Locoregional therapy for hepatocellular carcinoma: radioembolization with yttrium-90 microspheres.

Compared with other malignant tumours, hepatocellular carcinoma (HCC) exhibits particular characteristics regarding its supplying vessels and tumour biology. If a potentially curative surgical approach, such as resection or liver transplantation, is due to technical or prognostical reasons no option, these characteristics are a fundamental prerequisite for the possibility to effectively treat this tumour by local ablation methods. Microsphere and particle technology with selective transport of tumoricidal substances or radiation represents a new generation of therapeutics in interventional oncology. With the intrahepatic application of radioactive microspheres via the hepatic artery (radioembolization) local ablation can be performed even of diffuse and multifocal liver tumours, which hitherto, could only be approached with systemic therapy. The present standard for radioembolization, is the use of yttrium-90 glass or resin microspheres. The indications, technique and current results of radioembolization with yttrium-90 microspheres for the treatment of HCC are discussed in this review.

Impact of immunosuppressive therapy on hepatitis C infection after renal transplantation.

BACKGROUND: Among patients after renal transplantation (NTx), hepatitis C virus (HCV) infection is a risk factor for graft loss and patient death caused by hepatic decompensation. Also, HCV has been implicated in the pathogenesis of glomerular diseases in native and transplanted kidneys. Therefore, the aim of this retrospective cohort study was to determine the effects of the widely used calcineurin inhibitors (CNI) cyclosporine A (CsA) and tacrolimus (Tac) on hepatitis C virus replication, inflammatory activity, development of liver fibrosis, and long-term renal graft function. SUBJECTS AND METHODS: A cohort of 71 patients with HCV infection after kidney transplantation under immunosuppression with either CsA or Tac were analyzed for viral kinetics and serum transaminases. In addition, presence of liver fibrosis was detected by non-invasive measurements using the FibroScan. Graft function was determined biochemically. Patients with interferon therapy prior to transplantation were excluded from the study in order to avoid any impact of the antiviral therapy on outcomes. RESULTS: In the early period after transplantation, hepatitis C viral load was lower in patients treated with Tac as compared to CsA. This effect became negligible 3 months after transplantation. However, hepatic inflammatory activity was reduced in the CsA-treated group. Extent of liver fibrosis was similar in both groups of HCV-infected patients as well as in a control group of non-HCV-infected patients after renal transplantation (NTx), respectively. Renal function and glomerular filtration rate, as calculated by the modification of diet in renal disease (MDRD) formula, were significantly better in patients treated with Tac. CONCLUSIONS: During long-term immunosuppression, the CNIs cyclosporine A versus tacrolimus showed no significant differences in HCV-infected patients after renal transplantation with respect to viral replication and development of liver fibrosis. However, function of the renal graft is significantly better preserved in patients receiving tacrolimus.

[Selective internal radiotherapy (SIRT) for hepatocellular carcinoma]. / Selektive interne Radiotherapie (SIRT) beim hepatozellulären Karzinom.

Microsphere-based radioembolization represents a new generation of therapeutics in interventional oncology. The intrahepatic application of radioactive microspheres via the hepatic artery allows locoregional therapy of diffuse or multifocal liver tumors, for which to date systemic therapy was the only remaining option. The current standard for this selective internal radiotherapy or radioembolization is yttrium-90 glass or resin microspheres. This review discusses the indications, the technique, and the therapeutic results of microsphere-based radioembolization.

Angiography-based C-arm CT for the assessment of extrahepatic shunting before radioembolization.

