Laura Albertoni

PDCD4/miR-21 dysregulation in inflammatory bowel disease-associated carcinogenesis

Inflammatory bowel diseases (IBDs; both ulcerative colitis [UC] and Crohn’s colitis [CC]) are well-established predisposing pathological conditions for colorectal cancer (CRC) development. In IBDs, both the endoscopy and the histology assessment of CRC precursors (i.e., dysplasia, also defined as intraepithelial neoplasia) are associated with low interobserver consistency, and no reliable dysplasia-specific biomarker is available. The programmed cell death 4 (PDCD4) tumor suppressor gene is involved in sporadic colorectal oncogenesis, but scanty information is available on its involvement in IBD-associated colorectal oncogenesis. One hundred twenty tissue samples representative of active and inactive IBD and of flat dysplasia were obtained from 30 cases of UC and 30 of CC who undergone colectomy. Twenty additional biopsy samples obtained from patients with irritable bowel syndrome acted as normal controls. PDCD4 expression was assessed by immunohistochemistry; the expression of miR-21 (a major PDCD4 regulator) was investigated by quantitative real-time PCR and in situ hybridization in different series of a hundred samples. Tissue specimens from both controls and inactive IBD consistently featured strong PDCD4 nuclear immunostain; conversely, lower PDCD4 nuclear expression was featured by both active IBD and IBD-associated dysplastic lesions. Significant PDCD4 down-regulation distinguished IBD-associated dysplasia (p < 0.001) versus active IBD. In both active IBD and dysplasia, PDCD4 down-regulation was significantly associated with miR-21 up-regulation. PDCD4 nuclear down-regulation (which parallels miR-21 up-regulation) is involved in the molecular pathway of IBD-associated carcinogenesis. PDCD4 nuclear expression may be usefully applied as ancillary maker in the histological assessment of IBD-associated dysplastic lesions.

Isolated Tumor Cells in Regional Lymph Nodes as Relapse Predictors in Stage I and II Colorectal Cancer

PURPOSE Lymph node (LN) involvement is the most important prognostic factor in colorectal cancer (CRC), and pN-positive status identifies patients who require adjuvant chemotherapy. Approximately 15% to 20% of patients without nodal metastases (pN0) develop recurrent disease. In this study, we tested the prognostic significance of isolated tumor cells (ITCs) in LNs of patients with pN0 CRC (stages I and II). PATIENTS AND METHODS ITCs in LNs regional to CRC were assessed in 312 consecutive patients with pN0 CRC who were followed up clinically and/or endoscopically for at least 6 months after surgery (mean, 67 months; median, 64 months; range, 8 to 102 months). LNs were dissected from gross surgical specimens according to a standardized protocol (with a mean of 17 LNs per patient; range, five to 107 LNs). In all, 5,313 pN0 LNs were collected and assessed by using cytokeratin immunostaining in two serial histology sections from each LN, which amounting to a total of 10,626 specimens. The correlation between ITC status and cancer recurrence was tested by using univariate and multivariate statistics. RESULTS ITCs were documented in 185 of 312 patients (59%). CRC relapsed in 31 of 312 patients (10%), and 25 of 31 recurrences (81%) were documented among ITC-positive patients. CRC recurrence rates among ITC-positive and ITC-negative patients were 14% (25 of 185 patients) and 4.7% (six of 127 patients), respectively. In both univariate and multivariate analyses, ITC status was the only variable significantly associated with cancer relapse (Cox model; hazard ratio, 3.00; 95% CI, 1.23 to 7.32; P = .013). CONCLUSION In patients with pN0 CRC, cancer relapse was significantly associated with ITCs in regional LNs. ITCs should be considered among the clinicobiologic variables that identify high-risk patients who can benefit from adjuvant chemotherapy.

