Therapeutic targeting of the oncogenic Wnt signaling pathway for treating colorectal cancer and other colonic disorders.

The canonical Wnt pathway is one of the key cellular signaling cascades that regulates, via the transcriptional co-activator ß-catenin, numerous embryogenic developmental processes, as well as tissue homeostasis. It is therefore not surprising that misregulation of the Wnt/ß-catenin pathway has been implicated in carcinogenesis. Aberrant Wnt signaling has been reported in a variety of malignancies, and its role in both hereditary and sporadic colorectal cancer (CRC), has been the subject of intensive study. Interestingly, the vast majority of colorectal tumors harbor mutations in the tumor suppressor gene adenomatous polyposis coli (APC). The Wnt pathway is complex, and despite decades of research, the mechanisms that underlie its functions are not completely known. Thus, although the Wnt cascade is an attractive target for therapeutic intervention against CRC, one of the malignancies with the highest morbidity and mortality rates, achieving efficacy and safety is yet extremely challenging. Here, we review the current knowledge of the Wnt different epistatic signaling components and the mechanism/s by which the signal is transduced in both health and disease, focusing on CRC. We address some of the important questions in the field and describe various therapeutic strategies designed to combat unregulated Wnt signaling, the development of targeted therapy approaches and the emerging challenges that are associated with these advanced methods.

Therapeutic Opportunities for Intestinal Angioectasia- Targeting PPARγ and Oxidative Stress.

Recurrent and acute bleeding from intestinal tract angioectasia (AEC) presents a major challenge for clinical intervention. Current treatments are empiric, with frequent poor clinical outcomes. Improvements in understanding the pathophysiology of these lesions will help guide treatment. Using data from the US Food and Drug Administration (FDA)'s Adverse Event Reporting System (FAERS), we analyzed 12 million patient reports to identify drugs inversely correlated with gastrointestinal bleeding and potentially limiting AEC severity. FAERS analysis revealed that drugs used in patients with diabetes and those targeting PPARγ-related mechanisms were associated with decreased AEC phenotypes (P < 0.0001). Electronic health records (EHRs) at University of Cincinnati Hospital were analyzed to validate FAERS analysis. EHR data showed a 5.6% decrease in risk of AEC and associated phenotypes in patients on PPARγ agonists. Murine knockout models of AEC phenotypes were used to construct a gene-regulatory network of candidate drug targets and pathways, which revealed that wound healing, vasculature development and regulation of oxidative stress were impacted in AEC pathophysiology. Human colonic tissue was examined for expression differences across key pathway proteins, PPARγ, HIF1α, VEGF, and TGFß1. In vitro analysis of human AEC tissues showed lower expression of PPARγ and TGFß1 compared with controls (0.55 ± 0.07 and 0.49 ± 0.05). National Center for Biotechnology Information (NCBI) Gene Expression Omnibus (GEO) RNA-Seq data was analyzed to substantiate human tissue findings. This integrative discovery approach showing altered expression of key genes involved in oxidative stress and injury repair mechanisms presents novel insight into AEC etiology, which will improve targeted mechanistic studies and more optimal medical therapy for AEC.

Early Combined Immunosuppression May Be More Effective for Reducing Complications in Isolated Colonic- vs Ileal-Dominant Crohn Disease.

BACKGROUND: We assessed whether differential efficacy of early combined immunosuppression (ECI) in comparison with conventional management (CM) is present in patients with Crohn disease (CD) according to disease location. METHODS: In this posthoc analysis of the Randomized Evaluation of an Algorithm for Crohn's Treatment trial, the effect of ECI vs CM modified by disease location (isolated-colonic vs ileal-dominant) in terms of time to first complication (hospitalization, surgery, or disease-related complications-presence of a new abscess, fistula, or stricture; serious worsening of disease activity; extraintestinal manifestations) was analyzed using a marginal Cox proportional hazard model to account for cluster randomization. Factors adjusted included practice size, country, and other covariates selected in a backward logistic regression analysis with the first composition as outcome and P < 0.10. RESULTS: Of the 1969 patients with CD, 435 had isolated colonic CD (ECI n = 257, CM n = 178) and 1534 had ileal CD (ECI n = 817, CM n = 717). Over 24 months there was a significant differential impact for ECI vs CM for reducing the risk of a CD-related complication between patients with colonic CD and ileal CD (colonic CD hazard ratio [HR] = 0.51; 95% CI, 0.30-0.85 vs ileal CD HR = 0.79; 95% CI, 0.57-1.10; P = 0.033). No difference was identified between ECI vs CM for reducing the risk of surgery (colonic HR = 0.52 vs ileal HR = 0.74; P = 0.468) or hospitalization (colonic HR = 0.77 vs ileal HR = 0.83; P = 0.806). CONCLUSIONS: In this posthoc analysis of the Randomized Evaluation of an Algorithm for Crohn's Treatment trial, symptom-based ECI was associated with greater efficacy for reducing the risk of CD-related complications in patients with colonic disease location relative to ileal disease location.

