Interleukin 6/interleukin 6 receptor interaction and its role as a therapeutic target for treatment of cachexia and cancer.

Interleukin 6 (IL6) mediates pleiotropic physiological functions through its interaction with the IL6 receptor (IL6R). Signal transduction can occur via cis- and trans-signaling. The role of IL6/IL6R interaction via autocrine and paracrine loops in tumor proliferation and progression is discussed. The potential role of IL6/IL6R interaction in different experimental systems and tumor entities is summarized while the focus is on inhibition of IL6 signaling with monoclonal antibodies directed against IL6 or IL6R and their potential impact for treatment of tumor-associated cachexia and as antitumoral agents as monotherapy and in combination with small molecule compounds.

ALCAM/CD166: cancer-related issues.

Activated leucocyte adhesion molecule (ALCAM) was originally identified as a transmembrane receptor which is involved in T-cell activation and has other still unresolved functions in hematopoiesis, development, inflammation and transendothelial migration of neutrophils. ALCAM is a member of a subfamily of immunoglobulin receptors with five immunoglobulin-like domains (VVC2C2C2) in the extracellular domain and is expressed in many types of tumors. The tumor-type-dependent impact of its expression level with respect to prognosis points to a possible context-dependent function. Most functional investigations have focused on malignant melanoma, in which high ALCAM expression at the protein level correlates with a poor prognosis. ALCAM mediates low-affinity homophilic interactions and much stronger interactions with CD6. Modulation of ALCAM function with agents such as transfected dominant negative ALCAM and ligand-binding secreted ALCAM both lead to inhibition of matrix metalloproteinase-2 activation, but their impact with respect to invasion in vitro and metastasis in vivo are different. Single-chain Fv fragments directed against ALCAM are efficiently internalized, paving the way for exploration of immunoconjugates as therapeutic agents. Validation experiments of the target with modulatory agents for possible therapeutic application in oncology are discussed.

Human variation databases.

More than 100,000 human genetic variations have been described in various genes that are associated with a wide variety of diseases. Such data provides invaluable information for both clinical medicine and basic science. A number of locus-specific databases have been developed to exploit this huge amount of data. However, the scope, format and content of these databases differ strongly and as no standard for variation databases has yet been adopted, the way data is presented varies enormously. This review aims to give an overview of current resources for human variation data in public and commercial resources.

Cancer-related issues of CD147.

CD147 is involved in many physiological functions, such as lymphocyte responsiveness, spermatogenesis, implantation, fertilization and neurological functions at early stages of development. Here we specifically review the role of CD147 in cancer. We focus on the following aspects: expression of CD147 in malignant versus normal tissues and its possible impact on prognosis, interaction of tumor cell-expressed CD147 with stroma cells and induction of matrix metalloproteinases, as well as the role of CD147 in tumor angiogenesis. The function of CD147 in supercomplexes with monocarboxylate transporters (MCT) and amino acid transporters such as CD98hc and large neutral amino acid transporter 1 (LAT1), as well as the functional contribution of CD147 in complexes with caveolin-1 and integrins, is discussed. Target validation experiments making use of CD147-directed RNAi and monoclonal antibodies are summarized. Finally, the relevance of CD147 as a target for therapeutic intervention in cancer patients is discussed.

The Roche Cancer Genome Database (RCGDB).

Sequence variations are being studied for a better understanding of the mechanism and development of cancer as a mutation-driven disease. The systematic sequencing of genes in tumors and technological advances in high-throughput techniques combined with efficient data acquisition methods have resulted in an explosion of available cancer genome-related data. Despite the technological progress and increase of data, improvements in the application area, for example, drug target discovery, have failed to keep pace with increased research and development spending. One reason for this discrepancy is the ever increasing number of databases and the absence of a unified access to the mutation data. Currently, researchers typically have to browse several, often highly specialized databases to obtain the required information. A more complete understanding of relations and dependencies between mutations and cancer, however, requires the availability of an efficient integrative cancer genome information system. To facilitate this, we developed the Roche Cancer Genome Database (RCGDB), a freely available biological information system integrating different kinds of mutation data. The database is the first comprehensive integration of disparate cancer genome data like single nucleotide variants, single nucleotide polymorphisms, and chromosomal aberrations (CGH and FISH). RCGDB is freely accessible via a Google-like Web interface at http://rcgdb.bioinf.uni-sb.de/MutomeWeb/.

