The Experts below are selected from a list of 357 Experts worldwide ranked by ideXlab platform

Kiyoyuki Yamada - One of the best experts on this subject based on the ideXlab platform.

Hendrik Luesch - One of the best experts on this subject based on the ideXlab platform.

  • The Cyanobacterial Origin of Potent Anticancer Agents Originally Isolated from Sea Hares
    Current Medicinal Chemistry, 2002
    Co-Authors: Hendrik Luesch, Gilles H. Goetz, F. David Horgen
    Abstract:

    It is increasingly evident that the true biological origin of many metabolites originally isolated from certain marine macroorganisms is cyanobacterial. For example, several dolastatins, potent cytotoxic compounds originally derived from the sea hare Dolabella auricularia, have now been isolated from marine cyanobacteria of the genera Lyngbya and Symploca. This review discusses the isolation of dolastatins and close structural analogues from cyanobacteria. Biosynthetic signatures of metabolites isolated from sea hares, but which are most probably cyanobacterial in origin, are also presented. Finally, some more complex ecology involving movement of cyanobacterial metabolites through the marine food web is presented.

  • isolation of dolastatin 10 from the marine cyanobacterium symploca species vp642 and total stereochemistry and biological evaluation of its analogue symplostatin 1
    Journal of Natural Products, 2001
    Co-Authors: Hendrik Luesch, Susan L Mooberry, Richard E. Moore, Valerie J. Paul, Thomas H Corbett
    Abstract:

    The potent antitumor agent dolastatin 10 (1) was originally isolated from the sea hare Dolabella auricularia, and we now report its isolation from the marine cyanobacterium Symploca sp. VP642 from Palau. The chemically related analogue symplostatin 1 (2) has been reisolated from Guamanian and Hawaiian varieties of S. hydnoides and its total stereochemistry completed by determining the N,N-dimethylisoleucine unit to be l. Symplostatin 1 (2), like dolastatin 10 (1), is a potent microtubule inhibitor. The antitumor activity of 2 was assessed in vivo against several murine tumors. Symplostatin 1 (2) was effective against a drug-insensitive mammary tumor and a drug-insensitive colon tumor; however, it was only slightly effective against two MDR tumors.

  • isolation structure determination and biological activity of lyngbyabellin a from the marine cyanobacterium lyngbya majuscula
    Journal of Natural Products, 2000
    Co-Authors: Hendrik Luesch, Richard E. Moore, Wesley Y. Yoshida, Valerie J. Paul, Susan L Mooberry
    Abstract:

    Lyngbyabellin A (1), a significantly cytotoxic compound with unusual structural features, was isolated from a Guamanian strain of the marine cyanobacterium Lyngbya majuscula. This novel peptolide is structurally related to dolabellin (2) in that both depsipeptides bear a dichlorinated β-hydroxy acid and two functionalized thiazole carboxylic acid units. Its gross structure has been elucidated by spectral analysis, including 2D NMR techniques. The absolute stereochemistry of 1 was determined by chiral HPLC analysis of hydrolysis products and by characterization of the degradation products methyl 7,7-dichloro-3-hydroxy-2,2-dimethyloctanoate (3) and the corresponding acid 4. The total structure was further supported by molecular modeling studies. The isolation of 1 from L. majuscula once more supports the proposal that many compounds originally isolated from the sea hare Dolabella auricularia are of cyanobacterial origin. Lyngbyabellin A (1) was shown to be a potent disrupter of the cellular microfilament ne...

  • symplostatin 2 a dolastatin 13 analogue from the marine cyanobacterium symploca hydnoides
    Journal of Natural Products, 1999
    Co-Authors: Hendrik Luesch, Wesley Y. Yoshida, Richard E. Moore, Valerie J. Paul
    Abstract:

    An analogue of dolastatin 13 (2) has been isolated from a marine cyanobacterium, Symploca hydnoides, collected near Guam. This new cyclic depsipeptide contains a l-methionine sulfoxide residue; however, the sulfoxide exists as both R- and S-forms, resulting in the doubling of several signals in the 1H and 13C NMR spectra. Structure elucidation required extensive application of 2-D NMR techniques such as COSY, HMQC, HMBC, and ROESY. The trivial name symplostatin 2 (1) has been assigned to the new metabolite and its isolation from S. hydnoides further supports the proposal that many compounds originally isolated from the sea hare Dolabella auricularia are most probably of cyanobacterial origin.

  • symplostatin 1 a dolastatin 10 analogue from the marine cyanobacterium symploca hydnoides
    Journal of Natural Products, 1998
    Co-Authors: Hendrik Luesch, Susan L Mooberry, Thomas H Corbett, Wesley Y. Yoshida, Richard E. Moore, Valerie J. Paul, Fred Valeriote
    Abstract:

    A new solid tumor selective cytotoxic analogue of dolastatin 10 (1) has been isolated from the marine cyanobacterium Symploca hydnoides, collected near Guam. This metabolite has been assigned the trivial name symplostatin 1 (2). This discovery supports the proposal that many compounds isolated from the seahare Dolabella auricularia, the original source of the dolastatins, are of dietary origin.

Valerie J. Paul - One of the best experts on this subject based on the ideXlab platform.

