Preparation, characterisation and biological evaluation of new N-phenyl amidobenzenesulfonates and N-phenyl ureidobenzenesulfonates inducing DNA double-strand breaks. Part 3. Modulation of ring A

N-Phenyl ureidobenzenesulfonates, a novel class of human dihydroorotate dehydrogenase inhibitors inducing differentiation and apoptosis in acute myeloid leukemia cells

N-Phenyl ureidobenzensulfonates (PUB-SOs) are a novel family of dihydroorotate dehydrogenase (DHODH) inhibitors. Herein, we investigate the potential of PUB-SOs to induce acute myeloid leukemia (AML) cell differentiation and apoptosis. To that end, we screened our chemolibrary to select the most potent PUB-SOs based on their antiproliferative activity and their ability to arrest the cell progression of AML cells in the S phase. The most promising PUB-SOs show antiproliferative activity in the range of 0.13-23 µM against THP-1, MOLM-13 and HL-60 AML cells. Moreover, those PUB-SOs arrested the cell cycle progression in the S phase. In addition, molecular docking studies evidenced their potential to bind in the brequinar-binding site located on DHODH which was confirmed using the DHODH inhibition assay showing that PUB-SOs are potent DHODH inhibitors (half maximal inhibitory concentration (IC50) = 7.7-1000 nM). Our results also show that selected PUB-SOs induced the differentiation of THP-1 and HL-60 cells into cluster of differentiation (CD) 11b+/CD14+ phenotypes, up to 74 % and 50 %, respectively. They also promoted CD11b+ differentiation in MOLM-13 cells (up to 44 %). Additionally, the prototypical PUB-SOs SFOM-0046 induced lactate dehydrogenase (LDH) release, mitochondrial stress and mitochondrial membrane potential loss in MOLM-13 cell line. Furthermore, SFOM-0046 induced apoptosis in MOLM-13 cells, which was confirmed by the increase of annexin V/propidium iodide (PI) and caspase 3/7 positive cells. In summary, our results highlight PUB-SOs as a novel family of DHODH inhibitors inducing both cell differentiation and apoptosis in AML cells, underscoring their potential as therapeutic agents for AML treatment.

Preparation and biological evaluation of new antimicrotubule agents: Modification of the imidazolidin-2-one moiety of phenyl 4-(2-oxoimidazolidin-1-yl)benzenesulfonates

We prepared and biologically evaluated 32 novel molecules named phenyl 4-(dioxoimidazolidin-1-yl)benzenesulfonates (PID-SOs) and ethyl 2-(3-(4-(phenoxysulfonyl)phenyl)ureido)acetates (EPA-SOs). The antiproliferative activity of PID-SOs and EPA-SOs was assessed on four cancer cell lines (HT-1080, HT-29, M21, and MCF7). The most potent PID-SOs bearing an imidazolidin-2,4-dione group show antiproliferative activity in the nanomolar to low micromolar range (0.066 - 6 µM) while EPA-SOs and PID-SOs bearing an imidazolidin-2,5-dione moiety are mostly not active, exhibiting antiproliferative activity over 100 µM. The most potent PID-SOs (16-18) arrest the cell cycle progression in G2/M phase and interact with the colchicine-binding site leading to the microtubule and cytoskeleton disruption. Moreover, their antiproliferative activity is not impaired in vinblastine-, paclitaxel-, and multidrug-resistant cell lines. Finally, our study confirms that PID-SOs bearing the imidazolidin-2,4-dione moiety are a new family of promising antimitotics.

Synthesis of N-2(5H)-furanonyl sulfonyl hydrazone derivatives and their biological evaluation in vitro and in vivo activity against MCF-7 breast cancer cells

A series of (E)-N-2(5H)-furanonyl sulfonyl hydrazone derivatives have been rationally designed and efficiently synthesized by one-pot reaction with good yields for the first time. This green approach with wide substrate range and good selectivity can be achieved at room temperature in a short time in the presence of metal-free catalyst. The cytotoxic activities against three human cancer cell lines of all newly obtained compounds have been evaluated by MTT assay. Among them, compound 5 k exhibits high cytotoxic activity against MCF-7 human breast cancer cells with an IC₅₀ value of 14.35 μM. The cytotoxic mechanism may involve G2/M phase arrest pathway, which is probably caused by activating DNA damage. Comet test and immunofluorescence results show that compound 5 k can induce DNA damage in time- and dose-dependent manner. Importantly, 5 k also can effectively inhibit the proliferation of MCF-7 cells and angiogenesis in the zebrafish xenograft model. It is potential to further develop N-2(5H)-furanonyl sulfonyl hydrazone derivatives as potent drugs for breast cancer treatment with higher cytotoxic activity by modifying the structure of the compound.

N-phenyl ureidobenzenesulfonates, a novel class of promising human dihydroorotate dehydrogenase inhibitors

N-phenyl ureidobenzenesulfonates (PUB-SOs) is a new class of promising anticancer agents inducing replication stresses and cell cycle arrest in S-phase. However, the pharmacological target of PUB-SOs was still unidentified. Consequently, the objective of the present study was to identify and confirm the pharmacological target of the prototypical PUB-SO named 2-ethylphenyl 4-(3-ethylureido)benzenesulfonate (SFOM-0046) leading to the cell cycle arrest in S-phase. The antiproliferative and the cytotoxic activities of SFOM-0046 were characterized using the NCI-60 screening program and its fingerprint was analyzed by COMPARE algorithm. Then, human dihydroorotate dehydrogenase (hDHODH) colorimetric assay, uridine rescuing cell proliferation and molecular docking in the brequinar-binding site were performed. As a result, SFOM-0046 exhibited a mean antiproliferative activity of 3.5 μM in the NCI-60 screening program and evidenced that leukemia and colon cancer cell panels were more sensitive to SFOM-0046. COMPARE algorithm showed that the SFOM-0046 cytotoxic profile is equivalent to the ones of brequinar and dichloroallyl lawsone, two inhibitors of hDHODH. SFOM-0046 inhibited the hDHODH in the low nanomolar range (IC₅₀ = 72 nM) and uridine rescued the cell proliferation of HT-29, HT-1080, M21 and MCF-7 cancer cell lines in the presence of SFOM-0046. Finally, molecular docking showed a binding pose of SFOM-0046 interacting with Met43 and Phe62 present in the brequinar-binding site. In conclusion, PUB-SOs and notably SFOM-0046 are new small molecules hDHODH inhibitors triggering replication stresses and S-phase arrest.