DNA Methylation Profiles Are Stable in H3 K27M-Mutant Diffuse Midline Glioma Neurosphere Cell Lines

Diffuse midline gliomas are among the deadliest human cancers and have had little progress in treatment in the last 50 years. Cell cultures of these tumors have been developed recently, but the degree to which such cultures retain the characteristics of the source tumors is unknown. DNA methylation profiling offers a powerful tool to look at genome-wide epigenetic changes that are biologically meaningful and can help assess the similarity of cultured tumor cells to their in vivo progenitors. Paraffinized diagnostic tissue from three diffuse intrinsic pontine gliomas with H3 K27M mutations was compared with subsequent passages of neurosphere cell cultures from those tumors. Each cell line was passaged 3-4 times and analyzed with DNA methylation arrays and standard algorithms that provided a comparison of diagnostic classification and cluster analysis. All samples tested maintained high classifier scores and clustered within the reference group of H3 K27M-mutant diffuse midline gliomas. There was a gain of 1q in all cell lines, with two cell lines initially manifesting the gain of 1q only during culture. In vitro cell cultures of H3 K27M-mutant gliomas maintain high degrees of similarity in DNA methylation profiles to their source tumor, confirming their fidelity even with some chromosomal changes.

Establishment and Characterization of a New Human Intrahepatic Cholangiocarcinoma Cell Line LIV27

Cholangiocarcinoma (CCA) is a highly lethal cancer arising from the biliary tract epithelium. The cancer biology of this neoplasm is not well understood. To date, only a few CCA cell lines have been reported, which were mostly developed from Asian patients. In this study, we report and characterize a new intrahepatic CCA cell line, LIV27, derived from a surgically resected tumor in a 67-year-old Caucasian woman with primary sclerosing cholangitis (PSC). LIV27 cells grow well in collagen-coated flasks or plates with a doubling time of 57.8 h at passage 14. LIV27 cells have high tumorigenicity in nude mice and stain positive for CK7 and CK19, markers that differentiate CCA from hepatocellular carcinoma. Karyotype analysis showed that LIV27 is aneuploid. We established a single-locus short tandem repeat profile for the LIV27 cell line. This newly established cell line will be a useful model for studying the molecular pathogenesis of, and developing novel therapies for, cholangiocarcinoma.

DNA Methylation Markers for Detection of Cholangiocarcinoma: Discovery, Validation, and Clinical Testing in Biliary Brushings and Plasma

Cholangiocarcinoma (CCA) has poor prognosis due to late-stage, symptomatic presentation. Altered DNA methylation markers may improve diagnosis of CCA. Reduced-representation bisulfite sequencing was performed on DNA extracted from frozen CCA tissues and matched to adjacent benign biliary epithelia or liver parenchyma. Methylated DNA markers (MDMs) identified from sequenced differentially methylated regions were selected for biological validation on DNA from independent formalin-fixed, paraffin-embedded CCA tumors and adjacent hepatobiliary control tissues using methylation-specific polymerase chain reaction. Selected MDMs were then blindly assayed on DNA extracted from independent archival biliary brushing specimens, including 12 perihilar cholangiocarcinoma, 4 distal cholangiocarcinoma cases, and 18 controls. Next, MDMs were blindly assayed on plasma DNA from patients with extrahepatic CCA (eCCA), including 54 perihilar CCA and 5 distal CCA cases and 95 healthy and 22 primary sclerosing cholangitis controls, balanced for age and sex. From more than 3,600 MDMs discovered in frozen tissues, 39 were tested in independent samples. In the clinical pilot of 16 MDMs on cytology brushings, methylated EMX1 (empty spiracles homeobox 1) had an area under the curve (AUC) of 0.98 (95% confidence interval [CI], 0.95-1.0). In the clinical pilot on plasma, a cross-validated recursive partitioning tree prediction model from nine MDMs was accurate for de novo eCCA (AUC, 0.88 [0.81-0.95]) but not for primary sclerosing cholangitis-associated eCCA (AUC, 0.54 [0.35-0.73]). Conclusion: Next-generation DNA sequencing yielded highly discriminant methylation markers for CCA. Confirmation of these findings in independent tissues, cytology brushings, and plasma supports further development of DNA methylation to augment diagnosis of CCA.

Knockout of sulfatase 2 is associated with decreased steatohepatitis and fibrosis in a mouse model of nonalcoholic fatty liver disease

Sulfatase 2 (SULF2) is a heparan sulfate editing enzyme that regulates the milieu of growth factors and cytokines involved in a variety of cellular processes. We used a murine model of diet-induced steatohepatitis to assess the effect of SULF2 downregulation on the development of nonalcoholic steatohepatitis (NASH) and liver fibrosis. Wild-type B6;129 mice (WT) and Sulf2-knockout B6;129P2-SULF2^{Gt(PST111)Byg} mice (Sulf2-KO) were fed a fast-food diet (FFD) rich in saturated fats, cholesterol, and fructose or a standard chow diet (SC) ad libitum for 9 mo. WT mice on FFD showed a threefold increase in hepatic Sulf2 mRNA expression, and a 2.2-fold increase in hepatic SULF2 protein expression compared with WT mice on SC. Knockout of Sulf2 led to a significant decrease in diet-mediated weight gain and dyslipidemia compared with WT mice on FFD. Knockout of Sulf2 also abrogated diet-induced steatohepatitis and hepatic fibrosis compared with WT mice on FFD. Furthermore, expression levels of the profibrogenic receptors TGFβR2 and PDGFRβ were significantly decreased in Sulf2-KO mice compared with WT mice on FFD. Together, our data suggest that knockout of Sulf2 significantly downregulates dyslipidemia, steatohepatitis, and hepatic fibrosis in a diet-induced mouse model of NAFLD, suggesting that targeting of SULF2 signaling may be a potential therapeutic mechanism in NASH.NEW & NOTEWORTHY We report for the first time that in wild-type (WT) mice, fast-food diet (FFD) induced a threefold increase in hepatic Sulf2 mRNA and a 2.2-fold increase in sulfatase 2 (SULF2) protein expression compared with WT mice on standard chow diet (SC). We showed that knockout of SULF2 ameliorates FFD-induced obesity, hyperlipidemia, steatohepatitis, and fibrosis. These data, along with work from other laboratories, suggest that SULF2 may be critical to the ability of the liver to progress to nonalcoholic steatohepatitis and fibrosis in conditions of overnutrition.

Pan-cancer analysis of whole genomes

Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale1-3. Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter4; identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation5,6; analyses timings and patterns of tumour evolution7; describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity8,9; and evaluates a range of more-specialized features of cancer genomes8,10-18.

