Reduced Lipid Peroxidation Predicts Unfavorable Prognosis in Hepatocellular Carcinoma, but Not Intrahepatic Cholangiocarcinoma.

Primary liver cancer, including hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (iCCA), remains a significant contributor to cancer-related mortality worldwide. Oxidative stress and lipid peroxidation play a key role in chronic liver diseases and have been shown to be pivotal for tumor initiation and progression. 4-hydroxy-nonenal (4-HNE), one of the major mediators of oxidative stress and a well-established biomarker for lipid peroxidation, can act as a signal transducer, inducing inflammation and exerting carcinogenic effects. However, the role of 4-HNE in primary liver cancer remains poorly explored. In this study, we investigated 4-HNE levels in 797 liver carcinomas, including 561 HCC and 236 iCCA, by immunohistochemistry. We then correlated 4-HNE levels with comprehensive clinical data and survival outcomes. In HCC, lower expression levels of 4-HNE were associated with vascular invasion, a high tumor grade, a macrotrabecular-massive HCC subtype, and poor overall survival. Concerning iCCA, large duct iCCA showed significantly higher 4-HNE levels when compared to small duct iCCA. Yet, in iCCA, 4-HNE levels did not correlate with known prognostic parameters or survival outcomes. To conclude, in HCC but not in iCCA, low amounts of 4-HNE predict unfavorable survival outcomes and are associated with aggressive tumor behavior. These findings provide insights into the role of 4-HNE in liver cancer progression and may enable novel therapeutic strategies.

Constitutive Occurrence of E:N-cadherin Heterodimers in Adherens Junctions of Hepatocytes and Derived Tumors.

Cell-cell junctions are pivotal for embryogenesis and tissue homeostasis but also play a major role in tumorigenesis, tumor invasion, and metastasis. E-cadherin (CDH1) and N-cadherin (CDH2) are two adherens junction's transmembrane glycoproteins with tissue-specific expression patterns in epithelial and neural/mesenchymal cells. Aberrant expression has been implicated in the process of epithelial-mesenchymal transition (EMT) in malignant tumors. We could hitherto demonstrate cis-E:N-cadherin heterodimer in endoderm-derived cells. Using immunoprecipitation in cultured cells of the line PLC as well as in human hepatocellular carcinoma (HCC)-lysates, we isolated E-N-cadherin heterodimers in a complex with the plaque proteins α- and ß-catenin, plakoglobin, and vinculin. In confocal laser scanning microscopy, E-cadherin co-localized with N-cadherin at the basolateral membrane of normal hepatocytes, hepatocellular adenoma (HCA), and in most cases of HCC. In addition, we analyzed E- and N-cadherin expression via immunohistochemistry in a large cohort of 868 HCCs from 570 patients, 25 HCA, and respective non-neoplastic liver tissue, and correlated our results with multiple prognostic markers. While E- or N-cadherin were similarly expressed in tumor sites with vascular invasion or HCC metastases, HCC with vascular encapsulated tumor clusters (VETC) displayed slightly reduced E-cadherin, and slightly increased N-cadherin expression. Analyzing The Cancer Genome Atlas patient cohort, we found that reduced mRNA levels of CDH1, but not CDH2 were significantly associated with unfavorable prognosis; however, in multivariate analysis, CDH1 did not correlate with prognosis. In summary, E- and N-cadherin are specific markers for hepatocytes and derived HCA and HCC. E:N-cadherin heterodimers are constitutively expressed in the hepatocytic lineage and only slightly altered in malignant progression, thereby not complying with the concept of EMT.

Transforming Growth Factor-ß Activated Kinase 1 (Tak1) Is Activated in Hepatocellular Carcinoma, Mediates Tumor Progression, and Predicts Unfavorable Outcome.

Although knowledge on inflammatory signaling pathways driving cancer initiation and progression has been increasing, molecular mechanisms in hepatocarcinogenesis are still far from being completely understood. Hepatocyte-specific deletion of the MAPKKK Tak1 in mice recapitulates important steps of hepatocellular carcinoma (HCC) development, including the occurrence of cell death, steatohepatitis, dysplastic nodules, and HCCs. However, overactivation of Tak1 in mice upon deletion of its deubiquitinase Cyld also results in steatohepatitis and HCC development. To investigate Tak1 and Cyld in human HCCs, we created a tissue microarray to analyze their expression by immunohistochemistry in a large and well-characterized cohort of 871 HCCs of 561 patients. In the human liver and HCC, Tak1 is predominantly present as its isoform Tak1A and predominantly localizes to cell nuclei. Tak1 is upregulated in diethylnitrosamine-induced mouse HCCs as well as in human HCCs independent of etiology and is further induced in distant metastases. A high nuclear Tak1 expression is associated with short survival and vascular invasion. When we overexpressed Tak1A in Huh7 cells, we observed increased tumor cell migration, whereas overexpression of full-length Tak1 had no significant effect. A combined score of low Cyld and high Tak1 expression was an independent prognostic marker in a multivariate Cox regression model.

Comprehensive clinicopathologic study of alpha fetoprotein-expression in a large cohort of patients with hepatocellular carcinoma.

