Chitinase 3-like 1 is a profibrogenic factor overexpressed in the aging liver and in patients with liver cirrhosis.

Older age at the time of infection with hepatitis viruses is associated with an increased risk of liver fibrosis progression. We hypothesized that the pace of fibrosis progression may reflect changes in gene expression within the aging liver. We compared gene expression in liver specimens from 54 adult donors without evidence of fibrosis, including 36 over 40 y old and 18 between 18 and 40 y old. Chitinase 3-like 1 (CHI3L1), which encodes chitinase-like protein YKL-40/CHI3L1, was identified as the gene with the greatest age-dependent increase in expression in liver tissue. We investigated the cellular source of CHI3L1 in the liver and its function using liver tissue specimens and in vitro models. CHI3L1 expression was significantly higher in livers of patients with cirrhosis of diverse etiologies compared with controls represented by patients who underwent liver resection for hemangioma. The highest intrahepatic CHI3L1 expression was observed in cirrhosis due to hepatitis D virus, followed by hepatitis C virus, hepatitis B virus, and alcohol-induced cirrhosis. In situ hybridization of CHI3L1 messenger RNA (mRNA) identified hepatocytes as the major producers of CHI3L1 in normal liver and in cirrhotic tissue, wherein hepatocytes adjacent to fibrous septa showed higher CHI3L1 expression than did those in more distal areas. In vitro studies showed that recombinant CHI3L1 promotes proliferation and activation of primary human hepatic stellate cells (HSCs), the major drivers of liver fibrosis. These findings collectively demonstrate that CHI3L1 promotes liver fibrogenesis through a direct effect on HSCs and support a role for CHI3L1 in the increased susceptibility of aging livers to fibrosis progression.

Improving outcomes of in situ split liver transplantation in Italy over the last 25 years.

BACKGROUND & AIMS: Split liver transplant(ation) (SLT) is still considered a challenging procedure that is by no means widely accepted. We aimed to present data on 25-year trends in SLT in Italy, and to investigate if, and to what extent, outcomes have improved nationwide during this time. METHODS: The study included all consecutive SLTs performed from May 1993 to December 2019, divided into three consecutive periods: 1993-2005, 2006-2014, and 2015-2019, which match changes in national allocation policies. Primary outcomes were patient and graft survival, and the relative impact of each study period. RESULTS: SLT accounted for 8.9% of all liver transplants performed in Italy. A total of 1,715 in situ split liver grafts were included in the analysis: 868 left lateral segments (LLSs) and 847 extended right grafts (ERGs). A significant improvement in patient and graft survival (p <0.001) was observed with ERGs over the three periods. Predictors of graft survival were cold ischaemia time (CIT) <6 h (p = 0.009), UNOS status 2b (p <0.001), UNOS status 3 (p = 0.009), and transplant centre volumes: 25-50 cases vs. <25 cases (p = 0.003). Patient survival was significantly higher with LLS grafts in period 2 vs. period 1 (p = 0.008). No significant improvement in graft survival was seen over the three periods, where predictors of graft survival were CIT <6 h (p = 0.007), CIT <6 h vs. ≥10 h (p = 0.019), UNOS status 2b (p = 0.038), and UNOS status 3 (p = 0.009). Retransplantation was a risk factor in split liver graft recipients, with significantly worse graft and patient survival for both types of graft (p <0.001). CONCLUSIONS: Our analysis showed Italian SLT outcomes to have improved over the last 25 years. These results could help to dispel reservations regarding the use of this procedure. IMPACT AND IMPLICATIONS: Split liver transplant(ation) (SLT) is still considered a challenging procedure and is by no means widely accepted. This study included all consecutive in situ SLTs performed in Italy from May 1993 to December 2019. With more than 1,700 cases, it is one of the largest series, examining long-term national trends in in situ SLT since its introduction. The data presented indicate that the outcomes of SLT improved during this 25-year period. Improvements are probably due to better recipient selection, refinements in surgical technique, conservative graft-to-recipient matching, and the continuous, yet carefully managed, expansion of donor selection criteria under a strict mandatory split liver allocation policy. These results could help to dispel reservations regarding the use of this procedure.