Application of T cell-based transcriptomics to identify three candidate biomarkers for monitoring anti-TGFbetaR therapy.

OBJECTIVES: The development of targeted drugs would greatly benefit from the simultaneous identification of biomarkers to determine the aspects of bioactivity, drug safety and efficacy, particularly when affecting receptor-signaling pathways. However, the establishment of appropriate systems to monitor drug-induced events requires an accessible surrogate tissue for functional read out. METHODS: Therefore we present a universal platform based upon T cell-based gene expression profiling for the identification of biomarkers using the antitransforming growth factor beta receptor inhibitor LY2109761 as an example. RESULTS: Our initial screen revealed 12 candidate genes specifically regulated in T cells by the inhibitor. In subsequent in-vitro and in-vivo analyses, the combined monitoring of independent gene regulation of three genes was established in peripheral blood mononuclear cells as novel pharmacodynamic candidate biomarkers for antitransforming growth factor beta receptor based therapies. CONCLUSION: Overall, the proposed concept of biomarker identification can be easily adapted towards other drug candidates for whom gene regulation can be established in cellular components of peripheral blood.

Virally infected mouse liver endothelial cells trigger CD8+ T-cell immunity.

BACKGROUND & AIMS: Dendritic cell activation through ligation of pattern recognition receptors leading to full functional maturation causes induction of CD8(+) T-cell immunity through increased delivery of costimulatory signals instead of tolerance. Here we investigate whether organ-resident antigen-presenting cells, such as liver sinusoidal endothelial cells (LSECs), also switch from tolerogenic to immunogenic CD8(+) T-cell activation upon such stimulation. METHODS: Murine LSECs were isolated by immunomagnetic separation and analyzed for functional maturation upon triggering pattern recognition receptors or viral infection employing gene expression analysis and T cell coculture assays. In vivo relevance of the findings was confirmed with bone-marrow chimeric animals. RESULTS: LSECs expressed numerous pattern recognition receptors that allowed for sentinel function, but ligand-induced activation of these receptors was not sufficient to overcome tolerance induction of CD8(+) T cells. Importantly, viral infection with murine cytomegalovirus caused functional maturation of antigen-presenting LSECs and was sufficient to promote antigen-specific differentiation into effector CD8(+) T cells in the absence of dendritic cells and independent of CD80/86. CONCLUSIONS: These results shed new light on the generation of organ-specific immunity and may contribute to overcoming tolerance in relevant situations, such as cancer.

miRNA deregulation by epigenetic silencing disrupts suppression of the oncogene PLAG1 in chronic lymphocytic leukemia.

MicroRNAs (miRNA) play a key role in cellular regulation and, if deregulated, in the development of neoplastic disorders including chronic lymphocytic leukemia (CLL). RNAs from primary cells of 50 treatment-naive CLL patients and peripheral B cells of 14 healthy donors were applied to miRNA expression profiling using bead chip technology. In CLL cells, a set of 7 up- and 19 down-regulated miRNAs was identified. Among the miRNAs down-regulated in CLL cells, 6 of 10 miRNA promoters examined showed gain of methylation compared with normal B-cell controls. Subsequent target prediction of deregulated miRNAs revealed a highly significant binding prediction at the 3' untranslated region of the pleomorphic adenoma gene 1 (PLAG1) oncogene. Luciferase reporter assays including site-directed mutagenesis of binding sites revealed a significant regulation of PLAG1 by miR-181a, miR-181b, miR-107, and miR-424. Although expression of PLAG1 mRNA was not affected, PLAG1 protein expression was shown to be significantly elevated in CLL cells compared with the levels in healthy donor B cells. In summary, we could demonstrate disruption of miRNA-mediated translational control, partly due to epigenetic transcriptional silencing of miRNAs, with subsequent overexpression of the oncogenic transcription factor PLAG1 as a putative novel mechanism of CLL pathogenesis.

Cancer vaccine enhanced, non-tumor-reactive CD8(+) T cells exhibit a distinct molecular program associated with "division arrest anergy".

