Nuno A. L. Pereira

Bio: Nuno A. L. Pereira is an academic researcher from University of Lisbon. The author has contributed to research in topics: Excitotoxicity & NMDA receptor. The author has an hindex of 7, co-authored 10 publications receiving 165 citations.

Reactivation of wild-type and mutant p53 by tryptophanolderived oxazoloisoindolinone SLMP53-1, a novel anticancer small-molecule

Abstract: Restoration of the p53 pathway, namely by reactivation of mutant (mut) p53, represents a valuable anticancer strategy. Herein, we report the identification of the enantiopure tryptophanol-derived oxazoloisoindolinone SLMP53-1 as a novel reactivator of wild-type (wt) and mut p53, using a yeast-based screening strategy. SLMP53-1 has a p53-dependent anti-proliferative activity in human wt and mut p53R280K-expressing tumor cells. Additionally, SLMP53-1 enhances p53 transcriptional activity and restores wt-like DNA binding ability to mut p53R280K. In wt/mut p53-expressing tumor cells, SLMP53-1 triggers p53 transcription-dependent and mitochondrial apoptotic pathways involving BAX, and wt/mut p53 mitochondrial translocation. SLMP53-1 inhibits the migration of wt/mut p53-expressing tumor cells, and it shows promising p53-dependent synergistic effects with conventional chemotherapeutics. In xenograft mice models, SLMP53-1 inhibits the growth of wt/mut p53-expressing tumors, but not of p53-null tumors, without apparent toxicity. Collectively, besides the potential use of SLMP53-1 as anticancer drug, the tryptophanol-derived oxazoloisoindolinone scaffold represents a promissing starting point for the development of effective p53-reactivating drugs.

Enantiopure Indolizinoindolones with in vitro Activity against Blood- and Liver-Stage Malaria Parasites

Abstract: Malaria continues to be a major cause of morbidity and mortality to this day, and resistance to drugs like chloroquine has led to an urgent need to discover novel chemical entities aimed at new targets. Here, we report the discovery of a novel class of potential antimalarial compounds containing an indolizinoindolone scaffold. These novel enantiopure indolizinoindolones were synthesized, in good-to-excellent yields and excellent diastereoselectivities, by cyclocondensation reaction of (S)- or (R)-tryptophanol and 2-acyl benzoic acids, followed by intramolecular α-amidoalkylation. Interestingly, we were able to synthesize for the first time 7,13b-cis indolizinoindolones in a two-step route. The novel compounds showed promising activity against erythrocytic stages of the human malaria parasite, Plasmodium falciparum, and liver stages of the rodent parasite Plasmodium berghei. In particular, an (S)-tryptophanol-derived isoindolinone was identified as a promising starting scaffold to search for novel antimalarials, combining excellent activity against both stages of the parasite's life cycle with low cytotoxicity and excellent metabolic and chemical stability in vitro.

Synthesis of phenylalaninol-derived oxazolopyrrolidone lactams and evaluation as NMDA receptor antagonists

Abstract: N-Methyl-d-aspartate (NMDA) receptor antagonists are known to rescue neuronal cell death caused by excessive activation of glutamate receptors This phenomenon, known as excitotoxicity, is implicated in the pathogenesis of several neurodegenerative disorders including ischemia, Alzheimer’s disease, Parkinson’s disease, and Huntington’s disease Unfortunately, some NMDA receptor antagonists have shown discouraging results when tested in clinical trials However, recent advances in the physiology and pharmacology of the NMDA receptor have kept interest alive in modulating NMDA receptors for therapeutic intervention We present here the synthesis of a small library of phenylalaninol-derived oxazolopyrrolidone lactams and their evaluation as NMDA receptor antagonists The compounds were easily synthesized in yields up to 92 % In addition, one of the compounds has a 50 % inhibitory concentration (IC 50) of 62 μM and offers potential to develop more potent NMDA receptor antagonists

Discovery of a small-molecule protein kinase Cδ-selective activator with promising application in colon cancer therapy

Abstract: Protein kinase C (PKC) isozymes play major roles in human diseases, including cancer. Yet, the poor understanding of isozymes-specific functions and the limited availability of selective pharmacological modulators of PKC isozymes have limited the clinical translation of PKC-targeting agents. Here, we report the first small-molecule PKCδ-selective activator, the 7α-acetoxy-6β-benzoyloxy-12-O-benzoylroyleanone (Roy-Bz), which binds to the PKCδ-C1-domain. Roy-Bz potently inhibited the proliferation of colon cancer cells by inducing a PKCδ-dependent mitochondrial apoptotic pathway involving caspase-3 activation. In HCT116 colon cancer cells, Roy-Bz specifically triggered the translocation of PKCδ but not other phorbol ester responsive PKCs. Roy-Bz caused a marked inhibition in migration of HCT116 cells in a PKCδ-dependent manner. Additionally, the impairment of colonosphere growth and formation, associated with depletion of stemness markers, indicate that Roy-Bz also targets drug-resistant cancer stem cells, preventing tumor dissemination and recurrence. Notably, in xenograft mouse models, Roy-Bz showed a PKCδ-dependent antitumor effect, through anti-proliferative, pro-apoptotic, and anti-angiogenic activities. Besides, Roy-Bz was non-genotoxic, and in vivo it had no apparent toxic side effects. Collectively, our findings reveal a novel promising anticancer drug candidate. Most importantly, Roy-Bz opens the way to a new era on PKC biology and pharmacology, contributing to the potential redefinition of the structural requirements of isozyme-selective agents, and to the re-establishment of PKC isozymes as feasible therapeutic targets in human diseases.

How To Design a Successful p53-MDM2/X Interaction Inhibitor: A Thorough Overview Based on Crystal Structures.

Abstract: A recent therapeutic strategy in oncology is based on blocking the protein-protein interaction between the murine double minute (MDM) homologues MDM2/X and the tumor-suppressor protein p53. Inhibiting the binding between wild-type (WT) p53 and its negative regulators MDM2 and/or MDMX has become an important target in oncology to restore the antitumor activity of p53, the so-called guardian of our genome. Interestingly, based on the multiple disclosed compound classes and structural analysis of small-molecule-MDM2 adducts, the p53-MDM2 complex is perhaps the best studied and most targeted protein-protein interaction. Several classes of small molecules have been identified as potent, selective, and efficient inhibitors of the p53-MDM2/X interaction, and many co-crystal structures with the protein are available. Herein we review the properties as well as preclinical and clinical studies of these small molecules and peptides, categorized by scaffold type. A particular emphasis is made on crystallographic structures and the observed binding modes of these compounds, including conserved water molecules present.