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Rodríguez López, José Neptuno

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Rodríguez López, José Neptuno
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Universidad de Murcia. Departamento de Bioquímica y Biología MolecularA
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  • Publication
    Open Access
    The critical role of alpha-folate receptor in the resistance of melanoma to methotrexate
    (WILEY, 2009-01-10) Cabezas Herrera, Juan; Montenegro Arce, María Fernanda; Rodríguez López, José Neptuno; Sánchez del Campo Ferrer, Luis; Bioquímica y Biología Molecular A
    Although methotrexate (MTX) is an effective drug for several types of cancer, it is not active against melanoma. Experiments following methotrexate treatment indicated a reduced accumulation of the drug in the cytosolic compartment in melanoma cells, suggesting that the mechanisms that control the transport and retention of this drug could be altered in melanoma. For this reason, we analyzed the presence and function of folate receptor-alpha (FR alpha) in melanoma cells. In this study, we have identified the presence of FR alpha in normal and pathological melanocytes and demonstrated that MTX is preferentially transported through this receptor in melanoma cells. FR alpha-induced endocytic transport of MTX, together with drug melanosomal sequestration and cellular exportation, ensures reduced accumulation of this cytotoxic compound in intracellular compartments. The critical role of FR alpha in this mechanism of resistance and the therapeutic consequences of these findings are also discussed.
  • Publication
    Open Access
    Directed Phenotype Switching as an Effective Antimelanoma Strategy
    (Cell Press, 2013-06-20) Sáez Ayala, Magalí; Fernández Pérez, María Piedad; Chazarra Parres, Soledad; Freter, Rasmus; Middleton, Mark; Piñero Madrona, Antonio; Cabezas Herrera, Juan; Goding, Colin R.; Montenegro Arce, María Fernanda; Rodríguez López, José Neptuno; Sánchez del Campo Ferrer, Luis; Bioquímica y Biología Molecular A; Cirugía, Pediatría y Obstetricia y Ginecología
    Therapeutic resistance in melanoma and other cancers arises via irreversible genetic, and dynamic phenotypic, heterogeneity. Here, we use directed phenotype switching in melanoma to sensitize melanoma cells to lineage-specific therapy. We show that methotrexate (MTX) induces microphthalmia-associated transcription factor (MITF) expression to inhibit invasiveness and promote differentiation-associated expression of the melanocyte-specific Tyrosinase gene. Consequently, MTX sensitizes melanomas to a tyrosinase-processed antifolate prodrug 3-O-(3,4,5-trimethoxybenzoyl)-(−)-epicatechin (TMECG), that inhibits the essential enzyme DHFR with high affinity. The combination of MTX and TMECG leads to depletion of thymidine pools, double-strand DNA breaks, and highly efficient E2F1-mediated apoptosis in culture and in vivo. Importantly, this drug combination delivers an effective and tissue-restricted antimelanoma therapy in vitro and in vivo irrespective of BRAF, MEK, or p53 status.
  • Publication
    Open Access
    Lebein, a snake venom disintegrin, induces apoptosis in human melanoma cells
    (MDPI, 2016-07-05) Hammouda, Manel B.; Zakraoui, Ons; Aloui, Zohra; Riahi-Chebbi, Ichrak; Karoui, Habib; Essafi Benkhadir, Khadija; Montenegro Arce, María Fernanda; Rodríguez López, José Neptuno; Sánchez del Campo Ferrer, Luis; Bioquímica y Biología Molecular A
    Melanoma, the most threatening form of skin cancer, has a very poor prognosis and is characterized by its very invasive and chemoresistant properties. Despite the recent promising news from the field of immunotherapy, there is an urgent need for new therapeutic approaches that are free of resistance mechanisms and side effects. Anti-neoplasic properties have been highlighted for different disintegrins from snake venom including Lebein; however, the exact effect of Lebein on melanoma has not yet been defined. In this study, we showed that Lebein blocks melanoma cell proliferation and induces a more differentiated phenotype with inhibition of extracellular signal-regulated kinase (ERK) phosphorylation and microphthalmia-associated transcription factor (MITF) overexpression. Melanoma cells became detached but were less invasive with upregulation of E-cadherin after Lebein exposure. Lebein induced a caspase-independent apoptotic program with apoptosis inducing factor (AIF), BCL-2-associated X protein (BAX) and Bim overexpression together with downregulation of B-cell lymphoma-2 (BCL-2). It generated a distinct response in reactive oxygen species (ROS) generation and p53 levels depending on the p53 cell line status (wild type or mutant). Therefore, we propose Lebein as a new candidate for development of potential therapies for melanoma.
