A randomized, double-blind, placebo-controlled trial with mannan-conjugated birch pollen allergoids.

BACKGROUND: There is still great need to develop new strategies to improve the efficacy of allergen immunotherapies with optimal safety standards for patients. A new promising approach is to couple allergoids to mannan. The objective of this phase IIa/IIb study was to identify the optimal dose of mannan-conjugated birch pollen allergoids for the short-course treatment of birch pollen-induced allergic rhinoconjunctivitis. METHODS: For this prospective, randomized, double-blind, placebo-controlled, dose-finding study, 246 birch pollen-allergic adults received 0.5 mL placebo or 1000, 3000 or 10,000 mTU/mL of mannan-conjugated birch pollen allergoids at five pre-seasonal visits. Efficacy was assessed by comparing allergic rhinoconjunctivitis symptoms and use of anti-allergic medication during the peak of the birch pollen season 2020. Immunologic, tolerability and safety effects were also analysed. RESULTS: The highest dose of mannan-conjugated birch pollen allergoids reduced the combined symptom and medication score during the peak birch pollen season by a median of 24.7% compared to placebo. The production of Bet v 1 specific IgG4 significantly increased in a dose-dependent manner (3.6- and 4.5-fold) in the 3000 and 10,000 mTU/mL groups. The Bet v 1 specific IgE/IgG4 ratio was also strongly reduced (up to -70%). No fatalities nor serious adverse events were reported, and no adrenaline was used. In total, four systemic reactions occurred (two grade I and two grade II). CONCLUSION: All doses of mannan-conjugated birch pollen allergoids can be considered as safe. Since the application of 10,000 mTU/mL resulted in the highest efficacy, this dose qualifies for further investigation.

Ivy leaves extract EA 575 in the treatment of cough during acute respiratory tract infections: meta-analysis of double-blind, randomized, placebo-controlled trials.

Ivy leaves extracts have been used successfully to treat acute cough, and data from well-controlled trials is accumulating. We present a meta-analysis of two double-blind, randomized, placebo-controlled trials. Patients with acute respiratory tract infection (ARTI) received ivy leaves dry extract EA 575 (n = 228) or placebo (n = 162) for 7 days, followed by a 7-day period without treatment. The main efficacy outcome was the Bronchitis Severity Score (BSS). Individual patient data meta-analyses were performed using mixed models for repeated measures, analysis of covariance and logistic ordinal regression. Significant BSS differences between EA 575 and placebo occurred already after 2 days and increased until treatment end, with BSS reductions of 8.6 ± 0.2 and 6.2 ± 0.2 (marginal means ± SEM; p < 0.001). The score reduction for placebo after 7 days was comparable to that for EA 575 after 4 days. In the EA 575 group, the proportion of cough-free patients was 18.1% at treatment end and 56.2% at end of follow-up, compared to 9.3% and 25.6% for placebo, respectively. Adverse event rates for EA 575 and placebo were comparable. EA 575 reduces effectively the intensity of acute cough associated with ARTIs and leads to a significant acceleration of recovery. No safety signals were observed.

A meta-analysis on allergen-specific immunotherapy using MCT® (MicroCrystalline Tyrosine)-adsorbed allergoids in pollen allergic patients suffering from allergic rhinoconjunctivitis.

BACKGROUND: The World Allergy Organization and the European Academy of Allergy and Clinical Immunology recommend to perform product-specific meta-analyses for allergen-specific immunotherapies because of the high degree of heterogeneity between individual products. This meta-analysis evaluates the efficacy and safety of Glutaraldehyde-modified and MCT® (MicroCrystalline Tyrosine)-adsorbed allergoids (MATA). METHODS: The databases MEDLINE, LILACS, embase, LIVIVO, Web of Science and Google (Scholar) were searched for publications on MATA up to June 2019. Primary endpoint was the combined symptom and medication score (CSMS). Secondary endpoints were single scores, immunogenicity and improvement of allergic condition. Secondary safety endpoints were the occurrence of side effects. A random effects model was applied with (standardized) mean differences ([S]MDs) including confidence intervals (CI). Heterogeneity was analyzed using the I2 index and publication bias using Egger's test and Funnel plots. Subgroups were analyzed regarding age and asthma status. RESULTS: Eight randomized double-blind placebo-controlled trials were selected for efficacy and 43 publications for safety analysis. In total, 4531 patients were included in this analysis including eight studies containing data on children and adolescents. AIT with MATA significantly reduced allergic symptoms and medication use with a SMD for CSMS of -0.8 (CI: -1.24, -0.36) in comparison to placebo. Heterogeneity was moderate between the studies. The total symptom score (-1.2 [CI: -2.11, -0.29]) and the total medication score (-2.2 [CI: -3.65, -0.74]) were also significantly reduced after MATA treatment. Patient's condition improved significantly after treatment with MATA, with an odds ratio of 3.05 (CI: 1.90, 4.90) when compared to placebo. The proportion of patients, who developed side effects was 38% (CI: 19%, 57%). No serious side effects occurred. Safety in the subgroups of asthmatic patients, children and adolescents did not differ from the overall patient population. CONCLUSIONS: This meta-analysis reveals a large body of evidence from publications investigating MATA. MATA significantly improved allergic symptoms and reduced the use of anti-allergic medication in comparison to placebo, with an excellent safety profile. Especially for children and asthmatic patients, the use of MATAs can be considered as safe, because the safety profiles in these groups did not differ from the total patient population.

