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Pereira JFS, Bessa C, Matos P, Jordan P. Pro-Inflammatory Cytokines Trigger the Overexpression of Tumour-Related Splice Variant RAC1B in Polarized Colorectal Cells. Cancers (Basel) 2022; 14:cancers14061393. [PMID: 35326545 PMCID: PMC8946262 DOI: 10.3390/cancers14061393] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 03/06/2022] [Accepted: 03/07/2022] [Indexed: 02/04/2023] Open
Abstract
Simple Summary Tumours are now known to develop more quickly when the tumour cell mass is located in a tissue that shows signs of chronic inflammation. Under such conditions, inflammatory cells from the surrounding tumour microenvironment provide survival signals to which cancer cells respond. We have previously found that some colorectal tumours overexpress the protein RAC1B that sustains tumour cell survival. Here we used a colon mucosa-like in vitro cell model and found that the presence of cancer-associated fibroblasts and pro-inflammatory macrophages stimulated colorectal cells to increase their RAC1B levels. Under these conditions, the secreted survival signals were analysed, and interleukin-6 identified as the main trigger for the increase in RAC1B levels. The results contribute to understand the tumour-promoting effect of inflammation at the molecular level. Abstract An inflammatory microenvironment is a tumour-promoting condition that provides survival signals to which cancer cells respond with gene expression changes. One example is the alternative splicing variant Rat Sarcoma Viral Oncogene Homolog (Ras)-Related C3 Botulinum Toxin Substrate 1 (RAC1)B, which we previously identified in a subset of V-Raf Murine Sarcoma Viral Oncogene Homolog B (BRAF)-mutated colorectal tumours. RAC1B was also increased in samples from inflammatory bowel disease patients or in an acute colitis mouse model. Here, we used an epithelial-like layer of polarized Caco-2 or T84 colorectal cancer (CRC) cells in co-culture with fibroblasts, monocytes or macrophages and analysed the effect on RAC1B expression in the CRC cells by RT-PCR, Western blot and confocal fluorescence microscopy. We found that the presence of cancer-associated fibroblasts and M1 macrophages induced the most significant increase in RAC1B levels in the polarized CRC cells, accompanied by a progressive loss of epithelial organization. Under these conditions, we identified interleukin (IL)-6 as the main trigger for the increase in RAC1B levels, associated with Signal Transducer and Activator of Transcription (STAT)3 activation. IL-6 neutralization by a specific antibody abrogated both RAC1B overexpression and STAT3 phosphorylation in polarized CRC cells. Our data identify that pro-inflammatory extracellular signals from stromal cells can trigger the overexpression of tumour-related RAC1B in polarized CRC cells. The results will help to understand the tumour-promoting effect of inflammation and identify novel therapeutic strategies.
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Affiliation(s)
- Joana F. S. Pereira
- Department of Human Genetics, National Institute of Health ‘Dr. Ricardo Jorge’, 1649-016 Lisbon, Portugal; (J.F.S.P.); (C.B.); (P.M.)
- BioISI—Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisbon, 1749-016 Lisbon, Portugal
| | - Cláudia Bessa
- Department of Human Genetics, National Institute of Health ‘Dr. Ricardo Jorge’, 1649-016 Lisbon, Portugal; (J.F.S.P.); (C.B.); (P.M.)
- BioISI—Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisbon, 1749-016 Lisbon, Portugal
| | - Paulo Matos
- Department of Human Genetics, National Institute of Health ‘Dr. Ricardo Jorge’, 1649-016 Lisbon, Portugal; (J.F.S.P.); (C.B.); (P.M.)
- BioISI—Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisbon, 1749-016 Lisbon, Portugal
| | - Peter Jordan
- Department of Human Genetics, National Institute of Health ‘Dr. Ricardo Jorge’, 1649-016 Lisbon, Portugal; (J.F.S.P.); (C.B.); (P.M.)