The extracellular sulfatase SULF2 promotes liver tumorigenesis by stimulating assembly of a promoter-looping GLI1-STAT3 transcriptional complex

The expression of the extracellular sulfatase SULF2 has been associated with increased hepatocellular carcinoma (HCC) growth and poor patient survival. However, the molecular mechanisms underlying SULF2-associated tumor growth remain unclear. To address this gap, here we developed a transgenic mouse overexpressing Sulf2 in hepatocytes under the control of the transthyretin promoter. In this model, Sulf2 overexpression potentiated diethylnitrosamine-induced HCC. Further analysis indicated that the transcription factor GLI family zinc finger 1 (GLI1) mediates Sulf2 expression during HCC development. A cross of the Sulf2-overexpressing with Gli1-knockout mice revealed that Gli1 inactivation impairs SULF2-induced HCC. Transcriptomic analysis revealed that Sulf2 overexpression is associated with signal transducer and activator of transcription 3 (STAT3)-specific gene signatures. Interestingly, the Gli1 knockout abrogated SULF2-mediated induction of several STAT3 target genes, including suppressor of cytokine signaling 2/3 (Socs2/3); Pim-1 proto-oncogene, Ser/Thr kinase (Pim1); and Fms-related tyrosine kinase 4 (Flt4). Human orthologs were similarly regulated by SULF2, dependent on intact GLI1 and STAT3 functions in HCC cells. SULF2 overexpression promoted a GLI1-STAT3 interaction and increased GLI1 and STAT3 enrichment at the promoters of their target genes. Interestingly, the SULF2 overexpression resulted in GLI1 enrichment at select STAT3 consensus sites, and vice versa. siRNA-mediated STAT3 or GLI1 knockdown reduced promoter binding of GLI1 and STAT3, respectively. Finally, chromatin-capture PCR confirmed long-range co-regulation of SOCS2 and FLT3 through changes in promoter conformation. These findings define a mechanism whereby SULF2 drives HCC by stimulating formation of a GLI1-STAT3 transcriptional complex.

Induction of Lysosome-associated Protein Transmembrane 4 Beta via Sulfatase 2 Enhances Autophagic Flux in Liver Cancer Cells

Autophagy has been shown to be a key cellular event controlling tumor growth in different neoplasms including hepatocellular carcinoma (HCC). Although this biological role of autophagy has been clearly established, the mechanism underlying its regulation remains elusive. Here, we demonstrate a role of sulfatase 2 (SULF2), a 6‐O‐endosulfatase modulating various growth factors and cytokine‐related signaling pathways controlling tumor cell proliferation and survival, in the regulation of autophagy in HCC cells. SULF2 increased autophagosome formation, shown by increased LC3B‐II protein and green fluorescent protein–LC3 puncta. Increased fusion between autophagosomes and lysosomes/lysosomal enzymes, higher expression of lysosomal membrane protein, and an increase in autolysosomes were also shown by western blot, immunofluorescence, and electron microscopy of SULF2‐expressing cells, indicating enhanced autophagic flux. In contrast, RNA‐interference silencing of SULF2 in Huh7 cells induced lysosomal membrane permeabilization with diffuse cytosolic staining of cathepsin D and punctate staining of galectin‐3. Analysis of the mechanism showed that inhibition of lysosome‐associated protein transmembrane 4 beta (LAPTM4B), a gene induced by SULF2, resulted in decreased autophagosome formation, decreased fusion between autophagosomes and lysosomes, and increased lysosomal membrane permeabilization. Interestingly, down‐regulation of LAPTM4B also phenocopies the knockdown of SULF2, significantly reducing cell viability and colony formation. Conclusion: Our results demonstrate a role for SULF2 in the regulation of autophagic flux that is mediated through LAPTM4B induction in HCC cells, and provide a foundation for future translational efforts targeting autophagy in liver malignancies.

GALAD Score for Hepatocellular Carcinoma Detection in Comparison with Liver Ultrasound and Proposal of GALADUS Score

BACKGROUND

The GALAD score is a serum biomarker-based model that predicts the probability of having hepatocellular carcinoma (HCC) in patients with chronic liver disease. We aimed to assess the performance of the GALAD score in comparison with liver ultrasound for detection of HCC.

METHODS

A single-center cohort of 111 HCC patients and 180 controls with cirrhosis or chronic hepatitis B and a multicenter cohort of 233 early HCC and 412 cirrhosis patients from the Early Detection Research Network (EDRN) phase II HCC Study were analyzed.

RESULTS

The area under the ROC curve (AUC) of the GALAD score for HCC detection was 0.95 [95% confidence interval (CI), 0.93-97], which was higher than the AUC of ultrasound (0.82, P <0.01). At a cutoff of -0.76, the GALAD score had a sensitivity of 91% and a specificity of 85% for HCC detection. The AUC of the GALAD score for early-stage HCC detection remained high at 0.92 (95% CI, 0.88-0.96; cutoff -1.18, sensitivity 92%, specificity 79%). The AUC of the GALAD score for HCC detection was 0.88 (95% CI, 0.85-0.91) in the EDRN cohort. The combination of GALAD and ultrasound (GALADUS score) further improved the performance of the GALAD score in the single-center cohort, achieving an AUC of 0.98 (95% CI, 0.96-0.99; cutoff -0.18, sensitivity 95%, specificity 91%).

CONCLUSIONS

The performance of the GALAD score was superior to ultrasound for HCC detection. The GALADUS score further enhanced the performance of the GALAD score.

IMPACT

The GALAD score was validated in the United States.

Preclinical In Vitro and In Vivo Evidence of an Antitumor Effect of CX-4945, a Casein Kinase II Inhibitor, in Cholangiocarcinoma

PURPOSE: We investigated the antitumor effect of the casein kinase II (CK2) inhibitor CX-4945 on cholangiocarcinoma (CCA). METHODS: We assessed the effect of CX-4945 alone and/or in combination with gemcitabine and cisplatin on cell viability, colony formation, and apoptosis of CCA cell lines and on in vivo growth of HuCCT1 xenografts. RESULTS: CX-4945 dose-dependently decreased viability of HuCCT1, EGI-1, and Liv27 and decreased phospho-AKT/total AKT and phospho-PTEN/total PTEN ratios. CX-4945 significantly increased caspase 3/7 activity in a dose- and time-dependent manner. CX-4945 significantly enhanced the effect of gemcitabine or cisplatin on HuCCT1, EGI-1, and Liv27 cells and inhibited the phosphorylation of DNA repairing enzymes XRCC1 and MDC1. Further, CX-4945 alone significantly inhibited growth of HuCCT1 mouse xenograft tumors. Combining CX-4945 with gemcitabine and cisplatin was more potent than CX-4945 alone or gemcitabine/cisplatin. The effect of CX-4945 on cell proliferation, apoptosis, the PI3K/AKT pathway, and DNA repair was confirmed in the mouse xenografts. CONCLUSION: CX-4945 has an antiproliferative effect on CCA and enhances the effect of gemcitabine and cisplatin through its inhibitory effect on the PI3K/AKT pathway and DNA repair.

