Objectives: To investigate the effects of serotonin and melatonin (MLT) on the regulation of malignant growth and the activity of serotonin receptors (5HTR1a/-1b) in prostate cancer (PCa) cell lines. Materials and Methods: In four PCa cell lines (LNCaP, 22RV1, PC3, DU145) and two reference cell lines 5HTR1a and -1b, relative mRNA expression levels were assessed. Different serotonin and MLT receptor agonists and antagonists were used in stimulation and inhibition experiments. Results: mRNA expression of 5HTR1b was higher than that of 5HTR1a in all PCa cell lines. Serotonin showed a significant growth stimulatory effect in all PCa lines. The 5HTR1a and -1b agonists/antagonists did not significantly affect viability. MLT inhibited viability only in PC3 cells. Similarly, the 5HTR1a antagonist induced apoptotic changes in PC3 cells only at 10–4M, while the 5HTR1b antagonist induced necrosis at 10–4M in all cell lines. Cell cycle alterations were seen in PC3 and DU145 cells under the influence of the 5HTR1a antagonist. Conclusions: Serotonin receptor antagonists and agonists as well as MLT influence viability and apoptosis of PCa cell lines at supraphysiologic concentrations. In contrast to other reports, our results do not support a regulatory role of serotonin or MLT receptor activation or inhibition in PCa growth. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

La 7β-hydroxy-épiandrostérone, stéroïde endogène dérivant de la DHEA, présente des propriétés anti-inflammatoires. En effet, elle module la voie des prostaglandines (PGs) en inhibant la production de la PGE2 pro-inflammatoires et en augmentant la production de la 15-Deoxy-∆12,14-PGJ2 cyto-protectrice in vivo et in vitro. Les faibles doses de 7β-hydroxy-épiandrostérone (1nM, 10nM, 100nM) pour lesquelles ces effets sont observés, suggèrent une liaison à un récepteur spécifique. L’inflammation et la production des PGs jouent un rôle important dans le développement et la prolifération des tumeurs mammaires estrogéno-dépendantes. Le 17β-estradiol (E2), en se fixant sur les récepteurs des estrogènes (REs), induit la production de PGE2 et la prolifération cellulaire dans ces cellules tumorales. De ce fait, notre objectif était de tester les effets de la 7β-hydroxy-épiandrostérone sur la prolifération (comptage avec exclusion au bleu trypan), le cycle cellulaire et l’apoptose (cytométrie de flux) dans les lignées cellulaires de cancer du sein MCF-7 (REα+, REβ+, GPR30+) et MDA-MB-231 (REα-, REβ+, GPR30+) et d’identifier une(des) cible(s) potentielle(s) dans ces cellules (transactivation) et dans des cellules négatives pour les REs nucléaires SKBr3 (GPR30+) (études de prolifération). Cette étude a montré que la 7β-hydroxy-épiandrostérone exerce des effets anti-estrogéniques dans les cellules MCF-7 et MDA-MB-231 associés à une inhibition de la prolifération et un arrêt du cycle cellulaire. Les études de transactivation et de prolifération avec les agonistes spécifiques des REs ont montré une interaction avec le REβ. De plus, les résultats des études de proliférations sur les trois lignées cellulaires suggèrent que la 7β-hydroxy-épiandrostérone pourrait également interagir avec le GPR30. Ces résultats indiquent que ce stéroïde androgène agit comme un anti-estrogène. De plus, c’est la première fois qu’un stéroïde androgène à faible dose montre une action anti-proliférative dans des lignées de cancers du sein. Des études ultérieures restent à réaliser afin de mieux comprendre ces effets observés. / 7β-hydroxy-epiandrosterone, an endogenous androgenic derivative of DHEA, has previously been shown to exert anti-inflammatory action in vitro and in vivo via a shift from prostaglandin E2 (PGE2) to 15-deoxy-∆12,14-PGJ2 production. This modulation in prostaglandin production was obtained with low concentrations of 7β-hydroxy-epiandrosterone (1–100 nM) and suggested that it might act through a specific receptor. Inflammation and prostaglandin synthesis is important in the development and survival of estrogen-dependent mammary cancers. Estrogen induced PGE2 production and cell proliferation via its binding to estrogen receptors (ERs) in these tumors. Our objective was to test the effects of 7β-hydroxy-epiandrosterone on the proliferation (by counting with trypan blue exclusion), cell cycle and cell apoptosis (by flow cytometry) of breast cancer cell lines MCF-7 (ERα+, ERβ +, G-protein coupled receptor 30 : GPR30+) and MDA-MB-231 (ERα-, ERβ +, GPR30+) and to identify a potential target of this steroid in these cell lineages (by transactivations) and in the nuclear ER-negative SKBr3 cells (GPR30+) (by proliferation assays). 