FLT3 kinase is a potential drug target in acute myeloid leukemia (AML). Patients with FLT3 mutations typically have higher relapse rates and worse outcomes than patients without FLT3 mutations. In this study, we investigated the suitability of various heterocycles as central cores of FLT3 inhibitors, including thieno[3,2-d]pyrimidine, pyrazolo[1,5-a]pyrimidine, imidazo[4,5-b]pyridine, pyrido[4,3-d]pyrimidine, and imidazo[1,2-b]pyridazine. Our assays revealed a series of imidazo[1,2-b]pyridazines with high potency against FLT3. Compound 34f showed nanomolar inhibitory activity against recombinant FLT3-ITD and FLT3-D835Y (IC50 values 4 and 1 nM, respectively) as well as in the FLT3-ITD-positive AML cell lines MV4-11, MOLM-13, and MOLM-13 expressing the FLT3-ITD-D835Y mutant (GI50 values of 7, 9, and 4 nM, respectively). In contrast, FLT3-independent cell lines were much less sensitive. In vitro experiments confirmed suppression of FLT3 downstream signaling pathways. Finally, the treatment of MV4-11 xenograft-bearing mice with 34f at doses of 5 and 10 mg/kg markedly blocked tumor growth without any adverse effects.

• MeSH
• akutní myeloidní leukemie * patologie   MeSH
• apoptóza MeSH
• inhibitory proteinkinas farmakologie   terapeutické užití   MeSH
• lidé MeSH
• mutace MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• protinádorové látky * farmakologie   terapeutické užití   MeSH
• pyridaziny * farmakologie   terapeutické užití   MeSH
• pyrimidiny farmakologie   MeSH
• tyrosinkinasa 3 podobná fms genetika   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• FLT3 protein, human MeSH Prohlížeč
• inhibitory proteinkinas MeSH
• protinádorové látky * MeSH
• pyridazine MeSH Prohlížeč
• pyridaziny * MeSH
• pyrimidiny MeSH
• tyrosinkinasa 3 podobná fms MeSH

Therapy of FLT3-positive acute myeloid leukemia still remains complicated, despite the availability of newly approved kinase inhibitors. Various strategies to avoid the reduced efficacy of therapy have been explored, including the development of dual targeting compounds, which inhibit FLT3 and another kinase necessary for the survival and proliferation of AML cells. We have designed new 2,7,9-trisubstituted 8-oxopurines as FLT3 inhibitors and report here the structure-activity relationship studies. We demonstrated that substituents at positions 7 and 9 modulate activity between CDK4 and FLT3 kinase, and the isopropyl group at position 7 substantially increased the selectivity toward FLT3 kinase, which led to the discovery of compound 15a (9-cyclopentyl-7-isopropyl-2-((4-(piperazin-1-yl)phenyl)amino)-7,9-dihydro-8H-purin-8-one). Cellular analyses in MV4-11 cells revealed inhibition of autophosphorylation of FLT3 kinase in nanomolar doses, including the suppression of downstream STAT5 and ERK1/2 phosphorylation. We also describe mechanistic studies in cell lines and activity in a mouse xenograft model in vivo.

• Klíčová slova
• FLT3, acute myeloid leukemia, cyclin-dependent kinase, inhibitor, purine,
• MeSH
• akutní myeloidní leukemie * farmakoterapie   MeSH
• apoptóza MeSH
• fosforylace MeSH
• inhibitory proteinkinas terapeutické užití   MeSH
• lidé MeSH
• mutace MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• proliferace buněk MeSH
• tyrosinkinasa 3 podobná fms MeSH
• vztahy mezi strukturou a aktivitou MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• FLT3 protein, human MeSH Prohlížeč
• inhibitory proteinkinas MeSH
• tyrosinkinasa 3 podobná fms MeSH

We report 31 new compounds designed, synthesized and evaluated on Bcr-Abl, BTK and FLT3-ITD as part of our program to develop 2,6,9-trisubstituted purine derivatives as inhibitors of oncogenic kinases. The design was inspired by the chemical structures of well-known kinase inhibitors and our previously developed purine derivatives. The synthesis of these purines was simple and used a microwave reactor for the final step. Kinase assays showed three inhibitors with high selectivity for each protein that were identified: 4f (IC50 = 70 nM for Bcr-Abl), 5j (IC50 = 0.41 μM for BTK) and 5b (IC50 = 0.38 μM for FLT-ITD). The 3D-QSAR analysis and molecular docking studies suggested that two fragments are potent and selective inhibitors of these three kinases: a substitution at the 6-phenylamino ring and the length and volume of the alkyl group at N-9. The N-7 and the N-methyl-piperazine moiety linked to the aminophenyl ring at C-2 are also requirements for obtaining the activity. Furthermore, most of these purine derivatives were shown to have a significant inhibitory effect in vitro on the proliferation of leukaemia and lymphoma cells (HL60, MV4-11, CEM, K562 and Ramos) at low concentrations. Finally, we show that the selected purines (4i, 5b and 5j) inhibit the downstream signalling of the respective kinases in cell models. Thus, this study provides new evidence regarding how certain chemical modifications of purine ring substituents provide novel inhibitors of target kinases as potential anti-leukaemia drugs.