Decreased Expression of Sulfatase 2 in the Brains of Alzheimer's Disease Patients: Implications for Regulation of Neuronal Cell Signaling

Background:

The human sulfatase 1 (SULF1) and sulfatase 2 (SULF2) genes modulate cell signaling and homeostasis in many tissues. Gene expression analyses have implicated SULF2 in disease pathogenesis, including Alzheimer’s disease (AD), but changes in brain SULF2 expression have not been directly established.

Objective:

To investigate the expression of SULF1 and SULF2 in brain tissues from AD cases and cognitively normal controls.

Methods:

Autopsy tissue from AD cases (n = 20) and age-and gender-matched cognitively normal controls (n = 20) were identified from the Mayo Clinic Alzheimer’s Disease Patient Registry neuropathology database. Tissue slides were stained for SULF1 and SULF2 protein expression in the hippocampus and frontal lobe and an expression score computed from the proportion of cells stained and the intensity of staining (range 0 [no expression] to 9 [marked expression]).

Results:

SULF2 expression was reduced in AD cases. Compared to cognitively normal controls, SULF2 expression in AD cases was significantly decreased in the hippocampal Cornu Ammonis (CA) (mean score of 6.5 in cases versus 8.3 in controls; p = 0.003), in the gray matter of the parahippocampal gyrus (5.6 in cases versus 7.6 in controls; p = 0.003), and in the frontal lobe gray matter (5.4 in cases versus 7.4 in controls; p = 0.002). There was no difference in SULF1 expression in the hippocampus or frontal lobe of AD cases and controls. As expected there were no differences in SULF1 or SULF2 expression in white matter in AD cases compared to cognitively normal controls.

Conclusion:

Decreased SULF2 in specific regions of the brain occurs in AD.

Identification of fucosylated Fetuin-A as a potential biomarker for cholangiocarcinoma

PURPOSE

Cholangiocarcinoma (CCA) is a malignancy of the bile ducts. The purpose of this discovery study was to identify effective serum markers for surveillance of cholangiocarcinoma.

EXPERIMENTAL DESIGN

Using a glycomic method, patients with CCA were determined to have increased levels of alpha-1,3 and alpha-1,6 linked fucosylated glycan. Proteomic analysis of the serum fucosylated proteome identified proteins such as alpha-2-macroglobulin, kininogen, hemopexin, fetuin-A, alpha-1 anti-trypsin, and ceruloplasmin as being hyperfucosylated in HCC. The levels of these glycoproteins in 109 patients with CCA, primary sclerosing cholangitis (PSC), and control patients were compared to the performance of CA-19-9, the current "gold standard" assay for cholangiocarcinoma.

RESULTS

Fucosylated Fetuin-A (fc-Fetuin-A) had the best ability to differentiate CCA from PSC, with an AUROC of 0.812 or 0.8665 at differentiating CCA from those with PSC or other liver disease. CA-19-9 had poor ability to differentiate PSC from cholangiocarcinoma (AUROC of 0.625).

CONCLUSION AND CLINICAL RELEVANCE

Using glycomic and proteomic methods we identified a set of proteins that contain altered glycan in the sera of those with CCA. One of these proteins, fucosylated Fetuin-A may have value in the surveillance of people at risk for the development of cholangiocarcinoma.

Transcriptional Induction of Periostin by a Sulfatase 2-TGFβ1-SMAD Signaling Axis Mediates Tumor Angiogenesis in Hepatocellular Carcinoma

Existing antiangiogenic approaches to treat metastatic hepatocellular carcinoma (HCC) are weakly effectual, prompting further study of tumor angiogenesis in this disease setting. Here, we report a novel role for sulfatase 2 (SULF2) in driving HCC angiogenesis. Sulf2-deficient mice (Sulf2 KO) exhibited resistance to diethylnitrosamine-induced HCC and did not develop metastases like wild-type mice (Sulf2 WT). The smaller and less numerous tumors formed in Sulf2 KO mice exhibited a markedly lower microvascular density. In human HCC cells, SULF2 overexpression increased endothelial proliferation, adhesion, chemotaxis, and tube formation in a paracrine fashion. Mechanistic analyses identified the extracellular matrix protein periostin (POSTN), a ligand of αvβ3/5 integrins, as an effector protein in SULF2-induced angiogenesis. POSTN silencing in HCC cells attenuated SULF2-induced angiogenesis and tumor growth in vivo The TGFβ1/SMAD pathway was identified as a critical signaling axis between SULF2 and upregulation of POSTN transcription. In clinical HCC specimens, elevated levels of SULF2 correlated with increased microvascular density, POSTN levels, and relatively poorer patient survival. Together, our findings define an important axis controlling angiogenesis in HCC and a mechanistic foundation for rational drug development. Cancer Res; 77(3); 632-45. ©2016 AACR.

Antitumor effect of FGFR inhibitors on a novel cholangiocarcinoma patient derived xenograft mouse model endogenously expressing an FGFR2-CCDC6 fusion protein

Cholangiocarcinoma is a highly lethal cancer with limited therapeutic options. Recent genomic analysis of cholangiocarcinoma has revealed the presence of fibroblast growth factor receptor 2 (FGFR2) fusion proteins in up to 13% of intrahepatic cholangiocarcinoma (iCCA). FGFR fusions have been identified as a novel oncogenic and druggable target in a number of cancers. In this study, we established a novel cholangiocarcinoma patient derived xenograft (PDX) mouse model bearing an FGFR2-CCDC6 fusion protein from a metastatic lung nodule of an iCCA patient. Using this PDX model, we confirmed the ability of the FGFR inhibitors, ponatinib, dovitinib and BGJ398, to modulate FGFR signaling, inhibit cell proliferation and induce cell apoptosis in cholangiocarcinoma tumors harboring FGFR2 fusions. In addition, BGJ398 appeared to be superior in potency to ponatinib and dovitinib in this model. Our findings provide a strong rationale for the investigation of FGFR inhibitors, particularly BGJ398, as a therapeutic option for cholangiocarcinoma patients harboring FGFR2 fusions.

