Combined effects of radiation and simulated microgravity on intestinal tumorigenesis in C3B6F1 ApcMin/+ mice.

Explorations of the Moon and Mars are planned as future manned space missions, during which humans will be exposed to both radiation and microgravity. We do not, however, know the health effects for such combined exposures. In a ground-based experiment, we evaluated the combined effects of radiation and simulated microgravity on tumorigenesis by performing X-irradiation and tail suspension in C3B6F1 ApcMin/+ mice, a well-established model for intestinal tumorigenesis. Mice were irradiated at 2 weeks of age and underwent tail suspension for 3 or 11 weeks using a special device that avoids damage to the tail. The tail suspension treatment significantly reduced the thymus weight after 3 weeks but not 11 weeks, suggesting a transient stress response. The combination of irradiation and tail suspension significantly increased the number of small intestinal tumors less than 2 mm in diameter as compared with either treatment alone. The combined treatment also increased the fraction of malignant tumors among all small intestinal tumors as compared with the radiation-only treatment. Thus, the C3B6F1 ApcMin/+ mouse is a useful model for assessing cancer risk in a simulated space environment, in which simulated microgravity accelerates tumor progression when combined with radiation exposure.

Diet and lifestyle in relation to small intestinal cancer risk: findings from the European Prospective Investigation into Cancer and Nutrition (EPIC).

PURPOSE: The incidence of small intestinal cancer (SIC) is increasing, however, its aetiology remains unclear due to a lack of data from large-scale prospective cohorts. We examined modifiable risk factors in relation to SIC overall and by histological subtype. METHODS: We analysed 450,107 participants enrolled in the European Prospective Investigation into Cancer and Nutrition cohort. Cox proportional hazards models were used to estimate univariable and multivariable hazard ratios (HRs) and 95% confidence intervals (CIs). RESULTS: During an average of 14.1 years of follow-up, 160 incident SICs (62 carcinoids, 51 adenocarcinomas) were identified. Whilst univariable models revealed a positive association for current versus never smokers and SIC (HR, 95% CI: 1.77, 1.21-2.60), this association attenuated in multivariable models. In energy-adjusted models, there was an inverse association across vegetable intake tertiles for SIC overall (HRT3vsT1, 95% CI: 0.48, 0.32-0.71, p-trend: < 0.001) and for carcinoids (HRT3vsT1, 95% CI: 0.44, 0.24-0.82, p-trend: 0.01); however, these attenuated in multivariable models. Total fat was also inversely associated with total SIC and both subtypes but only in the second tertile (SIC univariable HRT2vsT1, 95% CI: 0.57, 0.38-0.84; SIC multivariable HRT2vsT1, 95% CI: 0.55, 0.37-0.81). Physical activity, intake of alcohol, red or processed meat, dairy products, or fibre were not associated with SIC. CONCLUSION: These exploratory analyses found limited evidence for a role of modifiable risk factors in SIC aetiology. However, sample size was limited, particularly for histologic subtypes; therefore, larger studies are needed to delineate these associations and robustly identify risk factors for SIC.

Progress in the Treatment of Small Intestine Cancer.

OPINION STATEMENT: Small intestine cancer is rare, accounting for approximately 3% of all gastrointestinal malignancies. The most common histological subtypes include adenocarcinoma, neuroendocrine tumours (NETs) and gastrointestinal stromal tumours (GISTs). In localised disease, surgery remains the mainstay of treatment and the best approach to improve survival. Current treatment for small intestine adenocarcinoma (SIA) is extrapolated from small studies and data from colorectal cancer (CRC). There is limited evidence to guide therapy in the adjuvant setting. However, there are small phase II studies in the advanced setting providing evidence for the role of chemotherapy and immunotherapy. There is also limited evidence assessing the efficacy of targeted therapies. Small intestine NETs are rare, with evidence for somatostatin analogue therapy, particularly in the low to intermediate-grade well-differentiated tumours. Poorly differentiated NETs are generally managed with chemotherapy but have worse outcomes compared with well-differentiated NETs. The management of small intestine GISTs is largely targeting KIT mutations with imatinib. Recent trials have provided evidence for effective therapies in imatinib-resistant tumours and the potential role of immunotherapy. The aim of this article was to review the evidence for the current management and recent advances in the management of small intestine adenocarcinoma, NETs and GISTs.

