Andreas Petri

Silencing of microRNA-155 in mice during acute inflammatory response leads to derepression of c/ebp Beta and down-regulation of G-CSF

microRNA-155 (miR-155) has been implicated as a central regulator of the immune system, but its function during acute inflammatory responses is still poorly understood. Here we show that exposure of cultured macrophages and mice to lipopolysaccharide (LPS) leads to up-regulation of miR-155 and that the transcription factor c/ebp Beta is a direct target of miR-155. Interestingly, expression profiling of LPS-stimulated macrophages combined with overexpression and silencing of miR-155 in murine macrophages and human monocytic cells uncovered marked changes in the expression of granulocyte colony-stimulating factor (G-CSF), a central regulator of granulopoiesis during inflammatory responses. Consistent with these data, we show that silencing of miR-155 in LPS-treated mice by systemically administered LNA-antimiR results in derepression of the c/ebp Beta isoforms and down-regulation of G-CSF expression in mouse splenocytes. Finally, we report for the first time on miR-155 silencing in vivo in a mouse inflammation model, which underscores the potential of miR-155 antagonists in the development of novel therapeutics for treatment of chronic inflammatory diseases.

IL-21 induces in vivo immune activation of NK cells and CD8+ T cells in patients with metastatic melanoma and renal cell carcinoma

PurposeHuman interleukin-21 (IL-21) is a class I cytokine previously reported in clinical studies on immune responsive cancers. Here we report the effects of systemic IL-21 therapy on the immune system in two phase 1 trials with this novel cytokine.Experimental designRecombinant IL-21 was administered by intravenous bolus injection at dose levels from 1 to 100xa0μg/kg using two planned treatment regimens: thrice weekly for 6xa0weeks (3/week); or once daily for five consecutive days followed by nine dose-free days (5xa0+xa09). The following biomarkers were studied in peripheral blood mononuclear cells (PBMC) during treatment: phosphorylation of STAT3, alterations in the composition of leukocyte subsets, ex vivo cytotoxicity, expression of effector molecules in enriched CD8+ T cells and CD56+ NK cells by quantitative RT-PCR, and gene array profiling of CD8+ T cells.ResultsEffects of IL-21 were observed at all dose levels. In the 5xa0+xa09 regimen IL-21 induced a dose dependent decrease in circulating NK cells and T cells followed by a return to baseline in resting periods. In both CD8+ T cells and CD56+ NK cells we found up-regulation of perforin and granzyme B mRNA. In addition, full transcriptome analysis of CD8+ T cells displayed changes in several transcripts associated with increased cell cycle progression, cellular motility, and immune activation. Finally, cytotoxicity assays showed that IL-21 enhanced the ability of NK cells to kill sensitive targets ex vivo.ConclusionsIL-21 was biologically active at all dose levels administered with evidence of in vivo NK cell and CD8+ T cell activation.

Coexpression network analysis in abdominal and gluteal adipose tissue reveals regulatory genetic loci for metabolic syndrome and related phenotypes.

Metabolic Syndrome (MetS) is highly prevalent and has considerable public health impact, but its underlying genetic factors remain elusive. To identify gene networks involved in MetS, we conducted whole-genome expression and genotype profiling on abdominal (ABD) and gluteal (GLU) adipose tissue, and whole blood (WB), from 29 MetS cases and 44 controls. Co-expression network analysis for each tissue independently identified nine, six, and zero MetS–associated modules of coexpressed genes in ABD, GLU, and WB, respectively. Of 8,992 probesets expressed in ABD or GLU, 685 (7.6%) were expressed in ABD and 51 (0.6%) in GLU only. Differential eigengene network analysis of 8,256 shared probesets detected 22 shared modules with high preservation across adipose depots (DABD-GLUu200a=u200a0.89), seven of which were associated with MetS (FDR P<0.01). The strongest associated module, significantly enriched for immune response–related processes, contained 94/620 (15%) genes with inter-depot differences. In an independent cohort of 145/141 twins with ABD and WB longitudinal expression data, median variability in ABD due to familiality was greater for MetS–associated versus un-associated modules (ABD: 0.48 versus 0.18, Pu200a=u200a0.08; GLU: 0.54 versus 0.20, Pu200a=u200a7.8×10−4). Cis-eQTL analysis of probesets associated with MetS (FDR P<0.01) and/or inter-depot differences (FDR P<0.01) provided evidence for 32 eQTLs. Corresponding eSNPs were tested for association with MetS–related phenotypes in two GWAS of >100,000 individuals; rs10282458, affecting expression of RARRES2 (encoding chemerin), was associated with body mass index (BMI) (Pu200a=u200a6.0×10−4); and rs2395185, affecting inter-depot differences of HLA-DRB1 expression, was associated with high-density lipoprotein (Pu200a=u200a8.7×10−4) and BMI–adjusted waist-to-hip ratio (Pu200a=u200a2.4×10−4). Since many genes and their interactions influence complex traits such as MetS, integrated analysis of genotypes and coexpression networks across multiple tissues relevant to clinical traits is an efficient strategy to identify novel associations.

Gene therapy for lung cancer

In the pre-clinical research into the development of gene therapy for cancer, different strategies have evolved and shown promising results in the laboratory. However, most of these strategies will need further refinement to obtain clinical success. This is partly due to the lack of suitable vector systems which specifically can deliver the therapeutic gene to the target cells, and ensure expression of the therapeutic gene. In this review we will give an introduction to different strategies used in cancer gene therapy for neoplasms of the lung, and focus on how to target gene delivery to disseminated lung cancer cells. Tumor specific gene expression can be accomplished at different levels. One way to accomplish targeted gene delivery is by coupling of receptor specific ligands to the vector. Specific gene delivery to cells expressing the target receptor will occur by receptor mediated endocytosis of the vector. Further restriction of gene expression to cancer cells can be accomplished by utilizing promoters predominantly active in tumors. When gene therapy is targeted at different levels, efficient gene delivery to disseminated cancer cells by systemic vector administration will be an attractive future prospect.

Array-A-Lizer: A serial DNA microarray quality analyzer

BackgroundThe proliferate nature of DNA microarray results have made it necessary to implement a uniform and quick quality control of experimental results to ensure the consistency of data across multiple experiments prior to actual data analysis.ResultsArray-A-Lizer is a small and convenient stand-alone tool providing the necessary initial analysis of hybridization quality of an unlimited number of microarray experiments. The experiments are analyzed for even hybridization across the slide and between fluorescent dyes in two-color experiments in spotted DNA microarrays.ConclusionsArray-A-Lizer allows the expedient determination of the quality of multiple DNA microarray experiments allowing for a rapid initial screening of results before progressing to further data analysis. Array-A-Lizer is directed towards speed and ease-of-use allowing both the expert and non-expert microarray researcher to rapidly assess the quality of multiple microarray hybridizations. Array-A-Lizer is available from the Internet as both source code and as a binary installation package.