Antitumor effect of the novel sphingosine kinase 2 inhibitor ABC294640 is enhanced by inhibition of autophagy and by sorafenib in human cholangiocarcinoma cells

Sphingosine kinase 2 (Sphk2) has an oncogenic role in cancer. A recently developed first-in-class Sphk2 specific inhibitor ABC294640 displays antitumor activity in many cancer models. However, the role of Sphk2 and the antitumor activity of its inhibitor ABC294640 are not known in cholangiocarcinoma. We investigated the potential of targeting Sphk2 for the treatment of cholangiocarcinoma. We found that Sphk2 is overexpressed in five established human cholangiocarcinoma cell lines (WITT, HuCCT1, EGI-1, OZ and HuH28) and a new patient-derived cholangiocarcinoma cell line (LIV27) compared to H69 normal cholangiocytes. Inhibition of Sphk2 by ABC294640 inhibited proliferation and induced caspase-dependent apoptosis. Furthermore, we found that ABC294640 inhibited STAT3 phosphorylation, one of the key signaling pathways regulating cholangiocarcinoma cell proliferation and survival. ABC294640 also induced autophagy. Inhibition of autophagy by bafilomycin A1 or chloroquine potentiated ABC294640-induced cytotoxicity and apoptosis. In addition, ABC294640 in combination with sorafenib synergistically inhibited cell proliferation of cholangiocarcinoma cells. Strong decreases in STAT3 phosphorylation were observed in WITT and HuCCT1 cells exposed to the ABC294640 and sorafenib combination. These findings provide novel evidence that Sphk2 may be a rational therapeutic target in cholangiocarcinoma. Combinations of ABC294640 with sorafenib and/or autophagy inhibitors may provide novel strategies for the treatment of cholangiocarcinoma.

Association between variants in inflammation and cancer-associated genes and risk and survival of cholangiocarcinoma

Genetic risk factors for cholangiocarcinoma (CCA) remain poorly understood. We assessed the effect of single-nucleotide polymorphisms (SNPs) of genes modulating inflammation or carcinogenesis on CCA risk and survival. We conducted a case-control, candidate gene association study of 370 CCA patients and 740 age-, sex-, and residential area-matched healthy controls. Eighteen functional or putatively functional SNPs in nine genes were genotyped. The log-additive genotype effects of SNPs on CCA risk and survival were determined using logistic regression and the log-rank test, respectively. Initial analysis identified significant associations between SNP rs2143417 and rs689466 in cyclooxygenase 2 (COX-2) and CCA risk, after adjusting for multiple comparisons (cutoff of P = 0.0028). However, these findings were not replicated in another independent cohort of 212 CCA cases and 424 matched controls. No significant association was found between any SNP and survival of CCA patients. Although COX-2 has been shown to contribute to cholangiocarcinogenesis, the COX-2 SNPs tested were not associated with risk of CCA. This study shows a lack of association between variants of genes related to inflammation and carcinogenesis and CCA risk and survival. Other factors than these genetic variants may play more important roles in CCA risk and survival.

Combinations of biomarkers and Milan criteria for predicting hepatocellular carcinoma recurrence after liver transplantation

Growing evidence suggests that pretransplant alpha-fetoprotein (AFP) predicts outcomes of hepatocellular carcinoma (HCC) patients treated with liver transplantation. We aimed to determine whether pretransplant AFP, Lens culinaris agglutinin-reactive alpha-fetoprotein (AFP-L3), and des-gamma-carboxyprothrombin (DCP) predicted HCC recurrence after transplantation. A retrospective cohort study of 313 HCC patients undergoing transplantation between 2000 and 2008 was conducted, and 48 (15.3%) developed recurrence during a median follow-up of 90.8 months. The 127 patients with available serum drawn before transplantation were included; they included 86 without recurrence and 41 with recurrence. Serum was tested for AFP, AFP-L3%, and DCP in a blinded fashion with the μTASWako i30 immunoanalyzer. All biomarkers were significantly associated with HCC recurrence. The hazard ratios (HRs) were 3.5 [95% confidence interval (CI), 1.9-6.7; P < 0.0001] for DCP ≥ 7.5 ng/mL and 2.8 (95% CI, 1.4-5.4; P = 0.002) for AFP ≥ 250 ng/mL. The HR increased to 5.2 (95% CI, 2.3-12.0; P < 0.0001) when AFP ≥ 250 ng/mL and DCP ≥7.5 ng/mL were considered together. When they were combined with the Milan criteria, the HR increased from 2.6 (95% CI, 1.4-4.7; P = 0.003) for outside the Milan criteria to 8.6 (95% CI, 3.0-24.6; P < 0.0001) for outside the Milan criteria and AFP ≥ 250 ng/mL and to 7.2 (95% CI, 2.8-18.1; P < 0.0001) for outside the Milan criteria and DCP ≥7.5 ng/mL. Our findings suggest that biomarkers are useful for predicting the risk of HCC recurrence after transplantation. Using both biomarkers and the Milan criteria may be better than using the Milan criteria alone in optimizing the decision of liver transplantation eligibility.

Restoration of epigenetically silenced SULF1 expression by 5-aza-2-deoxycytidine sensitizes hepatocellular carcinoma cells to chemotherapy-induced apoptosis

Background

Hepatocellular carcinoma (HCC) is the second most frequent cause of cancer death worldwide. Sulfatase 1 (SULF1) functions as a tumor suppressor in HCC cell lines in vitro but also has an oncogenic effect in some HCCs in vivo.

Aim

The purpose of this study was to examine the mechanisms regulating SULF1 and its function in HCC.

Methods

First, SULF1 mRNA and protein expression were examined. Second, we examined SULF1 gene copy numbers in HCC cells. Third, we assessed whether DNA methylation or methylation and/or acetylation of histone marks on the promoter regulate SULF1 expression. Finally, we examined the effect of 5-aza-2′-deoxycytidine (5-Aza-dC) on sulfatase activity and drug-induced apoptosis.

Results

SULF1 mRNA was downregulated in nine of eleven HCC cell lines, but only in six of ten primary tumors. SULF1 mRNA correlated with protein expression. Gene copy number assessment by fluorescence in situ hybridization showed intact SULF1 alleles in low-SULF1-expressing cell lines. CpG island methylation in the SULF1 promoter and two downstream CpG islands did not show an inverse correlation between DNA methylation and SULF1 expression. However, chromatin immunoprecipitation showed that the SULF1 promoter acquires a silenced chromatin state in low-SULF1-expressing cells through an increase in di/trimethyl-K9H3 and trimethyl-K27H3 and a concomitant loss of activating acetyl K9, K14H3 marks. 5-Aza-dC restored SULF1 mRNA expression in SULF1-negative cell lines, with an associated increase in sulfatase activity and sensitization of HCC cells to cisplatin-induced apoptosis.

Conclusion

SULF1 gene silencing in HCC occurs through histone modifications on the SULF1 promoter. Restoration of SULF1 mRNA expression by 5-Aza-dC sensitized HCC cells to drug-induced apoptosis.