7β-hydroxy-epiandrosterone exerted anti-estrogenic effects in MCF-7 and MDA-MB-231 cells associated with cell proliferation inhibition and cell cycle arrest. Moreover, transactivation and proliferation with ER agonists assays indicated that 7β-hydroxy-epiandrosterone interacted with ERβ. Data from proliferation assays on the MCF-7, MDA-MB-231 and SKBr3 cell lines suggested that 7β-hydroxy-epiandrosterone may also act through the membrane GPR30 receptor.These results support that this androgenic steroid acts as an anti-estrogenic compound. Moreover, this is the first evidence that low doses of androgenic steroid exert antiproliferative effects in these mammary cancer cells. Further investigations are needed to improve understanding of the observed actions of endogenous 7β-hydroxy-epiandrosterone.

Made available in DSpace on 2014-08-20T13:32:50Z (GMT). No. of bitstreams: 1 dissertacao_natalia_camacho.pdf: 752258 bytes, checksum: 4db6bde27e4ad1a1adedd5d44779d4aa (MD5) Previous issue date: 2007-06-01 / Lectins are proteins or glicoproteins of non-immune origin with binding specificities for carbohidrates, that interact with glicocomponents present in plant and animal cells, bacteria and viruses. This property makes lectins remarkable markers used in histochemical and biochemical studies, and for characterization and differentiation of cells. Leguminous plants are the major source of lectins, proteins that possess important biological activities, like insecticidal and antiproliferative against cancer cell lines. Thus, the aim of this work was to develop a heterologous expression system for a recombinant lectin from Bauhinia forficata, a leguminous plant popularly known as pata-de-vaca , in E. coli, to study its characteristics and biological activities. The lectin gene bfl was amplified by PCR from genomic DNA, and cloned to expression vectors pQE30 e pET32a(+). Recombinant BFL was expressed in E. coli in insoluble form by using the vector pET32a(+)/bfl. The lectin was purified by Ni +2 -Sepharose affinity chromatography, with a yield of 40 mg.L -1 . The sequence and carbohidrate specificity of rBFL is similar to other related lectins. The rBFL lectin presents in monomer and dimer forms, with aparent molecular mass of 44 and 94 kDa, respectively, shows biological activity in hemagglutination assay in the presence of divalent metal cations (Ca +2 and Mn +2 ) and antiproliferative effect on human cancer cell lines MCF-7 (breast cancer), HT-29 (colon cancer) and HL-60 (leukemia) according as the concentration used. The rBFL lectin showed dose-dependent inhibition in HT-29 cells, stimulatory effect on proliferation of MCF-7 cells in higher concentrations, and no induction of cell death was observed in any cancer cell line. The results obtained in this work, about rBFL lectin, never before isolated or produced in heterologous system, motivates the performance of new characterization assays to elucidate possible applications. / Lectinas são proteínas ou glicoproteínas de origem não imune com propriedade de ligação especifíca a carboidratos, capazes de interagir com glicocomponentes presentes em células de plantas, animais, bactérias e vírus. Essa propriedade faz das lectinas notáveis marcadores utilizados em estudos histoquímicos, bioquímicos e na caracterização e diferenciação de células. Plantas leguminosas constituem-se na maior fonte de lectinas, que possuem atividades biológicas importantes, como atividade inseticida e antiproliferativa sobre células tumorais. Diante disto, o objetivo deste trabalho foi desenvolver um sistema de expressão heteróloga para uma lectina de Bauhinia forficata (rBFL), popularmente conhecida como pata-de-vaca , em E. coli, com o intuito de elucidar suas características e atividades biológicas. O gene bfl da lectina foi amplificado por PCR a partir do DNA genômico, e clonado nos vetores de expressão pQE30 e pET32a(+). A lectina rBFL foi expressa em larga escala pelo vetor pET32a(+)/bfl em E. coli, na forma insolúvel. A purificação foi realizada por cromatografia