Antoni Riera
University of Barcelona
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Antoni Riera.
Cancer Cell | 2012
Alexandre Calon; Elisa Espinet; Sergio Palomo-Ponce; Daniele V. F. Tauriello; Mar Iglesias; María Virtudes Céspedes; Marta Sevillano; Cristina Nadal; Peter Jung; Xiang H.-F. Zhang; Daniel Byrom; Antoni Riera; David Rossell; Ramon Mangues; Joan Massagué; Elena Sancho; Eduard Batlle
A large proportion of colorectal cancers (CRCs) display mutational inactivation of the TGF-β pathway, yet, paradoxically, they are characterized by elevated TGF-β production. Here, we unveil a prometastatic program induced by TGF-β in the microenvironment that associates with a high risk of CRC relapse upon treatment. The activity of TGF-β on stromal cells increases the efficiency of organ colonization by CRC cells, whereas mice treated with a pharmacological inhibitor of TGFBR1 are resilient to metastasis formation. Secretion of IL11 by TGF-β-stimulated cancer-associated fibroblasts (CAFs) triggers GP130/STAT3 signaling in tumor cells. This crosstalk confers a survival advantage to metastatic cells. The dependency on the TGF-β stromal program for metastasis initiation could be exploited to improve the diagnosis and treatment of CRC.
Nature Genetics | 2015
Alexandre Calon; Enza Lonardo; Antonio Berenguer-Llergo; Elisa Espinet; Xavier Hernando-Momblona; Mar Iglesias; Marta Sevillano; Sergio Palomo-Ponce; Daniele V. F. Tauriello; Daniel Byrom; Carme Cortina; Clara Morral; Carles Barceló; Sébastien Tosi; Antoni Riera; Camille Stephan-Otto Attolini; David Rossell; Elena Sancho; Eduard Batlle
Recent molecular classifications of colorectal cancer (CRC) based on global gene expression profiles have defined subtypes displaying resistance to therapy and poor prognosis. Upon evaluation of these classification systems, we discovered that their predictive power arises from genes expressed by stromal cells rather than epithelial tumor cells. Bioinformatic and immunohistochemical analyses identify stromal markers that associate robustly with disease relapse across the various classifications. Functional studies indicate that cancer-associated fibroblasts (CAFs) increase the frequency of tumor-initiating cells, an effect that is dramatically enhanced by transforming growth factor (TGF)-β signaling. Likewise, we find that all poor-prognosis CRC subtypes share a gene program induced by TGF-β in tumor stromal cells. Using patient-derived tumor organoids and xenografts, we show that the use of TGF-β signaling inhibitors to block the cross-talk between cancer cells and the microenvironment halts disease progression.
Tetrahedron Letters | 1991
Marc Canas; Marta Poch; Xavier Verdaguer; Albert Moyano; Miquel A. Pericàs; Antoni Riera
Abstract A reinvestigation of the titanium(IV)-mediated reaction of primary amines with chiral 2,3-epoxyalcohols shows that, contrary to previous reports, this reaction constitutes a general and practical process for the enantioselective synthesis of 3-amino-1,2-diols.
Chemistry: A European Journal | 2002
Miquel A. Pericàs; Cristina Puigjaner; Antoni Riera; Anton Vidal-Ferran; Montserrat Gómez; Francisco Jiménez; Guillermo Muller; Mercè Rocamora
New families of enantiopure bis(oxazolines) with 4,5-trans (5 a-g) or 4,5-cis (6 c) stereochemistry at the individual rings have been prepared in high yield. Their eta(3)-allyl palladium complexes (8 a-g, 9 c and 10) have been used as catalytic precursors in allylic alkylation reactions with excellent enantioselectivities (up to 96 %) for the trans oxazoline derivatives, while Pd/6 c system was inactive. NMR studies on palladium eta(3)-1,3-diphenylallyl intermediates (11 a, c and e) showed the presence of syn/syn- and syn/anti-allyl isomers in solution; this resembles the first example of eta(3)-eta(1)-eta(3) isomerism in Pd allylic complexes containing bis(oxazolines) derived from malonic acid.
Tetrahedron Letters | 1989
Amos B. Smith; Karl J. Hale; Leif M. Laakso; Kwunmin Chen; Antoni Riera
Abstract An efficient asymmetric synthesis of the C(24)–C(34) fragment of the FK-506 family of immunosuppressants has been achieved.