Hepatocellular carcinoma and the risk of de novo malignancies after liver transplantation - a multicenter cohort study.

Patients with hepatocellular carcinoma (HCC) are at high risk of second primary malignancies. As HCC has become the leading indication of liver transplant (LT), the aim of this study was to investigate whether the presence of HCC before LT could influence the onset of de novo malignancies (DNM). A cohort study was conducted on 2653 LT recipients. Hazard ratios (HR) of DNM development for patients transplanted for HCC (HCC patients) were compared with those of patients without any previous malignancy (non-HCC patients). All models were adjusted for sex, age, calendar year at transplant, and liver disease etiology. Throughout 17 903 person-years, 6.6% of HCC patients and 7.4% of non-HCC patients developed DNM (202 cases). The median time from LT to first DNM diagnosis was shorter for solid tumors in HCC patients (2.7 vs 4.5 years for HCC and non-HCC patients, respectively, P < 0.01). HCC patients were at a higher risk of bladder cancer and skin melanoma. There were no differences in cumulative DNM-specific mortality by HCC status. This study suggests that primary HCC could be a risk factor for DNM in LT recipients, allowing for risk stratification and screening individualization.

Role of humoral immunity against hepatitis B virus core antigen in the pathogenesis of acute liver failure.

Hepatitis B virus (HBV)-associated acute liver failure (ALF) is a dramatic clinical syndrome leading to death or liver transplantation in 80% of cases. Due to the extremely rapid clinical course, the difficulties in obtaining liver specimens, and the lack of an animal model, the pathogenesis of ALF remains largely unknown. Here, we performed a comprehensive genetic and functional characterization of the virus and the host in liver tissue from HBV-associated ALF and compared the results with those of classic acute hepatitis B in chimpanzees. In contrast with acute hepatitis B, HBV strains detected in ALF livers displayed highly mutated HBV core antigen (HBcAg), associated with increased HBcAg expression ex vivo, which was independent of viral replication levels. Combined gene and miRNA expression profiling revealed a dominant B cell disease signature, with extensive intrahepatic production of IgM and IgG in germline configuration exclusively targeting HBcAg with subnanomolar affinities, and complement deposition. Thus, HBV ALF appears to be an anomalous T cell-independent, HBV core-driven B cell disease, which results from the rare and unfortunate encounter between a host with an unusual B cell response and an infecting virus with a highly mutated core antigen.

Infection with hepatitis C virus depends on TACSTD2, a regulator of claudin-1 and occludin highly downregulated in hepatocellular carcinoma.

Entry of hepatitis C virus (HCV) into hepatocytes is a complex process that involves numerous cellular factors, including the scavenger receptor class B type 1 (SR-B1), the tetraspanin CD81, and the tight junction (TJ) proteins claudin-1 (CLDN1) and occludin (OCLN). Despite expression of all known HCV-entry factors, in vitro models based on hepatoma cell lines do not fully reproduce the in vivo susceptibility of liver cells to primary HCV isolates, implying the existence of additional host factors which are critical for HCV entry and/or replication. Likewise, HCV replication is severely impaired within hepatocellular carcinoma (HCC) tissue in vivo, but the mechanisms responsible for this restriction are presently unknown. Here, we identify tumor-associated calcium signal transducer 2 (TACSTD2), one of the most downregulated genes in primary HCC tissue, as a host factor that interacts with CLDN1 and OCLN and regulates their cellular localization. TACSTD2 gene silencing disrupts the typical linear distribution of CLDN1 and OCLN along the cellular membrane in both hepatoma cells and primary human hepatocytes, recapitulating the pattern observed in vivo in primary HCC tissue. Mechanistic studies suggest that TACSTD2 is involved in the phosphorylation of CLDN1 and OCLN, which is required for their proper cellular localization. Silencing of TACSTD2 dramatically inhibits HCV infection with a pan-genotype effect that occurs at the level of viral entry. Our study identifies TACSTD2 as a novel regulator of two major HCV-entry factors, CLDN1 and OCLN, which is strongly downregulated in malignant hepatocytes. These results provide new insights into the complex process of HCV entry into hepatocytes and may assist in the development of more efficient cellular systems for HCV propagation in vitro.