  • Publication
    Open Access
    Persister state-directed transitioning and vulnerability in melanoma
    (Springer Nature, 2022-06-01) Chauvistré, Heike; Shannan, Batool; Daignault-Mill, Sheena M.; Ju, Robert J.; Picard, Daniel; Egetemaier, Stefanie; Váraljai, Renáta; Gibhardt, Christine; Sechi, Antonio; Kaschani, Farnusch; Keminer, Oliver; Stehbens, Samantha J.; Liu, Qin; Yin, Xiangfan; Jeyakumar, Kirujan; Vogel, Felix C.E.; Krepler, Clemens; Rebecca, Vito W.; Kubat, Linda; Lueong, Smiths S.; Forster, Jan; Horn, Susanne; Remke, Marc; Ehrmann, Michael; Paschen, Annette; Becker, Jürgen C.; Helfrich, Iris; Rauh, Daniel; Kaiser, Markus; Gul, Sheraz; Herlyn, Meenhard; Bogeski, Ivan; Haass, Nikolas; Schadendorf, Dirk; Roesch, Alexander; Rodríguez López, José Neptuno; Bioquímica y Biología Molecular A
    Melanoma is a highly plastic tumor characterized by dynamic interconversion of different cell identities depending on the biological context. Melanoma cells with high expression of the H3K4 demethylase KDM5B (JARID1B) rest in a slow-cycling, yet reversible persister state. Over time, KDM5Bhigh cells can promote rapid tumor repopulation with equilibrated KDM5B expression heterogeneity. The cellular identity of KDM5Bhigh persister cells has not been studied so far, missing an important cell state-directed treatment opportunity in melanoma. Here, we have established a doxycycline-titratable system for genetic induction of permanent intratumor expression of KDM5B and screened for chemical agents that phenocopy this effect. Transcriptional profiling and cell functional assays confirmed that the dihydropyridine 2-phenoxyethyl 4-(2-fluorophenyl)-2,7,7-trimethyl-5-oxo-1,4,5,6,7,8-hexa-hydro-quinoline-3-carboxylate (termed Cpd1) supports high KDM5B expression and directs melanoma cells towards differentiation along the melanocytic lineage and to cell cycle-arrest. The high KDM5B state additionally prevents cell proliferation through negative regulation of cytokinetic abscission. Moreover, treatment with Cpd1 promoted the expression of the melanocyte-specific tyrosinase gene specifically sensitizing melanoma cells for the tyrosinase-processed antifolate prodrug 3-O-(3,4,5-trimethoxybenzoyl)-(-)-epicatechin (TMECG). In summary, our study provides proof-of-concept for a dual hit strategy in melanoma, in which persister state-directed transitioning limits tumor plasticity and primes melanoma cells towards lineage-specific elimination
  • Publication
    Open Access
    Suppression of antifolate resistance by targeting the myosin va trafficking pathway in melanoma
    (Elsevier, 2014-02-28) Fernández Pérez, Maria Piedad; Sáez Ayala, Magalí; Piñero Madrona, Antonio; Cabezas Herrera, Juan; Montenegro Arce, María Fernanda; Rodríguez López, José Neptuno; Sánchez del Campo Ferrer, Luis; Bioquímica y Biología Molecular A
    Human melanoma is a significant clinical problem. As most melanoma patients relapse with lethal drug-resistant disease, understanding and preventing mechanism(s) of resistance is one of the highest priorities to improve melanoma therapy. Melanosomal sequestration and the cellular exportation of cytotoxic drugs have been proposed to be important melanoma-specific mechanisms that contribute to multidrug resistance in melanoma. Concretely, we found that treatment of melanoma with methotrexate (MTX) altered melanogenesis and accelerated the exportation of melanosomes; however, the cellular and molecular processes by which MTX is trapped into melanosomes and exported out of cells have not been elucidated. In this study, we identified myosin Va (MyoVa) as a possible mediator of these cellular processes. The results demonstrated that melanoma treatment with MTX leads to Akt2-dependent MyoVa phosphorylation, which enhances its ability to interact with melanosomes and accelerates their exportation. To understand the mechanism(s) by which MTX activates Akt2, we examined the effects of this drug on the activity of protein phosphatase 2A, an Akt inhibitor activated by the methylation of its catalytic subunit. Taken together, this study identified a novel trafficking pathway in melanoma that promotes tumor resistance through Akt2/MyoVa activation. Because of these findings, we explored several MTX combination therapies to increase the susceptibility of melanoma to this drug. By avoiding MTX exportation, we observed that the E2F1 apoptotic pathway is functional in melanoma, and its induction activates p73 and apoptosis protease-activating factor 1 following a p53-autonomous proapoptotic signaling event.
