Sunitinib malate inhibits intestinal tumor development in male ApcMin/+ mice by down-regulating inflammation-related factors with suppressing ß-cateinin/c-Myc pathway and re-balancing Bcl-6 and Caspase-3.

Sunitinib is a tyrosine kinase inhibitor for many tumors. Inflammation is one of the most important factors in the development of intestinal tumors. Many inflammation-related factors are regulated by tyrosine kinase receptors. It is reasonable to hypothesize that sunitinib can regulate the development of intestinal tumors by regulating the expression and/or activity of inflammation-related factors. Here, ApcMin/+ male mouse model was used to investigate the effect and mechanism of sunitinib malate against intestinal cancer. Results show that compared to vehicle, after sunitinib malate treatment, overall survival of ApcMin/+ mice was lengthened up to 25 days, with a gain of body weight, reduction of spleen/body weight index, and RBC, WBC and HGC regulated to normal levels of wild type mice, and a number of polyps no less than 1 mm significantly reduced. Meanwhile, in the intestines, the nuclear ß-Catenin protein and c-Myc mRNA were both down-regulated, and Bcl-6 was significantly reduced with Caspase-3 up regulated. Furthermore, inflammation-related factors including IL-6, TNF-α, IL-1α, IL-1ß and IFN-γ were down-regulated at mRNA levels in the intestines. These results suggest that sunitinib malate can significantly improve the survival status and inhibit intestinal tumor development in male ApcMin/+ mice, through inhibiting inflammation-related factors, while suppressing ß-cateinin/c-Myc pathway and re-balancing protein levels of Bcl-6 and Caspase-3.

Intestinal Epithelial TBK1 Prevents Differentiation of T-helper 17 Cells and Tumorigenesis in Mice.

BACKGROUND & AIMS: Intestinal epithelial cells (IECs) regulate intestinal immune cells, particularly development of T-helper 17 (Th17) cells. Deregulation of this process leads to intestinal inflammation and tumorigenesis, via unknown mechanisms. TANK-binding kinase 1 (TBK1) is expressed by IECs and cells in the innate immune system. We studied the functions of TBK1 in the intestinal immune response and tumorigenesis in mice. METHODS: We performed studies of wild-type mice, mice with conditional disruption of Tbk1 (Tbk1IEC-KO), Tbk1IEC-KO mice crossed with ApcMin/+ mice, and Mt-/- mice crossed with ApcMin/+ mice. Some mice were given intraperitoneal injections of a neutralizing antibody against interleukin 17 (IL17) or IL1ß. Intestine tissues were collected from mice and analyzed by histology, for numbers of adenomas and Th17 cells, and expression of inflammatory cytokines by real-time PCR. IECs were isolated from wild-type and Tbk1IEC-KO mice, stimulated with lipopolysaccharide, co-cultured for with bone marrow-derived macrophages, and analyzed by RNA sequencing and biochemical analyses. RESULTS: Compared to ApcMin/+Tbk1WT mice, ApcMin/+Tbk1IEC-KO mice had significant increases in number and size of intestinal polyps, and significantly more Th17 cells in lamina propria. Administration of an antibody against IL17 reduced the number of intestinal polyps in ApcMin/+Tbk1IEC-KO mice to that observed in ApcMin/+Tbk1WT mice. In culture, TBK1-deficient IECs promoted expression of IL1ß by macrophages, which induced differentiation of naïve CD4+ T cells into Th17 cells. RNA sequencing analysis revealed that the TBK1-deficient IECs had increased expression of metallothionein 1 (MT1), an immune regulator that promotes intestinal inflammation. Intestine tissues from ApcMin/+Mt-/- mice had significant fewer Th17 cells than ApcMin/+Mt+/+ mice, and a significantly lower number of polyps. Analyses of colorectal tumors in the Cancer Genome Atlas found colorectal tumors with high levels of MT1 and IL17 mRNAs to be associated with reduced survival times of patients. CONCLUSIONS: Expression of TBK1 by IECs suppresses expression of MT1 and prevents expression of IL1ß by macrophages and differentiation of Th17 cells, to prevent inflammation and tumorigenesis. Strategies to block this pathway might be developed for colorectal tumorigenesis.

Knocking out matrix metalloproteinase 12 causes the accumulation of M2 macrophages in intestinal tumor microenvironment of mice.