• Klíčová slova
• 3D-QSAR, leukaemia, molecular docking, purine derivatives, tyrosine kinases inhibitors,
• Publikační typ
• časopisecké články MeSH

An evaluation of possible interactions with enzymes of drug metabolism (cytochromes P450, CYP) is an important part of studies on safety and, in general, on the properties of any drug or biologically active compound. The article is focused on the preliminary metabolic study of selected 2,6,9-trisubstituted purine kinase inhibitors with significant anticancer activities which we have developed. The compounds BP-21 and BP-117 represent strong CDK inhibitors and the compound BPA-302 was developed as selective FLT3-ITD kinase inhibitor. Here, emphasis is placed on interactions of these compounds with the nine most important forms of CYP to evaluate the possibility of inhibition of these enzymes. The possibility of their inhibitory effect was studied in vitro on selected human liver microsomal CYP enzymes. The most affected enzyme was CYP2C19. Its activity dropped to 22 % of its original value by BPA 302, to 13 % by BP-21 and to 6 % by BP-117 at the highest concentration tested (250 µmol·l(-1)). The results suggest that the metabolism of concomitantly administered drugs should not be significantly affected at lower doses. Molecular docking of BPA-302 indicated that it can bind to active site of both CYP2C19 and CYP2D6 enzymes above the heme cofactor corroborating the experimental data.

• MeSH
• inhibitory cytochromu P450 chemie   farmakologie   MeSH
• inhibitory proteinkinas chemie   farmakologie   MeSH
• izoenzymy MeSH
• jaterní mikrozomy účinky léků   enzymologie   MeSH
• kinetika MeSH
• konformace proteinů MeSH
• lékové interakce MeSH
• lidé MeSH
• puriny chemie   farmakologie   MeSH
• simulace molekulového dockingu MeSH
• systém (enzymů) cytochromů P-450 chemie   metabolismus   MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• inhibitory cytochromu P450 MeSH
• inhibitory proteinkinas MeSH
• izoenzymy MeSH
• puriny MeSH
• systém (enzymů) cytochromů P-450 MeSH

We designed, synthesized, and evaluated novel 2,6,9-trisubstituted purine derivatives for their prospective role as antitumor compounds. Using simple and efficient methodologies, 31 compounds were obtained. We tested these compounds in vitro to draw conclusions about their cell toxicity on seven cancer cells lines and one non-neoplastic cell line. Structural requirements for antitumor activity on two different cancer cell lines were analyzed with SAR and 3D-QSAR. The 3D-QSAR models showed that steric properties could better explain the cytotoxicity of compounds than electronic properties (70% and 30% of contribution, respectively). From this analysis, we concluded that an arylpiperazinyl system connected at position 6 of the purine ring is beneficial for cytotoxic activity, while the use of bulky systems at position C-2 of the purine is not favorable. Compound 7h was found to be an effective potential agent when compared with a currently marketed drug, cisplatin, in four out of the seven cancer cell lines tested. Compound 7h showed the highest potency, unprecedented selectivity, and complied with all the Lipinski rules. Finally, it was demonstrated that 7h induced apoptosis and caused cell cycle arrest at the S-phase on HL-60 cells. Our study suggests that substitution in the purine core by arylpiperidine moiety is essential to obtain derivatives with potential anticancer activity.

• Klíčová slova
• 3D-QSAR, apoptosis, cancer, cell cycle, cytotoxicity, purine derivatives,
• MeSH
• apoptóza účinky léků   MeSH
• kontrolní body fáze S buněčného cyklu účinky léků   MeSH
• krystalografie rentgenová MeSH
• kvantitativní vztahy mezi strukturou a aktivitou * MeSH
• lidé MeSH
• molekulární konformace MeSH
• nádorové buněčné linie MeSH
• protinádorové látky chemická syntéza   chemie   farmakologie   MeSH
• puriny chemická syntéza   chemie   farmakologie   MeSH
• screeningové testy protinádorových léčiv MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• protinádorové látky MeSH
• purine MeSH Prohlížeč
• puriny MeSH