Oral delivery of self-assembling bioactive peptides to target gastrointestinal tract disease.

Peptides are known for their diverse bioactivities including antioxidant, antimicrobial, and anticancer activity, all three of which are potentially useful in treating colon-associated diseases. Beside their capability to stimulate positive health effects once released in the body, peptides are able to form useful nanostructures such as hydrogels. Combining peptide bioactivity and peptide gel-forming potentials can create interesting systems that can be used for oral delivery. This combination, acting as a two-in-one system, has the potential to avoid the need for delicate entrapment of a drug or natural bioactive compound. We here review the context and research progress, to date, in this area.

Hodkgin lymphoma concomitant of tuberculosis, a therapeutic challenge for multidisciplinary management.

Hodgkin lymphoma (HL) is a disease characterized by a high curability rate, and the treatment benefit-risk balance must be carefully addressed to achieve complete disease control with low risk of long-term toxicities. Most patients are treated with a combination of chemotherapy and radiotherapy, after disease staging and response to treatment evaluated by FDG PET/CT. We report the case of a 28-year-old patient concomitantly diagnosed of a Hodgkin lymphoma and active tuberculosis. Initial staging was difficult due to pulmonary and abdominal tuberculosis localization that induced FDG PET/CT hypermetabolism. Anti-tuberculosis treatment was first started, allowing secondary an early accurate Hodgkin lymphoma staging by FDG PET/CT. The patient was then treated by chemotherapy and radiotherapy. Helical TomoTherapy® was used with involved site (IS) irradiation volume was performed to decrease the high doses to organs-at-risk (OAR), especially lungs in this context of tuberculosis.

Advances in colon-targeted nano-drug delivery systems: challenges and solutions.

Nano-drug delivery systems (NDDS) for colon-targeted drug delivery are an active area of research on local diseases affecting the colon, such as ulcerative colitis, Crohn's disease, colon cancer, and for the delivery of peptide or protein drugs and vaccinations. In particular, targeted nano-drug delivery to the colon is advantageous for colon-specific diseases because nanoparticles can accumulate in diseased parts, improve the efficacies of therapeutics, and enable localized treatments, which reduces systemic toxicity. However, there are many hurdles, such as burst drug release, enzyme and acidic degradation of drug and carrier in the stomach, pH variations, mucus entrapment, and systemic uptake in the upper small intestine, which could challenge and compromise the successful delivery of NDDS to the colon. With advancements in NDDS, it may be possible to overcome these challenges leading to efficient drug delivery for colon-specific disorders. This review describes a few of the potential colon-specific drug delivery areas and the challenges faced by colon-targeted orally administered delivery systems, and provides an updated summary of recent advances in the development of orally administered NDDS for colon targeting, and the future advances in this research.

Walnut phenolic extract inhibits nuclear factor kappaB signaling in intestinal epithelial cells, and ameliorates experimental colitis and colitis-associated colon cancer in mice.

PURPOSE: Walnuts (Juglans regia) are known to have anti-cancer and immunomodulatory effects. However, little information is available on the effects of walnut phenolic extract (WPE) on intestinal inflammation and colitis-associated colon cancer. METHODS: COLO205 cells were pretreated with WPE and then stimulated with tumor necrosis factor (TNF)-α. In the acute colitis model, wild type mice (C57BL/6) were administered 4% dextran sulfate sodium (DSS) for 5 days. In the chronic colitis model, interleukin (IL)-10-/- mice were administered with either the vehicle or WPE (20 mg/kg) by oral gavage daily for 2 weeks. In an inflammation-associated tumor model, wild type mice were administered a single intraperitoneal injection of azoxymethane followed by three cycles of 2% DSS for 5 days and 2 weeks of free water consumption. RESULTS: WPE significantly inhibited IL-8 and IL-1α expression in COLO205 cells. WPE attenuated both the TNF-α-induced IκB phosphorylation/degradation and NF-κB DNA binding activity. The administration of oral WPE significantly reduced the severity of colitis in both acute and chronic colitis models, including the IL-10-/- mice. In immunohistochemical staining, WPE attenuated NF-κB signaling in the colons of both colitis models. Finally, WPE also significantly reduced tumor development in a murine model of colitis-associated colon cancer (CAC). CONCLUSIONS: WPE ameliorates acute and chronic colitis and CAC in mice, suggesting that WPE may have potentials for the treatment of inflammatory bowel disease.