Immune-mediated tumor rejection relies on fully functional T-cell responses and neutralization of an adverse tumor microenvironment. In clinical trials, we detected peptide-specific but non-tumor-reactive and therefore not fully functional CD8(+) T cells post-vaccination against tumor antigens. Understanding the molecular mechanisms behind nontumor reactivity will be a prerequisite to overcome this CD8(+) T-cell deviation. We report that these non-tumor-reactive CD8(+) T cells are characterized by a molecular program associated with hallmarks of "division arrest anergy." Non-tumor-reactive CD8(+) T cells are characterized by coexpression of CD7, CD25, and CD69 as well as elevated levels of lck(p505) and p27(kip1). In vivo quantification revealed high prevalence of non-tumor-reactive CD8(+) T cells with increased levels during cancer vaccination. Furthermore, their presence was associated with a trend toward shorter survival. Dynamics and frequencies of non-target-reactive CD8(+) T cells need to be further addressed in context of therapeutic vaccine development in cancer, chronic infections, and autoimmune diseases.

L1-CAM as a target for treatment of cancer with monoclonal antibodies.

L1 cell adhesion molecule (L1-CAM) is a neuronal adhesion molecule which is expressed in many tumor entities. L1-CAM was shown to be involved in proliferation, invasion and metastasis both in vitro and in vivo. L1-CAM is engaged in homophilic interactions and complexes with many other ligands in a context-dependent manner. Activation and modulation of the extracellular signal-related kinase pathway by L1-CAM has been documented. In normal tissues, L1-CAM expression is restricted to nerve bundles and kidney tubules; however, L1-CAM is expressed in many tumor entities and, with the exception of neuroblastoma, L1-CAM expression correlates with poor prognosis. L1-CAM occurs in two isoforms, full-length L1-CAM and a variant in which exons 2 and 27 have been deleted. Preclinical experiments with available monoclonal antibodies are summarized and L1-CAM is analysed as a target for treatment of cancer with monoclonal antibodies.

RNA fingerprints provide direct evidence for the inhibitory role of TGFbeta and PD-1 on CD4+ T cells in Hodgkin lymphoma.

A hallmark of various human malignancies is the expression of immunoinhibitory factors within the tumor microenvironment. There is indirect evidence based on in vitro experiments that tumor-infiltrating T cells in human malignancies are suppressed by such factors. Still, direct evidence of the influence of individual inhibitory factors on immune cells in human cancer in vivo is lacking. To address this question, we used Hodgkin lymphoma (HL) as a model because histopathological characteristics of HL are thought to be due mostly to the effects of a wide variety of cytokines, including TGFbeta or membrane-bound receptors such as PD-1 that are suspected to contribute to immune evasion of tumor cells. Using a genome-wide transcriptional approach, we established specific RNA fingerprints of TGFbeta and PD-1 signaling in human T cells in vitro. Applying these specific fingerprints, we directly demonstrate that CD4+ T cells in HL--but not in follicular lymphoma (FL)--are under the inhibitory influence of both TGFbeta and PD-1 in vivo. This approach can be easily generalized to provide direct evidence of the impact of any given soluble or cell-bound factor on any cell type within diseased tissue.

Indoleamine 2,3-dioxygenase-expressing dendritic cells form suppurative granulomas following Listeria monocytogenes infection.

Control of pathogens by formation of abscesses and granulomas is a major strategy of the innate immune system, especially when effector mechanisms of adaptive immunity are insufficient. We show in human listeriosis that DCs expressing indoleamine 2,3-dioxygenase (IDO), together with macrophages, are major cellular components of suppurative granulomas in vivo. Induction of IDO by DCs is a cell-autonomous response to Listeria monocytogenes infection and was also observed in other granulomatous infections with intracellular bacteria, such as Bartonella henselae. Reporting on our use of the clinically applied anti-TNF-alpha antibody infliximab, we further demonstrate in vitro that IDO induction is TNF-alpha dependent. Repression of IDO therefore might result in exacerbation of granulomatous diseases observed during anti-TNF-alpha therapy. These findings place IDO(+) DCs not only at the intersection of innate and adaptive immunity but also at the forefront of bacterial containment in granulomatous infections.