Open Access

Cancer cells, including leukemic cells, can react to therapeutic treatment by altering their metabolic phenotype (“metabolic reprogramming”) to keep their accelerated proliferative state, eventually becoming resistant to the treatment. There is an increasing amount of evidence indicating that metabolic reprogramming is one of the key mechanisms of acquisition of drug resistance by cancer cells. In agreement, several metabolic studies targeting leukaemia and specifically acute myeloid leukaemia (AML) and chronic myeloid leukaemia (CML), have been conducted over the last decades. However, there is still a lack of understanding the metabolic features of both AML and CML leukaemia specially in the acquisition of drug resistance, that is needed for unveiling novel and effective treatments for resistant and non-resistant patients. Therefore, the main objective of this thesis was to investigate the rewiring of cell metabolism occurring in the process of acquisition of resistance to conventional therapeutic treatments in AML and CML malignancies. Next, by revealing this metabolic rewiring, we intended to highlight potential metabolic and non-metabolic targets that could be exploited to overcome resistance to treatments. To this end, we have performed a comprehensive and comparative multi-OMIC study to analyse the links between the metabolic reprogramming and the resistance acquisition of THP-1 and HL-60 AML cell models sensitive or resistant to cytarabine (AraC) and doxorubicin (Dox), and of KU812 CML cell model sensitive or resistant to imatinib, all under normoxic (21% O2) and hypoxic (1% O2) conditions. The results of this thesis are divided into two chapters. On the one hand, in Chapter 1, the multi-OMIC study performed in AML parental and resistant cells unveiled that the acquisition of AraC resistance causes the reprogramming of the glucose metabolism of THP-1 and HL-60 cells by increasing the glycolytic flux whereas it is not associated with an alteration in the mitochondrial respiration. Moreover, our results also exhibited a possible disfunction of ETC complex I as well as alterations in glutamine and serine-glycine-1C metabolism in AML cells that display a more active mitochondrial metabolism. Moreover, we have also identified that the acquisition of Dox resistance causes alterations in the glucose and amino acid metabolism. Importantly, we have observed an important loss of mitochondrial respiration capacity of AML cells resistant to Dox chemotherapeutic drug, which constitutes a potential metabolic vulnerability that can be exploited for the treatment of AML patients resistant to Dox. On the other hand, in Chapter 2 is shown that the acquisition of imatinib resistance causes the reprogramming of glucose metabolism by enhancing the glycolytic flux, PPP, and glycogen metabolism, thus highlighting these metabolic pathways as potential metabolic weaknesses of KU812 cells resistant to imatinib. Moreover, we have observed a high metabolic plasticity of KU812 cells resistant to imatinib which includes the orchestration of many metabolic routes associated with the amino acid metabolism. Importantly, the CML multi-OMIC study has also unveiled an enhanced mitochondrial respiration capacity, which constitutes another potential vulnerability that can be exploited to overcome imatinib resistance. Finally, both AML and CML multi-OMIC studies have allowed us to propose and/or validate different metabolic and non-metabolic targets. In this regard, in this thesis we have identified and validated a battery of single-hit inhibitions that were able to reduce the cell viability of both parental and resistant AML and CML cells. Finally, we have confirmed that the repurposing of Dox chemotherapeutic drug counteracts the imatinib resistance in the KU812 cells resistant to imatinib.

The early acquisition of Greek compounds by two monolingual Greek girls aged between 1;8 and 3;0 years is studied in a usage-based theoretical framework. Special importance is attached to the morphological structure of Greek compound types occurring in child speech and child-directed speech. Greek nominal compound formation does not consist in the mere juxtaposition of words or roots, but involves stems as well as a compound marker. Major questions addressed are the transparency of compounds and productive nominal compound formation. Evidence for productivity of nominal compound formation has been found with only one of the two girls. In contrast to other languages, neoclassical nominal compounds by far exceed endocentric subordinative ones tokenwise in Greek child speech and child-directed speech providing evidence of entrenchment rather than productivity. In a cross-linguistic comparison it is shown that, in spite of the fact that both Standard Modern Greek and German are rich in nominal compounds, their number is much more limited in Greek than in German child speech. An explanation for this apparent paradox is provided by an onomasiological approach to lexical typology based on a sample list of nominal compounds occurring in German child language and their Greek translational equivalents. It has been found that while use of nominal compounds is common in colloquial German including child-centered situations, it is more typical of Greek formal than colloquial registers.

In the Hittite phonological system there was a labialized velar fricative /xw/ beside the plain velar fricative /x/ parallel to the opposition between the velar stops /kw/ and /k/. The frequent syllable /xwa/ was spelled either hu-(u) or hu-wa. Evidence from the frequency of words with initial hu in the lexicon, from spelling variations and from ablaut alternations is presented to demonstrate the existence of /xw/. It is suggested that Hittite /xw/ regularly corresponds to the reflexes of *w in the non-Anatolian Indo-European languages.

Unter der Signatur VI/273 befinden sich in der Stiftsbibliothek Kremsmünster acht Pergamentstreifen unterschiedlicher Breite (...) und unregelmäßiger Länge (...). Es handelt sich um die Reste von zwei Pergamentdoppelblättern (...). Die Schrift gehört wohl noch dem 12. Jahrhundert an, sie macht jedenfalls einen altertümlicheren Eindruck als die der Göttinger Bruchstücke, der bisher ältesten Überlieferung des Lucidarius (...). Inhaltlich erweist sich die vorliegende Textpartie zugehörig zum 3. Buch des Lucidarius (...).