Activation of the transforming growth factor-β/SMAD transcriptional pathway underlies a novel tumor-promoting role of sulfatase 1 in hepatocellular carcinoma

In vitro studies have proposed a tumor suppressor role for sulfatase 1 (SULF1) in hepatocellular carcinoma (HCC); however, high expression in human HCC has been associated with poor prognosis. The reason underlying this paradoxical observation remains to be explored. Using a transgenic (Tg) mouse model overexpressing Sulf1 (Sulf1-Tg), we assessed the effects of SULF1 on the diethylnitrosamine model of liver carcinogenesis. Sulf1-Tg mice show a higher incidence of large and multifocal tumors with diethylnitrosamine injection compared to wild-type mice. Lung metastases were found in 75% of Sulf1-Tg mice but not in wild-type mice. Immunohistochemistry, immunoblotting, and reporter assays all show a significant activation of the transforming growth factor-β (TGF-β)/SMAD transcriptional pathway by SULF1 both in vitro and in vivo. This effect of SULF1 on the TGF-β/SMAD pathway is functional; overexpression of SULF1 promotes TGF-β-induced gene expression and epithelial-mesenchymal transition and enhances cell migration/invasiveness. Mechanistic analyses demonstrate that inactivating mutation of the catalytic site of SULF1 impairs the above actions of SULF1 and diminishes the release of TGF-β from the cell surface. We also show that SULF1 expression decreases the interaction between TGF-β1 and its heparan sulfate proteoglycan sequestration receptor, TGFβR3. Finally, using gene expression from human HCCs, we show that patients with high SULF1 expression have poorer recurrence-free survival (hazard ratio 4.1, 95% confidence interval 1.9-8.3; P = 0.002) compared to patients with low SULF1. We also found strong correlations of SULF1 expression with TGF-β expression and with several TGF-β-related epithelial-mesenchymal transition genes in human HCC.

CONCLUSION

Our study proposes a novel role of SULF1 in HCC tumor progression through augmentation of the TGF-β pathway, thus defining SULF1 as a potential biomarker for tumor progression and a novel target for drug development for HCC.

Brivanib attenuates hepatic fibrosis in vivo and stellate cell activation in vitro by inhibition of FGF, VEGF and PDGF signaling

Background and Aims

Brivanib is a selective inhibitor of vascular endothelial growth factor receptor (VEGFR) and fibroblast growth factor receptor (FGFR) tyrosine kinases, which are both involved in mechanisms of liver fibrosis. We hypothesized that inhibition of VEGFR and FGFR by brivanib would inhibit liver fibrosis. We therefore examined the effect of brivanib on liver fibrosis in three mouse models of fibrosis.

Methods

In vivo, we induced liver fibrosis by bile duct ligation (BDL), chronic carbon tetrachloride (CCl₄), and chronic thioacetamide (TAA) administration. Liver fibrosis was examined by immunohistochemistry and Western immunoblotting. In vitro, we used LX-2 human hepatic stellate cells (HSCs) to assess the effect of brivanib on stellate cell proliferation and activation.

Results

After in vivo induction with BDL, CCl₄, and TAA, mice treated with brivanib showed reduced liver fibrosis and decreased expression of collagen Iα1 and α-smooth muscle actin in the liver. In vitro, brivanib decreased proliferation of HSCs induced by platelet-derived growth factor (PDGF), VEGF, and FGF. Brivanib also decreased stellate cell viability and inhibited PDGFBB-induced phosphorylation of its cognate receptor.

Conclusion

Brivanib reduces liver fibrosis in three different animal models and decreases human hepatic stellate cell activation. Brivanib may represent a novel therapeutic approach to treatment of liver fibrosis and prevention of liver cancer.

Activation of the transcription factor GLI1 by WNT signaling underlies the role of SULFATASE 2 as a regulator of tissue regeneration

Tissue regeneration requires the activation of a set of specific growth signaling pathways. The identity of these cascades and their biological roles are known; however, the molecular mechanisms regulating the interplay between these pathways remain poorly understood. Here, we define a new role for SULFATASE 2 (SULF2) in regulating tissue regeneration and define the WNT-GLI1 axis as a novel downstream effector for this sulfatase in a liver model of tissue regeneration. SULF2 is a heparan sulfate 6-O-endosulfatase, which releases growth factors from extracellular storage sites turning active multiple signaling pathways. We demonstrate that SULF2-KO mice display delayed regeneration after partial hepatectomy (PH). Mechanistic analysis of the SULF2-KO phenotype showed a decrease in WNT signaling pathway activity in vivo. In isolated hepatocytes, SULF2 deficiency blocked WNT-induced β-CATENIN nuclear translocation, TCF activation, and proliferation. Furthermore, we identified the transcription factor GLI1 as a novel target of the SULF2-WNT cascade. WNT induces GLI1 expression in a SULF2- and β-CATENIN-dependent manner. GLI1-KO mice phenocopied the SULF2-KO, showing delayed regeneration and decreased hepatocyte proliferation. Moreover, we identified CYCLIN D1, a key mediator of cell growth during tissue regeneration, as a GLI1 transcriptional target. GLI1 binds to the cyclin d1 promoter and regulates its activity and expression. Finally, restoring GLI1 expression in the liver of SULF2-KO mice after PH rescues CYCLIN D1 expression and hepatocyte proliferation to wild-type levels. Thus, together these findings define a novel pathway in which SULF2 regulates tissue regeneration in part via the activation of a novel WNT-GLI1-CYCLIN D1 pathway.

Methylated Bone Morphogenetic Protein 3 (BMP3) Gene: Evaluation of Tumor Suppressor Function and Biomarker Potential in Biliary Cancer

Background

Although cholangiocarcinoma (CC) is an uncommon and highly lethal malignancy, early detection enables the application of potentially curative therapies and improves survival. Consequently, tools to improve the early diagnosis of CC are urgently needed. During a screen for genes epigenetically suppressed by methylation in CC that might serve as methylation markers for CC, we found that the BMP3 gene is methylated in CC cell lines, but the potential diagnostic value and the function of BMP3 in CC are unknown.

Methods

We aimed to quantitatively assess BMP3 methylation in resected CC tumor specimens using methylation specific PCR and evaluate the tumor suppressor role of BMP3 in biliary cancer cell lines in comparison to an immortalized normal cholangiocyte cell line. Expression of BMP3 was quantified by mRNA levels before and after treatment with 5-Aza-2’-deoxycytidine and trichostatin A. After transfection with a BMP3-containing plasmid, cell viability was measured using the bromodeoxyuridine incorporation assay and apoptosis quantified by caspase assay.

