Annalisa Altimari

Increased expression of p16(INK4a) and p27(Kip1) cyclin-dependent kinase inhibitor genes in aging human kidney and chronic allograft nephropathy

BACKGROUND The goal of the current study was to examine the potential value of p16(INK4a) and p27(Kip1) cyclin-dependent kinase inhibitor (CDKI) genes in the process of human kidney aging in vivo, and in the development of chronic allograft nephropathy (CAN). METHODS Expression of p16(INK4a) and p27(Kip1) CDKI genes was evaluated and compared in 20 normal human kidney tissues of different ages (range, 21 to 80 years) and in 9 chronically rejected kidney grafts. Age dependency of marker expression was analyzed by the Pearson correlation and linear regression. RESULTS Expression of p16 in cortical tubular (CTS) and interstitial (CIS) cells of normal kidney was age dependent (correlation coefficients: 0.608 and 0.726, 95% confidence interval [CI]: 0.227 to 0.828 and 0.417 to 0.884, respectively). Cortical tubular expression of p27 was also correlated with increasing age (0.672, 95% CI: 0.327 to 0.859). Linear regression analyses confirmed the linearity of marker relationship with age (coefficient of determination R(2):0.370, 0.452, and 0.527 for CIS p16, CTS p27, and CTS p16, respectively). The mean chronological and predicted graft ages (53 +/- 21 and 76 +/- 8.9 years, respectively) were significantly different (P = 0.0126). The glomeruli, tubules, and interstitial cells of rejected grafts expressed significantly higher levels of p16 and p27 than normal kidneys. Expression of p16 in glomerular and cortical interstitial cells was higher in grade 3 of CAN than in grade 2 (P = 0.013 and 0.004, respectively). CONCLUSION The results of the current study show that expression of p16(INK4a) and p27(Kip1) CDKI genes is increased in cortical cells of the aging human kidney and in chronic allograft rejection, supporting the senescence theory of CAN.

Diagnostic role of circulating free plasma DNA detection in patients with localized prostate cancer

To analyze the potential diagnostic relevance of free plasma DNA (FPDNA), we enrolled 64 patients with localized prostate cancer (CaP). FPDNA was quantified by real-time polymerase chain reaction assessment of the HTERT gene in blood samples from 64 patients with CaP and 45 healthy males. Methylation of the GSTP1 gene was used to confirm the neoplastic origin of FPDNA in selected cases. The mean +/- SD levels of FPDNA were higher in patients with CaP (15.4 +/- 10.9 ng/mL) than in control subjects (5.5 +/- 3.5 ng/mL; P <.001). By using the best cutoff value, the sensitivity of the test was 80%, the specificity was 82%, the area under the receiver operating characteristic curve, 0.881. High FPDNA values were significantly associated with pathologic T3 stage (P = . 035). Methylation of the GSTP1 gene was found in 4 (25%) of 16 FPDNA samples and 15 (94%) of 16 tissue samples. Quantification of FPDNA discriminates between patients with CaP and healthy subjects and correlates with pathologic tumor stage. FPDNA is a candidate biomarker for early diagnosis and monitoring of CaP.

Investigation of ErbB1 and ErbB2 expression for therapeutic targeting in primary liver tumours

BACKGROUND Molecular targets are needed for primary liver tumours. AIMS ErbB1 and ErbB2 expression was analysed in neoplastic and surrounding tissue in surgical specimens from 52 hepatocellular carcinomas and 48 intrahepatic cholangiocarcinomas, randomly chosen from cases surgically treated in this institution. METHODS ErbB1 and ErbB2 expression were evaluated immunohistochemically, the latter by Herceptest. Gene amplification of ErbB2 was tested by chromogenic in situ hybridisation. RESULTS In normal/cirrhotic non-neoplastic tissue, the ErbB1 (but not ErbB2) antibody commonly stained normal hepatocytes and mature intrahepatic ducts. In neoplastic tissue, moderate/strong ErbB1 immunostaining occurred in 43/52 (85%) hepatocellular carcinomas and 39/48 (81%) intra-hepatic cholangiocarcinomas. With ErbB2 Herceptest, 0/52 (0%) hepatocellular carcinomas and 2/48 (4%) intra-hepatic cholangiocarcinomas had treatable scores of 2+/3+ (chromogenic in situ hybridisation confirmed gene amplification in the latter two cases only). Neither ErbB1 nor ErbB2 expression correlated with any of the main clinical-pathologic features or survival. CONCLUSIONS Although not related to prognosis, ErbB1 could be a molecular target in a large percentage of patients with hepatocellular carcinoma or intrahepatic cholangiocarcinoma. Inclusion of anti-ErbB1 drugs such as ZD 1839 and c225 (and possibly also anti-ErbB2 drugs like Trastuzumab for a small subset of patients) in clinical trials is suggested.

