Zugl.: Giessen, Univ., Diss., 2007

In Canada, colorectal cancer is the second leading cause of cancer death for both men and women. There are many different factors that contribute to the progression and spread of the disease. However, increasing evidence now suggests that the tumor microenvironment plays a paramount role in these processes. CD26 is a multifunctional, cell-surface glycoprotein that has intrinsic enzyme activity, binds adenosine deaminase and interacts with the extracellular matrix. Through its various functions it serves to constrain cancer progression. For example, it is known to cleave CXCL12, the ligand for CXCR4. The CXCL12:CXCR4 axis is normally involved in cancer metastasis by promoting cancer cell migration, invasion and proliferation. Down-regulation of CD26 is observed in certain cancers - this has been shown in vitro to occur in response to certain soluble mediators. The first part of this study looked at the effects of glucose and its metabolic product lactate on CD26 expression in colorectal carcinoma cells. Our study showed that CD26 expression is lower in cancer cells that are grown in low-glucose, high-lactate conditions, which replicates the situation within a tumor. The second part of this study examined the effect of adenosine, a purine nucleoside, on colorectal carcinoma cells and supportive stromal cells - cancer-associated HS675.T fibroblasts (CAFs) and Met-5a mesothelial cells. Adenosine increased the proliferation of CAFs and increased CXCL12 mRNA in both stromal cell lines. It also increased MMP-13 mRNA in stromal cells as well as colorectal cancer cells, suggesting that adenosine may promote progression and metastasis through various mechanisms. The last section focused on the ability of cellular products and 3-dimensional tissue topology to coordinate and affect the behaviour of the different cell populations. Here we show that secretory products from colorectal cancer cells promote CAF proliferation but inhibit mesothelial cell proliferation, and are also able to modulate MMP-13 expression. Finally, certain responses are enhanced in multicellular spheroids. In conclusion, the tumor microenvironment represents a major consideration in the treatment of solid tumors. Our data suggest that various soluble mediators, such as adenosine, may have therapeutic implications in cancer treatment and might represent novel targets for future research.

Despite recent advances in oncology and extensive research efforts, gliomas remain essentially incurable. Glioblastoma multiforme (GBM, WHO grade IV) is the most common glioma and may arise de novo or progress from a lower-grade lesion. GBM is characterized by invasive growth, aberrant angiogenesis and necrosis. The heterogeneity of GBM is further complicated by the contribution of the inflammation that is facilitated by immune cells that reside in and infiltrate this immuno-privileged organ. One of the cells types present in the tumor microenvironment are mast cells (MC) that accumulate in the tumor in a grade-dependent manner. GBM cells secrete a plethora of cytokines acting as chemoattractants in MC recruitment and to a lesser degree induce MC proliferation in situ. Expression of one of the cytokines secreted by GBM cells - macrophage migration inhibitory factor (MIF) - correlates with MC accumulation in vivo. GBM cells invade the surrounding parenchyma making complete resection impossible. Here, migration was studied with the focus on RAP1 and its negative regulator RAP1GAP. Activation of RAP1 signaling by lentiviral silencing of RAP1GAP lead to decrease in cell migration and a shift in expression of SOX2 and GFAP, presumably enhancing stem cell phenotype. MicroRNAs are small non-coding RNAs known to regulate the mRNA network. miR-21 is highly overexpressed in the majority of cancers including GBM. Its expression is strictly regulated during embryonic development of the brain. SOX2 is co-regulated with miR-21 demarcating a cell population with neural/glial progenitor/stem cell properties. In an experimental mouse model, expression of miR-21 can be sustained by forced expression of PDGF-BB leading to gliomagenesis. GBM cells seem to be addicted to oncogenic properties of miR-21 as its knockdown leads to extensive apoptosis. This observation combined with the fact that miR-21 is absent in the normal adult mammalian brain suggest miR-21 to be an excellent therapeutic target. Effects of conventional therapy (surgery combined with radiochemotherapy) on prolonging patient survival have reached a plateau. New effective personalized therapeutic modalities need to be designed and implemented. Targeting the tumor microenvironment as well as cell intrinsic properties like invasive potential, stemness and onco-miR addiction studied in this thesis will hopefully lead to efficient disruption of GBM’s aberrant ecosystem.