Lifestyle Factors and Development and Natural Course of Gastroenteropancreatic Neuroendocrine Tumors: A Review of the Literature.

INTRODUCTION: The rarity of neuroendocrine tumors (NETs) and their heterogeneous presentation complicate the identification of risk factors for their development and natural course. Several tumor-specific prognostic factors have been identified, but less attention has been given to lifestyle factors as risk and prognostic factors. This review aimed to identify studies on smoking, alcohol use, physical activity, diet, body mass index (BMI), and diabetes and their association with the development and course of gastroenteropancreatic (GEP-) NETs. METHODS: The literature was systematically searched for articles on lifestyle factors and NETs available via PubMed and Embase. Study quality was assessed using the Newcastle-Ottawa scale. RESULTS: A total of 25 eligible studies out of 3,021 screened articles were included. Most studies reported on smoking and alcohol, reporting conflicting results. Diet seems to have an influence on NET development, but few studies were published. Articles reporting on BMI were not unanimous on the effect on GEP-NETs. Diabetes was reported as a risk factor for NETs, while a protective effect was observed with metformin use. CONCLUSION: Different tissues, i.e., the pancreas and small intestine, may respond differently to exposure to alcohol and smoking. Evidence for diet so far is too limited to draw conclusions. Diabetes seems to be an important risk factor for the development of pancreatic NETs with a protective role in disease progression, while BMI is not unequivocally associated with the development and prognosis of NETs. Hence, our findings suggest that lifestyle factors play an important role in NET development as a disease course. Future research should consider lifestyle as an influence on disease progression and treatment response.

Intestinal Cancer and Dysplasia in Crohn's Disease.

Crohn's disease is associated with an increased risk of adenocarcinoma of the involved portions of the small bowel and colorectum and has similar risk factors to those described in ulcerative colitis, most significantly, extent of bowel involvement, PSC, and duration of unresected disease. Prevention strategies include risk stratification and secondary prevention with colonoscopic screening and surveillance to identify dysplasia or early-stage cancers, with surgery when needed. There is emerging information to suggest that control of inflammation may provide primary prevention of neoplasia, but further studies are required to test this strategy.

Gastroenteropancreatic Neuroendocrine Neoplasms in Patients with Inflammatory Bowel Disease: An ECCO CONFER Multicentre Case Series.

BACKGROUND: Gastroenteropancreatic neuroendocrine neoplasms [GEP-NENs] have rarely been reported in association with inflammatory bowel diseases [IBDs]. METHODS: An ECCO COllaborative Network For Exceptionally Rare case reports project [ECCO-CONFER] collects cases of GEP-NENs diagnosed in patients with IBD. RESULTS: GEP-NEN was diagnosed in 100 IBD patients; 61% female, 55% Crohn's disease, median age 48 years (interquartile range [IQR] 38-59]). The most common location was the appendix [39%] followed by the colon [22%]. Comprehensive IBD-related data were available for 50 individuals with a median follow-up of 30 months [IQR 11-70] following NEN diagnosis. Median duration of IBD at NEN diagnosis was 84 months [IQR 10-151], and in 18% of cases NEN and IBD were diagnosed concomitantly. At diagnosis, 20/50 were stage-I [T1N0M0], and 28/50 were graded G1 [ki67 ≤2%]. Incidental diagnosis of NEN and concomitantly IBD diagnosis were associated with an earlier NEN stage [p = 0.01 and p = 0.02, respectively]. Exposure to immunomodulatory or biologic therapy was not associated with advanced NEN stage or grade. Primary GEP-NEN were more frequently found in the segment affected by IBD [62% vs 38%]. At the last follow-up data, 47/50 patients were alive, and only two deaths were related to NEN. CONCLUSIONS: In the largest case series to date, prognosis of patients with GEP-NEN and IBD seems favourable. Incidental NEN diagnosis correlates with an earlier NEN stage, and IBD-related therapies are probably independent of NEN stage and grade. The association of GEP-NEN location and the segment affected by IBD may suggest a possible role of inflammation in NEN tumorigenesis.