Local delivery of macromolecules to treat diseases associated with the colon.

Current treatments for intestinal diseases including inflammatory bowel diseases, irritable bowel syndrome, and colonic bacterial infections are typically small molecule oral dosage forms designed for systemic delivery. The intestinal permeability hurdle to achieve systemic delivery from oral formulations of macromolecules is challenging, but this drawback can be advantageous if an intestinal region is associated with the disease. There are some promising formulation approaches to release peptides, proteins, antibodies, antisense oligonucleotides, RNA, and probiotics in the colon to enable local delivery and efficacy. We briefly review colonic physiology in relation to the main colon-associated diseases (inflammatory bowel disease, irritable bowel syndrome, infection, and colorectal cancer), along with the impact of colon physiology on dosage form design of macromolecules. We then assess formulation strategies designed to achieve colonic delivery of small molecules and concluded that they can also be applied some extent to macromolecules. We describe examples of formulation strategies in preclinical research aimed at colonic delivery of macromolecules to achieve high local concentration in the lumen, epithelial-, or sub-epithelial tissue, depending on the target, but with the benefit of reduced systemic exposure and toxicity. Finally, the industrial challenges in developing macromolecule formulations for colon-associated diseases are presented, along with a framework for selecting appropriate delivery technologies.

Effects of melatonin on colonic anastomosis healing following chemotherapy in rats.

INTRODUCTION: This study aimed to investigate the effects of melatonin on the healing of colon anastomosis following chemotherapy. METHODS: 32 rats were randomised into four groups: (a) control group, which underwent sigmoid colon transection and primary anastomosis; (b) melatonin group, which received melatonin daily following anastomosis; (c) 5-fluorouracil (5-FU) group, which received 5-FU for five days prior to anastomosis; and (d) 5-FU+melatonin group, which received 5-FU for five days prior to anastomosis and melatonin daily following anastomosis. The rats were sacrificed on Postoperative Day 7 and anastomotic bursting pressures were measured. The anastomotic segment was extracted for hydroxyproline, luminol and lucigenin measurement and histopathological examination. Blood samples were obtained from the vena cava for measurement of tumour necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1ß) plasma levels. RESULTS: Compared to the 5-FU group, bursting pressures of anastomosis and hydroxyproline levels were significantly higher, while luminol and lucigenin levels were significantly lower, in the control and 5-FU+melatonin groups. In addition, TNF-α and IL-1ß plasma levels were significantly lower in the control and 5-FU+melatonin groups than in the 5-FU group. Histopathological examination showed a significant decrease in inflammation and necrosis formation in the melatonin group when compared to the control group. The positive effect of melatonin was also seen in the rats that received 5-FU. CONCLUSION: Our study results showed that the adverse effects of chemotherapy on the mechanical, biochemical and histopathological parameters of anastomosis healing were attenuated through melatonin treatment.

Suppression of methionine-induced colon injury of young rats by cysteine and N-acetyl-L-cysteine.

Changes in the methionine metabolism can cause a state called hyperhomocysteinemia, inducing oxidative stress in the gut. The production of free radicals is important in the colon damage caused by methionine. This study aimed at evaluating the effect of the use of L-cysteine and N-acetyl-L-cysteine on the colon morphometry of young rats treated with methionine. A total number of 32 male rats were distributed in a randomized experimental design in 4 groups: control group treated with saline; methionine group; cysteine + methionine group, and N-acetyl-L-cysteine + methionine group. After 21 days of treatment, rats were sacrificed and the colon samples were taken for histological and biochemical analysis. Methionine load increased depth of crypts, the lamina muscularis mucosae thickness, the mucosal height, and the number of cells in lamina propria (p < 0.01). Combination of methionine with L-cysteine (C group) and with N-acetyl-L-cysteine (N group) reversed methionine effects. Methionine treatment increased the GPx activity and MDA concentration, while L-cysteine and N-acetyl-L-cysteine increased the catalase activity compared to methionine group. It was concluded that the use of L-cysteine and N-acetyl-L-cysteine was beneficial to decrease intestinal mucosal height and oxidative damage when methionine was used in combination with them.