Predictive Value of Biological Markers for Hepatocellular Carcinoma Patients Treated with Orthotopic Liver Transplantation

Purpose: To help stratify candidates with hepatocellular carcinoma (HCC) for orthotopic liver transplantation (OLT), biomarkers are needed that are capable of predicting recurrence of disease (ROD). We investigated the prognostic role in this setting of immunohistochemical markers reported previously to predict poor prognosis in HCC patients treated with resection. Experimental Design: Eighty-three patients with HCC who underwent OLT between 1987 and 2001 with a minimum clinical follow up of 12 months were included in this retrospective study. We analyzed immunohistochemical expression of the adhesion molecules E-cadherin and β-catenin (membrane/nuclear localization), MIB-1 proliferative index and the cyclin-dependent kinase inhibitor p27, alongside the main clinical-pathological variables. Results: At univariate analysis, vascular thrombosis, high MIB-1 index, lower membrane expression of E-cadherin and β-catenin, and nuclear β-catenin localization were associated with ROD. At multivariate analysis, only MIB-1 index, low equal E-cadherin (with respect to non-neoplastic surrounding tissue), and nuclear β-catenin appeared as independent predictors of ROD. The logistic regression analysis model indicated that detection of any one parameter was associated with at least 88% estimated risk of ROD (up to 99% for all three). Conclusions: We propose these three molecular parameters as an additional tool for rational selection of OLT candidates among HCC patients (stratification according to the risk of ROD might help provide a similar life expectancy for cirrhotic candidates with and without HCC).

454 next generation-sequencing outperforms allele-specific PCR, Sanger sequencing, and pyrosequencing for routine KRAS mutation analysis of formalin-fixed, paraffin-embedded samples.

Detection of KRAS mutations in archival pathology samples is critical for therapeutic appropriateness of anti-EGFR monoclonal antibodies in colorectal cancer. We compared the sensitivity, specificity, and accuracy of Sanger sequencing, ARMS-Scorpion (TheraScreen®) real-time polymerase chain reaction (PCR), pyrosequencing, chip array hybridization, and 454 next-generation sequencing to assess KRAS codon 12 and 13 mutations in 60 nonconsecutive selected cases of colorectal cancer. Twenty of the 60 cases were detected as wild-type KRAS by all methods with 100% specificity. Among the 40 mutated cases, 13 were discrepant with at least one method. The sensitivity was 85%, 90%, 93%, and 92%, and the accuracy was 90%, 93%, 95%, and 95% for Sanger sequencing, TheraScreen real-time PCR, pyrosequencing, and chip array hybridization, respectively. The main limitation of Sanger sequencing was its low analytical sensitivity, whereas TheraScreen real-time PCR, pyrosequencing, and chip array hybridization showed higher sensitivity but suffered from the limitations of predesigned assays. Concordance between the methods was k = 0.79 for Sanger sequencing and k > 0.85 for the other techniques. Tumor cell enrichment correlated significantly with the abundance of KRAS-mutated deoxyribonucleic acid (DNA), evaluated as ΔCt for TheraScreen real-time PCR (P = 0.03), percentage of mutation for pyrosequencing (P = 0.001), ratio for chip array hybridization (P = 0.003), and percentage of mutation for 454 next-generation sequencing (P = 0.004). Also, 454 next-generation sequencing showed the best cross correlation for quantification of mutation abundance compared with all the other methods (P < 0.001). Our comparison showed the superiority of next-generation sequencing over the other techniques in terms of sensitivity and specificity. Next-generation sequencing will replace Sanger sequencing as the reference technique for diagnostic detection of KRAS mutation in archival tumor tissues.

