Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide. Despite the prevalence of HCC, there is no effective, systemic treatment. The transcription factor LSF is a promising protein target for chemotherapy; it is highly expressed in HCC patient samples and cell lines, and promotes oncogenesis in rodent xenograft models of HCC. Here, we identify small molecules that effectively inhibit LSF cellular activity. The lead compound, factor quinolinone inhibitor 1 (FQI1), inhibits LSF DNA-binding activity both in vitro, as determined by electrophoretic mobility shift assays, and in cells, as determined by ChIP. Consistent with such inhibition, FQI1 eliminates transcriptional stimulation of LSF-dependent reporter constructs. FQI1 also exhibits antiproliferative activity in multiple cell lines. In LSF-overexpressing cells, including HCC cells, cell death is rapidly induced; however, primary or immortalized hepatocytes are unaffected by treatment with FQI1. The highly concordant structure–activity relationship of a panel of 23 quinolinones strongly suggests that the growth inhibitory activity is due to a single biological target or family. Coupled with the striking agreement between the concentrations required for antiproliferative activity (GI 50 s) and for inhibition of LSF transactivation (IC 50 s), we conclude that LSF is the specific biological target of FQIs. Based on these in vitro results, we tested the efficacy of FQI1 in inhibiting HCC tumor growth in a mouse xenograft model. As a single agent, tumor growth was dramatically inhibited with no observable general tissue cytotoxicity. These findings support the further development of LSF inhibitors for cancer chemotherapy.

Chiral amino alcohols are valuable building blocks in the synthesis of drugs, natural products, and chiral ligands used in enantioselective catalysis. The Petasis borono-Mannich reaction is a multicomponent condensation reaction of aldehydes, amines, and boronic acids to afford chiral amines. This report describes a practical, easily scaled, enantioselective Petasis borono-Mannich reaction of glycolaldehyde, with primary or secondary amines, and boronates catalyzed by BINOLderived catalysts to afford chiral 1,2-amino alcohols in high yields and enantioselectivities. The reactions are executed at room temperature in ethanol or trifluorotoluene using commercially available reagents and leverage an inherently attractive feature of the multicomponent reaction; the ability to use amines and boronates that possess a wide range of structural and electronic properties. Computational modeling of the diastereomeric transition states using DFT calculations identified a non-conventional CH…O interaction as a key feature that selectively stabilizes the transition state leading to the major enantiomer. The enantioselective catalytic reaction exemplifies a truly practical multicomponent condensation to afford 1,2-amino alcohols in highly enantioenriched form.

IntroductionLeishmaniasis is a parasitic disease that affects more than 1 million people worldwide annually, predominantly in resource-limited settings. The challenge in compound development is to exhibit potent activity against the intracellular stage of the parasite (the stage present in the mammalian host) without harming the infected host cells. We have identified a compound series (pyrazolopyrrolidinones) active against the intracellular parasites of Leishmania donovani and L. major; the causative agents of visceral and cutaneous leishmaniasis in the Old World, respectively.MethodsIn this study, we performed medicinal chemistry on a newly-discovered antileishmanial chemotype, with over 100 analogs tested. Studies included assessments of antileishmanial potency, toxicity towards host cells, and in vitro ADME screening of key drug properties.Results and discussionMembers of the series showed high potency against the deadliest form, visceral leishmaniasis (approximate EC50 ≥ 0.01 µM without harming the host macrophage up to 10.0 µM). In comparison, the most efficient monotherapy treatment for visceral leishmaniasis is amphotericin B, which presents similar activity in the same assay (EC50 = 0.2 µM) while being cytotoxic to the host cell at 5.0 µM. Continued development of this compound series with the Discovery Partnership with Academia (DPAc) program at the GlaxoSmithKline Diseases of the Developing World (GSK DDW) laboratories found that the compounds passed all of GSK’s criteria to be defined as a potential lead drug series for leishmaniasis.ConclusionHere, we describe preliminary structure-activity relationships for antileishmanial pyrazolopyrrolidinones, and our progress towards the identification of candidates for future in vivo assays in models of visceral and cutaneous leishmaniasis.

Chiral amino alcohols are valuable building blocks in the synthesis of drugs, natural products, and chiral ligands used in enantioselective catalysis. The Petasis borono-Mannich reaction is a multicomponent condensation reaction of aldehydes, amines, and boronic acids to afford chiral amines. This report describes a practical, easily scaled, enantioselective Petasis borono-Mannich reaction of glycolaldehyde, with primary or secondary amines, and boronates catalyzed by BINOLderived catalysts to afford chiral 1,2-amino alcohols in high yields and enantioselectivities. The reactions are executed at room temperature in ethanol or trifluorotoluene using commercially available reagents and leverage an inherently attractive feature of the multicomponent reaction; the ability to use amines and boronates that possess a wide range of structural and electronic properties. Computational modeling of the diastereomeric transition states using DFT calculations identified a non-conventional CH…O interaction as a key feature that selectively stabilizes the transition state leading to the major enantiomer. The enantioselective catalytic reaction exemplifies a truly practical multicomponent condensation to afford 1,2-amino alcohols in highly enantioenriched form.

Introduction: Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the second leading cause of cancer mortality. The transcription factor Late SV40 Factor (LSF) functions as an oncogene in HCC, making it a potential protein target for HCC therapy. LSF overexpression correlates with pathogenesis of liver, colorectal and pancreatic cancers, for which there are limited molecularly targeted therapy options. A library of dihydroquinolinones, termed Factor Quinolinone Inhibitors (FQIs), inhibits LSF-DNA binding and specific LSF-protein interactions in in vitro and in cellular assays. The initial lead compound FQI1 causes dramatic mitotic defects in HCC cell lines but has no toxic consequences on immortalized human hepatocytes or primary mouse hepatocytes. Additionally, FQI1 has proven efficacious in endogenous HCC mouse models, with no evidence of associated toxicity. Methods: A series of dihydroquinolinone compounds were synthesized and tested for potency in two HCC cell lines, Huh7 and SNU423, by a cell proliferation assay. The FQI analogs, FQI34, N-oxide FQI34 and FQI37, were separated by chiral chromatography to the corresponding R and S enantiomers. Direct target engagement of the three lead compounds, FQI1, FQI34 and FQI37, is shown with cellular thermal stability assays on Huh7 cells. Results: More than 20 compounds were synthesized and characterized. Among them, FQI37 showed the most potent activity (GI50 = 70 nM) against Huh7 HCC cells. Structure-activity-relationship studies suggest that the amide portion of quinolinone core is important for optimal activity. Growth inhibition assays revealed enantiomeric specificity; the (S)-enantiomers are more potent than the (R)-compounds and the racemate. The cellular thermal shift assay in Huh7 cells demonstrated the direct target binding of FQIs to LSF in cells at micromolar concentrations. Growth inhibition assays also identified colorectal cancer and pancreatic cancer lines to be sensitive to the dihydroquinolinones treatment. Conclusions: Aryl-dihydroquinolinones are promising small molecule chemotherapies for LSF-driven cancers such as HCC, colorectal cancer, and pancreatic cancer. Citation Format: Niranjana Pokharel, John Kavouris, Jessica Biagi, Ulla Hansen, Scott E. Schaus. Assessing the sensitivity of LSF inhibitors against liver cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4021.