Effects of ectoine containing nasal spray and eye drops on symptoms of seasonal allergic rhinoconjunctivitis.

BACKGROUND: Patients are often dissatisfied with the symptom control obtained from available pharmacological treatments for seasonal allergic rhinoconjunctivitis (ARC). Therefore, patients seek for alternative, nonpharmacological options to treat their symptoms. Here, we assessed the efficacy of ectoine nasal spray and ectoine eye drops in comparison to placebo to prevent nasal and ocular symptoms following exposure to pollen in patients with ARC. METHODS: In this double-blind, randomized, placebo-controlled, cross-over study, 46 patients with ARC applied ectoine eye drops and nasal spray in immediate succession or placebo eye drops and nasal spray for 13 days before ARC symptoms were induced in an environmental exposure chamber. Primary endpoint was the baseline-adjusted area under the curve (AUC) posttreatment total nasal symptom score (TNSS) and the total ocular symptom score (TOSS) using analysis of covariance. Secondary endpoints were, amongst others, total nonnasal symptoms score (TNNSS) and nasal patency (measured using acoustic rhinometry). RESULTS: Treatment with both ectoine and placebo reduced TNSS, TOSS, and TNNSS upon allergen exposure. The analysis of parameters at baseline and after allergen exposure demonstrated that ectoine induced a clinically relevant improvement in ARC symptoms compared to placebo: the least square mean difference for baseline-adjusted AUC was -1.87 for TNSS, -1.45 for TOSS and -2.20 for TNNSS. The mean change from baseline AUC of TNNSS for ectoine was also significantly greater than for placebo (-5.49 vs. -3.46; p = 0.011). Ectoine significantly improved the singular symptoms "sneezing," "watery eyes" and "itchy eyes" (p ≤ 0.021) as well as "itchy ear/palate" (p = 0.036) in comparison to placebo. Mean cross sectional areas of the nasal cavity were reduced to a lesser extent after treatment with ectoine (-0.020 ± 0.022) than with placebo (-0.047 ± 0.029). The current study also demonstrated a very good safety profile of ectoine treatment. Few AEs with comparable numbers in both treatment groups were reported during the study, which were mild in severity and resolved without medical treatment. CONCLUSION: The study suggests that ectoine is effective in reducing nasal and ocular symptoms associated with ARC. Being a natural, bacteria derived stress protection molecule functioning by a physical mode of action, it therefore represents an alternative nonpharmacological treatment option.

Pharmaco-epidemiological research on herbal medicinal products in the paediatric population: data from the PhytoVIS study.

In paediatrics, clinical study data are limited, especially on herbal medicinal products. To address this gap, 2063 datasets from the paediatric population were evaluated in the PhytoVIS data base. By screening for paediatric data, information on indication, gender, treatment, co-medication and tolerability were evaluated. The majority of patients was treated because of common cold, fever, digestive complaints, skin diseases, sleep disturbances and anxiety. The perceived effect of the therapy was rated in 84% of the patients as very good or good without adverse events. The data shed light on a still neglected field of phyto-pharmacotherapy by giving information on the use of herbal medicines in an unselected cohort of paediatric patients. The results confirm the good clinical effects and safety of herbal medicinal products in this patient population and show that they are widely used in Germany.What is Known:• In Germany, about 85% of children receive one or more herbal medicinal products per year.• Despite international initiatives to promote clinical research in paediatrics, there are still many gaps of knowledge in the use of drugs in paediatrics.What is New:• The PhytoVIS project evaluated 2063 data sets from the paediatric population using herbal medicinal products.• The majority of patients was treated because of common cold, fever, digestive complaints, skin diseases, sleep disturbances and anxiety, and 84% of the patients rated the therapy as very good or good without adverse events.

