title: Development of novel cyclic peptides as pro-apoptotic agents.
abstract: Our recent finding that paclitaxel behaves as a peptidomimetic of the endogenous protein Nur77 inspired the design of two peptides (PEP1 and PEP2) reproducing the effects of paclitaxel on Bcl-2 and tubulin, proving the peptidomimetic nature of paclitaxel. Starting from these peptide-hits, we herein describe the synthesis and the biological investigation of linear and cyclic peptides structurally related to PEP2. While linear peptides (2a,b, 3a,b, 4, 6a-f) were found inactive in cell-based assays, biological analysis revealed a pro-apoptotic effect for most of the cyclic peptides (5a-g). Cellular permeability of 5a (and also of 2a,b) on HL60 cells was assessed through confocal microscopy analysis. Further cellular studies on a panel of leukemic cell lines (HL60, Jurkat, MEC, EBVB) and solid tumor cell lines (breast cancer MCF-7 cells, human melanoma A375 and 501Mel cells, and murine melanoma B16F1 cells) confirmed the pro-apoptotic effect of the cyclic peptides. Cell cycle analysis revealed that treatment with 5a, 5c, 5d or 5f resulted in an increase in the number of cells in the sub-G0/G1 peak. Direct interaction with tubulin (turbidimetric assay) and with microtubules (immunostaining experiments) was assessed in vitro for the most promising compounds.
authors.affiliation: European Research Centre for Drug Discovery and Development (NatSynDrugs), Siena University, via Aldo Moro 2, I-53100 Siena, Italy; Istituto Toscano Tumori, Siena University, via Aldo Moro 2, I-53100 Siena, Italy.
authors.forename: Margherita
authors.initials: M
authors.lastname: Brindisi
authors.affiliation: European Research Centre for Drug Discovery and Development (NatSynDrugs), Siena University, via Aldo Moro 2, I-53100 Siena, Italy; Istituto Toscano Tumori, Siena University, via Aldo Moro 2, I-53100 Siena, Italy.
authors.forename: Samuele
authors.initials: S
authors.lastname: Maramai
authors.affiliation: European Research Centre for Drug Discovery and Development (NatSynDrugs), Siena University, via Aldo Moro 2, I-53100 Siena, Italy; Istituto Toscano Tumori, Siena University, via Aldo Moro 2, I-53100 Siena, Italy.
authors.forename: Simone
authors.initials: S
authors.lastname: Brogi
authors.affiliation: Department of Life Sciences, via Aldo Moro 2, I-53100 Siena, Italy.
authors.forename: Emanuela
authors.initials: E
authors.lastname: Fanigliulo
authors.affiliation: European Research Centre for Drug Discovery and Development (NatSynDrugs), Siena University, via Aldo Moro 2, I-53100 Siena, Italy; Istituto Toscano Tumori, Siena University, via Aldo Moro 2, I-53100 Siena, Italy. Electronic address: butini3@unisi.it.
authors.forename: Stefania
authors.initials: S
authors.lastname: Butini
authors.affiliation: European Research Centre for Drug Discovery and Development (NatSynDrugs), Siena University, via Aldo Moro 2, I-53100 Siena, Italy; Istituto Toscano Tumori, Siena University, via Aldo Moro 2, I-53100 Siena, Italy.
authors.forename: Egeria
authors.initials: E
authors.lastname: Guarino
authors.affiliation: European Research Centre for Drug Discovery and Development (NatSynDrugs), Siena University, via Aldo Moro 2, I-53100 Siena, Italy; Istituto Toscano Tumori, Siena University, via Aldo Moro 2, I-53100 Siena, Italy.
authors.forename: Alice
authors.initials: A
authors.lastname: Casagni
authors.affiliation: European Research Centre for Drug Discovery and Development (NatSynDrugs), Siena University, via Aldo Moro 2, I-53100 Siena, Italy; Istituto Toscano Tumori, Siena University, via Aldo Moro 2, I-53100 Siena, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Lamponi
authors.affiliation: European Research Centre for Drug Discovery and Development (NatSynDrugs), Siena University, via Aldo Moro 2, I-53100 Siena, Italy; Istituto Toscano Tumori, Siena University, via Aldo Moro 2, I-53100 Siena, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Bonechi
authors.affiliation: School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, 152-160 Pearse Street, Dublin 2, Ireland.