Alpha fetoprotein (AFP) is the most widely used diagnostic and prognostic serum biomarker for hepatocellular carcinoma (HCC). Despite its wide clinical use, a systematic clinicopathologic study comparing AFP expression in HCC in situ with serum AFP concentrations has not yet been conducted. To analyze AFP expression in a large cohort of patients by immunohistochemistry, we employed a comprehensive tissue microarray with 871 different HCCs of overall 561 patients. AFP immunoreactivity was detected in only about 20% of HCC core biopsies, whereas 48.9% of the patients displayed increased serum values (>12 ng/mL). Immunostaining of whole tumor slides revealed that lack of detectable immunoreactivity in core biopsies in a subgroup of patients with elevated AFP serum concentrations is due to heterogeneous intratumoral AFP expression. Serum AFP concentrations and AFP expression in situ were moderately correlated (Spearman's rank correlation coefficient .53, P = 1.2e - 13). High AFP expression detected in serum (>227.3 ng/mL) or in situ predicted unfavorable prognosis and was associated with vascular invasion, higher tumor grade and macrotrabecular-massive tumor subtype. Multivariate and ROC curve analysis demonstrated that high AFP concentrations in serum is an independent prognostic parameter and represents the more robust prognostic predictor in comparison to AFP immunostaining of core biopsies. The previously published vessels encapsulating tumor clusters (VETC) pattern turned out as an additional, statistically independent prognostic parameter. AFP-positivity was associated with increased tumor cell apoptosis, but not with increased vascular densities. Additionally, AFP-positive tumors displayed increased proliferation rates, urea cycle dysregulation and signs of genomic instability, which may constitute the basis for their increased aggressiveness.

Key Enzymes in Pyrimidine Synthesis, CAD and CPS1, Predict Prognosis in Hepatocellular Carcinoma.

Patients with hepatocellular carcinoma (HCC) have a highly variable clinical course. Therefore, there is an urgent need to identify new prognostic markers to determine prognosis and select specific therapies. Recently, it has been demonstrated that dysregulation of the urea cycle (UC) is a common phenomenon in multiple types of cancer. Upon UC dysregulation, nitrogen is diverted toward the multifunctional enzyme carbamoyl-phosphate synthetase 2, aspartate transcarbamoylase, and dihydroorotase (CAD), and increases pyrimidine synthesis. In this study, we investigated the role of CAD and carbamoyl-phosphate synthetase 1 (CPS1), a rate-limiting enzyme of the UC highly expressed in hepatocytes, in HCC. We created a tissue microarray to analyze expression of both enzymes by immunohistochemistry in a large and well-characterized overall cohort of 871 HCCs of 561 patients that underwent surgery. CAD was induced in recurrent HCCs, and high expression predicted shorter overall survival. CPS1 was downregulated in HCC and further reduced in recurrent tumors and distant metastases. Additionally, low CPS1 was associated with short overall survival. A combined score of both enzymes was an independent prognostic marker in a multivariate Cox regression model (HR = 1.37, 95% confidence interval 1.06-1.75, p = 0.014). Inhibition of pyrimidine synthesis may represent a novel therapeutic strategy for HCC.

Endogenous THBD (Thrombomodulin) Mediates Angiogenesis in the Ischemic Brain-Brief Report.

OBJECTIVE: THBD (thrombomodulin) is part of the anticoagulant protein C-system that acts at the endothelium and is involved in anti-inflammatory and barrier-stabilizing processes. A recombinant soluble form of THBD was shown to have protective effects in different organs, but how the endogenous THBD is regulated during ischemia, particularly in the brain is not known to date. The aim of this study was to investigate the role of THBD, especially in brain endothelial cells, during ischemic stroke. Approach and Results: To induce ischemic brain damage, we occluded the middle cerebral artery of mice. We found an increased endothelial expression of Thbd in the peri-infarct area, whereas in the core of the ischemic tissue Thbd expression was decreased compared with the contralateral side. We generated a novel Cre/loxP-based mouse line that allows for the inducible deletion of Thbd specifically in brain endothelial cells, which worsened stroke outcome 48 hours after middle cerebral artery occlusion. Unexpectedly, we found no signs of increased coagulation, thrombosis, or inflammation in the brain but decreased vessel diameters and impaired angiogenesis in the peri-infarct area that led to a reduced overall vessel length 1 week after stroke induction. CONCLUSIONS: Endogenous THBD acts as a protective factor in the brain during ischemic stroke and enhances vessel diameter and proliferation. These previously unknown properties of THBD could offer new opportunities to affect vessel function after ischemia and thereby improve stroke outcome.

[Hepatocellular carcinoma in an inflammatory adenoma with ß-catenin mutation in a patient with hepatocellular adenomatosis due to germline mutation in HNF1α]. / Entstehung eines hepatozellulären Karzinoms in einem inflammatorischen Adenom mit ß-Catenin-Mutation bei einem Patienten mit hepatozellulärer Adenomatose und HNF1α-Keimbahnmutation.

Hepatocyte nuclear factor 1 α (HNF1α) mutations cause maturity-onset diabetes of the young (MODY) type 3 and are associated with hepatocellular adenomatosis. Malignant transformation of HNF1α-mutated hepatocellular adenomas is rare. We report a case of a 28-year-old man with HNF1α-inactivated adenomatosis who developed an inflammatory adenoma with ß catenin mutation with malignant transformation into a well-differentiated hepatocellular carcinoma (HCC).