Liposomal Eye Spray Is as Effective as Antihistamine Eye Drops in Patients with Allergic Rhinoconjunctivitis Induced by Conjunctival Provocation Testing.

BACKGROUND: Liposomal eye spray (LS) has been introduced for the treatment of dry eye. Whether LS can also relieve symptoms due to allergic rhinoconjunctivitis (ARC) has not yet been sufficiently investigated. OBJECTIVES: The aim of this study was to assess the onset of action, the reduction of allergy symptoms, and the safety of LS - a nonpharmacological treatment option - compared with those of antihistamine eye drops (AD). METHODS: In this open, prospective, controlled, monocenter noninterventional study, adults with ARC received either LS or AD for the relief of eye irritation after a positive conjunctival provocation test (CPT). All patients completed a questionnaire before and after the CPT. Eye irritation was rated on a visual analogue scale (VAS) at 6 time points. Conjunctival redness was analyzed using objective digital analysis based on images taken during the study visit. RESULTS: Data were collected from 40 patients (20 per group). In both groups, 80% of patients perceived an onset of action within 0-2 min after application of LS or AD following the CPT. Relief of eye irritation (as determined by VAS) increased throughout the visit for both groups. In the digital analysis, the mean proportion of redness of the eye decreased from 10.3 to 7.0% for LS and from 10.4 to 6.5% for AD, with the largest difference observed 10 min after application (LS: 8.9%; AD: 6.0%; p = 0.094). CONCLUSIONS: LS is a nonpharmacological treatment option for ARC, showing no significant difference or relevant numerical inferiority to AD in any parameter studied. It was generally safe and well tolerated.

Early nonreactivity in the conjunctival provocation test predicts beneficial outcome of sublingual immunotherapy.

BACKGROUND: Clinical practice needs a common parameter that can provide an early, reliable estimation of the outcome of sublingual immunotherapy (SLIT) in an upcoming pollen season. We investigated whether the conjunctival provocation test (CPT) can predict the beneficial outcome of SLIT in patients with allergic rhinoconjunctivitis after 4 weeks of treatment. METHODS: We conducted two separate prospective, randomized, double-blind, placebo-controlled, multicenter trials. Adults 18-75 years of age received placebo or SLIT tablets containing tree or grass pollen allergoids and underwent CPTs. Participants receiving SLIT were divided into two groups (reactive, nonreactive) according to their CPT reactions after 4 weeks of treatment. These two groups were compared with regard to clinical outcome parameters (total combined score, rhinoconjunctivitis total symptom score, total rescue medication score, well days) assessed during the pollen season for the 14-day (tree) or 30-day (tree/grass) peaks and for the entire 60-day seasons. Participants' global evaluations of therapy after completing treatment were also compared. RESULTS: The tree pollen trial randomized 188 participants; 182 participants were evaluable, 76 of whom received SLIT and were suitable for this post hoc analysis. The grass pollen trial included 90 participants; 82 participants were evaluable, 44 of whom underwent SLIT. Comparing SLIT participants who reacted to the CPT after 4 weeks (tree: 77.6%; grass: 79.5%) with those who ceased to show a reaction (tree: 22.4%; grass: 20.5%) (tree: P = 0.0001; grass: P = 0.003), the total combined score for the 14-day (P = 0.017) and 30-day peaks (P = 0.042) as well as the rhinoconjunctivitis total symptom score assessed for the 14-day peak (P = 0.024) were significantly lower in the nonreactive group of the tree pollen trial. In the grass pollen trial, the nonreactive group rated their SLIT treatment significantly better (P = 0.019). CONCLUSIONS: Using clinically meaningful outcome parameters during the pollen season, both trials independently led to similar results when comparing participants' reactions to the CPT 4 weeks after beginning SLIT. These results suggest that CPT allows an early estimation of allergic rhinoconjunctivitis symptoms before an upcoming season. Thus, the CPT can be used as a valuable parameter to predict the beneficial outcome of ongoing SLIT. TRIAL REGISTRATION: Both trials registered with the Medical Ethics Committee of the North Rhine Medical Council (EudraCT numbers 2012-004916-79 (grass pollen trial) and 2013-002129-43 (tree pollen trial)) and the German Federal Ministry of Health (Paul-Ehrlich-Institut).

