Novel piperazine-1,2,3-triazole leads for the potential treatment of pancreatic cancer.

From lead 1, (N-(4-((4-(3-(4-(3-methoxyphenyl)-1H-1,2,3-triazol-1-yl)propyl)piperazin-1-yl)sulfonyl)-phenyl)acetamide), a S100A2-p53 protein-protein interaction inhibitor based on an in silico modelling driven hypothesis, four focused libraries were designed and synthesised. Growth inhibition screening was performed against 16 human cancer cell lines including the pancreatic cell lines MiaPaCa2, BxPC3, AsPC-1, Capan-2, HPAC, PANC-1 and the drug resistant CFPAC1. Modification of 1's phenylacetamide moiety, gave Library 1 with only modest pancreatic cancer activity. Modification of the 3-OCH3Ph moiety (Library 2) gave 4-CH3 (26), 4-CH2CH3 (27), 4-CF3 (31) and 4-NO2 (32) with sterically bulky groups more active. A 4-CF3 acetamide replacement enhanced cytotoxicity (Library 3). The 4-C(CH3)336 resulted in a predicted steric clash in the S100A2-p53 binding groove, with a potency decrease. Alkyl moieties afforded more potent analogues, 34 (4-CH3) and 35 (CH2CH3), a trend evident against pancreatic cancer: GI50 3.7 (35; BxPC-3) to 18 (40; AsPC-1) µM. Library 4 analogues with a 2-CF3 and 3-CF3 benzenesulfonamide moiety were less active than the corresponding Library 3 analogues. Two additional analogues were designed: 51 (4-CF3; 4-OCH3) and 52 (4-CF3; 2-OCH3) revealed 52 to be 10-20 fold more active than 51, against the pancreatic cancer cell lines examined with sub-micromolar GI50 values 0.43 (HPAC) to 0.61 µM (PANC-1). MOE calculated binding scores for each pose are also consistent with the observed biological activity with 52. The obtained SAR data is consistent with the proposed interaction within the S100A2-p53 bonding groove.

Oral administration of a 2-aminopyrimidine robenidine analogue (NCL195) significantly reduces Staphylococcus aureus infection and reduces Escherichia coli infection in combination with sub-inhibitory colistin concentrations in a bioluminescent mouse model.

We have previously reported promising in vivo activity of the first-generation 2-aminopyramidine robenidine analogue NCL195 against Gram-positive bacteria (GPB) when administered via the systemic route. In this study, we examined the efficacy of oral treatment with NCL195 (± low-dose colistin) in comparison to oral moxifloxacin in bioluminescent Staphylococcus aureus and Escherichia coli peritonitis-sepsis models. Four oral doses of 50 mg/kg NCL195, commencing immediately post-infection, were administered at 4 h intervals in the S. aureus peritonitis-sepsis model. We used a combination of four oral doses of 50 mg/kg NCL195 and four intraperitoneal doses of colistin at 0.125 mg/kg, 0.25 mg/kg, or 0.5 mg/kg in the E. coli peritonitis-sepsis model. Subsequently, the dose rates of four intraperitoneal doses of colistin were increased to 0.5 mg/kg, 1 mg/kg, or 2 mg/kg at 4 h intervals to treat a colistin-resistant E. coli infection. In the S. aureus infection model, oral treatment of mice with NCL195 resulted in significantly reduced S. aureus infection loads (P < 0.01) and longer survival times (P < 0.001) than vehicle-only treated mice. In the E. coli infection model, co-administration of NCL195 and graded doses of colistin resulted in a dose-dependent significant reduction in colistin-susceptible (P < 0.01) or colistin-resistant (P < 0.05) E. coli loads compared to treatment with colistin alone at similar concentrations. Our results confirm that NCL195 is a potential candidate for further preclinical development as a specific treatment for multidrug-resistant infections, either as a stand-alone antibiotic for GPB or in combination with sub-inhibitory concentrations of colistin for Gram-negative bacteria.

The sulfonadyns: a class of aryl sulfonamides inhibiting dynamin I GTPase and clathrin mediated endocytosis are anti-seizure in animal models.