  • isolation of dolastatin 10 from the marine cyanobacterium symploca species vp642 and total stereochemistry and biological evaluation of its analogue symplostatin 1
    Journal of Natural Products, 2001
    Co-Authors: Hendrik Luesch, Susan L Mooberry, Richard E. Moore, Valerie J. Paul, Thomas H Corbett
    Abstract:

    The potent antitumor agent dolastatin 10 (1) was originally isolated from the sea hare Dolabella auricularia, and we now report its isolation from the marine cyanobacterium Symploca sp. VP642 from Palau. The chemically related analogue symplostatin 1 (2) has been reisolated from Guamanian and Hawaiian varieties of S. hydnoides and its total stereochemistry completed by determining the N,N-dimethylisoleucine unit to be l. Symplostatin 1 (2), like dolastatin 10 (1), is a potent microtubule inhibitor. The antitumor activity of 2 was assessed in vivo against several murine tumors. Symplostatin 1 (2) was effective against a drug-insensitive mammary tumor and a drug-insensitive colon tumor; however, it was only slightly effective against two MDR tumors.

  • isolation structure determination and biological activity of lyngbyabellin a from the marine cyanobacterium lyngbya majuscula
    Journal of Natural Products, 2000
    Co-Authors: Hendrik Luesch, Richard E. Moore, Wesley Y. Yoshida, Valerie J. Paul, Susan L Mooberry
    Abstract:

    Lyngbyabellin A (1), a significantly cytotoxic compound with unusual structural features, was isolated from a Guamanian strain of the marine cyanobacterium Lyngbya majuscula. This novel peptolide is structurally related to dolabellin (2) in that both depsipeptides bear a dichlorinated β-hydroxy acid and two functionalized thiazole carboxylic acid units. Its gross structure has been elucidated by spectral analysis, including 2D NMR techniques. The absolute stereochemistry of 1 was determined by chiral HPLC analysis of hydrolysis products and by characterization of the degradation products methyl 7,7-dichloro-3-hydroxy-2,2-dimethyloctanoate (3) and the corresponding acid 4. The total structure was further supported by molecular modeling studies. The isolation of 1 from L. majuscula once more supports the proposal that many compounds originally isolated from the sea hare Dolabella auricularia are of cyanobacterial origin. Lyngbyabellin A (1) was shown to be a potent disrupter of the cellular microfilament ne...

  • Unpalatable Compounds in the Marine Gastropod Dolabella auricularia: Distribution and Effect of Diet
    Journal of Chemical Ecology, 1999
    Co-Authors: Steven C. Pennings, Valerie J. Paul, D. Chuck Dunbar, Mark T. Hamann, Wilfred A. Lumbang, Brandie Novack, Robert S. Jacobs
    Abstract:

    Sea hares are a rich source of novel secondary metabolites, most of which are derived from their algal diet, but the natural function(s) of these metabolites are largely unknown. We used field and laboratory assays to measure the palatability of extracts from the tissues, ink, and eggs of Dolabella auricularia. Digestive-gland extracts contained a wide variety of secondary metabolites, including the red algal compound prepacifinol epoxide and its derivative johnstonol, and they were unpalatable to reef fishes. Skin extracts were moderately unpalatable, but our bioassay-guided fractionation led us to (–)-7-dehydrocholesterol, rather than to an algal secondary metabolite. Ink extracts were consistently unpalatable to reef fishes only at high concentrations, suggesting either that ink must be concentrated to deter predators, that unpalatable components of ink rapidly decompose, or that ink has other functions. Unpalatability of ink was traced to a purple fraction, consistent with the hypothesis that the active compound is aplysioviolin, a known ink constituent modified from a red algal pigment. Egg extracts were moderately unpalatable; however, we could not trace this activity to any algal-derived secondary metabolite. Body-wall extract was highly palatable. Our results suggest that dietary-derived secondary metabolites play a role in chemical defense of D. auricularia via the ink, but are not responsible for unpalatability of skin or eggs. Accumulation of dietary-derived metabolites in the digestive gland may occur to detoxify a chemically rich diet, rather than or in addition to deterring predators.

  • symplostatin 2 a dolastatin 13 analogue from the marine cyanobacterium symploca hydnoides
    Journal of Natural Products, 1999
    Co-Authors: Hendrik Luesch, Wesley Y. Yoshida, Richard E. Moore, Valerie J. Paul
    Abstract:

    An analogue of dolastatin 13 (2) has been isolated from a marine cyanobacterium, Symploca hydnoides, collected near Guam. This new cyclic depsipeptide contains a l-methionine sulfoxide residue; however, the sulfoxide exists as both R- and S-forms, resulting in the doubling of several signals in the 1H and 13C NMR spectra. Structure elucidation required extensive application of 2-D NMR techniques such as COSY, HMQC, HMBC, and ROESY. The trivial name symplostatin 2 (1) has been assigned to the new metabolite and its isolation from S. hydnoides further supports the proposal that many compounds originally isolated from the sea hare Dolabella auricularia are most probably of cyanobacterial origin.

  • symplostatin 1 a dolastatin 10 analogue from the marine cyanobacterium symploca hydnoides
    Journal of Natural Products, 1998
    Co-Authors: Hendrik Luesch, Susan L Mooberry, Thomas H Corbett, Wesley Y. Yoshida, Richard E. Moore, Valerie J. Paul, Fred Valeriote
    Abstract:

    A new solid tumor selective cytotoxic analogue of dolastatin 10 (1) has been isolated from the marine cyanobacterium Symploca hydnoides, collected near Guam. This metabolite has been assigned the trivial name symplostatin 1 (2). This discovery supports the proposal that many compounds isolated from the seahare Dolabella auricularia, the original source of the dolastatins, are of dietary origin.

Wesley Y. Yoshida - One of the best experts on this subject based on the ideXlab platform.