A review of allergoid immunotherapy: is cat allergy a suitable target?

To modify the course of allergy, different types of specific allergen immunotherapy have been developed such as sublingual immunotherapy and subcutaneous immunotherapy with native allergens or subcutaneous immunotherapy with polymerized allergoids. However, the optimal specific immunotherapy, especially for cat allergy, remains undetermined. Few studies investigating immunotherapy in cat allergy have been published, and the risk of serious adverse reactions and systemic reactions has often been an important issue. Monomeric allergoids have lower allergenic potential while their immunogenicity remains constant, resulting in excellent safety with notable efficacy. Specific immunotherapy with monomeric allergoids could, therefore, be of high value, especially in cat allergy as well as other types of allergy, and bring relief to a great community of patients.

Statins activate the canonical hedgehog-signaling and aggravate non-cirrhotic portal hypertension, but inhibit the non-canonical hedgehog signaling and cirrhotic portal hypertension.

Liver cirrhosis but also portal vein obstruction cause portal hypertension (PHT) and angiogenesis. This study investigated the differences of angiogenesis in cirrhotic and non-cirrhotic PHT with special emphasis on the canonical (Shh/Gli) and non-canonical (Shh/RhoA) hedgehog pathway. Cirrhotic (bile duct ligation/BDL; CCl4 intoxication) and non-cirrhotic (partial portal vein ligation/PPVL) rats received either atorvastatin (15 mg/kg; 7d) or control chow before sacrifice. Invasive hemodynamic measurement and Matrigel implantation assessed angiogenesis in vivo. Angiogenesis in vitro was analysed using migration and tube formation assay. In liver and vessel samples from animals and humans, transcript expression was analyzed using RT-PCR and protein expression using Western blot. Atorvastatin decreased portal pressure, shunt flow and angiogenesis in cirrhosis, whereas atorvastatin increased these parameters in PPVL rats. Non-canonical Hh was upregulated in experimental and human liver cirrhosis and was blunted by atorvastatin. Moreover, atorvastatin blocked the non-canonical Hh-pathway RhoA dependently in activated hepatic steallate cells (HSCs). Interestingly, hepatic and extrahepatic Hh-pathway was enhanced in PPVL rats, which resulted in increased angiogenesis. In summary, statins caused contrary effects in cirrhotic and non-cirrhotic portal hypertension. Atorvastatin inhibited the non-canonical Hh-pathway and angiogenesis in cirrhosis. In portal vein obstruction, statins enhanced the canonical Hh-pathway and aggravated PHT and angiogenesis.

Plasmid transfer of plasminogen K1-5 reduces subcutaneous hepatoma growth by affecting inflammatory factors.

There is evidence that plasminogen K1-5 (PlgK1-5) directly affects tumour cells and inflammation. Therefore, we analysed if PlgK1-5 has immediate effects on hepatoma cells and inflammatory factors in vitro and in vivo. In vitro, effects of plasmid encoding PlgK1-5 (pK1-5) on Hepa129, Hepa1-6, and HuH7 cell viability, apoptosis, and proliferation as well as VEGF and TNF-alpha expression and STAT3-phosphorylation were investigated. In vivo, tumour growth, proliferation, vessel density, and effects on vascular endothelial growth factor (VEGF) and tumour necrosis factor alpha (TNF-alpha) expression were examined following treatment with pK1-5. In vivo, pK1-5 halved cell viability; cell death was increased by up to 15% compared to the corresponding controls. Proliferation was not affected. VEGF, TNF-alpha, and STAT3-phosphorylation were affected following treatment with pK1-5. In vivo, ten days after treatment initiation, pK1-5 reduced subcutaneous tumour growth by 32% and mitosis by up to 77% compared to the controls. Vessel density was reduced by 50%. TNF-alpha levels in tumour and liver tissue were increased, whereas VEGF levels in tumours and livers were reduced after pK1-5 treatment. Taken together, plasmid gene transfer of PlgK1-5 inhibits hepatoma (cell) growth not only by reducing vessel density but also by inducing apoptosis, inhibiting proliferation, and triggering inflammation.