PURPOSE: To retrospectively assess the accuracy of angiography-based C-arm CT for the detection of extrahepatic shunting before SIRT. MATERIALS AND METHODS: 30 patients (mean age: 64+/-12 years) with hypervascularized hepatic tumors underwent hepatic angiography, coil embolization of gastrointestinal collaterals and 99mTc-macroaggregated albumin (MAA) SPECT/CT before SIRT. Before MAA injection via a microcatheter from the intended treatment position, an angiography and angiography-based C-arm CT (XperCT, Philips Healthcare) were acquired. Angiographies and XperCT were performed from 48 microcatheter positions followed by MAA injections and MAA-SPECT/CT. MAA-SPECT/CT served as the reference standard for determining the accuracy of hepatic arteriography and C-arm CT for the detection of extrahepatic shunting. RESULTS: MAA-SPECT/CT revealed extrahepatic shunting in 5 patients (17%). Hepatic arteriography yielded a true negative in 22 (73%), a false negative in 5 (17%), and an unclear result in 3 patients (10%). C-arm CT yielded a true positive in 3 (10%), true negative in 24 (80%), false positive in 1 (3%), and false negative in 2 patients (7%). The specificity and the NPV of hepatic arteriography for the detection of extrahepatic shunting were 88% and 81%, respectively. For C-arm CT the sensitivity, specificity, PPV, NPV, and accuracy for the detection of extrahepatic shunting were 60%, 96%, 75%, 92%, and 90%, respectively. CONCLUSION: C-arm CT offers additional information to angiography when assessing SIRT patients for extrahepatic shunting. More accurate detection of extrahepatic shunting may optimize the workflow in SIRT preparations by avoiding unnecessary repeat angiographies.

Analytical performance characteristics and clinical utility of a novel assay for total hepatitis C virus core antigen quantification.

The detection and quantification of hepatitis C virus (HCV) core antigen in serum or plasma by the use of different assay formats have previously been shown to represent useful markers of viral replication. In the present study, the intrinsic performance characteristics and the potential clinical utility of a novel assay for the quantification of total HCV core antigen were comprehensively assessed by using clinical serum samples and specimens contained in various evaluation panels. The Architect HCV Ag assay showed a specificity of 100%. The intra- and interassay coefficients of variation ranged from 3.6 to 8.0% and from 4.7 to 9.5%, respectively. Except for HCV genotype 2 isolates, the analytical sensitivity was always less than 10 fmol core antigen/liter, corresponding to approximately 500 to 3,000 IU of HCV RNA/ml. Linearity was guaranteed throughout the dynamic range (10 to 20,000 fmol/liter). When seroconversion panels were tested, the assay was not inferior to HCV RNA detection and reduced the preseroconversion period by 4 to 16 days. The results obtained by core antigen and HCV RNA quantification for 385 clinical specimens were correlated by regression analysis (r = 0.857), but the calculated conversion equation differed significantly from the line of identity. Monitoring of viral kinetics by use of either core antigen or RNA concentrations in 38 HCV-infected patients undergoing antiviral combination therapy resulted in very similarly shaped curves in all cases. Finally, the Architect HCV Ag assay was also shown to enable high-throughput screening of in vitro HCV RNA replication. With these results taken together, the Architect HCV Ag assay proved to be a specific, reproducible, highly sensitive, and clinically applicable test format which will find its future place in the context of virological HCV diagnostics.

[Selective internal radiotherapy (radioembolization) and radiation therapy for HCC--current status and perspectives]. / Selektive interne Radiotherapie (Radioembolisation) und Strahlentherapie beim HCC--Stand und Perspektiven.

Microsphere and particle technologies for the selective transport of tumoricidal agents or radiation represent a new generation of therapeutics in interventional oncology. The intrahepatic application of radioactive microspheres via the hepatic artery, for instance, allows locoregional therapy of diffuse or multifocal liver tumours, for which to date systemic therapy was the only remaining option. Current standards for this selective internal radiotherapy or radioembolisation are 90-yttrium glass or resin microspheres. Indication, technique, and the current results are extensively discussed. In addition to 90-yttrium microspheres, other radiopharmaceuticals, such as 131-iodine or 188-rhenium lipiodol, have been successful used for SIRT. As a result of new, more selective radiation techniques, internal radiotherapy for the locoregional treatment of HCC has been recently complemented by an increasing use of percutaneous radiotherapy.