MMP12 is mainly secreted by macrophages, is involved in macrophage development, and decomposes the extracellular matrix. Herein, we investigated whether macrophages would change in the intestinal tumor microenvironment after MMP12 knockout. ApcMin/+;MMP12-/-mice were obtained by crossbreeding ApcMin/+ mice with MMP12 knockout mice (MMP12-/- mice). The data showed that the number and volume of intestinal tumors were significantly increased in ApcMin/+;MMP12-/- mice compared with ApcMin/+ mice. Additionally, the tumor biomarkers CA19-9, CEA, and ß-catenin appeared relatively early in intestinal tumors in ApcMin/+;MMP12-/- mice. The results demonstrated that knocking out MMP12 accelerated the tumor growth and pathological process. On further investigation of its mechanism, the proportions of M2 macrophages in the spleen and among peritoneal macrophages were significantly up-regulated in ApcMin/+;MMP12-/- mice. Expression of M2 macrophage-related genes was up-regulated in tumor and peritoneal macrophages. The M2-related cytokine levels of IL-4 and IL-13 were increased in the serum of ApcMin/+;MMP12-/-mice. In vitro, bone marrow-derived M2 macrophages were obtained by treating bone marrow cells with IL-4 and IL-13, and these M2 macrophages secreted cytokines being changed. This finding reveals the crucial role of MMP12 in macrophage development and provides a new target for the control of macrophage polarization. Knocking out MMP12 causes intestinal M2 macrophage accumulation in tumor microenvironment, promoting the growth of intestinal tumors in ApcMin/+ mice.

Epithelial RNase H2 Maintains Genome Integrity and Prevents Intestinal Tumorigenesis in Mice.

BACKGROUND & AIMS: RNase H2 is a holoenzyme, composed of 3 subunits (ribonuclease H2 subunits A, B, and C), that cleaves RNA:DNA hybrids and removes mis-incorporated ribonucleotides from genomic DNA through ribonucleotide excision repair. Ribonucleotide incorporation by eukaryotic DNA polymerases occurs during every round of genome duplication and produces the most frequent type of naturally occurring DNA lesion. We investigated whether intestinal epithelial proliferation requires RNase H2 function and whether RNase H2 activity is disrupted during intestinal carcinogenesis. METHODS: We generated mice with epithelial-specific deletion of ribonuclease H2 subunit B (H2bΔIEC) and mice that also had deletion of tumor-suppressor protein p53 (H2b/p53ΔIEC); we compared phenotypes with those of littermate H2bfl/fl or H2b/p53fl/fl (control) mice at young and old ages. Intestinal tissues were collected and analyzed by histology. We isolated epithelial cells, generated intestinal organoids, and performed RNA sequence analyses. Mutation signatures of spontaneous tumors from H2b/p53ΔIEC mice were characterized by exome sequencing. We collected colorectal tumor specimens from 467 patients, measured levels of ribonuclease H2 subunit B, and associated these with patient survival times and transcriptome data. RESULTS: The H2bΔIEC mice had DNA damage to intestinal epithelial cells and proliferative exhaustion of the intestinal stem cell compartment compared with controls and H2b/p53ΔIEC mice. However, H2b/p53ΔIEC mice spontaneously developed small intestine and colon carcinomas. DNA from these tumors contained T>G base substitutions at GTG trinucleotides. Analyses of transcriptomes of human colorectal tumors associated lower levels of RNase H2 with shorter survival times. CONCLUSIONS: In analyses of mice with disruption of the ribonuclease H2 subunit B gene and colorectal tumors from patients, we provide evidence that RNase H2 functions as a colorectal tumor suppressor. H2b/p53ΔIEC mice can be used to study the roles of RNase H2 in tissue-specific carcinogenesis.

Simultaneous Loss of Both Atypical Protein Kinase C Genes in the Intestinal Epithelium Drives Serrated Intestinal Cancer by Impairing Immunosurveillance.

Serrated adenocarcinoma, an alternative pathway for colorectal cancer (CRC) development, accounts for 15%-30% of all CRCs and is aggressive and treatment resistant. We show that the expression of atypical protein kinase C ζ (PKCζ) and PKCλ/ι was reduced in human serrated tumors. Simultaneous inactivation of the encoding genes in the mouse intestinal epithelium resulted in spontaneous serrated tumorigenesis that progressed to advanced cancer with a strongly reactive and immunosuppressive stroma. Whereas epithelial PKCλ/ι deficiency led to immunogenic cell death and the infiltration of CD8+ T cells, which repressed tumor initiation, PKCζ loss impaired interferon and CD8+ T cell responses, which resulted in tumorigenesis. Combined treatment with a TGF-ß receptor inhibitor plus anti-PD-L1 checkpoint blockade showed synergistic curative activity. Analysis of human samples supported the relevance of these kinases in the immunosurveillance defects of human serrated CRC. These findings provide insight into avenues for the detection and treatment of this poor-prognosis subtype of CRC.

