[show abstract][hide abstract] ABSTRACT: Initially identified as an inhibitor of transforming growth factor (TGF)-β mainly owing to its ability to bind TGF-β receptor type I and abrogate TGF-β-driven signaling, Smad7 can interact with additional intracellular proteins and regulate TGF-β-independent pathways, thus having a key role in the control of neoplastic processes in various organs. Genome-wide association studies have shown that common alleles of Smad7 influence the risk of colorectal cancer (CRC), even though the contribution of Smad7 in colon carcinogenesis is not fully understood. In this study, we assessed the expression and role of Smad7 in human and mouse models of sporadic CRC. We document a significant increase of Smad7 in human CRC relative to the surrounding nontumor tissues and show that silencing of Smad7 inhibits the growth of CRC cell lines both in vitro and in vivo after transplantation into immunodeficient mice. Knockdown of Smad7 results in enhanced phosphorylation of the cyclin-dependent kinase (CDK)2, accumulation of CRC cells in S phase and enhanced cell death. Smad7-deficient CRC cells have lower levels of CDC25A, a phosphatase that dephosphorylates CDK2, and hyperphosphorylated eukaryotic initiation factor 2 (eIF2)α, a negative regulator of CDC25 protein translation. Consistently, knockdown of Smad7 associates with inactivation of eIF2α, lower CDC25A expression and diminished fraction of proliferating cells in human CRC explants, and reduces the number of intestinal tumors in Apc(min/+) mice. Altogether, these data support a role for Smad7 in sustaining colon tumorigenesis.
Cell Death & Disease 01/2014; 5:e1073. · 6.04 Impact Factor
[show abstract][hide abstract] ABSTRACT: During the course of inflammatory bowel disease (IBD), surgery may be needed. Approximately 20% of patients with ulcerative colitis (UC) will require surgery, whereas up to 80% of Crohn's disease (CD) patients will undergo an operation during their lifetime. For UC patients requiring surgery, total proctocolectomy and ileoanal pouch anastomosis (IPAA) is the operation of choice as it provides a permanent cure and good quality of life. Nevertheless a permanent stoma is a good option in selected patients, especially the elderly. Minimally invasive surgery has replaced the conventional open approach in many specialized centres worldwide. Laparoscopic colectomy and restorative IPAA is rapidly becoming the standard of care in the treatment of UC requiring surgery, whilst laparoscopic ileo-cecal resection is already the new gold standard in the treatment of complicated CD of terminal ileum. Short term advantages of laparoscopic surgery includes faster recovery time and reduced requirement for analgesics. It is, however, in the long term that minimally invasive surgery has demonstrated its superiority over the open approach. A better cosmesis, a reduced number of incisional hernias and fewer adhesions are the long term advantages of laparoscopy in IBD surgery. A reduction in abdominal adhesions is of great benefit when a second operation is needed in CD and this influences positively the pregnancy rate in young women undergoing restorative IPAA. In developing the therapeutic plan for IBD patients it should be recognized that the surgical approach to the abdomen has changed and that surgical treatment of complicated IBD can be safely performed with a true minimally invasive approach with great patient satisfaction.
World Journal of Gastroenterology 04/2013; 19(16):2445-2448. · 2.55 Impact Factor
[show abstract][hide abstract] ABSTRACT: To compare computed tomography enteroclysis (CTE) vs small intestine contrast ultrasonography (SICUS) for assessing small bowel lesions in Crohn's disease (CD), when using surgical pathology as gold standard.
From January 2007 to July 2008, 15 eligible patients undergoing elective resection of the distal ileum and coecum (or right colon) were prospectively enrolled. All patients were under follow-up. The study population included 6 males and 9 females, with a median age of 44 years (range: 18-80 years). Inclusion criteria: (1) certain diagnosis of small bowel requiring elective ileo-colonic resection; (2) age between 18-80 years; (3) elective surgery in our Surgical Unit; and (4) written informed consent. SICUS and CTE were performed ≤ 3 mo before surgery, followed by surgical pathology. The following small bowel lesions were blindly reported by one sonologist, radiologist, surgeon and histolopathologist: disease site, extent, strictures, abscesses, fistulae, small bowel dilation. Comparison between findings at SICUS, CTE, surgical specimens and histological examination was made by assessing the specificity, sensitivity and accuracy of each technique, when using surgical findings as gold standard.
