Original article Pure enantiomers of benzoylamino-tranylcypromine: LSD1 inhibition, gene modulation in human leukemia cells and effects on clonogenic potential of murine promyelocytic blasts Sergio Valente a , Veronica Rodriguez a , Ciro Mercurio b , Paola Vianello c , Bruna Saponara d , Roberto Cirilli d , Giuseppe Ciossani e , Donatella Labella a , Biagina Marrocco a , Daria Monaldi a , Giovanni Ruoppolo f , Mats Tilset g , Oronza A. Botrugno c , Paola Dessanti c , Saverio Minucci c, h , Andrea Mattevi e , Mario Varasi c , Antonello Mai a, i, * a Department of Drug Chemistry and Technologies, Sapienza University of Roma, P.le A. Moro 5, 00185 Roma, Italy b Genextra Group, DAC s.r.l. Via Adamello 16, 20139 Milano, Italy c Dipartimento di Oncologia Sperimentale, IEO e European Institute of Oncology, Via Adamello 16, 20139 Milano, Italy d Italian National Institute of Health, Department of Therapeutic Research and Medicines Evaluation, Via Regina Elena 299, 00161 Roma, Italy e Department of Biology and Biotechnology, University of Pavia, Via Ferrata 1, 27100 Pavia, Italy f Department of Sense Organs, Sapienza University of Roma, P.le A. Moro 5, 00185 Roma, Italy g Centre of Theoretical and Computational Chemistry (CTCC), Department of Chemistry, P.O. Box 1033, Blindern, N-0315 Oslo, Norway h Department of Biosciences, University of Milan, 20100 Milan, Italy i Pasteur Institute e Cenci Bolognetti Foundation, Sapienza University of Roma, P.le A. Moro 5, 00185 Roma, Italy article info Article history: Received 15 October 2014 Received in revised form 27 February 2015 Accepted 28 February 2015 Available online 3 March 2015 Keywords: Epigenetics Leukemia Lysine-specific demethylase 1 Stereoisomers Tranylcypromine abstract The pure enantiomers of the N-(2-, 3-, and 4-(2-aminocyclopropyl)phenyl)benzamides hydrochlorides 11aej were prepared and tested against LSD1 and MAO enzymes. The evaluation of the regioisomers 11a ej highlighted a net increase of the anti-LSD1 potency by shifting the benzamide moiety from ortho to meta and mainly to para position of tranylcypromine phenyl ring, independently from their trans or cis stereochemistry. In particular, the para-substituted 11a,b (trans) and 11g,h (cis) compounds displayed LSD1 and MAO-A inhibition at low nanomolar levels, while were less potent against MAO-B. The meta analogs 11c,d (trans) and 11i,j (cis) were in general less potent, but more efficient against MAO-A than against LSD1. In cellular assays, all the para and meta enantiomers were able to inhibit LSD1 by inducing Gfi-1b and ITGAM gene expression, with 11b,c and 11gei giving the highest effects. Moreover, 11b and 11g,h strongly inhibited the clonogenic potential of murine promyelocytic blasts. © 2015 Elsevier Masson SAS. All rights reserved. 1. Introduction Post-translational methylation of histones is a covalent modifi- cation intimately linked with either transcriptional activation or repression. The histone lysine (Lys, K) residues can undergo mono-, di- and trimethylation, and each methylation state represents a specific epigenetic marker with a precise biological meaning and a well-defined chromatin localization [1e4]. In particular, methyl- ation at the histone 3 lysine 4 (H3K4), H3K36, or H3K79 residue leads to transcriptional activation, whereas methylation at H3K9, H3K27, or H4K20 are markers of gene silencing [1e4]. Lys meth- ylations are reversible marks due to the action of histone Lys demethylases (KDMs), a large family of “erasers” that catalyze the removal of methyl groups from (poly)methylated Lys substrates [5e7]. There are two known classes of KDMs, differing in their reaction chemistry, co-factor/co-substrate used, and Lys-substrate speci- ficity [8]. The flavin-dependent KDMs, lysine-specific demethylase 1 and 2 (LSD1 and LSD2), only act on mono- and di-methylated Lys and produce formaldehyde and hydrogen peroxide in addition to unmethylated or monomethylated Lys, whereas the Jumonji- containing KDMs, utilizing Fe(II) and a-ketoglutarate as co- substrates, can act on mono-, di- and tri-methylated Lys side chains [6e9]. LSD1 typically acts on mono- and di-methylated * Corresponding author. E-mail address: antonello.mai@uniroma1.it (A. Mai). Contents lists available at ScienceDirect European Journal of Medicinal Chemistry journal homepage: http://www.elsevier.com/locate/ejmech http://dx.doi.org/10.1016/j.ejmech.2015.02.060 0223-5234/© 2015 Elsevier Masson SAS. All rights reserved. European Journal of Medicinal Chemistry 94 (2015) 163e174