Liver transplantation for hepatocellular carcinoma after yttrium therapy: a case report.

Yttrium-90 microspheres constitute one of the most recent treatment options for hepatocellular carcinoma (HCC) in the setting of cirrhosis. As such, their spectrum of indication is not yet fully established. Herein, we have reported the case of a patient with HCC beyond the listing criteria for liver transplantation (OLT) who was treated preoperatively with selective transarterial chemoembolization and yttrium-90 microspheres. He was subsequently transplanted with a liver from an 81-year-old donor allocated through Eurotransplant as a "rescue offer." The posttransplant course was uneventful. Pathologic examination revealed a multifocal, well-differentiated pT2 tumor with no vascular invasion. The patient is currently alive and in good condition at 14 months posttransplant, with no evidence of tumor recurrence by a current computed tomography scan. This report provided encouraging information on the potential of yttrium-90 microspheres as a bridging option before OLT for multifocal HCC.

Ribavirin with either standard or pegylated interferon to treat recurrent hepatitis C after liver transplantation.

AIM: To investigate the efficacy of two anti-viral protocols in hepatitis C virus-reinfected liver transplant recipients. METHODS: In this prospective study, 26 liver transplant patients were treated with standard interferon-alpha2b for 12 months or standard interferon-alpha2b for 3 months followed by pegylated interferon-alpha2b for 9 months. Interferon was combined with ribavirin in all patients. The histological course of the study population was compared with an untreated historic control group (n = 38) with similar baseline characteristics. RESULTS: The sustained virological response rates in the standard interferon group and in the pegylated interferon group were 27.3% and 26.7%, respectively. Only 29% of patients with sustained virological response had end of treatment histological response, whereas 47% of viral non-responders showed end of treatment histological response. The percentage of patients with histological improvement was significantly higher in the study population when compared to the controls. Univariate analysis indicated that hepatitis C virus genotype non-1, high baseline alanine aminotransferase, the time interval between liver transplant and interferon therapy and the body mass index predicted sustained virological response. In the multivariate model, baseline alanine aminotransferase and the body mass index remained a significant predictor of sustained virological response. CONCLUSIONS: Both treatment regimens offer similar efficacy profiles. Failure to eradicate hepatitis C virus should not lead to treatment discontinuation if serial liver biopsies demonstrate histological response.

A novel casein kinase 2 alpha-subunit regulates membrane protein traffic in the human hepatoma cell line HuH-7.

A previously isolated endocytic trafficking mutant (TRF1) isolated from HuH-7 cells is defective in the distribution of subpopulations of cell-surface receptors for asialoorosomucoid (asialoglycoprotein receptor (ASGR)), transferrin, and mannose-terminating glycoproteins. The pleiotropic phenotype of TRF1 also includes an increased sensitivity to Pseudomonas toxin and deficient assembly and function of gap junctions. HuH-7xTRF1 hybrids exhibited a normal subcellular distribution of ASGR, consistent with the TRF1 mutation being recessive. A cDNA expression library derived from HuH-7 mRNA was transfected into TRF1 cells, which were subsequently selected for resistance to Pseudomonas toxin. Sequence analysis of a recovered cDNA revealed a unique isoform of casein kinase 2 (CK2), CK2alpha". Western blot analysis of TRF1 proteins revealed a 60% reduction in total CK2alpha expression. Consistent with this finding, the hybrids HuH-7xHuH-7 and HuH-7xTRF1 expressed equivalent amounts of total CK2alpha. Immunoblots using antibodies against peptides unique to the previously described CK2 isoforms CK2alpha and CK2alpha' and the novel CK2alpha" isoform showed that, although TRF1 and parental HuH-7 cells expressed comparable amounts of CK2alpha and CK2alpha', the mutant did not express CK2alpha". Based on the genomic DNA sequence, RNA transcripts encoding CK2alpha" apparently originate from alternative splicing of a primary transcript. Protein overexpression following transfection of TRF1 cells with cDNAs encoding either CK2alpha or the newly cloned CK2alpha" restored the parental HuH-7 phenotype, including Pseudomonas toxin resistance, cell-surface ASGR binding activity, phosphorylation, and the assembly of gap junctions. This study suggests that HuH-7 cells express at least three CK2alpha isoforms and that the pleiotropic TRF1 phenotype is a consequence of a reduction in total CK2 expression.

