@article{KimGrimmigGrimmetal.2013, author = {Kim, Mia and Grimmig, Tanja and Grimm, Martin and Lazariotou, Maria and Meier, Eva and Rosenwald, Andreas and Tsaur, Igor and Blaheta, Roman and Heemann, Uwe and Germer, Christoph-Thomas and Waaga-Gasser, Ana Maria and Gasser, Martin}, title = {Expression of Foxp3 in Colorectal Cancer but Not in Treg Cells Correlates with Disease Progression in Patients with Colorectal Cancer}, series = {PLoS ONE}, volume = {8}, journal = {PLoS ONE}, number = {1}, doi = {10.1371/journal.pone.0053630}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-130340}, pages = {e53630}, year = {2013}, abstract = {Background Measles virus (MV) causes T cell suppression by interference with phosphatidylinositol-3-kinase (PI3K) activation. We previously found that this interference affected the activity of splice regulatory proteins and a T cell inhibitory protein isoform was produced from an alternatively spliced pre-mRNA. Hypothesis Differentially regulated and alternatively splice variant transcripts accumulating in response to PI3K abrogation in T cells potentially encode proteins involved in T cell silencing. Methods To test this hypothesis at the cellular level, we performed a Human Exon 1.0 ST Array on RNAs isolated from T cells stimulated only or stimulated after PI3K inhibition. We developed a simple algorithm based on a splicing index to detect genes that undergo alternative splicing (AS) or are differentially regulated (RG) upon T cell suppression. Results Applying our algorithm to the data, 9\% of the genes were assigned as AS, while only 3\% were attributed to RG. Though there are overlaps, AS and RG genes differed with regard to functional regulation, and were found to be enriched in different functional groups. AS genes targeted extracellular matrix (ECM)-receptor interaction and focal adhesion pathways, while RG genes were mainly enriched in cytokine-receptor interaction and Jak-STAT. When combined, AS/RG dependent alterations targeted pathways essential for T cell receptor signaling, cytoskeletal dynamics and cell cycle entry. Conclusions PI3K abrogation interferes with key T cell activation processes through both differential expression and alternative splicing, which together actively contribute to T cell suppression.}, language = {en} } @article{WedelHudakSeibeletal.2011, author = {Wedel, Steffen and Hudak, Lukasz and Seibel, Jens-Michael and Makarevic, Jasmina and Juengel, Eva and Tsaur, Igor and Waaga-Gasser, Ana and Haferkamp, Axel and Blaheta, Roman A.}, title = {Molecular targeting of prostate cancer cells by a triple drug combination down-regulates integrin driven adhesion processes, delays cell cycle progression and interferes with the cdk-cyclin axis}, series = {BMC Cancer}, volume = {11}, journal = {BMC Cancer}, number = {375}, doi = {10.1186/1471-2407-11-375}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-141075}, pages = {1-14}, year = {2011}, abstract = {Background: Single drug use has not achieved satisfactory results in the treatment of prostate cancer, despite application of increasingly widespread targeted therapeutics. In the present study, the combined impact of the mammalian target of rapamycin (mTOR)-inhibitor RAD001, the dual EGFr and VGEFr tyrosine kinase inhibitor AEE788 and the histone deacetylase (HDAC)-inhibitor valproic acid (VPA) on prostate cancer growth and adhesion in vitro was investigated. Methods: PC-3, DU-145 and LNCaP cells were treated with RAD001, AEE788 or VPA or with a RAD-AEE-VPA combination. Tumor cell growth, cell cycle progression and cell cycle regulating proteins were then investigated by MTT-assay, flow cytometry and western blotting, respectively. Furthermore, tumor cell adhesion to vascular endothelium or to immobilized extracellular matrix proteins as well as migratory properties of the cells was evaluated, and