High levels of BCL-2 messenger RNA detected by in situ hybridization in human hepatocellular and cholangiocellular carcinomas.

Immunocytochemistry has indicated that, in the liver, the bcl-2 gene is generally expressed in bile duct cells and tumors of biliary origin. Both in situ hybridization and immunocytochemistry were used to analyze the expression of bcl-2 messenger RNA (mRNA) and its protein product (Bcl-2) in the tissue of 50 pure primary liver tumor (PLT) specimens including 40 hepatocellular carcinoma (HCC) specimens and 10 cholangiocellular carcinoma (CC) specimens. The phenotype of the tumors expressing bcl-2 was confirmed by immunocytochemical assessment of the cytokeratin (CK) profile (CK8, CK18, CK7, and CK19). Whereas positive immunoreaction with the anti-Bcl-2 MoAb was revealed in only 8 (20%) of 40 HCC specimens and 1 (10%) of 10 CC specimens, high contents of bcl-2 mRNA were found in 26 (65%) of 40 HCC specimens and 9 (90%) of 10 CC specimens. Regarding the CK profile, only 25 (62%) of 40 HCC specimens showed pure hepatocytic lineage (CKs 8-18), whereas among the remaining 15 HCC specimens, positivity for either CK7 (12 specimens) or CK19 (5 specimens) was observed. All 10 CC specimens stained with CKs 8-18-19, and 8 of 10 stained with CK 7 as well. These results indicate that PLTs display a greater expression of bcl-2 mRNA than of the Bcl-2 protein. Furthermore, CK profile assessment confirmed that bcl-2 expression is not confined to liver tumors of biliary origin. In the absence of a well-demonstrated post-transcriptional control of the gene, the authors propose the detection of bcl-2 mRNA by in situ hybridization as a possible alternative method for assessing the expression of bcl-2 mRNA in PLT.

Blood Monitoring of Granzyme B and Perforin Expression After Intestinal Transplantation : Considerations on Clinical Relevance

Background. The use of biomarkers for rejection monitoring represents a major goal in intestinal transplantation. We analyzed the blood expression of Granzyme B (GB) and Perforin (PF) in the following pathological conditions after intestinal transplantation: acute rejection (AR), Epstein-Barr virus (EBV) and cytomegalovirus (CMV) infection, and posttransplant lymphoproliferative disease (PTLD). The diagnostic accuracy and the clinical utility of these tests are finally discussed. Methods. GB and PF levels were measured by real time polymerase chain reaction on peripheral blood samples from 32 intestinal recipients. Blood samples (n=494) after comparison of clinical, histological, and microbiological data were assigned to the following groups: normal (n=307), AR (n=30), EBV infection (n=107), CMV infection (n=25), and PTLD (n=25). Results. Mean levels of GB and PF in the AR (GB=279.7; PF=256.7), PTLD (GB=199; PF=185.9), EBV (GB=133.2; PF=143.7), and CMV (GB=151.3; PF=144) groups were significantly higher than in the normal group (GB=100.1; PF=101.1) (all P<0.05, except for PF in CMV infection). The best accuracy was obtained for the diagnosis of AR with sensitivity and specificity of 80% and 79% for GB and 70% and 79% for PF, respectively. The area under the receiver-operator characteristics curve was 0.87 for GB and 0.82 for PF. Conclusions. GB and PF are diagnostic molecular markers of AR. GB and PF blood levels are also increased in case of viral infections or PTLD. Serial blood testing for GB and PF might be predictive of early intestinal graft dysfunction and should be interpreted in the context of the histological and virological analyses.

Early and Late Virological Monitoring of Cytomegalovirus, Epstein-Barr Virus, and Human Herpes Virus 6 Infections in Small Bowel/Multivisceral Transplant Recipients

