Cardiovascular complications are a side effect of cancer therapy, potentially through reduced blood vessel function. ONC201 (TIC10) is currently used in phase 2 clinical trials to treat high-grade gliomas. TIC10 is a phosphatidylinositol 3-kinase (PI3K)/AKT/extracellular signal-regulated kinase (ERK) inhibitor that induces apoptosis via upregulation of TNF-related apoptosis-inducing ligand, which via stimulation of FOXO and death receptor could increase eNOS upregulation. This has the potential to improve vascular function through increased NO bioavailability. Our aim was to investigate the role of TIC10 on vascular function to determine if it would affect the risk of CVD. Excised abdominal aorta from White New Zealand male rabbits were cut into rings. Vessels were incubated with TIC10 and AS1842856 (FOXO1 inhibitor) followed by cumulative doses of acetylcholine (Ach) to assess vessel function. Vessels were then processed for immunohistochemistry. Incubation of blood vessels with TIC10 resulted in enhanced vasodilatory capacity. Combination treatment with the FOXO1 inhibitor and TIC10 resulted in reduced vascular function compared to control. Immunohistochemical analysis indicated a 3-fold increase in death receptor 5 (DR5) expression in the TIC10-treated blood vessels but the addition of the FOXO1 inhibitor downregulated DR5 expression. The expression of DR4 receptor was not significantly increased in the presence of TIC10; however, addition of the FOXO1 inhibitor downregulated expression. TIC10 has the capacity to improve the function of healthy vessels when stimulated with the vasodilator Ach. This highlights its therapeutic potential not only in cancer treatment without cardiovascular side effects, but also as a possible drug to treat established CVD.
- MeSH
- Phosphatidylinositol 3-Kinases MeSH
- Imidazoles * MeSH
- Rabbits MeSH
- Humans MeSH
- Forkhead Box Protein O3 * MeSH
- TNF-Related Apoptosis-Inducing Ligand MeSH
- Animals MeSH
- Check Tag
- Rabbits MeSH
- Humans MeSH
- Male MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
FOXO transcription factors are critical regulators of cell homeostasis and steer cell death, differentiation and longevity in mammalian cells. By combined pharmacophore-modeling-based in silico and fluorescence polarization-based screening we identified small molecules that physically interact with the DNA-binding domain (DBD) of FOXO3 and modulate the FOXO3 transcriptional program in human cells. The mode of interaction between compounds and the FOXO3-DBD was assessed via NMR spectroscopy and docking studies. We demonstrate that compounds S9 and its oxalate salt S9OX interfere with FOXO3 target promoter binding, gene transcription and modulate the physiologic program activated by FOXO3 in cancer cells. These small molecules prove the druggability of the FOXO-DBD and provide a structural basis for modulating these important homeostasis regulators in normal and malignant cells.
- MeSH
- DNA chemistry genetics metabolism MeSH
- Transcription, Genetic drug effects MeSH
- Gene Knockdown Techniques MeSH
- HEK293 Cells MeSH
- Small Molecule Libraries chemistry metabolism pharmacology MeSH
- Nucleic Acid Conformation MeSH
- Humans MeSH
- Magnetic Resonance Spectroscopy MeSH
- Models, Molecular MeSH
- Cell Line, Tumor MeSH
- Promoter Regions, Genetic genetics MeSH
- Forkhead Box Protein O3 chemistry genetics metabolism MeSH
- Protein Domains MeSH
- Molecular Docking Simulation MeSH
- Gene Expression Profiling methods MeSH
- Protein Binding MeSH
- Binding Sites genetics MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
The patients with mantle cell lymphoma (MCL) have translocation t(11;14) associated with cyclin D1 overexpression. We observed that iron (an essential cofactor of dioxygenases including prolyl hydroxylases [PHDs]) depletion by deferoxamine blocked MCL cells' proliferation, increased expression of DNA damage marker γH2AX, induced cell cycle arrest and decreased cyclin D1 level. Treatment of MCL cell lines with dimethyloxalylglycine, which blocks dioxygenases involving PHDs by competing with their substrate 2-oxoglutarate, leads to their decreased proliferation and the decrease of cyclin D1 level. We then postulated that loss of EGLN2/PHD1 in MCL cells may lead to down-regulation of cyclin D1 by blocking the degradation of FOXO3A, a cyclin D1 suppressor. However, the CRISPR/Cas9-based loss-of-function of EGLN2/PHD1 did not affect cyclin D1 expression and the loss of FOXO3A did not restore cyclin D1 levels after iron chelation. These data suggest that expression of cyclin D1 in MCL is not controlled by ENGL2/PHD1-FOXO3A pathway and that chelation- and 2-oxoglutarate competition-mediated down-regulation of cyclin D1 in MCL cells is driven by yet unknown mechanism involving iron- and 2-oxoglutarate-dependent dioxygenases other than PHD1. These data support further exploration of the use of iron chelation and 2-oxoglutarate-dependent dioxygenase inhibitors as a novel therapy of MCL.