Expression and Molecular Regulation of the Cox2 Gene in Gastroenteropancreatic Neuroendocrine Tumors and Antiproliferation of Nonsteroidal Anti-Inflammatory Drugs (NSAIDs).

BACKGROUND Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) has had a significant increase over the past 4 decades. The pathophysiological role of the cyclooxygenase-2 (cox-2) gene and factors responsible for the expression in GEP-NETs is of clinical value. Current study determined the expression of cox-2 gene in human GEP-NET tissues and corresponding cell lines, investigated the molecular mechanisms underlying the regulation of cox-2 gene expression and assessed the effect of nonsteroidal anti-inflammatory drugs (NSAIDs) on both anchorage-dependent and independent growth of GEP-NET cells. MATERIAL AND METHODS GEP-NET tissues and QGP-1, BON, and LCC-18 GEP-NET cell lines were used. The expression of cox-2 gene was analyzed by immunohistochemistry, western blot, RT-PCR, and enzyme immunoassay. Transient transfection and luciferase assays along with electrophoretic mobility shift assays were conducted to explore the regulation of cox-2 gene expression. The effect of COX-inhibitors on GEP-NET cell growth was determined by proliferation assays and colony growth assessment. RESULTS We found 87.8% of GEP-NET tissues stained positive for COX-2. QGP-1 and LCC-18 cells expressed cox-2 gene. PGE2 (prostaglandin E2) amounts quantified in the supernatants of NET cells matched to cox-2 expression level. The CRE-E-box element (-56 to -48 bp) and binding of USF1, USF2, and CREB transcription factors to this proximal promoter element were essential for cox-2 promoter activity in GEP-NET cells. COX-2-specific inhibitor NS-398 potently and dose-dependently inhibited PGE2 release from QGP-1 cells. Interestingly, both NS-398 and acetylic salicylic acid effectively suppressed proliferation of QGP-1 and BON cells in a dose-dependent manner. CONCLUSIONS The majority of GEP-NETs over express cox-2 gene. The binding of CREB and USF-1/-2 transcription factors to a proximal, overlapping CRE-Ebox element is the underlying mechanism for cox-2 gene expression. NSAIDs potently suppressed the proliferations and may offer a novel approach for chemoprevention and therapy of GEP-NETs.

Clinicopathological and prognostic significance of heme oxygenase-1 expression in small intestinal adenocarcinomas.

Heme oxygenase-1 (HO-1), a stress-response protein, is highly induced in various carcinomas. It is implicated in carcinogenesis and tumor progression. High HO-1 expression is associated with better prognosis of patients with colorectal and gastric cancers. Induction or inhibition of HO-1 can mediate chemo-sensitivity, therefore it might be a therapeutic target to develop anticancer agents. To define the clinicopathological and prognostic significance of HO-1 expression in small-intestinal adenocarcinomas (SIACs), immunohistochemical microarray analysis of HO-1 expression was performed for 191 surgically resected SIAC cases and results were compared with various clinicopathologic variables, including survival. HO-1 was highly expressed in 127 (66.5%) cases. Patients with high HO-1 expression were associated with younger age (P = 0.048), lower pT category (P = 0.017), and less pancreatic invasion (P = 0.047). Patients with high HO-1 expression tended to have longer overall survival (median, 38.5 months) than those with low HO-1 expression (24.5 months), although the difference in overall survival was not statistically significant (P = 0.677). In summary, high HO-1 expression is frequently observed in SIACs. It is related to favorable clinicopathologic parameters, including younger age, lower T category, and less pancreatic invasion. Therefore, HO-1 may serve as a prognostic marker and a new target to modulate chemotherapeutic effects in patients with SIACs.

IgA Antibodies Against Gliadin and Tissue Transglutaminase in Dogs With Chronic Enteritis and Intestinal T-Cell Lymphoma.