BACKGROUND Cytomegalovirus (CMV) and Epstein-Barr virus (EBV) are the major causes of graft failure and posttransplantation mortality among small bowel and multivisceral transplantations (SB/MVT). Little is known about human herpes virus 6 (HHV-6) infections in transplant recipients. STUDY PURPOSE The purposes of this study were to analyze the clinical relevance of CMV, EBV, and HHV-6 infections after small bowel transplantation and to establish whether routine monitoring for HHV-6 infection should be recommended for the prevention of severe complications in this population. METHODS Ten adult patients were monitored based on CMV, EBV, and HHV6 DNA quantifications in blood and biopsy tissue samples. Three patients were monitored for at least 5 months (early period) and 7 patients were monitored for 1 to 5 years after transplantation (late period). RESULTS In the early period, despite prophylaxis all 3 patients developed symptomatic CMV infections: 1 fever/diarrhea, 1 enteritis and rejection, as well as 1 fever and pneumonia. Only 1 patient developed EBV and HHV-6 infections. The average time of onset of CMV infection was 3 months after transplantation and only 24 days for HHV6 infection. In the late period, of the 7 SB/MVT recipients only 1 developed an EBV infection at 2 years after transplantation. No CMV or HHV-6 infections were identified in any patient. CONCLUSIONS CMV infection is a major cause of organ disease and rejection in the early period after transplantation. EBV infection in adult recipients must be considered also in the late period, particularly in association with severe immunosuppression. Because HHV-6 infection occurs earlier than CMV/EBV, it may serve as an indicator for more intense virological surveillance.

Primary paraganglioma strictly confined to the liver and mimicking hepatocellular carcinoma: an immunohistochemical and in situ hybridization study.

We describe a case of primary nonfunctioning paraganglioma that, unlike any other previously reported case, was strictly confined to the liver and must therefore have arisen on liver parenchyma. An asymptomatic 46-year-old man was referred to us for laparotomy and a right hemihepatectomy after a preoperative diagnosis of fibrolamellar hepatocellular carcinoma, based on a fine-needle biopsy. An 8-cm resiliently firm, pale gray nodule with a large central area of fibrosis and a thin fibrous capsule was resected. The polygonal eosinophilic tumor cells containing round nuclei lacking nucleoli were arranged in small nests set in a vascularly rich stroma. At immunohistochemistry neoplastic cells were strongly positive for chromogranin A, neuron-specific enolase, synaptophysin, and IGF-II protein; they were negative for keratin, S-100 protein, CD10, vimentin, and smooth muscle actin. In situ hybridization confirmed that, as in other sites, liver paraganglioma can express IGF-II gene. Conversely (and unlike hepatocellular carcinomas), the neoplastic cells did not express albumin mRNA, which was detected only in surrounding hepatocytes. The clinical course was benign and the patient is well and free of neoplastic disease 9 years after surgery. Knowledge of the entity should avoid possible confusion with hepatocellular carcinoma, especially of the fibrolamellar variety.

Interferon-γ is increased in the gut of patients with irritable bowel syndrome and modulates serotonin metabolism

Mucosal immune activation and altered serotonin metabolism participate in the pathophysiology of irritable bowel syndrome (IBS). However, the reciprocal interplay between these two systems remains unknown. We evaluated the expression and release of interferon (IFN)-γ from the colonic mucosa of patients with IBS and its impact on serotonin reuptake transporter (SERT) gene expression in Caco-2 cells. qPCR was used to evaluate IFN-γ gene expression in colonic mucosal biopsies, whereas IFN-γ protein amount was assessed by ELISA. Colonic T box expressed in T cells (T-bet) and phosphorylated signal transducer and activator of transcription 4 protein amount were evaluated by Western blot. The impact of colonic mucosal mediators on SERT gene expression was evaluated in Caco-2 cells using qPCR. IFN-γ receptor was silenced in Caco-2 cells to determine the effect of IFN-γ released by mucosal biopsies. Compared with asymptomatic controls (ACs), the expression of IFN-γ gene and its transcription factor T-bet were markedly increased in the colonic mucosa of patients with IBS. Compared with ACs, IFN-γ protein tissue levels and its release by mucosal biopsies were significantly increased in IBS. The exposure of Caco-2 cells to IBS supernatants induced a significant decrease in SERT gene expression, independently of IBS subtypes, compared with AC mucosal supernatants. In Caco-2 cells, IFN-γ receptor silencing reversed the reduction of SERT expression evoked by IBS supernatants vs. nonsilenced cell lines. IFN-γ gene, its transcription factor T-bet, IFN-γ protein expression, and its release are increased in the colonic mucosa of patients with IBS and downregulate SERT gene expression in vitro. These results suggest that IFN-γ downregulates SERT expression, hence likely playing a role in altered serotonin metabolism of patients with IBS.