Orientador: Sandra Helena Penha de Oliveira / Banca: Edson Antunes / Banca: Lucia Helena Faccioli / Resumo: A quimiocina C-X-X motif ligand 12 (CXCL12) e seu receptor de quimiocina 4 (CXCR4) desenvolvem um papel crítico na inflamação das vias aéreas. No entanto, os efeitos da ativação da via CXCL12/CXCR4 sobre fibroblastos pulmonares ainda são desconhecidos. Neste estudo, investigamos o efeito da via CXCL12/CXCR4 sobre a quimiocina (C-C motif) ligante 3 (CCL3) e (C-X-C motif) ligante 2 (CXCL2) e sobre os mediadores lipídicos leucotrienos B4 (LTB4) e C4 (LTC4) por fibroblastos pulmonares e a sinalização intracelular envolvida neste processo. CXCL12 foi capaz de induzir a produção de CCL3, CXCL2, LTB4 e LTC4; a produção de CCL3 não é dependente da produção de CXCL2, mas a produção de CXCL2 é dependente da produção de CCL3. A produção de LTB4 pode ser parcialmente regulada por CXCL2 e CCL3 e a produção de LTC4 é dependente da produção de CCL3 e CXCL2. Fibroblastos pulmonares constitutivamente expressam CXCR4 e a estimulação com CXCL12 induz sua expressão. Análises de Western blot mostraram que CXCL12 aumenta a expressão proteica de CXCR4 e induz a fosforilação da S339 do CXCR4. A expressão gênica constitutiva e induzida de CXCR4 foram inibidas pelo anticorpo anti-CXCL2. No entanto, o anticorpo anti-CCL3 e o inibidor farmacológico MK886 foram capazes de diminuir a expressão gênica induzida de CXCR4. Os fibroblastos pulmonares foram pré-tratados com MK886, dexametasona (Dexa) e/ou loratadina (Lor). MK886 e Lor promoveram a diminuição da produção de LTC4 e LTB4, mas não a de CCL3 e CXCL2. Dexa diminuiu níveis de CCL3, CXCL2, LTB4 e LTC4, e quando associado com Lor esta diminuição foi mais eficaz. Identificamos... / Abstract: C-X-X motif ligand 12 (CXCL12) and its specific receptor Chemokine receptor 4 (CXCR4) play a critical role in airway inflammation. However, the effects of CXCL12/CXCR4 axis on pulmonary fibroblast activation are unknown. In this study, we investigated the effect of CXCL12/CXCR4 axis on chemokine (C-C motif) ligand 3 (CCL3), chemokine (C-X-C motif) ligand 2 (CXCL2), leukotrienes B4 (LTB4) and C4 (LTC4) production by pulmonary fibroblasts and the intracellular signaling involved in the process. CXCL12 induced CCL3, CXCL2, LTB4 and LTC4 production, and CCL3 production is not dependent on CXCL2; but CXCL2 production is dependent on CCL3 production. LTB4 production can be partially down-regulated by CXCL2 and CCL3 production and LTC4 production is dependent on CCL3 and CXCL2 production. Pulmonary fibroblasts constitutively expressed CXCR4, and CXCL12 stimulation up-regulated its expression. Western blot analysis showed that CXCL12 increased protein expression of CXCR4 and induced phosphorylation at S339 of CXCR4. Constitutive CXCR4 expression was decreased by anti-CCL3 antibody or MK 886. Inducible CXCR4 was inhibited by anti-CXCL2 antibody. Indeed pulmonary fibroblasts were pretreated with MK886, dexamethasone (Dexa) and loratadine (Lor). MK886 and loratadine was able to reduced LTB4 and LTC4 production but not CCL3 and CXCL2. Dexa decreased CCL3, CXCL2, LTB4 and LTC4 production, and when associated with Lor this decrease was more effective. We found that PI-3K and JNK intracellular signaling play a role in CCL3 production; p38, MEK1/2, PI-3K and JNK are involved in CXCL2 production and p38 and MEK1/2 pathways are involved in LTB4 production by... / Mestre