- BioISI—Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisbon, 1749-016 Lisbon, Portugal
- Correspondence:
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2
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Bessa C, Matos P, Jordan P, Gonçalves V. Alternative Splicing: Expanding the Landscape of Cancer Biomarkers and Therapeutics. Int J Mol Sci 2020; 21:ijms21239032. [PMID: 33261131 PMCID: PMC7729450 DOI: 10.3390/ijms21239032] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 11/24/2020] [Accepted: 11/25/2020] [Indexed: 02/07/2023] Open
Abstract
Alternative splicing (AS) is a critical post-transcriptional regulatory mechanism used by more than 95% of transcribed human genes and responsible for structural transcript variation and proteome diversity. In the past decade, genome-wide transcriptome sequencing has revealed that AS is tightly regulated in a tissue- and developmental stage-specific manner, and also frequently dysregulated in multiple human cancer types. It is currently recognized that splicing defects, including genetic alterations in the spliced gene, altered expression of both core components or regulators of the precursor messenger RNA (pre-mRNA) splicing machinery, or both, are major drivers of tumorigenesis. Hence, in this review we provide an overview of our current understanding of splicing alterations in cancer, and emphasize the need to further explore the cancer-specific splicing programs in order to obtain new insights in oncology. Furthermore, we also discuss the recent advances in the identification of dysregulated splicing signatures on a genome-wide scale and their potential use as biomarkers. Finally, we highlight the therapeutic opportunities arising from dysregulated splicing and summarize the current approaches to therapeutically target AS in cancer.
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Affiliation(s)
- Cláudia Bessa
- Department of Human Genetics, National Health Institute Dr. Ricardo Jorge, 1649-016 Lisbon, Portugal; (C.B.); (P.M.)
- BioISI—Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisbon, 1749-016 Lisbon, Portugal
| | - Paulo Matos
- Department of Human Genetics, National Health Institute Dr. Ricardo Jorge, 1649-016 Lisbon, Portugal; (C.B.); (P.M.)
- BioISI—Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisbon, 1749-016 Lisbon, Portugal
| | - Peter Jordan
- Department of Human Genetics, National Health Institute Dr. Ricardo Jorge, 1649-016 Lisbon, Portugal; (C.B.); (P.M.)
- BioISI—Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisbon, 1749-016 Lisbon, Portugal
- Correspondence: (P.J.); (V.G.); Tel.: +351-217-519-380 (P.J.)
| | - Vânia Gonçalves
- Department of Human Genetics, National Health Institute Dr. Ricardo Jorge, 1649-016 Lisbon, Portugal; (C.B.); (P.M.)
- BioISI—Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisbon, 1749-016 Lisbon, Portugal
- Correspondence: (P.J.); (V.G.); Tel.: +351-217-519-380 (P.J.)
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3
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Garcia C, Ntungwe E, Rebelo A, Bessa C, Stankovic T, Dinic J, Díaz-Lanza A, P Reis C, Roberto A, Pereira P, Cebola MJ, Saraiva L, Pesic M, Duarte N, Rijo P. Parvifloron D from Plectranthus strigosus: Cytotoxicity Screening of Plectranthus spp. Extracts. Biomolecules 2019; 9:biom9100616. [PMID: 31627339 PMCID: PMC6843537 DOI: 10.3390/biom9100616] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 10/09/2019] [Accepted: 10/13/2019] [Indexed: 12/16/2022] Open
Abstract
The Plectranthus genus is commonly used in traditional medicine due to its potential to treat several illnesses, including bacterial infections and cancer. As such, aiming to screen the antibacterial and cytotoxic activities of extracts, sixteen selected Plectranthus species with medicinal potential were studied. In total, 31 extracts obtained from 16 Plectranthus spp. were tested for their antibacterial and anticancer properties. Well diffusion method was used for preliminary antibacterial screening. The minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values of the five most active acetonic extracts (P. aliciae, P. japonicus, P. madagascariensis var. “Lynne”, P. stylesii, and P. strigosus) were determined. After preliminary toxicity evaluation on Artemia salina L., their cytotoxic properties were assessed on three human cancer cell lines (HCT116, MCF-7, and H460). These were also selected for mechanism of resistance studies (on NCI-H460/R and DLD1-TxR cells). An identified compound—parvifloron D—was tested in a pair of sensitive and MDR-Multidrug resistance cancer cells (NCI-H460 and NCI-H460/R) and in normal bronchial fibroblasts MRC-5. The chemical composition of the most active extract was studied through high performance liquid chromatography with a diode array detector (HPLC-DAD/UV) and liquid chromatography–mass spectrometry (LC–MS). Overall, P. strigosus acetonic extract showed the strongest antimicrobial and cytotoxic potential that could be explained by the presence of parvifloron D, a highly cytotoxic diterpene. This study provides valuable information on the use of the Plectranthus genus as a source of bioactive compounds, namely P. strigosus with the potential active ingredient the parvifloron D.
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Affiliation(s)
- Catarina Garcia
- Research Center for Biosciences & Health Technologies (CBIOS), Universidade Lusófona de Humanidades e Tecnologias, 1749-024 Lisboa, Portugal.
- Department of Biomedical Sciences, Faculty of Pharmacy, University of Alcalá, Campus Universitario, 28871 Alcalá de Henares, Spain.
| | - Epole Ntungwe
- Research Center for Biosciences & Health Technologies (CBIOS), Universidade Lusófona de Humanidades e Tecnologias, 1749-024 Lisboa, Portugal.
