PB183, a PET probe suitable in prostate adenocarcinoma.
PB183, a non-selective sigma receptor ligand displaying high sigma-1 and sigma-2 receptor affinity, was evaluated in prostate tumour cell lines ...for its suitability as PET radiotracer. The pharmacodynamic and pharmacokinetic properties suggested
PB183 as a potential PET radiotracer to visualize prostate adenocarcinoma.
The Cannabinoid 2 receptor, CB2R, belonging to the endocannabinoid system, ECS, is involved in the first steps of neurodegeneration and cancer evolution and progression and thus its modulation may be ...exploited in the therapeutic and diagnostic fields. However, CB2Rs distribution and signaling pathways in physiological and pathological conditions are still controversial mainly because of the lack of reliable diagnostic tools. With the aim to produce green and safe systems to detect CB2R, we designed a series of fluorescent ligands with three different green fluorescent moieties (4-dimethylaminophthalimide, 4-DMAP, 7-nitro-4-yl-aminobenzoxadiazole, NBD, and Fluorescein-thiourea, FTU) linked to the N1-position of the CB2R pharmacophore N-adamantyl-4-oxo-1,4-dihydroquinoline-3-carboxamide through polymethylene chains. Compound 28 emerged for its compromise between good pharmacodynamic properties (CB2R Ki = 130 nM and no affinity vs the other subtype CB1R) and optimal fluorescent spectroscopic properties. Therefore, compound 28 was studied through FACS (saturation and competitive binding studies) and fluorescence microscopy (visualization and competitive binding) in engineered cells (CB2R-HEK293 cells) and in diverse tumour cells. The fluoligand binding assays were successfully set up, and affinity values for the two reference compounds GW405833 and WIN55,212-2, comparable to the values obtained by radioligand binding assays, were obtained. Fluoligand 28 also allowed the detection of the presence and quantification of the CB2R in the same cell lines. The interactions of compound 28 within the CB2R binding site were also investigated by molecular docking simulations, and indications for the improvement of the CB2R affinity of this class of compounds were provided. Overall, the results obtained through these studies propose compound 28 as a safe and green alternative to the commonly used radioligands for in vitro investigations.
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•CB2R is involved in neurodegeneration and in cancer evolution and progression.•Its physiological and pathological distribution and signaling are controversial.•Fluorescent ligands with green emitting moieties were designed to detect CB2R.•28 emerged for its pharmacodynamic and fluorescent spectroscopic properties.•28 was successfully used as CB2R fluorescent probe by FACS and immunofluorescence.
Generations of modulators of the efflux pump P-glycoprotein (P-gp) have been produced as tools to counteract the Multidrug Resistance (MDR) phenomenon in tumor therapy, but clinical trials were not ...successful so far. With the aim of contributing to the development of novel P-gp modulators, we started from recently studied high-affinity sigma-2 (σ2) receptor ligands that showed also potent interaction with P-gp. For σ2 receptors high-affinity binding, a basic N-atom is a strict requirement. Therefore, we reduced the basic character of the N-atom present in these ligands, and we obtained potent P-gp modulators with poor or null σ2 receptor affinity. We also evaluated whether modulation of P-gp by these novel compounds involved consumption of ATP (as P-gp substrates do), as a source of energy to support the efflux. Surprisingly, even small structural changes resulted in opposite behavior, with amide 13 depleting ATP, in contrast to its isomer 18. Two compounds, 15 and 25, emerged for their potent activity at P-gp, and deserve further investigations as tools for P-gp modulation.
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•Drastic reduction of σ2 receptor affinity through reduction of N-atom basicity starting from mixed σ2/P-gp active amines.•P-gp modulation activity kept in the ‘less-basic’ novel compounds.•Isomeric structural changes confer different mechanisms of interaction with P-gp (‘ATP-depleting’ and ‘non ATP-depleting’).
An in vitro model was developed to understand if celecoxib could synergize with Mitomycin C (MMC), commonly used for the prevention of non-muscle invasive bladder cancer recurrence, and eventually ...elucidate if the mechanism of interaction involves multi drug resistance (MDR) transporters.