Resumo: O acúmulo de toxinas urêmicas gerado pela diminuição da taxa de filtração glomerular no paciente com doença renal crônica (DRC) vem acompanhado por alterações metabólicas e vasculares no organismo que predispõem esses pacientes ao desenvolvimento de doença cardiovascular (DCV). O Stromal cell-derived factor 1 (SDF-1/CXCL12), é uma quimiocina de ação pleiotrópica, com expressão alterada em tecidos inflamados e lesionados, capaz de mobilizar células da medula óssea para o local da lesão, mediando o reparo e regeneração tecidual. No presente trabalho, através de uma combinação de estudos in vivo e in vitro, investigamos o efeito da uremia na expressão de CXCL12 e proliferação celular. Para isso, amostras provenientes de um estudo anterior com dados publicados por Stinghen et al. 2010 foram utilizadas. No presente estudo foram analisados marcadores de inflamação sistêmica como proteína C reativa (PCR) e interleucina-6 (IL-6), em níveis plasmáticos. Além da inflamação, foi feita a avaliação da disfunção endotelial pelos níveis plasmáticos de Interleucina-8 (IL-8) e verificada a sinalização de regeneração vascular pelos níveis plasmáticos e em sobrenadante celular de CXCL12. O modelo experimental foi realizado com células endoteliais humanas extraídas de veia de cordão umbilical (HUVECs). Tratamentos específicos utilizando meio de cultivo acrescido de plasma urêmico de pacientes em hemodiálise (pool de plasmas urêmicos) ou com plasma normal (pool de plasma de indivíduos saudáveis) foram feitos com cinética de 0 h, 6 h e 12 h. As concentrações plasmáticas médias de PCR, IL-6, IL-8 e CXCL12 foram respectivamente 4,9 ±4,8 mg/mL, 6,76±8,1 pg/mL, 128,2±206,2 pg/mL e 2625,87±1288,58 pg/mL. Foi observado uma correlação positiva entre PCR e a IL-6 (?=0,57, P<0,005) e CXCL12 com IL-8 (?=0,4462, P<0,05). A análise da expressão de CXCL12 em sobrenadante de cultura revelou que após 6 horas de tratamento as células em ambiente saudável expressam mais CXCL12 do que as tratadas com plasma urêmico (54,5 x 15,7%). As análises do ciclo celular revelaram que células endoteliais submetidas a tratamento com plasma saudável, apresentam um padrão de crescimento celular regular (cresce, duplica e com o passar do tempo, morre). Diferentemente das células submetidas ao tratamento com plasma urêmico que apresentam uma alta porcentagem de morte celular. Nossos dados demonstram que os níveis plasmáticos das quimiocinas CXCL12 e IL-8 estão correlacionados em pacientes em HD. Tal correlação ocorre em paralelo ao aumento dos marcadores de inflamação sistêmica. A literatura descreve que tanto IL-8 quanto CXCL12 atuam em conjunto na manutenção e reparo de lesões teciduais, e que a produção de CXCL12 pode estar relacionada a biodisponibilidade do óxido nítrico (NO) e ligação a seus receptores (CXCR4 e CXCR7) na superfície celular. Assim, sugerimos que os níveis de CXCL12 e IL-8 encontrados nestes pacientes podem refletir um sistema de reparo ativado, e que a toxicidade urêmica esteja inibindo a produção de CXCL12, seja pela diminuição de NO ou pela saturação da ligação a seus receptores CXCR4 e CXCR7, entretanto estudos adicionais são necessários para comprovação de tais hipóteses.