Among the 15 patients enrolled, CTE was not feasible in 2 patients, due to urgent surgery in one patients and to low compliance in the second patient, refusing to perform CTE due to the discomfort related to the naso-jejunal tube. The analysis for comparing CTE vs SICUS findings was therefore performed in 13 out of the 15 CD patients enrolled. Differently from CTE, SICUS was feasible in all the 15 patients enrolled. No complications were observed when using SICUS or CTE. Surgical pathology findings in the tested population included: small bowel stricture in 13 patients, small bowel dilation above ileal stricture in 10 patients, abdominal abscesses in 2 patients, enteric fistulae in 5 patients, lymphnodes enlargement (> 1 cm) in 7 patients and mesenteric enlargement in 9 patients. In order to compare findings by using SICUS, CTE, histology and surgery, characteristics of the small bowel lesions observed in CD each patient were blindly reported in the same form by one gastroenterologist-sonologist, radiologist, surgeon and anatomopathologist. At surgery, lesions related to CD were detected in the distal ileum in all 13 patients, also visualized by both SICUS and CTE in all 13 patients. Ileal lesions > 10 cm length were detected at surgery in all the 13 CD patients, confirmed by SICUS and CTE in the same 12 out of the 13 patients. When using surgical findings as a gold standard, SICUS and CTE showed the exactly same sensitivity, specificity and accuracy for detecting the presence of small bowel fistulae (accuracy 77% for both) and abscesses (accuracy 85% for both). In the tested CD population, SICUS and CTE were also quite comparable in terms of accuracy for detecting the presence of small bowel strictures (92% vs 100%), small bowel fistulae (77% for both) and small bowel dilation (85% vs 82%).
In our study population, CTE and the non-invasive and radiation-free SICUS showed a comparable high accuracy for assessing small bowel lesions in CD.
World Journal of Gastroenterology 11/2012; 18(42):6088-95. · 2.55 Impact Factor
[show abstract][hide abstract] ABSTRACT: Celiac disease (CD)-associated inflammation is characterized by high interleukin- 21 (IL-21), but the mechanisms that control IL-21 production are not fully understood. Here we analyzed IL-21 cell sources and examined how IL-21 production is regulated in CD. Intraepithelial lymphocytes (IELs) and lamina propria lymphocytes (LPLs), isolated from CD patients and non-CD controls, were analyzed for cell markers, cytokines, and transcription factors by flow cytometry. IL-21 was highly produced by CD4+ and CD4+/CD8+ IELs and LPLs in active CD. IL-21-producing cells coexpressed interferon-γ (IFN-γ) and to a lesser extent T helper type 17 (Th17) cytokines. Treatment of control LPLs with IL-15, a cytokine overproduced in CD, activated Akt and STAT3 (signal transducer and activator of transcription 3), thus enhancing IL-21 synthesis. Active CD biopsies contained elevated levels of Akt, and blockade of IL-15 in those samples reduced IL-21. Similarly, neutralization of IL-15 in biopsies of inactive CD patients inhibited peptic-tryptic digest of gliadin-induced IL-21 expression. These findings indicate that in CD, IL-15 positively regulates IL-21 production.Mucosal Immunology advance online publication 11 July 2012. doi:10.1038/mi.2012.65.
[show abstract][hide abstract] ABSTRACT: COX-2 (cyclo-oxygenase-2) and PGE₂ (prostaglandin E₂) play a key role in sustaining CRC (colorectal cancer) cell growth and survival. Indeed, the use of agents targeting the COX-2/PGE₂ axis has been associated with a reduction in the development of CRC in both humans and murine models of colon carcinogenesis. In the present study, we investigated whether 2-methoxy-5-amino-N-hydroxybenzamide (herein termed 2-14), a derivative of mesalamine that inhibits CRC cell growth both in vitro and in vivo, negatively regulates COX-2/PGE₂ expression in CRC cells and assessed whether the 2-14-mediated anti-neoplastic effect is strictly dependent on the inhibition of this pathway. Our results show that 2-14 blocks the growth and enhances the death of HT-115, a CRC cell line overexpressing COX-2, and that these effects associate with inhibition of COX-2 but not COX-1. 2-14 also down-regulates TNFα (tumour necrosis factor α)-induced COX-2 in HT-29 cells as well as COX-2/PGE₂ expression in ex vivo cultures of human CRC explants. Similarly, 2-14 reduces COX-2, but not COX-1, in tumoural areas developing in a mouse model of CAC (colitis-associated colon cancer). Finally, we show that 2-14 exhibits in vitro and in vivo anti-mitogenic effects in DLD-1, a COX-deficient CRC cell line. Taken together, these results suggest that 2-14 inhibits CRC cell growth through COX-2-dependent and -independent mechanisms.
[show abstract][hide abstract] ABSTRACT: To compare long-term results of gastric cancer patients undergoing laparoscopic and open gastrectomy in a single unit.
From February 2000 to September 2004, all patients with adenocarcinoma of the stomach were assessed to entry in this longitudinal prospective non-randomized trial. Primary endpoint was cancer-related survival and secondary endpoints were overall survival, evaluation of surgical complications and mortality.