Molecular clonality analysis of T-cell receptor (TCR) genes for diagnosing T-cell lymphoma is widely used in veterinary medicine. However, differentiating chronic enteritis (CE) from intestinal lymphoma is challenging because of the incompatibility between histopathologic and clonality analysis results. On the basis of findings that canine intestinal T-cell lymphoma and celiac disease share some common features, we conducted serologic examinations in combination with histopathologic and T-cell receptor clonality analyses in 48 dogs diagnosed with either CE or intestinal lymphoma. Immunoglobulin A (IgA) and immunoglobulin G (IgG) antibodies against gliadin and tissue transglutaminase (tTG) were quantitatively measured using ELISA. The conditions were classified according to the histopathologic diagnosis, clonality analysis, and combined histopathologic/clonality analysis. Histopathologic analysis showed that dogs with intestinal lymphoma were likely to have high levels of serum IgA antibodies against gliadin and tTG, and serum IgG antibodies against tTG. No correlation between the diagnosed groups and control group was observed in the results of the clonality analysis and histopathologic/clonality analysis. It is interesting that dogs with intestinal lymphoma had a higher serum IgA titer against gliadin and tTG than did dogs with CE. These results suggest an association between repetitive inflammatory stimulation by gliadin peptides and subsequent intestinal lymphoma in dogs.

Oncogenic ß-catenin and PIK3CA instruct network states and cancer phenotypes in intestinal organoids.

Colorectal cancer is driven by cooperating oncogenic mutations. In this study, we use organotypic cultures derived from transgenic mice inducibly expressing oncogenic ß-catenin and/or PIK3CAH1047R to follow sequential changes in cancer-related signaling networks, intestinal cell metabolism, and physiology in a three-dimensional environment mimicking tissue architecture. Activation of ß-catenin alone results in the formation of highly clonogenic cells that are nonmotile and prone to undergo apoptosis. In contrast, coexpression of stabilized ß-catenin and PIK3CAH1047R gives rise to intestinal cells that are apoptosis-resistant, proliferative, stem cell-like, and motile. Systematic inhibitor treatments of organoids followed by quantitative phenotyping and phosphoprotein analyses uncover key changes in the signaling network topology of intestinal cells after induction of stabilized ß-catenin and PIK3CAH1047R We find that survival and motility of organoid cells are associated with 4EBP1 and AKT phosphorylation, respectively. Our work defines phenotypes, signaling network states, and vulnerabilities of transgenic intestinal organoids as a novel approach to understanding oncogene activities and guiding the development of targeted therapies.

Secreted Phospholipases A2 Are Intestinal Stem Cell Niche Factors with Distinct Roles in Homeostasis, Inflammation, and Cancer.

The intestinal stem cell niche provides cues that actively maintain gut homeostasis. Dysregulation of these cues may compromise intestinal regeneration upon tissue insult and/or promote tumor growth. Here, we identify secreted phospholipases A2 (sPLA2s) as stem cell niche factors with context-dependent functions in the digestive tract. We show that group IIA sPLA2, a known genetic modifier of mouse intestinal tumorigenesis, is expressed by Paneth cells in the small intestine, while group X sPLA2 is expressed by Paneth/goblet-like cells in the colon. During homeostasis, group IIA/X sPLA2s inhibit Wnt signaling through intracellular activation of Yap1. However, upon inflammation they are secreted into the intestinal lumen, where they promote prostaglandin synthesis and Wnt signaling. Genetic ablation of both sPLA2s improves recovery from inflammation but increases colon cancer susceptibility due to release of their homeostatic Wnt-inhibitory role. This "trade-off" effect suggests sPLA2s have important functions as genetic modifiers of inflammation and colon cancer.

IPMK: A versatile regulator of nuclear signaling events.

Inositol-derived metabolites (e.g., phosphoinositides and inositol polyphosphates) are key second messengers that are essential for controlling a wide range of cellular events. Inositol polyphosphate multikinase (IPMK) exhibits complex catalytic activities that eventually yield water-soluble inositol polyphosphates (e.g., IP4 and IP5) and lipid-bound phosphatidylinositol 3,4,5-trisphosphate. A series of recent studies have suggested that IPMK may be a multifunctional regulator in the nucleus of mammalian cells. In this review, we highlight the novel modes of action of IPMK in transcriptional and epigenetic regulation, and discuss its roles in physiology and disease.

Feline intestinal mast cell tumours: clinicopathological characterisation and KIT mutation analysis.