de afinidade em coluna de Ni +2 -Sepharose, com rendimento de 40 mg.L -1 . A seqüência da lectina rBFL e sua especificidade por carboidrato é similar a de lectinas relacionadas. A lectina rBFL apresenta-se na forma de monômeros e dímeros, com massa molecular aparente de 44 e 94 kDa, respectivamente, possui atividade biológica em ensaio de hemaglutinação na presença de cátions divalentes (Ca +2 and Mn +2 ) e demonstra efeito antiproliferativo sobre as linhagens tumorais humanas MCF-7 (câncer de mama), HT-29 (câncer de cólon) e HL-60 (leucêmica), dependendo da concentração utilizada. A rBFL demonstrou efeito inibitório dose-dependente sobre HT-29, e efeito estimulatório sobre a proliferação da linhagem MCF-7 em altas concentrações, não induzindo morte celular em nenhuma das linhagens. Os resultados obtidos neste trabalho acerca da rBFL, nunca antes isolada ou produzida em sistema heterólogo, motivam a realização de novos ensaios de caracterização visando possíveis aplicações.

Cancer cells have been known for some time to have very different metabolismas compared to that of normal non proliferating cells. As metabolism is involvedin almost every aspect of cell function, there has been a recent resurgence ofinterest in inhibiting cancer metabolism as a therapeutic strategy. Inhibitors thatspecifically target altered metabolic components in cancer cells are being developedas antiproliferative agents. However, many such inhibitors have not progressedinto the clinic due to limited efficacy either in vitro or in vivo. In this study weexplore the hypothesis that this is often due to the robustness of the metabolicnetwork and the differences between individual cancer cell lines in their metaboliccharacteristics. We take a systems biology approach. We investigate the cellular bioenergetic profiles of a panel of five non-small celllung cancer cell lines before and after treatment with a novel inhibitor of theglutaminase-1 (GLS1) enzyme. Additionally, we explore the effects of this inhibitoron intracellular metabolism of these cell lines as well as on the uptake and secretionof glucose, lactate and amino acids. To be able to do the latter robustly, wehad to modify the experimental assay considerably from procedures that seemto be standard in the literature; using these earlier procedures the metabolicenvironment of the cells was highly variable, leading to misleading results onthe metabolic effects of the inhibitor. We reduced cell density, altered mediumvolume and changed the time-window of the assay. This led to the cells growingexponentially, appearing indifferent to the few remaining changes. In this newassay, the metabolic effects of the glutaminase inhibitor became robust. One of the most significant results of this study is the metabolic heterogeneitydisplayed across the cell line panel under basal conditions. Differences in themetabolic functioning of the cell lines were observed in terms of both theirbioenergetic and metabolic profile. The amount of respiration attributed tooxidative phosphorylation differed between cell lines and respiratory capacity wasattenuated in most cells. However, the rate of glycolysis was similar betweencell lines in this assay. These results suggest that the Warburg effect arisesthrough a greater diversity of mechanisms than traditionally assumed, involvingvarious combinations of changes in the expression of glycolytic and mitochondrialmetabolic enzymes. The effects of GLS1 inhibition on cellular bioenergetics and metabolism alsodiffered between cell lines, even between resistant cell lines, indicating that theremay also be a diversity of resistance mechanisms. The metabolomic response ofcell lines to treatment suggests potential resistance mechanisms through metabolicadaptation or through the prior differences in the metabolic function of resistantcell lines. Part of the metabolome response to GLS1 inhibition was quite specificfor sensitive cells, with high concentrations of IMP as the strongest marker. Our results suggest that the metabolome is a significant player in what determinesthe response of cells to metabolic inhibitors, that its responses differ between cancercells, that responses are not beyond systems understanding, and that thereforethe metabolome should be taken into account in the design of and therapy withanti-cancer drugs.