Made available in DSpace on 2014-08-27T14:36:45Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-08-05Bitstream added on 2014-08-27T15:57:02Z : No. of bitstreams: 1 000749985.pdf: 1413898 bytes, checksum: 7421bc33cc6d75478dcb676de29021bd (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A quimiocina C-X-X motif ligand 12 (CXCL12) e seu receptor de quimiocina 4 (CXCR4) desenvolvem um papel crítico na inflamação das vias aéreas. No entanto, os efeitos da ativação da via CXCL12/CXCR4 sobre fibroblastos pulmonares ainda são desconhecidos. Neste estudo, investigamos o efeito da via CXCL12/CXCR4 sobre a quimiocina (C-C motif) ligante 3 (CCL3) e (C-X-C motif) ligante 2 (CXCL2) e sobre os mediadores lipídicos leucotrienos B4 (LTB4) e C4 (LTC4) por fibroblastos pulmonares e a sinalização intracelular envolvida neste processo. CXCL12 foi capaz de induzir a produção de CCL3, CXCL2, LTB4 e LTC4; a produção de CCL3 não é dependente da produção de CXCL2, mas a produção de CXCL2 é dependente da produção de CCL3. A produção de LTB4 pode ser parcialmente regulada por CXCL2 e CCL3 e a produção de LTC4 é dependente da produção de CCL3 e CXCL2. Fibroblastos pulmonares constitutivamente expressam CXCR4 e a estimulação com CXCL12 induz sua expressão. Análises de Western blot mostraram que CXCL12 aumenta a expressão proteica de CXCR4 e induz a fosforilação da S339 do CXCR4. A expressão gênica constitutiva e induzida de CXCR4 foram inibidas pelo anticorpo anti-CXCL2. No entanto, o anticorpo anti-CCL3 e o inibidor farmacológico MK886 foram capazes de diminuir a expressão gênica induzida de CXCR4. Os fibroblastos pulmonares foram pré-tratados com MK886, dexametasona (Dexa) e/ou loratadina (Lor). MK886 e Lor promoveram a diminuição da produção de LTC4 e LTB4, mas não a de CCL3 e CXCL2. Dexa diminuiu níveis de CCL3, CXCL2, LTB4 e LTC4, e quando associado com Lor esta diminuição foi mais eficaz. Identificamos... / C-X-X motif ligand 12 (CXCL12) and its specific receptor Chemokine receptor 4 (CXCR4) play a critical role in airway inflammation. However, the effects of CXCL12/CXCR4 axis on pulmonary fibroblast activation are unknown. In this study, we investigated the effect of CXCL12/CXCR4 axis on chemokine (C-C motif) ligand 3 (CCL3), chemokine (C-X-C motif) ligand 2 (CXCL2), leukotrienes B4 (LTB4) and C4 (LTC4) production by pulmonary fibroblasts and the intracellular signaling involved in the process. CXCL12 induced CCL3, CXCL2, LTB4 and LTC4 production, and CCL3 production is not dependent on CXCL2; but CXCL2 production is dependent on CCL3 production. LTB4 production can be partially down-regulated by CXCL2 and CCL3 production and LTC4 production is dependent on CCL3 and CXCL2 production. Pulmonary fibroblasts constitutively expressed CXCR4, and CXCL12 stimulation up-regulated its expression. Western blot analysis showed that CXCL12 increased protein expression of CXCR4 and induced phosphorylation at S339 of CXCR4. Constitutive CXCR4 expression was decreased by anti-CCL3 antibody or MK 886. Inducible CXCR4 was inhibited by anti-CXCL2 antibody. Indeed pulmonary fibroblasts were pretreated with MK886, dexamethasone (Dexa) and loratadine (Lor). MK886 and loratadine was able to reduced LTB4 and LTC4 production but not CCL3 and CXCL2. Dexa decreased CCL3, CXCL2, LTB4 and LTC4 production, and when associated with Lor this decrease was more effective. We found that PI-3K and JNK intracellular signaling play a role in CCL3 production; p38, MEK1/2, PI-3K and JNK are involved in CXCL2 production and p38 and MEK1/2 pathways are involved in LTB4 production by...

