increased liver zinc also indicates altered liver zinc mobilization and failure to regulate zinc homeostasis. During the transformation from normal colonic mucosa to colonic epithelial hyperplasia and aberrant crypt formation, a reduction in zinc concentration is observed. It will be interesting to study further if the same trend continues throughout tumor progression towards adenocarcinomas. Lowered local zinc concentrations in the colon epithelium may not just reflect a bystander effect, but may induce cell proliferation and compromise DNA integrity due to impairment of zinc-containing proteins. In congruence with the tissue zinc concentrations, metallothionein levels were found to be less induced in AOM -administered colon compared to normal healthy colon. Lowered tissue zinc levels in small and large intestine were also associated with increased expression of mRNA and protein ZnT1. In this regard, the mode of zinc responsiveness to ZnT1 mimics that of metallothionein, albeit at a lower level for ZnT1.

Pomegranate (Punica granatum L.) Peel and Probiotics Modulate Oxidative Stress and Intestinal Microbiota Associated with Chemically Induced Colon Cancer in High-Fat-Diet Fed Rats

Introduction: Colon cancer is a real public health problem. Pomegranate peel and probiotics are thought to be important therapeutic nutritional strategies for colon cancer prevention. The aim of this study was to evaluate the modulation effect of pomegranate peel alone or in combination with probiotics against the oxidative disorders and intestinal dysbiosis associated with chemically-induced precancerous lesions in rat colon. Materials and Methods: Thirty-six male Wistar rats were divided into six groups: Groups1and 2 were negative DMH-untreated control rats receiving Standard Diet (SD) for G1 and high-fat diet (HFD) for G2; while Groups 3 and 4 were positive DMH-treated control receiving SD for G3 and HFD for G4; Groups 5 and 6 were DMH-treated and fed with 2.5% pomegranate peel-supplemented HFD diet in the presence of probiotics (4×109 CFU/kg diet) for G6. After 16 weeks of experimentation, biochemical analysis, oxidative parameters, histopathological examination of the colon, and microbial analysis were performed. Results: Findings showed that pomegranate peels and probiotics induced a significant increase in ferric reducing the ability of plasma levels by 67% and reduction in the malonaldehyde content by 66%. In addition, this treatment helped to improve the histological architecture of the colon in the rats of groups G5 and G6, in comparison with the HFD positive DMH-treated control group (G4). Furthermore, this treatment was also the most effective in decreasing the pathogenic bacteria amount involved in the intestinal dysbiosis (7 to 43%) and increasing in beneficial bacteria (60%). Conclusions: These results suggest that pomegranate peel and probiotics act as a chemopreventive agent against preneoplastic lesions.

Piperine Regulates Nrf-2/Keap-1 Signalling and Exhibits Anticancer Effect in Experimental Colon Carcinogenesis in Wistar Rats.

Colon cancer is the most common cancer in men and women globally, killing millions of people annually. Though there widespread development has been made in the management of colorectal cancer, still there is an urgent need to find novel targets for its effective treatment. Piperine is an alkaloid found in black pepper having anticancer, anti-inflammatory activities, safe and nutritive for human consumption. Nuclear factor-erythroid 2–kelch-like ECH-associated protein 1(Nrf-2/Keap-1)/Heme-oxygenase1 (HO-1) signaling pathway plays a vital part in shielding cells from intracellular oxidative stress and inflammation. A potential cross-talk between the Nrf-2 and NF-κB pathways is recognized during cancerous growth and expansion. We studied this pathway extensively in the present study to discover novel targets in the prevention of chemically induced colon cancer with piperine to simulate human colon cancer pathology. Animals were divided into four groups. Groups1 and 2 were used as a negative control and positive control where 1,2–Dimethylhydrazine, DMH was administered in group 2, while group 3 and 4 were prevention groups where piperine at two different doses was given two weeks prior to DMH and continued until end of experiment. We found that piperine inhibited NF-κB by the activation of Nrf-2, blocking downstream inflammatory mediators/cytokines (TNF-α, IL-6, IL-1β, Cox-2, PGE-2, iNOS, NO, MPO), triggering an antioxidant response machinery (HO-1, NQO-1, GSH, GR, GPx, CAT, SOD), scavenging ROS, and decreasing lipid peroxidation. Histological findings further validated our molecular findings. It also downregulates CEA, MDF and ACF, markers of precancerous lesions in colon, alleviates infiltration of mast cells and depletes the mucous layer. Our results indicate that piperine may be an effective molecule for the prophylactic treatment of colon carcinogenesis by targeting the NF-κB/Nrf-2/Keap-1/HO-1 pathway as a progressive strategy in the preclusion and effective treatment of colorectal cancer.