Heparan sulfate proteoglycans initiate dengue virus infection of hepatocytes.

Dengue viruses (DEN) cause a broad spectrum of clinical manifestations including potentially life-threatening conditions such as hemorrhagic shock syndrome and less frequently acute hepatitis with liver failure and encephalopathy. In addition, dengue viruses provide a potential model to understand the initiation of hepatocyte infection by the structurally closely related hepatitis C virus (HCV), because this virus at present cannot be grown in cell culture. Although the initial steps of viral infection are a critical determinant of tissue tropism and therefore pathogenesis, little is known about the molecular basis of binding and endocytic trafficking of DEN or of any other flavivirus. Our studies revealed that binding of radiolabeled DEN to the human hepatoma cell line HuH-7 was strictly pH dependent and substantially inhibitable by the glycosaminoglycan heparin. Ligand-blot analysis, performed as a viral overlay assay, showed two heparan sulfate (HS) containing cell-surface binding proteins resolving at 33 and 37 kd. Based on the sensitivity of unprotected virus and the viral binding site on the cell surface to trypsin, viral internalization was quantified as an increase in trypsin protected virus over time. Virus trafficking to the site of degradation was inhibited by pH dissociation of the clathrin coat and dependent on IP(3)-mediated homotypic endosomal fusion. These findings confirm the hypothesis that binding and internalization of DEN by hepatocytes are mediated primarily by HS containing proteoglycans and suggest that flaviviruses traffic the major clathrin-dependent endocytic pathway during infection.

Trial of oral miltefosine for visceral leishmaniasis.

BACKGROUND: There is no effective oral treatment for visceral leishmaniasis (kala-azar), a disseminated intracellular protozoal infection that occurs worldwide. Miltefosine, an alkyl phospholipid developed as an oral antineoplastic agent, is active against visceral infection in animal models. We tested safety, tolerance, and efficacy of miltefosine in kala-azar. METHODS: Oral doses of miltefosine were given to six groups of five Indian men for 28 days: 50 mg every second day (group 1), 100 mg every second day (group 2), 100 mg/day (group 3), 150 mg/day (group 4), 200 mg/day (group 5), and 250 mg/day (group 6). Assessment for apparent cure--taken as an afebrile state with decreased spleen size and a splenic-aspirate parasite-density score of 0--was done on days 14 and 28. Definitive cure at 8 months required a parasite-free bone-marrow aspirate and no clinical evidence of relapse. FINDINGS: 21 of 30 patients were apparently cured on day 14. Transient episodes of vomiting and diarrhoea, were common during weeks 1-2 and were seen in 22 patients. Four other patients in groups 5 and 6 had miltefosine withdrawn after 7-10 days because of vomiting. One patient in group 6 developed renal insufficiency and severe diarrhoea and died on day 21. On day 28, all 29 remaining patients were apparently cured. By 8 months, seven of ten patients in groups 1 and 2 had relapsed; however, 18 of 19 patients treated daily (groups 3-6) appeared to be cured. Among the 21 definitive cures were the four patients treated for 10 days or less and 12 for whom previous therapy with pentavalent antimony had failed. INTERPRETATION: Treatment with miltefosine at 100-150 mg/day for 4 weeks has promise as an effective oral treatment of visceral leishmaniasis including antimony-resistant infection.

[The "nutcracker syndrome" of the renal vein (superior mesenteric artery syndrome) as the cause of gastrointestinal complaints]. / Das "Nussknacker-Syndrom" der Vena renalis (Arteria-mesenterica-superior-Syndrom) als Ursache gastrointestinaler Beschwerden.