Next-generation sequencing of the intrahepatic antibody repertoire delineates a unique B-cell response in HBV-associated acute liver failure.

Hepatitis B virus (HBV) is a major cause of acute liver failure (ALF) worldwide. While liver damage in classic acute hepatitis B is believed to be T-cell mediated, the pathogenesis of HBV-associated ALF remains largely unknown. Access to liver specimens from well-characterized patients with HBV-associated ALF provided us with the opportunity to perform next-generation sequencing (NGS) of the entire VH repertoires of IgM and IgG from the livers of four ALF patients, a control liver donor and a patient with chronic HBV infection. We found that ALF is not associated with expansion of specific B-cell lineages. However, NGS showed that the intrahepatic VH repertoires from ALF patients were characterized by the abundant presence of antibodies in germline configuration in contrast to their marginal prevalence in controls. Moreover, NGS identified a large number of VH genes in germline configuration with identical VDJ sequences in the IgM and IgG repertoires in all four ALF patients, indicating that isotype switch from IgM to IgG had occurred without somatic hypermutation. The results of this study indicate that the presence of intrahepatic antibodies in unmutated germline configuration is a broad phenomenon in the global antibody repertoire generated from total RNA derived from whole-liver tissue that is strongly associated with ALF, suggesting a major role of T cell-independent humoral immunity in the pathogenesis of ALF.

Survival after the diagnosis of de novo malignancy in liver transplant recipients.

In the setting of liver transplant (LT), the survival after the diagnosis of de novo malignancies (DNMs) has been poorly investigated. In this study, we assessed the impact of DNMs on survival of LT recipients as compared to corresponding LT recipients without DNM. A nested case-control study was conducted in a cohort of 2,818 LT recipients enrolled in nine Italian centres between 1985 and 2014. Cases were 244 LT recipients who developed DNMs after LT. For each case, two controls matched for gender, age, and year at transplant were selected by incidence density sampling among cohort members without DNM. The survival probabilities were estimated using the Kaplan-Meier method. Hazard ratios (HRs) of death and 95% confidence intervals (CIs) were estimated using Cox proportional hazard models. The all-cancer 10-year survival was 43% in cases versus 70% in controls (HR = 4.66; 95% CI: 3.17-6.85). Survival was impaired in cases for all the most frequent cancer types, including lung (HR = 37.13; 95% CI: 4.98-276.74), non-Hodgkin lymphoma (HR = 6.57; 95% CI: 2.15-20.01), head and neck (HR = 4.65; 95% CI: 1.81-11.95), and colon-rectum (HR = 3.61; 95% CI: 1.08-12.07). The survival gap was observed for both early and late mortality, although the effect was more pronounced in the first year after cancer diagnosis. No significant differences in survival emerged for Kaposi's sarcoma and nonmelanoma skin cancers. The survival gap herein quantified included a broad range of malignancies following LT and prompts close monitoring during the post-transplant follow-up to ensure early cancer diagnosis and to improve survival.

A national mandatory-split liver policy: A report from the Italian experience.