  • isolation and structure determination of malevamide e a dolastatin 14 analogue from the marine cyanobacterium symploca laete viridis
    Journal of Natural Products, 2008
    Co-Authors: Beatrice Adams, Hans E Westenburg, Emily Pittman, Peter Porzgen, Wesley Y. Yoshida, David F Horgen
    Abstract:

    A new depsipeptide, malevamide E (1), was isolated from field-collected colonies of the filamentous cyanobacterium Symploca laete-viridis. The gross structure of 1 was determined by spectroscopic analyses, including one- and two-dimensional NMR and accurately measured MS/MS. Chiral HPLC analyses of an acid hydrolysate of 1 allowed the stereochemical assignments of its amino acid residues, which include N-methyl-l-alanine, α-N,γ-N-dimethyl-l-asparagine, N-methyl-l-phenylalanine, l-proline, d-valine, and N-methyl-l-valine. LC-MS/MS analysis of S. laete-viridis fractions established the co-occurrence of malevamide E (1) and its homologue dolastatin 14 (2), which was previously reported in low yield from the sea hare Dolabella auricularia. Malevamide E (1) demonstrated a dose-dependent (2–45 µM) inhibition of store-operated Ca2+ entry in thapsigargin-treated human embryonic kidney (HEK) cells, indicating an inhibitory effect on Ca2+ release-activated Ca2+ (CRAC) channels.

  • malevamide d isolation and structure determination of an isodolastatin h analogue from the marine cyanobacterium symploca hydnoides
    Journal of Natural Products, 2002
    Co-Authors: David F Horgen, Emily B Kazmierski, Hans E Westenburg, Wesley Y. Yoshida, Peter J Scheuer
    Abstract:

    Malevamide D (1), a highly cytotoxic peptide ester, and the known compound curacin D (5) were isolated from a Hawaiian sample of Symploca hydnoides. The structure of 1 was elucidated by spectroscopic analysis including NMR and high-resolution MS/MS. Partial stereochemical assignments of 1 were made by chiral HPLC analysis of acid and base hydrolysates. Malevamide D (1) demonstrated toxicity against P-388, A-549, HT-29, and MEL-28 cell lines in the subnanomolar range, while curacin D (5) was weakly cytotoxic. Malevamide D (1) is closely related to isodolastatin H (2), which was previously isolated in low yield from the sea hare Dolabella auricularia. A second Hawaiian sample of S. hydnoides yielded curacin D (5) along with the known dolastatin-10 analogue symplostatin-1 (3).

  • isolation structure determination and biological activity of lyngbyabellin a from the marine cyanobacterium lyngbya majuscula
    Journal of Natural Products, 2000
    Co-Authors: Hendrik Luesch, Richard E. Moore, Wesley Y. Yoshida, Valerie J. Paul, Susan L Mooberry
    Abstract:

    Lyngbyabellin A (1), a significantly cytotoxic compound with unusual structural features, was isolated from a Guamanian strain of the marine cyanobacterium Lyngbya majuscula. This novel peptolide is structurally related to dolabellin (2) in that both depsipeptides bear a dichlorinated β-hydroxy acid and two functionalized thiazole carboxylic acid units. Its gross structure has been elucidated by spectral analysis, including 2D NMR techniques. The absolute stereochemistry of 1 was determined by chiral HPLC analysis of hydrolysis products and by characterization of the degradation products methyl 7,7-dichloro-3-hydroxy-2,2-dimethyloctanoate (3) and the corresponding acid 4. The total structure was further supported by molecular modeling studies. The isolation of 1 from L. majuscula once more supports the proposal that many compounds originally isolated from the sea hare Dolabella auricularia are of cyanobacterial origin. Lyngbyabellin A (1) was shown to be a potent disrupter of the cellular microfilament ne...

  • symplostatin 2 a dolastatin 13 analogue from the marine cyanobacterium symploca hydnoides
    Journal of Natural Products, 1999
    Co-Authors: Hendrik Luesch, Wesley Y. Yoshida, Richard E. Moore, Valerie J. Paul
    Abstract:

    An analogue of dolastatin 13 (2) has been isolated from a marine cyanobacterium, Symploca hydnoides, collected near Guam. This new cyclic depsipeptide contains a l-methionine sulfoxide residue; however, the sulfoxide exists as both R- and S-forms, resulting in the doubling of several signals in the 1H and 13C NMR spectra. Structure elucidation required extensive application of 2-D NMR techniques such as COSY, HMQC, HMBC, and ROESY. The trivial name symplostatin 2 (1) has been assigned to the new metabolite and its isolation from S. hydnoides further supports the proposal that many compounds originally isolated from the sea hare Dolabella auricularia are most probably of cyanobacterial origin.

  • symplostatin 1 a dolastatin 10 analogue from the marine cyanobacterium symploca hydnoides
    Journal of Natural Products, 1998
    Co-Authors: Hendrik Luesch, Susan L Mooberry, Thomas H Corbett, Wesley Y. Yoshida, Richard E. Moore, Valerie J. Paul, Fred Valeriote
    Abstract:

    A new solid tumor selective cytotoxic analogue of dolastatin 10 (1) has been isolated from the marine cyanobacterium Symploca hydnoides, collected near Guam. This metabolite has been assigned the trivial name symplostatin 1 (2). This discovery supports the proposal that many compounds isolated from the seahare Dolabella auricularia, the original source of the dolastatins, are of dietary origin.

Ruiz-torres Verónica - One of the best experts on this subject based on the ideXlab platform.