Tendência de aumento do número de casos de câncer de intestino exige estratégias de prevenção

Quase 30% de todos os cânceres colorretais (cânceres de intestino) podem ser evitados com alimentação saudável, prática de atividades físicas e abandono de bebidas alcoólicas. Essas ações preventivas são importantes para redução de casos e mortes, para a manutenção da produtividade laboral e para a redução dos gastos públicos com o tratamento do câncer de intestino.

Mice carrying an epithelial deletion of the glucocorticoid receptor NR3C1 develop a higher tumor load in experimental colitis-associated cancer.

The glucocorticoid receptor NR3C1 is expressed in multiple cell types in the gut and elsewhere. Intestinal epithelial cells both produce and respond to glucocorticoids in different physiological and pathological contexts. In experimental colitis, glucocorticoids have been shown to exert a dual role, dampening inflammation while producing a deterioration in animal status, including death. Mice with tamoxifen-inducible, intestinal epithelial-specific deletion of NR3C1 (NR3C1ΔIEC mice) are protected against experimental colitis, suggesting glucocorticoid epithelial actions are deleterious. Since glucocorticoids modulate epithelial proliferation, it follows that they may affect the development of colon cancer. In this study, we set out to test this hypothesis using the dextran sulfate sodium-azoxymethane model of colitis-associated cancer. Knockout (KO) mice were found to exhibit a twofold higher tumor load but similar incidence and tumor size. Tumors had a higher trend to extend close to the submucosal layer (36% vs. 0%) in NR3C1ΔIEC mice, and overexpressed Lgr5, Egfr, and Myc, consistent with distinct expression of proliferative/stemness markers. Snai1 and Snai2 were upregulated specifically in tumors of NR3C1ΔIEC mice, suggesting enhanced epithelial to mesenchymal transition in the absence of the intestinal epithelial glucocorticoid (GC) receptor. We conclude that endogenous GC epithelial signaling is involved in colitis-associated cancer.NEW & NOTEWORTHY Mice carrying a tamoxifen-inducible deletion of the glucocorticoid receptor in intestinal epithelial cells (NR3C1ΔIEC mice) and their corresponding controls were subjected to the azoxymethane-dextran sulfate sodium model of colitis-associated cancer. KO mice exhibit a twofold higher tumor load, with a higher trend to extend close to the submucosal layer (36% vs. 0%), but with similar incidence and tumor size. Colonic tumors in NR3C1ΔIEC mice showed signs of increased neoplastic transformation and tumor-associated inflammation.

Appendiceal carcinoid in a pediatric patient with Peutz-Jeghers syndrome: A case report and comprehensive literature review.

RATIONALE: Peutz-Jeghers syndrome (PJS), a rare autosomal dominant disorder, is characterized by mucocutaneous pigmentations, hamartomatous polyps in the gastrointestinal tract, and a high risk of developing various malignancies. To the best of our knowledge, only 1 case of appendiceal carcinoid associated with PJS has been previously reported in the pediatric population. PATIENT CONCERNS: We report a 7-year-old girl who was admitted for severe, intermittent abdominal pain and cramps, nausea, and vomiting. Multiple brown melanotic macules on the lips, buccal mucosa, and the tongue were noted. DIAGNOSIS: A plain abdominal X-ray in a standing position revealed dilated intestinal loops with multiple air-fluid levels. A computed tomography scan of the abdomen showing a "coffee bean" appearance of the jejunal loop with a transition point to the duodenal loop. Axial-contrast-enhanced computed tomography scan of the abdomen showing dilated jejunum loops, filled with fluid with the swirled appearance of mesentery typical for volvulus. The diagnosis of PJS was based on clinical findings along with the histopathologic confirmation of the hamartomatous polyps. INTERVENTIONS: An emergency laparotomy was performed, revealing a jejunojejunal intussusception starting 40 cm from the duodenojejunal flexure. Jejunotomy revealed that a lead-point intussusception was a necrotic hamartomatous polyp. After resecting the involved jejunal necrotic segment, including the polyp, end-to-end jejuno-jejunal anastomosis was performed. Further exploration revealed the presence of a jejunal mass 80 cm from the duodenojejunal flexure identified as another hamartomatous pedunculated polyp. The polyp was resected, and the enterotomy was then closed transversely. The grossly normal appendix was also removed. OUTCOMES: Clinical findings along with the histopathologically confirmed hamartomatous polyps were consistent with PJS. An appendiceal carcinoid (well-differentiated neuroendocrine tumor, European Neuroendocrine Tumor Society stage pT2) was incidentally detected during histological examination of the appendix. The patient and parents were counseled accordingly, focusing on active surveillance and control of symptoms. Two additional hamartomatous polyps (gastric and jejunal) were detected endoscopically and resected in the fourth postoperative week. A regular, 1-year follow-up and surveillance revealed no complications or recurrences. LESSONS: Unusual neoplasms can occasionally be encountered in well-defined syndromes such as PJS. Therefore, active follow-up and surveillance are mandatory for all patients with PJS.