- Department of Biomedical Sciences, Faculty of Pharmacy, University of Alcalá, Campus Universitario, 28871 Alcalá de Henares, Spain.
| | - Ana Rebelo
- Research Center for Biosciences & Health Technologies (CBIOS), Universidade Lusófona de Humanidades e Tecnologias, 1749-024 Lisboa, Portugal.
- Department of Biomedical Sciences, Faculty of Pharmacy, University of Alcalá, Campus Universitario, 28871 Alcalá de Henares, Spain.
| | - Cláudia Bessa
- LAQV/REQUIMTE, Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira n. 228, 4050-313 Porto, Portugal.
| | - Tijana Stankovic
- Institute for Biological Research, "Siniša Stanković", University of Belgrade, Despota Stefana 142, 11060 Belgrade, Serbia.
| | - Jelena Dinic
- Institute for Biological Research, "Siniša Stanković", University of Belgrade, Despota Stefana 142, 11060 Belgrade, Serbia.
| | - Ana Díaz-Lanza
- Department of Biomedical Sciences, Faculty of Pharmacy, University of Alcalá, Campus Universitario, 28871 Alcalá de Henares, Spain.
| | - Catarina P Reis
- Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, 1649-003 Lisboa, Portugal.
| | - Amílcar Roberto
- Research Center for Biosciences & Health Technologies (CBIOS), Universidade Lusófona de Humanidades e Tecnologias, 1749-024 Lisboa, Portugal.
| | - Paula Pereira
- Research Center for Biosciences & Health Technologies (CBIOS), Universidade Lusófona de Humanidades e Tecnologias, 1749-024 Lisboa, Portugal.
- CERENA-Centre for Natural Resources and the Environment, Instituto Superior Técnico (IST), Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal.
| | - Maria-João Cebola
- Research Center for Biosciences & Health Technologies (CBIOS), Universidade Lusófona de Humanidades e Tecnologias, 1749-024 Lisboa, Portugal.
- CERENA-Centre for Natural Resources and the Environment, Instituto Superior Técnico (IST), Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal.
| | - Lucília Saraiva
- LAQV/REQUIMTE, Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira n. 228, 4050-313 Porto, Portugal.
| | - Milica Pesic
- Institute for Biological Research, "Siniša Stanković", University of Belgrade, Despota Stefana 142, 11060 Belgrade, Serbia.
| | - Noélia Duarte
- Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, 1649-003 Lisboa, Portugal.
| | - Patrícia Rijo
- Research Center for Biosciences & Health Technologies (CBIOS), Universidade Lusófona de Humanidades e Tecnologias, 1749-024 Lisboa, Portugal.
- Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, 1649-003 Lisboa, Portugal.
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4
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Bessa C, Soares J, Raimundo L, Loureiro JB, Gomes C, Reis F, Soares ML, Santos D, Dureja C, Chaudhuri SR, Lopez-Haber C, Kazanietz MG, Gonçalves J, Simões MF, Rijo P, Saraiva L. Discovery of a small-molecule protein kinase Cδ-selective activator with promising application in colon cancer therapy. Cell Death Dis 2018; 9:23. [PMID: 29348560 PMCID: PMC5833815 DOI: 10.1038/s41419-017-0154-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 11/06/2017] [Accepted: 11/09/2017] [Indexed: 12/12/2022]
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.
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Affiliation(s)
- Cláudia Bessa
- UCIBIO/REQUIMTE, Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
| | - Joana Soares
- UCIBIO/REQUIMTE, Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
| | - Liliana Raimundo
- UCIBIO/REQUIMTE, Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
| | - Joana B Loureiro
- UCIBIO/REQUIMTE, Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
| | - Célia Gomes
- Laboratory of Pharmacology and Experimental Therapeutics, Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, & CNC.IBILI Research Consortium, University of Coimbra, Coimbra, Portugal
| | - Flávio Reis
- Laboratory of Pharmacology and Experimental Therapeutics, Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, & CNC.IBILI Research Consortium, University of Coimbra, Coimbra, Portugal
| | - Miguel L Soares
- Laboratório de Apoio à Investigação em Medicina Molecular, Departamento de Biomedicina, Faculdade de Medicina da Universidade do Porto, Porto, Portugal
| | - Daniel Santos
- REQUIMTE, Faculdade de Ciências da Universidade do Porto, Porto, Portugal
| | - Chetna Dureja
- CSIR-Institute of Microbial Technology, Sector 39A, Chandigarh, India
| | | | - Cynthia Lopez-Haber
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
| | - Marcelo G Kazanietz
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
| | - Jorge Gonçalves
- Laboratório de Farmacologia, Departamento de Ciências do Medicamento, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
| | - Maria F Simões
- CBIOS-Centro de Investigação em Biociências e Tecnologias da Saúde, Universidade Lusófona, Lisboa, Portugal.,iMed.ULisboa, Instituto de Investigação do Medicamento, Faculdade de Farmácia da Universidade de Lisboa, Lisboa, Portugal
| | - Patrícia Rijo
- CBIOS-Centro de Investigação em Biociências e Tecnologias da Saúde, Universidade Lusófona, Lisboa, Portugal. .,iMed.ULisboa, Instituto de Investigação do Medicamento, Faculdade de Farmácia da Universidade de Lisboa, Lisboa, Portugal.