Bien qu’au 11ème rang des cancers les plus fréquents et au 12ème rang des cancers les plus mortels, le mélanome reste un problème médical majeur préoccupant. En effet, cette pathologie, au stade métastatique, reste réfractaire à la chimiothérapie et aux thérapies ciblées. Un certain nombre d’arguments définissent la résistance à l’apoptose comme un point crucial dans l’échec aux traitements anti-cancéreux. Ces mécanismes de résistance et chimiorésistance spécifiques aux mélanomes, déclenchés en réponse aux traitements traditionnels, sont la conséquence d’une dérégulation des voies apoptotiques suite à l’activation des protéines anti-apoptotiques, l’inactivation des protéines pro-apoptotiques avec renforcement des signaux de survie (voies de survie PI3K/Akt, NF-κB et MAPK/ERK). Une étude effectuée sur la lignée murine de mélanome B16-F0 a introduit la mélanogenèse comme une forme de résistance à l’apoptose induite par l’acide ursolique (AU), un triterpène pentacyclique d’origine naturelle ; ainsi les cellules entrant en apoptose sont capables de déclencher une résistance qui se manifeste par une surproduction de la mélanine tout en retardant la mort cellulaire. D’autres études ont montré l’implication de la COX-2 dans un mécanisme de résitance à l’apoptose dans plusieurs types de cancers dans le but de retarder leur mort cellulaire. Dans cette optique, nous nous sommes intéressés à étudier l’implication de la mélanogenèse et de la voie COX-2/PGE2 dans la résistance à l’apoptose dans le mélanome et plus précisément dans un modèle d’apoptose induite par l’AU sur la lignée humaine de mélanome M4Beu. Par la suite, nous avons décrit une interaction probable entre ces deux voies distinctes, la mélanogenèse et la voie COX-2/PGE2. Dans un autre contexte, nous avons montré que l’AU inhibe les voies de survie PI3K/Akt et ERK1/2, ce qui favorise ses effets pro-apoptotique et anti-prolifératif. Notre étude permet de mieux explorer les mécanismes de résistance spécifiques aux mélanomes tout en suggérant l’effet bénéfique de l’AU comme adjuvant naturel aux traitements chimio-thérapeutiques traditionnels. / Despite the deployment of targeted therapies, the incidence and mortality rates of cutaneous melanoma is increasing very fast making it a pre-eminent public health threat. Previously, we had showed that B16-F0 murine melanoma cells undergoing apoptosis are able to delay their own death induced by ursolic acid (UA), a natural pentacyclic triterpenoid compound. We had demonstrated that tyrosinase and TRP-1 up-regulation in apoptotic cells and the subsequent production of melanin were implicated in an apoptosis resistance mechanism. Several resistance mechanisms to apoptosis have been characterized in melanoma such as hyperactivation of DNA repair mechanisms, drug efflux systems, and reinforcement of survival signals (PI3K/Akt, NF-κB and MAPK/ERK pathways). Otherwise, other mechanisms of apoptosis resistance involving different proteins, such as cyclooxygenase-2 (COX-2), have been described in many cancer types. In this study, we demonstrated the involvement of melanogenesis and COX-2/PGE2 pathway in resistance to UA-induced apoptosis in human M4Beu melanoma cells. Then, we established the evidence that an interaction exists between these two pathways by investigating on the one hand the effect of inhibiting melanogenesis by N-phenylthiourea (PTU) on COX-2 expression and its product PGE2, and on the other hand the effect of inhibiting COX-2 activity using NS-398 on tyrosinase expression and melanin production. Furthermore, we showed that anti-proliferative and proapoptotic effects of UA were mediated through modulation of multiple signaling pathways including Akt and ERK-1/2 proteins. Our study not only uncovers underlying molecular mechanisms of UA action in human melanoma cancer cells but also suggest its great potential as an adjuvant in treatment and cancer prevention.