Effectiveness of Banxia Xiexin Decoction in the treatment of precancerous lesions: A protocol for systematic review and meta-analysis.

BACKGROUND: Gastric precancerous lesion (GPL) is a necessary stage in the occurrence and development of gastric cancer. At present, the incidence of gastric cancer is increasing year by year. It is important to prevent and control gastric cancer through early detection and intervention. Banxia Xiexin Decoction (BXD) has a good effect in improving symptoms, reducing inflammation, promoting the repair of gastric mucosa, reversing its atrophy and intestinal metaplasia. BXD may be a foreground choice for the treatment of GPL. METHODS: Randomized controlled trials of BXD for GPL will be searched in the relevant database, including PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang Database, Chinese Biomedical Literature Database (CBM), and Chinese Scientific Journal Database (VIP database). The studies of electronic searches will be exported to EndNote V.9.1 software. We will run meta-analyses using the Review Manager (RevMan) V.5.3 software. Any disagreement will be solved in consultation with a third reviewer. RESULTS: Our study aims to explore the efficacy of BXD for GPL and to provide up-to-date evidence for clinical of GPL. CONCLUSION: The conclusion of this study will provide evidence for the efficacy of BXD on GPL. INPLASY REGISTRATION NUMBER: INPLASY 202130102.

Studying host genetic background effects on multimorbidity of intestinal cancer development, type 2 diabetes and obesity in response to oral bacterial infection and high-fat diet using the collaborative cross (CC) lines.

Background: Multimorbidity of intestinal cancer (IC), type 2 diabetes (T2D) and obesity is a complex set of diseases, affected by environmental and genetic risk factors. High-fat diet (HFD) and oral bacterial infection play important roles in the etiology of these diseases through inflammation and various biological mechanisms. Methods: To study the complexity of this multimorbidity, we used the collaborative cross (CC) mouse genetics reference population. We aimed to study the multimorbidity of IC, T2D, and obesity using CC lines, measuring their responses to HFD and oral bacterial infection. The study used 63 mice of both sexes generated from two CC lines (IL557 and IL711). For 12 weeks, experimental mice were maintained on specific dietary regimes combined with co-infection with oral bacteria Porphyromonas gingivalis and Fusobacterium nucleatum, while control groups were not infected. Body weight (BW) and results of a intraperitoneal glucose tolerance test (IPGTT) were recorded at the end of 12 weeks, after which length and size of the intestines were assessed for polyp counts. Results: Polyp counts ranged between 2 and 10 per CC line. The combination of HFD and infection significantly reduced (P < .01) the colon polyp size of IL557 females to 2.5 cm2, compared to the other groups. Comparing BW gain, IL557 males on HFD gained 18 g, while the females gained 10 g under the same conditions and showed the highest area under curve (AUC) values of 40 000-45 000 (min mg/dL) in the IPGTT. Conclusion: The results show that mice from different genetic backgrounds respond differently to a high fat diet and oral infection in terms of polyp development and glucose tolerance, and this effect is gender related.