To implement split liver transplantation (SLT) a mandatory-split policy has been adopted in Italy since August 2015: donors aged 18-50 years at standard risk are offered for SLT, resulting in a left-lateral segment (LLS) graft for children and an extended-right graft (ERG) for adults. We aim to analyze the impact of the new mandatory-split policy on liver transplantation (LT)-waiting list and SLT outcomes, compared to old allocation policy. Between August 2015 and December 2016 out of 413 potentially "splittable" donors, 252 (61%) were proposed for SLT, of whom 53 (21%) donors were accepted for SLT whereas 101 (40.1%) were excluded because of donor characteristics and 98 (38.9%) for absence of suitable pediatric recipients. The SLT rate augmented from 6% to 8.4%. Children undergoing SLT increased from 49.3% to 65.8% (P = .009) and the pediatric LT-waiting list time dropped (229 [10-2121] vs 80 [12-2503] days [P = .045]). The pediatric (4.5% vs 2.5% [P = .398]) and adult (9.7% to 5.2% [P < .001]) LT-waiting list mortality reduced; SLT outcomes remained stable. Retransplantation (HR = 2.641, P = .035) and recipient weight >20 kg (HR = 5.113, P = .048) in LLS, and ischemic time >8 hours (HR = 2.475, P = .048) in ERG were identified as predictors of graft failure. A national mandatory-split policy maximizes the SLT donor resources, whose selection criteria can be safely expanded, providing favorable impact on the pediatric LT-waiting list and priority for adult sick LT candidates.

Analysis of Genomes and Transcriptomes of Hepatocellular Carcinomas Identifies Mutations and Gene Expression Changes in the Transforming Growth Factor-ß Pathway.

BACKGROUND & AIMS: Development of hepatocellular carcinoma (HCC) is associated with alterations in the transforming growth factor-beta (TGF-ß) signaling pathway, which regulates liver inflammation and can have tumor suppressor or promoter activities. Little is known about the roles of specific members of this pathway at specific of HCC development. We took an integrated approach to identify and validate the effects of changes in this pathway in HCC and identify therapeutic targets. METHODS: We performed transcriptome analyses for a total of 488 HCCs that include data from The Cancer Genome Atlas. We also screened 301 HCCs reported in the Catalogue of Somatic Mutations in Cancer and 202 from Cancer Genome Atlas for mutations in genome sequences. We expressed mutant forms of spectrin beta, non-erythrocytic 1 (SPTBN1) in HepG2, SNU398, and SNU475 cells and measured phosphorylation, nuclear translocation, and transcriptional activity of SMAD family member 3 (SMAD3). RESULTS: We found somatic mutations in at least 1 gene whose product is a member of TGF-ß signaling pathway in 38% of HCC samples. SPTBN1 was mutated in the largest proportion of samples (12 of 202, 6%). Unsupervised clustering of transcriptome data identified a group of HCCs with activation of the TGF-ß signaling pathway (increased transcription of genes in the pathway) and a group of HCCs with inactivation of TGF-ß signaling (reduced expression of genes in this pathway). Patients with tumors with inactivation of TGF-ß signaling had shorter survival times than patients with tumors with activation of TGF-ß signaling (P = .0129). Patterns of TGF-ß signaling correlated with activation of the DNA damage response and sirtuin signaling pathways. HepG2, SNU398, and SNU475 cells that expressed the D1089Y mutant or with knockdown of SPTBN1 had increased sensitivity to DNA crosslinking agents and reduced survival compared with cells that expressed normal SPTBN1 (controls). CONCLUSIONS: In genome and transcriptome analyses of HCC samples, we found mutations in genes in the TGF-ß signaling pathway in almost 40% of samples. These correlated with changes in expression of genes in the pathways; up-regulation of genes in this pathway would contribute to inflammation and fibrosis, whereas down-regulation would indicate loss of TGF-ß tumor suppressor activity. Our findings indicate that therapeutic agents for HCCs can be effective, based on genetic features of the TGF-ß pathway; agents that block TGF-ß should be used only in patients with specific types of HCCs.

Diminished viral replication and compartmentalization of hepatitis C virus in hepatocellular carcinoma tissue.