COVID-19: An Opportunity to Reimagine Colorectal Cancer Diagnostic Testing—A New Paradigm Shift

COVID-19: An Opportunity to Reimagine Colorectal Cancer Diagnostic Testing—A New Paradigm Shift

Immune tolerance to colon cancer is mediated by colon dysbiosis: Human results and experimental In Vivo validation.

e16062 Background: Lynch syndrome (Ly) but not Sporadic (Sp) CRC patients are responsive to immunotherapies. We have shown micorbiota from CRC patients induces precancerous colonic lesions in germ-free mice. The aim was to investigate microbiota linked compromised anti tumor immune response. Methods: We compared 1) Whole metagenomic fecal microbiotas of CRC patients [Sp, n = 53+Ly, n = 19] to controls (n = 90) or being first degree relatives of Ly patients (n = 14), respectively; 2) Tumoral to normal mucosa-adherent microbiota (16sRNA sequences); 3) Normal to tumoral tissues’ mRNA RT-PCRs of IL1b, IL4, IL6, IL8, IL17, TNFa, TGFb, FasL, Granzyme A&amp;B, Thy1; 4) CD3, CD4, CD8, Granzym, KL1, FoxP3, RORgT, MastCell, cells in tumor tissues quantified by immunohistochemistry (IHC), between subgroups. Associations between bacteria, tissue immune cell infiltrates and clinical data (3-yrs follow up or death) were established by using unsupervised Systems Biology and Bioinformatics analyses (Institut Pasteur Shaman platform and Qlucor program). Anti tumoral immune response links with bacteria were based on differences between Ly and Sp CRC patients. Tumor tolerance links with bacteria were identified using germ-free mice (n = 185) who orally received microbiota (9 Sp CRC patients vs 9 controls) with colonic mucosa examined 3 months after human fecal transfer (whole exome sequencing, methylchips, IHC for CD3, CD11b, FoxP3, RORgT, ILC3). Results: Enrichment in Peptostreptococcus, Thermodesulfovibrio and diminution in Ruminococcus, Eubacterium, Coprococcus were linked with FoxP3 and IL-17 over expressions in tumor tissues. Enrichment in Escherichia, Enterobacter, Thioalkalimicrobium, and diminution in Eubacterium, Faecalibacterium and Butyrovibrio were associated with higher FoxP3, FasL, Granzyms A&amp;B, Perforin, Thy1 mRNAs/mRNACD3. Diminution of Eubacterium, Dorea, Faecalibacterium genera and enrichment in Fusobacterium, E. Coli/Shigella were associated with higher CD3, FoxP3, GranzymA and B and FOXP3-RORgT cells in tumor tissues. Higher fecal enrichments in oral bacteria (parvimonas micra) and lack of Thermodesulfovibrio enrichment were associated with higher FoxP3-RORgt cells and short survival; in mice ILC3 and FoxP3-RORgT cells were linked with Sp CRC dysbiosis. Species linked with immunotolerance are identified. Conclusions: Fecal and tissue microbiota can impact failure of anti tumoral immune response in sporadic CRC patients by enhancing overexpression of IL-17 and reducing cytotoxic T-cell infiltration in tumors. Clinical trial information: NCT01270360 .

Genome-wide expression profiling in colorectal cancer focusing on lncRNAs in the adenoma-carcinoma transition

BackgroundLong non-coding RNAs (lncRNAs) play a fundamental role in colorectal cancer (CRC) development, however, lncRNA expression profiles in CRC and its precancerous stages remain to be explored. We aimed to study whole genomic lncRNA expression patterns in colorectal adenoma–carcinoma transition and to analyze the underlying functional interactions of aberrantly expressed lncRNAs.MethodsLncRNA expression levels of colonic biopsy samples (20 CRCs, 20 adenomas (Ad), 20 healthy controls (N)) were analyzed with Human Transcriptome Array (HTA) 2.0. Expression of a subset of candidates was verified by qRT-PCR and in situ hybridization (ISH) analyses. Furthermore, in silico validation was performed on an independent HTA 2.0, on HGU133Plus 2.0 array data and on the TCGA COAD dataset. MiRNA targets of lncRNAs were predicted with miRCODE and lncBase v2 algorithms and miRNA expression was analyzed on miRNA3.0 Array data. MiRNA-mRNA target prediction was performed using miRWALK and c-Met protein levels were analyzed by immunohistochemistry. Comprehensive lncRNA-mRNA-miRNA co-expression pattern analysis was also performed.ResultsBased on our HTA results, a subset of literature-based CRC-associated lncRNAs showed remarkable expression changes already in precancerous colonic lesions. In both Ad vs. normal and CRC vs. normal comparisons 16 lncRNAs, including downregulated LINC02023, MEG8, AC092834.1, and upregulated CCAT1, CASC19 were identified showing differential expression during early carcinogenesis that persisted until CRC formation (FDR-adjusted p < 0.05). The intersection of CRC vs. N and CRC vs. Ad comparisons defines lncRNAs characteristic of malignancy in colonic tumors, where significant downregulation of LINC01752 and overexpression of UCA1 and PCAT1 were found. Two candidates with the greatest increase in expression in the adenoma-carcinoma transition were further confirmed by qRT-PCR (UCA1, CCAT1) and by ISH (UCA1). In line with aberrant expression of certain lncRNAs in tumors, the expression of miRNA and mRNA targets showed systematic alterations. For example, UCA1 upregulation in CRC samples occurred in parallel with hsa-miR-1 downregulation, accompanied by c-Met target mRNA overexpression (p < 0.05).ConclusionThe defined lncRNA sets may have a regulatory role in the colorectal adenoma-carcinoma transition. A subset of CRC-associated lncRNAs showed significantly differential expression in precancerous samples, raising the possibility of developing adenoma-specific markers for early detection of colonic lesions.

