Ulcerative colitis (UC) is a chronic inflammatory bowel disease that is closely associated with colon cancer. Expression of the enzyme heparanase is clearly linked to colon carcinoma progression, but its role in UC is unknown. Here we demonstrate for what we believe to be the first time the importance of heparanase in sustaining the immune-epithelial crosstalk underlying colitis-associated tumorigenesis. Using histological specimens from UC patients and a mouse model of dextran sodium sulfate-induced colitis, we found that heparanase was constantly overexpressed and activated throughout the disease. We demonstrate, using heparanase-overexpressing transgenic mice, that heparanase overexpression markedly increased the incidence and severity of colitis-associated colonic tumors. We found that highly coordinated interactions between the epithelial compartment (contributing heparanase) and mucosal macrophages preserved chronic inflammatory conditions and created a tumor-promoting microenvironment characterized by enhanced NF-κB signaling and induction of STAT3. Our results indicate that heparanase generates a vicious cycle that powers colitis and the associated tumorigenesis: heparanase, acting synergistically with the intestinal flora, stimulates macrophage activation, while macrophages induce production (via TNF-α-dependent mechanisms) and activation (via secretion of cathepsin L) of heparanase contributed by the colon epithelium. Thus, disruption of the heparanase-driven chronic inflammatory circuit is highly relevant to the design of therapeutic interventions in colitis and the associated cancer.

The mechanism of action of natural killer (NK) cells in type 1 diabetes is still unknown. Here we show that the activating receptor NKp46 recognizes mouse and human ligands on pancreatic beta cells. NK cells appeared in the pancreas when insulitis progressed to type 1 diabetes, and NKp46 engagement by beta cells led to degranulation of NK cells. NKp46-deficient mice had less development of type 1 diabetes induced by injection of a low dose of streptozotocin. Injection of soluble NKp46 proteins into nonobese diabetic mice during the early phase of insulitis and the prediabetic stage prevented the development of type 1 diabetes. Our findings demonstrate that NKp46 is essential for the development of type 1 diabetes and highlight potential new therapeutic modalities for this disease.

Type 1 diabetes is characterized by the infiltration of inflammatory cells into pancreatic islets of Langerhans, followed by the selective and progressive destruction of insulin-secreting beta cells. Isletinfiltrating leukocytes secrete cytokines such as IL-1␤ and IFN-␥, which contribute to beta cell death. In vitro evidence suggests that cytokine-induced activation of the transcription factor NF-B is an important component of the signal triggering beta cell apoptosis. To study the in vivo role of NF-B in beta cell death, we generated a transgenic mouse line expressing a degradation-resistant NF-B protein inhibitor (⌬NI B␣), acting specifically in beta cells, in an inducible and reversible manner, by using the tet-on regulation system. In vitro, islets expressing the ⌬NI B␣ protein were resistant to the deleterious effects of IL-1␤ and IFN-␥, as assessed by reduced NO production and beta-cell apoptosis. This effect was even more striking in vivo, where nearly complete protection against multiple low-dose streptozocin-induced diabetes was observed, with reduced intraislet lymphocytic infiltration. Our results show in vivo that beta cell-specific activation of NF-B is a key event in the progressive loss of beta cells in diabetes. Inhibition of this process could be a potential effective strategy for beta-cell protection.apoptosis ͉ cytokine ͉ diabetes ͉ transgenic mice ͉ insulin

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Summary Objective  Glucagonoma is a pancreatic neuroendocrine tumour that arises from alpha cells in the pancreas and is often accompanied by a characteristic clinical syndrome. Design  In this report, we present the cumulative experience and clinical characteristics of six patients diagnosed with glucagonoma and the glucagonoma syndrome and treated at our centre during the past 25 years. Results  Although the course of the disease was variable, some features were similar. The median age at diagnosis was 53·5 years; the median time from onset of symptoms to diagnosis was 39 months. Presenting symptoms were as follows: weight loss 5/6 (83%), necrotizing migratory erythema (NME) 5/6 (83%), diabetes mellitus 4/6 (66%) and diarrhoea, weakness and thrombosis 2/6 (33%). Plasma glucagon was elevated in all patients upon diagnosis (range 200–10 000 pm; N < 50). Skin biopsy was diagnostic only in 1/6 specimens obtained, even after revision. Metastatic disease developed in all patients; 4/6 initially presented with hepatic metastasis. All patient symptoms responded to somatostatin analogue therapy. In 4/6, the NME responded to amino acid solutions. Other modes of therapy were as follows: surgery in 3/6 patients, peptide receptor radioligand therapy with 90Y‐DOTATOC (PRRT) in 3/6 patients (two responses) and chemotherapy in three patients (two responded). Four out of six patients died of the disease, and median survival time was 6·25 years (range 2–11) from diagnosis and 8 years (range 8–16) from initial symptoms. Five‐year survival was 66%. Conclusion  Our data indicate that somatostatin analogues and an aggressive surgical approach offer symptom relief and tumour control. Among other available treatment modalities, PRRT seems to hold the most promise.

The aim of the present study was to evaluate the toxicity of biodegradable hydrogels in the rat with a future aim of utilizing this hydrogel as a vehicle for brachytherapy delivery in cancer patients. Two types of chitosan hydrogels: fast degrading and slow degrading; were prepared and surgically implanted in rats. The adjacent tissue response to the gels after subcutaneous and intraperitoneal implantation was examined histologically and found to be identical to typical foreign body response and was milder than the response to absorbable surgical sutures (Vicril). Neither tissue damage nor gel fragments could be detected in distant organs (brain, heart, lungs, liver, spleen, kidney, and sternal bone marrow) after implantation of the hydrogels. The degradation mechanism of the gels was studied in vivo, and it was deduced that an oxidative process degraded the chitosan. Loading the hydrogels with a radioisotope (131I-norcholesterol) caused a severe tissue response and necrosis in adjacent tissues only at a distance of several microns. It is concluded that crosslinked chitosan implants could serve as alternative, biocompatible, and safe biodegradable devices for radioisotope delivery in brachytherapy for cancer.

We evaluated the latest pathological criteria for completion right hemicolectomy (RHC) in patients with appendiceal neuroendocrine tumors (ANETs) with emphasis on the size of the primary tumor. Data of 28 consecutive patients who underwent RHC for ANETs in three tertiary hospitals were reviewed retrospectively to assess the indications for completion RHC. 10/28 patients were found to have residual disease (36%). In 8/28 patients (29%), the tumor diameter was <1 cm (mean 0.7 ± 0.2 cm, range 0.5-0.9 cm); the indications for RHC included: tumor presence in surgical margins (1 patient), extensive mesoappendiceal invasion (EMI) (1 patient), vascular invasion (VI) (3 patients), Ki-67 ≥2% (3 patients); residual disease was present in 1 patient (3.5%). In 13/28 patients (46%), the tumor diameter was ≥1 and <2 cm (mean 1.30 ± 0.2 cm, range 1.0-1.8 cm); the indications for RHC were: EMI (2 patients), VI (2 patients), Ki-67 ≥2% (2 patients); residual disease was present in 5 patients (18%). In 7/28 patients (25%), the tumor diameter was ≥2 cm (mean 2.5 ± 0.7 cm, range 2.0-4.0 cm). In this final subgroup, RHC was an accepted practice irrespective of other pathologic findings: the tumor was present in surgical margins in 2 patients, in 5 patients VI was demonstrated, and Ki-67 ≥2% was found in 5 patients; residual disease was present in 4 patients (14%). Using the latest European Neuroendocrine Tumor Society criteria for RHC, residual disease may be missed in 18% of ANET patients.