Toxic damage increases angiogenesis and metastasis in fibrotic livers via PECAM-1.

Excessive ethanol consumption is one of the main causes of liver fibrosis. However, direct effects of ethanol exposure on endothelial cells and their contribution to fibrogenesis and metastasis were not investigated. Therefore we analysed whether ethanol directly affects endothelial cells and if this plays a role during fibrogenesis and metastasis in the liver. Murine and human endothelial cells were exposed to ethanol for up to 72 hours. In vitro, effects on VEGF, HIF-1alpha, PECAM-1, and endothelial cell functions were analysed. In vivo, effects of continuous liver damage on blood vessel formation and metastasis were analysed by PECAM-1 immunohistochemistry. Ethanol increased HIF-1alpha and VEGF levels in murine and human endothelial cells. This resulted in enhanced intracellular signal transduction, and PECAM-1 expression as well as tube formation and wound healing. In vivo, toxic liver damage increased angiogenesis during fibrogenesis. Metastasis was also enhanced in fibrotic livers and located to PECAM-1 positive blood vessels compared to nonfibrotic mice. In conclusion, ethanol had strong effects on endothelial cells, which--at least in part--led to a profibrotic and prometastatic environment mediated by PECAM-1. Blockade of increased PECAM-1 expression could be a promising tool to inhibit fibrogenesis and metastasis in the liver.

Improving immunotherapy of hepatocellular carcinoma (HCC) using dendritic cells (DC) engineered to express IL-12 in vivo.

BACKGROUND: Interleukin 12 (IL-12), one of the most potent Th1-cytokines, has been used to improve dendritic cells (DC)-based immunotherapy of cancer. However, it failed to achieve clinical response in patients with hepatocellular carcinoma (HCC). In this study, improved conditions of immunotherapy with DC engineered to express IL-12 were studied in murine subcutaneous HCC. METHODS: Tumour-lysate pulsed DC were transduced with IL-12-encoding adenoviruses or cultivated with recombinant (r)IL-12. DC were injected intratumourally, subcutaneously or intravenously at different stages of tumour-development. RESULTS: Dendritic cell overexpressing IL-12 by adenoviruses showed enhanced expression of costimulatory molecules and stronger priming of HCC-specific effector cells than DC cultured with rIL-12. Intratumoural but not systemic injections of IL-12-DC induced the strongest antitumoural effects reaching complete regressions in 75% of early-staged tumours and in 33% of advanced tumours. Importantly, antitumoural effects could be further enhanced through combination with sorafenib. Analysing the tumour-environment, IL-12-DC increased the levels of Th1-cytokines/chemokines and of CD4(+) -, CD8(+) -T- and NK-cells. Induced immunity was tumour-specific and sustained since all tumour-free animals were protected towards hepatic tumour-cell rechallenge. However, IL-12-DC also enhanced immunosuppressive cytokines, regulatory T cells and even myeloid-derived suppressor cells within the tumours. CONCLUSIONS: Induced IL-12-overexpression by adenoviral vectors can effectively immunostimulate DC. Intratumoural but not systemic injection of activated IL-12-DC was crucial for effective tumour regression. The mechanism of this approach seems to be the induction of a sufficient Th1 tumour-environment allowing the recruitment of effector cells rather than the inhibition of tumour immunosuppression. Thus, improved immunotherapy with IL-12-DC represents a promising approach towards HCC.

Anti-tumoural effects of PlgK1-5 are directly linked to reduced ICAM expression, resulting in hepatoma cell apoptosis.

PURPOSE: Angiostatin and angiostatin-like molecules are known as anti-angiogenic factors, which inhibit endothelial cell functions resulting in reduced tumour growth. Recent data indicate that these molecules, especially PlgK1-5, directly affect tumour cells, which could explain the strong anti-tumoural effects of PlgK1-5. Therefore, we have analysed whether PlgK1-5 alters tumour cell functions and expression levels of cell adhesion molecules in murine and human hepatoma cells in vitro and in vivo. METHODS: First, effects on tumour growth, proliferation and apoptosis were investigated in vivo in a subcutaneous tumour model. In vitro, effects of PlgK1-5 on tumour cell apoptosis, clonal expansion, migration, corresponding ICAM expression and intracellular signal transduction in murine Hepa129 and human HuH7 hepatoma cells have been analysed. RESULTS: In vivo, subcutaneous tumour growth was reduced by 75% in PlgK1-5-treated animals compared to the controls. This was accompanied by increased tumour cell apoptosis (up to 33%) and decreased tumour cell proliferation (by up to 21%). In vitro, PlgK1-5 induced apoptosis in hepatoma cells, corresponding to increased caspase-8 cleavage and reduced AKT phosphorylation. Migration and clonal expansion was also diminished in PlgK1-5-treated Hepa129, corresponding to decreased ICAM expression levels. CONCLUSIONS: Here, we show that PlgK1-5 directly affects tumour cells by decreasing cell adhesion resulting-at least partly-in apoptosis. This is mediated by altered intracellular signal transduction and by activation of the caspase cascade. These findings further underscore the potential therapeutic role of PlgK1-5 in the treatment of HCC.

