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Background: 15-20% of all patients initially diagnosed with colorectal cancer develop metastatic disease and surgical resection remains the only potentially curative treatment available. Current 5-year survival following R0-resection of liver metastases is 28-39%, but recurrence eventually occurs in up to 70%. To date, adjuvant chemotherapy has not improved clinical outcomes significantly. The primary objective of the ongoing LICC trial (L-BLP25 In Colorectal Cancer) is to determine whether L-BLP25, an active cancer immunotherapy, extends recurrence-free survival (RFS) time over placebo in colorectal cancer patients following R0/R1 resection of hepatic metastases. L-BLP25 targets MUC1 glycoprotein, which is highly expressed in hepatic metastases from colorectal cancer. In a phase IIB trial, L-BLP25 has shown acceptable tolerability and a trend towards longer survival in patients with stage IIIB locoregional NSCLC.
Methods: This is a multinational, phase II, multicenter, randomized, double-blind, placebo-controlled trial with a sample size of 159 patients from 20 centers in 3 countries. Patients with stage IV colorectal adenocarcinoma limited to liver metastases are included. Following curative-intent complete resection of the primary tumor and of all synchronous/metachronous metastases, eligible patients are randomized 2:1 to receive either L-BLP25 or placebo. Those allocated to L-BLP25 receive a single dose of 300 mg/m2 cyclophosphamide (CP) 3 days before first L-BLP25 dose, then primary treatment with s.c. L-BLP25 930 mug once weekly for 8 weeks, followed by s.c. L-BLP25 930 mug maintenance doses at 6-week (years 1&2) and 12-week (year 3) intervals unless recurrence occurs. In the control arm, CP is replaced by saline solution and L-BLP25 by placebo. Primary endpoint is the comparison of recurrence-free survival (RFS) time between groups. Secondary endpoints are overall survival (OS) time, safety, tolerability, RFS/OS in MUC-1 positive cancers. Exploratory immune response analyses are planned. The primary endpoint will be assessed in Q3 2016. Follow-up will end Q3 2017. Interim analyses are not planned.
Discussion: The design and implementation of such a vaccination study in colorectal cancer is feasible. The study will provide recurrence-free and overall survival rates of groups in an unbiased fashion. Trial Registration EudraCT Number 2011-000218-20
BACKGROUND: There is agreement that the infectivity assay with the duck hepatitis B virus (DHBV) is a suitable surrogate test to validate disinfectants for hepatitis B virucidal activity. However, since this test is not widely used, information is necessary whether disinfectants with limited virucidal activity also inactivate DHBV. In general, disinfectants with limited virucidal activity are used for skin and sensitive surfaces while agents with full activity are more aggressive. The present study compares the activity of five different biocides against DHBV and the classical test virus for limited virucidal activity, the vaccinia virus strain Lister Elstree (VACV) or the modified vaccinia Ankara strain (MVA).
METHODS: Virucidal assay was performed as suspension test according to the German DVV/RKI guideline. Duck hepatitis B virus obtained from congenitally infected Peking ducks was propagated in primary duck embryonic hepatocytes and was detected by indirect immunofluorescent antigen staining.
RESULTS: The DHBV was inactivated by the use of 40% ethanol within 1-min and 30% isopropanol within 2-min exposure. In comparison, 40% ethanol within 2-min and 40% isopropanol within 1-min exposure were effective against VACV/MVA. These alcohols only have limited virucidal activity, while the following agents have full activity. 0.01% peracetic acid inactivated DHBV within 2 min and a concentration of 0.005% had virucidal efficacy against VACV/MVA within 1 min. After 2-min exposure, 0.05% glutardialdehyde showed a comparable activity against DHBV and VACV/MVA. This is also the case for 0.7% formaldehyde after a contact time of 30 min.
CONCLUSIONS: Duck hepatitis B virus is at least as sensitive to limited virucidal activity as VACV/MVA. Peracetic acid is less effective against DHBV, while the alcohols are less effective against VACV/MVA. It can be expected that in absence of more direct tests the results may be extrapolated to HBV.
