title: In vitro antitumor mechanism of (E)-N-(2-methoxy-5-(((2,4,6-trimethoxystyryl)sulfonyl)methyl)pyridin-3-yl)methanesulfonamide.
abstract: ON01910.Na [sodium (E)-2-(2-methoxy-5-((2,4,6-trimethoxystyrylsulfonyl)methyl)phenylamino)acetate; Rigosertib, Estybon], a styryl benzylsulfone, is a phase III stage anticancer agent. This non-ATP competitive kinase inhibitor has multitargeted activity, promoting mitotic arrest and apoptosis. Extensive phase I/II studies with ON01910.Na, conducted in patients with solid tumors and hematologic cancers, demonstrate excellent efficacy. However, issues remain affecting its development. These include incomplete understanding of antitumor mechanisms, low oral bioavailability, and unpredictable pharmacokinetics. We have identified a novel (E)-styrylsulfonyl methylpyridine [(E)-N-(2-methoxy-5-((2,4,6-trimethoxystyrylsulfonyl)methyl)pyridin-3-yl)methanesulfonamide (TL-77)] which has shown improved oral bioavailability compared with ON01910.Na. Here, we present detailed cellular mechanisms of TL-77 in comparison with ON01910.Na. TL-77 displays potent growth inhibitory activity in vitro (GI50 < 1μM against HCT-116 cells), demonstrating 3- to 10-fold greater potency against tumor cell lines when compared with normal cells. Cell-cycle analyses reveal that TL-77 causes significant G2/M arrest in cancer cells, followed by the onset of apoptosis. In cell-free conditions, TL-77 potently inhibits tubulin polymerization. Mitotically arrested cells display multipolar spindles and misalignment of chromosomes, indicating that TL-77 interferes with mitotic spindle assembly in cancer cells. These effects are accompanied by induction of DNA damage, inhibition of Cdc25C phosphorylation [indicative of Plk1 inhibition], and downstream inhibition of cyclin B1. However, kinase assays failed to confirm inhibition of Plk1. Nonsignificant effects on phosphoinositide 3-kinase/Akt signal transduction were observed after TL-77 treatment. Analysis of apoptotic signaling pathways reveals that TL-77 downregulates expression of B-cell lymphoma 2 family proteins (Bid, Bcl-xl, and Mcl-1) and stimulates caspase activation. Taken together, TL-77 represents a promising anticancer agent worthy of further evaluation.
authors.affiliation: School of Pharmacy and Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham, United Kingdom (T.L., C.A.L., T.D.B.); and Centre for Drug Discovery and Development, Sansom Institute for Health Research, and School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, Australia (S.W.).
authors.forename: Tiangong
authors.initials: T
authors.lastname: Lu
authors.affiliation: School of Pharmacy and Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham, United Kingdom (T.L., C.A.L., T.D.B.); and Centre for Drug Discovery and Development, Sansom Institute for Health Research, and School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, Australia (S.W.).
authors.forename: Charles A
authors.initials: CA
authors.lastname: Laughton
authors.affiliation: School of Pharmacy and Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham, United Kingdom (T.L., C.A.L., T.D.B.); and Centre for Drug Discovery and Development, Sansom Institute for Health Research, and School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, Australia (S.W.).
authors.forename: Shudong
authors.initials: S
authors.lastname: Wang
authors.affiliation: School of Pharmacy and Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham, United Kingdom (T.L., C.A.L., T.D.B.); and Centre for Drug Discovery and Development, Sansom Institute for Health Research, and School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, Australia (S.W.) tracey.bradshaw@nottingham.ac.uk.
authors.forename: Tracey D
authors.initials: TD
authors.lastname: Bradshaw
mesh_terms: D000970:Antineoplastic Agents / Q000138:chemical synthesis / Q000494:pharmacology*; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D005998:Glycine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D045325:HCT116 Cells; D006367:HeLa Cells; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D066298:In Vitro Techniques; D061986:MCF-7 Cells; D009369:Neoplasms / Q000188:drug therapy / Q000473:pathology*; D015398:Signal Transduction / Q000187:drug effects; D008941:Spindle Apparatus / Q000187:drug effects; D013343:Styrenes / Q000138:chemical synthesis / Q000494:pharmacology*; D013449:Sulfonamides / Q000138:chemical synthesis / Q000494:pharmacology*; D013450:Sulfones / Q000494:pharmacology*; D014404:Tubulin / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; C000588581:N-(2-methoxy-5-(((2,4,6-trimethoxystyryl)sulfonyl)methyl)pyridin-3-yl)methanesulfonamide; D013343:Styrenes; D013449:Sulfonamides; D013450:Sulfones; D014404:Tubulin; C507134:ON 01910; D005998:Glycine