The Phytocomplex from Fucus vesiculosus and Ascophyllum nodosum Controls Postprandial Plasma Glucose Levels: An In Vitro and In Vivo Study in a Mouse Model of NASH

Edible seaweeds have been consumed by Asian coastal communities since ancient times. Fucus vesiculosus and Ascophyllum nodosum extracts have been traditionally used for the treatment of obesity and several gastrointestinal diseases. We evaluated the ability of extracts obtained from these algae to inhibit the digestive enzymes α-amylase and α-glucosidase in vitro, and control postprandial plasma glucose levels in a mouse model of non-alcoholic steatohepatitis (NASH); a liver disease often preceding the development of Type 2 diabetes (T2DM). This model was obtained by the administration of a high-fat diet. Our results demonstrate that these algae only delayed and reduced the peak of blood glucose (p < 0.05) in mice fed with normal diet, without changing the area under the blood glucose curve (AUC). In the model of NASH, the phytocomplex was able to reduce both the postprandial glycaemic peak, and the AUC. The administration of the extract in a diet particularly rich in fat is associated with a delay in carbohydrate digestion, but also with a decrease in its assimilation. In conclusion, our results indicate that this algal extract may be useful in the control of carbohydrate digestion and absorption. This effect may be therapeutically exploited to prevent the transition of NASH to T2DM.

Differential Effect of Liver Cirrhosis on the Pregnane X Receptor–Mediated Induction of CYP3A1 and 3A2 in the Rat

Conflicting results have been obtained by clinical studies investigating the effect of liver cirrhosis on enzyme induction. Because ethical concerns do not give consent for methodologically rigorous studies in humans, we addressed this question by examining the effect of the prototypical inducer dexamethasone (DEX) on the pregnane X receptor (PXR)–mediated induction of CYP3A1 and 3A2 in a validated animal model of liver cirrhosis obtained by exposure of rats to carbon tetrachloride. For this purpose, we assessed mRNA levels, protein expressions, and enzymatic activities of both CYP3A enzymes, as well as mRNA and protein expressions of PXR in rat populations rigorously stratified according to the severity of liver insufficiency. Constitutive mRNA and protein expressions of CYP3A1 and CYP3A2 and their basal enzyme activities were not affected by liver dysfunction. DEX treatment markedly increased steady-state mRNA level, protein content, and enzymatic activity of CYP3A1 in healthy and cirrhotic rats, irrespective of the degree of liver dysfunction. On the contrary, the inducing effect of DEX on gene and protein expressions and enzyme activity of CYP3A2 was preserved in moderate liver insufficiency, whereas it was greatly curtailed when liver insufficiency became severe. mRNA and protein expressions of PXR were neither reduced by liver dysfunction nor increased by DEX treatment. These results indicate that even the inducibility of cytochrome P450 isoforms under the transcriptional control of the same nuclear receptor may be differentially affected by cirrhosis and may partly explain why conflicting results were obtained by human studies.

Colonic phenotype of the ileum in Crohn's disease: a prospective study before and after ileocolonic resection.

Background:Colonic metaplasia has been described in pouchitis. In a prospective study, we investigated whether colonic phenotype may develop in Crohns disease (CD) ileum. The expression of sulfomucins (colonic mucin), sialomucins, and CD10 (small intestine mucin and phenotype) was evaluated before and after ileocolonic resection for CD. Methods:From February 2007 to March 2010, 22 patients with CD undergoing surgery were enrolled. Clinical (Crohns Disease Activity Index >150) and endoscopic recurrence (Rutgeerts score ≥1) rates were assessed at 6 and 12 months. Ileal samples were taken at surgery (T0), at 6 (T1), and 12 months (T2) for histology, histochemistry (High Iron Diamine-Alcian Blue), and immunohistochemistry (anti-CD10). Results:In 22 patients, recurrence was assessed at 6 and 12 months (clinical recurrence 9% and 18%; endoscopic recurrence 73% and 77%). In all 22 patients, ileal samples were taken at 6 and 12 months (involved area in patients with recurrence). In 19 of 22 (86.3%) patients, the involved ileum was also studied at surgery. At T0, T1, and T2, the expression of sialomucins and CD10 (small intestine mucin and phenotype) was comparable and higher (P < 0.0001) than the expression of sulfomucins (colonic mucin) (mean [range], T0:82 [35–100] versus 75 [0–100] versus 16 [0–50]; T1:96 [60–100] versus 94.7 [50–100] versus 3.89 [0–40]; T2:93.3 [60–100] versus 88.1 [25–100] versus 6.6 [0–40]). The expression of small-intestine mucin and phenotype was higher at T1 (P = 0.025) versus T0 (P = 0.026). Differently, the expression of colonic mucin was lower at T1 versus T0 (P = 0.027). Conclusions:In CD, the ileum involved by severe/established lesions develops a “metaplastic” colonic mucosa phenotype. Differently, CD ileum with no lesions or with early recurrence maintains the “native” small intestine type mucin secretion and phenotype.