Identification of translationally deregulated proteins during inflammation-associated tumorigenesis
(2012)
The translation of mRNAs into proteins is an elaborate and highly regulated process. Translational regulation primarily takes place at the level of initiation. During initation the eukaryotic initiation factors (eIFs) form a complex that binds to the 5’end of the mRNA to scan for a start codon. Once recognized, the ribosome is recruited to the mRNA and protein synthesis starts. Initiation of translation can basically occur via two distinct mechanisms, i.e. cap-dependent and cap-independent that is mediated via internal ribosome entry sites (IRESs). The former is mediated by a 5’cap structure composed of a 7-methylguanylate which is added to every mRNA during transcription and recruits the initiation complex. IRES-dependent translation involves elements within the 5’untranslated region (UTR) of the mRNA that mostly bind IRES trans-acting factors (ITAFs) which associate either with the initiation complex or with the ribosome itself and consequently allow for internal initiation of translation.
During tumorigenesis the demand for proteins is increased due to rapid cell growth, which consequently requires enhanced translation. Many factors that regulate translation are overexpressed in tumors. Moreover, signaling pathways that trigger translation or further hyperactivated by the surrounding tumor microenvironment. This environment is largely generated by infiltration of immune cells such as macrophages that secrete cytokines and other mediators to promote tumorigenesis. As the effects of inflammatory conditions on the translation of specific targets are only poorly characterized, my study aimed at identifying translationally deregulated targets during inflammation-associated tumorigenesis.
For this purpose, I cocultured MCF7 breast tumor cells with conditioned medium of activated monocyte-derived U937 macrophages (CM). Polysome profiling and microarray analysis identified 42 targets to be regulated at the level of translation. The results were validated by quantitative PCR and one target - early growth response 2 (EGR2) - was chosen for in depth analysis of the mechanism leading to its enhanced translation.
In order to identify upstream signaling molecules causing enhanced EGR2 protein synthesis the cytokine profile of CM was analyzed and the impact of several cytokines on EGR2 translation was examined. Preincubation of CM with neutralizing antibodies revealed that lowering interleukin 6 (IL-6) had only little effect, whereas depletion of IL 1β significantly reduced EGR2 translation. This finding was corroborated by the fact that treatment with recombinant IL-1β enhanced EGR2 translation to virtually the same extend as CM. Further experiments revealed that this effect was mediated via the p38-MAPK signaling cascade.
Interestingly, I observed that the mTOR inhibitor rapamycin, which reduces cap-dependent translation, specifically stimulated EGR2 translation. This result argued for an IRES-dependent mechanism that might account for EGR2 translation. The use of bicistronic reporter assays verified this hypothesis. In line with the above mentioned results, CM, IL-1β and p38-MAPK induced EGR2-IRES activity.
Since IRESs commonly require ITAFs to mediate translation initiation, the binding of proteins to the 5’UTR was analyzed using mass spectrometry. Among others, several previously described ITAFs, such as polypyrimidine tract-binding protein (PTB) and heterogeneous nuclear ribonucleoprotein A1 (hnRNP-A1) were identified to directly bind to the EGR2-5’UTR. Furthermore, overexpression of hnRNP-A1 enhanced EGR2-IRES activity whereas a dominant negative form of hnRNP-A1 significantly decreased it, thus, showing its importance for EGR2 translation.
In summary, my data provide evidence that EGR2 expression can be controlled by IRES-dependent translational regulation, which is responsive to an inflammatory environment. The identified mechanism may not be exclusive for one target but might be representative for gene expression regulation mechanisms during tumorigenesis. This is of special interest for the treatment of cancer patients and development of more specific therapies to reduce tumor outcome.
Immunomodulatory properties and molecular effects in inflammatory diseases of low-dose X-irradiation
(2012)
Inflammatory diseases are the result of complex and pathologically unbalanced multicellular interactions. For decades, low-dose X-irradiation therapy (LD-RT) has been clinically documented to exert an anti-inflammatory effect on benign diseases and chronic degenerative disorders. By contrast, experimental studies to confirm the effectiveness and to reveal underlying cellular and molecular mechanisms are still at their early stages. During the last decade, however, the modulation of a multitude of immunological processes by LD-RT has been explored in vitro and in vivo. These include leukocyte/endothelial cell adhesion, adhesion molecule and cytokine/chemokine expression, apoptosis induction, and mononuclear/polymorphonuclear cell metabolism and activity. Interestingly, these mechanisms display comparable dose dependences and dose-effect relationships with a maximum effect in the range between 0.3 and 0.7 Gy, already empirically identified to be most effective in the clinical routine. This review summarizes data and models exploring the mechanisms underlying the immunomodulatory properties of LD-RT that may serve as a prerequisite for further systematic analyses to optimize low-dose irradiation procedures in future clinical practice.