Metabolic factors and the risk of small intestine cancers: Pooled study of 800 000 individuals in the metabolic syndrome and cancer project.

To explore the largely unknown etiology of small intestine cancer, we examined metabolic factors and risk of small intestine cancer overall and by subtypes. Among 404 220 women and 403 265 men in six European cohorts, we applied Cox regression with adjustment for smoking and body mass index (BMI), to calculate sex-specific hazard ratios (HRs) of small intestine cancer by levels of BMI, mean arterial pressure (MAP) and plasma total cholesterol, triglycerides and glucose. We also calculated HRs for these factors combined (metabolic score; MetS) and used Wald test statistics to investigate pairwise interactions between metabolic factors on risk. We also performed analyses separately per subtype (neuroendocrine tumors [NETs] and adenocarcinomas). During a median follow-up of 16.9 years, 144 women and 195 men were diagnosed with small intestine cancer, including 184 NETs and 99 adenocarcinomas. Among men, no main associations or interactions between metabolic factors were observed in relation to the risk of small intestine cancer. Among women, triglycerides were positively and linearly associated with risk (HR per standard deviation [SD]: 1.23, 95% confidence interval [CI]: 1.04-1.46), and a positive association was also observed for the MetS (HR per SD: 1.25, 95% CI: 1.02-1.52). Positive interactions were observed among women between triglycerides and cholesterol (P = .0005), and between MAP and glucose (P = .009), on risk. Glucose was positively associated with adenocarcinomas among women. This large, prospective study suggests that elevated triglycerides, and metabolic factors in interaction, confer an increased risk of small intestine cancer among women, but not among men.

Immunophenotypic Spectrum and Genomic Landscape of Refractory Celiac Disease Type II.

Refractory celiac disease type II (RCD II), also referred to as "cryptic" enteropathy-associated T-cell lymphoma (EATL) or "intraepithelial T-cell lymphoma," is a rare clonal lymphoproliferative disorder that arises from innate intraepithelial lymphocytes. RCD II has a poor prognosis and frequently evolves to EATL. The pathogenesis of RCD II is not well understood and data regarding the immunophenotypic spectrum of this disease and underlying genetic alterations are limited. To gain further biological insights, we performed comprehensive immunophenotypic, targeted next-generation sequencing, and chromosome microarray analyses of 11 RCD II cases: CD4-/CD8- (n=6), CD8+ (n=4), and CD4+ (n=1), and 2 of 3 ensuing EATLs. Genetic alterations were identified in 9/11 (82%) of the RCD II cases. All 9 displayed mutations in members of the JAK-STAT signaling pathway, including frequent, recurrent STAT3 (7/9, 78%) and JAK1 (4/9, 44%) mutations, and 9/10 evaluable cases expressed phospho-STAT3. The mutated cases also harbored recurrent alterations in epigenetic regulators (TET2, n=5 and KMT2D, n=5), nuclear factor-κB (TNFAIP3, n=4), DNA damage repair (POT1, n=3), and immune evasion (CD58, n=2) pathway genes. The CD4-/CD8- and other immunophenotypic subtypes of RCD II exhibited similar molecular features. Longitudinal genetic analyses of 4 RCD II cases revealed stable mutation profiles, however, additional mutations were detected in the EATLs, which occurred at extraintestinal sites and were clonally related to antecedent RCD II. Chromosome microarray analysis demonstrated copy number changes in 3/6 RCD II cases, and 1 transformed EATL with sufficient neoplastic burden for informative analysis. Our findings provide novel information about the immunophenotypic and genomic characteristics of RCD II, elucidate early genetic events in EATL pathogenesis, and reveal potential therapeutic targets.

Inflammatory bowel disease and risk of gastric, small bowel and colorectal cancer: a meta-analysis of 26 observational studies.