  • Publication
    Open Access
    MITF induces escape from innate immunity in melanoma
    (BMC, 2021) Martí-Díaz, Román; González-Guerrero, Rebeca; Martínez-Barba, Enrique; Piñero-Madrona, Antonio; Cabezas-Herrera, Juan; Goding, Colin R.; Montenegro Arce, María Fernanda; Hernández Caselles, Trinidad; Rodríguez López, José Neptuno; Sánchez del Campo Ferrer, Luis; Bioquímica y Biología Molecular B e Inmunología
    Background: The application of immune-based therapies has revolutionized cancer treatment. Yet how the immune system responds to phenotypically heterogeneous populations within tumors is poorly understood. In melanoma, one of the major determinants of phenotypic identity is the lineage survival oncogene MITF that integrates diverse microenvironmental cues to coordinate melanoma survival, senescence bypass, differentiation, proliferation, invasion, metabolism and DNA damage repair. Whether MITF also controls the immune response is unknown. Methods: By using several mouse melanoma models, we examine the potential role of MITF to modulate the anti-melanoma immune response. ChIP-seq data analysis, ChIP-qPCR, CRISPR-Cas9 genome editing, and luciferase reporter assays were utilized to identify ADAM10 as a direct MITF target gene. Western blotting, confocal microscopy, flow cytometry, and natural killer (NK) cytotoxicity assays were used to determine the underlying mechanisms by which MITF-driven phenotypic plasticity modulates melanoma NK cell-mediated killing. Results: Here we show that MITF regulates expression of ADAM10, a key sheddase that cleaves the MICA/B family of ligands for NK cells. By controlling melanoma recognition by NK-cells MITF thereby controls the melanoma response to the innate immune system. Consequently, while melanoma MITFLow cells can be effectively suppressed by NK-mediated killing, MITF-expressing cells escape NK cell surveillance. Conclusion: Our results reveal how modulation of MITF activity can impact the anti-melanoma immune response with implications for the application of anti-melanoma immunotherapies.
  • Publication
    Open Access
    Mechanism of Dihydrofolate Reductase Downregulation in Melanoma by 3-O-(3,4,5-Trimethoxybenzoyl)-(-)-Epicatechin
    (WILEY, 2010-06-01) Chazarra Parres, Soledad; Cabezas Herrera, Juan; Montenegro Arce, María Fernanda; Rodríguez López, José Neptuno; Sánchez del Campo Ferrer, Luis; Bioquímica y Biología Molecular A
    In our search to improve the stability and cellular absorption of tea polyphenols, we synthesized 3-O-(3,4,5-trimethoxybenzoyl)-(-)-epicatechin (TMECG), which showed high antiproliferative activity against melanoma. TMECG downregulates dihydrofolate reductase (DHFR) expression in melanoma cells and we detail the sequential mechanisms that result from this even. TMECG is specifically activated in melanoma cells to form a stable quinone methide (TMECG-QM). TMECG-QM has a dual action on these cells. First, it acts as a potent antifolate compound, disrupting folate metabolism and increasing intracellular oxidized folate coenzymes, such as dihydrofolate, which is a noncompetitive inhibitor of dihydropterine reductase, an enzyme essential for tetrahydrobiopterin (H4B) recycling. Such inhibition results in H4B deficiency, endothelial nitric oxide synthase (eNOS) uncoupling and superoxide production. Second, TMECG-QM acts as an efficient superoxide scavenger and promotes intra-cellular H2O2 accumulation. Here, we present evidence that TMECG markedly reduces melanoma H4B and NO bioavailability and that TMECG action is abolished by the eNOS inhibitor N-omega-nitro-L-arginine methyl ester or the H2O2 scavenger catalase, which strongly suggests H2O2-dependent DHFR downregulation. In addition, the data presented here indicate that the simultaneous targeting of important pathways for melanoma survival, such as the folate cycle, H4B recycling, and the eNOS reaction, could represent an attractive strategy for fighting this malignant skin pathology
  • Publication
    Open Access
    Comparison of a Pair of Synthetic Tea-Catechin-Derived Epimers: Synthesis, Antifolate Activity, and Tyrosinase-Mediated Activation in Melanoma
    (WILEY, 2011-03-07) Sáez Ayala, Magalí; Chazarra Parres, Soledad; Tárraga Tomás, Alberto; Cabezas Herrera, Juan; Montenegro Arce, María Fernanda; Rodríguez López, José Neptuno; Sánchez del Campo Ferrer, Luis; Bioquímica y Biología Molecular A
    Despite bioavailability issues, tea catechins have emerged as promising chemopreventive agents because of their efficacy in various animal models. We synthesized two catechin-derived compounds, 3-O-(3,4,5-trimethoxybenzoyl)-(-)-catechin (TMCG) and 3-O-(3,4,5-trimethoxybenzoyl)-(-)-epicatechin (TMECG), in an attempt to improve the stability and cellular absorption of tea polyphenols. The antiproliferative and pro-apoptotic activities of both compounds were analyzed with various cancer cell systems, and TMCG, which was easily synthesized in excellent yield, was more active than TMECG in both melanoma and non-melanoma cell lines. TMCG was also a better inhibitor of dihydrofolate reductase and was more efficiently oxidized by tyrosinase, potentially explaining the difference in activity between these epimers.