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22319号 / 医博第4560号 / 新制||医||1041(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 濵﨑 洋子, 教授 稲垣 暢也, 教授 清水 章 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Final publication is available at http://www.sciencedirect.com/science/article/pii/S0006291X15310664 / 京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第19598号 / 医博第4105号 / 新制||医||1014(附属図書館) / 32634 / 京都大学大学院医学研究科医学専攻 / (主査)教授 三森 経世, 教授 開 祐司, 教授 妻木 範行 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第21009号 / 医博第4355号 / 新制||医||1028(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 羽賀 博典, 教授 前川 平, 教授 江藤 浩之 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Untersucht wurde der Einfluss mehrerer Chemotherapeutika auf den Chemokinrezeptor CXCR4 in Myelomzelllinien auf Ebene des Promotors, der mRNA und der Rezeptorverteilung, wobei drei Substanzen (Etoposid, Bortezomib und Dexamethason) als potenzielle Suppressoren des Promotors ausgemacht werden konnten. Abhängig vom Myelom-Zelltyp und der Dosierung können so evtl. Rückschlüsse auf die beobachtete Suppression von CXCR4 bei erkrankten Patienten mit hoher CXCR4-Aktivität (hier: Malignes Myelom) durch die begleitende Chemotherapie gezogen werden, welche eine Diagnostik und Therapie bei diesen Patienten erschwert. Hintergrund: Hintergrund für diese Arbeit waren Beobachtungen in klinischen Fallstudien von Lapa et al. am Universitätsklinikum Würzburg, die sich auf CXCR4 bezogen, welches u.a. bei Patienten mit Multiplem Myelom überexprimiert wird und dadurch bereits als Target für Diagnostik und Therapie in der Klinik Anwendung findet. Dabei konnte bei PET-CT Untersuchungen in der Nuklearmedizin beobachtet werden, dass es durch die begleitende Chemotherapie der Patienten zu einer Suppression des markierten CXCR4-Signals kam, so dass es nicht mehr zur Verlaufsbeobachtung und vor allem nicht mehr zur Radiotherapie und Therapiekontrolle verwendet werden konnte. Um den Einfluss und mögliche Interaktionen der Chemotherapeutika auf CXCR4 zu untersuchen, war es Ziel dieser Arbeit, ein vergleichbares Szenario in-vitro nachzustellen und Einflüsse messbar zu machen, um so mögliche Ansätze und Verbesserungsvorschläge für die klinische Anwendung zu liefern. Methoden/Ergebnisse: Hierfür wurden im ersten Teil INA-6 (Myelomzellen) und Mesenchymale Stammzellen (MSC) kultiviert, in Ko-Kultur gebracht und nach einer bestimmten Zeit wieder getrennt, um anschließend den gegenseitigen Einfluss in Bezug auf CXCR4 zu messen. Zudem wurde der Einfluss von Dexamethason untersucht. Es zeigte sich eine enge Bindung zwischen INA-6 und MSC sowie eine hohe CXCR4-Aktivität bei INA-6, jedoch konnte keine Induktion der CXCR4-Aktivität in MSC durch INA-6-Kontakt oder Dexamethason quantifiziert werden. Die Immunzytologie erwies sich aufgrund einer schweren Anfärbbarkeit von CXCR4 – auch mit verschiedensten Antikörpern und sogar Liganden-gekoppeltem Farbstoff– als kaum auswertbar, wobei eine Darstellung von CXCR4 generell aber gelang. Der CXCR4-Promotor wurde mittels Software genauer analysiert, wobei einige relevante Bindestellen, u.a. für Glukokortikoide und NFkB gefunden wurden. Die Herstellung eines CXCR4- pGl4.14-Promotor-Konstrukts war erfolgreich, ebenso dessen Einschleusung in Myelomzellen. Auch gelang die Herstellung stabiler transfizierter INA-6, sodass mit diesen anschließend konstantere Ergebnisse erzielt werden konnten. Im größten Teil der Arbeit wurden geeignete Chemotherapeutika-Konzentrationen ermittelt und in Viabilitäts- und Apoptose-Versuchen überprüft. Die Stimulationsversuche mit diesen zeigten variable Effekte abhängig vom Zelltyp (INA-6, MM1S), jedoch konnten Bortezomib, Etoposid und Dexamethason konzentrationsabhängig als starke Suppressoren der CXCR4-Aktivität ausgemacht werden, was sich v.a. auf Ebene der Promotoraktivität – gemessen mittels Luciferase - zeigte. Interpretation: In-vitro konnten somit drei potenzielle Suppressoren der CXCR4-Aktivität ausgemacht werden: Etoposid, Bortezomib und Dexamethason. Zumindest beim INA-6-Zelltyp fiel dieser Effekt deutlich aus, wobei in der Klinik der entsprechende Zelltyp sowie die