| | - Lucília Saraiva
- UCIBIO/REQUIMTE, Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal.
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5
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Soares J, Raimundo L, Pereira NAL, Monteiro Â, Gomes S, Bessa C, Pereira C, Queiroz G, Bisio A, Fernandes J, Gomes C, Reis F, Gonçalves J, Inga A, Santos MMM, Saraiva L. Reactivation of wild-type and mutant p53 by tryptophanolderived oxazoloisoindolinone SLMP53-1, a novel anticancer small-molecule. Oncotarget 2016; 7:4326-43. [PMID: 26735173 PMCID: PMC4826208 DOI: 10.18632/oncotarget.6775] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 11/28/2015] [Indexed: 12/28/2022] Open
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.
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Affiliation(s)
- Joana Soares
- UCIBIO/REQUIMTE, Universidade do Porto, Porto, Portugal.,Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
| | - Liliana Raimundo
- UCIBIO/REQUIMTE, Universidade do Porto, Porto, Portugal.,Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
| | - Nuno A L Pereira
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Lisboa, Portugal
| | - Ângelo Monteiro
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Lisboa, Portugal
| | - Sara Gomes
- UCIBIO/REQUIMTE, Universidade do Porto, Porto, Portugal.,Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
| | - Cláudia Bessa
- UCIBIO/REQUIMTE, Universidade do Porto, Porto, Portugal.,Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
| | - Clara Pereira
- UCIBIO/REQUIMTE, Universidade do Porto, Porto, Portugal.,Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
| | - Glória Queiroz
- Laboratório de Farmacologia, Departamento de Ciências do Medicamento, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
| | - Alessandra Bisio
- CIBIO, Centre for Integrative Biology, Laboratory of Transcriptional Networks, University of Trento, Trento, Italy
| | - João Fernandes
- Laboratório de Farmacologia e Terapêutica Experimental, IBILI, Faculdade de Medicina, Universidade de Coimbra, Coimbra, Portugal
| | - Célia Gomes
- Laboratório de Farmacologia e Terapêutica Experimental, IBILI, Faculdade de Medicina, Universidade de Coimbra, Coimbra, Portugal
| | - Flávio Reis
- Laboratório de Farmacologia e Terapêutica Experimental, IBILI, Faculdade de Medicina, Universidade de Coimbra, Coimbra, Portugal
| | - Jorge Gonçalves
- Laboratório de Farmacologia, Departamento de Ciências do Medicamento, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
| | - Alberto Inga
- CIBIO, Centre for Integrative Biology, Laboratory of Transcriptional Networks, University of Trento, Trento, Italy
| | - Maria M M Santos
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Lisboa, Portugal
| | - Lucília Saraiva
- UCIBIO/REQUIMTE, Universidade do Porto, Porto, Portugal.,Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
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6
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Abstract
Aspergillus fumigatus conidia have been linked to severe aspergillosis in immunocompromised patients. Recently, the cytotoxic effect of secondary metabolites from A. fumigatus conidia was reported. In the present work, a methodology used to detect cell death markers in fungal hyphae was adapted to study conidia cell death. Additionally, the mechanism of H2O2-induced cell death was studied in A. fumigatus conidia for the first time. Data presented in this work reveal that the H2O2-induced conidial cell death was associated with a marked increase of TUNEL- and PI-positive cells. It is therefore suggested that conidia cell death occurs in a dose-dependent manner through a secondary necrosis mechanism. The knowledge of conidia cell death machinery may provide insights into the molecular mechanism of conidia-mediated toxicity to the respiratory tract and may pave the way for improved therapeutic approaches against A. fumigatus conidia-mediated diseases.