We show that dansylcadaverine (1) a known in-cell inhibitor of clathrin mediated endocytosis (CME), moderately inhibits dynamin I (dynI) GTPase activity (IC50 45 µM) and transferrin (Tfn) endocytosis in U2OS cells (IC50 205 µM). Synthesis gave a new class of GTP-competitive dynamin inhibitors, the Sulfonadyns™. The introduction of a terminal cinnamyl moiety greatly enhanced dynI inhibition. Rigid diamine or amide links between the dansyl and cinnamyl moieties were detrimental to dynI inhibition. Compounds with in vitro inhibition of dynI activity <10 µM were tested in-cell for inhibition of CME. These data unveiled a number of compounds, e.g. analogues 33 ((E)-N-(6-{[(3-(4-bromophenyl)-2-propen-1-yl]amino}hexyl)-5-isoquinolinesulfonamide)) and 47 ((E)-N-(3-{[3-(4-bromophenyl)-2-propen-1-yl]amino}propyl)-1-naphthalenesulfonamide)isomers that showed dyn IC50 <4 µM, IC50(CME) <30 µM and IC50(SVE) from 12-265 µM. Both analogues (33 and 47) are at least 10 times more potent that the initial lead, dansylcadaverine (1). Enzyme kinetics revealed these sulfonamide analogues as being GTP competitive inhibitors of dynI. Sulfonadyn-47, the most potent SVE inhibitor observed (IC50(SVE) = 12.3 µM), significantly increased seizure threshold in a 6 Hz mouse psychomotor seizure test at 30 (p = 0.003) and 100 mg kg-1 ip (p < 0.0001), with similar anti-seizure efficacy to the established anti-seizure medication, sodium valproate (400 mg kg-1). The Sulfonadyn™ class of drugs target dynamin and show promise as novel leads for future anti-seizure medications.

Expansion of a Synthesized Library of N-Benzyl Sulfonamides Derived from an Indole Core to Target Pancreatic Cancer.

In an effort to further investigate previously observed activity of indolyl sulfonamides towards pancreatic cancer cell lines, a library of 44 compounds has been synthesized. The biological activity of the compounds has been determined using two different screening assay techniques against 7 pancreatic cancer cell lines and 9 non-pancreatic cancer cell lines. In the first assay, the cytotoxicity of the compounds was evaluated using a traditional (48 hour compound exposure) method. An in silico investigation was conducted to determine if the compounds might be inducing cell death by inhibiting the S100A2-p53 protein-protein interaction. In the second assay, the potential role of the compounds as metabolic inhibitors of ATP production was evaluated using a rapid screening (1-2 hour compound exposure) method. IC50 values of the hit compounds were obtained and four compounds displayed sub-micromolar potency against PANC-1 cells. The investigation has provided several compounds that display selective in vitro activity toward pancreatic cancer that warrant further development.

Systematic literature review reveals suboptimal use of chemical probes in cell-based biomedical research.

Chemical probes have reached a prominent role in biomedical research, but their impact is governed by experimental design. To gain insight into the use of chemical probes, we conducted a systematic review of 662 publications, understood here as primary research articles, employing eight different chemical probes in cell-based research. We summarised (i) concentration(s) at which chemical probes were used in cell-based assays, (ii) inclusion of structurally matched target-inactive control compounds and (iii) orthogonal chemical probes. Here, we show that only 4% of analysed eligible publications used chemical probes within the recommended concentration range and included inactive compounds as well as orthogonal chemical probes. These findings indicate that the best practice with chemical probes is yet to be implemented in biomedical research. To achieve this, we propose 'the rule of two': At least two chemical probes (either orthogonal target-engaging probes, and/or a pair of a chemical probe and matched target-inactive compound) to be employed at recommended concentrations in every study.

Molecular Imprinting of Benzylpiperazine: A Comparison of the Self-Assembly and Semi-Covalent Approaches.