  • Efecto antiproliferativo de extractos procedente de invertebrados marinos mediado por estrés en modelos celulares humanos de cáncer de colon
    2021
    Co-Authors: Ruiz-torres Verónica
    Abstract:

    Cancer i s o ne o f t he l eading c auses o f d eath w orldwide and requires the attention and e ffort o f t he s cientific c ommunity f or t he d evelopment o f n ew strategies a nd t he d iscovery o f d rugs t hat h elp f ight t he d isease [1]. It is necessary to discover novel effective therapies focused on avoiding cancer cell proliferation and reducing side effects. Marine compounds, produced to survive in response to harsh and competitive environmental conditions, are postulated as a potential anticancer source. In the last decades, marine metabolites have shown novel wide chemical structures, which have been attributed to interesting biological activities and this fact has been registered by the increasing numbers of drugs approved by the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA). In particular, marine invertebrates are considered one of the richest biodiverse groups. To date, a large number of natural products e xtracted o r s ynthesized b ased o n m arine c ompounds f rom invertebrates have been established as antineoplastic drugs. In chapter 1, the current marine natural products (MNPs) that have been established as antineoplastic drugs were reviewed and their putative mechanisms of action in the different hallmarks of cancer described, giving an overview o f t he r ichness o f t he c hemical s tructures t hat t hey o ffer a nd introducing the use of virtual screening for drug discovery. This t hesis, in chapter 2, f ocuses o n t he search o f t he antiproliferative effect of several invertebrate marine extracts in human colon cancer cell models. The first part of the project focuses on the search for marine organisms that have intra and interspecific competence through the production of bioactive compounds. A selection of 20 organisms was made based on bibliographic sources and relayed on observations of competence in experimental aquariums. The next part consisted in to screen the in vitro antiproliferative effect on a panel of colon cancer cell models. Four extracts were selected due to their potential cytotoxic effect: Phyllidia varicosa (NA extract) and Dolabella auricularia (NB extract), obtained from two nudibranchs, Carotalcyon sp (CR extract) obtained from a soft coral and Pseudocolochirus violaceus (PS extract) from a holothurian. The main bioactive compounds (98 compounds) represented in these four extracts were identified using an HPLC-ESI-TOF-MS analysis. Among the most abundant compounds characterized in each extract, terpenes and diterpenes, and steroids (CR); cembranolides (PS); diterpenes, polyketides and indole terpenes (NA); and porphyrin, drimenyl cyclohexanone and polar steroids (NB), were proposed to be the candidates for the observed activity. CR, PS, NA, and NB showed strong antiproliferative ability and a cytostatic effect arresting the cell cycle in the G2/M phase. Likewise, CR, NA and NB extracts induced early apoptosis and PS extract exerted necrotic cell death. The four extracts showed a remarkable effect consisting on a dramatic intracellular reactive oxygen species (ROS) accumulation and mitochondrial depolarization, caspase activation and DNA damage. In Chapter 3 , the e ffect o f m arine natural p roducts a s i nhibitors o f rapamycin t arget ( mTOR) i n m ammals w as s tudied. T his kinase i s a master regulator of cell growth and metabolism and is deregulated in many types of cancer. Our results showed evidence of 11 pure compounds (selected by molecular coupling and calculated ADMET parameters) and two marine extracts to inhibit mTOR with the same effectiveness. Finally, in Chapter 4, we explored in depth the antiproliferative effect of NB extract mediated by an induction of oxidative and endoplasmic reticulum stress i n t he human c olon c ancer c ell m odel H CT-116. First, we found an overexpression o f e ndoplasmic r eticulum ( ER) s tress markers a nd a n overproduction of reactive oxygen species (ROS) basally in the colon cancer cell model compared to the normal colon cells. This difference in the basal stress level made the tumor cells more sensitive to the NB extract. The results suggest that NB extract significantly increases cellular stress by inducing ROS and overexpressing proteins related to ER stress through the response to unfolding proteins. In addition to the antiproliferative capacity, the ability of NB to inhibit one o f t he m ost d angerous c haracteristics o f t umor c ells, t he migration a nd invasion qualities of superinvasive models from HCT-116 was studied. The results were promising in showing that NB significantly reduced the migration and invasion rate of the most superinvasive populations with a smaller effect on the non-tumor line. This thesis, therefore, demonstrates t hat marine c ompounds a re a potential source of anti-cancer drugs due to the chemical diversity and broad biological activity that they offer. This fact is r eflected i n t he i ncrease i n t he number of drugs of marine origin that have been approved to date and the large number of scientific studies related to the field that are underway. In addition, this thesis offers interesting results about potential antitumor activity from marine invertebrate extracts and reveals some strengths of its mechanism of action. Likewise, the present study offers results of how the new strategies of computational screening that allow the search of regulatory compounds of key targets against cancer increase the effectiveness in the search of antitumor compounds.El c áncer e s u na d e l as principales c ausas d e muerte e n t odo e l m undo y requiere la atención y el esfuerzo de la comunidad científica para el desarrollo de nuevas estrategias en el descubrimiento de fármacos que ayuden a combatir la enfermedad [1]. Es necesario descubrir nuevas terapias efectivas que se centren e n e vitar l a p roliferación de células cancerosas y evitar los efectos secundarios. Los compuestos