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Affiliation(s)
- M Oliveira
- a Instituto de Investigação e Inovação em Saúde, Universidade Do Porto, Portugal.,b Instituto de Patologia e Imunologia Molecular da Universidade do Porto, Porto, Portugal.,c Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Porto, Portugal
| | - C Pereira
- d UCIBIO/REQUIMTE, Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Rua Jorge Viterbo Ferreira, 228; 4050-313 Porto, Portugal
| | - C Bessa
- d UCIBIO/REQUIMTE, Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Rua Jorge Viterbo Ferreira, 228; 4050-313 Porto, Portugal
| | - R Araujo
- b Instituto de Patologia e Imunologia Molecular da Universidade do Porto, Porto, Portugal
| | - L Saraiva
- d UCIBIO/REQUIMTE, Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Rua Jorge Viterbo Ferreira, 228; 4050-313 Porto, Portugal
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7
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Oliveira M, Pereira C, Bessa C, Araujo R, Saraiva L. Chronological aging in conidia of pathogenic Aspergillus: Comparison between species. J Microbiol Methods 2015; 118:57-63. [PMID: 26341609 DOI: 10.1016/j.mimet.2015.08.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 08/27/2015] [Accepted: 08/27/2015] [Indexed: 11/28/2022]
Abstract
Aspergillus fumigatus, Aspergillus flavus, Aspergillus terreus and Aspergillus niger are common airborne fungi, and the most frequent causative agents of human fungal infections. However, the resistance and lifetime persistence of these fungi in the atmosphere, and the mechanism of aging of Aspergillus conidia are unknown.With this work, we intended to study the processes underlying conidial aging of these four relevant and pathogenic Aspergillus species. Chronological aging was therefore evaluated in A. fumigatus, A. flavus, A. terreus and A. niger conidia exposed to environmental and human body temperatures. The results showed that the aging process in Aspergillus conidia involves apoptosis,with metacaspase activation, DNA fragmentation, and reactive oxygen species production, associated with secondary necrosis. Distinct results were observed for the selected pathogenic species. At environmental conditions, A. niger was the species with the highest resistance to aging, indicating a higher adaption to environmental conditions, whereas A. flavus followed by A. terreus were the most sensitive species. At higher temperatures (37 °C), A. fumigatus presented the longest lifespan, in accordance with its good adaptation to the human body temperature. Altogether,with this work new insights regarding conidia aging are provided, which may be useful when designing treatments for aspergillosis.
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Affiliation(s)
- Manuela Oliveira
- Instituto de Investigação e Inovação em Saúde, Universidade Do Porto, Portugal; Instituto de Patologia e Imunologia Molecular da Universidade do Porto, Porto, Portugal; Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Porto, Portugal
| | - Clara Pereira
- UCIBIO/REQUIMTE, Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
| | - Cláudia Bessa
- UCIBIO/REQUIMTE, Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
| | - Ricardo Araujo
- Instituto de Patologia e Imunologia Molecular da Universidade do Porto, Porto, Portugal
| | - Lucília Saraiva
- UCIBIO/REQUIMTE, Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal.
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Soares J, Pereira NAL, Monteiro Â, Leão M, Bessa C, Dos Santos DJVA, Raimundo L, Queiroz G, Bisio A, Inga A, Pereira C, Santos MMM, Saraiva L. Oxazoloisoindolinones with in vitro antitumor activity selectively activate a p53-pathway through potential inhibition of the p53-MDM2 interaction. Eur J Pharm Sci 2014; 66:138-47. [PMID: 25312347 DOI: 10.1016/j.ejps.2014.10.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 09/29/2014] [Accepted: 10/02/2014] [Indexed: 10/24/2022]
Abstract
One of the most appealing targets for anticancer treatment is the p53 tumor suppressor protein. In half of human cancers, this protein is inactivated due to endogenous negative regulators such as MDM2. Actually, restoring the p53 activity, particularly through the inhibition of its interaction with MDM2, is considered a valuable therapeutic strategy against cancers with a wild-type p53 status. In this work, we report the synthesis of nine enantiopure phenylalaninol-derived oxazolopyrrolidone lactams and the evaluation of their biological effects as p53-MDM2 interaction inhibitors. Using a yeast-based screening assay, two oxazoloisoindolinones, compounds 1b and 3a, were identified as potential p53-MDM2 interaction inhibitors. The molecular mechanism of oxazoloisoindolinone 3a was further validated in human colon adenocarcinoma HCT116 cells with wild-type p53 (HCT116 p53(+/+)) and in its isogenic derivative without p53 (HCT116 p53(-/-)). Indeed, using these cells, we demonstrated that oxazoloisoindolinone 3a exhibited a p53-dependent in vitro antitumor activity through induction of G0/G1-phase cell cycle arrest and apoptosis. The selective activation of a p53-apoptotic pathway by oxazoloisoindolinone 3a was further supported by the occurrence of PARP cleavage only in p53-expressing HCT116 cells. Moreover, oxazoloisoindolinone 3a led to p53 protein stabilization and to the up-regulation of p53 transcriptional activity with increased expression levels of several p53 target genes, as p21(WAF1/CIP1), MDM2, BAX and PUMA, in p53(+/+) but not in p53(-/-) HCT116 cells. Additionally, the ability of oxazoloisoindolinone 3a to block the p53-MDM2 interaction in HCT116 p53(+/+) cells was confirmed by co-immunoprecipitation. Finally, the molecular docking analysis of the interactions between the synthesized compounds and MDM2 revealed that oxazoloisoindolinone 3a binds to MDM2. Altogether, this work adds, for the first time, the oxazoloisoindolinone scaffold to the list of chemotypes activators of a wild-type p53-pathway with promising antitumor activity. Moreover, it may open the way to the development of a new class of p53-MDM2 interaction inhibitors.