Molecularly imprinted polymers (MIPs) for benzylpiperazine (BZP, 1), an illicit designer drug, were developed by using both self-assembly and semi-covalent approaches. From an array of potential functional monomers (FMs) and using a combination of pre-synthetic interaction studies (by molecular modelling and NMR analysis) and binding assays, the highest performing self-assembly 1-MIPs were confirmed to result from methacrylic acid (7) as FM, ethylene glycol dimethacrylate (EGDMA) or trimethylolpropane trimethacrylate (TRIM) as crosslinkers and chloroform as the porogen and rebinding solvent at template (T): FM ratios of 1:1 and 1:2, giving imprinting factors (IF) 3 to 7. The semi-covalent 1-MIPs were designed using benzylpiperazine (4-vinylphenyl) carbamate (16) as the template-monomer adduct in combination with either EDGMA or TRIM. Our comparative analysis showed the semi-covalent polymers to have a stronger affinity for 1 (significantly lower Kd values and higher IFs) and faster uptake than the self-assembly systems. Both approaches have comparable cross-reactivity: marginal to low against cocaine (17) and morphine (18) and high against ephedrine (19) and phenylpiperazine (20). They also have comparable selectivity: highly selective towards 1 against 17, moderate against 18 and non-selective against 19. EGDMA-based self-assembly MIPs displayed a greater imprinting effect (higher IFs and NIP-to-MIP Kd ratios) than TRIM-based MIPs, while the TRIM-based semi-covalent MIP outperformed its EGDMA-based equivalent. By virtue of its modest selectivity against the test illicit drugs, 1-MIPs could potentially be used as a dummy MIP for the broad-based capture and enrichment of illicit drug blends for subsequent laboratory analysis.

Wiskostatin and other carbazole scaffolds as off target inhibitors of dynamin I GTPase activity and endocytosis.

Wiskostatin (1-(3,6-dibromo-9H-carbazol-9-yl)-3-(dimethylamino)propan-2-ol) (1) is a carbazole-based compound reported as a specific and relatively potent inhibitor of the N-WASP actin remodelling complex (S-isomer EC50 = 4.35 µM; R-isomer EC50 = 3.44 µM). An NMR solution structure showed that wiskostatin interacts with a cleft in the regulatory GTPase binding domain of N-WASP. However, numerous studies have reported wiskostatin's actions on membrane transport and cytokinesis that are independent of the N-WASP-Arp2/3 complex pathway, but offer limited alternative explanation. The large GTPase, dynamin has established functional roles in these pathways. This study reveals that wiskostatin and its analogues, as well as other carbazole-based compounds, are inhibitors of helical dynamin GTPase activity and endocytosis. We characterise the effects of wiskostatin on in vitro dynamin GTPase activity, in-cell endocytosis, and determine the importance of wiskostatin functional groups on these activities through design and synthesis of libraries of wiskostatin analogues. We also examine whether other carbazole-based scaffolds frequently used in research or the clinic also modulate dynamin and endocytosis. Understanding off-targets for compounds used as research tools is important to be able to confidently interpret their action on biological systems, particularly when the target and off-targets affect overlapping mechanisms (e.g. cytokinesis and endocytosis). Herein we demonstrate that wiskostatin is a dynamin inhibitor (IC50 20.7 ± 1.2 µM) and a potent inhibitor of clathrin mediated endocytosis (IC50 = 6.9 ± 0.3 µM). Synthesis of wiskostatin analogues gave rise to 1-(9H-carbazol-9-yl)-3-((4-methylbenzyl)amino)propan-2-ol (35) and 1-(9H-carbazol-9-yl)-3-((4-chlorobenzyl)amino)propan-2-ol (43) as potent dynamin inhibitors (IC50 = 1.0 ± 0.2 µM), and (S)-1-(3,6-dibromo-9H-carbazol-9-yl)-3-(dimethylamino)propan-2-ol (8a) and (R)-1-(3,6-dibromo-9H-carbazol-9-yl)-3-(dimethylamino)propan-2-ol (8b) that are amongst the most potent inhibitors of clathrin mediated endocytosis yet reported (IC50 = 2.3 ± 3.3 and 2.1 ± 1.7 µM, respectively).

Prodrugs of the Archetypal Dynamin Inhibitor Bis-T-22.

