Inhibition of AKR1B10-mediated metabolism of daunorubicin as a novel off-target effect for the Bcr-Abl tyrosine kinase inhibitor dasatinib.

Bcr-Abl tyrosine kinase inhibitors significantly improved Philadelphia chromosome-positive leukaemia therapy. Apart from Bcr-Abl kinase, imatinib, dasatinib, nilotinib, bosutinib and ponatinib are known to have additional off-target effects that might contribute to their antitumoural activities. In our study, we identified aldo-keto reductase 1B10 (AKR1B10) as a novel target for dasatinib. The enzyme AKR1B10 is upregulated in several cancers and influences the metabolism of chemotherapy drugs, including anthracyclines. AKR1B10 reduces anthracyclines to alcohol metabolites that show less antineoplastic properties and tend to accumulate in cardiac tissue. In our experiments, clinically achievable concentrations of dasatinib selectively inhibited AKR1B10 both in experiments with recombinant enzyme (Ki = 0.6 µM) and in a cellular model (IC50 = 0.5 µM). Subsequently, the ability of dasatinib to attenuate AKR1B10-mediated daunorubicin (Daun) resistance was determined in AKR1B10-overexpressing cells. We have demonstrated that dasatinib can synergize with Daun in human cancer cells and enhance its therapeutic effectiveness. Taken together, our results provide new information on how dasatinib may act beyond targeting Bcr-Abl kinase, which may help to design new chemotherapy regimens, including those with anthracyclines.

Olaparib Synergizes the Anticancer Activity of Daunorubicin via Interaction with AKR1C3.

Olaparib is a potent poly (ADP-ribose) polymerase inhibitor currently used in targeted therapy for treating cancer cells with BRCA mutations. Here we investigate the possible interference of olaparib with daunorubicin (Daun) metabolism, mediated by carbonyl-reducing enzymes (CREs), which play a significant role in the resistance of cancer cells to anthracyclines. Incubation experiments with the most active recombinant CREs showed that olaparib is a potent inhibitor of the aldo-keto reductase 1C3 (AKR1C3) enzyme. Subsequent inhibitory assays in the AKR1C3-overexpressing cellular model transfected human colorectal carcinoma HCT116 cells, demonstrating that olaparib significantly inhibits AKR1C3 at the intracellular level. Consequently, molecular docking studies have supported these findings and identified the possible molecular background of the interaction. Drug combination experiments in HCT116, human liver carcinoma HepG2, and leukemic KG1α cell lines showed that this observed interaction can be exploited for the synergistic enhancement of Daun's antiproliferative effect. Finally, we showed that olaparib had no significant effect on the mRNA expression of AKR1C3 in HepG2 and KG1α cells. In conclusion, our data demonstrate that olaparib interferes with anthracycline metabolism, and suggest that this phenomenon might be utilized for combating anthracycline resistance.

SYNTHESIS AND AMINOPEPTIDASE N INHIBITING ACTIVITY OF 3-(NITROPHENOXYMETHYL)-[1,3,2]DIOXABOROLAN-2-OLS AND THEIR OPEN ANALOGUES.

Aminopeptidase N (APN) represents a class of zinc metallopeptidases with broad substrate specifity. This enzyme is involved in control of angioneogenesis in cancer and microvascular conditions. It also serves as a superficial cellular receptor that enables attachment of some viruses including coronaviruses to the host cell. APN takes part also in metabolism of some important neuropeptides. That is why APN can be a promising therapeutic target and compounds which influence its activity interesting potential drugs. Here, synthesis of compounds which in most contain 3-phenoxypropan-1,2 diol moiety and evaluation of their inhibition activity against APN is described. 4-[1-, 2- and 3-(Nitrophenoxymethyl)]-[1,3,2]dioxaborolan-2-ols are novel compounds which have never been previously reported in the literature. 3-(Aminophenoxy)propyl-1,2-diols revealed greater activity than both 3-(nitrophenoxy)propyl-1,2-diols and 3-(nitrophenoxymethyl)-[1,3,2]dioxaborolan-2-ols. A QSAR study revealed a linear correlation between lipophilicity and inhibition activity.