Results

In primary CC tumor tissue specimens significantly more methylated BMP3 copies were found when compared to matched benign bile duct epithelium from the same patient, with high specificity. BMP3 expression was absent in cell lines with BMP3 methylation; this suppression of BMP3 expression was reversed by treatment with a DNA demethylating agent and histone de-acetylase inhibitor. Transfection of a BMP3-expressing construct into a BMP3-negative biliary cancer cell line restored BMP3 mRNA expression and reduced cell proliferation and cell viability while increasing the rate of apoptosis.

Conclusion

These findings strongly support a tumor suppressor role for BMP3 in CC and suggest that BMP3 methylation may be a new biomarker for early detection of CCs. of the peptidome are also involved.

The transcription factor GLI1 mediates TGFβ1 driven EMT in hepatocellular carcinoma via a SNAI1-dependent mechanism

The role of the epithelial-to-mesenchymal transition (EMT) during hepatocellular carcinoma (HCC) progression is well established, however the regulatory mechanisms modulating this phenomenon remain unclear. Here, we demonstrate that transcription factor glioma-associated oncogene 1 (GLI1) modulates EMT through direct up-regulation of SNAI1 and serves as a downstream effector of the transforming growth factor-β1 (TGFβ1) pathway, a well-known regulator of EMT in cancer cells. Overexpression of GLI1 increased proliferation, viability, migration, invasion, and colony formation by HCC cells. Conversely, GLI1 knockdown led to a decrease in all the above-mentioned cancer-associated phenotypes in HCC cells. Further analysis of GLI1 regulated cellular functions showed that this transcription factor is able to induce EMT and identified SNAI1 as a transcriptional target of GLI1 mediating this cellular effect in HCC cells. Moreover, we demonstrated that an intact GLI1-SNAI1 axis is required by TGFβ1 to induce EMT in these cells. Together, these findings define a novel cellular mechanism regulated by GLI1, which controls the growth and EMT phenotype in HCC.

The human sulfatase 2 inhibitor 2,4-disulfonylphenyl-tert-butylnitrone (OKN-007) has an antitumor effect in hepatocellular carcinoma mediated via suppression of TGFB1/SMAD2 and Hedgehog/GLI1 signaling

Human sulfatase 2 (SULF2) functions as an oncoprotein in hepatocellular carcinoma (HCC) development by promoting tumor growth and metastasis via enhancement of fibroblast growth factor-2/extracellular signal-regulated kinase and WNT/β-catenin signaling. Recent results implicate that SULF2 activates the transforming growth factor beta (TGFB) and Hedgehog/GLI1 pathways in HCC. OKN-007 is a novel phenyl-sulfonyl compound that inhibits the enzymatic activity of SULF2. To investigate the antitumor effect of OKN-007 in HCC, we treated Huh7 cells, which express high levels of SULF2, with OKN-007 and found that it significantly promoted tumor cell apoptosis and inhibited cell proliferation, viability, and migration. To understand the action of OKN-007 on SULF2, we used Huh7 cells which normally express SULF2 and Hep3B cells that do not normally express SULF2. Utilizing Huh7 cells transfected with short hairpin RNA targeting SULF2 and transfection of Hep3B cells with a SULF2 plasmid to enhance SULF2 expression, we showed that the antitumor activity of OKN-007 was more pronounced in cells expressing SULF2. Furthermore, in vivo experiments verified that OKN-007 repressed tumor growth significantly. These results identify SULF2 as an important target of the antitumor effect of OKN-007. To determine the molecular mechanism of the antitumor effect of OKN-007, both TGFB1/SMAD and Hedgehog/GLI1 signaling pathway activity were measured by Western blot and SMAD- or GLI-reporter luciferase assays. We found that both signaling pathways were inhibited by OKN-007. Together, these results show that OKN-007 can suppress TGFB1/SMAD and Hedgehog/GLI1 signaling via its inhibition of SULF2 enzymatic activity. We conclude that OKN-007 or more potent derivatives may be promising agents for the treatment of HCC.

Utility of serum immunoglobulin G4 in distinguishing immunoglobulin G4-associated cholangitis from cholangiocarcinoma

Elevated serum immunoglobulin G4 (sIgG4) is a feature of autoimmune pancreatitis (AIP) and IgG4-associated cholangitis (IAC); a >2-fold increase in sIgG4 is considered highly specific for these disorders. Many patients with IAC present with biliary strictures and obstructive jaundice, making cholangiocarcinoma (CCA) an important differential diagnosis. We determined the value of sIgG4 in distinguishing IAC from CCA. sIgG4 levels were measured in a test cohort of 126 CCA and 50 IAC patients. The results were confirmed in a validation cohort of 161 CCA and 47 IAC patients. Of the 126 CCA patients in the test cohort, 17 (13.5%) had elevated sIgG4 (>140 mg/dL) and four (3.2%) had a >2-fold (>280 mg/dL) increase. Primary sclerosing cholangitis (PSC) was present in 31/126 CCA patients, of whom seven (22.6%) had elevated sIgG4 and two (6.5%) had a >2-fold elevation. Of the 50 IAC patients, 39 (78.0%) had elevated sIgG4 and 25 (50.0%) had a >2-fold increase. The results in the validation cohort were consistent with those of the test cohort.

CONCLUSION

Although elevated sIgG4 levels are characteristic of IAC, some patients with CCA, particularly with PSC, have elevated sIgG4 levels, including a small percentage with a more than a 2-fold increase in sIgG4. Therefore, sIgG4 elevation alone does not exclude the diagnosis of CCA. Depending on the prevalence of the two diagnoses, the use of a 2-fold cutoff for sIgG4 may not reliably distinguish IAC from CCA. At a cutoff of 4 times the upper limit of normal, sIgG4 is 100% specific for IAC.

The oncogenic effect of sulfatase 2 in human hepatocellular carcinoma is mediated in part by glypican 3-dependent Wnt activation

Heparan sulfate proteoglycans (HSPGs) act as coreceptors or storage sites for growth factors and cytokines such as fibroblast growth factor and Wnts. Glypican 3 (GPC3) is the most highly expressed HSPG in hepatocellular carcinoma (HCC). Sulfatase 2 (SULF2), an enzyme with 6-O-desulfatase activity on HSPGs, is up-regulated in 60% of primary HCCs and is associated with a worse prognosis. We have previously shown that the oncogenic effect of SULF2 in HCC may be mediated in part through up-regulation of GPC3. Here we demonstrate that GPC3 stimulates the Wnt/β-catenin pathway and mediates the oncogenic function of SULF2 in HCC. Wnt signaling in vitro and in vivo was assessed in SULF2-negative Hep3B HCC cells transfected with SULF2 and in SULF2-expressing Huh7 cells transfected with short hairpin RNA targeting SULF2. The interaction between GPC3, SULF2, and Wnt3a was assessed by coimmunoprecipitation and flow cytometry. β-catenin-dependent transcriptional activity was assessed with the TOPFLASH (T cell factor reporter plasmid) luciferase assay. In HCC cells, SULF2 increased cell surface GPC3 and Wnt3a expression, stabilized β-catenin, and activated T cell factor transcription factor activity and expression of the Wnt/β-catenin target gene cyclin D1. Opposite effects were observed in SULF2-knockdown models. In vivo, nude mouse xenografts established from SULF2-transfected Hep3B cells showed enhanced GPC3, Wnt3a, and β-catenin levels.