  • Publication
    Open Access
    Macrovipecetin, a C-type lectin from Macrovipera lebetina venom, inhibits proliferation migration and invasion of SK-MEL-28 human melanoma cells and enhances their sensitivity to cisplatin
    (Pergamon, Elsevier Science Ltd, 2018-03) Hammouda, Manel B.; Riahi-Chebbi, Ichrak; Souid, Soumaya; Othman, Houcemeddine; Aloui, Zohra; Srairi-Abid, Najet; Karoui, Habib; Gasmi, Ammar; Magnenat, Edith M.; Wells, Timothy N.C.; Clemetson, Kenneth J.; Essafi-Benkhadir, Khadija; Rodríguez López, José Neptuno; Bioquímica y Biología Molecular A
    Background The resistance of melanoma cells to cisplatin restricts its clinical use. Therefore, the search for novel tumor inhibitors and effective combination treatments that sensitize tumor cells to this drug are still needed. We purified macrovipecetin, a novel heterodimeric C-type lectin, from Macrovipera lebetina snake venom and investigated its anti-tumoral effect on its own or combined with cisplatin, in human melanoma cells. Methods Biochemical characterization, in vitro cells assays such as viability, apoptosis, adhesion, migration, invasion, Western blotting and in silico analysis were used in this study. Results Macrovipecetin decreased melanoma cell viability 100 times more than cisplatin. Interestingly, when combined with the drug, macrovipecetin enhanced the sensitivity of SK-MEL-28 cells by augmenting their apoptosis through increased expression of the apoptosis inducing factor (AIF) and activation of ERK1/2, p38, AKT and NF-κB. Moreover, macrovipecetin alone or combined with cisplatin induced the expression of TRADD, p53, Bax, Bim and Bad and down-regulated the Bcl-2 expression and ROS levels in SK-MEL-28 cells. Interestingly, these treatments impaired SK-MEL-28 cell adhesion, migration and invasion through modulating the function and expression of αvβ3 integrin along with regulating E-cadherin, vimentin, β-catenin, c-Src and RhoA expression. In silico study suggested that only the α chain of macrovipecetin interacts with a region overlapping the RGD motif binding site on this integrin. Conclusions We validated the antitumor effect of macrovipecetin when combined, or not, with cisplatin on SK-MEL-28 cells. General significance The presented work proposes the potential use of macrovipecetin and cisplatin in combination as an effective anti-melanoma treatment.
  • Publication
    Open Access
    Acriflavine, a Potent Inhibitor of HIF-1α, Disturbs Glucose Metabolism and Suppresses ATF4-Protective Pathways in Melanoma under Non-Hypoxic Conditions
    (MDPI, 2020-12-31) Martí Díaz, Román; Cabezas Herrera, Juan; Goding, Colin; Montenegro Arce, María Fernanda; Rodríguez López, José Neptuno; Sánchez del Campo Ferrer, Luis; Bioquímica y Biología Molecular A
    Hypoxia-inducible factor (HIF)-1α is constitutively expressed in melanoma cells under normoxic conditions and its elevated expression correlates with the aggressiveness of melanoma tumors. Here, we used acriflavine, a potent inhibitor of HIF-1α dimerization, as a tool to investigate whether HIF-1α-regulated pathways contribute to the growth of melanoma cells under normoxia. We observed that acriflavine differentially modulated HIF-1α-regulated targets in melanoma under normoxic conditions, although acriflavine treatment resulted in over-expression of vascular endothelial growth factor (VEGF), its action clearly downregulated the expression of pyruvate dehydrogenase kinase 1 (PDK1), a well-known target of HIF-1α. Consequently, downregulation of PDK1 by acrifavine resulted in reduced glucose availability and suppression of the Warburg effect in melanoma cells. In addition, by inhibiting the AKT and RSK2 phosphorylation, acriflavine also avoided protective pathways necessary for survival under conditions of oxidative stress. Interestingly, we show that acriflavine targets activating transcription factor 4 (ATF4) for proteasomal degradation while suppressing the expression of microphthalmia-associated transcription factor (MITF), a master regulator of melanocyte development and a melanoma oncogene. Since acriflavine treatment results in the consistent death of melanoma cells, our results suggest that inhibition of HIF-1α function in melanoma could open new avenues for the treatment of this deadly disease regardless of the hypoxic condition of the tumor.