Combination of hypoxia and RNA-interference targeting VEGF induces apoptosis in hepatoma cells via autocrine mechanisms.

Control of VEGF signaling is an intense objective of pre-clinical and clinical studies in HCC disease with steadily increasing clinical application. Despite its emerging role, several aspects of anti-VEGF based treatments are poorly investigated, like the impact on tumor cells themselves, such as the effect on intracellular signaling and apoptosis induction in hepatoma cells. Effects of siRNA-VEGF on VEGF, VEGF-receptor expression and VEGF-A signaling such as AKT and JNK phosphorylation were determined under normoxic or hypoxic conditions in murine hepatoma cells. Apoptosis induction was analyzed by SubG1-fraction, JC1-staining and caspase-8 activation. VEGF receptor expression was analysed by semiquantitative real time PCR. Independent of oxygen status, siRNA-VEGF reduced VEGF levels resulting in decreased AKT and increased JNK phosphorylation in Hepa129 cells. The VEGF-receptors neuropilin-1 (Nrp1) and neuropilin-2 (Nrp2) were downregulated following siRNA-VEGF treatment or hypoxia induction respectively. Functionally, hypoxia significantly increased the apoptosis rate (as analyzed by SubG1-fraction, JC1-staining and JNKphosphorylation) which was further stimulated by siRNA-VEGF treatment. Our data indicate that antitumoral efficacy of an anti-VEGF based treatment with siRNA is partly based on negative autocrine feedback mechanisms which are even enhanced under hypoxic conditions. This observation helps to understand why antitumoral efficacy can be maintained despite of counteracting stimulation of tumoral VEGF secretion due to hypoxia. The direct impact on tumor cells further underscores the attractiveness of an anti-VEGF based siRNA treatment.

Apoptotic potency of angiostatic compounds in the treatment of cancer.

When tumours outgrow their vascular supply, they become hypoxic because of nutrient deficiency. This increases the expression and secretion of proangiogenic factors, like vascular endothelial growth factor (VEGF), leading to the activation of endothelial cells. The activated endothelial cells migrate, proliferate and form new blood vessels, resulting in increased tumour growth. This process is called tumour angiogenesis. Inhibiting tumour angiogenesis and therefore tumour growth is a well known concept in the treatment of cancer, such as hepatocellular carcinoma (HCC). This can be done by endogenous angiogenesis inhibitors, like angiostatin and its derivates. These are known to affect endothelial cell functions including the induction of apoptosis. The impact of these angiostatic factors on the cell is manifold. This also applies for so called small molecules, which affect tyrosine kinases such as receptors or intracellular signal transduction proteins. Other approaches, like monoclonal antibodies, target a single molecule, mainly VEGF, to inhibit receptor binding and downstream signal transduction. Gene silencing, mainly via RNA interference (RNAi) intervenes on RNAlevel, leading to reduced gene expression and protein secretion. Due to intense research in this field, there is rising evidence that also tumour cells themselves are influenced by angiostatic treatment approaches and the underlying molecular mechanisms are more and more revealed. Here we give a (short) review regarding the pro-apoptotic potency of antiangiogenic compounds like angiostatic molecules, sequestering antibodies, small molecules and RNAi approaches targeting endothelial and tumour cell survival to inhibit angiogenesis and tumour growth.