HISTORY AND CLINICAL FINDINGS: Since the age of 19 a now 22-year-old man had complained of intermittent abdominal pain, irregular stools and paroxysmal tachycardia. The only preceding illness had been a single episode of iron-deficiency anemia. A laparoscopy, done 8 months after the onset of symptoms, had revealed an inflamed Meckel's diverticulum which was surgically removed. After transient improvement the symptoms recurred 5 months postoperatively. On admission to clarify the cause of the symptoms he had discrete abdominal pain on pressure, but physical examination was otherwise unremarkable. INVESTIGATIONS: Routine biochemical tests and endoscopy were normal. Abdominal computed tomography was suspicious of severe narrowing of the left renal artery by a crossing superior mesenteric artery. As a result the left testicular vein and the peripelvic venous network were markedly dilated by retrograde congestion, strongly suggesting the "nutcracker syndrome" of obstruction of the left renal vein. This diagnosis was confirmed by selective renal phlebography and pressure measurement. TREATMENT AND COURSE: The vascular anomaly was corrected surgically by reimplanting the left renal vein into the inferior vena cava 3-4 cm further caudally. The patients has been completely symptom-free since then. CONCLUSIONS: The nutcracker-syndrome is a rare cause of hematuria. The coexistence of this anomaly with gastrointestinal symptoms has not been previously described, but it is likely that congestion of the splanchnic veins by obstruction of the left renal vein was at least partly responsible for them, in view of the postoperative relief.

Gene trapping identifies inhibitors of oncogenic transformation. The tissue inhibitor of metalloproteinases-3 (TIMP3) and collagen type I alpha2 (COL1A2) are epidermal growth factor-regulated growth repressors.

A gene trap strategy has been used to identify genes that are repressed in cells transformed by an activated epidermal growth factor (EGF)/EGF receptor signal transduction pathway. EGF receptor-expressing NIH3T3 cells (HER1 cells) were infected with a retrovirus containing coding sequences for the human CD2 antigen and for secreted alkaline phosphatase in the U3 region. By selecting for and against CD2 expression, we obtained clones in which the gene trap had integrated into genes selectively repressed by EGF. Two of these clones encoded for the secreted extracellular matrix proteins TIMP3 and COL1A2. We show here that both genes are downstream targets of RAS and are specifically repressed by EGF-induced transformation. Moreover, this strategy tags tumor suppressor genes in their normal chromosomal location, thereby improving target-specific screens for antineoplastic drugs.

Characterization of gonadotropin-releasing hormone analogs based on a sensitive cellular luciferase reporter gene assay.

A novel cellular assay for the functional characterization of agonistic and antagonistic analogs of gonadotropin-releasing hormone (GnRH) was developed. This assay is based on a fusion of the c-fos immediate-early gene promoter to Photinus pyralis luciferase (Luc) as a reporter gene, stably transfected in a recombinant cell line expressing the human GnRH receptor. Transcription of endogenous c-fos and fos-Luc fusion gene are transiently induced quite similar by fetal calf serum or the superagonistic analog [D-Trp6] GnRH in a selected cell line. The reporter gene was therefore used to monitor agonist-induced signaling via the human GnRH receptor. Whereas Luc activity was induced in a dose-dependent manner by GnRH or [D-Trp6] GnRH, different antagonistic peptides completely inhibited this stimulation. The antagonistic potency (IC50) of various peptides with Cetrorelix and Antarelix as lead compounds in general correlated well with the binding affinity (KD) as determined from ligand binding experiments. The specificity of an inhibitory effect was confirmed by GnRH receptor-independent stimulation with the phorbol ester 12-O-tetradecanoylphorbol 13-acetate or basic fibroblast growth factor. Since this new reporter gene assay is sensitive and simple and can be performed in a microtiter plate, it will significantly facilitate screening and functional characterization of GnRH analogs.

D-21266, a new heterocyclic alkylphospholipid with antitumour activity.

