Person:
Rodríguez López, José Neptuno

Profile Picture
Name
Rodríguez López, José Neptuno
publication.page.department
Universidad de Murcia. Departamento de Bioquímica y Biología MolecularA
Repository logoRepository logoRepository logoRepository logoRepository logoRepository logo

Filters

2009 - 200922010 - 20141
4
Reset filters

Settings

Has files: Yes × Subject: Antifolates ×

Search Results

Now showing 1 - 4 of 4
  • Thumbnail Image
    Publication
    Open Access
    Targeting the epigenetic machinery of cancer cells
    (Springer Nature, 2014-01-27) Fernández Pérez, María Piedad; Sáez Ayala, Magalí; Cabezas Herrera, Juan; Montenegro Arce, María Fernanda; Rodríguez López, José Neptuno; Sánchez del Campo Ferrer, Luis; Bioquímica y Biología Molecular A
    Cancer is characterised by uncontrolled cell growth and the acquisition of metastatic properties. In most cases, the activation of oncogenes and/or deactivation of tumour suppressor genes lead to uncontrolled cell cycle progression and inactivation of apoptotic mechanisms. Although the underlying mechanisms of carcinogenesis remain unknown, increasing evidence links aberrant regulation of methylation to tumourigenesis. In addition to the methylation of DNA and histones, methylation of non-histone proteins, such as transcription factors, is also implicated in the biology and development of cancer. Because the metabolic cycling of methionine is a key pathway for many of these methylating reactions, strategies to target the epigenetic machinery of cancer cells could result in novel and efficient anti-cancer therapies. The application of these new epigenetic therapies could be of utility to promote E2F1-dependent apoptosis in cancer cells, avoid metastatic pathways and/or sensitise tumour cells to radiotherapy.
  • Thumbnail Image
    Publication
    Open Access
    Targeting the epigenetics of the DNA damage response in breast cancer
    (Springer Nature, ) González Guerrero, Rebeca; Piñero Madrona, Antonio; Cabezas Herrera, Juan; Montenegro Arce, María Fernanda; Rodríguez López, José Neptuno; Sánchez del Campo Ferrer, Luis; Bioquímica y Biología Molecular A
    Cancer is as much an epigenetic disease as it is a genetic disease, and epigenetic alterations in cancer often serve as potent surrogates for genetic mutations. Because the epigenetic factors involved in the DNA damage response are regulated by multiple elements, therapies to target specific components of the epigenetic machinery can be inefficient. In contrast, therapies aimed at inhibiting the methionine cycle can indirectly inhibit both DNA and protein methylation, and the wide variety of genes and pathways that are affected by these methylations make this global strategy very attractive. In the present study, we propose an adjuvant therapy that targets the epigenetics of the DNA damage response in breast cancer cells and that results in efficient apoptosis and a reduction in distant metastases in vivo. We observed that a combined therapy designed to uncouple adenosine metabolism using dipyridamole in the presence of a new synthetic antifolate, 3-O-(3,4,5-trimethoxybenzoyl)-(−)-catechin, simultaneously and efficiently blocked both the folic cycle and the methionine cycle in breast cancer cells and sensitized these cells to radiotherapy. The treatment impeded the recruitment of 53BP1 and BRCA1 to the chromatin regions flanking DNA double-strand breaks and thereby avoided the DNA damage responses in breast cancer cells that were exposed to ionizing radiation. In addition, this hypomethylating therapy was also efficient in reducing the self-renewal capability of breast cancer-initiating cells and induced reversion of mesenchymal phenotypes in breast cancer cells
  • Thumbnail Image
    Publication
    Open Access
    Melanoma Activation of 3-O-(3,4,5-Trimethoxybenzoyl)-(-)-Epicatechin to a Potent Irreversible Inhibitor of Dihydrofolate Reductase
    (2009-04-09) Tárraga Tomás, Alberto; 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 because it is resistant to treatment by most chemotherapeutic agents, including antifolates. It is therefore a desirable goal to develop a second generation of low-toxicity antifolate drugs to overcome acquired resistance to the prevention and treatment of this skin pathology. In our efforts to improve the stability and bioavailability of green tea polyphenols for cancer therapy, we synthesized a trimethoxy derivative of epicatechin-3-gallate, which showed high anti proliferative and proapoptotic activity against melanoma. This derivative, 3-O-(3,4,5-trimethoxybenzoyl)-(-)-epicatechin (TMECG), is a prodrug that is selectively activated by the specific melanocyte enzyme tyrosinase. Upon activation, TMECG generates a stable quinone methide product that strongly inhibits dihydrofolate reductase in an irreversible manner. The treatment of melanoma cells with TMECG also affected cellular folate transport and the gene expression of DHFR, which supported the antifolate nature of this compound. In addition, its pharmacological efficacy has been confirmed in a mouse melanoma model, in which tumor growth and metastasis were inhibited, significantly enhancing the mean survival of the treated groups. TMECG, therefore, shows a potential for clinical use in melanoma therapy.
  • Thumbnail Image
    Publication
    Open Access
    Binding of Natural and Synthetic Polyphenols to Human Dihydrofolate Reductase
    (MDPI, 2009-12-18) Sáez Ayala, Magalí; Chazarra Parres, Soledad; Cabezas Herrera, Juan; Rodríguez López, José Neptuno; Sánchez del Campo Ferrer, Luis; Bioquímica y Biología Molecular A
    Dihydrofolate reductase (DHFR) is the subject of intensive investigation since it appears to be the primary target enzyme for antifolate drugs. Fluorescence quenching experiments show that the ester bond-containing tea polyphenols (-)-epigallocatechin gallate (EGCG) and (-)-epicatechin gallate (ECG) are potent inhibitors of DHFR with dissociation constants (K-D) of 0.9 and 1.8 mu M, respectively, while polyphenols lacking the ester bound gallate moiety [e.g., (-)-epigallocatechin (EGC) and (-)-epicatechin (EC)] did not bind to this enzyme. To avoid stability and bioavailability problems associated with tea catechins we synthesized a methylated derivative of ECG (3-O-(3,4,5-trimethoxybenzoyl)(-)-epicatechin; TMECG), which effectively binds to DHFR (K-D = 2.1 mu M). In alkaline solution, TMECG generates a stable quinone methide product that strongly binds to the enzyme with a K-D of 8.2 nM. Quercetin glucuronides also bind to DHFR but its effective binding was highly dependent of the sugar residue, with quercetin-3-xyloside being the stronger inhibitor of the enzyme with a K-D of 0.6 mu M. The finding that natural polyphenols are good inhibitors of human DHFR could explain the epidemiological data on their prophylactic effects for certain forms of cancer and open a possibility for the use of natural and synthetic polyphenols in cancer chemotherapy.
Ir a Estadísticas