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Affiliation(s)
- Joana Soares
- REQUIMTE, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira n.° 164, 4050-313 Porto, Portugal; Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira n.° 164, 4050-313 Porto, Portugal
| | - Nuno A L Pereira
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - Ângelo Monteiro
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - Mariana Leão
- REQUIMTE, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira n.° 164, 4050-313 Porto, Portugal; Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira n.° 164, 4050-313 Porto, Portugal
| | - Cláudia Bessa
- REQUIMTE, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira n.° 164, 4050-313 Porto, Portugal; Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira n.° 164, 4050-313 Porto, Portugal
| | - Daniel J V A Dos Santos
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal; REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal
| | - Liliana Raimundo
- REQUIMTE, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira n.° 164, 4050-313 Porto, Portugal; Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira n.° 164, 4050-313 Porto, Portugal
| | - Glória Queiroz
- REQUIMTE, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira n.° 164, 4050-313 Porto, Portugal; Laboratório de Farmacologia, Departamento de Ciências do Medicamento, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira n.° 164, 4050-313 Porto, Portugal
| | - Alessandra Bisio
- CIBIO, Centre for Integrative Biology, Laboratory of Transcriptional Networks, University of Trento, Via delle Regole, 101, 38123 Trento, Italy
| | - Alberto Inga
- CIBIO, Centre for Integrative Biology, Laboratory of Transcriptional Networks, University of Trento, Via delle Regole, 101, 38123 Trento, Italy
| | - Clara Pereira
- REQUIMTE, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira n.° 164, 4050-313 Porto, Portugal; Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira n.° 164, 4050-313 Porto, Portugal
| | - Maria M M Santos
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal.
| | - Lucília Saraiva
- REQUIMTE, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira n.° 164, 4050-313 Porto, Portugal; Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira n.° 164, 4050-313 Porto, Portugal.
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Leão M, Gomes S, Soares J, Bessa C, Maciel C, Ciribilli Y, Pereira C, Inga A, Saraiva L. Novel simplified yeast-based assays of regulators of p53-MDMX interaction and p53 transcriptional activity. FEBS J 2013; 280:6498-507. [PMID: 24119020 DOI: 10.1111/febs.12552] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 09/05/2013] [Accepted: 09/25/2013] [Indexed: 11/27/2022]
Abstract
Yeast has proven to be an efficient model system for functional and pharmacological studies of the p53 tumour suppressor protein. In this work, the human p53-MDMX regulatory pathway was reconstituted in yeast. Additionally, by using the known inhibitor of p53-MDMX interaction, SJ-172550, the efficacy of a simplified yeast-based screening assay to search for inhibitors of p53-MDMX interaction is demonstrated for the first time. Moreover, further insights on p53 transcriptional activity in yeast are provided. In particular, it is shown that the reported wild-type (wt) p53-induced yeast growth inhibition and cell cycle arrest is associated with actin depolarization and with an increase of actin mRNA and protein expression levels. The increase of actin protein levels was not observed with the p53 R273H mutant (a loss of function p53 mutation hotspot) and was further intensified with the toxic p53 V122A mutant (reported to exhibit higher transcriptional activity than wt p53 for selected p53 target sequences). Moreover, it is shown that the wt p53-induced actin protein levels are modulated by natural (MDM2 and MDMX) and chemical (pifithrin-α, nutlin-3a and SJ-172550) regulators of p53 activity. Furthermore, wt p53 could stimulate transcription from a minimal promoter containing a fragment of the ACT1 upstream sequence. Thus, ACT1 is proposed as a putative endogenous p53 target gene. This finding may open the way for the development of simpler yeast p53 transactivation assays, not based on artificial reporter constructs, for the analysis of the impact of mutants, cofactors and small molecules on p53 transcriptional activity.
