Synthesis of Glycolysis Inhibitor PFK15 and Its Synergistic Action with an Approved Multikinase Antiangiogenic Drug on Human Endothelial Cell Migration and Proliferation.

Activated endothelial, immune, and cancer cells prefer glycolysis to obtain energy for their proliferation and migration. Therefore, the blocking of glycolysis can be a promising strategy against cancer and autoimmune disease progression. Inactivation of the glycolytic enzyme PFKFB3 (6-phosphofructo-2-kinase/fructose-2,6-biphosphatase) suppresses glycolysis level and contributes to decreased proliferation and migration of cancer (tumorigenesis) and endothelial (angiogenesis) cells. Recently, several glycolysis inhibitors have been developed, among them (E)-1-(pyridin-4-yl)-3-(quinolin-2-yl)prop-2-en-1-one (PFK15) that is considered as one of the most promising. It is known that PFK15 decreases glucose uptake into the endothelial cells and efficiently blocks pathological angiogenesis. However, no study has described sufficiently PFK15 synthesis enabling its general availability. In this paper we provide all necessary details for PFK15 preparation and its advanced characterization. On the other hand, there are known tyrosine kinase inhibitors (e.g., sunitinib), that affect additional molecular targets and efficiently block angiogenesis. From a biological point of view, we have studied and proved the synergistic inhibitory effect by simultaneous administration of glycolysis inhibitor PFK15 and multikinase inhibitor sunitinib on the proliferation and migration of HUVEC. Our results suggest that suppressing the glycolytic activity of endothelial cells in combination with growth factor receptor blocking can be a promising antiangiogenic treatment.

Novel CLK1 inhibitors based on N-aryloxazol-2-amine skeleton - A possible way to dual VEGFR2 TK/CLK ligands.

BACKGROUND: Inhibitors of CLK protein kinases suppress cell growth and induce apoptosis by modulating pre-mRNA splicing in cancer. CLK family kinases are also involved in alternative splicing and RNA processing in Duchenne muscular dystrophy, Alzheimer's disease, HIV-1, and influenza virus. Small inhibitors are valuable tools for better understanding the molecular mechanisms of splicing and may serve as seeds for a novel class of therapeutics. ACHIEVEMENTS: Here we describe a discovery of four novel CLK1 inhibitors possessing N-aryloxazol-2-amine skeleton. Their activity against CLK1 (IC50: 20, 30, 40 and 80 nM) and some other CMGC kinases, predicted CLK binding poses, synthesis and physico-chemical characteristics are also stated. Additionally analysis of all PDB available CLK structures and interactions of their ligands was performed. There are only few powerful dual CLK/VEGFR inhibitors known in the literature. We proposed that our inhibitors have similar binding places and interactions in CLK1, 3 and VEGFR2 TK mostly due to the joint N-aryloxazol-2-amine pharmacophoric fragment. One of our N-aryloxazol-2-amines already proved a good activity against both VEGFR2 and CLK1 enzymes (23/80 nM, resp). We proposed that the presented class of compounds has a potential to be developed in dual VEGFR2/CLK clinical compounds with prospective synergy to treat cancer.

Synthesis of 5-(ethylsulfonyl)-2-methoxyaniline: An important pharmacological fragment of VEGFR2 and other inhibitors.

BACKGROUND: 5-(Ethylsulfonyl)-2-methoxyaniline (5) is part of the structure in 131 compounds possessing different biological activities. In most cases, they have antitumor properties (112 compounds). Other compounds are described as cardiovascular agents, ion-channel blockers, nervous-system blockers, anti-inflammatory agents, or antidiabetic, antiosteoporotic and hypolipemic species. Compound 5 is a precursor of different protein-kinase inhibitors or enzyme modulators (EGFR, PDGFR, ckit, CDK 2 and 4, MMPs 2, 3, 9 and 13, etc.). The structure of 5 represents a fragment for several powerful inhibitors of VEGFR2, a key angiogenic receptor. Antiangiogenic inhibitors slow down or stop new blood-vessel formation from pre-existing vasculature. Some antiangiogenic drugs inhibiting the VEGFR2 receptor are successfully used in clinics for the treatment of several types of tumours in synergy with chemotherapy (e.g., Nexavar(®) from Bayer, Sutent(®) from Pfizer and Votrient(®) from GlaxoSmithKline, approved by the FDA in 2005, 2006 and 2009, respectively). The structure of 5 is an important pharmacophoric fragment of potent VEGFR2 inhibitors (e.g., AAZ from PDB complex 1Y6A, enzymatic IC(50) = 22 nM). Up to now, 25 VEGFR2 inhibitors possessing a fragment of 5 can be found in the literature. Despite the high significance of 5-(ethylsulfonyl)-2-methoxyaniline (5) its preparation has not yet been described. RESULTS: Here we have developed a convenient synthesis of important polyheterosubstituted aniline 5 starting from commercially available 4-methoxybenzene-1-sulfonyl chloride (1) in four steps and 59% overall yield. The target 5-(ethylsulfonyl)-2-methoxyaniline (5) and its synthetic intermediates 2-4 together with a new compound 5-(ethylsulfonyl)-2-methoxy-1,3-dinitrobenzene (4a) have been precisely physicochemically characterised.