Roberto Perrone

Bio: Roberto Perrone is an academic researcher from University of Bari. The author has contributed to research in topics: Receptor & Agonist. The author has an hindex of 36, co-authored 157 publications receiving 3619 citations.

Cyclohexylpiperazine derivative PB28, a σ2 agonist and σ1 antagonist receptor, inhibits cell growth, modulates P-glycoprotein, and synergizes with anthracyclines in breast cancer

Abstract: σ Ligands have recently been shown to have cytotoxic activity, to induce ceramide-dependent/caspase-independent apoptosis, and to down-regulate P-glycoprotein (P-gp) mRNA levels in some mouse and human models. In this study, we verified whether a mixed σ2 agonist/σ1 antagonist, PB28, was able to have antitumor activity and to enhance anthracycline efficacy in two human breast cancer cell lines, MCF7 and MCF7 ADR, both characterized by significant σ2 receptor expression, by high and low σ1 receptor expression, and low and high P-gp expression, respectively. In both cell lines, PB28 showed high σ2 receptor affinity and low σ1 receptor affinity; furthermore, it inhibited cell growth with a clear effect at 48 hours (IC50 in nanomolar range), a consistent time exposure-independent increase of G-G1-phase fraction (of ∼20% of both cell lines) and caspase-independent apoptosis (15% increased after 1-day drug exposure). PB28 also reduced P-gp expression in a concentration- and time-dependent manner (∼60% in MCF7 and 90% in MCF7 ADR). We showed also a strong synergism between PB28 and doxorubicin by adopting either simultaneous or sequential schedules of the two drugs. We suggest that this synergism could depend on PB28-induced increase of intracellular accumulation of doxorubicin (∼50% in MCF7 and 75% in MCF7 ADR by flow cytometry analysis). In conclusion, we suggest that the σ2 agonist PB28 could be an interesting antitumor agent either in monotherapy or in combination with conventional drugs. [Mol Cancer Ther 2006;5(7):1807–16]

Perspectives of P-glycoprotein modulating agents in oncology and neurodegenerative diseases: pharmaceutical, biological, and diagnostic potentials.