marinos, producidos como consecuencia de un intento de supervivencia ante condiciones adversas y de competencia, se presentan como una fuente potencial contra el cáncer. En las últimas décadas, los metabolitos marinos han mostrado una oferta de estructuras químicas novedosas a las que se le han atribuido actividades biológicas interesantes. Este hecho q ue q ueda r egistrado p or e l c reciente n úmero d e m edicamentos aprobados por la Administración de Drogas y Alimentos de los Estados Unidos (FDA) y l a Agencia E uropea d e M edicamentos ( EMA) d e o rigen marino. E n particular, los invertebrados marinos se proponen como fuente potencial de moléculas bioactivas por representar uno de los grupos más biodiversos. Hasta la fecha, una gran cantidad de productos naturales han sido extraídos o sintetizados en base a compuestos marinos de invertebrados y se han establecido como fármacos antineoplásicos. En e l c apítulo 1 d e e sta t esis, se r evisaron los actuales productos naturales marinos (MNP) que se establecieron como medicamentos antineoplásicos, describiendo sus posibles mecanismos de acción contra dianas moleculares e specíficas c ontra e l c áncer, b rindando u na v isión g eneral d e l a riqueza de las e structuras químicas q ue o frecen e introduciendo el uso d e la detección virtual para el descubrimiento de fármacos. Esta tesis, en el capítulo 2, se incluyen resultados sobre la búsqueda del efecto antiproliferativo de extractos marinos procedentes de invertebrados en modelos de células de cáncer d e c olon h umano. L a p rimera p arte d el p royecto se c entró e n l a búsqueda d e o rganismos m arinos q ue t ienen c ompetencia i ntra e interespecífica a través de la producción de compuestos bioactivos. Se realizó una selección de 20 organismos en base a fuentes bibliográficas y se hizo una selección de aquellos organismos que presentaron competencia en acuarios experimentales. Una vez seleccionados los organismos de interés, se analizó el efecto antiproliferativo in vitro en tres modelos celulares humanos de cáncer de colon (HGUE-C-1, HT-29 y SW-480). Los cuatros extractos con mayor efecto citotóxico fueron de los nudibránquios Phyllidia varicosa (extracto NA) y Dolabella auricularia (extracto NB), del coral blando Carotalcyon sp (extracto CR) y uno de la holoturia Pseudocolochirus violaceus (extracto PS). Los principales compuestos bioactivos (98 compuestos) representados en estos cuatro extractos se identificaron utilizando un análisis HPLC-ESI-TOF-MS. Entre los compuestos más abundantes caracterizados en cada extracto se encontraron: diterpenos, esteroides, sesqui y sester-terpenos en el extracto CR; cembranólidos e n P S; diterpenos, policétidos e indol terpenos en NA; y se propone que la porfirina, la drimenol ciclohexanona y los esteroides polares de NB, todos ellos fueron los responsables de la actividad observada. Los cuatro extractos mostraron una fuerte capacidad antiproliferativa, mediante un efecto citostático a través de la parada del ciclo celular en la fase G2/M. Mientras que CR, NA y NB indujeron la activación de caspasas y apoptosis, PS promovió la muerte por necrosis sumada a l a apoptótica. Además, los extractos marinos aumentaron las especies reactivas del oxígeno e indujeron estrés oxidativo, desestabilizaron la membrana mitocondrial y dañaron el ADN. En el capítulo 3, se estudió el efecto de los productos naturales marinos como inhibidores de la diana de rapamicina (mTOR) en mamíferos. Esta quinasa es clave en el crecimiento y el metabolismo celular y se encuentra desregulada en muchos tipos de cáncer. Nuestros resultados mostraron evidencias de 11 compuestos puros (seleccionados por acoplamiento molecular y parámetros ADMET calculados) y de dos extractos marinos para inhibir mTOR. Además, extractos marinos y compuestos puros mostraron similitud enFinalmente, en el capítulo 4, la tesis aborda el estudio en profundidad del efecto antiproliferativo del extracto NB mediado por una inducción del estrés oxidativo y endoplásmico en el modelo celular de cáncer de colon humano HCT-116. En primer lugar, encontramos una sobreexpresión de marcadores del estrés del retículo endoplasmático (ER) y una sobreproducción de especies reactivas del oxígeno (del inglés reactive oxygen species, ROS) de forma basal en el modelo de células de cáncer de colon en comparación con las células de colon normales. Esta diferencia en el nivel de estrés basal hizo que las células tumorales fueran más sensibles al extracto NB. Los resultados sugieren que el extracto de NB consigue aumentar considerablemente el estrés celular mediante la inducción de ROS y la sobreexpresión de proteínas relacionadas c on e l e strés d el R E a t ravés d e l a r espuesta a proteínas desplegadas. Además de la capacidad antiproliferativa, se estudió la capacidad de NB para inhibir una de las características más peligrosas de las células tumorales, la capacidad de migración e invasión de modelos superinvasivos procedentes de HCT-116. Los resultados fueron prometedores al mostrar que NB redujo considerablemente la tasa de migración e invasión de las poblaciones más superinvasivas y además se observó que ejercía un menor efecto en la línea no tumoral. Esta tesis, por tanto, demuestra que los compuestos marinos son una fuente potencial de fármacos contra el cáncer ya que ofrecen una diversidad química y actividad biológica amplia. El incremento del número de fármacos de origen marino aprobados, así como el número de estudios científicos en este ámbito corroboran el impacto de este campo en la sociedad actual. Además, esta tesis ofrece resultados interesantes acerca de potenciales antitumorales procedentes de extractos de invertebrados marinos y desvela algunos puntos fuertes de su mecanismo de acción. Asimismo, el presente estudio ofrece resultados de como las nuevas estrategias de cribado computacional que permiten la búsqueda d e compuestos r eguladores d e d ianas claves contra e l cáncer aumentan la efectividad en la búsqueda de compuestos antitumorales. los resultados de inhibición con esta diana.Programa de Doctorado en Biología Molecular y Celula