nefficient intracellular protein trafficking is a critical issue in the pathogenesis of a variety of diseases and in recombinant protein production. Here we investigated the trafficking of factor VIII (FVIII), which is affected in the coagulation disorder hemophilia A. We hypothesized that chemical chaperones may be useful to enhance folding and processing of FVIII in recombinant protein production, and as a therapeutic approach in patients with impaired FVIII secretion. A tagged B-domain-deleted version of human FVIII was expressed in cultured Chinese Hamster Ovary cells to mimic the industrial production of this important protein. Of several chemical chaperones tested, the addition of betaine resulted in increased secretion of FVIII, by increasing solubility of intracellular FVIII aggregates and improving transport from endoplasmic reticulum to Golgi. Similar results were obtained in experiments monitoring recombinant full-length FVIII. Oral betaine administration also increased FVIII and factor IX (FIX) plasma levels in FVIII or FIX knockout mice following gene transfer. Moreover, in vitro and in vivo applications of betaine were also able to rescue a trafficking-defective FVIII mutant (FVIIIQ305P). We conclude that chemical chaperones such as betaine might represent a useful treatment concept for hemophilia and other diseases caused by deficient intracellular protein trafficking.
Ein charakteristisches Merkmal von Autoimmunerkrankungen ist der selektive Angriff des Immunsystems auf einen einzigen Zelltyp, ein Organ oder Gewebe durch bestimmte T- und B-Lymphozyten. Die genaue Ursache von Autoimmunerkrankungen bleibt bislang ungeklärt, jedoch scheint eine bestimmte genetische Konstellation bei Zusammentreffen mit im weitesten Sinne umweltbedingten Faktoren die Reaktionen zu erklären. Zu solchen umweltbedingten Faktoren gehören auch Infektionen. Häufig werden Assoziationen zwischen Infektion und autoimmuner Erkrankung beobachtet. Auch kann bei einer akuten Infektion ein vorhandener Autoimmunprozess exazerbieren. Eine schnelle Verteidigung gegen Infektionen gewährleistet das angeborene Immunsystem, bevor das adaptive Immunsystem zum Tragen kommt. Die Moleküle, die bei diesen Abwehrprozessen frei werden, können zur T-Zell-Vermehrung führen, die einerseits eine effektive Selbstverteidigung möglich macht; ander erseits können sie aber auch die Vermehrung autoreaktiver T-Zellen zur Folge haben. An frühen Vorgängen nach dem Kontakt mit einem Pathogen ist eine Vielzahl von Zyto- und Chemokinen beteiligt. Typ-1-Interferone (IFN1) sind ebensolche Zytokine, die vor allem in der Abwehr gegen Viren eine Rolle spielen und in mehrschrittigen Prozessen auch zur Aktivierung von T- und B-Zellen führen. IFIH1 ist ein intrazellulärer Rezeptor, der dsRNA im Zytosol detektiert und in der Folge die Transkription von IFN1 aktiviert. Veränderungen im Gen dieses Rezeptors zeigen Assoziationen zu Typ-1-Diabetes (T1D) und bieten einen funktionellen Berührungspunkt zwischen früher Infektabwehr durch das angeborene Immunsystem und der letztlich gewebszerstörerischen T- und B-Zell-Reaktion. In dieser Arbeit wurde daher die Assoziation dreier endokriner Autoimmunopathien mit dem IFH1-Polymorphismus rs1990760 durchgeführt, der in der Literatur als deutlich assoziiert mit T1D beschrieben wird. Mit Hashimoto-Thyreoditis, Morbus Basedow und Morbus Addison wurden Krankheiten gewählt, die im genetischen Hintergrund viele Gemeinsamkeiten untereinander und mit T1D aufweisen. Durch die in der Literatur beschriebenen Assoziationen mit T1D rückt nun der IFIH1-rs1990760 Polymorphismus potentiell auch in das genetische Anfälligkeitsprofil dieser endokrinen Autoimmunopathien. Für die Assoziationsanalyse wurde in dieser Arbeit DNA von betroffenen Individuen und gesunden Kontrollen mittels RT-PCR auf den IFIH1-Polymorphismus rs1990760 (Allele „A“/„G“) typisiert und die Genotyp- und Allelhäufigkeiten verglichen. Außerdem wurden Familienanalysen durchgeführt und die Transmission der Allele auf Unterschiede im Vererbungsverhalten hin untersucht. Es konnten keine statistisch relevanten