Předkládaná diplomová práce se zabývá stavbou živých živočišných buněk a jejich odezvou na mechanické zatěžování. Zobecněným zaměřením práce je popis mechanického chování buňky nejenom ve fyziologickém, ale i v patologickém stavu. Výchozím předpokladem pro úspěšné řešení zadané úlohy je vysoce interdisciplinární přístup kombinující výpočtové přístupy mechaniky těles (v~tomto případě metodu konečných prvků) s lékařským výzkumem. Nejdůležitějším bodem při tvorbě výpočtového modelu, pomocí něhož je možné aproximovat chování živé buňky při zatížení, je zejména identifikace mechanicky významných komponent a~jejich materiálových parametrů. V tomto případě jsou jako mechanicky význačné identifikovány spojité součásti jádro, membrána a cytoplazma, které jsou nově propojeny s prvky diskrétními (mitochondriální sítí) v hybridním modelu, jehož platnost je ověřena pomocí experimentálních dat. Tento model slouží jako podklad k vyhodnocení míry vlivu mitochondrií na celkovou tuhost buňky.

Les inhibiteurs de poly(ADP-ribose) polymérase (PARPi) ciblent sélectivement les cellules porteuses de défauts des voies de réparation de l’ADN tels que les mutations de BRCA1/2 et les défauts d’ERCC1. Sur le plan clinique, plusieurs PARPi ont été approuvés pour le traitement des cancers BRCA-mutés ou platine-sensibles du sein et de l’ovaire, et des essais cliniques sont en cours pour évaluer l’efficacité des PARPi dans le cancer bronchique non-à-petites cellules (CBNPC) platine-sensible. Alors que les PARPi ont un fort potentiel thérapeutique dans les cancers comportant des défauts de réparation de l’ADN, de plus en plus d’essais cliniques évaluent également l’efficacité de ces médicaments en combinaison avec les « inhibiteurs d’immune checkpoints » (ICI) dans diverses populations de patients. Dans ce contexte, il est essentiel de mieux comprendre comment les PARPi modulent la réponse immunitaire anti-tumorale, et d’étudier le potentiel immunologique inhérent de ces médicaments.Dans cette étude, nous avons établi que les cellules de CBNPC déficientes en ERCC1 expriment fortement la signature interféron (IFN) de type I, et que les tumeurs de CBNPC ayant une faible expression d’ERCC1 ont un infiltrat lymphocytaire renforcé. En utilisant des lignées cellulaires isogéniques et des xénogreffes dérivées de patients, nous avons montré que plusieurs PARPi, notamment l’olaparib et le rucaparib, ont des propriétés immunomodulatrices dans les modèles de CBNPC ERCC1-déficients et de cancers du sein triple-négatifs (CSTN) BRCA1-mutés. D’un point de vue mécanistique, les PARPi génèrent des fragments d’ADN cytoplasmiques ayant les caractéristiques de micronoyaux ; ceux-ci activent la voie cGAS/STING et déclenchent une réponse IFN de type I, associée à la sécrétion de la cytokine CCL5. De manière importante, ces effets sont largement diminués dans les cellules de CSTN BRCA1-révertantes et les cellules de CBNPC ré-exprimant ERCC1, ce qui suggère que les défauts de réparation de l’ADN amplifient les phénotypes immunitaires associés au traitement par PARPi. En outre, ces effets sont totalement abrogés dans les cellules de CSTN PARP1-neutralisées, ce qui confirme que les phénotypes observés dépendent d’un effet spécifique des PARPi sur leur cible.Au-delà de leur potentiel d’activation d’une immunité spécifique des cellules cancéreuses via cGAS/STING et la signalisation IFN de type I, nous avons également constaté que les PARPi potentialisent les effets inducteurs de l‘IFN de type II sur l’expression de PD-L1 dans des lignées cellulaires et