Analysis of hepatitis C virus (HCV) replication and quasispecies distribution within the tumor of patients with HCV-associated hepatocellular carcinoma (HCC) can provide insight into the role of HCV in hepatocarcinogenesis and, conversely, the effect of HCC on the HCV lifecycle. In a comprehensive study of serum and multiple liver specimens from patients with HCC who underwent liver transplantation, we found a sharp and significant decrease in HCV RNA in the tumor compared with surrounding nontumorous tissues, but found no differences in multiple areas of control non-HCC cirrhotic livers. Diminished HCV replication was not associated with changes in miR-122 expression. HCV genetic diversity was significantly higher in livers containing HCC compared with control non-HCC cirrhotic livers. Tracking of individual variants demonstrated changes in the viral population between tumorous and nontumorous areas, the extent of which correlated with the decline in HCV RNA, suggesting HCV compartmentalization within the tumor. In contrast, compartmentalization was not observed between nontumorous areas and serum, or in controls between different areas of the cirrhotic liver or between liver and serum. Our findings indicate that HCV replication within the tumor is restricted and compartmentalized, suggesting segregation of specific viral variants in malignant hepatocytes.

Risk of virus and non-virus related malignancies following immunosuppression in a cohort of liver transplant recipients. Italy, 1985-2014.

This cohort study assessed, in Italy, the overall pattern of risk of de novo malignancies following liver transplantation (LT). The study group included 2,832 individuals who underwent LT between 1985 and 2014 in nine centers all over Italy. Person-years (PYs) at cancer risk were computed from 30 days after LT to the date of cancer diagnosis, to the date of death or to the end of follow-up. Excess cancer risk, as compared to the general population, was estimated using standardized incidence ratios (SIRs) and 95% confidence intervals (CIs). During 18,642 PYs, 246 LT recipients developed 266 de novo malignancies, corresponding to a 1.8-fold higher cancer risk (95% CI: 1.6-2.0). SIRs were particularly elevated for virus-related malignancies, including Kaposi's sarcoma (SIR = 53.6, 95% CI: 30.0-88.5), non-Hodgkin lymphomas (SIR = 7.1, 95% CI: 4.8-10.1) and cervix uteri (SIR = 5.4, 95% CI: 1.1-15.8). Among virus-unrelated malignancies, elevated risks emerged for head and neck (SIR = 4.4, 95% CI: 3.1-6.2), esophagus (SIR = 6.7, 95% CI: 2.9-13.3) and adrenal gland (SIR = 22.9, 95% CI: 2.8-82.7). Borderline statistically significant elevated risks were found for lung cancer (SIR = 1.4, 95% CI: 1.0-2.1) and skin melanoma (SIR = 2.6, 95% CI: 1.0-5.3). A reduced risk emerged for prostate cancer (SIR = 0.1, 95% CI: 0.0-0.5). These findings underline the need of preventive interventions and early detection of malignancies, specifically tailored to LT recipients.

Systematic transcriptome analysis reveals elevated expression of alcohol-metabolizing genes in NAFLD livers.

Obese animals and non-alcoholic fatty liver disease (NAFLD) patients exhibit elevated blood alcohol, suggesting potential contributions of alcohol metabolism to the development of NAFLD. Liver gene expression in patients with biopsy-proven mild (N = 40) and severe (N = 32) NAFLD were compared to that in healthy liver donors (N = 7) and alcoholic hepatitis (AH; N = 15) using microarrays. Principal components analyses (PCA) revealed similar gene expression patterns between mild and severe NAFLD which clustered with those of AH but were distinct from those of healthy livers. Differential gene expression between NAFLD and healthy livers was consistent with established NAFLD-associated genes and NAFLD pathophysiology. Alcohol-metabolizing enzymes including ADH, ALDH, CYP2E1, and CAT were up-regulated in NAFLD livers. The expression level of alcohol-metabolizing genes in severe NAFLD was similar to that in AH. The NAFLD gene expression profiles provide new directions for future investigations to identify disease markers and targets for prevention and treatment, as well as to foster our understanding of NAFLD pathogenesis and pathophysiology. Particularly, increased expression of alcohol-metabolizing genes in NAFLD livers supports a role for endogenous alcohol metabolism in NAFLD pathology and provides further support for gut microbiome therapy in NAFLD management. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley © Sons, Ltd.

Laparoscopic removal of a very large uterus weighting 5320 g is feasible and safe: a case report.