CONCLUSION

Together, these findings identify a novel mechanism mediating the oncogenic function of SULF2 in HCC that includes GPC3-mediated activation of Wnt signaling via the Wnt3a/glycogen synthase kinase 3 beta axis.

Sulfatase 2 protects hepatocellular carcinoma cells against apoptosis induced by the PI3K inhibitor LY294002 and ERK and JNK kinase inhibitors

BACKGROUND

Sulfatase 2 (SULF2), an extracellular heparan sulphate 6-O-endosulphatase, has an oncogenic effect in hepatocellular carcinoma (HCC) that is partially mediated through glypican 3, which promotes heparin-binding growth factor signalling and HCC cell growth. SULF2 also increases phosphorylation of the anti-apoptotic Akt kinase substrate GSK3β and SULF2 expression is associated with a decreased apoptotic index in human HCCs.

METHODS

We investigated the functional and mechanistic effects of SULF2 on drug-induced apoptosis of HCC cells using immunohistochemistry, Western immunoblotting, gene transfection, real-time quantitative polymerase chain reaction, MTT and apoptosis assays and immunocytochemistry.

RESULTS

The increased expression of SULF2 in human HCCs was confirmed by immunohistochemistry and immunoblotting. Treatment with inhibitors of MEK, JNK and PI3 kinases decreased the viability of SULF2-negative Hep3B HCC cells and induced apoptotic caspase 3 and 7 activity, which was most strongly induced by the PI3K inhibitor LY294002. Forced expression of SULF2 in Hep3B cells significantly decreased activity of the apoptotic caspases 3 and 7 and induced resistance to LY294002-induced apoptosis. As expected, LY294002 inhibited activation of Akt kinase by PI3K. Conversely, knockdown of SULF2 using an shRNA construct targeting the SULF2 mRNA induced profound cell growth arrest and sensitized the endogenously SULF2-expressing HCC cell lines Huh7 and SNU182 to drug-induced apoptosis. The effects of knockdown of SULF2 on HCC cells were mediated by decreased Akt phosphorylation, downregulation of cyclin D1 and the anti-apoptotic molecule Bcl-2, and upregulation of the pro-apoptotic molecule BAD.

CONCLUSION

The prosurvival, anti-apoptotic effect of SULF2 in HCC is mediated through activation of the PI3K/Akt pathway.

Additive effect of apicidin and doxorubicin in sulfatase 1 expressing hepatocellular carcinoma in vitro and in vivo

BACKGROUND/AIMS

There are limited chemotherapy options for hepatocellular carcinoma (HCC). The heparin-degrading endosulfatase SULF1 functions as a liver tumor suppressor. We investigated the effects of the histone deacetylase inhibitor apicidin in combination with doxorubicin in SULF1-expressing HCC cells in vitro and in SULF1-expressing xenografts in nude mice.

METHODS

We evaluated the effects of apicidin alone or combined with doxorubicin on apoptosis, caspase activity, and phosphorylation of Erk and Akt in SULF1-transfected Huh7 and Hep3B cells in vitro and in vivo.

RESULTS

Apicidin induced HCC cell apoptosis and caspase activation in a dose- and time-dependent manner. Apicidin-induced caspase activation was significantly inhibited by the caspase inhibitor Z-Vad-fmk. Apicidin also decreased phosphorylation of both Erk and Akt. Expression of constitutively-active Mek1 and Akt significantly decreased apicidin-induced apoptosis. The combination of doxorubicin with apicidin significantly increased the anti-tumor effect in the SULF1-expressing Huh7 and Hep3B cells as compared to either apicidin or doxorubicin alone, both in vitro and in vivo.

CONCLUSIONS

The combination of a histone deacetylase inhibitor with doxorubicin may be a novel and promising therapeutic modality for HCCs, particularly for SULF1-expressing HCCs.

Sulfatase 2 up-regulates glypican 3, promotes fibroblast growth factor signaling, and decreases survival in hepatocellular carcinoma

It has been shown that the heparin-degrading endosulfatase, sulfatase 1 (SULF1), functions as a liver tumor suppressor, but the role of the related sulfatase, sulfatase 2 (SULF2), in liver carcinogenesis remains to be elucidated. We investigated the effect of SULF2 on liver tumorigenesis. Expression of SULF2 was increased in 79 (57%) of 139 hepatocellular carcinomas (HCCs) and 8 (73%) of 11 HCC cell lines. Forced expression of SULF2 increased HCC cell growth and migration, whereas knockdown of SULF2 using short hairpin RNA targeting SULF2 abrogated HCC cell proliferation and migration in vitro. Because SULF1 and SULF2 desulfate heparan sulfate proteoglycans (HSPGs) and the HSPG glypican 3 (GPC3) is up-regulated in HCC, we investigated the effects of SULF2 on GPC3 expression and the association of SULF2 with GPC3. SULF2-mediated cell growth was associated with increased binding of fibroblast growth factor 2 (FGF2), phosphorylation of extracellular signal-regulated kinase and AKT, and expression of GPC3. Knockdown of GPC3 attenuated FGF2 binding in SULF2-expressing HCC cells. The effects of SULF2 on up-regulation of GPC3 and tumor growth were confirmed in nude mouse xenografts. Moreover, HCC patients with increased SULF2 expression in resected HCC tissues had a worse prognosis and a higher rate of recurrence after surgery.

CONCLUSION

In contrast to the tumor suppressor effect of SULF1, SULF2 has an oncogenic effect in HCC mediated in part through up-regulation of FGF signaling and GPC3 expression.

The utility of Lens culinaris agglutinin-reactive alpha-fetoprotein in the diagnosis of hepatocellular carcinoma: evaluation in a United States referral population

BACKGROUND & AIMS

The percentage of Lens culinaris agglutinin-reactive (alpha)-fetoprotein (AFP-L3%) is proposed as a diagnostic and prognostic marker for hepatocellular carcinoma (HCC). We evaluated the utility of AFP-L3% for diagnosis of HCC in a US referral population.

METHODS

This retrospective study included 272 patients: 166 with HCC and 106 with benign liver disease (chronic liver disease, 77; benign liver mass, 29). The AFP-L3% was measured using a clinical auto-analyzer.