Dosierung der Medikamente berücksichtigt werden müssen. Hinzu kommen weitere Einflussfaktoren des menschlichen Körpers, die nicht berücksichtig werden konnten. Die genauen Mechanismen der Suppression könnten sich aus den Bindestellen des Promotors erklären, die von uns analysiert wurden, aber auf die in weiteren Arbeiten noch näher eingegangen werden muss. / The influence of several chemotherapeutic agents on the chemokine receptor CXCR4 in myeloma cell lines at the level of the promoter, the mRNA and the receptor distribution was examined, whereby three substances (etoposide, bortezomib and dexamethasone) could be identified as potential suppressors of the promoter. Depending on the cell type and the dosage, conclusions can be drawn about the observed suppression of CXCR4 in patients with diseases with high CXCR4 activity (here: multiple myeloma) due to the accompanying chemotherapy, which impairs theranostic applications like diagnostic imaging using PET/CT and may in particular abolish the chances of radiotherapeutic intervention in these patients. Background: The background for this work were observations in clinical case studies by Lapa et al. at the University Hospital Würzburg, which referred to CXCR4, which is overexpressed in patients with multiple myeloma and is therefore already used as a target for diagnostics and therapy in the clinic. During PET-CT examinations in nuclear medicine, it could be observed that the accompanying chemotherapy of the patients led to a suppression of the marked CXCR4 signal, which is why it could no longer be used for monitoring the follow-up, but also was lost as a radiotherapeutic target. In order to investigate the influence and possible interactions of chemotherapeutic agents on CXCR4, the aim of this work was to simulate a comparable scenario in vitro and to make influences measurable in order to provide possible approaches and suggestions for improvement for clinical application. Methods/Conclusions: For this purpose, INA-6 (myeloma cells) and mesenchymal stem cells (MSC) were cultivated in the first part, brought into co-culture and separated again after a certain time in order to then measure the mutual influence with regard to CXCR4 expression. The influence of dexamethasone was also examined. There were intensive contacts between INA-6 and MSC and high CXCR4 activity in INA-6, but no induction of CXCR4 activity in MSC by INA-6 or dexamethasone could be quantified. The immunocytology turned out to be difficult due to the difficulty of staining CXCR4 - even with a wide variety of antibodies and ligand-coupled dyes - although CXCR4 was generally able to be represented. The CXCR4 promoter was analyzed in more detail using the Genomatix software, and some relevant binding sites, including response elements for glucocorticoids and NFkB, were found. The production of a CXCR4-pGl4.14 luciferase-reporter construct was successful, as was its introduction into myeloma cells. The production of stably transfected INA-6 was also successful, so that more constant results could then be achieved. In a large part of the work, suitable chemotherapeutic concentrations were determined and checked in viability and apoptosis tests. The stimulation experiments with these showed variable effects depending on the cell type (INA-6, MM1S). However, depending on the concentration, bortezomib, etoposide and dexamethasone could be identified as strong suppressors of CXCR4 activity, which was particularly evident at the level of activity of our luciferase-reporter construct. Interpretation: Overall, three potential suppressors of CXCR4 activity could be identified in-vitro: etoposide, bortezomib and dexamethasone. At least with the INA-6 cell type, this effect was clear, although the corresponding cell type and the dosage of the medication must be taken into account in the clinic. In addition, there may be other influencing factors of the human organism in vivo that could not be considered. The exact mechanisms of suppression could be explained by the binding sites of the promoter, which we analyzed, but which will have to be discussed in more detail in further work.