Medical treatment or surgery for colorectal endometriosis? Results of a shared decision-making approach.

STUDY QUESTION: What is the degree of patient satisfaction in women with symptomatic colorectal endometriosis who choose medical or surgical treatment after a shared decision-making (SDM) process? SUMMARY ANSWER: The degree of satisfaction with treatment was high both in women who chose medical treatment with a low-dose oral contraceptive (OCP) or a progestin, and in those who chose to undergo surgical resection of bowel endometriosis. WHAT IS KNOWN ALREADY: Hormonal therapies and surgery for colorectal endometriosis have been investigated in non-comparative studies with inconsistent results. STUDY DESIGN, SIZE, DURATION: Parallel cohort study conducted on 87 women referring to our centre with an indication to surgery for colorectal endometriosis. A standardised SDM process was adopted, allowing women to choose their preferred treatment. Median follow-up was 40 [18-60] months in the medical therapy group and 45 [30-67] in the surgery group. PARTICIPANTS/MATERIALS, SETTING, METHODS: Patients with endometriosis infiltrating the proximal rectum, the rectosigmoid junction, and the sigmoid, not causing severe sub-occlusive symptoms were enroled. A total of 50 patients chose treatment with an OCP (n = 12) or a progestin (n = 38), whereas 37 women confirmed their previous indication to surgery. Patient satisfaction was graded according to a 5-category scale. Variations in bowel and pain symptoms were measured by means of a 0-10 numeric rating scale. Constipation was assessed with the Knowles-Eccersley-Scott Symptom Questionnaire (KESS), health-related quality of life with the Short Form-12 questionnaire (SF-12), psychological status with the Hospital Anxiety and Depression scale (HADS) and sexual functioning with the Female Sexual Function Index (FSFI). MAIN RESULTS AND THE ROLE OF CHANCE: Six women in the medical therapy group requested surgery because of drug inefficacy (n = 3) or intolerance (n = 3). Seven major complications were observed in the surgery group (19%). At 12-month follow-up, 39 (78%) women in the medical therapy group were satisfied with their treatment, compared with 28 (76%) in the surgery group (adjusted odds ratio (OR), 1.37; 95% confidence interval (CI), 0.45-4.15; intention-to-treat analysis). Corresponding figures at final follow-up assessment were 72% in the former group and 65% in the latter one (adjusted OR, 1.74; 95% CI, 0.62-4.85). The 60-month cumulative proportion of dissatisfaction-free participants was 71% in the medical therapy group compared with 61% in the surgery group (P = 0.61); the Hazard incidence rate ratio was 1.21 (95% CI, 0.57-2.62). Intestinal complaints were ameliorated by both treatments. Significant between-group differences in favour of medical treatment were observed at 12-month follow-up in diarrhoea, dysmenorrhoea, non-menstrual pelvic pain and SF-12 physical component scores. The total HADS score improved significantly in both groups, whereas the total FSFI score improved only in women who chose medical therapy. LIMITATIONS REASONS FOR CAUTION: As treatments were not randomly assigned, selection bias and confounding are likely. The small sample size exposes to the risk of type II errors. WIDER IMPLICATIONS OF THE FINDINGS: When adequately informed and empowered through a SDM process, most patients with non-occlusive colorectal endometriosis who had already received a surgical indication, preferred medical therapy. The possibility of choosing the preferred treatment may allow maximisation of the potential effect of the interventions. STUDY FUNDING/COMPETING INTEREST(S): This study was financed by Italian fiscal contribution '5 × 1000'-Ministero dell'Istruzione, dell'Università e della Ricerca-devolved to Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Ca' Granda Ospedale Maggiore Policlinico, Milano, Italy. P.V., M.P.F., R.R., D.D., A.R., P.M., O.D.G. and M.C. declare that they have no conflicts of interest. E.S. received grants from Ferring and Serono.