RESULTS

The AFP-L3% is not reported for a total alpha-fetoprotein (AFP) less than 10 ng/mL, and all patients with an AFP greater than 200 ng/mL had HCC; thus the AFP-L3% was noninformative for these patients. In patients with a total AFP of 10-200 ng/mL, an AFP-L3% greater than 10% had a sensitivity of 71% and a specificity of 63% for diagnosis of HCC. An AFP-L3% greater than 35% had a reduced sensitivity of 33%, but an increased specificity of 100%. The high specificity of the AFP-L3% cut-off of 35% allowed the confident diagnosis of an additional 10% of HCCs not diagnosed using an AFP cut-off of 200 ng/mL. After adjustment for AFP level, no association was observed between AFP-L3% and tumor size, stage, vascular invasion, grade, or survival.

CONCLUSIONS

Patients with indeterminate total AFP values of 10-200 ng/mL present a diagnostic dilemma. We found that an AFP-L3% greater than 35% has 100% specificity for HCC in these patients. AFP-L3%, used in combination with AFP, may be a clinically useful adjunct marker for the diagnosis of HCC.

SULF1 inhibits tumor growth and potentiates the effects of histone deacetylase inhibitors in hepatocellular carcinoma

BACKGROUND & AIMS

Hepatocellular carcinoma (HCC) is the third most common cause of cancer death worldwide. Improved treatments for advanced HCC are urgently needed. The recently identified human sulfatase 1 enzyme (SULF1) desulfates cell surface heparan sulfate glycosaminoglycans and down-regulates cell growth signaling in HCC cells in vitro. While investigating the epigenetic regulation of SULF1, we discovered that histone H4 acetylation is up-regulated by SULF1 in HCC cells. Histone deacetylase (HDAC) inhibitors reprogram cellular gene expression through the acetylation of nucleosomal histones and promote cell growth arrest and apoptosis. Hence, they are a promising modality for cancer treatment.

METHODS

To explore the interaction between SULF1 expression and HDAC inhibitor action, we examined the effects of SULF1 expression on HCC cells and xenografts treated with HDAC inhibitors.

RESULTS

(1) Forced expression of SULF1 significantly delayed the growth of Huh7 and Hep3B xenografts in nude mice in vivo. (2) SULF1 increased histone H4 acetylation by modulation of cellular HDAC and histone acetyltransferase activities. (3) SULF1 enhanced the induction of apoptosis by the HDAC inhibitors apicidin and scriptaid. (4) SULF1 enhanced the inhibition of tumor growth, migration, and angiogenesis by HDAC inhibitors. We also demonstrate that knockdown of SULF1 with shRNA constructs up-regulates phosphorylation of AKT and Erk and attenuates apicidin-induced apoptosis. The interaction between SULF1 and apicidin was confirmed in vivo in Huh7 and Hep3B xenografts.

CONCLUSIONS

These results show that SULF1 promotes histone H4 acetylation, potentiates the effects of HDAC inhibitors, and inhibits HCC tumorigenesis.

Cardiovascular responses to beta-blockade and 5 degrees C cold air stress

To determine the cardiovascular responses to beta-blockade and cold air stress, six males were randomly exposed at rest to three drug conditions (placebo, nonselective beta-blockade (propranolol), and selective beta-blockade (atenolol)) in each of two environments (5 and 25 degrees C) for 1 h. Cardiac output was lower on beta-blockade than on the placebo in both the 25 and 5 degrees C environments. Cardiac output on propranolol (4.2 +/- 0.3 L.min-1) at 5 degrees C was lower than on atenolol (4.7 +/- 0.4 L.min-1, p < 0.05). Mean arterial pressure was greater (p < 0.05) at 5 than 25 degrees C for each drug condition. There was no drug effect on total peripheral resistance at 25 degrees C. At 5 degrees C, total peripheral resistance on both beta-blockers (propranolol 1942.7 +/- 169.9 dyn.s.cm-5 (1 dyn = 10 microN); atenolol 1706.7 +/- 160.0 dyn.s.cm-5) was higher (p < 0.05) than on the placebo (1485.3 +/- 111.8 dyn.s.cm-5). Total peripheral resistance was also higher on propranolol than atenolol (p < 0.05). In conclusion, cold air stress interacts with beta-blockade to elevate total peripheral resistance by decreasing cardiac output while having little effect on mean arterial pressure. These effects are greater on nonselective than on selective blockade.

cis-acting mutations that affect rop protein control of plasmid copy number

A number of pMB1 derivatives provide a trans-acting function that can suppress lethal runaway replication of a temperature-sensitive copy-number mutant of NTP1. Deletion analysis indicates that the region of the pMB1 genome that contains the rop gene is required for this suppression. Mutant derivatives of the temperature-sensitive copy-number mutant plasmid whose conditional lethal phenotype is not suppressed in trans by the region encoding the rop gene have been isolated. These rop-insensitive derivatives contain single nucleotide changes within the RNA I coding region.

Suppressors of a temperature-sensitive copy-number mutation in plasmid NTP1

A temperature-sensitive high copy-number mutant of plasmid NTP1, first described by Grindley et al. (1978), is lethal to bacterial cells at the non-permissive temperature. This behavior has been used to select mutations in the plasmid replication origin region that suppress the over-replication phenotype. We have identified the site of the original ts lethal mutation and the positions of the reversion mutations. The ts mutation, designated orp, for over-replication, is a single nucleotide change 23 base-pairs upstream from the transcription start site for RNA I, the repressor of plasmid replication. This change simultaneously affects the promoter for RNA I and the precursor of the primer for plasmid replication, RNA II, which is also transcribed from this region. Fusions of the mutant promoter region with the galK gene indicate that transcription is not temperature sensitive. This result suggests that the mutation affects RNA II secondary structure. The reversion mutations are also located within the RNA II coding region more than 200 bp from the site of the original ts mutation. These mutations may also affect RNA II structure.

[Horner's syndrome: a rare complication of internal jugular vein cannulation (author's transl)]

Percutaneous internal jugular vein cannulation has become an accepted method for insertion of central venous catheters. There are many indications for such a procedure, but a variety of complications may arise due either to direct injury of local structures or else to secondary tissue damage due to long-standing presence of the catheter in situ. Direct injury to the sympathetic trunk causing Horner's syndrome is extremely rare. This report describes a case in which Horner's syndrome occurred a few days after insertion of the catheter into the right internal jugular vein.

[Amanita phalloides poisoning in Austria (author's transl)]

An analysis of 28 cases of amanita phalloides poisoning serves as basis for a discussion of the clinical features and therapeutic problems involved. A critical review of recent experimental investigations in animals points to new possibilities in the treatment of amanita phalloides poisoning.