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Affiliation(s)
- Mariana Leão
- REQUIMTE, Laboratório de Microbiologia, Departamento de Ciências Biológicas, Universidade do Porto, Portugal
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Bessa C, Pereira C, Leão M, Maciel C, Gomes S, Gonçalves J, Corte-Real M, Costa V, Saraiva L. Using yeast to uncover the regulation of protein kinase Cδ by ceramide. FEMS Yeast Res 2013; 13:700-5. [PMID: 23937324 DOI: 10.1111/1567-1364.12069] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Revised: 07/29/2013] [Accepted: 08/06/2013] [Indexed: 10/26/2022] Open
Abstract
The regulation of protein kinase C (PKC) isoforms by ceramide is still controversial. In this work, the yeast Saccharomyces cerevisiae was used as a model to elucidate the effect of ceramide on the activity of mammalian PKC isoforms. For that, isc1Δ cells, with a deletion in the pathway for ceramide production by hydrolysis of complex sphingolipids, individually expressing mammalian PKCα, δ and ζ were used. Contrary to PKCα and ζ, expression of PKCδ in isc1Δ cells exhibited a similar phenotype to that observed with wild-type yeast cells expressing PKCδ treated with a PKC activator, as phorbol 12-myristate 13-acetate (PMA), specifically a growth inhibition associated with a G2/M cell cycle arrest. Interestingly, in isc1Δ yeast cells expressing PKCδ this phenotype was completely abrogated in the presence of exogenous ceramide. Moreover, using a yeast-based assay previously developed for the screening of PKC inhibitors, it was also shown that, like the known PKC inhibitor NPC 15437, ceramide reduced the PMA-induced growth inhibition, supporting an inhibitory effect of ceramide on PKCδ. Altogether, these results may indicate that ceramide distinctly interfere with the activity of PKCα, δ and ζ. Most importantly, they showed that ceramide is an inhibitor of PKCδ.
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Affiliation(s)
- Cláudia Bessa
- REQUIMTE, Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
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Pereira C, Bessa C, Saraiva L. Endocytosis inhibition during H2O2-induced apoptosis in yeast. FEMS Yeast Res 2012; 12:755-60. [DOI: 10.1111/j.1567-1364.2012.00825.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Revised: 06/18/2012] [Accepted: 06/25/2012] [Indexed: 11/30/2022] Open
Affiliation(s)
- Clara Pereira
- REQUIMTE; Laboratory of Microbiology; Department of Biological Sciences; Faculty of Pharmacy; University of Porto; Porto; Portugal
| | - Cláudia Bessa
- REQUIMTE; Laboratory of Microbiology; Department of Biological Sciences; Faculty of Pharmacy; University of Porto; Porto; Portugal
| | - Lucília Saraiva
- REQUIMTE; Laboratory of Microbiology; Department of Biological Sciences; Faculty of Pharmacy; University of Porto; Porto; Portugal
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Vidal J, Carvalho N, Felix S, Bessa C, Vieira L, Patury P, Franco V, Silva A, Almeida L, Moreira M. 1159 Diversity of HPV Genotypes in Cervical Tumors From Rio De Janeiro, Brazil. Eur J Cancer 2012. [DOI: 10.1016/s0959-8049(12)71755-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Abstract
Cancer is a devastating disease with a profound impact on society. In recent years, yeast has provided a valuable contribution with respect to uncovering the molecular mechanisms underlying this disease, allowing the identification of new targets and novel therapeutic opportunities. Indeed, several attributes make yeast an ideal model system for the study of human diseases. It combines a high level of conservation between its cellular processes and those of mammalian cells, with advantages such as a short generation time, ease of genetic manipulation and a wealth of experimental tools for genome- and proteome-wide analyses. Additionally, the heterologous expression of disease-causing proteins in yeast has been successfully used to gain an understanding of the functions of these proteins and also to provide clues about the mechanisms of disease progression. Yeast research performed in recent years has demonstrated the tremendous potential of this model system, especially with the validation of findings obtained with yeast in more physiologically relevant models. The present review covers the major aspects of the most recent developments in the yeast research area with respect to cancer. It summarizes our current knowledge on yeast as a cellular model for investigating the molecular mechanisms of action of the major cancer-related proteins that, even without yeast orthologues, still recapitulate in yeast some of the key aspects of this cellular pathology. Moreover, the most recent contributions of yeast genetics and high-throughput screening technologies that aim to identify some of the potential causes underpinning this disorder, as well as discover new therapeutic agents, are discussed.