Angewandte Chemie | 2010
Marc Revés; Catalina Ferrer; Thierry León; Séan Doran; Pablo Etayo; Anton Vidal-Ferran; Antoni Riera; Xavier Verdaguer
Chiral phosphine ligands are central to asymmetric metal catalysis. The effect of the majority of these ligands arises from the chirality of their backbones; however, P-stereogenic (P*) ligands have garnered renewed interest. After the decisive work of Knowles and co-workers with PAMP and DIPAMP ligands, several efficient syntheses of all-carbon P* compounds have been reported. In contrast, P* compounds that contain heteroatoms directly linked to the phosphorus center are scarce, and have found little application in catalysis. This class of substances includes secondary phosphine oxides, which exist in equilibrium with their trivalent phosphinite form. P* aminophosphines, which are the corresponding nitrogen analogues, are even more rare, as free primary aminophosphines tend to dimerize with the evolution of ammonia. However, Kolodiazhnyi et al. have reported that borane aminophosphines of type I are stable and that they can be obtained in diastereomerically pure form using 2-phenylethylamine as a chiral amine (Scheme 1). Nonetheless, type I compounds do not have any reported applications in asymmetric catalysis, nor has their hydrogenolysis been described. We envisioned that reductive cleavage of the arylethyl fragment should provide boraneprotected primary aminophosphines of type II, which would be amenable to further transformations and become useful P* building blocks in catalysis. Herein, we report the synthesis of enantiopure P-chiral primary and secondary aminophosphines (II) and diphosphinoamines (III). We began by investigating the hydrogenolysis of the known compound 1a, which contains a tert-butyl(phenyl)phosphinamine moiety (Scheme 2), under various
Nature | 2018
Daniele V. F. Tauriello; Sergio Palomo-Ponce; Diana Stork; Antonio Berenguer-Llergo; Jordi Badia-Ramentol; Mar Iglesias; Marta Sevillano; Sales Ibiza; Adrià Cañellas; Xavier Hernando-Momblona; Daniel Byrom; Joan A. Matarin; Alexandre Calon; Elisa I. Rivas; Angel R. Nebreda; Antoni Riera; Camille Stephan-Otto Attolini; Eduard Batlle
Most patients with colorectal cancer die as a result of the disease spreading to other organs. However, no prevalent mutations have been associated with metastatic colorectal cancers. Instead, particular features of the tumour microenvironment, such as lack of T-cell infiltration, low type 1 T-helper cell (TH1) activity and reduced immune cytotoxicity or increased TGFβ levels predict adverse outcomes in patients with colorectal cancer. Here we analyse the interplay between genetic alterations and the tumour microenvironment by crossing mice bearing conditional alleles of four main colorectal cancer mutations in intestinal stem cells. Quadruple-mutant mice developed metastatic intestinal tumours that display key hallmarks of human microsatellite-stable colorectal cancers, including low mutational burden, T-cell exclusion and TGFβ-activated stroma. Inhibition of the PD-1–PD-L1 immune checkpoint provoked a limited response in this model system. By contrast, inhibition of TGFβ unleashed a potent and enduring cytotoxic T-cell response against tumour cells that prevented metastasis. In mice with progressive liver metastatic disease, blockade of TGFβ signalling rendered tumours susceptible to anti-PD-1–PD-L1 therapy. Our data show that increased TGFβ in the tumour microenvironment represents a primary mechanism of immune evasion that promotes T-cell exclusion and blocks acquisition of the TH1-effector phenotype. Immunotherapies directed against TGFβ signalling may therefore have broad applications in treating patients with advanced colorectal cancer.
Journal of the American Chemical Society | 2011
Thierry León; Antoni Riera; Xavier Verdaguer
A highly diastereoselective and efficient synthesis of P-stereogenic bulky alkyl and aryl aminophosphines that relies on ring opening of tert-butyl-oxazaphospholidine 2 is described. Ring opening with several organometallic reagents takes place with inversion of configuration at the phosphorus center as it has been demonstrated by X-ray analysis of two ring-opened intermediates. The unprecedented reactivity observed is attributed to the presence of a free NH functionality that facilitates the attack of the organometallic reagent in an S(N)2@P-type process.
Tetrahedron | 1996
Patricia Castejón; Albert Moyano; Miquel A. Pericàs; Antoni Riera
Abstract A convenient entry to enantiopure syn or anti β-hydroxy-γ-amino acids is described. The starting compounds for the synthesis, anti 3-amino-1,2-diols, are readily available in high enantiomeric purity through catalytic asymmetric epoxidation of an allylic alcohol and titanium-promoted oxirane opening. After adequate protection of the nitrogen, a stereodivergent sequence leads to both anti and syn N-Boc-aminoalkyl epoxides. Subsequent regioselective ring-opening with cyanide, protection of the resulting secondary alcohol and nitrile to carboxyl conversion afford, in good yields, protected β-hydroxy-γ-amino acids belonging to either the anti (erythro) or syn (threo) series. This methodology has been applied to the enantioselective preparation of cyclohexylstatine, a key component of several aspartyl protease inhibitors, in fully protected form.
Pure and Applied Chemistry | 2002
Miquel A. Pericàs; Jaume Balsells; Jaume Castro; Iolanda Marchueta; Albert Moyano; Antoni Riera; Jordi Vázquez; Xavier Verdaguer
Semiempirical and density functional theory (DFT) calculations have been performed on the key steps of the commonly accepted mechanism of the PausonKhand reaction (PKR). In this context, the high reactivity of ynamine complexes in the cycloaddition process has been rationalized on the basis of an anomerically assisted dissociation of CO. Moreover, an explanation has been provided for the correlation between olefin strain and reactivity in the PKR. Inspired by these results, new selective syntheses of cyclopentanones and phenols based on PKR with cyclopropene have been developed. On the other hand, the theoretical analysis of phosphine-substituted dicobalt carbonyl complexes of alkynes has helped in the development of efficient chelating (P,N) and bridging (P,S) ligands for the stereochemical control of the reaction and in the understanding of their action modes.