UMUC-3, a non COX-2 expressing bladder cancer cell line, and UMUC-3-CX, a COX-2 overexpressing transfectant, as well as 5637, a COX-2 overexpressing cell line, and 5637si-CX, a non COX-2 expressing silenced 5637 cell line, were used in the present study. The expression of COX-2 and MDR pumps (P-gp, MDR-1 and BCRP) was explored through western blot. The anti-proliferative effect of celecoxib and MMC was studied with MTT test. Three biological permeability assays (Drug Transport Experiment, Substrate Transporter Inhibition, and ATP cell depletion) were combined to study the interaction between MDR transporters and celecoxib. Finally, the ability of celecoxib to restore MMC cell accumulation was investigated.
The anti-proliferative effect of celecoxib and MMC were investigated alone and in co-administration, in UMUC-3, UMUC-3-CX, 5637 and 5637si-CX cells. When administered alone, the effect of MMC was 8-fold greater in UMUC-3. However, co-administration of 1 μM, 5 μM, and 10 μM celecoxib and MMC caused a 2,3-fold cytotoxicity increase in UMUC-3-CX cell only. MMC cytotoxicity was not affected by celecoxib co-administration either in 5637, or in 5637si-CX cells. As a result of all finding from the permeability experiments, celecoxib was classified as P-gp unambiguous substrate: celecoxib is transported by MDR pumps and interferes with the efflux of MMC. Importantly, among all transporters, BCRP was only overexpressed in UMUC-3-CX cells, but not in 5637 and 5637si-CX.
The UMUC-3-CX cell line resembles a more aggressive phenotype with a lower response to MMC compared to the wt counterpart. However, the administration of celecoxib in combination to MMC causes a significant and dose dependent gain of the anti-proliferative activity. This finding may be the result of a direct interaction between celecoxib and MDR transporters. Indeed, BCRP is overexpressed in UMUC-3-CX, but not in UMUC-3, 5637, and 5637si-CX, in which celecoxib is ineffective.
P-glycoprotein (P-gp) is a membrane protein responsible for the active transport of several endogenous and exogenous substances. It constitutes a defense mechanism and, at the same time, it severely ...compromises the success rate of antitumor chemotherapy. In this study a small library of alkyl/oxyalkyl derivatives of MC70 4'-(6,7-dimethoxy-3,4-dihydro-1H-isoquinolin-2-ylmethyl)biphenyl-4-ol, a well-known P-gp inhibitor, was synthesized through straightforward functionalization of the phenolic group present in the structure of MC70. All compounds were characterized for their effect on P-gp, proving capable of blocking P-gp-mediated calcein-AM efflux with micromolar potency, following their ability to act as high-affinity substrates of this transporter. Excitingly, compound 4 6,7-dimethoxy-2-((4'-butoxybiphen-4-yl)methyl)-1,2,3,4-tetrahydroisoquinoline exhibited low nanomolar potency (5.2 nm) and had a peculiar activity profile, acting both as a positive allosteric modulator and as a substrate of the transporter. A new and more efficient synthesis of MC70 is also described.
Why PB28 Could Be a Covid 2019 Game Changer? Colabufo, Nicola Antonio; Leopoldo, Marcello; Ferorelli, Savina ...
ACS medicinal chemistry letters,
10/2020, Letnik:
11, Številka:
10
Journal Article
Recenzirano
Odprti dostop
PB28, a cyclohexylpiperazine derivative, could be a potential strategy for Covid 19 because in a recent study it has been found more active than hydroxychloroquine without interaction with cardiac ...proteins. PB28 has been designed, developed, and biologically evaluated in the past decade in our research group. A possible mechanism to explain its surprising anti-COVID-19 activity is suggested..