  • Efecto antiproliferativo de extractos procedente de invertebrados marinos mediado por estrés en modelos celulares humanos de cáncer de colon
    2021
    Co-Authors: Ruiz-torres Verónica
    Abstract:

    Cancer i s o ne o f t he l eading c auses o f d eath w orldwide and requires the attention and e ffort o f t he s cientific c ommunity f or t he d evelopment o f n ew strategies a nd t he d iscovery o f d rugs t hat h elp f ight t he d isease [1]. It is necessary to discover novel effective therapies focused on avoiding cancer cell proliferation and reducing side effects. Marine compounds, produced to survive in response to harsh and competitive environmental conditions, are postulated as a potential anticancer source. In the last decades, marine metabolites have shown novel wide chemical structures, which have been attributed to interesting biological activities and this fact has been registered by the increasing numbers of drugs approved by the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA). In particular, marine invertebrates are considered one of the richest biodiverse groups. To date, a large number of natural products e xtracted o r s ynthesized b ased o n m arine c ompounds f rom invertebrates have been established as antineoplastic drugs. In chapter 1, the current marine natural products (MNPs) that have been established as antineoplastic drugs were reviewed and their putative mechanisms of action in the different hallmarks of cancer described, giving an overview o f t he r ichness o f t he c hemical s tructures t hat t hey o ffer a nd introducing the use of virtual screening for drug discovery. This t hesis, in chapter 2, f ocuses o n t he search o f t he antiproliferative effect of several invertebrate marine extracts in human colon cancer cell models. The first part of the project focuses on the search for marine organisms that have intra and interspecific competence through the production of bioactive compounds. A selection of 20 organisms was made based on bibliographic sources and relayed on observations of competence in experimental aquariums. The next part consisted in to screen the in vitro antiproliferative effect on a panel of colon cancer cell models. Four extracts were selected due to their potential cytotoxic effect: Phyllidia varicosa (NA extract) and Dolabella auricularia (NB extract), obtained from two nudibranchs, Carotalcyon sp (CR extract) obtained from a soft coral and Pseudocolochirus violaceus (PS extract) from a holothurian. The main bioactive compounds (98 compounds) represented in these four extracts were identified using an HPLC-ESI-TOF-MS analysis. Among the most abundant compounds characterized in each extract, terpenes and diterpenes, and steroids (CR); cembranolides (PS); diterpenes, polyketides and indole terpenes (NA); and porphyrin, drimenyl cyclohexanone and polar steroids (NB), were proposed to be the candidates for the observed activity. CR, PS, NA, and NB showed strong antiproliferative ability and a cytostatic effect arresting the cell cycle in the G2/M phase. Likewise, CR, NA and NB extracts induced early apoptosis and PS extract exerted necrotic cell death. The four extracts showed a remarkable effect consisting on a dramatic intracellular reactive oxygen species (ROS) accumulation and mitochondrial depolarization, caspase activation and DNA damage. In Chapter 3 , the e ffect o f m arine natural p roducts a s i nhibitors o f rapamycin t arget ( mTOR) i n m ammals w as s tudied. T his kinase i s a master regulator of cell growth and metabolism and is deregulated in many types of cancer. Our results showed evidence of 11 pure compounds (selected by molecular coupling and calculated ADMET parameters) and two marine extracts to inhibit mTOR with the same effectiveness. Finally, in Chapter 4, we explored in depth the antiproliferative effect of NB extract mediated by an induction of oxidative and endoplasmic reticulum stress i n t he human c olon c ancer c ell m odel H CT-116. First, we found an overexpression o f e ndoplasmic r eticulum ( ER) s tress markers a nd a n overproduction of reactive oxygen species (ROS) basally in the colon cancer cell model compared to the normal colon cells. This difference in the basal stress level made the tumor cells more sensitive to the NB extract. The results suggest that NB extract significantly increases cellular stress by inducing ROS and overexpressing proteins related to ER stress through the response to unfolding proteins. In addition to the antiproliferative capacity, the ability of NB to inhibit one o f t he m ost d angerous c haracteristics o f t umor c ells, t he migration a nd invasion qualities of superinvasive models from HCT-116 was studied. The results were promising in showing that NB significantly reduced the migration and invasion rate of the most superinvasive populations with a smaller effect on the non-tumor line. This thesis, therefore, demonstrates t hat marine c ompounds a re a potential source of anti-cancer drugs due to the chemical diversity and broad biological activity that they offer. This fact is r eflected i n t he i ncrease i n t he number of drugs of marine origin that have been approved to date and the large number of scientific studies related to the field that are underway. In addition, this thesis offers interesting results about potential antitumor activity from marine invertebrate extracts and reveals some strengths of its mechanism of action. Likewise, the present study offers results of how the new strategies of computational screening that allow the search of regulatory compounds of key targets against cancer increase the effectiveness in the search of antitumor compounds.El c áncer e s u na d e l as principales c ausas d e muerte e n t odo e l m undo y requiere la atención y el esfuerzo de la comunidad científica para el desarrollo de nuevas estrategias en el descubrimiento de fármacos que ayuden a combatir la enfermedad [1]. Es necesario descubrir nuevas terapias efectivas que se centren e n e vitar l a p roliferación de células cancerosas y evitar los efectos