OBJECTIVES: Feline intestinal mast cell tumours (FIMCTs) are rare and reportedly characterised by poor differentiation, aggressive biological behaviour and lack of reliable therapeutic aids. KIT proto-oncogene-activating mutations have never been investigated in these tumours. This study describes the main clinicopathological and microscopic features observed in 17 FIMCTs. METHODS: Tumour degree of differentiation, proliferative activity, Kit protein expression and KIT mutations were evaluated and correlated with survival to assess their prognostic relevance. RESULTS: Ten tumours were located in the small intestine, two in the ileocaecocolic junction, and five in the large intestine. Survival times ranged from 3-538 days. Fifteen tumours were evaluated histologically, and there were six well-differentiated, six moderately differentiated and three poorly differentiated FIMCTs. The last showed a medium-to-large deposition of collagen tissue (P <0.001), and significantly higher mitotic and Ki67 indexes compared with more differentiated tumours (P = 0.011). On survival analysis, tumour degree of differentiation (P <0.001) and a mitotic index >2 (P = 0.022) were significantly associated with decreased survival times. Twelve cases showed Kit protein immunoexpression. The Kit pattern was membranous in five cases (33.3%), focal paranuclear in five (33.3%) and diffuse cytoplasmic in two (13.3%). Cytoplasmic Kit patterns were associated with a lesser differentiation (P = 0.015). Mutation analysis was successfully performed on 12 primary tumours and four lymph node metastases; however, no encoding mutation was detected. CONCLUSIONS AND RELEVANCE: Contrary to reports in the literature, FIMCTs seem to have an extremely variable biological behaviour. We propose a classification based on tumour degree of differentiation and proliferative activity. These findings need to be confirmed in larger series, and exploration of further genomic regions of KIT is warranted to clarify its role in the development and progression of these neoplasms.

Unravelling the transcriptomic landscape of the major phase II UDP-glucuronosyltransferase drug metabolizing pathway using targeted RNA sequencing.

A comprehensive view of the human UDP-glucuronosyltransferase (UGT) transcriptome is a prerequisite to the establishment of an individual's UGT metabolic glucuronidation signature. Here, we uncover the transcriptome landscape of the 10 human UGT gene loci in normal and tumoral metabolic tissues by targeted RNA next-generation sequencing. Alignment on the human hg19 reference genome identifies 234 novel exon-exon junctions. We recover all previously known UGT1 and UGT2 enzyme-coding transcripts and identify over 130 structurally and functionally diverse novel UGT variants. We further expose a revised genomic structure of UGT loci and provide a comprehensive repertoire of transcripts for each UGT gene. Data also uncover a remodelling of the UGT transcriptome occurring in a tissue- and tumor-specific manner. The complex alternative splicing program regulating UGT expression and protein functions is likely critical in determining detoxification capacity of an organ and stress-related responses, with significant impact on drug responses and diseases.

Cyclin-Dependent Kinase Activity Correlates with the Prognosis of Patients Who Have Gastrointestinal Stromal Tumors.

BACKGROUND: The estimation of recurrence risk remains a critical issue in relation to gastrointestinal stromal tumors (GISTs) treated with adjuvant therapy. The accuracy of the commonly used risk stratifications is not always adequate. METHODS: For this study, data were prospectively collected from 68 patients with GISTs who underwent R0 surgery between 2004 and 2009. The results from this analysis cohort were evaluated using the data obtained from an additional 40 patients in the validation cohort. Cyclin-dependent kinase 1 (CDK1)- and CDK2-specific activities were measured using a non-RI kinase assay system. RESULTS: The specific activities of CDK1 and CDK2, but not their expression, significantly correlated with recurrence. The specific activities of both CDK1 and CDK2 were independently correlated with mitosis and significantly correlated with recurrence-free survival (RFS). In the multivariate analysis, CDK2-specific activity (P = 0.0006), tumor size (P = 0.0347), and KIT deletion mutations (P = 0.0006) were significantly correlated with RFS in the analysis cohort. In the validation cohort, CDK2-specific activity (P = 0.0368) was identified as an independent prognostic factor for tumor recurrences with tumor location (P = 0.0442). CONCLUSION: The results suggest that the specific activities of CDK1 and CDK2 may reflect the proliferative activity of GISTs and that CDK2-specific activity is a good prognostic factor predicting recurrence after macroscopic complete resection of GISTs.

ERBB2 gene as a potential therapeutic target in small bowel adenocarcinoma.