The Bis-T series of compounds comprise some of the most potent inhibitors of dynamin GTPase activity yet reported, e. g., (2E,2'E)-N,N'-(propane-1,3-diyl)bis(2-cyano-3-(3,4-dihydroxyphenyl)acrylamide) (2), Bis-T-22. The catechol moieties are believed to limit cell permeability, rendering these compounds largely inactive in cells. To solve this problem, a prodrug strategy was envisaged and eight ester analogues were synthesised. The shortest and bulkiest esters (acetate and butyl/tert-butyl) were found to be insoluble under physiological conditions, whilst the remaining five were soluble and stable under these conditions. These five were analysed for plasma stability and half-lives ranged from ∼2.3 min (propionic ester 4), increasing with size and bulk, to greater than 24 hr (dimethyl carbamate 10). Similar profiles where observed with the rate of formation of Bis-T-22 with half-lives ranging from ∼25 mins (propionic ester 4). Propionic ester 4 was chosen to undergo further testing and was found to inhibit endocytosis in a dose-dependent manner with IC50 ∼8 µM, suggesting this compound is able to effectively cross the cell membrane where it is rapidly hydrolysed to the desired Bis-T-22 parent compound.

In Vitro Activity of Robenidine Analogues NCL259 and NCL265 against Gram-Negative Pathogens.

Multidrug-resistant (MDR) Gram-negative pathogens, especially Acinetobacter baumannii, Pseudomonas aeruginosa, Escherichia coli and Enterobacter spp., are recognized by the World Health Organization as the most critical priority pathogens in urgent need of drug development. In this study, the in vitro antimicrobial activity of robenidine analogues NCL259 and NCL265 was tested against key human and animal Gram-negative clinical isolates and reference strains. NCL259 and NCL265 demonstrated moderate antimicrobial activity against these Gram-negative priority pathogens with NCL265 consistently more active, achieving lower minimum inhibitory concentrations (MICs) in the range of 2−16 µg/mL. When used in combination with sub-inhibitory concentrations of polymyxin B to permeabilize the outer membrane, NCL259 and NCL265 elicited a synergistic or additive activity against the reference strains tested, reducing the MIC of NCL259 by 8- to 256- fold and the MIC of NCL265 by 4- to 256- fold. A small minority of Klebsiella spp. isolates (three) were resistant to both NCL259 and NCL265 with MICs > 256 µg/mL. This resistance was completely reversed in the presence of the efflux pump inhibitor phenylalanine-arginine-beta-naphthylamide (PAßN) to yield MIC values of 8−16 µg/mL and 2−4 µg/mL for NCL259 and NCL256, respectively. When NCL259 and NCL265 were tested against wild-type E. coli isolate BW 25113 and its isogenic multidrug efflux pump subunit AcrB deletion mutant (∆AcrB), the MIC of both compounds against the mutant ∆AcrB isolate was reduced 16-fold compared to the wild-type parent, indicating a significant role for the AcrAB-TolC efflux pump from Enterobacterales in imparting resistance to these robenidine analogues. In vitro cytotoxicity testing revealed that NCL259 and NCL265 had much higher levels of toxicity to a range of human cell lines compared to the parent robenidine, thus precluding their further development as novel antibiotics against Gram-negative pathogens.

Light-mediated multi-target protein degradation using arylazopyrazole photoswitchable PROTACs (AP-PROTACs).

Light-activable spatiotemporal control of PROTAC-induced protein degradation was achieved with novel arylazopyrazole photoswitchable PROTACs (AP-PROTACs). The use of a promiscuous kinase inhibitor in the design enables this unique photoswitchable PROTAC to selectively degrade four protein kinases together with on/off optical control using different wavelengths of light.

Antigiardial Activity of Novel Guanidine Compounds.