integrin alpha and beta subtypes were analyzed. Finally, effects of drug treatment on cell signaling pathways were determined. Results: All drugs, separately applied, reduced tumor cell adhesion, migration and growth. A much stronger anticancer effect was evoked by the triple drug combination. Particularly, cdk1, 2 and 4 and cyclin B were reduced, whereas p27 was elevated. In addition, simultaneous application of RAD001, AEE788 and VPA altered the membranous, cytoplasmic and gene expression pattern of various integrin alpha and beta subtypes, reduced integrin-linked kinase (ILK) and deactivated focal adhesion kinase (FAK). Signaling analysis revealed that EGFr and the downstream target Akt, as well as p70S6k was distinctly modified in the presence of the drug combination. Conclusions: Simultaneous targeting of several key proteins in prostate cancer cells provides an advantage over targeting a single pathway. Since strong anti-tumor properties became evident with respect to cell growth and adhesion dynamics, the triple drug combination might provide progress in the treatment of advanced prostate cancer.}, language = {en} } @phdthesis{Tsaur2006, author = {Tsaur, Igor}, title = {Untersuchungen zum immunologischen Monitoring chronischer Abstoßung bei nierentransplantierten Patienten unter unterschiedlichen immunsuppressiven Protokollen}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-23017}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2006}, abstract = {Heutzutage existieren verschiedene immunsuppressive Protokolle, die bei Patienten nach Nierentransplantation mit dem Ziel der Unterdr{\"u}ckung der immunologischen Abstoßungs-reaktion eingesetzt werden. Welche von diesen Protokollen aber seine Aufgabe am besten verwirklicht, ist bis jetzt noch offen geblieben. Das relativ neue Pr{\"a}parat MMF findet zu-nehmend im klinischen Alltag im Rahmen dieser Therapie seine Verwendung. In dieser Arbeit wurden die Funktionen regulatorischer T-Zellen aus Patienten nach Nierentrans-plantationen unter MMF basierter Immunsuppression untersucht. Sie wurden mit Hilfe verschiedener Verfahren mit dem Ziel charakterisiert, die g{\"u}nstigste immunsuppressive Kombination zu finden und ihre Wirkungen auf zellul{\"a}rer Ebene zu analysieren. Insgesamt wurde festgestellt, dass die T-Zelllinien aus Patienten mit chronischer Abstoßung vom Th1-Zytokin-Profil und die aus stabilen Patienten vom Th2-Muster gepr{\"a}gt waren. Dies verdeutlicht die Rolle der Th1-Zellen bei der Induktion und Aufrechterhaltung der chroni-schen Abstoßung und die immunregulatorischen Eigenschaften der Th2-Zellen. Alle T-Zelllinien wiesen Spender-Peptid spezifische und signifikante Proliferationsaktivit{\"a}t, wo-bei die Antwort bei den Zelllinien aus chronischen Patienten viel h{\"o}her ausfiel. Diese Tat-sache weist auf die besondere immunologische Aktivit{\"a}t der Th1-Zellen. Unter den T-Zelllinien aus stabilen Patienten unter Tacrolimus, MMF und Prednisolon wurden viel mehr CD4+CD25+ Zellen mit regulatorischen Eigenschaften beobachtet als bei stabilen Patienten unter anderen therapeutischen Kombinationen, was darauf hinweist, dass dieses Regime insbesondere die regulatorischen T-Zellen f{\"o}rdert. Tats{\"a}chlich hat die statistische Analyse des l{\"a}ngerfristigen Verlaufs der Transplantatsituation von den Patienten aus dieser Studie gezeigt, dass unter Tacrolimus, MMF und Prednisolon der geringste Anteil an chro-nischen Abstoßungsreaktionen vorkam. Diese Tatsache k{\"o}nnte enorme Bedeutung f{\"u}r die Klinik haben, denn unsere Arbeit beweist erstmals auf zellul{\"a}rer Ebene, dass gerade diese immunsuppressive Kombination die Toleranzmechanismen am st{\"a}rksten f{\"o}rdert und somit am besten zum langzeitigen Transplantat{\"u}berleben beitr{\"a}gt, wodurch sie in n{\"a}herer Zu-kunft das Therapieregime der Wahl werden kann.}, language = {de} }