Use of Grafts From Anti-HBc–Positive Donors in Liver Transplantation: A 5-Year, Single-Center Experience

INTRODUCTION Liver transplantation (OLT) is the treatment of choice for advanced hepatic disease. The growing gap between waiting list patients and the number of donations has led to acceptance of less than optimal donors. The aim of this study was to evaluate the 5-year experience with anti hepatitis B core antigen (HBc)-positive liver donors. PATIENTS AND METHODS All recipients of anti-HBc-positive grafts from January 2005 to December 2010 were evaluated annually after OLT for liver disease etiology, Model for End-Stage Liver Disease (MELD) score, and the presence of hepatocellular carcinoma (HCC) liver biopsy histology and serology for hepatitis B virus (HBsAg, anti-HBs, HBV-DNA), hepatitis C virus, and hepatitis D virus as well as antiviral prophylaxis to prevent de novo HBV. RESULTS Among the 249 OLT performed from January 2005 to December 2010, (9.3%) cases used grafts from anti-HBc-positive donors. Etiologics of liver disease among the recipients were HBV (n = 13; 32.5%), HCV (n = 13; 32.5%) or other causes (n = 14; 35%). In 20 of the 40 patients (50%), HCC was found in the explanted organ. Of 40 recipients of anti-HBc-positive grafts 11 died, and 7 (17.5%) required retransplantation. Various regimens were employed as post-transplantation antiviral prophylaxis: (l) Immune globulin (25.8%); (2) Oral antiviral drugs (9.7%); and (3) combined prophylaxis (51.6%) or no treatment (12.9%). No difference was observed in patient or graft survival in relation to the etiology of liver disease, the MELD score, or the presence of HCC at the time of OLT, except graft survival was significantly reduced among recipient who underwent transplantation for non-HBV or non-HCV liver diseases compared with those engrafted due to viral hepatitis (P = .0062). No difference was observed in histologic features (grading and staging) compared with the antiviral prophylactic therapy; the 2 patients (5%) who developed de novo HBV had not received prophylaxis after OLT. CONCLUSIONS Matching anti-HBc-positive grafts to recipients without HBV infection before OLT, may be especially safe.

Pregnane X receptor and constitutive androstane receptor modulate differently CYP3A-mediated metabolism in early- and late-stage cholestasis