AIM OF THE STUDY: Small bowel adenocarcinoma (SBA) is a rare and aggressive tumour with poor outcomes. Because of its low incidence, the number prospective studies remains insufficient leading to poor knowledge and absence of standard of care. Aiming to better understand small bowel carcinogenesis we investigated the frequency of somatic mutations in a large data set of patients in more than 740 mutational hotspots among 46 genes. METHODS: In total, 83 SBA cases were selected from two European databases. The sequencing was performed using the Ion 316 Chip. Additionally we looked into ERBB2 expression and microsatellite instability (MSI) status. RESULTS: The tumours most frequently were duodenal (47%) and stage ⩾3 (63%). Eight genes were mutated with a frequency >5%: KRAS, TP53, APC, SMAD4, PIK3CA, ERBB2, BRAF and FBXW7. ERBB2 alterations are present in 10 patients (12%) through mutations (7 cases) or amplifications (3 cases). ERBB2 mutations were significantly associated with duodenal tumour location (P=0.04). In this group, there was a positive association with dMMR status (P=0.006) and APC mutation (P=0.02) but negative association with p53 mutations (P=0.038). CONCLUSIONS: This study describes the first large screening of somatic mutations in SBA using next generation sequencing. The ERBB2 mutation was revealed to be one of the most frequent alterations in SBA with a distribution dependent on tumour location. In most cases ERBB2 mutation was identical (p.L755S). In clinical practice, this may suggest that more than 10% of the patients with SBA could be treated using an anti-ERBB2-targeted agent.

Carbonic anhydrase IX expression is associated with favorable prognostic factors in small intestinal carcinoma.

Tumor hypoxia is associated with more aggressive behavior and resistance to chemotherapy and radiotherapy. Carbonic anhydrase IX (CA9) level increases under hypoxia and is related to poor prognostic factors. The aim of this study was to evaluate the expression of CA9 and to identify its prognostic significance in small intestinal carcinomas (SICs). CA9 expression was observed in 36% (63/175) of SICs. CA9 expression showed significant correlation with well- and moderately differentiated tumors compared with poorly differentiated tumors (p=0.039), tumors with no lymph node metastasis (p=0.005), and lower stage carcinomas (p=0.009). CA9 expression showed an inverse correlation with perineural invasion (p=0.021) and lymphatic invasion (p=0.022). No significant correlation was observed between CA9 expression and gross type, histological type, pathological tumor (pT) classification, vascular invasion, pancreas invasion, and retroperitoneal seeding. SICs with CA9 overexpression showed better overall survival compared with those with no or weak CA9 expression (p=0.048). In the multivariate analysis, poorly differentiated SICs (p<0.001) and SICs with lymph node metastasis (p=0.002) were independent poor prognostic factors. CA9 expression in SICs is more frequently associated with good prognostic markers and better overall survival; however, it is not an independent prognostic factor.

Chemopreventive effects of an HDAC2-selective inhibitor on rat colon carcinogenesis and APCmin/+ mouse intestinal tumorigenesis.

Epigenetic modulators, particularly histone deacetylases (HDACs), are valid targets for cancer prevention and therapy. Recent studies report that HDAC2 overexpression is associated with colon tumor progression and is a potential target for colon cancer prevention. This study tested chemopreventive and dose-response effects of Ohio State University HDAC42 (OSU-HDAC42), a selective HDAC2 inhibitor, using a rat colon carcinogenesis model to assess aberrant crypt foci inhibition and a familial adenomatous polyposis model to assess intestinal tumor inhibition. Colonic aberrant crypt foci were induced by azoxymethane (AOM) (15 mg/kg body weight, once-weekly subcutaneous injections at 8 and 9 weeks age). One week after AOM treatment, groups of rats were fed an AIN-76A diet containing 0, 75, 150, and 300 ppm OSU-HDAC42 for 8 weeks, and colonic aberrant crypt foci were evaluated. To assess the inhibitory effect of OSU-HDAC42 on small-intestinal polyps and colon tumor growth, 6-week-old male C57Bl/6J-APC(min/+)mice were fed an AIN-76A diet containing 150 ppm OSU-HADC42 or 300 ppm pan-HDAC inhibitor suberoylanilide hydroxyamic acid (SAHA) for 80 days. Our results demonstrate that dietary OSU-HDAC42 produced dose-dependent inhibition of AOM-induced colonic aberrant crypt foci formation (13-50%; P < 0.01 to < 0.0001) and reduced multiple crypts with ≥ 4 crypts per focus (25-57%; P < 0.01 to < 0.0001) in F344 rats. Our findings show that 150 ppm OSU-HDAC42 significantly inhibited small-intestinal polyps (>46%; P < 0.001), with polyp size measuring >1 mm (P < 0.001), and colon tumors (>26%) in APC(min/+)mice, whereas 300 ppm SAHA showed nonsignificant inhibition. Mice fed 150 ppm OSU-HDAC42 had significantly decreased HDAC2, proliferating cell nuclear antigen, B cell lymphoma 2, cyclin-dependent kinase 2, and cell division cycle homolog 25C expression levels and increased p53 expression levels. These observations demonstrate the chemopreventive efficacy of OSU-HDAC42 against chemically induced and polyposis models of intestinal tumorigenesis.