BACKGROUND: Total laparoscopic hysterectomy (TLH) has demonstrated to be feasible and safe in the presence of very large uteri. However, it is currently difficult to establish the upper uterine weight limit for successful performance of a laparoscopic hysterectomy. CASE PRESENTATION: Here we report the case of a TLH performed for a very large fibromatous uteri weighing 5320 g in a 40-year-old Caucasian woman. The surgery had no complications with an operating time of approximately 220 min. The patient was discharged from the hospital on postoperative day 3 in very good condition. To our knowledge, the present paper is the only to describe a uterus of this size removed by laparoscopic hysterectomy. CONCLUSIONS: Our case demonstrates that uterine size is not a determinant for a final surgical decision to use laparoscopic hysterectomy. Therefore, if not contraindicated by the patient's comorbidities or peculiar anatomical conditions, we believe that laparoscopic hysterectomy could be performed in the presence of large uteri without hypothetical weight limits.

Analysis of long noncoding RNA expression in hepatocellular carcinoma of different viral etiology.

BACKGROUND: Dysregulation of long noncoding RNA (lncRNA) expression contributes to the pathogenesis of many human diseases, including liver diseases. Several lncRNAs have been reported to play a role in the development of hepatocellular carcinoma (HCC). However, most studies have analyzed lncRNAs only in hepatitis B virus (HBV)-related HCC or in a single group of HCC patients regardless of the viral etiology. METHODS: To investigate whether lncRNAs are differentially expressed in HCC of different viral etiology, we profiled 101 disease-related lncRNAs, including 25 lncRNAs previously associated with HCC, in liver specimens obtained from well-characterized patients with HBV-, hepatitis C virus (HCV)-, or hepatitis D virus (HDV)-associated HCC. RESULTS: We identified eight novel HCC-related lncRNAs that were significantly dysregulated in HCC tissues compared to their surrounding non-tumorous tissues. Some of these lncRNAs were significantly dysregulated predominantly in one specific hepatitis virus-related HCC, including PCAT-29 in HBV-related HCC, aHIF and PAR5 in HCV-related HCC, and Y3 in HDV-related HCC. Among the lncRNAs previously reported in HCC, we found that DBH-AS1, hDREH and hPVT1 were differentially expressed in HCC of different viral etiology. CONCLUSIONS: Our study suggests that HCC of different viral etiology is regulated by different lncRNAs. The identification of lncRNAs unique to specific hepatitis virus-related HCC may provide new tools for improving the diagnosis of HCC and open new avenues for disease-specific therapeutic interventions.

Long-Term Survival in a Patient With Abdominal Sarcomatosis From Uterine Leiomyosarcoma: Role of Repeated Laparoscopic Surgery in Treatment and Follow-Up.

Uterine leiomyosarcoma (LMS) in some cases may disseminate through the abdominal cavity, without extra-abdominal spreading, determining a condition of abdominal sarcomatosis, which represents a peculiar situation. Only radical surgical removal offers a chance of long-term survival in such cases of LMS. Here we describe a case of diffuse abdominal sarcomatosis from uterine LMS in a 51-year-old perimenopausal woman who underwent laparoscopic radical hysterectomy, bilateral salpingo-oophorectomy, total pelvic peritonectomy, pelvic lymphadenectomy to the mesenteric inferior artery, and omentectomy. Then, given the high probability of disease recurrence, the patient underwent a close follow-up consisting of positron emission tomography (PET)/computed tomography every 3 months and diagnostic (and if necessary operative) laparoscopy every 6 months. To date, the patient had 11 laparoscopies; 5 of them were preceded by a PET indicative of the presence of disease with high metabolic activity, which was confirmed at surgery and each time completely removed laparoscopically with no evidence of residual disease. To date, 5 years from diagnosis the patient is alive and continues her follow-up. Our report brings to light the ability of laparoscopic surgery to obtain disease control in a case of LMS with abdominal dissemination. Moreover, laparoscopic surgery, as demonstrated in our case, may have an important role in the close follow-up of the disease and allow a timely and early radical surgical approach of relapses before they become extremely large and difficult to remove radically.