PURPOSE: The purpose of this meta-analysis was to assess the associations between inflammatory bowel disease (IBD) and risk of the gastric, small bowel and colorectal cancer. METHODS: We searched the PubMed and Web of Science for observational studies published before June 2020, and the quality of each included study was evaluated according to the Newcastle-Ottawa-Scale. RESULTS: Twenty-six studies comprising 531 449 IBD patients and more than 65 million reference individuals were included. Although IBD was significantly associated with 67% increased risk of the total gastric, small bowel and colorectal cancer. After stratifying by cancer location, IBD mainly increased the risk of intestinal cancer instead of gastric cancer. Furthermore, Crohn's disease (CD) significantly increased the risk of both small bowel cancer and colorectal cancer, while ulcerative colitis (UC) only increased the risk of colorectal cancer. In subgroup analysis, associations between IBD and risk of total gastric, small bowel and colorectal cancer were similar between male and female, except for that male IBD patients but not female had a significantly higher risk of small bowel cancer. Additionally, IBD patients in different geographical areas had different associations with risk of various gastrointestinal tract cancers. CONCLUSIONS: IBD is mainly associated with increased risk of cancers in the lower gastrointestinal tract, including small bowel cancer and colorectal cancer. Because studies about the association between IBD and risk of gastric cancer and the populations in Asia are limited, more observational studies are required in the future.

Inflammatory bowel disease and risk of small bowel cancer: a binational population-based cohort study from Denmark and Sweden.

OBJECTIVE: Crohn's disease (CD) is associated with increased risk of small bowel cancer (SBC), but previous studies have been small. We aimed to examine the risk of incident SBC and death from SBC in patients with inflammatory bowel disease (IBD). DESIGN: In a binational, population-based cohort study from Sweden and Denmark of patients with IBD during 1969-2017 and matched reference individuals from the general population, we evaluated the risk of incident SBC and death from SBC. Cox regression was used to estimate adjusted hazard ratios (aHRs). RESULTS: We identified 161 896 individuals with IBD (CD: 47 370; UC: 97 515; unclassified IBD: 17 011). During follow-up, 237 cases of SBC were diagnosed in patients with IBD (CD: 24.4/100 000 person-years; UC: 5.88/100 000 person-years), compared with 640 cases in reference individuals (2.81/100 000 person-years and 3.32/100 000 person-years, respectively). This corresponded to one extra case of SBC in 385 patients with CD and one extra case in 500 patients with UC, followed up for 10 years. The aHR for incident SBC was 9.09 (95% CI 7.34 to 11.3) in CD and 1.85 (95% CI 1.43 to 2.39) in UC. Excluding the first year after an IBD diagnosis, the aHRs for incident SBC decreased to 4.96 in CD and 1.69 in UC. Among patients with CD, HRs were independently highest for recently diagnosed, childhood-onset, ileal and stricturing CD. The relative hazard of SBC-related death was increased in both patients with CD (aHR 6.59, 95% CI 4.74 to 9.15) and patients with UC (aHR 1.57; 95% CI 1.07 to 2.32). CONCLUSION: SBC and death from SBC were more common in patients with IBD, particularly among patients with CD, although absolute risks were low.

Adenocarcinoma arising in the multiple heterotopic submucosal glands of the intestine in a Satoyoshi syndrome patient: A case report.

Satoyoshi syndrome is a rare multisystemic disorder of unknown etiology characterized by progressive muscle spasms, alopecia and diarrhea. Multiple protruding lesions with cystic glands, namely gastroenterocolitis cystica polyposa, manifest in the gastrointestinal tract. Since the first report of these lesions in 1977, which was unique to Satoyoshi syndrome, few studies have focused on their role, and the associated clinicopathological features are not well understood. Here, we report a 64-year-old Japanese woman with Satoyoshi syndrome who presented with multiple polypoid lesions in the stomach, duodenum, jejunum, ileum and colon. Histologically, the polypoid lesions in the intestine comprised multiple heterotopic submucosal glands containing cystically dilated glands and smooth muscle fibers in the lamina propria mucosa and/or submucosa. Additionally, we observed stromal changes, such as fibrosis, discontinuous and thinning muscularis mucosae, and diffuse neural fiber proliferation in the entire intestinal tract. Furthermore, multiple foci of adenocarcinomas were identified within several heterotopic submucosal glands. We hypothesized that multiple heterotopic submucosal glands in the present case corresponded to previously reported gastroenterocolitis cystica polyposa, suggesting that these lesions are essential in the histopathology and are a unique manifestation of Satoyoshi syndrome.