AIM To ascertain whether cholestasis affects the expression of two CYP3A isoforms (CYP3A1 and CYP3A2) and of pregnane X receptor (PXR) and constitutive androstane receptor (CAR). METHODS Cholestasis was induced by bile duct ligation in 16 male Wistar rats; whereas 8 sham-operated rats were used as controls. Severity of cholestasis was assessed on histological examination of liver sections, and serum concentrations of albumin, AST, ALT, GGT, ALPK and bilirubin. Gene and protein expressions of PXR, CAR, CYP3A1 and CYP3A2 were assessed by means of qRT-PCR and Western blot, respectively. Alterations in CYP3A activity were measured by calculating the kinetic parameters of 4-OH and 1’-OH-midazolam hydroxylation, marker reactions for CYP3A enzymes. RESULTS The mRNA and protein expression of CYP3A1 increased significantly in mild cholestasis (P < 0.01). At variance, mRNA and protein expression of CYP3A2 didn’t change in mild cholestasis, whereas the expression and activity of both CYP3A1 and CYP3A2 decreased dramatically when cholestasis became severe. Consistently with these observations, the nuclear expression of both PXR and CAR, which was measured because they both translocate into the cell nucleus after their activation, virtually disappeared in the late stage of cholestatic injury, after an initial increase. These results indicate that early- and late-stage cholestasis affects CYP3A-mediated drug metabolism differently, probably as consequence of the different activation of PXR and CAR. CONCLUSION Early- and late-stage cholestasis affects CYP3A-mediated drug metabolism differently. PXR and CAR might be targeted therapeutically to promote CYP3A-mediated liver detoxification.

141 USE OF ANTI-HBc POSITIVE DONORS IN LIVER TRANSPLANTATION: THE EXPERIENCE OF PADUA LIVER TRANSPLANT CENTRE

141 USE OF ANTI-HBc POSITIVE DONORS IN LIVER TRANSPLANTATION: THE EXPERIENCE OF PADUA LIVER TRANSPLANT CENTRE I. Bortoluzzi, M. Gambato, L. Albertoni, C. Mescoli, M. Pacenti, R. Cusinato, G. Germani, M. Senzolo, M. Rugge, G. Zanus, P. Boccagni, U. Cillo, P. Burra, F.P. Russo. Dept. of Surgical, Oncological and Gastroenterological Sciences, University Hospital Padova, Department of Medicine, Surgical Pathology & Cytopathology Unit, University Hospital Padova, Department of Molecular Medicine, Microbiology Unit, University Hospital Padova, Dept. of Surgical, Oncological and Gastroenterological Sciences, Hepatobiliary and Liver Transplantation Unit, University Hospital Padova, Padova, Italy E-mail: ilabortoluzzi@yahoo.it

Abstract 3219: Isolated tumor cells (ITC) in regional lymph nodes predict colorectal cancer (CRC) relapse

Proceedings: AACR 102nd Annual Meeting 2011‐‐ Apr 2‐6, 2011; Orlando, FL Involvement of the lymph nodes (LN) is the most important prognostic factor in CRC and pN+ve status identifies patients requiring adjuvant chemotherapy. Among pN0-patients, 20-30% develop recurrent disease. ITC+ve LNs in such patients (as assessed by immunohistochemistry) may potentially predict cancer recurrence. No prospective long-term follow-up trial has consistently validated the prognostic meaning of ITCs. ITCs in regional LNs were prospectively assessed in a cohort of 361 consecutive pN0-CRC patients. From each gross surgical specimen, LNs were microdissected according to a standardized protocol (mean LNs per patient=16.4; range 5-107). In all, 5,920 pN0-ve LNs were collected and immunohistochemically assessed (MNF116 staining was performed in 2 serial histology sections of each LN [11,840 histology specimens in all]). Overall cancer death and recurrence rates were calculated. The prognostic impact of ITC was also tested by multivariate statistics. ITCs were documented in 200 of 361 patients (55.5%). No relationship was documented between ITC+ve status and overall survival. CRC recurred in 36/361 (9%) cases and 29/36 (80%) recurrences were documented among ITC+ve patients. The prevalence of recurrent CRC among ITC+ve and ITC-ve patients was 14.5% and 4.3%, respectively. ITC+ status significantly correlated with cancer recurrence (p = 0.002, OR = 3.57; 95% CI=1.46-9.95; case-control Pearsons chi-squared) and disease-free interval (p=0.0005). In multivariate analysis, ITC-status was the only variable significantly associated with cancer recurrence. These results suggest considering ITC+ve status a reliable marker of cancer recurrence, and that pN0 ITC+ve cancer patients form a subgroup of candidates for adjuvant chemotherapy. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3219. doi:10.1158/1538-7445.AM2011-3219