Trotz intensiver Forschung stellen bis heute maligne Tumorerkrankungen die zweithäufigste Todesursache in Industrienationen dar. Der Biochemiker Otto Warburg postulierte bereits vor 90 Jahren den nicht zu unterschätzenden Einfluss des Kohlenhydrat-Stoffwechsels in der malignen Entartung von Zellen. Als Nebenprodukt der Glykolyse entsteht das toxische Methylglyoxal, welches durch das nahezu ubiquitär vorkommende Glyoxalase-System neutralisiert werden kann. Speziell für die Glyoxalase 1 (Glo1) wird eine entscheidende Rolle in der Tumorgenese/-progression vermutet. In dieser Arbeit konnte basierend auf shRNA-vermittelten Glo1-knockdown Versuchen eine inhibitorische Rolle der Glo1 in der Ausbildung maligner Tumoreigenschaften wie Invasion, Migration und Proliferation in Astrozytomzellen gezeigt werden. Weiterhin wurde ein monoklonaler muriner Antikörper gegen die humane Isoform der Glo1 generiert und dessen Spezifität und Sensitivität bestätigt. Immunhistochemische Untersuchungen in primären Hirntumorgeweben offenbarten wiederum keine direkte Korrelation zwischen WHO-Stadium und Expressionsgrad bzw. subzellulärer Lokalisation der Glo1. Expressionsanalysen in malignen Tumorzelllinien unterschiedlicher Genese demonstrierten, dass besonders fortgeschrittene, therapieresistente Mamma- und Prostatakarzinomzellen niedrige Glo1-Level aufweisen. Basierend auf diesen Ergebnissen wurde ein zuvor identifizierter Inhibitor der Glo1 – das Phytotherapeutikum Curcumin – auf einen potentiellen Effekt in der Tumorprogression untersucht. Curcumin demonstrierte eine signifikante Reduktion der Proliferationsrate aller getesteter Tumorzelllinien. Darüber hinaus konnte ein in vivo -Tumormodell etabliert werden, mit welchem eine signifikante Tumorreduktion durch intraperitoneale und orale Applikation von Curcumin in Her-2/neu überexprimierenden Fibroblastenzellen erzielt wurde.

Given that chronic hyperglycemia generates toxic methylglyoxal, the detoxifying effect of glyoxalase-1 (Glo1) on chronic hyperglycemia induced explant-derived cardiac stem cell (EDC) dysfunction was investigated. Wildtype (WT) and Glo1 over-expressing (Glo1TG) mice with or without streptozotocin treatment were studied. Hyperglycemia reduced overall culture yields while increasing the reactive dicarbonyl content within WT mice. These intrinsic cell changes reduced the angiogenic potential and nanoparticle production by hyperglycemic EDCs while promoting cell senescence. Compared to transplant of normoglycemic WT EDCs, hyperglycemic EDCs reduced myocardial function following infarction by inhibiting angiogenesis and endogenous repair mechanisms. In contrast, EDCs from hyperglycemic Glo1TG mice decreased reactive dicarbonyl content and restored culture yields. Intramyocardial injection of hyperglycemic Glo1TG EDCs also boosted myocardial function and reduced scarring. These findings demonstrate that, while chronic hyperglycemia decreases the regenerative performance of EDCs, over-expression of Glo1 reduces dicarbonyl stress and rescues the adverse effects of hyperglycemia on EDCs.

The energy metabolism of most tumor cells relies on aerobic glycolysis (Warburg effect) characterized by an increased glycolytic flux that is accompanied by the increased formation of the cytotoxic metabolite methylglyoxal (MGO). Consequently, the rate of detoxification of this reactive glycolytic byproduct needs to be increased in order to prevent deleterious effects to the cells. This is brought about by an increased expression of glyoxalase 1 (GLO1) that is the rate-limiting enzyme of the MGO-detoxifying glyoxalase system. Here, we overexpressed GLO1 in HEK 293 cells and silenced it in MCF-7 cells using shRNA. Tumor-related properties of wild type and transformed cells were compared and key glycolytic enzyme activities assessed. Furthermore, the cells were subjected to hypoxic conditions to analyze the impact on cell proliferation and enzyme activities. Our results demonstrate that knockdown of GLO1 in the cancer cells significantly reduced tumor-associated properties such as migration and proliferation, whereas no functional alterations where found by overexpression of GLO1 in HEK 293 cells. In contrast, hypoxia caused inhibition of cell growth of all cells except of those overexpressing GLO1. Altogether, we conclude that GLO1 on one hand is crucial to maintaining tumor characteristics of malignant cells, and, on the other hand, supports malignant transformation of cells in a hypoxic environment when overexpressed.

The energy metabolism of most tumor cells relies on aerobic glycolysis (Warburg effect) characterized by an increased glycolytic flux that is accompanied by the increased formation of the cytotoxic metabolite methylglyoxal (MGO). Consequently, the rate of detoxification of this reactive glycolytic byproduct needs to be increased in order to prevent deleterious effects to the cells. This is brought about by an increased expression of glyoxalase 1 (GLO1) that is the rate-limiting enzyme of the MGO-detoxifying glyoxalase system. Here, we overexpressed GLO1 in HEK 293 cells and silenced it in MCF-7 cells using shRNA. Tumor-related properties of wild type and transformed cells were compared and key glycolytic enzyme activities assessed. Furthermore, the cells were subjected to hypoxic conditions to analyze the impact on cell proliferation and enzyme activities. Our results demonstrate that knockdown of GLO1 in the cancer cells significantly reduced tumor-associated properties such as migration and proliferation, whereas no functional alterations where found by overexpression of GLO1 in HEK 293 cells. In contrast, hypoxia caused inhibition of cell growth of all cells except of those overexpressing GLO1. Altogether, we conclude that GLO1 on one hand is crucial to maintaining tumor characteristics of malignant cells, and, on the other hand, supports malignant transformation of cells in a hypoxic environment when overexpressed.

Diabetes is a chronic disease with high prevalence and significant morbidity. Chronic changes in the wall of small and large vessels lead to main diabetes complications. Apart from long- term hyperglycemia, several factors are involved in the development of diabetes vasculopathy. The aim of this work was to describe new early biomarkers of these vascular changes, to identify risky patients. Alongside, gene polymorphisms involved in protective pathways of glucose metabolism were studied. In three human studies with Type 1 (T1D) and Type 2 (T2D) diabetes patients special biochemical parameters of receptor for advanced glycation endproducts (RAGE) and its ligands, deglycation enzyme glyoxalase 1 (GLO1) and fructosamine 3-kinase (FN3K) gene polymorphisms were analyzed. Non-invasive measurement of glycation by skin autofluorescence (SAF) was assessed in all subjects. Soluble RAGE, HMGB1 and endothelial dysfunction markers were increased in patients with diabetes as compared with controls, however the differences between T1D and T2D were not significant. For the first time, an association between FN3K (rs1056534) and (rs3848403) polymorphism and sRAGE concentration in diabetes was shown. GLO1 (rs4746) polymorphism was associated with changes in endothelial dysfunction. Patients with diabetes had higher...