From four focused compound libraries based on the known anticoccidial agent robenidine, 44 compounds total were synthesised and screened for antigiardial activity. All active compounds were counter-screened for antibiotic and cytotoxic action. Of the analogues examined, 21 displayed IC50 <5 µM, seven with IC50 <1.0 µM. Most active were 2,2'-bis{[4-(trifluoromethoxy)phenyl]methylene}carbonimidic dihydrazide hydrochloride (30), 2,2'-bis{[4-(trifluoromethylsulfanyl)phenyl]methylene}carbonimidic dihydrazide hydrochloride (32), and 2,2'-bis[(2-bromo-4,5-dimethoxyphenyl)methylene]carbonimidic dihydrazide hydrochloride (41) with IC50 =0.2 µM. The maximal observed activity was a 5 h IC50 value of 0.2 µM for 41. The clinically used metronidazole was inactive at this timepoint at a concentration of 25 µM. Robenidine off-target effects at bacteria and cell line toxicity were removed. Analogue 41 was well tolerated in mice treated orally (100 mg/kg). Following 5 h treatment with 41, no Giardia regrowth was noted after 48 h.

Amino Alcohols as Potential Antibiotic and Antifungal Leads.

Five focused compound libraries (forty-nine compounds), based on prior studies in our laboratory were synthesized and screened for antibiotic and anti-fungal activity against S. aureus, E. coli, K. pneumoniae, P. aeruginosa, A. baumannii, C. albicans and C. neoformans. Low levels of activity, at the initial screening concentration of 32 µg/mL, were noted with analogues of (Z)-2-(3,4-dichlorophenyl)-3-phenylacrylonitriles which made up the first two focused libraries produced. The most promising analogues possessing additional substituents on the terminal aromatic ring of the synthesised acrylonitriles. Modifications of the terminal aromatic moiety were explored through epoxide installation flowed by flow chemistry mediated ring opening aminolysis with discreet sets of amines to the corresponding amino alcohols. Three new focused libraries were developed from substituted anilines, cyclic amines, and phenyl linked heterocyclic amines. The aniline-based compounds were inactive against the bacterial and fungal lines screened. The introduction of a cyclic, such as piperidine, piperazine, or morpholine, showed >50% inhibition when evaluated at 32 µg/mL compound concentration against methicillin-resistant Staphylococcus aureus. Examination of the terminal aromatic substituent via oxirane aminolysis allowed for the synthesis of three new focused libraries of afforded amino alcohols. Aromatic substituted piperidine or piperazine switched library activity from antibacterial to anti-fungal activity with ((Z)-2-(3,4-dichlorophenyl)-3-(4-(2-hydroxy-3-(4-methylpiperazin-1-yl)propoxy)phenyl)acrylonitrile), ((Z)-2-(3,4-dichlorophenyl)-3-(4-(2-hydroxy-3-(4-(4-hydroxyphenyl)piperazin-1-yl)propoxy)-phenyl)acrylonitrile) and ((Z)-3-(4-(3-(4-cyclohexylpiperazin-1-yl)-2-hydroxypropoxy)-phenyl)-2-(3,4-dichlorophenyl)-acrylonitrile) showing >95% inhibition of Cryptococcus neoformans var. grubii H99 growth at 32 µg/mL. While (Z)-3-(4-(3-(cyclohexylamino)-2-hydroxypropoxy)phenyl)-2-(3,4-dichlorophenyl)-acrylonitrile, (S,Z)-2-(3,4-dichlorophenyl)-3-(4-(2-hydroxy-3-(piperidin-1-yl)propoxy)phenyl)acrylonitrile, (R,Z)-2-(3,4-dichlorophenyl)-3-(4-(2-hydroxy-3-(piperidin-1-yl)propoxy)phenyl)acrylonitrile, (Z)-2-(3,4-dichlorophenyl)-3-(4-(2-hydroxy-3-(D-11-piperidin-1-yl)propoxy)phenyl)-acrylonitrile, and (Z)-3-(4-(3-(4-cyclohexylpiperazin-1-yl)-2-hydroxypropoxy)-phenyl)-2-(3,4-dichlorophenyl)-acrylonitrile 32 µg/mL against Staphylococcus aureus.

3,5-Bis(trifluoromethyl)phenylsulfonamides, a novel pancreatic cancer active lead. Investigation of the terminal aromatic moiety.