High Sensitivity to Cholic Acid-induced Colonic Tumorigenesis Makes Female PIRC Rats (F344/NTac-Apcam1137) a Suitable Model for Studying CRC-promoting Agents.

Rats of the adenomatous polyposis coli (Apc)-mutated female polyposis in rat (PIRC) (F344/NTac-Apcam1137) model exhibit a low level of intestinal tumorigenesis and are thus potentially exploitable as a model for identifying substances increasing colorectal cancer (CRC). To test this possibility, we treated such rats with the bile acid (BA) cholic acid (CA) (0.3% w/w in the diet), known to promote CRC, and assessed tumorigenesis. Precancerous colonic lesions (mucin-depleted foci) and intestinal tumors were dramatically increased in CA-treated rats compared to controls (p<0.01). Colon mucosa proliferation was higher and apoptosis lower than those in controls. Expression of nuclear receptor 1h4 (Nr1h4) gene [encoding for BA receptor farnesoid X receptor (FXR)], organic solute transporter beta (Ostb) and fatty acid-binding protein 6 (Fabp6), FXR-dependent BA transporters, were dramatically down-regulated in CA-treated rats. CA-increased tumorigenesis in female PIRC rats, with mechanisms involving increased proliferation, reduced apoptosis and marked down-regulation of genes controlling BA homeostasis. Since BAs have been implicated in CRC, we suggest that female PIRC rats can be used to identify CRC-promoting agents.

Inhibitory Effect of Dietary Curcumin on 1, 2-Dimethylhydrazine-Induced Colon Preneoplasia in Irradiated Rats

Introduction: Prevention of cancer remains a primary need and new chemopreventive agents must be developed for this purpose. It is well known that the radiotherapy is associated with severe side effects and offers no firm expectation for a cure. Thus, there is a constant need for the investigation of other potentially useful options. One of the widely sought approaches is cancer chemoprevention that uses natural agents. Curcumin, a natural plant product, has been shown to have anti-inflammatory and antioxidant properties and which, thus, may be a potential anticancer drug. Material and Methods: The inhibitory effects of dietary curcumin (0.6 % in diet) on colonic precancerous lesions in rats treated with 1,2-dimethylhydrazine, (DMH, 20 mg/kg, s.c. once weekly for 6 weeks) or exposed to γ-radiation (6.5 Gy) alone or in combination were evaluated histologically and histochemically. Results: The results showed clear features of colonic dysplasia with DMH treatment. The dysplastic crypts exhibited marked hyperchromatism, loss of polarity besides nuclear and cellular stratification. Whereas, γ-irradiation revealed marked crypt dilatation accompanied by disorganized crypt structure and alteration of surface epithelium. The results also demonstrate an apparent synergy between the radiation and the chemical carcinogen in the induction of augmentation of mucosal abnormalities accompanied with increased total DNA content and cell proliferation. Consistent with these observations, changes in the type of mucous secretion with predominance of sialomucins were observed in the areas of mild to moderate dysplasia whilst the surrounding normal epithelium produced sulphated material. Mucus depletion was a common feature in areas of severe dysplasia. Addition of curcumin to the diet remarkably reduced the amount and severity of dysplastic lesions with DMH-induced colon preneoplasia without appreciable toxicity. Moreover, curcumin could prevent or improve the disruption of colonic architecture caused by γ- irradiation. Such improvement was also investigated but to a lesser extent with the combined radiation and DMH. Conclusion: These results indicated that curcumin is potent in inhibiting the preneoplastic lesions and other cellular events relevant to colon and was, therefore, of value as a safe chemotherapeutic agent.