- MeSH
- Amino Acids, Dicarboxylic pharmacology MeSH
- Iron Chelating Agents pharmacology MeSH
- Cyclin D1 metabolism MeSH
- Deferoxamine pharmacology MeSH
- Iron Deficiencies MeSH
- Dioxygenases antagonists & inhibitors metabolism MeSH
- Down-Regulation drug effects MeSH
- Hydroxylation MeSH
- Cell Hypoxia drug effects MeSH
- Enzyme Inhibitors pharmacology MeSH
- Ketoglutaric Acids pharmacology MeSH
- Humans MeSH
- Lymphoma, Mantle-Cell enzymology MeSH
- RNA, Messenger genetics metabolism MeSH
- Cell Line, Tumor MeSH
- DNA Damage MeSH
- Hypoxia-Inducible Factor-Proline Dioxygenases metabolism MeSH
- Forkhead Box Protein O3 genetics metabolism MeSH
- Iron MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
FOXO transcription factors regulate cellular homeostasis, longevity and response to stress. FOXO1 (also known as FKHR) is a key regulator of hepatic glucose production and lipid metabolism, and its specific inhibition may have beneficial effects on diabetic hyperglycemia by reducing hepatic glucose production. Moreover, all FOXO proteins are considered potential drug targets for drug resistance prevention in cancer therapy. However, the development of specific FOXO inhibitors requires a detailed understanding of structural differences between individual FOXO DNA-binding domains. The high-resolution structure of the DNA-binding domain of FOXO1 reported in this study and its comparison with structures of other FOXO proteins revealed differences in both their conformation and flexibility. These differences are encoded by variations in protein sequences and account for the distinct functions of FOXO proteins. In particular, the positions of the helices H1, H2 and H3, whose interface form the hydrophobic core of the Forkhead domain, and the interactions between hydrophobic residues located on the interface between the N-terminal segment, the H2-H3 loop, and the recognition helix H3 differ among apo FOXO1, FOXO3 and FOXO4 proteins. Therefore, the availability of apo structures of DNA-binding domains of all three major FOXO proteins will support the development of FOXO-type-specific inhibitors.
- MeSH
- Forkhead Box Protein O1 chemistry genetics metabolism MeSH
- Forkhead Transcription Factors chemistry genetics metabolism MeSH
- Hydrophobic and Hydrophilic Interactions MeSH
- Humans MeSH
- Magnetic Resonance Spectroscopy MeSH
- Models, Molecular MeSH
- Mice MeSH
- Forkhead Box Protein O3 chemistry genetics metabolism MeSH
- Protein Domains MeSH
- Protein Structure, Secondary MeSH
- Sequence Analysis, Protein MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- MeSH
- Chromosome Deletion * MeSH
- Leukemia, Lymphocytic, Chronic, B-Cell * blood genetics mortality MeSH
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Chromosomes, Human, Pair 6 genetics MeSH
- Survival Rate MeSH
- Neoplasm Proteins * biosynthesis genetics MeSH
- Disease-Free Survival MeSH
- Forkhead Box Protein O3 * biosynthesis genetics MeSH
- Gene Expression Regulation, Leukemic * MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Letter MeSH
- Multicenter Study MeSH
- Research Support, Non-U.S. Gov't MeSH
- Geographicals
- Czech Republic MeSH