Role of hypoxia-inducible transcription factor 1alpha for progression and chemosensitivity of murine hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a hypervascularized tumor entity with association of arterial vessel density with poor prognosis. The hypoxia-inducible transcription factor HIF-1alpha represents a pivotal regulator of angiogenesis and is thought to determine the angiogenic nature of HCC. However, the precise role of HIF-1alpha during the pathogenesis of HCC remains elusive. We established a functional inactivation of HIF-1alpha in vitro and in vivo via RNAi and Cre/loxP-mediated recombination, respectively, to determine HIF-1alpha's role for tumor growth and chemosensitivity in transgenic and orthotopic murine HCC models. HIF-1alpha-deficient HCC cells displayed significantly reduced anchorage-independent growth and enhanced sensitivity toward etoposide, while basic cellular proliferation was unaffected. Analysis of gross tumor growth failed to detect reduced growth of HIF-1alpha-deficient tumors in the orthotopic and the transgenic HCC model, respectively. In line with the in vitro data, treatment of HIF-1alpha-deficient tumors with etoposide resulted in greater antiproliferative efficacy when compared to wild-type mice. Taken together, our study does not support a pivotal role of HIF-1alpha for tumor growth and angiogenesis in two murine HCC models. However, our data point toward a significant function of HIF-1alpha in determining chemosensitivity of HCC and therefore warrant validation of HIF-1alpha-inhibitors as adjuvant therapeutic agents in clinical studies of human HCC.

No functional and transductional significance of specific neuropilin 1 siRNA inhibition in colon carcinoma cell lines lacking VEGF receptor 2.

Neuropilins are membrane proteins that mediate effects on tumor cells directly and indirectly by affecting angiogenesis. Recent findings indicate that neuropilin 1 (NRP1) and the associated tyrosine kinase vascular endothelial growth factor receptor 2 (VEGFR2) play a regulatory role in developmental angiogenesis as well as in tumor angiogenesis. NRP1 and VEGFR2 might play a role in colon carcinogenesis and development of metastases. The significance of NRP1 expression in colon cancer seems to be controversial. Therefore, we aimed to distinguish between different expression patterns of signalling cascades in human colon carcinoma cell lines in order to analyze the role of NRP1 in tumorigenesis. We analyzed the biological significance of NRP1 in respect to VEGFR, EGFR, neuropilin and their ligands by RT-PCR and western blot with functional knock-out of NRP1 in different colon adenocarcinoma cell lines. There was no expression of VEGFR2 in tumor cell lines. There were cells that expressed: i) only NRP1 (HT-29, LS174T), ii) NRP2 (Colo320) or iii) both (SW480, LoVo). Cells without NRP1 expression strongly expressed EGFR but only when NRP2 was co-expressed. Inhibition of NRP1 expression by RNA interference did not alter growth characteristics in soft agar experiments. Furthermore, there were no differences in intracellular signalling pathways (ERK1/2 or AKT) in NRP1 inhibited cells. In ex vivo transfer experiments animals with tumors from siRNA-NRP1 transfected cells showed no significant inhibition of tumor growth compared to siRNA control. In conclusion, our results question the role of NRP1 function in VEGFR2 negative colon adenocarcinoma cells. NRP1 seems to have no detectable effect on proliferation or migration nor does it induce any changes in intracellular signalling pathways without the expression of VEGFR2. According to our data, further studies are needed to analyze the therapeutic relevance of NRP1 inhibition in vivo.

Plasminogen fragment K1-3 inhibits expression of adhesion molecules and experimental HCC recurrence in the liver.

PURPOSE: There is no established adjuvant or neo-adjuvant treatment to curb tumor recurrence of hepatocellular carcinoma (HCC). Recent data showed that angiostatic factors can inhibit tumor cell adhesion to the endothelium and therefore recurrence/metastasis. We tested a potential preventive, pre-operative strategy using plasminogen kringles 1-3 (K1-3) to overcome this hurdle. MATERIALS AND METHODS: Effects of K1-3 on the intercellular cell adhesion molecule (ICAM) and vascular cell adhesion molecule (VCAM) expression was analyzed in vitro and in vivo on RNA and protein levels. Influence of K1-3 on HCC recurrence in the liver was analyzed in an orthotopic tumor model. RESULTS: K1-3 decreased ICAM expression in Hepa129 tumor cells and VCAM expression in SVEC4-10 endothelial cells in vitro. In vivo, ICAM was reduced in histological tumor sections. Preventive treatment with AdK1-3 inhibited experimental HCC recurrence and tumor growth in the liver. CONCLUSIONS: We were able to show that K1-3 inhibits intrahepatic tumor recurrence. This novel aspect elucidates a possible approach to prevent HCC recurrence.