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Affiliation(s)
- Clara Pereira
- REQUIMTE, Department of Biological Sciences, Laboratory of Microbiology, University of Porto, Portugal
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Bessa C, Teixeira CA, Dias A, Alves M, Rocha S, Lacerda L, Loureiro L, Guimarães A, Ribeiro MG. CLN2/TPP1 deficiency: the novel mutation IVS7-10A>G causes intron retention and is associated with a mild disease phenotype. Mol Genet Metab 2008; 93:66-73. [PMID: 17959406 DOI: 10.1016/j.ymgme.2007.08.124] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2007] [Revised: 08/28/2007] [Accepted: 08/28/2007] [Indexed: 11/19/2022]
Abstract
The classical form of late infantile neuronal ceroid lipofuscinosis (LINCL) is a childhood hereditary neurodegenerative disease usually fatal in the first decade of life. The underlying gene, CLN2, encodes the lysosomal soluble enzyme tripeptidyl-peptidase 1 (TPP1). In a Portuguese patient with juvenile form of the disease, the histochemical study revealed the presence of curvilinear inclusions typical of LINCL. In vitro TPP1 activity was deficient in patient's cells. CLN2 gene analysis revealed the transition IVS7-10A>G (g.4196A>G) in both alleles. In silico analysis suggested that A-to-G change in the A-rich region of intron 7 could cause aberrant splicing of exon 8 by creating a novel acceptor splice site. However, because the wild-type acceptor of intron 7 is weak and it was not apparently affected, the severity of this mutation could not be established through sequencing data of gDNA. Normal level of spliced CLN2/mRNA was observed in patient's fibroblasts. In the cDNA, the 9-nt retention of intronic sequence (c.886_887ins9) was observed. The mutation is predicted to result in a protein with three extra amino acids between proline 295 and glycine 296. In patient's fibroblasts the level of mutant CLN2p was reduced to about 60% but the migration pattern was similar to the wild-type protein, suggesting that it was correctly targeted to the lysosomes. Taken together, these findings suggest that the first "ag" is selected for splicing and the mutant protein must retain some residual catalytic activity, thus explaining the late onset and the delayed progression of the disease.
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Affiliation(s)
- C Bessa
- Unidade de Enzimologia, Instituto de Genética Médica Jacinto Magalhães, Pç. Pedro Nunes 88, 4050-466 Porto, Portugal
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Bessa C, Teixeira CAF, Mangas M, Dias A, Sá Miranda MC, Guimarães A, Ferreira JC, Canas N, Cabral P, Ribeiro MG. Two novel CLN5 mutations in a Portuguese patient with vLINCL: insights into molecular mechanisms of CLN5 deficiency. Mol Genet Metab 2006; 89:245-53. [PMID: 16814585 DOI: 10.1016/j.ymgme.2006.04.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2006] [Revised: 04/09/2006] [Accepted: 04/09/2006] [Indexed: 11/22/2022]
Abstract
The neuronal ceroid-lipofuscinoses are the most common neurodegenerative disorders in childhood characterized by progressive blindness, epilepsy, brain atrophy, and premature death. Based on the age at onset, disease progression and ultrastructural features three classical (infantile, late-infantile, and juvenile) and three variant late-infantile forms are generally distinguished (Finnish variant, Costa Rican variant, and epilepsy with progressive motor retardation). The Finnish variant late-infantile form has been associated with CLN5 gene defects, with only five mutations described to date. We report a patient with vLINCL/CLN5 who represents the first evidence of the disease in the Portuguese population. Mutational screening revealed the previously described missense mutation c.835G>A (D279N) inherited from the mother, and two novel mutations, c.565C>T (Q189X) and c.335G>C (R112P) from paternal and maternal inheritance, respectively. Based on data here reported: (i) the number of possible mutations in CLN5 gene is now 7; (ii) the CLN5 Portuguese case represents the third description of the disease outside northern Europe; (iii) the CLN5/mRNA expression level reduced to 45% supports the existence of one mRNA non-producing allele, further noticeable at the protein level; (iv) Western blotting data using a specific antibody to human CLN5p provided evidence for the presence of four integral membrane isoforms in human fibroblasts; (v) data from differential expression of CLN2, CLN3, and CLN5 suggest down-regulation of CLN3 gene expression in CLN2 and CLN5-deficient human patients and this observation strengths the hypothesis of functional redundancy of the CLN system.
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Affiliation(s)
- C Bessa
- Unidade de Enzimologia, Instituto de Genética Médica Jacinto Magalhães, Porto, Portugal
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