Virtual screening identified N-(6-((4-bromobenzyl)amino)hexyl)-3,5-bis(trifluoromethyl)benzenesulfonamide (1) a lead compound that bound to the S100A2-p53 binding groove. S100A2 is a Ca2+ binding protein with implications in cell signaling and is known to be upregulated in pancreatic cancer. It is a validated pancreatic cancer drug target. Lead 1, inhibited the growth of the MiaPaCa-2 pancreatic cancer cell line (GI50 = 2.97 µM). Focused compound libraries were developed to explore the SAR of this compound class with 4 libraries and 43 compounds total. Focused library (Library 1) development identified lipophillic sulfonamides as preferred for MiaPaCa-2 activity, with -CF3 and -C(CH3)3 substituents well tolerated (MiaPaCa-2 GI50 < 6 µM). Contraction of the hexylamino spacer to ethyl (Library 2) and propyl (Library 3) proved beneficial to activity against a broad spectrum panel of cancer cell lines: HT29 (lung), MCF-7 (breast), A2780 (ovarian), H460 (colon), A431 (skin), Du145 (prostate), BE2-C (neuroblastoma), U87 and SJ-G2 (glioblastoma) (cohort-1); and a pancreatic cancer cell line panel: MiaPaCa-2, BxPC-3, AsPC-1, Capan-2, HPAC and PANC-1 (cohort-2). With a marked preference for a propyl linker the observed GI50 values ranged from 1.4 to 30 µM against cohort-1 and 1.4-30 µM against cohort-2 cell lines. In Library 4 the terminal aromatic moiety was explored with 4-substituted analogues preferred (with activity of 48 (4-Cl) > 47 (3-Cl) > 46 (2-Cl)) against the cell lines examined. The introduction of bulky aromatic moieties was well tolerated, e.g. dihydrobenzo[b][1,4]dioxine (51) returned cohort-2 GI50 values of 1.2-3.4 µM. In all instances the observed docked binding poses and binding scores were consistent with the observed cytotoxicity. This in turn supports, but does not prove, that these analogues function via S100A2-p53 binding groove inhibition.

Impact of a Novel Anticoccidial Analogue on Systemic Staphylococcus aureus Infection in a Bioluminescent Mouse Model.

In this study, we investigated the potential of an analogue of robenidine (NCL179) to expand its chemical diversity for the treatment of multidrug-resistant (MDR) bacterial infections. We show that NCL179 exhibits potent bactericidal activity, returning minimum inhibitory concentration/minimum bactericidal concentrations (MICs/MBCs) of 1-2 µg/mL against methicillin-resistant Staphylococcus aureus, MICs/MBCs of 1-2 µg/mL against methicillin-resistant S. pseudintermedius and MICs/MBCs of 2-4 µg/mL against vancomycin-resistant enterococci. NCL179 showed synergistic activity against clinical isolates and reference strains of Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa in the presence of sub-inhibitory concentrations of colistin, whereas NCL179 alone had no activity. Mice given oral NCL179 at 10 mg/kg and 50 mg/kg (4 × doses, 4 h apart) showed no adverse clinical effects and no observable histological effects in any of the organs examined. In a bioluminescent S. aureus sepsis challenge model, mice that received four oral doses of NCL179 at 50 mg/kg at 4 h intervals exhibited significantly reduced bacterial loads, longer survival times and higher overall survival rates than the vehicle-only treated mice. These results support NCL179 as a valid candidate for further development to treat MDR bacterial infections as a stand-alone antibiotic or in combination with existing antibiotic classes.

Dynole 34-2 and Acrylo-Dyn 2-30, Novel Dynamin GTPase Chemical Biology Probes.

This protocol describes the chemical synthesis of the dynamin inhibitors Dynole 34-2 and Acrylo-Dyn 2-30, and their chemical scaffold matched partner inactive compounds. The chosen active and inactive paired compounds represent potent dynamin inhibitors and very closely related dynamin-inactive compounds, with the synthesis of three of the four compounds readily possible via a common intermediate. Combined with the assay data provided, this allows the interrogation of dynamin in vitro and potentially in vivo.