Fifty-eight patients were enrolled. Forty-seven patients were followed-up (range 11-103, median 38 mo). Four patients were lost at follow up. Twenty-two patients underwent a laparoscopic gastric surgery (LGS) and 25 had a standard open procedure (OGS). No statistical difference was found between the two groups in terms of 5 years cancer-related mortality rate (50% vs 52%, P = 1), and 5 years overall mortality rate (54.5% vs 56%, P = 1). Accordingly, cancer-related and overall survival probability by Kaplan-Meier method showed comparable results (P = 0.81 and P = 0.83, respectively). We found no differences in surgical complications in the 2 groups. There was no conversion to open surgery in this series.
LGS is as effective as OGS in the management of advanced gastric cancer. However LGS cannot be recommended routinely over OGS for the treatment of advanced gastric cancer.
World Journal of Gastroenterology 11/2011; 17(41):4602-6. · 2.55 Impact Factor
[show abstract][hide abstract] ABSTRACT: Duplications of the alimentary tract (ATD) are rare congenital anomalies often found early in life. They may occur anywhere in the intestinal tract but the ileum is the most frequently affected site. Clinical presentation of ATD in adults is variable and because these lesions occur so infrequently they are rarely suspected. In the present report we describe a case of ileal duplication in a 61-year-old patient with Crohn's disease. Despite various radiological investigations and medical consultations, the diagnosis was only made on the surgical specimen.
World journal of gastrointestinal surgery. 08/2011; 3(8):128-30.
[show abstract][hide abstract] ABSTRACT: The pathogenesis of inflammatory bowel disease (IBD) is believed to involve an altered balance between effector and regulatory T cells. Aryl hydrocarbon receptor (AhR), a ligand-dependent transcription factor that mediates the toxicity of dioxins, controls T-cell responses. We investigated the role of AhR in inflammation and pathogenesis of IBD in humans and mouse models.
AhR expression was evaluated in intestinal tissue samples from patients with IBD and controls by real-time polymerase chain reaction (PCR) and flow cytometry. Intestinal lamina propria mononuclear cells (LPMCs) were activated in the presence or absence of the AhR agonist 6-formylindolo(3, 2-b)carbazole (Ficz). Colitis was induced in mice using trinitrobenzene sulfonic acid (TNBS), dextran sulfate sodium (DSS), or T-cell transfer. Mice were given injections of Ficz or the AhR antagonist 2-metyl-2H-pyrazole-3-carboxylic acid; some mice first received injections of a blocking antibody against interleukin (IL)-22. Cytokines were quantified by real-time PCR and flow cytometry.
Intestine tissue from patients with IBD expressed significantly less AhR than controls. In LPMCs from patients with IBD, incubation with Ficz reduced levels of interferon gamma (IFN)-γ and up-regulated IL-22. Mice injected with Ficz were protected against TNBS-, DSS-, and T-cell transfer-induced colitis; they had marked down-regulation of inflammatory cytokines and induction of IL-22. Mice given AhR antagonist produced more inflammatory cytokines and less IL-22 and developed a severe colitis. Neutralization of endogenous IL-22 disrupted the protective effect of Ficz on TNBS-induced colitis.
AhR is down-regulated in intestinal tissue of patients with IBD; AhR signaling, via IL-22, inhibits inflammation and colitis in the gastrointestinal tract of mice. AhR-related compounds might be developed to treat patients with IBDs.
[show abstract][hide abstract] ABSTRACT: The long-term risk of neoplasia in Crohn's disease (CD) patients treated with infliximab is undefined. The aim was to assess, in a multicenter, matched-pair study, whether infliximab use in CD is associated with an increased frequency of neoplasia in the long term.
A multicenter, long-term, matched-pair study was conducted in 12 referral inflammatory bowel disease (IBD) centers. An initial cohort of 808 CD patients, including 404 infliximab-treated (CD-IFX) and 404 matched CD controls never treated with infliximab (CD-C) studied from 1999 to 2004, was followed up for an additional 4 years (2004-2008). Cases and controls were matched for: sex, age (±5 years), CD site, follow-up (±5 years), immunosuppressant use, and CD duration (±5 years). From 1999 to 2008 the frequency and characteristics of neoplasia were compared between CD-IFX and CD-C.
In 2008, 591 patients (304 CD-IFX, 287 CD-C) were in follow-up. Matched couples included 442 patients: 221 CD-IFX and 221 CD-C (median follow-up, months: 72, range 48-114 versus 75, range 44-114). From 1999 to 2008 the frequency of neoplasia among the 591 patients did not differ between CD-IFX (12/304; 3.94%) and CD-C (12/287; 4.19%; P = 0.95). A comparable frequency of neoplasia was also observed between the 221 matched couples (CD-IFX: 8/221; 3.61% versus CD-C: 9/221; 4.07%; P = 1). No specific histotype of cancer appeared associated with infliximab use.