18FMC225 has been developed as a weak substrate of P-glycoprotein (P-gp) aimed to measure changes in the P-gp function at the blood–brain barrier with positron emission tomography. This study ...evaluates 18FMC225 kinetics in non-human primates and investigates the effect of both scan duration and P-gp inhibition. Three rhesus monkeys underwent two 91-min dynamic scans with blood sampling at baseline and after P-gp inhibition (8 mg/kg tariquidar). Data were analyzed using the 1-tissue compartment model (1-TCM) and 2-tissue compartment model (2-TCM) fits using metabolite-corrected plasma as the input function and for various scan durations (10, 20, 30, 60, and 91 min). The preferred model was chosen according to the Akaike information criterion and the standard errors (%) of the estimated parameters. For the 91-min scan duration, the influx constant K 1 increased by 40.7% and the volume of distribution (V T) by 30.4% after P-gp inhibition, while the efflux constant k 2 did not change significantly. Similar changes were found for all evaluated scan durations. K 1 did not depend on scan duration (10 minK 1 = 0.2191 vs 91 minK 1 = 0.2258), while V T and k 2 did. A scan duration of 10 min seems sufficient to properly evaluate the P-gp function using K 1 obtained with 1-TCM. For the 91-min scan, V T and K 1 can be estimated with a 2-TCM, and both parameters can be used to assess P-gp function.
Three analogues of To042, a tocainide‐related lead compound recently reported for the treatment of myotonia, were synthesized and evaluated in vitro as skeletal muscle sodium channel blockers ...possibly endowed with enhanced use‐dependent behavior. Patch‐clamp experiments on hNav1.4 expressed in HEK293 cells showed that N‐(naphthalen‐1‐yl)methyl‐4‐(2,6‐dimethyl)phenoxybutan‐2‐amine, the aryloxyalkyl bioisostere of To042, exerted a higher use‐dependent block than To042 thus being able to preferentially block the channels in over‐excited membranes while preserving healthy tissue function. It also showed the lowest active transport across BBB according to the results of P‐glycoprotein (P‐gp) interacting activity evaluation and the highest cytoprotective effect on HeLa cells. Quantum mechanical calculations and dockings gave insights on the most probable conformation of the aryloxyalkyl bioisostere of To042 in solution and the target residues involved in the binding, respectively. Both approaches indicated the conformations that might be adopted in both the unbound and bound state of the ligand. Overall, N‐(naphthalen‐1‐yl)methyl‐4‐(2,6‐dimethyl)phenoxybutan‐2‐amine exhibits an interesting toxico‐pharmacological profile and deserves further investigation.
Proper neural activity: A bioisosteric replacement approach allowed the identification of a use‐dependent sodium channel blocker (17 a) with low P‐glycoprotein‐mediated active transport across the blood‐brain barrier and a cytoprotective effect on HeLa cells. The target residues involved in binding hNav1.4 were identified by molecular docking studies.
Amyloid β oligomers (Aβo) are the main toxic species in Alzheimer's disease, which have been targeted for single drug treatment with very little success. In this work we report a new approach for ...identifying functional Aβo binding compounds. A tailored library of 971 fluorine containing compounds was selected by a computational method, developed to generate molecular diversity. These compounds were screened for Aβo binding by a combined
19
F and STD NMR technique. Six hits were evaluated in three parallel biochemical and functional assays. Two compounds disrupted Aβo binding to its receptor PrP
C
in HEK293 cells. They reduced the pFyn levels triggered by Aβo treatment in neuroprogenitor cells derived from human induced pluripotent stem cells (hiPSC). Inhibitory effects on pTau production in cortical neurons derived from hiPSC were also observed. These drug-like compounds connect three of the pillars in Alzheimer's disease pathology,
i.e.
prion, Aβ and Tau, affecting three different pathways through specific binding to Aβo and are, indeed, promising candidates for further development.
A new approach combining virtual screening,
19
F and STD NMR, and biochemical assays using hiPSC and targetting multiple pathways involving Aβ, PrP
C
and Tau provides a more effective strategy for Alzheimer's disease drug discovery than Aβ only approach.
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