Assoziationen zwischen dem IFIH1-Polymorphismus rs1990760 und Hashimoto-Thyreoditis, Morbus Basedow und Morbus Addison gefunden werden. Weiterhin wurden Subgruppen gebildet, um eventuell in der Gesamtgruppe nicht erkennbare Trends aufzudecken. Für Hashimoto-Thyreoditis und Morbus Basedow wurde der HLA-Typ DQ2 als Risikotyp angenommen, für Morbus Addison der Typ HLA-DQ2/DQ8. Der Antikörperstatus der untersuchten Individuen wurde ebenfalls in die Untersuchung einbezogen. In der Familienanalyse mit an Hashimoto-Thyreoditis erkranktem Kind wurden Subgruppen gebildet, die den TPO-Ak und Tg-Ak-Status der Eltern berücksichtigen. Bei Morbus Basedow wurde der TSH-R-Antikörper bei der Fall-Kontroll-Analyse zur Subgruppenbildung herangezogen. Wenn sich auch keine statistisch eindeutigen Assoziationen nachweisen ließen, so waren bei Hashimoto-Thyreoditis und Morbus Basedow in einigen Subgruppen doch Tendenzen zu erkennen, die eine Beteiligung des Polymorphismus an der genetischen Anfälligkeit vermuten lassen könnten. Die beobachteten Trends deuten darauf hin, dass in bestimmten Patientengruppen der untersuchte Polymorphismus eine Rolle in der Anfälligkeit spielen könnte.
Oncolytic effects of a novel Influenza A virus expressing Interleukin-15 from the NS reading frame
(2012)
Oncolytic influenza A viruses with deleted NS1 gene (delNS1) replicate selectively in tumour cells with defective interferon response and/or activated Ras/Raf/MEK/ERK signalling pathway. To develop a delNS1 virus with specific immunostimulatory properties, we used an optimised technology to insert the interleukin-15 (IL-15) coding sequence into the viral NS gene segment (delNS1-IL-15). DelNS1 and delNS1-IL-15 exerted similar oncolytic effects. Both viruses replicated and caused caspase-dependent apoptosis in interferon-defective melanoma cells. Virus replication was required for their oncolytic activity. Cisplatin enhanced the oncolytic activity of delNS1 viruses. The cytotoxic drug increased delNS1 replication and delNS1-induced caspase-dependent apoptosis. Interference with MEK/ERK signalling by RNAi-mediated depletion or the MEK inhibitor U0126 did not affect the oncolytic effects of the delNS1 viruses. In oncolysis sensitive melanoma cells, delNS1-IL-15 (but not delNS1) infection resulted in the production of IL-15 levels ranging from 70 to 1140 pg/mL in the cell culture supernatants. The supernatants of delNS1-IL-15-infected (but not of delNS1-infected) melanoma cells induced primary human natural killer cell-mediated lysis of non-infected tumour cells. In conclusion, we constructed a novel oncolytic influenza virus that combines the oncolytic activity of delNS1 viruses with immunostimulatory properties through production of functional IL-15. Moreover, we showed that the oncolytic activity of delNS1 viruses can be enhanced in combination with cytotoxic anti-cancer drugs.
Introduction: Despite the excellent anti-inflammatory and immunosuppressive action of glucocorticoids (GCs), their use for the treatment of inflammatory bowel disease (IBD) still carries significant risks in terms of frequently occurring severe side effects, such as the impairment of intestinal tissue repair. The recently-introduced selective glucocorticoid receptor (GR) agonists (SEGRAs) offer anti-inflammatory action comparable to that of common GCs, but with a reduced side effect profile.
Methods: The in vitro effects of the non-steroidal SEGRAs Compound A (CpdA) and ZK216348, were investigated in intestinal epithelial cells and compared to those of Dexamethasone (Dex). GR translocation was shown by immunfluorescence and Western blot analysis. Trans-repressive effects were studied by means of NF-κB/p65 activity and IL-8 levels, trans-activation potency by reporter gene assay. Flow cytometry was used to assess apoptosis of cells exposed to SEGRAs. The effects on IEC-6 and HaCaT cell restitution were determined using an in vitro wound healing model, cell proliferation by BrdU assay. In addition, influences on the TGF-β- or EGF/ERK1/2/MAPK-pathway were evaluated by reporter gene assay, Western blot and qPCR analysis.