The frequency of neoplasia was comparable in an adult population of CD patients treated or not with infliximab, matched for clinical variables and followed up for a median of 6 years.
[show abstract][hide abstract] ABSTRACT: An altered balance between effector and regulatory factors is supposed to sustain the tissue-damaging immune response in inflammatory bowel disease (IBD). We have recently shown that in IBD, there is a defective synthesis of the counter-regulatory cytokine, interleukin (IL)-25. In this study we investigated factors that control IL-25 production in the gut. IBD patients produced less IL-25 when compared with normal controls. Stimulation of normal intestinal explants with tumor necrosis factor-α (TNF-α), but not interferon-γ (IFN-γ) or IL-21, reduced IL-25 synthesis. Consistently, IL-25 production was enhanced by anti-TNF-α both in vitro and in vivo. Upregulation of IL-25 was also seen in normal colonic explants stimulated with transforming growth factor-β1 (TGF-β1). As in IBD, TGF-β1 activity is abrogated by Smad7, we next assessed whether inhibition of Smad7 with an antisense oligonucleotide enhanced IL-25 expression. Knockdown of Smad7 was accompanied by an increase in IL-25 production. Data show that IL-25 production is differently regulated by TNF-α and TGF-β1 in the human gut.
[show abstract][hide abstract] ABSTRACT: Ileocolonoscopy (IC) is the gold standard for assessing Crohn's Disease (CD) recurrence after ileo-colonic resection. In a prospective longitudinal study we compared findings related to CD recurrence when using techniques visualizing either the luminal or the extraluminal surface (IC and small bowel follow through, SBFT vs Small Intestine Contrast Ultrasonography, SICUS).
From 2003 to 2008, 25 CD patients undergoing ileo-colonic resection were enrolled. Clinical assessment (CDAI) was performed at 1, 2 and 3 years. IC was performed at 1 (n=25) and 3 years (n=15), SBFT at 2 years (n=21) and SICUS at 1 (n=25), 2 (n=21) and 3 years (n=15). Recurrence was assessed by SBFT and SICUS (bowel wall thickness, BWT) when using IC as gold standard.
At 1 year, all patients were inactive and recurrence was detected by IC in 24/25 (96%) and by SICUS in 25/25 patients. At 2 years, 6/21 patients (29%) were active and recurrence was detected by SBFT in 12/21 (57%) and by SICUS in 21/21 patients. At 3 years, 5/15 patients (33%) were active, IC showed recurrence in 14/15 (93%), and SICUS in 15/15 patients. The endoscopic score at 1 year was higher in patients developing relapse at 2 years (n=5) than in patients maintaining remission (n=10) (median: 4, range 3-4 vs 2, range 0-3; p=0.003). The same finding was not observed by using SICUS (median BWT at 1 year: 5, range 4-7 vs 3.7, range 3.5-6; p=0.19).
Although IC and SICUS provide a different view of the bowel wall, in experienced hands SICUS provides findings compatible with endoscopic recurrence after ileo-colonic resection for CD. Discrepant findings may be observed in a low proportion of patients with minor lesions related to CD recurrence.
Journal of Crohn s and Colitis 09/2010; 4(3):319-28. · 3.39 Impact Factor
[show abstract][hide abstract] ABSTRACT: We previously demonstrated that in inflammatory bowel disease (IBD) there is enhanced production of interleukin (IL)-21, a cytokine that activates multiple pathways that sustain mucosal inflammation. However, the phenotype of IL-21-producing cells in IBD, and the cytokine(s) they coproduce, is not known. We here characterized the cell source of IL-21 and determined which factors regulate IL-21 in the human gut.
Cytokines were analyzed in CD4+ T intestinal lamina propria lymphocytes (T-LPL) isolated from IBD patients and controls by flow cytometry. Moreover, IL-21 was evaluated in mucosal T follicular cells (TFH). To assess the involvement of IL-12 and IL-23 in the production of IL-21, T-LPL were activated in the presence or absence of IL-12 or IL-23.
The proportion of IL-21-producing CD4+ T-LPL was increased in IBD compared to controls. The majority of IL-21-producing T-LPL coexpressed interferon (IFN)-gamma, and to a lesser extent IL-4 or IL-17A. Activation of CD4+ T-LPL with IL-12 but not IL-23 enhanced the fraction of cells coexpressing IL-21 and IFN-gamma. TFH cells in LPL were identified by CXCR5 expression and expressed IL-21 both in IBD and controls; however, the fraction of IL-21-positive TFH cells was higher in Crohn's disease than in ulcerative colitis and controls. Treatment of CD4+ T-LPL with IL-12 enhanced the frequency of CXCR5+ IL-21-producing TFH cells.
These findings indicate that in IBD IL-21 is mostly produced by CD4+ T-LPL coexpressing IFN-gamma, reinforcing the concept that distinct subsets of T cells can produce IL-21.