secundarios. Los compuestos marinos, producidos como consecuencia de un intento de supervivencia ante condiciones adversas y de competencia, se presentan como una fuente potencial contra el cáncer. En las últimas décadas, los metabolitos marinos han mostrado una oferta de estructuras químicas novedosas a las que se le han atribuido actividades biológicas interesantes. Este hecho q ue q ueda r egistrado p or e l c reciente n úmero d e m edicamentos aprobados por la Administración de Drogas y Alimentos de los Estados Unidos (FDA) y l a Agencia E uropea d e M edicamentos ( EMA) d e o rigen marino. E n particular, los invertebrados marinos se proponen como fuente potencial de moléculas bioactivas por representar uno de los grupos más biodiversos. Hasta la fecha, una gran cantidad de productos naturales han sido extraídos o sintetizados en base a compuestos marinos de invertebrados y se han establecido como fármacos antineoplásicos. En e l c apítulo 1 d e e sta t esis, se r evisaron los actuales productos naturales marinos (MNP) que se establecieron como medicamentos antineoplásicos, describiendo sus posibles mecanismos de acción contra dianas moleculares e specíficas c ontra e l c áncer, b rindando u na v isión g eneral d e l a riqueza de las e structuras químicas q ue o frecen e introduciendo el uso d e la detección virtual para el descubrimiento de fármacos. Esta tesis, en el capítulo 2, se incluyen resultados sobre la búsqueda del efecto antiproliferativo de extractos marinos procedentes de invertebrados en modelos de células de cáncer d e c olon h umano. L a p rimera p arte d el p royecto se c entró e n l a búsqueda d e o rganismos m arinos q ue t ienen c ompetencia i ntra e interespecífica a través de la producción de compuestos bioactivos. Se realizó una selección de 20 organismos en base a fuentes bibliográficas y se hizo una selección de aquellos organismos que presentaron competencia en acuarios experimentales. Una vez seleccionados los organismos de interés, se analizó el efecto antiproliferativo in vitro en tres modelos celulares humanos de cáncer de colon (HGUE-C-1, HT-29 y SW-480). Los cuatros extractos con mayor efecto citotóxico fueron de los nudibránquios Phyllidia varicosa (extracto NA) y Dolabella auricularia (extracto NB), del coral blando Carotalcyon sp (extracto CR) y uno de la holoturia Pseudocolochirus violaceus (extracto PS). Los principales compuestos bioactivos (98 compuestos) representados en estos cuatro extractos se identificaron utilizando un análisis HPLC-ESI-TOF-MS. Entre los compuestos más abundantes caracterizados en cada extracto se encontraron: diterpenos, esteroides, sesqui y sester-terpenos en el extracto CR; cembranólidos e n P S; diterpenos, policétidos e indol terpenos en NA; y se propone que la porfirina, la drimenol ciclohexanona y los esteroides polares de NB, todos ellos fueron los responsables de la actividad observada. Los cuatro extractos mostraron una fuerte capacidad antiproliferativa, mediante un efecto citostático a través de la parada del ciclo celular en la fase G2/M. Mientras que CR, NA y NB indujeron la activación de caspasas y apoptosis, PS promovió la muerte por necrosis sumada a l a apoptótica. Además, los extractos marinos aumentaron las especies reactivas del oxígeno e indujeron estrés oxidativo, desestabilizaron la membrana mitocondrial y dañaron el ADN. En el capítulo 3, se estudió el efecto de los productos naturales marinos como inhibidores de la diana de rapamicina (mTOR) en mamíferos. Esta quinasa es clave en el crecimiento y el metabolismo celular y se encuentra desregulada en muchos tipos de cáncer. Nuestros resultados mostraron evidencias de 11 compuestos puros (seleccionados por acoplamiento molecular y parámetros ADMET calculados) y de dos extractos marinos para inhibir mTOR. Además, extractos marinos y compuestos puros mostraron similitud enFinalmente, en el capítulo 4, la tesis aborda el estudio en profundidad del efecto antiproliferativo del extracto NB mediado por una inducción del estrés oxidativo y endoplásmico en el modelo celular de cáncer de colon humano HCT-116. En primer lugar, encontramos una sobreexpresión de marcadores del estrés del retículo endoplasmático (ER) y una sobreproducción de especies reactivas del oxígeno (del inglés reactive oxygen species, ROS) de forma basal en el modelo de células de cáncer de colon en comparación con las células de colon normales. Esta diferencia en el nivel de estrés basal hizo que las células tumorales fueran más sensibles al extracto NB. Los resultados sugieren que el extracto de NB consigue aumentar considerablemente el estrés celular mediante la inducción de ROS y la sobreexpresión de proteínas relacionadas c on e l e strés d el R E a t ravés d e l a r espuesta a proteínas desplegadas. Además de la capacidad antiproliferativa, se estudió la capacidad de NB para inhibir una de las características más peligrosas de las células tumorales, la capacidad de migración e invasión de modelos superinvasivos procedentes de HCT-116. Los resultados fueron prometedores al mostrar que NB redujo considerablemente la tasa de migración e invasión de las poblaciones más superinvasivas y además se observó que ejercía un menor efecto en la línea no tumoral. Esta tesis, por tanto, demuestra que los compuestos marinos son una fuente potencial de fármacos contra el cáncer ya que ofrecen una diversidad química y actividad biológica amplia. El incremento del número de fármacos de origen marino aprobados, así como el número de estudios científicos en este ámbito corroboran el impacto de este campo en la sociedad actual. Además, esta tesis ofrece resultados interesantes acerca de potenciales antitumorales procedentes de extractos de invertebrados marinos y desvela algunos puntos fuertes de su mecanismo de acción. Asimismo, el presente estudio ofrece resultados de como las nuevas estrategias de cribado computacional que permiten la búsqueda d e compuestos r eguladores d e d ianas claves contra e l cáncer aumentan la efectividad en la búsqueda de compuestos antitumorales. los resultados de inhibición con esta diana