Synthesis of Phthaladyn-29 and Naphthalimide-10, GTP Site Directed Dynamin GTPase Inhibitors.

Herein we describe the detailed synthesis of the dynamin inhibitors Phthaladyn-29 and Napthaladyn-10, and their chemical scaffold matched partner inactive compounds. Combined with the assay data provided, this allows the interrogation of dynamin in vitro and potentially in vivo.

Pyrimidyn-Based Dynamin Inhibitors as Novel Cytotoxic Agents.

Five focused libraries of pyrimidine-based dynamin GTPase inhibitors, in total 69 compounds were synthesised, and their dynamin inhibition and broad-spectrum cytotoxicity examined. Dynamin plays a crucial role in mitosis, and as such inhibition of dynamin was expected to broadly correlate with the observed cytotoxicity. The pyrimidines synthesised ranged from mono-substituted to trisubstituted. The highest levels of dynamin inhibition were noted with di- and tri- substituted pyrimidines, especially those with pendent amino alkyl chains. Short chains and simple heterocyclic rings reduced dynamin activity. There were three levels of dynamin activity noted: 1-10, 10-25 and 25-60 µM. Screening of these compounds in a panel of cancer cell lines: SW480 (colon), HT29 (colon), SMA (spontaneous murine astrocytoma), MCF-7 (breast), BE2-C (glioblastoma), SJ-G2 (neuroblastoma), MIA (pancreas), A2780 (ovarian), A431 (skin), H460 (lung), U87 (glioblastoma) and DU145 (prostate) cell lines reveal a good correlation between the observed dynamin inhibition and the observed cytotoxicity. The most active analogues (31 a,b) developed returned average GI50 values of 1.0 and 0.78 µM across the twelve cell lines examined. These active analogues were: N2 -(3-dimethylaminopropyl)-N4 -dodecyl-6-methylpyrimidine-2,4-diamine (31 a) and N4 -(3-dimethylaminopropyl)-N2 -dodecyl-6-methylpyrimidine-2,4-diamine (31 b).

Shutting the gate: targeting endocytosis in acute leukemia.

Endocytosis entails selective packaging of cell surface cargos in cytoplasmic vesicles, thereby controlling key intrinsic cellular processes as well as the response of normal and malignant cells to their microenvironment. The purpose of this review is to outline the latest advances in the development of endocytosis-targeting therapeutic strategies in hematological malignancies.

Amino alcohol acrylonitriles as broad spectrum and tumour selective cytotoxic agents.

We have identified specific dichlorophenylacrylonitriles as lead compounds in the development of novel anticancer compounds, notably, (Z)-N-(4-(2-cyano-2-(3,4-dichlorophenyl)vinyl)phenyl)acetamide (1) and ANI-7 (2). Herein we specifically probe the SAR associated with the terminal aromatic ring and associated cytoxicity in a broad range of human cancer cell lines. Synthesis of three focused libraries revealed a poor tolerance for electron withdrawing and donating moieties (Library A). A clear preference for hydrophobic substituents on a terminal piperazine moiety (Library B) with good levels of broad spectrum cytotoxicity, e.g. 13a (GI50 2.5-6.0 µM), as did the introduction of a methylene spacer with 13i (4-CH3PhCH2; GI50 1.5-4.5 µM). Removal of the aromatic moiety and installation of simple hydrophobic groups (Library C), in particular an adamantyl moiety, afforded highly active broad spectrum cytotoxic agents with GI50 values ranging from 1.7 µM (14k; 1-adamantyl) to 5.6 µM (14i; pyrrolidine). Within these libraries we note lung cancer selectivity, relative to normal cells, of 13h (fluoro substituted acrylonitrile, GI50 1.6 µM, 9.3-fold selective); the colorectal selectivity of 14h (methylpiperidine analogue, GI50 0.36 µM, 6.9-fold selective) and the breast cancer selectivity of 13f (nitrile substituted acrylonitrile, GI50 2.3-6.0 µM, up to 20-fold selective). The latter was confirmed as a novel AhR ligand and a CYP1A1 activating compound, that likely induces cell death following bioactivation; a phenomenon previously described in breast cancer cell populations.