Prdm5 suppresses Apc(Min)-driven intestinal adenomas and regulates monoacylglycerol lipase expression.

PRDM proteins are tissue-specific transcription factors often deregulated in diseases, particularly in cancer where different members have been found to act as oncogenes or tumor suppressors. PRDM5 is a poorly characterized member of the PRDM family for which several studies have reported a high frequency of promoter hypermethylation in cancer types of gastrointestinal origin. We report here the characterization of Prdm5 knockout mice in the context of intestinal carcinogenesis. We demonstrate that loss of Prdm5 increases the number of adenomas throughout the murine small intestine on an Apc(Min) background. By using the genome-wide ChIP-seq (chromatin immunoprecipitation (ChIP) followed by DNA sequencing) and transcriptome analyses we identify loci encoding proteins involved in metabolic processes as prominent PRDM5 targets and characterize monoacylglycerol lipase (Mgll) as a direct PRDM5 target in human colon cancer cells and in Prdm5 mutant mouse intestines. Moreover, we report the downregulation of PRDM5 protein expression in human colon neoplastic lesions. In summary, our data provide the first causal link between Prdm5 loss and intestinal carcinogenesis, and uncover an extensive and novel PRDM5 target repertoire likely facilitating the tumor-suppressive functions of PRDM5.

Intestinal acyl-CoA synthetase 5: activation of long chain fatty acids and behind.

The intestinal mucosa is characterized by a high complexity in terms of structure and functions and allows for a controlled demarcation towards the gut lumen. On the one hand it is responsible for pulping and selective absorption of alimentary substances ensuring the immunological tolerance, on the other hand it prevents the penetration of micro-organisms as well as bacterial outgrowth. The continuous regeneration of surface epithelia along the crypt-villus-axis in the small intestine is crucial to assuring these various functions. The core phenomena of intestinal epithelia regeneration comprise cell proliferation, migration, differentiation, and apoptosis. These partly contrarily oriented processes are molecularly balanced through numerous interacting signaling pathways like Wnt/ß-catenin, Notch and Hedgehog, and regulated by various modifying factors. One of these modifiers is acyl-CoA synthetase 5 (ACSL5). It plays a key role in de novo lipid synthesis, fatty acid degradation and membrane modifications, and regulates several intestinal processes, primarily through different variants of protein lipidation, e.g., palmitoylation. ACSL5 was shown to interact with proapoptotic molecules, and besides seems to inhibit proliferation along the crypt-villus-axis. Because of its proapoptotic and antiproliferative characteristics it could be of significant relevance for intestinal homeostasis, cellular disorder and tumor development.

Inflammatory myofibroblastic tumor with RANBP2 and ALK gene rearrangement: a report of two cases and literature review.

Inflammatory myofibroblastic tumors (IMTs) are categorized as intermediate biologic neoplasms, whereas IMTs with genetic features of ran-binding protein 2 (RANBP2) and anaplastic lymphoma kinase (ALK) rearrangement (IMT-RAs) are possibly related to a more aggressive clinical course. However, fewer than 10 cases of IMT-RA have been reported to date. Herein, we present 2 new cases of IMT-RA in which both tumors recurred quickly after primary surgery; one patient died 3 months later from the disease, and the other patient has been living with the disease for 12 months. IMT-RAs are characterized by noncohesive epithelioid and rounded tumoral cell morphology, commonly derived from pelvic and peritoneal cavities, and frequently show larger tumor sizes. The relation between the clinicopathologic features and poor prognosis of IMT-RA is discussed. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/3314123381007714.