Surgical outcome and complications of total laparoscopic hysterectomy for very large myomatous uteri in relation to uterine weight: a prospective study in a continuous series of 461 procedures.

PURPOSE: To analyze whether a large uterine size was associated with increased rate of intraoperative and postoperative surgical complications in patients who underwent total laparoscopic hysterectomy (TLH) for myomatous uteri. METHODS: We examined prospectively data from 461 consecutive TLHs performed by a single surgeon between August 2004 and August 2014 at the Department of Obstetrics and Gynecology, Sirai Hospital, Carbonia, and at the Department of Gynecologic Oncology, Businco Hospital, Cagliari, Italy. Demographic and surgical data were stratified by uterine weight (range 90-5500 g) into four groups: <300 g; from 300 to 500 g; from 500 to 800 g; and >800 g. Outcomes examined included blood loss, operative time, intraoperative and postoperative complications, and duration of hospital stay. A linear regression analysis was performed to identify whether uterine weight was an independent predictor affecting these outcomes. In addition, BMI, previous surgery with adhesiolysis, and endometriosis were tested as a predictor of surgical complications and outcomes. RESULTS: No significant difference was found in intraoperative and postoperative complications, as well as hospital stay, by uterine weight. Increased uterine size was significantly associated with longer operative time and increased blood loss. Beside uterine weight, prior surgery was predictive of postoperative complications. In contrast, higher BMI was not associated with increased complication rate. Independent predictors of longer operative time included previous surgery, endometriosis, and BMI. CONCLUSIONS: Our results showed that in experienced hands, TLH is feasible and safe also in presence of very large uteri. TLH results in a few complications and short hospital stay regardless of uterine weight.

Integrated ordination of miRNA and mRNA expression profiles.

BACKGROUND: Several studies have investigated miRNA and mRNA co-expression to identify regulatory networks at the transcriptional level. A typical finding of these studies is the presence of both negative and positive miRNA-mRNA correlations. Negative correlations are consistent with the expected, faster degradation of target mRNAs, whereas positive correlations denote the existence of feed-forward regulations mediated by transcription factors. Both mechanisms have been characterized at the molecular level, although comprehensive methods to represent miRNA-mRNA correlations are lacking. At present, genome-wide studies are able to assess the expression of more than 1000 mature miRNAs and more than 35,000 well-characterized human genes. Even if studies are generally restricted to a small subset of genes differentially expressed in specific diseases or experimental conditions, the number of potential correlations remains very high, and needs robust multivariate methods to be conveniently summarized by a small set of data. RESULTS: Nonparametric Kendall correlations were calculated between miRNAs and mRNAs differentially expressed in livers of patients with acute liver failure (ALF) using normal livers as controls. Spurious correlations due to the histopathological composition of samples were removed by partial correlations. Correlations were then transformed into distances and processed by multidimensional scaling (MDS) to map the miRNA and mRNA relationships. These showed: (a) a prominent displacement of miRNA and mRNA clusters in ALF livers, as compared to control livers, indicative of gene expression dysregulation; (b) a clustering of mRNAs consistent with their functional annotations [CYP450, transcription factors, complement, proliferation, HLA class II, monocytes/macrophages, T cells, T-NK cells and B cells], as well as a clustering of miRNAs with the same seed sequence; and (c) a tendency of miRNAs and mRNAs to populate distinct regions of the MDS plot. MDS also allowed to visualize the network of miRNA-mRNA target pairs. CONCLUSIONS: Different features of miRNA and mRNA relationships can be represented as thematic maps within the framework of MDS obtained from pairwise correlations. The symmetric distribution of positive and negative correlations between miRNA and mRNA expression suggests that miRNAs are involved in a complex bidirectional molecular network, including, but not limited to, the inhibitory regulation of miRNA targets.

Head and neck and esophageal cancers after liver transplant: results from a multicenter cohort study. Italy, 1997-2010.