Abstract: Human ATP binding cassette (ABC) transporters belong to a family of 49 genes classified into seven subfamilies: ABCA, ABC-B, ABC-C, ABC-D, ABC-E, ABC-F, ABC-G Some of these transporters are involved in multidrug resistance (MDR), in particular ABC-B1, better known as Pglycoprotein (P-gp), ABC-G2, better known as breast cancer resistance protein (BCRP), and ABC-C1-6, also known as multidrug resistance associated proteins (MRP1-6) 3 These transporters are overexpressed in several tumor cell lines and are responsible for drug efflux out of the cells They use the energyofATPhydrolysis to extrude compoundsbya complex translocation process Three models for P-gp translocation have been suggested: (1) pore, (2) flippase, and (3) hydrophobic vacuum cleaner models In the pore model, drugs binding P-gp to the cytosol are transported out through a protein channel In the flippase model, P-gp flips drugs that are transported from the inner to the outer compartment of the plasmamembrane against a concentration gradient In the hydrophobic vacuum cleaner model, molecules recognized by P-gp in the lipid bilayer enter the protein from the membranous site and exit through the central cavity P-gp contains 12 transmembrane helices organized in two membrane spanning domains (MSDs), each containing six transmembrane helices, and two nucleotide binding domains (NBDs) responsible for ATP binding BCRP is a “half transporter” because it is formed by only one MSD and one NBD although it dimerizes to be fully active MRPs differ from P-gp because they display three MSDs, and the additional domain contains five transmembrane domains This review will focus on the physiological and pathological role of P-gp and will highlight the involvement of this protein both in MDR of tumors and in the physiological function of several barriers P-gp overexpression is a significant factor in chemotherapy failure due to the ability of this pump to limit the cell accumulation of antineoplastic drugs Moreover, P-gp is expressed in barriers such as the blood-brain barrier (BBB), bloodcerebro spinal fluid (B-CSF) barrier, and blood-testis barrier (BTB) It modulates the absorption and excretion of xenobiotics across these barriers P-gp is localized at the apical membranes of liver, kidney, placenta, and the villus tip of enterocytes in the gut In the gut, P-gp displays a strategic activity modulating access of drugs to the CYP3A4 enzyme, thereby regulating drug metabolism and absorption 11 P-gp Involvement in Cancer and CNS DiseasesMDR is a complex phenomenon that is caused by tumor microenvironment changes or cancer cell-specific factors Cancer cell-specific factors can occur at different levels: (i) increased drug efflux or decreased drug influx; (ii) drug inactivation; (iii) drug target modification; (iv) apoptosis evasion The first of these mechanisms can be mediated by plasma membrane transporters such as P-gp Asmentioned above, high levels of P-gp are reported in the luminal membrane of the endothelial cells constituting the BBB, B-CSF, and BTB This strategic localization gives P-gp a crucial physiologically role in keeping drugs in the blood P-gp exerts a protective function in the BBB; indeed, recent studies have reported a potential correlation between P-gp activity and/or expression in CNS disorders such as Alzheimer’s disease (AD), Parkinson’s disease (PD), and epilepsy AD, a neurodegenerative disorder characterized by a progressive loss of cognitive function, evolves as several forms of dementia that display insoluble β-amyloid (Aβ) plaques and neurofibrillary tangles (NFTs) Aβ secretion is *To whom correspondence should be addressed Phone: þ39-0805442727 Fax þ39-080-5442231 E-mail: colabufo@farmchimunibait Abbreviations: Aβ, β-amyloid; AB, apical-basolateral; ABC, ATP binding cassette; AD, Alzheimer’s disease; AML, acute myelogenous leukemia; ATP, adenosine 50-triphosphate; BA, basolateral-apical; Bmax, maximal bound; BBB, blood-brain barrier; BCRP, breast cancer resistance protein; B-CSF, blood-cerebro spinal fluid; BTB, blood-testis barrier; Caco-2, human colonic carcinoma; calcein-AM, calcein acethoxymethyl ester; CD56þ, peripheral blood mononuclear cells; CHOP, cyclophosphamide, hydroxydaunorubicin (adriamycin), oncovin (vincristine), prednisone/prednisolone; CNS, central nervous system; C-PIB, C-Pittsburgh compound B; CYP3A4, cytochrome P-4503A4; DV, distribution volume; FDA, Food and Drug Administration; F-FDDNP, F(2-(1-{6-[(2-[F]fluoroethyl(methyl)amino]-2-naphthyl}ethylidene)malononitrile; FMZ, flumazenil; GI, gastrointestinal; HCT-8, human colorectale adenocarcinoma; ISF, interstitial fluid; Kd, dissociation constant; LBs, Lewy bodies; LLC-PK1, porcine kidney cell line; LRP1, low density lipoprotein receptor-related protein; MDCK, Madin-Darby canine kidney; MDE, multidrug efflux; MDR, multidrug resistance;MPPþ, 1-methyl-4-phenylpyridinium;MRP,multidrug resistance associated proteins;MSA, multisystem atrophy;MSD, membrane spanning domain; MTD, maximum tolerated dose; MTL, medial temporal lobe; NBD, nucleotide binding domain; NFTs, neurofibrillary tangles; NSCLC, non-small-cell lung cancer; PAHG, hippocampus, parahippocampal, ambient gyrus; Papp, apparent permeability; PD, Parkinson’s disease; PET, positron emission tomography; P-gp, Pglycoprotein; PSP, progressive supranuclear palsy; SCLC, small-cell lung cancer; SNP, single nucleotide polymorphism; SPECT, single photon emission computed tomography; T8, T-suppressor cells; TLE, temporal lobe epilepsy

Antiproliferative and cytotoxic effects of some σ2 agonists and σ1 antagonists in tumour cell lines

Abstract: To establish the activity of σ ligands at σ1 and σ2 receptor, we chose two tumour cell lines, the human SK-N-SH neuroblastoma and the rat C6 glioma lines, which express σ2 receptors at a high density and σ1 receptors in their high-affinity or low-affinity state. We tested the σ2 receptor agonist PB28 and the σ2 antagonist AC927, and (+)-pentazocine and NE100 as agonist and antagonist, respectively, at σ1 receptors, with regard to antiproliferative and cytotoxic effects. In addition, 1,3-di(2-tolyl)guanidine (DTG) and haloperidol were tested as reference compounds displaying nearly equipotent σ affinity (σ2>σ1 and σ1>σ2, respectively). In both SK-N-SH and C6 cells, PB28 and NE100 displayed the most potent results both in antiproliferative and cytotoxic assay while AC927 and (+)-pentazocine were inactive in both assays. The cytotoxic and antiproliferative effects of DTG and haloperidol reflected their σ1 antagonist activity and σ2 agonist activity. Moreover, our results in the tumour cell lines correlated well with those for σ2 activity found previously in a functional assay in the guinea-pig bladder. These findings establish a new model for evaluating both σ2 and σ1 receptor activity of σ ligands, which could be useful for developing new ligands having mixed σ2 agonist/σ1 antagonist activity as potential antineoplastic agents.