Results: Dex, CpdA and ZK216348 were found to be functional GR agonists. In terms of trans-repression, CpdA and ZK216348 effectively inhibited NF-κB activity and IL-8 secretion, but showed less trans-activation potency. Furthermore, unlike SEGRAs, Dex caused a dose-dependent inhibition of cell restitution with no effect on cell proliferation. These differences in epithelial restitution were TGF-β-independent but Dex inhibited the EGF/ERK1/2/MAPK-pathway important for intestinal epithelial wound healing by induction of MKP-1 and Annexin-1 which was not affected by CpdA or ZK216348.
Conclusion: Collectively, our results indicate that, while their anti-inflammatory activity is comparable to Dex, SEGRAs show fewer side effects with respect to wound healing. The fact that SEGRAs did not have a similar effect on cell restitution might be due to a different modulation of EGF/ERK1/2 MAPK signalling.
Allogeneic stem cell transplantation (allo-SCT) has become an important treatment modality for patients with high-risk acute myeloid leukemia (AML) and is also under investigation for soft tissue sarcomas. The therapeutic success is still limited by minimal residual disease (MRD) status ultimately leading to patients’ relapse. Adoptive donor lymphocyte infusions based on MRD status using IL-15-expanded cytokine-induced killer (CIK) cells may prevent relapse without causing graft-versus-host-disease (GvHD). To generate preclinical data we developed mouse models to study anti-leukemic- and anti-tumor-potential of CIK cells in vivo. Immunodeficient mice (NOD/SCID/IL-2Rγc−, NSG) were injected intravenously with human leukemic cell lines THP-1, SH-2 and with human rhabdomyosarcoma (RMS) cell lines RH41 and RH30 at minimal doses required for leukemia or tumor engraftment. Mice transplanted with THP-1 or RH41 cells were randomly assigned for analysis of CIK cell treatment. Organs of mice were analyzed by flow cytometry as well as quantitative polymerase chain reaction for engraftment of malignant cells and CIK cells. Potential of CIK cells to induce GvHD was determined by histological analysis. Tissues of the highest degree of THP-1 cell expansion included bone marrow followed by liver, lung, spleen, peripheral blood (PB), and brain. RH30 and RH41 engraftment mainly took place in liver and lung, but was also detectable in spleen and PB. In spite of delayed CIK cell expansion compared with malignant cells, CIK cells injected at equal amounts were sufficient for significant reduction of RH41 cells, whereas against fast-expanding THP-1 cells 250 times more CIK than THP-1 cells were needed to achieve comparable results. Our preclinical in vivo mouse models showed a reliable 100% engraftment of malignant cells which is essential for analysis of anti-cancer therapy. Furthermore our data demonstrated that IL-15-activated CIK cells have potent cytotoxic capacity against AML and RMS cells without causing GvHD.
Acute ethanol gavage attenuates hemorrhage/resuscitation-induced hepatic oxidative stress in rats
(2012)
Acute ethanol intoxication increases the production of reactive oxygen species (ROS). Hemorrhagic shock with subsequent resuscitation (H/R) also induces ROS resulting in cellular and hepatic damage in vivo. We examined the role of acute ethanol intoxication upon oxidative stress and subsequent hepatic cell death after H/R. 14 h before H/R, rats were gavaged with single dose of ethanol or saline (5 g/kg, EtOH and ctrl; H/R_EtOH or H/R_ctrl, resp.). Then, rats were hemorrhaged to a mean arterial blood pressure of 30 ± 2 mmHg for 60 min and resuscitated. Two control groups underwent surgical procedures without H/R (sham_ctrl and sham_EtOH, resp.). Liver tissues were harvested at 2, 24, and 72 h after resuscitation. EtOH-gavage induced histological picture of acute fatty liver. Hepatic oxidative (4-hydroxynonenal, 4-HNE) and nitrosative (3-nitrotyrosine, 3-NT) stress were significantly reduced in EtOH-gavaged rats compared to controls after H/R. Proapoptotic caspase-8 and Bax expressions were markedly diminished in EtOH-gavaged animals compared with controls 2 h after resuscitation. EtOH-gavage increased antiapoptotic Bcl-2 gene expression compared with controls 2 h after resuscitation. iNOS protein expression increased following H/R but was attenuated in EtOH-gavaged animals after H/R. Taken together, the data suggest that acute EtOH-gavage may attenuate H/R-induced oxidative stress thereby reducing cellular injury in rat liver.