authors.forename: Seema M
authors.initials: SM
authors.lastname: Nathwani
authors.affiliation: Istituto Toscano Tumori, Siena University, via Aldo Moro 2, I-53100 Siena, Italy; Department of Life Sciences, via Aldo Moro 2, I-53100 Siena, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Finetti
authors.affiliation: Department of Experimental Medicine, Università degli Studi di Perugia, P.le Gambuli, I-06132 Perugia, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Ragonese
authors.affiliation: Department of Experimental Medicine, Università degli Studi di Perugia, P.le Gambuli, I-06132 Perugia, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Arcidiacono
authors.affiliation: Dipartimento DIFARMA, Università di Salerno, I-84084 Fisciano, Salerno, Italy.
authors.forename: Pietro
authors.initials: P
authors.lastname: Campiglia
authors.affiliation: European Research Centre for Drug Discovery and Development (NatSynDrugs), Siena University, via Aldo Moro 2, I-53100 Siena, Italy; Istituto Toscano Tumori, Siena University, via Aldo Moro 2, I-53100 Siena, Italy.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Valenti
authors.affiliation: European Research Centre for Drug Discovery and Development (NatSynDrugs), Siena University, via Aldo Moro 2, I-53100 Siena, Italy; Dipartimento di Farmacia, University of Naples Federico II, via D. Montesano 49, I-80131 Naples, Italy.
authors.forename: Ettore
authors.initials: E
authors.lastname: Novellino
authors.affiliation: Department of Experimental Medicine, Università degli Studi di Perugia, P.le Gambuli, I-06132 Perugia, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Spaccapelo
authors.affiliation: Istituto Toscano Tumori, Siena University, via Aldo Moro 2, I-53100 Siena, Italy; Department of Life Sciences, via Aldo Moro 2, I-53100 Siena, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Morbidelli
authors.affiliation: School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, 152-160 Pearse Street, Dublin 2, Ireland.
authors.forename: Daniela M
authors.initials: DM
authors.lastname: Zisterer
authors.affiliation: School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, 152-160 Pearse Street, Dublin 2, Ireland.
authors.forename: Clive D
authors.initials: CD
authors.lastname: Williams
authors.affiliation: European Research Centre for Drug Discovery and Development (NatSynDrugs), Siena University, via Aldo Moro 2, I-53100 Siena, Italy; Istituto Toscano Tumori, Siena University, via Aldo Moro 2, I-53100 Siena, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Donati
authors.affiliation: Department of Life Sciences, via Aldo Moro 2, I-53100 Siena, Italy.
authors.forename: Cosima
authors.initials: C
authors.lastname: Baldari
authors.affiliation: European Research Centre for Drug Discovery and Development (NatSynDrugs), Siena University, via Aldo Moro 2, I-53100 Siena, Italy; Istituto Toscano Tumori, Siena University, via Aldo Moro 2, I-53100 Siena, Italy. Electronic address: campiani@unisi.it.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Campiani
authors.affiliation: Department of Life Sciences, via Aldo Moro 2, I-53100 Siena, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Ulivieri
authors.affiliation: European Research Centre for Drug Discovery and Development (NatSynDrugs), Siena University, via Aldo Moro 2, I-53100 Siena, Italy; Istituto Toscano Tumori, Siena University, via Aldo Moro 2, I-53100 Siena, Italy.
authors.forename: Sandra
authors.initials: S
authors.lastname: Gemma
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D051379:Mice; D008870:Microtubules / Q000378:metabolism; D010456:Peptides, Cyclic / Q000737:chemistry / Q000494:pharmacology*; D057786:Peptidomimetics / Q000737:chemistry / Q000494:pharmacology; D013329:Structure-Activity Relationship; D014404:Tubulin / Q000187:drug effects
chemical_list: D010456:Peptides, Cyclic; D057786:Peptidomimetics; D014404:Tubulin
keywords: Anticancer agents; Bcl-2; Confocal microscopy; Cyclic peptides; FACS analysis; Molecular modeling; NMR studies; Nur77; Peptidomimetics; Pro-apoptotic agents; Tubulin