cellules tumorales fraîches de patients CBNPC, surtout en présence de défauts d’ERCC1. De plus, nous avons montré que certains PARPi, utilisés à des concentrations létales, activent de manière indépendante les éléments moléculaires clés de la mort cellulaire immunogénique, dont l’exposition de la calréticuline à la surface des cellules cancéreuses, la sécrétion d’ATP et le relargage d’HMGB1 en grandes quantités dans le milieu extracellulaire.Dans l’ensemble, ces données précliniques suggèrent que les PARPi ont des propriétés immunomodulatrices intrinsèques qui participent à l’activation de réponses immunitaires anti-tumorales ; ce potentiel pourrait être exploité cliniquement en combinaison avec les ICI dans des populations adéquatement sélectionnées au plan moléculaire. / Poly(ADP-ribose) polymerase inhibitors (PARPi) selectively target cancer cells with DNA repair deficiencies such as BRCA1/2 mutations or ERCC1 defects. Clinically, several PARPi are currently approved for the treatment of BRCA-mutant or platinum-sensitive advanced ovarian and breast cancers, and ongoing clinical trials are investigating the efficacy of PARPi in platinum-sensitive Non-Small Cell Lung Cancer (NSCLC). While PARPi constitute potent targeted therapies for the treatment of DNA repair-deficient malignancies, an increasing number of clinical trials are also evaluating their efficacy in combination with immune checkpoint inhibitor (ICI) in various populations. In this context, it is of critical importance to better understand how PARPi might modulate immune responses against cancer, and to investigate the inherent immunological potential of these agents.In this study, we show that ERCC1-defective NSCLC cells exhibit an enhanced type I interferon (IFN) transcriptomic signature and that low ERCC1 expression correlates with increased lymphocytic infiltration in human NSCLC tumours. Using isogenic cell lines and patient-derived xenografts, we further demonstrate that several clinical PARPi, including olaparib and rucaparib, display cell-autonomous immunomodulatory properties in ERCC1-defective NSCLC and BRCA1-mutant triple-negative breast cancer (TNBC) models. Mechanistically, PARPi generate cytoplasmic chromatin fragments with micronuclei characteristics; this activates the cGAS/STING pathway and elicits downstream type I IFN signalling and CCL5 secretion. Importantly, these effects are suppressed in BRCA1-reverted TNBC cells and ERCC1-rescued NSCLC cells, suggesting that DNA repair defects exacerbate the innate immunity-related phenotypes triggered by PARPi. Similarly, these effects are totally abrogated in PARP1-null TNBC cells, supporting the on-target effect of PARPi in mediating such phenotypes. Besides this potential to activate tumour cell-autonomous immunity through cGAS/STING and type I IFN signalling, we also observed that PARPi synergize with type II IFN to induce PD-L1 expression in NSCLC cell lines and fresh patient tumour cells, especially in the ERCC1-deficient setting. Moreover, we show that lethal concentrations of some PARPi independently activate the key damage-associated molecular patterns dictating the immunogenicity of cancer cell death, including calreticulin exposure at the tumour cell surface, ATP secretion and HMGB1 release in the extracellular compartment.Together, these preclinical data suggest that PARPi have intrinsic immunomodulatory properties that activate anti-cancer immune responses; this could be exploited clinically in combination with ICI in appropriately molecularly-selected populations.