The aim of this study was to determine the antitumour effects of D-21266 in a rodent tumour model. Hexadecylphosphocholine (INN: Miltefosine) represents the first anticancer agent which was specifically formulated for topical use in cancer patients. The development as an oral drug was hampered by the gastrointestinal toxicity. Hexadecylphosphocholine derivatives were sought with a better therapeutic index. Octadecyl-(1,1-dimethyl-4-piperidylio) phosphate (D-21266) was identified as a suitable candidate. This compound is highly active in vitro inhibiting the growth of a number of human cancer cell lines. Mammary carcinomas were induced in Sprague-Dawley rats using DMBA, and oral doses of D-21266, in various schedules, were given to the animals. A high antineoplastic potency was observed without inducing loss of body weight at highly effective doses. The antitumour effect could be enhanced by introducing a dose schedule consisting of a high loading dose followed by a low maintenance dose, both of which are only marginally active when given alone. Therefore, D-21266 with its favourable pharmacological and toxicological profile, warrants evaluation in the clinic. However, the concept of clinical trials requires new approaches to dose finding and response evaluation, because the dose-response relationship of this compound is distinctly different from that of classical cytostatic agents.

The development of alkylphosphocholines as signal transduction inhibitors: experimental and clinical challenges.

Alkylphosphocholines are a new class of anticancer agents. Their mode of action is considered to be related to the inhibition of phospholipase C and protein kinase C. These enzymes play a major role in intracellular signalling pathways. Their inhibition by alkylphosphocholines leads in the dimethylbenzanthracene-induced mammary carcinoma of the rat to a response pattern similar to that of the antiestrogen zindoxifene. This suggests that the inhibition of transcription factor formation might be the common pathway for alkylphosphocholines and antihormones. Based on the experimental dose-response pattern, new clinical strategies for dose finding and response evaluation will have to be developed for inhibitors of signal transduction, such as alkylphosphocholines.

Reversible tumorigenesis in mice by conditional expression of the HER2/c-erbB2 receptor tyrosine kinase.

In the present study we describe the reversible transformation of NIH3T3 fibroblasts by overexpression of the HER2/c-erbB2 receptor tyrosine kinase. Cell lines expressing HER2 under control of a tetracycline-responsive promoter were isolated. Induction of HER2 expression resulted in cellular transformation in vitro as depicted by growth in soft agar and focus formation in tissue culture. Subsequent treatment of these cells with the effector anhydrotetracyline switched-off HER2 expression and induced morphological and functional changes characteristic for non-transformed cells. Subcutaneous transplantation of cells in nude mice resulted in the formation of solid tumors. Interestingly tumor formation was completely suppressed by treatment of the animals with anhydrotetracyline. Our findings indicate that overexpression of HER2 induces the transformed phenotype of NIH3T3 cells and is required for tumor formation and progression in nude mice. By linking the expression of the marker gene secreted placental alkaline phosphatase to the expression of HER2, a sensitive monitoring of tumor development in nude mice was feasible.

Pharmacological studies with cetrorelix (SB-75), a potent antagonist of luteinising hormone-releasing hormone.

The antitumour and hormone-suppressive effects of the luteinising hormone-releasing hormone LH-RH antagonist Cetrorelix (D-20761) and its pamoate salt (D-20762) were investigated in the model of the DMBA-induced mammary carcinoma of female rats and by testosterone determinations in normal male rats. Treatment with single high doses of D-20761 induced a rapid decrease of tumour weights with a dose-dependent duration of action. Strong antitumour effects were also observed by applying different multiple dose schedules, including a initial high dose (3.16 mg/kg, s.c.) followed by a low maintenance dose (31.6 micrograms/kg, s.c.). The stability of the molecule against degrading enzymes led to the idea of using the poorly soluble pamoate salt for facilitating a sustained release of active compound. This salt indeed induced a prolonged suppression of tumour growth and of testosterone levels. In conclusion, we found that Cetrorelix is a highly effective LH-RH antagonist which should be further developed for the treatment of hormone-dependent diseases.