ABSTRACT
Centrosomes associate with spindle poles; thus, the presence of two centrosomes promotes bipolar spindle assembly in normal cells. Cancer cells often contain supernumerary centrosomes, and to avoid multipolar mitosis and cell death, these are clustered into two poles by the microtubule motor protein HSET. We report the discovery of an allosteric inhibitor of HSET, CW069, which we designed using a methodology on an interface of chemistry and biology. Using this approach, we explored millions of compounds in silico and utilized convergent syntheses. Only compound CW069 showed marked activity against HSET in vitro. The inhibitor induced multipolar mitoses only in cells containing supernumerary centrosomes. CW069 therefore constitutes a valuable tool for probing HSET function and, by reducing the growth of cells containing supernumerary centrosomes, paves the way for new cancer therapeutics.
Subject(s)
Antineoplastic Agents/pharmacology , Centrosome/drug effects , Drug Design , Enzyme Inhibitors/pharmacology , Kinesins/antagonists & inhibitors , Phenylalanine/analogs & derivatives , ortho-Aminobenzoates/pharmacology , Allosteric Regulation/drug effects , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Cell Line, Tumor , Cell Proliferation/drug effects , Centrosome/metabolism , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , HeLa Cells , Humans , Kinesins/metabolism , MCF-7 Cells , Models, Molecular , Molecular Structure , Phenylalanine/chemical synthesis , Phenylalanine/chemistry , Phenylalanine/pharmacology , Structure-Activity Relationship , ortho-Aminobenzoates/chemical synthesis , ortho-Aminobenzoates/chemistryABSTRACT
The combretastatins have been investigated for their antimitotic and antivascular properties, and it is widely postulated that a 3,4,5-trimethoxyaryl A-ring is essential to maintain potent activity. We have synthesized new tetrazole analogues (32-34), demonstrating that 3,5-dihalogenation can consistently increase potency by up to 5-fold when compared to the equivalent trimethoxy compound on human umbilical vein endothelial cells (HUVECs) and a range of cancer cells. Moreover, this increased potency offsets that lost by installing the tetrazole bridge into combretastatin A-4 (1), giving crystalline, soluble compounds that have low nanomolar activity, arrest cells in G2/M phase, and retain microtubule inhibitory activity. Molecular modeling has shown that optimized packing within the binding site resulting in increased Coulombic interaction may be responsible for this improved activity.
ABSTRACT
Rhodium-catalyzed carbozincation of ynamides using diorganozinc reagents or functionalized organozinc halides is described. Using a tri(2-furyl)phosphine-modified rhodium catalyst, the reaction course is altered to hydrozincation when diethylzinc is employed as the organozinc reagent. Trapping of the alkenylzinc intermediates produced in these reactions in further functionalization reactions is possible. Collectively, these processes enable access to a range of multisubstituted enamides in stereo- and regiocontrolled fashion.