Expression of R-Spondin 1 in ApcMin/+ Mice Suppresses Growth of Intestinal Adenomas by Altering Wnt and Transforming Growth Factor Beta Signaling.

BACKGROUND & AIMS: Mutations in the APC gene and other genes in the Wnt signaling pathway contribute to development of colorectal carcinomas. R-spondins (RSPOs) are secreted proteins that amplify Wnt signaling in intestinal stem cells. Alterations in RSPO genes have been identified in human colorectal tumors. We studied the effects of RSPO1 overexpression in ApcMin/+ mutant mice. METHODS: An adeno associated viral vector encoding RSPO1-Fc fusion protein, or control vector, was injected into ApcMin/+mice. Their intestinal crypts were isolated and cultured as organoids. which were incubated with or without RSPO1-Fc and an inhibitor of transforming growth factor beta receptor (TGFBR). Livers were collected from mice and analyzed by immunohistochemistry. Organoids and adenomas were analyzed by quantitative reverse-transcription PCR, single cell RNA sequencing, and immunohistochemistry. RESULTS: Intestines from Apc+/+ mice injected with the vector encoding RSPO1-Fc had significantly deeper crypts, longer villi, with increased EdU labeling, indicating increased proliferation of epithelial cells, in comparison to mice given control vector. AAV-RSPO1-Fc-transduced ApcMin/+ mice also developed fewer and smaller intestinal tumors and had significantly longer survival times. Adenomas of ApcMin/+ mice injected with the RSPO1-Fc vector showed a rapid increase in apoptosis and in the expression of Wnt target genes, followed by reduced expression of messenger RNAs and proteins regulated by the Wnt pathway, reduced cell proliferation, and less crypt branching than adenomas of mice given the control vector. Addition of RSPO1 reduced the number of adenoma organoids derived from ApcMin/+ mice and suppressed expression of Wnt target genes but increased phosphorylation of SMAD2 and transcription of genes regulated by SMAD. Inhibition of TGFBR signaling in organoids stimulated with RSPO1-Fc restored organoid formation and expression of genes regulated by Wnt. The TGFBR inhibitor restored apoptosis in adenomas from ApcMin/+ mice expressing RSPO1-Fc back to the same level as in the adenomas from mice given the control vector. CONCLUSIONS: Expression of RSPO1 in ApcMin/+ mice increases apoptosis and reduces proliferation and Wnt signaling in adenoma cells, resulting in development of fewer and smaller intestinal tumors and longer mouse survival. Addition of RSPO1 to organoids derived from adenomas inhibits their growth and promotes proliferation of intestinal stem cells that retain the APC protein; these effects are reversed by TGFB inhibitor. Strategies to increase the expression of RSPO1 might be developed for the treatment of intestinal adenomas.

Necroptosis in Intestinal Inflammation and Cancer: New Concepts and Therapeutic Perspectives.

Necroptosis is a caspases-independent programmed cell death displaying intermediate features between necrosis and apoptosis. Albeit some physiological roles during embryonic development such tissue homeostasis and innate immune response are documented, necroptosis is mainly considered a pro-inflammatory cell death. Key actors of necroptosis are the receptor-interacting-protein-kinases, RIPK1 and RIPK3, and their target, the mixed-lineage-kinase-domain-like protein, MLKL. The intestinal epithelium has one of the highest rates of cellular turnover in a process that is tightly regulated. Altered necroptosis at the intestinal epithelium leads to uncontrolled microbial translocation and deleterious inflammation. Indeed, necroptosis plays a role in many disease conditions and inhibiting necroptosis is currently considered a promising therapeutic strategy. In this review, we focus on the molecular mechanisms of necroptosis as well as its involvement in human diseases. We also discuss the present developing therapies that target necroptosis machinery.