This study quantified the risk of head and neck (HN) and esophageal cancers in 2770 Italian liver transplant (LT) recipients. A total of 186 post-transplant cancers were diagnosed-including 32 cases of HN cancers and nine cases of esophageal carcinoma. The 10-year cumulative risk for HN and esophageal carcinoma was 2.59%. Overall, HN cancers were nearly fivefold more frequent in LT recipients than expected (standardized incidence ratios - SIR=4.7, 95% CI: 3.2-6.6), while esophageal carcinoma was ninefold more frequent (SIR=9.1, 95% CI: 4.1-17.2). SIRs ranged from 11.8 in LT with alcoholic liver disease (ALD) to 1.8 for LT without ALD for HN cancers, and from 23.7 to 2.9, respectively, for esophageal carcinoma. Particularly elevated SIRs in LT with ALD were noted for carcinomas of tongue (23.0) or larynx (13.7). Our findings confirmed and quantified the large cancer excess risk in LT recipients with ALD. The risk magnitude and the prevalence of ALD herein documented stress the need of timely and specifically organized programs for the early diagnosis of cancer among LT recipients, particularly for high-risk recipients like those with ALD.

A liver donor with double hepatic artery aneurysm: a saved graft.

The shortage of organs and the increasing median age of deceased donors for orthotopic liver transplantation stimulate transplant centres to accept grafts that otherwise would have been discarded due to severe vascular abnormalities. We encountered a donor with two arterial aneurysms and a left accessory hepatic artery: an arterial aneurysm of the common hepatic artery and a left accessory hepatic artery arising from a second aneurysm of the left gastric artery (Michels type V). A complex reconstruction was created to transplant the liver. Multiple arterial anastomosis was made and the hepatic inflow of the transplanted liver restored. Although the procedure increased the risk of hepatic artery thrombosis, one more organ supposed to be discarded was saved.

Viral expression and molecular profiling in liver tissue versus microdissected hepatocytes in hepatitis B virus-associated hepatocellular carcinoma.

BACKGROUND: The molecular mechanisms whereby hepatitis B virus (HBV) induces hepatocellular carcinoma (HCC) remain elusive. We used genomic and molecular techniques to investigate host-virus interactions by studying multiple areas of the same liver from patients with HCC. METHODS: We compared the gene signature of whole liver tissue (WLT) versus laser capture-microdissected (LCM) hepatocytes along with the intrahepatic expression of HBV. Gene expression profiling was performed on up to 17 WLT specimens obtained at various distances from the tumor center from individual livers of 11 patients with HCC and on selected LCM samples. HBV markers in liver and serum were determined by real-time polymerase chain reaction (PCR) and confocal immunofluorescence. RESULTS: Analysis of 5 areas of the liver showed a sharp change in gene expression between the immediate perilesional area and tumor periphery that correlated with a significant decrease in the intrahepatic expression of HB surface antigen (HBsAg). The tumor was characterized by a large preponderance of down-regulated genes, mostly involved in the metabolism of lipids and fatty acids, glucose, amino acids and drugs, with down-regulation of pathways involved in the activation of PXR/RXR and PPARα/RXRα nuclear receptors, comprising PGC-1α and FOXO1, two key regulators critically involved not only in the metabolic functions of the liver but also in the life cycle of HBV, acting as essential transcription factors for viral gene expression. These findings were confirmed by gene expression of microdissected hepatocytes. Moreover, LCM of malignant hepatocytes also revealed up-regulation of unique genes associated with cancer and signaling pathways, including two novel HCC-associated cancer testis antigen genes, NUF2 and TTK. CONCLUSIONS: Integrated gene expression profiling of whole liver tissue with that of microdissected hepatocytes demonstrated that HBV-associated HCC is characterized by a metabolism switch-off and by a significant reduction in HBsAg. LCM proved to be a critical tool to validate gene signatures associated with HCC and to identify genes that may play a role in hepatocarcinogenesis, opening new perspectives for the discovery of novel diagnostic markers and therapeutic targets.