Ark Therapeutics Oy

Kuopio, Finland

Ark Therapeutics Oy

Kuopio, Finland
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Kontturi L.-S.,University of Helsinki | Yliperttula M.,University of Helsinki | Toivanen P.,Ark Therapeutics Oy | Toivanen P.,University of Eastern Finland | And 3 more authors.
Journal of Controlled Release | Year: 2011

Microencapsulated and genetically engineered cells may be used for prolonged delivery of therapeutically active proteins. The objective of this study was to develop a simple, inexpensive and flexible laboratory-scale device for the production of cell microcapsules, especially capsules of small diameter (<300 μm). Many microencapsulation devices are expensive, difficult to assemble and to use, and often more suitable for large-scale experiments. However, the simplicity and low price of the encapsulation system should not limit the quality of capsules and reproducibility of the process: for successful in vitro and in vivo experiments it is important to be able to produce uniform, spherical microcapsules without deformities with high reproducibility. In addition, an advantage of the present procedure compared to other similar, co-axial laminar gas flow systems is the possibility to produce also small microcapsules, less than 200 μm in diameter, with narrow size distribution. First, design, optimization and reproducibility testing of this custom-built device were carried out. Second, microencapsulated retinal pigment epithelial cells (ARPE-19) capable of secreting soluble vascular endothelial growth factor receptor 1 (sVEGFR1) were engineered. The cells remained viable in alginate-poly-L-lysine-alginate microcapsules and secreted sVEGFR1 for prolonged periods. © 2011 Elsevier B.V.

Wirth T.,University of Eastern Finland | Pikkarainen J.T.,University of Eastern Finland | Samaranayake H.D.,University of Eastern Finland | Lehtolainen-Dalkilic P.,Ark Therapeutics Oy | And 5 more authors.
Journal of Gene Medicine | Year: 2012

Background: A considerable percentage of tumors are not amenable to surgery. We have designed a simple and powerful targeting system that offers an alternative option for the multi-component pre-targeting strategies used clinically. This targeting system can be used for any type of solid tumors independent of the tumor type, thereby omitting the need to engineer unique antibodies for each specific application or tumour type. In the present study, we show the expression of a chimeric fusion protein, which contains the low-density lipoprotein receptor transmembrane domains and avidin, after local gene transfer and its ability to bind biotinylated compounds in vivo. Methods: Semliki Forest virus and lentivirus vectors were used to express the fusion protein with a high affinity binding site for biotinylated compounds in the tumor. Three different animal models and imaging modalities were used for the demonstration of the functionality and efficacy of the targeting system in vitro and in vivo. Results: We demonstrate targeting of biotinylated compounds after local gene transfer in vivo using two different gene transfer vectors. The findings were confirmed by immunohistochemistry, single-photon emission computed tomography and magnetic resonance imaging. The therapeutic efficacy was tested in a syngeneic rat glioma model by injecting biotinylated-90Yttrium into the tail vein of glioma bearing rats. The study demonstrates that animals, which were treated by using the gene therapy based targeting system, lived significantly longer than control animals. Conclusions: Our gene therapy based targeting system is a promising tool for the treatment of inoperable tumors and other disease conditions, as well as diagnostic imaging. © 2012 John Wiley & Sons, Ltd.

Stedt H.,University of Eastern Finland | Alasaarela L.,University of Eastern Finland | Samaranayake H.,University of Eastern Finland | Pikkarainen J.,University of Eastern Finland | And 7 more authors.
Molecular Therapy - Nucleic Acids | Year: 2012

Malignant glioma is a severe cancer with a poor prognosis. Local occurrence and rare metastases of malignant glioma make it a suitable target for gene therapy. Several studies have demonstrated the importance of Src kinase in different cancers. However, these studies have focused mainly on Src-deficient mice or pharmacological inhibitors of Src. In this study we have used Src small hairpin RNAs (shRNAs) in a lentiviral backbone to mimic a long-term stable treatment and determined the role of Src in tumor tissues. Efficacy of Src shRNAs was confirmed in vitro demonstrating up to 90% target gene inhibition. In a mouse malignant glioma model, Src shRNA tumors were almost 50-fold smaller in comparison to control tumors and had significantly reduced vascularity. In a syngenic rat intracranial glioma model, Src shRNA-transduced tumors were smaller and these rats had a survival benefit over the control rats. In vivo treatment was enhanced by chemotherapy and histone deacetylase inhibition. Our results emphasise the importance of Src in tumorigenesis and demonstrate that it can be efficiently inhibited in vitro and in vivo in two independent malignant glioma models. In conclusion, Src is a potential target for RNA interference-mediated treatment of malignant glioma. © 2012 American Society of Gene and Cell Therapy All rights reserved.

Matilainen J.M.,University of Eastern Finland | Husso T.,University of Eastern Finland | Toropainen S.,University of Eastern Finland | Seuter S.,University of Luxembourg | And 6 more authors.
Biochimica et Biophysica Acta - Molecular Cell Research | Year: 2010

The biologically most active vitamin D compound, 1α,25-dihydroxyvitamin D3 (1α,25(OH)2D3), influences the status of inflammation by modulating the expression of several cytokine genes. In this study, we have examined the mechanism of transcriptional regulation of interleukin 10 (IL-10) by 1α,25(OH)2D3 in lipopolysaccharide (LPS)-treated human monocytes (THP-1). Quantitative PCR showed that IL-10 mRNA expression was significantly down-regulated (2.8-fold) during the first 8h of 1α,25(OH)2D3 treatment, while after 48h it was up-regulated (3-fold). Gel shift and quantitative chromatin immunoprecipitation (ChIP) assays showed that the vitamin D receptor (VDR) binds in a cyclical fashion to a promoter region 1500-1700bp upstream of the IL-10 transcription start site (TSS) containing two conserved VDR binding sites. Targeting of VDR binding sites by enhancer specific duplex RNAs revealed that only the more distal element is functional and chromosome conformation capture analysis suggested that this region loops 1α,25(OH)2D3-dependently to the TSS. Quantitative ChIP and micrococcal nuclease assays also revealed 1α,25(OH)2D3-dependent cyclical epigenetic changes and nucleosome remodeling at this promoter region. In conclusion, in LPS-treated THP-1 cells the primary effect of 1α,25(OH)2D3 on IL-10 expression is down-regulation, which is achieved via a cyclical recruitment of VDR to the promoter. © 2010 Elsevier B.V.

Turhanen P.A.,University of Eastern Finland | Weisell J.,University of Eastern Finland | Lehtolainen-Dalkilic P.,Ark Therapeutics Oy | Maatta A.-M.,Ark Therapeutics Oy | And 2 more authors.
MedChemComm | Year: 2011

Two 111In radiolabelled biotin-DOTA conjugates were prepared containing an enzymatically stable amine bond (-CH 2-NH-CH 2-). Syntheses are straightforward and molecules were labelled with high radiochemical purity. They were also found to be stable in human plasma. This strategy provides a method to produce a simple biotin derivative not requiring any additional protection groups against biotinidase. © 2011 The Royal Society of Chemistry.

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