Synthesis and biological evaluation of novel anti-tumour (E)-styrylsulfonyl methylpyridines

ON01910.Na (Rigosertib, Estybon®), a styryl benzylsulfone, is a Phase III stage anti-cancer agent. This non-ATP competitive kinase inhibitor has multi-targeted activity, promoting mitotic arrest and apoptosis. Extensive Phase I/II studies with ON01910.Na, conducted in patients with solid tumours and haematological cancers demonstrate excellent efficacy. However, issues remain affecting its development. These include incomplete understanding of anti-tumour mechanisms, low oral bioavailability and unpredictable pharmacokinetics. In an attempt to improve drug-likeness and ADME properties of ON01910.Na analogues, a novel series of (E)-styrylsulfonyl methylpyridine derivatives was designed and synthesised. The SAR of this novel series is discussed. The lead compounds TL-68, TL-77, and AH-123 are highly potent mitotic inhibitors. Their selective cytotoxicity to cancer cells was identified in the screening cascade. Impressively, TL-77 possesses excellent pharmaceutical properties, with improved oral bioavailability when compared to ON01910.Na. The detailed cellular mechanisms of TL-77 were further investigated in comparison with ON01910.Na. TL-77 exhibits potent anti-proliferative activity against a wide range of human tumour cell lines, and demonstrated > 2 fold greater potency in cancer cell lines over normal cells.. Cell cycle analyses reveal that TL-77 evokes profound G2/M cell cycle arrest at ≥ 6 h in cancer cells, followed by the onset of apoptosis. In cell-free conditions, TL-77 as well as ON01910.Na potently inhibits tubulin polymerization. Mitotically arrested cells display multipolar spindles and misalignment of chromosomes, indicating TL-77 interfere mitotic spindle assembly in cancer cells. These effects are accompanied by induction of DNA damage, inhibition of Cdc25c (Ser198) phosphorylation [indicative polo-like kinase 1 (Plk1) inhibition], and downstream inhibition of cyclin B1. However, kinase assays failed to confirm the inhibition of Plk1. Non-significant effects on PI3K/AKT signal transduction are observed after TL-77 treatment. Analysis of apoptotic signalling pathways reveals that TL-77 down-regulates expression of B-cell lymphoma 2 (Bcl-2) family proteins [Bid (BH3 interacting-domain death agonist), Bcl-xl (B-cell lymphoma-extra large) and Mcl-1 (induced myeloid leukaemia cell differentiation protein)] and stimulates caspase activation. These effects are comparable to those elicited by ON01910.Na. Unlike ON01910.Na, however, TL-77 causes preferential toxicity in cancer cells when compared to normal cells and mediates rapid mitotic inhibitory effects. In summary, selective in vitro anti-tumour activity and multi-faceted mechanisms of action of a novel molecule TL-77 have been identified, presenting a strong rationale for further development of (E)-styrylsulfonyl methylpyridine derivatives as therapeutic agents for cancer

Synthesis and biological evaluation of novel anti-tumour (E)-styrylsulfonyl methylpyridines

ON01910.Na (Rigosertib, Estybon®), a styryl benzylsulfone, is a Phase III stage anti-cancer agent. This non-ATP competitive kinase inhibitor has multi-targeted activity, promoting mitotic arrest and apoptosis. Extensive Phase I/II studies with ON01910.Na, conducted in patients with solid tumours and haematological cancers demonstrate excellent efficacy. However, issues remain affecting its development. These include incomplete understanding of anti-tumour mechanisms, low oral bioavailability and unpredictable pharmacokinetics. In an attempt to improve drug-likeness and ADME properties of ON01910.Na analogues, a novel series of (E)-styrylsulfonyl methylpyridine derivatives was designed and synthesised. The SAR of this novel series is discussed. The lead compounds TL-68, TL-77, and AH-123 are highly potent mitotic inhibitors. Their selective cytotoxicity to cancer cells was identified in the screening cascade. Impressively, TL-77 possesses excellent pharmaceutical properties, with improved oral bioavailability when compared to ON01910.Na. The detailed cellular mechanisms of TL-77 were further investigated in comparison with ON01910.Na. TL-77 exhibits potent anti-proliferative activity against a wide range of human tumour cell lines, and demonstrated > 2 fold greater potency in cancer cell lines over normal cells.. Cell cycle analyses reveal that TL-77 evokes profound G2/M cell cycle arrest at ≥ 6 h in cancer cells, followed by the onset of apoptosis. In cell-free conditions, TL-77 as well as ON01910.Na potently inhibits tubulin polymerization. Mitotically arrested cells display multipolar spindles and misalignment of chromosomes, indicating TL-77 interfere mitotic spindle assembly in cancer cells. These effects are accompanied by induction of DNA damage, inhibition of Cdc25c (Ser198) phosphorylation [indicative polo-like kinase 1 (Plk1) inhibition], and downstream inhibition of cyclin B1. However, kinase assays failed to confirm the inhibition of Plk1. Non-significant effects on PI3K/AKT signal transduction are observed after TL-77 treatment. Analysis of apoptotic signalling pathways reveals that TL-77 down-regulates expression of B-cell lymphoma 2 (Bcl-2) family proteins [Bid (BH3 interacting-domain death agonist), Bcl-xl (B-cell lymphoma-extra large) and Mcl-1 (induced myeloid leukaemia cell differentiation protein)] and stimulates caspase activation. These effects are comparable to those elicited by ON01910.Na. Unlike ON01910.Na, however, TL-77 causes preferential toxicity in cancer cells when compared to normal cells and mediates rapid mitotic inhibitory effects. In summary, selective in vitro anti-tumour activity and multi-faceted mechanisms of action of a novel molecule TL-77 have been identified, presenting a strong rationale for further development of (E)-styrylsulfonyl methylpyridine derivatives as therapeutic agents for cancer

In vitro antitumor mechanism of (E)-N-(2-methoxy-5-(((2,4,6-trimethoxystyryl)sulfonyl)methyl)pyridin-3-yl)methanesulfonamide

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

Discovery of (E)-3-((Styrylsulfonyl) methyl) pyridine and (E)-2-((Styrylsulfonyl) methyl) pyridine Derivatives as Anticancer Agents: Synthesis, Structure–Activity Relationships, and Biological Activities

ON01910.Na is a highly effective anticancer agent that induces mitotic arrest and apoptosis. Clinical studies with ON01910 in cancer patients have shown efficacy along with an impressive safety profile. While ON01910 is highly active against cancer cells, it has a low oral availability and requires continuous intravenous infusion or multiple gram doses to ensure sufficient drug exposure for biological activity in patients. We have identified two novel series of styrylsulfonyl-methylpyridines. Lead compounds 8, 9a, 18 and 19a are highly potent mitotic inhibitors and selectively cytotoxic to cancer cells. Impressively, these compounds possess excellent pharmaceutical properties and two lead drug candidates 9a and 18 demonstrated antitumor activities in animal models.Tiangong Lu, Aik Wye Goh, Mingfeng Yu, Julian Adams, Frankie Lam, Theodosia Teo, Peng Li, Ben Noll, Longjin Zhong, Sarah Diab, Osama Chahrour, Anran Hu, Abdullahi Y. Abbas, Xiangrui Liu, Shiliang Huang, Christopher J. Sumby, Robert Milne, Carol Midgley, and Shudong Wan