  • Marine Invertebrate Extracts Induce Colon Cancer Cell Death via ROS-Mediated DNA Oxidative Damage and Mitochondrial Impairment
    2020
    Co-Authors: Ruiz-torres Verónica, Rodríguez-pérez Celia, Herranz-lópez María, Martín-garcía Beatriz, Gómez-caravaca Ana-maría, Arráez-román David, Segura-carretero Antonio, Barrajón-catalán Enrique, Micol Vicente
    Abstract:

    Marine compounds are a potential source of new anticancer drugs. In this study, the antiproliferative e_ects of 20 invertebrate marine extracts on three colon cancer cell models (HGUE-C-1, HT-29, and SW-480) were evaluated. Extracts from two nudibranchs (Phyllidia varicosa, NA and Dolabella auricularia, NB), a holothurian (Pseudocol ochirus violaceus, PS), and a soft coral (Carotalcyon sp., CR) were selected due to their potent cytotoxic capacities. The four marine extracts exhibited strong antiproliferative e_ects and induced cell cycle arrest at the G2/Mtransition, which evolved into early apoptosis in the case of the CR, NA, and NB extracts and necrotic cell death in the case of the PS extract. All the extracts induced, to some extent, intracellular ROS accumulation, mitochondrial depolarization, caspase activation, and DNA damage. The compositions of the four extracts were fully characterized via HPLC-ESI-TOF-MS analysis, which identified up to 98 compounds. We propose that, among the most abundant compounds identified in each extract, diterpenes, steroids, and sesqui- and seterterpenes (CR); cembranolides (PS); diterpenes, polyketides, and indole terpenes (NA); and porphyrin, drimenyl cyclohexanone, and polar steroids (NB) might be candidates for the observed activity. We postulate that reactive oxygen species (ROS) accumulation is responsible for the subsequent DNA damage, mitochondrial depolarization, and cell cycle arrest, ultimately inducing cell death by either apoptosis or necrosisThis research was funded by projects AGL2015-67995-C3-1-R, AGL2015-67995-C3-2-R AGL2015-67995-C3-3-R, RTI2018-096724-B-C21,and 2018-096724-B-C22 from the Spanish Ministry of Science, Innovation and Universities;Project P11-CTS-7625 from Andalusian Regional Government Council of Innovation and Scienceprojects PROMETEO/2012/007, PROMETEO/2016/006, and VALi+D fellowship (ACIF/2015/158) from Generalitat Valenciana to VR-Tand CIBER (CB12/03/3003

  • Marine Invertebrate Extracts Induce Colon Cancer Cell Death via ROS-Mediated DNA Oxidative Damage and Mitochondrial Impairment
    MDPI, 2019
    Co-Authors: Ruiz-torres Verónica, Rodríguez-pérez Celia, Herranz-lópez María, Martín-garcía Beatriz, Arráez-román David, Segura-carretero Antonio, Barrajón-catalán Enrique, Gómez-caravaca, Ana María, Micol Molina Vicente
    Abstract:

    Marine compounds are a potential source of new anticancer drugs. In this study, the antiproliferative effects of 20 invertebrate marine extracts on three colon cancer cell models (HGUE-C-1, HT-29, and SW-480) were evaluated. Extracts from two nudibranchs (Phyllidia varicosa, NA and Dolabella auricularia, NB), a holothurian (Pseudocol ochirus violaceus, PS), and a soft coral (Carotalcyon sp., CR) were selected due to their potent cytotoxic capacities. The four marine extracts exhibited strong antiproliferative effects and induced cell cycle arrest at the G2/Mtransition, which evolved into early apoptosis in the case of the CR, NA, and NB extracts and necrotic cell death in the case of the PS extract. All the extracts induced, to some extent, intracellular ROS accumulation, mitochondrial depolarization, caspase activation, and DNA damage. The compositions of the four extracts were fully characterized via HPLC-ESI-TOF-MS analysis, which identified up to 98 compounds. We propose that, among the most abundant compounds identified in each extract, diterpenes, steroids, and sesqui- and seterterpenes (CR); cembranolides (PS); diterpenes, polyketides, and indole terpenes (NA); and porphyrin, drimenyl cyclohexanone, and polar steroids (NB) might be candidates for the observed activity. We postulate that reactive oxygen species (ROS) accumulation is responsible for the subsequent DNA damage, mitochondrial depolarization, and cell cycle arrest, ultimately inducing cell death by either apoptosis or necrosis.This research was funded by projects AGL2015-67995-C3-1-R, AGL2015-67995-C3-2-R AGL2015-67995-C3-3-R, RTI2018-096724-B-C21, and 2018-096724-B-C22 from the Spanish Ministry of Science, Innovation and Universities; Project P11-CTS-7625 from Andalusian Regional Government Council of Innovation and Science; projects PROMETEO/2012/007, PROMETEO/2016/006, and VALi+D fellowship (ACIF/2015/158) from Generalitat Valenciana to VR-Tand CIBER (CB12/03/30038, Fisiopatología de la Obesidad y la Nutrición, CIBERobn)