Isocitrate dehydrogenase 2 inhibitor enasidenib synergizes daunorubicin cytotoxicity by targeting aldo-keto reductase 1C3 and ATP-binding cassette transporters

Targeting mutations that trigger acute myeloid leukaemia (AML) has emerged as a refined therapeutic approach in recent years. Enasidenib (Idhifa) is the first selective inhibitor of mutated forms of isocitrate dehydrogenase 2 (IDH2) approved against relapsed/refractory AML. In addition to its use as monotherapy, a combination trial of enasidenib with standard intensive induction therapy (daunorubicin + cytarabine) is being evaluated. This study aimed to decipher enasidenib off-target molecular mechanisms involved in anthracycline resistance, such as reduction by carbonyl reducing enzymes (CREs) and drug efflux by ATP-binding cassette (ABC) transporters. We analysed the effect of enasidenib on daunorubicin (Daun) reduction by several recombinant CREs and different human cell lines expressing aldo-keto reductase 1C3 (AKR1C3) exogenously (HCT116) or endogenously (A549 and KG1a). Additionally, A431 cell models overexpressing ABCB1, ABCG2, or ABCC1 were employed to evaluate enasidenib modulation of Daun efflux. Furthermore, the potential synergism of enasidenib over Daun cytotoxicity was quantified amongst all the cell models. Enasidenib selectively inhibited AKR1C3-mediated inactivation of Daun in vitro and in cell lines expressing AKR1C3, as well as its extrusion by ABCB1, ABCG2, and ABCC1 transporters, thus synergizing Daun cytotoxicity to overcome resistance. This work provides in vitro evidence on enasidenib-mediated targeting of the anthracycline resistance actors AKR1C3 and ABC transporters under clinically achievable concentrations. Our findings may encourage its combination with intensive chemotherapy and even suggest that the effectiveness of enasidenib as monotherapy against AML could lie beyond the targeting of mIDH2.

Dried blood spot as an alternative sample for screening of fatty acids, amino acids, and keto acids metabolism in humans

The dried blood spot is a simple and non-invasive sample collection technique allowing self-collection at home. It can be used as an alternative sample for the screening of metabolism in humans since changes in the levels of some fatty acids, amino acids, and keto acids can be associated with metabolic disorders (for example diabetes mellitus). In this study we optimized three different methods that are sensitive enough for the determination of above-mentioned analytes from a small volume of a biological material in dried blood spot. In total 20 amino acids, 5 keto acids, and 24 fatty acids were determined. This sample technique was applied to prepare samples from 60 individuals by a finger prick. Samples were analysed with chromatographic methods and acquired data were statistically evaluated. Even though most analytes were higher in men, only 5 amino acids, 3 keto acids and 8 fatty acids showed significant gender-dependency (α = 0.05). Asparagine, serine, α- and γ-linolenic acids showed significant age-dependency (α = 0.05). The most of statistically significant correlations were positive and were found within one category. This work shows that because of many benefits, the dried blood spot sample could be a good alternative to whole blood sample collection for the screening of metabolism in humans in general or in individualised medicine. The chromatographic methods can be used in the next research, for example to set reference range or plasma-correction factors (various aspects as age or gender should be considered).

Gas Chromatographic-Mass Spectrometric Method for the Simultaneous Determination of Resveratrol Isomers and 2,4,6-Trihydroxyphenanthrene in Red Wines Exposed to UV-Light

Resveratrol (3,5,4'-trihydroxystilbene) is one of the most abundant polyphenols in red grapes, and red wine represents one of the most important dietary sources of this compound. Although its beneficial properties on human health have been widely investigated over the last 30 years, very little is known about its derivatives. Resveratrol can indeed undergo glycosylation, oligomerization and, upon UV-light exposure, it can isomerize from the trans-to the cis-isomer, which can further cyclize to 2,4,6-trihydroxyphenanthrene (THP). Although the effects of THP on human health are not yet known, being a polycyclic aromatic hydrocarbon, it can be potentially harmful. Because no data about THP occurrence in plant food and beverages are available, a simple procedure based on liquid-liquid extraction and gas chromatography-mass spectrometry has been developed and validated for the simultaneous qualitative and quantitative analysis of trans-resveratrol, cis-resveratrol, and THP in red wine, before and after UV-light exposure.