Objectives: To investigate the effects of serotonin and melatonin (MLT) on the regulation of malignant growth and the activity of serotonin receptors (5HTR1a/-1b) in prostate cancer (PCa) cell lines. Materials and Methods: In four PCa cell lines (LNCaP, 22RV1, PC3, DU145) and two reference cell lines 5HTR1a and -1b, relative mRNA expression levels were assessed. Different serotonin and MLT receptor agonists and antagonists were used in stimulation and inhibition experiments. Results: mRNA expression of 5HTR1b was higher than that of 5HTR1a in all PCa cell lines. Serotonin showed a significant growth stimulatory effect in all PCa lines. The 5HTR1a and -1b agonists/antagonists did not significantly affect viability. MLT inhibited viability only in PC3 cells. Similarly, the 5HTR1a antagonist induced apoptotic changes in PC3 cells only at 10–4M, while the 5HTR1b antagonist induced necrosis at 10–4M in all cell lines. Cell cycle alterations were seen in PC3 and DU145 cells under the influence of the 5HTR1a antagonist. Conclusions: Serotonin receptor antagonists and agonists as well as MLT influence viability and apoptosis of PCa cell lines at supraphysiologic concentrations. In contrast to other reports, our results do not support a regulatory role of serotonin or MLT receptor activation or inhibition in PCa growth. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Background: Pancreatic cancer is one of the leading causes of cancer-related death. Using DNA gene expression analysis based on a custom made Affymetrix cancer array, we investigated the expression pattern of both primary and established pancreatic carcinoma cell lines. Methods: We analyzed the gene expression of 5 established pancreatic cancer cell lines (AsPC-1, BxPC-3, Capan-1, Capan-2 and HPAF II) and 5 primary isolates, 1 of them derived from benign pancreatic duct cells. Results: Out of 1,540 genes which were expressed in at least 3 experiments, we found 122 genes upregulated and 18 downregulated in tumor cell lines compared to benign cells with a fold change > 3. Several of the upregulated genes (like Prefoldin 5, ADAM9 and E-cadherin) have been associated with pancreatic cancer before. The other differentially regulated genes, however, play a so far unknown role in the course of human pancreatic carcinoma. By means of immunohistochemistry we could show that thymosin [β-10 (TMSB10), upregulated in tumor cell lines, is expressed in human pancreatic carcinoma, but not in non-neoplastic pancreatic tissue, suggesting a role for TMSB10 in the carcinogenesis of pancreatic carcinoma. Conclusion: Using gene expression profiling of pancreatic cell lines we were able to identify genes differentially expressed in pancreatic adenocarcinoma, which might contribute to pancreatic cancer development. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

A major challenge in designing cancer therapies is the induction of cancer cell apoptosis, although activation of intrinsic apoptotic pathways by targeting gold nanoparticles to mitochondria is promising. We report an in vitro procedure targeting mitochondria with conjugated gold nanoparticles and investigating effects on apoptosis induction in the human breast cancer cell line Jimt-1. Gold nanoparticles were conjugated to a variant of turbo green fluorescent protein (mitoTGFP) harbouring an amino-terminal mitochondrial localization signal. Au nanoparticle conjugates were further complexed with cationic maltotriose-modified poly(propylene imine) third generation dendrimers. Fluorescence and transmission electron microscopy revealed that Au nanoparticle conjugates were directed to mitochondria upon transfection, causing partial rupture of the outer mitochondrial membrane, triggering cell death. The ability to target Au nanoparticles into mitochondria of breast cancer cells and induce apoptosis reveals an alternative application of Au nanoparticles in photothermal therapy of cancer.