Structure-affinity relationship study on N-[4-(4-arylpiperazin-1-yl)butyl]arylcarboxamides as potent and selective dopamine D3 receptor ligands

Abstract: The benzamide PB12 (N-[2-[4-(4-chlorophenyl)piperazin-1-yl]ethyl]-3-methoxybenzamide) (1), already reported as potent and selective dopamine D(4) receptor ligand, has been modified searching for structural features that could lead to D(3) receptor affinity. Changes in the aromatic ring linked to N-1 piperazine ring led to the identification of 2-methoxyphenyl and 2,3-dichlorophenyl derivatives (compounds 6 and 13) displaying moderate D(3) affinity (K(i) = 145 and 31 nM, respectively). Intermediate alkyl chain elongation in compounds 1, 6, and 13 improved binding affinity for the D(3) receptor and decreased the D(4) affinity (compounds 18-26). Among these latter compounds, the N-[4-[4-(2,3-dichlorophenyl)piperazin-1-yl]butyl]-3-methoxybenzamide (19) was further modified with the replacement or of the 2,3-dichlorophenyl moiety (compounds 27-30) or of the 3-methoxyphenyl ring (compounds 31-41). In this way, we identified several high-affinity D(3) ligands (0.13 nM < K(i)'s < 4.97 nM) endowed with high selectivity over D(2), D(4), 5-HT(1A), and alpha(1) receptors. In addition, N-[4-[4-(2,3-dimethylphenyl)piperazin-1-yl]butyl]-3-methoxybenzamide (27) and N-[4-[4-(2,3-dichlorophenyl)piperazin-1-yl]butyl]-7-methoxy-2-benzofurancarboxamide (41) appear to be valuable candidates for positron emission tomography (PET) because of their affinity values, lipophilicity properties, and liability of (11)C labeling in the O-methyl position.

Profound methyl effects in drug discovery and a call for new C-H methylation reactions.

Abstract: The methyl group is one of the most commonly occurring carbon fragments in small-molecule drugs. This simplest alkyl fragment appears in more than 67 % of the top-selling drugs of 2011 and can modulate both the biological and physical properties of a molecule. This Review focuses on so-called magic methyl effects on binding potency, where the seemingly mundane change of CH to CMe improves the IC50 value of a drug candidate more than 100-fold. This discussion is followed by a survey of recent advances in synthetic chemistry that allow the direct methylation of C(sp(2) )H and C(sp(3) )H bonds. It is our hope that the relevance of the meager methyl group to drug discovery as presented herein will inspire reports on new CH methylation reactions.

Reducing safety-related drug attrition: the use of in vitro pharmacological profiling

Abstract: In vitro pharmacological profiling is increasingly being used earlier in the drug discovery process to identify undesirable off-target activity profiles that could hinder or halt the development of candidate drugs or even lead to market withdrawal if discovered after a drug is approved Here, for the first time, the rationale, strategies and methodologies for in vitro pharmacological profiling at four major pharmaceutical companies (AstraZeneca, GlaxoSmithKline, Novartis and Pfizer) are presented and illustrated with examples of their impact on the drug discovery process We hope that this will enable other companies and academic institutions to benefit from this knowledge and consider joining us in our collaborative knowledge sharing

Hepatocyte growth factor induces gefitinib resistance of lung adenocarcinoma with epidermal growth factor receptor-activating mutations

Abstract: Lung cancer with epidermal growth factor receptor (EGFR)-activating mutations responds favorably to the EGFR tyrosine kinase inhibitors gefitinib and erlotinib. However, 25% to 30% of patients with EGFR-activating mutations show intrinsic resistance, and the responders invariably acquire resistance to gefitinib. Here, we showed that hepatocyte growth factor (HGF), a ligand of MET oncoprotein, induces gefitinib resistance of lung adenocarcinoma cells with EGFR-activating mutations by restoring the phosphatidylinositol 3-kinase/Akt signaling pathway via phosphorylation of MET, but not EGFR or ErbB3. Strong immunoreactivity for HGF in cancer cells was detected in lung adenocarcinoma patients harboring EGFR-activating mutations, but no T790M mutation or MET amplification, who showed intrinsic or acquired resistance to gefitinib. The findings indicate that HGF-mediated MET activation is a novel mechanism of gefitinib resistance in lung adenocarcinoma with EGFR-activating mutations. Therefore, inhibition of HGF-MET signaling may be a considerable strategy for more successful treatment with gefitinib.